| Quellcodebibliothek Statistik Leitseite products/Sources/formale Sprachen/GAP/hpcgap/extern/gc/ (Algebra von RWTH Aachen Version 4.15.1©) Datei vom 18.9.2025 mit Größe 187 kB |
|
Quellcode-Bibliothek os_dep.cSprache: C |
|||||||||||||||
|
/* * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved. * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved. * Copyright (c) 2008-2021 Ivan Maidanski * * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. * * Permission is hereby granted to use or copy this program * for any purpose, provided the above notices are retained on all copies. * Permission to modify the code and to distribute modified code is granted, * provided the above notices are retained, and a notice that the code was * modified is included with the above copyright notice. */ #include "private/gc_priv.h" #if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \ && !defined(MSWINCE) && !defined(SN_TARGET_ORBIS) \ && !defined(SN_TARGET_PSP2) && !defined(__CC_ARM) # include <sys/types.h> # if !defined(MSWIN32) && !defined(MSWIN_XBOX1) # include <unistd.h> # endif #endif #include <stdio.h> #if defined(MSWINCE) || defined(SN_TARGET_PS3) # define SIGSEGV 0 /* value is irrelevant */ #else # include <signal.h> #endif #if defined(UNIX_LIKE) || defined(CYGWIN32) || defined(NACL) \ || defined(SYMBIAN) # include <fcntl.h> #endif #if defined(LINUX) || defined(LINUX_STACKBOTTOM) # include <ctype.h> #endif /* Blatantly OS dependent routines, except for those that are related */ /* to dynamic loading. */ #ifdef AMIGA # define GC_AMIGA_DEF # include "extra/AmigaOS.c" # undef GC_AMIGA_DEF #endif #ifdef MACOS # include <Processes.h> #endif #ifdef IRIX5 # include <sys/uio.h> # include <malloc.h> /* for locking */ #endif #if defined(MMAP_SUPPORTED) || defined(ADD_HEAP_GUARD_PAGES) # if defined(USE_MUNMAP) && !defined(USE_MMAP) && !defined(CPPCHECK) # error Invalid config: USE_MUNMAP requires USE_MMAP # endif # include <sys/types.h> # include <sys/mman.h> # include <sys/stat.h> #endif #if defined(ADD_HEAP_GUARD_PAGES) || defined(LINUX_STACKBOTTOM) \ || defined(MMAP_SUPPORTED) || defined(NEED_PROC_MAPS) # include <errno.h> #endif #ifdef DARWIN /* for get_etext and friends */ # include <mach-o/getsect.h> #endif #ifdef DJGPP /* Apparently necessary for djgpp 2.01. May cause problems with */ /* other versions. */ typedef long unsigned int caddr_t; #endif #ifdef PCR # include "il/PCR_IL.h" # include "th/PCR_ThCtl.h" # include "mm/PCR_MM.h" #endif #if defined(GC_DARWIN_THREADS) && defined(MPROTECT_VDB) /* Declare GC_mprotect_stop and GC_mprotect_resume as extern "C". */ # include "private/darwin_stop_world.h" #endif #if !defined(NO_EXECUTE_PERMISSION) STATIC GC_bool GC_pages_executable = TRUE; #else STATIC GC_bool GC_pages_executable = FALSE; #endif #define IGNORE_PAGES_EXECUTABLE 1 /* Undefined on GC_pages_executable real use. */ #if ((defined(LINUX_STACKBOTTOM) || defined(NEED_PROC_MAPS) \ || defined(PROC_VDB) || defined(SOFT_VDB)) && !defined(PROC_READ)) \ || defined(CPPCHECK) # define PROC_READ read /* Should probably call the real read, if read is wrapped. */ #endif #if defined(LINUX_STACKBOTTOM) || defined(NEED_PROC_MAPS) /* Repeatedly perform a read call until the buffer is filled */ /* up, or we encounter EOF or an error. */ STATIC ssize_t GC_repeat_read(int fd, char *buf, size_t count) { size_t num_read = 0; ASSERT_CANCEL_DISABLED(); while (num_read < count) { ssize_t result = PROC_READ(fd, buf + num_read, count - num_read); if (result < 0) return result; if (result == 0) break; num_read += result; } return num_read; } #endif /* LINUX_STACKBOTTOM || NEED_PROC_MAPS */ #ifdef NEED_PROC_MAPS /* We need to parse /proc/self/maps, either to find dynamic libraries, */ /* and/or to find the register backing store base (IA64). Do it once */ /* here. */ #ifdef THREADS /* Determine the length of a file by incrementally reading it into a */ /* buffer. This would be silly to use it on a file supporting lseek, */ /* but Linux /proc files usually do not. */ /* As of Linux 4.15.0, lseek(SEEK_END) fails for /proc/self/maps. */ STATIC size_t GC_get_file_len(int f) { size_t total = 0; ssize_t result; # define GET_FILE_LEN_BUF_SZ 500 char buf[GET_FILE_LEN_BUF_SZ]; do { result = PROC_READ(f, buf, sizeof(buf)); if (result == -1) return 0; total += result; } while (result > 0); return total; } STATIC size_t GC_get_maps_len(void) { int f = open("/proc/self/maps", O_RDONLY); size_t result; if (f < 0) return 0; /* treat missing file as empty */ result = GC_get_file_len(f); close(f); return result; } #endif /* THREADS */ /* Copy the contents of /proc/self/maps to a buffer in our address */ /* space. Return the address of the buffer. */ GC_INNER const char * GC_get_maps(void) { ssize_t result; static char *maps_buf = NULL; static size_t maps_buf_sz = 1; size_t maps_size; # ifdef THREADS size_t old_maps_size = 0; # endif /* The buffer is essentially static, so there must be a single client. */ GC_ASSERT(I_HOLD_LOCK()); /* Note that in the presence of threads, the maps file can */ /* essentially shrink asynchronously and unexpectedly as */ /* threads that we already think of as dead release their */ /* stacks. And there is no easy way to read the entire */ /* file atomically. This is arguably a misfeature of the */ /* /proc/self/maps interface. */ /* Since we expect the file can grow asynchronously in rare */ /* cases, it should suffice to first determine */ /* the size (using read), and then to reread the file. */ /* If the size is inconsistent we have to retry. */ /* This only matters with threads enabled, and if we use */ /* this to locate roots (not the default). */ # ifdef THREADS /* Determine the initial size of /proc/self/maps. */ maps_size = GC_get_maps_len(); if (0 == maps_size) ABORT("Cannot determine length of /proc/self/maps"); # else maps_size = 4000; /* Guess */ # endif /* Read /proc/self/maps, growing maps_buf as necessary. */ /* Note that we may not allocate conventionally, and */ /* thus can't use stdio. */ do { int f; while (maps_size >= maps_buf_sz) { # ifdef LINT2 /* Workaround passing tainted maps_buf to a tainted sink. */ GC_noop1((word)maps_buf); # else GC_scratch_recycle_no_gww(maps_buf, maps_buf_sz); # endif /* Grow only by powers of 2, since we leak "too small" buffers.*/ while (maps_size >= maps_buf_sz) maps_buf_sz *= 2; maps_buf = GC_scratch_alloc(maps_buf_sz); if (NULL == maps_buf) ABORT_ARG1("Insufficient space for /proc/self/maps buffer", ", %lu bytes requested", (unsigned long)maps_buf_sz); # ifdef THREADS /* Recompute initial length, since we allocated. */ /* This can only happen a few times per program */ /* execution. */ maps_size = GC_get_maps_len(); if (0 == maps_size) ABORT("Cannot determine length of /proc/self/maps"); # endif } GC_ASSERT(maps_buf_sz >= maps_size + 1); f = open("/proc/self/maps", O_RDONLY); if (-1 == f) ABORT_ARG1("Cannot open /proc/self/maps", ": errno= %d", errno); # ifdef THREADS old_maps_size = maps_size; # endif maps_size = 0; do { result = GC_repeat_read(f, maps_buf, maps_buf_sz-1); if (result < 0) { ABORT_ARG1("Failed to read /proc/self/maps", ": errno= %d", errno); } maps_size += result; } while ((size_t)result == maps_buf_sz-1); close(f); if (0 == maps_size) ABORT("Empty /proc/self/maps"); # ifdef THREADS if (maps_size > old_maps_size) { /* This might be caused by e.g. thread creation. */ WARN("Unexpected asynchronous /proc/self/maps growth" " (to %" WARN_PRIdPTR " bytes)\n", maps_size); } # endif } while (maps_size >= maps_buf_sz # ifdef THREADS || maps_size < old_maps_size # endif ); maps_buf[maps_size] = '\0'; return maps_buf; } /* * GC_parse_map_entry parses an entry from /proc/self/maps so we can * locate all writable data segments that belong to shared libraries. * The format of one of these entries and the fields we care about * is as follows: * XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537 name of mapping...\n * ^^^^^^^^ ^^^^^^^^ ^^^^ ^^ * start end prot maj_dev * * Note that since about august 2003 kernels, the columns no longer have * fixed offsets on 64-bit kernels. Hence we no longer rely on fixed offsets * anywhere, which is safer anyway. */ /* Assign various fields of the first line in maps_ptr to (*start), */ /* (*end), (*prot), (*maj_dev) and (*mapping_name). mapping_name may */ /* be NULL. (*prot) and (*mapping_name) are assigned pointers into the */ /* original buffer. */ #if (defined(DYNAMIC_LOADING) && defined(USE_PROC_FOR_LIBRARIES)) \ || defined(IA64) || defined(INCLUDE_LINUX_THREAD_DESCR) \ || (defined(REDIRECT_MALLOC) && defined(GC_LINUX_THREADS)) GC_INNER const char *GC_parse_map_entry(const char *maps_ptr, ptr_t *start, ptr_t *end, const char **prot, unsigned *maj_dev, const char **mapping_name) { const unsigned char *start_start, *end_start, *maj_dev_start; const unsigned char *p; /* unsigned for isspace, isxdigit */ if (maps_ptr == NULL || *maps_ptr == '\0') { return NULL; } p = (const unsigned char *)maps_ptr; while (isspace(*p)) ++p; start_start = p; GC_ASSERT(isxdigit(*start_start)); *start = (ptr_t)strtoul((const char *)start_start, (char **)&p, 16); GC_ASSERT(*p=='-'); ++p; end_start = p; GC_ASSERT(isxdigit(*end_start)); *end = (ptr_t)strtoul((const char *)end_start, (char **)&p, 16); GC_ASSERT(isspace(*p)); while (isspace(*p)) ++p; GC_ASSERT(*p == 'r' || *p == '-'); *prot = (const char *)p; /* Skip past protection field to offset field */ while (!isspace(*p)) ++p; while (isspace(*p)) p++; GC_ASSERT(isxdigit(*p)); /* Skip past offset field, which we ignore */ while (!isspace(*p)) ++p; while (isspace(*p)) p++; maj_dev_start = p; GC_ASSERT(isxdigit(*maj_dev_start)); *maj_dev = strtoul((const char *)maj_dev_start, NULL, 16); if (mapping_name != NULL) { while (*p && *p != '\n' && *p != '/' && *p != '[') p++; *mapping_name = (const char *)p; } while (*p && *p++ != '\n'); return (const char *)p; } #endif /* REDIRECT_MALLOC || DYNAMIC_LOADING || IA64 || ... */ #if defined(IA64) || defined(INCLUDE_LINUX_THREAD_DESCR) /* Try to read the backing store base from /proc/self/maps. */ /* Return the bounds of the writable mapping with a 0 major device, */ /* which includes the address passed as data. */ /* Return FALSE if there is no such mapping. */ GC_INNER GC_bool GC_enclosing_mapping(ptr_t addr, ptr_t *startp, ptr_t *endp) { const char *prot; ptr_t my_start, my_end; unsigned int maj_dev; const char *maps_ptr = GC_get_maps(); for (;;) { maps_ptr = GC_parse_map_entry(maps_ptr, &my_start, &my_end, &prot, &maj_dev, 0); if (NULL == maps_ptr) break; if (prot[1] == 'w' && maj_dev == 0 && (word)my_end > (word)addr && (word)my_start <= (word)addr) { *startp = my_start; *endp = my_end; return TRUE; } } return FALSE; } #endif /* IA64 || INCLUDE_LINUX_THREAD_DESCR */ #if defined(REDIRECT_MALLOC) && defined(GC_LINUX_THREADS) /* Find the text(code) mapping for the library whose name, after */ /* stripping the directory part, starts with nm. */ GC_INNER GC_bool GC_text_mapping(char *nm, ptr_t *startp, ptr_t *endp) { size_t nm_len = strlen(nm); const char *prot, *map_path; ptr_t my_start, my_end; unsigned int maj_dev; const char *maps_ptr = GC_get_maps(); for (;;) { maps_ptr = GC_parse_map_entry(maps_ptr, &my_start, &my_end, &prot, &maj_dev, &map_path); if (NULL == maps_ptr) break; if (prot[0] == 'r' && prot[1] == '-' && prot[2] == 'x') { const char *p = map_path; /* Set p to point just past last slash, if any. */ while (*p != '\0' && *p != '\n' && *p != ' ' && *p != '\t') ++p; while (*p != '/' && (word)p >= (word)map_path) --p; ++p; if (strncmp(nm, p, nm_len) == 0) { *startp = my_start; *endp = my_end; return TRUE; } } } return FALSE; } #endif /* REDIRECT_MALLOC */ #ifdef IA64 static ptr_t backing_store_base_from_proc(void) { ptr_t my_start, my_end; if (!GC_enclosing_mapping(GC_save_regs_in_stack(), &my_start, &my_end)) { GC_COND_LOG_PRINTF("Failed to find backing store base from /proc\n"); return 0; } return my_start; } #endif #endif /* NEED_PROC_MAPS */ #if defined(SEARCH_FOR_DATA_START) /* The I386 case can be handled without a search. The Alpha case */ /* used to be handled differently as well, but the rules changed */ /* for recent Linux versions. This seems to be the easiest way to */ /* cover all versions. */ # if defined(LINUX) || defined(HURD) /* Some Linux distributions arrange to define __data_start. Some */ /* define data_start as a weak symbol. The latter is technically */ /* broken, since the user program may define data_start, in which */ /* case we lose. Nonetheless, we try both, preferring __data_start.*/ /* We assume gcc-compatible pragmas. */ EXTERN_C_BEGIN # pragma weak __data_start # pragma weak data_start extern int __data_start[], data_start[]; EXTERN_C_END # endif /* LINUX */ ptr_t GC_data_start = NULL; GC_INNER void GC_init_linux_data_start(void) { ptr_t data_end = DATAEND; # if (defined(LINUX) || defined(HURD)) && defined(USE_PROG_DATA_START) /* Try the easy approaches first: */ /* However, this may lead to wrong data start value if libgc */ /* code is put into a shared library (directly or indirectly) */ /* which is linked with -Bsymbolic-functions option. Thus, */ /* the following is not used by default. */ if (COVERT_DATAFLOW(__data_start) != 0) { GC_data_start = (ptr_t)(__data_start); } else { GC_data_start = (ptr_t)(data_start); } if (COVERT_DATAFLOW(GC_data_start) != 0) { if ((word)GC_data_start > (word)data_end) ABORT_ARG2("Wrong __data_start/_end pair", ": %p .. %p", (void *)GC_data_start, (void *)data_end); return; } # ifdef DEBUG_ADD_DEL_ROOTS GC_log_printf("__data_start not provided\n"); # endif # endif /* LINUX */ if (GC_no_dls) { /* Not needed, avoids the SIGSEGV caused by */ /* GC_find_limit which complicates debugging. */ GC_data_start = data_end; /* set data root size to 0 */ return; } GC_data_start = (ptr_t)GC_find_limit(data_end, FALSE); } #endif /* SEARCH_FOR_DATA_START */ #ifdef ECOS # ifndef ECOS_GC_MEMORY_SIZE # define ECOS_GC_MEMORY_SIZE (448 * 1024) # endif /* ECOS_GC_MEMORY_SIZE */ /* TODO: This is a simple way of allocating memory which is */ /* compatible with ECOS early releases. Later releases use a more */ /* sophisticated means of allocating memory than this simple static */ /* allocator, but this method is at least bound to work. */ static char ecos_gc_memory[ECOS_GC_MEMORY_SIZE]; static char *ecos_gc_brk = ecos_gc_memory; static void *tiny_sbrk(ptrdiff_t increment) { void *p = ecos_gc_brk; ecos_gc_brk += increment; if ((word)ecos_gc_brk > (word)(ecos_gc_memory + sizeof(ecos_gc_memory))) { ecos_gc_brk -= increment; return NULL; } return p; } # define sbrk tiny_sbrk #endif /* ECOS */ #if defined(NETBSD) && defined(__ELF__) ptr_t GC_data_start = NULL; EXTERN_C_BEGIN extern char **environ; EXTERN_C_END GC_INNER void GC_init_netbsd_elf(void) { /* This may need to be environ, without the underscore, for */ /* some versions. */ GC_data_start = (ptr_t)GC_find_limit(&environ, FALSE); } #endif /* NETBSD */ #if defined(ADDRESS_SANITIZER) && (defined(UNIX_LIKE) \ || defined(NEED_FIND_LIMIT) || defined(MPROTECT_VDB)) \ && !defined(CUSTOM_ASAN_DEF_OPTIONS) /* To tell ASan to allow GC to use its own SIGBUS/SEGV handlers. */ /* The function is exported just to be visible to ASan library. */ GC_API const char *__asan_default_options(void) { return "allow_user_segv_handler=1"; } #endif #ifdef OPENBSD static struct sigaction old_segv_act; STATIC JMP_BUF GC_jmp_buf_openbsd; STATIC void GC_fault_handler_openbsd(int sig GC_ATTR_UNUSED) { LONGJMP(GC_jmp_buf_openbsd, 1); } # ifdef GC_OPENBSD_UTHREADS # include <sys/syscall.h> EXTERN_C_BEGIN extern sigset_t __syscall(quad_t, ...); EXTERN_C_END /* Don't use GC_find_limit() because siglongjmp() outside of the */ /* signal handler by-passes our userland pthreads lib, leaving */ /* SIGSEGV and SIGPROF masked. Instead, use this custom one that */ /* works-around the issues. */ /* Return the first non-addressable location > p or bound. */ /* Requires the allocation lock. */ STATIC ptr_t GC_find_limit_openbsd(ptr_t p, ptr_t bound) { static volatile ptr_t result; /* Safer if static, since otherwise it may not be */ /* preserved across the longjmp. Can safely be */ /* static since it's only called with the */ /* allocation lock held. */ struct sigaction act; word pgsz = (word)sysconf(_SC_PAGESIZE); GC_ASSERT((word)bound >= pgsz); GC_ASSERT(I_HOLD_LOCK()); act.sa_handler = GC_fault_handler_openbsd; sigemptyset(&act.sa_mask); act.sa_flags = SA_NODEFER | SA_RESTART; /* act.sa_restorer is deprecated and should not be initialized. */ sigaction(SIGSEGV, &act, &old_segv_act); if (SETJMP(GC_jmp_buf_openbsd) == 0) { result = (ptr_t)((word)p & ~(pgsz-1)); for (;;) { if ((word)result >= (word)bound - pgsz) { result = bound; break; } result += pgsz; /* no overflow expected */ GC_noop1((word)(*result)); } } # ifdef THREADS /* Due to the siglongjump we need to manually unmask SIGPROF. */ __syscall(SYS_sigprocmask, SIG_UNBLOCK, sigmask(SIGPROF)); # endif sigaction(SIGSEGV, &old_segv_act, 0); return(result); } # endif /* GC_OPENBSD_UTHREADS */ static volatile int firstpass; /* Return first addressable location > p or bound. */ /* Requires the allocation lock. */ STATIC ptr_t GC_skip_hole_openbsd(ptr_t p, ptr_t bound) { static volatile ptr_t result; struct sigaction act; word pgsz = (word)sysconf(_SC_PAGESIZE); GC_ASSERT((word)bound >= pgsz); GC_ASSERT(I_HOLD_LOCK()); act.sa_handler = GC_fault_handler_openbsd; sigemptyset(&act.sa_mask); act.sa_flags = SA_NODEFER | SA_RESTART; /* act.sa_restorer is deprecated and should not be initialized. */ sigaction(SIGSEGV, &act, &old_segv_act); firstpass = 1; result = (ptr_t)((word)p & ~(pgsz-1)); if (SETJMP(GC_jmp_buf_openbsd) != 0 || firstpass) { firstpass = 0; if ((word)result >= (word)bound - pgsz) { result = bound; } else { result += pgsz; /* no overflow expected */ GC_noop1((word)(*result)); } } sigaction(SIGSEGV, &old_segv_act, 0); return(result); } #endif /* OPENBSD */ # ifdef OS2 # include <stddef.h> # if !defined(__IBMC__) && !defined(__WATCOMC__) /* e.g. EMX */ struct exe_hdr { unsigned short magic_number; unsigned short padding[29]; long new_exe_offset; }; #define E_MAGIC(x) (x).magic_number #define EMAGIC 0x5A4D #define E_LFANEW(x) (x).new_exe_offset struct e32_exe { unsigned char magic_number[2]; unsigned char byte_order; unsigned char word_order; unsigned long exe_format_level; unsigned short cpu; unsigned short os; unsigned long padding1[13]; unsigned long object_table_offset; unsigned long object_count; unsigned long padding2[31]; }; #define E32_MAGIC1(x) (x).magic_number[0] #define E32MAGIC1 'L' #define E32_MAGIC2(x) (x).magic_number[1] #define E32MAGIC2 'X' #define E32_BORDER(x) (x).byte_order #define E32LEBO 0 #define E32_WORDER(x) (x).word_order #define E32LEWO 0 #define E32_CPU(x) (x).cpu #define E32CPU286 1 #define E32_OBJTAB(x) (x).object_table_offset #define E32_OBJCNT(x) (x).object_count struct o32_obj { unsigned long size; unsigned long base; unsigned long flags; unsigned long pagemap; unsigned long mapsize; unsigned long reserved; }; #define O32_FLAGS(x) (x).flags #define OBJREAD 0x0001L #define OBJWRITE 0x0002L #define OBJINVALID 0x0080L #define O32_SIZE(x) (x).size #define O32_BASE(x) (x).base # else /* IBM's compiler */ /* A kludge to get around what appears to be a header file bug */ # ifndef WORD # define WORD unsigned short # endif # ifndef DWORD # define DWORD unsigned long # endif # define EXE386 1 # include <newexe.h> # include <exe386.h> # endif /* __IBMC__ */ # define INCL_DOSEXCEPTIONS # define INCL_DOSPROCESS # define INCL_DOSERRORS # define INCL_DOSMODULEMGR # define INCL_DOSMEMMGR # include <os2.h> # endif /* OS/2 */ /* Find the page size */ GC_INNER size_t GC_page_size = 0; #if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32) # ifndef VER_PLATFORM_WIN32_CE # define VER_PLATFORM_WIN32_CE 3 # endif # if defined(MSWINCE) && defined(THREADS) GC_INNER GC_bool GC_dont_query_stack_min = FALSE; # endif GC_INNER SYSTEM_INFO GC_sysinfo; GC_INNER void GC_setpagesize(void) { GetSystemInfo(&GC_sysinfo); # if defined(CYGWIN32) && (defined(MPROTECT_VDB) || defined(USE_MUNMAP)) /* Allocations made with mmap() are aligned to the allocation */ /* granularity, which (at least on 64-bit Windows OS) is not the */ /* same as the page size. Probably a separate variable could */ /* be added to distinguish the allocation granularity from the */ /* actual page size, but in practice there is no good reason to */ /* make allocations smaller than dwAllocationGranularity, so we */ /* just use it instead of the actual page size here (as Cygwin */ /* itself does in many cases). */ GC_page_size = (size_t)GC_sysinfo.dwAllocationGranularity; GC_ASSERT(GC_page_size >= (size_t)GC_sysinfo.dwPageSize); # else GC_page_size = (size_t)GC_sysinfo.dwPageSize; # endif # if defined(MSWINCE) && !defined(_WIN32_WCE_EMULATION) { OSVERSIONINFO verInfo; /* Check the current WinCE version. */ verInfo.dwOSVersionInfoSize = sizeof(OSVERSIONINFO); if (!GetVersionEx(&verInfo)) ABORT("GetVersionEx failed"); if (verInfo.dwPlatformId == VER_PLATFORM_WIN32_CE && verInfo.dwMajorVersion < 6) { /* Only the first 32 MB of address space belongs to the */ /* current process (unless WinCE 6.0+ or emulation). */ GC_sysinfo.lpMaximumApplicationAddress = (LPVOID)((word)32 << 20); # ifdef THREADS /* On some old WinCE versions, it's observed that */ /* VirtualQuery calls don't work properly when used to */ /* get thread current stack committed minimum. */ if (verInfo.dwMajorVersion < 5) GC_dont_query_stack_min = TRUE; # endif } } # endif } # ifndef CYGWIN32 # define is_writable(prot) ((prot) == PAGE_READWRITE \ || (prot) == PAGE_WRITECOPY \ || (prot) == PAGE_EXECUTE_READWRITE \ || (prot) == PAGE_EXECUTE_WRITECOPY) /* Return the number of bytes that are writable starting at p. */ /* The pointer p is assumed to be page aligned. */ /* If base is not 0, *base becomes the beginning of the */ /* allocation region containing p. */ STATIC word GC_get_writable_length(ptr_t p, ptr_t *base) { MEMORY_BASIC_INFORMATION buf; word result; word protect; result = VirtualQuery(p, &buf, sizeof(buf)); if (result != sizeof(buf)) ABORT("Weird VirtualQuery result"); if (base != 0) *base = (ptr_t)(buf.AllocationBase); protect = (buf.Protect & ~(PAGE_GUARD | PAGE_NOCACHE)); if (!is_writable(protect)) { return(0); } if (buf.State != MEM_COMMIT) return(0); return(buf.RegionSize); } GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb) { ptr_t trunc_sp; word size; /* Set page size if it is not ready (so client can use this */ /* function even before GC is initialized). */ if (!GC_page_size) GC_setpagesize(); trunc_sp = (ptr_t)((word)GC_approx_sp() & ~(GC_page_size - 1)); /* FIXME: This won't work if called from a deeply recursive */ /* client code (and the committed stack space has grown). */ size = GC_get_writable_length(trunc_sp, 0); GC_ASSERT(size != 0); sb -> mem_base = trunc_sp + size; return GC_SUCCESS; } # else /* CYGWIN32 */ /* An alternate version for Cygwin (adapted from Dave Korn's */ /* gcc version of boehm-gc). */ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb) { # ifdef X86_64 sb -> mem_base = ((NT_TIB*)NtCurrentTeb())->StackBase; # else void * _tlsbase; __asm__ ("movl %%fs:4, %0" : "=r" (_tlsbase)); sb -> mem_base = _tlsbase; # endif return GC_SUCCESS; } # endif /* CYGWIN32 */ # define HAVE_GET_STACK_BASE #else /* !MSWIN32 */ GC_INNER void GC_setpagesize(void) { # if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(SOFT_VDB) \ || defined(USE_MMAP) GC_page_size = (size_t)GETPAGESIZE(); # if !defined(CPPCHECK) if (0 == GC_page_size) ABORT("getpagesize failed"); # endif # else /* It's acceptable to fake it. */ GC_page_size = HBLKSIZE; # endif } #endif /* !MSWIN32 */ #ifdef HAIKU # include <kernel/OS.h> GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb) { thread_info th; get_thread_info(find_thread(NULL),&th); sb->mem_base = th.stack_end; return GC_SUCCESS; } # define HAVE_GET_STACK_BASE #endif /* HAIKU */ #ifdef OS2 GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb) { PTIB ptib; /* thread information block */ PPIB ppib; if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) { WARN("DosGetInfoBlocks failed\n", 0); return GC_UNIMPLEMENTED; } sb->mem_base = ptib->tib_pstacklimit; return GC_SUCCESS; } # define HAVE_GET_STACK_BASE #endif /* OS2 */ # ifdef AMIGA # define GC_AMIGA_SB # include "extra/AmigaOS.c" # undef GC_AMIGA_SB # define GET_MAIN_STACKBASE_SPECIAL # endif /* AMIGA */ # if defined(NEED_FIND_LIMIT) || defined(UNIX_LIKE) typedef void (*GC_fault_handler_t)(int); # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \ || defined(HAIKU) || defined(HURD) || defined(FREEBSD) \ || defined(NETBSD) static struct sigaction old_segv_act; # if defined(_sigargs) /* !Irix6.x */ || defined(HPUX) \ || defined(HURD) || defined(NETBSD) || defined(FREEBSD) static struct sigaction old_bus_act; # endif # else static GC_fault_handler_t old_segv_handler; # ifdef HAVE_SIGBUS static GC_fault_handler_t old_bus_handler; # endif # endif GC_INNER void GC_set_and_save_fault_handler(GC_fault_handler_t h) { # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \ || defined(HAIKU) || defined(HURD) || defined(FREEBSD) \ || defined(NETBSD) || defined(OPENBSD) struct sigaction act; act.sa_handler = h; # ifdef SIGACTION_FLAGS_NODEFER_HACK /* Was necessary for Solaris 2.3 and very temporary */ /* NetBSD bugs. */ act.sa_flags = SA_RESTART | SA_NODEFER; # else act.sa_flags = SA_RESTART; # endif (void) sigemptyset(&act.sa_mask); /* act.sa_restorer is deprecated and should not be initialized. */ # ifdef GC_IRIX_THREADS /* Older versions have a bug related to retrieving and */ /* and setting a handler at the same time. */ (void) sigaction(SIGSEGV, 0, &old_segv_act); (void) sigaction(SIGSEGV, &act, 0); # else (void) sigaction(SIGSEGV, &act, &old_segv_act); # if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \ || defined(HPUX) || defined(HURD) || defined(NETBSD) \ || defined(FREEBSD) /* Under Irix 5.x or HP/UX, we may get SIGBUS. */ /* Pthreads doesn't exist under Irix 5.x, so we */ /* don't have to worry in the threads case. */ (void) sigaction(SIGBUS, &act, &old_bus_act); # endif # endif /* !GC_IRIX_THREADS */ # else old_segv_handler = signal(SIGSEGV, h); # ifdef HAVE_SIGBUS old_bus_handler = signal(SIGBUS, h); # endif # endif # if defined(CPPCHECK) && defined(ADDRESS_SANITIZER) GC_noop1((word)&__asan_default_options); # endif } # endif /* NEED_FIND_LIMIT || UNIX_LIKE */ # if defined(NEED_FIND_LIMIT) \ || (defined(USE_PROC_FOR_LIBRARIES) && defined(THREADS)) /* Some tools to implement HEURISTIC2 */ # define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */ GC_INNER JMP_BUF GC_jmp_buf; STATIC void GC_fault_handler(int sig GC_ATTR_UNUSED) { LONGJMP(GC_jmp_buf, 1); } GC_INNER void GC_setup_temporary_fault_handler(void) { /* Handler is process-wide, so this should only happen in */ /* one thread at a time. */ GC_ASSERT(I_HOLD_LOCK()); GC_set_and_save_fault_handler(GC_fault_handler); } GC_INNER void GC_reset_fault_handler(void) { # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \ || defined(HAIKU) || defined(HURD) || defined(FREEBSD) \ || defined(NETBSD) || defined(OPENBSD) (void) sigaction(SIGSEGV, &old_segv_act, 0); # if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \ || defined(HPUX) || defined(HURD) || defined(NETBSD) \ || defined(FREEBSD) (void) sigaction(SIGBUS, &old_bus_act, 0); # endif # else (void) signal(SIGSEGV, old_segv_handler); # ifdef HAVE_SIGBUS (void) signal(SIGBUS, old_bus_handler); # endif # endif } /* Return the first non-addressable location > p (up) or */ /* the smallest location q s.t. [q,p) is addressable (!up). */ /* We assume that p (up) or p-1 (!up) is addressable. */ /* Requires allocation lock. */ GC_ATTR_NO_SANITIZE_ADDR STATIC ptr_t GC_find_limit_with_bound(ptr_t p, GC_bool up, ptr_t bound) { static volatile ptr_t result; /* Safer if static, since otherwise it may not be */ /* preserved across the longjmp. Can safely be */ /* static since it's only called with the */ /* allocation lock held. */ GC_ASSERT(up ? (word)bound >= MIN_PAGE_SIZE : (word)bound <= ~(word)MIN_PAGE_SIZE); GC_ASSERT(I_HOLD_LOCK()); GC_setup_temporary_fault_handler(); if (SETJMP(GC_jmp_buf) == 0) { result = (ptr_t)(((word)(p)) & ~(MIN_PAGE_SIZE-1)); for (;;) { if (up) { if ((word)result >= (word)bound - MIN_PAGE_SIZE) { result = bound; break; } result += MIN_PAGE_SIZE; /* no overflow expected */ } else { if ((word)result <= (word)bound + MIN_PAGE_SIZE) { result = bound - MIN_PAGE_SIZE; /* This is to compensate */ /* further result increment (we */ /* do not modify "up" variable */ /* since it might be clobbered */ /* by setjmp otherwise). */ break; } result -= MIN_PAGE_SIZE; /* no underflow expected */ } GC_noop1((word)(*result)); } } GC_reset_fault_handler(); if (!up) { result += MIN_PAGE_SIZE; } return(result); } void * GC_find_limit(void * p, int up) { return GC_find_limit_with_bound((ptr_t)p, (GC_bool)up, up ? (ptr_t)GC_WORD_MAX : 0); } # endif /* NEED_FIND_LIMIT || USE_PROC_FOR_LIBRARIES */ #ifdef HPUX_MAIN_STACKBOTTOM # include <sys/param.h> # include <sys/pstat.h> STATIC ptr_t GC_hpux_main_stack_base(void) { struct pst_vm_status vm_status; int i = 0; while (pstat_getprocvm(&vm_status, sizeof(vm_status), 0, i++) == 1) { if (vm_status.pst_type == PS_STACK) return (ptr_t)vm_status.pst_vaddr; } /* Old way to get the stack bottom. */ # ifdef STACK_GROWS_UP return (ptr_t)GC_find_limit(GC_approx_sp(), /* up= */ FALSE); # else /* not HP_PA */ return (ptr_t)GC_find_limit(GC_approx_sp(), TRUE); # endif } #endif /* HPUX_MAIN_STACKBOTTOM */ #ifdef HPUX_STACKBOTTOM #include <sys/param.h> #include <sys/pstat.h> GC_INNER ptr_t GC_get_register_stack_base(void) { struct pst_vm_status vm_status; int i = 0; while (pstat_getprocvm(&vm_status, sizeof(vm_status), 0, i++) == 1) { if (vm_status.pst_type == PS_RSESTACK) { return (ptr_t) vm_status.pst_vaddr; } } /* old way to get the register stackbottom */ return (ptr_t)(((word)GC_stackbottom - BACKING_STORE_DISPLACEMENT - 1) & ~(BACKING_STORE_ALIGNMENT - 1)); } #endif /* HPUX_STACK_BOTTOM */ #ifdef LINUX_STACKBOTTOM # include <sys/types.h> # include <sys/stat.h> # define STAT_SKIP 27 /* Number of fields preceding startstack */ /* field in /proc/self/stat */ # ifdef USE_LIBC_PRIVATES EXTERN_C_BEGIN # pragma weak __libc_stack_end extern ptr_t __libc_stack_end; # ifdef IA64 # pragma weak __libc_ia64_register_backing_store_base extern ptr_t __libc_ia64_register_backing_store_base; # endif EXTERN_C_END # endif # ifdef IA64 GC_INNER ptr_t GC_get_register_stack_base(void) { ptr_t result; # ifdef USE_LIBC_PRIVATES if (0 != &__libc_ia64_register_backing_store_base && 0 != __libc_ia64_register_backing_store_base) { /* Glibc 2.2.4 has a bug such that for dynamically linked */ /* executables __libc_ia64_register_backing_store_base is */ /* defined but uninitialized during constructor calls. */ /* Hence we check for both nonzero address and value. */ return __libc_ia64_register_backing_store_base; } # endif result = backing_store_base_from_proc(); if (0 == result) { result = (ptr_t)GC_find_limit(GC_save_regs_in_stack(), FALSE); /* This works better than a constant displacement heuristic. */ } return result; } # endif /* IA64 */ STATIC ptr_t GC_linux_main_stack_base(void) { /* We read the stack bottom value from /proc/self/stat. We do this */ /* using direct I/O system calls in order to avoid calling malloc */ /* in case REDIRECT_MALLOC is defined. */ # define STAT_BUF_SIZE 4096 char stat_buf[STAT_BUF_SIZE]; int f; word result; ssize_t i, buf_offset = 0, len; /* First try the easy way. This should work for glibc 2.2 */ /* This fails in a prelinked ("prelink" command) executable */ /* since the correct value of __libc_stack_end never */ /* becomes visible to us. The second test works around */ /* this. */ # ifdef USE_LIBC_PRIVATES if (0 != &__libc_stack_end && 0 != __libc_stack_end ) { # if defined(IA64) /* Some versions of glibc set the address 16 bytes too */ /* low while the initialization code is running. */ if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) { return __libc_stack_end + 0x10; } /* Otherwise it's not safe to add 16 bytes and we fall */ /* back to using /proc. */ # elif defined(SPARC) /* Older versions of glibc for 64-bit SPARC do not set this */ /* variable correctly, it gets set to either zero or one. */ if (__libc_stack_end != (ptr_t) (unsigned long)0x1) return __libc_stack_end; # else return __libc_stack_end; # endif } # endif f = open("/proc/self/stat", O_RDONLY); if (-1 == f) ABORT_ARG1("Could not open /proc/self/stat", ": errno= %d", errno); len = GC_repeat_read(f, stat_buf, sizeof(stat_buf)); if (len < 0) ABORT_ARG1("Failed to read /proc/self/stat", ": errno= %d", errno); close(f); /* Skip the required number of fields. This number is hopefully */ /* constant across all Linux implementations. */ for (i = 0; i < STAT_SKIP; ++i) { while (buf_offset < len && isspace(stat_buf[buf_offset++])) { /* empty */ } while (buf_offset < len && !isspace(stat_buf[buf_offset++])) { /* empty */ } } /* Skip spaces. */ while (buf_offset < len && isspace(stat_buf[buf_offset])) { buf_offset++; } /* Find the end of the number and cut the buffer there. */ for (i = 0; buf_offset + i < len; i++) { if (!isdigit(stat_buf[buf_offset + i])) break; } if (buf_offset + i >= len) ABORT("Could not parse /proc/self/stat"); stat_buf[buf_offset + i] = '\0'; result = (word)STRTOULL(&stat_buf[buf_offset], NULL, 10); if (result < 0x100000 || (result & (sizeof(word) - 1)) != 0) ABORT_ARG1("Absurd stack bottom value", ": 0x%lx", (unsigned long)result); return (ptr_t)result; } #endif /* LINUX_STACKBOTTOM */ #ifdef FREEBSD_STACKBOTTOM /* This uses an undocumented sysctl call, but at least one expert */ /* believes it will stay. */ # include <unistd.h> # include <sys/types.h> # include <sys/sysctl.h> STATIC ptr_t GC_freebsd_main_stack_base(void) { int nm[2] = {CTL_KERN, KERN_USRSTACK}; ptr_t base; size_t len = sizeof(ptr_t); int r = sysctl(nm, 2, &base, &len, NULL, 0); if (r) ABORT("Error getting main stack base"); return base; } #endif /* FREEBSD_STACKBOTTOM */ #if defined(ECOS) || defined(NOSYS) ptr_t GC_get_main_stack_base(void) { return STACKBOTTOM; } # define GET_MAIN_STACKBASE_SPECIAL #elif defined(SYMBIAN) EXTERN_C_BEGIN extern int GC_get_main_symbian_stack_base(void); EXTERN_C_END ptr_t GC_get_main_stack_base(void) { return (ptr_t)GC_get_main_symbian_stack_base(); } # define GET_MAIN_STACKBASE_SPECIAL #elif defined(EMSCRIPTEN) # include <emscripten.h> static void* emscripten_stack_base; static void scan_stack_cb(void *begin, void *end) { (void)begin; emscripten_stack_base = end; } ptr_t GC_get_main_stack_base(void) { emscripten_scan_stack(scan_stack_cb); return (ptr_t)emscripten_stack_base; } # define GET_MAIN_STACKBASE_SPECIAL #elif !defined(AMIGA) && !defined(HAIKU) && !defined(OS2) \ && !defined(MSWIN32) && !defined(MSWINCE) && !defined(CYGWIN32) \ && !defined(GC_OPENBSD_THREADS) \ && (!defined(GC_SOLARIS_THREADS) || defined(_STRICT_STDC)) # if (defined(HAVE_PTHREAD_ATTR_GET_NP) || defined(HAVE_PTHREAD_GETATTR_NP)) \ && (defined(THREADS) || defined(USE_GET_STACKBASE_FOR_MAIN)) # include <pthread.h> # ifdef HAVE_PTHREAD_NP_H # include <pthread_np.h> /* for pthread_attr_get_np() */ # endif # elif defined(DARWIN) && !defined(NO_PTHREAD_GET_STACKADDR_NP) /* We could use pthread_get_stackaddr_np even in case of a */ /* single-threaded gclib (there is no -lpthread on Darwin). */ # include <pthread.h> # undef STACKBOTTOM # define STACKBOTTOM (ptr_t)pthread_get_stackaddr_np(pthread_self()) # endif ptr_t GC_get_main_stack_base(void) { ptr_t result; # if (defined(HAVE_PTHREAD_ATTR_GET_NP) \ || defined(HAVE_PTHREAD_GETATTR_NP)) \ && (defined(USE_GET_STACKBASE_FOR_MAIN) \ || (defined(THREADS) && !defined(REDIRECT_MALLOC))) pthread_attr_t attr; void *stackaddr; size_t size; # ifdef HAVE_PTHREAD_ATTR_GET_NP if (pthread_attr_init(&attr) == 0 && (pthread_attr_get_np(pthread_self(), &attr) == 0 ? TRUE : (pthread_attr_destroy(&attr), FALSE))) # else /* HAVE_PTHREAD_GETATTR_NP */ if (pthread_getattr_np(pthread_self(), &attr) == 0) # endif { if (pthread_attr_getstack(&attr, &stackaddr, &size) == 0 && stackaddr != NULL) { (void)pthread_attr_destroy(&attr); # ifdef STACK_GROWS_DOWN stackaddr = (char *)stackaddr + size; # endif return (ptr_t)stackaddr; } (void)pthread_attr_destroy(&attr); } WARN("pthread_getattr_np or pthread_attr_getstack failed" " for main thread\n", 0); # endif # ifdef STACKBOTTOM result = STACKBOTTOM; # else # ifdef HEURISTIC1 # define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1) # ifdef STACK_GROWS_DOWN result = (ptr_t)(((word)GC_approx_sp() + STACKBOTTOM_ALIGNMENT_M1) & ~STACKBOTTOM_ALIGNMENT_M1); # else result = (ptr_t)((word)GC_approx_sp() & ~STACKBOTTOM_ALIGNMENT_M1); # endif # elif defined(HPUX_MAIN_STACKBOTTOM) result = GC_hpux_main_stack_base(); # elif defined(LINUX_STACKBOTTOM) result = GC_linux_main_stack_base(); # elif defined(FREEBSD_STACKBOTTOM) result = GC_freebsd_main_stack_base(); # elif defined(HEURISTIC2) { ptr_t sp = GC_approx_sp(); # ifdef STACK_GROWS_DOWN result = (ptr_t)GC_find_limit(sp, TRUE); # if defined(HEURISTIC2_LIMIT) && !defined(CPPCHECK) if ((word)result > (word)HEURISTIC2_LIMIT && (word)sp < (word)HEURISTIC2_LIMIT) { result = HEURISTIC2_LIMIT; } # endif # else result = (ptr_t)GC_find_limit(sp, FALSE); # if defined(HEURISTIC2_LIMIT) && !defined(CPPCHECK) if ((word)result < (word)HEURISTIC2_LIMIT && (word)sp > (word)HEURISTIC2_LIMIT) { result = HEURISTIC2_LIMIT; } # endif # endif } # elif defined(STACK_NOT_SCANNED) || defined(CPPCHECK) result = NULL; # else # error None of HEURISTIC* and *STACKBOTTOM defined! # endif # if defined(STACK_GROWS_DOWN) && !defined(CPPCHECK) if (result == 0) result = (ptr_t)(signed_word)(-sizeof(ptr_t)); # endif # endif # if !defined(CPPCHECK) GC_ASSERT((word)GC_approx_sp() HOTTER_THAN (word)result); # endif return(result); } # define GET_MAIN_STACKBASE_SPECIAL #endif /* !AMIGA, !HAIKU, !OPENBSD, !OS2, !Windows */ #if (defined(HAVE_PTHREAD_ATTR_GET_NP) || defined(HAVE_PTHREAD_GETATTR_NP)) \ && defined(THREADS) && !defined(HAVE_GET_STACK_BASE) # include <pthread.h> # ifdef HAVE_PTHREAD_NP_H # include <pthread_np.h> # endif GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b) { pthread_attr_t attr; size_t size; # ifdef IA64 DCL_LOCK_STATE; # endif # ifdef HAVE_PTHREAD_ATTR_GET_NP if (pthread_attr_init(&attr) != 0) ABORT("pthread_attr_init failed"); if (pthread_attr_get_np(pthread_self(), &attr) != 0) { WARN("pthread_attr_get_np failed\n", 0); (void)pthread_attr_destroy(&attr); return GC_UNIMPLEMENTED; } # else /* HAVE_PTHREAD_GETATTR_NP */ if (pthread_getattr_np(pthread_self(), &attr) != 0) { WARN("pthread_getattr_np failed\n", 0); return GC_UNIMPLEMENTED; } # endif if (pthread_attr_getstack(&attr, &(b -> mem_base), &size) != 0) { ABORT("pthread_attr_getstack failed"); } (void)pthread_attr_destroy(&attr); # ifdef STACK_GROWS_DOWN b -> mem_base = (char *)(b -> mem_base) + size; # endif # ifdef IA64 /* We could try backing_store_base_from_proc, but that's safe */ /* only if no mappings are being asynchronously created. */ /* Subtracting the size from the stack base doesn't work for at */ /* least the main thread. */ LOCK(); { IF_CANCEL(int cancel_state;) ptr_t bsp; ptr_t next_stack; DISABLE_CANCEL(cancel_state); bsp = GC_save_regs_in_stack(); next_stack = GC_greatest_stack_base_below(bsp); if (0 == next_stack) { b -> reg_base = GC_find_limit(bsp, FALSE); } else { /* Avoid walking backwards into preceding memory stack and */ /* growing it. */ b -> reg_base = GC_find_limit_with_bound(bsp, FALSE, next_stack); } RESTORE_CANCEL(cancel_state); } UNLOCK(); # elif defined(E2K) b -> reg_base = NULL; # endif return GC_SUCCESS; } # define HAVE_GET_STACK_BASE #endif /* THREADS && (HAVE_PTHREAD_ATTR_GET_NP || HAVE_PTHREAD_GETATTR_NP) */ #if defined(GC_DARWIN_THREADS) && !defined(NO_PTHREAD_GET_STACKADDR_NP) # include <pthread.h> GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b) { /* pthread_get_stackaddr_np() should return stack bottom (highest */ /* stack address plus 1). */ b->mem_base = pthread_get_stackaddr_np(pthread_self()); GC_ASSERT((word)GC_approx_sp() HOTTER_THAN (word)b->mem_base); return GC_SUCCESS; } # define HAVE_GET_STACK_BASE #endif /* GC_DARWIN_THREADS */ #ifdef GC_OPENBSD_THREADS # include <sys/signal.h> # include <pthread.h> # include <pthread_np.h> /* Find the stack using pthread_stackseg_np(). */ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb) { stack_t stack; if (pthread_stackseg_np(pthread_self(), &stack)) ABORT("pthread_stackseg_np(self) failed"); sb->mem_base = stack.ss_sp; return GC_SUCCESS; } # define HAVE_GET_STACK_BASE #endif /* GC_OPENBSD_THREADS */ #if defined(GC_SOLARIS_THREADS) && !defined(_STRICT_STDC) # include <thread.h> # include <signal.h> # include <pthread.h> /* These variables are used to cache ss_sp value for the primordial */ /* thread (it's better not to call thr_stksegment() twice for this */ /* thread - see JDK bug #4352906). */ static pthread_t stackbase_main_self = 0; /* 0 means stackbase_main_ss_sp value is unset. */ static void *stackbase_main_ss_sp = NULL; GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b) { stack_t s; pthread_t self = pthread_self(); if (self == stackbase_main_self) { /* If the client calls GC_get_stack_base() from the main thread */ /* then just return the cached value. */ b -> mem_base = stackbase_main_ss_sp; GC_ASSERT(b -> mem_base != NULL); return GC_SUCCESS; } if (thr_stksegment(&s)) { /* According to the manual, the only failure error code returned */ /* is EAGAIN meaning "the information is not available due to the */ /* thread is not yet completely initialized or it is an internal */ /* thread" - this shouldn't happen here. */ ABORT("thr_stksegment failed"); } /* s.ss_sp holds the pointer to the stack bottom. */ GC_ASSERT((word)GC_approx_sp() HOTTER_THAN (word)s.ss_sp); if (!stackbase_main_self && thr_main() != 0) { /* Cache the stack bottom pointer for the primordial thread */ /* (this is done during GC_init, so there is no race). */ stackbase_main_ss_sp = s.ss_sp; stackbase_main_self = self; } b -> mem_base = s.ss_sp; return GC_SUCCESS; } # define HAVE_GET_STACK_BASE #endif /* GC_SOLARIS_THREADS */ #ifdef GC_RTEMS_PTHREADS GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *sb) { sb->mem_base = rtems_get_stack_bottom(); return GC_SUCCESS; } # define HAVE_GET_STACK_BASE #endif /* GC_RTEMS_PTHREADS */ #ifndef HAVE_GET_STACK_BASE # ifdef NEED_FIND_LIMIT /* Retrieve the stack bottom. */ /* Using the GC_find_limit version is risky. */ /* On IA64, for example, there is no guard page between the */ /* stack of one thread and the register backing store of the */ /* next. Thus this is likely to identify way too large a */ /* "stack" and thus at least result in disastrous performance. */ /* TODO: Implement better strategies here. */ GC_API int GC_CALL GC_get_stack_base(struct GC_stack_base *b) { IF_CANCEL(int cancel_state;) DCL_LOCK_STATE; LOCK(); DISABLE_CANCEL(cancel_state); /* May be unnecessary? */ # ifdef STACK_GROWS_DOWN b -> mem_base = GC_find_limit(GC_approx_sp(), TRUE); # else b -> mem_base = GC_find_limit(GC_approx_sp(), FALSE); # endif # ifdef IA64 b -> reg_base = GC_find_limit(GC_save_regs_in_stack(), FALSE); # elif defined(E2K) b -> reg_base = NULL; # endif RESTORE_CANCEL(cancel_state); UNLOCK(); return GC_SUCCESS; } # else GC_API int GC_CALL GC_get_stack_base( struct GC_stack_base *b GC_ATTR_UNUSED) { # if defined(GET_MAIN_STACKBASE_SPECIAL) && !defined(THREADS) \ && !defined(IA64) b->mem_base = GC_get_main_stack_base(); return GC_SUCCESS; # else return GC_UNIMPLEMENTED; # endif } # endif /* !NEED_FIND_LIMIT */ #endif /* !HAVE_GET_STACK_BASE */ #ifndef GET_MAIN_STACKBASE_SPECIAL /* This is always called from the main thread. Default implementation. */ ptr_t GC_get_main_stack_base(void) { struct GC_stack_base sb; if (GC_get_stack_base(&sb) != GC_SUCCESS) ABORT("GC_get_stack_base failed"); GC_ASSERT((word)GC_approx_sp() HOTTER_THAN (word)sb.mem_base); return (ptr_t)sb.mem_base; } #endif /* !GET_MAIN_STACKBASE_SPECIAL */ /* Register static data segment(s) as roots. If more data segments are */ /* added later then they need to be registered at that point (as we do */ /* with SunOS dynamic loading), or GC_mark_roots needs to check for */ /* them (as we do with PCR). Called with allocator lock held. */ # ifdef OS2 void GC_register_data_segments(void) { PTIB ptib; PPIB ppib; HMODULE module_handle; # define PBUFSIZ 512 UCHAR path[PBUFSIZ]; FILE * myexefile; struct exe_hdr hdrdos; /* MSDOS header. */ struct e32_exe hdr386; /* Real header for my executable */ struct o32_obj seg; /* Current segment */ int nsegs; # if defined(CPPCHECK) hdrdos.padding[0] = 0; /* to prevent "field unused" warnings */ hdr386.exe_format_level = 0; hdr386.os = 0; hdr386.padding1[0] = 0; hdr386.padding2[0] = 0; seg.pagemap = 0; seg.mapsize = 0; seg.reserved = 0; # endif if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) { ABORT("DosGetInfoBlocks failed"); } module_handle = ppib -> pib_hmte; if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) { ABORT("DosQueryModuleName failed"); } myexefile = fopen(path, "rb"); if (myexefile == 0) { ABORT_ARG1("Failed to open executable", ": %s", path); } if (fread((char *)(&hdrdos), 1, sizeof(hdrdos), myexefile) < sizeof(hdrdos)) { ABORT_ARG1("Could not read MSDOS header", " from: %s", path); } if (E_MAGIC(hdrdos) != EMAGIC) { ABORT_ARG1("Bad DOS magic number", " in file: %s", path); } if (fseek(myexefile, E_LFANEW(hdrdos), SEEK_SET) != 0) { ABORT_ARG1("Bad DOS magic number", " in file: %s", path); } if (fread((char *)(&hdr386), 1, sizeof(hdr386), myexefile) < sizeof(hdr386)) { ABORT_ARG1("Could not read OS/2 header", " from: %s", path); } if (E32_MAGIC1(hdr386) != E32MAGIC1 || E32_MAGIC2(hdr386) != E32MAGIC2) { ABORT_ARG1("Bad OS/2 magic number", " in file: %s", path); } if (E32_BORDER(hdr386) != E32LEBO || E32_WORDER(hdr386) != E32LEWO) { ABORT_ARG1("Bad byte order in executable", " file: %s", path); } if (E32_CPU(hdr386) == E32CPU286) { ABORT_ARG1("GC cannot handle 80286 executables", ": %s", path); } if (fseek(myexefile, E_LFANEW(hdrdos) + E32_OBJTAB(hdr386), SEEK_SET) != 0) { ABORT_ARG1("Seek to object table failed", " in file: %s", path); } for (nsegs = E32_OBJCNT(hdr386); nsegs > 0; nsegs--) { int flags; if (fread((char *)(&seg), 1, sizeof(seg), myexefile) < sizeof(seg)) { ABORT_ARG1("Could not read obj table entry", " from file: %s", path); } flags = O32_FLAGS(seg); if (!(flags & OBJWRITE)) continue; if (!(flags & OBJREAD)) continue; if (flags & OBJINVALID) { GC_err_printf("Object with invalid pages?\n"); continue; } GC_add_roots_inner((ptr_t)O32_BASE(seg), (ptr_t)(O32_BASE(seg)+O32_SIZE(seg)), FALSE); } (void)fclose(myexefile); } # else /* !OS2 */ # if defined(GWW_VDB) # ifndef MEM_WRITE_WATCH # define MEM_WRITE_WATCH 0x200000 # endif # ifndef WRITE_WATCH_FLAG_RESET # define WRITE_WATCH_FLAG_RESET 1 # endif /* Since we can't easily check whether ULONG_PTR and SIZE_T are */ /* defined in Win32 basetsd.h, we define own ULONG_PTR. */ # define GC_ULONG_PTR word typedef UINT (WINAPI * GetWriteWatch_type)( DWORD, PVOID, GC_ULONG_PTR /* SIZE_T */, PVOID *, GC_ULONG_PTR *, PULONG); static FARPROC GetWriteWatch_func; static DWORD GetWriteWatch_alloc_flag; # define GC_GWW_AVAILABLE() (GetWriteWatch_func != 0) static void detect_GetWriteWatch(void) { static GC_bool done; HMODULE hK32; if (done) return; # if defined(MPROTECT_VDB) { char * str = GETENV("GC_USE_GETWRITEWATCH"); # if defined(GC_PREFER_MPROTECT_VDB) if (str == NULL || (*str == '0' && *(str + 1) == '\0')) { /* GC_USE_GETWRITEWATCH is unset or set to "0". */ done = TRUE; /* falling back to MPROTECT_VDB strategy. */ /* This should work as if GWW_VDB is undefined. */ return; } # else if (str != NULL && *str == '0' && *(str + 1) == '\0') { /* GC_USE_GETWRITEWATCH is set "0". */ done = TRUE; /* falling back to MPROTECT_VDB strategy. */ return; } # endif } # endif # ifdef MSWINRT_FLAVOR { MEMORY_BASIC_INFORMATION memInfo; SIZE_T result = VirtualQuery((void*)(word)GetProcAddress, &memInfo, sizeof(memInfo)); if (result != sizeof(memInfo)) ABORT("Weird VirtualQuery result"); hK32 = (HMODULE)memInfo.AllocationBase; } # else hK32 = GetModuleHandle(TEXT("kernel32.dll")); # endif if (hK32 != (HMODULE)0 && (GetWriteWatch_func = GetProcAddress(hK32, "GetWriteWatch")) != 0) { /* Also check whether VirtualAlloc accepts MEM_WRITE_WATCH, */ /* as some versions of kernel32.dll have one but not the */ /* other, making the feature completely broken. */ void * page; GC_ASSERT(GC_page_size != 0); page = VirtualAlloc(NULL, GC_page_size, MEM_WRITE_WATCH | MEM_RESERVE, PAGE_READWRITE); if (page != NULL) { PVOID pages[16]; GC_ULONG_PTR count = 16; DWORD page_size; /* Check that it actually works. In spite of some */ /* documentation it actually seems to exist on Win2K. */ /* This test may be unnecessary, but ... */ if ((*(GetWriteWatch_type)(word)GetWriteWatch_func)( WRITE_WATCH_FLAG_RESET, page, GC_page_size, pages, &count, &page_size) != 0) { /* GetWriteWatch always fails. */ GetWriteWatch_func = 0; } else { GetWriteWatch_alloc_flag = MEM_WRITE_WATCH; } VirtualFree(page, 0 /* dwSize */, MEM_RELEASE); } else { /* GetWriteWatch will be useless. */ GetWriteWatch_func = 0; } } done = TRUE; } # else # define GetWriteWatch_alloc_flag 0 # endif /* !GWW_VDB */ # if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32) # ifdef MSWIN32 /* Unfortunately, we have to handle win32s very differently from NT, */ /* Since VirtualQuery has very different semantics. In particular, */ /* under win32s a VirtualQuery call on an unmapped page returns an */ /* invalid result. Under NT, GC_register_data_segments is a no-op */ /* and all real work is done by GC_register_dynamic_libraries. Under */ /* win32s, we cannot find the data segments associated with dll's. */ /* We register the main data segment here. */ GC_INNER GC_bool GC_no_win32_dlls = FALSE; /* This used to be set for gcc, to avoid dealing with */ /* the structured exception handling issues. But we now have */ /* assembly code to do that right. */ GC_INNER GC_bool GC_wnt = FALSE; /* This is a Windows NT derivative, i.e. NT, Win2K, XP or later. */ GC_INNER void GC_init_win32(void) { # if defined(_WIN64) || (defined(_MSC_VER) && _MSC_VER >= 1800) /* MS Visual Studio 2013 deprecates GetVersion, but on the other */ /* hand it cannot be used to target pre-Win2K. */ GC_wnt = TRUE; # else /* Set GC_wnt. If we're running under win32s, assume that no */ /* DLLs will be loaded. I doubt anyone still runs win32s, but... */ DWORD v = GetVersion(); GC_wnt = !(v & 0x80000000); GC_no_win32_dlls |= ((!GC_wnt) && (v & 0xff) <= 3); # endif # ifdef USE_MUNMAP if (GC_no_win32_dlls) { /* Turn off unmapping for safety (since may not work well with */ /* GlobalAlloc). */ GC_unmap_threshold = 0; } # endif } /* Return the smallest address a such that VirtualQuery */ /* returns correct results for all addresses between a and start. */ /* Assumes VirtualQuery returns correct information for start. */ STATIC ptr_t GC_least_described_address(ptr_t start) { MEMORY_BASIC_INFORMATION buf; LPVOID limit = GC_sysinfo.lpMinimumApplicationAddress; ptr_t p = (ptr_t)((word)start & ~(GC_page_size - 1)); GC_ASSERT(GC_page_size != 0); for (;;) { size_t result; LPVOID q = (LPVOID)(p - GC_page_size); if ((word)q > (word)p /* underflow */ || (word)q < (word)limit) break; result = VirtualQuery(q, &buf, sizeof(buf)); if (result != sizeof(buf) || buf.AllocationBase == 0) break; p = (ptr_t)(buf.AllocationBase); } return p; } # endif /* MSWIN32 */ # if defined(USE_WINALLOC) && !defined(REDIRECT_MALLOC) /* We maintain a linked list of AllocationBase values that we know */ /* correspond to malloc heap sections. Currently this is only called */ /* during a GC. But there is some hope that for long running */ /* programs we will eventually see most heap sections. */ /* In the long run, it would be more reliable to occasionally walk */ /* the malloc heap with HeapWalk on the default heap. But that */ /* apparently works only for NT-based Windows. */ STATIC size_t GC_max_root_size = 100000; /* Appr. largest root size. */ /* In the long run, a better data structure would also be nice ... */ STATIC struct GC_malloc_heap_list { void * allocation_base; struct GC_malloc_heap_list *next; } *GC_malloc_heap_l = 0; /* Is p the base of one of the malloc heap sections we already know */ /* about? */ STATIC GC_bool GC_is_malloc_heap_base(void *p) { struct GC_malloc_heap_list *q = GC_malloc_heap_l; while (0 != q) { if (q -> allocation_base == p) return TRUE; q = q -> next; } return FALSE; } STATIC void *GC_get_allocation_base(void *p) { MEMORY_BASIC_INFORMATION buf; size_t result = VirtualQuery(p, &buf, sizeof(buf)); if (result != sizeof(buf)) { ABORT("Weird VirtualQuery result"); } return buf.AllocationBase; } GC_INNER void GC_add_current_malloc_heap(void) { struct GC_malloc_heap_list *new_l = (struct GC_malloc_heap_list *) malloc(sizeof(struct GC_malloc_heap_list)); void *candidate; if (NULL == new_l) return; new_l -> allocation_base = NULL; /* to suppress maybe-uninitialized gcc warning */ candidate = GC_get_allocation_base(new_l); if (GC_is_malloc_heap_base(candidate)) { /* Try a little harder to find malloc heap. */ size_t req_size = 10000; do { void *p = malloc(req_size); if (0 == p) { free(new_l); return; } candidate = GC_get_allocation_base(p); free(p); req_size *= 2; } while (GC_is_malloc_heap_base(candidate) && req_size < GC_max_root_size/10 && req_size < 500000); if (GC_is_malloc_heap_base(candidate)) { free(new_l); return; } } GC_COND_LOG_PRINTF("Found new system malloc AllocationBase at %p\n", candidate); new_l -> allocation_base = candidate; new_l -> next = GC_malloc_heap_l; GC_malloc_heap_l = new_l; } /* Free all the linked list nodes. Could be invoked at process exit */ /* to avoid memory leak complains of a dynamic code analysis tool. */ STATIC void GC_free_malloc_heap_list(void) { struct GC_malloc_heap_list *q = GC_malloc_heap_l; GC_malloc_heap_l = NULL; while (q != NULL) { struct GC_malloc_heap_list *next = q -> next; free(q); q = next; } } # endif /* USE_WINALLOC && !REDIRECT_MALLOC */ /* Is p the start of either the malloc heap, or of one of our */ /* heap sections? */ GC_INNER GC_bool GC_is_heap_base(void *p) { int i; # if defined(USE_WINALLOC) && !defined(REDIRECT_MALLOC) if (GC_root_size > GC_max_root_size) GC_max_root_size = GC_root_size; if (GC_is_malloc_heap_base(p)) return TRUE; # endif for (i = 0; i < (int)GC_n_heap_bases; i++) { if (GC_heap_bases[i] == p) return TRUE; } return FALSE; } #ifdef MSWIN32 STATIC void GC_register_root_section(ptr_t static_root) { MEMORY_BASIC_INFORMATION buf; LPVOID p; char * base; char * limit; if (!GC_no_win32_dlls) return; p = base = limit = GC_least_described_address(static_root); while ((word)p < (word)GC_sysinfo.lpMaximumApplicationAddress) { size_t result = VirtualQuery(p, &buf, sizeof(buf)); char * new_limit; DWORD protect; if (result != sizeof(buf) || buf.AllocationBase == 0 || GC_is_heap_base(buf.AllocationBase)) break; new_limit = (char *)p + buf.RegionSize; protect = buf.Protect; if (buf.State == MEM_COMMIT && is_writable(protect)) { if ((char *)p == limit) { limit = new_limit; } else { if (base != limit) GC_add_roots_inner(base, limit, FALSE); base = (char *)p; limit = new_limit; } } if ((word)p > (word)new_limit /* overflow */) break; p = (LPVOID)new_limit; } if (base != limit) GC_add_roots_inner(base, limit, FALSE); } #endif /* MSWIN32 */ void GC_register_data_segments(void) { # ifdef MSWIN32 GC_register_root_section((ptr_t)&GC_pages_executable); /* any other GC global variable would fit too. */ # endif } # else /* !OS2 && !Windows */ # if (defined(SVR4) || defined(AIX) || defined(DGUX) \ || (defined(LINUX) && defined(SPARC))) && !defined(PCR) ptr_t GC_SysVGetDataStart(size_t max_page_size, ptr_t etext_addr) { word text_end = ((word)(etext_addr) + sizeof(word) - 1) & ~(word)(sizeof(word) - 1); /* etext rounded to word boundary */ word next_page = ((text_end + (word)max_page_size - 1) & ~((word)max_page_size - 1)); word page_offset = (text_end & ((word)max_page_size - 1)); volatile ptr_t result = (char *)(next_page + page_offset); /* Note that this isn't equivalent to just adding */ /* max_page_size to &etext if &etext is at a page boundary */ GC_setup_temporary_fault_handler(); if (SETJMP(GC_jmp_buf) == 0) { /* Try writing to the address. */ # ifdef AO_HAVE_fetch_and_add volatile AO_t zero = 0; (void)AO_fetch_and_add((volatile AO_t *)result, zero); # else /* Fallback to non-atomic fetch-and-store. */ char v = *result; # if defined(CPPCHECK) GC_noop1((word)&v); # endif *result = v; # endif GC_reset_fault_handler(); } else { GC_reset_fault_handler(); /* We got here via a longjmp. The address is not readable. */ /* This is known to happen under Solaris 2.4 + gcc, which place */ /* string constants in the text segment, but after etext. */ /* Use plan B. Note that we now know there is a gap between */ /* text and data segments, so plan A brought us something. */ result = (char *)GC_find_limit(DATAEND, FALSE); } return (/* no volatile */ ptr_t)result; } # endif #ifdef DATASTART_USES_BSDGETDATASTART /* Its unclear whether this should be identical to the above, or */ /* whether it should apply to non-X86 architectures. */ /* For now we don't assume that there is always an empty page after */ /* etext. But in some cases there actually seems to be slightly more. */ /* This also deals with holes between read-only data and writable data. */ GC_INNER ptr_t GC_FreeBSDGetDataStart(size_t max_page_size, ptr_t etext_addr) { word text_end = ((word)(etext_addr) + sizeof(word) - 1) & ~(word)(sizeof(word) - 1); /* etext rounded to word boundary */ volatile word next_page = (text_end + (word)max_page_size - 1) & ~((word)max_page_size - 1); volatile ptr_t result = (ptr_t)text_end; GC_setup_temporary_fault_handler(); if (SETJMP(GC_jmp_buf) == 0) { /* Try reading at the address. */ /* This should happen before there is another thread. */ for (; next_page < (word)DATAEND; next_page += (word)max_page_size) *(volatile char *)next_page; GC_reset_fault_handler(); } else { GC_reset_fault_handler(); /* As above, we go to plan B */ result = (ptr_t)GC_find_limit(DATAEND, FALSE); } return(result); } #endif /* DATASTART_USES_BSDGETDATASTART */ #ifdef AMIGA # define GC_AMIGA_DS # include "extra/AmigaOS.c" # undef GC_AMIGA_DS #elif defined(OPENBSD) /* Depending on arch alignment, there can be multiple holes */ /* between DATASTART and DATAEND. Scan in DATASTART .. DATAEND */ /* and register each region. */ void GC_register_data_segments(void) { ptr_t region_start = DATASTART; if ((word)region_start - 1U >= (word)DATAEND) ABORT_ARG2("Wrong DATASTART/END pair", ": %p .. %p", (void *)region_start, (void *)DATAEND); for (;;) { # ifdef GC_OPENBSD_UTHREADS ptr_t region_end = GC_find_limit_openbsd(region_start, DATAEND); # else ptr_t region_end = GC_find_limit_with_bound(region_start, TRUE, DATAEND); # endif GC_add_roots_inner(region_start, region_end, FALSE); if ((word)region_end >= (word)DATAEND) break; region_start = GC_skip_hole_openbsd(region_end, DATAEND); } } # else /* !OS2 && !Windows && !AMIGA && !OPENBSD */ # if !defined(PCR) && !defined(MACOS) && defined(REDIRECT_MALLOC) \ && defined(GC_SOLARIS_THREADS) EXTERN_C_BEGIN extern caddr_t sbrk(int); EXTERN_C_END # endif void GC_register_data_segments(void) { # if !defined(PCR) && !defined(MACOS) # if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS) /* As of Solaris 2.3, the Solaris threads implementation */ /* allocates the data structure for the initial thread with */ /* sbrk at process startup. It needs to be scanned, so that */ /* we don't lose some malloc allocated data structures */ /* hanging from it. We're on thin ice here ... */ GC_ASSERT(DATASTART); { ptr_t p = (ptr_t)sbrk(0); if ((word)DATASTART < (word)p) GC_add_roots_inner(DATASTART, p, FALSE); } # else if ((word)DATASTART - 1U >= (word)DATAEND) { /* Subtract one to check also for NULL */ /* without a compiler warning. */ ABORT_ARG2("Wrong DATASTART/END pair", ": %p .. %p", (void *)DATASTART, (void *)DATAEND); } GC_add_roots_inner(DATASTART, DATAEND, FALSE); # ifdef GC_HAVE_DATAREGION2 if ((word)DATASTART2 - 1U >= (word)DATAEND2) ABORT_ARG2("Wrong DATASTART/END2 pair", ": %p .. %p", (void *)DATASTART2, (void *)DATAEND2); GC_add_roots_inner(DATASTART2, DATAEND2, FALSE); # endif # endif # endif # if defined(MACOS) { # if defined(THINK_C) extern void* GC_MacGetDataStart(void); /* globals begin above stack and end at a5. */ GC_add_roots_inner((ptr_t)GC_MacGetDataStart(), (ptr_t)LMGetCurrentA5(), FALSE); # else # if defined(__MWERKS__) # if !__POWERPC__ extern void* GC_MacGetDataStart(void); /* MATTHEW: Function to handle Far Globals (CW Pro 3) */ # if __option(far_data) extern void* GC_MacGetDataEnd(void); # endif /* globals begin above stack and end at a5. */ GC_add_roots_inner((ptr_t)GC_MacGetDataStart(), (ptr_t)LMGetCurrentA5(), FALSE); /* MATTHEW: Handle Far Globals */ # if __option(far_data) /* Far globals follow he QD globals: */ GC_add_roots_inner((ptr_t)LMGetCurrentA5(), (ptr_t)GC_MacGetDataEnd(), FALSE); # endif # else extern char __data_start__[], __data_end__[]; GC_add_roots_inner((ptr_t)&__data_start__, (ptr_t)&__data_end__, FALSE); # endif /* __POWERPC__ */ # endif /* __MWERKS__ */ # endif /* !THINK_C */ } # endif /* MACOS */ /* Dynamic libraries are added at every collection, since they may */ /* change. */ } # endif /* !AMIGA */ # endif /* !MSWIN32 && !MSWINCE */ # endif /* !OS2 */ /* * Auxiliary routines for obtaining memory from OS. */ # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \ && !defined(USE_WINALLOC) && !defined(MACOS) && !defined(DOS4GW) \ && !defined(NINTENDO_SWITCH) && !defined(NONSTOP) \ && !defined(SN_TARGET_ORBIS) && !defined(SN_TARGET_PS3) \ && !defined(SN_TARGET_PSP2) && !defined(RTEMS) && !defined(__CC_ARM) # define SBRK_ARG_T ptrdiff_t #if defined(MMAP_SUPPORTED) #ifdef USE_MMAP_FIXED # define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE /* Seems to yield better performance on Solaris 2, but can */ /* be unreliable if something is already mapped at the address. */ #else # define GC_MMAP_FLAGS MAP_PRIVATE #endif #ifdef USE_MMAP_ANON # define zero_fd -1 # if defined(MAP_ANONYMOUS) && !defined(CPPCHECK) # define OPT_MAP_ANON MAP_ANONYMOUS # else # define OPT_MAP_ANON MAP_ANON # endif #else static int zero_fd = -1; # define OPT_MAP_ANON 0 #endif # ifndef MSWIN_XBOX1 # if defined(SYMBIAN) && !defined(USE_MMAP_ANON) EXTERN_C_BEGIN extern char *GC_get_private_path_and_zero_file(void); EXTERN_C_END # endif STATIC ptr_t GC_unix_mmap_get_mem(size_t bytes) { void *result; static ptr_t last_addr = HEAP_START; # ifndef USE_MMAP_ANON static GC_bool initialized = FALSE; if (!EXPECT(initialized, TRUE)) { # ifdef SYMBIAN char *path = GC_get_private_path_and_zero_file(); if (path != NULL) { zero_fd = open(path, O_RDWR | O_CREAT, 0644); free(path); } # else zero_fd = open("/dev/zero", O_RDONLY); # endif if (zero_fd == -1) ABORT("Could not open /dev/zero"); if (fcntl(zero_fd, F_SETFD, FD_CLOEXEC) == -1) WARN("Could not set FD_CLOEXEC for /dev/zero\n", 0); initialized = TRUE; } # endif GC_ASSERT(GC_page_size != 0); if (bytes & (GC_page_size - 1)) ABORT("Bad GET_MEM arg"); result = mmap(last_addr, bytes, (PROT_READ | PROT_WRITE) | (GC_pages_executable ? PROT_EXEC : 0), GC_MMAP_FLAGS | OPT_MAP_ANON, zero_fd, 0/* offset */); # undef IGNORE_PAGES_EXECUTABLE if (EXPECT(MAP_FAILED == result, FALSE)) { if (HEAP_START == last_addr && GC_pages_executable && EACCES == errno) ABORT("Cannot allocate executable pages"); return NULL; } last_addr = (ptr_t)(((word)result + bytes + GC_page_size - 1) & ~(GC_page_size - 1)); # if !defined(LINUX) if (last_addr == 0) { /* Oops. We got the end of the address space. This isn't */ /* usable by arbitrary C code, since one-past-end pointers */ /* don't work, so we discard it and try again. */ munmap(result, ~GC_page_size - (size_t)result + 1); /* Leave last page mapped, so we can't repeat. */ return GC_unix_mmap_get_mem(bytes); } # else GC_ASSERT(last_addr != 0); # endif if (((word)result % HBLKSIZE) != 0) ABORT( "GC_unix_get_mem: Memory returned by mmap is not aligned to HBLKSIZE."); return((ptr_t)result); } # endif /* !MSWIN_XBOX1 */ #endif /* MMAP_SUPPORTED */ #if defined(USE_MMAP) ptr_t GC_unix_get_mem(size_t bytes) { return GC_unix_mmap_get_mem(bytes); } #else /* !USE_MMAP */ STATIC ptr_t GC_unix_sbrk_get_mem(size_t bytes) { ptr_t result; # ifdef IRIX5 /* Bare sbrk isn't thread safe. Play by malloc rules. */ /* The equivalent may be needed on other systems as well. */ __LOCK_MALLOC(); # endif { ptr_t cur_brk = (ptr_t)sbrk(0); SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1); GC_ASSERT(GC_page_size != 0); if ((SBRK_ARG_T)bytes < 0) { result = 0; /* too big */ goto out; } if (lsbs != 0) { if((ptr_t)sbrk((SBRK_ARG_T)GC_page_size - lsbs) == (ptr_t)(-1)) { result = 0; goto out; } } # ifdef ADD_HEAP_GUARD_PAGES /* This is useful for catching severe memory overwrite problems that */ /* span heap sections. It shouldn't otherwise be turned on. */ { ptr_t guard = (ptr_t)sbrk((SBRK_ARG_T)GC_page_size); if (mprotect(guard, GC_page_size, PROT_NONE) != 0) ABORT("ADD_HEAP_GUARD_PAGES: mprotect failed"); } # endif /* ADD_HEAP_GUARD_PAGES */ result = (ptr_t)sbrk((SBRK_ARG_T)bytes); if (result == (ptr_t)(-1)) result = 0; } out: # ifdef IRIX5 __UNLOCK_MALLOC(); # endif return(result); } ptr_t GC_unix_get_mem(size_t bytes) { # if defined(MMAP_SUPPORTED) /* By default, we try both sbrk and mmap, in that order. */ static GC_bool sbrk_failed = FALSE; ptr_t result = 0; if (GC_pages_executable) { /* If the allocated memory should have the execute permission */ /* then sbrk() cannot be used. */ return GC_unix_mmap_get_mem(bytes); } if (!sbrk_failed) result = GC_unix_sbrk_get_mem(bytes); if (0 == result) { sbrk_failed = TRUE; result = GC_unix_mmap_get_mem(bytes); } if (0 == result) { /* Try sbrk again, in case sbrk memory became available. */ result = GC_unix_sbrk_get_mem(bytes); } return result; # else /* !MMAP_SUPPORTED */ return GC_unix_sbrk_get_mem(bytes); # endif } #endif /* !USE_MMAP */ # endif /* UN*X */ # ifdef OS2 void * os2_alloc(size_t bytes) { void * result; if (DosAllocMem(&result, bytes, (PAG_READ | PAG_WRITE | PAG_COMMIT) | (GC_pages_executable ? PAG_EXECUTE : 0)) != NO_ERROR) { return(0); } /* FIXME: What's the purpose of this recursion? (Probably, if */ /* DosAllocMem returns memory at 0 address then just retry once.) */ if (result == 0) return(os2_alloc(bytes)); return(result); } # endif /* OS2 */ #ifdef MSWIN_XBOX1 ptr_t GC_durango_get_mem(size_t bytes) { if (0 == bytes) return NULL; return (ptr_t)VirtualAlloc(NULL, bytes, MEM_COMMIT | MEM_TOP_DOWN, PAGE_READWRITE); } #elif defined(MSWINCE) ptr_t GC_wince_get_mem(size_t bytes) { ptr_t result = 0; /* initialized to prevent warning. */ word i; GC_ASSERT(GC_page_size != 0); bytes = ROUNDUP_PAGESIZE(bytes); /* Try to find reserved, uncommitted pages */ for (i = 0; i < GC_n_heap_bases; i++) { if (((word)(-(signed_word)GC_heap_lengths[i]) & (GC_sysinfo.dwAllocationGranularity-1)) >= bytes) { result = GC_heap_bases[i] + GC_heap_lengths[i]; break; } } if (i == GC_n_heap_bases) { /* Reserve more pages */ size_t res_bytes = SIZET_SAT_ADD(bytes, (size_t)GC_sysinfo.dwAllocationGranularity-1) & ~((size_t)GC_sysinfo.dwAllocationGranularity-1); /* If we ever support MPROTECT_VDB here, we will probably need to */ /* ensure that res_bytes is strictly > bytes, so that VirtualProtect */ /* never spans regions. It seems to be OK for a VirtualFree */ /* argument to span regions, so we should be OK for now. */ result = (ptr_t) VirtualAlloc(NULL, res_bytes, MEM_RESERVE | MEM_TOP_DOWN, GC_pages_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE); if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result"); /* If I read the documentation correctly, this can */ /* only happen if HBLKSIZE > 64 KB or not a power of 2. */ if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections"); if (result == NULL) return NULL; GC_heap_bases[GC_n_heap_bases] = result; GC_heap_lengths[GC_n_heap_bases] = 0; GC_n_heap_bases++; } /* Commit pages */ result = (ptr_t) VirtualAlloc(result, bytes, MEM_COMMIT, GC_pages_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE); # undef IGNORE_PAGES_EXECUTABLE if (result != NULL) { if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result"); GC_heap_lengths[i] += bytes; } return(result); } #elif defined(USE_WINALLOC) /* && !MSWIN_XBOX1 */ || defined(CYGWIN32) # ifdef USE_GLOBAL_ALLOC # define GLOBAL_ALLOC_TEST 1 # else # define GLOBAL_ALLOC_TEST GC_no_win32_dlls # endif # if (defined(GC_USE_MEM_TOP_DOWN) && defined(USE_WINALLOC)) \ || defined(CPPCHECK) DWORD GC_mem_top_down = MEM_TOP_DOWN; /* Use GC_USE_MEM_TOP_DOWN for better 64-bit */ /* testing. Otherwise all addresses tend to */ /* end up in first 4 GB, hiding bugs. */ # else # define GC_mem_top_down 0 # endif /* !GC_USE_MEM_TOP_DOWN */ ptr_t GC_win32_get_mem(size_t bytes) { ptr_t result; # ifndef USE_WINALLOC result = GC_unix_get_mem(bytes); # else # if defined(MSWIN32) && !defined(MSWINRT_FLAVOR) if (GLOBAL_ALLOC_TEST) { /* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE. */ /* There are also unconfirmed rumors of other */ /* problems, so we dodge the issue. */ result = (ptr_t)GlobalAlloc(0, SIZET_SAT_ADD(bytes, HBLKSIZE)); /* Align it at HBLKSIZE boundary. */ result = (ptr_t)(((word)result + HBLKSIZE - 1) & ~(word)(HBLKSIZE - 1)); } else # endif /* else */ { /* VirtualProtect only works on regions returned by a */ /* single VirtualAlloc call. Thus we allocate one */ /* extra page, which will prevent merging of blocks */ /* in separate regions, and eliminate any temptation */ /* to call VirtualProtect on a range spanning regions. */ /* This wastes a small amount of memory, and risks */ /* increased fragmentation. But better alternatives */ /* would require effort. */ # ifdef MPROTECT_VDB /* We can't check for GC_incremental here (because */ /* GC_enable_incremental() might be called some time */ /* later after the GC initialization). */ # ifdef GWW_VDB # define VIRTUAL_ALLOC_PAD (GC_GWW_AVAILABLE() ? 0 : 1) # else # define VIRTUAL_ALLOC_PAD 1 # endif # else # define VIRTUAL_ALLOC_PAD 0 # endif /* Pass the MEM_WRITE_WATCH only if GetWriteWatch-based */ /* VDBs are enabled and the GetWriteWatch function is */ /* available. Otherwise we waste resources or possibly */ /* cause VirtualAlloc to fail (observed in Windows 2000 */ /* SP2). */ result = (ptr_t) VirtualAlloc(NULL, SIZET_SAT_ADD(bytes, VIRTUAL_ALLOC_PAD), GetWriteWatch_alloc_flag | (MEM_COMMIT | MEM_RESERVE) | GC_mem_top_down, GC_pages_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE); # undef IGNORE_PAGES_EXECUTABLE } # endif /* USE_WINALLOC */ if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result"); /* If I read the documentation correctly, this can */ /* only happen if HBLKSIZE > 64 KB or not a power of 2. */ if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections"); if (0 != result) GC_heap_bases[GC_n_heap_bases++] = result; return(result); } #endif /* USE_WINALLOC || CYGWIN32 */ #if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32) \ || defined(MSWIN_XBOX1) GC_API void GC_CALL GC_win32_free_heap(void) { # if defined(USE_WINALLOC) && !defined(REDIRECT_MALLOC) \ && !defined(MSWIN_XBOX1) GC_free_malloc_heap_list(); # endif # if (defined(USE_WINALLOC) && !defined(MSWIN_XBOX1) \ && !defined(MSWINCE)) || defined(CYGWIN32) # ifndef MSWINRT_FLAVOR # ifndef CYGWIN32 if (GLOBAL_ALLOC_TEST) # endif { while (GC_n_heap_bases-- > 0) { # ifdef CYGWIN32 /* FIXME: Is it OK to use non-GC free() here? */ # else GlobalFree(GC_heap_bases[GC_n_heap_bases]); # endif GC_heap_bases[GC_n_heap_bases] = 0; } return; } # endif /* !MSWINRT_FLAVOR */ # ifndef CYGWIN32 /* Avoiding VirtualAlloc leak. */ while (GC_n_heap_bases > 0) { VirtualFree(GC_heap_bases[--GC_n_heap_bases], 0, MEM_RELEASE); GC_heap_bases[GC_n_heap_bases] = 0; } # endif # endif /* USE_WINALLOC || CYGWIN32 */ } #endif /* Windows */ #ifdef AMIGA # define GC_AMIGA_AM # include "extra/AmigaOS.c" # undef GC_AMIGA_AM #endif #if defined(HAIKU) # include <stdlib.h> ptr_t GC_haiku_get_mem(size_t bytes) { void* mem; GC_ASSERT(GC_page_size != 0); if (posix_memalign(&mem, GC_page_size, bytes) == 0) return mem; return NULL; } #endif /* HAIKU */ #if (defined(USE_MUNMAP) || defined(MPROTECT_VDB)) && !defined(USE_WINALLOC) # define ABORT_ON_REMAP_FAIL(C_msg_prefix, start_addr, len) \ ABORT_ARG3(C_msg_prefix " failed", \ " at %p (length %lu), errno= %d", \ (void *)(start_addr), (unsigned long)(len), errno) #endif #ifdef USE_MUNMAP /* For now, this only works on Win32/WinCE and some Unix-like */ /* systems. If you have something else, don't define */ /* USE_MUNMAP. */ #if !defined(NN_PLATFORM_CTR) && !defined(MSWIN32) && !defined(MSWINCE) \ && !defined(MSWIN_XBOX1) # include <unistd.h> # ifdef SN_TARGET_PS3 # include <sys/memory.h> # else # include <sys/mman.h> # endif # include <sys/stat.h> # include <sys/types.h> #endif /* Compute a page aligned starting address for the unmap */ /* operation on a block of size bytes starting at start. */ /* Return 0 if the block is too small to make this feasible. */ STATIC ptr_t GC_unmap_start(ptr_t start, size_t bytes) { ptr_t result = (ptr_t)(((word)start + GC_page_size - 1) & ~(GC_page_size - 1)); GC_ASSERT(GC_page_size != 0); if ((word)(result + GC_page_size) > (word)(start + bytes)) return 0; return result; } /* Under Win32/WinCE we commit (map) and decommit (unmap) */ /* memory using VirtualAlloc and VirtualFree. These functions */ /* work on individual allocations of virtual memory, made */ /* previously using VirtualAlloc with the MEM_RESERVE flag. */ /* The ranges we need to (de)commit may span several of these */ /* allocations; therefore we use VirtualQuery to check */ /* allocation lengths, and split up the range as necessary. */ /* We assume that GC_remap is called on exactly the same range */ /* as a previous call to GC_unmap. It is safe to consistently */ /* round the endpoints in both places. */ static void block_unmap_inner(ptr_t start_addr, size_t len) { if (0 == start_addr) return; # ifdef USE_WINALLOC while (len != 0) { MEMORY_BASIC_INFORMATION mem_info; word free_len; if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info)) != sizeof(mem_info)) ABORT("Weird VirtualQuery result"); free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize; if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT)) ABORT("VirtualFree failed"); GC_unmapped_bytes += free_len; start_addr += free_len; len -= free_len; } # else /* We immediately remap it to prevent an intervening mmap from */ /* accidentally grabbing the same address space. */ if (len != 0) { # ifdef SN_TARGET_PS3 ps3_free_mem(start_addr, len); # elif defined(AIX) || defined(CYGWIN32) || defined(HAIKU) \ || (defined(LINUX) && !defined(PREFER_MMAP_PROT_NONE)) \ || defined(HPUX) /* On AIX, mmap(PROT_NONE) fails with ENOMEM unless the */ /* environment variable XPG_SUS_ENV is set to ON. */ /* On Cygwin, calling mmap() with the new protection flags on */ /* an existing memory map with MAP_FIXED is broken. */ /* However, calling mprotect() on the given address range */ /* with PROT_NONE seems to work fine. */ /* On Linux, low RLIMIT_AS value may lead to mmap failure. */ # if defined(LINUX) && !defined(FORCE_MPROTECT_BEFORE_MADVISE) /* On Linux, at least, madvise() should be sufficient. */ # else if (mprotect(start_addr, len, PROT_NONE)) ABORT_ON_REMAP_FAIL("unmap: mprotect", start_addr, len); # endif # if !defined(CYGWIN32) /* On Linux (and some other platforms probably), */ /* mprotect(PROT_NONE) is just disabling access to */ /* the pages but not returning them to OS. */ if (madvise(start_addr, len, MADV_DONTNEED) == -1) ABORT_ON_REMAP_FAIL("unmap: madvise", start_addr, len); # endif # elif defined(EMSCRIPTEN) /* Nothing to do, mmap(PROT_NONE) is not supported and */ /* mprotect() is just a no-op. */ # else void * result = mmap(start_addr, len, PROT_NONE, MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON, zero_fd, 0/* offset */); if (EXPECT(MAP_FAILED == result, FALSE)) ABORT_ON_REMAP_FAIL("unmap: mmap", start_addr, len); if (result != (void *)start_addr) ABORT("unmap: mmap() result differs from start_addr"); # if defined(CPPCHECK) || defined(LINT2) /* Explicitly store the resource handle to a global variable. */ GC_noop1((word)result); # endif # endif GC_unmapped_bytes += len; } # endif } GC_INNER void GC_unmap(ptr_t start, size_t bytes) { ptr_t start_addr = GC_unmap_start(start, bytes); ptr_t end_addr = GC_unmap_end(start, bytes); block_unmap_inner(start_addr, (size_t)(end_addr - start_addr)); } GC_INNER void GC_remap(ptr_t start, size_t bytes) { ptr_t start_addr = GC_unmap_start(start, bytes); ptr_t end_addr = GC_unmap_end(start, bytes); word len = end_addr - start_addr; if (0 == start_addr) return; /* FIXME: Handle out-of-memory correctly (at least for Win32) */ # ifdef USE_WINALLOC while (len != 0) { MEMORY_BASIC_INFORMATION mem_info; word alloc_len; ptr_t result; if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info)) != sizeof(mem_info)) ABORT("Weird VirtualQuery result"); alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize; result = (ptr_t)VirtualAlloc(start_addr, alloc_len, MEM_COMMIT, GC_pages_executable ? PAGE_EXECUTE_READWRITE : PAGE_READWRITE); if (result != start_addr) { if (GetLastError() == ERROR_NOT_ENOUGH_MEMORY || GetLastError() == ERROR_OUTOFMEMORY) { ABORT("Not enough memory to process remapping"); } else { ABORT("VirtualAlloc remapping failed"); } } # ifdef LINT2 GC_noop1((word)result); # endif GC_unmapped_bytes -= alloc_len; start_addr += alloc_len; len -= alloc_len; } # undef IGNORE_PAGES_EXECUTABLE # else /* It was already remapped with PROT_NONE. */ { # if !defined(SN_TARGET_PS3) && !defined(FORCE_MPROTECT_BEFORE_MADVISE) \ && defined(LINUX) && !defined(PREFER_MMAP_PROT_NONE) /* Nothing to unprotect as madvise() is just a hint. */ # elif defined(NACL) || defined(NETBSD) /* NaCl does not expose mprotect, but mmap should work fine. */ /* In case of NetBSD, mprotect fails (unlike mmap) even */ /* without PROT_EXEC if PaX MPROTECT feature is enabled. */ void *result = mmap(start_addr, len, (PROT_READ | PROT_WRITE) | (GC_pages_executable ? PROT_EXEC : 0), MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON, zero_fd, 0 /* offset */); if (EXPECT(MAP_FAILED == result, FALSE)) ABORT_ON_REMAP_FAIL("remap: mmap", start_addr, len); if (result != (void *)start_addr) ABORT("remap: mmap() result differs from start_addr"); # if defined(CPPCHECK) || defined(LINT2) GC_noop1((word)result); # endif # undef IGNORE_PAGES_EXECUTABLE # else if (mprotect(start_addr, len, (PROT_READ | PROT_WRITE) | (GC_pages_executable ? PROT_EXEC : 0))) ABORT_ON_REMAP_FAIL("remap: mprotect", start_addr, len); # undef IGNORE_PAGES_EXECUTABLE # endif /* !NACL */ } GC_unmapped_bytes -= len; # endif } /* Two adjacent blocks have already been unmapped and are about to */ /* be merged. Unmap the whole block. This typically requires */ /* that we unmap a small section in the middle that was not previously */ /* unmapped due to alignment constraints. */ GC_INNER void GC_unmap_gap(ptr_t start1, size_t bytes1, ptr_t start2, size_t bytes2) { ptr_t start1_addr = GC_unmap_start(start1, bytes1); ptr_t end1_addr = GC_unmap_end(start1, bytes1); ptr_t start2_addr = GC_unmap_start(start2, bytes2); ptr_t start_addr = end1_addr; ptr_t end_addr = start2_addr; GC_ASSERT(start1 + bytes1 == start2); if (0 == start1_addr) start_addr = GC_unmap_start(start1, bytes1 + bytes2); if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2); block_unmap_inner(start_addr, (size_t)(end_addr - start_addr)); } #endif /* USE_MUNMAP */ /* Routine for pushing any additional roots. In THREADS */ /* environment, this is also responsible for marking from */ /* thread stacks. */ #ifndef THREADS # ifdef EMSCRIPTEN static void scan_regs_cb(void *begin, void *end) { GC_push_all_stack((ptr_t)begin, (ptr_t)end); } STATIC void GC_CALLBACK GC_default_push_other_roots(void) { /* This needs "-s ASYNCIFY -s ASYNCIFY_STACK_SIZE=128000" */ /* but hopefully the latter is only required for gctest. */ emscripten_scan_registers(scan_regs_cb); } # else # define GC_default_push_other_roots 0 # endif #else /* THREADS */ # ifdef PCR PCR_ERes GC_push_thread_stack(PCR_Th_T *t, PCR_Any dummy) { struct PCR_ThCtl_TInfoRep info; PCR_ERes result; info.ti_stkLow = info.ti_stkHi = 0; result = PCR_ThCtl_GetInfo(t, &info); GC_push_all_stack((ptr_t)(info.ti_stkLow), (ptr_t)(info.ti_stkHi)); return(result); } /* Push the contents of an old object. We treat this as stack */ /* data only because that makes it robust against mark stack */ /* overflow. */ PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any data) { GC_push_all_stack((ptr_t)p, (ptr_t)p + size); return(PCR_ERes_okay); } extern struct PCR_MM_ProcsRep * GC_old_allocator; /* defined in pcr_interface.c. */ STATIC void GC_CALLBACK GC_default_push_other_roots(void) { /* Traverse data allocated by previous memory managers. */ if ((*(GC_old_allocator->mmp_enumerate))(PCR_Bool_false, GC_push_old_obj, 0) != PCR_ERes_okay) { ABORT("Old object enumeration failed"); } /* Traverse all thread stacks. */ if (PCR_ERes_IsErr( PCR_ThCtl_ApplyToAllOtherThreads(GC_push_thread_stack,0)) || PCR_ERes_IsErr(GC_push_thread_stack(PCR_Th_CurrThread(), 0))) { ABORT("Thread stack marking failed"); } } # elif defined(SN_TARGET_PS3) STATIC void GC_CALLBACK GC_default_push_other_roots(void) { ABORT("GC_default_push_other_roots is not implemented"); } void GC_push_thread_structures(void) { ABORT("GC_push_thread_structures is not implemented"); } # else /* GC_PTHREADS, or GC_WIN32_THREADS, etc. */ STATIC void GC_CALLBACK GC_default_push_other_roots(void) { GC_push_all_stacks(); } # endif #endif /* THREADS */ GC_push_other_roots_proc GC_push_other_roots = GC_default_push_other_roots; GC_API void GC_CALL GC_set_push_other_roots(GC_push_other_roots_proc fn) { GC_push_other_roots = fn; } GC_API GC_push_other_roots_proc GC_CALL GC_get_push_other_roots(void) { return GC_push_other_roots; } #if defined(SOFT_VDB) && !defined(NO_SOFT_VDB_LINUX_VER_RUNTIME_CHECK) \ || (defined(GLIBC_2_19_TSX_BUG) && defined(THREADS)) GC_INNER int GC_parse_version(int *pminor, const char *pverstr) { char *endp; unsigned long value = strtoul(pverstr, &endp, 10); int major = (int)value; if (major < 0 || (char *)pverstr == endp || (unsigned)major != value) { /* Parse error. */ return -1; } if (*endp != '.') { /* No minor part. */ *pminor = -1; } else { value = strtoul(endp + 1, &endp, 10); *pminor = (int)value; if (*pminor < 0 || (unsigned)(*pminor) != value) { return -1; } } return major; } #endif /* * Routines for accessing dirty bits on virtual pages. * There are six ways to maintain this information: * DEFAULT_VDB: A simple dummy implementation that treats every page * as possibly dirty. This makes incremental collection * useless, but the implementation is still correct. * Manual VDB: Stacks and static data are always considered dirty. * Heap pages are considered dirty if GC_dirty(p) has been * called on some pointer p pointing to somewhere inside * an object on that page. A GC_dirty() call on a large * object directly dirties only a single page, but for the * manual VDB we are careful to treat an object with a dirty * page as completely dirty. * In order to avoid races, an object must be marked dirty * after it is written, and a reference to the object * must be kept on a stack or in a register in the interim. * With threads enabled, an object directly reachable from the * stack at the time of a collection is treated as dirty. * In single-threaded mode, it suffices to ensure that no * collection can take place between the pointer assignment * and the GC_dirty() call. * PCR_VDB: Use PPCRs virtual dirty bit facility. * PROC_VDB: Use the /proc facility for reading dirty bits. Only * works under some SVR4 variants. Even then, it may be * too slow to be entirely satisfactory. Requires reading * dirty bits for entire address space. Implementations tend * to assume that the client is a (slow) debugger. * SOFT_VDB: Use the /proc facility for reading soft-dirty PTEs. * Works on Linux 3.18+ if the kernel is properly configured. * The proposed implementation iterates over GC_heap_sects and * GC_static_roots examining the soft-dirty bit of the words * in /proc/self/pagemap corresponding to the pages of the * sections; finally all soft-dirty bits of the process are * cleared (by writing some special value to * /proc/self/clear_refs file). In case the soft-dirty bit is * not supported by the kernel, MPROTECT_VDB may be defined as * a fallback strategy. * MPROTECT_VDB:Protect pages and then catch the faults to keep track of * dirtied pages. The implementation (and implementability) * is highly system dependent. This usually fails when system * calls write to a protected page. We prevent the read system * call from doing so. It is the clients responsibility to * make sure that other system calls are similarly protected * or write only to the stack. * GWW_VDB: Use the Win32 GetWriteWatch functions, if available, to * read dirty bits. In case it is not available (because we * are running on Windows 95, Windows 2000 or earlier), * MPROTECT_VDB may be defined as a fallback strategy. */ #if (defined(CHECKSUMS) && (defined(GWW_VDB) || defined(SOFT_VDB))) \ || defined(PROC_VDB) /* Add all pages in pht2 to pht1. */ STATIC void GC_or_pages(page_hash_table pht1, page_hash_table pht2) { unsigned i; for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i]; } #endif /* CHECKSUMS && (GWW_VDB || SOFT_VDB) || PROC_VDB */ #ifdef GWW_VDB # define GC_GWW_BUF_LEN (MAXHINCR * HBLKSIZE / 4096 /* X86 page size */) /* Still susceptible to overflow, if there are very large allocations, */ /* and everything is dirty. */ static PVOID gww_buf[GC_GWW_BUF_LEN]; # ifndef MPROTECT_VDB # define GC_gww_dirty_init GC_dirty_init # endif GC_INNER GC_bool GC_gww_dirty_init(void) { detect_GetWriteWatch(); return GC_GWW_AVAILABLE(); } GC_INLINE void GC_gww_read_dirty(GC_bool output_unneeded) { word i; if (!output_unneeded) BZERO(GC_grungy_pages, sizeof(GC_grungy_pages)); for (i = 0; i != GC_n_heap_sects; ++i) { GC_ULONG_PTR count; do { PVOID * pages = gww_buf; DWORD page_size; count = GC_GWW_BUF_LEN; /* GetWriteWatch is documented as returning non-zero when it */ /* fails, but the documentation doesn't explicitly say why it */ /* would fail or what its behavior will be if it fails. It */ /* does appear to fail, at least on recent Win2K instances, if */ /* the underlying memory was not allocated with the appropriate */ /* flag. This is common if GC_enable_incremental is called */ /* shortly after GC initialization. To avoid modifying the */ /* interface, we silently work around such a failure, it only */ /* affects the initial (small) heap allocation. If there are */ /* more dirty pages than will fit in the buffer, this is not */ /* treated as a failure; we must check the page count in the */ /* loop condition. Since each partial call will reset the */ /* status of some pages, this should eventually terminate even */ /* in the overflow case. */ if ((*(GetWriteWatch_type)(word)GetWriteWatch_func)( WRITE_WATCH_FLAG_RESET, GC_heap_sects[i].hs_start, GC_heap_sects[i].hs_bytes, pages, &count, &page_size) != 0) { static int warn_count = 0; struct hblk * start = (struct hblk *)GC_heap_sects[i].hs_start; static struct hblk *last_warned = 0; size_t nblocks = divHBLKSZ(GC_heap_sects[i].hs_bytes); if (i != 0 && last_warned != start && warn_count++ < 5) { last_warned = start; WARN("GC_gww_read_dirty unexpectedly failed at %p: " "Falling back to marking all pages dirty\n", start); } if (!output_unneeded) { unsigned j; for (j = 0; j < nblocks; ++j) { word hash = PHT_HASH(start + j); set_pht_entry_from_index(GC_grungy_pages, hash); } } count = 1; /* Done with this section. */ } else /* succeeded */ if (!output_unneeded) { PVOID * pages_end = pages + count; while (pages != pages_end) { struct hblk * h = (struct hblk *) *pages++; struct hblk * h_end = (struct hblk *) ((char *) h + page_size); do { set_pht_entry_from_index(GC_grungy_pages, PHT_HASH(h)); } while ((word)(++h) < (word)h_end); } } } while (count == GC_GWW_BUF_LEN); /* FIXME: It's unclear from Microsoft's documentation if this loop */ /* is useful. We suspect the call just fails if the buffer fills */ /* up. But that should still be handled correctly. */ } # ifdef CHECKSUMS GC_ASSERT(!output_unneeded); GC_or_pages(GC_written_pages, GC_grungy_pages); # endif } #elif defined(SOFT_VDB) static int clear_refs_fd = -1; # define GC_GWW_AVAILABLE() (clear_refs_fd != -1) #else # define GC_GWW_AVAILABLE() FALSE #endif /* !GWW_VDB && !SOFT_VDB */ #ifdef DEFAULT_VDB /* All of the following assume the allocation lock is held. */ /* The client asserts that unallocated pages in the heap are never */ /* written. */ /* Initialize virtual dirty bit implementation. */ GC_INNER GC_bool GC_dirty_init(void) { GC_VERBOSE_LOG_PRINTF("Initializing DEFAULT_VDB...\n"); /* GC_dirty_pages and GC_grungy_pages are already cleared. */ return TRUE; } #endif /* DEFAULT_VDB */ #ifndef GC_DISABLE_INCREMENTAL # if !defined(THREADS) || defined(HAVE_LOCKFREE_AO_OR) # define async_set_pht_entry_from_index(db, index) \ set_pht_entry_from_index_concurrent(db, index) # elif defined(AO_HAVE_test_and_set_acquire) /* We need to lock around the bitmap update (in the write fault */ /* handler or GC_dirty) in order to avoid the risk of losing a bit. */ /* We do this with a test-and-set spin lock if possible. */ GC_INNER volatile AO_TS_t GC_fault_handler_lock = AO_TS_INITIALIZER; static void async_set_pht_entry_from_index(volatile page_hash_table db, size_t index) { GC_acquire_dirty_lock(); set_pht_entry_from_index(db, index); GC_release_dirty_lock(); } # else # error No test_and_set operation: Introduces a race. # endif /* THREADS && !AO_HAVE_test_and_set_acquire */ #endif /* !GC_DISABLE_INCREMENTAL */ #ifdef MPROTECT_VDB /* * This implementation maintains dirty bits itself by catching write * faults and keeping track of them. We assume nobody else catches * SIGBUS or SIGSEGV. We assume no write faults occur in system calls. * This means that clients must ensure that system calls don't write * to the write-protected heap. Probably the best way to do this is to * ensure that system calls write at most to pointer-free objects in the * heap, and do even that only if we are on a platform on which those * are not protected. Another alternative is to wrap system calls * (see example for read below), but the current implementation holds * applications. * We assume the page size is a multiple of HBLKSIZE. * We prefer them to be the same. We avoid protecting pointer-free * objects only if they are the same. */ # ifdef DARWIN /* Using vm_protect (mach syscall) over mprotect (BSD syscall) seems to decrease the likelihood of some of the problems described below. */ # include <mach/vm_map.h> STATIC mach_port_t GC_task_self = 0; # define PROTECT_INNER(addr, len, allow_write, C_msg_prefix) \ if (vm_protect(GC_task_self, (vm_address_t)(addr), (vm_size_t)(len), \ FALSE, VM_PROT_READ \ | ((allow_write) ? VM_PROT_WRITE : 0) \ | (GC_pages_executable ? VM_PROT_EXECUTE : 0)) \ == KERN_SUCCESS) {} else ABORT(C_msg_prefix \ "vm_protect() failed") # elif !defined(USE_WINALLOC) # include <sys/mman.h> # include <signal.h> # if !defined(CYGWIN32) && !defined(HAIKU) # include <sys/syscall.h> # endif # define PROTECT_INNER(addr, len, allow_write, C_msg_prefix) \ if (mprotect((caddr_t)(addr), (size_t)(len), \ PROT_READ | ((allow_write) ? PROT_WRITE : 0) \ | (GC_pages_executable ? PROT_EXEC : 0)) >= 0) { \ } else if (GC_pages_executable) { \ ABORT_ON_REMAP_FAIL(C_msg_prefix \ "mprotect vdb executable pages", \ addr, len); \ } else ABORT_ON_REMAP_FAIL(C_msg_prefix "mprotect vdb", addr, len) # undef IGNORE_PAGES_EXECUTABLE # else /* USE_WINALLOC */ # ifndef MSWINCE # include <signal.h> # endif static DWORD protect_junk; # define PROTECT_INNER(addr, len, allow_write, C_msg_prefix) \ if (VirtualProtect(addr, len, \ GC_pages_executable ? \ ((allow_write) ? PAGE_EXECUTE_READWRITE : \ PAGE_EXECUTE_READ) : \ (allow_write) ? PAGE_READWRITE : \ PAGE_READONLY, \ &protect_junk)) { \ } else ABORT_ARG1(C_msg_prefix "VirtualProtect failed", \ ": errcode= 0x%X", (unsigned)GetLastError()) # endif /* USE_WINALLOC */ # define PROTECT(addr, len) PROTECT_INNER(addr, len, FALSE, "") # define UNPROTECT(addr, len) PROTECT_INNER(addr, len, TRUE, "un-") # if defined(MSWIN32) typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_HNDLR_PTR; # undef SIG_DFL # define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER)((signed_word)-1) # elif defined(MSWINCE) typedef LONG (WINAPI *SIG_HNDLR_PTR)(struct _EXCEPTION_POINTERS *); # undef SIG_DFL # define SIG_DFL (SIG_HNDLR_PTR) (-1) # elif defined(DARWIN) typedef void (* SIG_HNDLR_PTR)(); # else typedef void (* SIG_HNDLR_PTR)(int, siginfo_t *, void *); typedef void (* PLAIN_HNDLR_PTR)(int); # endif #ifndef DARWIN STATIC SIG_HNDLR_PTR GC_old_segv_handler = 0; /* Also old MSWIN32 ACCESS_VIOLATION filter */ # if defined(FREEBSD) || defined(HPUX) || defined(HURD) || defined(LINUX) STATIC SIG_HNDLR_PTR GC_old_bus_handler = 0; # ifndef LINUX STATIC GC_bool GC_old_bus_handler_used_si = FALSE; # endif # endif # if !defined(MSWIN32) && !defined(MSWINCE) STATIC GC_bool GC_old_segv_handler_used_si = FALSE; # endif /* !MSWIN32 */ #endif /* !DARWIN */ #ifdef THREADS /* This function is used only by the fault handler. Potential data */ /* race between this function and GC_install_header, GC_remove_header */ /* should not be harmful because the added or removed header should */ /* be already unprotected. */ GC_ATTR_NO_SANITIZE_THREAD static GC_bool is_header_found_async(void *addr) { # ifdef HASH_TL hdr *result; GET_HDR((ptr_t)addr, result); return result != NULL; # else return HDR_INNER(addr) != NULL; # endif } #else # define is_header_found_async(addr) (HDR(addr) != NULL) #endif /* !THREADS */ #ifndef DARWIN # if !defined(MSWIN32) && !defined(MSWINCE) # include <errno.h> # if defined(FREEBSD) || defined(HURD) || defined(HPUX) # define SIG_OK (sig == SIGBUS || sig == SIGSEGV) # else # define SIG_OK (sig == SIGSEGV) /* Catch SIGSEGV but ignore SIGBUS. */ # endif # if defined(FREEBSD) # ifndef SEGV_ACCERR # define SEGV_ACCERR 2 # endif # if defined(AARCH64) || defined(ARM32) || defined(MIPS) \ || __FreeBSD__ >= 7 # define CODE_OK (si -> si_code == SEGV_ACCERR) # elif defined(POWERPC) # define AIM /* Pretend that we're AIM. */ # include <machine/trap.h> # define CODE_OK (si -> si_code == EXC_DSI \ || si -> si_code == SEGV_ACCERR) # else # define CODE_OK (si -> si_code == BUS_PAGE_FAULT \ || si -> si_code == SEGV_ACCERR) # endif # elif defined(OSF1) # define CODE_OK (si -> si_code == 2 /* experimentally determined */) # elif defined(IRIX5) # define CODE_OK (si -> si_code == EACCES) # elif defined(CYGWIN32) || defined(HAIKU) || defined(HURD) # define CODE_OK TRUE # elif defined(LINUX) # define CODE_OK TRUE /* Empirically c.trapno == 14, on IA32, but is that useful? */ /* Should probably consider alignment issues on other */ /* architectures. */ # elif defined(HPUX) # define CODE_OK (si -> si_code == SEGV_ACCERR \ || si -> si_code == BUS_ADRERR \ || si -> si_code == BUS_UNKNOWN \ || si -> si_code == SEGV_UNKNOWN \ || si -> si_code == BUS_OBJERR) # elif defined(SUNOS5SIGS) # define CODE_OK (si -> si_code == SEGV_ACCERR) # endif # ifndef NO_GETCONTEXT # include <ucontext.h> # endif STATIC void GC_write_fault_handler(int sig, siginfo_t *si, void *raw_sc) # else # define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode \ == STATUS_ACCESS_VIOLATION) # define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] \ == 1) /* Write fault */ STATIC LONG WINAPI GC_write_fault_handler( struct _EXCEPTION_POINTERS *exc_info) # endif /* MSWIN32 || MSWINCE */ { # if !defined(MSWIN32) && !defined(MSWINCE) char *addr = (char *)si->si_addr; # else char * addr = (char *) (exc_info -> ExceptionRecord -> ExceptionInformation[1]); # endif if (SIG_OK && CODE_OK) { struct hblk * h = (struct hblk *)((word)addr & ~(GC_page_size-1)); GC_bool in_allocd_block; size_t i; GC_ASSERT(GC_page_size != 0); # ifdef CHECKSUMS GC_record_fault(h); # endif # ifdef SUNOS5SIGS /* Address is only within the correct physical page. */ in_allocd_block = FALSE; for (i = 0; i < divHBLKSZ(GC_page_size); i++) { if (is_header_found_async(&h[i])) { in_allocd_block = TRUE; break; } } # else in_allocd_block = is_header_found_async(addr); # endif if (!in_allocd_block) { /* FIXME - We should make sure that we invoke the */ /* old handler with the appropriate calling */ /* sequence, which often depends on SA_SIGINFO. */ /* Heap blocks now begin and end on page boundaries */ SIG_HNDLR_PTR old_handler; # if defined(MSWIN32) || defined(MSWINCE) old_handler = GC_old_segv_handler; # else GC_bool used_si; # if defined(FREEBSD) || defined(HURD) || defined(HPUX) if (sig == SIGBUS) { old_handler = GC_old_bus_handler; used_si = GC_old_bus_handler_used_si; } else # endif /* else */ { old_handler = GC_old_segv_handler; used_si = GC_old_segv_handler_used_si; } # endif if (old_handler == (SIG_HNDLR_PTR)(signed_word)SIG_DFL) { # if !defined(MSWIN32) && !defined(MSWINCE) ABORT_ARG1("Unexpected bus error or segmentation fault", " at %p", (void *)addr); # else return(EXCEPTION_CONTINUE_SEARCH); # endif } else { /* * FIXME: This code should probably check if the * old signal handler used the traditional style and * if so call it using that style. */ # if defined(MSWIN32) || defined(MSWINCE) return((*old_handler)(exc_info)); # else if (used_si) ((SIG_HNDLR_PTR)old_handler) (sig, si, raw_sc); else /* FIXME: should pass nonstandard args as well. */ ((PLAIN_HNDLR_PTR)(signed_word)old_handler)(sig); return; # endif } } UNPROTECT(h, GC_page_size); /* We need to make sure that no collection occurs between */ /* the UNPROTECT and the setting of the dirty bit. Otherwise */ /* a write by a third thread might go unnoticed. Reversing */ /* the order is just as bad, since we would end up unprotecting */ /* a page in a GC cycle during which it's not marked. */ /* Currently we do this by disabling the thread stopping */ /* signals while this handler is running. An alternative might */ /* be to record the fact that we're about to unprotect, or */ /* have just unprotected a page in the GC's thread structure, */ /* and then to have the thread stopping code set the dirty */ /* flag, if necessary. */ for (i = 0; i < divHBLKSZ(GC_page_size); i++) { word index = PHT_HASH(h+i); async_set_pht_entry_from_index(GC_dirty_pages, index); } /* The write may not take place before dirty bits are read. */ /* But then we'll fault again ... */ # if defined(MSWIN32) || defined(MSWINCE) return(EXCEPTION_CONTINUE_EXECUTION); # else return; # endif } # if defined(MSWIN32) || defined(MSWINCE) return EXCEPTION_CONTINUE_SEARCH; # else ABORT_ARG1("Unexpected bus error or segmentation fault", " at %p", (void *)addr); # endif } # if defined(GC_WIN32_THREADS) && !defined(CYGWIN32) GC_INNER void GC_set_write_fault_handler(void) { SetUnhandledExceptionFilter(GC_write_fault_handler); } # endif # ifdef SOFT_VDB static GC_bool soft_dirty_init(void); # endif GC_INNER GC_bool GC_dirty_init(void) { # if !defined(MSWIN32) && !defined(MSWINCE) struct sigaction act, oldact; act.sa_flags = SA_RESTART | SA_SIGINFO; act.sa_sigaction = GC_write_fault_handler; (void)sigemptyset(&act.sa_mask); # if defined(THREADS) && !defined(GC_OPENBSD_UTHREADS) \ && !defined(GC_WIN32_THREADS) && !defined(NACL) /* Arrange to postpone the signal while we are in a write fault */ /* handler. This effectively makes the handler atomic w.r.t. */ /* stopping the world for GC. */ (void)sigaddset(&act.sa_mask, GC_get_suspend_signal()); # endif # endif /* !MSWIN32 */ GC_VERBOSE_LOG_PRINTF( "Initializing mprotect virtual dirty bit implementation\n"); if (GC_page_size % HBLKSIZE != 0) { ABORT("Page size not multiple of HBLKSIZE"); } # ifdef GWW_VDB if (GC_gww_dirty_init()) { GC_COND_LOG_PRINTF("Using GetWriteWatch()\n"); return TRUE; } # elif defined(SOFT_VDB) if (soft_dirty_init()) { GC_COND_LOG_PRINTF("Using soft-dirty bit feature\n"); return TRUE; } # endif # ifdef MSWIN32 GC_old_segv_handler = SetUnhandledExceptionFilter( GC_write_fault_handler); if (GC_old_segv_handler != NULL) { GC_COND_LOG_PRINTF("Replaced other UnhandledExceptionFilter\n"); } else { GC_old_segv_handler = SIG_DFL; } # elif defined(MSWINCE) /* MPROTECT_VDB is unsupported for WinCE at present. */ /* FIXME: implement it (if possible). */ # else /* act.sa_restorer is deprecated and should not be initialized. */ # if defined(GC_IRIX_THREADS) sigaction(SIGSEGV, 0, &oldact); sigaction(SIGSEGV, &act, 0); # else { int res = sigaction(SIGSEGV, &act, &oldact); if (res != 0) ABORT("Sigaction failed"); } # endif if (oldact.sa_flags & SA_SIGINFO) { GC_old_segv_handler = oldact.sa_sigaction; GC_old_segv_handler_used_si = TRUE; } else { GC_old_segv_handler = (SIG_HNDLR_PTR)(signed_word)oldact.sa_handler; GC_old_segv_handler_used_si = FALSE; } if (GC_old_segv_handler == (SIG_HNDLR_PTR)(signed_word)SIG_IGN) { WARN("Previously ignored segmentation violation!?\n", 0); GC_old_segv_handler = (SIG_HNDLR_PTR)(signed_word)SIG_DFL; } if (GC_old_segv_handler != (SIG_HNDLR_PTR)(signed_word)SIG_DFL) { GC_VERBOSE_LOG_PRINTF("Replaced other SIGSEGV handler\n"); } # if defined(HPUX) || defined(LINUX) || defined(HURD) \ || (defined(FREEBSD) && defined(SUNOS5SIGS)) sigaction(SIGBUS, &act, &oldact); if ((oldact.sa_flags & SA_SIGINFO) != 0) { GC_old_bus_handler = oldact.sa_sigaction; # if !defined(LINUX) GC_old_bus_handler_used_si = TRUE; # endif } else { GC_old_bus_handler = (SIG_HNDLR_PTR)(signed_word)oldact.sa_handler; } if (GC_old_bus_handler == (SIG_HNDLR_PTR)(signed_word)SIG_IGN) { WARN("Previously ignored bus error!?\n", 0); # if !defined(LINUX) GC_old_bus_handler = (SIG_HNDLR_PTR)(signed_word)SIG_DFL; # else /* GC_old_bus_handler is not used by GC_write_fault_handler. */ # endif } else if (GC_old_bus_handler != (SIG_HNDLR_PTR)(signed_word)SIG_DFL) { GC_VERBOSE_LOG_PRINTF("Replaced other SIGBUS handler\n"); } # endif /* HPUX || LINUX || HURD || (FREEBSD && SUNOS5SIGS) */ # endif /* ! MS windows */ # if defined(CPPCHECK) && defined(ADDRESS_SANITIZER) GC_noop1((word)&__asan_default_options); # endif return TRUE; } #endif /* !DARWIN */ GC_API int GC_CALL GC_incremental_protection_needs(void) { GC_ASSERT(GC_is_initialized); # if defined(GWW_VDB) || defined(SOFT_VDB) /* Only if the incremental mode is already switched on. */ if (GC_GWW_AVAILABLE()) return GC_PROTECTS_NONE; # endif if (GC_page_size == HBLKSIZE) { return GC_PROTECTS_POINTER_HEAP; } else { return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP; } } #define HAVE_INCREMENTAL_PROTECTION_NEEDS #define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0) #define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1)) STATIC void GC_protect_heap(void) { unsigned i; GC_bool protect_all = (0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP)); GC_ASSERT(GC_page_size != 0); for (i = 0; i < GC_n_heap_sects; i++) { ptr_t start = GC_heap_sects[i].hs_start; size_t len = GC_heap_sects[i].hs_bytes; if (protect_all) { PROTECT(start, len); } else { struct hblk * current; struct hblk * current_start; /* Start of block to be protected. */ struct hblk * limit; GC_ASSERT(PAGE_ALIGNED(len)); GC_ASSERT(PAGE_ALIGNED(start)); current_start = current = (struct hblk *)start; limit = (struct hblk *)(start + len); while ((word)current < (word)limit) { hdr * hhdr; word nhblks; GC_bool is_ptrfree; GC_ASSERT(PAGE_ALIGNED(current)); GET_HDR(current, hhdr); if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) { /* This can happen only if we're at the beginning of a */ /* heap segment, and a block spans heap segments. */ /* We will handle that block as part of the preceding */ /* segment. */ GC_ASSERT(current_start == current); current_start = ++current; continue; } if (HBLK_IS_FREE(hhdr)) { GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz)); nhblks = divHBLKSZ(hhdr -> hb_sz); is_ptrfree = TRUE; /* dirty on alloc */ } else { nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz); is_ptrfree = IS_PTRFREE(hhdr); } if (is_ptrfree) { if ((word)current_start < (word)current) { PROTECT(current_start, (ptr_t)current - (ptr_t)current_start); } current_start = (current += nhblks); } else { current += nhblks; } } if ((word)current_start < (word)current) { PROTECT(current_start, (ptr_t)current - (ptr_t)current_start); } } } } /* * Acquiring the allocation lock here is dangerous, since this * can be called from within GC_call_with_alloc_lock, and the cord * package does so. On systems that allow nested lock acquisition, this * happens to work. */ /* We no longer wrap read by default, since that was causing too many */ /* problems. It is preferred that the client instead avoids writing */ /* to the write-protected heap with a system call. */ #endif /* MPROTECT_VDB */ #if !defined(THREADS) && (defined(PROC_VDB) || defined(SOFT_VDB)) static pid_t saved_proc_pid; /* pid used to compose /proc file names */ #endif #ifdef PROC_VDB /* This implementation assumes a Solaris 2.X like /proc */ /* pseudo-file-system from which we can read page modified bits. This */ /* facility is far from optimal (e.g. we would like to get the info for */ /* only some of the address space), but it avoids intercepting system */ /* calls. */ # include <errno.h> # include <sys/types.h> # include <sys/signal.h> # include <sys/syscall.h> # include <sys/stat.h> # ifdef GC_NO_SYS_FAULT_H /* This exists only to check PROC_VDB code compilation (on Linux). */ # define PG_MODIFIED 1 struct prpageheader { int dummy[2]; /* pr_tstamp */ unsigned long pr_nmap; unsigned long pr_npage; }; struct prasmap { char *pr_vaddr; size_t pr_npage; char dummy1[64+8]; /* pr_mapname, pr_offset */ unsigned pr_mflags; unsigned pr_pagesize; int dummy2[2]; }; # else # include <sys/fault.h> # include <sys/procfs.h> # endif # define INITIAL_BUF_SZ 16384 STATIC size_t GC_proc_buf_size = INITIAL_BUF_SZ; STATIC char *GC_proc_buf = NULL; STATIC int GC_proc_fd = -1; static GC_bool proc_dirty_open_files(void) { char buf[40]; pid_t pid = getpid(); (void)snprintf(buf, sizeof(buf), "/proc/%ld/pagedata", (long)pid); buf[sizeof(buf) - 1] = '\0'; GC_proc_fd = open(buf, O_RDONLY); if (-1 == GC_proc_fd) { WARN("/proc open failed; cannot enable GC incremental mode\n", 0); return FALSE; } if (syscall(SYS_fcntl, GC_proc_fd, F_SETFD, FD_CLOEXEC) == -1) WARN("Could not set FD_CLOEXEC for /proc\n", 0); # ifndef THREADS saved_proc_pid = pid; /* updated on success only */ # endif return TRUE; } # ifdef CAN_HANDLE_FORK GC_INNER void GC_dirty_update_child(void) { if (-1 == GC_proc_fd) return; /* GC incremental mode is off */ close(GC_proc_fd); if (!proc_dirty_open_files()) GC_incremental = FALSE; /* should be safe to turn it off */ } # endif /* CAN_HANDLE_FORK */ GC_INNER GC_bool GC_dirty_init(void) { if (GC_bytes_allocd != 0 || GC_bytes_allocd_before_gc != 0) { memset(GC_written_pages, 0xff, sizeof(page_hash_table)); GC_VERBOSE_LOG_PRINTF( "Allocated %lu bytes: all pages may have been written\n", (unsigned long)(GC_bytes_allocd + GC_bytes_allocd_before_gc)); } if (!proc_dirty_open_files()) return FALSE; GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size); if (GC_proc_buf == NULL) ABORT("Insufficient space for /proc read"); return TRUE; } GC_INLINE void GC_proc_read_dirty(GC_bool output_unneeded) { int nmaps; char * bufp = GC_proc_buf; int i; # ifndef THREADS /* If the current pid differs from the saved one, then we are in */ /* the forked (child) process, the current /proc file should be */ /* closed, the new one should be opened with the updated path. */ /* Note, this is not needed for multi-threaded case because */ /* fork_child_proc() reopens the file right after fork. */ if (getpid() != saved_proc_pid && (-1 == GC_proc_fd /* no need to retry */ || (close(GC_proc_fd), !proc_dirty_open_files()))) { /* Failed to reopen the file. Punt! */ if (!output_unneeded) memset(GC_grungy_pages, 0xff, sizeof(page_hash_table)); memset(GC_written_pages, 0xff, sizeof(page_hash_table)); return; } # endif BZERO(GC_grungy_pages, sizeof(GC_grungy_pages)); if (PROC_READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) { /* Retry with larger buffer. */ size_t new_size = 2 * GC_proc_buf_size; char *new_buf; WARN("/proc read failed: GC_proc_buf_size= %" WARN_PRIdPTR "\n", (signed_word)GC_proc_buf_size); new_buf = GC_scratch_alloc(new_size); if (new_buf != 0) { GC_scratch_recycle_no_gww(bufp, GC_proc_buf_size); GC_proc_buf = bufp = new_buf; GC_proc_buf_size = new_size; } if (PROC_READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) { WARN("Insufficient space for /proc read\n", 0); /* Punt: */ if (!output_unneeded) memset(GC_grungy_pages, 0xff, sizeof (page_hash_table)); memset(GC_written_pages, 0xff, sizeof(page_hash_table)); return; } } /* Copy dirty bits into GC_grungy_pages */ nmaps = ((struct prpageheader *)bufp) -> pr_nmap; # ifdef DEBUG_DIRTY_BITS GC_log_printf("Proc VDB read: pr_nmap= %u, pr_npage= %lu\n", nmaps, ((struct prpageheader *)bufp)->pr_npage); # endif # if defined(GC_NO_SYS_FAULT_H) && defined(CPPCHECK) GC_noop1(((struct prpageheader *)bufp)->dummy[0]); # endif bufp += sizeof(struct prpageheader); for (i = 0; i < nmaps; i++) { struct prasmap * map = (struct prasmap *)bufp; ptr_t vaddr = (ptr_t)(map -> pr_vaddr); unsigned long npages = map -> pr_npage; unsigned pagesize = map -> pr_pagesize; ptr_t limit; # if defined(GC_NO_SYS_FAULT_H) && defined(CPPCHECK) GC_noop1(map->dummy1[0] + map->dummy2[0]); # endif # ifdef DEBUG_DIRTY_BITS GC_log_printf( "pr_vaddr= %p, npage= %lu, mflags= 0x%x, pagesize= 0x%x\n", (void *)vaddr, npages, map->pr_mflags, pagesize); # endif bufp += sizeof(struct prasmap); limit = vaddr + pagesize * npages; for (; (word)vaddr < (word)limit; vaddr += pagesize) { if ((*bufp++) & PG_MODIFIED) { struct hblk * h; ptr_t next_vaddr = vaddr + pagesize; # ifdef DEBUG_DIRTY_BITS GC_log_printf("dirty page at: %p\n", (void *)vaddr); # endif for (h = (struct hblk *)vaddr; (word)h < (word)next_vaddr; h++) { word index = PHT_HASH(h); set_pht_entry_from_index(GC_grungy_pages, index); } } } bufp = (char *)(((word)bufp + (sizeof(long)-1)) & ~(word)(sizeof(long)-1)); } # ifdef DEBUG_DIRTY_BITS GC_log_printf("Proc VDB read done\n"); # endif /* Update GC_written_pages (even if output_unneeded). */ GC_or_pages(GC_written_pages, GC_grungy_pages); } #endif /* PROC_VDB */ #ifdef SOFT_VDB # ifndef VDB_BUF_SZ # define VDB_BUF_SZ 16384 # endif static int open_proc_fd(pid_t pid, const char *proc_filename, int mode) { int f; char buf[40]; (void)snprintf(buf, sizeof(buf), "/proc/%ld/%s", (long)pid, proc_filename); buf[sizeof(buf) - 1] = '\0'; f = open(buf, mode); if (-1 == f) { WARN("/proc/self/%s open failed; cannot enable GC incremental mode\n", proc_filename); } else if (fcntl(f, F_SETFD, FD_CLOEXEC) == -1) { WARN("Could not set FD_CLOEXEC for /proc\n", 0); } return f; } # include <stdint.h> /* for uint64_t */ typedef uint64_t pagemap_elem_t; static pagemap_elem_t *soft_vdb_buf; static int pagemap_fd; static GC_bool soft_dirty_open_files(void) { pid_t pid = getpid(); clear_refs_fd = open_proc_fd(pid, "clear_refs", O_WRONLY); if (-1 == clear_refs_fd) return FALSE; pagemap_fd = open_proc_fd(pid, "pagemap", O_RDONLY); if (-1 == pagemap_fd) { close(clear_refs_fd); clear_refs_fd = -1; return FALSE; } # ifndef THREADS saved_proc_pid = pid; /* updated on success only */ # endif return TRUE; } # ifdef CAN_HANDLE_FORK GC_INNER void GC_dirty_update_child(void) { if (-1 == clear_refs_fd) return; /* GC incremental mode is off */ close(clear_refs_fd); close(pagemap_fd); if (!soft_dirty_open_files()) GC_incremental = FALSE; } # endif /* CAN_HANDLE_FORK */ /* The bit 55 of the 64-bit qword of pagemap file is the soft-dirty one. */ # define PM_SOFTDIRTY_MASK ((pagemap_elem_t)1 << 55) static GC_bool detect_soft_dirty_supported(ptr_t vaddr) { off_t fpos; pagemap_elem_t buf[1]; *vaddr = 1; /* make it dirty */ /* Read the relevant PTE from the pagemap file. */ GC_ASSERT(GC_page_size != 0); fpos = (off_t)((word)vaddr / GC_page_size * sizeof(pagemap_elem_t)); if (lseek(pagemap_fd, fpos, SEEK_SET) == (off_t)(-1)) return FALSE; if (PROC_READ(pagemap_fd, buf, sizeof(buf)) != (int)sizeof(buf)) return FALSE; /* Is the soft-dirty bit set? */ return (buf[0] & PM_SOFTDIRTY_MASK) != 0; } # ifndef NO_SOFT_VDB_LINUX_VER_RUNTIME_CHECK # include <sys/utsname.h> # include <string.h> /* for strcmp() */ /* Ensure the linux (kernel) major/minor version is as given or higher. */ static GC_bool ensure_min_linux_ver(int major, int minor) { struct utsname info; int actual_major; int actual_minor = -1; if (uname(&info) == -1) { return FALSE; /* uname() failed, should not happen actually. */ } if (strcmp(info.sysname, "Linux")) { WARN("Cannot ensure Linux version as running on other OS: %s\n", info.sysname); return FALSE; } actual_major = GC_parse_version(&actual_minor, info.release); return actual_major > major || (actual_major == major && actual_minor >= minor); } # endif # ifdef MPROTECT_VDB static GC_bool soft_dirty_init(void) # else GC_INNER GC_bool GC_dirty_init(void) # endif { GC_ASSERT(NULL == soft_vdb_buf); # ifdef MPROTECT_VDB char * str = GETENV("GC_USE_GETWRITEWATCH"); # ifdef GC_PREFER_MPROTECT_VDB if (str == NULL || (*str == '0' && *(str + 1) == '\0')) return FALSE; /* the environment variable is unset or set to "0" */ # else if (str != NULL && *str == '0' && *(str + 1) == '\0') return FALSE; /* the environment variable is set "0" */ # endif # endif # ifndef NO_SOFT_VDB_LINUX_VER_RUNTIME_CHECK if (!ensure_min_linux_ver(3, 18)) { GC_COND_LOG_PRINTF( "Running on old kernel lacking correct soft-dirty bit support\n"); return FALSE; } # endif if (!soft_dirty_open_files()) return FALSE; soft_vdb_buf = (pagemap_elem_t *)GC_scratch_alloc(VDB_BUF_SZ); if (NULL == soft_vdb_buf) ABORT("Insufficient space for /proc pagemap buffer"); if (!detect_soft_dirty_supported((ptr_t)soft_vdb_buf)) { GC_COND_LOG_PRINTF("Soft-dirty bit is not supported by kernel\n"); /* Release the resources. */ GC_scratch_recycle_no_gww(soft_vdb_buf, VDB_BUF_SZ); soft_vdb_buf = NULL; close(clear_refs_fd); clear_refs_fd = -1; close(pagemap_fd); return FALSE; } return TRUE; } static off_t pagemap_buf_fpos; /* valid only if pagemap_buf_len > 0 */ static size_t pagemap_buf_len; /* Read bytes from /proc/self/pagemap at given file position. */ /* len - the maximum number of bytes to read; (*pres) - amount of */ /* bytes actually read, always bigger than 0 but never exceeds len; */ /* next_fpos_hint - the file position of the next bytes block to read */ /* ahead if possible (0 means no information provided). */ static const pagemap_elem_t *pagemap_buffered_read(size_t *pres, off_t fpos, size_t len, off_t next_fpos_hint) { ssize_t res; size_t ofs; GC_ASSERT(len > 0); if (pagemap_buf_fpos <= fpos && fpos < pagemap_buf_fpos + (off_t)pagemap_buf_len) { /* The requested data is already in the buffer. */ ofs = (size_t)(fpos - pagemap_buf_fpos); res = (ssize_t)(pagemap_buf_fpos + pagemap_buf_len - fpos); } else { off_t aligned_pos = fpos & ~(GC_page_size < VDB_BUF_SZ ? GC_page_size-1 : VDB_BUF_SZ-1); for (;;) { size_t count; if ((0 == pagemap_buf_len || pagemap_buf_fpos + (off_t)pagemap_buf_len != aligned_pos) && lseek(pagemap_fd, aligned_pos, SEEK_SET) == (off_t)(-1)) ABORT_ARG2("Failed to lseek /proc/self/pagemap", ": offset= %lu, errno= %d", (unsigned long)fpos, errno); /* How much to read at once? */ ofs = (size_t)(fpos - aligned_pos); GC_ASSERT(ofs < VDB_BUF_SZ); if (next_fpos_hint > aligned_pos && next_fpos_hint - aligned_pos < VDB_BUF_SZ) { count = VDB_BUF_SZ; } else { count = len + ofs; if (count > VDB_BUF_SZ) count = VDB_BUF_SZ; } GC_ASSERT(count % sizeof(pagemap_elem_t) == 0); res = PROC_READ(pagemap_fd, soft_vdb_buf, count); if (res > (ssize_t)ofs) break; if (res <= 0) ABORT_ARG1("Failed to read /proc/self/pagemap", ": errno= %d", res < 0 ? errno : 0); /* Retry (once) w/o page-alignment. */ aligned_pos = fpos; } /* Save the buffer (file window) position and size. */ pagemap_buf_fpos = aligned_pos; pagemap_buf_len = (size_t)res; res -= (ssize_t)ofs; } GC_ASSERT(ofs % sizeof(pagemap_elem_t) == 0); *pres = (size_t)res < len ? (size_t)res : len; return &soft_vdb_buf[ofs / sizeof(pagemap_elem_t)]; } static void soft_set_grungy_pages(ptr_t vaddr /* start */, ptr_t limit, ptr_t next_start_hint) { GC_ASSERT(GC_page_size != 0); while ((word)vaddr < (word)limit) { size_t res; word limit_buf; const pagemap_elem_t *bufp = pagemap_buffered_read(&res, (off_t)((word)vaddr / GC_page_size * sizeof(pagemap_elem_t)), (size_t)((((word)limit - (word)vaddr + GC_page_size-1) / GC_page_size) * sizeof(pagemap_elem_t)), (off_t)((word)next_start_hint / GC_page_size * sizeof(pagemap_elem_t))); if (res % sizeof(pagemap_elem_t) != 0) { /* Punt: */ memset(GC_grungy_pages, 0xff, sizeof(page_hash_table)); WARN("Incomplete read of pagemap, not multiple of entry size\n", 0); break; } limit_buf = ((word)vaddr & ~(GC_page_size-1)) + (res / sizeof(pagemap_elem_t)) * GC_page_size; for (; (word)vaddr < limit_buf; vaddr += GC_page_size, bufp++) if ((*bufp & PM_SOFTDIRTY_MASK) != 0) { struct hblk * h; ptr_t next_vaddr = vaddr + GC_page_size; /* If the bit is set, the respective PTE was written to */ /* since clearing the soft-dirty bits. */ # ifdef DEBUG_DIRTY_BITS GC_log_printf("dirty page at: %p\n", (void *)vaddr); # endif for (h = (struct hblk *)vaddr; (word)h < (word)next_vaddr; h++) { word index = PHT_HASH(h); set_pht_entry_from_index(GC_grungy_pages, index); } } /* Read the next portion of pagemap file if incomplete. */ } } GC_INLINE void GC_soft_read_dirty(GC_bool output_unneeded) { ssize_t res; # ifndef THREADS /* Similar as for GC_proc_read_dirty. */ if (getpid() != saved_proc_pid && (-1 == clear_refs_fd /* no need to retry */ || (close(clear_refs_fd), close(pagemap_fd), !soft_dirty_open_files()))) { /* Failed to reopen the files. */ if (!output_unneeded) { /* Punt: */ memset(GC_grungy_pages, 0xff, sizeof(page_hash_table)); # ifdef CHECKSUMS memset(GC_written_pages, 0xff, sizeof(page_hash_table)); # endif } return; } # endif if (!output_unneeded) { word i; BZERO(GC_grungy_pages, sizeof(GC_grungy_pages)); pagemap_buf_len = 0; /* invalidate soft_vdb_buf */ for (i = 0; i != GC_n_heap_sects; ++i) { ptr_t vaddr = GC_heap_sects[i].hs_start; soft_set_grungy_pages(vaddr, vaddr + GC_heap_sects[i].hs_bytes, i < GC_n_heap_sects-1 ? GC_heap_sects[i+1].hs_start : NULL); } # ifdef CHECKSUMS GC_or_pages(GC_written_pages, GC_grungy_pages); # endif # ifndef NO_VDB_FOR_STATIC_ROOTS for (i = 0; (int)i < n_root_sets; ++i) { soft_set_grungy_pages(GC_static_roots[i].r_start, GC_static_roots[i].r_end, (int)i < n_root_sets-1 ? GC_static_roots[i+1].r_start : NULL); } # endif } /* Clear soft-dirty bits from the task's PTEs. */ res = write(clear_refs_fd, "4\n", 2); if (res != 2) ABORT_ARG1("Failed to write to /proc/self/clear_refs", ": errno= %d", res < 0 ? errno : 0); } #endif /* SOFT_VDB */ #ifdef PCR_VDB # include "vd/PCR_VD.h" # define NPAGES (32*1024) /* 128 MB */ PCR_VD_DB GC_grungy_bits[NPAGES]; STATIC ptr_t GC_vd_base = NULL; /* Address corresponding to GC_grungy_bits[0] */ /* HBLKSIZE aligned. */ GC_INNER GC_bool GC_dirty_init(void) { /* For the time being, we assume the heap generally grows up */ GC_vd_base = GC_heap_sects[0].hs_start; if (GC_vd_base == 0) { ABORT("Bad initial heap segment"); } if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE) != PCR_ERes_okay) { ABORT("Dirty bit initialization failed"); } return TRUE; } #endif /* PCR_VDB */ #ifndef GC_DISABLE_INCREMENTAL GC_INNER GC_bool GC_manual_vdb = FALSE; /* Manually mark the page containing p as dirty. Logically, this */ /* dirties the entire object. */ GC_INNER void GC_dirty_inner(const void *p) { word index = PHT_HASH(p); # if defined(MPROTECT_VDB) /* Do not update GC_dirty_pages if it should be followed by the */ /* page unprotection. */ GC_ASSERT(GC_manual_vdb); # endif async_set_pht_entry_from_index(GC_dirty_pages, index); } /* Retrieve system dirty bits for the heap to a local buffer (unless */ /* output_unneeded). Restore the systems notion of which pages are */ /* dirty. We assume that either the world is stopped or it is OK to */ /* lose dirty bits while it's happening (as in GC_enable_incremental).*/ GC_INNER void GC_read_dirty(GC_bool output_unneeded) { if (GC_manual_vdb # if defined(MPROTECT_VDB) || !GC_GWW_AVAILABLE() # endif ) { if (!output_unneeded) BCOPY((/* no volatile */ void *)GC_dirty_pages, GC_grungy_pages, sizeof(GC_dirty_pages)); BZERO((/* no volatile */ void *)GC_dirty_pages, sizeof(GC_dirty_pages)); # ifdef MPROTECT_VDB if (!GC_manual_vdb) GC_protect_heap(); # endif return; } # ifdef GWW_VDB GC_gww_read_dirty(output_unneeded); # elif defined(PROC_VDB) GC_proc_read_dirty(output_unneeded); # elif defined(SOFT_VDB) GC_soft_read_dirty(output_unneeded); # elif defined(PCR_VDB) /* lazily enable dirty bits on newly added heap sects */ { static int onhs = 0; int nhs = GC_n_heap_sects; for (; onhs < nhs; onhs++) { PCR_VD_WriteProtectEnable( GC_heap_sects[onhs].hs_start, GC_heap_sects[onhs].hs_bytes); } } if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits) != PCR_ERes_okay) { ABORT("Dirty bit read failed"); } # endif } # if !defined(NO_VDB_FOR_STATIC_ROOTS) && !defined(PROC_VDB) GC_INNER GC_bool GC_is_vdb_for_static_roots(void) { if (GC_manual_vdb) return FALSE; # if defined(MPROTECT_VDB) /* Currently used only in conjunction with SOFT_VDB. */ return GC_GWW_AVAILABLE(); # else GC_ASSERT(GC_incremental); return TRUE; # endif } # endif /* Is the HBLKSIZE sized page at h marked dirty in the local buffer? */ /* If the actual page size is different, this returns TRUE if any */ /* of the pages overlapping h are dirty. This routine may err on the */ /* side of labeling pages as dirty (and this implementation does). */ GC_INNER GC_bool GC_page_was_dirty(struct hblk *h) { word index; # ifdef PCR_VDB if (!GC_manual_vdb) { if ((word)h < (word)GC_vd_base || (word)h >= (word)(GC_vd_base + NPAGES * HBLKSIZE)) { return TRUE; } return GC_grungy_bits[h-(struct hblk*)GC_vd_base] & PCR_VD_DB_dirtyBit; } # elif defined(DEFAULT_VDB) if (!GC_manual_vdb) return TRUE; # elif defined(PROC_VDB) /* Unless manual VDB is on, the bitmap covers all process memory. */ if (GC_manual_vdb) # endif { if (NULL == HDR(h)) return TRUE; } index = PHT_HASH(h); return get_pht_entry_from_index(GC_grungy_pages, index); } # if defined(CHECKSUMS) || defined(PROC_VDB) /* Could any valid GC heap pointer ever have been written to this page? */ GC_INNER GC_bool GC_page_was_ever_dirty(struct hblk *h) { # if defined(GWW_VDB) || defined(PROC_VDB) || defined(SOFT_VDB) word index; # ifdef MPROTECT_VDB if (!GC_GWW_AVAILABLE()) return TRUE; # endif # if defined(PROC_VDB) if (GC_manual_vdb) # endif { if (NULL == HDR(h)) return TRUE; } index = PHT_HASH(h); return get_pht_entry_from_index(GC_written_pages, index); # else /* TODO: implement me for MANUAL_VDB. */ (void)h; return TRUE; # endif } # endif /* CHECKSUMS || PROC_VDB */ /* We expect block h to be written shortly. Ensure that all pages */ /* containing any part of the n hblks starting at h are no longer */ /* protected. If is_ptrfree is false, also ensure that they will */ /* subsequently appear to be dirty. Not allowed to call GC_printf */ /* (and the friends) here, see Win32 GC_stop_world for the details. */ GC_INNER void GC_remove_protection(struct hblk *h, word nblocks, GC_bool is_ptrfree) { # ifdef PCR_VDB (void)is_ptrfree; if (!GC_auto_incremental) return; PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE); PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE); # elif defined(MPROTECT_VDB) struct hblk * h_trunc; /* Truncated to page boundary */ struct hblk * h_end; /* Page boundary following block end */ struct hblk * current; if (!GC_auto_incremental || GC_GWW_AVAILABLE()) return; GC_ASSERT(GC_page_size != 0); h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1)); h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size - 1) & ~(GC_page_size - 1)); if (h_end == h_trunc + 1 && get_pht_entry_from_index(GC_dirty_pages, PHT_HASH(h_trunc))) { /* already marked dirty, and hence unprotected. */ return; } for (current = h_trunc; (word)current < (word)h_end; ++current) { word index = PHT_HASH(current); if (!is_ptrfree || (word)current < (word)h || (word)current >= (word)(h + nblocks)) { async_set_pht_entry_from_index(GC_dirty_pages, index); } } UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc); # else /* Ignore write hints. They don't help us here. */ (void)h; (void)nblocks; (void)is_ptrfree; # endif } #endif /* !GC_DISABLE_INCREMENTAL */ #if defined(MPROTECT_VDB) && defined(DARWIN) /* The following sources were used as a "reference" for this exception handling code: 1. Apple's mach/xnu documentation 2. Timothy J. Wood's "Mach Exception Handlers 101" post to the omnigroup's macosx-dev list. www.omnigroup.com/mailman/archive/macosx-dev/2000-June/014178.html 3. macosx-nat.c from Apple's GDB source code. */ /* The bug that caused all this trouble should now be fixed. This should eventually be removed if all goes well. */ /* #define BROKEN_EXCEPTION_HANDLING */ #include <mach/mach.h> #include <mach/mach_error.h> #include <mach/exception.h> #include <mach/task.h> #include <pthread.h> EXTERN_C_BEGIN /* Some of the following prototypes are missing in any header, although */ /* they are documented. Some are in mach/exc.h file. */ extern boolean_t exc_server(mach_msg_header_t *, mach_msg_header_t *); extern kern_return_t exception_raise(mach_port_t, mach_port_t, mach_port_t, exception_type_t, exception_data_t, mach_msg_type_number_t); extern kern_return_t exception_raise_state(mach_port_t, mach_port_t, mach_port_t, exception_type_t, exception_data_t, mach_msg_type_number_t, thread_state_flavor_t*, thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t*); extern kern_return_t exception_raise_state_identity(mach_port_t, mach_port_t, mach_port_t, exception_type_t, exception_data_t, mach_msg_type_number_t, thread_state_flavor_t*, thread_state_t, mach_msg_type_number_t, thread_state_t, mach_msg_type_number_t*); GC_API_OSCALL kern_return_t catch_exception_raise(mach_port_t exception_port, mach_port_t thread, mach_port_t task, exception_type_t exception, exception_data_t code, mach_msg_type_number_t code_count); GC_API_OSCALL kern_return_t catch_exception_raise_state(mach_port_name_t exception_port, int exception, exception_data_t code, mach_msg_type_number_t codeCnt, int flavor, thread_state_t old_state, int old_stateCnt, thread_state_t new_state, int new_stateCnt); GC_API_OSCALL kern_return_t catch_exception_raise_state_identity(mach_port_name_t exception_port, mach_port_t thread, mach_port_t task, int exception, exception_data_t code, mach_msg_type_number_t codeCnt, int flavor, thread_state_t old_state, int old_stateCnt, thread_state_t new_state, int new_stateCnt); EXTERN_C_END /* These should never be called, but just in case... */ GC_API_OSCALL kern_return_t catch_exception_raise_state(mach_port_name_t exception_port GC_ATTR_UNUSED, int exception GC_ATTR_UNUSED, exception_data_t code GC_ATTR_UNUSED, mach_msg_type_number_t codeCnt GC_ATTR_UNUSED, int flavor GC_ATTR_UNUSED, thread_state_t old_state GC_ATTR_UNUSED, int old_stateCnt GC_ATTR_UNUSED, thread_state_t new_state GC_ATTR_UNUSED, int new_stateCnt GC_ATTR_UNUSED) { ABORT_RET("Unexpected catch_exception_raise_state invocation"); return(KERN_INVALID_ARGUMENT); } GC_API_OSCALL kern_return_t catch_exception_raise_state_identity( mach_port_name_t exception_port GC_ATTR_UNUSED, mach_port_t thread GC_ATTR_UNUSED, mach_port_t task GC_ATTR_UNUSED, int exception GC_ATTR_UNUSED, exception_data_t code GC_ATTR_UNUSED, mach_msg_type_number_t codeCnt GC_ATTR_UNUSED, int flavor GC_ATTR_UNUSED, thread_state_t old_state GC_ATTR_UNUSED, int old_stateCnt GC_ATTR_UNUSED, thread_state_t new_state GC_ATTR_UNUSED, int new_stateCnt GC_ATTR_UNUSED) { ABORT_RET("Unexpected catch_exception_raise_state_identity invocation"); return(KERN_INVALID_ARGUMENT); } #define MAX_EXCEPTION_PORTS 16 static struct { mach_msg_type_number_t count; exception_mask_t masks[MAX_EXCEPTION_PORTS]; exception_handler_t ports[MAX_EXCEPTION_PORTS]; exception_behavior_t behaviors[MAX_EXCEPTION_PORTS]; thread_state_flavor_t flavors[MAX_EXCEPTION_PORTS]; } GC_old_exc_ports; STATIC struct ports_s { void (*volatile os_callback[3])(void); mach_port_t exception; # if defined(THREADS) mach_port_t reply; # endif } GC_ports = { { /* This is to prevent stripping these routines as dead. */ (void (*)(void))catch_exception_raise, (void (*)(void))catch_exception_raise_state, (void (*)(void))catch_exception_raise_state_identity }, # ifdef THREADS 0, /* for 'exception' */ # endif 0 }; typedef struct { mach_msg_header_t head; } GC_msg_t; typedef enum { GC_MP_NORMAL, GC_MP_DISCARDING, GC_MP_STOPPED } GC_mprotect_state_t; #ifdef THREADS /* FIXME: 1 and 2 seem to be safe to use in the msgh_id field, but it */ /* is not documented. Use the source and see if they should be OK. */ # define ID_STOP 1 # define ID_RESUME 2 /* This value is only used on the reply port. */ # define ID_ACK 3 STATIC GC_mprotect_state_t GC_mprotect_state = GC_MP_NORMAL; /* The following should ONLY be called when the world is stopped. */ STATIC void GC_mprotect_thread_notify(mach_msg_id_t id) { struct buf_s { GC_msg_t msg; mach_msg_trailer_t trailer; } buf; mach_msg_return_t r; /* remote, local */ buf.msg.head.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND, 0); buf.msg.head.msgh_size = sizeof(buf.msg); buf.msg.head.msgh_remote_port = GC_ports.exception; buf.msg.head.msgh_local_port = MACH_PORT_NULL; buf.msg.head.msgh_id = id; r = mach_msg(&buf.msg.head, MACH_SEND_MSG | MACH_RCV_MSG | MACH_RCV_LARGE, sizeof(buf.msg), sizeof(buf), GC_ports.reply, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); if (r != MACH_MSG_SUCCESS) ABORT("mach_msg failed in GC_mprotect_thread_notify"); if (buf.msg.head.msgh_id != ID_ACK) ABORT("Invalid ack in GC_mprotect_thread_notify"); } /* Should only be called by the mprotect thread */ STATIC void GC_mprotect_thread_reply(void) { GC_msg_t msg; mach_msg_return_t r; /* remote, local */ msg.head.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND, 0); msg.head.msgh_size = sizeof(msg); msg.head.msgh_remote_port = GC_ports.reply; msg.head.msgh_local_port = MACH_PORT_NULL; msg.head.msgh_id = ID_ACK; r = mach_msg(&msg.head, MACH_SEND_MSG, sizeof(msg), 0, MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); if (r != MACH_MSG_SUCCESS) ABORT("mach_msg failed in GC_mprotect_thread_reply"); } GC_INNER void GC_mprotect_stop(void) { GC_mprotect_thread_notify(ID_STOP); } GC_INNER void GC_mprotect_resume(void) { GC_mprotect_thread_notify(ID_RESUME); } #else /* The compiler should optimize away any GC_mprotect_state computations */ # define GC_mprotect_state GC_MP_NORMAL #endif /* !THREADS */ struct mp_reply_s { mach_msg_header_t head; char data[256]; }; struct mp_msg_s { mach_msg_header_t head; mach_msg_body_t msgh_body; char data[1024]; }; STATIC void *GC_mprotect_thread(void *arg) { mach_msg_return_t r; /* These two structures contain some private kernel data. We don't */ /* need to access any of it so we don't bother defining a proper */ /* struct. The correct definitions are in the xnu source code. */ struct mp_reply_s reply; struct mp_msg_s msg; mach_msg_id_t id; if ((word)arg == GC_WORD_MAX) return 0; /* to prevent a compiler warning */ # if defined(CPPCHECK) reply.data[0] = 0; /* to prevent "field unused" warnings */ msg.data[0] = 0; # endif # if defined(HAVE_PTHREAD_SETNAME_NP_WITHOUT_TID) (void)pthread_setname_np("GC-mprotect"); # endif # if defined(THREADS) && !defined(GC_NO_THREADS_DISCOVERY) GC_darwin_register_mach_handler_thread(mach_thread_self()); # endif for(;;) { r = mach_msg(&msg.head, MACH_RCV_MSG | MACH_RCV_LARGE | (GC_mprotect_state == GC_MP_DISCARDING ? MACH_RCV_TIMEOUT : 0), 0, sizeof(msg), GC_ports.exception, GC_mprotect_state == GC_MP_DISCARDING ? 0 : MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); id = r == MACH_MSG_SUCCESS ? msg.head.msgh_id : -1; # if defined(THREADS) if(GC_mprotect_state == GC_MP_DISCARDING) { if(r == MACH_RCV_TIMED_OUT) { GC_mprotect_state = GC_MP_STOPPED; GC_mprotect_thread_reply(); continue; } if(r == MACH_MSG_SUCCESS && (id == ID_STOP || id == ID_RESUME)) ABORT("Out of order mprotect thread request"); } # endif /* THREADS */ if (r != MACH_MSG_SUCCESS) { ABORT_ARG2("mach_msg failed", ": errcode= %d (%s)", (int)r, mach_error_string(r)); } switch(id) { # if defined(THREADS) case ID_STOP: if(GC_mprotect_state != GC_MP_NORMAL) ABORT("Called mprotect_stop when state wasn't normal"); GC_mprotect_state = GC_MP_DISCARDING; break; case ID_RESUME: if(GC_mprotect_state != GC_MP_STOPPED) ABORT("Called mprotect_resume when state wasn't stopped"); GC_mprotect_state = GC_MP_NORMAL; GC_mprotect_thread_reply(); break; # endif /* THREADS */ default: /* Handle the message (calls catch_exception_raise) */ if(!exc_server(&msg.head, &reply.head)) ABORT("exc_server failed"); /* Send the reply */ r = mach_msg(&reply.head, MACH_SEND_MSG, reply.head.msgh_size, 0, MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); if(r != MACH_MSG_SUCCESS) { /* This will fail if the thread dies, but the thread */ /* shouldn't die... */ # ifdef BROKEN_EXCEPTION_HANDLING GC_err_printf("mach_msg failed with %d %s while sending " "exc reply\n", (int)r, mach_error_string(r)); # else ABORT("mach_msg failed while sending exception reply"); # endif } } /* switch */ } /* for(;;) */ } /* All this SIGBUS code shouldn't be necessary. All protection faults should be going through the mach exception handler. However, it seems a SIGBUS is occasionally sent for some unknown reason. Even more odd, it seems to be meaningless and safe to ignore. */ #ifdef BROKEN_EXCEPTION_HANDLING /* Updates to this aren't atomic, but the SIGBUS'es seem pretty rare. */ /* Even if this doesn't get updated property, it isn't really a problem. */ STATIC int GC_sigbus_count = 0; STATIC void GC_darwin_sigbus(int num, siginfo_t *sip, void *context) { if (num != SIGBUS) ABORT("Got a non-sigbus signal in the sigbus handler"); /* Ugh... some seem safe to ignore, but too many in a row probably means trouble. GC_sigbus_count is reset for each mach exception that is handled */ if (GC_sigbus_count >= 8) { ABORT("Got more than 8 SIGBUSs in a row!"); } else { GC_sigbus_count++; WARN("Ignoring SIGBUS\n", 0); } } #endif /* BROKEN_EXCEPTION_HANDLING */ GC_INNER GC_bool GC_dirty_init(void) { kern_return_t r; mach_port_t me; pthread_t thread; pthread_attr_t attr; exception_mask_t mask; # ifdef CAN_HANDLE_FORK if (GC_handle_fork) { /* To both support GC incremental mode and GC functions usage in */ /* the forked child, pthread_atfork should be used to install */ /* handlers that switch off GC_incremental in the child */ /* gracefully (unprotecting all pages and clearing */ /* GC_mach_handler_thread). For now, we just disable incremental */ /* mode if fork() handling is requested by the client. */ WARN("Can't turn on GC incremental mode as fork()" " handling requested\n", 0); return FALSE; } # endif GC_VERBOSE_LOG_PRINTF("Initializing mach/darwin mprotect" " virtual dirty bit implementation\n"); # ifdef BROKEN_EXCEPTION_HANDLING WARN("Enabling workarounds for various darwin " "exception handling bugs\n", 0); # endif if (GC_page_size % HBLKSIZE != 0) { ABORT("Page size not multiple of HBLKSIZE"); } GC_task_self = me = mach_task_self(); r = mach_port_allocate(me, MACH_PORT_RIGHT_RECEIVE, &GC_ports.exception); /* TODO: WARN and return FALSE in case of a failure. */ if (r != KERN_SUCCESS) ABORT("mach_port_allocate failed (exception port)"); r = mach_port_insert_right(me, GC_ports.exception, GC_ports.exception, MACH_MSG_TYPE_MAKE_SEND); if (r != KERN_SUCCESS) ABORT("mach_port_insert_right failed (exception port)"); # if defined(THREADS) r = mach_port_allocate(me, MACH_PORT_RIGHT_RECEIVE, &GC_ports.reply); if(r != KERN_SUCCESS) ABORT("mach_port_allocate failed (reply port)"); # endif /* The exceptions we want to catch */ mask = EXC_MASK_BAD_ACCESS; r = task_get_exception_ports(me, mask, GC_old_exc_ports.masks, &GC_old_exc_ports.count, GC_old_exc_ports.ports, GC_old_exc_ports.behaviors, GC_old_exc_ports.flavors); if (r != KERN_SUCCESS) ABORT("task_get_exception_ports failed"); r = task_set_exception_ports(me, mask, GC_ports.exception, EXCEPTION_DEFAULT, GC_MACH_THREAD_STATE); if (r != KERN_SUCCESS) ABORT("task_set_exception_ports failed"); if (pthread_attr_init(&attr) != 0) ABORT("pthread_attr_init failed"); if (pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) != 0) ABORT("pthread_attr_setdetachedstate failed"); # undef pthread_create /* This will call the real pthread function, not our wrapper */ if (pthread_create(&thread, &attr, GC_mprotect_thread, NULL) != 0) ABORT("pthread_create failed"); (void)pthread_attr_destroy(&attr); /* Setup the sigbus handler for ignoring the meaningless SIGBUSs */ # ifdef BROKEN_EXCEPTION_HANDLING { struct sigaction sa, oldsa; sa.sa_handler = (SIG_HNDLR_PTR)GC_darwin_sigbus; sigemptyset(&sa.sa_mask); sa.sa_flags = SA_RESTART|SA_SIGINFO; /* sa.sa_restorer is deprecated and should not be initialized. */ if (sigaction(SIGBUS, &sa, &oldsa) < 0) ABORT("sigaction failed"); if (oldsa.sa_handler != (SIG_HNDLR_PTR)(signed_word)SIG_DFL) { GC_VERBOSE_LOG_PRINTF("Replaced other SIGBUS handler\n"); } } # endif /* BROKEN_EXCEPTION_HANDLING */ # if defined(CPPCHECK) GC_noop1((word)GC_ports.os_callback[0]); # endif return TRUE; } /* The source code for Apple's GDB was used as a reference for the */ /* exception forwarding code. This code is similar to be GDB code only */ /* because there is only one way to do it. */ STATIC kern_return_t GC_forward_exception(mach_port_t thread, mach_port_t task, exception_type_t exception, exception_data_t data, mach_msg_type_number_t data_count) { unsigned int i; kern_return_t r; mach_port_t port; exception_behavior_t behavior; thread_state_flavor_t flavor; thread_state_data_t thread_state; mach_msg_type_number_t thread_state_count = THREAD_STATE_MAX; for (i=0; i < GC_old_exc_ports.count; i++) if (GC_old_exc_ports.masks[i] & (1 << exception)) break; if (i == GC_old_exc_ports.count) ABORT("No handler for exception!"); port = GC_old_exc_ports.ports[i]; behavior = GC_old_exc_ports.behaviors[i]; flavor = GC_old_exc_ports.flavors[i]; if (behavior == EXCEPTION_STATE || behavior == EXCEPTION_STATE_IDENTITY) { r = thread_get_state(thread, flavor, thread_state, &thread_state_count); if(r != KERN_SUCCESS) ABORT("thread_get_state failed in forward_exception"); } switch(behavior) { case EXCEPTION_STATE: r = exception_raise_state(port, thread, task, exception, data, data_count, &flavor, thread_state, thread_state_count, thread_state, &thread_state_count); break; case EXCEPTION_STATE_IDENTITY: r = exception_raise_state_identity(port, thread, task, exception, data, data_count, &flavor, thread_state, thread_state_count, thread_state, &thread_state_count); break; /* case EXCEPTION_DEFAULT: */ /* default signal handlers */ default: /* user-supplied signal handlers */ r = exception_raise(port, thread, task, exception, data, data_count); } if (behavior == EXCEPTION_STATE || behavior == EXCEPTION_STATE_IDENTITY) { r = thread_set_state(thread, flavor, thread_state, thread_state_count); if (r != KERN_SUCCESS) ABORT("thread_set_state failed in forward_exception"); } return r; } #define FWD() GC_forward_exception(thread, task, exception, code, code_count) #ifdef ARM32 # define DARWIN_EXC_STATE ARM_EXCEPTION_STATE # define DARWIN_EXC_STATE_COUNT ARM_EXCEPTION_STATE_COUNT # define DARWIN_EXC_STATE_T arm_exception_state_t # define DARWIN_EXC_STATE_DAR THREAD_FLD_NAME(far) #elif defined(AARCH64) # define DARWIN_EXC_STATE ARM_EXCEPTION_STATE64 # define DARWIN_EXC_STATE_COUNT ARM_EXCEPTION_STATE64_COUNT # define DARWIN_EXC_STATE_T arm_exception_state64_t # define DARWIN_EXC_STATE_DAR THREAD_FLD_NAME(far) #elif defined(POWERPC) # if CPP_WORDSZ == 32 # define DARWIN_EXC_STATE PPC_EXCEPTION_STATE # define DARWIN_EXC_STATE_COUNT PPC_EXCEPTION_STATE_COUNT # define DARWIN_EXC_STATE_T ppc_exception_state_t # else # define DARWIN_EXC_STATE PPC_EXCEPTION_STATE64 # define DARWIN_EXC_STATE_COUNT PPC_EXCEPTION_STATE64_COUNT # define DARWIN_EXC_STATE_T ppc_exception_state64_t # endif # define DARWIN_EXC_STATE_DAR THREAD_FLD_NAME(dar) #elif defined(I386) || defined(X86_64) # if CPP_WORDSZ == 32 # if defined(i386_EXCEPTION_STATE_COUNT) \ && !defined(x86_EXCEPTION_STATE32_COUNT) /* Use old naming convention for 32-bit x86. */ # define DARWIN_EXC_STATE i386_EXCEPTION_STATE # define DARWIN_EXC_STATE_COUNT i386_EXCEPTION_STATE_COUNT # define DARWIN_EXC_STATE_T i386_exception_state_t # else # define DARWIN_EXC_STATE x86_EXCEPTION_STATE32 # define DARWIN_EXC_STATE_COUNT x86_EXCEPTION_STATE32_COUNT # define DARWIN_EXC_STATE_T x86_exception_state32_t # endif # else # define DARWIN_EXC_STATE x86_EXCEPTION_STATE64 # define DARWIN_EXC_STATE_COUNT x86_EXCEPTION_STATE64_COUNT # define DARWIN_EXC_STATE_T x86_exception_state64_t # endif # define DARWIN_EXC_STATE_DAR THREAD_FLD_NAME(faultvaddr) #elif !defined(CPPCHECK) # error FIXME for non-arm/ppc/x86 darwin #endif /* This violates the namespace rules but there isn't anything that can */ /* be done about it. The exception handling stuff is hard coded to */ /* call this. catch_exception_raise, catch_exception_raise_state and */ /* and catch_exception_raise_state_identity are called from OS. */ GC_API_OSCALL kern_return_t catch_exception_raise(mach_port_t exception_port GC_ATTR_UNUSED, mach_port_t thread, mach_port_t task GC_ATTR_UNUSED, exception_type_t exception, exception_data_t code, mach_msg_type_number_t code_count GC_ATTR_UNUSED) { kern_return_t r; char *addr; thread_state_flavor_t flavor = DARWIN_EXC_STATE; mach_msg_type_number_t exc_state_count = DARWIN_EXC_STATE_COUNT; DARWIN_EXC_STATE_T exc_state; if (exception != EXC_BAD_ACCESS || code[0] != KERN_PROTECTION_FAILURE) { # ifdef DEBUG_EXCEPTION_HANDLING /* We aren't interested, pass it on to the old handler */ GC_log_printf("Exception: 0x%x Code: 0x%x 0x%x in catch...\n", exception, code_count > 0 ? code[0] : -1, code_count > 1 ? code[1] : -1); # endif return FWD(); } r = thread_get_state(thread, flavor, (natural_t*)&exc_state, &exc_state_count); if(r != KERN_SUCCESS) { /* The thread is supposed to be suspended while the exception */ /* handler is called. This shouldn't fail. */ # ifdef BROKEN_EXCEPTION_HANDLING GC_err_printf("thread_get_state failed in catch_exception_raise\n"); return KERN_SUCCESS; # else ABORT("thread_get_state failed in catch_exception_raise"); # endif } /* This is the address that caused the fault */ addr = (char*) exc_state.DARWIN_EXC_STATE_DAR; if (!is_header_found_async(addr)) { /* Ugh... just like the SIGBUS problem above, it seems we get */ /* a bogus KERN_PROTECTION_FAILURE every once and a while. We wait */ /* till we get a bunch in a row before doing anything about it. */ /* If a "real" fault ever occurs it'll just keep faulting over and */ /* over and we'll hit the limit pretty quickly. */ # ifdef BROKEN_EXCEPTION_HANDLING static char *last_fault; static int last_fault_count; if(addr != last_fault) { last_fault = addr; last_fault_count = 0; } if(++last_fault_count < 32) { if(last_fault_count == 1) WARN("Ignoring KERN_PROTECTION_FAILURE at %p\n", addr); return KERN_SUCCESS; } GC_err_printf("Unexpected KERN_PROTECTION_FAILURE at %p; aborting...\n", (void *)addr); /* Can't pass it along to the signal handler because that is */ /* ignoring SIGBUS signals. We also shouldn't call ABORT here as */ /* signals don't always work too well from the exception handler. */ EXIT(); # else /* BROKEN_EXCEPTION_HANDLING */ /* Pass it along to the next exception handler (which should call SIGBUS/SIGSEGV) */ return FWD(); # endif /* !BROKEN_EXCEPTION_HANDLING */ } # ifdef BROKEN_EXCEPTION_HANDLING /* Reset the number of consecutive SIGBUSs */ GC_sigbus_count = 0; # endif GC_ASSERT(GC_page_size != 0); if (GC_mprotect_state == GC_MP_NORMAL) { /* common case */ struct hblk * h = (struct hblk*)((word)addr & ~(GC_page_size-1)); size_t i; UNPROTECT(h, GC_page_size); for (i = 0; i < divHBLKSZ(GC_page_size); i++) { word index = PHT_HASH(h+i); async_set_pht_entry_from_index(GC_dirty_pages, index); } } else if (GC_mprotect_state == GC_MP_DISCARDING) { /* Lie to the thread for now. No sense UNPROTECT()ing the memory when we're just going to PROTECT() it again later. The thread will just fault again once it resumes */ } else { /* Shouldn't happen, i don't think */ GC_err_printf("KERN_PROTECTION_FAILURE while world is stopped\n"); return FWD(); } return KERN_SUCCESS; } #undef FWD #ifndef NO_DESC_CATCH_EXCEPTION_RAISE /* These symbols should have REFERENCED_DYNAMICALLY (0x10) bit set to */ /* let strip know they are not to be stripped. */ __asm__(".desc _catch_exception_raise, 0x10"); __asm__(".desc _catch_exception_raise_state, 0x10"); __asm__(".desc _catch_exception_raise_state_identity, 0x10"); #endif #endif /* DARWIN && MPROTECT_VDB */ #ifndef HAVE_INCREMENTAL_PROTECTION_NEEDS GC_API int GC_CALL GC_incremental_protection_needs(void) { GC_ASSERT(GC_is_initialized); return GC_PROTECTS_NONE; } #endif /* !HAVE_INCREMENTAL_PROTECTION_NEEDS */ #ifdef ECOS /* Undo sbrk() redirection. */ # undef sbrk #endif /* If value is non-zero then allocate executable memory. */ GC_API void GC_CALL GC_set_pages_executable(int value) { GC_ASSERT(!GC_is_initialized); /* Even if IGNORE_PAGES_EXECUTABLE is defined, GC_pages_executable is */ /* touched here to prevent a compiler warning. */ GC_pages_executable = (GC_bool)(value != 0); } /* Returns non-zero if the GC-allocated memory is executable. */ /* GC_get_pages_executable is defined after all the places */ /* where GC_get_pages_executable is undefined. */ GC_API int GC_CALL GC_get_pages_executable(void) { # ifdef IGNORE_PAGES_EXECUTABLE return 1; /* Always allocate executable memory. */ # else return (int)GC_pages_executable; # endif } /* Call stack save code for debugging. Should probably be in */ /* mach_dep.c, but that requires reorganization. */ /* I suspect the following works for most X86 *nix variants, so */ /* long as the frame pointer is explicitly stored. In the case of gcc, */ /* compiler flags (e.g. -fomit-frame-pointer) determine whether it is. */ #if defined(I386) && defined(LINUX) && defined(SAVE_CALL_CHAIN) # include <features.h> struct frame { struct frame *fr_savfp; long fr_savpc; # if NARGS > 0 long fr_arg[NARGS]; /* All the arguments go here. */ # endif }; #endif #if defined(SPARC) # if defined(LINUX) # include <features.h> # if defined(SAVE_CALL_CHAIN) struct frame { long fr_local[8]; long fr_arg[6]; struct frame *fr_savfp; long fr_savpc; # ifndef __arch64__ char *fr_stret; # endif long fr_argd[6]; long fr_argx[0]; }; # endif # elif defined (DRSNX) # include <sys/sparc/frame.h> # elif defined(OPENBSD) # include <frame.h> # elif defined(FREEBSD) || defined(NETBSD) # include <machine/frame.h> # else # include <sys/frame.h> # endif # if NARGS > 6 # error We only know how to get the first 6 arguments # endif #endif /* SPARC */ #ifdef NEED_CALLINFO /* Fill in the pc and argument information for up to NFRAMES of my */ /* callers. Ignore my frame and my callers frame. */ #ifdef LINUX # include <unistd.h> #endif #endif /* NEED_CALLINFO */ #if defined(GC_HAVE_BUILTIN_BACKTRACE) # ifdef _MSC_VER # include "private/msvc_dbg.h" # else # include <execinfo.h> # endif #endif #ifdef SAVE_CALL_CHAIN #if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \ && defined(GC_HAVE_BUILTIN_BACKTRACE) #ifdef REDIRECT_MALLOC /* Deal with possible malloc calls in backtrace by omitting */ /* the infinitely recursing backtrace. */ # ifdef THREADS __thread /* If your compiler doesn't understand this */ /* you could use something like pthread_getspecific. */ # endif GC_bool GC_in_save_callers = FALSE; #endif GC_INNER void GC_save_callers(struct callinfo info[NFRAMES]) { void * tmp_info[NFRAMES + 1]; int npcs, i; # define IGNORE_FRAMES 1 /* We retrieve NFRAMES+1 pc values, but discard the first, since it */ /* points to our own frame. */ # ifdef REDIRECT_MALLOC if (GC_in_save_callers) { info[0].ci_pc = (word)(&GC_save_callers); for (i = 1; i < NFRAMES; ++i) info[i].ci_pc = 0; return; } GC_in_save_callers = TRUE; # endif GC_ASSERT(I_HOLD_LOCK()); /* backtrace may call dl_iterate_phdr which is also */ /* used by GC_register_dynamic_libraries, and */ /* dl_iterate_phdr is not guaranteed to be reentrant. */ GC_STATIC_ASSERT(sizeof(struct callinfo) == sizeof(void *)); npcs = backtrace((void **)tmp_info, NFRAMES + IGNORE_FRAMES); if (npcs > IGNORE_FRAMES) BCOPY(&tmp_info[IGNORE_FRAMES], info, (npcs - IGNORE_FRAMES) * sizeof(void *)); for (i = npcs - IGNORE_FRAMES; i < NFRAMES; ++i) info[i].ci_pc = 0; # ifdef REDIRECT_MALLOC GC_in_save_callers = FALSE; # endif } #else /* No builtin backtrace; do it ourselves */ #if (defined(OPENBSD) || defined(NETBSD) || defined(FREEBSD)) && defined(SPARC) # define FR_SAVFP fr_fp # define FR_SAVPC fr_pc #else # define FR_SAVFP fr_savfp # define FR_SAVPC fr_savpc #endif #if defined(SPARC) && (defined(__arch64__) || defined(__sparcv9)) # define BIAS 2047 #else # define BIAS 0 #endif GC_INNER void GC_save_callers(struct callinfo info[NFRAMES]) { struct frame *frame; struct frame *fp; int nframes = 0; # ifdef I386 /* We assume this is turned on only with gcc as the compiler. */ asm("movl %%ebp,%0" : "=r"(frame)); fp = frame; # else frame = (struct frame *)GC_save_regs_in_stack(); fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS); #endif for (; !((word)fp HOTTER_THAN (word)frame) # ifndef THREADS && !((word)GC_stackbottom HOTTER_THAN (word)fp) # elif defined(STACK_GROWS_UP) && fp != NULL # endif && nframes < NFRAMES; fp = (struct frame *)((long) fp -> FR_SAVFP + BIAS), nframes++) { # if NARGS > 0 int i; # endif info[nframes].ci_pc = fp->FR_SAVPC; # if NARGS > 0 for (i = 0; i < NARGS; i++) { info[nframes].ci_arg[i] = ~(fp->fr_arg[i]); } # endif /* NARGS > 0 */ } if (nframes < NFRAMES) info[nframes].ci_pc = 0; } #endif /* No builtin backtrace */ #endif /* SAVE_CALL_CHAIN */ #ifdef NEED_CALLINFO /* Print info to stderr. We do NOT hold the allocation lock */ GC_INNER void GC_print_callers(struct callinfo info[NFRAMES]) { int i; static int reentry_count = 0; DCL_LOCK_STATE; /* FIXME: This should probably use a different lock, so that we */ /* become callable with or without the allocation lock. */ LOCK(); ++reentry_count; UNLOCK(); # if NFRAMES == 1 GC_err_printf("\tCaller at allocation:\n"); # else GC_err_printf("\tCall chain at allocation:\n"); # endif for (i = 0; i < NFRAMES; i++) { # if defined(LINUX) && !defined(SMALL_CONFIG) GC_bool stop = FALSE; # endif if (0 == info[i].ci_pc) break; # if NARGS > 0 { int j; GC_err_printf("\t\targs: "); for (j = 0; j < NARGS; j++) { if (j != 0) GC_err_printf(", "); GC_err_printf("%d (0x%X)", ~(info[i].ci_arg[j]), ~(info[i].ci_arg[j])); } GC_err_printf("\n"); } # endif if (reentry_count > 1) { /* We were called during an allocation during */ /* a previous GC_print_callers call; punt. */ GC_err_printf("\t\t##PC##= 0x%lx\n", (unsigned long)info[i].ci_pc); continue; } { char buf[40]; char *name; # if defined(GC_HAVE_BUILTIN_BACKTRACE) \ && !defined(GC_BACKTRACE_SYMBOLS_BROKEN) char **sym_name = backtrace_symbols((void **)(&(info[i].ci_pc)), 1); if (sym_name != NULL) { name = sym_name[0]; } else # endif /* else */ { (void)snprintf(buf, sizeof(buf), "##PC##= 0x%lx", (unsigned long)info[i].ci_pc); buf[sizeof(buf) - 1] = '\0'; name = buf; } # if defined(LINUX) && !defined(SMALL_CONFIG) /* Try for a line number. */ do { FILE *pipe; # define EXE_SZ 100 static char exe_name[EXE_SZ]; # define CMD_SZ 200 char cmd_buf[CMD_SZ]; # define RESULT_SZ 200 static char result_buf[RESULT_SZ]; size_t result_len; char *old_preload; # define PRELOAD_SZ 200 char preload_buf[PRELOAD_SZ]; static GC_bool found_exe_name = FALSE; static GC_bool will_fail = FALSE; /* Try to get it via a hairy and expensive scheme. */ /* First we get the name of the executable: */ if (will_fail) break; if (!found_exe_name) { int ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ); if (ret_code < 0 || ret_code >= EXE_SZ || exe_name[0] != '/') { will_fail = TRUE; /* Don't try again. */ break; } exe_name[ret_code] = '\0'; found_exe_name = TRUE; } /* Then we use popen to start addr2line -e <exe> <addr> */ /* There are faster ways to do this, but hopefully this */ /* isn't time critical. */ (void)snprintf(cmd_buf, sizeof(cmd_buf), "/usr/bin/addr2line -f -e %s 0x%lx", exe_name, (unsigned long)info[i].ci_pc); cmd_buf[sizeof(cmd_buf) - 1] = '\0'; old_preload = GETENV("LD_PRELOAD"); if (0 != old_preload) { size_t old_len = strlen(old_preload); if (old_len >= PRELOAD_SZ) { will_fail = TRUE; break; } BCOPY(old_preload, preload_buf, old_len + 1); unsetenv ("LD_PRELOAD"); } pipe = popen(cmd_buf, "r"); if (0 != old_preload && 0 != setenv ("LD_PRELOAD", preload_buf, 0)) { WARN("Failed to reset LD_PRELOAD\n", 0); } if (NULL == pipe) { will_fail = TRUE; break; } result_len = fread(result_buf, 1, RESULT_SZ - 1, pipe); (void)pclose(pipe); if (0 == result_len) { will_fail = TRUE; break; } if (result_buf[result_len - 1] == '\n') --result_len; result_buf[result_len] = 0; if (result_buf[0] == '?' || (result_buf[result_len-2] == ':' && result_buf[result_len-1] == '0')) break; /* Get rid of embedded newline, if any. Test for "main" */ { char * nl = strchr(result_buf, '\n'); if (nl != NULL && (word)nl < (word)(result_buf + result_len)) { *nl = ':'; } if (strncmp(result_buf, "main", nl != NULL ? (size_t)((word)nl /* a cppcheck workaround */ - COVERT_DATAFLOW(result_buf)) : result_len) == 0) { stop = TRUE; } } if (result_len < RESULT_SZ - 25) { /* Add in hex address */ (void)snprintf(&result_buf[result_len], sizeof(result_buf) - result_len, " [0x%lx]", (unsigned long)info[i].ci_pc); result_buf[sizeof(result_buf) - 1] = '\0'; } # if defined(CPPCHECK) GC_noop1((unsigned char)name[0]); /* name computed previously is discarded */ # endif name = result_buf; } while (0); # endif /* LINUX */ GC_err_printf("\t\t%s\n", name); # if defined(GC_HAVE_BUILTIN_BACKTRACE) \ && !defined(GC_BACKTRACE_SYMBOLS_BROKEN) if (sym_name != NULL) free(sym_name); /* May call GC_[debug_]free; that's OK */ # endif } # if defined(LINUX) && !defined(SMALL_CONFIG) if (stop) break; # endif } LOCK(); --reentry_count; UNLOCK(); } #endif /* NEED_CALLINFO */ #if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG) /* Dump /proc/self/maps to GC_stderr, to enable looking up names for */ /* addresses in FIND_LEAK output. */ void GC_print_address_map(void) { const char *maps = GC_get_maps(); GC_err_printf("---------- Begin address map ----------\n"); GC_err_puts(maps); GC_err_printf("---------- End address map ----------\n"); } #endif /* LINUX && ELF */
¤ Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.0.120Bemerkung: (vorverarbeitet am 2026-04-27) ¤*Bot Zugriff |
|
||||||||||||||
2026-05-26