/* Initialize symbol maps and path of vmlinux/modules */ int init_probe_symbol_maps(bool user_only)
{ int ret;
perf_env__init(&host_env);
symbol_conf.allow_aliases = true;
ret = symbol__init(NULL); if (ret < 0) {
pr_debug("Failed to init symbol map.\n"); goto out;
}
if (host_machine || user_only) /* already initialized */ return 0;
if (symbol_conf.vmlinux_name)
pr_debug("Use vmlinux: %s\n", symbol_conf.vmlinux_name);
host_machine = machine__new_host(&host_env); if (!host_machine) {
pr_debug("machine__new_host() failed.\n");
symbol__exit();
ret = -1;
}
out: if (ret < 0)
pr_warning("Failed to init vmlinux path.\n"); return ret;
}
map = kernel_get_module_map(NULL); if (map) {
ret = address <= map__start(map) || map__end(map) < address; if (ret)
pr_warning("%s is out of .text, skip it.\n", symbol);
map__put(map);
} if (!ret && kprobe_blacklist__listed(address)) {
pr_warning("%s is blacklisted function, skip it.\n", symbol);
ret = true;
}
return ret;
}
/* * @module can be module name of module file path. In case of path, * inspect elf and find out what is actual module name. * Caller has to free mod_name after using it.
*/ staticchar *find_module_name(constchar *module)
{ int fd;
Elf *elf;
GElf_Ehdr ehdr;
GElf_Shdr shdr;
Elf_Data *data;
Elf_Scn *sec; char *mod_name = NULL; int name_offset;
fd = open(module, O_RDONLY); if (fd < 0) return NULL;
data = elf_getdata(sec, NULL); if (!data || !data->d_buf) goto ret_err;
/* * NOTE: * '.gnu.linkonce.this_module' section of kernel module elf directly * maps to 'struct module' from linux/module.h. This section contains * actual module name which will be used by kernel after loading it. * But, we cannot use 'struct module' here since linux/module.h is not * exposed to user-space. Offset of 'name' has remained same from long * time, so hardcoding it here.
*/ if (ehdr.e_ident[EI_CLASS] == ELFCLASS32)
name_offset = 12; else/* expect ELFCLASS64 by default */
name_offset = 24;
map = machine__kernel_map(host_machine);
dso = map__dso(map); if (!dso__has_build_id(dso))
dso__read_running_kernel_build_id(dso, host_machine);
vmlinux_name = symbol_conf.vmlinux_name;
*dso__load_errno(dso) = 0; if (vmlinux_name)
ret = dso__load_vmlinux(dso, map, vmlinux_name, false); else
ret = dso__load_vmlinux_path(dso, map);
found:
*pdso = dso; return ret;
}
/* * Some binaries like glibc have special symbols which are on the symbol * table, but not in the debuginfo. If we can find the address of the * symbol from map, we can translate the address back to the probe point.
*/ staticint find_alternative_probe_point(struct debuginfo *dinfo, struct perf_probe_point *pp, struct perf_probe_point *result, constchar *target, struct nsinfo *nsi, bool uprobes)
{ struct map *map = NULL; struct symbol *sym;
u64 address = 0; int ret = -ENOENT;
size_t idx;
/* This can work only for function-name based one */ if (!pp->function || pp->file) return -ENOTSUP;
map = get_target_map(target, nsi, uprobes); if (!map) return -EINVAL;
/* Find the address of given function */
map__for_each_symbol_by_name(map, pp->function, sym, idx) { if (uprobes) {
address = sym->start; if (sym->type == STT_GNU_IFUNC)
pr_warning("Warning: The probe function (%s) is a GNU indirect function.\n" "Consider identifying the final function used at run time and set the probe directly on that.\n",
pp->function);
} else
address = map__unmap_ip(map, sym->start) - map__reloc(map); break;
} if (!address) {
ret = -ENOENT; goto out;
}
pr_debug("Symbol %s address found : %" PRIx64 "\n",
pp->function, address);
ret = debuginfo__find_probe_point(dinfo, address, result); if (ret <= 0)
ret = (!ret) ? -ENOENT : ret; else {
result->offset += pp->offset;
result->line += pp->line;
result->retprobe = pp->retprobe;
ret = 0;
}
/* Open new debuginfo of given module */ staticstruct debuginfo *open_debuginfo(constchar *module, struct nsinfo *nsi, bool silent)
{ constchar *path = module; char reason[STRERR_BUFSIZE]; struct debuginfo *ret = NULL; struct dso *dso = NULL; struct nscookie nsc; int err;
if (!module || !strchr(module, '/')) {
err = kernel_get_module_dso(module, &dso); if (err < 0) { if (!dso || *dso__load_errno(dso) == 0) { if (!str_error_r(-err, reason, STRERR_BUFSIZE))
strcpy(reason, "(unknown)");
} else
dso__strerror_load(dso, reason, STRERR_BUFSIZE); if (dso)
ret = open_from_debuginfod(dso, nsi, silent); if (ret) return ret; if (!silent) { if (module)
pr_err("Module %s is not loaded, please specify its full path name.\n", module); else
pr_err("Failed to find the path for the kernel: %s\n", reason);
} return NULL;
}
path = dso__long_name(dso);
}
nsinfo__mountns_enter(nsi, &nsc);
ret = debuginfo__new(path); if (!ret && !silent) {
pr_warning("The %s file has no debug information.\n", path); if (!module || !strtailcmp(path, ".ko"))
pr_warning("Rebuild with CONFIG_DEBUG_INFO=y, "); else
pr_warning("Rebuild with -g, ");
pr_warning("or install an appropriate debuginfo package.\n");
}
nsinfo__mountns_exit(&nsc); return ret;
}
/* For caching the last debuginfo */ staticstruct debuginfo *debuginfo_cache; staticchar *debuginfo_cache_path;
/* * Convert trace point to probe point with debuginfo
*/ staticint find_perf_probe_point_from_dwarf(struct probe_trace_point *tp, struct perf_probe_point *pp, bool is_kprobe)
{ struct debuginfo *dinfo = NULL;
u64 stext = 0;
u64 addr = tp->address; int ret = -ENOENT;
/* convert the address to dwarf address */ if (!is_kprobe) { if (!addr) {
ret = -EINVAL; goto error;
}
ret = get_text_start_address(tp->module, &stext, NULL); if (ret < 0) goto error;
addr += stext;
} elseif (tp->symbol) { /* If the module is given, this returns relative address */
ret = kernel_get_symbol_address_by_name(tp->symbol, &addr, false, !!tp->module); if (ret != 0) goto error;
addr += tp->offset;
}
pr_debug("try to find information at %" PRIx64 " in %s\n", addr,
tp->module ? : "kernel");
dinfo = debuginfo_cache__open(tp->module, verbose <= 0); if (dinfo)
ret = debuginfo__find_probe_point(dinfo, addr, pp); else
ret = -ENOENT;
if (ret > 0) {
pp->retprobe = tp->retprobe; return 0;
}
error:
pr_debug("Failed to find corresponding probes from debuginfo.\n"); return ret ? : -ENOENT;
}
/* Adjust symbol name and address */ staticint post_process_probe_trace_point(struct probe_trace_point *tp, struct map *map, u64 offs)
{ struct symbol *sym;
u64 addr = tp->address - offs;
sym = map__find_symbol(map, addr); if (!sym) { /* * If the address is in the inittext section, map can not * find it. Ignore it if we are probing offline kernel.
*/ return (symbol_conf.ignore_vmlinux_buildid) ? 0 : -ENOENT;
}
if (strcmp(sym->name, tp->symbol)) { /* If we have no realname, use symbol for it */ if (!tp->realname)
tp->realname = tp->symbol; else
free(tp->symbol);
tp->symbol = strdup(sym->name); if (!tp->symbol) return -ENOMEM;
}
tp->offset = addr - sym->start;
tp->address -= offs;
return 0;
}
/* * Rename DWARF symbols to ELF symbols -- gcc sometimes optimizes functions * and generate new symbols with suffixes such as .constprop.N or .isra.N * etc. Since those symbols are not recorded in DWARF, we have to find * correct generated symbols from offline ELF binary. * For online kernel or uprobes we don't need this because those are * rebased on _text, or already a section relative address.
*/ staticint
post_process_offline_probe_trace_events(struct probe_trace_event *tevs, int ntevs, constchar *pathname)
{ struct map *map;
u64 stext = 0; int i, ret = 0;
/* Prepare a map for offline binary */
map = dso__new_map(pathname); if (!map || get_text_start_address(pathname, &stext, NULL) < 0) {
pr_warning("Failed to get ELF symbols for %s\n", pathname); return -EINVAL;
}
for (i = 0; i < ntevs; i++) {
ret = post_process_probe_trace_point(&tevs[i].point,
map, stext); if (ret < 0) break;
}
map__put(map);
return ret;
}
staticint add_exec_to_probe_trace_events(struct probe_trace_event *tevs, int ntevs, constchar *exec, struct nsinfo *nsi)
{ int i, ret = 0;
u64 stext = 0;
if (!exec) return 0;
ret = get_text_start_address(exec, &stext, nsi); if (ret < 0) return ret;
for (i = 0; i < ntevs && ret >= 0; i++) { /* point.address is the address of point.symbol + point.offset */
tevs[i].point.address -= stext;
tevs[i].point.module = strdup(exec); if (!tevs[i].point.module) {
ret = -ENOMEM; break;
}
tevs[i].uprobes = true;
}
return ret;
}
staticint
post_process_module_probe_trace_events(struct probe_trace_event *tevs, int ntevs, constchar *module, struct debuginfo *dinfo)
{
Dwarf_Addr text_offs = 0; int i, ret = 0; char *mod_name = NULL; struct map *map;
if (!module) return 0;
map = get_target_map(module, NULL, false); if (!map || debuginfo__get_text_offset(dinfo, &text_offs, true) < 0) {
pr_warning("Failed to get ELF symbols for %s\n", module); return -EINVAL;
}
mod_name = find_module_name(module); for (i = 0; i < ntevs; i++) {
ret = post_process_probe_trace_point(&tevs[i].point,
map, text_offs); if (ret < 0) break;
tevs[i].point.module =
strdup(mod_name ? mod_name : module); if (!tevs[i].point.module) {
ret = -ENOMEM; break;
}
}
free(mod_name);
map__put(map);
return ret;
}
staticint
post_process_kernel_probe_trace_events(struct probe_trace_event *tevs, int ntevs)
{ struct ref_reloc_sym *reloc_sym; struct map *map; char *tmp; int i, skipped = 0;
/* Skip post process if the target is an offline kernel */ if (symbol_conf.ignore_vmlinux_buildid) return post_process_offline_probe_trace_events(tevs, ntevs,
symbol_conf.vmlinux_name);
reloc_sym = kernel_get_ref_reloc_sym(&map); if (!reloc_sym) {
pr_warning("Relocated base symbol is not found! " "Check /proc/sys/kernel/kptr_restrict\n" "and /proc/sys/kernel/perf_event_paranoid. " "Or run as privileged perf user.\n\n"); return -EINVAL;
}
for (i = 0; i < ntevs; i++) { if (!tevs[i].point.address) continue; if (tevs[i].point.retprobe && !kretprobe_offset_is_supported()) continue; /* * If we found a wrong one, mark it by NULL symbol. * Since addresses in debuginfo is same as objdump, we need * to convert it to addresses on memory.
*/ if (kprobe_warn_out_range(tevs[i].point.symbol,
map__objdump_2mem(map, tevs[i].point.address))) {
tmp = NULL;
skipped++;
} else {
tmp = strdup(reloc_sym->name); if (!tmp) return -ENOMEM;
} /* If we have no realname, use symbol for it */ if (!tevs[i].point.realname)
tevs[i].point.realname = tevs[i].point.symbol; else
free(tevs[i].point.symbol);
tevs[i].point.symbol = tmp;
tevs[i].point.offset = tevs[i].point.address -
(map__reloc(map) ? reloc_sym->unrelocated_addr :
reloc_sym->addr);
} return skipped;
}
/* Post processing the probe events */ staticint post_process_probe_trace_events(struct perf_probe_event *pev, struct probe_trace_event *tevs, int ntevs, constchar *module, bool uprobe, struct debuginfo *dinfo)
{ int ret;
if (uprobe)
ret = add_exec_to_probe_trace_events(tevs, ntevs, module,
pev->nsi); elseif (module) /* Currently ref_reloc_sym based probe is not for drivers */
ret = post_process_module_probe_trace_events(tevs, ntevs,
module, dinfo); else
ret = post_process_kernel_probe_trace_events(tevs, ntevs);
if (ret >= 0)
arch__post_process_probe_trace_events(pev, ntevs);
return ret;
}
/* Try to find perf_probe_event with debuginfo */ staticint try_to_find_probe_trace_events(struct perf_probe_event *pev, struct probe_trace_event **tevs)
{ bool need_dwarf = perf_probe_event_need_dwarf(pev); struct perf_probe_point tmp; struct debuginfo *dinfo; int ntevs, ret = 0;
/* Workaround for gcc #98776 issue. * Perf failed to add kretprobe event with debuginfo of vmlinux which is * compiled by gcc with -fpatchable-function-entry option enabled. The * same issue with kernel module. The retprobe doesn`t need debuginfo. * This workaround solution use map to query the probe function address * for retprobe event.
*/ if (pev->point.retprobe) return 0;
dinfo = open_debuginfo(pev->target, pev->nsi, !need_dwarf); if (!dinfo) { if (need_dwarf) return -ENODATA;
pr_debug("Could not open debuginfo. Try to use symbols.\n"); return 0;
}
pr_debug("Try to find probe point from debuginfo.\n"); /* Searching trace events corresponding to a probe event */
ntevs = debuginfo__find_trace_events(dinfo, pev, tevs);
if (ntevs == 0) { /* Not found, retry with an alternative */
ret = get_alternative_probe_event(dinfo, pev, &tmp); if (!ret) {
ntevs = debuginfo__find_trace_events(dinfo, pev, tevs); /* * Write back to the original probe_event for * setting appropriate (user given) event name
*/
clear_perf_probe_point(&pev->point);
memcpy(&pev->point, &tmp, sizeof(tmp));
}
}
if (ntevs > 0) { /* Succeeded to find trace events */
pr_debug("Found %d probe_trace_events.\n", ntevs);
ret = post_process_probe_trace_events(pev, *tevs, ntevs,
pev->target, pev->uprobes, dinfo); if (ret < 0 || ret == ntevs) {
pr_debug("Post processing failed or all events are skipped. (%d)\n", ret);
clear_probe_trace_events(*tevs, ntevs);
zfree(tevs);
ntevs = 0;
}
}
debuginfo__delete(dinfo);
if (ntevs == 0) { /* No error but failed to find probe point. */ char *probe_point = synthesize_perf_probe_point(&pev->point);
pr_warning("Probe point '%s' not found.\n", probe_point);
free(probe_point); return -ENODEV;
} elseif (ntevs < 0) { /* Error path : ntevs < 0 */
pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs); if (ntevs == -EBADF)
pr_warning("Warning: No dwarf info found in the vmlinux - " "please rebuild kernel with CONFIG_DEBUG_INFO=y.\n"); if (!need_dwarf) {
pr_debug("Trying to use symbols.\n"); return 0;
}
} return ntevs;
}
/* * Show line-range always requires debuginfo to find source file and * line number.
*/ staticint __show_line_range(struct line_range *lr, constchar *module, bool user)
{ int l = 1; struct int_node *ln; struct debuginfo *dinfo;
FILE *fp; int ret; char *tmp; char sbuf[STRERR_BUFSIZE]; char sbuild_id[SBUILD_ID_SIZE] = "";
/* Search a line range */
dinfo = open_debuginfo(module, NULL, false); if (!dinfo) return -ENOENT;
ret = debuginfo__find_line_range(dinfo, lr); if (!ret) { /* Not found, retry with an alternative */
pr_debug2("Failed to find line range in debuginfo. Fallback to alternative\n");
ret = get_alternative_line_range(dinfo, lr, module, user); if (!ret)
ret = debuginfo__find_line_range(dinfo, lr); else/* Ignore error, we just failed to find it. */
ret = -ENOENT;
} if (dinfo->build_id) { struct build_id bid;
fp = fopen(lr->path, "r"); if (fp == NULL) {
pr_warning("Failed to open %s: %s\n", lr->path,
str_error_r(errno, sbuf, sizeof(sbuf))); return -errno;
} /* Skip to starting line number */ while (l < lr->start) {
ret = skip_one_line(fp, l++); if (ret < 0) goto end;
}
intlist__for_each_entry(ln, lr->line_list) { for (; ln->i > (unsignedlong)l; l++) {
ret = show_one_line(fp, l - lr->offset); if (ret < 0) goto end;
}
ret = show_one_line_with_num(fp, l++ - lr->offset); if (ret < 0) goto end;
}
if (lr->end == INT_MAX)
lr->end = l + NR_ADDITIONAL_LINES; while (l <= lr->end) {
ret = show_one_line_or_eof(fp, l++ - lr->offset); if (ret <= 0) break;
}
end:
fclose(fp); return ret;
}
int show_line_range(struct line_range *lr, constchar *module, struct nsinfo *nsi, bool user)
{ int ret; struct nscookie nsc;
ret = init_probe_symbol_maps(user); if (ret < 0) return ret;
nsinfo__mountns_enter(nsi, &nsc);
ret = __show_line_range(lr, module, user);
nsinfo__mountns_exit(&nsc);
exit_probe_symbol_maps();
buf = synthesize_perf_probe_point(&pev->point); if (!buf) return -EINVAL;
pr_debug("Searching variables at %s\n", buf);
ret = debuginfo__find_available_vars_at(dinfo, pev, &vls); if (!ret) { /* Not found, retry with an alternative */
ret = get_alternative_probe_event(dinfo, pev, &tmp); if (!ret) {
ret = debuginfo__find_available_vars_at(dinfo, pev,
&vls); /* Release the old probe_point */
clear_perf_probe_point(&tmp);
}
} if (ret <= 0) { if (ret == 0 || ret == -ENOENT) {
pr_err("Failed to find the address of %s\n", buf);
ret = -ENOENT;
} else
pr_warning("Debuginfo analysis failed.\n"); goto end;
}
/* Some variables are found */
fprintf(stdout, "Available variables at %s\n", buf); for (i = 0; i < ret; i++) {
vl = &vls[i]; /* * A probe point might be converted to * several trace points.
*/
fprintf(stdout, "\t@<%s+%lu>\n", vl->point.symbol,
vl->point.offset);
zfree(&vl->point.symbol);
nvars = 0; if (vl->vars) {
strlist__for_each_entry(node, vl->vars) {
var = strchr(node->s, '\t') + 1; if (strfilter__compare(_filter, var)) {
fprintf(stdout, "\t\t%s\n", node->s);
nvars++;
}
}
strlist__delete(vl->vars);
} if (nvars == 0)
fprintf(stdout, "\t\t(No matched variables)\n");
}
free(vls);
end:
free(buf); return ret;
}
/* Show available variables on given probe point */ int show_available_vars(struct perf_probe_event *pevs, int npevs, struct strfilter *_filter)
{ int i, ret = 0; struct debuginfo *dinfo;
ret = init_probe_symbol_maps(pevs->uprobes); if (ret < 0) return ret;
dinfo = open_debuginfo(pevs->target, pevs->nsi, false); if (!dinfo) {
ret = -ENOENT; goto out;
}
setup_pager();
for (i = 0; i < npevs && ret >= 0; i++)
ret = show_available_vars_at(dinfo, &pevs[i], _filter);
errno = 0;
*val = strtol(*ptr, ptr, 0); if (errno || *ptr == start) {
semantic_error("'%s' is not a valid number.\n", what); return -EINVAL;
} return 0;
}
/* Check the name is good for event, group or function */ staticbool is_c_func_name(constchar *name)
{ if (!isalpha(*name) && *name != '_') returnfalse; while (*++name != '\0') { if (!isalpha(*name) && !isdigit(*name) && *name != '_') returnfalse;
} returntrue;
}
/* * Stuff 'lr' according to the line range described by 'arg'. * The line range syntax is described by: * * SRC[:SLN[+NUM|-ELN]] * FNC[@SRC][:SLN[+NUM|-ELN]] * * FNC@SRC accepts `FNC@*` which forcibly specify FNC as function name. * SRC and FUNC can be quoted by double/single quotes.
*/ int parse_line_range_desc(constchar *arg, struct line_range *lr)
{ char *buf = strdup(arg); char *p; int err = 0;
if (!buf) return -ENOMEM;
lr->start = 0;
lr->end = INT_MAX;
p = strpbrk_esq(buf, ":"); if (p) { if (p == buf) {
semantic_error("No file/function name in '%s'.\n", p);
err = -EINVAL; goto out;
}
*(p++) = '\0';
err = parse_line_num(&p, &lr->start, "start line"); if (err) goto out;
if (*p == '+' || *p == '-') { constchar c = *(p++);
err = parse_line_num(&p, &lr->end, "end line"); if (err) goto out;
if (c == '+') {
lr->end += lr->start; /* * Adjust the number of lines here. * If the number of lines == 1, the * end of line should be equal to * the start of line.
*/
lr->end--;
}
}
pr_debug("Line range is %d to %d\n", lr->start, lr->end);
err = -EINVAL; if (lr->start > lr->end) {
semantic_error("Start line must be smaller" " than end line.\n"); goto out;
} if (*p != '\0') {
semantic_error("Tailing with invalid str '%s'.\n", p); goto out;
}
}
p = strpbrk_esq(buf, "@"); if (p) {
*p++ = '\0'; if (strcmp(p, "*")) {
lr->file = strdup_esq(p); if (lr->file == NULL) {
err = -ENOMEM; goto out;
}
} if (*buf != '\0')
lr->function = strdup_esq(buf); if (!lr->function && !lr->file) {
semantic_error("Only '@*' is not allowed.\n");
err = -EINVAL; goto out;
}
} elseif (strpbrk_esq(buf, "/."))
lr->file = strdup_esq(buf); elseif (is_c_func_name(buf))/* We reuse it for checking funcname */
lr->function = strdup_esq(buf); else { /* Invalid name */
semantic_error("'%s' is not a valid function name.\n", buf);
err = -EINVAL; goto out;
}
pev->event = strdup_esq(*arg); if (pev->event == NULL) return -ENOMEM;
if (!pev->sdt && !is_c_func_name(pev->event)) {
zfree(&pev->event);
ng_name:
zfree(&pev->group);
semantic_error("%s is bad for event name -it must " "follow C symbol-naming rule.\n", *arg); return -EINVAL;
} return 0;
}
if (is_sdt_event(arg)) {
pev->sdt = true; if (arg[0] == '%')
arg++;
}
ptr = strpbrk_esq(arg, ";=@+%"); if (pev->sdt) { if (ptr) { if (*ptr != '@') {
semantic_error("%s must be an SDT name.\n",
arg); return -EINVAL;
} /* This must be a target file name or build id */
tmp = build_id_cache__complement(ptr + 1); if (tmp) {
pev->target = build_id_cache__origname(tmp);
free(tmp);
} else
pev->target = strdup_esq(ptr + 1); if (!pev->target) return -ENOMEM;
*ptr = '\0';
}
ret = parse_perf_probe_event_name(&arg, pev); if (ret == 0) { if (asprintf(&pev->point.function, "%%%s", pev->event) < 0)
ret = -errno;
} return ret;
}
if (ptr && *ptr == '=') { /* Event name */
*ptr = '\0';
tmp = ptr + 1;
ret = parse_perf_probe_event_name(&arg, pev); if (ret < 0) return ret;
arg = tmp;
}
/* * Check arg is function or file name and copy it. * * We consider arg to be a file spec if and only if it satisfies * all of the below criteria:: * - it does not include any of "+@%", * - it includes one of ":;", and * - it has a period '.' in the name. * * Otherwise, we consider arg to be a function specification.
*/ if (!strpbrk_esc(arg, "+@%")) {
ptr = strpbrk_esc(arg, ";:"); /* This is a file spec if it includes a '.' before ; or : */ if (ptr && memchr(arg, '.', ptr - arg))
file_spec = true;
}
if (arg[0] == '\0')
tmp = NULL; else {
tmp = strdup_esq(arg); if (tmp == NULL) return -ENOMEM;
}
if (file_spec)
pp->file = tmp; else {
pp->function = tmp;
/* * Keep pp->function even if this is absolute address, * so it can mark whether abs_address is valid. * Which make 'perf probe lib.bin 0x0' possible. * * Note that checking length of tmp is not needed * because when we access tmp[1] we know tmp[0] is '0', * so tmp[1] should always valid (but could be '\0').
*/ if (tmp && !strncmp(tmp, "0x", 2)) {
pp->abs_address = strtoull(pp->function, &tmp, 0); if (*tmp != '\0') {
semantic_error("Invalid absolute address.\n"); return -EINVAL;
}
}
}
/* Parse other options */ while (ptr) {
arg = ptr;
c = nc; if (c == ';') { /* Lazy pattern must be the last part */
pp->lazy_line = strdup(arg); /* let leave escapes */ if (pp->lazy_line == NULL) return -ENOMEM; break;
}
ptr = strpbrk_esq(arg, ";:+@%"); if (ptr) {
nc = *ptr;
*ptr++ = '\0';
} switch (c) { case':': /* Line number */
pp->line = strtoul(arg, &tmp, 0); if (*tmp != '\0') {
semantic_error("There is non-digit char" " in line number.\n"); return -EINVAL;
} break; case'+': /* Byte offset from a symbol */
pp->offset = strtoul(arg, &tmp, 0); if (*tmp != '\0') {
semantic_error("There is non-digit character" " in offset.\n"); return -EINVAL;
} break; case'@': /* File name */ if (pp->file) {
semantic_error("SRC@SRC is not allowed.\n"); return -EINVAL;
} if (!strcmp(arg, "*")) break;
pp->file = strdup_esq(arg); if (pp->file == NULL) return -ENOMEM; break; case'%': /* Probe places */ if (strcmp(arg, "return") == 0) {
pp->retprobe = 1;
} else { /* Others not supported yet */
semantic_error("%%%s is not supported.\n", arg); return -ENOTSUP;
} break; default: /* Buggy case */
pr_err("This program has a bug at %s:%d.\n",
__FILE__, __LINE__); return -ENOTSUP; break;
}
}
/* Exclusion check */ if (pp->lazy_line && pp->line) {
semantic_error("Lazy pattern can't be used with" " line number.\n"); return -EINVAL;
}
if (pp->lazy_line && pp->offset) {
semantic_error("Lazy pattern can't be used with offset.\n"); return -EINVAL;
}
if (pp->line && pp->offset) {
semantic_error("Offset can't be used with line number.\n"); return -EINVAL;
}
if (!pp->line && !pp->lazy_line && pp->file && !pp->function) {
semantic_error("File always requires line number or " "lazy pattern.\n"); return -EINVAL;
}
if (pp->offset && !pp->function) {
semantic_error("Offset requires an entry function.\n"); return -EINVAL;
}
if ((pp->offset || pp->line || pp->lazy_line) && pp->retprobe) {
semantic_error("Offset/Line/Lazy pattern can't be used with " "return probe.\n"); return -EINVAL;
}
tmp = strchr(str, '@'); if (tmp && tmp != str && !strcmp(tmp + 1, "user")) { /* user attr */ if (!user_access_is_supported()) {
semantic_error("ftrace does not support user access\n"); return -EINVAL;
}
*tmp = '\0';
arg->user_access = true;
pr_debug("user_access ");
}
tmp = strchr(str, ':'); if (tmp) { /* Type setting */
*tmp = '\0';
arg->type = strdup(tmp + 1); if (arg->type == NULL) return -ENOMEM;
pr_debug("type:%s ", arg->type);
}
tmp = strpbrk(str, "-.["); if (!is_c_varname(str) || !tmp) { /* A variable, register, symbol or special value */
arg->var = strdup(str); if (arg->var == NULL) return -ENOMEM;
pr_debug("%s\n", arg->var); return 0;
}
/* Structure fields or array element */
arg->var = strndup(str, tmp - str); if (arg->var == NULL) return -ENOMEM;
goodname = arg->var;
pr_debug("%s, ", arg->var);
fieldp = &arg->field;
/* If no name is specified, set the last field name (not array index)*/ if (!arg->name) {
arg->name = strdup(goodname); if (arg->name == NULL) return -ENOMEM;
} return 0;
}
/* Parse perf-probe event command */ int parse_perf_probe_command(constchar *cmd, struct perf_probe_event *pev)
{ char **argv; int argc, i, ret = 0;
argv = argv_split(cmd, &argc); if (!argv) {
pr_debug("Failed to split arguments.\n"); return -ENOMEM;
} if (argc - 1 > MAX_PROBE_ARGS) {
semantic_error("Too many probe arguments (%d).\n", argc - 1);
ret = -ERANGE; goto out;
} /* Parse probe point */
ret = parse_perf_probe_point(argv[0], pev); if (ret < 0) goto out;
/* Generate event name if needed */ if (!pev->event && pev->point.function && pev->point.line
&& !pev->point.lazy_line && !pev->point.offset) { if (asprintf(&pev->event, "%s_L%d", pev->point.function,
pev->point.line) < 0) {
ret = -ENOMEM; goto out;
}
}
/* Copy arguments and ensure return probe has no C argument */
pev->nargs = argc - 1;
pev->args = zalloc(sizeof(struct perf_probe_arg) * pev->nargs); if (pev->args == NULL) {
ret = -ENOMEM; goto out;
} for (i = 0; i < pev->nargs && ret >= 0; i++) {
ret = parse_perf_probe_arg(argv[i + 1], &pev->args[i]); if (ret >= 0 &&
is_c_varname(pev->args[i].var) && pev->point.retprobe) {
semantic_error("You can't specify local variable for" " kretprobe.\n");
ret = -EINVAL;
}
}
out:
argv_free(argv);
return ret;
}
/* Returns true if *any* ARG is either C variable, $params or $vars. */ bool perf_probe_with_var(struct perf_probe_event *pev)
{ int i = 0;
for (i = 0; i < pev->nargs; i++) if (is_c_varname(pev->args[i].var) ||
!strcmp(pev->args[i].var, PROBE_ARG_PARAMS) ||
!strcmp(pev->args[i].var, PROBE_ARG_VARS)) returntrue; returnfalse;
}
/* Return true if this perf_probe_event requires debuginfo */ bool perf_probe_event_need_dwarf(struct perf_probe_event *pev)
{ if (pev->point.file || pev->point.line || pev->point.lazy_line) returntrue;
if (perf_probe_with_var(pev)) returntrue;
returnfalse;
}
/* Parse probe_events event into struct probe_point */ int parse_probe_trace_command(constchar *cmd, struct probe_trace_event *tev)
{ struct probe_trace_point *tp = &tev->point; char pr; char *p; char *argv0_str = NULL, *fmt, *fmt1_str, *fmt2_str, *fmt3_str; int ret, i, argc; char **argv;
pr_debug("Parsing probe_events: %s\n", cmd);
argv = argv_split(cmd, &argc); if (!argv) {
pr_debug("Failed to split arguments.\n"); return -ENOMEM;
} if (argc < 2) {
semantic_error("Too few probe arguments.\n");
ret = -ERANGE; goto out;
}
/* Scan module name(if there), function name and offset */
p = strchr(argv[1], ':'); if (p) {
tp->module = strndup(argv[1], p - argv[1]); if (!tp->module) {
ret = -ENOMEM; goto out;
}
tev->uprobes = (tp->module[0] == '/');
p++;
} else
p = argv[1];
fmt1_str = strtok_r(p, "+", &fmt); /* only the address started with 0x */ if (fmt1_str[0] == '0') { /* * Fix a special case: * if address == 0, kernel reports something like: * p:probe_libc/abs_0 /lib/libc-2.18.so:0x (null) arg1=%ax * Newer kernel may fix that, but we want to * support old kernel also.
*/ if (strcmp(fmt1_str, "0x") == 0) { if (!argv[2] || strcmp(argv[2], "(null)")) {
ret = -EINVAL; goto out;
}
tp->address = 0;
free(argv[2]); for (i = 2; argv[i + 1] != NULL; i++)
argv[i] = argv[i + 1];
argv[i] = NULL;
argc -= 1;
} else
tp->address = strtoull(fmt1_str, NULL, 0);
} else { /* Only the symbol-based probe has offset */
tp->symbol = strdup(fmt1_str); if (tp->symbol == NULL) {
ret = -ENOMEM; goto out;
}
fmt2_str = strtok_r(NULL, "", &fmt); if (fmt2_str == NULL)
tp->offset = 0; else
tp->offset = strtoul(fmt2_str, NULL, 10);
}
if (tev->uprobes) {
fmt2_str = strchr(p, '('); if (fmt2_str)
tp->ref_ctr_offset = strtoul(fmt2_str + 1, NULL, 0);
}
tev->nargs = argc - 2;
tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs); if (tev->args == NULL) {
ret = -ENOMEM; goto out;
} for (i = 0; i < tev->nargs; i++) {
p = strchr(argv[i + 2], '='); if (p) /* We don't need which register is assigned. */
*p++ = '\0'; else
p = argv[i + 2];
tev->args[i].name = strdup(argv[i + 2]); /* TODO: parse regs and offset */
tev->args[i].value = strdup(p); if (tev->args[i].name == NULL || tev->args[i].value == NULL) {
ret = -ENOMEM; goto out;
}
}
ret = 0;
out:
free(argv0_str);
argv_free(argv); return ret;
}
/* Print argument type */ if (!err && arg->type)
err = strbuf_addf(buf, ":%s", arg->type);
return err;
}
staticint
synthesize_probe_trace_args(struct probe_trace_event *tev, struct strbuf *buf)
{ int i, ret = 0;
for (i = 0; i < tev->nargs && ret >= 0; i++)
ret = synthesize_probe_trace_arg(&tev->args[i], buf);
return ret;
}
staticint
synthesize_uprobe_trace_def(struct probe_trace_point *tp, struct strbuf *buf)
{ int err;
/* Uprobes must have tp->module */ if (!tp->module) return -EINVAL; /* * If tp->address == 0, then this point must be a * absolute address uprobe. * try_to_find_absolute_address() should have made * tp->symbol to "0x0".
*/ if (!tp->address && (!tp->symbol || strcmp(tp->symbol, "0x0"))) return -EINVAL;
/* Use the tp->address for uprobes */
err = strbuf_addf(buf, "%s:0x%" PRIx64, tp->module, tp->address);
ret = find_perf_probe_point_from_dwarf(tp, pp, is_kprobe); if (!ret) return 0;
ret = find_perf_probe_point_from_map(tp, pp, is_kprobe); if (!ret) return 0;
pr_debug("Failed to find probe point from both of dwarf and map.\n");
if (tp->symbol) {
pp->function = strdup(tp->symbol);
pp->offset = tp->offset;
} else {
ret = e_snprintf(buf, 128, "0x%" PRIx64, tp->address); if (ret < 0) return ret;
pp->function = strdup(buf);
pp->offset = 0;
} if (pp->function == NULL) return -ENOMEM;
pp->retprobe = tp->retprobe;
return 0;
}
staticint convert_to_perf_probe_event(struct probe_trace_event *tev, struct perf_probe_event *pev, bool is_kprobe)
{ struct strbuf buf = STRBUF_INIT; int i, ret;
for (i = 0; i < pev->nargs; i++) {
zfree(&pev->args[i].name);
zfree(&pev->args[i].var);
zfree(&pev->args[i].type);
field = pev->args[i].field; while (field) {
next = field->next;
zfree(&field->name);
free(field);
field = next;
}
}
pev->nargs = 0;
zfree(&pev->args);
}
staticint perf_probe_event__sprintf(constchar *group, constchar *event, struct perf_probe_event *pev, constchar *module, struct strbuf *result)
{ int i, ret; char *buf;
if (asprintf(&buf, "%s:%s", group, event) < 0) return -errno;
ret = strbuf_addf(result, " %-20s (on ", buf);
free(buf); if (ret) return ret;
/* Synthesize only event probe point */
buf = synthesize_perf_probe_point(&pev->point); if (!buf) return -ENOMEM;
ret = strbuf_addstr(result, buf);
free(buf);
if (!ret && module)
ret = strbuf_addf(result, " in %s", module);
if (!ret && pev->nargs > 0) {
ret = strbuf_add(result, " with", 5); for (i = 0; !ret && i < pev->nargs; i++) {
buf = synthesize_perf_probe_arg(&pev->args[i]); if (!buf) return -ENOMEM;
ret = strbuf_addf(result, " %s", buf);
free(buf);
}
} if (!ret)
ret = strbuf_addch(result, ')');
return ret;
}
/* Show an event */ int show_perf_probe_event(constchar *group, constchar *event, struct perf_probe_event *pev, constchar *module, bool use_stdout)
{ struct strbuf buf = STRBUF_INIT; int ret;
ret = perf_probe_event__sprintf(group, event, pev, module, &buf); if (ret >= 0) { if (use_stdout)
printf("%s\n", buf.buf); else
pr_info("%s\n", buf.buf);
}
strbuf_release(&buf);
/* At first, check the event name itself */ if (strfilter__compare(filter, tev->event)) returntrue;
/* Next, check the combination of name and group */ if (e_snprintf(tmp, 128, "%s:%s", tev->group, tev->event) < 0) returnfalse; return strfilter__compare(filter, tmp);
}
rawlist = probe_file__get_rawlist(fd); if (!rawlist) return -ENOMEM;
strlist__for_each_entry(ent, rawlist) {
ret = parse_probe_trace_command(ent->s, &tev); if (ret >= 0) { if (!filter_probe_trace_event(&tev, filter)) goto next;
ret = convert_to_perf_probe_event(&tev, &pev,
is_kprobe); if (ret < 0) goto next;
ret = show_perf_probe_event(pev.group, pev.event,
&pev, tev.point.module, true);
}
next:
clear_perf_probe_event(&pev);
clear_probe_trace_event(&tev); if (ret < 0) break;
}
strlist__delete(rawlist); /* Cleanup cached debuginfo if needed */
debuginfo_cache__exit();
return ret;
}
/* List up current perf-probe events */ int show_perf_probe_events(struct strfilter *filter)
{ int kp_fd, up_fd, ret;
setup_pager();
if (probe_conf.cache) return probe_cache__show_all_caches(filter);
ret = init_probe_symbol_maps(false); if (ret < 0) return ret;
ret = probe_file__open_both(&kp_fd, &up_fd, 0); if (ret < 0) return ret;
if (kp_fd >= 0)
ret = __show_perf_probe_events(kp_fd, true, filter); if (up_fd >= 0 && ret >= 0)
ret = __show_perf_probe_events(up_fd, false, filter); if (kp_fd > 0)
close(kp_fd); if (up_fd > 0)
close(up_fd);
exit_probe_symbol_maps();