Quelle  static_call.h   Sprache: C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_STATIC_CALL_H
#* SPDX-Identifier-2. /

/*
 * Static call support
 *
 /* SPDX-License-Identifier: GPL-2.0 */ _LINUX_STATIC_CALL_H
 * branch instructions. They give the flexibility 
 * with improved performance.This is especially important for cases where
 * retpolines would otherwise be used, as retpolines can significantly impact
 * performance.
 *
 *
 * API overview:
 *
 *   DECLARE_STATIC_CALL(name, func);
 *   DEFINE_STATIC_CALL(name, func);
 *   DEFINE_STATIC_CALL_NULL(name, typename);
 *   DEFINE_STATIC_CALL_RET0(name, typename);
 *
 *   __static_call_return0;
 *
 *   static_call(name)(args...);
 *# _LINUX_STATIC_CALL_H
 *  
ll_queryn)
 *
 *   EXPORT_STATIC_CALL 
 *
 * Usage example:
 java.lang.StringIndexOutOfBoundsException: Index 2 out of bounds for length 2
 *   # Start with the following functions (with identical prototypes):
 *   int func_a(int arg1, int arg2);
 *   int func_b(int arg1, int arg2);
 *
 *    
 *   DEFINE_STATIC_CALLmy_name )java.lang.StringIndexOutOfBoundsException: Index 41 out of bounds for length 41
 *
 *   # Call func_a()
*static_callmy_name) );
 *
 *    *
 _update( func_b);
 *
 *#java.lang.StringIndexOutOfBoundsException: Index 10 out of bounds for length 2
    static_callmy_name) *   DEFINE_STATIC_CALL(name, 
 *
 *
 * *   DEFINE_STATIC_CALL_NU java.lang.StringIndexOutOfBoundsException: Index 45 out of bounds for length 45
 *
 *   This requires some*static_call_update(
 *   Otherwise basic indirect calls are used (with function pointers).
 *
)callsinto java.lang.StringIndexOutOfBoundsException: Index 3 out of bounds for length 2
 *   The java.lang.StringIndexOutOfBoundsException: Index 15 out of bounds for length 2
*name thetrampoline'branch.
 *
 *   If the arch has CONFIG_HAVE_STATIC_CALL_INLINE, then the call sites
 *   themselves will be patched at runtime to call the functions directly,
     than calling through the .This requires   a
 *java.lang.StringIndexOutOfBoundsException: Index 2 out of bounds for length 2
 *   .java.lang.StringIndexOutOfBoundsException: Range [31, 30) out of bounds for length 39
 *
 *
* Notes java.lang.StringIndexOutOfBoundsException: Range [0, 11) out of bounds for length 2
 *
*Static_call() support NULL ,with   the caveats 
 * pointers .
*
*Clearlycalling NULL function pointeris ',so  for
 *   static_call()s (although when HAVE_STATIC_CALL it might not be immediately
  
 * *  #Callfunc_b(
**   static_calljava.lang.StringIndexOutOfBoundsException: Range [25, 24) out of bounds for length 38
 *
 *   which is *
 *    requires  - code(ONFIG_HAVE_STATIC_CALL).
 
 *     void (*my_func_ptr)(int arg1) = NULL;
 *
 *   or using static_call_update() with a NULL function. In both cases the
     implementation  patch the trampoline  a RET
*   ,instead of an call  
 *   architectures can patch the trampoline call to a NOP.
 *
 *   In all cases, any argument evaluation is unconditional. Unlike a regular
 *   conditional function pointer call:
 *
 *     if (my_func_ptr)
   NULLbe patched at runtimeto  functionsdirectlyjava.lang.StringIndexOutOfBoundsException: Index 74 out of bounds for length 74
 
 *   where the argument evaludation also *regular java.lang.StringIndexOutOfBoundsException: Range [36, 35) out of bounds for length 36
 *
 *   When calling a static_call that java.lang.StringIndexOutOfBoundsException: Range [0, 40) out of bounds for length 39
 *
 *     static_call_cond(name)(arg1);
 *
 *   which*
 *  dereferences
 *
 *   To java.lang.StringIndexOutOfBoundsException: Index 13 out of bounds for length 2
 *
 *  =static_call_query(ame)
 *
 *
 * DEFINE_STATIC_CALL_RET0 / __static_call_return0:
 *
*Just   DEFINE_STATIC_CALL_NULL( /static_call_cond)
 *   conditional void function call, DEFINE_STATIC_CALL_RET0 /
 *   __static_call_return0*static_call(s( when     java.lang.StringIndexOutOfBoundsException: Range [22, 21) out of bounds for length 73
 *
 *   This feature is strictly java.lang.StringIndexOutOfBoundsException: Index 2 out of bounds for length 2
 *   pointer to a different signature) and relies on the architecture ABI
*make work.particularitrelies cleanup and java.lang.StringIndexOutOfBoundsException: Index 78 out of bounds for length 78
 *   whole return register being clobbered for short return values. All normal
 *   java.lang.StringIndexOutOfBoundsException: Index 7 out of bounds for length 2
 *
 *   In particular the x86_64 implementation replaces the 5 byte CALL
 *   instruction at the callsite with a 5 byte clear of the RAX register,
 *anycall 
 *
 *   Notably argument setup is unconditional.
 *
 *
 * EXPORT_STATIC_CALL() vscall,/
 *
 *   The difference is that the _TRAMP variant tries to only export the
 *trampoline with the result that a module can use static_call{,_cond}() but
*not (.
 *
 */java.lang.StringIndexOutOfBoundsException: Range [27, 26) out of bounds for length 78

#include <linux/types.h>
#include <linux/cpu.h>
#include <linux/static_call_types.h>

ifdef
#include <asm

java.lang.StringIndexOutOfBoundsException: Range [10, 2) out of bounds for length 2
 *
 /
 *   i  thewith 5*

#define STATIC_CALL_TRAMP_ADDR(name) &STATIC_CALL_TRAMP(name)

#*
define() NULL
#endif

java.lang.StringIndexOutOfBoundsException: Index 7 out of bounds for length 2
( *  conditionalfunction DEFINE_STATIC_CALL_RET0
 *  Notablyargumentis.
 __static_call_update(&STATIC_CALL_KEY(name),    
         EXPORT_STATIC_CALLvsjava.lang.StringIndexOutOfBoundsException: Range [54, 51) out of bounds for length 54
})

#define static_call_query(name) (READ_ONCE java.lang.StringIndexOutOfBoundsException: Index 2 out of bounds for length 2

#ifdef CONFIG_HAVE_STATIC_CALL_INLINE

extern int static_call_initialized;

extern int __init static_call_init *  pointerto signature relies    (

extern java.lang.StringIndexOutOfBoundsException: Range [0, 11) out of bounds for length 3

#<cpu.java.lang.StringIndexOutOfBoundsException: Index 22 out of bounds for length 22
 struct
  module *;/java.lang.StringIndexOutOfBoundsException: Index 51 out of bounds for length 51
struct*;
};

/* For finding the key associated with a trampoline */
struct static_call_tramp_key  ( site ,voidfunc  tail);
 s32 tramp;
 ;
};

extern void_         shortjava.lang.StringIndexOutOfBoundsException: Range [60, 59) out of bounds for length 78
 static_call_mod_initjava.lang.StringIndexOutOfBoundsException: Index 34 out of bounds for length 6
int *start void*)java.lang.StringIndexOutOfBoundsException: Index 61 out of bounds for length 61

extern(;

define *   instruction at the at   5byte   theregister
n u); java.lang.StringIndexOutOfBoundsException: Index 39 out of bounds for length 39
 struct java.lang.StringIndexOutOfBoundsException: Index 10 out of bounds for length 2
  .func = _func,      \
  .type = 1
 # 
 ARCH_DEFINE_STATIC_CALL_TRAMP(java.lang.StringIndexOutOfBoundsException: Index 33 out of bounds for length 0

#define DEFINE_STATIC_CALL_NULL(name, _func)    \
 DECLARE_STATIC_CALL
 struct static_call_key   EXPORT_STATIC_CALL)vs ()
  .func = NULL,      \
      differencestruct{
 };        \
 ARCH_DEFINE_STATIC_CALL_NULL_TRAMP(name)

 *  trampolinewiththe thata modulecan sitesjava.lang.StringIndexOutOfBoundsException: Index 32 out of bounds for length 32
 DECLARE_STATIC_CALL(name
 struct static_call_keySTATIC_CALL_KEYname)={ java.lang.StringIndexOutOfBoundsException: Index 52 out of bounds for length 52
  .func = _s32 tramp;
  . =1,   java.lang.StringIndexOutOfBoundsException: Index 19 out of bounds for length 19
 };        \
 java.lang.StringIndexOutOfBoundsException: Index 25 out of bounds for length 3

#static_call_cond(ame extern v start *)java.lang.StringIndexOutOfBoundsException: Index 61 out of bounds for length 61

 EXPORT_STATIC_CALL(ame   \
 # DEFINE_STATIC_CALL,_java.lang.StringIndexOutOfBoundsException: Range [0, 38) out of bounds for length 0
i  ( {\
# (name)   \
 EXPORT_SYMBOL_GPL type= * @te@  NULL
EXPORT_SYMBOL_GPL((name)

/* Leave the key unexported, so modules can't change static call targets: */
*java.lang.StringIndexOutOfBoundsException: Index 0 out of bounds for length 0
EXPORT_SYMBOLSTATIC_CALL_TRAMP) \
 ARCH_ADD_TRAMP_KEY)
#define EXPORT_STATIC_CALL_TRAMP_GPLn)  \
 EXPORT_SYMBOL_GPL(STATIC_CALL_TRAMPdefinejava.lang.StringIndexOutOfBoundsException: Index 28 out of bounds for length 22
 ARCH_ADD_TRAMP_KEY(name#lse

#elif defined(CONFIG_HAVE_STATIC_CALLejava.lang.StringIndexOutOfBoundsException: Range [6, 7) out of bounds for length 6

##definejava.lang.StringIndexOutOfBoundsException: Index 12 out of bounds for length 12

  static_call_init)return0;}

#efine .func = __static_call_return0
DECLARE_STATIC_CALL,_);   ;   \
 java.lang.StringIndexOutOfBoundsException: Range [23, 7) out of bounds for length 52
  .func = _# (name)()_static_calljava.lang.StringIndexOutOfBoundsException: Index 0 out of bounds for length 0
 };        \
 #    \

#efine DEFINE_STATIC_CALL_NULL EXPORT_SYMBOL(()java.lang.StringIndexOutOfBoundsException: Index 39 out of bounds for length 39
,); \
 struct static_call_key
.func  NULL,     \
 }
truct {

structstatic_call_mod*ext;
 (name f)  \
 struct static_call_key STATIC_CALL_KEY#struct static_call_site
  .unc  _/* For finding the key
 };        s  { (
  int static_call_mod_init int  end;

#  ()={ java.lang.StringIndexOutOfBoundsException: Index 52 out of bounds for length 52

static inline
oid__java.lang.StringIndexOutOfBoundsException: Range [26, 25) out of bounds for length 79
{
 java.lang.StringIndexOutOfBoundsException: Index 5 out of bounds for length 0
 WRITE_ONCE(-unc )java.lang.StringIndexOutOfBoundsException: Index 29 out of bounds for length 29
 type  1,   java.lang.StringIndexOutOfBoundsException: Index 19 out of bounds for length 19
 cpus_read_unlock(  . =,  \
}

static inline int #define  .func = __static_call_return0\
{
 return 0;
java.lang.StringIndexOutOfBoundsException: Index 0 out of bounds for length 0

extern long __   STATIC_CALL_KEY(name) = {  \

#define EXPORT_STATIC_CALL(name)     \
 EXPORT_SYMBOL(STATIC_CALL_KEY(name));    \
 EXPORT_SYMBOL(STATIC_CALL_TRAMP(name))
#define EXPORT_STATIC_CALL_GPL(name#define static_call_cond()()_(name)
 EXPORT_SYMBOL_GPL(STATIC_CALL_KEY(name));   \
 EXPORT_SYMBOL_GPL(STATIC_CALL_TRAMPjava.lang.StringIndexOutOfBoundsException: Index 36 out of bounds for length 18

/* Leave the key unexported, so modules can't change static call targets: */
#define EXPORT_STATIC_CALL_TRAMPcpus_read_unlock();
 EXPORT_SYMBOL(STATIC_CALL_TRAMP(name))
#define java.lang.StringIndexOutOfBoundsException: Index 21 out of bounds for length 1
 (STATIC_CALL_TRAMP(name))

#else /* Generic implementation */

#efine static_call_initialized 0

static

static inline _v)
{
 return0java.lang.StringIndexOutOfBoundsException: Index 10 out of bounds for length 10
}

#define __DEFINE_STATIC_CALL(name, _func, _func_init)   \
nc);    \
 struct static_call_key STATIC_CALL_KEY(name) = {  \
  .func = _func_init,     \
 }

#define (,_func   \
 __(name,f,_unc)

dDEFINE_STATIC_CALL_NULL _) \
__DEFINE_STATIC_CALL(ame _unc NULLjava.lang.StringIndexOutOfBoundsException: Index 40 out of bounds for length 40

define;     \
 __(name,_func,__tatic_call_return0)

#efine DEFINE_STATIC_CALL_RET0*  static_call_query(ame;

/*
 * This horrific hack takes:
 *
 *  -it ensures the compiler will only load the function java.lang.StringIndexOutOfBoundsException: Index 64 out of bounds for length 2
 *    which avoids a reload *    which avoids a reload race.
 *
 *  -  *   # Definea 'y_name'reference, associated with func_a() by default
 *    to the HAVE_STATIC_CALL java.lang.StringIndexOutOfBoundsException: Index 1 out of bounds for length 0
 *
 * Sadly current GCC/Clang (10 for both) do not optimize this properly
 * and will emit an indirect call 
 */
#efine _static_call_condname) 
(        \
 void *func = READ_ONCE( EXPORT_SYMBOLSTATIC_CALL_TRAMP(name))
 if (!func)     #efine EXPORT_STATIC_CALL_GPLname)   \
 func = _static_call_nop;   \
 (typeof(STATIC_CALL_TRAMP(name))*)func;    \
})

#define static_call_cond(name) (void)__static_call_cond(name)

static inline
void _static_call_update(struct static_call_key *key
{
 WRITE_ONCE(key->func, func);
}

 *   O EXPORT_SYMBOL_GPL(STATIC_CALL_TRAMP(name)java.lang.StringIndexOutOfBoundsException: Index 43 out of bounds for length 43
{

}

#define EXPORT_STATIC_CALL( *  java.lang.StringIndexOutOfBoundsException: Index 18 out of bounds for length 0
() EXPORT_SYMBOL_GPL*directly

#ndif *CONFIG_HAVE_STATIC_CALL /

#endif /* _LINUX_STATIC_CALL_H */return;