include/rseq/rseq-x86-thread-pointer.h

   1 /* SPDX-License-Identifier: MIT */
   2 /* SPDX-FileCopyrightText: 2021 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> */
   3
   4 /*
   5  * rseq-x86-thread-pointer.h
   6  */
   7
   8 #ifndef _RSEQ_X86_THREAD_POINTER
   9 #define _RSEQ_X86_THREAD_POINTER
  10
  11 #include <features.h>
  12
  13 #ifdef __cplusplus
  14 extern "C" {
  15 #endif
  16
  17 #if __GNUC_PREREQ (11, 1)
  18 static inline void *rseq_thread_pointer(void)
  19 {
  20         return __builtin_thread_pointer();
  21 }
  22 #else
  23 static inline void *rseq_thread_pointer(void)
  24 {
  25         void *__result;
  26
  27 # ifdef __x86_64__
  28         __asm__ ("mov %%fs:0, %0" : "=r" (__result));
  29 # else
  30         __asm__ ("mov %%gs:0, %0" : "=r" (__result));
  31 # endif
  32         return __result;
  33 }
  34 #endif /* !GCC 11 */
  35
  36 #ifdef __cplusplus
  37 }
  38 #endif
  39
  40 #endif