linux-user/host/x86_64/hostdep.h

   1 /*
   2  * hostdep.h : things which are dependent on the host architecture
   3  *
   4  *  * Written by Peter Maydell <peter.maydell@linaro.org>
   5  *
   6  * Copyright (C) 2016 Linaro Limited
   7  *
   8  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   9  * See the COPYING file in the top-level directory.
  10  */
  11
  12 #ifndef X86_64_HOSTDEP_H
  13 #define X86_64_HOSTDEP_H
  14
  15 /* We have a safe-syscall.inc.S */
  16 #define HAVE_SAFE_SYSCALL
  17
  18 #ifndef __ASSEMBLER__
  19
  20 /* These are defined by the safe-syscall.inc.S file */
  21 extern char safe_syscall_start[];
  22 extern char safe_syscall_end[];
  23
  24 /* Adjust the signal context to rewind out of safe-syscall if we're in it */
  25 static inline void rewind_if_in_safe_syscall(void *puc)
  26 {
  27     ucontext_t *uc = puc;
  28     greg_t *pcreg = &uc->uc_mcontext.gregs[REG_RIP];
  29
  30     if (*pcreg > (uintptr_t)safe_syscall_start
  31         && *pcreg < (uintptr_t)safe_syscall_end) {
  32         *pcreg = (uintptr_t)safe_syscall_start;
  33     }
  34 }
  35
  36 #endif /* __ASSEMBLER__ */
  37
  38 #endif