libjava/include/x86_64-signal.h

   1 // x86_64-signal.h - Catch runtime signals and turn them into exceptions
   2 // on an x86_64 based GNU/Linux system.
   3
   4 /* Copyright (C) 2003  Free Software Foundation
   5
   6    This file is part of libgcj.
   7
   8 This software is copyrighted work licensed under the terms of the
   9 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
  10 details.  */
  11
  12
  13 #ifndef JAVA_SIGNAL_H
  14 #define JAVA_SIGNAL_H 1
  15
  16 #include <signal.h>
  17 #include <sys/syscall.h>
  18
  19 #ifdef __x86_64__
  20
  21 #define HANDLE_SEGV 1
  22
  23 #define SIGNAL_HANDLER(_name)   \
  24 static void _Jv_##_name (int, siginfo_t *_sip, void *_p)
  25
  26 extern "C"
  27 {
  28   struct kernel_sigaction
  29   {
  30     void (*k_sa_sigaction)(int,siginfo_t *,void *);
  31     unsigned long k_sa_flags;
  32     void (*k_sa_restorer) (void);
  33     sigset_t k_sa_mask;
  34   };
  35 }
  36
  37 #define MAKE_THROW_FRAME(_exception)                                    \
  38 do                                                                      \
  39 {                                                                       \
  40   /* Advance the program counter so that it is after the start of the   \
  41      instruction:  the x86_64 exception handler expects                 \
  42      the PC to point to the instruction after a call. */                \
  43   struct ucontext *_uc = (struct ucontext *)_p;                         \
  44   struct sigcontext *_sc = (struct sigcontext *) &_uc->uc_mcontext;     \
  45   _sc->rip += 2;                                                        \
  46 }                                                                       \
  47 while (0)
  48
  49 #define RESTORE(name, syscall) RESTORE2 (name, syscall)
  50 #define RESTORE2(name, syscall)                 \
  51 asm                                             \
  52   (                                             \
  53    ".byte 0  # Yes, this really is necessary\n" \
  54    ".align 16\n"                                \
  55    "__" #name ":\n"                             \
  56    "    movq $" #syscall ", %rax\n"             \
  57    "    syscall\n"                              \
  58    );
  59
  60 /* The return code for realtime-signals.  */
  61 RESTORE (restore_rt, __NR_rt_sigreturn)
  62 static void restore_rt (void) asm ("__restore_rt");
  63
  64 #define INIT_SEGV                                               \
  65 do                                                              \
  66   {                                                             \
  67     nullp = new java::lang::NullPointerException ();            \
  68     struct kernel_sigaction act;                                \
  69     act.k_sa_sigaction = _Jv_catch_segv;                        \
  70     sigemptyset (&act.k_sa_mask);                               \
  71     act.k_sa_flags = SA_SIGINFO|0x4000000;                      \
  72     act.k_sa_restorer = restore_rt;                             \
  73     syscall (SYS_rt_sigaction, SIGSEGV, &act, NULL, _NSIG / 8); \
  74   }                                                             \
  75 while (0)
  76
  77 /* We use syscall(SYS_rt_sigaction) in INIT_SEGV instead of
  78  * sigaction() because on some systems the pthreads wrappers for
  79  * signal handlers are not compiled with unwind information, so it's
  80  * not possible to unwind through them.  This is a problem that will
  81  * go away if all systems ever have pthreads libraries that are
  82  * compiled with unwind info.  */
  83
  84 #else /* __x86_64__ */
  85
  86 /* This is for the 32-bit subsystem on on x86-64.  Catching signals
  87    doesn't yet work on that target.  */
  88
  89 #undef HANDLE_SEGV
  90 #undef HANDLE_FPE
  91
  92 #define INIT_SEGV   do {} while (0)
  93 #define INIT_FPE   do {} while (0)
  94
  95 #endif /* __x86_64__ */
  96 #endif /* JAVA_SIGNAL_H */