libjava/include/dwarf2-signal.h

   1 // dwarf2-signal.h - Catch runtime signals and turn them into exceptions.
   2
   3 /* Copyright (C) 2000, 2001, 2009  Free Software Foundation
   4
   5    This file is part of libgcj.
   6
   7    Use this file for a target for which the dwarf2 unwinder in libgcc
   8    can unwind through signal handlers.
   9
  10 This software is copyrighted work licensed under the terms of the
  11 Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
  12 details.  */
  13
  14 #ifndef JAVA_SIGNAL_H
  15 #define JAVA_SIGNAL_H 1
  16
  17 #include <signal.h>
  18 #include <sys/syscall.h>
  19
  20 #define HANDLE_SEGV 1
  21 #undef HANDLE_FPE
  22
  23 #define SIGNAL_HANDLER(_name)   \
  24 static void _Jv_##_name (int, siginfo_t *_sip, void *_p)
  25
  26 class java::lang::Throwable;
  27
  28 // Unwind the stack to the point at which the signal was generated and
  29 // then throw an exception.  With the dwarf2 unwinder we don't usually
  30 // need to do anything, with some minor exceptions.
  31
  32 #ifdef __ia64__
  33
  34 #define MAKE_THROW_FRAME(_exception)                                    \
  35 do                                                                      \
  36 {                                                                       \
  37   /* IA-64 either leaves PC pointing at a faulting instruction or the   \
  38    following instruction, depending on the signal.  SEGV always does    \
  39    the former, so we adjust the saved PC to point to the following      \
  40    instruction; this is what the handler in libgcc expects.  */         \
  41   /* Note that we are lying to the unwinder here, which expects the     \
  42    faulting pc, not pc+1.  But we claim the unwind information can't    \
  43    be changed by such a ld or st instruction, so it doesn't matter. */  \
  44   struct sigcontext *_sc = (struct sigcontext *)_p;                     \
  45   _sc->sc_ip++;                                                         \
  46 }                                                                       \
  47 while (0)
  48
  49 #else
  50 #define MAKE_THROW_FRAME(_exception)            \
  51 do                                              \
  52 {                                               \
  53   (void)_p;                                     \
  54 }                                               \
  55 while (0)
  56 #endif
  57
  58 #if defined(__sparc__)
  59 #if defined(__arch64__)
  60 extern "C" {
  61     static void __rt_sigreturn_stub(void)
  62     {
  63       __asm__("mov %0, %%g1\n\t"
  64               "ta  0x6d\n\t"
  65               : /* no outputs */
  66               : "i" (__NR_rt_sigreturn));
  67     }
  68     struct kernel_sigaction
  69     {
  70       void (*k_sa_sigaction)(int,siginfo_t *,void *);
  71       unsigned long k_sa_flags;
  72       void (*k_sa_restorer)(void);
  73       sigset_t k_sa_mask;
  74     };
  75 }
  76 #define INIT_SEGV                                               \
  77 do                                                              \
  78   {                                                             \
  79     struct kernel_sigaction act;                                \
  80     unsigned long stub = ((unsigned long)&__rt_sigreturn_stub); \
  81     act.k_sa_sigaction = _Jv_catch_segv;                        \
  82     sigemptyset (&act.k_sa_mask);                               \
  83     act.k_sa_flags = SA_SIGINFO;                                \
  84     act.k_sa_restorer = NULL;                                   \
  85     syscall (SYS_rt_sigaction, SIGSEGV, &act, NULL,             \
  86              stub - 8, _NSIG / 8);                              \
  87   }                                                             \
  88 while (0)
  89
  90 #define INIT_FPE                                                \
  91 do                                                              \
  92   {                                                             \
  93     struct kernel_sigaction act;                                \
  94     unsigned long stub = ((unsigned long)&__rt_sigreturn_stub); \
  95     act.k_sa_sigaction = _Jv_catch_fpe;                         \
  96     sigemptyset (&act.k_sa_mask);                               \
  97     act.k_sa_flags = SA_SIGINFO;                                \
  98     act.k_sa_restorer = NULL;                                   \
  99     syscall (SYS_rt_sigaction, SIGFPE, &act, NULL,              \
 100              stub - 8, _NSIG / 8);                              \
 101   }                                                             \
 102 while (0)
 103 #else /* __arch64__ */
 104
 105 extern "C" {
 106     struct kernel_sigaction
 107     {
 108       void (*k_sa_sigaction)(int,siginfo_t *,void *);
 109       unsigned long k_sa_mask, k_sa_flags;
 110       void (*k_sa_restorer)(void);
 111     };
 112 }
 113
 114 #define INIT_SEGV                                               \
 115 do                                                              \
 116   {                                                             \
 117     struct kernel_sigaction act;                                \
 118     act.k_sa_sigaction = _Jv_catch_segv;                        \
 119     act.k_sa_mask = 0;                                          \
 120     act.k_sa_flags = SA_SIGINFO;                                \
 121     act.k_sa_restorer = NULL;                                   \
 122     syscall (SYS_sigaction, -SIGSEGV, &act, NULL);              \
 123   }                                                             \
 124 while (0)
 125
 126 #define INIT_FPE                                                \
 127 do                                                              \
 128   {                                                             \
 129     struct kernel_sigaction act;                                \
 130     act.k_sa_sigaction = _Jv_catch_fpe;                         \
 131     act.k_sa_mask = 0;                                          \
 132     act.k_sa_flags = SA_SIGINFO;                                \
 133     act.k_sa_restorer = NULL;                                   \
 134     syscall (SYS_sigaction, -SIGFPE, &act, NULL);               \
 135   }                                                             \
 136 while (0)
 137 #endif
 138 #elif !defined(__ia64__)
 139 #define INIT_SEGV                                               \
 140 do                                                              \
 141   {                                                             \
 142     struct sigaction act;                                       \
 143     act.sa_sigaction = _Jv_catch_segv;                          \
 144     sigemptyset (&act.sa_mask);                                 \
 145     act.sa_flags = SA_SIGINFO;                                  \
 146     syscall (SYS_sigaction, SIGSEGV, &act, NULL);               \
 147   }                                                             \
 148 while (0)
 149
 150 #define INIT_FPE                                                \
 151 do                                                              \
 152   {                                                             \
 153     struct sigaction act;                                       \
 154     act.sa_sigaction = _Jv_catch_fpe;                           \
 155     sigemptyset (&act.sa_mask);                                 \
 156     act.sa_flags = SA_SIGINFO;                                  \
 157     syscall (SYS_sigaction, SIGFPE, &act, NULL);                \
 158   }                                                             \
 159 while (0)
 160
 161 /* We use syscall(SYS_sigaction) in INIT_SEGV and INIT_FPE instead of
 162  * sigaction() because on some systems the pthreads wrappers for
 163  * signal handlers are not compiled with unwind information, so it's
 164  * not possible to unwind through them.  This is a problem that will
 165  * go away once all systems have pthreads libraries that are
 166  * compiled with full unwind info.  */
 167
 168 #else  /* __ia64__ */
 169
 170 // On IA64, unwind information is mandatory, so we can unwind
 171 // correctly through glibc frames.  Thus we call the ordinary
 172 // sigaction.
 173
 174 #define INIT_SEGV                                               \
 175 do                                                              \
 176   {                                                             \
 177     struct sigaction act;                                       \
 178     act.sa_sigaction = _Jv_catch_segv;                          \
 179     sigemptyset (&act.sa_mask);                                 \
 180     act.sa_flags = SA_SIGINFO;                                  \
 181     sigaction (SIGSEGV, &act, NULL);                            \
 182   }                                                             \
 183 while (0)
 184
 185 #define INIT_FPE                                                \
 186 do                                                              \
 187   {                                                             \
 188     struct sigaction act;                                       \
 189     act.sa_sigaction = _Jv_catch_fpe;                           \
 190     sigemptyset (&act.sa_mask);                                 \
 191     act.sa_flags = SA_SIGINFO;                                  \
 192     sigaction (SIGFPE, &act, NULL);                             \
 193   }                                                             \
 194 while (0)
 195 #endif /* __ia64__ || __sparc__ */
 196 #endif /* JAVA_SIGNAL_H */