libjava/include/powerpc-signal.h

   1 // powerpc-signal.h - Catch runtime signals and turn them into exceptions
   2 // on a powerpc based Linux system.
   3
   4 /* Copyright (C) 2003, 2006  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 #define HANDLE_SEGV 1
  20 #undef HANDLE_FPE
  21
  22 #define SIGNAL_HANDLER(_name)                                           \
  23   static void _name (int /* _signal */, struct sigcontext *_sc)
  24
  25 /* MD_FALLBACK_FRAME_STATE_FOR takes care of special casing PC
  26    before the faulting instruction, so we don't need to do anything
  27    here.  */
  28
  29 #define MAKE_THROW_FRAME(_exception)
  30
  31 /* For an explanation why we cannot simply use sigaction to
  32    install the handlers, see i386-signal.h.  */
  33
  34 /* We use kernel_old_sigaction here because we're calling the kernel
  35    directly rather than via glibc. The sigaction structure that the
  36    syscall uses is a different shape from the one in userland and not
  37    visible to us in a header file so we define it here.
  38    Additionally we want a proper prototype for the handler function
  39    with the struct sigcontext pointer passed by the kernel as the 2nd
  40    argument, which isn't there in userland headers.
  41
  42    Note that we explicitly avoid the SA_SIGINFO flag in INIT_SEGV and
  43    INIT_FPE below. Using the ucontext pointer passed as 3rd argument
  44    of a SA_SIGINFO type handler would need complicated backwards
  45    compatibility hacks in MAKE_THROW_FRAME, as the ucontext layout
  46    on PPC changed during the 2.5 kernel series.  */
  47
  48 #ifndef __powerpc64__
  49 struct kernel_old_sigaction {
  50   void (*k_sa_handler) (int, struct sigcontext *);
  51   unsigned long k_sa_mask;
  52   unsigned long k_sa_flags;
  53   void (*k_sa_restorer) (void);
  54 };
  55
  56 #define INIT_SEGV                                                       \
  57 do                                                                      \
  58   {                                                                     \
  59     struct kernel_old_sigaction kact;                                   \
  60     kact.k_sa_handler = catch_segv;                                     \
  61     kact.k_sa_mask = 0;                                                 \
  62     kact.k_sa_flags = 0;                                                \
  63     if (syscall (SYS_sigaction, SIGSEGV, &kact, NULL) != 0)             \
  64       __asm__ __volatile__ (".long 0");                                 \
  65   }                                                                     \
  66 while (0)
  67
  68 #define INIT_FPE                                                        \
  69 do                                                                      \
  70   {                                                                     \
  71     struct kernel_old_sigaction kact;                                   \
  72     kact.k_sa_handler = catch_fpe;                                      \
  73     kact.k_sa_mask = 0;                                                 \
  74     kact.k_sa_flags = 0;                                                \
  75     if (syscall (SYS_sigaction, SIGFPE, &kact, NULL) != 0)              \
  76       __asm__ __volatile__ (".long 0");                                 \
  77   }                                                                     \
  78 while (0)
  79
  80 #else /* powerpc64 */
  81
  82 struct kernel_sigaction
  83 {
  84   void (*k_sa_handler) (int, struct sigcontext *);
  85   unsigned long k_sa_flags;
  86   void (*k_sa_restorer)(void);
  87   unsigned long k_sa_mask;
  88 };
  89
  90 #define INIT_SEGV                                                       \
  91 do                                                                      \
  92   {                                                                     \
  93     struct kernel_sigaction kact;                                       \
  94     memset (&kact, 0, sizeof (kact));                                   \
  95     kact.k_sa_handler = catch_segv;                                     \
  96     if (syscall (SYS_rt_sigaction, SIGSEGV, &kact, NULL, 8) != 0)       \
  97       __asm__ __volatile__ (".long 0");                                 \
  98   }                                                                     \
  99 while (0)
 100
 101 #define INIT_FPE                                                        \
 102 do                                                                      \
 103   {                                                                     \
 104     struct kernel_sigaction kact;                                       \
 105     memset (&kact, 0, sizeof (kact));                                   \
 106     kact.k_sa_handler = catch_fpe;                                      \
 107     if (syscall (SYS_rt_sigaction, SIGFPE, &kact, NULL, 8) != 0)        \
 108       __asm__ __volatile__ (".long 0");                                 \
 109   }                                                                     \
 110 while (0)
 111 #endif
 112
 113 #endif /* JAVA_SIGNAL_H */