src/runtime/interrupt.h

   1 /*
   2  * This software is part of the SBCL system. See the README file for
   3  * more information.
   4  *
   5  * This software is derived from the CMU CL system, which was
   6  * written at Carnegie Mellon University and released into the
   7  * public domain. The software is in the public domain and is
   8  * provided with absolutely no warranty. See the COPYING and CREDITS
   9  * files for more information.
  10  */
  11
  12 #if !defined(_INCLUDE_INTERRUPT_H_)
  13 #define _INCLUDE_INTERRUPT_H_
  14
  15 #include <signal.h>
  16
  17 /*
  18  * This is a workaround for some slightly silly Linux/GNU Libc
  19  * behaviour: glibc defines sigset_t to support 1024 signals, which is
  20  * more than the kernel.  This is usually not a problem, but becomes
  21  * one when we want to save a signal mask from a ucontext, and restore
  22  * it later into another ucontext: the ucontext is allocated on the
  23  * stack by the kernel, so copying a libc-sized sigset_t into it will
  24  * overflow and cause other data on the stack to be corrupted */
  25 /* FIXME: do not rely on NSIG being a multiple of 8 */
  26 #define REAL_SIGSET_SIZE_BYTES ((NSIG/8))
  27
  28 static inline void
  29 sigcopyset(sigset_t *new, sigset_t *old)
  30 {
  31     memcpy(new, old, REAL_SIGSET_SIZE_BYTES);
  32 }
  33
  34 /* maximum signal nesting depth
  35  *
  36  * Note: In CMU CL, this was 4096, but there was no explanation given,
  37  * and it's hard to see why we'd need that many nested interrupts, so
  38  * I've scaled it back (to 256) to see what happens. -- WHN 20000730
  39
  40  * Nothing happened, so let's creep it back a bit further -- dan 20030411 */
  41 #define MAX_INTERRUPTS 32
  42
  43 union interrupt_handler {
  44     lispobj lisp;
  45     void (*c)(int, siginfo_t*, void*);
  46 };
  47
  48 struct interrupt_data {
  49     void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*) ;
  50     union interrupt_handler interrupt_handlers[NSIG];
  51
  52     /* signal information for pending signal.  pending_signal=0 when there
  53      * is no pending signal. */
  54     void (*pending_handler) (int, siginfo_t*, void*) ;
  55     int pending_signal;
  56     siginfo_t pending_info;
  57     sigset_t pending_mask;
  58 };
  59
  60
  61 extern void interrupt_init();
  62 extern void fake_foreign_function_call(os_context_t* context);
  63 extern void undo_fake_foreign_function_call(os_context_t* context);
  64 extern void arrange_return_to_lisp_function(os_context_t *, lispobj);
  65 extern void interrupt_handle_now(int, siginfo_t*, void*);
  66 extern void interrupt_handle_pending(os_context_t*);
  67 extern void interrupt_internal_error(int, siginfo_t*, os_context_t*,
  68                                      boolean continuable);
  69 extern boolean handle_guard_page_triggered(os_context_t *,os_vm_address_t);
  70 extern boolean interrupt_maybe_gc(int, siginfo_t*, void*);
  71 extern boolean interrupt_maybe_gc_int(int, siginfo_t *, void *);
  72 extern boolean maybe_defer_handler(void *handler, struct interrupt_data *data,
  73                                    int signal, siginfo_t *info,
  74                                    os_context_t *context);
  75 #if defined LISP_FEATURE_GENCGC
  76 /* assembly language stub that executes trap_PendingInterrupt */
  77 extern void do_pending_interrupt(void);
  78 #endif
  79
  80 #ifdef LISP_FEATURE_SB_THREAD
  81 extern void interrupt_thread_handler(int, siginfo_t*, void*);
  82 extern void sig_stop_for_gc_handler(int, siginfo_t*, void*);
  83 #endif
  84 extern void undoably_install_low_level_interrupt_handler (int signal,
  85                                                           void
  86                                                           handler(int,
  87                                                                   siginfo_t*,
  88                                                                   void*));
  89 extern unsigned long install_handler(int signal,
  90                                      void handler(int, siginfo_t*, void*));
  91
  92 extern union interrupt_handler interrupt_handlers[NSIG];
  93
  94 /* Set all deferrable signals into *s. */
  95 void sigaddset_deferrable(sigset_t *s);
  96 /* Set all blockable signals into *s. */
  97 void sigaddset_blockable(sigset_t *s);
  98
  99 /* The void* casting here avoids having to mess with the various types
 100  * of function argument lists possible for signal handlers:
 101  * SA_SIGACTION handlers have one signature, and the default old-style
 102  * signal(..) handlers have another, and attempting to represent them
 103  * "cleanly" with union types is in fact a mess. */
 104 #define ARE_SAME_HANDLER(x, y) ((void*)(x) == (void*)(y))
 105
 106 #endif