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 #include <string.h>
  17
  18 /*
  19  * This is a workaround for some slightly silly Linux/GNU Libc
  20  * behaviour: glibc defines sigset_t to support 1024 signals, which is
  21  * more than the kernel.  This is usually not a problem, but becomes
  22  * one when we want to save a signal mask from a ucontext, and restore
  23  * it later into another ucontext: the ucontext is allocated on the
  24  * stack by the kernel, so copying a libc-sized sigset_t into it will
  25  * overflow and cause other data on the stack to be corrupted */
  26 /* FIXME: do not rely on NSIG being a multiple of 8 */
  27 #define REAL_SIGSET_SIZE_BYTES ((NSIG/8))
  28
  29 extern void check_blockables_blocked_or_lose();
  30 extern void check_gc_signals_unblocked_or_lose();
  31 extern void unblock_gc_signals();
  32
  33 static inline void
  34 sigcopyset(sigset_t *new, sigset_t *old)
  35 {
  36     memcpy(new, old, REAL_SIGSET_SIZE_BYTES);
  37 }
  38
  39 /* maximum signal nesting depth
  40  *
  41  * Note: In CMU CL, this was 4096, but there was no explanation given,
  42  * and it's hard to see why we'd need that many nested interrupts, so
  43  * I've scaled it back (to 256) to see what happens. -- WHN 20000730
  44
  45  * Nothing happened, so let's creep it back a bit further -- dan 20030411 */
  46 #define MAX_INTERRUPTS 32
  47
  48 union interrupt_handler {
  49     lispobj lisp;
  50     void (*c)(int, siginfo_t*, void*);
  51 };
  52
  53 extern union interrupt_handler interrupt_handlers[NSIG];
  54
  55 struct interrupt_data {
  56     /* signal information for pending signal.  pending_signal=0 when there
  57      * is no pending signal. */
  58     void (*pending_handler) (int, siginfo_t*, void*) ;
  59     int pending_signal;
  60     siginfo_t pending_info;
  61     sigset_t pending_mask;
  62 };
  63
  64
  65 extern void interrupt_init();
  66 extern void fake_foreign_function_call(os_context_t* context);
  67 extern void undo_fake_foreign_function_call(os_context_t* context);
  68 extern void arrange_return_to_lisp_function(os_context_t *, lispobj);
  69 extern void interrupt_handle_now(int, siginfo_t*, os_context_t*);
  70 extern void interrupt_handle_pending(os_context_t*);
  71 extern void interrupt_internal_error(os_context_t*, boolean continuable);
  72 extern boolean handle_guard_page_triggered(os_context_t *,os_vm_address_t);
  73 extern boolean maybe_defer_handler(void *handler, struct interrupt_data *data,
  74                                    int signal, siginfo_t *info,
  75                                    os_context_t *context);
  76 #if defined LISP_FEATURE_GENCGC
  77 /* assembly language stub that executes trap_PendingInterrupt */
  78 extern void do_pending_interrupt(void);
  79 #endif
  80
  81 #ifdef LISP_FEATURE_SB_THREAD
  82 extern void interrupt_thread_handler(int, siginfo_t*, void*);
  83 extern void sig_stop_for_gc_handler(int, siginfo_t*, void*);
  84 #endif
  85 typedef void (*interrupt_handler_t)(int, siginfo_t *, void *);
  86 extern void undoably_install_low_level_interrupt_handler (
  87                         int signal,
  88                         interrupt_handler_t handler);
  89 extern unsigned long install_handler(int signal,
  90                                      interrupt_handler_t handler);
  91
  92 extern union interrupt_handler interrupt_handlers[NSIG];
  93
  94 /* Set all deferrable signals into *s. */
  95 extern void sigaddset_deferrable(sigset_t *s);
  96 /* Set all blockable signals into *s. */
  97 extern void sigaddset_blockable(sigset_t *s);
  98
  99 extern void block_blockable_signals();
 100
 101 /* The void* casting here avoids having to mess with the various types
 102  * of function argument lists possible for signal handlers:
 103  * SA_SIGACTION handlers have one signature, and the default old-style
 104  * signal(..) handlers have another, and attempting to represent them
 105  * "cleanly" with union types is in fact a mess. */
 106 #define ARE_SAME_HANDLER(x, y) ((void*)(x) == (void*)(y))
 107
 108 extern void handle_trap(os_context_t *context, int trap);
 109
 110 #ifndef LISP_FEATURE_WIN32
 111 extern void lisp_memory_fault_error(os_context_t *context, os_vm_address_t addr);
 112 #endif
 113
 114 #endif