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 "runtime.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
  28 #ifdef LISP_FEATURE_WIN32
  29 # define REAL_SIGSET_SIZE_BYTES (4)
  30 #else
  31 # define REAL_SIGSET_SIZE_BYTES ((NSIG/8))
  32 #endif
  33
  34 static inline void
  35 sigcopyset(sigset_t *new, sigset_t *old)
  36 {
  37     memcpy(new, old, REAL_SIGSET_SIZE_BYTES);
  38 }
  39
  40 extern void get_current_sigmask(sigset_t *sigset);
  41
  42 /* Set all deferrable signals into *s. */
  43 extern void sigaddset_deferrable(sigset_t *s);
  44 /* Set all blockable signals into *s. */
  45 extern void sigaddset_blockable(sigset_t *s);
  46 /* Set all gc signals into *s. */
  47 extern void sigaddset_gc(sigset_t *s);
  48
  49 extern sigset_t deferrable_sigset;
  50 extern sigset_t blockable_sigset;
  51 extern sigset_t gc_sigset;
  52
  53 extern boolean deferrables_blocked_p(sigset_t *sigset);
  54 extern boolean blockables_blocked_p(sigset_t *sigset);
  55 extern boolean gc_signals_blocked_p(sigset_t *sigset);
  56
  57 extern void check_deferrables_blocked_or_lose(sigset_t *sigset);
  58 extern void check_blockables_blocked_or_lose(sigset_t *sigset);
  59 extern void check_gc_signals_blocked_or_lose(sigset_t *sigset);
  60
  61 extern void check_deferrables_unblocked_or_lose(sigset_t *sigset);
  62 extern void check_blockables_unblocked_or_lose(sigset_t *sigset);
  63 extern void check_gc_signals_unblocked_or_lose(sigset_t *sigset);
  64
  65 extern void block_deferrable_signals(sigset_t *where, sigset_t *old);
  66 extern void block_blockable_signals(sigset_t *where, sigset_t *old);
  67 extern void block_gc_signals(sigset_t *where, sigset_t *old);
  68
  69 extern void unblock_deferrable_signals(sigset_t *where, sigset_t *old);
  70 extern void unblock_blockable_signals(sigset_t *where, sigset_t *old);
  71 extern void unblock_gc_signals(sigset_t *where, sigset_t *old);
  72
  73 extern void maybe_save_gc_mask_and_block_deferrables(sigset_t *sigset);
  74
  75 /* maximum signal nesting depth
  76  *
  77  * FIXME: In CMUCL this was 4096, and it was first scaled down to 256
  78  * and then 32, until finally Stumpwm broke: it is possible to receive
  79  * interrupts in sufficiently quick succession that handler nesting
  80  * can become preposterous. Scaling this back up to 1024 is a bandaid:
  81  * for a real fix we should consider the following things:
  82  *
  83  *   We should almost certainly always use
  84  *   arrange_return_to_lisp_function, though it needs to be thought
  85  *   about arguments, and it needs to be able to pass a frobbable
  86  *   context to the callee...
  87  *
  88  *   There are cases when nesting handlers is exactly what we want:
  89  *   eg. SIGINT.
  90  *
  91  *   There are cases when we probably want to drop duplicate signals
  92  *   on the floor if they arrive before the previous one has been handled.
  93  *   Eg. SIGPROF.
  94  *
  95  *   There are cases when we probably want to handle duplicate signals
  96  *   after the previous handler has returned, not before. Eg. SIGALARM.
  97  *
  98  * -- NS 2007-01-29
  99  */
 100 /* No longer defined here, but in 'compiler/generic/parms.lisp' due to
 101    requirement that Lisp skip this many words when assigning thread-local
 102    storage indices */
 103 // #define MAX_INTERRUPTS 1024
 104
 105 union interrupt_handler {
 106     lispobj lisp;
 107     void (*c)(int, siginfo_t*, os_context_t*);
 108 };
 109
 110 extern union interrupt_handler interrupt_handlers[NSIG];
 111
 112 struct interrupt_data {
 113     /* signal information for pending signal.  pending_signal=0 when there
 114      * is no pending signal. */
 115     void (*pending_handler) (int, siginfo_t*, os_context_t*) ;
 116     int pending_signal;
 117     siginfo_t pending_info;
 118     sigset_t pending_mask;
 119     /* Was pending mask saved for gc request? True if GC_PENDING or
 120      * SIG_STOP_FOR_GC happened in a pseudo atomic with GC_INHIBIT NIL
 121      * and with no pending handler. Both deferrable interrupt handlers
 122      * and gc are careful not to clobber each other's pending_mask. */
 123     boolean gc_blocked_deferrables;
 124 #ifdef GENCGC_IS_PRECISE
 125     /* On PPC when consing wants to turn to alloc(), it does so via a
 126      * trap. When alloc() wants to save the sigmask it consults
 127      * allocation_trap_context. It does not look up the most recent
 128      * context, because alloc() can be called from other places
 129      * too. */
 130     os_context_t *allocation_trap_context;
 131 #endif
 132 };
 133
 134 typedef lispobj (*call_into_lisp_lookalike)(
 135     lispobj fun, lispobj *args, int nargs);
 136
 137 extern boolean interrupt_handler_pending_p(void);
 138 extern void interrupt_init(void);
 139 extern void fake_foreign_function_call(os_context_t* context);
 140 extern void undo_fake_foreign_function_call(os_context_t* context);
 141 extern void arrange_return_to_c_function(
 142     os_context_t *, call_into_lisp_lookalike, lispobj);
 143 extern void arrange_return_to_lisp_function(os_context_t *, lispobj);
 144 extern void interrupt_handle_now(int, siginfo_t*, os_context_t*);
 145 extern void interrupt_handle_pending(os_context_t*);
 146 extern void interrupt_internal_error(os_context_t*, boolean continuable);
 147 extern boolean handle_guard_page_triggered(os_context_t *,os_vm_address_t);
 148 extern boolean maybe_defer_handler(void *handler, struct interrupt_data *data,
 149                                    int signal, siginfo_t *info,
 150                                    os_context_t *context);
 151 #if defined LISP_FEATURE_GENCGC
 152 /* assembly language stub that executes trap_PendingInterrupt */
 153 extern void do_pending_interrupt(void);
 154 #endif
 155
 156 #ifdef LISP_FEATURE_SB_THREAD
 157 extern void sig_stop_for_gc_handler(int, siginfo_t*, os_context_t*);
 158 #endif
 159 typedef void (*interrupt_handler_t)(int, siginfo_t *, os_context_t *);
 160 extern void undoably_install_low_level_interrupt_handler (
 161                         int signal,
 162                         interrupt_handler_t handler);
 163 extern uword_t install_handler(int signal,
 164                                interrupt_handler_t handler,
 165                                int synchronous);
 166
 167 extern union interrupt_handler interrupt_handlers[NSIG];
 168
 169 /* The void* casting here avoids having to mess with the various types
 170  * of function argument lists possible for signal handlers:
 171  * SA_SIGACTION handlers have one signature, and the default old-style
 172  * signal(..) handlers have another, and attempting to represent them
 173  * "cleanly" with union types is in fact a mess. */
 174 #define ARE_SAME_HANDLER(x, y) ((void*)(x) == (void*)(y))
 175
 176 extern void handle_trap(os_context_t *context, int trap);
 177
 178 #ifndef LISP_FEATURE_WIN32
 179 extern void lisp_memory_fault_error(os_context_t *context,
 180                                     os_vm_address_t addr);
 181 #endif
 182
 183 #include "thread.h"
 184
 185 extern void lower_thread_control_stack_guard_page(struct thread *th);
 186 extern void reset_thread_control_stack_guard_page(struct thread *th);
 187
 188 #if defined(LISP_FEATURE_SB_SAFEPOINT) && !defined(LISP_FEATURE_WIN32)
 189 # ifdef LISP_FEATURE_SB_THRUPTION
 190 void thruption_handler(int signal, siginfo_t *info, os_context_t *context);
 191 # endif
 192 #endif
 193
 194 #endif