2 * This software is part of the SBCL system. See the README file for
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.
12 #if !defined(_INCLUDE_INTERRUPT_H_)
13 #define _INCLUDE_INTERRUPT_H_
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))
29 /* Set all deferrable signals into *s. */
30 extern void sigaddset_deferrable(sigset_t *s);
31 /* Set all blockable signals into *s. */
32 extern void sigaddset_blockable(sigset_t *s);
33 /* Set all gc signals into *s. */
34 extern void sigaddset_gc(sigset_t *s);
36 extern sigset_t deferrable_sigset;
37 extern sigset_t blockable_sigset;
38 extern sigset_t gc_sigset;
40 extern void block_deferrable_signals(void);
41 extern void block_blockable_signals(void);
42 extern void unblock_deferrable_signals(void);
43 extern void unblock_gc_signals(void);
44 extern void unblock_signals_in_context_and_maybe_warn(os_context_t *context);
46 extern boolean deferrables_blocked_in_sigset_p(sigset_t *sigset);
47 extern void check_deferrables_blocked_or_lose(void);
48 extern void check_blockables_blocked_or_lose(void);
49 extern void check_gc_signals_unblocked_or_lose(void);
50 extern void check_gc_signals_unblocked_in_sigset_or_lose(sigset_t *sigset);
52 extern void maybe_save_gc_mask_and_block_deferrables(sigset_t *sigset);
55 sigcopyset(sigset_t *new, sigset_t *old)
57 memcpy(new, old, REAL_SIGSET_SIZE_BYTES);
60 /* maximum signal nesting depth
62 * FIXME: In CMUCL this was 4096, and it was first scaled down to 256
63 * and then 32, until finally Stumpwm broke: it is possible to receive
64 * interrupts in sufficiently quick succession that handler nesting
65 * can become preposterous. Scaling this back up to 1024 is a bandaid:
66 * for a real fix we should consider the following things:
68 * We should almost certainly always use
69 * arrange_return_to_lisp_function, though it needs to be thought
70 * about arguments, and it needs to be able to pass a frobbable
71 * context to the callee...
73 * There are cases when nesting handlers is exactly what we want:
76 * There are cases when we probably want to drop duplicate signals
77 * on the floor if they arrive before the previous one has been handled.
80 * There are cases when we probably want to handle duplicate signals
81 * after the previous handler has returned, not before. Eg. SIGALARM.
85 #define MAX_INTERRUPTS 1024
87 union interrupt_handler {
89 void (*c)(int, siginfo_t*, os_context_t*);
92 extern union interrupt_handler interrupt_handlers[NSIG];
94 struct interrupt_data {
95 /* signal information for pending signal. pending_signal=0 when there
96 * is no pending signal. */
97 void (*pending_handler) (int, siginfo_t*, os_context_t*) ;
99 siginfo_t pending_info;
100 sigset_t pending_mask;
101 /* Was pending mask saved for gc request? True if GC_PENDING or
102 * SIG_STOP_FOR_GC happened in a pseudo atomic with no GC_INHIBIT
103 * NIL. Both deferrable interrupt handlers and gc are careful not
104 * to clobber each other's pending_mask. */
105 boolean gc_blocked_deferrables;
108 extern boolean interrupt_handler_pending_p(void);
109 extern void interrupt_init(void);
110 extern void fake_foreign_function_call(os_context_t* context);
111 extern void undo_fake_foreign_function_call(os_context_t* context);
112 extern void arrange_return_to_lisp_function(os_context_t *, lispobj);
113 extern void interrupt_handle_now(int, siginfo_t*, os_context_t*);
114 extern void interrupt_handle_pending(os_context_t*);
115 extern void interrupt_internal_error(os_context_t*, boolean continuable);
116 extern boolean handle_guard_page_triggered(os_context_t *,os_vm_address_t);
117 extern boolean maybe_defer_handler(void *handler, struct interrupt_data *data,
118 int signal, siginfo_t *info,
119 os_context_t *context);
120 #if defined LISP_FEATURE_GENCGC
121 /* assembly language stub that executes trap_PendingInterrupt */
122 extern void do_pending_interrupt(void);
125 #ifdef LISP_FEATURE_SB_THREAD
126 extern void sig_stop_for_gc_handler(int, siginfo_t*, os_context_t*);
128 typedef void (*interrupt_handler_t)(int, siginfo_t *, os_context_t *);
129 extern void undoably_install_low_level_interrupt_handler (
131 interrupt_handler_t handler);
132 extern unsigned long install_handler(int signal,
133 interrupt_handler_t handler);
135 extern union interrupt_handler interrupt_handlers[NSIG];
137 /* The void* casting here avoids having to mess with the various types
138 * of function argument lists possible for signal handlers:
139 * SA_SIGACTION handlers have one signature, and the default old-style
140 * signal(..) handlers have another, and attempting to represent them
141 * "cleanly" with union types is in fact a mess. */
142 #define ARE_SAME_HANDLER(x, y) ((void*)(x) == (void*)(y))
144 extern void handle_trap(os_context_t *context, int trap);
146 #ifndef LISP_FEATURE_WIN32
147 extern void lisp_memory_fault_error(os_context_t *context,
148 os_vm_address_t addr);