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 extern sigset_t deferrable_sigset;
30 extern sigset_t blockable_sigset;
32 extern void check_deferrables_blocked_or_lose(void);
33 extern void check_blockables_blocked_or_lose(void);
34 extern void check_gc_signals_unblocked_or_lose(void);
35 extern void unblock_gc_signals(void);
38 sigcopyset(sigset_t *new, sigset_t *old)
40 memcpy(new, old, REAL_SIGSET_SIZE_BYTES);
43 /* maximum signal nesting depth
45 * FIXME: In CMUCL this was 4096, and it was first scaled down to 256
46 * and then 32, until finally Stumpwm broke: it is possible to receive
47 * interrupts in sufficiently quick succession that handler nesting
48 * can become preposterous. Scaling this back up to 1024 is a bandaid:
49 * for a real fix we should consider the following things:
51 * We should almost certainly always use
52 * arrange_return_to_lisp_function, though it needs to be thought
53 * about arguments, and it needs to be able to pass a frobbable
54 * context to the callee...
56 * There are cases when nesting handlers is exactly what we want:
59 * There are cases when we probably want to drop duplicate signals
60 * on the floor if they arrive before the previous one has been handled.
63 * There are cases when we probably want to handle duplicate signals
64 * after the previous handler has returned, not before. Eg. SIGALARM.
68 #define MAX_INTERRUPTS 1024
70 union interrupt_handler {
72 void (*c)(int, siginfo_t*, void*);
75 extern union interrupt_handler interrupt_handlers[NSIG];
77 struct interrupt_data {
78 /* signal information for pending signal. pending_signal=0 when there
79 * is no pending signal. */
80 void (*pending_handler) (int, siginfo_t*, void*) ;
82 siginfo_t pending_info;
83 sigset_t pending_mask;
87 extern void interrupt_init(void);
88 extern void fake_foreign_function_call(os_context_t* context);
89 extern void undo_fake_foreign_function_call(os_context_t* context);
90 extern void arrange_return_to_lisp_function(os_context_t *, lispobj);
91 extern void interrupt_handle_now(int, siginfo_t*, os_context_t*);
92 extern void interrupt_handle_pending(os_context_t*);
93 extern void interrupt_internal_error(os_context_t*, boolean continuable);
94 extern boolean handle_guard_page_triggered(os_context_t *,os_vm_address_t);
95 extern boolean maybe_defer_handler(void *handler, struct interrupt_data *data,
96 int signal, siginfo_t *info,
97 os_context_t *context);
98 #if defined LISP_FEATURE_GENCGC
99 /* assembly language stub that executes trap_PendingInterrupt */
100 extern void do_pending_interrupt(void);
103 #ifdef LISP_FEATURE_SB_THREAD
104 extern void interrupt_thread_handler(int, siginfo_t*, void*);
105 extern void sig_stop_for_gc_handler(int, siginfo_t*, void*);
106 extern void sig_resume_from_gc_handler(int, siginfo_t*, void*);
108 typedef void (*interrupt_handler_t)(int, siginfo_t *, void *);
109 extern void undoably_install_low_level_interrupt_handler (
111 interrupt_handler_t handler);
112 extern unsigned long install_handler(int signal,
113 interrupt_handler_t handler);
115 extern union interrupt_handler interrupt_handlers[NSIG];
117 /* Set all deferrable signals into *s. */
118 extern void sigaddset_deferrable(sigset_t *s);
119 /* Set all blockable signals into *s. */
120 extern void sigaddset_blockable(sigset_t *s);
122 extern void block_blockable_signals(void);
123 extern void unblock_deferrable_signals(void);
125 /* The void* casting here avoids having to mess with the various types
126 * of function argument lists possible for signal handlers:
127 * SA_SIGACTION handlers have one signature, and the default old-style
128 * signal(..) handlers have another, and attempting to represent them
129 * "cleanly" with union types is in fact a mess. */
130 #define ARE_SAME_HANDLER(x, y) ((void*)(x) == (void*)(y))
132 extern void handle_trap(os_context_t *context, int trap);
134 #ifndef LISP_FEATURE_WIN32
135 extern void lisp_memory_fault_error(os_context_t *context,
136 os_vm_address_t addr);