X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fruntime%2Finterrupt.c;h=f191cd38db3b6f37112225411c2bb3925fa291f6;hb=b4831dc945c0754b3ba77881e67c8ea4d0a3d905;hp=fdf1ab253b415aacc09c49609be7264875a334ab;hpb=a530bbe337109d898d5b4a001fc8f1afa3b5dc39;p=sbcl.git diff --git a/src/runtime/interrupt.c b/src/runtime/interrupt.c index fdf1ab2..f191cd3 100644 --- a/src/runtime/interrupt.c +++ b/src/runtime/interrupt.c @@ -13,18 +13,10 @@ * files for more information. */ -/* - * $Header$ - */ - #include - +#include +#include #include -#ifdef mach /* KLUDGE: #ifdef on lowercase symbols? Ick. -- WHN 19990904 */ -#ifdef mips -#include -#endif -#endif #include "runtime.h" #include "arch.h" @@ -39,6 +31,8 @@ #include "alloc.h" #include "dynbind.h" #include "interr.h" +#include "genesis/fdefn.h" +#include "genesis/simple-fun.h" void sigaddset_blockable(sigset_t *s) { @@ -48,6 +42,7 @@ void sigaddset_blockable(sigset_t *s) sigaddset(s, SIGPIPE); sigaddset(s, SIGALRM); sigaddset(s, SIGURG); + sigaddset(s, SIGFPE); sigaddset(s, SIGTSTP); sigaddset(s, SIGCHLD); sigaddset(s, SIGIO); @@ -67,7 +62,7 @@ void sigaddset_blockable(sigset_t *s) * becomes 'yes'.) */ boolean internal_errors_enabled = 0; -os_context_t *lisp_interrupt_contexts[MAX_INTERRUPTS]; +struct interrupt_data * global_interrupt_data; /* As far as I can tell, what's going on here is: * @@ -77,65 +72,48 @@ os_context_t *lisp_interrupt_contexts[MAX_INTERRUPTS]; * In that case, the Lisp-level handler is stored in interrupt_handlers[..] * and interrupt_low_level_handlers[..] is cleared. * - * However, some signals need special handling, e.g. the SIGSEGV (for - * Linux) or SIGBUS (for FreeBSD) used by the garbage collector to - * detect violations of write protection, because some cases of such - * signals are handled at C level and never passed on to Lisp. For - * such signals, we still store any Lisp-level handler in - * interrupt_handlers[..], but for the outermost handle we use the - * value from interrupt_low_level_handlers[..], instead of the - * ordinary interrupt_handle_now(..) or interrupt_handle_later(..). + * However, some signals need special handling, e.g. * - * -- WHN 20000728 */ -void (*interrupt_low_level_handlers[NSIG]) (int, siginfo_t*, void*) = {0}; -union interrupt_handler interrupt_handlers[NSIG]; - -/* signal number, siginfo_t, and old mask information for pending signal + * o the SIGSEGV (for e.g. Linux) or SIGBUS (for e.g. FreeBSD) used by the + * garbage collector to detect violations of write protection, + * because some cases of such signals (e.g. GC-related violations of + * write protection) are handled at C level and never passed on to + * Lisp. For such signals, we still store any Lisp-level handler + * in interrupt_handlers[..], but for the outermost handle we use + * the value from interrupt_low_level_handlers[..], instead of the + * ordinary interrupt_handle_now(..) or interrupt_handle_later(..). * - * pending_signal=0 when there is no pending signal. */ -static int pending_signal = 0; -static siginfo_t pending_info; -static sigset_t pending_mask; + * o the SIGTRAP (Linux/Alpha) which Lisp code uses to handle breakpoints, + * pseudo-atomic sections, and some classes of error (e.g. "function + * not defined"). This never goes anywhere near the Lisp handlers at all. + * See runtime/alpha-arch.c and code/signal.lisp + * + * - WHN 20000728, dan 20010128 */ + -static boolean maybe_gc_pending = 0; +boolean maybe_gc_pending = 0; /* * utility routines used by various signal handlers */ -void -fake_foreign_function_call(os_context_t *context) +void +build_fake_control_stack_frames(struct thread *th,os_context_t *context) { - int context_index; -#ifndef __i386__ +#ifndef LISP_FEATURE_X86 + lispobj oldcont; -#endif - /* Get current Lisp state from context. */ -#ifdef reg_ALLOC - current_dynamic_space_free_pointer = - (lispobj *)(*os_context_register_addr(context, reg_ALLOC)); -#ifdef alpha - if ((long)current_dynamic_space_free_pointer & 1) { - lose("dead in fake_foreign_function_call, context = %x", context); - } -#endif -#endif -#ifdef reg_BSP - current_binding_stack_pointer = - (lispobj *)(*os_context_register_addr(context, reg_BSP)); -#endif + /* Build a fake stack frame or frames */ -#ifndef __i386__ - /* Build a fake stack frame. */ current_control_frame_pointer = (lispobj *)(*os_context_register_addr(context, reg_CSP)); if ((lispobj *)(*os_context_register_addr(context, reg_CFP)) == current_control_frame_pointer) { /* There is a small window during call where the callee's * frame isn't built yet. */ - if (LowtagOf(*os_context_register_addr(context, reg_CODE)) - == type_FunctionPointer) { + if (lowtag_of(*os_context_register_addr(context, reg_CODE)) + == FUN_POINTER_LOWTAG) { /* We have called, but not built the new frame, so * build it for them. */ current_control_frame_pointer[0] = @@ -152,12 +130,14 @@ fake_foreign_function_call(os_context_t *context) oldcont = (lispobj)(*os_context_register_addr(context, reg_OCFP)); } } - /* ### We can't tell if we are still in the caller if it had to - * reg_ALLOCate the stack frame due to stack arguments. */ - /* ### Can anything strange happen during return? */ - else + /* We can't tell whether we are still in the caller if it had to + * allocate a stack frame due to stack arguments. */ + /* This observation provoked some past CMUCL maintainer to ask + * "Can anything strange happen during return?" */ + else { /* normal case */ oldcont = (lispobj)(*os_context_register_addr(context, reg_CFP)); + } current_control_stack_pointer = current_control_frame_pointer + 8; @@ -166,24 +146,44 @@ fake_foreign_function_call(os_context_t *context) current_control_frame_pointer[2] = (lispobj)(*os_context_register_addr(context, reg_CODE)); #endif +} + +void +fake_foreign_function_call(os_context_t *context) +{ + int context_index; + struct thread *thread=arch_os_get_current_thread(); + + /* Get current Lisp state from context. */ +#ifdef reg_ALLOC + dynamic_space_free_pointer = + (lispobj *)(*os_context_register_addr(context, reg_ALLOC)); +#ifdef alpha + if ((long)dynamic_space_free_pointer & 1) { + lose("dead in fake_foreign_function_call, context = %x", context); + } +#endif +#endif +#ifdef reg_BSP + current_binding_stack_pointer = + (lispobj *)(*os_context_register_addr(context, reg_BSP)); +#endif + + build_fake_control_stack_frames(thread,context); /* Do dynamic binding of the active interrupt context index * and save the context in the context array. */ - context_index = SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX)>>2; - /* FIXME: Ick! Why use abstract "make_fixnum" in some places if - * you're going to convert from fixnum by bare >>2 in other - * places? Use fixnum_value(..) here, and look for other places - * which do bare >> and << for fixnum_value and make_fixnum. */ - + context_index = + fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)); + if (context_index >= MAX_INTERRUPTS) { - lose("maximum interrupt nesting depth (%d) exceeded", - MAX_INTERRUPTS); + lose("maximum interrupt nesting depth (%d) exceeded", MAX_INTERRUPTS); } bind_variable(FREE_INTERRUPT_CONTEXT_INDEX, - make_fixnum(context_index + 1)); + make_fixnum(context_index + 1),thread); - lisp_interrupt_contexts[context_index] = context; + thread->interrupt_contexts[context_index] = context; /* no longer in Lisp now */ foreign_function_call_active = 1; @@ -192,6 +192,7 @@ fake_foreign_function_call(os_context_t *context) void undo_fake_foreign_function_call(os_context_t *context) { + struct thread *thread=arch_os_get_current_thread(); /* Block all blockable signals. */ sigset_t block; sigemptyset(&block); @@ -207,12 +208,13 @@ undo_fake_foreign_function_call(os_context_t *context) * FREE_INTERRUPT_CONTEXT_INDEX? If so, we should say so. And * perhaps yes, unbind_to_here() really would be clearer and less * fragile.. */ - unbind(); + /* dan (2001.08.10) thinks the above supposition is probably correct */ + unbind(thread); #ifdef reg_ALLOC /* Put the dynamic space free pointer back into the context. */ *os_context_register_addr(context, reg_ALLOC) = - (unsigned long) current_dynamic_space_free_pointer; + (unsigned long) dynamic_space_free_pointer; #endif } @@ -222,7 +224,7 @@ void interrupt_internal_error(int signal, siginfo_t *info, os_context_t *context, boolean continuable) { - lispobj context_sap; + lispobj context_sap = 0; fake_foreign_function_call(context); @@ -256,22 +258,37 @@ interrupt_internal_error(int signal, siginfo_t *info, os_context_t *context, } } +/* This function handles pending interrupts. Note that in C/kernel + * terms we dealt with the signal already; we just haven't decided + * whether to call a Lisp handler or do a GC or something like that. + * If it helps, you can think of pending_{signal,mask,info} as a + * one-element queue of signals that we have acknowledged but not + * processed */ + void interrupt_handle_pending(os_context_t *context) { - boolean were_in_lisp = !foreign_function_call_active; + struct thread *thread; + struct interrupt_data *data; - SetSymbolValue(INTERRUPT_PENDING, NIL); +#ifndef __i386__ + boolean were_in_lisp = !foreign_function_call_active; +#endif +#ifdef LISP_FEATURE_SB_THREAD + while(stop_the_world) kill(getpid(),SIGSTOP); +#endif + thread=arch_os_get_current_thread(); + data=thread->interrupt_data; + SetSymbolValue(INTERRUPT_PENDING, NIL,thread); if (maybe_gc_pending) { - maybe_gc_pending = 0; #ifndef __i386__ if (were_in_lisp) #endif { fake_foreign_function_call(context); } - funcall0(SymbolFunction(MAYBE_GC)); + funcall0(SymbolFunction(SUB_GC)); #ifndef __i386__ if (were_in_lisp) #endif @@ -280,16 +297,40 @@ interrupt_handle_pending(os_context_t *context) } } - /* FIXME: How come we unconditionally copy from pending_mask into - * the context, and then test whether pending_signal is set? If - * pending_signal wasn't set, how could pending_mask be valid? */ - memcpy(os_context_sigmask_addr(context), &pending_mask, sizeof(sigset_t)); - sigemptyset(&pending_mask); - if (pending_signal) { - int signal = pending_signal; + /* FIXME: This isn't very clear. It would be good to reverse + * engineer it and rewrite the code more clearly, or write a clear + * explanation of what's going on in the comments, or both. + * + * WHN's question 1a: How come we unconditionally copy from + * pending_mask into the context, and then test whether + * pending_signal is set? + * + * WHN's question 1b: If pending_signal wasn't set, how could + * pending_mask be valid? + * + * Dan Barlow's reply (sbcl-devel 2001-03-13): And the answer is - + * or appears to be - because interrupt_maybe_gc set it that way + * (look in the #ifndef __i386__ bit). We can't GC during a + * pseudo-atomic, so we set maybe_gc_pending=1 and + * arch_set_pseudo_atomic_interrupted(..) When we come out of + * pseudo_atomic we're marked as interrupted, so we call + * interrupt_handle_pending, which does the GC using the pending + * context (it needs a context so that it has registers to use as + * GC roots) then notices there's no actual interrupt handler to + * call, so doesn't. That's the second question [1b] answered, + * anyway. Why we still need to copy the pending_mask into the + * context given that we're now done with the context anyway, I + * couldn't say. */ +#if 0 + memcpy(os_context_sigmask_addr(context), &pending_mask, + 4 /* sizeof(sigset_t) */ ); +#endif + sigemptyset(&data->pending_mask); + if (data->pending_signal) { + int signal = data->pending_signal; siginfo_t info; - memcpy(&info, &pending_info, sizeof(siginfo_t)); - pending_signal = 0; + memcpy(&info, &data->pending_info, sizeof(siginfo_t)); + data->pending_signal = 0; interrupt_handle_now(signal, &info, context); } } @@ -298,27 +339,41 @@ interrupt_handle_pending(os_context_t *context) * the two main signal handlers: * interrupt_handle_now(..) * maybe_now_maybe_later(..) + * + * to which we have added interrupt_handle_now_handler(..). Why? + * Well, mostly because the SPARC/Linux platform doesn't quite do + * signals the way we want them done. The third argument in the + * handler isn't filled in by the kernel properly, so we fix it up + * ourselves in the arch_os_get_context(..) function; however, we only + * want to do this when we first hit the handler, and not when + * interrupt_handle_now(..) is being called from some other handler + * (when the fixup will already have been done). -- CSR, 2002-07-23 */ void interrupt_handle_now(int signal, siginfo_t *info, void *void_context) { os_context_t *context = (os_context_t*)void_context; - int were_in_lisp; - union interrupt_handler handler; - -#ifdef __linux__ - SET_FPU_CONTROL_WORD(context->__fpregs_mem.cw); + struct thread *thread=arch_os_get_current_thread(); +#ifndef __i386__ + boolean were_in_lisp; #endif + union interrupt_handler handler; - handler = interrupt_handlers[signal]; +#ifdef LISP_FEATURE_LINUX + /* Under Linux on some architectures, we appear to have to restore + the FPU control word from the context, as after the signal is + delivered we appear to have a null FPU control word. */ + os_restore_fp_control(context); +#endif + handler = thread->interrupt_data->interrupt_handlers[signal]; if (ARE_SAME_HANDLER(handler.c, SIG_IGN)) { return; } - - were_in_lisp = !foreign_function_call_active; + #ifndef __i386__ + were_in_lisp = !foreign_function_call_active; if (were_in_lisp) #endif { @@ -326,7 +381,9 @@ interrupt_handle_now(int signal, siginfo_t *info, void *void_context) } #ifdef QSHOW_SIGNALS - FSHOW((stderr, "in interrupt_handle_now(%d, info, context)\n", signal)); + FSHOW((stderr, + "/entering interrupt_handle_now(%d, info, context)\n", + signal)); #endif if (ARE_SAME_HANDLER(handler.c, SIG_DFL)) { @@ -336,15 +393,14 @@ interrupt_handle_now(int signal, siginfo_t *info, void *void_context) * support decides to pass on it. */ lose("no handler for signal %d in interrupt_handle_now(..)", signal); - } else if (LowtagOf(handler.lisp) == type_FunctionPointer) { + } else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) { /* Allocate the SAPs while the interrupts are still disabled. * (FIXME: Why? This is the way it was done in CMU CL, and it * even had the comment noting that this is the way it was * done, but no motivation..) */ - lispobj context_sap = alloc_sap(context); - lispobj info_sap = alloc_sap(info); - + lispobj info_sap,context_sap = alloc_sap(context); + info_sap = alloc_sap(info); /* Allow signals again. */ sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0); @@ -374,104 +430,167 @@ interrupt_handle_now(int signal, siginfo_t *info, void *void_context) { undo_fake_foreign_function_call(context); } + +#ifdef QSHOW_SIGNALS + FSHOW((stderr, + "/returning from interrupt_handle_now(%d, info, context)\n", + signal)); +#endif } static void -maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context) +store_signal_data_for_later (struct interrupt_data *data, int signal, + siginfo_t *info, os_context_t *context) { - os_context_t *context = (os_context_t*)void_context; - - /* FIXME: See Debian cmucl 2.4.17, and mail from DTC on the CMU CL - * mailing list 23 Oct 1999, for changes in FPU handling at - * interrupt time which should be ported into SBCL. - * - * (Is this related to the way that it seems that if we do decide - * to handle the interrupt later, we've now screwed up the FPU - * control word?) */ -#ifdef __linux__ - SET_FPU_CONTROL_WORD(context->__fpregs_mem.cw); -#endif - - if (SymbolValue(INTERRUPTS_ENABLED) == NIL) { - - /* FIXME: This code is exactly the same as the code in the - * other leg of the if(..), and should be factored out into - * a shared function. */ - pending_signal = signal; - memcpy(&pending_info, info, sizeof(siginfo_t)); - memcpy(&pending_mask, - os_context_sigmask_addr(context), - sizeof(sigset_t)); - sigaddset_blockable(os_context_sigmask_addr(context)); + data->pending_signal = signal; + memcpy(&(data->pending_info), info, sizeof(siginfo_t)); + memcpy(&(data->pending_mask), + os_context_sigmask_addr(context), + sizeof(sigset_t)); + sigaddset_blockable(os_context_sigmask_addr(context)); +} - SetSymbolValue(INTERRUPT_PENDING, T); +static void +maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context) +{ + os_context_t *context = arch_os_get_context(&void_context); + struct thread *thread=arch_os_get_current_thread(); + struct interrupt_data *data=thread->interrupt_data; +#ifdef LISP_FEATURE_LINUX + os_restore_fp_control(context); +#endif + /* see comments at top of code/signal.lisp for what's going on here + * with INTERRUPTS_ENABLED/INTERRUPT_HANDLE_NOW + */ + if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) { + store_signal_data_for_later(data,signal,info,context); + SetSymbolValue(INTERRUPT_PENDING, T,thread); } else if ( #ifndef __i386__ (!foreign_function_call_active) && #endif arch_pseudo_atomic_atomic(context)) { - - /* FIXME: It would probably be good to replace these bare - * memcpy(..) calls with calls to cpy_siginfo_t and - * cpy_sigset_t, so that we only have to get the sizeof - * expressions right in one place, and after that static type - * checking takes over. */ - pending_signal = signal; - memcpy(&pending_info, info, sizeof(siginfo_t)); - memcpy(&pending_mask, - os_context_sigmask_addr(context), - sizeof(sigset_t)); - sigaddset_blockable(os_context_sigmask_addr(context)); - + store_signal_data_for_later(data,signal,info,context); arch_set_pseudo_atomic_interrupted(context); - } else { interrupt_handle_now(signal, info, context); } } + +void +interrupt_handle_now_handler(int signal, siginfo_t *info, void *void_context) +{ + os_context_t *context = arch_os_get_context(&void_context); + interrupt_handle_now(signal, info, context); +} + /* * stuff to detect and handle hitting the GC trigger */ -#ifndef INTERNAL_GC_TRIGGER +#ifndef LISP_FEATURE_GENCGC +/* since GENCGC has its own way to record trigger */ static boolean gc_trigger_hit(int signal, siginfo_t *info, os_context_t *context) { if (current_auto_gc_trigger == NULL) return 0; else{ - lispobj *badaddr=(lispobj *)arch_get_bad_addr(signal, - info, - context); - - return (badaddr >= current_auto_gc_trigger && - badaddr < current_dynamic_space + DYNAMIC_SPACE_SIZE); + void *badaddr=arch_get_bad_addr(signal,info,context); + return (badaddr >= (void *)current_auto_gc_trigger && + badaddr <((void *)current_dynamic_space + DYNAMIC_SPACE_SIZE)); } } #endif -#ifndef __i386__ -boolean -interrupt_maybe_gc(int signal, siginfo_t *info, os_context_t *context) +/* and similarly for the control stack guard page */ + +boolean handle_control_stack_guard_triggered(os_context_t *context,void *addr) { - if (!foreign_function_call_active -#ifndef INTERNAL_GC_TRIGGER - && gc_trigger_hit(signal, info, context) + struct thread *th=arch_os_get_current_thread(); + /* note the os_context hackery here. When the signal handler returns, + * it won't go back to what it was doing ... */ + if(addr>=(void *)CONTROL_STACK_GUARD_PAGE(th) && + addr<(void *)(CONTROL_STACK_GUARD_PAGE(th)+os_vm_page_size)) { + void *fun; + void *code; + /* fprintf(stderr, "hit end of control stack\n"); */ + /* we hit the end of the control stack. disable protection + * temporarily so the error handler has some headroom */ + protect_control_stack_guard_page(th->pid,0L); + + fun = (void *) + native_pointer((lispobj) SymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR)); + code = &(((struct simple_fun *) fun)->code); + + /* Build a stack frame showing `interrupted' so that the + * user's backtrace makes (as much) sense (as usual) */ + build_fake_control_stack_frames(th,context); + /* signal handler will "return" to this error-causing function */ + *os_context_pc_addr(context) = code; +#ifdef LISP_FEATURE_X86 + *os_context_register_addr(context,reg_ECX) = 0; +#else + /* this much of the calling convention is common to all + non-x86 ports */ + *os_context_register_addr(context,reg_NARGS) = 0; + *os_context_register_addr(context,reg_LIP) = code; + *os_context_register_addr(context,reg_CFP) = + current_control_frame_pointer; #endif - ) { -#ifndef INTERNAL_GC_TRIGGER - clear_auto_gc_trigger(); +#ifdef ARCH_HAS_NPC_REGISTER + *os_context_npc_addr(context) = + 4 + *os_context_pc_addr(context); #endif +#ifdef LISP_FEATURE_SPARC + /* Bletch. This is a feature of the SPARC calling convention, + which sadly I'm not going to go into in large detail here, + as I don't know it well enough. Suffice to say that if the + line + + (INST MOVE CODE-TN FUNCTION) + + in compiler/sparc/call.lisp is changed, then this bit can + probably go away. -- CSR, 2002-07-24 */ + *os_context_register_addr(context,reg_CODE) = + fun + FUN_POINTER_LOWTAG; +#endif + return 1; + } + else return 0; +} + +#ifndef LISP_FEATURE_GENCGC +/* This function gets called from the SIGSEGV (for e.g. Linux or + * OpenBSD) or SIGBUS (for e.g. FreeBSD) handler. Here we check + * whether the signal was due to treading on the mprotect()ed zone - + * and if so, arrange for a GC to happen. */ +extern unsigned long bytes_consed_between_gcs; /* gc-common.c */ + +boolean +interrupt_maybe_gc(int signal, siginfo_t *info, void *void_context) +{ + os_context_t *context=(os_context_t *) void_context; + struct thread *th=arch_os_get_current_thread(); + struct interrupt_data *data= + th ? th->interrupt_data : global_interrupt_data; + + if(!foreign_function_call_active && gc_trigger_hit(signal, info, context)){ + clear_auto_gc_trigger(); if (arch_pseudo_atomic_atomic(context)) { + /* don't GC during an atomic operation. Instead, copy the + * signal mask somewhere safe. interrupt_handle_pending + * will detect pending_signal==0 and know to do a GC with the + * signal context instead of calling a Lisp-level handler */ maybe_gc_pending = 1; - if (pending_signal == 0) { + if (data->pending_signal == 0) { /* FIXME: This copy-pending_mask-then-sigaddset_blockable * idiom occurs over and over. It should be factored out * into a function with a descriptive name. */ - memcpy(&pending_mask, + memcpy(&(data->pending_mask), os_context_sigmask_addr(context), sizeof(sigset_t)); sigaddset_blockable(os_context_sigmask_addr(context)); @@ -480,10 +599,13 @@ interrupt_maybe_gc(int signal, siginfo_t *info, os_context_t *context) } else { fake_foreign_function_call(context); - funcall0(SymbolFunction(MAYBE_GC)); + /* SUB-GC may return without GCing if *GC-INHIBIT* is set, + * in which case we will be running with no gc trigger + * barrier thing for a while. But it shouldn't be long + * until the end of WITHOUT-GCING. */ + funcall0(SymbolFunction(SUB_GC)); undo_fake_foreign_function_call(context); - } - + } return 1; } else { return 0; @@ -495,22 +617,55 @@ interrupt_maybe_gc(int signal, siginfo_t *info, os_context_t *context) * noise to install handlers */ -/* Install a special low-level handler for signal; or if handler is - * SIG_DFL, remove any special handling for signal. */ +/* SBCL used to have code to restore signal handlers on exit, which + * has been removed from the threaded version until we decide: exit of + * _what_ ? */ + +/* SBCL comment: The "undoably" aspect is because we also arrange with + * atexit() for the handler to be restored to its old value. This is + * for tidiness: it shouldn't matter much ordinarily, but it does + * remove a window where e.g. memory fault signals (SIGSEGV or SIGBUS, + * which in ordinary operation of SBCL are sent to the generational + * garbage collector, then possibly onward to Lisp code) or SIGINT + * (which is ordinarily passed to Lisp code) could otherwise be + * handled bizarrely/brokenly because the Lisp code would try to deal + * with them using machinery (like stream output buffers) which has + * already been dismantled. */ + +/* I'm not sure (a) whether this is a real concern, (b) how it helps + anyway */ + +void +uninstall_low_level_interrupt_handlers_atexit(void) +{ +} + void -interrupt_install_low_level_handler (int signal, - void handler(int, siginfo_t*, void*)) +undoably_install_low_level_interrupt_handler (int signal, + void handler(int, + siginfo_t*, + void*)) { struct sigaction sa; + struct thread *th=arch_os_get_current_thread(); + struct interrupt_data *data= + th ? th->interrupt_data : global_interrupt_data; + + if (0 > signal || signal >= NSIG) { + lose("bad signal number %d", signal); + } sa.sa_sigaction = handler; sigemptyset(&sa.sa_mask); sigaddset_blockable(&sa.sa_mask); sa.sa_flags = SA_SIGINFO | SA_RESTART; - +#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK + if(signal==SIG_MEMORY_FAULT) sa.sa_flags|= SA_ONSTACK; +#endif + sigaction(signal, &sa, NULL); - interrupt_low_level_handlers[signal] = - (ARE_SAME_HANDLER(handler,SIG_DFL) ? 0 : handler); + data->interrupt_low_level_handlers[signal] = + (ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler); } /* This is called from Lisp. */ @@ -520,8 +675,11 @@ install_handler(int signal, void handler(int, siginfo_t*, void*)) struct sigaction sa; sigset_t old, new; union interrupt_handler oldhandler; + struct thread *th=arch_os_get_current_thread(); + struct interrupt_data *data= + th ? th->interrupt_data : global_interrupt_data; - FSHOW((stderr, "entering POSIX install_handler(%d, ..)\n", signal)); + FSHOW((stderr, "/entering POSIX install_handler(%d, ..)\n", signal)); sigemptyset(&new); sigaddset(&new, signal); @@ -530,42 +688,44 @@ install_handler(int signal, void handler(int, siginfo_t*, void*)) sigemptyset(&new); sigaddset_blockable(&new); - FSHOW((stderr, "interrupt_low_level_handlers[signal]=%d\n", + FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%d\n", interrupt_low_level_handlers[signal])); - if (interrupt_low_level_handlers[signal]==0) { + if (data->interrupt_low_level_handlers[signal]==0) { if (ARE_SAME_HANDLER(handler, SIG_DFL) || ARE_SAME_HANDLER(handler, SIG_IGN)) { sa.sa_sigaction = handler; } else if (sigismember(&new, signal)) { sa.sa_sigaction = maybe_now_maybe_later; } else { - sa.sa_sigaction = interrupt_handle_now; + sa.sa_sigaction = interrupt_handle_now_handler; } sigemptyset(&sa.sa_mask); sigaddset_blockable(&sa.sa_mask); sa.sa_flags = SA_SIGINFO | SA_RESTART; - sigaction(signal, &sa, NULL); } - oldhandler = interrupt_handlers[signal]; - interrupt_handlers[signal].c = handler; + oldhandler = data->interrupt_handlers[signal]; + data->interrupt_handlers[signal].c = handler; sigprocmask(SIG_SETMASK, &old, 0); - FSHOW((stderr, "leaving POSIX install_handler(%d, ..)\n", signal)); + FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal)); return (unsigned long)oldhandler.lisp; } void -interrupt_init(void) +interrupt_init() { int i; + SHOW("entering interrupt_init()"); + global_interrupt_data=calloc(sizeof(struct interrupt_data), 1); + /* Set up high level handler information. */ for (i = 0; i < NSIG; i++) { - interrupt_handlers[i].c = + global_interrupt_data->interrupt_handlers[i].c = /* (The cast here blasts away the distinction between * SA_SIGACTION-style three-argument handlers and * signal(..)-style one-argument handlers, which is OK @@ -573,4 +733,6 @@ interrupt_init(void) * 3-argument form is expected.) */ (void (*)(int, siginfo_t*, void*))SIG_DFL; } + + SHOW("returning from interrupt_init()"); }