* files for more information.
*/
+
+/* As far as I can tell, what's going on here is:
+ *
+ * In the case of most signals, when Lisp asks us to handle the
+ * signal, the outermost handler (the one actually passed to UNIX) is
+ * either interrupt_handle_now(..) or maybe_now_maybe_later(..).
+ * 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.
+ *
+ * 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(..).
+ *
+ * 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 */
+
+
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <errno.h>
+#include "sbcl.h"
#include "runtime.h"
#include "arch.h"
-#include "sbcl.h"
#include "os.h"
#include "interrupt.h"
#include "globals.h"
#include "interr.h"
#include "genesis/fdefn.h"
#include "genesis/simple-fun.h"
+#include "genesis/cons.h"
+
+
+
+void run_deferred_handler(struct interrupt_data *data, void *v_context) ;
+static void store_signal_data_for_later (struct interrupt_data *data,
+ void *handler, int signal,
+ siginfo_t *info,
+ os_context_t *context);
+boolean interrupt_maybe_gc_int(int signal, siginfo_t *info, void *v_context);
+
+extern volatile lispobj all_threads_lock;
void sigaddset_blockable(sigset_t *s)
{
sigaddset(s, SIGWINCH);
sigaddset(s, SIGUSR1);
sigaddset(s, SIGUSR2);
+#ifdef LISP_FEATURE_SB_THREAD
+ sigaddset(s, SIG_STOP_FOR_GC);
+ sigaddset(s, SIG_INTERRUPT_THREAD);
+#endif
+}
+
+static sigset_t blockable_sigset;
+
+inline static void check_blockables_blocked_or_lose()
+{
+ /* Get the current sigmask, by blocking the empty set. */
+ sigset_t empty,current;
+ int i;
+ sigemptyset(&empty);
+ thread_sigmask(SIG_BLOCK, &empty, ¤t);
+ for(i=0;i<NSIG;i++) {
+ if (sigismember(&blockable_sigset, i) && !sigismember(¤t, i))
+ lose("blockable signal %d not blocked",i);
+ }
+}
+
+inline static void check_interrupts_enabled_or_lose(os_context_t *context)
+{
+ struct thread *thread=arch_os_get_current_thread();
+ if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL)
+ lose("interrupts not enabled");
+ if (
+#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
+ (!foreign_function_call_active) &&
+#endif
+ arch_pseudo_atomic_atomic(context))
+ lose ("in pseudo atomic section");
}
/* When we catch an internal error, should we pass it back to Lisp to
struct interrupt_data * global_interrupt_data;
-/* As far as I can tell, what's going on here is:
- *
- * In the case of most signals, when Lisp asks us to handle the
- * signal, the outermost handler (the one actually passed to UNIX) is
- * either interrupt_handle_now(..) or interrupt_handle_later(..).
- * 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.
- *
- * 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(..).
- *
- * 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 */
+/* At the toplevel repl we routinely call this function. The signal
+ * mask ought to be clear anyway most of the time, but may be non-zero
+ * if we were interrupted e.g. while waiting for a queue. */
+
+void reset_signal_mask ()
+{
+ sigset_t new;
+ sigemptyset(&new);
+ thread_sigmask(SIG_SETMASK,&new,0);
+}
+
-boolean maybe_gc_pending = 0;
\f
/*
* utility routines used by various signal handlers
void
build_fake_control_stack_frames(struct thread *th,os_context_t *context)
{
-#ifndef LISP_FEATURE_X86
+#ifndef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
lispobj oldcont;
int context_index;
struct thread *thread=arch_os_get_current_thread();
+ /* context_index incrementing must not be interrupted */
+ check_blockables_blocked_or_lose();
+
/* Get current Lisp state from context. */
#ifdef reg_ALLOC
dynamic_space_free_pointer =
(lispobj *)(*os_context_register_addr(context, reg_ALLOC));
-#ifdef alpha
+#if defined(LISP_FEATURE_ALPHA)
if ((long)dynamic_space_free_pointer & 1) {
lose("dead in fake_foreign_function_call, context = %x", context);
}
foreign_function_call_active = 1;
}
+/* blocks all blockable signals. If you are calling from a signal handler,
+ * the usual signal mask will be restored from the context when the handler
+ * finishes. Otherwise, be careful */
+
void
undo_fake_foreign_function_call(os_context_t *context)
{
sigset_t block;
sigemptyset(&block);
sigaddset_blockable(&block);
- sigprocmask(SIG_BLOCK, &block, 0);
+ thread_sigmask(SIG_BLOCK, &block, 0);
/* going back into Lisp */
foreign_function_call_active = 0;
- /* Undo dynamic binding. */
- /* ### Do I really need to unbind_to_here()? */
- /* FIXME: Is this to undo the binding of
- * FREE_INTERRUPT_CONTEXT_INDEX? If so, we should say so. And
- * perhaps yes, unbind_to_here() really would be clearer and less
- * fragile.. */
- /* dan (2001.08.10) thinks the above supposition is probably correct */
+ /* Undo dynamic binding of FREE_INTERRUPT_CONTEXT_INDEX */
unbind(thread);
#ifdef reg_ALLOC
{
lispobj context_sap = 0;
+ check_blockables_blocked_or_lose();
fake_foreign_function_call(context);
/* Allocate the SAP object while the interrupts are still
context_sap = alloc_sap(context);
}
- sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
+ thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
if (internal_errors_enabled) {
SHOW("in interrupt_internal_error");
-#if QSHOW
+#ifdef QSHOW
/* Display some rudimentary debugging information about the
* error, so that even if the Lisp error handler gets badly
* confused, we have a chance to determine what's going on. */
* before the Lisp error handling mechanism is set up. */
lose("internal error too early in init, can't recover");
}
- undo_fake_foreign_function_call(context);
+ undo_fake_foreign_function_call(context); /* blocks signals again */
if (continuable) {
arch_skip_instruction(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)
{
struct thread *thread;
struct interrupt_data *data;
-#ifndef __i386__
- boolean were_in_lisp = !foreign_function_call_active;
-#endif
-#ifdef LISP_FEATURE_SB_THREAD
- while(stop_the_world) kill(getpid(),SIGSTOP);
-#endif
+ check_blockables_blocked_or_lose();
+ check_interrupts_enabled_or_lose(context);
+
thread=arch_os_get_current_thread();
data=thread->interrupt_data;
- SetSymbolValue(INTERRUPT_PENDING, NIL,thread);
-
- if (maybe_gc_pending) {
-#ifndef __i386__
- if (were_in_lisp)
-#endif
- {
- fake_foreign_function_call(context);
- }
- funcall0(SymbolFunction(SUB_GC));
-#ifndef __i386__
- if (were_in_lisp)
-#endif
- {
- undo_fake_foreign_function_call(context);
- }
- }
- /* 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, &data->pending_info, sizeof(siginfo_t));
- data->pending_signal = 0;
- interrupt_handle_now(signal, &info, context);
+ /* Pseudo atomic may trigger several times for a single interrupt,
+ * and while without-interrupts should not, a false trigger by
+ * pseudo-atomic may eat a pending handler even from
+ * without-interrupts. */
+ if (data->pending_handler) {
+
+ /* If we're here as the result of a pseudo-atomic as opposed
+ * to WITHOUT-INTERRUPTS, then INTERRUPT_PENDING is already
+ * NIL, because maybe_defer_handler sets
+ * PSEUDO_ATOMIC_INTERRUPTED only if interrupts are enabled.*/
+ SetSymbolValue(INTERRUPT_PENDING, NIL,thread);
+
+ /* restore the saved signal mask from the original signal (the
+ * one that interrupted us during the critical section) into the
+ * os_context for the signal we're currently in the handler for.
+ * This should ensure that when we return from the handler the
+ * blocked signals are unblocked */
+ sigcopyset(os_context_sigmask_addr(context), &data->pending_mask);
+
+ sigemptyset(&data->pending_mask);
+ /* This will break on sparc linux: the deferred handler really wants
+ * to be called with a void_context */
+ run_deferred_handler(data,(void *)context);
}
}
\f
{
os_context_t *context = (os_context_t*)void_context;
struct thread *thread=arch_os_get_current_thread();
-#ifndef __i386__
+#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
boolean were_in_lisp;
#endif
union interrupt_handler handler;
+ check_blockables_blocked_or_lose();
+ check_interrupts_enabled_or_lose(context);
#ifdef LISP_FEATURE_LINUX
/* Under Linux on some architectures, we appear to have to restore
return;
}
-#ifndef __i386__
+#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
were_in_lisp = !foreign_function_call_active;
if (were_in_lisp)
#endif
lose("no handler for signal %d in interrupt_handle_now(..)", signal);
} else if (lowtag_of(handler.lisp) == FUN_POINTER_LOWTAG) {
+ /* Once we've decided what to do about contexts in a
+ * return-elsewhere world (the original context will no longer
+ * be available; should we copy it or was nobody using it anyway?)
+ * then we should convert this to return-elsewhere */
+
+ /* CMUCL comment said "Allocate the SAPs while the interrupts
+ * are still disabled.". I (dan, 2003.08.21) assume this is
+ * because we're not in pseudoatomic and allocation shouldn't
+ * be interrupted. In which case it's no longer an issue as
+ * all our allocation from C now goes through a PA wrapper,
+ * but still, doesn't hurt */
- /* 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 info_sap,context_sap = alloc_sap(context);
info_sap = alloc_sap(info);
/* Allow signals again. */
- sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
+ thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
#ifdef QSHOW_SIGNALS
SHOW("calling Lisp-level handler");
#endif
/* Allow signals again. */
- sigprocmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
+ thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
(*handler.c)(signal, info, void_context);
}
-#ifndef __i386__
+#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
if (were_in_lisp)
#endif
{
- undo_fake_foreign_function_call(context);
+ undo_fake_foreign_function_call(context); /* block signals again */
}
#ifdef QSHOW_SIGNALS
#endif
}
+/* This is called at the end of a critical section if the indications
+ * are that some signal was deferred during the section. Note that as
+ * far as C or the kernel is concerned we dealt with the signal
+ * already; we're just doing the Lisp-level processing now that we
+ * put off then */
+
+void
+run_deferred_handler(struct interrupt_data *data, void *v_context) {
+ /* The pending_handler may enable interrupts (see
+ * interrupt_maybe_gc_int) and then another interrupt may hit,
+ * overwrite interrupt_data, so reset the pending handler before
+ * calling it. Trust the handler to finish with the siginfo before
+ * enabling interrupts. */
+ void (*pending_handler) (int, siginfo_t*, void*)=data->pending_handler;
+ data->pending_handler=0;
+ (*pending_handler)(data->pending_signal,&(data->pending_info), v_context);
+}
+
+boolean
+maybe_defer_handler(void *handler, struct interrupt_data *data,
+ int signal, siginfo_t *info, os_context_t *context)
+{
+ struct thread *thread=arch_os_get_current_thread();
+
+ check_blockables_blocked_or_lose();
+
+ if (SymbolValue(INTERRUPT_PENDING,thread) != NIL)
+ lose("interrupt already pending");
+ /* If interrupts are disabled then INTERRUPT_PENDING is set and
+ * not PSEDUO_ATOMIC_INTERRUPTED. This is important for a pseudo
+ * atomic section inside a without-interrupts.
+ */
+ if (SymbolValue(INTERRUPTS_ENABLED,thread) == NIL) {
+ store_signal_data_for_later(data,handler,signal,info,context);
+ SetSymbolValue(INTERRUPT_PENDING, T,thread);
+#ifdef QSHOW_SIGNALS
+ FSHOW((stderr,
+ "/maybe_defer_handler(%x,%d),thread=%ld: deferred\n",
+ (unsigned int)handler,signal,thread->os_thread));
+#endif
+ return 1;
+ }
+ /* a slightly confusing test. arch_pseudo_atomic_atomic() doesn't
+ * actually use its argument for anything on x86, so this branch
+ * may succeed even when context is null (gencgc alloc()) */
+ if (
+#if !defined(LISP_FEATURE_X86) && !defined(LISP_FEATURE_X86_64)
+ (!foreign_function_call_active) &&
+#endif
+ arch_pseudo_atomic_atomic(context)) {
+ store_signal_data_for_later(data,handler,signal,info,context);
+ arch_set_pseudo_atomic_interrupted(context);
+#ifdef QSHOW_SIGNALS
+ FSHOW((stderr,
+ "/maybe_defer_handler(%x,%d),thread=%ld: deferred(PA)\n",
+ (unsigned int)handler,signal,thread->os_thread));
+#endif
+ return 1;
+ }
+#ifdef QSHOW_SIGNALS
+ FSHOW((stderr,
+ "/maybe_defer_handler(%x,%d),thread=%ld: not deferred\n",
+ (unsigned int)handler,signal,thread->os_thread));
+#endif
+ return 0;
+}
+
static void
-store_signal_data_for_later (struct interrupt_data *data, int signal,
+store_signal_data_for_later (struct interrupt_data *data, void *handler,
+ int signal,
siginfo_t *info, os_context_t *context)
{
+ if (data->pending_handler)
+ lose("tried to overwrite pending interrupt handler %x with %x\n",
+ data->pending_handler, handler);
+ if (!handler)
+ lose("tried to defer null interrupt handler\n");
+ data->pending_handler = handler;
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));
+ if(info)
+ memcpy(&(data->pending_info), info, sizeof(siginfo_t));
+ if(context) {
+ /* the signal mask in the context (from before we were
+ * interrupted) is copied to be restored when
+ * run_deferred_handler happens. Then the usually-blocked
+ * signals are added to the mask in the context so that we are
+ * running with blocked signals when the handler returns */
+ sigcopyset(&(data->pending_mask),os_context_sigmask_addr(context));
+ sigaddset_blockable(os_context_sigmask_addr(context));
+ }
}
-
static void
maybe_now_maybe_later(int signal, siginfo_t *info, void *void_context)
{
#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) &&
+ if(maybe_defer_handler(interrupt_handle_now,data,
+ signal,info,context))
+ return;
+ interrupt_handle_now(signal, info, context);
+#ifdef LISP_FEATURE_DARWIN
+ /* Work around G5 bug */
+ DARWIN_FIX_CONTEXT(context);
#endif
- arch_pseudo_atomic_atomic(context)) {
- store_signal_data_for_later(data,signal,info,context);
- arch_set_pseudo_atomic_interrupted(context);
- } else {
- interrupt_handle_now(signal, info, context);
+}
+
+static void
+low_level_interrupt_handle_now(int signal, siginfo_t *info, void *void_context)
+{
+ os_context_t *context = (os_context_t*)void_context;
+ struct thread *thread=arch_os_get_current_thread();
+
+#ifdef LISP_FEATURE_LINUX
+ os_restore_fp_control(context);
+#endif
+ check_blockables_blocked_or_lose();
+ check_interrupts_enabled_or_lose(context);
+ (*thread->interrupt_data->interrupt_low_level_handlers[signal])
+ (signal, info, void_context);
+#ifdef LISP_FEATURE_DARWIN
+ /* Work around G5 bug */
+ DARWIN_FIX_CONTEXT(context);
+#endif
+}
+
+static void
+low_level_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
+ if(maybe_defer_handler(low_level_interrupt_handle_now,data,
+ signal,info,context))
+ return;
+ low_level_interrupt_handle_now(signal, info, context);
+#ifdef LISP_FEATURE_DARWIN
+ /* Work around G5 bug */
+ DARWIN_FIX_CONTEXT(context);
+#endif
+}
+
+#ifdef LISP_FEATURE_SB_THREAD
+void
+sig_stop_for_gc_handler(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();
+ sigset_t ss;
+ int i;
+
+ /* need the context stored so it can have registers scavenged */
+ fake_foreign_function_call(context);
+
+ sigemptyset(&ss);
+ for(i=1;i<NSIG;i++) sigaddset(&ss,i); /* Block everything. */
+ thread_sigmask(SIG_BLOCK,&ss,0);
+
+ /* The GC can't tell if a thread is a zombie, so this would be a
+ * good time to let the kernel reap any of our children in that
+ * awful state, to stop them from being waited for indefinitely.
+ * Userland reaping is done later when GC is finished */
+ if(thread->state!=STATE_STOPPING) {
+ lose("sig_stop_for_gc_handler: wrong thread state: %ld\n",
+ fixnum_value(thread->state));
+ }
+ thread->state=STATE_STOPPED;
+
+ sigemptyset(&ss); sigaddset(&ss,SIG_STOP_FOR_GC);
+ sigwaitinfo(&ss,0);
+ if(thread->state!=STATE_STOPPED) {
+ lose("sig_stop_for_gc_handler: wrong thread state on wakeup: %ld\n",
+ fixnum_value(thread->state));
}
+ thread->state=STATE_RUNNING;
+
+ undo_fake_foreign_function_call(context);
}
-\f
+#endif
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);
+#ifdef LISP_FEATURE_DARWIN
+ DARWIN_FIX_CONTEXT(context);
+#endif
}
/*
}
#endif
-/* and similarly for the control stack guard page */
+/* manipulate the signal context and stack such that when the handler
+ * returns, it will call function instead of whatever it was doing
+ * previously
+ */
-boolean handle_control_stack_guard_triggered(os_context_t *context,void *addr)
+#if (defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
+int *context_eflags_addr(os_context_t *context);
+#endif
+
+extern lispobj call_into_lisp(lispobj fun, lispobj *args, int nargs);
+extern void post_signal_tramp(void);
+void arrange_return_to_lisp_function(os_context_t *context, lispobj function)
{
+#if !(defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64))
+ void * fun=native_pointer(function);
+ void *code = &(((struct simple_fun *) fun)->code);
+#endif
+
+ /* Build a stack frame showing `interrupted' so that the
+ * user's backtrace makes (as much) sense (as usual) */
+
+ /* FIXME: what about restoring fp state? */
+ /* FIXME: what about restoring errno? */
+#ifdef LISP_FEATURE_X86
+ /* Suppose the existence of some function that saved all
+ * registers, called call_into_lisp, then restored GP registers and
+ * returned. It would look something like this:
+
+ push ebp
+ mov ebp esp
+ pushfl
+ pushal
+ push $0
+ push $0
+ pushl {address of function to call}
+ call 0x8058db0 <call_into_lisp>
+ addl $12,%esp
+ popal
+ popfl
+ leave
+ ret
+
+ * What we do here is set up the stack that call_into_lisp would
+ * expect to see if it had been called by this code, and frob the
+ * signal context so that signal return goes directly to call_into_lisp,
+ * and when that function (and the lisp function it invoked) returns,
+ * it returns to the second half of this imaginary function which
+ * restores all registers and returns to C
+
+ * For this to work, the latter part of the imaginary function
+ * must obviously exist in reality. That would be post_signal_tramp
+ */
+
+ u32 *sp=(u32 *)*os_context_register_addr(context,reg_ESP);
+
+ *(sp-15) = post_signal_tramp; /* return address for call_into_lisp */
+ *(sp-14) = function; /* args for call_into_lisp : function*/
+ *(sp-13) = 0; /* arg array */
+ *(sp-12) = 0; /* no. args */
+ /* this order matches that used in POPAD */
+ *(sp-11)=*os_context_register_addr(context,reg_EDI);
+ *(sp-10)=*os_context_register_addr(context,reg_ESI);
+
+ *(sp-9)=*os_context_register_addr(context,reg_ESP)-8;
+ /* POPAD ignores the value of ESP: */
+ *(sp-8)=0;
+ *(sp-7)=*os_context_register_addr(context,reg_EBX);
+
+ *(sp-6)=*os_context_register_addr(context,reg_EDX);
+ *(sp-5)=*os_context_register_addr(context,reg_ECX);
+ *(sp-4)=*os_context_register_addr(context,reg_EAX);
+ *(sp-3)=*context_eflags_addr(context);
+ *(sp-2)=*os_context_register_addr(context,reg_EBP);
+ *(sp-1)=*os_context_pc_addr(context);
+
+#elif defined(LISP_FEATURE_X86_64)
+ u64 *sp=(u64 *)*os_context_register_addr(context,reg_RSP);
+ *(sp-20) = post_signal_tramp; /* return address for call_into_lisp */
+
+ *(sp-19)=*os_context_register_addr(context,reg_R15);
+ *(sp-18)=*os_context_register_addr(context,reg_R14);
+ *(sp-17)=*os_context_register_addr(context,reg_R13);
+ *(sp-16)=*os_context_register_addr(context,reg_R12);
+ *(sp-15)=*os_context_register_addr(context,reg_R11);
+ *(sp-14)=*os_context_register_addr(context,reg_R10);
+ *(sp-13)=*os_context_register_addr(context,reg_R9);
+ *(sp-12)=*os_context_register_addr(context,reg_R8);
+ *(sp-11)=*os_context_register_addr(context,reg_RDI);
+ *(sp-10)=*os_context_register_addr(context,reg_RSI);
+ *(sp-9)=*os_context_register_addr(context,reg_RSP)-16;
+ *(sp-8)=0;
+ *(sp-7)=*os_context_register_addr(context,reg_RBX);
+ *(sp-6)=*os_context_register_addr(context,reg_RDX);
+ *(sp-5)=*os_context_register_addr(context,reg_RCX);
+ *(sp-4)=*os_context_register_addr(context,reg_RAX);
+ *(sp-3)=*context_eflags_addr(context);
+ *(sp-2)=*os_context_register_addr(context,reg_RBP);
+ *(sp-1)=*os_context_pc_addr(context);
+
+ *os_context_register_addr(context,reg_RDI) = function; /* function */
+ *os_context_register_addr(context,reg_RSI) = 0; /* arg. array */
+ *os_context_register_addr(context,reg_RDX) = 0; /* no. args */
+#else
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;
+ build_fake_control_stack_frames(th,context);
+#endif
+
#ifdef LISP_FEATURE_X86
- *os_context_register_addr(context,reg_ECX) = 0;
+ *os_context_pc_addr(context) = call_into_lisp;
+ *os_context_register_addr(context,reg_ECX) = 0;
+ *os_context_register_addr(context,reg_EBP) = sp-2;
+#ifdef __NetBSD__
+ *os_context_register_addr(context,reg_UESP) = sp-15;
+#else
+ *os_context_register_addr(context,reg_ESP) = sp-15;
+#endif
+#elif defined(LISP_FEATURE_X86_64)
+ *os_context_pc_addr(context) = call_into_lisp;
+ *os_context_register_addr(context,reg_RCX) = 0;
+ *os_context_register_addr(context,reg_RBP) = sp-2;
+ *os_context_register_addr(context,reg_RSP) = sp-20;
#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;
+ /* this much of the calling convention is common to all
+ non-x86 ports */
+ *os_context_pc_addr(context) = code;
+ *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
#ifdef ARCH_HAS_NPC_REGISTER
- *os_context_npc_addr(context) =
- 4 + *os_context_pc_addr(context);
+ *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
+ *os_context_register_addr(context,reg_CODE) =
+ fun + FUN_POINTER_LOWTAG;
+#endif
+}
- (INST MOVE CODE-TN FUNCTION)
+#ifdef LISP_FEATURE_SB_THREAD
+void interrupt_thread_handler(int num, siginfo_t *info, void *v_context)
+{
+ os_context_t *context = (os_context_t*)arch_os_get_context(&v_context);
+ /* The order of interrupt execution is peculiar. If thread A
+ * interrupts thread B with I1, I2 and B for some reason recieves
+ * I1 when FUN2 is already on the list, then it is FUN2 that gets
+ * to run first. But when FUN2 is run SIG_INTERRUPT_THREAD is
+ * enabled again and I2 hits pretty soon in FUN2 and run
+ * FUN1. This is of course just one scenario, and the order of
+ * thread interrupt execution is undefined. */
+ struct thread *th=arch_os_get_current_thread();
+ struct cons *c;
+ get_spinlock(&th->interrupt_fun_lock,(long)th);
+ c=((struct cons *)native_pointer(th->interrupt_fun));
+ arrange_return_to_lisp_function(context,c->car);
+ th->interrupt_fun=(lispobj *)(c->cdr);
+ release_spinlock(&th->interrupt_fun_lock);
+}
- 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
+
+/* KLUDGE: Theoretically the approach we use for undefined alien
+ * variables should work for functions as well, but on PPC/Darwin
+ * we get bus error at bogus addresses instead, hence this workaround,
+ * that has the added benefit of automatically discriminating between
+ * functions and variables.
+ */
+void undefined_alien_function() {
+ funcall0(SymbolFunction(UNDEFINED_ALIEN_FUNCTION_ERROR));
+}
+
+boolean handle_guard_page_triggered(os_context_t *context,void *addr){
+ 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 >= CONTROL_STACK_GUARD_PAGE(th) &&
+ addr < CONTROL_STACK_GUARD_PAGE(th) + os_vm_page_size) {
+ /* We hit the end of the control stack: disable guard page
+ * protection so the error handler has some headroom, protect the
+ * previous page so that we can catch returns from the guard page
+ * and restore it. */
+ protect_control_stack_guard_page(th->os_thread,0);
+ protect_control_stack_return_guard_page(th->os_thread,1);
+
+ arrange_return_to_lisp_function
+ (context, SymbolFunction(CONTROL_STACK_EXHAUSTED_ERROR));
+ return 1;
+ }
+ else if(addr >= CONTROL_STACK_RETURN_GUARD_PAGE(th) &&
+ addr < CONTROL_STACK_RETURN_GUARD_PAGE(th) + os_vm_page_size) {
+ /* We're returning from the guard page: reprotect it, and
+ * unprotect this one. This works even if we somehow missed
+ * the return-guard-page, and hit it on our way to new
+ * exhaustion instead. */
+ protect_control_stack_guard_page(th->os_thread,1);
+ protect_control_stack_return_guard_page(th->os_thread,0);
+ return 1;
+ }
+ else if (addr >= undefined_alien_address &&
+ addr < undefined_alien_address + os_vm_page_size) {
+ arrange_return_to_lisp_function
+ (context, SymbolFunction(UNDEFINED_ALIEN_VARIABLE_ERROR));
return 1;
}
else return 0;
}
#ifndef LISP_FEATURE_GENCGC
-/* This function gets called from the SIGSEGV (for e.g. Linux or
+/* This function gets called from the SIGSEGV (for e.g. Linux, NetBSD, &
* 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. */
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 (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(&(data->pending_mask),
- os_context_sigmask_addr(context),
- sizeof(sigset_t));
- sigaddset_blockable(os_context_sigmask_addr(context));
- }
- arch_set_pseudo_atomic_interrupted(context);
- }
- else {
- fake_foreign_function_call(context);
- /* 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;
+ if(!data->pending_handler && !foreign_function_call_active &&
+ gc_trigger_hit(signal, info, context)){
+ clear_auto_gc_trigger();
+ if(!maybe_defer_handler(interrupt_maybe_gc_int,
+ data,signal,info,void_context))
+ interrupt_maybe_gc_int(signal,info,void_context);
+ return 1;
}
+ return 0;
}
+
#endif
-\f
-/*
- * noise to install handlers
- */
-/* 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_ ? */
+/* this is also used by gencgc, in alloc() */
+boolean
+interrupt_maybe_gc_int(int signal, siginfo_t *info, void *void_context)
+{
+ os_context_t *context=(os_context_t *) void_context;
-/* 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. */
+ check_blockables_blocked_or_lose();
+ fake_foreign_function_call(context);
-/* I'm not sure (a) whether this is a real concern, (b) how it helps
- anyway */
+ /* 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.
+ *
+ * FIXME: It would be good to protect the end of dynamic space
+ * and signal a storage condition from there.
+ */
-void
-uninstall_low_level_interrupt_handlers_atexit(void)
-{
+ /* restore the signal mask from the interrupted context before
+ * calling into Lisp */
+ if (context)
+ thread_sigmask(SIG_SETMASK, os_context_sigmask_addr(context), 0);
+
+ funcall0(SymbolFunction(SUB_GC));
+
+ undo_fake_foreign_function_call(context);
+ return 1;
}
+\f
+/*
+ * noise to install handlers
+ */
+
void
undoably_install_low_level_interrupt_handler (int signal,
void handler(int,
lose("bad signal number %d", signal);
}
- sa.sa_sigaction = handler;
+ if (sigismember(&blockable_sigset,signal))
+ sa.sa_sigaction = low_level_maybe_now_maybe_later;
+ else
+ 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;
+ if((signal==SIG_MEMORY_FAULT)
+#ifdef SIG_INTERRUPT_THREAD
+ || (signal==SIG_INTERRUPT_THREAD)
+#endif
+ )
+ sa.sa_flags|= SA_ONSTACK;
#endif
- sigaction(signal, &sa, NULL);
+ sigaction(signal, &sa, NULL);
data->interrupt_low_level_handlers[signal] =
(ARE_SAME_HANDLER(handler, SIG_DFL) ? 0 : handler);
}
sigemptyset(&new);
sigaddset(&new, signal);
- sigprocmask(SIG_BLOCK, &new, &old);
+ thread_sigmask(SIG_BLOCK, &new, &old);
sigemptyset(&new);
sigaddset_blockable(&new);
- FSHOW((stderr, "/interrupt_low_level_handlers[signal]=%d\n",
- interrupt_low_level_handlers[signal]));
+ FSHOW((stderr, "/data->interrupt_low_level_handlers[signal]=%x\n",
+ (unsigned int)data->interrupt_low_level_handlers[signal]));
if (data->interrupt_low_level_handlers[signal]==0) {
if (ARE_SAME_HANDLER(handler, SIG_DFL) ||
ARE_SAME_HANDLER(handler, SIG_IGN)) {
oldhandler = data->interrupt_handlers[signal];
data->interrupt_handlers[signal].c = handler;
- sigprocmask(SIG_SETMASK, &old, 0);
+ thread_sigmask(SIG_SETMASK, &old, 0);
FSHOW((stderr, "/leaving POSIX install_handler(%d, ..)\n", signal));
{
int i;
SHOW("entering interrupt_init()");
+ sigemptyset(&blockable_sigset);
+ sigaddset_blockable(&blockable_sigset);
+
global_interrupt_data=calloc(sizeof(struct interrupt_data), 1);
/* Set up high level handler information. */
projects / sbcl.git / blobdiff