scavenge(&function_ptr->name, 1);
scavenge(&function_ptr->arglist, 1);
scavenge(&function_ptr->type, 1);
- scavenge(&function_ptr->xrefs, 1);
+ scavenge(&function_ptr->info, 1);
}
return n_words;
* outer context.
*/
#ifndef LISP_FEATURE_WIN32
- check_gc_signals_unblocked_in_sigset_or_lose
- (os_context_sigmask_addr(context));
- unblock_gc_signals();
+ check_gc_signals_unblocked_or_lose(os_context_sigmask_addr(context));
+ unblock_gc_signals(0, 0);
#endif
FSHOW((stderr, "/maybe_gc: calling SUB_GC\n"));
/* FIXME: Nothing must go wrong during GC else we end up running
* here. */
((SymbolValue(INTERRUPTS_ENABLED,thread) != NIL) ||
(SymbolValue(ALLOW_WITH_INTERRUPTS,thread) != NIL))) {
+#ifndef LISP_FEATURE_WIN32
sigset_t *context_sigmask = os_context_sigmask_addr(context);
- if (!deferrables_blocked_in_sigset_p(context_sigmask)) {
- FSHOW((stderr, "/maybe_gc: calling POST_GC\n"));
+ if (!deferrables_blocked_p(context_sigmask)) {
thread_sigmask(SIG_SETMASK, context_sigmask, 0);
- check_gc_signals_unblocked_or_lose();
+ check_gc_signals_unblocked_or_lose(0);
+#endif
+ FSHOW((stderr, "/maybe_gc: calling POST_GC\n"));
funcall0(StaticSymbolFunction(POST_GC));
+#ifndef LISP_FEATURE_WIN32
} else {
FSHOW((stderr, "/maybe_gc: punting on POST_GC due to blockage\n"));
}
+#endif
}
undo_fake_foreign_function_call(context);
FSHOW((stderr, "/maybe_gc: returning\n"));
return (gc_happened != NIL);
}
+
+#define BYTES_ZERO_BEFORE_END (1<<12)
+
+/* There used to be a similar function called SCRUB-CONTROL-STACK in
+ * Lisp and another called zero_stack() in cheneygc.c, but since it's
+ * shorter to express in, and more often called from C, I keep only
+ * the C one after fixing it. -- MG 2009-03-25 */
+
+/* Zero the unused portion of the control stack so that old objects
+ * are not kept alive because of uninitialized stack variables.
+ *
+ * "To summarize the problem, since not all allocated stack frame
+ * slots are guaranteed to be written by the time you call an another
+ * function or GC, there may be garbage pointers retained in your dead
+ * stack locations. The stack scrubbing only affects the part of the
+ * stack from the SP to the end of the allocated stack." - ram, on
+ * cmucl-imp, Tue, 25 Sep 2001
+ *
+ * So, as an (admittedly lame) workaround, from time to time we call
+ * scrub-control-stack to zero out all the unused portion. This is
+ * supposed to happen when the stack is mostly empty, so that we have
+ * a chance of clearing more of it: callers are currently (2002.07.18)
+ * REPL, SUB-GC and sig_stop_for_gc_handler. */
+
+/* Take care not to tread on the guard page and the hard guard page as
+ * it would be unkind to sig_stop_for_gc_handler. Touching the return
+ * guard page is not dangerous. For this to work the guard page must
+ * be zeroed when protected. */
+
+/* FIXME: I think there is no guarantee that once
+ * BYTES_ZERO_BEFORE_END bytes are zero the rest are also zero. This
+ * may be what the "lame" adjective in the above comment is for. In
+ * this case, exact gc may lose badly. */
+void
+scrub_control_stack(void)
+{
+ struct thread *th = arch_os_get_current_thread();
+ os_vm_address_t guard_page_address = CONTROL_STACK_GUARD_PAGE(th);
+ os_vm_address_t hard_guard_page_address = CONTROL_STACK_HARD_GUARD_PAGE(th);
+ lispobj *sp;
+#ifdef LISP_FEATURE_C_STACK_IS_CONTROL_STACK
+ sp = (lispobj *)&sp - 1;
+#else
+ sp = current_control_stack_pointer;
+#endif
+ scrub:
+ if ((((os_vm_address_t)sp < (hard_guard_page_address + os_vm_page_size)) &&
+ ((os_vm_address_t)sp >= hard_guard_page_address)) ||
+ (((os_vm_address_t)sp < (guard_page_address + os_vm_page_size)) &&
+ ((os_vm_address_t)sp >= guard_page_address) &&
+ (th->control_stack_guard_page_protected != NIL)))
+ return;
+#ifdef LISP_FEATURE_STACK_GROWS_DOWNWARD_NOT_UPWARD
+ do {
+ *sp = 0;
+ } while (((unsigned long)sp--) & (BYTES_ZERO_BEFORE_END - 1));
+ if ((os_vm_address_t)sp < (hard_guard_page_address + os_vm_page_size))
+ return;
+ do {
+ if (*sp)
+ goto scrub;
+ } while (((unsigned long)sp--) & (BYTES_ZERO_BEFORE_END - 1));
+#else
+ do {
+ *sp = 0;
+ } while (((unsigned long)++sp) & (BYTES_ZERO_BEFORE_END - 1));
+ if ((os_vm_address_t)sp >= hard_guard_page_address)
+ return;
+ do {
+ if (*sp)
+ goto scrub;
+ } while (((unsigned long)++sp) & (BYTES_ZERO_BEFORE_END - 1));
+#endif
+}