1.0.5.25:

[sbcl.git] / src / runtime / backtrace.c

diff --git a/src/runtime/backtrace.c b/src/runtime/backtrace.c
index 07af8fe..42ddb2e 100644 (file)
--- a/src/runtime/backtrace.c
+++ b/src/runtime/backtrace.c
@@ -165,7 +165,7 @@ previous_info(struct call_info *info)
 {
     struct call_frame *this_frame;
     struct thread *thread=arch_os_get_current_thread();
-    int free;
+    int free_ici;
 
     if (!cs_valid_pointer_p(info->frame)) {
         printf("Bogus callee value (0x%08lx).\n", (unsigned long)info->frame);
@@ -182,10 +182,10 @@ previous_info(struct call_info *info)
 
     if (info->lra == NIL) {
         /* We were interrupted. Find the correct signal context. */
-        free = SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread)>>2;
-        while (free-- > 0) {
+        free_ici = fixnum_value(SymbolValue(FREE_INTERRUPT_CONTEXT_INDEX,thread));
+        while (free_ici-- > 0) {
             os_context_t *context =
-                thread->interrupt_contexts[free];
+                thread->interrupt_contexts[free_ici];
             if ((struct call_frame *)(unsigned long)
                     (*os_context_register_addr(context, reg_CFP))
                 == info->frame) {
@@ -284,15 +284,31 @@ backtrace(int nframes)
 #else
 
 static int
+altstack_pointer_p (void *p) {
+#ifndef LISP_FEATURE_WIN32
+    char* stack_start = ((char *) arch_os_get_current_thread())
+        + dynamic_values_bytes;
+    char* stack_end = stack_start + 32*SIGSTKSZ;
+
+    return (p > stack_start && p <= stack_end);
+#else
+    /* Win32 doesn't do altstack */
+    return 0;
+#endif
+}
+
+static int
 stack_pointer_p (void *p)
 {
   /* we are using sizeof(long) here, because that is the right value on both
    * x86 and x86-64.  (But note that false positives would not cause much harm
    * given the heuristical nature of x86_call_context.) */
   unsigned long stack_alignment = sizeof(long);
-  return (p < (void *) arch_os_get_current_thread()->control_stack_end
-          && p > (void *) &p
-          && (((unsigned long) p) & (stack_alignment-1)) == 0);
+
+  return (altstack_pointer_p(p)
+          || (p < (void *) arch_os_get_current_thread()->control_stack_end
+              && (p > (void *) &p || altstack_pointer_p(&p))
+              && (((unsigned long) p) & (stack_alignment-1)) == 0));
 }
 
 static int
@@ -511,20 +527,15 @@ print_entry_points (struct code *code)
   }
 }
 
+/* This function has been split from backtrace() to enable Lisp
+ * backtraces from gdb with call backtrace_from_fp(...). Useful for
+ * example when debugging threading deadlocks.
+ */
 void
-backtrace(int nframes)
+backtrace_from_fp(void *fp, int nframes)
 {
-  void *fp;
   int i;
 
-#if defined(LISP_FEATURE_X86)
-  asm("movl %%ebp,%0" : "=g" (fp));
-#elif defined (LISP_FEATURE_X86_64)
-  asm("movq %%rbp,%0" : "=g" (fp));
-#else
-#error "How did we get here?"
-#endif
-
   for (i = 0; i < nframes; ++i) {
     lispobj *p;
     void *ra;
@@ -563,4 +574,21 @@ backtrace(int nframes)
   }
 }
 
+void
+backtrace(int nframes)
+{
+  void *fp;
+  int i;
+
+#if defined(LISP_FEATURE_X86)
+  asm("movl %%ebp,%0" : "=g" (fp));
+#elif defined (LISP_FEATURE_X86_64)
+  asm("movq %%rbp,%0" : "=g" (fp));
+#else
+#error "How did we get here?"
+#endif
+
+  backtrace_from_fp(fp, nframes);
+}
+
 #endif