merge backtrace into gdb

grub-core/Makefile.core.def

@@ -1709,6 +1709,12 @@ module = {
   common = commands/testload.c;
 };
 
+module = {
+  name = backtrace;
+  common = lib/i386/backtrace.c;
+  enable = x86;
+};
+
 module = {
   name = lsapm;
   common = commands/i386/pc/lsapm.c;

grub-core/gdb/cstub.c

@@ -210,6 +210,15 @@ grub_gdb_trap (int trap_no)
   char *ptr;
   int newPC;
 
+  if (!grub_gdb_port)
+    {
+      grub_printf ("Unhandled exception 0x%x at ", trap_no);
+      grub_backtrace_print_address (grub_gdb_regs[PC]);
+      grub_printf ("\n");
+      grub_backtrace_pointer (grub_gdb_regs[EBP]);
+      grub_abort ();
+    }
+
   sig_no = grub_gdb_trap2sig (trap_no);
 
   ptr = grub_gdb_outbuf;

grub-core/lib/i386/backtrace.c

@@ -0,0 +1,110 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2009  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/misc.h>
+#include <grub/command.h>
+#include <grub/err.h>
+#include <grub/dl.h>
+#include <grub/mm.h>
+#include <grub/term.h>
+#include <grub/backtrace.h>
+
+#define MAX_STACK_FRAME 102400
+
+GRUB_MOD_LICENSE ("GPLv3+");
+
+void
+grub_backtrace_print_address (void *addr)
+{
+  grub_dl_t mod;
+
+  FOR_DL_MODULES (mod)
+  {
+    grub_dl_segment_t segment;
+    for (segment = mod->segment; segment; segment = segment->next)
+      if (segment->addr <= addr && (grub_uint8_t *) segment->addr
+	  + segment->size > (grub_uint8_t *) addr)
+	{
+	  grub_printf ("%s.%x+%" PRIxGRUB_SIZE, mod->name, segment->section,
+		       (grub_uint8_t *) addr - (grub_uint8_t *) segment->addr);
+	  return;
+	}
+  }
+
+  grub_printf ("%p", addr);
+}
+
+void
+grub_backtrace_pointer (void *ebp)
+{
+  void *ptr, *nptr;
+  unsigned i;
+
+  ptr = ebp;
+  while (1)
+    {
+      grub_printf ("%p: ", ptr);
+      grub_backtrace_print_address (((void **) ptr)[1]);
+      grub_printf (" (");
+      for (i = 0; i < 2; i++)
+	grub_printf ("%p,", ((void **)ptr) [i + 2]);
+      grub_printf ("%p)\n", ((void **)ptr) [i + 2]);
+      nptr = *(void **)ptr;
+      if (nptr < ptr || (void **) nptr - (void **) ptr > MAX_STACK_FRAME
+	  || nptr == ptr)
+	{
+	  grub_printf ("Invalid stack frame at %p (%p)\n", ptr, nptr);
+	  break;
+	}
+      ptr = nptr;
+    }
+}
+
+void
+grub_backtrace (void)
+{
+#ifdef __x86_64__
+  asm volatile ("movq %rbp, %rdi\n"
+		"call grub_backtrace_pointer");
+#else
+  asm volatile ("movl %ebp, %eax\n"
+		"call grub_backtrace_pointer");
+#endif
+}
+
+static grub_err_t
+grub_cmd_backtrace (grub_command_t cmd __attribute__ ((unused)),
+		    int argc __attribute__ ((unused)),
+		    char **args __attribute__ ((unused)))
+{
+  grub_backtrace ();
+  return 0;
+}
+
+static grub_command_t cmd;
+
+GRUB_MOD_INIT(backtrace)
+{
+  cmd = grub_register_command ("backtrace", grub_cmd_backtrace,
+			       0, "Print backtrace.");
+}
+
+GRUB_MOD_FINI(backtrace)
+{
+  grub_unregister_command (cmd);
+}

include/grub/backtrace.h

@@ -0,0 +1,25 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2009  Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef GRUB_BACKTRACE_HEADER
+#define GRUB_BACKTRACE_HEADER	1
+
+void grub_backtrace (void);
+void grub_backtrace_pointer (void *ptr);
+
+#endif