diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def
index c19381e62..49651345a 100644
--- a/grub-core/Makefile.core.def
+++ b/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;
diff --git a/grub-core/gdb/cstub.c b/grub-core/gdb/cstub.c
index a13c8220f..b7dd2200b 100644
--- a/grub-core/gdb/cstub.c
+++ b/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;
diff --git a/grub-core/lib/i386/backtrace.c b/grub-core/lib/i386/backtrace.c
new file mode 100644
index 000000000..27f82a85e
--- /dev/null
+++ b/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 .
+ */
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+
+#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);
+}
diff --git a/include/grub/backtrace.h b/include/grub/backtrace.h
new file mode 100644
index 000000000..a0503b8b7
--- /dev/null
+++ b/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 .
+ */
+
+#ifndef GRUB_BACKTRACE_HEADER
+#define GRUB_BACKTRACE_HEADER 1
+
+void grub_backtrace (void);
+void grub_backtrace_pointer (void *ptr);
+
+#endif