When the system panics, include the kernel offset in the report to assist
in debugging.

Signed-off-by: Kees Cook <keesc...@chromium.org>
---
 arch/x86/kernel/setup.c |   26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index f0de629..1708862 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -824,6 +824,20 @@ static void __init trim_low_memory_range(void)
 }
        
 /*
+ * Dump out kernel offset information on panic.
+ */
+static int
+dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
+{
+       pr_emerg("Kernel Offset: 0x%lx from 0x%lx "
+                "(relocation range: 0x%lx-0x%lx)\n",
+                (unsigned long)&_text - __START_KERNEL, __START_KERNEL,
+                __START_KERNEL_map, MODULES_VADDR-1);
+
+       return 0;
+}
+
+/*
  * Determine if we were loaded by an EFI loader.  If so, then we have also been
  * passed the efi memmap, systab, etc., so we should use these data structures
  * for initialization.  Note, the efi init code path is determined by the
@@ -1242,3 +1256,15 @@ void __init i386_reserve_resources(void)
 }
 
 #endif /* CONFIG_X86_32 */
+
+static struct notifier_block kernel_offset_notifier = {
+       .notifier_call = dump_kernel_offset
+};
+
+static int __init register_kernel_offset_dumper(void)
+{
+       atomic_notifier_chain_register(&panic_notifier_list,
+                                       &kernel_offset_notifier);
+       return 0;
+}
+__initcall(register_kernel_offset_dumper);
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to