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Commit f32360ef authored by Kees Cook's avatar Kees Cook Committed by H. Peter Anvin
Browse files

x86, kaslr: Report kernel offset on panic 



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

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Link: http://lkml.kernel.org/r/1381450698-28710-6-git-send-email-keescook@chromium.org


Signed-off-by: default avatarH. Peter Anvin <hpa@linux.intel.com>
parent 82fa9637

arch/x86/kernel/setup.c

+26 −0
Original line number Diff line number Diff line
@@ -823,6 +823,20 @@ static void __init trim_low_memory_range(void) 
	memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));

}

	

/*

 * 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
@@ -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);