Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752784Ab3JATiD (ORCPT ); Tue, 1 Oct 2013 15:38:03 -0400 Received: from smtp.outflux.net ([198.145.64.163]:38509 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751518Ab3JAThx (ORCPT ); Tue, 1 Oct 2013 15:37:53 -0400 From: Kees Cook To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, kernel-hardening@lists.openwall.com, adurbin@google.com, Eric Northup , jln@google.com, wad@google.com, Mathias Krause , Zhang Yanfei , "H. Peter Anvin" , keescook@chromium.org Subject: [PATCH 6/7] x86, kaslr: report kernel offset on panic Date: Tue, 1 Oct 2013 12:37:24 -0700 Message-Id: <1380656245-29975-7-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1380656245-29975-1-git-send-email-keescook@chromium.org> References: <1380656245-29975-1-git-send-email-keescook@chromium.org> X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1721 Lines: 57 When the system panics, include the kernel offset in the report to assist in debugging. Signed-off-by: Kees Cook --- 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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/