From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935104AbcJ0Hjn (ORCPT ); Thu, 27 Oct 2016 03:39:43 -0400 Received: from terminus.zytor.com ([198.137.202.10]:54696 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933572AbcJ0Hjl (ORCPT ); Thu, 27 Oct 2016 03:39:41 -0400 Date: Thu, 27 Oct 2016 00:38:45 -0700 From: tip-bot for Josh Poimboeuf Message-ID: Cc: torvalds@linux-foundation.org, luto@kernel.org, hpa@zytor.com, brgerst@gmail.com, linux-kernel@vger.kernel.org, peterz@infradead.org, bp@alien8.de, dvlasenk@redhat.com, tglx@linutronix.de, mingo@kernel.org, jpoimboe@redhat.com Reply-To: peterz@infradead.org, linux-kernel@vger.kernel.org, mingo@kernel.org, jpoimboe@redhat.com, tglx@linutronix.de, bp@alien8.de, dvlasenk@redhat.com, hpa@zytor.com, luto@kernel.org, torvalds@linux-foundation.org, brgerst@gmail.com In-Reply-To: <2d897898f324e275943b590d160b55e482bba65f.1477496147.git.jpoimboe@redhat.com> References: <2d897898f324e275943b590d160b55e482bba65f.1477496147.git.jpoimboe@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:x86/asm] x86/unwind: Detect bad stack return address Git-Commit-ID: b6959a362177053c1c90db6dc1af25b6bddd8548 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: b6959a362177053c1c90db6dc1af25b6bddd8548 Gitweb: http://git.kernel.org/tip/b6959a362177053c1c90db6dc1af25b6bddd8548 Author: Josh Poimboeuf AuthorDate: Wed, 26 Oct 2016 10:41:51 -0500 Committer: Ingo Molnar CommitDate: Thu, 27 Oct 2016 08:32:38 +0200 x86/unwind: Detect bad stack return address If __kernel_text_address() doesn't recognize a return address on the stack, it probably means that it's some generated code which __kernel_text_address() doesn't know about yet. Otherwise there's probably some stack corruption. Either way, warn about it. Use printk_deferred_once() because the unwinder can be called with the console lock by lockdep via save_stack_trace(). Signed-off-by: Josh Poimboeuf Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/2d897898f324e275943b590d160b55e482bba65f.1477496147.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/unwind_frame.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/unwind_frame.c b/arch/x86/kernel/unwind_frame.c index 9be9a8f..5639db6 100644 --- a/arch/x86/kernel/unwind_frame.c +++ b/arch/x86/kernel/unwind_frame.c @@ -20,7 +20,15 @@ unsigned long unwind_get_return_address(struct unwind_state *state) addr = ftrace_graph_ret_addr(state->task, &state->graph_idx, *addr_p, addr_p); - return __kernel_text_address(addr) ? addr : 0; + if (!__kernel_text_address(addr)) { + printk_deferred_once(KERN_WARNING + "WARNING: unrecognized kernel stack return address %p at %p in %s:%d\n", + (void *)addr, addr_p, state->task->comm, + state->task->pid); + return 0; + } + + return addr; } EXPORT_SYMBOL_GPL(unwind_get_return_address);