Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966740AbbBCXy1 (ORCPT ); Tue, 3 Feb 2015 18:54:27 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:54940 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750983AbbBCXPQ (ORCPT ); Tue, 3 Feb 2015 18:15:16 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Engelhardt , linux-arch@vger.kernel.org, Linus Torvalds Subject: [PATCH 3.18 06/57] vm: make stack guard page errors return VM_FAULT_SIGSEGV rather than SIGBUS Date: Tue, 3 Feb 2015 15:13:57 -0800 Message-Id: <20150203231212.582603397@linuxfoundation.org> X-Mailer: git-send-email 2.2.2 In-Reply-To: <20150203231211.486950145@linuxfoundation.org> References: <20150203231211.486950145@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1760 Lines: 48 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Linus Torvalds commit 9c145c56d0c8a0b62e48c8d71e055ad0fb2012ba upstream. The stack guard page error case has long incorrectly caused a SIGBUS rather than a SIGSEGV, but nobody actually noticed until commit fee7e49d4514 ("mm: propagate error from stack expansion even for guard page") because that error case was never actually triggered in any normal situations. Now that we actually report the error, people noticed the wrong signal that resulted. So far, only the test suite of libsigsegv seems to have actually cared, but there are real applications that use libsigsegv, so let's not wait for any of those to break. Reported-and-tested-by: Takashi Iwai Tested-by: Jan Engelhardt Acked-by: Heiko Carstens # "s390 still compiles and boots" Cc: linux-arch@vger.kernel.org Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/memory.c +++ b/mm/memory.c @@ -2645,7 +2645,7 @@ static int do_anonymous_page(struct mm_s /* Check if we need to add a guard page to the stack */ if (check_stack_guard_page(vma, address) < 0) - return VM_FAULT_SIGBUS; + return VM_FAULT_SIGSEGV; /* Use the zero-page for reads */ if (!(flags & FAULT_FLAG_WRITE)) { -- 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/