From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 64173 invoked by alias); 29 Nov 2017 00:21:55 -0000 Mailing-List: contact newlib-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: newlib-owner@sourceware.org Received: (qmail 63279 invoked by uid 89); 29 Nov 2017 00:21:55 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-26.7 required=5.0 tests=BAYES_00,GIT_PATCH_0,GIT_PATCH_1,GIT_PATCH_2,GIT_PATCH_3,KB_WAM_FROM_NAME_SINGLEWORD,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy= X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 29 Nov 2017 00:21:54 +0000 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id C4D16C04B952 for ; Wed, 29 Nov 2017 00:21:52 +0000 (UTC) Received: from localhost.localdomain (ovpn-120-11.rdu2.redhat.com [10.10.120.11]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5E150600D1 for ; Wed, 29 Nov 2017 00:21:52 +0000 (UTC) From: Yaakov Selkowitz To: newlib@sourceware.org Subject: [PATCH v4 01/10] ssp: add APIs for Stack Smashing Protection Date: Wed, 29 Nov 2017 00:21:00 -0000 Message-Id: <20171129002143.12500-2-yselkowi@redhat.com> In-Reply-To: <20171129002143.12500-1-yselkowi@redhat.com> References: <20171129002143.12500-1-yselkowi@redhat.com> X-SW-Source: 2017/txt/msg01148.txt.bz2 Compiling with any of the -fstack-protector* flags requires the __stack_chk_guard data import (which needs to be initialized) and the __stack_chk_fail{,_local} functions. While GCC's own libssp can provide these, it is better that we provide these ourselves. The implementation is custom due to being OS-specific. Signed-off-by: Yaakov Selkowitz --- newlib/libc/ssp/stack_protector.c | 45 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) create mode 100644 newlib/libc/ssp/stack_protector.c diff --git a/newlib/libc/ssp/stack_protector.c b/newlib/libc/ssp/stack_protector.c new file mode 100644 index 000000000..ee014b69d --- /dev/null +++ b/newlib/libc/ssp/stack_protector.c @@ -0,0 +1,45 @@ +#include +#include +#include +#include +#include +#include + +uintptr_t __stack_chk_guard = 0; + +void +__attribute__((__constructor__)) +__stack_chk_init (void) +{ + if (__stack_chk_guard != 0) + return; + +#if defined(__CYGWIN__) || defined(__rtems__) + arc4random_buf(&__stack_chk_guard, sizeof(__stack_chk_guard)); +#else + /* If getentropy is not available, use the "terminator canary". */ + ((unsigned char *)&__stack_chk_guard)[0] = 0; + ((unsigned char *)&__stack_chk_guard)[1] = 0; + ((unsigned char *)&__stack_chk_guard)[2] = '\n'; + ((unsigned char *)&__stack_chk_guard)[3] = 255; +#endif +} + +void +__attribute__((__noreturn__)) +__stack_chk_fail (void) +{ + char msg[] = "*** stack smashing detected ***: terminated\n"; + write (2, msg, strlen (msg)); + raise (SIGABRT); + _exit (127); +} + +#ifdef __ELF__ +void +__attribute__((visibility ("hidden"))) +__stack_chk_fail_local (void) +{ + __stack_chk_fail(); +} +#endif -- 2.15.0