From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL,SPF_HELO_PASS,SPF_PASS shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from sourceware.org (server1.sourceware.org [209.132.180.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dcvr.yhbt.net (Postfix) with ESMTPS id 2A4CE1F463 for ; Tue, 17 Dec 2019 21:48:55 +0000 (UTC) DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:subject:date:message-id:in-reply-to :references; q=dns; s=default; b=nmOIkq2xf7KumiZ2QsBC7O5NcvsvSMj oJnjXdhKNxsfZNQM06Pi2Yo2dyUzSaDHSpVWI0hGacC1nafq4ab+VZFYVVdvKOTd RuGoRSN/ylZmoN54jvpTSm5HQ4mRTd5QdDiQRVWtszJgnhJcqifdDfi7/C7jN+/s unGLzwytAQew= DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id :list-unsubscribe:list-subscribe:list-archive:list-post :list-help:sender:from:to:subject:date:message-id:in-reply-to :references; s=default; bh=XbJ0ogZKtRFyOHZeDZjLKICfG9A=; b=gBjSN vKPzmGVQyGWAn5hSMT99I3scFwsftUNvOWkFSewKjK4hva6C+j4JG8/zlpKS1PsZ gCOTyufjf8rkdvXn/o+/qNVgAbCCgMHFGKrRnwdQHNVOHgG90SUbi5eARzmaEtLx f5X7MuKrcjklZ54dMogwAyOCGoLXBj4+8kfUVY= Received: (qmail 110723 invoked by alias); 17 Dec 2019 21:47:48 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Received: (qmail 110685 invoked by uid 89); 17 Dec 2019 21:47:48 -0000 Authentication-Results: sourceware.org; auth=none X-HELO: mail-pj1-f66.google.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:subject:date:message-id:in-reply-to:references; bh=cdhT9pkFyuo/DsH5l2GQyUgJuqDHBxRQFxXTskLU8X4=; b=RTC9IXEHnjNJRxAEMhigKGbmHu+OGFOvKo8v2anFjNaij9L/1XxwwOs20j9ExBQpOr 8JBVmyQ+256ID1T/rqruNKFtZ14h7oS+XRJoVKFLOHffllfYClMDYRrS7y8DaQRcQpZW Y2zpHiCpiq4x/OwppCRH9KXbwb/OWw0jYYWrAi46OKTa3hATiAeH6924cWVCd0z3LFFR oiCpPS9oIkzIopZWncPiRqKGJBH/2HhSAlK5JPNiH0e7TP2d5IFN3KSncX1OoVtK54L1 VgmwdU750GdIXVySTGk+YpwlVbpY3WX5TnbUHhn8GgaQkhmk9qArdBl824RthVcAg7h6 QSkg== From: Adhemerval Zanella To: libc-alpha@sourceware.org Subject: [PATCH v3 08/16] elf: Enable relro for static build Date: Tue, 17 Dec 2019 18:47:20 -0300 Message-Id: <20191217214728.2886-8-adhemerval.zanella@linaro.org> In-Reply-To: <20191217214728.2886-1-adhemerval.zanella@linaro.org> References: <20191217214728.2886-1-adhemerval.zanella@linaro.org> Changes from previous version: - The tests were removed and instead I will use the ones proposed by Florian's patch 'elf: Add tests for working RELRO protection' [1]. I also plan to send additional coverage for '.data.rel.ro' which trigger failures for the static case on both partial and full relro which is fixed by this patch once the patch is upstream. -- The code is similar to the one at elf/dl-reloc.c, where it checks for the l_relro_size from the link_map (obtained from PT_GNU_RELRO header from program headers) and calls_dl_protected_relro. Checked on x86_64-linux-gnu, i686-linux-gnu, powerpc64le-linux-gnu, aarch64-linux-gnu, s390x-linux-gnu, and sparc64-linux-gnu. I also check with --enable-static pie on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu which seems the only architectures where static PIE is actually working (as per 9d7a3741c9e, on arm-linux-gnueabihf, powerpc64{le}-linux-gnu, and s390x-linux-gnu I am seeing runtime issues not related to my patch). [1] https://sourceware.org/ml/libc-alpha/2019-10/msg00059.html --- elf/dl-support.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) diff --git a/elf/dl-support.c b/elf/dl-support.c index 5526d5ee6e..b2b1b12f6f 100644 --- a/elf/dl-support.c +++ b/elf/dl-support.c @@ -367,14 +367,24 @@ _dl_non_dynamic_init (void) if (_dl_platform != NULL) _dl_platformlen = strlen (_dl_platform); - /* Scan for a program header telling us the stack is nonexecutable. */ if (_dl_phdr != NULL) - for (uint_fast16_t i = 0; i < _dl_phnum; ++i) - if (_dl_phdr[i].p_type == PT_GNU_STACK) + for (const ElfW(Phdr) *ph = _dl_phdr; ph < &_dl_phdr[_dl_phnum]; ++ph) + switch (ph->p_type) { - _dl_stack_flags = _dl_phdr[i].p_flags; + /* Check if the stack is nonexecutable. */ + case PT_GNU_STACK: + _dl_stack_flags = ph->p_flags; + break; + + case PT_GNU_RELRO: + _dl_main_map.l_relro_addr = ph->p_vaddr; + _dl_main_map.l_relro_size = ph->p_memsz; break; } + + /* Setup relro on the binary itself. */ + if (_dl_main_map.l_relro_size != 0) + _dl_protect_relro (&_dl_main_map); } #ifdef DL_SYSINFO_IMPLEMENTATION -- 2.17.1