From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 832CDC7EE22 for ; Fri, 12 May 2023 02:25:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:From:Subject:Message-ID: Mime-Version:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Owner; bh=CkTenjqGmcRz3jJtuYq5FO7ay+CBSgtiCEK4MHiLKII=; b=1+C 8BcomdDWSTX6CWFK9ODF7boLbMH1X5QtU58QB2Mc09FdbHbloka5GcEBmibQh+CAPkAlx9x++fwOm Rivg8N1a2MAMhPNHj2Eegl1Ko+iq2IAnjwBFPXaG+LNFJUO12i8qJquXIoub8unX8ae4hm32yjYkt wJVT4VTs2joF4rVa5sUY9JJpMwkx3gvFZfegCWhL7P8bTdmrVb3UpQ2syUcUXYuzzTF8KbamvjrQc ik9vNth9uQCJ3rqitj+zL8OfeHL6qGppvPeZDvLdKMnNfQCIhSyd/I7Yd/159dyyax6cbRG3ABqr2 VZocaG/on2ljx1j2azOl/+3lRlh628g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1pxITd-00Aj6s-2l; Fri, 12 May 2023 02:25:49 +0000 Received: from mail-yb1-xb4a.google.com ([2607:f8b0:4864:20::b4a]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1pxITa-00Aj47-2O for kexec@lists.infradead.org; Fri, 12 May 2023 02:25:48 +0000 Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-ba6939e78a0so10147741276.0 for ; Thu, 11 May 2023 19:25:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1683858336; x=1686450336; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=dVrdsQc/biAwpt188V4iZWfS19eaXCE07QPOY9kbdyc=; b=GQ8UVH9IygDETvgeENJQeoTFRl8IK6C71cn0eEf8SRe+fcNkVbogqZTEV5spZj3AYl QZY1fCTKrPPA3LJqQI2S73wLreGYzUHXWf6jF0T3V0Qu2J4n42ehYtbxn6HfNim8BzQ1 XB9T4j5TtAct937a1GogPDZ/VyvmPySCrq9ascVSC6HrVysL7S+Dup0RfS+TdHzyffYu +BWPKv5kR//I9uGLkkmM1C3DClzHSfgrHLothXTbfzQ5CPksh3m7s891AsCXvqTXm/Y2 A1ieQSQhQR+UsriiFUS5QNIen/0Zzln7A3aNqNaK8dDOFZlLywHR3jGaZiAOcllmGMaW 5X+w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683858336; x=1686450336; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=dVrdsQc/biAwpt188V4iZWfS19eaXCE07QPOY9kbdyc=; b=WA27iLhpE0MhyiLbOjlGfwBtra4y0NR2Iad1/i9jRVtD4uukmF0f/K2L7ELFiZ3ZLT 6/7+6aWFHpFFlr+g4i9uYDeqviXpvrd329Fn882MM4mac96LFnuDAikKqWaK55XlFwSV uEQ/mm7/D+ZWkatiBxERAk6KmYQT0odV+2paMyQsw1nXfv+uhD1p9Tah4wwQ9CUv0+l3 +/yvGUi2JlVq0e0qngkHHWf8uNCWV8x25aOI/q1dRxMBsxLvxJcOJfSlrH9m1AO33Pvt mO22Gyj9zqufrVdMMf3Gvj4nUlTRoHv0QDOXWPiGLLqr+4EIP4EalCpP0kD9bMvlVpI4 LUZg== X-Gm-Message-State: AC+VfDw9OafbqpguHonh0QHTdPrkurJromHD+G5aOTnezZbeECWHzJY9 rvLPAF/RI7gpNJpQtH9P4SuTmxUBxFKu X-Google-Smtp-Source: ACHHUZ6PjgAnQ4yHVTWsepQlN0qPo9uDN+LDYTHYcGjsv2wb8UltmdJTc0fhG08ccIWbq0MSRLcoxeq80x19 X-Received: from meowing-l.c.googlers.com ([fda3:e722:ac3:cc00:24:72f4:c0a8:3eba]) (user=maskray job=sendgmr) by 2002:a05:690c:10c:b0:55c:a5db:869 with SMTP id bd12-20020a05690c010c00b0055ca5db0869mr19325168ywb.4.1683858336753; Thu, 11 May 2023 19:25:36 -0700 (PDT) Date: Fri, 12 May 2023 02:25:28 +0000 Mime-Version: 1.0 Message-ID: <20230512022528.3430327-1-maskray@google.com> Subject: [PATCH] coredump, vmcore: Set p_align to 4 for PT_NOTE From: Fangrui Song To: Alexander Viro , Christian Brauner , Eric Biederman , Kees Cook , Baoquan He , Vivek Goyal , Dave Young , linux-fsdevel@vger.kernel.org, kexec@lists.infradead.org Cc: linux-kernel@vger.kernel.org, Fangrui Song X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230511_192546_780135_87FABBFA X-CRM114-Status: GOOD ( 13.06 ) X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+kexec=archiver.kernel.org@lists.infradead.org Tools like readelf/llvm-readelf use p_align to parse a PT_NOTE program header as an array of 4-byte entries or 8-byte entries. Currently, there are workarounds[1] in place for Linux to treat p_align==0 as 4. However, it would be more appropriate to set the correct alignment so that tools do not have to rely on guesswork. FreeBSD coredumps set p_align to 4 as well. [1]: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=82ed9683ec099d8205dc499ac84febc975235af6 [2]: https://reviews.llvm.org/D150022 --- fs/binfmt_elf.c | 2 +- fs/binfmt_elf_fdpic.c | 2 +- fs/proc/vmcore.c | 4 ++-- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index 1033fbdfdbec..44b4c42ab8e8 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1517,7 +1517,7 @@ static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) phdr->p_filesz = sz; phdr->p_memsz = 0; phdr->p_flags = 0; - phdr->p_align = 0; + phdr->p_align = 4; } static void fill_note(struct memelfnote *note, const char *name, int type, diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 05a1471d5283..d76ad3d4f676 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -1269,7 +1269,7 @@ static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offs phdr->p_filesz = sz; phdr->p_memsz = 0; phdr->p_flags = 0; - phdr->p_align = 0; + phdr->p_align = 4; return; } diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index 03f5963914a1..cb80a7703d58 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -877,7 +877,7 @@ static int __init merge_note_headers_elf64(char *elfptr, size_t *elfsz, phdr.p_offset = roundup(note_off, PAGE_SIZE); phdr.p_vaddr = phdr.p_paddr = 0; phdr.p_filesz = phdr.p_memsz = phdr_sz; - phdr.p_align = 0; + phdr.p_align = 4; /* Add merged PT_NOTE program header*/ tmp = elfptr + sizeof(Elf64_Ehdr); @@ -1068,7 +1068,7 @@ static int __init merge_note_headers_elf32(char *elfptr, size_t *elfsz, phdr.p_offset = roundup(note_off, PAGE_SIZE); phdr.p_vaddr = phdr.p_paddr = 0; phdr.p_filesz = phdr.p_memsz = phdr_sz; - phdr.p_align = 0; + phdr.p_align = 4; /* Add merged PT_NOTE program header*/ tmp = elfptr + sizeof(Elf32_Ehdr); -- 2.40.1.606.ga4b1b128d6-goog _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec