From patchwork Tue Dec 21 15:14:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "H.J. Lu" X-Patchwork-Id: 49153 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id BC74C3858006 for ; Tue, 21 Dec 2021 15:14:57 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BC74C3858006 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1640099697; bh=vzudlVICs35gnMSFQrpfR81AVXPAPeU/mcMd6Q1yirc=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=E6w/Jx0FAks4vQxkJjmDX+M6xzpt1aPjODvvTHHN4nsXyN0KC3AEDeMJC+wN5xxLe SzvfSsLe0VZUUhvcYFrrwFwXjg22yJaeAy3UPfz7VJjKPGN+LzfCyHq0xvADrwEykW K75Flw9rjsyhyo2lrkAZYjaiqIg3l+AqrIVg9+R4= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by sourceware.org (Postfix) with ESMTPS id 9B4583858C2C for ; Tue, 21 Dec 2021 15:14:35 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 9B4583858C2C Received: by mail-pl1-x636.google.com with SMTP id q17so10982225plr.11 for ; Tue, 21 Dec 2021 07:14:35 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:subject:date:message-id:mime-version :content-transfer-encoding; bh=vzudlVICs35gnMSFQrpfR81AVXPAPeU/mcMd6Q1yirc=; b=v2T7lP0lU5JFIVmu//9sWFaLDAKzOp+N1vfXuujy6qIYiExO1r3TUBLsZDaSK+41ZW uh7p4ZV/VvnE+S1NXODT8OjhSwoWcO35Cb0CronA5RUbaePGdI4+ofeUF7diNnGB+3rE bX10+1YSipzsoq6jPB40R8KNT8NtMGIHh70APkWOk+EmxwanC2zaEjWkgNChDG5xqN1k qD/POjx9sBeOlRtNnD6riBk6pysv++Xpy6UVBsBQACsMKm7mddh4eRIePTmcm2DQSdq+ Z3rp0g2ZmBaTrDQSLiaOMPRWhiF4MJllR3MJuY7mgwIVPK7hHa9M5d2S/IozM63eViYh uXCw== X-Gm-Message-State: AOAM530+dqwFsje6+kdJ8chHeM92tiUvuPZvDytEq9Aoe0gOw6RMmmg6 ipVVdMIJBMp9NGh2EweMCkV7UECnAYk= X-Google-Smtp-Source: ABdhPJwpc3B5AUDMiSWzyQd0zhk+BLWpxi7hQR9OdY+cjaUmzCY5/DfPKfF/RCHhnDu/ci6L6LnJjw== X-Received: by 2002:a17:902:b197:b0:148:a2e7:fb4d with SMTP id s23-20020a170902b19700b00148a2e7fb4dmr3651632plr.142.1640099674523; Tue, 21 Dec 2021 07:14:34 -0800 (PST) Received: from gnu-tgl-3.localdomain ([172.58.35.133]) by smtp.gmail.com with ESMTPSA id m3sm2940474pjz.10.2021.12.21.07.14.34 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Dec 2021 07:14:34 -0800 (PST) Received: from gnu-tgl-2.localdomain (gnu-tgl-2 [192.168.1.42]) by gnu-tgl-3.localdomain (Postfix) with ESMTPS id 0B29BC0722 for ; Tue, 21 Dec 2021 07:14:33 -0800 (PST) Received: from gnu-tgl-2.. (localhost [IPv6:::1]) by gnu-tgl-2.localdomain (Postfix) with ESMTP id 4B24F3003DA for ; Tue, 21 Dec 2021 07:14:29 -0800 (PST) To: libc-alpha@sourceware.org Subject: [PATCH v5 1/2] elf: Properly align all PT_LOAD segments [BZ #28676] Date: Tue, 21 Dec 2021 07:14:28 -0800 Message-Id: <20211221151429.1596402-1-hjl.tools@gmail.com> X-Mailer: git-send-email 2.33.1 MIME-Version: 1.0 X-Spam-Status: No, score=-3029.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_BARRACUDACENTRAL, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: "H.J. Lu via Libc-alpha" From: "H.J. Lu" Reply-To: "H.J. Lu" Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" Linker may set p_align of a PT_LOAD segment larger than p_align of the first PT_LOAD segment to satisfy a section alignment: Elf file type is DYN (Shared object file) Entry point 0x0 There are 10 program headers, starting at offset 64 Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flags Align LOAD 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000834 0x0000000000000834 R E 0x1000 LOAD 0x0000000000000e00 0x0000000000001e00 0x0000000000001e00 0x0000000000000230 0x0000000000000230 RW 0x1000 LOAD 0x0000000000400000 0x0000000000400000 0x0000000000400000 0x0000000000000004 0x0000000000000008 RW 0x400000 ... Section to Segment mapping: Segment Sections... 00 .note.gnu.property .note.gnu.build-id .gnu.hash .dynsym .dynstr .gnu.version .gnu.version_r .rela.dyn .rela.plt .init .plt .plt.got .text .fini .rodata .eh_frame_hdr .eh_frame 01 .init_array .fini_array .data.rel.ro .dynamic .got .got.plt 02 .data .bss We should align the first PT_LOAD segment to the maximum p_align of all PT_LOAD segments, similar to the kernel commit: commit ce81bb256a224259ab686742a6284930cbe4f1fa Author: Chris Kennelly Date: Thu Oct 15 20:12:32 2020 -0700 fs/binfmt_elf: use PT_LOAD p_align values for suitable start address --- elf/dl-load.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/elf/dl-load.c b/elf/dl-load.c index 721593135e..e61515771a 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -1101,6 +1101,7 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, size_t nloadcmds = 0; bool has_holes = false; bool empty_dynamic = false; + ElfW(Addr) p_align_max = 0; /* The struct is initialized to zero so this is not necessary: l->l_ld = 0; @@ -1151,7 +1152,9 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, c->mapend = ALIGN_UP (ph->p_vaddr + ph->p_filesz, GLRO(dl_pagesize)); c->dataend = ph->p_vaddr + ph->p_filesz; c->allocend = ph->p_vaddr + ph->p_memsz; - c->mapalign = ph->p_align; + /* Remember the maximum p_align. */ + if (ph->p_align > p_align_max) + p_align_max = ph->p_align; c->mapoff = ALIGN_DOWN (ph->p_offset, GLRO(dl_pagesize)); /* Determine whether there is a gap between the last segment @@ -1226,6 +1229,10 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd, goto lose; } + /* Align all PT_LOAD segments to the maximum p_align. */ + for (size_t i = 0; i < nloadcmds; i++) + loadcmds[i].mapalign = p_align_max; + /* dlopen of an executable is not valid because it is not possible to perform proper relocations, handle static TLS, or run the ELF constructors. For PIE, the check needs the dynamic From patchwork Tue Dec 21 15:14:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "H.J. Lu" X-Patchwork-Id: 49154 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 043343858016 for ; Tue, 21 Dec 2021 15:15:40 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 043343858016 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1640099740; bh=zeYW1ZqJfgl9nyG2LahEHuVt2R0J2h/Fp0v+0GW7CTA=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To: From; b=R4msbswAquUVwoo7rhbZzXa7MfjFLn9JFC+EF6IND0JaPVKRFLtrCTPRZ7xx0myx+ DGfGfyDytagPWKqN83u38roGTp1pyfcOu4zetX+TUMggbtYyrItIdueNXStPd/hRTo gNZ7lXCDqMo0Qrg0YqEzc9g9bEBuSfJRFjOi7LuQ= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from mail-pg1-x52a.google.com (mail-pg1-x52a.google.com [IPv6:2607:f8b0:4864:20::52a]) by sourceware.org (Postfix) with ESMTPS id CF8EA3858401 for ; Tue, 21 Dec 2021 15:14:35 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org CF8EA3858401 Received: by mail-pg1-x52a.google.com with SMTP id f125so12641492pgc.0 for ; Tue, 21 Dec 2021 07:14:35 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=zeYW1ZqJfgl9nyG2LahEHuVt2R0J2h/Fp0v+0GW7CTA=; b=EmTZhFl7Cv/72bubUWm6JOUf43dL3OPnSIjAFqSijlt+RlfhKwpQZFzsHF9au2PBpj b40NP2fRL+/c31eFnlfSzuGo78MLhd5GPcx+hhxRTg86sDHbOqBRAQQiHomsiJs9Xm8w zpT0ZogzbUFqZWD/lKh3d3zAroUgefUhDnhRYUdgEkNsDuOFR+BK/5OLjGr8/pxEfEM/ 8ezSWZEkMhxbyIrkHmwfmcbyieDkMrSUsYUF4KYvU7L4NSouhW8BKLFbmhLAQGylUITP F9QBQYF4m2iQw6wCDIyWQOwonIx6PLsPvoDhjWsGQMazkZ4KzgQ7CG8c8EROI2TWtiQu 1ALA== X-Gm-Message-State: AOAM532u8MRxIM3dP8cQ1lx7XLAYbpB0jORONQbtSPiPXC7Zmz1uNwcs ZuVu+XyHgb3YTuzeHb12hmQfCtJVuIA= X-Google-Smtp-Source: ABdhPJww8Z8MaNxGWQFxujwGsKVXDaiLE8H32Ru0fsStCLIaTQd4RSxKFitIL3xFoNJHHKrzd9GnyQ== X-Received: by 2002:a63:cd58:: with SMTP id a24mr3319901pgj.15.1640099674692; Tue, 21 Dec 2021 07:14:34 -0800 (PST) Received: from gnu-tgl-3.localdomain ([172.58.35.133]) by smtp.gmail.com with ESMTPSA id y128sm11387838pfb.24.2021.12.21.07.14.34 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Dec 2021 07:14:34 -0800 (PST) Received: from gnu-tgl-2.localdomain (gnu-tgl-2 [192.168.1.42]) by gnu-tgl-3.localdomain (Postfix) with ESMTPS id 09C7EC06D6 for ; Tue, 21 Dec 2021 07:14:33 -0800 (PST) Received: from gnu-tgl-2.. (localhost [IPv6:::1]) by gnu-tgl-2.localdomain (Postfix) with ESMTP id 4C1653003DB for ; Tue, 21 Dec 2021 07:14:29 -0800 (PST) To: libc-alpha@sourceware.org Subject: [PATCH v5 2/2] elf: Add a test for PT_LOAD segments with mixed p_align [BZ #28676] Date: Tue, 21 Dec 2021 07:14:29 -0800 Message-Id: <20211221151429.1596402-2-hjl.tools@gmail.com> X-Mailer: git-send-email 2.33.1 In-Reply-To: <20211221151429.1596402-1-hjl.tools@gmail.com> References: <20211221151429.1596402-1-hjl.tools@gmail.com> MIME-Version: 1.0 X-Spam-Status: No, score=-3029.1 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, KAM_SHORT, RCVD_IN_BARRACUDACENTRAL, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: "H.J. Lu via Libc-alpha" From: "H.J. Lu" Reply-To: "H.J. Lu" Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" Add tst-alignmod3-edit to edit the copy of tst-alignmod3.so to lower p_align of the first PT_LOAD segment and verify that the shared library is mapped with the maximum p_align of all PT_LOAD segments. --- elf/Makefile | 18 ++++++ elf/tst-alignmod3-edit.c | 130 +++++++++++++++++++++++++++++++++++++++ elf/tst-p_align1.c | 27 ++++++++ 3 files changed, 175 insertions(+) create mode 100644 elf/tst-alignmod3-edit.c create mode 100644 elf/tst-p_align1.c diff --git a/elf/Makefile b/elf/Makefile index fe42caeb0e..c3402c65b2 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -378,6 +378,13 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \ tst-auditmod18 \ tst-audit18mod \ +ifeq (yesyes,$(build-shared)$(run-built-tests)) +tests += \ + tst-alignmod3-edit \ + tst-p_align1 \ + +endif + # Most modules build with _ISOMAC defined, but those filtered out # depend on internal headers. modules-names-tests = $(filter-out ifuncmod% tst-tlsmod%,\ @@ -1995,3 +2002,14 @@ $(objpfx)tst-ro-dynamic-mod.so: $(objpfx)tst-ro-dynamic-mod.os \ $(objpfx)tst-ro-dynamic-mod.os $(objpfx)tst-rtld-run-static.out: $(objpfx)/ldconfig + +$(objpfx)tst-p_align1: $(objpfx)tst-p_alignmod1.so + +# Make a copy of tst-alignmod3.so and lower p_align of the first PT_LOAD +# segment. +$(objpfx)tst-p_alignmod1.so: $(objpfx)tst-alignmod3-edit \ + $(objpfx)tst-alignmod3.so + rm -f $@ + cp $(objpfx)tst-alignmod3.so $@ + $(test-wrapper-env) $(run-program-env) $(rtld-prefix) \ + $(objpfx)tst-alignmod3-edit $@ diff --git a/elf/tst-alignmod3-edit.c b/elf/tst-alignmod3-edit.c new file mode 100644 index 0000000000..14ef8aa3a6 --- /dev/null +++ b/elf/tst-alignmod3-edit.c @@ -0,0 +1,130 @@ +/* Lower p_align of the first PT_LOAD segment. + Copyright (C) 2021 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +int +main (int argc, char ** argv) +{ + if (argc != 2) + { + printf ("Usage: %s: file\n", argv[0]); + return 0; + } + + const char *file_name = argv[1]; + struct stat statbuf; + int errno_saved; + + if (stat (file_name, &statbuf) < 0) + error (1, errno, "%s: not exist", file_name); + + ElfW(Ehdr) *ehdr; + + if (statbuf.st_size < sizeof (*ehdr)) + error (1, 0, "%s: too small", file_name); + + int fd = open (file_name, O_RDWR); + if (fd < 0) + error (1, errno, "%s: can't open", file_name); + + /* Map in the whole file. */ + void *base = mmap (NULL, statbuf.st_size, PROT_READ | PROT_WRITE, + MAP_SHARED, fd, 0); + if (base == MAP_FAILED) + { + errno_saved = errno; + close (fd); + error (1, errno_saved, "%s: failed to map", file_name); + } + + ehdr = (ElfW(Ehdr) *) base; + if (ehdr->e_ident[EI_MAG0] != ELFMAG0 + || ehdr->e_ident[EI_MAG1] != ELFMAG1 + || ehdr->e_ident[EI_MAG2] != ELFMAG2 + || ehdr->e_ident[EI_MAG3] != ELFMAG3) + { + close (fd); + error (1, 0, "%s: bad ELF header", file_name); + } + + if (ehdr->e_type != ET_DYN) + { + close (fd); + error (1, 0, "%s: not shared library", file_name); + } + + bool unsupported_class = true; + switch (ehdr->e_ident[EI_CLASS]) + { + default: + break; + + case ELFCLASS32: + unsupported_class = __ELF_NATIVE_CLASS != 32; + break; + + case ELFCLASS64: + unsupported_class = __ELF_NATIVE_CLASS != 64; + break; + } + + if (unsupported_class) + { + close (fd); + error (1, 0, "%s: unsupported ELF class: %d", + file_name, ehdr->e_ident[EI_CLASS]); + } + + size_t phdr_size = sizeof (ElfW(Phdr)) * ehdr->e_phentsize; + if (statbuf.st_size < (ehdr->e_phoff + phdr_size)) + { + close (fd); + error (1, 0, "%s: too small", file_name); + } + + size_t pagesize = sysconf (_SC_PAGESIZE); + + ElfW(Phdr) *phdr = (ElfW(Phdr) *) (base + ehdr->e_phoff); + for (int i = 0; i < ehdr->e_phnum; i++, phdr++) + if (phdr->p_type == PT_LOAD) + { + /* Reduce p_align of the first PT_LOAD segment by half. */ + if ((phdr->p_align >> 1) < pagesize) + { + close (fd); + error (1, 0, "%s: p_align (0x%zx) < 2 * page size (0x%zx)", + file_name, phdr->p_align, 2 * pagesize); + } + phdr->p_align >>= 1; + break; + } + + munmap (base, statbuf.st_size); + close (fd); + + return 0; +} diff --git a/elf/tst-p_align1.c b/elf/tst-p_align1.c new file mode 100644 index 0000000000..cab9793220 --- /dev/null +++ b/elf/tst-p_align1.c @@ -0,0 +1,27 @@ +/* Check different alignments of PT_LOAD segments in a shared library. + Copyright (C) 2021 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +extern int do_load_test (void); + +static int +do_test (void) +{ + return do_load_test (); +} + +#include