From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ot1-x332.google.com (mail-ot1-x332.google.com [IPv6:2607:f8b0:4864:20::332]) by sourceware.org (Postfix) with ESMTPS id 22B07385841A for ; Fri, 21 Jan 2022 20:00:44 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 22B07385841A Received: by mail-ot1-x332.google.com with SMTP id c3-20020a9d6c83000000b00590b9c8819aso13115765otr.6 for ; Fri, 21 Jan 2022 12:00:44 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:cc:references:from:in-reply-to :content-transfer-encoding; bh=emNLTGxkgr4LTelfAzZgDo4cCedRYpwQ9CtjnkxC8M0=; b=3BhmKMtwiCsMSPpAyOKbYHqy/S1VdGQQMKKJlaBMIi0ei80CyGKO1xaiWj8HTyw1Yo OM21LjixkaVt1rFVP1Jles/Ro/wA90qM1AmvDE3vrit6nusgJILrON1PRyzGC4hXT1vp t4+9oU9gjRRq3DTU0WSntmGIEAuSzRGe7p7mREdMAW5LlljkR4lURg4x5e/wp1F7iDBI DeVgD/gZ2EbWCzajHoTFIKYOs5Uz0r7Fq9wD/itoxowdK0YF4jqsv0eoVGsHFtH7em3E m8gb1+KbeF2qN4Bb1dZwzMlmXpt4AzzZkx/tDJ/PKM/YoMsCIASl3xkqf5fKQeTMGVho vt0g== X-Gm-Message-State: AOAM533+akG9BspJQVFPer2kRL4uX2ayrYVg3CfbgvR/z2WQVDu12ydT Wrv2hayDRzFde3L9kjz2dIhrGg== X-Google-Smtp-Source: ABdhPJzFPprdCC3N447+CD8+XYF0uaxR8V2/JLPzzTLQnz0OyfiVZpB+nFlffw0/toEPwOcPJScdaw== X-Received: by 2002:a05:6830:19ee:: with SMTP id t14mr4026116ott.176.1642795243226; Fri, 21 Jan 2022 12:00:43 -0800 (PST) Received: from ?IPV6:2804:431:c7cb:27f8:f8b7:bc61:9607:9ecb? ([2804:431:c7cb:27f8:f8b7:bc61:9607:9ecb]) by smtp.gmail.com with ESMTPSA id h2sm1431458otm.11.2022.01.21.12.00.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 21 Jan 2022 12:00:42 -0800 (PST) Message-ID: <24b9dc0d-f953-fae0-79e3-8068fb3e1e0c@linaro.org> Date: Fri, 21 Jan 2022 17:00:40 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH v8 2/4] elf: Add a test for PT_LOAD segments with mixed p_align [BZ #28676] Content-Language: en-US To: "H.J. Lu" , libc-alpha@sourceware.org Cc: Florian Weimer References: <20220118215731.1320930-1-hjl.tools@gmail.com> <20220118215731.1320930-3-hjl.tools@gmail.com> From: Adhemerval Zanella In-Reply-To: <20220118215731.1320930-3-hjl.tools@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-12.8 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, NICE_REPLY_A, 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-List-Received-Date: Fri, 21 Jan 2022 20:00:47 -0000 On 18/01/2022 18:57, H.J. Lu wrote: > Add tst-p_alignmod1-edit to edit the copy of tst-p_alignmod-base.so to > reduce p_align of the first PT_LOAD segment by half and verify that the > shared library is mapped with the maximum p_align of all PT_LOAD segments. > --- > elf/Makefile | 16 +++++ > elf/tst-elf-edit.h | 126 +++++++++++++++++++++++++++++++++++++ > elf/tst-p_align.h | 20 ++++++ > elf/tst-p_align1.c | 27 ++++++++ > elf/tst-p_alignmod-base.c | 41 ++++++++++++ > elf/tst-p_alignmod1-edit.c | 34 ++++++++++ > 6 files changed, 264 insertions(+) > create mode 100644 elf/tst-elf-edit.h > create mode 100644 elf/tst-p_align.h > create mode 100644 elf/tst-p_align1.c > create mode 100644 elf/tst-p_alignmod-base.c > create mode 100644 elf/tst-p_alignmod1-edit.c > > diff --git a/elf/Makefile b/elf/Makefile > index 692a65b061..94ebcab1fa 100644 > --- a/elf/Makefile > +++ b/elf/Makefile > @@ -412,6 +412,8 @@ tests += \ > tst-nodelete-opened \ > tst-noload \ > tst-null-argv \ > + tst-p_alignmod1-edit \ > + tst-p_align1 \ > tst-relsort1 \ > tst-ro-dynamic \ > tst-rtld-run-static \ > @@ -728,6 +730,7 @@ modules-names = \ > tst-nodelete-dlclose-plugin \ > tst-nodelete-opened-lib \ > tst-null-argv-lib \ > + tst-p_alignmod-base \ > tst-relsort1mod1 \ > tst-relsort1mod2 \ > tst-ro-dynamic-mod \ > @@ -2578,3 +2581,16 @@ CFLAGS-tst-dl_find_object-mod6.c += -funwind-tables > CFLAGS-tst-dl_find_object-mod7.c += -funwind-tables > CFLAGS-tst-dl_find_object-mod8.c += -funwind-tables > CFLAGS-tst-dl_find_object-mod9.c += -funwind-tables > + > +$(objpfx)tst-p_alignmod-base.so: $(libsupport) > + > +$(objpfx)tst-p_align1: $(objpfx)tst-p_alignmod1.so > + > +# Make a copy of tst-p_alignmod-base.so and lower p_align of the first > +# PT_LOAD segment. > +$(objpfx)tst-p_alignmod1.so: $(objpfx)tst-p_alignmod1-edit \ > + $(objpfx)tst-p_alignmod-base.so > + rm -f $@ > + cp $(objpfx)tst-p_alignmod-base.so $@ > + $(test-wrapper-env) $(run-program-env) $(rtld-prefix) \ > + $(objpfx)tst-p_alignmod1-edit $@ > diff --git a/elf/tst-elf-edit.h b/elf/tst-elf-edit.h > new file mode 100644 > index 0000000000..b764e78933 > --- /dev/null > +++ b/elf/tst-elf-edit.h > @@ -0,0 +1,126 @@ > +/* Update p_align of the first PT_LOAD segment. > + Copyright (C) 2022 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 > + > +const char *file_name; > + > +static size_t update_p_align (size_t); > + > +int > +main (int argc, char ** argv) > +{ > + if (argc != 2) > + { > + printf ("Usage: %s: file\n", argv[0]); > + return 0; > + } > + > + 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); > + } > + > + 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) > + { > + /* Update p_align of the first PT_LOAD segment. */ > + phdr->p_align = update_p_align (phdr->p_align); > + break; > + } > + > + munmap (base, statbuf.st_size); > + close (fd); > + > + return 0; > +} > diff --git a/elf/tst-p_align.h b/elf/tst-p_align.h > new file mode 100644 > index 0000000000..cef92330fb > --- /dev/null > +++ b/elf/tst-p_align.h > @@ -0,0 +1,20 @@ > +/* Prototypes to check different alignments of PT_LOAD segments in > + a shared library. > + Copyright (C) 2022 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); > diff --git a/elf/tst-p_align1.c b/elf/tst-p_align1.c > new file mode 100644 > index 0000000000..961c7fbbf1 > --- /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) 2022 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 "tst-p_align.h" > + > +static int > +do_test (void) > +{ > + return do_load_test (); > +} > + > +#include I am seeing a failure with GNU ld (GNU Binutils) 2.37.20220112: $ make test t=elf/tst-p_align1 [...] FAIL: elf/tst-p_align1 original exit status 1 foo: 0x7fdddbecb000 error: tst-p_alignmod-base.c:39: not true: is_aligned_p (&foo, ALIGN) error: 1 test failures Without -Wl,-z,max-page-size=0x200000 the tst-p_alignmod-base.so is still 0x1000: $ readelf -l elf/tst-p_alignmod-base.so [...] Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flags Align LOAD 0x0000000000000000 0x0000000000000000 0x0000000000000000 0x0000000000000998 0x0000000000000998 R 0x1000 LOAD 0x0000000000001000 0x0000000000001000 0x0000000000001000 0x0000000000000589 0x0000000000000589 R E 0x1000 LOAD 0x0000000000002000 0x0000000000002000 0x0000000000002000 0x00000000000003f8 0x00000000000003f8 R 0x1000 LOAD 0x0000000000002df0 0x0000000000003df0 0x0000000000003df0 0x0000000000000288 0x0000000000000288 RW 0x1000 LOAD 0x0000000000200000 0x0000000000200000 0x0000000000200000 0x0000000000200004 0x0000000000200018 RW 0x1000 [...] I think you will need to use the same strategy from tst-align3 to force the maximum alignment: diff --git a/elf/Makefile b/elf/Makefile index 94ebcab1fa..cdb41c686e 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -2583,6 +2583,7 @@ CFLAGS-tst-dl_find_object-mod8.c += -funwind-tables CFLAGS-tst-dl_find_object-mod9.c += -funwind-tables $(objpfx)tst-p_alignmod-base.so: $(libsupport) +LDFLAGS-tst-p_alignmod-base.so += -Wl,-z,max-page-size=0x200000 $(objpfx)tst-p_align1: $(objpfx)tst-p_alignmod1.so diff --git a/elf/tst-p_alignmod1-edit.c b/elf/tst-p_alignmod1-edit.c index cdb453e696..06d9c636fd 100644 --- a/elf/tst-p_alignmod1-edit.c +++ b/elf/tst-p_alignmod1-edit.c @@ -23,12 +23,5 @@ static size_t update_p_align (size_t p_align) { - size_t pagesize = sysconf (_SC_PAGESIZE); - size_t new_p_align = p_align >> 1; - - if (new_p_align >= pagesize) - error (1, 0, "%s: new p_align (0x%zx) >= page size (0x%zx)", - file_name, new_p_align, pagesize); - - return new_p_align; + return p_align >> 1; } The rest looks ok. > diff --git a/elf/tst-p_alignmod-base.c b/elf/tst-p_alignmod-base.c > new file mode 100644 > index 0000000000..0fc1b75523 > --- /dev/null > +++ b/elf/tst-p_alignmod-base.c > @@ -0,0 +1,41 @@ > +/* Check alignment of PT_LOAD segment in a shared library. > + Copyright (C) 2022 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 "tst-p_align.h" > + > +int foo __attribute__ ((aligned (ALIGN))) = 1; > + > +bool > +__attribute__ ((weak, noclone, noinline)) > +is_aligned_p (void *p, int align) > +{ > + return (((uintptr_t) p) & (align - 1)) == 0; > +} > + > +int > +do_load_test (void) > +{ > + printf ("foo: %p\n", &foo); > + TEST_VERIFY (is_aligned_p (&foo, ALIGN)); > + return 0; > +} > diff --git a/elf/tst-p_alignmod1-edit.c b/elf/tst-p_alignmod1-edit.c > new file mode 100644 > index 0000000000..cdb453e696 > --- /dev/null > +++ b/elf/tst-p_alignmod1-edit.c > @@ -0,0 +1,34 @@ > +/* Reduce p_align of the first PT_LOAD segment by half. > + Copyright (C) 2022 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 "tst-elf-edit.h" > + > +/* Reduce p_align by half. */ > + > +static size_t > +update_p_align (size_t p_align) > +{ > + size_t pagesize = sysconf (_SC_PAGESIZE); > + size_t new_p_align = p_align >> 1; > + > + if (new_p_align >= pagesize) > + error (1, 0, "%s: new p_align (0x%zx) >= page size (0x%zx)", > + file_name, new_p_align, pagesize); > + > + return new_p_align; > +}