From patchwork Fri Dec 10 12:39:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rongwei Wang X-Patchwork-Id: 48778 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 0E3F93858024 for ; Fri, 10 Dec 2021 12:41:03 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 0E3F93858024 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1639140063; bh=K0tLs8Nf2xx6sPxja9cjkPARM3AmNLPlqHX5J5rB3OU=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=Xn3leGsQXx2m5KJAsCzo/z9u3D7kbOSMy39GTSoamLK78FdDjrClHhdETayVZ7KGK Lm87mP/KF8sTxWT/F/4g0i9v9C/fqhtxbtoglAU9YHYPpodUPhb5BsORHlussbNX00 DkvlUmZMWuFVm9nYfmDlA777xcmQ5iJsoWVkN+jQ= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from out30-131.freemail.mail.aliyun.com (out30-131.freemail.mail.aliyun.com [115.124.30.131]) by sourceware.org (Postfix) with ESMTPS id 1B81D385800E for ; Fri, 10 Dec 2021 12:39:19 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 1B81D385800E X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R361e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04400; MF=rongwei.wang@linux.alibaba.com; NM=1; PH=DS; RN=5; SR=0; TI=SMTPD_---0V-9u4OF_1639139951; Received: from localhost.localdomain(mailfrom:rongwei.wang@linux.alibaba.com fp:SMTPD_---0V-9u4OF_1639139951) by smtp.aliyun-inc.com(127.0.0.1); Fri, 10 Dec 2021 20:39:13 +0800 To: libc-alpha@sourceware.org, hjl.tools@gmail.com, fweimer@redhat.com Subject: [PATCH v5 1/2] elf: Properly align PT_LOAD segments Date: Fri, 10 Dec 2021 20:39:10 +0800 Message-Id: <20211210123911.86568-2-rongwei.wang@linux.alibaba.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211210123911.86568-1-rongwei.wang@linux.alibaba.com> References: <20211204045848.71105-1-rongwei.wang@linux.alibaba.com> <20211210123911.86568-1-rongwei.wang@linux.alibaba.com> MIME-Version: 1.0 X-Spam-Status: No, score=-20.3 required=5.0 tests=BAYES_00, ENV_AND_HDR_SPF_MATCH, GIT_PATCH_0, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, UNPARSEABLE_RELAY, USER_IN_DEF_SPF_WL 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: Rongwei Wang via Libc-alpha From: Rongwei Wang Reply-To: Rongwei Wang Cc: xuyu@linux.alibaba.com, gavin.dg@linux.alibaba.com Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" When PT_LOAD segment alignment > the page size, allocate enough space to ensure that the segment can be properly aligned. And this fix can help code segments use huge pages become simple and available. This fixes [BZ #28676]. Signed-off-by: Xu Yu Signed-off-by: Rongwei Wang Reviewed-by: H.J. Lu --- elf/dl-load.c | 1 + elf/dl-load.h | 2 +- elf/dl-map-segments.h | 49 +++++++++++++++++++++++++++++++++++++++---- 3 files changed, 47 insertions(+), 5 deletions(-) diff --git a/elf/dl-load.c b/elf/dl-load.c index bf8957e73c..9a23590bf4 100644 --- a/elf/dl-load.c +++ b/elf/dl-load.c @@ -1150,6 +1150,7 @@ _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; c->mapoff = ALIGN_DOWN (ph->p_offset, GLRO(dl_pagesize)); /* Determine whether there is a gap between the last segment diff --git a/elf/dl-load.h b/elf/dl-load.h index e329d49a81..c121e3456c 100644 --- a/elf/dl-load.h +++ b/elf/dl-load.h @@ -74,7 +74,7 @@ ELF_PREFERRED_ADDRESS_DATA; Its details have been expanded out and converted. */ struct loadcmd { - ElfW(Addr) mapstart, mapend, dataend, allocend; + ElfW(Addr) mapstart, mapend, dataend, allocend, mapalign; ElfW(Off) mapoff; int prot; /* PROT_* bits. */ }; diff --git a/elf/dl-map-segments.h b/elf/dl-map-segments.h index f9fb110ee3..74abf324ed 100644 --- a/elf/dl-map-segments.h +++ b/elf/dl-map-segments.h @@ -18,6 +18,50 @@ #include +/* Map a segment and align it properly. */ + +static __always_inline ElfW(Addr) +_dl_map_segment (const struct loadcmd *c, ElfW(Addr) mappref, + const size_t maplength, int fd) +{ + if (__glibc_likely (c->mapalign <= GLRO(dl_pagesize))) + return (ElfW(Addr)) __mmap ((void *) mappref, maplength, c->prot, + MAP_COPY|MAP_FILE, fd, c->mapoff); + + /* If the segment alignment > the page size, allocate enough space to + ensure that the segment can be properly aligned. */ + ElfW(Addr) maplen = (maplength >= c->mapalign + ? (maplength + c->mapalign) + : (2 * c->mapalign)); + ElfW(Addr) map_start = (ElfW(Addr)) __mmap ((void *) mappref, maplen, + PROT_NONE, + MAP_ANONYMOUS|MAP_PRIVATE, + -1, 0); + if (__glibc_unlikely ((void *) map_start == MAP_FAILED)) + return map_start; + + ElfW(Addr) map_start_aligned = ALIGN_UP (map_start, c->mapalign); + map_start_aligned = (ElfW(Addr)) __mmap ((void *) map_start_aligned, + maplength, c->prot, + MAP_COPY|MAP_FILE|MAP_FIXED, + fd, c->mapoff); + if (__glibc_unlikely ((void *) map_start_aligned == MAP_FAILED)) + __munmap ((void *) map_start, maplen); + else + { + /* Unmap the unused regions. */ + ElfW(Addr) delta = map_start_aligned - map_start; + if (delta) + __munmap ((void *) map_start, delta); + ElfW(Addr) map_end = map_start_aligned + maplength; + delta = map_start + maplen - map_end; + if (delta) + __munmap ((void *) map_end, delta); + } + + return map_start_aligned; +} + /* This implementation assumes (as does the corresponding implementation of _dl_unmap_segments, in dl-unmap-segments.h) that shared objects are always laid out with all segments contiguous (or with gaps @@ -53,10 +97,7 @@ _dl_map_segments (struct link_map *l, int fd, - MAP_BASE_ADDR (l)); /* Remember which part of the address space this object uses. */ - l->l_map_start = (ElfW(Addr)) __mmap ((void *) mappref, maplength, - c->prot, - MAP_COPY|MAP_FILE, - fd, c->mapoff); + l->l_map_start = _dl_map_segment (c, mappref, maplength, fd); if (__glibc_unlikely ((void *) l->l_map_start == MAP_FAILED)) return DL_MAP_SEGMENTS_ERROR_MAP_SEGMENT; From patchwork Fri Dec 10 12:39:11 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rongwei Wang X-Patchwork-Id: 48777 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 032003857C43 for ; Fri, 10 Dec 2021 12:40:21 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 032003857C43 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1639140021; bh=iPRd2712Uz5/gemR96/RWIjMIFTpPETl+mn7xoOCgFU=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=YT8TnRd271QzvFhGIlV7qMJqAfqsP8Qgq+3lQQlNaA3KPAcnlGlina6jED40Ox/OT kHGupiaVyEVf6Vg7r5uIl7qwR4JSLzBsKJfrZM71dpKu9+rLM8pRnz9cNKTegk0aoj 4ZcRItLxi9ITTfV5ziZfoZGFTeA01uI9seP31FwA= X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from out30-56.freemail.mail.aliyun.com (out30-56.freemail.mail.aliyun.com [115.124.30.56]) by sourceware.org (Postfix) with ESMTPS id A3A803858D35 for ; Fri, 10 Dec 2021 12:39:18 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org A3A803858D35 X-Alimail-AntiSpam: AC=PASS; BC=-1|-1; BR=01201311R121e4; CH=green; DM=||false|; DS=||; FP=0|-1|-1|-1|0|-1|-1|-1; HT=e01e04426; MF=rongwei.wang@linux.alibaba.com; NM=1; PH=DS; RN=5; SR=0; TI=SMTPD_---0V-9u4OF_1639139951; Received: from localhost.localdomain(mailfrom:rongwei.wang@linux.alibaba.com fp:SMTPD_---0V-9u4OF_1639139951) by smtp.aliyun-inc.com(127.0.0.1); Fri, 10 Dec 2021 20:39:14 +0800 To: libc-alpha@sourceware.org, hjl.tools@gmail.com, fweimer@redhat.com Subject: [PATCH v5 2/2] Add a testcase to check alignment of PT_LOAD segment Date: Fri, 10 Dec 2021 20:39:11 +0800 Message-Id: <20211210123911.86568-3-rongwei.wang@linux.alibaba.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20211210123911.86568-1-rongwei.wang@linux.alibaba.com> References: <20211204045848.71105-1-rongwei.wang@linux.alibaba.com> <20211210123911.86568-1-rongwei.wang@linux.alibaba.com> MIME-Version: 1.0 X-Spam-Status: No, score=-19.9 required=5.0 tests=BAYES_00, ENV_AND_HDR_SPF_MATCH, GIT_PATCH_0, KAM_DMARC_STATUS, KAM_SHORT, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, UNPARSEABLE_RELAY, USER_IN_DEF_SPF_WL 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: Rongwei Wang via Libc-alpha From: Rongwei Wang Reply-To: Rongwei Wang Cc: xuyu@linux.alibaba.com, gavin.dg@linux.alibaba.com Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org Sender: "Libc-alpha" From: "H.J. Lu" This patch adds a testcase for PT_LOAD segment to check it is properly aligned when the alignment > the page size. Signed-off-by: "H.J. Lu" Signed-off-by: Rongwei Wang --- elf/Makefile | 14 ++++++++++++-- elf/tst-align3.c | 37 +++++++++++++++++++++++++++++++++++++ elf/tst-alignmod3.c | 31 +++++++++++++++++++++++++++++++ 3 files changed, 80 insertions(+), 2 deletions(-) create mode 100644 elf/tst-align3.c create mode 100644 elf/tst-alignmod3.c diff --git a/elf/Makefile b/elf/Makefile index ef36008673..b16128ac8b 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -207,7 +207,7 @@ tests += restest1 preloadtest loadfail multiload origtest resolvfail \ tst-tls4 tst-tls5 \ tst-tls10 tst-tls11 tst-tls12 tst-tls13 tst-tls14 tst-tls15 \ tst-tls16 tst-tls17 tst-tls18 tst-tls19 tst-tls-dlinfo \ - tst-align tst-align2 \ + tst-align tst-align2 tst-align3 \ tst-dlmodcount tst-dlopenrpath tst-deep1 \ tst-dlmopen1 tst-dlmopen3 tst-dlmopen4 \ unload3 unload4 unload5 unload6 unload7 unload8 tst-global1 order2 \ @@ -241,6 +241,9 @@ tests-internal += loadtest unload unload2 circleload1 \ tests-container += tst-pldd tst-dlopen-tlsmodid-container \ tst-dlopen-self-container tst-preload-pthread-libc test-srcs = tst-pathopt +ifeq (yes,$(have-fpie)) +tests-pie += tst-align3 +endif selinux-enabled := $(shell cat /selinux/enforce 2> /dev/null) ifneq ($(selinux-enabled),1) tests-execstack-yes = tst-execstack tst-execstack-needed tst-execstack-prog @@ -302,7 +305,7 @@ modules-names = testobj1 testobj2 testobj3 testobj4 testobj5 testobj6 \ circlemod3 circlemod3a \ reldep8mod1 reldep8mod2 reldep8mod3 \ reldep9mod1 reldep9mod2 reldep9mod3 \ - tst-alignmod tst-alignmod2 \ + tst-alignmod tst-alignmod2 tst-alignmod3 \ $(modules-execstack-$(have-z-execstack)) \ tst-dlopenrpathmod tst-deep1mod1 tst-deep1mod2 tst-deep1mod3 \ tst-dlmopen1mod tst-auditmod1 \ @@ -1088,6 +1091,13 @@ CFLAGS-tst-alignmod.c += $(stack-align-test-flags) CFLAGS-tst-alignmod2.c += $(stack-align-test-flags) $(objpfx)tst-align.out: $(objpfx)tst-alignmod.so $(objpfx)tst-align2: $(objpfx)tst-alignmod2.so +$(objpfx)tst-align3: $(objpfx)tst-alignmod3.so +ifeq (yes,$(have-fpie)) +CFLAGS-tst-align3.c += $(PIE-ccflag) +endif +LDFLAGS-tst-align3 += -Wl,-z,max-page-size=0x200000 +LDFLAGS-tst-alignmod3.so += -Wl,-z,max-page-size=0x200000 +$(objpfx)tst-alignmod3.so: $(libsupport) $(objpfx)unload3.out: $(objpfx)unload3mod1.so $(objpfx)unload3mod2.so \ $(objpfx)unload3mod3.so $(objpfx)unload3mod4.so diff --git a/elf/tst-align3.c b/elf/tst-align3.c new file mode 100644 index 0000000000..5697c0bbaf --- /dev/null +++ b/elf/tst-align3.c @@ -0,0 +1,37 @@ +/* Check alignment of PT_LOAD segment 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 + . */ + +#include +#include + +#define ALIGN 0x200000 + +int bar __attribute__ ((aligned (ALIGN))) = 1; + +extern int do_load_test (void); + +static int +do_test (void) +{ + printf ("bar: %p\n", &bar); + TEST_VERIFY (is_aligned (&bar, ALIGN) == 0); + + return do_load_test (); +} + +#include diff --git a/elf/tst-alignmod3.c b/elf/tst-alignmod3.c new file mode 100644 index 0000000000..50ec08462c --- /dev/null +++ b/elf/tst-alignmod3.c @@ -0,0 +1,31 @@ +/* Check alignment of PT_LOAD segment 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 + . */ + +#include +#include + +#define ALIGN 0x200000 + +int foo __attribute__ ((aligned (ALIGN))) = 1; + +void +do_load_test (void) +{ + printf ("foo: %p\n", &foo); + TEST_VERIFY (is_aligned (&foo, ALIGN) == 0); +}