From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pj1-x1031.google.com (mail-pj1-x1031.google.com [IPv6:2607:f8b0:4864:20::1031]) by sourceware.org (Postfix) with ESMTPS id E87403858C78 for ; Thu, 3 Feb 2022 18:09:52 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org E87403858C78 Received: by mail-pj1-x1031.google.com with SMTP id m7so3210713pjk.0 for ; Thu, 03 Feb 2022 10:09:52 -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:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=Or+WVb5rXrYsvdhasbV9QkWy+ToNh7k/Dn7u1EQ/wAA=; b=KuGsB4Oa0qWfz5wwXQ+yLT0Fs3Np+YokbJb7YnuM09PN9J29uqI/E558nx+VwFb/zS /1FuneeZxilUMr9AjjMrH7cNzn4mNBODjGladpYYD7XwxChUimQJigMmzFVYImicnTgD OYG+Eo6DP4NjpUsdHuED7f8MliM4P1/tP0J+NsFr7CS1G3oZ4CerXo3ugh+Ei/llfkQm lCjJq74ZWtRWdN1K4UL8tnEBduXRR1LAOEiQTyNVpGrrLUfvafo1iHKDHJaxn3RigB9X jpar7dX8qhQPVr6CARCTUQjRylH2+N1Ct0R0GWM0sYwEuYR4FFcRNkhUFvzgyW0v0cXV WO1A== X-Gm-Message-State: AOAM530OqNvD6SYrGo74/cKns79J7cHizYE78mAFwrd2kBWJGO+9KlnW 7xp8y7mBEEBwx+pa6+xp3ZxF0n6ADbM= X-Google-Smtp-Source: ABdhPJzLbu1DI4XX7shTcrbNyOOx7TN8cJuJC7ziAOWjZjuBkRNTwtGXQZ6O6Dd7XCDjz/6Jl2DpEw== X-Received: by 2002:a17:903:1210:: with SMTP id l16mr34407009plh.63.1643911791915; Thu, 03 Feb 2022 10:09:51 -0800 (PST) Received: from gnu-tgl-2.localdomain ([172.58.38.240]) by smtp.gmail.com with ESMTPSA id o1sm32112019pfu.88.2022.02.03.10.09.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Feb 2022 10:09:50 -0800 (PST) Received: from gnu-tgl-2.. (localhost [IPv6:::1]) by gnu-tgl-2.localdomain (Postfix) with ESMTP id CFB8A3004A6; Thu, 3 Feb 2022 10:09:48 -0800 (PST) From: "H.J. Lu" To: libc-alpha@sourceware.org Subject: [PATCH 2/7] elf: Properly handle zero DT_RELA/DT_REL values Date: Thu, 3 Feb 2022 10:09:43 -0800 Message-Id: <20220203180948.2744-3-hjl.tools@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220203180948.2744-1-hjl.tools@gmail.com> References: <20220203180948.2744-1-hjl.tools@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-3020.0 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, FREEMAIL_FROM, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP, T_SCC_BODY_TEXT_LINE, UNWANTED_LANGUAGE_BODY 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: Thu, 03 Feb 2022 18:09:54 -0000 With DT_RELR, there may be no relocations in DT_RELA/DT_REL and their entry values are zero. Don't relocate DT_RELA/DT_REL and update the combined relocation start address if their entry values are zero. --- elf/dynamic-link.h | 6 +++++- elf/get-dynamic-info.h | 18 ++++++++++++++---- 2 files changed, 19 insertions(+), 5 deletions(-) diff --git a/elf/dynamic-link.h b/elf/dynamic-link.h index 916439a586..d6c26d95e4 100644 --- a/elf/dynamic-link.h +++ b/elf/dynamic-link.h @@ -84,7 +84,9 @@ elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[], __typeof (((ElfW(Dyn) *) 0)->d_un.d_val) nrelative; int lazy; } \ ranges[2] = { { 0, 0, 0, 0 }, { 0, 0, 0, 0 } }; \ \ - if ((map)->l_info[DT_##RELOC]) \ + /* With DT_RELR, DT_RELA/DT_REL can have zero value. */ \ + if ((map)->l_info[DT_##RELOC] \ + && (map)->l_info[DT_##RELOC]->d_un.d_ptr != 0) \ { \ ranges[0].start = D_PTR ((map), l_info[DT_##RELOC]); \ ranges[0].size = (map)->l_info[DT_##RELOC##SZ]->d_un.d_val; \ @@ -98,6 +100,8 @@ elf_machine_lazy_rel (struct link_map *map, struct r_scope_elem *scope[], ElfW(Addr) start = D_PTR ((map), l_info[DT_JMPREL]); \ ElfW(Addr) size = (map)->l_info[DT_PLTRELSZ]->d_un.d_val; \ \ + if (ranges[0].start == 0) \ + ranges[0].start = start; \ if (ranges[0].start + ranges[0].size == (start + size)) \ ranges[0].size -= size; \ if (!(do_lazy) \ diff --git a/elf/get-dynamic-info.h b/elf/get-dynamic-info.h index 6c2a3a12b1..f4b957684b 100644 --- a/elf/get-dynamic-info.h +++ b/elf/get-dynamic-info.h @@ -83,16 +83,26 @@ elf_get_dynamic_info (struct link_map *l, bool bootstrap, ADJUST_DYN_INFO (DT_PLTGOT); ADJUST_DYN_INFO (DT_STRTAB); ADJUST_DYN_INFO (DT_SYMTAB); + ADJUST_DYN_INFO (DT_RELR); + ADJUST_DYN_INFO (DT_JMPREL); + ADJUST_DYN_INFO (VERSYMIDX (DT_VERSYM)); + ADJUST_DYN_INFO (ADDRIDX (DT_GNU_HASH)); +# undef ADJUST_DYN_INFO + + /* DT_RELA/DT_REL are mandatory. But they may have zero value if + there is DT_RELR. Don't relocate them if they are zero. */ +# define ADJUST_DYN_INFO(tag) \ + do \ + if (info[tag] != NULL && info[tag]->d_un.d_ptr != 0) \ + info[tag]->d_un.d_ptr += l_addr; \ + while (0) + # if ! ELF_MACHINE_NO_RELA ADJUST_DYN_INFO (DT_RELA); # endif # if ! ELF_MACHINE_NO_REL ADJUST_DYN_INFO (DT_REL); # endif - ADJUST_DYN_INFO (DT_RELR); - ADJUST_DYN_INFO (DT_JMPREL); - ADJUST_DYN_INFO (VERSYMIDX (DT_VERSYM)); - ADJUST_DYN_INFO (ADDRIDX (DT_GNU_HASH)); # undef ADJUST_DYN_INFO } if (info[DT_PLTREL] != NULL) -- 2.34.1