From patchwork Tue Aug 8 16:40:40 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Lu, Hongjiu" X-Patchwork-Id: 21984 Received: (qmail 43118 invoked by alias); 8 Aug 2017 16:40:44 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 42025 invoked by uid 89); 8 Aug 2017 16:40:43 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-24.3 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_LAZY_DOMAIN_SECURITY, NO_DNS_FOR_FROM, RP_MATCHES_RCVD autolearn=ham version=3.3.2 spammy= X-HELO: mga04.intel.com X-ExtLoop1: 1 Date: Tue, 8 Aug 2017 09:40:40 -0700 From: "H.J. Lu" To: GNU C Library Subject: [PATCH] Enable hidden visibility in libc.a compiled with PIE Message-ID: <20170808164040.GA31184@gmail.com> Reply-To: "H.J. Lu" MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.8.3 (2017-05-23) When building libc.a with PIE, enable hidden visibility to allow direct access to definitions within libc.a without using GOT. Size comparison of elf/ldconfig when the compiler defaults to -fPIE: On x86-64: text data bss dec hex Before: 619206 20132 5488 644826 9d6da After : 619062 20132 5488 644682 9d64a On i686: text data bss dec hex Before: 556305 10816 3056 570177 8b341 After : 553688 10756 3056 567500 8a8cc OK for master? H.J. --- * include/libc-symbols.h (attribute_hidden): Enable hidden visibility in libc.a compiled with PIE. --- include/libc-symbols.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/libc-symbols.h b/include/libc-symbols.h index fe3ab81c51..d6a1c260f6 100644 --- a/include/libc-symbols.h +++ b/include/libc-symbols.h @@ -363,7 +363,8 @@ for linking") strong_alias(real, name) #endif -#if defined SHARED || defined LIBC_NONSHARED +#if defined SHARED || defined LIBC_NONSHARED \ + || (BUILD_PIE_DEFAULT && IS_IN (libc)) # define attribute_hidden __attribute__ ((visibility ("hidden"))) #else # define attribute_hidden