From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 3214 invoked by alias); 14 Dec 2004 15:11:02 -0000 Mailing-List: contact binutils-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: binutils-owner@sources.redhat.com Received: (qmail 3183 invoked from network); 14 Dec 2004 15:10:54 -0000 Received: from unknown (HELO sunsite.mff.cuni.cz) (195.113.15.26) by sourceware.org with SMTP; 14 Dec 2004 15:10:54 -0000 Received: from sunsite.mff.cuni.cz (sunsite.mff.cuni.cz [127.0.0.1]) by sunsite.mff.cuni.cz (8.13.1/8.13.1) with ESMTP id iBEFApEE003406; Tue, 14 Dec 2004 16:10:51 +0100 Received: (from jj@localhost) by sunsite.mff.cuni.cz (8.13.1/8.13.1/Submit) id iBEFAoJS003401; Tue, 14 Dec 2004 16:10:50 +0100 Date: Tue, 14 Dec 2004 15:11:00 -0000 From: Jakub Jelinek To: binutils@sources.redhat.com Cc: Ulrich Drepper Subject: [PATCH] Try to avoid unneeded gaps with -z relro (take 2) Message-ID: <20041214151050.GL5149@sunsite.mff.cuni.cz> Reply-To: Jakub Jelinek References: <20041213164624.GJ5149@sunsite.mff.cuni.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20041213164624.GJ5149@sunsite.mff.cuni.cz> User-Agent: Mutt/1.4.1i X-SW-Source: 2004-12/txt/msg00156.txt.bz2 On Mon, Dec 13, 2004 at 05:46:24PM +0100, Jakub Jelinek wrote: > When linking i686 libc.so which is -z relro, we sometimes end up with > unneeded gap between RE and RW segments: Unfortunately, on i686 linuxthreads glibc build this patch uncovered a typo that has been introduced in early October. So here is updated patch that fixes that problem (missing ~) as well. Ok to commit? 2004-12-14 Jakub Jelinek * ldexp.h (exp_data_seg): Add min_base and maxpagesize fields. * ldexp.c (fold_binary) : Initialize them. * ldlang.c (lang_size_sections): Use them to avoid wasting virtual address space at DATA_SEGMENT_ALIGN. Fix computation of expected PT_GNU_RELRO segment end. --- ld/ldexp.h.jj 2004-12-09 14:21:39.000000000 +0100 +++ ld/ldexp.h 2004-12-13 16:38:26.000000000 +0100 @@ -100,7 +100,7 @@ extern struct exp_data_seg { exp_dataseg_relro_adjust, exp_dataseg_adjust } phase; - bfd_vma base, relro_end, end, pagesize; + bfd_vma base, min_base, relro_end, end, pagesize, maxpagesize; } exp_data_seg; /* A maps from a segment name to a base address. */ --- ld/ldexp.c.jj 2004-12-09 14:21:39.000000000 +0100 +++ ld/ldexp.c 2004-12-13 16:38:43.000000000 +0100 @@ -435,8 +435,10 @@ fold_binary (etree_type *tree, if (allocation_done == lang_allocating_phase_enum) { exp_data_seg.phase = exp_dataseg_align_seen; + exp_data_seg.min_base = align_n (dot, maxpage); exp_data_seg.base = result.value; exp_data_seg.pagesize = other.value; + exp_data_seg.maxpagesize = maxpage; exp_data_seg.relro_end = 0; } } --- ld/ldlang.c.jj 2004-12-09 14:21:39.000000000 +0100 +++ ld/ldlang.c 2004-12-14 11:50:31.243330544 +0100 @@ -3858,15 +3858,21 @@ lang_size_sections { /* If DATA_SEGMENT_ALIGN DATA_SEGMENT_RELRO_END pair was seen, try to put exp_data_seg.relro on a (common) page boundary. */ - bfd_vma old_base, relro_end; + bfd_vma old_min_base, relro_end, maxpage; exp_data_seg.phase = exp_dataseg_relro_adjust; - old_base = exp_data_seg.base; + old_min_base = exp_data_seg.min_base; + maxpage = exp_data_seg.maxpagesize; exp_data_seg.base += (-exp_data_seg.relro_end & (exp_data_seg.pagesize - 1)); /* Compute the expected PT_GNU_RELRO segment end. */ relro_end = (exp_data_seg.relro_end + exp_data_seg.pagesize - 1) - & (exp_data_seg.pagesize - 1); + & ~(exp_data_seg.pagesize - 1); + if (old_min_base + maxpage < exp_data_seg.base) + { + exp_data_seg.base -= maxpage; + relro_end -= maxpage; + } result = lang_size_sections_1 (s, output_section_statement, prev, fill, dot, relax, check_regions); if (exp_data_seg.relro_end > relro_end) @@ -3888,7 +3894,7 @@ lang_size_sections if (((bfd_vma) 1 << max_alignment_power) < exp_data_seg.pagesize) { if (exp_data_seg.base - (1 << max_alignment_power) - < old_base) + < old_min_base) exp_data_seg.base += exp_data_seg.pagesize; exp_data_seg.base -= (1 << max_alignment_power); result = lang_size_sections_1 (s, output_section_statement, Jakub