From eec2f3ed9f053653ed5d629eb50e08e3ee61e9bd Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Fri, 10 Jan 2014 21:11:46 +1030 Subject: [PATCH] Don't adjust LOAD segment to match GNU_RELRO segment Instead, fix Jakub's original code setting up the PR_GNU_RELRO header from the PT_LOAD header. PR ld/14207 PR ld/16322 PR binutils/16323 bfd/ * elf.c (assign_file_positions_for_load_sections): Revert last change. (assign_file_positions_for_non_load_sections): When setting up PT_GNU_RELRO header, don't require a corresponding PT_LOAD header that completely covers the relro region. ld/ * ldlang.c (lang_size_sections): Remove unneeded RELRO base adjust. Tidy comments. * ld.texinfo (DATA_SEGMENT_RELRO_END): Correct description. ld/testsuite/ * ld-x86-64/pr14207.d: Adjust --- bfd/ChangeLog | 10 +++++++++ bfd/elf.c | 37 -------------------------------- ld/ChangeLog | 9 ++++++++ ld/ld.texinfo | 6 ++++-- ld/ldlang.c | 21 ++++++++---------- ld/testsuite/ChangeLog | 4 ++++ ld/testsuite/ld-x86-64/pr14207.d | 2 +- 7 files changed, 37 insertions(+), 52 deletions(-) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 18f0f06f1d4..597bcf224fb 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,13 @@ +2014-01-10 Alan Modra + + PR ld/14207 + PR ld/16322 + PR binutils/16323 + * elf.c (assign_file_positions_for_load_sections): Revert last change. + (assign_file_positions_for_non_load_sections): When setting up + PT_GNU_RELRO header, don't require a corresponding PT_LOAD + header that completely covers the relro region. + 2014-01-09 Tristan Gingold * coff-rs6000.c (rs6000coff_vec, pmac_xcoff_vec): use jump diff --git a/bfd/elf.c b/bfd/elf.c index 870e28192a8..3815e32103b 100644 --- a/bfd/elf.c +++ b/bfd/elf.c @@ -4376,7 +4376,6 @@ assign_file_positions_for_load_sections (bfd *abfd, unsigned int alloc; unsigned int i, j; bfd_vma header_pad = 0; - bfd_vma relro_start = 0, relro_end = 0; if (link_info == NULL && !_bfd_elf_map_sections_to_segments (abfd, link_info)) @@ -4447,23 +4446,6 @@ assign_file_positions_for_load_sections (bfd *abfd, header_pad -= off; off += header_pad; - /* Get start and end of PT_GNU_RELRO segment. */ - if (link_info != NULL) - { - relro_start = link_info->relro_start; - relro_end = link_info->relro_end; - } - else - { - for (m = elf_seg_map (abfd); m != NULL; m = m->next) - if (m->p_type == PT_GNU_RELRO) - { - relro_start = m->p_paddr; - relro_end = relro_start + m->p_size; - break; - } - } - for (m = elf_seg_map (abfd), p = phdrs, j = 0; m != NULL; m = m->next, p++, j++) @@ -4807,22 +4789,6 @@ assign_file_positions_for_load_sections (bfd *abfd, } } - if (relro_start != 0 - && p->p_type == PT_LOAD - && p->p_vaddr >= relro_start) - { - /* If PT_LOAD segment doesn't fit PT_GNU_RELRO segment, - adjust its p_filesz and p_memsz. */ - if (p->p_vaddr + p->p_filesz < relro_end) - { - bfd_vma adjust = relro_end - (p->p_vaddr + p->p_filesz); - p->p_filesz += adjust; - off += adjust; - } - if (p->p_vaddr + p->p_memsz < relro_end) - p->p_memsz += relro_end - (p->p_vaddr + p->p_memsz); - } - off -= off_adjust; /* Check that all sections are in a PT_LOAD segment. @@ -5024,14 +4990,11 @@ assign_file_positions_for_non_load_sections (bfd *abfd, { if (lp->p_type == PT_LOAD && lp->p_vaddr < link_info->relro_end - && lp->p_vaddr + lp->p_filesz >= link_info->relro_end && lm->count != 0 && lm->sections[0]->vma >= link_info->relro_start) break; } - /* PR ld/14207. If the RELRO segment doesn't fit in the - LOAD segment, it should be removed. */ BFD_ASSERT (lm != NULL); } else diff --git a/ld/ChangeLog b/ld/ChangeLog index 41996a5b513..2b7a5738ee5 100644 --- a/ld/ChangeLog +++ b/ld/ChangeLog @@ -1,3 +1,12 @@ +2014-01-10 Alan Modra + + PR ld/14207 + PR ld/16322 + PR binutils/16323 + * ldlang.c (lang_size_sections): Remove unneeded RELRO base + adjust. Tidy comments. + * ld.texinfo (DATA_SEGMENT_RELRO_END): Correct description. + 2014-01-10 Hans-Peter Nilsson * emulparams/crislinux.sh (COMMONPAGESIZE): Define. diff --git a/ld/ld.texinfo b/ld/ld.texinfo index 398dd5942f1..ae3d568721d 100644 --- a/ld/ld.texinfo +++ b/ld/ld.texinfo @@ -5916,13 +5916,15 @@ evaluation purposes. @item DATA_SEGMENT_RELRO_END(@var{offset}, @var{exp}) @kindex DATA_SEGMENT_RELRO_END(@var{offset}, @var{exp}) This defines the end of the @code{PT_GNU_RELRO} segment when -@samp{-z relro} option is used. Second argument is returned. +@samp{-z relro} option is used. When @samp{-z relro} option is not present, @code{DATA_SEGMENT_RELRO_END} does nothing, otherwise @code{DATA_SEGMENT_ALIGN} is padded so that @var{exp} + @var{offset} is aligned to the most commonly used page boundary for particular target. If present in the linker script, it must always come in between @code{DATA_SEGMENT_ALIGN} and -@code{DATA_SEGMENT_END}. +@code{DATA_SEGMENT_END}. Evaluates to the second argument plus any +padding needed at the end of the @code{PT_GNU_RELRO} segment due to +section alignment. @smallexample . = DATA_SEGMENT_RELRO_END(24, .); diff --git a/ld/ldlang.c b/ld/ldlang.c index 7851615dac0..c5e7a3d88cd 100644 --- a/ld/ldlang.c +++ b/ld/ldlang.c @@ -5362,18 +5362,14 @@ lang_size_sections (bfd_boolean *relax, bfd_boolean check_regions) && link_info.relro && expld.dataseg.relro_end) { /* If DATA_SEGMENT_ALIGN DATA_SEGMENT_RELRO_END pair was seen, try - to put expld.dataseg.relro on a (common) page boundary. */ - bfd_vma min_base, old_base, relro_end, maxpage; + to put expld.dataseg.relro_end on a (common) page boundary. */ + bfd_vma min_base, relro_end, maxpage; expld.dataseg.phase = exp_dataseg_relro_adjust; maxpage = expld.dataseg.maxpagesize; /* MIN_BASE is the absolute minimum address we are allowed to start the read-write segment (byte before will be mapped read-only). */ min_base = (expld.dataseg.min_base + maxpage - 1) & ~(maxpage - 1); - /* OLD_BASE is the address for a feasible minimum address which will - still not cause a data overlap inside MAXPAGE causing file offset skip - by MAXPAGE. */ - old_base = expld.dataseg.base; expld.dataseg.base += (-expld.dataseg.relro_end & (expld.dataseg.pagesize - 1)); /* Compute the expected PT_GNU_RELRO segment end. */ @@ -5389,9 +5385,9 @@ lang_size_sections (bfd_boolean *relax, bfd_boolean check_regions) if (expld.dataseg.relro_end > relro_end) { /* The alignment of sections between DATA_SEGMENT_ALIGN - and DATA_SEGMENT_RELRO_END caused huge padding to be - inserted at DATA_SEGMENT_RELRO_END. Try to start a bit lower so - that the section alignments will fit in. */ + and DATA_SEGMENT_RELRO_END can cause excessive padding to + be inserted at DATA_SEGMENT_RELRO_END. Try to start a + bit lower so that the section alignments will fit in. */ asection *sec; unsigned int max_alignment_power = 0; @@ -5405,9 +5401,10 @@ lang_size_sections (bfd_boolean *relax, bfd_boolean check_regions) if (((bfd_vma) 1 << max_alignment_power) < expld.dataseg.pagesize) { - if (expld.dataseg.base - (1 << max_alignment_power) < old_base) - expld.dataseg.base += expld.dataseg.pagesize; - /* Properly align base to max_alignment_power. */ + /* Aligning the adjusted base guarantees the padding + between sections won't change. This is better than + simply subtracting 1 << max_alignment_power which is + what we used to do here. */ expld.dataseg.base &= ~((1 << max_alignment_power) - 1); lang_reset_memory_regions (); one_lang_size_sections_pass (relax, check_regions); diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog index da8ce899ae9..756e7aebaca 100644 --- a/ld/testsuite/ChangeLog +++ b/ld/testsuite/ChangeLog @@ -1,3 +1,7 @@ +2014-01-10 Alan Modra + + * ld-x86-64/pr14207.d: Adjust. + 2014-01-09 H.J. Lu * ld-elf/binutils.exp (binutils_test): Check if GNU_RELRO segment diff --git a/ld/testsuite/ld-x86-64/pr14207.d b/ld/testsuite/ld-x86-64/pr14207.d index b1e2d5a2465..d4e22a1b2b0 100644 --- a/ld/testsuite/ld-x86-64/pr14207.d +++ b/ld/testsuite/ld-x86-64/pr14207.d @@ -11,7 +11,7 @@ There are 4 program headers, starting at offset 64 Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x0001e0 0x0001e0 R 0x200000 - LOAD 0x000b48 0x0000000000200b48 0x0000000000200b48 0x0004b8 0x000cf8 RW 0x200000 + LOAD 0x000b48 0x0000000000200b48 0x0000000000200b48 0x0004b0 0x000cf8 RW 0x200000 DYNAMIC 0x000b90 0x0000000000200b90 0x0000000000200b90 0x0001c0 0x0001c0 RW 0x8 GNU_RELRO 0x000b48 0x0000000000200b48 0x0000000000200b48 0x0004b8 0x0004b8 R 0x1 -- 2.30.2