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[PATCH] PR ld/16322: ld fails to generate GNU_RELRO segment
- From: "H.J. Lu" <hongjiu dot lu at intel dot com>
- To: binutils at sourceware dot org
- Cc: Nick Clifton <nickc at redhat dot com>
- Date: Thu, 12 Dec 2013 10:58:03 -0800
- Subject: [PATCH] PR ld/16322: ld fails to generate GNU_RELRO segment
- Authentication-results: sourceware.org; auth=none
- Reply-to: "H.J. Lu" <hjl dot tools at gmail dot com>
Hi,
There are 2 bugs:
1. lang_size_sections didn't properly align base to the maximum
alignment power of sections between DATA_SEGMENT_ALIGN and
DATA_SEGMENT_RELRO_END.
2. ld failed to adjust LOAD segment to generate GNU_RELRO segment
when LOAD segment doesn't fit GNU_RELRO segment. This is
https://sourceware.org/bugzilla/show_bug.cgi?id=14207
We "fixed" ld by not generating GNU_RELRO segment. This patch
adjusts LOAD segment to generate GNU_RELRO segment. It fixes
PR ld/16322 and at the same time it also fixes PR binutils/16323
since now we can adjust LOAD segment if it is too small. OK
to install?
Thanks.
H.J.
---
bfd/
2013-12-12 H.J. Lu <hongjiu.lu@intel.com>
PR ld/14207
PR ld/16322
PR binutils/16323
* elf.c (_bfd_elf_map_sections_to_segments): Don't check section
size for PT_GNU_RELRO segment.
(assign_file_positions_for_load_sections): If PT_LOAD segment
doesn't fit PT_GNU_RELRO segment, adjust its p_filesz and p_memsz.
ld/
2013-12-12 H.J. Lu <hongjiu.lu@intel.com>
PR ld/14207
PR ld/16322
PR binutils/16323
* ldlang.c (lang_size_sections): Properly align RELRO base.
ld/testsuite/
2013-12-12 H.J. Lu <hongjiu.lu@intel.com>
PR ld/14207
PR ld/16322
PR binutils/16323
* ld-elf/pr16322.d: New file.
* ld-elf/pr16322.s: Likewise.
* ld-x86-64/pr14207.d: Expect PT_GNU_RELRO segment.
diff --git a/bfd/elf.c b/bfd/elf.c
index 66d9644..65d579b 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -4176,11 +4176,7 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info)
== (SEC_LOAD | SEC_HAS_CONTENTS))
break;
- if (i == (unsigned) -1)
- continue;
-
- if (m->sections[i]->vma + m->sections[i]->size
- >= info->relro_end)
+ if (i != (unsigned) -1)
break;
}
}
@@ -4369,6 +4365,7 @@ 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))
@@ -4439,6 +4436,23 @@ 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++)
@@ -4781,6 +4795,23 @@ assign_file_positions_for_load_sections (bfd *abfd,
p->p_flags |= PF_W;
}
}
+
+ 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.
diff --git a/ld/ldlang.c b/ld/ldlang.c
index ba7f493..7851615 100644
--- a/ld/ldlang.c
+++ b/ld/ldlang.c
@@ -5407,7 +5407,8 @@ lang_size_sections (bfd_boolean *relax, bfd_boolean check_regions)
{
if (expld.dataseg.base - (1 << max_alignment_power) < old_base)
expld.dataseg.base += expld.dataseg.pagesize;
- expld.dataseg.base -= (1 << max_alignment_power);
+ /* Properly align base to max_alignment_power. */
+ 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/ld-elf/pr16322.d b/ld/testsuite/ld-elf/pr16322.d
new file mode 100644
index 0000000..f9f7329
--- /dev/null
+++ b/ld/testsuite/ld-elf/pr16322.d
@@ -0,0 +1,7 @@
+#ld: -shared -z relro
+#readelf: -l --wide
+#target: *-*-linux-gnu *-*-gnu*
+
+#...
+ GNU_RELRO .*
+#pass
diff --git a/ld/testsuite/ld-elf/pr16322.s b/ld/testsuite/ld-elf/pr16322.s
new file mode 100644
index 0000000..18259b0
--- /dev/null
+++ b/ld/testsuite/ld-elf/pr16322.s
@@ -0,0 +1,6 @@
+ .globl p1
+ .section .data.rel.ro,"aw",%progbits
+ .align 32
+ .type p1, %object
+p1:
+ .dc.a f1
diff --git a/ld/testsuite/ld-x86-64/pr14207.d b/ld/testsuite/ld-x86-64/pr14207.d
index 2362e88..b1e2d5a 100644
--- a/ld/testsuite/ld-x86-64/pr14207.d
+++ b/ld/testsuite/ld-x86-64/pr14207.d
@@ -2,8 +2,23 @@
#as: --64
#ld: -melf_x86_64 -shared -z relro -z now
#readelf: -l --wide
+#target: x86_64-*-linux*
-#failif
-#...
- NULL +.*
-#...
+Elf file type is DYN \(Shared object file\)
+Entry point 0x1d9
+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
+ DYNAMIC 0x000b90 0x0000000000200b90 0x0000000000200b90 0x0001c0 0x0001c0 RW 0x8
+ GNU_RELRO 0x000b48 0x0000000000200b48 0x0000000000200b48 0x0004b8 0x0004b8 R 0x1
+
+ Section to Segment mapping:
+ Segment Sections...
+ 00 .hash .dynsym .dynstr
+ 01 .init_array .fini_array .jcr .data.rel.ro .dynamic .got .bss
+ 02 .dynamic
+ 03 .init_array .fini_array .jcr .data.rel.ro .dynamic .got
+#pass
--
1.8.3.1