| Summary: | Broken sysv-style hash table when --hash-style=both | ||
|---|---|---|---|
| Product: | binutils | Reporter: | Kito Cheng <kito> |
| Component: | gold | Assignee: | Cary Coutant <ccoutant> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | ccoutant, iant, kito, mh-sourceware |
| Priority: | P2 | ||
| Version: | unspecified | ||
| Target Milestone: | --- | ||
| Host: | Target: | ||
| Build: | Last reconfirmed: | ||
| Attachments: |
Verify tools
Reorder the output order between .gnu.hash and .hash Reorder the output order between .gnu.hash and .hash v2 |
||
Generate by gold --hash-style=sysv
SysV Hash table header
nbuckets : 3
buckets : 0x1216dc8
chains : 0x1216dd4
buckets 0 :
sym : _edata
sym : f
sym : _Jv_RegisterClasses
sym : _init
sym : __gmon_start__
sym :
buckets 1 :
sym : _end
sym : _fini
sym :
buckets 2 :
sym : __bss_start
sym : __cxa_finalize
sym :
Generate by gold --hash-style=both
SysV Hash table header
nbuckets : 3
buckets : 0xf2eea8
chains : 0xf2eeb4
buckets 0 :
sym : _init
sym : _end
sym : _edata
sym : __cxa_finalize
sym : __gmon_start__
sym :
buckets 1 :
sym : _fini
sym : _Jv_RegisterClasses
sym :
buckets 2 :
sym : __bss_start
sym : f
sym :
Hey, it's seem the string table are rearranged after sysv-hash table generated.
Generate by gold --hash-style=sysv
SysV Hash table header
nbuckets : 3
buckets : 0x5a6dc8
chains : 0x5a6dd4
buckets 0 :
sym : _edata (7)
^^^ index
sym : f (6)
sym : _Jv_RegisterClasses (5)
sym : _init (2)
sym : __gmon_start__ (1)
sym : (0)
buckets 1 :
sym : _end (9)
sym : _fini (3)
sym : (0)
buckets 2 :
sym : __bss_start (8)
sym : __cxa_finalize (4)
sym : (0)
Generate by gold --hash-style=both
SysV Hash table header
nbuckets : 3
buckets : 0x643ea8
chains : 0x643eb4
buckets 0 :
sym : _init (7)
sym : _end (6)
sym : _edata (5)
sym : __cxa_finalize (2)
sym : __gmon_start__ (1)
sym : (0)
buckets 1 :
sym : _fini (9)
sym : _Jv_RegisterClasses (3)
sym : (0)
buckets 2 :
sym : __bss_start (8)
sym : f (4)
sym : (0)
Created attachment 6161 [details]
Reorder the output order between .gnu.hash and .hash
The root cause seem the gold::Dynobj::create_gnu_hash_table will
change the dynsym_index,
so this patch just reorder the symbol table generate order to
guarantee the gold::Dynobj::create_elf_hash_table get correct
dynsym_index.
However it's will change the section order between .hash and
.gnu.hash, any suggestion ?
I don't know of any reason why the section order would matter. Generating the .gnu.hash first sounds like the best fix to me. I'd suggest adding a comment that explains why the order matters, though. -cary Created attachment 6162 [details]
Reorder the output order between .gnu.hash and .hash v2
Add comment above creating hash table
Create GNU-sytle hash table first since string table index will
change during creating GNU-sytle hash table. It's will break
the SysV-sytle hash table since SysV-style hash table contain
out-of-date string table index.
I just hit this bug today. What's holding it being fixed? This is an automated email from the git hooks/post-receive script. It was
generated because a ref change was pushed to the repository containing
the project "gdb and binutils".
The branch, master has been updated
via cd6da0366dc6684d32f349b729b5558258fc3af4 (commit)
from d83ad864a285fe3127e1a98830197e8461ad2745 (commit)
Those revisions listed above that are new to this repository have
not appeared on any other notification email; so we list those
revisions in full, below.
- Log -----------------------------------------------------------------
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=cd6da0366dc6684d32f349b729b5558258fc3af4
commit cd6da0366dc6684d32f349b729b5558258fc3af4
Author: Kito Cheng <kito@0xlab.org>
Date: Tue Sep 30 14:36:46 2014 -0700
Fix SysV-style hash table when --hash-style=both.
When --hash-style-both is used, gold currently builds the sysv hash
table first, then the gnu hash table. Building the gnu hash table
renumbers the dynamic symbol table, invalidating the sysv hash
table. This patch reverses the order in which the hash tables are
build so that both hash tables are correct.
gold/
PR gold/13597
* layout.cc (Layout::create_dynamic_symtab): Build gnu-style
hash table before sysv-style hash table.
-----------------------------------------------------------------------
Summary of changes:
gold/ChangeLog | 6 ++++++
gold/layout.cc | 42 ++++++++++++++++++++++--------------------
2 files changed, 28 insertions(+), 20 deletions(-)
Sorry, I thought the proposed patch had already been applied. |
Created attachment 6159 [details] Verify tools The gold linker would generate broken sysv-style hash table when --hash-style=both attach is our verify tools, it's include pre-build so file, link by ld.gold and ld.bfd. and the verify tool are only support 32-bit only now. Tool usage # ./elf-verify-hash libtest.bfd.so verify '_edata'...pass verify 'f'...pass verify '_end'...pass verify '__bss_start'...pass verify '_init'...pass verify '_fini'...pass ^^^^ # pass mean the lookup result of gnu-style & sysv hash are same # ./elf-verify-hash libtest.gold.so verify 'f'...SysV-style: 0 GNU-style: 4 ^^^^^^^^^^^^^^^^^^^^^^^^^^ # if lookup result are different, the tool will print the lookup result verify '_edata'...pass verify '_end'...SysV-style: 0 GNU-style: 6 verify '_init'...pass verify '__bss_start'...pass verify '_fini'...pass