breeze/glibc
1
0
Fork 0
mirror of https://mirrors.tuna.tsinghua.edu.cn/git/glibc.git synced 2026-01-12 00:20:19 +08:00
Code Issues Packages Projects Releases Wiki Activity

elf: Add DL_ADDRESS_WITHOUT_RELOC [BZ #33088]

Browse Source 
Add DL_ADDRESS_WITHOUT_RELOC to force an address into a general purpose
register to prevent loading it into a vector register directly before
run-time relocation.  This is an updated fix for BZ #33088.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Reviewed-by: Florian Weimer <fweimer@redhat.com>
This commit is contained in:
H.J. Lu
2025-06-15 11:38:54 +08:00
parent eeb7b079d5
commit 632d895f3e
2 changed files with 17 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
elf/rtld.c
View File

@@ -476,11 +476,10 @@ _dl_start_final (void *arg, struct dl_start_final_info *info)
#endif
_dl_setup_hash (&_dl_rtld_map);
_dl_rtld_map.l_real = &_dl_rtld_map;
_dl_rtld_map.l_map_start = (ElfW(Addr)) &__ehdr_start;
/* Prevent run-time relocations against __ehdr_start and _end. */
asm ("" : "+g" (_dl_rtld_map.l_map_start));
_dl_rtld_map.l_map_end = (ElfW(Addr)) _end;
asm ("" : "+g" (_dl_rtld_map.l_map_end));
_dl_rtld_map.l_map_start
= (ElfW(Addr)) DL_ADDRESS_WITHOUT_RELOC (&__ehdr_start);
_dl_rtld_map.l_map_end
= (ElfW(Addr)) DL_ADDRESS_WITHOUT_RELOC (_end);
/* Copy the TLS related data if necessary. */
#ifndef DONT_USE_BOOTSTRAP_MAP
# if NO_TLS_OFFSET != 0

13
include/elf.h
View File

@@ -15,6 +15,19 @@
# define ELF_NOTE_NEXT_OFFSET(namesz, descsz, align) \
ALIGN_UP (ELF_NOTE_DESC_OFFSET ((namesz), (align)) + (descsz), (align))
# ifdef HIDDEN_VAR_NEEDS_DYNAMIC_RELOC
# define DL_ADDRESS_WITHOUT_RELOC(expr) (expr)
# else
/* Evaluate EXPR without run-time relocation for it. EXPR should be an
array, an address of an object, or a string literal. */
# define DL_ADDRESS_WITHOUT_RELOC(expr) \
({ \
__auto_type _result = (expr); \
asm ("" : "+r" (_result)); \
_result; \
})
# endif
/* Some information which is not meant for the public and therefore not
in <elf.h>. */
# include <dl-dtprocnum.h>