[v2] elf: Inline do_tunable_update_val/tunable_initialize [BZ #28712]
Checks
Context |
Check |
Description |
dj/TryBot-apply_patch |
success
|
Patch applied to master at the time it was sent
|
dj/TryBot-32bit |
success
|
Build for i686
|
Commit Message
Changes in v2:
1. Replace inline with __always_inline.
In static PIE, __tunables_init is called before _dl_relocate_static_pie
in LIBC_START_MAIN in csu/libc-start.c:
__tunables_init (__environ);
ARCH_INIT_CPU_FEATURES ();
/* Do static pie self relocation after tunables and cpu features
are setup for ifunc resolvers. Before this point relocations
must be avoided. */
_dl_relocate_static_pie ();
/* Perform IREL{,A} relocations. */
ARCH_SETUP_IREL ();
Inline do_tunable_update_val and tunable_initialize to prevent compiler
from generating dynamic relocation against tunable_list which causes
__tunables_init to fail in static PIE on x86-64:
FAIL: elf/tst-env-setuid
since
.L35:
movq $-88, %rax
subq .LC3(%rip), %rax
^^^^ This is executed before the .LC3 entry has been relocated.
movq %rax, 8(%rsp)
...
.section .data.rel.ro.local,"aw"
.align 8
.LC3:
.quad tunable_list
Tested on x86-64, x32 and i686 with GCC 11 and GCC 12.
This fixes BZ #28712.
---
elf/dl-tunables.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
Comments
* H. J. Lu via Libc-alpha:
> Inline do_tunable_update_val and tunable_initialize to prevent compiler
> from generating dynamic relocation against tunable_list which causes
> __tunables_init to fail in static PIE on x86-64:
>
> FAIL: elf/tst-env-setuid
>
> since
>
> .L35:
> movq $-88, %rax
> subq .LC3(%rip), %rax
> ^^^^ This is executed before the .LC3 entry has been relocated.
> movq %rax, 8(%rsp)
> ...
> .section .data.rel.ro.local,"aw"
> .align 8
> .LC3:
> .quad tunable_list
>
> Tested on x86-64, x32 and i686 with GCC 11 and GCC 12.
This is a GCC bug that needs to be fixed, or we have to
PI_STATIC_AND_HIDDEN as 0 on x86-64, which has lots of unwanted
consequences.
Thanks,
Florian
@@ -92,7 +92,7 @@ get_next_env (char **envp, char **name, size_t *namelen, char **val,
return NULL;
}
-static void
+static void __always_inline
do_tunable_update_val (tunable_t *cur, const tunable_val_t *valp,
const tunable_num_t *minp,
const tunable_num_t *maxp)
@@ -139,7 +139,7 @@ do_tunable_update_val (tunable_t *cur, const tunable_val_t *valp,
/* Validate range of the input value and initialize the tunable CUR if it looks
good. */
-static void
+static void __always_inline
tunable_initialize (tunable_t *cur, const char *strval)
{
tunable_val_t val;