|
 |
d5474c |
commit 558251bd8785760ad40fcbfeaaee5d27fa5b0fe4
|
|
|
d5474c |
Author: Szabolcs Nagy <szabolcs.nagy@arm.com>
|
|
|
d5474c |
Date: Thu Oct 22 17:55:01 2020 +0100
|
|
|
d5474c |
|
|
|
d5474c |
aarch64: Fix DT_AARCH64_VARIANT_PCS handling [BZ #26798]
|
|
|
d5474c |
|
|
|
d5474c |
The variant PCS support was ineffective because in the common case
|
|
|
d5474c |
linkmap->l_mach.plt == 0 but then the symbol table flags were ignored
|
|
|
d5474c |
and normal lazy binding was used instead of resolving the relocs early.
|
|
|
d5474c |
(This was a misunderstanding about how GOT[1] is setup by the linker.)
|
|
|
d5474c |
|
|
|
d5474c |
In practice this mainly affects SVE calls when the vector length is
|
|
|
d5474c |
more than 128 bits, then the top bits of the argument registers get
|
|
|
d5474c |
clobbered during lazy binding.
|
|
|
d5474c |
|
|
|
d5474c |
Fixes bug 26798.
|
|
|
d5474c |
|
|
|
d5474c |
diff --git a/sysdeps/aarch64/dl-machine.h b/sysdeps/aarch64/dl-machine.h
|
|
|
d5474c |
index b39eae4acf4086ee..3fd3c8a265d012b1 100644
|
|
|
d5474c |
--- a/sysdeps/aarch64/dl-machine.h
|
|
|
d5474c |
+++ b/sysdeps/aarch64/dl-machine.h
|
|
|
d5474c |
@@ -391,13 +391,6 @@ elf_machine_lazy_rel (struct link_map *map,
|
|
|
d5474c |
/* Check for unexpected PLT reloc type. */
|
|
|
d5474c |
if (__builtin_expect (r_type == AARCH64_R(JUMP_SLOT), 1))
|
|
|
d5474c |
{
|
|
|
d5474c |
- if (map->l_mach.plt == 0)
|
|
|
d5474c |
- {
|
|
|
d5474c |
- /* Prelinking. */
|
|
|
d5474c |
- *reloc_addr += l_addr;
|
|
|
d5474c |
- return;
|
|
|
d5474c |
- }
|
|
|
d5474c |
-
|
|
|
d5474c |
if (__glibc_unlikely (map->l_info[DT_AARCH64 (VARIANT_PCS)] != NULL))
|
|
|
d5474c |
{
|
|
|
d5474c |
/* Check the symbol table for variant PCS symbols. */
|
|
|
d5474c |
@@ -421,7 +414,10 @@ elf_machine_lazy_rel (struct link_map *map,
|
|
|
d5474c |
}
|
|
|
d5474c |
}
|
|
|
d5474c |
|
|
|
d5474c |
- *reloc_addr = map->l_mach.plt;
|
|
|
d5474c |
+ if (map->l_mach.plt == 0)
|
|
|
d5474c |
+ *reloc_addr += l_addr;
|
|
|
d5474c |
+ else
|
|
|
d5474c |
+ *reloc_addr = map->l_mach.plt;
|
|
|
d5474c |
}
|
|
|
d5474c |
else if (__builtin_expect (r_type == AARCH64_R(TLSDESC), 1))
|
|
|
d5474c |
{
|