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| author | H.J. Lu <hjl.tools@gmail.com> | 2015-03-16 14:58:43 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2015-08-02 06:54:17 -0700 |
| commit | b15f277bac14482c8b2dda4931ebf919644932fa (patch) | |
| tree | 41606945d17ffac35f42d60cf3825f0014f02ad1 | |
| parent | 20f87a053b1e6a9106851f764c205d59fd4b6879 (diff) | |
| download | glibc-b15f277bac14482c8b2dda4931ebf919644932fa.tar.gz | |
Preserve bound registers in _dl_runtime_resolve
We need to add a BND prefix before indirect branch at the end of
_dl_runtime_resolve to preserve bound registers.
[BZ #18134]
* sysdeps/x86_64/dl-trampoline.S (PRESERVE_BND_REGS_PREFIX): New.
(_dl_runtime_resolve): Add a BND prefix before indirect branch.
| -rw-r--r-- | sysdeps/x86_64/dl-trampoline.S | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/sysdeps/x86_64/dl-trampoline.S b/sysdeps/x86_64/dl-trampoline.S index 394441dd40..5f9b35dc3f 100644 --- a/sysdeps/x86_64/dl-trampoline.S +++ b/sysdeps/x86_64/dl-trampoline.S @@ -30,6 +30,7 @@ /* X32 saves RCX, RDX, RSI, RDI, R8 and R9 plus RAX. */ # define REGISTER_SAVE_AREA (8 * 7) # define REGISTER_SAVE_RAX 0 +# define PRESERVE_BND_REGS_PREFIX #else /* X86-64 saves RCX, RDX, RSI, RDI, R8 and R9 plus RAX as well as BND0, BND1, BND2, BND3. */ @@ -40,6 +41,11 @@ # define REGISTER_SAVE_BND2 (REGISTER_SAVE_BND1 + 16) # define REGISTER_SAVE_BND3 (REGISTER_SAVE_BND2 + 16) # define REGISTER_SAVE_RAX (REGISTER_SAVE_BND3 + 16) +# ifdef HAVE_MPX_SUPPORT +# define PRESERVE_BND_REGS_PREFIX bnd +# else +# define PRESERVE_BND_REGS_PREFIX .byte 0xf2 +# endif #endif #define REGISTER_SAVE_RCX (REGISTER_SAVE_RAX + 8) #define REGISTER_SAVE_RDX (REGISTER_SAVE_RCX + 8) @@ -112,6 +118,8 @@ _dl_runtime_resolve: # Adjust stack(PLT did 2 pushes) addq $(REGISTER_SAVE_AREA + 16), %rsp cfi_adjust_cfa_offset(-(REGISTER_SAVE_AREA + 16)) + # Preserve bound registers. + PRESERVE_BND_REGS_PREFIX jmp *%r11 # Jump to function address. cfi_endproc .size _dl_runtime_resolve, .-_dl_runtime_resolve |