[PATCH] powerpc/64: Avoid link stack corruption in kexec_wait()

Christophe Leroy
2021-08-23T07:53:12Z

Use bcl 20,31,+4 instead of bl in order to preserve link stack.

See commit c974809a26a1 ("powerpc/vdso: Avoid link stack corruption
in __get_datapage()") for details.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
arch/powerpc/kernel/misc_64.S | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 4b761a18a74d..613509907166 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -255,7 +255,7 @@ _GLOBAL(scom970_write)
* Physical (hardware) cpu id should be in r3.
*/
_GLOBAL(kexec_wait)
- bl 1f
+ bcl 20,31,1f
1: mflr r5
addi r5,r5,kexec_flag-1b

--
2.25.0