[tip:x86/debug] x86/asm/crypto: Don't use RBP as a scratch register
From: tip-bot for Josh Poimboeuf
Date: Thu Feb 25 2016 - 00:50:33 EST
Commit-ID: 68874ac3304ade7ed5ebb12af00d6b9bbbca0a16
Gitweb: http://git.kernel.org/tip/68874ac3304ade7ed5ebb12af00d6b9bbbca0a16
Author: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
AuthorDate: Thu, 21 Jan 2016 16:49:18 -0600
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 24 Feb 2016 08:35:42 +0100
x86/asm/crypto: Don't use RBP as a scratch register
The frame pointer (RBP) is getting clobbered in
sha1_mb_mgr_submit_avx2() before a function call, which can mess up
stack traces. Use R12 instead.
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Bernd Petrovitsch <bernd@xxxxxxxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Chris J Arges <chris.j.arges@xxxxxxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Jiri Slaby <jslaby@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Marek <mmarek@xxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Pedro Alves <palves@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: live-patching@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/15a3eb7ebe68e37755927915f45e4f0bde4d18c5.1453405861.git.jpoimboe@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S b/arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S
index a5a14c6..c3b9447 100644
--- a/arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S
+++ b/arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S
@@ -86,8 +86,8 @@ job_rax = %rax
len = %rax
DWORD_len = %eax
-lane = %rbp
-tmp3 = %rbp
+lane = %r12
+tmp3 = %r12
tmp = %r9
DWORD_tmp = %r9d
@@ -99,7 +99,7 @@ lane_data = %r10
# arg 2 : rdx : job
ENTRY(sha1_mb_mgr_submit_avx2)
push %rbx
- push %rbp
+ push %r12
mov _unused_lanes(state), unused_lanes
mov unused_lanes, lane
@@ -190,7 +190,7 @@ len_is_0:
movl DWORD_tmp, _result_digest+1*16(job_rax)
return:
- pop %rbp
+ pop %r12
pop %rbx
ret