From 68874ac3304ade7ed5ebb12af00d6b9bbbca0a16 Mon Sep 17 00:00:00 2001 From: Josh Poimboeuf Date: Thu, 21 Jan 2016 16:49:18 -0600 Subject: [PATCH] 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 Cc: Andrew Morton Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Arnaldo Carvalho de Melo Cc: Bernd Petrovitsch Cc: Borislav Petkov Cc: Brian Gerst Cc: Chris J Arges Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Jiri Slaby Cc: Linus Torvalds Cc: Michal Marek Cc: Namhyung Kim Cc: Pedro Alves Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: live-patching@vger.kernel.org Link: http://lkml.kernel.org/r/15a3eb7ebe68e37755927915f45e4f0bde4d18c5.1453405861.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar --- 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 a5a14c62d843..c3b944781d3f 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 -- 2.20.1