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authorJosh Poimboeuf <jpoimboe@redhat.com>2017-09-18 14:42:06 -0500
committerHerbert Xu <herbert@gondor.apana.org.au>2017-09-20 17:42:35 +0800
commit6488bce756861b94810e54f83416d5e74c0f18bf (patch)
treea2f9b51a97bb955c4cb91a7f85efafecb574c26d /arch
parentd7b1722c72aa915283ada27709c6feeb392f6038 (diff)
crypto: x86/sha1-ssse3 - Fix RBP usage
Using RBP as a temporary register breaks frame pointer convention and breaks stack traces when unwinding from an interrupt in the crypto code. Swap the usages of R12 and RBP. Use R12 for the REG_D register, and use RBP to store the pre-aligned stack pointer. Reported-by: Eric Biggers <ebiggers@google.com> Reported-by: Peter Zijlstra <peterz@infradead.org> Tested-by: Eric Biggers <ebiggers@google.com> Acked-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/crypto/sha1_ssse3_asm.S11
1 files changed, 5 insertions, 6 deletions
diff --git a/arch/x86/crypto/sha1_ssse3_asm.S b/arch/x86/crypto/sha1_ssse3_asm.S
index a4109506a5e8..6204bd53528c 100644
--- a/arch/x86/crypto/sha1_ssse3_asm.S
+++ b/arch/x86/crypto/sha1_ssse3_asm.S
@@ -37,7 +37,7 @@
#define REG_A %ecx
#define REG_B %esi
#define REG_C %edi
-#define REG_D %ebp
+#define REG_D %r12d
#define REG_E %edx
#define REG_T1 %eax
@@ -74,10 +74,10 @@
ENTRY(\name)
push %rbx
- push %rbp
push %r12
+ push %rbp
+ mov %rsp, %rbp
- mov %rsp, %r12
sub $64, %rsp # allocate workspace
and $~15, %rsp # align stack
@@ -99,10 +99,9 @@
xor %rax, %rax
rep stosq
- mov %r12, %rsp # deallocate workspace
-
- pop %r12
+ mov %rbp, %rsp # deallocate workspace
pop %rbp
+ pop %r12
pop %rbx
ret