| Message ID | 12db8df183584a6c605d233c22b1ca0a19e08c56.1504029132.git.jpoimboe@redhat.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Herbert Xu |
| Headers | show |
On 08/29/2017 11:05 AM, Josh Poimboeuf wrote: > Using RBP as a temporary register breaks frame pointer convention and > breaks stack traces when unwinding from an interrupt in the crypto code. > > Use R11 instead of RBP. Since R11 isn't a callee-saved register, it > doesn't need to be saved and restored on the stack. These changes seem okay. Thanks. Tim > > Reported-by: Eric Biggers <ebiggers@google.com> > Reported-by: Peter Zijlstra <peterz@infradead.org> > Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> > --- > arch/x86/crypto/sha1_avx2_x86_64_asm.S | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/arch/x86/crypto/sha1_avx2_x86_64_asm.S b/arch/x86/crypto/sha1_avx2_x86_64_asm.S > index 1eab79c9ac48..9f712a7dfd79 100644 > --- a/arch/x86/crypto/sha1_avx2_x86_64_asm.S > +++ b/arch/x86/crypto/sha1_avx2_x86_64_asm.S > @@ -89,7 +89,7 @@ > #define REG_RE %rdx > #define REG_RTA %r12 > #define REG_RTB %rbx > -#define REG_T1 %ebp > +#define REG_T1 %r11d > #define xmm_mov vmovups > #define avx2_zeroupper vzeroupper > #define RND_F1 1 > @@ -637,7 +637,6 @@ _loop3: > ENTRY(\name) > > push %rbx > - push %rbp > push %r12 > push %r13 > push %r14 > @@ -673,7 +672,6 @@ _loop3: > pop %r14 > pop %r13 > pop %r12 > - pop %rbp > pop %rbx > > ret >
diff --git a/arch/x86/crypto/sha1_avx2_x86_64_asm.S b/arch/x86/crypto/sha1_avx2_x86_64_asm.S index 1eab79c9ac48..9f712a7dfd79 100644 --- a/arch/x86/crypto/sha1_avx2_x86_64_asm.S +++ b/arch/x86/crypto/sha1_avx2_x86_64_asm.S @@ -89,7 +89,7 @@ #define REG_RE %rdx #define REG_RTA %r12 #define REG_RTB %rbx -#define REG_T1 %ebp +#define REG_T1 %r11d #define xmm_mov vmovups #define avx2_zeroupper vzeroupper #define RND_F1 1 @@ -637,7 +637,6 @@ _loop3: ENTRY(\name) push %rbx - push %rbp push %r12 push %r13 push %r14 @@ -673,7 +672,6 @@ _loop3: pop %r14 pop %r13 pop %r12 - pop %rbp pop %rbx ret
Using RBP as a temporary register breaks frame pointer convention and breaks stack traces when unwinding from an interrupt in the crypto code. Use R11 instead of RBP. Since R11 isn't a callee-saved register, it doesn't need to be saved and restored on the stack. Reported-by: Eric Biggers <ebiggers@google.com> Reported-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> --- arch/x86/crypto/sha1_avx2_x86_64_asm.S | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-)