crypto: x86/cast5 - Fix RBP usage
authorJosh Poimboeuf <jpoimboe@redhat.com>
Mon, 18 Sep 2017 19:42:02 +0000 (14:42 -0500)
committerHerbert Xu <herbert@gondor.apana.org.au>
Wed, 20 Sep 2017 09:42:32 +0000 (17:42 +0800)
commit4b15606664a2f8d7c4f0092fb0305fe1c7c65b7b
tree207a3d51441bf2376b8f084f154db23adfc98847
parentb46c9d717645529417ca9045cfdbf59f84922573
crypto: x86/cast5 - 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.

Use R15 instead of RBP.  R15 can't be used as the RID1 register because
of x86 instruction encoding limitations.  So use R15 for CTX and RDI for
CTX.  This means that CTX is no longer an implicit function argument.
Instead it needs to be explicitly copied from RDI.

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>
arch/x86/crypto/cast5-avx-x86_64-asm_64.S