[PATCH 4.2 086/120] crypto: vmx - Fixing GHASH Key issue on little endian

Greg Kroah-Hartman
2015-09-19T17:49:12Z

From: Leonidas Da Silva Barbosa <leosilva@linux.vnet.ibm.com>

commit 3c5f0ed78e976be705218cad62acf6a68e9d121e upstream.

GHASH table algorithm is using a big endian key.
In little endian machines key will be LE ordered.
After a lxvd2x instruction key is loaded as it is,
LE/BE order, in first case it'll generate a wrong
table resulting in wrong hashes from the algorithm.

Bug affects only LE machines.
In order to fix it we do a swap for loaded key.

Signed-off-by: Leonidas S Barbosa <leosilva@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/crypto/vmx/ghashp8-ppc.pl | 6 ++++++
1 file changed, 6 insertions(+)

--- a/drivers/crypto/vmx/ghashp8-ppc.pl
+++ b/drivers/crypto/vmx/ghashp8-ppc.pl
@@ -61,6 +61,12 @@ $code=<<___;
mtspr 256,r0
li r10,0x30
lvx_u $H,0,r4 # load H
+ le?xor r7,r7,r7
+ le?addi r7,r7,0x8 # need a vperm start with 08
+ le?lvsr 5,0,r7
+ le?vspltisb 6,0x0f
+ le?vxor 5,5,6 # set a b-endian mask
+ le?vperm $H,$H,$H,5

vspltisb $xC2,-16 # 0xf0
vspltisb $t0,1 # one