[ARM] Fix csumpartial corner case

Ji-In Park discovered a bug in csumpartial which caused wrong
checksums with misaligned buffers.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/lib/csumpartial.S b/arch/arm/lib/csumpartial.S
index cb5e3708f118bcf9b01d65ffa9deac1381b2561f..fe797cf320bb488646d187c041452deac0223a14 100644 (file)
--- a/arch/arm/lib/csumpartial.S
+++ b/arch/arm/lib/csumpartial.S
@@ -39,6 +39,7 @@ td3   .req    lr
 
                /* we must have at least one byte. */
                tst     buf, #1                 @ odd address?
+               movne   sum, sum, ror #8
                ldrneb  td0, [buf], #1
                subne   len, len, #1
                adcnes  sum, sum, td0, put_byte_1
@@ -103,6 +104,9 @@ ENTRY(csum_partial)
                cmp     len, #8                 @ Ensure that we have at least
                blo     .less8                  @ 8 bytes to copy.
 
+               tst     buf, #1
+               movne   sum, sum, ror #8
+
                adds    sum, sum, #0            @ C = 0
                tst     buf, #3                 @ Test destination alignment
                blne    .not_aligned            @ aligh destination, return here