[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 cb5e370..fe797cf 100644
--- a/arch/arm/lib/csumpartial.S
+++ b/arch/arm/lib/csumpartial.S
@@ -39,6 +39,7 @@
/* 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 @@
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