[PATCH 6.1 149/473] Revert "sh: Handle calling csum_partial with misaligned data"

Greg Kroah-Hartman
2024-06-06T14:14:30Z

From: Guenter Roeck <linux@roeck-us.net>

[ Upstream commit b5319c96292ff877f6b58d349acf0a9dc8d3b454 ]

This reverts commit cadc4e1a2b4d20d0cc0e81f2c6ba0588775e54e5.

Commit cadc4e1a2b4d ("sh: Handle calling csum_partial with misaligned
data") causes bad checksum calculations on unaligned data. Reverting
it fixes the problem.

# Subtest: checksum
# module: checksum_kunit
1..5
# test_csum_fixed_random_inputs: ASSERTION FAILED at lib/checksum_kunit.c:500
Expected ( u64)result == ( u64)expec, but
( u64)result == 53378 (0xd082)
( u64)expec == 33488 (0x82d0)
# test_csum_fixed_random_inputs: pass:0 fail:1 skip:0 total:1
not ok 1 test_csum_fixed_random_inputs
# test_csum_all_carry_inputs: ASSERTION FAILED at lib/checksum_kunit.c:525
Expected ( u64)result == ( u64)expec, but
( u64)result == 65281 (0xff01)
( u64)expec == 65280 (0xff00)
# test_csum_all_carry_inputs: pass:0 fail:1 skip:0 total:1
not ok 2 test_csum_all_carry_inputs
# test_csum_no_carry_inputs: ASSERTION FAILED at lib/checksum_kunit.c:573
Expected ( u64)result == ( u64)expec, but
( u64)result == 65535 (0xffff)
( u64)expec == 65534 (0xfffe)
# test_csum_no_carry_inputs: pass:0 fail:1 skip:0 total:1
not ok 3 test_csum_no_carry_inputs
# test_ip_fast_csum: pass:1 fail:0 skip:0 total:1
ok 4 test_ip_fast_csum
# test_csum_ipv6_magic: pass:1 fail:0 skip:0 total:1
ok 5 test_csum_ipv6_magic
# checksum: pass:2 fail:3 skip:0 total:5
# Totals: pass:2 fail:3 skip:0 total:5
not ok 22 checksum

Fixes: cadc4e1a2b4d ("sh: Handle calling csum_partial with misaligned data")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Link: https://lore.kernel.org/r/20240324231804.841099-1-linux@roeck-us.net
Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/sh/lib/checksum.S | 67 ++++++++++++------------------------------
1 file changed, 18 insertions(+), 49 deletions(-)

diff --git a/arch/sh/lib/checksum.S b/arch/sh/lib/checksum.S
index 3e07074e00981..06fed5a21e8ba 100644
--- a/arch/sh/lib/checksum.S
+++ b/arch/sh/lib/checksum.S
@@ -33,7 +33,8 @@
*/

/*
- * asmlinkage __wsum csum_partial(const void *buf, int len, __wsum sum);
+ * unsigned int csum_partial(const unsigned char *buf, int len,
+ * unsigned int sum);
*/

.text
@@ -45,31 +46,11 @@ ENTRY(csum_partial)
* Fortunately, it is easy to convert 2-byte alignment to 4-byte
* alignment for the unrolled loop.
*/
+ mov r5, r1
mov r4, r0
- tst #3, r0 ! Check alignment.
- bt/s 2f ! Jump if alignment is ok.
- mov r4, r7 ! Keep a copy to check for alignment
+ tst #2, r0 ! Check alignment.
+ bt 2f ! Jump if alignment is ok.
!
- tst #1, r0 ! Check alignment.
- bt 21f ! Jump if alignment is boundary of 2bytes.
-
- ! buf is odd
- tst r5, r5
- add #-1, r5
- bt 9f
- mov.b @r4+, r0
- extu.b r0, r0
- addc r0, r6 ! t=0 from previous tst
- mov r6, r0
- shll8 r6
- shlr16 r0
- shlr8 r0
- or r0, r6
- mov r4, r0
- tst #2, r0
- bt 2f
-21:
- ! buf is 2 byte aligned (len could be 0)
add #-2, r5 ! Alignment uses up two bytes.
cmp/pz r5 !
bt/s 1f ! Jump if we had at least two bytes.
@@ -77,17 +58,16 @@ ENTRY(csum_partial)
bra 6f
add #2, r5 ! r5 was < 2. Deal with it.
1:
+ mov r5, r1 ! Save new len for later use.
mov.w @r4+, r0
extu.w r0, r0
addc r0, r6
bf 2f
add #1, r6
2:
- ! buf is 4 byte aligned (len could be 0)
- mov r5, r1
mov #-5, r0
- shld r0, r1
- tst r1, r1
+ shld r0, r5
+ tst r5, r5
bt/s 4f ! if it's =0, go to 4f
clrt
.align 2
@@ -109,31 +89,30 @@ ENTRY(csum_partial)
addc r0, r6
addc r2, r6
movt r0
- dt r1
+ dt r5
bf/s 3b
cmp/eq #1, r0
- ! here, we know r1==0
- addc r1, r6 ! add carry to r6
+ ! here, we know r5==0
+ addc r5, r6 ! add carry to r6
4:
- mov r5, r0
+ mov r1, r0
and #0x1c, r0
tst r0, r0
- bt 6f
- ! 4 bytes or more remaining
- mov r0, r1
- shlr2 r1
+ bt/s 6f
+ mov r0, r5
+ shlr2 r5
mov #0, r2
5:
addc r2, r6
mov.l @r4+, r2
movt r0
- dt r1
+ dt r5
bf/s 5b
cmp/eq #1, r0
addc r2, r6
- addc r1, r6 ! r1==0 here, so it means add carry-bit
+ addc r5, r6 ! r5==0 here, so it means add carry-bit
6:
- ! 3 bytes or less remaining
+ mov r1, r5
mov #3, r0
and r0, r5
tst r5, r5
@@ -159,16 +138,6 @@ ENTRY(csum_partial)
mov #0, r0
addc r0, r6
9:
- ! Check if the buffer was misaligned, if so realign sum
- mov r7, r0
- tst #1, r0
- bt 10f
- mov r6, r0
- shll8 r6
- shlr16 r0
- shlr8 r0
- or r0, r6
-10:
rts
mov r6, r0

--
2.43.0