This is a note to let you know that I've just added the patch titled
crypto: x86/chacha20 - Avoid spurious jumps to other functions
to the 5.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
crypto-x86-chacha20-avoid-spurious-jumps-to-other-fu.patch
and it can be found in the queue-5.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit f313a6811238b433a8b95c0905ce432e7d674e58
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Date: Tue Mar 22 12:48:10 2022 +0100
crypto: x86/chacha20 - Avoid spurious jumps to other functions
[ Upstream commit 4327d168515fd8b5b92fa1efdf1d219fb6514460 ]
The chacha_Nblock_xor_avx512vl() functions all have their own,
identical, .LdoneN label, however in one particular spot {2,4} jump to
the 8 version instead of their own. Resulting in:
arch/x86/crypto/chacha-x86_64.o: warning: objtool: chacha_2block_xor_avx512vl() falls through to next function chacha_8block_xor_avx512vl()
arch/x86/crypto/chacha-x86_64.o: warning: objtool: chacha_4block_xor_avx512vl() falls through to next function chacha_8block_xor_avx512vl()
Make each function consistently use its own done label.
Reported-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Reviewed-by: Martin Willi <martin@xxxxxxxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/x86/crypto/chacha-avx512vl-x86_64.S b/arch/x86/crypto/chacha-avx512vl-x86_64.S
index 946f74dd6fba..259383e1ad44 100644
--- a/arch/x86/crypto/chacha-avx512vl-x86_64.S
+++ b/arch/x86/crypto/chacha-avx512vl-x86_64.S
@@ -172,7 +172,7 @@ SYM_FUNC_START(chacha_2block_xor_avx512vl)
# xor remaining bytes from partial register into output
mov %rcx,%rax
and $0xf,%rcx
- jz .Ldone8
+ jz .Ldone2
mov %rax,%r9
and $~0xf,%r9
@@ -438,7 +438,7 @@ SYM_FUNC_START(chacha_4block_xor_avx512vl)
# xor remaining bytes from partial register into output
mov %rcx,%rax
and $0xf,%rcx
- jz .Ldone8
+ jz .Ldone4
mov %rax,%r9
and $~0xf,%r9
