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Message-ID: <20220322115125.737671717@infradead.org>
User-Agent: quilt/0.66
Date:   Tue, 22 Mar 2022 12:48:10 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     x86@kernel.org
Cc:     linux-kernel@vger.kernel.org, peterz@infradead.org,
        linux-crypto@vger.kernel.org, ebiggers@google.com,
        herbert@gondor.apana.org.au, Jason@zx2c4.com,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Stephen Rothwell <sfr@canb.auug.org.au>
Subject: [PATCH 1/2] x86/chacha20: Avoid spurious jumps to other functions
References: <20220322114809.381992456@infradead.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Precedence: bulk

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@canb.auug.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
 arch/x86/crypto/chacha-avx512vl-x86_64.S |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- 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_avx512v
 	# 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_avx512v
 	# xor remaining bytes from partial register into output
 	mov		%rcx,%rax
 	and		$0xf,%rcx
-	jz		.Ldone8
+	jz		.Ldone4
 	mov		%rax,%r9
 	and		$~0xf,%r9