Commit c0d86f2a authored Mar 22, 2022 by Peter Zijlstra Committed by Greg Kroah-Hartman May 25, 2022

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@canb.auug.org.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent f0213894

arch/x86/crypto/chacha-avx512vl-x86_64.S

+2 −2

Original line number	Diff line number	Diff line
		@@ -172,7 +172,7 @@ ENTRY(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 @@ ENTRY(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