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	Without this patch, the chacha block counter is not incremented on neon rounds, resulting in incorrect calculations and corrupt packets. This also switches to using `--no-numbered --zero-commit` so that future diffs are smaller. Reported-by: Hans Geiblinger <cybrnook2002@yahoo.com> Reviewed-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com> Cc: David Bauer <mail@david-bauer.net> Cc: Petr Štetiar <ynezz@true.cz> Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
		
			
				
	
	
		
			59 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			59 lines
		
	
	
		
			2.3 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
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From: Ard Biesheuvel <ardb@kernel.org>
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Date: Fri, 17 Jan 2020 17:43:18 +0100
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Subject: [PATCH] crypto: arm/chacha - fix build failured when kernel mode NEON
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 is disabled
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commit 0bc81767c5bd9d005fae1099fb39eb3688370cb1 upstream.
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When the ARM accelerated ChaCha driver is built as part of a configuration
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that has kernel mode NEON disabled, we expect the compiler to propagate
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the build time constant expression IS_ENABLED(CONFIG_KERNEL_MODE_NEON) in
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a way that eliminates all the cross-object references to the actual NEON
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routines, which allows the chacha-neon-core.o object to be omitted from
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the build entirely.
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Unfortunately, this fails to work as expected in some cases, and we may
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end up with a build error such as
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  chacha-glue.c:(.text+0xc0): undefined reference to `chacha_4block_xor_neon'
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caused by the fact that chacha_doneon() has not been eliminated from the
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object code, even though it will never be called in practice.
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Let's fix this by adding some IS_ENABLED(CONFIG_KERNEL_MODE_NEON) tests
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that are not strictly needed from a logical point of view, but should
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help the compiler infer that the NEON code paths are unreachable in
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those cases.
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Fixes: b36d8c09e710c71f ("crypto: arm/chacha - remove dependency on generic ...")
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Reported-by: Russell King <linux@armlinux.org.uk>
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Cc: Arnd Bergmann <arnd@arndb.de>
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Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
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Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
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---
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 arch/arm/crypto/chacha-glue.c | 4 ++--
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 1 file changed, 2 insertions(+), 2 deletions(-)
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--- a/arch/arm/crypto/chacha-glue.c
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+++ b/arch/arm/crypto/chacha-glue.c
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@@ -115,7 +115,7 @@ static int chacha_stream_xor(struct skci
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 		if (nbytes < walk.total)
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 			nbytes = round_down(nbytes, walk.stride);
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-		if (!neon) {
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+		if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon) {
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 			chacha_doarm(walk.dst.virt.addr, walk.src.virt.addr,
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 				     nbytes, state, ctx->nrounds);
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 			state[12] += DIV_ROUND_UP(nbytes, CHACHA_BLOCK_SIZE);
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@@ -159,7 +159,7 @@ static int do_xchacha(struct skcipher_re
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 	chacha_init_generic(state, ctx->key, req->iv);
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-	if (!neon) {
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+	if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon) {
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 		hchacha_block_arm(state, subctx.key, ctx->nrounds);
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 	} else {
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 		kernel_neon_begin();
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