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authorArd Biesheuvel <ardb@kernel.org>2020-01-17 17:43:18 +0100
committerHerbert Xu <herbert@gondor.apana.org.au>2020-01-22 16:21:11 +0800
commit0bc81767c5bd9d005fae1099fb39eb3688370cb1 (patch)
tree46c1f807ad84e7916b567b59ee5ec72f92ce9edf /arch/arm/crypto
parent7e2b89fb4a2e636ad94fe47b76257c3cc0234666 (diff)
downloadlinux-0bc81767c5bd9d005fae1099fb39eb3688370cb1.tar.bz2
crypto: arm/chacha - fix build failured when kernel mode NEON is disabled
When the ARM accelerated ChaCha driver is built as part of a configuration that has kernel mode NEON disabled, we expect the compiler to propagate the build time constant expression IS_ENABLED(CONFIG_KERNEL_MODE_NEON) in a way that eliminates all the cross-object references to the actual NEON routines, which allows the chacha-neon-core.o object to be omitted from the build entirely. Unfortunately, this fails to work as expected in some cases, and we may end up with a build error such as chacha-glue.c:(.text+0xc0): undefined reference to `chacha_4block_xor_neon' caused by the fact that chacha_doneon() has not been eliminated from the object code, even though it will never be called in practice. Let's fix this by adding some IS_ENABLED(CONFIG_KERNEL_MODE_NEON) tests that are not strictly needed from a logical point of view, but should help the compiler infer that the NEON code paths are unreachable in those cases. Fixes: b36d8c09e710c71f ("crypto: arm/chacha - remove dependency on generic ...") Reported-by: Russell King <linux@armlinux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'arch/arm/crypto')
-rw-r--r--arch/arm/crypto/chacha-glue.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/crypto/chacha-glue.c b/arch/arm/crypto/chacha-glue.c
index 6ebbb2b241d2..6fdb0ac62b3d 100644
--- a/arch/arm/crypto/chacha-glue.c
+++ b/arch/arm/crypto/chacha-glue.c
@@ -115,7 +115,7 @@ static int chacha_stream_xor(struct skcipher_request *req,
if (nbytes < walk.total)
nbytes = round_down(nbytes, walk.stride);
- if (!neon) {
+ if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon) {
chacha_doarm(walk.dst.virt.addr, walk.src.virt.addr,
nbytes, state, ctx->nrounds);
state[12] += DIV_ROUND_UP(nbytes, CHACHA_BLOCK_SIZE);
@@ -159,7 +159,7 @@ static int do_xchacha(struct skcipher_request *req, bool neon)
chacha_init_generic(state, ctx->key, req->iv);
- if (!neon) {
+ if (!IS_ENABLED(CONFIG_KERNEL_MODE_NEON) || !neon) {
hchacha_block_arm(state, subctx.key, ctx->nrounds);
} else {
kernel_neon_begin();