From 9aec3058ef2cf1860de2f65298de32ec8fd7010d Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Mon, 1 Jun 2020 21:41:39 +0800 Subject: [PATCH] gcc-10: avoid shadowing standard library 'free()' in crypto MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 1a263ae60b04de959d9ce9caea4889385eefcc7b upstream. gcc-10 has started warning about conflicting types for a few new built-in functions, particularly 'free()'. This results in warnings like: crypto/xts.c:325:13: warning: conflicting types for built-in function ‘free’; expected ‘void(void *)’ [-Wbuiltin-declaration-mismatch] because the crypto layer had its local freeing functions called 'free()'. Gcc-10 is in the wrong here, since that function is marked 'static', and thus there is no chance of confusion with any standard library function namespace. But the simplest thing to do is to just use a different name here, and avoid this gcc mis-feature. [ Side note: gcc knowing about 'free()' is in itself not the mis-feature: the semantics of 'free()' are special enough that a compiler can validly do special things when seeing it. So the mis-feature here is that gcc thinks that 'free()' is some restricted name, and you can't shadow it as a local static function. Making the special 'free()' semantics be a function attribute rather than tied to the name would be the much better model ] Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman Signed-off-by: Yang Yingliang --- crypto/lrw.c | 4 ++-- crypto/xts.c | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/crypto/lrw.c b/crypto/lrw.c index 5504d1325a56..d55c9ee18817 100644 --- a/crypto/lrw.c +++ b/crypto/lrw.c @@ -453,7 +453,7 @@ static void exit_tfm(struct crypto_skcipher *tfm) crypto_free_skcipher(ctx->child); } -static void free(struct skcipher_instance *inst) +static void free_inst(struct skcipher_instance *inst) { crypto_drop_skcipher(skcipher_instance_ctx(inst)); kfree(inst); @@ -565,7 +565,7 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb) inst->alg.encrypt = encrypt; inst->alg.decrypt = decrypt; - inst->free = free; + inst->free = free_inst; err = skcipher_register_instance(tmpl, inst); if (err) diff --git a/crypto/xts.c b/crypto/xts.c index ccf55fbb8bc2..5542dd10aedf 100644 --- a/crypto/xts.c +++ b/crypto/xts.c @@ -393,7 +393,7 @@ static void exit_tfm(struct crypto_skcipher *tfm) crypto_free_cipher(ctx->tweak); } -static void free(struct skcipher_instance *inst) +static void free_inst(struct skcipher_instance *inst) { crypto_drop_skcipher(skcipher_instance_ctx(inst)); kfree(inst); @@ -504,7 +504,7 @@ static int create(struct crypto_template *tmpl, struct rtattr **tb) inst->alg.encrypt = encrypt; inst->alg.decrypt = decrypt; - inst->free = free; + inst->free = free_inst; err = skcipher_register_instance(tmpl, inst); if (err) -- GitLab