From d099ea6e6fde5f311bea5bcdadaa85fc3af79259 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Thu, 30 Apr 2020 23:30:43 +0200
Subject: [PATCH] crypto - Avoid free() namespace collision
Git-commit: d099ea6e6fde5f311bea5bcdadaa85fc3af79259
References: git-fixes
Patch-mainline: v5.8-rc1

gcc-10 complains about using the name of a standard library
function in the kernel, as we are not building with -ffreestanding:

crypto/xts.c:325:13: error: conflicting types for built-in function 'free'; expected 'void(void *)' [-Werror=builtin-declaration-mismatch]
  325 | static void free(struct skcipher_instance *inst)
      |             ^~~~
crypto/lrw.c:290:13: error: conflicting types for built-in function 'free'; expected 'void(void *)' [-Werror=builtin-declaration-mismatch]
  290 | static void free(struct skcipher_instance *inst)
      |             ^~~~
crypto/lrw.c:27:1: note: 'free' is declared in header '<stdlib.h>'

The xts and lrw cipher implementations run into this because they do
not use the conventional namespaced function names.

It might be better to rename all local functions in those files to
help with things like 'ctags' and 'grep', but just renaming these two
avoids the build issue. I picked the more verbose crypto_xts_free()
and crypto_lrw_free() names for consistency with several other drivers
that do use namespaced function names.

Fixes: f1c131b45410 ("crypto: xts - Convert to skcipher")
Fixes: 700cb3f5fe75 ("crypto: lrw - Convert to skcipher")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 crypto/lrw.c |    4 ++--
 crypto/xts.c |    4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

--- a/crypto/lrw.c
+++ b/crypto/lrw.c
@@ -289,7 +289,7 @@ static void exit_tfm(struct crypto_skcip
 	crypto_free_skcipher(ctx->child);
 }
 
-static void free(struct skcipher_instance *inst)
+static void crypto_lrw_free(struct skcipher_instance *inst)
 {
 	crypto_drop_skcipher(skcipher_instance_ctx(inst));
 	kfree(inst);
@@ -401,7 +401,7 @@ static int create(struct crypto_template
 	inst->alg.encrypt = encrypt;
 	inst->alg.decrypt = decrypt;
 
-	inst->free = free;
+	inst->free = crypto_lrw_free;
 
 	err = skcipher_register_instance(tmpl, inst);
 	if (err)
--- a/crypto/xts.c
+++ b/crypto/xts.c
@@ -216,7 +216,7 @@ static void exit_tfm(struct crypto_skcip
 	crypto_free_cipher(ctx->tweak);
 }
 
-static void free(struct skcipher_instance *inst)
+static void crypto_xts_free(struct skcipher_instance *inst)
 {
 	crypto_drop_skcipher(skcipher_instance_ctx(inst));
 	kfree(inst);
@@ -327,7 +327,7 @@ static int create(struct crypto_template
 	inst->alg.encrypt = encrypt;
 	inst->alg.decrypt = decrypt;
 
-	inst->free = free;
+	inst->free = crypto_xts_free;
 
 	err = skcipher_register_instance(tmpl, inst);
 	if (err)