crypto: aesni: shut up -Wmaybe-uninitialized warning
authorArnd Bergmann <arnd@arndb.de>
Thu, 10 Nov 2016 16:44:51 +0000 (17:44 +0100)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 11 Nov 2016 16:45:08 +0000 (08:45 -0800)
The rfc4106 encrypy/decrypt helper functions cause an annoying
false-positive warning in allmodconfig if we turn on
-Wmaybe-uninitialized warnings again:

  arch/x86/crypto/aesni-intel_glue.c: In function ‘helper_rfc4106_decrypt’:
  include/linux/scatterlist.h:67:31: warning: ‘dst_sg_walk.sg’ may be used uninitialized in this function [-Wmaybe-uninitialized]

The problem seems to be that the compiler doesn't track the state of the
'one_entry_in_sg' variable across the kernel_fpu_begin/kernel_fpu_end
section.

This takes the easy way out by adding a bogus initialization, which
should be harmless enough to get the patch into v4.9 so we can turn on
this warning again by default without producing useless output.  A
follow-up patch for v4.10 rearranges the code to make the warning go
away.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/x86/crypto/aesni-intel_glue.c

index 0ab5ee1..aa8b067 100644 (file)
@@ -888,7 +888,7 @@ static int helper_rfc4106_encrypt(struct aead_request *req)
        unsigned long auth_tag_len = crypto_aead_authsize(tfm);
        u8 iv[16] __attribute__ ((__aligned__(AESNI_ALIGN)));
        struct scatter_walk src_sg_walk;
-       struct scatter_walk dst_sg_walk;
+       struct scatter_walk dst_sg_walk = {};
        unsigned int i;
 
        /* Assuming we are supporting rfc4106 64-bit extended */
@@ -968,7 +968,7 @@ static int helper_rfc4106_decrypt(struct aead_request *req)
        u8 iv[16] __attribute__ ((__aligned__(AESNI_ALIGN)));
        u8 authTag[16];
        struct scatter_walk src_sg_walk;
-       struct scatter_walk dst_sg_walk;
+       struct scatter_walk dst_sg_walk = {};
        unsigned int i;
 
        if (unlikely(req->assoclen != 16 && req->assoclen != 20))