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Re: [patch] crypto: sha256-mb - cleanup a || vs | typo

From Tim Chen <tim.c.chen@linux.intel.com>
Newsgroups linux.kernel
Subject Re: [patch] crypto: sha256-mb - cleanup a || vs | typo
Date 2016-06-30 22:50 +0200
Message-ID <rPR4l-5Ld-11@gated-at.bofh.it> (permalink)
References <rPoYq-5oC-27@gated-at.bofh.it> <rPr9U-6Wn-17@gated-at.bofh.it>
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On Wed, 2016-06-29 at 10:05 -0700, H. Peter Anvin wrote:
> On 06/29/16 07:42, Dan Carpenter wrote:
> > 
> > > 
> > > > 
> > > > and | behave basically the same here but || is intended.  It causes a
> > static checker warning to mix up bitwise and logical operations.
> > 
> > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> > 
> > diff --git a/arch/x86/crypto/sha256-mb/sha256_mb.c b/arch/x86/crypto/sha256-mb/sha256_mb.c
> > index c9d5dcc..4ec895a 100644
> > --- a/arch/x86/crypto/sha256-mb/sha256_mb.c
> > +++ b/arch/x86/crypto/sha256-mb/sha256_mb.c
> > @@ -299,7 +299,7 @@ static struct sha256_hash_ctx *sha256_ctx_mgr_submit(struct sha256_ctx_mgr *mgr,
> >  	 * Or if the user's buffer contains less than a whole block,
> >  	 * append as much as possible to the extra block.
> >  	 */
> > -	if ((ctx->partial_block_buffer_length) | (len < SHA256_BLOCK_SIZE)) {
> > +	if ((ctx->partial_block_buffer_length) || (len < SHA256_BLOCK_SIZE)) {
> >  		/* Compute how many bytes to copy from user buffer into
> >  		 * extra block
> >  		 */
> > 
> As far as I know the | was an intentional optimization, so you may way
> to look at the generated code.
> 
> 	-hpa
> 

Yes, this is an intentional optimization.  Is there any scenario where things may
break with the compiler?

Tim

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Thread

[patch] crypto: sha256-mb - cleanup a || vs | typo Dan Carpenter <dan.carpenter@oracle.com> - 2016-06-29 16:50 +0200
  Re: [patch] crypto: sha256-mb - cleanup a || vs | typo "H. Peter Anvin" <hpa@zytor.com> - 2016-06-29 19:10 +0200
    Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Dan Carpenter <dan.carpenter@oracle.com> - 2016-06-30 10:00 +0200
      Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Joe Perches <joe@perches.com> - 2016-06-30 13:20 +0200
        Re: [patch] crypto: sha256-mb - cleanup a || vs | typo walter harms <wharms@bfs.de> - 2016-06-30 13:50 +0200
          Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Dan Carpenter <dan.carpenter@oracle.com> - 2016-06-30 14:40 +0200
    Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Tim Chen <tim.c.chen@linux.intel.com> - 2016-06-30 22:50 +0200
      Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Dan Carpenter <dan.carpenter@oracle.com> - 2016-07-01 00:20 +0200
      Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Ingo Molnar <mingo@kernel.org> - 2016-07-01 10:00 +0200
        Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Herbert Xu <herbert@gondor.apana.org.au> - 2016-07-01 11:30 +0200
          Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Ingo Molnar <mingo@kernel.org> - 2016-07-01 13:20 +0200
            Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Tim Chen <tim.c.chen@linux.intel.com> - 2016-07-08 18:30 +0200
              Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Herbert Xu <herbert@gondor.apana.org.au> - 2016-07-08 18:50 +0200
                Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Linus Torvalds <torvalds@linux-foundation.org> - 2016-07-08 19:20 +0200
                Re: [patch] crypto: sha256-mb - cleanup a || vs | typo Tim Chen <tim.c.chen@linux.intel.com> - 2016-07-08 19:20 +0200

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