mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: Kulikov Vasiliy <segooon@gmail.com>
To: kernel-janitors@vger.kernel.org
Cc: Dan Williams <dan.j.williams@intel.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Maciej Sosnowski <maciej.sosnowski@intel.com>,
	Nicolas Ferre <nicolas.ferre@atmel.com>,
	Anatolij Gustschin <agust@denx.de>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 3/5] dma: dmatest: fix potential sign bug
Date: Sat, 17 Jul 2010 19:19:48 +0400	[thread overview]
Message-ID: <1279379988-15232-1-git-send-email-segooon@gmail.com> (raw)

'cnt' is unsigned, so this code may become wrong in future as
dmatest_add_threads() can return error code:

	cnt = dmatest_add_threads(dtc, DMA_MEMCPY);
	thread_count += cnt > 0 ? cnt : 0;
		        ^^^^^^^

Now it can return only -EINVAL if and only if second argument of
dmatest_add_threads() is not one of DMA_MEMCPY, DMA_XOR, DMA_PQ.
So, now it is not wrong but may become wrong in future.


The semantic patch that finds this problem (many false-positive results):
(http://coccinelle.lip6.fr/)

// <smpl>
@ r1 @
identifier f;
@@
int f(...) { ... }

@@
identifier r1.f;
type T;
unsigned T x;
@@

*x = f(...)
 ...
*x > 0

Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
---
 drivers/dma/dmatest.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index 68d58c4..5589358 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -540,7 +540,7 @@ static int dmatest_add_channel(struct dma_chan *chan)
 	struct dmatest_chan	*dtc;
 	struct dma_device	*dma_dev = chan->device;
 	unsigned int		thread_count = 0;
-	unsigned int		cnt;
+	int cnt;
 
 	dtc = kmalloc(sizeof(struct dmatest_chan), GFP_KERNEL);
 	if (!dtc) {
-- 
1.7.0.4


                 reply	other threads:[~2010-07-17 15:20 UTC|newest]

Thread overview: [no followups] expand[flat|nested]  mbox.gz  Atom feed

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1279379988-15232-1-git-send-email-segooon@gmail.com \
    --to=segooon@gmail.com \
    --cc=agust@denx.de \
    --cc=akpm@linux-foundation.org \
    --cc=dan.j.williams@intel.com \
    --cc=kernel-janitors@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=maciej.sosnowski@intel.com \
    --cc=nicolas.ferre@atmel.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox

Powered by JetHome