Messages in this thread Patch in this message |  | | From | Kulikov Vasiliy <> | | Subject | [PATCH 3/5] dma: dmatest: fix potential sign bug | | Date | Sat, 17 Jul 2010 19:19:48 +0400 |
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'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
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