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Subject[PATCH 3/5] dma: dmatest: fix potential sign bug
Date
'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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