[PATCH][V2] dmaengine: coh901318: fix integer overflow when shifting more than 32 places

From: Colin King
Date: Thu Sep 29 2016 - 14:15:03 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

Currently U300_DMA_CHANNELS is set to 40, meaning that the shift of 1 can
be more than 32 places, which leads to a 32 bit integer overflow. Fix this
by using 1ULL instead of 1 before shifting it. Also add braces on the
for-loop to keep with coding style conventions.

Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/dma/coh901318.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c
index 2835f3e..74794c9 100644
--- a/drivers/dma/coh901318.c
+++ b/drivers/dma/coh901318.c
@@ -1352,9 +1352,10 @@ static ssize_t coh901318_debugfs_read(struct file *file, char __user *buf,

tmp += sprintf(tmp, "DMA -- enabled dma channels\n");

- for (i = 0; i < U300_DMA_CHANNELS; i++)
- if (started_channels & (1 << i))
+ for (i = 0; i < U300_DMA_CHANNELS; i++) {
+ if (started_channels & (1ULL << i))
tmp += sprintf(tmp, "channel %d\n", i);
+ }

tmp += sprintf(tmp, "Pool alloc nbr %d\n", pool_count);

--
2.9.3