* [PATCH 2/2] scsi: st: Replace GFP_ATOMIC with GFP_KERNEL in new_tape_buffer
@ 2018-04-10 12:38 Jia-Ju Bai
0 siblings, 0 replies; only message in thread
From: Jia-Ju Bai @ 2018-04-10 12:38 UTC (permalink / raw)
To: Kai.Makisara, jejb, martin.petersen; +Cc: linux-scsi, linux-kernel, Jia-Ju Bai
new_tape_buffer() is never called in atomic context.
new_tape_buffer() is only called by st_probe(),
which is only set as ".probe" in struct scsi_driver.
Despite never getting called from atomic context,
new_tape_buffer() calls kzalloc() with GFP_ATOMIC,
which does not sleep for allocation.
GFP_ATOMIC is not necessary and can be replaced with GFP_KERNEL,
which can sleep and improve the possibility of sucessful allocation.
This is found by a static analysis tool named DCNS written by myself.
And I also manually check it.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
drivers/scsi/st.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 94e402e..b987f6d 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -3878,7 +3878,7 @@ static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
{
struct st_buffer *tb;
- tb = kzalloc(sizeof(struct st_buffer), GFP_ATOMIC);
+ tb = kzalloc(sizeof(struct st_buffer), GFP_KERNEL);
if (!tb) {
printk(KERN_NOTICE "st: Can't allocate new tape buffer.\n");
return NULL;
@@ -3889,7 +3889,7 @@ static struct st_buffer *new_tape_buffer(int need_dma, int max_sg)
tb->buffer_size = 0;
tb->reserved_pages = kzalloc(max_sg * sizeof(struct page *),
- GFP_ATOMIC);
+ GFP_KERNEL);
if (!tb->reserved_pages) {
kfree(tb);
return NULL;
--
1.9.1
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