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@xxxxxxxxx> --- 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