linux-kernel - [PATCH 1/2] scsi: st: Replace GFP_ATOMIC with GFP_KERNEL in st

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Message-Id: <1523363879-31242-1-git-send-email-baijiaju1990@gmail.com>
Date:   Tue, 10 Apr 2018 20:37:59 +0800
From:   Jia-Ju Bai <baijiaju1990@...il.com>
To:     Kai.Makisara@...umbus.fi, jejb@...ux.vnet.ibm.com,
        martin.petersen@...cle.com
Cc:     linux-scsi@...r.kernel.org, linux-kernel@...r.kernel.org,
        Jia-Ju Bai <baijiaju1990@...il.com>
Subject: [PATCH 1/2] scsi: st: Replace GFP_ATOMIC with GFP_KERNEL in st_probe

st_probe() is never called in atomic context.

st_probe() is only set as ".probe" in struct scsi_driver.

Despite never getting called from atomic context,
st_probe() 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@...il.com>
---
 drivers/scsi/st.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 94e402e..1da42f3 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -4290,7 +4290,7 @@ static int st_probe(struct device *dev)
 		goto out_buffer_free;
 	}

-	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_ATOMIC);
+	tpnt = kzalloc(sizeof(struct scsi_tape), GFP_KERNEL);
 	if (tpnt == NULL) {
 		sdev_printk(KERN_ERR, SDp,
 			    "st: Can't allocate device descriptor.\n");
-- 
1.9.1