From: Jia-Ju Bai <baijiaju1990@gmail.com>
To: marcel@holtmann.org, gustavo@padovan.org, johan.hedberg@gmail.com
Cc: linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org,
Jia-Ju Bai <baijiaju1990@gmail.com>
Subject: [PATCH] bluetooth: btmrvl_main: Replace GFP_ATOMIC with GFP_KERNEL in btmrvl_send_sync_cmd
Date: Fri, 26 Jan 2018 23:57:01 +0800 [thread overview]
Message-ID: <1516982221-8524-1-git-send-email-baijiaju1990@gmail.com> (raw)
After checking all possible call chains to btmrvl_send_sync_cmd(),
my tool finds that this function is never called in atomic context,
namely never in an interrupt handler or holding a spinlock.
And it calls wait_event_interruptible_timeout() after bt_skb_alloc(),
so it indicates that btmrvl_send_sync_cmd()
can call function which can sleep.
Thus GFP_ATOMIC is not necessary, and it can be replaced with GFP_KERNEL.
This is found by a static analysis tool named DCNS written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
---
drivers/bluetooth/btmrvl_main.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/bluetooth/btmrvl_main.c b/drivers/bluetooth/btmrvl_main.c
index b280d46..f6c694a 100644
--- a/drivers/bluetooth/btmrvl_main.c
+++ b/drivers/bluetooth/btmrvl_main.c
@@ -183,7 +183,7 @@ static int btmrvl_send_sync_cmd(struct btmrvl_private *priv, u16 opcode,
return -EFAULT;
}
- skb = bt_skb_alloc(HCI_COMMAND_HDR_SIZE + len, GFP_ATOMIC);
+ skb = bt_skb_alloc(HCI_COMMAND_HDR_SIZE + len, GFP_KERNEL);
if (!skb) {
BT_ERR("No free skb");
return -ENOMEM;
--
1.7.9.5
next reply other threads:[~2018-01-26 15:57 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-26 15:57 Jia-Ju Bai [this message]
2018-02-07 8:55 ` [PATCH] bluetooth: btmrvl_main: Replace GFP_ATOMIC with GFP_KERNEL in btmrvl_send_sync_cmd Marcel Holtmann
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1516982221-8524-1-git-send-email-baijiaju1990@gmail.com \
--to=baijiaju1990@gmail.com \
--cc=gustavo@padovan.org \
--cc=johan.hedberg@gmail.com \
--cc=linux-bluetooth@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=marcel@holtmann.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).