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From:   Tony Lindgren <tony@atomide.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Daniel Starke <daniel.starke@siemens.com>,
        Gregory CLEMENT <gregory.clement@bootlin.com>,
        Jiri Slaby <jirislaby@kernel.org>,
        Johan Hovold <johan@kernel.org>,
        Zhenguo Zhao <Zhenguo.Zhao1@unisoc.com>,
        linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
        Dan Carpenter <dan.carpenter@oracle.com>
Subject: [PATCH] tty: n_gsm: Debug output allocation must use GFP_ATOMIC
Date:   Mon, 23 May 2022 18:50:52 +0300
Message-Id: <20220523155052.57129-1-tony@atomide.com>
MIME-Version: 1.0
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Precedence: bulk

Dan Carpenter <dan.carpenter@oracle.com> reported the following Smatch
warning:

drivers/tty/n_gsm.c:720 gsm_data_kick()
warn: sleeping in atomic context

This is because gsm_control_message() is holding a spin lock so
gsm_hex_dump_bytes() needs to use GFP_ATOMIC instead of GFP_KERNEL.

Fixes: 925ea0fa5277 ("tty: n_gsm: Fix packet data hex dump output")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/tty/n_gsm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -459,7 +459,7 @@ static void gsm_hex_dump_bytes(const char *fname, const u8 *data,
 		return;
 	}
 
-	prefix = kasprintf(GFP_KERNEL, "%s: ", fname);
+	prefix = kasprintf(GFP_ATOMIC, "%s: ", fname);
 	if (!prefix)
 		return;
 	print_hex_dump(KERN_INFO, prefix, DUMP_PREFIX_OFFSET, 16, 1, data, len,
-- 
2.36.1