[PATCH] tty: n_gsm: Debug output allocation must use GFP_ATOMIC

From: Tony Lindgren
Date: Mon May 23 2022 - 11:51:13 EST


Dan Carpenter <dan.carpenter@xxxxxxxxxx> 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@xxxxxxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
---
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