Commit 0c6d5c89 authored Jun 04, 2015 by Dan Carpenter Committed by Greg Kroah-Hartman Jun 12, 2015

w1: use correct lock on error in w1_seq_show()



I noticed there was a problem here because Smatch complained:

	drivers/w1/slaves/w1_therm.c:416 w1_seq_show() warn:
	inconsistent returns 'mutex:&sl->master->mutex'.
	  Locked on:   line 416
	  Unlocked on: line 413

The problem is that we lock ->mutex but we unlock ->bus_mutex on error.
David Fries says that ->bus_mutex is correct and ->mutex is incorrect.

Fixes: d9411e57 ('w1: Add support for DS28EA00 sequence to w1-therm')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent a14ef24b

drivers/w1/slaves/w1_therm.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -355,7 +355,7 @@ static ssize_t w1_seq_show(struct device *device,
		struct w1_reg_num *reg_num;
		int seq = 0;

		mutex_lock(&sl->master->mutex);
		mutex_lock(&sl->master->bus_mutex);
		/* Place all devices in CHAIN state */
		if (w1_reset_bus(sl->master))
		goto error;
		@@ -407,7 +407,7 @@ static ssize_t w1_seq_show(struct device *device,
		ack = w1_read_8(sl->master);
		if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
		goto error;
		mutex_unlock(&sl->master->mutex);
		mutex_unlock(&sl->master->bus_mutex);

		c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq);
		return PAGE_SIZE - c;