Commit c2239294 authored by Jonathan Lemon's avatar Jonathan Lemon Committed by Jakub Kicinski
Browse files

ptp: ocp: change sysfs attr group handling 



In the detach path, the driver calls sysfs_remove_group() for the
groups it believes has been registered.  However, if the group was
never previously registered, then this causes a splat.

Instead, compute the groups that should be registered in advance,
and then call sysfs_create_groups(), which registers them all at once.

Update the error handling appropriately.

Fixes: c205d53c ("ptp: ocp: Add firmware capability bits for feature gating")
Reported-by: default avatarZheyu Ma <zheyuma97@gmail.com>
Signed-off-by: default avatarJonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/r/20220517214600.10606-1-jonathan.lemon@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 090f9dd0

drivers/ptp/ptp_ocp.c

+42 −15
Original line number Diff line number Diff line
@@ -300,7 +300,7 @@ struct ptp_ocp { 
	struct platform_device	*spi_flash;

	struct clk_hw		*i2c_clk;

	struct timer_list	watchdog;

	const struct ocp_attr_group *attr_tbl;

	const struct attribute_group **attr_group;

	const struct ptp_ocp_eeprom_map *eeprom_map;

	struct dentry		*debug_root;

	time64_t		gnss_lost;
@@ -1836,6 +1836,42 @@ ptp_ocp_signal_init(struct ptp_ocp *bp) 
					     bp->signal_out[i]->mem);

}



static void

ptp_ocp_attr_group_del(struct ptp_ocp *bp)

{

	sysfs_remove_groups(&bp->dev.kobj, bp->attr_group);

	kfree(bp->attr_group);

}



static int

ptp_ocp_attr_group_add(struct ptp_ocp *bp,

		       const struct ocp_attr_group *attr_tbl)

{

	int count, i;

	int err;



	count = 0;

	for (i = 0; attr_tbl[i].cap; i++)

		if (attr_tbl[i].cap & bp->fw_cap)

			count++;



	bp->attr_group = kcalloc(count + 1, sizeof(struct attribute_group *),

				 GFP_KERNEL);

	if (!bp->attr_group)

		return -ENOMEM;



	count = 0;

	for (i = 0; attr_tbl[i].cap; i++)

		if (attr_tbl[i].cap & bp->fw_cap)

			bp->attr_group[count++] = attr_tbl[i].group;



	err = sysfs_create_groups(&bp->dev.kobj, bp->attr_group);

	if (err)

		bp->attr_group[0] = NULL;



	return err;

}



static void

ptp_ocp_sma_init(struct ptp_ocp *bp)

{
@@ -1905,7 +1941,6 @@ ptp_ocp_fb_board_init(struct ptp_ocp *bp, struct ocp_resource *r) 
	bp->flash_start = 1024 * 4096;

	bp->eeprom_map = fb_eeprom_map;

	bp->fw_version = ioread32(&bp->image->version);

	bp->attr_tbl = fb_timecard_groups;

	bp->fw_cap = OCP_CAP_BASIC;



	ver = bp->fw_version & 0xffff;
@@ -1919,6 +1954,10 @@ ptp_ocp_fb_board_init(struct ptp_ocp *bp, struct ocp_resource *r) 
	ptp_ocp_sma_init(bp);

	ptp_ocp_signal_init(bp);



	err = ptp_ocp_attr_group_add(bp, fb_timecard_groups);

	if (err)

		return err;



	err = ptp_ocp_fb_set_pins(bp);

	if (err)

		return err;
@@ -3389,7 +3428,6 @@ ptp_ocp_complete(struct ptp_ocp *bp) 
{

	struct pps_device *pps;

	char buf[32];

	int i, err;



	if (bp->gnss_port != -1) {

		sprintf(buf, "ttyS%d", bp->gnss_port);
@@ -3414,14 +3452,6 @@ ptp_ocp_complete(struct ptp_ocp *bp) 
	if (pps)

		ptp_ocp_symlink(bp, pps->dev, "pps");



	for (i = 0; bp->attr_tbl[i].cap; i++) {

		if (!(bp->attr_tbl[i].cap & bp->fw_cap))

			continue;

		err = sysfs_create_group(&bp->dev.kobj, bp->attr_tbl[i].group);

		if (err)

			return err;

	}



	ptp_ocp_debugfs_add_device(bp);



	return 0;
@@ -3493,15 +3523,11 @@ static void 
ptp_ocp_detach_sysfs(struct ptp_ocp *bp)

{

	struct device *dev = &bp->dev;

	int i;



	sysfs_remove_link(&dev->kobj, "ttyGNSS");

	sysfs_remove_link(&dev->kobj, "ttyMAC");

	sysfs_remove_link(&dev->kobj, "ptp");

	sysfs_remove_link(&dev->kobj, "pps");

	if (bp->attr_tbl)

		for (i = 0; bp->attr_tbl[i].cap; i++)

			sysfs_remove_group(&dev->kobj, bp->attr_tbl[i].group);

}



static void
@@ -3511,6 +3537,7 @@ ptp_ocp_detach(struct ptp_ocp *bp) 


	ptp_ocp_debugfs_remove_device(bp);

	ptp_ocp_detach_sysfs(bp);

	ptp_ocp_attr_group_del(bp);

	if (timer_pending(&bp->watchdog))

		del_timer_sync(&bp->watchdog);

	if (bp->ts0)