[PATCH v2] drivers/ptp: Convert snprintf to sysfs_emit

From: Li Zhijian
Date: Wed Jan 24 2024 - 20:56:40 EST


Per filesystems/sysfs.rst, show() should only use sysfs_emit()
or sysfs_emit_at() when formatting the value to be returned to user space.

coccinelle complains that there are still a couple of functions that use
snprintf(). Convert them to sysfs_emit().

> ./drivers/ptp/ptp_sysfs.c:27:8-16: WARNING: please use sysfs_emit

No functional change intended

CC: Richard Cochran <richardcochran@xxxxxxxxx>
CC: netdev@xxxxxxxxxxxxxxx
Signed-off-by: Li Zhijian <lizhijian@xxxxxxxxxxx>
---
V2:
- Address Rahul's comments:
Convert all leftover snprintf that is not detected by coccinelle to sysfs_emit
-
V2: extract patch from the patch set[1] so that maintainer can review/accept it separately.
[1] https://lore.kernel.org/lkml/20240116041129.3937800-1-lizhijian@xxxxxxxxxxx/
---
drivers/ptp/ptp_sysfs.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c
index f7a499a1bd39..a15460aaa03b 100644
--- a/drivers/ptp/ptp_sysfs.c
+++ b/drivers/ptp/ptp_sysfs.c
@@ -24,8 +24,7 @@ static ssize_t max_phase_adjustment_show(struct device *dev,
{
struct ptp_clock *ptp = dev_get_drvdata(dev);

- return snprintf(page, PAGE_SIZE - 1, "%d\n",
- ptp->info->getmaxphase(ptp->info));
+ return sysfs_emit(page, "%d\n", ptp->info->getmaxphase(ptp->info));
}
static DEVICE_ATTR_RO(max_phase_adjustment);

@@ -34,7 +33,7 @@ static ssize_t var##_show(struct device *dev, \
struct device_attribute *attr, char *page) \
{ \
struct ptp_clock *ptp = dev_get_drvdata(dev); \
- return snprintf(page, PAGE_SIZE-1, "%d\n", ptp->info->var); \
+ return sysfs_emit(page, "%d\n", ptp->info->var); \
} \
static DEVICE_ATTR(name, 0444, var##_show, NULL);

@@ -102,8 +101,8 @@ static ssize_t extts_fifo_show(struct device *dev,
if (!qcnt)
goto out;

- cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",
- event.index, event.t.sec, event.t.nsec);
+ cnt = sysfs_emit(page, "%u %lld %u\n",
+ event.index, event.t.sec, event.t.nsec);
out:
return cnt;
}
@@ -194,7 +193,7 @@ static ssize_t n_vclocks_show(struct device *dev,
if (mutex_lock_interruptible(&ptp->n_vclocks_mux))
return -ERESTARTSYS;

- size = snprintf(page, PAGE_SIZE - 1, "%u\n", ptp->n_vclocks);
+ size = sysfs_emit(page, "%u\n", ptp->n_vclocks);

mutex_unlock(&ptp->n_vclocks_mux);

@@ -270,7 +269,7 @@ static ssize_t max_vclocks_show(struct device *dev,
struct ptp_clock *ptp = dev_get_drvdata(dev);
ssize_t size;

- size = snprintf(page, PAGE_SIZE - 1, "%u\n", ptp->max_vclocks);
+ size = sysfs_emit(page, "%u\n", ptp->max_vclocks);

return size;
}
--
2.29.2