[PATCH 1/5] usb: atm: Remove snprintf() from sysfs call-backs and replace with sysfs_emit()

From: Lee Jones
Date: Thu Nov 30 2023 - 05:55:21 EST


Since snprintf() has the documented, but still rather strange trait of
returning the length of the data that *would have been* written to the
array if space were available, rather than the arguably more useful
length of data *actually* written, it is usually considered wise to use
something else instead in order to avoid confusion.

In the case of sysfs call-backs, new wrappers exist that do just that.

This patch replaces the 2 uses of snprintf() found in the sysfs .show()
call-backs with the new sysfs_emit() helpers. Whist we're at it, let's
replace the sprintf()s as well. For no other reason than consistency.

Link: https://lwn.net/Articles/69419/
Link: https://github.com/KSPP/linux/issues/105
Cc: Matthieu CASTET <castet.matthieu@xxxxxxx>
Cc: Stanislaw Gruszka <stf_xl@xxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Damien Bergamini <damien.bergamini@xxxxxxx>
Cc: linux-usb@xxxxxxxxxxxxxxx
Signed-off-by: Lee Jones <lee@xxxxxxxxxx>
---
drivers/usb/atm/ueagle-atm.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/atm/ueagle-atm.c b/drivers/usb/atm/ueagle-atm.c
index 5812f7ea7f902..8d5580d8d20a8 100644
--- a/drivers/usb/atm/ueagle-atm.c
+++ b/drivers/usb/atm/ueagle-atm.c
@@ -2252,7 +2252,7 @@ static ssize_t stat_status_show(struct device *dev, struct device_attribute *att
sc = dev_to_uea(dev);
if (!sc)
goto out;
- ret = snprintf(buf, 10, "%08x\n", sc->stats.phy.state);
+ ret = sysfs_emit(buf, "%08x\n", sc->stats.phy.state);
out:
mutex_unlock(&uea_mutex);
return ret;
@@ -2318,19 +2318,19 @@ static ssize_t stat_human_status_show(struct device *dev,

switch (modem_state) {
case 0:
- ret = sprintf(buf, "Modem is booting\n");
+ ret = sysfs_emit(buf, "Modem is booting\n");
break;
case 1:
- ret = sprintf(buf, "Modem is initializing\n");
+ ret = sysfs_emit(buf, "Modem is initializing\n");
break;
case 2:
- ret = sprintf(buf, "Modem is operational\n");
+ ret = sysfs_emit(buf, "Modem is operational\n");
break;
case 3:
- ret = sprintf(buf, "Modem synchronization failed\n");
+ ret = sysfs_emit(buf, "Modem synchronization failed\n");
break;
default:
- ret = sprintf(buf, "Modem state is unknown\n");
+ ret = sysfs_emit(buf, "Modem state is unknown\n");
break;
}
out:
@@ -2364,7 +2364,7 @@ static ssize_t stat_delin_show(struct device *dev, struct device_attribute *attr
delin = "LOSS";
}

- ret = sprintf(buf, "%s\n", delin);
+ ret = sysfs_emit(buf, "%s\n", delin);
out:
mutex_unlock(&uea_mutex);
return ret;
@@ -2384,7 +2384,7 @@ static ssize_t stat_##name##_show(struct device *dev, \
sc = dev_to_uea(dev); \
if (!sc) \
goto out; \
- ret = snprintf(buf, 10, "%08x\n", sc->stats.phy.name); \
+ ret = sysfs_emit(buf, "%08x\n", sc->stats.phy.name); \
if (reset) \
sc->stats.phy.name = 0; \
out: \
--
2.43.0.rc1.413.gea7ed67945-goog