[PATCH 2/2] blk-wbt: Replace strlcpy with strscpy

From: Azeem Shaikh
Date: Mon Jul 03 2023 - 13:22:51 EST


strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@xxxxxxxxx>
---
include/trace/events/wbt.h | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/trace/events/wbt.h b/include/trace/events/wbt.h
index 9c66e59d859c..4661f0d27062 100644
--- a/include/trace/events/wbt.h
+++ b/include/trace/events/wbt.h
@@ -33,7 +33,7 @@ TRACE_EVENT(wbt_stat,
),

TP_fast_assign(
- strlcpy(__entry->name, bdi_dev_name(bdi),
+ strscpy(__entry->name, bdi_dev_name(bdi),
ARRAY_SIZE(__entry->name));
__entry->rmean = stat[0].mean;
__entry->rmin = stat[0].min;
@@ -68,7 +68,7 @@ TRACE_EVENT(wbt_lat,
),

TP_fast_assign(
- strlcpy(__entry->name, bdi_dev_name(bdi),
+ strscpy(__entry->name, bdi_dev_name(bdi),
ARRAY_SIZE(__entry->name));
__entry->lat = div_u64(lat, 1000);
),
@@ -105,7 +105,7 @@ TRACE_EVENT(wbt_step,
),

TP_fast_assign(
- strlcpy(__entry->name, bdi_dev_name(bdi),
+ strscpy(__entry->name, bdi_dev_name(bdi),
ARRAY_SIZE(__entry->name));
__entry->msg = msg;
__entry->step = step;
@@ -141,7 +141,7 @@ TRACE_EVENT(wbt_timer,
),

TP_fast_assign(
- strlcpy(__entry->name, bdi_dev_name(bdi),
+ strscpy(__entry->name, bdi_dev_name(bdi),
ARRAY_SIZE(__entry->name));
__entry->status = status;
__entry->step = step;
--
2.41.0.255.g8b1d071c50-goog