[PATCH RESEND] locking/lockdep: fix format-truncation compiler-warning

From: Lucy Mielke
Date: Thu Oct 12 2023 - 06:44:41 EST


Compiler: gcc x86_64 v13.2.1
Config: allyesconfig, "treat warnings as errors" unset

This fixes the following compiler-warnings emitted by GCC:
kernel/locking/lockdep_proc.c:438:32: Warning: Format specifier '%lld' may
be truncated when writing 1 to 17 bytes into a region
of size 15 [-Wformat-truncation=]
kernel/locking/lockdep_proc.c:438:31: Note: Format directive argument is
in the range [-9223372036854775, 9223372036854775]
kernel/locking/lockdep_proc.c:438:9: Note: 'snprintf' has output
between 5 and 22 bytes into a target of size 15

The longest s64 is "-9223372036854775808"-ish, which converted to the
fixed-point float format is "-9223372036854775.80": 21 bytes,
plus termination is another byte: 22. Therefore, a buffer size of 22 is
needed here.

Signed-off-by: Lucy Mielke <lucymielke@xxxxxxxxxx>
---
kernel/locking/lockdep_proc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c
index 15fdc7fa5c68..e2bfb1db589d 100644
--- a/kernel/locking/lockdep_proc.c
+++ b/kernel/locking/lockdep_proc.c
@@ -440,7 +440,7 @@ static void snprint_time(char *buf, size_t bufsiz, s64 nr)

static void seq_time(struct seq_file *m, s64 time)
{
- char num[15];
+ char num[22];

snprint_time(num, sizeof(num), time);
seq_printf(m, " %14s", num);
--
2.41.0