GCC (15.2.1) warns on about the following string truncation in blkparse.c gcc -o blkparse.o -c -Wall -O2 -g -W -D_GNU_SOURCE -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 blkparse.c blkparse.c: In function ‘main’: blkparse.c:2103:68: warning: ‘):’ directive output may be truncated writing 2 bytes into a region of size between 1 and 41 [-Wformat-truncation=] 2103 | snprintf(line, sizeof(line) - 1, "CPU%d (%s):", | ^~ In function ‘show_device_and_cpu_stats’, inlined from ‘show_stats’ at blkparse.c:3064:3, inlined from ‘main’ at blkparse.c:3386:3: blkparse.c:2103:25: note: ‘snprintf’ output between 9 and 49 bytes into a destination of size 47 2103 | snprintf(line, sizeof(line) - 1, "CPU%d (%s):", | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 2104 | j, get_dev_name(pdi, name, sizeof(name))); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ gcc -Wall -O2 -g -W -D_GNU_SOURCE -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -o blkparse blkparse.o blkparse_fmt.o rbtree.o act_mask.o Add two more bytes to the string in order to mitigate the compiler warning. Signed-off-by: Johannes Thumshirn --- blkparse.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/blkparse.c b/blkparse.c index d6aaa8b..3f4d827 100644 --- a/blkparse.c +++ b/blkparse.c @@ -2023,7 +2023,7 @@ static void show_device_and_cpu_stats(void) struct io_stats total, *ios; unsigned long long rrate, wrate, msec; int i, j, pci_events; - char line[3 + 8/*cpu*/ + 2 + 32/*dev*/ + 3]; + char line[3 + 8/*cpu*/ + 2 + 32/*dev*/ + 3 + 2]; char name[32]; double ratio; -- 2.51.0