[PATCH v1 1/2] mmc-utils: Use memcpy instead of strncpy

From: Bean Huo
Date: Sun Nov 14 2021 - 15:44:38 EST


From: Bean Huo <beanhuo@xxxxxxxxxx>

The -Wstringop-truncation warning added in GCC 8.0:
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82944

If you use the GCC > v8.0, you probably will get this compilation error:

error: ‘__builtin_strncpy’ output may be truncated copying 8
bytes from a string of length 511 [-Werror=stringop-truncation]

Use memcpy instead of strncpy to avoid this compilation error.

Signed-off-by: Bean Huo <beanhuo@xxxxxxxxxx>
---
mmc_cmds.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mmc_cmds.c b/mmc_cmds.c
index 205e6e5b89f9..ecbde3937c81 100644
--- a/mmc_cmds.c
+++ b/mmc_cmds.c
@@ -1835,7 +1835,8 @@ int do_read_extcsd(int nargs, char **argv)

if (ext_csd_rev >= 7) {
memset(lbuf, 0, sizeof(lbuf));
- strncpy(lbuf, (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION], 8);
+ memcpy(lbuf, (char*)&ext_csd[EXT_CSD_FIRMWARE_VERSION], 8);
+ lbuf[8] = '\0';
printf("eMMC Firmware Version: %s\n", lbuf);
printf("eMMC Life Time Estimation A [EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_A]: 0x%02x\n",
ext_csd[EXT_CSD_DEVICE_LIFE_TIME_EST_TYP_A]);
--
2.25.1