kdb: Fix bound check compiler warning

The strncpy() function may leave the destination string buffer
unterminated, better use strscpy() instead.

This fixes the following warning with gcc 8.2:

kernel/debug/kdb/kdb_io.c: In function 'kdb_getstr':
kernel/debug/kdb/kdb_io.c:449:3: warning: 'strncpy' specified bound 256 equals destination size [-Wstringop-truncation]
   strncpy(kdb_prompt_str, prompt, CMD_BUFLEN);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Wenlin Kang <wenlin.kang@windriver.com>
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index 6a4b41484afe..3a5184eb6977 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -446,7 +446,7 @@ poll_again:
 char *kdb_getstr(char *buffer, size_t bufsize, const char *prompt)
 {
         if (prompt && kdb_prompt_str != prompt)
-                strncpy(kdb_prompt_str, prompt, CMD_BUFLEN);
+                strscpy(kdb_prompt_str, prompt, CMD_BUFLEN);
         kdb_printf(kdb_prompt_str);
         kdb_nextline = 1;       /* Prompt and input resets line number */
         return kdb_read(buffer, bufsize);