[PATCH] avoid GCC 10 warning -Wstringop-truncation

[Gedare Bloom]

This looks good to me. memcpy followed by explicit delimiter
assignment is better than strncpy. however, note below:

On Thu, Jul 30, 2020 at 5:36 AM Aschref Ben-Thabet
<aschref.ben-thabet at embedded-brains.de> wrote:
>
> From: Aschref Ben Thabet <aschref.ben-thabet at embedded-brains.de>
>
> GCC 10 warns about an overlapping using strncpy.
> -> Replace some calls of strncpy with a memcpy to avoid this issue.
> ---
>  cpukit/libblock/src/bdpart-mount.c   | 4 ++--
>  testsuites/psxtests/psxndbm01/init.c | 2 +-
>  2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/cpukit/libblock/src/bdpart-mount.c b/cpukit/libblock/src/bdpart-mount.c
> index cfc08ead30..f689b18ebb 100644
> --- a/cpukit/libblock/src/bdpart-mount.c
> +++ b/cpukit/libblock/src/bdpart-mount.c
> @@ -54,7 +54,7 @@ rtems_status_code rtems_bdpart_mount(
>    if (logical_disk_name == NULL) {
>      return RTEMS_NO_MEMORY;
>    }
> -  strncpy( logical_disk_name, disk_name, disk_name_size);
> +  memcpy( logical_disk_name, disk_name, disk_name_size);
>
is it guaranteed to have a NUL delimiter in disk_name up to
disk_name_size? (I don't think it does.)

It should be safer to follow this with:
logical_disk_name[disk_name_size] = '\0';

>    /* Get disk file name */
>    if (disk_file_name != NULL) {
> @@ -148,7 +148,7 @@ rtems_status_code rtems_bdpart_unmount(
>      esc = RTEMS_NO_MEMORY;
>      goto cleanup;
>    }
> -  strncpy( mount_point, mount_base, mount_base_size);
> +  memcpy( mount_point, mount_base, mount_base_size);
>    mount_point [mount_base_size] = '/';
>    strncpy( mount_point + mount_base_size + 1, disk_file_name, disk_file_name_size);

I guess this one doesn't give a warning? Would it still make any sense
to replace it?

>
> diff --git a/testsuites/psxtests/psxndbm01/init.c b/testsuites/psxtests/psxndbm01/init.c
> index a13afa7315..b524aff0df 100644
> --- a/testsuites/psxtests/psxndbm01/init.c
> +++ b/testsuites/psxtests/psxndbm01/init.c
> @@ -218,7 +218,7 @@ rtems_task Init(rtems_task_argument ignored)
>
>    puts( "Fetch non-existing record and confirm error." );
>    test_strings = (char*)malloc(6);
> -  strncpy( test_strings, "Hello", 5 );
> +  memcpy( test_strings, "Hello", 5 );
>
>    test_strings[5] = '\0';
>
> --
> 2.26.2
>
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