On Mon, 4 Feb 2019 10:59:44 +0100
Anisse Astier <aastier@xxxxxxxxxx> wrote:
> GCC 8.2 gives this warning:
>
> virtio/9p.c: In function ‘virtio_p9_create’:
> virtio/9p.c:335:21: error: passing argument 1 to restrict-qualified parameter aliases with argument 4 [-Werror=restrict]
> ret = snprintf(dfid->path, size, "%s/%s", dfid->path, name);
> ~~~~^~~~~~ ~~~~~~~~~~
>
> Fix it by allocating a temporary string with dfid->path content instead
> of overwriting it in-place, which is limited in glibc snprintf with the
> __restrict qualifier.
>
> Signed-off-by: Anisse Astier <aastier@xxxxxxxxxx>
Reviewed-by: Andre Przywara <andre.przywara@xxxxxxx>
Cheers,
Andre
> ---
> virtio/9p.c | 9 ++++++++-
> 1 file changed, 8 insertions(+), 1 deletion(-)
>
> diff --git a/virtio/9p.c b/virtio/9p.c
> index 6bae403..ac70dbc 100644
> --- a/virtio/9p.c
> +++ b/virtio/9p.c
> @@ -322,6 +322,7 @@ static void virtio_p9_create(struct p9_dev *p9dev,
> struct p9_qid qid;
> struct p9_fid *dfid;
> char full_path[PATH_MAX];
> + char *tmp_path;
> u32 dfid_val, flags, mode, gid;
>
> virtio_p9_pdu_readf(pdu, "dsddd", &dfid_val,
> @@ -332,7 +333,13 @@ static void virtio_p9_create(struct p9_dev *p9dev,
> goto err_out;
>
> size = sizeof(dfid->abs_path) - (dfid->path - dfid->abs_path);
> - ret = snprintf(dfid->path, size, "%s/%s", dfid->path, name);
> +
> + tmp_path = strdup(dfid->path);
> + if (!tmp_path)
> + goto err_out;
> +
> + ret = snprintf(dfid->path, size, "%s/%s", tmp_path, name);
> + free(tmp_path);
> if (ret >= (int)size) {
> errno = ENAMETOOLONG;
> if (size > 0)
