Re: [Qemu-devel] [PATCH 08/22] linux-user: remove two unchecked uses of strdup

[Peter Maydell]

On 9 May 2012 10:23, Jim Meyering <address@hidden> wrote:
> From: Jim Meyering <address@hidden>
>
> Remove unnecessary and unchecked uses of strdup,
> and add a comment that this strncpy use is ok.
>
> Signed-off-by: Jim Meyering <address@hidden>
> ---
>  linux-user/elfload.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/linux-user/elfload.c b/linux-user/elfload.c
> index f3b1552..25175cc 100644
> --- a/linux-user/elfload.c
> +++ b/linux-user/elfload.c
> @@ -2338,12 +2338,14 @@ static int fill_psinfo(struct target_elf_prpsinfo 
> *psinfo, const TaskState *ts)
>     psinfo->pr_uid = getuid();
>     psinfo->pr_gid = getgid();
>
> -    filename = strdup(ts->bprm->filename);
> -    base_filename = strdup(basename(filename));
> +    filename = ts->bprm->filename;
> +    base_filename = basename(filename);
> +    /*
> +     * Using strncpy here is fine: at max-length,
> +     * this field is not NUL-terminated.
> +     */
>     (void) strncpy(psinfo->pr_fname, base_filename,
>                    sizeof(psinfo->pr_fname));
> -    free(base_filename);
> -    free(filename);

This doesn't look right -- basename can modify
the string it's passed, which is why we create a copy
for it.

-- PMM