Re: [PATCH v3 1/2] use HOST_NAME_MAX to size buffers for gethostname(2)

["Torsten Bögershausen" <tboegi@web.de>]

On 2017-04-19 19:28, René Scharfe wrote:
[]
One or two minor comments inline
> diff --git a/builtin/gc.c b/builtin/gc.c
> index 2daede7820..4c1c01e87d 100644
> --- a/builtin/gc.c
> +++ b/builtin/gc.c
> @@ -228,21 +228,99 @@ static int need_to_gc(void)
>  	return 1;
>  }
>  
> +struct pidfile {
> +	struct strbuf buf;
> +	char *hostname;
> +};
> +
> +#define PIDFILE_INIT { STRBUF_INIT }
> +
> +static void pidfile_release(struct pidfile *pf)
> +{
> +	pf->hostname = NULL;
> +	strbuf_release(&pf->buf);
> +}
> +
> +static int pidfile_read(struct pidfile *pf, const char *path,
> +			unsigned int max_age_seconds)
> +{
> +	int fd;
> +	struct stat st;
> +	ssize_t len;
> +	char *space;
> +	int rc = -1;
> +
> +	fd = open(path, O_RDONLY);
> +	if (fd < 0)
> +		return rc;
> +
> +	if (fstat(fd, &st))
> +		goto out;
> +	if (time(NULL) - st.st_mtime > max_age_seconds)
> +		goto out;
> +	if (st.st_size > (size_t)st.st_size)

Minor: we need xsize_t here ?
if (st.st_size > xsize_t(st.st_size))

> +		goto out;
> +
> +	len = strbuf_read(&pf->buf, fd, st.st_size);
> +	if (len < 0)
> +		goto out;
> +
> +	space = strchr(pf->buf.buf, ' ');
> +	if (!space) {
> +		pidfile_release(pf);
> +		goto out;
> +	}
> +	pf->hostname = space + 1;
> +	*space = '\0';
> +
> +	rc = 0;
> +out:
> +	close(fd);
> +	return rc;
> +}
> +
> +static int parse_pid(const char *value, pid_t *ret)
> +{
> +	if (value && *value) {
> +		char *end;
> +		intmax_t val;
> +
> +		errno = 0;
> +		val = strtoimax(value, &end, 0);
> +		if (errno == ERANGE)
> +			return 0;
> +		if (*end)
> +			return 0;
> +		if (labs(val) > maximum_signed_value_of_type(pid_t)) {
> +			errno = ERANGE;
> +			return 0;
> +		}
> +		*ret = val;
> +		return 1;
> +	}
> +	errno = EINVAL;
> +	return 0;
> +}
> +
> +static int pidfile_process_exists(const struct pidfile *pf)
> +{
> +	pid_t pid;
> +	return parse_pid(pf->buf.buf, &pid) &&
> +		(!kill(pid, 0) || errno == EPERM);
> +}
> +
>  /* return NULL on success, else hostname running the gc */
> -static const char *lock_repo_for_gc(int force, pid_t* ret_pid)
> +static int lock_repo_for_gc(int force, struct pidfile *pf)
>  {
>  	static struct lock_file lock;
>  	char my_host[128];

Huh ?
should this be increased, may be in another path ?