[PATCH 1/7] PID namespace translation support

[Dmitry V. Levin]

On Sun, Jul 12, 2020 at 09:46:30PM +0200, Ákos Uzonyi wrote:
[...]
> +/**
> + * Returns a list of PID NS IDs for the specified PID.
> + *
> + * @param proc_pid PID (as present in /proc) to get information for.
> + * @param ns_buf   Pointer to buffer that is able to contain at least
> + *                 MAX_NS_DEPTH items.
> + * @param last     ID of NS on which ascencion can be interrupted.
> + *                 0 for no interruption.
> + * @return         Amount of NS in list. 0 indicates error, MAX_NS_DEPTH + 1
> + *                 indicates that ascension limit hasn't been reached (only
> + *                 MAX_NS_DEPTH values have been written to the array, however).
> + */
> +static size_t
> +get_ns_hierarchy(int proc_pid, uint64_t *ns_buf, size_t ns_buf_size)

Looks like the description of get_ns_hierarchy is out of sync with the
implementation.

> +{
> +	char path[PATH_MAX + 1];
> +	struct stat st;
> +	ssize_t ret;
> +	size_t n = 0;
> +	int fd;
> +	int parent_fd;
> +
> +	ret = snprintf(path, sizeof(path), "/proc/%s/ns/pid",
> +		       pid_to_str(proc_pid));
> +
> +	if ((ret < 0) || ((size_t) ret >= sizeof(path)))
> +		return 0;
> +
> +	fd = open(path, O_RDONLY | O_NONBLOCK);
> +	if (fd < 0)
> +		return 0;
> +
> +	while (1) {
> +		ret = fstat(fd, &st);
> +		if (ret)
> +			break;
> +
> +		/* 32 is the hierarchy depth on modern Linux */
> +		if ((n >= MAX_NS_DEPTH) || (n >= ns_buf_size)) {

Is ns_buf_size allowed to exceed MAX_NS_DEPTH?


-- 
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