procfs: use an enum for possible hidepid values

Previously, the hidepid parameter was checked by comparing literal integers 0, 1, 2. Let's add a proper enum for this, to make the checking more expressive: 0 → HIDEPID_OFF 1 → HIDEPID_NO_ACCESS 2 → HIDEPID_INVISIBLE This changes the internal labelling only, the userspace-facing interface remains unmodified, and still works with literal integers 0, 1, 2. No functional changes.

Lafcadio Wluiki committed 9 years ago

Commit 796f5711 parent a0a07b84 files · +13 −6Browse files

Unified · Split

4 files

fs/proc/base.c +4 −4
fs/proc/inode.c +1 −1
fs/proc/root.c +2 −1
include/linux/pid_namespace.h +6 −0

fs/proc/base.c+4−4

@@ -697,11 +697,11 @@ static int proc_pid_permission(struct inode *inode, int mask) · 696 unmodified lines
697	697	task = get_proc_task(inode);
698	698	if (!task)
699	699	return -ESRCH;
700		− has_perms = has_pid_permissions(pid, task, 1);
	700	+ has_perms = has_pid_permissions(pid, task, HIDEPID_NO_ACCESS);
701	701	put_task_struct(task);
702	702
703	703	if (!has_perms) {
704		− if (pid->hide_pid == 2) {
	704	+ if (pid->hide_pid == HIDEPID_INVISIBLE) {
705	705	/*
706	706	* Let's make getdents(), stat(), and open()
707	707	* consistent with each other. If a process
@@ -1737,7 +1737,7 @@ int pid_getattr(struct vfsmount mnt, struct dentry dentry, struct kstat *stat) · 1029 unmodified lines
1737	1737	stat->gid = GLOBAL_ROOT_GID;
1738	1738	task = pid_task(proc_pid(inode), PIDTYPE_PID);
1739	1739	if (task) {
1740		− if (!has_pid_permissions(pid, task, 2)) {
	1740	+ if (!has_pid_permissions(pid, task, HIDEPID_INVISIBLE)) {
1741	1741	rcu_read_unlock();
1742	1742	/*
1743	1743	* This doesn't prevent learning whether PID exists,
@@ -3168,7 +3168,7 @@ int proc_pid_readdir(struct file file, struct dir_context ctx) · 1424 unmodified lines
3168	3168	int len;
3169	3169
3170	3170	cond_resched();
3171		− if (!has_pid_permissions(ns, iter.task, 2))
	3171	+ if (!has_pid_permissions(ns, iter.task, HIDEPID_INVISIBLE))
3172	3172	continue;
3173	3173
3174	3174	len = snprintf(name, sizeof(name), "%d", iter.tgid);

fs/proc/inode.c+1−1

@@ -107,7 +107,7 @@ static int proc_show_options(struct seq_file seq, struct dentry root) · 106 unmodified lines
107	107
108	108	if (!gid_eq(pid->pid_gid, GLOBAL_ROOT_GID))
109	109	seq_printf(seq, ",gid=%u", from_kgid_munged(&init_user_ns, pid->pid_gid));
110		− if (pid->hide_pid != 0)
	110	+ if (pid->hide_pid != HIDEPID_OFF)
111	111	seq_printf(seq, ",hidepid=%u", pid->hide_pid);
112	112
113	113	return 0;

fs/proc/root.c+2−1

@@ -58,7 +58,8 @@ int proc_parse_options(char options, struct pid_namespace pid) · 57 unmodified lines
58	58	case Opt_hidepid:
59	59	if (match_int(&args[0], &option))
60	60	return 0;
61		− if (option < 0 \|\| option > 2) {
	61	+ if (option < HIDEPID_OFF \|\|
	62	+ option > HIDEPID_INVISIBLE) {
62	63	pr_err("proc: hidepid value must be between 0 and 2.\n");
63	64	return 0;
64	65	}

include/linux/pid_namespace.h+6−0

@@ -21,6 +21,12 @@ struct pidmap { · 20 unmodified lines
21	21
22	22	struct fs_pin;
23	23
	24	+enum { /* definitions for pid_namespace's hide_pid field */
	25	+ HIDEPID_OFF = 0,
	26	+ HIDEPID_NO_ACCESS = 1,
	27	+ HIDEPID_INVISIBLE = 2,
	28	+};
	29	+
24	30	struct pid_namespace {
25	31	struct kref kref;
26	32	struct pidmap pidmap[PIDMAP_ENTRIES];