The patch titled
Subject: selftests: proc: test subset=pid
has been removed from the -mm tree. Its filename was
proc-test-subset=pid.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Subject: selftests: proc: test subset=pid
Test that /proc instance mounted with
mount -t proc -o subset=pid
contains only ".", "..", "self", "thread-self" and pid directories.
Note:
Currently "subset=pid" doesn't return "." and ".." via readdir.
This must be a bug.
Link: https://lkml.kernel.org/r/YFYZZ7WGaZlsnChS@localhost.localdomain
Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Acked-by: Alexey Gladkov <gladkov.alexey@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/proc/Makefile | 1
tools/testing/selftests/proc/proc-subset-pid.c | 121 +++++++++++++++
2 files changed, 122 insertions(+)
--- a/tools/testing/selftests/proc/Makefile~proc-test-subset=pid
+++ a/tools/testing/selftests/proc/Makefile
@@ -12,6 +12,7 @@ TEST_GEN_PROGS += proc-self-map-files-00
TEST_GEN_PROGS += proc-self-map-files-002
TEST_GEN_PROGS += proc-self-syscall
TEST_GEN_PROGS += proc-self-wchan
+TEST_GEN_PROGS += proc-subset-pid
TEST_GEN_PROGS += proc-uptime-001
TEST_GEN_PROGS += proc-uptime-002
TEST_GEN_PROGS += read
--- /dev/null
+++ a/tools/testing/selftests/proc/proc-subset-pid.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2021 Alexey Dobriyan <adobriyan@xxxxxxxxx>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+/*
+ * Test that "mount -t proc -o subset=pid" hides everything but pids,
+ * /proc/self and /proc/thread-self.
+ */
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <sched.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mount.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <dirent.h>
+#include <unistd.h>
+#include <stdio.h>
+
+static inline bool streq(const char *a, const char *b)
+{
+ return strcmp(a, b) == 0;
+}
+
+static void make_private_proc(void)
+{
+ if (unshare(CLONE_NEWNS) == -1) {
+ if (errno == ENOSYS || errno == EPERM) {
+ exit(4);
+ }
+ exit(1);
+ }
+ if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) {
+ exit(1);
+ }
+ if (mount(NULL, "/proc", "proc", 0, "subset=pid") == -1) {
+ exit(1);
+ }
+}
+
+static bool string_is_pid(const char *s)
+{
+ while (1) {
+ switch (*s++) {
+ case '0':case '1':case '2':case '3':case '4':
+ case '5':case '6':case '7':case '8':case '9':
+ continue;
+
+ case '\0':
+ return true;
+
+ default:
+ return false;
+ }
+ }
+}
+
+int main(void)
+{
+ make_private_proc();
+
+ DIR *d = opendir("/proc");
+ assert(d);
+
+ struct dirent *de;
+
+ bool dot = false;
+ bool dot_dot = false;
+ bool self = false;
+ bool thread_self = false;
+
+ while ((de = readdir(d))) {
+ if (streq(de->d_name, ".")) {
+ assert(!dot);
+ dot = true;
+ assert(de->d_type == DT_DIR);
+ } else if (streq(de->d_name, "..")) {
+ assert(!dot_dot);
+ dot_dot = true;
+ assert(de->d_type == DT_DIR);
+ } else if (streq(de->d_name, "self")) {
+ assert(!self);
+ self = true;
+ assert(de->d_type == DT_LNK);
+ } else if (streq(de->d_name, "thread-self")) {
+ assert(!thread_self);
+ thread_self = true;
+ assert(de->d_type == DT_LNK);
+ } else {
+ if (!string_is_pid(de->d_name)) {
+ fprintf(stderr, "d_name '%s'\n", de->d_name);
+ assert(0);
+ }
+ assert(de->d_type == DT_DIR);
+ }
+ }
+
+ char c;
+ int rv = readlink("/proc/cpuinfo", &c, 1);
+ assert(rv == -1 && errno == ENOENT);
+
+ int fd = open("/proc/cpuinfo", O_RDONLY);
+ assert(fd == -1 && errno == ENOENT);
+
+ return 0;
+}
_
Patches currently in -mm which might be from adobriyan@xxxxxxxxx are
