4 files changed, 102 insertions, 0 deletions
diff --git a/tools/testing/selftests/proc/.gitignore b/tools/testing/selftests/proc/.gitignore
index 4bca5a9327a4..bed4b5318a86 100644
--- a/tools/testing/selftests/proc/.gitignore
+++ b/tools/testing/selftests/proc/.gitignore
@@ -2,7 +2,9 @@
 /fd-001-lookup
 /fd-002-posix-eq
 /fd-003-kthread
+/proc-fsconfig-hidepid
 /proc-loadavg-001
+/proc-multiple-procfs
 /proc-pid-vm
 /proc-self-map-files-001
 /proc-self-map-files-002
diff --git a/tools/testing/selftests/proc/Makefile b/tools/testing/selftests/proc/Makefile
index a8ed0f684829..8be8a03d2973 100644
--- a/tools/testing/selftests/proc/Makefile
+++ b/tools/testing/selftests/proc/Makefile
@@ -19,5 +19,7 @@ TEST_GEN_PROGS += self
 TEST_GEN_PROGS += setns-dcache
 TEST_GEN_PROGS += setns-sysvipc
 TEST_GEN_PROGS += thread-self
+TEST_GEN_PROGS += proc-multiple-procfs
+TEST_GEN_PROGS += proc-fsconfig-hidepid
 
 include ../lib.mk
diff --git a/tools/testing/selftests/proc/proc-fsconfig-hidepid.c b/tools/testing/selftests/proc/proc-fsconfig-hidepid.c
new file mode 100644
index 000000000000..b9af8f537185
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-fsconfig-hidepid.c
@@ -0,0 +1,50 @@
+/*
+ * Copyright © 2020 Alexey Gladkov <gladkov.alexey@gmail.com>
+ *
+ * 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.
+ */
+#include <assert.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <linux/mount.h>
+#include <linux/unistd.h>
+
+static inline int fsopen(const char *fsname, unsigned int flags)
+{
+	return syscall(__NR_fsopen, fsname, flags);
+}
+
+static inline int fsconfig(int fd, unsigned int cmd, const char *key, const void *val, int aux)
+{
+	return syscall(__NR_fsconfig, fd, cmd, key, val, aux);
+}
+
+int main(void)
+{
+	int fsfd, ret;
+	int hidepid = 2;
+
+	assert((fsfd = fsopen("proc", 0)) != -1);
+
+	ret = fsconfig(fsfd, FSCONFIG_SET_BINARY, "hidepid", &hidepid, 0);
+	assert(ret == -1);
+	assert(errno == EINVAL);
+
+	assert(!fsconfig(fsfd, FSCONFIG_SET_STRING, "hidepid", "2", 0));
+	assert(!fsconfig(fsfd, FSCONFIG_SET_STRING, "hidepid", "invisible", 0));
+
+	assert(!close(fsfd));
+
+	return 0;
+}
diff --git a/tools/testing/selftests/proc/proc-multiple-procfs.c b/tools/testing/selftests/proc/proc-multiple-procfs.c
new file mode 100644
index 000000000000..ab912ad95dab
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-multiple-procfs.c
@@ -0,0 +1,48 @@
+/*
+ * Copyright © 2020 Alexey Gladkov <gladkov.alexey@gmail.com>
+ *
+ * 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.
+ */
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <sys/mount.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+int main(void)
+{
+	struct stat proc_st1, proc_st2;
+	char procbuff[] = "/tmp/proc.XXXXXX/meminfo";
+	char procdir1[] = "/tmp/proc.XXXXXX";
+	char procdir2[] = "/tmp/proc.XXXXXX";
+
+	assert(mkdtemp(procdir1) != NULL);
+	assert(mkdtemp(procdir2) != NULL);
+
+	assert(!mount("proc", procdir1, "proc", 0, "hidepid=1"));
+	assert(!mount("proc", procdir2, "proc", 0, "hidepid=2"));
+
+	snprintf(procbuff, sizeof(procbuff), "%s/meminfo", procdir1);
+	assert(!stat(procbuff, &proc_st1));
+
+	snprintf(procbuff, sizeof(procbuff), "%s/meminfo", procdir2);
+	assert(!stat(procbuff, &proc_st2));
+
+	umount(procdir1);
+	umount(procdir2);
+
+	assert(proc_st1.st_dev != proc_st2.st_dev);
+
+	return 0;
+}