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-rw-r--r--tools/testing/selftests/proc/.gitignore27
-rw-r--r--tools/testing/selftests/proc/Makefile34
-rw-r--r--tools/testing/selftests/proc/config1
-rw-r--r--tools/testing/selftests/proc/fd-001-lookup.c168
-rw-r--r--tools/testing/selftests/proc/fd-002-posix-eq.c57
-rw-r--r--tools/testing/selftests/proc/fd-003-kthread.c178
-rw-r--r--tools/testing/selftests/proc/proc-2-is-kthread.c53
-rw-r--r--tools/testing/selftests/proc/proc-empty-vm.c541
-rw-r--r--tools/testing/selftests/proc/proc-fsconfig-hidepid.c50
-rw-r--r--tools/testing/selftests/proc/proc-loadavg-001.c82
-rw-r--r--tools/testing/selftests/proc/proc-maps-race.c976
-rw-r--r--tools/testing/selftests/proc/proc-multiple-procfs.c48
-rw-r--r--tools/testing/selftests/proc/proc-net-dev-lseek.c68
-rw-r--r--tools/testing/selftests/proc/proc-pid-vm.c592
-rw-r--r--tools/testing/selftests/proc/proc-pidns.c212
-rw-r--r--tools/testing/selftests/proc/proc-self-isnt-kthread.c37
-rw-r--r--tools/testing/selftests/proc/proc-self-map-files-001.c82
-rw-r--r--tools/testing/selftests/proc/proc-self-map-files-002.c94
-rw-r--r--tools/testing/selftests/proc/proc-self-syscall.c58
-rw-r--r--tools/testing/selftests/proc/proc-self-wchan.c40
-rw-r--r--tools/testing/selftests/proc/proc-subset-pid.c121
-rw-r--r--tools/testing/selftests/proc/proc-tid0.c81
-rw-r--r--tools/testing/selftests/proc/proc-uptime-001.c58
-rw-r--r--tools/testing/selftests/proc/proc-uptime-002.c92
-rw-r--r--tools/testing/selftests/proc/proc-uptime.h60
-rw-r--r--tools/testing/selftests/proc/proc.h51
-rw-r--r--tools/testing/selftests/proc/read.c148
-rw-r--r--tools/testing/selftests/proc/self.c39
-rw-r--r--tools/testing/selftests/proc/setns-dcache.c129
-rw-r--r--tools/testing/selftests/proc/setns-sysvipc.c133
-rw-r--r--tools/testing/selftests/proc/thread-self.c64
31 files changed, 4374 insertions, 0 deletions
diff --git a/tools/testing/selftests/proc/.gitignore b/tools/testing/selftests/proc/.gitignore
new file mode 100644
index 000000000..9c9735570
--- /dev/null
+++ b/tools/testing/selftests/proc/.gitignore
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: GPL-2.0-only
+/fd-001-lookup
+/fd-002-posix-eq
+/fd-003-kthread
+/proc-2-is-kthread
+/proc-fsconfig-hidepid
+/proc-loadavg-001
+/proc-maps-race
+/proc-multiple-procfs
+/proc-net-dev-lseek
+/proc-empty-vm
+/proc-pid-vm
+/proc-self-map-files-001
+/proc-self-map-files-002
+/proc-self-isnt-kthread
+/proc-self-syscall
+/proc-self-wchan
+/proc-subset-pid
+/proc-tid0
+/proc-uptime-001
+/proc-uptime-002
+/proc-pidns
+/read
+/self
+/setns-dcache
+/setns-sysvipc
+/thread-self
diff --git a/tools/testing/selftests/proc/Makefile b/tools/testing/selftests/proc/Makefile
new file mode 100644
index 000000000..a7de2bb6d
--- /dev/null
+++ b/tools/testing/selftests/proc/Makefile
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: GPL-2.0-only
+CFLAGS += -Wall -O2 -Wno-unused-function
+CFLAGS += $(TOOLS_INCLUDES)
+LDFLAGS += -pthread
+
+TEST_GEN_PROGS :=
+TEST_GEN_PROGS += fd-001-lookup
+TEST_GEN_PROGS += fd-002-posix-eq
+TEST_GEN_PROGS += fd-003-kthread
+TEST_GEN_PROGS += proc-2-is-kthread
+TEST_GEN_PROGS += proc-loadavg-001
+TEST_GEN_PROGS += proc-maps-race
+TEST_GEN_PROGS += proc-net-dev-lseek
+TEST_GEN_PROGS += proc-empty-vm
+TEST_GEN_PROGS += proc-pid-vm
+TEST_GEN_PROGS += proc-self-map-files-001
+TEST_GEN_PROGS += proc-self-map-files-002
+TEST_GEN_PROGS += proc-self-isnt-kthread
+TEST_GEN_PROGS += proc-self-syscall
+TEST_GEN_PROGS += proc-self-wchan
+TEST_GEN_PROGS += proc-subset-pid
+TEST_GEN_PROGS += proc-tid0
+TEST_GEN_PROGS += proc-uptime-001
+TEST_GEN_PROGS += proc-uptime-002
+TEST_GEN_PROGS += read
+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
+TEST_GEN_PROGS += proc-pidns
+
+include ../lib.mk
diff --git a/tools/testing/selftests/proc/config b/tools/testing/selftests/proc/config
new file mode 100644
index 000000000..68fbd2b35
--- /dev/null
+++ b/tools/testing/selftests/proc/config
@@ -0,0 +1 @@
+CONFIG_PROC_FS=y
diff --git a/tools/testing/selftests/proc/fd-001-lookup.c b/tools/testing/selftests/proc/fd-001-lookup.c
new file mode 100644
index 000000000..60d7948e7
--- /dev/null
+++ b/tools/testing/selftests/proc/fd-001-lookup.c
@@ -0,0 +1,168 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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.
+ */
+// Test /proc/*/fd lookup.
+
+#undef NDEBUG
+#include <assert.h>
+#include <dirent.h>
+#include <errno.h>
+#include <limits.h>
+#include <sched.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "proc.h"
+
+/* lstat(2) has more "coverage" in case non-symlink pops up somehow. */
+static void test_lookup_pass(const char *pathname)
+{
+ struct stat st;
+ ssize_t rv;
+
+ memset(&st, 0, sizeof(struct stat));
+ rv = lstat(pathname, &st);
+ assert(rv == 0);
+ assert(S_ISLNK(st.st_mode));
+}
+
+static void test_lookup_fail(const char *pathname)
+{
+ struct stat st;
+ ssize_t rv;
+
+ rv = lstat(pathname, &st);
+ assert(rv == -1 && errno == ENOENT);
+}
+
+static void test_lookup(unsigned int fd)
+{
+ char buf[64];
+ unsigned int c;
+ unsigned int u;
+ int i;
+
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%u", fd);
+ test_lookup_pass(buf);
+
+ /* leading junk */
+ for (c = 1; c <= 255; c++) {
+ if (c == '/')
+ continue;
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%c%u", c, fd);
+ test_lookup_fail(buf);
+ }
+
+ /* trailing junk */
+ for (c = 1; c <= 255; c++) {
+ if (c == '/')
+ continue;
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%u%c", fd, c);
+ test_lookup_fail(buf);
+ }
+
+ for (i = INT_MIN; i < INT_MIN + 1024; i++) {
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%d", i);
+ test_lookup_fail(buf);
+ }
+ for (i = -1024; i < 0; i++) {
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%d", i);
+ test_lookup_fail(buf);
+ }
+ for (u = INT_MAX - 1024; u <= (unsigned int)INT_MAX + 1024; u++) {
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%u", u);
+ test_lookup_fail(buf);
+ }
+ for (u = UINT_MAX - 1024; u != 0; u++) {
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%u", u);
+ test_lookup_fail(buf);
+ }
+
+
+}
+
+int main(void)
+{
+ struct dirent *de;
+ unsigned int fd, target_fd;
+
+ if (unshare(CLONE_FILES) == -1)
+ return 1;
+
+ /* Wipe fdtable. */
+ do {
+ DIR *d;
+
+ d = opendir("/proc/self/fd");
+ if (!d)
+ return 1;
+
+ de = xreaddir(d);
+ assert(de->d_type == DT_DIR);
+ assert(streq(de->d_name, "."));
+
+ de = xreaddir(d);
+ assert(de->d_type == DT_DIR);
+ assert(streq(de->d_name, ".."));
+next:
+ de = xreaddir(d);
+ if (de) {
+ unsigned long long fd_ull;
+ unsigned int fd;
+ char *end;
+
+ assert(de->d_type == DT_LNK);
+
+ fd_ull = xstrtoull(de->d_name, &end);
+ assert(*end == '\0');
+ assert(fd_ull == (unsigned int)fd_ull);
+
+ fd = fd_ull;
+ if (fd == dirfd(d))
+ goto next;
+ close(fd);
+ }
+
+ closedir(d);
+ } while (de);
+
+ /* Now fdtable is clean. */
+
+ fd = open("/", O_PATH|O_DIRECTORY);
+ assert(fd == 0);
+ test_lookup(fd);
+ close(fd);
+
+ /* Clean again! */
+
+ fd = open("/", O_PATH|O_DIRECTORY);
+ assert(fd == 0);
+ /* Default RLIMIT_NOFILE-1 */
+ target_fd = 1023;
+ while (target_fd > 0) {
+ if (dup2(fd, target_fd) == target_fd)
+ break;
+ target_fd /= 2;
+ }
+ assert(target_fd > 0);
+ close(fd);
+ test_lookup(target_fd);
+ close(target_fd);
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/fd-002-posix-eq.c b/tools/testing/selftests/proc/fd-002-posix-eq.c
new file mode 100644
index 000000000..417322ca9
--- /dev/null
+++ b/tools/testing/selftests/proc/fd-002-posix-eq.c
@@ -0,0 +1,57 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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.
+ */
+// Test that open(/proc/*/fd/*) opens the same file.
+#undef NDEBUG
+#include <assert.h>
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+int main(void)
+{
+ int fd0, fd1, fd2;
+ struct stat st0, st1, st2;
+ char buf[64];
+ int rv;
+
+ fd0 = open("/", O_DIRECTORY|O_RDONLY);
+ assert(fd0 >= 0);
+
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%u", fd0);
+ fd1 = open(buf, O_RDONLY);
+ assert(fd1 >= 0);
+
+ snprintf(buf, sizeof(buf), "/proc/thread-self/fd/%u", fd0);
+ fd2 = open(buf, O_RDONLY);
+ assert(fd2 >= 0);
+
+ rv = fstat(fd0, &st0);
+ assert(rv == 0);
+ rv = fstat(fd1, &st1);
+ assert(rv == 0);
+ rv = fstat(fd2, &st2);
+ assert(rv == 0);
+
+ assert(st0.st_dev == st1.st_dev);
+ assert(st0.st_ino == st1.st_ino);
+
+ assert(st0.st_dev == st2.st_dev);
+ assert(st0.st_ino == st2.st_ino);
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/fd-003-kthread.c b/tools/testing/selftests/proc/fd-003-kthread.c
new file mode 100644
index 000000000..dc591f97b
--- /dev/null
+++ b/tools/testing/selftests/proc/fd-003-kthread.c
@@ -0,0 +1,178 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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.
+ */
+// Test that /proc/$KERNEL_THREAD/fd/ is empty.
+
+#undef NDEBUG
+#include <sys/syscall.h>
+#include <assert.h>
+#include <dirent.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "proc.h"
+
+#define PF_KHTREAD 0x00200000
+
+/*
+ * Test for kernel threadness atomically with openat().
+ *
+ * Return /proc/$PID/fd descriptor if process is kernel thread.
+ * Return -1 if a process is userspace process.
+ */
+static int kernel_thread_fd(unsigned int pid)
+{
+ unsigned int flags = 0;
+ char buf[4096];
+ int dir_fd, fd;
+ ssize_t rv;
+
+ snprintf(buf, sizeof(buf), "/proc/%u", pid);
+ dir_fd = open(buf, O_RDONLY|O_DIRECTORY);
+ if (dir_fd == -1)
+ return -1;
+
+ /*
+ * Believe it or not, struct task_struct::flags is directly exposed
+ * to userspace!
+ */
+ fd = openat(dir_fd, "stat", O_RDONLY);
+ if (fd == -1) {
+ close(dir_fd);
+ return -1;
+ }
+ rv = read(fd, buf, sizeof(buf));
+ close(fd);
+ if (0 < rv && rv <= sizeof(buf)) {
+ unsigned long long flags_ull;
+ char *p, *end;
+ int i;
+
+ assert(buf[rv - 1] == '\n');
+ buf[rv - 1] = '\0';
+
+ /* Search backwards: ->comm can contain whitespace and ')'. */
+ for (i = 0; i < 43; i++) {
+ p = strrchr(buf, ' ');
+ assert(p);
+ *p = '\0';
+ }
+
+ p = strrchr(buf, ' ');
+ assert(p);
+
+ flags_ull = xstrtoull(p + 1, &end);
+ assert(*end == '\0');
+ assert(flags_ull == (unsigned int)flags_ull);
+
+ flags = flags_ull;
+ }
+
+ fd = -1;
+ if (flags & PF_KHTREAD) {
+ fd = openat(dir_fd, "fd", O_RDONLY|O_DIRECTORY);
+ }
+ close(dir_fd);
+ return fd;
+}
+
+static void test_readdir(int fd)
+{
+ DIR *d;
+ struct dirent *de;
+
+ d = fdopendir(fd);
+ assert(d);
+
+ de = xreaddir(d);
+ assert(streq(de->d_name, "."));
+ assert(de->d_type == DT_DIR);
+
+ de = xreaddir(d);
+ assert(streq(de->d_name, ".."));
+ assert(de->d_type == DT_DIR);
+
+ de = xreaddir(d);
+ assert(!de);
+}
+
+static inline int sys_statx(int dirfd, const char *pathname, int flags,
+ unsigned int mask, void *stx)
+{
+ return syscall(SYS_statx, dirfd, pathname, flags, mask, stx);
+}
+
+static void test_lookup_fail(int fd, const char *pathname)
+{
+ char stx[256] __attribute__((aligned(8)));
+ int rv;
+
+ rv = sys_statx(fd, pathname, AT_SYMLINK_NOFOLLOW, 0, (void *)stx);
+ assert(rv == -1 && errno == ENOENT);
+}
+
+static void test_lookup(int fd)
+{
+ char buf[64];
+ unsigned int u;
+ int i;
+
+ for (i = INT_MIN; i < INT_MIN + 1024; i++) {
+ snprintf(buf, sizeof(buf), "%d", i);
+ test_lookup_fail(fd, buf);
+ }
+ for (i = -1024; i < 1024; i++) {
+ snprintf(buf, sizeof(buf), "%d", i);
+ test_lookup_fail(fd, buf);
+ }
+ for (u = INT_MAX - 1024; u < (unsigned int)INT_MAX + 1024; u++) {
+ snprintf(buf, sizeof(buf), "%u", u);
+ test_lookup_fail(fd, buf);
+ }
+ for (u = UINT_MAX - 1024; u != 0; u++) {
+ snprintf(buf, sizeof(buf), "%u", u);
+ test_lookup_fail(fd, buf);
+ }
+}
+
+int main(void)
+{
+ unsigned int pid;
+ int fd;
+
+ /*
+ * In theory this will loop indefinitely if kernel threads are exiled
+ * from /proc.
+ *
+ * Start with kthreadd.
+ */
+ pid = 2;
+ while ((fd = kernel_thread_fd(pid)) == -1 && pid < 1024) {
+ pid++;
+ }
+ /* EACCES if run as non-root. */
+ if (pid >= 1024)
+ return 1;
+
+ test_readdir(fd);
+ test_lookup(fd);
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/proc-2-is-kthread.c b/tools/testing/selftests/proc/proc-2-is-kthread.c
new file mode 100644
index 000000000..f13668fb4
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-2-is-kthread.c
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2024 Alexey Dobriyan <adobriyan@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.
+ */
+/* Test that kernel thread is reported as such. */
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+int main(void)
+{
+ /*
+ * The following solutions don't really work:
+ *
+ * 1) jit kernel module which creates kernel thread:
+ * test becomes arch-specific,
+ * problems with mandatory module signing,
+ * problems with lockdown mode,
+ * doesn't work with CONFIG_MODULES=n at all,
+ * kthread creation API is formally unstable internal kernel API,
+ * need a mechanism to report test kernel thread's PID back,
+ *
+ * 2) ksoftirqd/0 and kswapd0 look like stable enough kernel threads,
+ * but their PIDs are unstable.
+ *
+ * Check against kthreadd which always seem to exist under pid 2.
+ */
+ int fd = open("/proc/2/status", O_RDONLY);
+ assert(fd >= 0);
+
+ char buf[4096];
+ ssize_t rv = read(fd, buf, sizeof(buf));
+ assert(0 <= rv && rv < sizeof(buf));
+ buf[rv] = '\0';
+
+ assert(strstr(buf, "Kthread:\t1\n"));
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/proc-empty-vm.c b/tools/testing/selftests/proc/proc-empty-vm.c
new file mode 100644
index 000000000..b3f898aab
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-empty-vm.c
@@ -0,0 +1,541 @@
+#if defined __amd64__ || defined __i386__
+/*
+ * Copyright (c) 2022 Alexey Dobriyan <adobriyan@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.
+ */
+/*
+ * Create a process without mappings by unmapping everything at once and
+ * holding it with ptrace(2). See what happens to
+ *
+ * /proc/${pid}/maps
+ * /proc/${pid}/numa_maps
+ * /proc/${pid}/smaps
+ * /proc/${pid}/smaps_rollup
+ */
+#undef _GNU_SOURCE
+#define _GNU_SOURCE
+
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/ptrace.h>
+#include <sys/resource.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#ifdef __amd64__
+#define TEST_VSYSCALL
+#endif
+
+#if defined __amd64__
+ #ifndef SYS_pkey_alloc
+ #define SYS_pkey_alloc 330
+ #endif
+ #ifndef SYS_pkey_free
+ #define SYS_pkey_free 331
+ #endif
+#elif defined __i386__
+ #ifndef SYS_pkey_alloc
+ #define SYS_pkey_alloc 381
+ #endif
+ #ifndef SYS_pkey_free
+ #define SYS_pkey_free 382
+ #endif
+#else
+ #error "SYS_pkey_alloc"
+#endif
+
+static int g_protection_key_support;
+
+static int protection_key_support(void)
+{
+ long rv = syscall(SYS_pkey_alloc, 0, 0);
+ if (rv > 0) {
+ syscall(SYS_pkey_free, (int)rv);
+ return 1;
+ } else if (rv == -1 && errno == ENOSYS) {
+ return 0;
+ } else if (rv == -1 && errno == EINVAL) {
+ // ospke=n
+ return 0;
+ } else {
+ fprintf(stderr, "%s: error: rv %ld, errno %d\n", __func__, rv, errno);
+ exit(EXIT_FAILURE);
+ }
+}
+
+/*
+ * 0: vsyscall VMA doesn't exist vsyscall=none
+ * 1: vsyscall VMA is --xp vsyscall=xonly
+ * 2: vsyscall VMA is r-xp vsyscall=emulate
+ */
+static volatile int g_vsyscall;
+static const char *g_proc_pid_maps_vsyscall;
+static const char *g_proc_pid_smaps_vsyscall;
+
+static const char proc_pid_maps_vsyscall_0[] = "";
+static const char proc_pid_maps_vsyscall_1[] =
+"ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 [vsyscall]\n";
+static const char proc_pid_maps_vsyscall_2[] =
+"ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]\n";
+
+static const char proc_pid_smaps_vsyscall_0[] = "";
+
+static const char proc_pid_smaps_vsyscall_1[] =
+"ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 [vsyscall]\n"
+"Size: 4 kB\n"
+"KernelPageSize: 4 kB\n"
+"MMUPageSize: 4 kB\n"
+"Rss: 0 kB\n"
+"Pss: 0 kB\n"
+"Pss_Dirty: 0 kB\n"
+"Shared_Clean: 0 kB\n"
+"Shared_Dirty: 0 kB\n"
+"Private_Clean: 0 kB\n"
+"Private_Dirty: 0 kB\n"
+"Referenced: 0 kB\n"
+"Anonymous: 0 kB\n"
+"KSM: 0 kB\n"
+"LazyFree: 0 kB\n"
+"AnonHugePages: 0 kB\n"
+"ShmemPmdMapped: 0 kB\n"
+"FilePmdMapped: 0 kB\n"
+"Shared_Hugetlb: 0 kB\n"
+"Private_Hugetlb: 0 kB\n"
+"Swap: 0 kB\n"
+"SwapPss: 0 kB\n"
+"Locked: 0 kB\n"
+"THPeligible: 0\n"
+;
+
+static const char proc_pid_smaps_vsyscall_2[] =
+"ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]\n"
+"Size: 4 kB\n"
+"KernelPageSize: 4 kB\n"
+"MMUPageSize: 4 kB\n"
+"Rss: 0 kB\n"
+"Pss: 0 kB\n"
+"Pss_Dirty: 0 kB\n"
+"Shared_Clean: 0 kB\n"
+"Shared_Dirty: 0 kB\n"
+"Private_Clean: 0 kB\n"
+"Private_Dirty: 0 kB\n"
+"Referenced: 0 kB\n"
+"Anonymous: 0 kB\n"
+"KSM: 0 kB\n"
+"LazyFree: 0 kB\n"
+"AnonHugePages: 0 kB\n"
+"ShmemPmdMapped: 0 kB\n"
+"FilePmdMapped: 0 kB\n"
+"Shared_Hugetlb: 0 kB\n"
+"Private_Hugetlb: 0 kB\n"
+"Swap: 0 kB\n"
+"SwapPss: 0 kB\n"
+"Locked: 0 kB\n"
+"THPeligible: 0\n"
+;
+
+static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___)
+{
+ _exit(EXIT_FAILURE);
+}
+
+#ifdef TEST_VSYSCALL
+static void sigaction_SIGSEGV_vsyscall(int _, siginfo_t *__, void *___)
+{
+ _exit(g_vsyscall);
+}
+
+/*
+ * vsyscall page can't be unmapped, probe it directly.
+ */
+static void vsyscall(void)
+{
+ pid_t pid;
+ int wstatus;
+
+ pid = fork();
+ if (pid < 0) {
+ fprintf(stderr, "fork, errno %d\n", errno);
+ exit(1);
+ }
+ if (pid == 0) {
+ setrlimit(RLIMIT_CORE, &(struct rlimit){});
+
+ /* Hide "segfault at ffffffffff600000" messages. */
+ struct sigaction act = {};
+ act.sa_flags = SA_SIGINFO;
+ act.sa_sigaction = sigaction_SIGSEGV_vsyscall;
+ sigaction(SIGSEGV, &act, NULL);
+
+ g_vsyscall = 0;
+ /* gettimeofday(NULL, NULL); */
+ uint64_t rax = 0xffffffffff600000;
+ asm volatile (
+ "call *%[rax]"
+ : [rax] "+a" (rax)
+ : "D" (NULL), "S" (NULL)
+ : "rcx", "r11"
+ );
+
+ g_vsyscall = 1;
+ *(volatile int *)0xffffffffff600000UL;
+
+ g_vsyscall = 2;
+ exit(g_vsyscall);
+ }
+ waitpid(pid, &wstatus, 0);
+ if (WIFEXITED(wstatus)) {
+ g_vsyscall = WEXITSTATUS(wstatus);
+ } else {
+ fprintf(stderr, "error: vsyscall wstatus %08x\n", wstatus);
+ exit(1);
+ }
+}
+#endif
+
+static int test_proc_pid_maps(pid_t pid)
+{
+ char buf[4096];
+ snprintf(buf, sizeof(buf), "/proc/%u/maps", pid);
+ int fd = open(buf, O_RDONLY);
+ if (fd == -1) {
+ perror("open /proc/${pid}/maps");
+ return EXIT_FAILURE;
+ } else {
+ ssize_t rv = read(fd, buf, sizeof(buf));
+ close(fd);
+ if (g_vsyscall == 0) {
+ assert(rv == 0);
+ } else {
+ size_t len = strlen(g_proc_pid_maps_vsyscall);
+ assert(rv == len);
+ assert(memcmp(buf, g_proc_pid_maps_vsyscall, len) == 0);
+ }
+ return EXIT_SUCCESS;
+ }
+}
+
+static int test_proc_pid_numa_maps(pid_t pid)
+{
+ char buf[4096];
+ snprintf(buf, sizeof(buf), "/proc/%u/numa_maps", pid);
+ int fd = open(buf, O_RDONLY);
+ if (fd == -1) {
+ if (errno == ENOENT) {
+ /*
+ * /proc/${pid}/numa_maps is under CONFIG_NUMA,
+ * it doesn't necessarily exist.
+ */
+ return EXIT_SUCCESS;
+ }
+ perror("open /proc/${pid}/numa_maps");
+ return EXIT_FAILURE;
+ } else {
+ ssize_t rv = read(fd, buf, sizeof(buf));
+ close(fd);
+ assert(rv == 0);
+ return EXIT_SUCCESS;
+ }
+}
+
+static int test_proc_pid_smaps(pid_t pid)
+{
+ char buf[4096];
+ snprintf(buf, sizeof(buf), "/proc/%u/smaps", pid);
+ int fd = open(buf, O_RDONLY);
+ if (fd == -1) {
+ if (errno == ENOENT) {
+ /*
+ * /proc/${pid}/smaps is under CONFIG_PROC_PAGE_MONITOR,
+ * it doesn't necessarily exist.
+ */
+ return EXIT_SUCCESS;
+ }
+ perror("open /proc/${pid}/smaps");
+ return EXIT_FAILURE;
+ }
+ ssize_t rv = read(fd, buf, sizeof(buf));
+ close(fd);
+
+ assert(0 <= rv);
+ assert(rv <= sizeof(buf));
+
+ if (g_vsyscall == 0) {
+ assert(rv == 0);
+ } else {
+ size_t len = strlen(g_proc_pid_smaps_vsyscall);
+ assert(rv > len);
+ assert(memcmp(buf, g_proc_pid_smaps_vsyscall, len) == 0);
+
+ if (g_protection_key_support) {
+#define PROTECTION_KEY "ProtectionKey: 0\n"
+ assert(memmem(buf, rv, PROTECTION_KEY, strlen(PROTECTION_KEY)));
+ }
+ }
+
+ return EXIT_SUCCESS;
+}
+
+static const char g_smaps_rollup[] =
+"00000000-00000000 ---p 00000000 00:00 0 [rollup]\n"
+"Rss: 0 kB\n"
+"Pss: 0 kB\n"
+"Pss_Dirty: 0 kB\n"
+"Pss_Anon: 0 kB\n"
+"Pss_File: 0 kB\n"
+"Pss_Shmem: 0 kB\n"
+"Shared_Clean: 0 kB\n"
+"Shared_Dirty: 0 kB\n"
+"Private_Clean: 0 kB\n"
+"Private_Dirty: 0 kB\n"
+"Referenced: 0 kB\n"
+"Anonymous: 0 kB\n"
+"KSM: 0 kB\n"
+"LazyFree: 0 kB\n"
+"AnonHugePages: 0 kB\n"
+"ShmemPmdMapped: 0 kB\n"
+"FilePmdMapped: 0 kB\n"
+"Shared_Hugetlb: 0 kB\n"
+"Private_Hugetlb: 0 kB\n"
+"Swap: 0 kB\n"
+"SwapPss: 0 kB\n"
+"Locked: 0 kB\n"
+;
+
+static int test_proc_pid_smaps_rollup(pid_t pid)
+{
+ char buf[4096];
+ snprintf(buf, sizeof(buf), "/proc/%u/smaps_rollup", pid);
+ int fd = open(buf, O_RDONLY);
+ if (fd == -1) {
+ if (errno == ENOENT) {
+ /*
+ * /proc/${pid}/smaps_rollup is under CONFIG_PROC_PAGE_MONITOR,
+ * it doesn't necessarily exist.
+ */
+ return EXIT_SUCCESS;
+ }
+ perror("open /proc/${pid}/smaps_rollup");
+ return EXIT_FAILURE;
+ } else {
+ ssize_t rv = read(fd, buf, sizeof(buf));
+ close(fd);
+ assert(rv == sizeof(g_smaps_rollup) - 1);
+ assert(memcmp(buf, g_smaps_rollup, sizeof(g_smaps_rollup) - 1) == 0);
+ return EXIT_SUCCESS;
+ }
+}
+
+static const char *parse_u64(const char *p, const char *const end, uint64_t *rv)
+{
+ *rv = 0;
+ for (; p != end; p += 1) {
+ if ('0' <= *p && *p <= '9') {
+ assert(!__builtin_mul_overflow(*rv, 10, rv));
+ assert(!__builtin_add_overflow(*rv, *p - '0', rv));
+ } else {
+ break;
+ }
+ }
+ assert(p != end);
+ return p;
+}
+
+/*
+ * There seems to be 2 types of valid output:
+ * "0 A A B 0 0 0\n" for dynamic exeuctables,
+ * "0 0 0 B 0 0 0\n" for static executables.
+ */
+static int test_proc_pid_statm(pid_t pid)
+{
+ char buf[4096];
+ snprintf(buf, sizeof(buf), "/proc/%u/statm", pid);
+ int fd = open(buf, O_RDONLY);
+ if (fd == -1) {
+ perror("open /proc/${pid}/statm");
+ return EXIT_FAILURE;
+ }
+
+ ssize_t rv = read(fd, buf, sizeof(buf));
+ close(fd);
+
+ assert(rv >= 0);
+ assert(rv <= sizeof(buf));
+
+ const char *p = buf;
+ const char *const end = p + rv;
+
+ /* size */
+ assert(p != end && *p++ == '0');
+ assert(p != end && *p++ == ' ');
+
+ uint64_t resident;
+ p = parse_u64(p, end, &resident);
+ assert(p != end && *p++ == ' ');
+
+ uint64_t shared;
+ p = parse_u64(p, end, &shared);
+ assert(p != end && *p++ == ' ');
+
+ uint64_t text;
+ p = parse_u64(p, end, &text);
+ assert(p != end && *p++ == ' ');
+
+ assert(p != end && *p++ == '0');
+ assert(p != end && *p++ == ' ');
+
+ /* data */
+ assert(p != end && *p++ == '0');
+ assert(p != end && *p++ == ' ');
+
+ assert(p != end && *p++ == '0');
+ assert(p != end && *p++ == '\n');
+
+ assert(p == end);
+
+ /*
+ * "text" is "mm->end_code - mm->start_code" at execve(2) time.
+ * munmap() doesn't change it. It can be anything (just link
+ * statically). It can't be 0 because executing to this point
+ * implies at least 1 page of code.
+ */
+ assert(text > 0);
+
+ /*
+ * These two are always equal. Always 0 for statically linked
+ * executables and sometimes 0 for dynamically linked executables.
+ * There is no way to tell one from another without parsing ELF
+ * which is too much for this test.
+ */
+ assert(resident == shared);
+
+ return EXIT_SUCCESS;
+}
+
+int main(void)
+{
+ int rv = EXIT_SUCCESS;
+
+#ifdef TEST_VSYSCALL
+ vsyscall();
+#endif
+
+ switch (g_vsyscall) {
+ case 0:
+ g_proc_pid_maps_vsyscall = proc_pid_maps_vsyscall_0;
+ g_proc_pid_smaps_vsyscall = proc_pid_smaps_vsyscall_0;
+ break;
+ case 1:
+ g_proc_pid_maps_vsyscall = proc_pid_maps_vsyscall_1;
+ g_proc_pid_smaps_vsyscall = proc_pid_smaps_vsyscall_1;
+ break;
+ case 2:
+ g_proc_pid_maps_vsyscall = proc_pid_maps_vsyscall_2;
+ g_proc_pid_smaps_vsyscall = proc_pid_smaps_vsyscall_2;
+ break;
+ default:
+ abort();
+ }
+
+ g_protection_key_support = protection_key_support();
+
+ pid_t pid = fork();
+ if (pid == -1) {
+ perror("fork");
+ return EXIT_FAILURE;
+ } else if (pid == 0) {
+ rv = ptrace(PTRACE_TRACEME, 0, NULL, NULL);
+ if (rv != 0) {
+ if (errno == EPERM) {
+ fprintf(stderr,
+"Did you know? ptrace(PTRACE_TRACEME) doesn't work under strace.\n"
+ );
+ kill(getppid(), SIGTERM);
+ return EXIT_FAILURE;
+ }
+ perror("ptrace PTRACE_TRACEME");
+ return EXIT_FAILURE;
+ }
+
+ /*
+ * Hide "segfault at ..." messages. Signal handler won't run.
+ */
+ struct sigaction act = {};
+ act.sa_flags = SA_SIGINFO;
+ act.sa_sigaction = sigaction_SIGSEGV;
+ sigaction(SIGSEGV, &act, NULL);
+
+#ifdef __amd64__
+ munmap(NULL, ((size_t)1 << 47) - 4096);
+#elif defined __i386__
+ {
+ size_t len;
+
+ for (len = -4096;; len -= 4096) {
+ munmap(NULL, len);
+ }
+ }
+#else
+#error "implement 'unmap everything'"
+#endif
+ return EXIT_FAILURE;
+ } else {
+ /*
+ * TODO find reliable way to signal parent that munmap(2) completed.
+ * Child can't do it directly because it effectively doesn't exist
+ * anymore. Looking at child's VM files isn't 100% reliable either:
+ * due to a bug they may not become empty or empty-like.
+ */
+ sleep(1);
+
+ if (rv == EXIT_SUCCESS) {
+ rv = test_proc_pid_maps(pid);
+ }
+ if (rv == EXIT_SUCCESS) {
+ rv = test_proc_pid_numa_maps(pid);
+ }
+ if (rv == EXIT_SUCCESS) {
+ rv = test_proc_pid_smaps(pid);
+ }
+ if (rv == EXIT_SUCCESS) {
+ rv = test_proc_pid_smaps_rollup(pid);
+ }
+ if (rv == EXIT_SUCCESS) {
+ rv = test_proc_pid_statm(pid);
+ }
+
+ /* Cut the rope. */
+ int wstatus;
+ waitpid(pid, &wstatus, 0);
+ assert(WIFSTOPPED(wstatus));
+ assert(WSTOPSIG(wstatus) == SIGSEGV);
+ }
+
+ return rv;
+}
+#else
+int main(void)
+{
+ return 4;
+}
+#endif
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 000000000..b9af8f537
--- /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-loadavg-001.c b/tools/testing/selftests/proc/proc-loadavg-001.c
new file mode 100644
index 000000000..fb4fe9188
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-loadavg-001.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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.
+ */
+/* Test that /proc/loadavg correctly reports last pid in pid namespace. */
+#include <errno.h>
+#include <sched.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+int main(void)
+{
+ pid_t pid;
+ int wstatus;
+
+ if (unshare(CLONE_NEWPID) == -1) {
+ if (errno == ENOSYS || errno == EPERM)
+ return 4;
+ return 1;
+ }
+
+ pid = fork();
+ if (pid == -1)
+ return 1;
+ if (pid == 0) {
+ char buf[128], *p;
+ int fd;
+ ssize_t rv;
+
+ fd = open("/proc/loadavg" , O_RDONLY);
+ if (fd == -1)
+ return 1;
+ rv = read(fd, buf, sizeof(buf));
+ if (rv < 3)
+ return 1;
+ p = buf + rv;
+
+ /* pid 1 */
+ if (!(p[-3] == ' ' && p[-2] == '1' && p[-1] == '\n'))
+ return 1;
+
+ pid = fork();
+ if (pid == -1)
+ return 1;
+ if (pid == 0)
+ return 0;
+ if (waitpid(pid, NULL, 0) == -1)
+ return 1;
+
+ lseek(fd, 0, SEEK_SET);
+ rv = read(fd, buf, sizeof(buf));
+ if (rv < 3)
+ return 1;
+ p = buf + rv;
+
+ /* pid 2 */
+ if (!(p[-3] == ' ' && p[-2] == '2' && p[-1] == '\n'))
+ return 1;
+
+ return 0;
+ }
+
+ if (waitpid(pid, &wstatus, 0) == -1)
+ return 1;
+ if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) == 0)
+ return 0;
+ return 1;
+}
diff --git a/tools/testing/selftests/proc/proc-maps-race.c b/tools/testing/selftests/proc/proc-maps-race.c
new file mode 100644
index 000000000..415eccb70
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-maps-race.c
@@ -0,0 +1,976 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2022 Google LLC.
+ * Author: Suren Baghdasaryan <surenb@google.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.
+ */
+/*
+ * Fork a child that concurrently modifies address space while the main
+ * process is reading /proc/$PID/maps and /proc/$PID/smaps, verifying the
+ * results. Address space modifications include:
+ * VMA splitting and merging
+ *
+ */
+#define _GNU_SOURCE
+#include "kselftest_harness.h"
+#include <errno.h>
+#include <fcntl.h>
+#include <pthread.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <linux/fs.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#define min(a, b) \
+ ({ \
+ typeof(a) _a = (a); \
+ typeof(b) _b = (b); \
+ _a < _b ? _a : _b; \
+ })
+
+/* /proc/pid/maps parsing routines */
+struct page_content {
+ char *data;
+ ssize_t size;
+};
+
+#define LINE_MAX_SIZE 256
+
+struct line_content {
+ char text[LINE_MAX_SIZE];
+ unsigned long start_addr;
+ unsigned long end_addr;
+};
+
+enum test_state {
+ INIT,
+ CHILD_READY,
+ PARENT_READY,
+ SETUP_READY,
+ SETUP_MODIFY_MAPS,
+ SETUP_MAPS_MODIFIED,
+ SETUP_RESTORE_MAPS,
+ SETUP_MAPS_RESTORED,
+ TEST_READY,
+ TEST_DONE,
+};
+
+enum maps_file {
+ MAPS,
+ SMAPS,
+};
+
+struct vma_modifier_info;
+
+FIXTURE(proc_maps_race)
+{
+ struct vma_modifier_info *mod_info;
+ struct page_content page1;
+ struct page_content page2;
+ struct line_content last_line;
+ struct line_content first_line;
+ unsigned long duration_sec;
+ enum maps_file maps_file;
+ int shared_mem_size;
+ int skip_pages;
+ int page_size;
+ int vma_count;
+ bool verbose;
+ int maps_fd;
+ pid_t pid;
+};
+
+FIXTURE_VARIANT(proc_maps_race)
+{
+ const enum maps_file maps_file;
+};
+
+FIXTURE_VARIANT_ADD(proc_maps_race, maps) {
+ .maps_file = MAPS,
+};
+
+FIXTURE_VARIANT_ADD(proc_maps_race, smaps) {
+ .maps_file = SMAPS,
+};
+
+typedef bool (*vma_modifier_op)(FIXTURE_DATA(proc_maps_race) *self);
+typedef bool (*vma_mod_result_check_op)(struct line_content *mod_last_line,
+ struct line_content *mod_first_line,
+ struct line_content *restored_last_line,
+ struct line_content *restored_first_line);
+
+struct vma_modifier_info {
+ int vma_count;
+ void *addr;
+ int prot;
+ void *next_addr;
+ vma_modifier_op vma_modify;
+ vma_modifier_op vma_restore;
+ vma_mod_result_check_op vma_mod_check;
+ pthread_mutex_t sync_lock;
+ pthread_cond_t sync_cond;
+ enum test_state curr_state;
+ bool exit;
+ void *child_mapped_addr[];
+};
+
+static bool read_page(FIXTURE_DATA(proc_maps_race) *self,
+ struct page_content *page)
+{
+ ssize_t bytes_read;
+
+ bytes_read = read(self->maps_fd, page->data, self->page_size);
+ if (bytes_read <= 0)
+ return false;
+
+ /* Make sure data always ends with a newline character. */
+ if (page->data[bytes_read - 1] != '\n')
+ return false;
+
+ page->size = bytes_read;
+
+ return true;
+}
+
+static bool parse_vma_line(char *line_start, char *line_end,
+ unsigned long *start, unsigned long *end)
+{
+ bool found;
+
+ *line_end = '\0'; /* stop sscanf at the EOL */
+ found = (sscanf(line_start, "%lx-%lx", start, end) == 2);
+ *line_end = '\n';
+
+ return found;
+}
+
+static int locate_containing_page(FIXTURE_DATA(proc_maps_race) *self,
+ unsigned long addr, unsigned long size)
+{
+ unsigned long start, end;
+ int page = 0;
+
+ if (lseek(self->maps_fd, 0, SEEK_SET) < 0)
+ return -1;
+
+ while (true) {
+ char *curr_pos;
+ char *end_pos;
+
+ if (!read_page(self, &self->page1))
+ return -1;
+
+ curr_pos = self->page1.data;
+ end_pos = self->page1.data + self->page1.size;
+ while (curr_pos < end_pos) {
+ char *line_end;
+
+ line_end = strchr(curr_pos, '\n');
+ if (!line_end)
+ break;
+
+ if (parse_vma_line(curr_pos, line_end, &start, &end) &&
+ start == addr && end == addr + size)
+ return page;
+
+ curr_pos = line_end + 1;
+ }
+ page++;
+ }
+
+ return 0;
+}
+
+static bool read_two_pages(FIXTURE_DATA(proc_maps_race) *self)
+{
+ if (lseek(self->maps_fd, 0, SEEK_SET) < 0)
+ return false;
+
+ for (int i = 0; i < self->skip_pages; i++)
+ if (!read_page(self, &self->page1))
+ return false;
+
+ return read_page(self, &self->page1) && read_page(self, &self->page2);
+}
+
+static void copy_line(const char *line_start, const char *line_end,
+ char *buf, size_t buf_size)
+{
+ size_t len = min(line_end - line_start, buf_size - 1);
+
+ strncpy(buf, line_start, len);
+ buf[len] = '\0';
+}
+
+static void copy_first_line(struct page_content *page, char *first_line,
+ size_t line_size)
+{
+ copy_line(page->data, strchr(page->data, '\n'), first_line, line_size);
+}
+
+static void copy_last_line(struct page_content *page, char *last_line,
+ size_t line_size)
+{
+ /* Get the last line in the first page */
+ const char *end = page->data + page->size - 1;
+ /* skip last newline */
+ const char *pos = end - 1;
+
+ /* search previous newline */
+ while (pos[-1] != '\n')
+ pos--;
+
+ copy_line(pos, end, last_line, line_size);
+}
+
+static bool copy_first_entry(struct page_content *page, char *first_line,
+ size_t line_size)
+{
+ char *start_pos = page->data;
+
+ while (start_pos < page->data + page->size) {
+ unsigned long start_addr;
+ unsigned long end_addr;
+ char *end_pos;
+
+ end_pos = strchr(start_pos, '\n');
+ if (!end_pos)
+ break;
+
+ if (parse_vma_line(start_pos, end_pos, &start_addr, &end_addr)) {
+ copy_line(start_pos, end_pos, first_line, line_size);
+ return true;
+ }
+
+ start_pos = end_pos + 1;
+ }
+
+ return false;
+}
+
+static bool copy_last_entry(struct page_content *page, char *last_line,
+ size_t line_size)
+{
+ char *end_pos = page->data + page->size - 1;
+ char *start_pos;
+
+ while (end_pos > page->data) {
+ unsigned long start_addr;
+ unsigned long end_addr;
+
+ /* skip last newline */
+ start_pos = end_pos - 1;
+ /* search previous newline */
+ while (start_pos > page->data && start_pos[-1] != '\n')
+ start_pos--;
+ if (parse_vma_line(start_pos, end_pos, &start_addr, &end_addr)) {
+ copy_line(start_pos, end_pos, last_line, line_size);
+ return true;
+ }
+
+ end_pos = start_pos - 1;
+ }
+
+ return false;
+}
+
+/* Read the last line of the first page and the first line of the second page */
+static bool read_boundary_lines(FIXTURE_DATA(proc_maps_race) *self,
+ struct line_content *last_line,
+ struct line_content *first_line)
+{
+ if (!read_two_pages(self))
+ return false;
+
+ if (self->maps_file == MAPS) {
+ copy_last_line(&self->page1, last_line->text, LINE_MAX_SIZE);
+ copy_first_line(&self->page2, first_line->text, LINE_MAX_SIZE);
+ } else if (self->maps_file == SMAPS) {
+ if (!copy_last_entry(&self->page1, last_line->text, LINE_MAX_SIZE) ||
+ !copy_first_entry(&self->page2, first_line->text, LINE_MAX_SIZE))
+ return false;
+ } else {
+ return false;
+ }
+
+ return sscanf(last_line->text, "%lx-%lx", &last_line->start_addr,
+ &last_line->end_addr) == 2 &&
+ sscanf(first_line->text, "%lx-%lx", &first_line->start_addr,
+ &first_line->end_addr) == 2;
+}
+
+/* Thread synchronization routines */
+static void wait_for_state(struct vma_modifier_info *mod_info, enum test_state state)
+{
+ pthread_mutex_lock(&mod_info->sync_lock);
+ while (mod_info->curr_state != state)
+ pthread_cond_wait(&mod_info->sync_cond, &mod_info->sync_lock);
+ pthread_mutex_unlock(&mod_info->sync_lock);
+}
+
+static void signal_state(struct vma_modifier_info *mod_info, enum test_state state)
+{
+ pthread_mutex_lock(&mod_info->sync_lock);
+ mod_info->curr_state = state;
+ pthread_cond_signal(&mod_info->sync_cond);
+ pthread_mutex_unlock(&mod_info->sync_lock);
+}
+
+static void stop_vma_modifier(struct vma_modifier_info *mod_info)
+{
+ wait_for_state(mod_info, SETUP_READY);
+ mod_info->exit = true;
+ signal_state(mod_info, SETUP_MODIFY_MAPS);
+}
+
+static void print_first_lines(char *text, int nr)
+{
+ const char *end = text;
+
+ while (nr && (end = strchr(end, '\n')) != NULL) {
+ nr--;
+ end++;
+ }
+
+ if (end) {
+ int offs = end - text;
+
+ text[offs] = '\0';
+ printf("%s", text);
+ text[offs] = '\n';
+ printf("\n");
+ } else {
+ printf("%s", text);
+ }
+}
+
+static void print_last_lines(char *text, int nr)
+{
+ const char *start = text + strlen(text);
+
+ nr++; /* to ignore the last newline */
+ while (nr) {
+ while (start > text && *start != '\n')
+ start--;
+ nr--;
+ start--;
+ }
+ printf("%s", start);
+}
+
+static void print_boundaries(const char *title, FIXTURE_DATA(proc_maps_race) *self)
+{
+ if (!self->verbose)
+ return;
+
+ printf("%s", title);
+ /* Print 3 boundary lines from each page */
+ print_last_lines(self->page1.data, 3);
+ printf("-----------------page boundary-----------------\n");
+ print_first_lines(self->page2.data, 3);
+}
+
+static bool print_boundaries_on(bool condition, const char *title,
+ FIXTURE_DATA(proc_maps_race) *self)
+{
+ if (self->verbose && condition)
+ print_boundaries(title, self);
+
+ return condition;
+}
+
+static void report_test_start(const char *name, bool verbose)
+{
+ if (verbose)
+ printf("==== %s ====\n", name);
+}
+
+static struct timespec print_ts;
+
+static void start_test_loop(struct timespec *ts, bool verbose)
+{
+ if (verbose)
+ print_ts.tv_sec = ts->tv_sec;
+}
+
+static void end_test_iteration(struct timespec *ts, bool verbose)
+{
+ if (!verbose)
+ return;
+
+ /* Update every second */
+ if (print_ts.tv_sec == ts->tv_sec)
+ return;
+
+ printf(".");
+ fflush(stdout);
+ print_ts.tv_sec = ts->tv_sec;
+}
+
+static void end_test_loop(bool verbose)
+{
+ if (verbose)
+ printf("\n");
+}
+
+static bool capture_mod_pattern(FIXTURE_DATA(proc_maps_race) *self,
+ struct line_content *mod_last_line,
+ struct line_content *mod_first_line,
+ struct line_content *restored_last_line,
+ struct line_content *restored_first_line)
+{
+ print_boundaries("Before modification", self);
+
+ signal_state(self->mod_info, SETUP_MODIFY_MAPS);
+ wait_for_state(self->mod_info, SETUP_MAPS_MODIFIED);
+
+ /* Copy last line of the first page and first line of the last page */
+ if (!read_boundary_lines(self, mod_last_line, mod_first_line))
+ return false;
+
+ print_boundaries("After modification", self);
+
+ signal_state(self->mod_info, SETUP_RESTORE_MAPS);
+ wait_for_state(self->mod_info, SETUP_MAPS_RESTORED);
+
+ /* Copy last line of the first page and first line of the last page */
+ if (!read_boundary_lines(self, restored_last_line, restored_first_line))
+ return false;
+
+ print_boundaries("After restore", self);
+
+ if (!self->mod_info->vma_mod_check(mod_last_line, mod_first_line,
+ restored_last_line, restored_first_line))
+ return false;
+
+ /*
+ * The content of these lines after modify+resore should be the same
+ * as the original.
+ */
+ return strcmp(restored_last_line->text, self->last_line.text) == 0 &&
+ strcmp(restored_first_line->text, self->first_line.text) == 0;
+}
+
+static bool query_addr_at(int maps_fd, void *addr,
+ unsigned long *vma_start, unsigned long *vma_end)
+{
+ struct procmap_query q;
+
+ memset(&q, 0, sizeof(q));
+ q.size = sizeof(q);
+ /* Find the VMA at the split address */
+ q.query_addr = (unsigned long long)addr;
+ q.query_flags = 0;
+ if (ioctl(maps_fd, PROCMAP_QUERY, &q))
+ return false;
+
+ *vma_start = q.vma_start;
+ *vma_end = q.vma_end;
+
+ return true;
+}
+
+static inline bool split_vma(FIXTURE_DATA(proc_maps_race) *self)
+{
+ /* PROT_NONE differs from both readable neighbors. */
+ return mmap(self->mod_info->addr, self->page_size, PROT_NONE,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0) != MAP_FAILED;
+}
+
+static inline bool merge_vma(FIXTURE_DATA(proc_maps_race) *self)
+{
+ return mmap(self->mod_info->addr, self->page_size, self->mod_info->prot,
+ MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0) != MAP_FAILED;
+}
+
+static inline bool check_split_result(struct line_content *mod_last_line,
+ struct line_content *mod_first_line,
+ struct line_content *restored_last_line,
+ struct line_content *restored_first_line)
+{
+ /* Make sure vmas at the boundaries are changing */
+ return strcmp(mod_last_line->text, restored_last_line->text) != 0 &&
+ strcmp(mod_first_line->text, restored_first_line->text) != 0;
+}
+
+static inline bool shrink_vma(FIXTURE_DATA(proc_maps_race) *self)
+{
+ return mremap(self->mod_info->addr, self->page_size * 3,
+ self->page_size, 0) != MAP_FAILED;
+}
+
+static inline bool expand_vma(FIXTURE_DATA(proc_maps_race) *self)
+{
+ return mremap(self->mod_info->addr, self->page_size,
+ self->page_size * 3, 0) != MAP_FAILED;
+}
+
+static inline bool check_shrink_result(struct line_content *mod_last_line,
+ struct line_content *mod_first_line,
+ struct line_content *restored_last_line,
+ struct line_content *restored_first_line)
+{
+ /* Make sure only the last vma of the first page is changing */
+ return strcmp(mod_last_line->text, restored_last_line->text) != 0 &&
+ strcmp(mod_first_line->text, restored_first_line->text) == 0;
+}
+
+static inline bool remap_vma(FIXTURE_DATA(proc_maps_race) *self)
+{
+ /*
+ * Remap the last page of the next vma into the middle of the vma.
+ * This splits the current vma and the first and middle parts (the
+ * parts at lower addresses) become the last vma objserved in the
+ * first page and the first vma observed in the last page.
+ */
+ return mremap(self->mod_info->next_addr + self->page_size * 2, self->page_size,
+ self->page_size, MREMAP_FIXED | MREMAP_MAYMOVE | MREMAP_DONTUNMAP,
+ self->mod_info->addr + self->page_size) != MAP_FAILED;
+}
+
+static inline bool patch_vma(FIXTURE_DATA(proc_maps_race) *self)
+{
+ return mprotect(self->mod_info->addr + self->page_size, self->page_size,
+ self->mod_info->prot) == 0;
+}
+
+static inline bool check_remap_result(struct line_content *mod_last_line,
+ struct line_content *mod_first_line,
+ struct line_content *restored_last_line,
+ struct line_content *restored_first_line)
+{
+ /* Make sure vmas at the boundaries are changing */
+ return strcmp(mod_last_line->text, restored_last_line->text) != 0 &&
+ strcmp(mod_first_line->text, restored_first_line->text) != 0;
+}
+
+FIXTURE_SETUP(proc_maps_race)
+{
+ const char *verbose = getenv("VERBOSE");
+ const char *duration = getenv("DURATION");
+ struct vma_modifier_info *mod_info;
+ pthread_mutexattr_t mutex_attr;
+ pthread_condattr_t cond_attr;
+ unsigned long first_map_addr;
+ unsigned long last_map_addr;
+ unsigned long duration_sec;
+ char fname[32];
+
+ self->page_size = (unsigned long)sysconf(_SC_PAGESIZE);
+ self->verbose = verbose && !strncmp(verbose, "1", 1);
+ self->maps_file = variant->maps_file;
+ duration_sec = duration ? atol(duration) : 0;
+ self->duration_sec = duration_sec ? duration_sec : 5UL;
+
+ /*
+ * Have to map enough vmas for /proc/pid/maps to contain more than one
+ * page worth of vmas. Assume at least 32 bytes per line in maps output
+ */
+ self->vma_count = self->page_size / 32 + 1;
+ self->shared_mem_size = sizeof(struct vma_modifier_info) + self->vma_count * sizeof(void *);
+
+ /* map shared memory for communication with the child process */
+ self->mod_info = (struct vma_modifier_info *)mmap(NULL, self->shared_mem_size,
+ PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+ ASSERT_NE(self->mod_info, MAP_FAILED);
+ mod_info = self->mod_info;
+
+ /* Initialize shared members */
+ pthread_mutexattr_init(&mutex_attr);
+ pthread_mutexattr_setpshared(&mutex_attr, PTHREAD_PROCESS_SHARED);
+ ASSERT_EQ(pthread_mutex_init(&mod_info->sync_lock, &mutex_attr), 0);
+ pthread_condattr_init(&cond_attr);
+ pthread_condattr_setpshared(&cond_attr, PTHREAD_PROCESS_SHARED);
+ ASSERT_EQ(pthread_cond_init(&mod_info->sync_cond, &cond_attr), 0);
+ mod_info->vma_count = self->vma_count;
+ mod_info->curr_state = INIT;
+ mod_info->exit = false;
+
+ self->pid = fork();
+ if (!self->pid) {
+ /* Child process modifying the address space */
+ int prot = PROT_READ | PROT_WRITE;
+ int i;
+
+ for (i = 0; i < mod_info->vma_count; i++) {
+ mod_info->child_mapped_addr[i] = mmap(NULL, self->page_size * 3, prot,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+ ASSERT_NE(mod_info->child_mapped_addr[i], MAP_FAILED);
+ /* change protection in adjacent maps to prevent merging */
+ prot ^= PROT_WRITE;
+ }
+ signal_state(mod_info, CHILD_READY);
+ wait_for_state(mod_info, PARENT_READY);
+ while (true) {
+ signal_state(mod_info, SETUP_READY);
+ wait_for_state(mod_info, SETUP_MODIFY_MAPS);
+ if (mod_info->exit)
+ break;
+
+ ASSERT_TRUE(mod_info->vma_modify(self));
+ signal_state(mod_info, SETUP_MAPS_MODIFIED);
+ wait_for_state(mod_info, SETUP_RESTORE_MAPS);
+ ASSERT_TRUE(mod_info->vma_restore(self));
+ signal_state(mod_info, SETUP_MAPS_RESTORED);
+
+ wait_for_state(mod_info, TEST_READY);
+ while (mod_info->curr_state != TEST_DONE) {
+ ASSERT_TRUE(mod_info->vma_modify(self));
+ ASSERT_TRUE(mod_info->vma_restore(self));
+ }
+ }
+ for (i = 0; i < mod_info->vma_count; i++)
+ munmap(mod_info->child_mapped_addr[i], self->page_size * 3);
+
+ exit(0);
+ }
+
+ switch (self->maps_file) {
+ case MAPS:
+ sprintf(fname, "/proc/%d/maps", self->pid);
+ break;
+ case SMAPS:
+ sprintf(fname, "/proc/%d/smaps", self->pid);
+ break;
+ default:
+ ksft_exit_fail();
+ }
+ self->maps_fd = open(fname, O_RDONLY);
+ ASSERT_NE(self->maps_fd, -1);
+
+ /* Wait for the child to map the VMAs */
+ wait_for_state(mod_info, CHILD_READY);
+
+ /* Read first two pages */
+ self->page1.data = malloc(self->page_size);
+ ASSERT_NE(self->page1.data, NULL);
+ self->page2.data = malloc(self->page_size);
+ ASSERT_NE(self->page2.data, NULL);
+
+ first_map_addr = (unsigned long)mod_info->child_mapped_addr[0];
+ last_map_addr = (unsigned long)mod_info->child_mapped_addr[mod_info->vma_count - 1];
+
+ self->skip_pages = locate_containing_page(self,
+ min(first_map_addr, last_map_addr),
+ self->page_size * 3);
+ ASSERT_NE(self->skip_pages, -1);
+ ASSERT_TRUE(read_boundary_lines(self, &self->last_line, &self->first_line));
+
+ /*
+ * Find the addresses corresponding to the last line in the first page
+ * and the first line in the last page.
+ */
+ mod_info->addr = NULL;
+ mod_info->next_addr = NULL;
+ for (int i = 0; i < mod_info->vma_count; i++) {
+ if (mod_info->child_mapped_addr[i] == (void *)self->last_line.start_addr) {
+ mod_info->addr = mod_info->child_mapped_addr[i];
+ mod_info->prot = PROT_READ;
+ /* Even VMAs have write permission */
+ if ((i % 2) == 0)
+ mod_info->prot |= PROT_WRITE;
+ } else if (mod_info->child_mapped_addr[i] == (void *)self->first_line.start_addr) {
+ mod_info->next_addr = mod_info->child_mapped_addr[i];
+ }
+
+ if (mod_info->addr && mod_info->next_addr)
+ break;
+ }
+ ASSERT_TRUE(mod_info->addr && mod_info->next_addr);
+
+ signal_state(mod_info, PARENT_READY);
+}
+
+FIXTURE_TEARDOWN(proc_maps_race)
+{
+ int status;
+
+ stop_vma_modifier(self->mod_info);
+
+ free(self->page2.data);
+ free(self->page1.data);
+
+ for (int i = 0; i < self->vma_count; i++)
+ munmap(self->mod_info->child_mapped_addr[i], self->page_size);
+ close(self->maps_fd);
+ waitpid(self->pid, &status, 0);
+ munmap(self->mod_info, self->shared_mem_size);
+}
+
+TEST_F(proc_maps_race, test_maps_tearing_from_split)
+{
+ struct vma_modifier_info *mod_info = self->mod_info;
+
+ struct line_content split_last_line;
+ struct line_content split_first_line;
+ struct line_content restored_last_line;
+ struct line_content restored_first_line;
+
+ wait_for_state(mod_info, SETUP_READY);
+
+ /* re-read the file to avoid using stale data from previous test */
+ ASSERT_TRUE(read_boundary_lines(self, &self->last_line, &self->first_line));
+
+ mod_info->vma_modify = split_vma;
+ mod_info->vma_restore = merge_vma;
+ mod_info->vma_mod_check = check_split_result;
+
+ report_test_start("Tearing from split", self->verbose);
+ ASSERT_TRUE(capture_mod_pattern(self, &split_last_line, &split_first_line,
+ &restored_last_line, &restored_first_line));
+
+ /* Now start concurrent modifications for self->duration_sec */
+ signal_state(mod_info, TEST_READY);
+
+ struct line_content new_last_line;
+ struct line_content new_first_line;
+ struct timespec start_ts, end_ts;
+
+ clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts);
+ start_test_loop(&start_ts, self->verbose);
+ do {
+ bool last_line_changed;
+ bool first_line_changed;
+ unsigned long vma_start;
+ unsigned long vma_end;
+
+ ASSERT_TRUE(read_boundary_lines(self, &new_last_line, &new_first_line));
+
+ /* Check if we read vmas after split */
+ if (!strcmp(new_last_line.text, split_last_line.text)) {
+ /*
+ * The vmas should be consistent with split results,
+ * however if vma was concurrently restored after a
+ * split, it can be reported twice (first the original
+ * split one, then the same vma but extended after the
+ * merge) because we found it as the next vma again.
+ * In that case new first line will be the same as the
+ * last restored line.
+ */
+ ASSERT_FALSE(print_boundaries_on(
+ strcmp(new_first_line.text, split_first_line.text) &&
+ strcmp(new_first_line.text, restored_last_line.text),
+ "Split result invalid", self));
+ } else {
+ /* The vmas should be consistent with merge results */
+ ASSERT_FALSE(print_boundaries_on(
+ strcmp(new_last_line.text, restored_last_line.text),
+ "Merge result invalid", self));
+ ASSERT_FALSE(print_boundaries_on(
+ strcmp(new_first_line.text, restored_first_line.text),
+ "Merge result invalid", self));
+ }
+ /*
+ * First and last lines should change in unison. If the last
+ * line changed then the first line should change as well and
+ * vice versa.
+ */
+ last_line_changed = strcmp(new_last_line.text, self->last_line.text) != 0;
+ first_line_changed = strcmp(new_first_line.text, self->first_line.text) != 0;
+ ASSERT_EQ(last_line_changed, first_line_changed);
+ if (self->maps_file == MAPS) {
+ /* Check if PROCMAP_QUERY ioclt() finds the right VMA */
+ ASSERT_TRUE(query_addr_at(self->maps_fd, mod_info->addr + self->page_size,
+ &vma_start, &vma_end));
+ /*
+ * The vma at the split address can be either the same as
+ * original one (if read before the split) or the same as the
+ * first line in the second page (if read after the split).
+ */
+ ASSERT_TRUE((vma_start == self->last_line.start_addr &&
+ vma_end == self->last_line.end_addr) ||
+ (vma_start == split_first_line.start_addr &&
+ vma_end == split_first_line.end_addr));
+ }
+ clock_gettime(CLOCK_MONOTONIC_COARSE, &end_ts);
+ end_test_iteration(&end_ts, self->verbose);
+ } while (end_ts.tv_sec - start_ts.tv_sec < self->duration_sec);
+ end_test_loop(self->verbose);
+
+ /* Signal the modifyer thread to stop and wait until it exits */
+ signal_state(mod_info, TEST_DONE);
+}
+
+TEST_F(proc_maps_race, test_maps_tearing_from_resize)
+{
+ struct vma_modifier_info *mod_info = self->mod_info;
+
+ struct line_content shrunk_last_line;
+ struct line_content shrunk_first_line;
+ struct line_content restored_last_line;
+ struct line_content restored_first_line;
+
+ wait_for_state(mod_info, SETUP_READY);
+
+ /* re-read the file to avoid using stale data from previous test */
+ ASSERT_TRUE(read_boundary_lines(self, &self->last_line, &self->first_line));
+
+ mod_info->vma_modify = shrink_vma;
+ mod_info->vma_restore = expand_vma;
+ mod_info->vma_mod_check = check_shrink_result;
+
+ report_test_start("Tearing from resize", self->verbose);
+ ASSERT_TRUE(capture_mod_pattern(self, &shrunk_last_line, &shrunk_first_line,
+ &restored_last_line, &restored_first_line));
+
+ /* Now start concurrent modifications for self->duration_sec */
+ signal_state(mod_info, TEST_READY);
+
+ struct line_content new_last_line;
+ struct line_content new_first_line;
+ struct timespec start_ts, end_ts;
+
+ clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts);
+ start_test_loop(&start_ts, self->verbose);
+ do {
+ unsigned long vma_start;
+ unsigned long vma_end;
+
+ ASSERT_TRUE(read_boundary_lines(self, &new_last_line, &new_first_line));
+
+ /* Check if we read vmas after shrinking it */
+ if (!strcmp(new_last_line.text, shrunk_last_line.text)) {
+ /*
+ * The vmas should be consistent with shrunk results,
+ * however if the vma was concurrently restored, it
+ * can be reported twice (first as shrunk one, then
+ * as restored one) because we found it as the next vma
+ * again. In that case new first line will be the same
+ * as the last restored line.
+ */
+ ASSERT_FALSE(print_boundaries_on(
+ strcmp(new_first_line.text, shrunk_first_line.text) &&
+ strcmp(new_first_line.text, restored_last_line.text),
+ "Shrink result invalid", self));
+ } else {
+ /* The vmas should be consistent with the original/resored state */
+ ASSERT_FALSE(print_boundaries_on(
+ strcmp(new_last_line.text, restored_last_line.text),
+ "Expand result invalid", self));
+ ASSERT_FALSE(print_boundaries_on(
+ strcmp(new_first_line.text, restored_first_line.text),
+ "Expand result invalid", self));
+ }
+ if (self->maps_file == MAPS) {
+ /* Check if PROCMAP_QUERY ioclt() finds the right VMA */
+ ASSERT_TRUE(query_addr_at(self->maps_fd, mod_info->addr,
+ &vma_start, &vma_end));
+ /*
+ * The vma should stay at the same address and have either the
+ * original size of 3 pages or 1 page if read after shrinking.
+ */
+ ASSERT_TRUE(vma_start == self->last_line.start_addr &&
+ (vma_end - vma_start == self->page_size * 3 ||
+ vma_end - vma_start == self->page_size));
+ }
+ clock_gettime(CLOCK_MONOTONIC_COARSE, &end_ts);
+ end_test_iteration(&end_ts, self->verbose);
+ } while (end_ts.tv_sec - start_ts.tv_sec < self->duration_sec);
+ end_test_loop(self->verbose);
+
+ /* Signal the modifyer thread to stop and wait until it exits */
+ signal_state(mod_info, TEST_DONE);
+}
+
+TEST_F(proc_maps_race, test_maps_tearing_from_remap)
+{
+ struct vma_modifier_info *mod_info = self->mod_info;
+
+ struct line_content remapped_last_line;
+ struct line_content remapped_first_line;
+ struct line_content restored_last_line;
+ struct line_content restored_first_line;
+
+ wait_for_state(mod_info, SETUP_READY);
+
+ /* re-read the file to avoid using stale data from previous test */
+ ASSERT_TRUE(read_boundary_lines(self, &self->last_line, &self->first_line));
+
+ mod_info->vma_modify = remap_vma;
+ mod_info->vma_restore = patch_vma;
+ mod_info->vma_mod_check = check_remap_result;
+
+ report_test_start("Tearing from remap", self->verbose);
+ ASSERT_TRUE(capture_mod_pattern(self, &remapped_last_line, &remapped_first_line,
+ &restored_last_line, &restored_first_line));
+
+ /* Now start concurrent modifications for self->duration_sec */
+ signal_state(mod_info, TEST_READY);
+
+ struct line_content new_last_line;
+ struct line_content new_first_line;
+ struct timespec start_ts, end_ts;
+
+ clock_gettime(CLOCK_MONOTONIC_COARSE, &start_ts);
+ start_test_loop(&start_ts, self->verbose);
+ do {
+ unsigned long vma_start;
+ unsigned long vma_end;
+
+ ASSERT_TRUE(read_boundary_lines(self, &new_last_line, &new_first_line));
+
+ /* Check if we read vmas after remapping it */
+ if (!strcmp(new_last_line.text, remapped_last_line.text)) {
+ /*
+ * The vmas should be consistent with remap results,
+ * however if the vma was concurrently restored, it
+ * can be reported twice (first as split one, then
+ * as restored one) because we found it as the next vma
+ * again. In that case new first line will be the same
+ * as the last restored line.
+ */
+ ASSERT_FALSE(print_boundaries_on(
+ strcmp(new_first_line.text, remapped_first_line.text) &&
+ strcmp(new_first_line.text, restored_last_line.text),
+ "Remap result invalid", self));
+ } else {
+ /* The vmas should be consistent with the original/resored state */
+ ASSERT_FALSE(print_boundaries_on(
+ strcmp(new_last_line.text, restored_last_line.text),
+ "Remap restore result invalid", self));
+ ASSERT_FALSE(print_boundaries_on(
+ strcmp(new_first_line.text, restored_first_line.text),
+ "Remap restore result invalid", self));
+ }
+ if (self->maps_file == MAPS) {
+ /* Check if PROCMAP_QUERY ioclt() finds the right VMA */
+ ASSERT_TRUE(query_addr_at(self->maps_fd, mod_info->addr + self->page_size,
+ &vma_start, &vma_end));
+ /*
+ * The vma should either stay at the same address and have the
+ * original size of 3 pages or we should find the remapped vma
+ * at the remap destination address with size of 1 page.
+ */
+ ASSERT_TRUE((vma_start == self->last_line.start_addr &&
+ vma_end - vma_start == self->page_size * 3) ||
+ (vma_start == self->last_line.start_addr + self->page_size &&
+ vma_end - vma_start == self->page_size));
+ }
+ clock_gettime(CLOCK_MONOTONIC_COARSE, &end_ts);
+ end_test_iteration(&end_ts, self->verbose);
+ } while (end_ts.tv_sec - start_ts.tv_sec < self->duration_sec);
+ end_test_loop(self->verbose);
+
+ /* Signal the modifyer thread to stop and wait until it exits */
+ signal_state(mod_info, TEST_DONE);
+}
+
+TEST_HARNESS_MAIN
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 000000000..ab912ad95
--- /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;
+}
diff --git a/tools/testing/selftests/proc/proc-net-dev-lseek.c b/tools/testing/selftests/proc/proc-net-dev-lseek.c
new file mode 100644
index 000000000..742a3e804
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-net-dev-lseek.c
@@ -0,0 +1,68 @@
+/*
+ * Copyright (c) 2025 Alexey Dobriyan <adobriyan@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.
+ */
+#undef _GNU_SOURCE
+#define _GNU_SOURCE
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+#include <sched.h>
+/*
+ * Test that lseek("/proc/net/dev/", 0, SEEK_SET)
+ * a) works,
+ * b) does what you think it does.
+ */
+int main(void)
+{
+ /* /proc/net/dev output is deterministic in fresh netns only. */
+ if (unshare(CLONE_NEWNET) == -1) {
+ if (errno == ENOSYS || errno == EPERM) {
+ return 4;
+ }
+ return 1;
+ }
+
+ const int fd = open("/proc/net/dev", O_RDONLY);
+ assert(fd >= 0);
+
+ char buf1[4096];
+ const ssize_t rv1 = read(fd, buf1, sizeof(buf1));
+ /*
+ * Not "<=", this file can't be empty:
+ * there is header, "lo" interface with some zeroes.
+ */
+ assert(0 < rv1);
+ assert(rv1 <= sizeof(buf1));
+
+ /* Believe it or not, this line broke one day. */
+ assert(lseek(fd, 0, SEEK_SET) == 0);
+
+ char buf2[4096];
+ const ssize_t rv2 = read(fd, buf2, sizeof(buf2));
+ /* Not "<=", see above. */
+ assert(0 < rv2);
+ assert(rv2 <= sizeof(buf2));
+
+ /* Test that lseek rewinds to the beginning of the file. */
+ assert(rv1 == rv2);
+ assert(memcmp(buf1, buf2, rv1) == 0);
+
+ /* Contents of the file is not validated: this test is about lseek(). */
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/proc-pid-vm.c b/tools/testing/selftests/proc/proc-pid-vm.c
new file mode 100644
index 000000000..4e6a3e53f
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-pid-vm.c
@@ -0,0 +1,592 @@
+/*
+ * Copyright (c) 2019 Alexey Dobriyan <adobriyan@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.
+ */
+/*
+ * Fork and exec tiny 1 page executable which precisely controls its VM.
+ * Test /proc/$PID/maps
+ * Test /proc/$PID/smaps
+ * Test /proc/$PID/smaps_rollup
+ * Test /proc/$PID/statm
+ *
+ * FIXME require CONFIG_TMPFS which can be disabled
+ * FIXME test other values from "smaps"
+ * FIXME support other archs
+ */
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/mount.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/uio.h>
+#include <linux/kdev_t.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <linux/fs.h>
+
+#ifndef __maybe_unused
+#define __maybe_unused __attribute__((__unused__))
+#endif
+
+#include "kselftest.h"
+
+static inline long sys_execveat(int dirfd, const char *pathname, char **argv, char **envp, int flags)
+{
+ return syscall(SYS_execveat, dirfd, pathname, argv, envp, flags);
+}
+
+static void make_private_tmp(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, "/tmp", "tmpfs", 0, NULL) == -1) {
+ exit(1);
+ }
+}
+
+static pid_t pid = -1;
+static void ate(void)
+{
+ if (pid > 0) {
+ kill(pid, SIGTERM);
+ }
+}
+
+struct elf64_hdr {
+ uint8_t e_ident[16];
+ uint16_t e_type;
+ uint16_t e_machine;
+ uint32_t e_version;
+ uint64_t e_entry;
+ uint64_t e_phoff;
+ uint64_t e_shoff;
+ uint32_t e_flags;
+ uint16_t e_ehsize;
+ uint16_t e_phentsize;
+ uint16_t e_phnum;
+ uint16_t e_shentsize;
+ uint16_t e_shnum;
+ uint16_t e_shstrndx;
+};
+
+struct elf64_phdr {
+ uint32_t p_type;
+ uint32_t p_flags;
+ uint64_t p_offset;
+ uint64_t p_vaddr;
+ uint64_t p_paddr;
+ uint64_t p_filesz;
+ uint64_t p_memsz;
+ uint64_t p_align;
+};
+
+#ifdef __x86_64__
+#define PAGE_SIZE 4096
+#define VADDR (1UL << 32)
+#define MAPS_OFFSET 73
+
+#define syscall 0x0f, 0x05
+#define mov_rdi(x) \
+ 0x48, 0xbf, \
+ (x)&0xff, ((x)>>8)&0xff, ((x)>>16)&0xff, ((x)>>24)&0xff, \
+ ((x)>>32)&0xff, ((x)>>40)&0xff, ((x)>>48)&0xff, ((x)>>56)&0xff
+
+#define mov_rsi(x) \
+ 0x48, 0xbe, \
+ (x)&0xff, ((x)>>8)&0xff, ((x)>>16)&0xff, ((x)>>24)&0xff, \
+ ((x)>>32)&0xff, ((x)>>40)&0xff, ((x)>>48)&0xff, ((x)>>56)&0xff
+
+#define mov_eax(x) \
+ 0xb8, (x)&0xff, ((x)>>8)&0xff, ((x)>>16)&0xff, ((x)>>24)&0xff
+
+static const uint8_t payload[] = {
+ /* Casually unmap stack, vDSO and everything else. */
+ /* munmap */
+ mov_rdi(VADDR + 4096),
+ mov_rsi((1ULL << 47) - 4096 - VADDR - 4096),
+ mov_eax(11),
+ syscall,
+
+ /* Ping parent. */
+ /* write(0, &c, 1); */
+ 0x31, 0xff, /* xor edi, edi */
+ 0x48, 0x8d, 0x35, 0x00, 0x00, 0x00, 0x00, /* lea rsi, [rip] */
+ 0xba, 0x01, 0x00, 0x00, 0x00, /* mov edx, 1 */
+ mov_eax(1),
+ syscall,
+
+ /* 1: pause(); */
+ mov_eax(34),
+ syscall,
+
+ 0xeb, 0xf7, /* jmp 1b */
+};
+
+static int make_exe(const uint8_t *payload, size_t len)
+{
+ struct elf64_hdr h;
+ struct elf64_phdr ph;
+
+ struct iovec iov[3] = {
+ {&h, sizeof(struct elf64_hdr)},
+ {&ph, sizeof(struct elf64_phdr)},
+ {(void *)payload, len},
+ };
+ int fd, fd1;
+ char buf[64];
+
+ memset(&h, 0, sizeof(h));
+ h.e_ident[0] = 0x7f;
+ h.e_ident[1] = 'E';
+ h.e_ident[2] = 'L';
+ h.e_ident[3] = 'F';
+ h.e_ident[4] = 2;
+ h.e_ident[5] = 1;
+ h.e_ident[6] = 1;
+ h.e_ident[7] = 0;
+ h.e_type = 2;
+ h.e_machine = 0x3e;
+ h.e_version = 1;
+ h.e_entry = VADDR + sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr);
+ h.e_phoff = sizeof(struct elf64_hdr);
+ h.e_shoff = 0;
+ h.e_flags = 0;
+ h.e_ehsize = sizeof(struct elf64_hdr);
+ h.e_phentsize = sizeof(struct elf64_phdr);
+ h.e_phnum = 1;
+ h.e_shentsize = 0;
+ h.e_shnum = 0;
+ h.e_shstrndx = 0;
+
+ memset(&ph, 0, sizeof(ph));
+ ph.p_type = 1;
+ ph.p_flags = (1<<2)|1;
+ ph.p_offset = 0;
+ ph.p_vaddr = VADDR;
+ ph.p_paddr = 0;
+ ph.p_filesz = sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr) + len;
+ ph.p_memsz = sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr) + len;
+ ph.p_align = 4096;
+
+ fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_EXCL|O_TMPFILE, 0700);
+ if (fd == -1) {
+ exit(1);
+ }
+
+ if (writev(fd, iov, 3) != sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr) + len) {
+ exit(1);
+ }
+
+ /* Avoid ETXTBSY on exec. */
+ snprintf(buf, sizeof(buf), "/proc/self/fd/%u", fd);
+ fd1 = open(buf, O_RDONLY|O_CLOEXEC);
+ close(fd);
+
+ return fd1;
+}
+#endif
+
+/*
+ * 0: vsyscall VMA doesn't exist vsyscall=none
+ * 1: vsyscall VMA is --xp vsyscall=xonly
+ * 2: vsyscall VMA is r-xp vsyscall=emulate
+ */
+static volatile int g_vsyscall;
+static const char *str_vsyscall __maybe_unused;
+
+static const char str_vsyscall_0[] __maybe_unused = "";
+static const char str_vsyscall_1[] __maybe_unused =
+"ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 [vsyscall]\n";
+static const char str_vsyscall_2[] __maybe_unused =
+"ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]\n";
+
+#ifdef __x86_64__
+static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___)
+{
+ _exit(g_vsyscall);
+}
+
+/*
+ * vsyscall page can't be unmapped, probe it directly.
+ */
+static void vsyscall(void)
+{
+ pid_t pid;
+ int wstatus;
+
+ pid = fork();
+ if (pid < 0) {
+ fprintf(stderr, "fork, errno %d\n", errno);
+ exit(1);
+ }
+ if (pid == 0) {
+ struct rlimit rlim = {0, 0};
+ (void)setrlimit(RLIMIT_CORE, &rlim);
+
+ /* Hide "segfault at ffffffffff600000" messages. */
+ struct sigaction act;
+ memset(&act, 0, sizeof(struct sigaction));
+ act.sa_flags = SA_SIGINFO;
+ act.sa_sigaction = sigaction_SIGSEGV;
+ (void)sigaction(SIGSEGV, &act, NULL);
+
+ g_vsyscall = 0;
+ /* gettimeofday(NULL, NULL); */
+ uint64_t rax = 0xffffffffff600000;
+ asm volatile (
+ "call *%[rax]"
+ : [rax] "+a" (rax)
+ : "D" (NULL), "S" (NULL)
+ : "rcx", "r11"
+ );
+
+ g_vsyscall = 1;
+ *(volatile int *)0xffffffffff600000UL;
+
+ g_vsyscall = 2;
+ exit(g_vsyscall);
+ }
+ waitpid(pid, &wstatus, 0);
+ if (WIFEXITED(wstatus)) {
+ g_vsyscall = WEXITSTATUS(wstatus);
+ } else {
+ fprintf(stderr, "error: wstatus %08x\n", wstatus);
+ exit(1);
+ }
+}
+
+int main(void)
+{
+ int pipefd[2];
+ int exec_fd;
+
+ vsyscall();
+ switch (g_vsyscall) {
+ case 0:
+ str_vsyscall = str_vsyscall_0;
+ break;
+ case 1:
+ str_vsyscall = str_vsyscall_1;
+ break;
+ case 2:
+ str_vsyscall = str_vsyscall_2;
+ break;
+ default:
+ abort();
+ }
+
+ atexit(ate);
+
+ make_private_tmp();
+
+ /* Reserve fd 0 for 1-byte pipe ping from child. */
+ close(0);
+ if (open("/", O_RDONLY|O_DIRECTORY|O_PATH) != 0) {
+ return 1;
+ }
+
+ exec_fd = make_exe(payload, sizeof(payload));
+
+ if (pipe(pipefd) == -1) {
+ return 1;
+ }
+ if (dup2(pipefd[1], 0) != 0) {
+ return 1;
+ }
+
+ pid = fork();
+ if (pid == -1) {
+ return 1;
+ }
+ if (pid == 0) {
+ sys_execveat(exec_fd, "", NULL, NULL, AT_EMPTY_PATH);
+ return 1;
+ }
+
+ char _;
+ if (read(pipefd[0], &_, 1) != 1) {
+ return 1;
+ }
+
+ struct stat st;
+ if (fstat(exec_fd, &st) == -1) {
+ return 1;
+ }
+
+ /* Generate "head -n1 /proc/$PID/maps" */
+ char buf0[256];
+ memset(buf0, ' ', sizeof(buf0));
+ int len = snprintf(buf0, sizeof(buf0),
+ "%08lx-%08lx r-xp 00000000 %02lx:%02lx %llu",
+ VADDR, VADDR + PAGE_SIZE,
+ MAJOR(st.st_dev), MINOR(st.st_dev),
+ (unsigned long long)st.st_ino);
+ buf0[len] = ' ';
+ snprintf(buf0 + MAPS_OFFSET, sizeof(buf0) - MAPS_OFFSET,
+ "/tmp/#%llu (deleted)\n", (unsigned long long)st.st_ino);
+
+ /* Test /proc/$PID/maps */
+ {
+ const size_t len = strlen(buf0) + strlen(str_vsyscall);
+ char buf[256];
+ ssize_t rv;
+ int fd;
+
+ snprintf(buf, sizeof(buf), "/proc/%u/maps", pid);
+ fd = open(buf, O_RDONLY);
+ if (fd == -1) {
+ return 1;
+ }
+ rv = read(fd, buf, sizeof(buf));
+ assert(rv == len);
+ assert(memcmp(buf, buf0, strlen(buf0)) == 0);
+ if (g_vsyscall > 0) {
+ assert(memcmp(buf + strlen(buf0), str_vsyscall, strlen(str_vsyscall)) == 0);
+ }
+ }
+
+ /* Test /proc/$PID/smaps */
+ {
+ char buf[4096];
+ ssize_t rv;
+ int fd;
+
+ snprintf(buf, sizeof(buf), "/proc/%u/smaps", pid);
+ fd = open(buf, O_RDONLY);
+ if (fd == -1) {
+ return 1;
+ }
+ rv = read(fd, buf, sizeof(buf));
+ assert(0 <= rv && rv <= sizeof(buf));
+
+ assert(rv >= strlen(buf0));
+ assert(memcmp(buf, buf0, strlen(buf0)) == 0);
+
+#define RSS1 "Rss: 4 kB\n"
+#define RSS2 "Rss: 0 kB\n"
+#define PSS1 "Pss: 4 kB\n"
+#define PSS2 "Pss: 0 kB\n"
+ assert(memmem(buf, rv, RSS1, strlen(RSS1)) ||
+ memmem(buf, rv, RSS2, strlen(RSS2)));
+ assert(memmem(buf, rv, PSS1, strlen(PSS1)) ||
+ memmem(buf, rv, PSS2, strlen(PSS2)));
+
+ static const char *S[] = {
+ "Size: 4 kB\n",
+ "KernelPageSize: 4 kB\n",
+ "MMUPageSize: 4 kB\n",
+ "Anonymous: 0 kB\n",
+ "AnonHugePages: 0 kB\n",
+ "Shared_Hugetlb: 0 kB\n",
+ "Private_Hugetlb: 0 kB\n",
+ "Locked: 0 kB\n",
+ };
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(S); i++) {
+ assert(memmem(buf, rv, S[i], strlen(S[i])));
+ }
+
+ if (g_vsyscall > 0) {
+ assert(memmem(buf, rv, str_vsyscall, strlen(str_vsyscall)));
+ }
+ }
+
+ /* Test /proc/$PID/smaps_rollup */
+ {
+ char bufr[256];
+ memset(bufr, ' ', sizeof(bufr));
+ len = snprintf(bufr, sizeof(bufr),
+ "%08lx-%08lx ---p 00000000 00:00 0",
+ VADDR, VADDR + PAGE_SIZE);
+ bufr[len] = ' ';
+ snprintf(bufr + MAPS_OFFSET, sizeof(bufr) - MAPS_OFFSET,
+ "[rollup]\n");
+
+ char buf[1024];
+ ssize_t rv;
+ int fd;
+
+ snprintf(buf, sizeof(buf), "/proc/%u/smaps_rollup", pid);
+ fd = open(buf, O_RDONLY);
+ if (fd == -1) {
+ return 1;
+ }
+ rv = read(fd, buf, sizeof(buf));
+ assert(0 <= rv && rv <= sizeof(buf));
+
+ assert(rv >= strlen(bufr));
+ assert(memcmp(buf, bufr, strlen(bufr)) == 0);
+
+ assert(memmem(buf, rv, RSS1, strlen(RSS1)) ||
+ memmem(buf, rv, RSS2, strlen(RSS2)));
+ assert(memmem(buf, rv, PSS1, strlen(PSS1)) ||
+ memmem(buf, rv, PSS2, strlen(PSS2)));
+
+ static const char *S[] = {
+ "Anonymous: 0 kB\n",
+ "AnonHugePages: 0 kB\n",
+ "Shared_Hugetlb: 0 kB\n",
+ "Private_Hugetlb: 0 kB\n",
+ "Locked: 0 kB\n",
+ };
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(S); i++) {
+ assert(memmem(buf, rv, S[i], strlen(S[i])));
+ }
+ }
+
+ /* Test /proc/$PID/statm */
+ {
+ char buf[64];
+ ssize_t rv;
+ int fd;
+
+ snprintf(buf, sizeof(buf), "/proc/%u/statm", pid);
+ fd = open(buf, O_RDONLY);
+ if (fd == -1) {
+ return 1;
+ }
+ rv = read(fd, buf, sizeof(buf));
+ assert(rv == 7 * 2);
+
+ assert(buf[0] == '1'); /* ->total_vm */
+ assert(buf[1] == ' ');
+ assert(buf[2] == '0' || buf[2] == '1'); /* rss */
+ assert(buf[3] == ' ');
+ assert(buf[4] == '0' || buf[2] == '1'); /* file rss */
+ assert(buf[5] == ' ');
+ assert(buf[6] == '1'); /* ELF executable segments */
+ assert(buf[7] == ' ');
+ assert(buf[8] == '0');
+ assert(buf[9] == ' ');
+ assert(buf[10] == '0'); /* ->data_vm + ->stack_vm */
+ assert(buf[11] == ' ');
+ assert(buf[12] == '0');
+ assert(buf[13] == '\n');
+ }
+
+ /* Test PROCMAP_QUERY ioctl() for /proc/$PID/maps */
+ {
+ char path_buf[256], exp_path_buf[256];
+ struct procmap_query q;
+ int fd, err;
+
+ snprintf(path_buf, sizeof(path_buf), "/proc/%u/maps", pid);
+ fd = open(path_buf, O_RDONLY);
+ if (fd == -1)
+ return 1;
+
+ /* CASE 1: exact MATCH at VADDR */
+ memset(&q, 0, sizeof(q));
+ q.size = sizeof(q);
+ q.query_addr = VADDR;
+ q.query_flags = 0;
+ q.vma_name_addr = (__u64)(unsigned long)path_buf;
+ q.vma_name_size = sizeof(path_buf);
+
+ err = ioctl(fd, PROCMAP_QUERY, &q);
+ assert(err == 0);
+
+ assert(q.query_addr == VADDR);
+ assert(q.query_flags == 0);
+
+ assert(q.vma_flags == (PROCMAP_QUERY_VMA_READABLE | PROCMAP_QUERY_VMA_EXECUTABLE));
+ assert(q.vma_start == VADDR);
+ assert(q.vma_end == VADDR + PAGE_SIZE);
+ assert(q.vma_page_size == PAGE_SIZE);
+
+ assert(q.vma_offset == 0);
+ assert(q.inode == st.st_ino);
+ assert(q.dev_major == MAJOR(st.st_dev));
+ assert(q.dev_minor == MINOR(st.st_dev));
+
+ snprintf(exp_path_buf, sizeof(exp_path_buf),
+ "/tmp/#%llu (deleted)", (unsigned long long)st.st_ino);
+ assert(q.vma_name_size == strlen(exp_path_buf) + 1);
+ assert(strcmp(path_buf, exp_path_buf) == 0);
+
+ /* CASE 2: NO MATCH at VADDR-1 */
+ memset(&q, 0, sizeof(q));
+ q.size = sizeof(q);
+ q.query_addr = VADDR - 1;
+ q.query_flags = 0; /* exact match */
+
+ err = ioctl(fd, PROCMAP_QUERY, &q);
+ err = err < 0 ? -errno : 0;
+ assert(err == -ENOENT);
+
+ /* CASE 3: MATCH COVERING_OR_NEXT_VMA at VADDR - 1 */
+ memset(&q, 0, sizeof(q));
+ q.size = sizeof(q);
+ q.query_addr = VADDR - 1;
+ q.query_flags = PROCMAP_QUERY_COVERING_OR_NEXT_VMA;
+
+ err = ioctl(fd, PROCMAP_QUERY, &q);
+ assert(err == 0);
+
+ assert(q.query_addr == VADDR - 1);
+ assert(q.query_flags == PROCMAP_QUERY_COVERING_OR_NEXT_VMA);
+ assert(q.vma_start == VADDR);
+ assert(q.vma_end == VADDR + PAGE_SIZE);
+
+ /* CASE 4: NO MATCH at VADDR + PAGE_SIZE */
+ memset(&q, 0, sizeof(q));
+ q.size = sizeof(q);
+ q.query_addr = VADDR + PAGE_SIZE; /* point right after the VMA */
+ q.query_flags = PROCMAP_QUERY_COVERING_OR_NEXT_VMA;
+
+ err = ioctl(fd, PROCMAP_QUERY, &q);
+ err = err < 0 ? -errno : 0;
+ assert(err == -ENOENT);
+
+ /* CASE 5: NO MATCH WRITABLE at VADDR */
+ memset(&q, 0, sizeof(q));
+ q.size = sizeof(q);
+ q.query_addr = VADDR;
+ q.query_flags = PROCMAP_QUERY_VMA_WRITABLE;
+
+ err = ioctl(fd, PROCMAP_QUERY, &q);
+ err = err < 0 ? -errno : 0;
+ assert(err == -ENOENT);
+ }
+
+ return 0;
+}
+#else
+int main(void)
+{
+ return 4;
+}
+#endif
diff --git a/tools/testing/selftests/proc/proc-pidns.c b/tools/testing/selftests/proc/proc-pidns.c
new file mode 100644
index 000000000..6f7c10fe9
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-pidns.c
@@ -0,0 +1,212 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Author: Aleksa Sarai <cyphar@cyphar.com>
+ * Copyright (C) 2025 SUSE LLC.
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <sched.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <sys/mount.h>
+#include <sys/stat.h>
+#include <sys/prctl.h>
+
+#include "kselftest_harness.h"
+
+#define ASSERT_ERRNO(expected, _t, seen) \
+ __EXPECT(expected, #expected, \
+ ({__typeof__(seen) _tmp_seen = (seen); \
+ _tmp_seen >= 0 ? _tmp_seen : -errno; }), #seen, _t, 1)
+
+#define ASSERT_ERRNO_EQ(expected, seen) \
+ ASSERT_ERRNO(expected, ==, seen)
+
+#define ASSERT_SUCCESS(seen) \
+ ASSERT_ERRNO(0, <=, seen)
+
+static int touch(char *path)
+{
+ int fd = open(path, O_WRONLY|O_CREAT|O_CLOEXEC, 0644);
+ if (fd < 0)
+ return -1;
+ return close(fd);
+}
+
+FIXTURE(ns)
+{
+ int host_mntns, host_pidns;
+ int dummy_pidns;
+};
+
+FIXTURE_SETUP(ns)
+{
+ /* Stash the old mntns. */
+ self->host_mntns = open("/proc/self/ns/mnt", O_RDONLY|O_CLOEXEC);
+ ASSERT_SUCCESS(self->host_mntns);
+
+ /* Create a new mount namespace and make it private. */
+ ASSERT_SUCCESS(unshare(CLONE_NEWNS));
+ ASSERT_SUCCESS(mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL));
+
+ /*
+ * Create a proper tmpfs that we can use and will disappear once we
+ * leave this mntns.
+ */
+ ASSERT_SUCCESS(mount("tmpfs", "/tmp", "tmpfs", 0, NULL));
+
+ /*
+ * Create a pidns we can use for later tests. We need to fork off a
+ * child so that we get a usable nsfd that we can bind-mount and open.
+ */
+ ASSERT_SUCCESS(mkdir("/tmp/dummy", 0755));
+ ASSERT_SUCCESS(touch("/tmp/dummy/pidns"));
+ ASSERT_SUCCESS(mkdir("/tmp/dummy/proc", 0755));
+
+ self->host_pidns = open("/proc/self/ns/pid", O_RDONLY|O_CLOEXEC);
+ ASSERT_SUCCESS(self->host_pidns);
+ ASSERT_SUCCESS(unshare(CLONE_NEWPID));
+
+ pid_t pid = fork();
+ ASSERT_SUCCESS(pid);
+ if (!pid) {
+ prctl(PR_SET_PDEATHSIG, SIGKILL);
+ ASSERT_SUCCESS(mount("/proc/self/ns/pid", "/tmp/dummy/pidns", NULL, MS_BIND, NULL));
+ ASSERT_SUCCESS(mount("proc", "/tmp/dummy/proc", "proc", 0, NULL));
+ exit(0);
+ }
+
+ int wstatus;
+ ASSERT_EQ(waitpid(pid, &wstatus, 0), pid);
+ ASSERT_TRUE(WIFEXITED(wstatus));
+ ASSERT_EQ(WEXITSTATUS(wstatus), 0);
+
+ ASSERT_SUCCESS(setns(self->host_pidns, CLONE_NEWPID));
+
+ self->dummy_pidns = open("/tmp/dummy/pidns", O_RDONLY|O_CLOEXEC);
+ ASSERT_SUCCESS(self->dummy_pidns);
+}
+
+FIXTURE_TEARDOWN(ns)
+{
+ ASSERT_SUCCESS(setns(self->host_mntns, CLONE_NEWNS));
+ ASSERT_SUCCESS(close(self->host_mntns));
+
+ ASSERT_SUCCESS(close(self->host_pidns));
+ ASSERT_SUCCESS(close(self->dummy_pidns));
+}
+
+TEST_F(ns, pidns_mount_string_path)
+{
+ ASSERT_SUCCESS(mkdir("/tmp/proc-host", 0755));
+ ASSERT_SUCCESS(mount("proc", "/tmp/proc-host", "proc", 0, "pidns=/proc/self/ns/pid"));
+ ASSERT_SUCCESS(access("/tmp/proc-host/self/", X_OK));
+
+ ASSERT_SUCCESS(mkdir("/tmp/proc-dummy", 0755));
+ ASSERT_SUCCESS(mount("proc", "/tmp/proc-dummy", "proc", 0, "pidns=/tmp/dummy/pidns"));
+ ASSERT_ERRNO_EQ(-ENOENT, access("/tmp/proc-dummy/1/", X_OK));
+ ASSERT_ERRNO_EQ(-ENOENT, access("/tmp/proc-dummy/self/", X_OK));
+}
+
+TEST_F(ns, pidns_fsconfig_string_path)
+{
+ int fsfd = fsopen("proc", FSOPEN_CLOEXEC);
+ ASSERT_SUCCESS(fsfd);
+
+ ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_SET_STRING, "pidns", "/tmp/dummy/pidns", 0));
+ ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0));
+
+ int mountfd = fsmount(fsfd, FSMOUNT_CLOEXEC, 0);
+ ASSERT_SUCCESS(mountfd);
+
+ ASSERT_ERRNO_EQ(-ENOENT, faccessat(mountfd, "1/", X_OK, 0));
+ ASSERT_ERRNO_EQ(-ENOENT, faccessat(mountfd, "self/", X_OK, 0));
+
+ ASSERT_SUCCESS(close(fsfd));
+ ASSERT_SUCCESS(close(mountfd));
+}
+
+TEST_F(ns, pidns_fsconfig_fd)
+{
+ int fsfd = fsopen("proc", FSOPEN_CLOEXEC);
+ ASSERT_SUCCESS(fsfd);
+
+ ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_SET_FD, "pidns", NULL, self->dummy_pidns));
+ ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0));
+
+ int mountfd = fsmount(fsfd, FSMOUNT_CLOEXEC, 0);
+ ASSERT_SUCCESS(mountfd);
+
+ ASSERT_ERRNO_EQ(-ENOENT, faccessat(mountfd, "1/", X_OK, 0));
+ ASSERT_ERRNO_EQ(-ENOENT, faccessat(mountfd, "self/", X_OK, 0));
+
+ ASSERT_SUCCESS(close(fsfd));
+ ASSERT_SUCCESS(close(mountfd));
+}
+
+TEST_F(ns, pidns_reconfigure_remount)
+{
+ ASSERT_SUCCESS(mkdir("/tmp/proc", 0755));
+ ASSERT_SUCCESS(mount("proc", "/tmp/proc", "proc", 0, ""));
+
+ ASSERT_SUCCESS(access("/tmp/proc/1/", X_OK));
+ ASSERT_SUCCESS(access("/tmp/proc/self/", X_OK));
+
+ ASSERT_ERRNO_EQ(-EBUSY, mount(NULL, "/tmp/proc", NULL, MS_REMOUNT, "pidns=/tmp/dummy/pidns"));
+
+ ASSERT_SUCCESS(access("/tmp/proc/1/", X_OK));
+ ASSERT_SUCCESS(access("/tmp/proc/self/", X_OK));
+}
+
+TEST_F(ns, pidns_reconfigure_fsconfig_string_path)
+{
+ int fsfd = fsopen("proc", FSOPEN_CLOEXEC);
+ ASSERT_SUCCESS(fsfd);
+
+ ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0));
+
+ int mountfd = fsmount(fsfd, FSMOUNT_CLOEXEC, 0);
+ ASSERT_SUCCESS(mountfd);
+
+ ASSERT_SUCCESS(faccessat(mountfd, "1/", X_OK, 0));
+ ASSERT_SUCCESS(faccessat(mountfd, "self/", X_OK, 0));
+
+ ASSERT_ERRNO_EQ(-EBUSY, fsconfig(fsfd, FSCONFIG_SET_STRING, "pidns", "/tmp/dummy/pidns", 0));
+ ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_CMD_RECONFIGURE, NULL, NULL, 0)); /* noop */
+
+ ASSERT_SUCCESS(faccessat(mountfd, "1/", X_OK, 0));
+ ASSERT_SUCCESS(faccessat(mountfd, "self/", X_OK, 0));
+
+ ASSERT_SUCCESS(close(fsfd));
+ ASSERT_SUCCESS(close(mountfd));
+}
+
+TEST_F(ns, pidns_reconfigure_fsconfig_fd)
+{
+ int fsfd = fsopen("proc", FSOPEN_CLOEXEC);
+ ASSERT_SUCCESS(fsfd);
+
+ ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_CMD_CREATE, NULL, NULL, 0));
+
+ int mountfd = fsmount(fsfd, FSMOUNT_CLOEXEC, 0);
+ ASSERT_SUCCESS(mountfd);
+
+ ASSERT_SUCCESS(faccessat(mountfd, "1/", X_OK, 0));
+ ASSERT_SUCCESS(faccessat(mountfd, "self/", X_OK, 0));
+
+ ASSERT_ERRNO_EQ(-EBUSY, fsconfig(fsfd, FSCONFIG_SET_FD, "pidns", NULL, self->dummy_pidns));
+ ASSERT_SUCCESS(fsconfig(fsfd, FSCONFIG_CMD_RECONFIGURE, NULL, NULL, 0)); /* noop */
+
+ ASSERT_SUCCESS(faccessat(mountfd, "1/", X_OK, 0));
+ ASSERT_SUCCESS(faccessat(mountfd, "self/", X_OK, 0));
+
+ ASSERT_SUCCESS(close(fsfd));
+ ASSERT_SUCCESS(close(mountfd));
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/proc/proc-self-isnt-kthread.c b/tools/testing/selftests/proc/proc-self-isnt-kthread.c
new file mode 100644
index 000000000..e01f4e0a9
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-self-isnt-kthread.c
@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2024 Alexey Dobriyan <adobriyan@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.
+ */
+/* Test that userspace program is not kernel thread. */
+#undef NDEBUG
+#include <assert.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+int main(void)
+{
+ int fd = open("/proc/self/status", O_RDONLY);
+ assert(fd >= 0);
+
+ char buf[4096];
+ ssize_t rv = read(fd, buf, sizeof(buf));
+ assert(0 <= rv && rv < sizeof(buf));
+ buf[rv] = '\0';
+
+ /* This test is very much not kernel thread. */
+ assert(strstr(buf, "Kthread:\t0\n"));
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/proc-self-map-files-001.c b/tools/testing/selftests/proc/proc-self-map-files-001.c
new file mode 100644
index 000000000..4209c6428
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-self-map-files-001.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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.
+ */
+/* Test readlink /proc/self/map_files/... */
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+
+static void pass(const char *fmt, unsigned long a, unsigned long b)
+{
+ char name[64];
+ char buf[64];
+
+ snprintf(name, sizeof(name), fmt, a, b);
+ if (readlink(name, buf, sizeof(buf)) == -1)
+ exit(1);
+}
+
+static void fail(const char *fmt, unsigned long a, unsigned long b)
+{
+ char name[64];
+ char buf[64];
+
+ snprintf(name, sizeof(name), fmt, a, b);
+ if (readlink(name, buf, sizeof(buf)) == -1 && errno == ENOENT)
+ return;
+ exit(1);
+}
+
+int main(void)
+{
+ const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
+ void *p;
+ int fd;
+ unsigned long a, b;
+
+ fd = open("/dev/zero", O_RDONLY);
+ if (fd == -1)
+ return 1;
+
+ p = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE, fd, 0);
+ if (p == MAP_FAILED)
+ return 1;
+
+ a = (unsigned long)p;
+ b = (unsigned long)p + PAGE_SIZE;
+
+ pass("/proc/self/map_files/%lx-%lx", a, b);
+ fail("/proc/self/map_files/ %lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx -%lx", a, b);
+ fail("/proc/self/map_files/%lx- %lx", a, b);
+ fail("/proc/self/map_files/%lx-%lx ", a, b);
+ fail("/proc/self/map_files/0%lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx-0%lx", a, b);
+ if (sizeof(long) == 4) {
+ fail("/proc/self/map_files/100000000%lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx-100000000%lx", a, b);
+ } else if (sizeof(long) == 8) {
+ fail("/proc/self/map_files/10000000000000000%lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx-10000000000000000%lx", a, b);
+ } else
+ return 1;
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/proc-self-map-files-002.c b/tools/testing/selftests/proc/proc-self-map-files-002.c
new file mode 100644
index 000000000..e6aa00a18
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-self-map-files-002.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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.
+ */
+/* Test readlink /proc/self/map_files/... with minimum address. */
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <stdlib.h>
+
+static void pass(const char *fmt, unsigned long a, unsigned long b)
+{
+ char name[64];
+ char buf[64];
+
+ snprintf(name, sizeof(name), fmt, a, b);
+ if (readlink(name, buf, sizeof(buf)) == -1)
+ exit(1);
+}
+
+static void fail(const char *fmt, unsigned long a, unsigned long b)
+{
+ char name[64];
+ char buf[64];
+
+ snprintf(name, sizeof(name), fmt, a, b);
+ if (readlink(name, buf, sizeof(buf)) == -1 && errno == ENOENT)
+ return;
+ exit(1);
+}
+
+int main(void)
+{
+ const int PAGE_SIZE = sysconf(_SC_PAGESIZE);
+ /*
+ * va_max must be enough bigger than vm.mmap_min_addr, which is
+ * 64KB/32KB by default. (depends on CONFIG_LSM_MMAP_MIN_ADDR)
+ */
+ const unsigned long va_max = 1UL << 20;
+ unsigned long va;
+ void *p;
+ int fd;
+ unsigned long a, b;
+
+ fd = open("/dev/zero", O_RDONLY);
+ if (fd == -1)
+ return 1;
+
+ for (va = 0; va < va_max; va += PAGE_SIZE) {
+ p = mmap((void *)va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
+ if (p == (void *)va)
+ break;
+ }
+ if (va == va_max) {
+ fprintf(stderr, "error: mmap doesn't like you\n");
+ return 1;
+ }
+
+ a = (unsigned long)p;
+ b = (unsigned long)p + PAGE_SIZE;
+
+ pass("/proc/self/map_files/%lx-%lx", a, b);
+ fail("/proc/self/map_files/ %lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx -%lx", a, b);
+ fail("/proc/self/map_files/%lx- %lx", a, b);
+ fail("/proc/self/map_files/%lx-%lx ", a, b);
+ fail("/proc/self/map_files/0%lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx-0%lx", a, b);
+ if (sizeof(long) == 4) {
+ fail("/proc/self/map_files/100000000%lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx-100000000%lx", a, b);
+ } else if (sizeof(long) == 8) {
+ fail("/proc/self/map_files/10000000000000000%lx-%lx", a, b);
+ fail("/proc/self/map_files/%lx-10000000000000000%lx", a, b);
+ } else
+ return 1;
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/proc-self-syscall.c b/tools/testing/selftests/proc/proc-self-syscall.c
new file mode 100644
index 000000000..8511dcfe6
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-self-syscall.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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 <unistd.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+static inline ssize_t sys_read(int fd, void *buf, size_t len)
+{
+ return syscall(SYS_read, fd, buf, len);
+}
+
+int main(void)
+{
+ char buf1[64];
+ char buf2[64];
+ int fd;
+ ssize_t rv;
+
+ fd = open("/proc/self/syscall", O_RDONLY);
+ if (fd == -1) {
+ if (errno == ENOENT)
+ return 4;
+ return 1;
+ }
+
+ /* Do direct system call as libc can wrap anything. */
+ snprintf(buf1, sizeof(buf1), "%ld 0x%lx 0x%lx 0x%lx",
+ (long)SYS_read, (long)fd, (long)buf2, (long)sizeof(buf2));
+
+ memset(buf2, 0, sizeof(buf2));
+ rv = sys_read(fd, buf2, sizeof(buf2));
+ if (rv < 0)
+ return 1;
+ if (rv < strlen(buf1))
+ return 1;
+ if (strncmp(buf1, buf2, strlen(buf1)) != 0)
+ return 1;
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/proc-self-wchan.c b/tools/testing/selftests/proc/proc-self-wchan.c
new file mode 100644
index 000000000..b467b98a4
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-self-wchan.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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 <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <unistd.h>
+
+int main(void)
+{
+ char buf[64];
+ int fd;
+
+ fd = open("/proc/self/wchan", O_RDONLY);
+ if (fd == -1) {
+ if (errno == ENOENT)
+ return 4;
+ return 1;
+ }
+
+ buf[0] = '\0';
+ if (read(fd, buf, sizeof(buf)) != 1)
+ return 1;
+ if (buf[0] != '0')
+ return 1;
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/proc-subset-pid.c b/tools/testing/selftests/proc/proc-subset-pid.c
new file mode 100644
index 000000000..d1052bcab
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-subset-pid.c
@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2021 Alexey Dobriyan <adobriyan@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.
+ */
+/*
+ * 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;
+}
diff --git a/tools/testing/selftests/proc/proc-tid0.c b/tools/testing/selftests/proc/proc-tid0.c
new file mode 100644
index 000000000..58c1d7c90
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-tid0.c
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2021 Alexey Dobriyan <adobriyan@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.
+ */
+// Test that /proc/*/task never contains "0".
+#include <sys/types.h>
+#include <dirent.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <pthread.h>
+
+static pid_t pid = -1;
+
+static void atexit_hook(void)
+{
+ if (pid > 0) {
+ kill(pid, SIGKILL);
+ }
+}
+
+static void *f(void *_)
+{
+ return NULL;
+}
+
+static void sigalrm(int _)
+{
+ exit(0);
+}
+
+int main(void)
+{
+ pid = fork();
+ if (pid == 0) {
+ /* child */
+ while (1) {
+ pthread_t pth;
+ pthread_create(&pth, NULL, f, NULL);
+ pthread_join(pth, NULL);
+ }
+ } else if (pid > 0) {
+ /* parent */
+ atexit(atexit_hook);
+
+ char buf[64];
+ snprintf(buf, sizeof(buf), "/proc/%u/task", pid);
+
+ signal(SIGALRM, sigalrm);
+ alarm(1);
+
+ while (1) {
+ DIR *d = opendir(buf);
+ struct dirent *de;
+ while ((de = readdir(d))) {
+ if (strcmp(de->d_name, "0") == 0) {
+ exit(1);
+ }
+ }
+ closedir(d);
+ }
+
+ return 0;
+ } else {
+ perror("fork");
+ return 1;
+ }
+}
diff --git a/tools/testing/selftests/proc/proc-uptime-001.c b/tools/testing/selftests/proc/proc-uptime-001.c
new file mode 100644
index 000000000..f335eec50
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-uptime-001.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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.
+ */
+// Test that boottime value in /proc/uptime and CLOCK_BOOTTIME increment
+// monotonically. We don't test idle time monotonicity due to broken iowait
+// task counting, cf: comment above get_cpu_idle_time_us()
+#undef NDEBUG
+#include <assert.h>
+#include <stdint.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "proc-uptime.h"
+
+int main(void)
+{
+ uint64_t start, u0, u1, c0, c1;
+ int fd;
+
+ fd = open("/proc/uptime", O_RDONLY);
+ assert(fd >= 0);
+
+ u0 = proc_uptime(fd);
+ start = u0;
+ c0 = clock_boottime();
+
+ do {
+ u1 = proc_uptime(fd);
+ c1 = clock_boottime();
+
+ /* Is /proc/uptime monotonic ? */
+ assert(u1 >= u0);
+
+ /* Is CLOCK_BOOTTIME monotonic ? */
+ assert(c1 >= c0);
+
+ /* Is CLOCK_BOOTTIME VS /proc/uptime monotonic ? */
+ assert(c0 >= u0);
+
+ u0 = u1;
+ c0 = c1;
+ } while (u1 - start < 100);
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/proc-uptime-002.c b/tools/testing/selftests/proc/proc-uptime-002.c
new file mode 100644
index 000000000..ae453daa9
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-uptime-002.c
@@ -0,0 +1,92 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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.
+ */
+// Test that boottime value in /proc/uptime and CLOCK_BOOTTIME increment
+// monotonically while shifting across CPUs. We don't test idle time
+// monotonicity due to broken iowait task counting, cf: comment above
+// get_cpu_idle_time_us()
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <stdint.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "proc-uptime.h"
+
+static inline int sys_sched_getaffinity(pid_t pid, unsigned int len, unsigned long *m)
+{
+ return syscall(SYS_sched_getaffinity, pid, len, m);
+}
+
+static inline int sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned long *m)
+{
+ return syscall(SYS_sched_setaffinity, pid, len, m);
+}
+
+int main(void)
+{
+ uint64_t u0, u1, c0, c1;
+ unsigned int len;
+ unsigned long *m;
+ unsigned int cpu;
+ int fd;
+
+ /* find out "nr_cpu_ids" */
+ m = NULL;
+ len = 0;
+ do {
+ len += sizeof(unsigned long);
+ free(m);
+ m = malloc(len);
+ } while (sys_sched_getaffinity(0, len, m) == -1 && errno == EINVAL);
+
+ fd = open("/proc/uptime", O_RDONLY);
+ assert(fd >= 0);
+
+ u0 = proc_uptime(fd);
+ c0 = clock_boottime();
+
+ for (cpu = 0; cpu < len * 8; cpu++) {
+ memset(m, 0, len);
+ m[cpu / (8 * sizeof(unsigned long))] |= 1UL << (cpu % (8 * sizeof(unsigned long)));
+
+ /* CPU might not exist, ignore error */
+ sys_sched_setaffinity(0, len, m);
+
+ u1 = proc_uptime(fd);
+ c1 = clock_boottime();
+
+ /* Is /proc/uptime monotonic ? */
+ assert(u1 >= u0);
+
+ /* Is CLOCK_BOOTTIME monotonic ? */
+ assert(c1 >= c0);
+
+ /* Is CLOCK_BOOTTIME VS /proc/uptime monotonic ? */
+ assert(c0 >= u0);
+
+ u0 = u1;
+ c0 = c1;
+ }
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/proc-uptime.h b/tools/testing/selftests/proc/proc-uptime.h
new file mode 100644
index 000000000..730cce4a3
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-uptime.h
@@ -0,0 +1,60 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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.
+ */
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <time.h>
+
+#include "proc.h"
+
+static uint64_t clock_boottime(void)
+{
+ struct timespec ts;
+ int err;
+
+ err = clock_gettime(CLOCK_BOOTTIME, &ts);
+ assert(err >= 0);
+
+ return (ts.tv_sec * 100) + (ts.tv_nsec / 10000000);
+}
+
+static uint64_t proc_uptime(int fd)
+{
+ uint64_t val1, val2;
+ char buf[64], *p;
+ ssize_t rv;
+
+ /* save "p < end" checks */
+ memset(buf, 0, sizeof(buf));
+ rv = pread(fd, buf, sizeof(buf), 0);
+ assert(0 <= rv && rv <= sizeof(buf));
+ buf[sizeof(buf) - 1] = '\0';
+
+ p = buf;
+
+ val1 = xstrtoull(p, &p);
+ assert(p[0] == '.');
+ assert('0' <= p[1] && p[1] <= '9');
+ assert('0' <= p[2] && p[2] <= '9');
+ assert(p[3] == ' ');
+
+ val2 = (p[1] - '0') * 10 + p[2] - '0';
+
+ return val1 * 100 + val2;
+}
diff --git a/tools/testing/selftests/proc/proc.h b/tools/testing/selftests/proc/proc.h
new file mode 100644
index 000000000..b7d57ea40
--- /dev/null
+++ b/tools/testing/selftests/proc/proc.h
@@ -0,0 +1,51 @@
+#pragma once
+#undef NDEBUG
+#include <assert.h>
+#include <dirent.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+
+static inline pid_t sys_getpid(void)
+{
+ return syscall(SYS_getpid);
+}
+
+static inline pid_t sys_gettid(void)
+{
+ return syscall(SYS_gettid);
+}
+
+static inline bool streq(const char *s1, const char *s2)
+{
+ return strcmp(s1, s2) == 0;
+}
+
+static unsigned long long xstrtoull(const char *p, char **end)
+{
+ if (*p == '0') {
+ *end = (char *)p + 1;
+ return 0;
+ } else if ('1' <= *p && *p <= '9') {
+ unsigned long long val;
+
+ errno = 0;
+ val = strtoull(p, end, 10);
+ assert(errno == 0);
+ return val;
+ } else
+ assert(0);
+}
+
+static struct dirent *xreaddir(DIR *d)
+{
+ struct dirent *de;
+
+ errno = 0;
+ de = readdir(d);
+ assert(de || errno == 0);
+ return de;
+}
diff --git a/tools/testing/selftests/proc/read.c b/tools/testing/selftests/proc/read.c
new file mode 100644
index 000000000..35ee78dff
--- /dev/null
+++ b/tools/testing/selftests/proc/read.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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.
+ */
+// Test
+// 1) read and lseek on every file in /proc
+// 2) readlink of every symlink in /proc
+// 3) recursively (1) + (2) for every directory in /proc
+// 4) write to /proc/*/clear_refs and /proc/*/task/*/clear_refs
+// 5) write to /proc/sysrq-trigger
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <dirent.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/vfs.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "proc.h"
+
+static void f_reg(DIR *d, const char *filename)
+{
+ char buf[4096];
+ int fd;
+ ssize_t rv;
+
+ /* read from /proc/kmsg can block */
+ fd = openat(dirfd(d), filename, O_RDONLY|O_NONBLOCK);
+ if (fd == -1)
+ return;
+ /* struct proc_ops::proc_lseek is mandatory if file is seekable. */
+ (void)lseek(fd, 0, SEEK_SET);
+ rv = read(fd, buf, sizeof(buf));
+ assert((0 <= rv && rv <= sizeof(buf)) || rv == -1);
+ close(fd);
+}
+
+static void f_reg_write(DIR *d, const char *filename, const char *buf, size_t len)
+{
+ int fd;
+ ssize_t rv;
+
+ fd = openat(dirfd(d), filename, O_WRONLY);
+ if (fd == -1)
+ return;
+ rv = write(fd, buf, len);
+ assert((0 <= rv && rv <= len) || rv == -1);
+ close(fd);
+}
+
+static void f_lnk(DIR *d, const char *filename)
+{
+ char buf[4096];
+ ssize_t rv;
+
+ rv = readlinkat(dirfd(d), filename, buf, sizeof(buf));
+ assert((0 <= rv && rv <= sizeof(buf)) || rv == -1);
+}
+
+static void f(DIR *d, unsigned int level)
+{
+ struct dirent *de;
+
+ de = xreaddir(d);
+ assert(de->d_type == DT_DIR);
+ assert(streq(de->d_name, "."));
+
+ de = xreaddir(d);
+ assert(de->d_type == DT_DIR);
+ assert(streq(de->d_name, ".."));
+
+ while ((de = xreaddir(d))) {
+ assert(!streq(de->d_name, "."));
+ assert(!streq(de->d_name, ".."));
+
+ switch (de->d_type) {
+ DIR *dd;
+ int fd;
+
+ case DT_REG:
+ if (level == 0 && streq(de->d_name, "sysrq-trigger")) {
+ f_reg_write(d, de->d_name, "h", 1);
+ } else if (level == 1 && streq(de->d_name, "clear_refs")) {
+ f_reg_write(d, de->d_name, "1", 1);
+ } else if (level == 3 && streq(de->d_name, "clear_refs")) {
+ f_reg_write(d, de->d_name, "1", 1);
+ } else {
+ f_reg(d, de->d_name);
+ }
+ break;
+ case DT_DIR:
+ fd = openat(dirfd(d), de->d_name, O_DIRECTORY|O_RDONLY);
+ if (fd == -1)
+ continue;
+ dd = fdopendir(fd);
+ if (!dd)
+ continue;
+ f(dd, level + 1);
+ closedir(dd);
+ break;
+ case DT_LNK:
+ f_lnk(d, de->d_name);
+ break;
+ default:
+ assert(0);
+ }
+ }
+}
+
+int main(void)
+{
+ DIR *d;
+ struct statfs sfs;
+
+ d = opendir("/proc");
+ if (!d)
+ return 4;
+
+ /* Ensure /proc is proc. */
+ if (fstatfs(dirfd(d), &sfs) == -1) {
+ return 1;
+ }
+ if (sfs.f_type != 0x9fa0) {
+ fprintf(stderr, "error: unexpected f_type %lx\n", (long)sfs.f_type);
+ return 2;
+ }
+
+ f(d, 0);
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/self.c b/tools/testing/selftests/proc/self.c
new file mode 100644
index 000000000..21c15a1ff
--- /dev/null
+++ b/tools/testing/selftests/proc/self.c
@@ -0,0 +1,39 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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.
+ */
+// Test that /proc/self gives correct TGID.
+#undef NDEBUG
+#include <assert.h>
+#include <stdio.h>
+#include <unistd.h>
+
+#include "proc.h"
+
+int main(void)
+{
+ char buf1[64], buf2[64];
+ pid_t pid;
+ ssize_t rv;
+
+ pid = sys_getpid();
+ snprintf(buf1, sizeof(buf1), "%u", pid);
+
+ rv = readlink("/proc/self", buf2, sizeof(buf2));
+ assert(rv == strlen(buf1));
+ buf2[rv] = '\0';
+ assert(streq(buf1, buf2));
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/setns-dcache.c b/tools/testing/selftests/proc/setns-dcache.c
new file mode 100644
index 000000000..60ab197a7
--- /dev/null
+++ b/tools/testing/selftests/proc/setns-dcache.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright © 2019 Alexey Dobriyan <adobriyan@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.
+ */
+/*
+ * Test that setns(CLONE_NEWNET) points to new /proc/net content even
+ * if old one is in dcache.
+ *
+ * FIXME /proc/net/unix is under CONFIG_UNIX which can be disabled.
+ */
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+
+static pid_t pid = -1;
+
+static void f(void)
+{
+ if (pid > 0) {
+ kill(pid, SIGTERM);
+ }
+}
+
+int main(void)
+{
+ int fd[2];
+ char _ = 0;
+ int nsfd;
+
+ atexit(f);
+
+ /* Check for priviledges and syscall availability straight away. */
+ if (unshare(CLONE_NEWNET) == -1) {
+ if (errno == ENOSYS || errno == EPERM) {
+ return 4;
+ }
+ return 1;
+ }
+ /* Distinguisher between two otherwise empty net namespaces. */
+ if (socket(AF_UNIX, SOCK_STREAM, 0) == -1) {
+ return 1;
+ }
+
+ if (pipe(fd) == -1) {
+ return 1;
+ }
+
+ pid = fork();
+ if (pid == -1) {
+ return 1;
+ }
+
+ if (pid == 0) {
+ if (unshare(CLONE_NEWNET) == -1) {
+ return 1;
+ }
+
+ if (write(fd[1], &_, 1) != 1) {
+ return 1;
+ }
+
+ pause();
+
+ return 0;
+ }
+
+ if (read(fd[0], &_, 1) != 1) {
+ return 1;
+ }
+
+ {
+ char buf[64];
+ snprintf(buf, sizeof(buf), "/proc/%u/ns/net", pid);
+ nsfd = open(buf, O_RDONLY);
+ if (nsfd == -1) {
+ return 1;
+ }
+ }
+
+ /* Reliably pin dentry into dcache. */
+ (void)open("/proc/net/unix", O_RDONLY);
+
+ if (setns(nsfd, CLONE_NEWNET) == -1) {
+ return 1;
+ }
+
+ kill(pid, SIGTERM);
+ pid = 0;
+
+ {
+ char buf[4096];
+ ssize_t rv;
+ int fd;
+
+ fd = open("/proc/net/unix", O_RDONLY);
+ if (fd == -1) {
+ return 1;
+ }
+
+#define S "Num RefCount Protocol Flags Type St Inode Path\n"
+ rv = read(fd, buf, sizeof(buf));
+
+ assert(rv == strlen(S));
+ assert(memcmp(buf, S, strlen(S)) == 0);
+ }
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/setns-sysvipc.c b/tools/testing/selftests/proc/setns-sysvipc.c
new file mode 100644
index 000000000..903890c5e
--- /dev/null
+++ b/tools/testing/selftests/proc/setns-sysvipc.c
@@ -0,0 +1,133 @@
+/*
+ * Copyright © 2019 Alexey Dobriyan <adobriyan@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.
+ */
+/*
+ * Test that setns(CLONE_NEWIPC) points to new /proc/sysvipc content even
+ * if old one is in dcache.
+ */
+#undef NDEBUG
+#include <assert.h>
+#include <errno.h>
+#include <stdio.h>
+#include <sched.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <sys/ipc.h>
+#include <sys/shm.h>
+
+static pid_t pid = -1;
+
+static void f(void)
+{
+ if (pid > 0) {
+ kill(pid, SIGTERM);
+ }
+}
+
+int main(void)
+{
+ int fd[2];
+ char _ = 0;
+ int nsfd;
+
+ atexit(f);
+
+ /* Check for priviledges and syscall availability straight away. */
+ if (unshare(CLONE_NEWIPC) == -1) {
+ if (errno == ENOSYS || errno == EPERM) {
+ return 4;
+ }
+ return 1;
+ }
+ /* Distinguisher between two otherwise empty IPC namespaces. */
+ if (shmget(IPC_PRIVATE, 1, IPC_CREAT) == -1) {
+ return 1;
+ }
+
+ if (pipe(fd) == -1) {
+ return 1;
+ }
+
+ pid = fork();
+ if (pid == -1) {
+ return 1;
+ }
+
+ if (pid == 0) {
+ if (unshare(CLONE_NEWIPC) == -1) {
+ return 1;
+ }
+
+ if (write(fd[1], &_, 1) != 1) {
+ return 1;
+ }
+
+ pause();
+
+ return 0;
+ }
+
+ if (read(fd[0], &_, 1) != 1) {
+ return 1;
+ }
+
+ {
+ char buf[64];
+ snprintf(buf, sizeof(buf), "/proc/%u/ns/ipc", pid);
+ nsfd = open(buf, O_RDONLY);
+ if (nsfd == -1) {
+ return 1;
+ }
+ }
+
+ /* Reliably pin dentry into dcache. */
+ (void)open("/proc/sysvipc/shm", O_RDONLY);
+
+ if (setns(nsfd, CLONE_NEWIPC) == -1) {
+ return 1;
+ }
+
+ kill(pid, SIGTERM);
+ pid = 0;
+
+ {
+ char buf[4096];
+ ssize_t rv;
+ int fd;
+
+ fd = open("/proc/sysvipc/shm", O_RDONLY);
+ if (fd == -1) {
+ return 1;
+ }
+
+#define S32 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n"
+#define S64 " key shmid perms size cpid lpid nattch uid gid cuid cgid atime dtime ctime rss swap\n"
+ rv = read(fd, buf, sizeof(buf));
+ if (rv == strlen(S32)) {
+ assert(memcmp(buf, S32, strlen(S32)) == 0);
+ } else if (rv == strlen(S64)) {
+ assert(memcmp(buf, S64, strlen(S64)) == 0);
+ } else {
+ assert(0);
+ }
+ }
+
+ return 0;
+}
diff --git a/tools/testing/selftests/proc/thread-self.c b/tools/testing/selftests/proc/thread-self.c
new file mode 100644
index 000000000..4b23b39b7
--- /dev/null
+++ b/tools/testing/selftests/proc/thread-self.c
@@ -0,0 +1,64 @@
+/*
+ * Copyright © 2018 Alexey Dobriyan <adobriyan@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.
+ */
+// Test that /proc/thread-self gives correct TGID/PID.
+#undef NDEBUG
+#include <assert.h>
+#include <sched.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/wait.h>
+
+#include "proc.h"
+
+int f(void *arg)
+{
+ char buf1[64], buf2[64];
+ pid_t pid, tid;
+ ssize_t rv;
+
+ pid = sys_getpid();
+ tid = sys_gettid();
+ snprintf(buf1, sizeof(buf1), "%u/task/%u", pid, tid);
+
+ rv = readlink("/proc/thread-self", buf2, sizeof(buf2));
+ assert(rv == strlen(buf1));
+ buf2[rv] = '\0';
+ assert(streq(buf1, buf2));
+
+ if (arg)
+ exit(0);
+ return 0;
+}
+
+int main(void)
+{
+ const int PAGE_SIZE = sysconf(_SC_PAGESIZE);
+ pid_t pid;
+ void *stack;
+
+ /* main thread */
+ f((void *)0);
+
+ stack = mmap(NULL, 2 * PAGE_SIZE, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+ assert(stack != MAP_FAILED);
+ /* side thread */
+ pid = clone(f, stack + PAGE_SIZE, CLONE_THREAD|CLONE_SIGHAND|CLONE_VM, (void *)1);
+ assert(pid > 0);
+ pause();
+
+ return 0;
+}