Merge tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - hfs and hfsplus kmap API modernization (Fabio Francesco)

 - make crash-kexec work properly when invoked from an NMI-time panic
   (Valentin Schneider)

 - ntfs bugfixes (Hawkins Jiawei)

 - improve IPC msg scalability by replacing atomic_t's with percpu
   counters (Jiebin Sun)

 - nilfs2 cleanups (Minghao Chi)

 - lots of other single patches all over the tree!

* tag 'mm-nonmm-stable-2022-10-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (71 commits)
  include/linux/entry-common.h: remove has_signal comment of arch_do_signal_or_restart() prototype
  proc: test how it holds up with mapping'less process
  mailmap: update Frank Rowand email address
  ia64: mca: use strscpy() is more robust and safer
  init/Kconfig: fix unmet direct dependencies
  ia64: update config files
  nilfs2: replace WARN_ONs by nilfs_error for checkpoint acquisition failure
  fork: remove duplicate included header files
  init/main.c: remove unnecessary (void*) conversions
  proc: mark more files as permanent
  nilfs2: remove the unneeded result variable
  nilfs2: delete unnecessary checks before brelse()
  checkpatch: warn for non-standard fixes tag style
  usr/gen_init_cpio.c: remove unnecessary -1 values from int file
  ipc/msg: mitigate the lock contention with percpu counter
  percpu: add percpu_counter_add_local and percpu_counter_sub_local
  fs/ocfs2: fix repeated words in comments
  relay: use kvcalloc to alloc page array in relay_alloc_page_array
  proc: make config PROC_CHILDREN depend on PROC_FS
  fs: uninline inode_maybe_inc_iversion()
  ...

4 files changed, 404 insertions, 40 deletions

diff --git a/tools/testing/selftests/proc/.gitignore b/tools/testing/selftests/proc/.gitignore
index c4e6a34f9657..a156ac5dd2c6 100644
--- a/tools/testing/selftests/proc/.gitignore
+++ b/tools/testing/selftests/proc/.gitignore
@@ -5,6 +5,7 @@
 /proc-fsconfig-hidepid
 /proc-loadavg-001
 /proc-multiple-procfs
+/proc-empty-vm
 /proc-pid-vm
 /proc-self-map-files-001
 /proc-self-map-files-002
diff --git a/tools/testing/selftests/proc/Makefile b/tools/testing/selftests/proc/Makefile
index 219fc6113847..cd95369254c0 100644
--- a/tools/testing/selftests/proc/Makefile
+++ b/tools/testing/selftests/proc/Makefile
@@ -8,6 +8,7 @@ TEST_GEN_PROGS += fd-001-lookup
 TEST_GEN_PROGS += fd-002-posix-eq
 TEST_GEN_PROGS += fd-003-kthread
 TEST_GEN_PROGS += proc-loadavg-001
+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
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 000000000000..d95b1cb43d9d
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-empty-vm.c
@@ -0,0 +1,386 @@
+/*
+ * 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 NDEBUG
+#include <assert.h>
+#include <errno.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/types.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+/*
+ * 0: vsyscall VMA doesn't exist	vsyscall=none
+ * 1: vsyscall VMA is --xp		vsyscall=xonly
+ * 2: vsyscall VMA is r-xp		vsyscall=emulate
+ */
+static 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 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"
+"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"
+/*
+ * "ProtectionKey:" field is conditional. It is possible to check it as well,
+ * but I don't have such machine.
+ */
+;
+
+static const char proc_pid_smaps_vsyscall_2[] =
+"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"
+"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"
+/*
+ * "ProtectionKey:" field is conditional. It is possible to check it as well,
+ * but I'm too tired.
+ */
+;
+
+static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___)
+{
+	_exit(EXIT_FAILURE);
+}
+
+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); */
+		asm volatile (
+			"call %P0"
+			:
+			: "i" (0xffffffffff600000), "D" (NULL), "S" (NULL)
+			: "rax", "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);
+	}
+}
+
+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/${pid}/smaps");
+		return EXIT_FAILURE;
+	} else {
+		ssize_t rv = read(fd, buf, sizeof(buf));
+		close(fd);
+		if (g_vsyscall == 0) {
+			assert(rv == 0);
+		} else {
+			size_t len = strlen(g_proc_pid_maps_vsyscall);
+			/* TODO "ProtectionKey:" */
+			assert(rv > len);
+			assert(memcmp(buf, g_proc_pid_maps_vsyscall, len) == 0);
+		}
+		return EXIT_SUCCESS;
+	}
+}
+
+static const char g_smaps_rollup[] =
+"00000000-00000000 ---p 00000000 00:00 0                                  [rollup]\n"
+"Rss:                   0 kB\n"
+"Pss:                   0 kB\n"
+"Pss_Dirty:             0 kB\n"
+"Pss_Anon:              0 kB\n"
+"Pss_File:              0 kB\n"
+"Pss_Shmem:             0 kB\n"
+"Shared_Clean:          0 kB\n"
+"Shared_Dirty:          0 kB\n"
+"Private_Clean:         0 kB\n"
+"Private_Dirty:         0 kB\n"
+"Referenced:            0 kB\n"
+"Anonymous:             0 kB\n"
+"LazyFree:              0 kB\n"
+"AnonHugePages:         0 kB\n"
+"ShmemPmdMapped:        0 kB\n"
+"FilePmdMapped:         0 kB\n"
+"Shared_Hugetlb:        0 kB\n"
+"Private_Hugetlb:       0 kB\n"
+"Swap:                  0 kB\n"
+"SwapPss:               0 kB\n"
+"Locked:                0 kB\n"
+;
+
+static int test_proc_pid_smaps_rollup(pid_t pid)
+{
+	char buf[4096];
+	snprintf(buf, sizeof(buf), "/proc/%u/smaps_rollup", pid);
+	int fd = open(buf, O_RDONLY);
+	if (fd == -1) {
+		if (errno == ENOENT) {
+			/*
+			 * /proc/${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;
+	}
+}
+
+int main(void)
+{
+	int rv = EXIT_SUCCESS;
+
+	vsyscall();
+
+	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();
+	}
+
+	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);
+#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);
+		}
+		/*
+		 * TODO test /proc/${pid}/statm, task_statm()
+		 * ->start_code, ->end_code aren't updated by munmap().
+		 * Output can be "0 0 0 2 0 0 0\n" where "2" can be anything.
+		 */
+
+		/* Cut the rope. */
+		int wstatus;
+		waitpid(pid, &wstatus, 0);
+		assert(WIFSTOPPED(wstatus));
+		assert(WSTOPSIG(wstatus) == SIGSEGV);
+	}
+
+	return rv;
+}
diff --git a/tools/testing/selftests/proc/proc-pid-vm.c b/tools/testing/selftests/proc/proc-pid-vm.c
index e5962f4794f5..69551bfa215c 100644
--- a/tools/testing/selftests/proc/proc-pid-vm.c
+++ b/tools/testing/selftests/proc/proc-pid-vm.c
@@ -213,22 +213,22 @@ static int make_exe(const uint8_t *payload, size_t len)
 
 /*
  * 0: vsyscall VMA doesn't exist	vsyscall=none
- * 1: vsyscall VMA is r-xp		vsyscall=emulate
- * 2: vsyscall VMA is --xp		vsyscall=xonly
+ * 1: vsyscall VMA is --xp		vsyscall=xonly
+ * 2: vsyscall VMA is r-xp		vsyscall=emulate
  */
-static int g_vsyscall;
+static volatile int g_vsyscall;
 static const char *str_vsyscall;
 
 static const char str_vsyscall_0[] = "";
 static const char str_vsyscall_1[] =
-"ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]\n";
-static const char str_vsyscall_2[] =
 "ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0                  [vsyscall]\n";
+static const char str_vsyscall_2[] =
+"ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]\n";
 
 #ifdef __x86_64__
 static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___)
 {
-	_exit(1);
+	_exit(g_vsyscall);
 }
 
 /*
@@ -255,6 +255,7 @@ static void vsyscall(void)
 		act.sa_sigaction = sigaction_SIGSEGV;
 		(void)sigaction(SIGSEGV, &act, NULL);
 
+		g_vsyscall = 0;
 		/* gettimeofday(NULL, NULL); */
 		asm volatile (
 			"call %P0"
@@ -262,45 +263,20 @@ static void vsyscall(void)
 			: "i" (0xffffffffff600000), "D" (NULL), "S" (NULL)
 			: "rax", "rcx", "r11"
 		);
-		exit(0);
-	}
-	waitpid(pid, &wstatus, 0);
-	if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) == 0) {
-		/* vsyscall page exists and is executable. */
-	} else {
-		/* vsyscall page doesn't exist. */
-		g_vsyscall = 0;
-		return;
-	}
-
-	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 = 1;
 		*(volatile int *)0xffffffffff600000UL;
-		exit(0);
+
+		g_vsyscall = 2;
+		exit(g_vsyscall);
 	}
 	waitpid(pid, &wstatus, 0);
-	if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) == 0) {
-		/* vsyscall page is readable and executable. */
-		g_vsyscall = 1;
-		return;
+	if (WIFEXITED(wstatus)) {
+		g_vsyscall = WEXITSTATUS(wstatus);
+	} else {
+		fprintf(stderr, "error: wstatus %08x\n", wstatus);
+		exit(1);
 	}
-
-	/* vsyscall page is executable but unreadable. */
-	g_vsyscall = 2;
 }
 
 int main(void)