Merge tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:
 "As usual, lots of singleton and doubleton patches all over the tree
  and there's little I can say which isn't in the individual changelogs.

  The lengthier patch series are

   - 'kdump: use generic functions to simplify crashkernel reservation
     in arch', from Baoquan He. This is mainly cleanups and
     consolidation of the 'crashkernel=' kernel parameter handling

   - After much discussion, David Laight's 'minmax: Relax type checks in
     min() and max()' is here. Hopefully reduces some typecasting and
     the use of min_t() and max_t()

   - A group of patches from Oleg Nesterov which clean up and slightly
     fix our handling of reads from /proc/PID/task/... and which remove
     task_struct.thread_group"

* tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits)
  scripts/gdb/vmalloc: disable on no-MMU
  scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n
  .mailmap: add address mapping for Tomeu Vizoso
  mailmap: update email address for Claudiu Beznea
  tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions
  .mailmap: map Benjamin Poirier's address
  scripts/gdb: add lx_current support for riscv
  ocfs2: fix a spelling typo in comment
  proc: test ProtectionKey in proc-empty-vm test
  proc: fix proc-empty-vm test with vsyscall
  fs/proc/base.c: remove unneeded semicolon
  do_io_accounting: use sig->stats_lock
  do_io_accounting: use __for_each_thread()
  ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error()
  ocfs2: fix a typo in a comment
  scripts/show_delta: add __main__ judgement before main code
  treewide: mark stuff as __ro_after_init
  fs: ocfs2: check status values
  proc: test /proc/${pid}/statm
  compiler.h: move __is_constexpr() to compiler.h
  ...

2 files changed, 158 insertions, 25 deletions

diff --git a/tools/testing/selftests/mm/run_vmtests.sh b/tools/testing/selftests/mm/run_vmtests.sh
index bf4c4cd46600..cc16f6ca8533 100755
--- a/tools/testing/selftests/mm/run_vmtests.sh
+++ b/tools/testing/selftests/mm/run_vmtests.sh
@@ -309,6 +309,7 @@ CATEGORY="hmm" run_test bash ./test_hmm.sh smoke
 # MADV_POPULATE_READ and MADV_POPULATE_WRITE tests
 CATEGORY="madv_populate" run_test ./madv_populate
 
+echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope
 CATEGORY="memfd_secret" run_test ./memfd_secret
 
 # KSM KSM_MERGE_TIME_HUGE_PAGES test with size of 100
diff --git a/tools/testing/selftests/proc/proc-empty-vm.c b/tools/testing/selftests/proc/proc-empty-vm.c
index ee71ce52cb6a..56198d4ca2bf 100644
--- a/tools/testing/selftests/proc/proc-empty-vm.c
+++ b/tools/testing/selftests/proc/proc-empty-vm.c
@@ -23,6 +23,9 @@
  *	/proc/${pid}/smaps
  *	/proc/${pid}/smaps_rollup
  */
+#undef _GNU_SOURCE
+#define _GNU_SOURCE
+
 #undef NDEBUG
 #include <assert.h>
 #include <errno.h>
@@ -34,6 +37,7 @@
 #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>
@@ -42,6 +46,43 @@
 #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
@@ -60,7 +101,7 @@ static const char proc_pid_maps_vsyscall_2[] =
 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"
+"ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0                  [vsyscall]\n"
 "Size:                  4 kB\n"
 "KernelPageSize:        4 kB\n"
 "MMUPageSize:           4 kB\n"
@@ -73,6 +114,7 @@ static const char proc_pid_smaps_vsyscall_1[] =
 "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"
@@ -83,14 +125,10 @@ static const char proc_pid_smaps_vsyscall_1[] =
 "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"
+"ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0                  [vsyscall]\n"
 "Size:                  4 kB\n"
 "KernelPageSize:        4 kB\n"
 "MMUPageSize:           4 kB\n"
@@ -103,6 +141,7 @@ static const char proc_pid_smaps_vsyscall_2[] =
 "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"
@@ -113,10 +152,6 @@ static const char proc_pid_smaps_vsyscall_2[] =
 "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 *___)
@@ -238,19 +273,27 @@ static int test_proc_pid_smaps(pid_t pid)
 		}
 		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 {
-		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);
+		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;
 	}
+
+	return EXIT_SUCCESS;
 }
 
 static const char g_smaps_rollup[] =
@@ -303,6 +346,95 @@ static int test_proc_pid_smaps_rollup(pid_t pid)
 	}
 }
 
+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));
+	if (0) {
+		write(1, buf, rv);
+	}
+
+	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;
@@ -328,6 +460,8 @@ int main(void)
 		abort();
 	}
 
+	g_protection_key_support = protection_key_support();
+
 	pid_t pid = fork();
 	if (pid == -1) {
 		perror("fork");
@@ -389,11 +523,9 @@ int main(void)
 		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.
-		 */
+		if (rv == EXIT_SUCCESS) {
+			rv = test_proc_pid_statm(pid);
+		}
 
 		/* Cut the rope. */
 		int wstatus;