Merge branch 'akpm' (patches from Andrew)

Merge misc updates from Andrew Morton:

 - a few misc things

 - ocfs2 updates

 - most of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (159 commits)
  tools/testing/selftests/proc/proc-self-syscall.c: remove duplicate include
  proc: more robust bulk read test
  proc: test /proc/*/maps, smaps, smaps_rollup, statm
  proc: use seq_puts() everywhere
  proc: read kernel cpu stat pointer once
  proc: remove unused argument in proc_pid_lookup()
  fs/proc/thread_self.c: code cleanup for proc_setup_thread_self()
  fs/proc/self.c: code cleanup for proc_setup_self()
  proc: return exit code 4 for skipped tests
  mm,mremap: bail out earlier in mremap_to under map pressure
  mm/sparse: fix a bad comparison
  mm/memory.c: do_fault: avoid usage of stale vm_area_struct
  writeback: fix inode cgroup switching comment
  mm/huge_memory.c: fix "orig_pud" set but not used
  mm/hotplug: fix an imbalance with DEBUG_PAGEALLOC
  mm/memcontrol.c: fix bad line in comment
  mm/cma.c: cma_declare_contiguous: correct err handling
  mm/page_ext.c: fix an imbalance with kmemleak
  mm/compaction: pass pgdat to too_many_isolated() instead of zone
  mm: remove zone_lru_lock() function, access ->lru_lock directly
  ...

8 files changed, 426 insertions, 5 deletions

diff --git a/tools/testing/selftests/proc/.gitignore b/tools/testing/selftests/proc/.gitignore
index 29bac5ef9a93..444ad39d3700 100644
--- a/tools/testing/selftests/proc/.gitignore
+++ b/tools/testing/selftests/proc/.gitignore
@@ -2,6 +2,7 @@
 /fd-002-posix-eq
 /fd-003-kthread
 /proc-loadavg-001
+/proc-pid-vm
 /proc-self-map-files-001
 /proc-self-map-files-002
 /proc-self-syscall
diff --git a/tools/testing/selftests/proc/Makefile b/tools/testing/selftests/proc/Makefile
index 434d033ee067..5163dc887aa3 100644
--- a/tools/testing/selftests/proc/Makefile
+++ b/tools/testing/selftests/proc/Makefile
@@ -6,6 +6,7 @@ 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-pid-vm
 TEST_GEN_PROGS += proc-self-map-files-001
 TEST_GEN_PROGS += proc-self-map-files-002
 TEST_GEN_PROGS += proc-self-syscall
diff --git a/tools/testing/selftests/proc/proc-loadavg-001.c b/tools/testing/selftests/proc/proc-loadavg-001.c
index fcff7047000d..471e2aa28077 100644
--- a/tools/testing/selftests/proc/proc-loadavg-001.c
+++ b/tools/testing/selftests/proc/proc-loadavg-001.c
@@ -30,7 +30,7 @@ int main(void)
 
 	if (unshare(CLONE_NEWPID) == -1) {
 		if (errno == ENOSYS || errno == EPERM)
-			return 2;
+			return 4;
 		return 1;
 	}
 
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 000000000000..bbe8150d18aa
--- /dev/null
+++ b/tools/testing/selftests/proc/proc-pid-vm.c
@@ -0,0 +1,406 @@
+/*
+ * 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 <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <sys/mount.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/uio.h>
+#include <linux/kdev_t.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) + sizeof(payload);
+	ph.p_memsz = sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr) + sizeof(payload);
+	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
+
+#ifdef __x86_64__
+int main(void)
+{
+	int pipefd[2];
+	int exec_fd;
+
+	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 */
+	{
+		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 == strlen(buf0));
+		assert(memcmp(buf, buf0, strlen(buf0)) == 0);
+	}
+
+	/* Test /proc/$PID/smaps */
+	{
+		char buf[1024];
+		ssize_t rv;
+		int fd;
+
+		snprintf(buf, sizeof(buf), "/proc/%u/smaps", pid);
+		fd = open(buf, O_RDONLY);
+		if (fd == -1) {
+			return 1;
+		}
+		rv = read(fd, buf, sizeof(buf));
+		assert(0 <= rv && rv <= sizeof(buf));
+
+		assert(rv >= strlen(buf0));
+		assert(memcmp(buf, buf0, strlen(buf0)) == 0);
+
+#define RSS1 "Rss:                   4 kB\n"
+#define RSS2 "Rss:                   0 kB\n"
+#define PSS1 "Pss:                   4 kB\n"
+#define PSS2 "Pss:                   0 kB\n"
+		assert(memmem(buf, rv, RSS1, strlen(RSS1)) ||
+		       memmem(buf, rv, RSS2, strlen(RSS2)));
+		assert(memmem(buf, rv, PSS1, strlen(PSS1)) ||
+		       memmem(buf, rv, PSS2, strlen(PSS2)));
+
+		static const char *S[] = {
+			"Size:                  4 kB\n",
+			"KernelPageSize:        4 kB\n",
+			"MMUPageSize:           4 kB\n",
+			"Anonymous:             0 kB\n",
+			"AnonHugePages:         0 kB\n",
+			"Shared_Hugetlb:        0 kB\n",
+			"Private_Hugetlb:       0 kB\n",
+			"Locked:                0 kB\n",
+		};
+		int i;
+
+		for (i = 0; i < sizeof(S)/sizeof(S[0]); i++) {
+			assert(memmem(buf, rv, S[i], strlen(S[i])));
+		}
+	}
+
+	/* Test /proc/$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 < sizeof(S)/sizeof(S[0]); 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');
+	}
+
+	return 0;
+}
+#else
+int main(void)
+{
+	return 4;
+}
+#endif
diff --git a/tools/testing/selftests/proc/proc-self-map-files-002.c b/tools/testing/selftests/proc/proc-self-map-files-002.c
index 85744425b08d..762cb01f2ca7 100644
--- a/tools/testing/selftests/proc/proc-self-map-files-002.c
+++ b/tools/testing/selftests/proc/proc-self-map-files-002.c
@@ -63,7 +63,7 @@ int main(void)
 	p = mmap((void *)va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
 	if (p == MAP_FAILED) {
 		if (errno == EPERM)
-			return 2;
+			return 4;
 		return 1;
 	}
 
diff --git a/tools/testing/selftests/proc/proc-self-syscall.c b/tools/testing/selftests/proc/proc-self-syscall.c
index 5ab5f4810e43..9f6d000c0245 100644
--- a/tools/testing/selftests/proc/proc-self-syscall.c
+++ b/tools/testing/selftests/proc/proc-self-syscall.c
@@ -20,7 +20,6 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <errno.h>
-#include <unistd.h>
 #include <string.h>
 #include <stdio.h>
 
@@ -39,7 +38,7 @@ int main(void)
 	fd = open("/proc/self/syscall", O_RDONLY);
 	if (fd == -1) {
 		if (errno == ENOENT)
-			return 2;
+			return 4;
 		return 1;
 	}
 
diff --git a/tools/testing/selftests/proc/proc-self-wchan.c b/tools/testing/selftests/proc/proc-self-wchan.c
index a38b2fbaa7ad..b467b98a457d 100644
--- a/tools/testing/selftests/proc/proc-self-wchan.c
+++ b/tools/testing/selftests/proc/proc-self-wchan.c
@@ -27,7 +27,7 @@ int main(void)
 	fd = open("/proc/self/wchan", O_RDONLY);
 	if (fd == -1) {
 		if (errno == ENOENT)
-			return 2;
+			return 4;
 		return 1;
 	}
 
diff --git a/tools/testing/selftests/proc/read.c b/tools/testing/selftests/proc/read.c
index 563e752e6eba..b3ef9e14d6cc 100644
--- a/tools/testing/selftests/proc/read.c
+++ b/tools/testing/selftests/proc/read.c
@@ -26,8 +26,10 @@
 #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>
 
@@ -123,10 +125,22 @@ static void f(DIR *d, unsigned int level)
 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;
 }