Merge branch 'akpm' (patches from Andrew)

Merge second patchbomb from Andrew Morton:

 - most of the rest of MM

 - lots of misc things

 - procfs updates

 - printk feature work

 - updates to get_maintainer, MAINTAINERS, checkpatch

 - lib/ updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (96 commits)
  exit,stats: /* obey this comment */
  coredump: add __printf attribute to cn_*printf functions
  coredump: use from_kuid/kgid when formatting corename
  fs/reiserfs: remove unneeded cast
  NILFS2: support NFSv2 export
  fs/befs/btree.c: remove unneeded initializations
  fs/minix: remove unneeded cast
  init/do_mounts.c: add create_dev() failure log
  kasan: remove duplicate definition of the macro KASAN_FREE_PAGE
  fs/efs: femove unneeded cast
  checkpatch: emit "NOTE: <types>" message only once after multiple files
  checkpatch: emit an error when there's a diff in a changelog
  checkpatch: validate MODULE_LICENSE content
  checkpatch: add multi-line handling for PREFER_ETHER_ADDR_COPY
  checkpatch: suggest using eth_zero_addr() and eth_broadcast_addr()
  checkpatch: fix processing of MEMSET issues
  checkpatch: suggest using ether_addr_equal*()
  checkpatch: avoid NOT_UNIFIED_DIFF errors on cover-letter.patch files
  checkpatch: remove local from codespell path
  checkpatch: add --showfile to allow input via pipe to show filenames
  ...

11 files changed, 227 insertions, 39 deletions

diff --git a/fs/befs/btree.c b/fs/befs/btree.c
index 0826e91..22c16628 100644
--- a/fs/befs/btree.c
+++ b/fs/befs/btree.c
@@ -137,8 +137,8 @@ static int
 befs_bt_read_super(struct super_block *sb, befs_data_stream * ds,
 		   befs_btree_super * sup)
 {
-	struct buffer_head *bh = NULL;
-	befs_disk_btree_super *od_sup = NULL;
+	struct buffer_head *bh;
+	befs_disk_btree_super *od_sup;
 
 	befs_debug(sb, "---> %s", __func__);
 
@@ -250,7 +250,7 @@ int
 befs_btree_find(struct super_block *sb, befs_data_stream * ds,
 		const char *key, befs_off_t * value)
 {
-	struct befs_btree_node *this_node = NULL;
+	struct befs_btree_node *this_node;
 	befs_btree_super bt_super;
 	befs_off_t node_off;
 	int res;
diff --git a/fs/coredump.c b/fs/coredump.c
index bbbe139..e52e006 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -70,7 +70,8 @@ static int expand_corename(struct core_name *cn, int size)
 	return 0;
 }
 
-static int cn_vprintf(struct core_name *cn, const char *fmt, va_list arg)
+static __printf(2, 0) int cn_vprintf(struct core_name *cn, const char *fmt,
+				     va_list arg)
 {
 	int free, need;
 	va_list arg_copy;
@@ -93,7 +94,7 @@ again:
 	return -ENOMEM;
 }
 
-static int cn_printf(struct core_name *cn, const char *fmt, ...)
+static __printf(2, 3) int cn_printf(struct core_name *cn, const char *fmt, ...)
 {
 	va_list arg;
 	int ret;
@@ -105,7 +106,8 @@ static int cn_printf(struct core_name *cn, const char *fmt, ...)
 	return ret;
 }
 
-static int cn_esc_printf(struct core_name *cn, const char *fmt, ...)
+static __printf(2, 3)
+int cn_esc_printf(struct core_name *cn, const char *fmt, ...)
 {
 	int cur = cn->used;
 	va_list arg;
@@ -209,11 +211,15 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm)
 				break;
 			/* uid */
 			case 'u':
-				err = cn_printf(cn, "%d", cred->uid);
+				err = cn_printf(cn, "%u",
+						from_kuid(&init_user_ns,
+							  cred->uid));
 				break;
 			/* gid */
 			case 'g':
-				err = cn_printf(cn, "%d", cred->gid);
+				err = cn_printf(cn, "%u",
+						from_kgid(&init_user_ns,
+							  cred->gid));
 				break;
 			case 'd':
 				err = cn_printf(cn, "%d",
@@ -221,7 +227,8 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm)
 				break;
 			/* signal that caused the coredump */
 			case 's':
-				err = cn_printf(cn, "%ld", cprm->siginfo->si_signo);
+				err = cn_printf(cn, "%d",
+						cprm->siginfo->si_signo);
 				break;
 			/* UNIX time of coredump */
 			case 't': {
diff --git a/fs/efs/super.c b/fs/efs/super.c
index 7fca462..c8411a3 100644
--- a/fs/efs/super.c
+++ b/fs/efs/super.c
@@ -67,7 +67,7 @@ static struct kmem_cache * efs_inode_cachep;
 static struct inode *efs_alloc_inode(struct super_block *sb)
 {
 	struct efs_inode_info *ei;
-	ei = (struct efs_inode_info *)kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL);
+	ei = kmem_cache_alloc(efs_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	return &ei->vfs_inode;
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a7b4b6e..5c78764 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -3446,7 +3446,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 	unsigned long journal_devnum = 0;
 	unsigned long def_mount_opts;
 	struct inode *root;
-	char *cp;
 	const char *descr;
 	int ret = -ENOMEM;
 	int blocksize, clustersize;
@@ -3477,8 +3476,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 			part_stat_read(sb->s_bdev->bd_part, sectors[1]);
 
 	/* Cleanup superblock name */
-	for (cp = sb->s_id; (cp = strchr(cp, '/'));)
-		*cp = '!';
+	strreplace(sb->s_id, '/', '!');
 
 	/* -EINVAL is default */
 	ret = -EINVAL;
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index 179d7d8..4ff3fad 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1135,7 +1135,6 @@ journal_t * jbd2_journal_init_dev(struct block_device *bdev,
 {
 	journal_t *journal = journal_init_common();
 	struct buffer_head *bh;
-	char *p;
 	int n;
 
 	if (!journal)
@@ -1148,9 +1147,7 @@ journal_t * jbd2_journal_init_dev(struct block_device *bdev,
 	journal->j_blk_offset = start;
 	journal->j_maxlen = len;
 	bdevname(journal->j_dev, journal->j_devname);
-	p = journal->j_devname;
-	while ((p = strchr(p, '/')))
-		*p = '!';
+	strreplace(journal->j_devname, '/', '!');
 	jbd2_stats_proc_init(journal);
 	n = journal->j_blocksize / sizeof(journal_block_tag_t);
 	journal->j_wbufsize = n;
@@ -1202,10 +1199,7 @@ journal_t * jbd2_journal_init_inode (struct inode *inode)
 	journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
 	journal->j_inode = inode;
 	bdevname(journal->j_dev, journal->j_devname);
-	p = journal->j_devname;
-	while ((p = strchr(p, '/')))
-		*p = '!';
-	p = journal->j_devname + strlen(journal->j_devname);
+	p = strreplace(journal->j_devname, '/', '!');
 	sprintf(p, "-%lu", journal->j_inode->i_ino);
 	jbd_debug(1,
 		  "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
diff --git a/fs/minix/inode.c b/fs/minix/inode.c
index 1182d1e..086cd0a 100644
--- a/fs/minix/inode.c
+++ b/fs/minix/inode.c
@@ -62,7 +62,7 @@ static struct kmem_cache * minix_inode_cachep;
 static struct inode *minix_alloc_inode(struct super_block *sb)
 {
 	struct minix_inode_info *ei;
-	ei = (struct minix_inode_info *)kmem_cache_alloc(minix_inode_cachep, GFP_KERNEL);
+	ei = kmem_cache_alloc(minix_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	return &ei->vfs_inode;
diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c
index 2218083..37dd6b0 100644
--- a/fs/nilfs2/namei.c
+++ b/fs/nilfs2/namei.c
@@ -496,8 +496,7 @@ static struct dentry *nilfs_fh_to_dentry(struct super_block *sb, struct fid *fh,
 {
 	struct nilfs_fid *fid = (struct nilfs_fid *)fh;
 
-	if ((fh_len != NILFS_FID_SIZE_NON_CONNECTABLE &&
-	     fh_len != NILFS_FID_SIZE_CONNECTABLE) ||
+	if (fh_len < NILFS_FID_SIZE_NON_CONNECTABLE ||
 	    (fh_type != FILEID_NILFS_WITH_PARENT &&
 	     fh_type != FILEID_NILFS_WITHOUT_PARENT))
 		return NULL;
@@ -510,7 +509,7 @@ static struct dentry *nilfs_fh_to_parent(struct super_block *sb, struct fid *fh,
 {
 	struct nilfs_fid *fid = (struct nilfs_fid *)fh;
 
-	if (fh_len != NILFS_FID_SIZE_CONNECTABLE ||
+	if (fh_len < NILFS_FID_SIZE_CONNECTABLE ||
 	    fh_type != FILEID_NILFS_WITH_PARENT)
 		return NULL;
 
diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig
index 2183fcf..d751fcb 100644
--- a/fs/proc/Kconfig
+++ b/fs/proc/Kconfig
@@ -71,3 +71,7 @@ config PROC_PAGE_MONITOR
 	  /proc/pid/smaps, /proc/pid/clear_refs, /proc/pid/pagemap,
 	  /proc/kpagecount, and /proc/kpageflags. Disabling these
           interfaces will reduce the size of the kernel by approximately 4kb.
+
+config PROC_CHILDREN
+	bool "Include /proc/<pid>/task/<tid>/children file"
+	default n
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 3f57dac..ce065cf 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -577,7 +577,7 @@ int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
 	return 0;
 }
 
-#ifdef CONFIG_CHECKPOINT_RESTORE
+#ifdef CONFIG_PROC_CHILDREN
 static struct pid *
 get_children_pid(struct inode *inode, struct pid *pid_prev, loff_t pos)
 {
@@ -700,4 +700,4 @@ const struct file_operations proc_tid_children_operations = {
 	.llseek  = seq_lseek,
 	.release = children_seq_release,
 };
-#endif /* CONFIG_CHECKPOINT_RESTORE */
+#endif /* CONFIG_PROC_CHILDREN */
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 286a422..1d540b3 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -196,18 +196,205 @@ static int proc_root_link(struct dentry *dentry, struct path *path)
 	return result;
 }
 
-static int proc_pid_cmdline(struct seq_file *m, struct pid_namespace *ns,
-			    struct pid *pid, struct task_struct *task)
+static ssize_t proc_pid_cmdline_read(struct file *file, char __user *buf,
+				     size_t _count, loff_t *pos)
 {
+	struct task_struct *tsk;
+	struct mm_struct *mm;
+	char *page;
+	unsigned long count = _count;
+	unsigned long arg_start, arg_end, env_start, env_end;
+	unsigned long len1, len2, len;
+	unsigned long p;
+	char c;
+	ssize_t rv;
+
+	BUG_ON(*pos < 0);
+
+	tsk = get_proc_task(file_inode(file));
+	if (!tsk)
+		return -ESRCH;
+	mm = get_task_mm(tsk);
+	put_task_struct(tsk);
+	if (!mm)
+		return 0;
+	/* Check if process spawned far enough to have cmdline. */
+	if (!mm->env_end) {
+		rv = 0;
+		goto out_mmput;
+	}
+
+	page = (char *)__get_free_page(GFP_TEMPORARY);
+	if (!page) {
+		rv = -ENOMEM;
+		goto out_mmput;
+	}
+
+	down_read(&mm->mmap_sem);
+	arg_start = mm->arg_start;
+	arg_end = mm->arg_end;
+	env_start = mm->env_start;
+	env_end = mm->env_end;
+	up_read(&mm->mmap_sem);
+
+	BUG_ON(arg_start > arg_end);
+	BUG_ON(env_start > env_end);
+
+	len1 = arg_end - arg_start;
+	len2 = env_end - env_start;
+
 	/*
-	 * Rely on struct seq_operations::show() being called once
-	 * per internal buffer allocation. See single_open(), traverse().
+	 * Inherently racy -- command line shares address space
+	 * with code and data.
 	 */
-	BUG_ON(m->size < PAGE_SIZE);
-	m->count += get_cmdline(task, m->buf, PAGE_SIZE);
-	return 0;
+	rv = access_remote_vm(mm, arg_end - 1, &c, 1, 0);
+	if (rv <= 0)
+		goto out_free_page;
+
+	rv = 0;
+
+	if (c == '\0') {
+		/* Command line (set of strings) occupies whole ARGV. */
+		if (len1 <= *pos)
+			goto out_free_page;
+
+		p = arg_start + *pos;
+		len = len1 - *pos;
+		while (count > 0 && len > 0) {
+			unsigned int _count;
+			int nr_read;
+
+			_count = min3(count, len, PAGE_SIZE);
+			nr_read = access_remote_vm(mm, p, page, _count, 0);
+			if (nr_read < 0)
+				rv = nr_read;
+			if (nr_read <= 0)
+				goto out_free_page;
+
+			if (copy_to_user(buf, page, nr_read)) {
+				rv = -EFAULT;
+				goto out_free_page;
+			}
+
+			p	+= nr_read;
+			len	-= nr_read;
+			buf	+= nr_read;
+			count	-= nr_read;
+			rv	+= nr_read;
+		}
+	} else {
+		/*
+		 * Command line (1 string) occupies ARGV and maybe
+		 * extends into ENVP.
+		 */
+		if (len1 + len2 <= *pos)
+			goto skip_argv_envp;
+		if (len1 <= *pos)
+			goto skip_argv;
+
+		p = arg_start + *pos;
+		len = len1 - *pos;
+		while (count > 0 && len > 0) {
+			unsigned int _count, l;
+			int nr_read;
+			bool final;
+
+			_count = min3(count, len, PAGE_SIZE);
+			nr_read = access_remote_vm(mm, p, page, _count, 0);
+			if (nr_read < 0)
+				rv = nr_read;
+			if (nr_read <= 0)
+				goto out_free_page;
+
+			/*
+			 * Command line can be shorter than whole ARGV
+			 * even if last "marker" byte says it is not.
+			 */
+			final = false;
+			l = strnlen(page, nr_read);
+			if (l < nr_read) {
+				nr_read = l;
+				final = true;
+			}
+
+			if (copy_to_user(buf, page, nr_read)) {
+				rv = -EFAULT;
+				goto out_free_page;
+			}
+
+			p	+= nr_read;
+			len	-= nr_read;
+			buf	+= nr_read;
+			count	-= nr_read;
+			rv	+= nr_read;
+
+			if (final)
+				goto out_free_page;
+		}
+skip_argv:
+		/*
+		 * Command line (1 string) occupies ARGV and
+		 * extends into ENVP.
+		 */
+		if (len1 <= *pos) {
+			p = env_start + *pos - len1;
+			len = len1 + len2 - *pos;
+		} else {
+			p = env_start;
+			len = len2;
+		}
+		while (count > 0 && len > 0) {
+			unsigned int _count, l;
+			int nr_read;
+			bool final;
+
+			_count = min3(count, len, PAGE_SIZE);
+			nr_read = access_remote_vm(mm, p, page, _count, 0);
+			if (nr_read < 0)
+				rv = nr_read;
+			if (nr_read <= 0)
+				goto out_free_page;
+
+			/* Find EOS. */
+			final = false;
+			l = strnlen(page, nr_read);
+			if (l < nr_read) {
+				nr_read = l;
+				final = true;
+			}
+
+			if (copy_to_user(buf, page, nr_read)) {
+				rv = -EFAULT;
+				goto out_free_page;
+			}
+
+			p	+= nr_read;
+			len	-= nr_read;
+			buf	+= nr_read;
+			count	-= nr_read;
+			rv	+= nr_read;
+
+			if (final)
+				goto out_free_page;
+		}
+skip_argv_envp:
+		;
+	}
+
+out_free_page:
+	free_page((unsigned long)page);
+out_mmput:
+	mmput(mm);
+	if (rv > 0)
+		*pos += rv;
+	return rv;
 }
 
+static const struct file_operations proc_pid_cmdline_ops = {
+	.read	= proc_pid_cmdline_read,
+	.llseek	= generic_file_llseek,
+};
+
 static int proc_pid_auxv(struct seq_file *m, struct pid_namespace *ns,
 			 struct pid *pid, struct task_struct *task)
 {
@@ -2572,7 +2759,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
 	ONE("syscall",    S_IRUSR, proc_pid_syscall),
 #endif
-	ONE("cmdline",    S_IRUGO, proc_pid_cmdline),
+	REG("cmdline",    S_IRUGO, proc_pid_cmdline_ops),
 	ONE("stat",       S_IRUGO, proc_tgid_stat),
 	ONE("statm",      S_IRUGO, proc_pid_statm),
 	REG("maps",       S_IRUGO, proc_pid_maps_operations),
@@ -2918,11 +3105,11 @@ static const struct pid_entry tid_base_stuff[] = {
 #ifdef CONFIG_HAVE_ARCH_TRACEHOOK
 	ONE("syscall",   S_IRUSR, proc_pid_syscall),
 #endif
-	ONE("cmdline",   S_IRUGO, proc_pid_cmdline),
+	REG("cmdline",   S_IRUGO, proc_pid_cmdline_ops),
 	ONE("stat",      S_IRUGO, proc_tid_stat),
 	ONE("statm",     S_IRUGO, proc_pid_statm),
 	REG("maps",      S_IRUGO, proc_tid_maps_operations),
-#ifdef CONFIG_CHECKPOINT_RESTORE
+#ifdef CONFIG_PROC_CHILDREN
 	REG("children",  S_IRUGO, proc_tid_children_operations),
 #endif
 #ifdef CONFIG_NUMA
diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index 3e0af31..0e4cf728 100644
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -589,8 +589,7 @@ static struct kmem_cache *reiserfs_inode_cachep;
 static struct inode *reiserfs_alloc_inode(struct super_block *sb)
 {
 	struct reiserfs_inode_info *ei;
-	ei = (struct reiserfs_inode_info *)
-	    kmem_cache_alloc(reiserfs_inode_cachep, GFP_KERNEL);
+	ei = kmem_cache_alloc(reiserfs_inode_cachep, GFP_KERNEL);
 	if (!ei)
 		return NULL;
 	atomic_set(&ei->openers, 0);