Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 503 insertions, 0 deletions

diff --git a/fs/hfs/super.c b/fs/hfs/super.c
new file mode 100644
index 000000000..5e6d66ff4
--- /dev/null
+++ b/fs/hfs/super.c
@@ -0,0 +1,503 @@
+/*
+ *  linux/fs/hfs/super.c
+ *
+ * Copyright (C) 1995-1997  Paul H. Hargrove
+ * (C) 2003 Ardis Technologies <roman@ardistech.com>
+ * This file may be distributed under the terms of the GNU General Public License.
+ *
+ * This file contains hfs_read_super(), some of the super_ops and
+ * init_hfs_fs() and exit_hfs_fs().  The remaining super_ops are in
+ * inode.c since they deal with inodes.
+ *
+ * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
+ */
+
+#include <linux/module.h>
+#include <linux/blkdev.h>
+#include <linux/backing-dev.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
+#include <linux/mount.h>
+#include <linux/init.h>
+#include <linux/nls.h>
+#include <linux/seq_file.h>
+#include <linux/slab.h>
+#include <linux/vfs.h>
+
+#include "hfs_fs.h"
+#include "btree.h"
+
+static struct kmem_cache *hfs_inode_cachep;
+
+MODULE_DESCRIPTION("Apple Macintosh file system support");
+MODULE_LICENSE("GPL");
+
+static int hfs_sync_fs(struct super_block *sb, int wait)
+{
+	int ret;
+
+	mutex_lock(&HFS_SB(sb)->mdb_lock);
+	is_hfs_cnid_counts_valid(sb);
+	ret = hfs_mdb_commit(sb);
+	mutex_unlock(&HFS_SB(sb)->mdb_lock);
+
+	return ret;
+}
+
+/*
+ * hfs_put_super()
+ *
+ * This is the put_super() entry in the super_operations structure for
+ * HFS filesystems.  The purpose is to release the resources
+ * associated with the superblock sb.
+ */
+static void hfs_put_super(struct super_block *sb)
+{
+	cancel_delayed_work_sync(&HFS_SB(sb)->mdb_work);
+	hfs_mdb_close(sb);
+	/* release the MDB's resources */
+	hfs_mdb_put(sb);
+}
+
+static void flush_mdb(struct work_struct *work)
+{
+	struct hfs_sb_info *sbi;
+	struct super_block *sb;
+
+	sbi = container_of(work, struct hfs_sb_info, mdb_work.work);
+	sb = sbi->sb;
+
+	spin_lock(&sbi->work_lock);
+	sbi->work_queued = 0;
+	spin_unlock(&sbi->work_lock);
+
+	mutex_lock(&sbi->mdb_lock);
+	is_hfs_cnid_counts_valid(sb);
+	hfs_mdb_commit(sb);
+	mutex_unlock(&sbi->mdb_lock);
+}
+
+void hfs_mark_mdb_dirty(struct super_block *sb)
+{
+	struct hfs_sb_info *sbi = HFS_SB(sb);
+	unsigned long delay;
+
+	if (sb_rdonly(sb))
+		return;
+
+	spin_lock(&sbi->work_lock);
+	if (!sbi->work_queued) {
+		delay = msecs_to_jiffies(dirty_writeback_interval * 10);
+		queue_delayed_work(system_dfl_long_wq, &sbi->mdb_work, delay);
+		sbi->work_queued = 1;
+	}
+	spin_unlock(&sbi->work_lock);
+}
+
+/*
+ * hfs_statfs()
+ *
+ * This is the statfs() entry in the super_operations structure for
+ * HFS filesystems.  The purpose is to return various data about the
+ * filesystem.
+ *
+ * changed f_files/f_ffree to reflect the fs_ablock/free_ablocks.
+ */
+static int hfs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+	struct super_block *sb = dentry->d_sb;
+	u64 id = huge_encode_dev(sb->s_bdev->bd_dev);
+
+	buf->f_type = HFS_SUPER_MAGIC;
+	buf->f_bsize = sb->s_blocksize;
+	buf->f_blocks = (u32)HFS_SB(sb)->fs_ablocks * HFS_SB(sb)->fs_div;
+	buf->f_bfree = (u32)HFS_SB(sb)->free_ablocks * HFS_SB(sb)->fs_div;
+	buf->f_bavail = buf->f_bfree;
+	buf->f_files = HFS_SB(sb)->fs_ablocks;
+	buf->f_ffree = HFS_SB(sb)->free_ablocks;
+	buf->f_fsid = u64_to_fsid(id);
+	buf->f_namelen = HFS_NAMELEN;
+
+	return 0;
+}
+
+static int hfs_reconfigure(struct fs_context *fc)
+{
+	struct super_block *sb = fc->root->d_sb;
+
+	sync_filesystem(sb);
+	fc->sb_flags |= SB_NODIRATIME;
+	if ((bool)(fc->sb_flags & SB_RDONLY) == sb_rdonly(sb))
+		return 0;
+
+	if (!(fc->sb_flags & SB_RDONLY)) {
+		if (!(HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_UNMNT))) {
+			pr_warn("filesystem was not cleanly unmounted, running fsck.hfs is recommended.  leaving read-only.\n");
+			sb->s_flags |= SB_RDONLY;
+			fc->sb_flags |= SB_RDONLY;
+		} else if (HFS_SB(sb)->mdb->drAtrb & cpu_to_be16(HFS_SB_ATTRIB_SLOCK)) {
+			pr_warn("filesystem is marked locked, leaving read-only.\n");
+			sb->s_flags |= SB_RDONLY;
+			fc->sb_flags |= SB_RDONLY;
+		}
+	}
+	return 0;
+}
+
+static int hfs_show_options(struct seq_file *seq, struct dentry *root)
+{
+	struct hfs_sb_info *sbi = HFS_SB(root->d_sb);
+
+	if (sbi->s_creator != cpu_to_be32(0x3f3f3f3f))
+		seq_show_option_n(seq, "creator", (char *)&sbi->s_creator, 4);
+	if (sbi->s_type != cpu_to_be32(0x3f3f3f3f))
+		seq_show_option_n(seq, "type", (char *)&sbi->s_type, 4);
+	seq_printf(seq, ",uid=%u,gid=%u",
+			from_kuid_munged(&init_user_ns, sbi->s_uid),
+			from_kgid_munged(&init_user_ns, sbi->s_gid));
+	if (sbi->s_file_umask != 0133)
+		seq_printf(seq, ",file_umask=%o", sbi->s_file_umask);
+	if (sbi->s_dir_umask != 0022)
+		seq_printf(seq, ",dir_umask=%o", sbi->s_dir_umask);
+	if (sbi->part >= 0)
+		seq_printf(seq, ",part=%u", sbi->part);
+	if (sbi->session >= 0)
+		seq_printf(seq, ",session=%u", sbi->session);
+	if (sbi->nls_disk)
+		seq_printf(seq, ",codepage=%s", sbi->nls_disk->charset);
+	if (sbi->nls_io)
+		seq_printf(seq, ",iocharset=%s", sbi->nls_io->charset);
+	if (sbi->s_quiet)
+		seq_printf(seq, ",quiet");
+	return 0;
+}
+
+static struct inode *hfs_alloc_inode(struct super_block *sb)
+{
+	struct hfs_inode_info *i;
+
+	i = alloc_inode_sb(sb, hfs_inode_cachep, GFP_KERNEL);
+	return i ? &i->vfs_inode : NULL;
+}
+
+static void hfs_free_inode(struct inode *inode)
+{
+	kmem_cache_free(hfs_inode_cachep, HFS_I(inode));
+}
+
+static const struct super_operations hfs_super_operations = {
+	.alloc_inode	= hfs_alloc_inode,
+	.free_inode	= hfs_free_inode,
+	.write_inode	= hfs_write_inode,
+	.evict_inode	= hfs_evict_inode,
+	.put_super	= hfs_put_super,
+	.sync_fs	= hfs_sync_fs,
+	.statfs		= hfs_statfs,
+	.show_options	= hfs_show_options,
+};
+
+enum {
+	opt_uid, opt_gid, opt_umask, opt_file_umask, opt_dir_umask,
+	opt_part, opt_session, opt_type, opt_creator, opt_quiet,
+	opt_codepage, opt_iocharset,
+};
+
+static const struct fs_parameter_spec hfs_param_spec[] = {
+	fsparam_u32	("uid",		opt_uid),
+	fsparam_u32	("gid",		opt_gid),
+	fsparam_u32oct	("umask",	opt_umask),
+	fsparam_u32oct	("file_umask",	opt_file_umask),
+	fsparam_u32oct	("dir_umask",	opt_dir_umask),
+	fsparam_u32	("part",	opt_part),
+	fsparam_u32	("session",	opt_session),
+	fsparam_string	("type",	opt_type),
+	fsparam_string	("creator",	opt_creator),
+	fsparam_flag	("quiet",	opt_quiet),
+	fsparam_string	("codepage",	opt_codepage),
+	fsparam_string	("iocharset",	opt_iocharset),
+	{}
+};
+
+/*
+ * hfs_parse_param()
+ *
+ * This function is called by the vfs to parse the mount options.
+ */
+static int hfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+	struct hfs_sb_info *hsb = fc->s_fs_info;
+	struct fs_parse_result result;
+	int opt;
+
+	/* hfs does not honor any fs-specific options on remount */
+	if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE)
+		return 0;
+
+	opt = fs_parse(fc, hfs_param_spec, param, &result);
+	if (opt < 0)
+		return opt;
+
+	switch (opt) {
+	case opt_uid:
+		hsb->s_uid = result.uid;
+		break;
+	case opt_gid:
+		hsb->s_gid = result.gid;
+		break;
+	case opt_umask:
+		hsb->s_file_umask = (umode_t)result.uint_32;
+		hsb->s_dir_umask = (umode_t)result.uint_32;
+		break;
+	case opt_file_umask:
+		hsb->s_file_umask = (umode_t)result.uint_32;
+		break;
+	case opt_dir_umask:
+		hsb->s_dir_umask = (umode_t)result.uint_32;
+		break;
+	case opt_part:
+		hsb->part = result.uint_32;
+		break;
+	case opt_session:
+		hsb->session = result.uint_32;
+		break;
+	case opt_type:
+		if (strlen(param->string) != 4) {
+			pr_err("type requires a 4 character value\n");
+			return -EINVAL;
+		}
+		memcpy(&hsb->s_type, param->string, 4);
+		break;
+	case opt_creator:
+		if (strlen(param->string) != 4) {
+			pr_err("creator requires a 4 character value\n");
+			return -EINVAL;
+		}
+		memcpy(&hsb->s_creator, param->string, 4);
+		break;
+	case opt_quiet:
+		hsb->s_quiet = 1;
+		break;
+	case opt_codepage:
+		if (hsb->nls_disk) {
+			pr_err("unable to change codepage\n");
+			return -EINVAL;
+		}
+		hsb->nls_disk = load_nls(param->string);
+		if (!hsb->nls_disk) {
+			pr_err("unable to load codepage \"%s\"\n",
+					param->string);
+			return -EINVAL;
+		}
+		break;
+	case opt_iocharset:
+		if (hsb->nls_io) {
+			pr_err("unable to change iocharset\n");
+			return -EINVAL;
+		}
+		hsb->nls_io = load_nls(param->string);
+		if (!hsb->nls_io) {
+			pr_err("unable to load iocharset \"%s\"\n",
+					param->string);
+			return -EINVAL;
+		}
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/*
+ * hfs_read_super()
+ *
+ * This is the function that is responsible for mounting an HFS
+ * filesystem.	It performs all the tasks necessary to get enough data
+ * from the disk to read the root inode.  This includes parsing the
+ * mount options, dealing with Macintosh partitions, reading the
+ * superblock and the allocation bitmap blocks, calling
+ * hfs_btree_init() to get the necessary data about the extents and
+ * catalog B-trees and, finally, reading the root inode into memory.
+ */
+static int hfs_fill_super(struct super_block *sb, struct fs_context *fc)
+{
+	struct hfs_sb_info *sbi = HFS_SB(sb);
+	struct hfs_find_data fd;
+	hfs_cat_rec rec;
+	struct inode *root_inode;
+	int silent = fc->sb_flags & SB_SILENT;
+	int res;
+
+	atomic64_set(&sbi->file_count, 0);
+	atomic64_set(&sbi->folder_count, 0);
+	atomic64_set(&sbi->next_id, 0);
+
+	/* load_nls_default does not fail */
+	if (sbi->nls_disk && !sbi->nls_io)
+		sbi->nls_io = load_nls_default();
+	sbi->s_dir_umask &= 0777;
+	sbi->s_file_umask &= 0577;
+
+	spin_lock_init(&sbi->work_lock);
+	INIT_DELAYED_WORK(&sbi->mdb_work, flush_mdb);
+
+	sbi->sb = sb;
+	sb->s_op = &hfs_super_operations;
+	sb->s_xattr = hfs_xattr_handlers;
+	sb->s_flags |= SB_NOATIME | SB_NODIRATIME;
+	mutex_init(&sbi->mdb_lock);
+	mutex_init(&sbi->bitmap_lock);
+
+	mutex_lock(&sbi->mdb_lock);
+	res = hfs_mdb_get(sb);
+	mutex_unlock(&sbi->mdb_lock);
+	if (res) {
+		if (!silent)
+			pr_warn("can't find a HFS filesystem on dev %s\n",
+				hfs_mdb_name(sb));
+		res = -EINVAL;
+		goto bail;
+	}
+
+	/* try to get the root inode */
+	res = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
+	if (res)
+		goto bail_no_root;
+	res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd);
+	if (!res) {
+		if (fd.entrylength != sizeof(rec.dir)) {
+			res =  -EIO;
+			goto bail_hfs_find;
+		}
+		hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
+		if (rec.type != HFS_CDR_DIR)
+			res = -EIO;
+	}
+	if (res)
+		goto bail_hfs_find;
+	res = -EINVAL;
+	root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
+	hfs_find_exit(&fd);
+	if (!root_inode)
+		goto bail_no_root;
+
+	if (is_bad_inode(root_inode)) {
+		iput(root_inode);
+		goto bail_no_root;
+	}
+
+	set_default_d_op(sb, &hfs_dentry_operations);
+	res = -ENOMEM;
+	sb->s_root = d_make_root(root_inode);
+	if (!sb->s_root)
+		goto bail_no_root;
+
+	/* everything's okay */
+	return 0;
+
+bail_hfs_find:
+	hfs_find_exit(&fd);
+bail_no_root:
+	pr_err("get root inode failed\n");
+bail:
+	hfs_mdb_put(sb);
+	return res;
+}
+
+static int hfs_get_tree(struct fs_context *fc)
+{
+	return get_tree_bdev(fc, hfs_fill_super);
+}
+
+static void hfs_free_fc(struct fs_context *fc)
+{
+	kfree(fc->s_fs_info);
+}
+
+static const struct fs_context_operations hfs_context_ops = {
+	.parse_param	= hfs_parse_param,
+	.get_tree	= hfs_get_tree,
+	.reconfigure	= hfs_reconfigure,
+	.free		= hfs_free_fc,
+};
+
+static int hfs_init_fs_context(struct fs_context *fc)
+{
+	struct hfs_sb_info *hsb;
+
+	hsb = kzalloc_obj(struct hfs_sb_info);
+	if (!hsb)
+		return -ENOMEM;
+
+	fc->s_fs_info = hsb;
+	fc->ops = &hfs_context_ops;
+
+	if (fc->purpose != FS_CONTEXT_FOR_RECONFIGURE) {
+		/* initialize options with defaults */
+		hsb->s_uid = current_uid();
+		hsb->s_gid = current_gid();
+		hsb->s_file_umask = 0133;
+		hsb->s_dir_umask = 0022;
+		hsb->s_type = cpu_to_be32(0x3f3f3f3f); /* == '????' */
+		hsb->s_creator = cpu_to_be32(0x3f3f3f3f); /* == '????' */
+		hsb->s_quiet = 0;
+		hsb->part = -1;
+		hsb->session = -1;
+	}
+
+	return 0;
+}
+
+static void hfs_kill_super(struct super_block *sb)
+{
+	struct hfs_sb_info *hsb = HFS_SB(sb);
+
+	kill_block_super(sb);
+	kfree(hsb);
+}
+
+static struct file_system_type hfs_fs_type = {
+	.owner		= THIS_MODULE,
+	.name		= "hfs",
+	.kill_sb	= hfs_kill_super,
+	.fs_flags	= FS_REQUIRES_DEV,
+	.init_fs_context = hfs_init_fs_context,
+};
+MODULE_ALIAS_FS("hfs");
+
+static void hfs_init_once(void *p)
+{
+	struct hfs_inode_info *i = p;
+
+	inode_init_once(&i->vfs_inode);
+}
+
+static int __init init_hfs_fs(void)
+{
+	int err;
+
+	hfs_inode_cachep = kmem_cache_create("hfs_inode_cache",
+		sizeof(struct hfs_inode_info), 0,
+		SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT, hfs_init_once);
+	if (!hfs_inode_cachep)
+		return -ENOMEM;
+	err = register_filesystem(&hfs_fs_type);
+	if (err)
+		kmem_cache_destroy(hfs_inode_cachep);
+	return err;
+}
+
+static void __exit exit_hfs_fs(void)
+{
+	unregister_filesystem(&hfs_fs_type);
+
+	/*
+	 * Make sure all delayed rcu free inodes are flushed before we
+	 * destroy cache.
+	 */
+	rcu_barrier();
+	kmem_cache_destroy(hfs_inode_cachep);
+}
+
+module_init(init_hfs_fs)
+module_exit(exit_hfs_fs)