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, 331 insertions, 0 deletions

diff --git a/fs/hfs/dir.c b/fs/hfs/dir.c
new file mode 100644
index 000000000..e1f1fb351
--- /dev/null
+++ b/fs/hfs/dir.c
@@ -0,0 +1,331 @@
+/*
+ *  linux/fs/hfs/dir.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 directory-related functions independent of which
+ * scheme is being used to represent forks.
+ *
+ * Based on the minix file system code, (C) 1991, 1992 by Linus Torvalds
+ */
+
+#include "hfs_fs.h"
+#include "btree.h"
+
+/*
+ * hfs_lookup()
+ */
+static struct dentry *hfs_lookup(struct inode *dir, struct dentry *dentry,
+				 unsigned int flags)
+{
+	hfs_cat_rec rec;
+	struct hfs_find_data fd;
+	struct inode *inode = NULL;
+	int res;
+
+	res = hfs_find_init(HFS_SB(dir->i_sb)->cat_tree, &fd);
+	if (res)
+		return ERR_PTR(res);
+	hfs_cat_build_key(dir->i_sb, fd.search_key, dir->i_ino, &dentry->d_name);
+	res = hfs_brec_read(&fd, &rec, sizeof(rec));
+	if (res) {
+		if (res != -ENOENT)
+			inode = ERR_PTR(res);
+	} else {
+		inode = hfs_iget(dir->i_sb, &fd.search_key->cat, &rec);
+		if (!inode)
+			inode = ERR_PTR(-EACCES);
+	}
+	hfs_find_exit(&fd);
+	return d_splice_alias(inode, dentry);
+}
+
+/*
+ * hfs_readdir
+ */
+static int hfs_readdir(struct file *file, struct dir_context *ctx)
+{
+	struct inode *inode = file_inode(file);
+	struct super_block *sb = inode->i_sb;
+	int len, err;
+	char strbuf[HFS_MAX_NAMELEN];
+	union hfs_cat_rec entry;
+	struct hfs_find_data fd;
+	struct hfs_readdir_data *rd;
+	u16 type;
+
+	if (ctx->pos >= inode->i_size)
+		return 0;
+
+	err = hfs_find_init(HFS_SB(sb)->cat_tree, &fd);
+	if (err)
+		return err;
+	hfs_cat_build_key(sb, fd.search_key, inode->i_ino, NULL);
+	err = hfs_brec_find(&fd);
+	if (err)
+		goto out;
+
+	if (ctx->pos == 0) {
+		/* This is completely artificial... */
+		if (!dir_emit_dot(file, ctx))
+			goto out;
+		ctx->pos = 1;
+	}
+	if (ctx->pos == 1) {
+		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
+			err = -EIO;
+			goto out;
+		}
+
+		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
+		if (entry.type != HFS_CDR_THD) {
+			pr_err("bad catalog folder thread\n");
+			err = -EIO;
+			goto out;
+		}
+		//if (fd.entrylength < HFS_MIN_THREAD_SZ) {
+		//	pr_err("truncated catalog thread\n");
+		//	err = -EIO;
+		//	goto out;
+		//}
+		if (!dir_emit(ctx, "..", 2,
+			    be32_to_cpu(entry.thread.ParID), DT_DIR))
+			goto out;
+		ctx->pos = 2;
+	}
+	if (ctx->pos >= inode->i_size)
+		goto out;
+	rd = file->private_data;
+	if (rd && rd->pos == ctx->pos) {
+		memcpy(fd.search_key, &rd->key, sizeof(struct hfs_cat_key));
+		err = hfs_brec_find(&fd);
+		if (err == -ENOENT)
+			err = hfs_brec_goto(&fd, 1);
+	} else {
+		err = hfs_brec_goto(&fd, ctx->pos - 1);
+	}
+	if (err)
+		goto out;
+
+	for (;;) {
+		if (be32_to_cpu(fd.key->cat.ParID) != inode->i_ino) {
+			pr_err("walked past end of dir\n");
+			err = -EIO;
+			goto out;
+		}
+
+		if (fd.entrylength > sizeof(entry) || fd.entrylength < 0) {
+			err = -EIO;
+			goto out;
+		}
+
+		hfs_bnode_read(fd.bnode, &entry, fd.entryoffset, fd.entrylength);
+		type = entry.type;
+		len = hfs_mac2asc(sb, strbuf, &fd.key->cat.CName);
+		if (type == HFS_CDR_DIR) {
+			if (fd.entrylength < sizeof(struct hfs_cat_dir)) {
+				pr_err("small dir entry\n");
+				err = -EIO;
+				goto out;
+			}
+			if (!dir_emit(ctx, strbuf, len,
+				    be32_to_cpu(entry.dir.DirID), DT_DIR))
+				break;
+		} else if (type == HFS_CDR_FIL) {
+			if (fd.entrylength < sizeof(struct hfs_cat_file)) {
+				pr_err("small file entry\n");
+				err = -EIO;
+				goto out;
+			}
+			if (!dir_emit(ctx, strbuf, len,
+				    be32_to_cpu(entry.file.FlNum), DT_REG))
+				break;
+		} else {
+			pr_err("bad catalog entry type %d\n", type);
+			err = -EIO;
+			goto out;
+		}
+		ctx->pos++;
+		if (ctx->pos >= inode->i_size)
+			goto out;
+		err = hfs_brec_goto(&fd, 1);
+		if (err)
+			goto out;
+	}
+	if (!rd) {
+		rd = kmalloc_obj(struct hfs_readdir_data);
+		if (!rd) {
+			err = -ENOMEM;
+			goto out;
+		}
+		file->private_data = rd;
+	}
+	rd->pos = ctx->pos;
+	memcpy(&rd->key, &fd.key->cat, sizeof(struct hfs_cat_key));
+out:
+	hfs_find_exit(&fd);
+	return err;
+}
+
+static int hfs_dir_release(struct inode *inode, struct file *file)
+{
+	kfree(file->private_data);
+	return 0;
+}
+
+/*
+ * hfs_create()
+ *
+ * This is the create() entry in the inode_operations structure for
+ * regular HFS directories.  The purpose is to create a new file in
+ * a directory and return a corresponding inode, given the inode for
+ * the directory and the name (and its length) of the new file.
+ */
+static int hfs_create(struct mnt_idmap *idmap, struct inode *dir,
+		      struct dentry *dentry, umode_t mode)
+{
+	struct inode *inode;
+	int res;
+
+	inode = hfs_new_inode(dir, &dentry->d_name, mode);
+	if (IS_ERR(inode))
+		return PTR_ERR(inode);
+
+	res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
+	if (res) {
+		clear_nlink(inode);
+		hfs_delete_inode(inode);
+		iput(inode);
+		return res;
+	}
+	d_instantiate(dentry, inode);
+	mark_inode_dirty(inode);
+	return 0;
+}
+
+/*
+ * hfs_mkdir()
+ *
+ * This is the mkdir() entry in the inode_operations structure for
+ * regular HFS directories.  The purpose is to create a new directory
+ * in a directory, given the inode for the parent directory and the
+ * name (and its length) of the new directory.
+ */
+static struct dentry *hfs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+				struct dentry *dentry, umode_t mode)
+{
+	struct inode *inode;
+	int res;
+
+	inode = hfs_new_inode(dir, &dentry->d_name, mode);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+
+	res = hfs_cat_create(inode->i_ino, dir, &dentry->d_name, inode);
+	if (res) {
+		clear_nlink(inode);
+		hfs_delete_inode(inode);
+		iput(inode);
+		return ERR_PTR(res);
+	}
+	d_instantiate(dentry, inode);
+	mark_inode_dirty(inode);
+	return NULL;
+}
+
+/*
+ * hfs_remove()
+ *
+ * This serves as both unlink() and rmdir() in the inode_operations
+ * structure for regular HFS directories.  The purpose is to delete
+ * an existing child, given the inode for the parent directory and
+ * the name (and its length) of the existing directory.
+ *
+ * HFS does not have hardlinks, so both rmdir and unlink set the
+ * link count to 0.  The only difference is the emptiness check.
+ */
+static int hfs_remove(struct inode *dir, struct dentry *dentry)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode *inode = d_inode(dentry);
+	int res;
+
+	if (S_ISDIR(inode->i_mode) && inode->i_size != 2)
+		return -ENOTEMPTY;
+
+	if (unlikely(!is_hfs_cnid_counts_valid(sb))) {
+	    pr_err("cannot remove file/folder\n");
+	    return -ERANGE;
+	}
+
+	res = hfs_cat_delete(inode->i_ino, dir, &dentry->d_name);
+	if (res)
+		return res;
+	clear_nlink(inode);
+	inode_set_ctime_current(inode);
+	hfs_delete_inode(inode);
+	mark_inode_dirty(inode);
+	return 0;
+}
+
+/*
+ * hfs_rename()
+ *
+ * This is the rename() entry in the inode_operations structure for
+ * regular HFS directories.  The purpose is to rename an existing
+ * file or directory, given the inode for the current directory and
+ * the name (and its length) of the existing file/directory and the
+ * inode for the new directory and the name (and its length) of the
+ * new file/directory.
+ * XXX: how do you handle must_be dir?
+ */
+static int hfs_rename(struct mnt_idmap *idmap, struct inode *old_dir,
+		      struct dentry *old_dentry, struct inode *new_dir,
+		      struct dentry *new_dentry, unsigned int flags)
+{
+	int res;
+
+	if (flags & ~RENAME_NOREPLACE)
+		return -EINVAL;
+
+	/* Unlink destination if it already exists */
+	if (d_really_is_positive(new_dentry)) {
+		res = hfs_remove(new_dir, new_dentry);
+		if (res)
+			return res;
+	}
+
+	res = hfs_cat_move(d_inode(old_dentry)->i_ino,
+			   old_dir, &old_dentry->d_name,
+			   new_dir, &new_dentry->d_name);
+	if (!res) {
+		struct inode *inode = d_inode(old_dentry);
+
+		hfs_cat_build_key(old_dir->i_sb,
+				  (btree_key *)&HFS_I(inode)->cat_key,
+				  new_dir->i_ino, &new_dentry->d_name);
+		inode_set_ctime_current(inode);
+		mark_inode_dirty(inode);
+	}
+	return res;
+}
+
+const struct file_operations hfs_dir_operations = {
+	.read		= generic_read_dir,
+	.iterate_shared	= hfs_readdir,
+	.llseek		= generic_file_llseek,
+	.release	= hfs_dir_release,
+};
+
+const struct inode_operations hfs_dir_inode_operations = {
+	.create		= hfs_create,
+	.lookup		= hfs_lookup,
+	.unlink		= hfs_remove,
+	.mkdir		= hfs_mkdir,
+	.rmdir		= hfs_remove,
+	.rename		= hfs_rename,
+	.setattr	= hfs_inode_setattr,
+	.fileattr_get	= hfs_fileattr_get,
+};