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, 582 insertions, 0 deletions

diff --git a/fs/affs/namei.c b/fs/affs/namei.c
new file mode 100644
index 000000000..6cb52efaf
--- /dev/null
+++ b/fs/affs/namei.c
@@ -0,0 +1,582 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  linux/fs/affs/namei.c
+ *
+ *  (c) 1996  Hans-Joachim Widmaier - Rewritten
+ *
+ *  (C) 1993  Ray Burr - Modified for Amiga FFS filesystem.
+ *
+ *  (C) 1991  Linus Torvalds - minix filesystem
+ */
+
+#include "affs.h"
+#include <linux/exportfs.h>
+
+typedef int (*toupper_t)(int);
+
+/* Simple toupper() for DOS\1 */
+
+static int
+affs_toupper(int ch)
+{
+	return ch >= 'a' && ch <= 'z' ? ch -= ('a' - 'A') : ch;
+}
+
+/* International toupper() for DOS\3 ("international") */
+
+static int
+affs_intl_toupper(int ch)
+{
+	return (ch >= 'a' && ch <= 'z') || (ch >= 0xE0
+		&& ch <= 0xFE && ch != 0xF7) ?
+		ch - ('a' - 'A') : ch;
+}
+
+static inline toupper_t
+affs_get_toupper(struct super_block *sb)
+{
+	return affs_test_opt(AFFS_SB(sb)->s_flags, SF_INTL) ?
+	       affs_intl_toupper : affs_toupper;
+}
+
+/*
+ * Note: the dentry argument is the parent dentry.
+ */
+static inline int
+__affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr, toupper_t fn, bool notruncate)
+{
+	const u8 *name = qstr->name;
+	unsigned long hash;
+	int retval;
+	u32 len;
+
+	retval = affs_check_name(qstr->name, qstr->len, notruncate);
+	if (retval)
+		return retval;
+
+	hash = init_name_hash(dentry);
+	len = min(qstr->len, AFFSNAMEMAX);
+	for (; len > 0; name++, len--)
+		hash = partial_name_hash(fn(*name), hash);
+	qstr->hash = end_name_hash(hash);
+
+	return 0;
+}
+
+static int
+affs_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
+{
+	return __affs_hash_dentry(dentry, qstr, affs_toupper,
+				  affs_nofilenametruncate(dentry));
+
+}
+
+static int
+affs_intl_hash_dentry(const struct dentry *dentry, struct qstr *qstr)
+{
+	return __affs_hash_dentry(dentry, qstr, affs_intl_toupper,
+				  affs_nofilenametruncate(dentry));
+
+}
+
+static inline int __affs_compare_dentry(unsigned int len,
+		const char *str, const struct qstr *name, toupper_t fn,
+		bool notruncate)
+{
+	const u8 *aname = str;
+	const u8 *bname = name->name;
+
+	/*
+	 * 'str' is the name of an already existing dentry, so the name
+	 * must be valid. 'name' must be validated first.
+	 */
+
+	if (affs_check_name(name->name, name->len, notruncate))
+		return 1;
+
+	/*
+	 * If the names are longer than the allowed 30 chars,
+	 * the excess is ignored, so their length may differ.
+	 */
+	if (len >= AFFSNAMEMAX) {
+		if (name->len < AFFSNAMEMAX)
+			return 1;
+		len = AFFSNAMEMAX;
+	} else if (len != name->len)
+		return 1;
+
+	for (; len > 0; len--)
+		if (fn(*aname++) != fn(*bname++))
+			return 1;
+
+	return 0;
+}
+
+static int
+affs_compare_dentry(const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name)
+{
+
+	return __affs_compare_dentry(len, str, name, affs_toupper,
+				     affs_nofilenametruncate(dentry));
+}
+
+static int
+affs_intl_compare_dentry(const struct dentry *dentry,
+		unsigned int len, const char *str, const struct qstr *name)
+{
+	return __affs_compare_dentry(len, str, name, affs_intl_toupper,
+				     affs_nofilenametruncate(dentry));
+
+}
+
+/*
+ * NOTE! unlike strncmp, affs_match returns 1 for success, 0 for failure.
+ */
+
+static inline int
+affs_match(struct dentry *dentry, const u8 *name2, toupper_t fn)
+{
+	const u8 *name = dentry->d_name.name;
+	int len = dentry->d_name.len;
+
+	if (len >= AFFSNAMEMAX) {
+		if (*name2 < AFFSNAMEMAX)
+			return 0;
+		len = AFFSNAMEMAX;
+	} else if (len != *name2)
+		return 0;
+
+	for (name2++; len > 0; len--)
+		if (fn(*name++) != fn(*name2++))
+			return 0;
+	return 1;
+}
+
+int
+affs_hash_name(struct super_block *sb, const u8 *name, unsigned int len)
+{
+	toupper_t fn = affs_get_toupper(sb);
+	u32 hash;
+
+	hash = len = min(len, AFFSNAMEMAX);
+	for (; len > 0; len--)
+		hash = (hash * 13 + fn(*name++)) & 0x7ff;
+
+	return hash % AFFS_SB(sb)->s_hashsize;
+}
+
+static struct buffer_head *
+affs_find_entry(struct inode *dir, struct dentry *dentry)
+{
+	struct super_block *sb = dir->i_sb;
+	struct buffer_head *bh;
+	toupper_t fn = affs_get_toupper(sb);
+	u32 key;
+
+	pr_debug("%s(\"%pd\")\n", __func__, dentry);
+
+	bh = affs_bread(sb, dir->i_ino);
+	if (!bh)
+		return ERR_PTR(-EIO);
+
+	key = be32_to_cpu(AFFS_HEAD(bh)->table[affs_hash_name(sb, dentry->d_name.name, dentry->d_name.len)]);
+
+	for (;;) {
+		affs_brelse(bh);
+		if (key == 0)
+			return NULL;
+		bh = affs_bread(sb, key);
+		if (!bh)
+			return ERR_PTR(-EIO);
+		if (affs_match(dentry, AFFS_TAIL(sb, bh)->name, fn))
+			return bh;
+		key = be32_to_cpu(AFFS_TAIL(sb, bh)->hash_chain);
+	}
+}
+
+struct dentry *
+affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int flags)
+{
+	struct super_block *sb = dir->i_sb;
+	struct buffer_head *bh;
+	struct inode *inode = NULL;
+	struct dentry *res;
+
+	pr_debug("%s(\"%pd\")\n", __func__, dentry);
+
+	affs_lock_dir(dir);
+	bh = affs_find_entry(dir, dentry);
+	if (IS_ERR(bh)) {
+		affs_unlock_dir(dir);
+		return ERR_CAST(bh);
+	}
+	if (bh) {
+		u32 ino = bh->b_blocknr;
+
+		/* store the real header ino in d_fsdata for faster lookups */
+		dentry->d_fsdata = (void *)(long)ino;
+		switch (be32_to_cpu(AFFS_TAIL(sb, bh)->stype)) {
+		//link to dirs disabled
+		//case ST_LINKDIR:
+		case ST_LINKFILE:
+			ino = be32_to_cpu(AFFS_TAIL(sb, bh)->original);
+		}
+		affs_brelse(bh);
+		inode = affs_iget(sb, ino);
+	}
+	res = d_splice_alias(inode, dentry);
+	if (!IS_ERR_OR_NULL(res))
+		res->d_fsdata = dentry->d_fsdata;
+	affs_unlock_dir(dir);
+	return res;
+}
+
+int
+affs_unlink(struct inode *dir, struct dentry *dentry)
+{
+	pr_debug("%s(dir=%llu, %llu \"%pd\")\n", __func__, dir->i_ino,
+		 d_inode(dentry)->i_ino, dentry);
+
+	return affs_remove_header(dentry);
+}
+
+int
+affs_create(struct mnt_idmap *idmap, struct inode *dir,
+	    struct dentry *dentry, umode_t mode)
+{
+	struct super_block *sb = dir->i_sb;
+	struct inode	*inode;
+	int		 error;
+
+	pr_debug("%s(%llu,\"%pd\",0%ho)\n",
+		 __func__, dir->i_ino, dentry, mode);
+
+	inode = affs_new_inode(dir);
+	if (!inode)
+		return -ENOSPC;
+
+	inode->i_mode = mode;
+	affs_mode_to_prot(inode);
+	mark_inode_dirty(inode);
+
+	inode->i_op = &affs_file_inode_operations;
+	inode->i_fop = &affs_file_operations;
+	inode->i_mapping->a_ops = affs_test_opt(AFFS_SB(sb)->s_flags, SF_OFS) ?
+				  &affs_aops_ofs : &affs_aops;
+	error = affs_add_entry(dir, inode, dentry, ST_FILE);
+	if (error) {
+		clear_nlink(inode);
+		iput(inode);
+		return error;
+	}
+	return 0;
+}
+
+struct dentry *
+affs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+	   struct dentry *dentry, umode_t mode)
+{
+	struct inode		*inode;
+	int			 error;
+
+	pr_debug("%s(%llu,\"%pd\",0%ho)\n",
+		 __func__, dir->i_ino, dentry, mode);
+
+	inode = affs_new_inode(dir);
+	if (!inode)
+		return ERR_PTR(-ENOSPC);
+
+	inode->i_mode = mode;
+	affs_mode_to_prot(inode);
+
+	inode->i_op = &affs_dir_inode_operations;
+	inode->i_fop = &affs_dir_operations;
+
+	error = affs_add_entry(dir, inode, dentry, ST_USERDIR);
+	if (error) {
+		clear_nlink(inode);
+		mark_inode_dirty(inode);
+		iput(inode);
+		return ERR_PTR(error);
+	}
+	return NULL;
+}
+
+int
+affs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+	pr_debug("%s(dir=%llu, %llu \"%pd\")\n", __func__, dir->i_ino,
+		 d_inode(dentry)->i_ino, dentry);
+
+	return affs_remove_header(dentry);
+}
+
+int
+affs_symlink(struct mnt_idmap *idmap, struct inode *dir,
+	     struct dentry *dentry, const char *symname)
+{
+	struct super_block	*sb = dir->i_sb;
+	struct buffer_head	*bh;
+	struct inode		*inode;
+	char			*p;
+	int			 i, maxlen, error;
+	char			 c, lc;
+
+	pr_debug("%s(%llu,\"%pd\" -> \"%s\")\n",
+		 __func__, dir->i_ino, dentry, symname);
+
+	maxlen = AFFS_SB(sb)->s_hashsize * sizeof(u32) - 1;
+	inode  = affs_new_inode(dir);
+	if (!inode)
+		return -ENOSPC;
+
+	inode->i_op = &affs_symlink_inode_operations;
+	inode_nohighmem(inode);
+	inode->i_data.a_ops = &affs_symlink_aops;
+	inode->i_mode = S_IFLNK | 0777;
+	affs_mode_to_prot(inode);
+
+	error = -EIO;
+	bh = affs_bread(sb, inode->i_ino);
+	if (!bh)
+		goto err;
+	i  = 0;
+	p  = (char *)AFFS_HEAD(bh)->table;
+	lc = '/';
+	if (*symname == '/') {
+		struct affs_sb_info *sbi = AFFS_SB(sb);
+		while (*symname == '/')
+			symname++;
+		spin_lock(&sbi->symlink_lock);
+		while (sbi->s_volume[i])	/* Cannot overflow */
+			*p++ = sbi->s_volume[i++];
+		spin_unlock(&sbi->symlink_lock);
+	}
+	while (i < maxlen && (c = *symname++)) {
+		if (c == '.' && lc == '/' && *symname == '.' && symname[1] == '/') {
+			*p++ = '/';
+			i++;
+			symname += 2;
+			lc = '/';
+		} else if (c == '.' && lc == '/' && *symname == '/') {
+			symname++;
+			lc = '/';
+		} else {
+			*p++ = c;
+			lc   = c;
+			i++;
+		}
+		if (lc == '/')
+			while (*symname == '/')
+				symname++;
+	}
+	*p = 0;
+	inode->i_size = i + 1;
+	mark_buffer_dirty(bh);
+	affs_brelse(bh);
+	mark_inode_dirty(inode);
+
+	error = affs_add_entry(dir, inode, dentry, ST_SOFTLINK);
+	if (error)
+		goto err;
+
+	return 0;
+
+err:
+	clear_nlink(inode);
+	mark_inode_dirty(inode);
+	iput(inode);
+	return error;
+}
+
+int
+affs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
+{
+	struct inode *inode = d_inode(old_dentry);
+
+	pr_debug("%s(%llu, %llu, \"%pd\")\n", __func__, inode->i_ino, dir->i_ino,
+		 dentry);
+
+	return affs_add_entry(dir, inode, dentry, ST_LINKFILE);
+}
+
+static int
+affs_rename(struct inode *old_dir, struct dentry *old_dentry,
+	    struct inode *new_dir, struct dentry *new_dentry)
+{
+	struct super_block *sb = old_dir->i_sb;
+	struct buffer_head *bh = NULL;
+	int retval;
+
+	retval = affs_check_name(new_dentry->d_name.name,
+				 new_dentry->d_name.len,
+				 affs_nofilenametruncate(old_dentry));
+
+	if (retval)
+		return retval;
+
+	/* Unlink destination if it already exists */
+	if (d_really_is_positive(new_dentry)) {
+		retval = affs_remove_header(new_dentry);
+		if (retval)
+			return retval;
+	}
+
+	bh = affs_bread(sb, d_inode(old_dentry)->i_ino);
+	if (!bh)
+		return -EIO;
+
+	/* Remove header from its parent directory. */
+	affs_lock_dir(old_dir);
+	retval = affs_remove_hash(old_dir, bh);
+	affs_unlock_dir(old_dir);
+	if (retval)
+		goto done;
+
+	/* And insert it into the new directory with the new name. */
+	affs_copy_name(AFFS_TAIL(sb, bh)->name, new_dentry);
+	affs_fix_checksum(sb, bh);
+	affs_lock_dir(new_dir);
+	retval = affs_insert_hash(new_dir, bh);
+	affs_unlock_dir(new_dir);
+	/* TODO: move it back to old_dir, if error? */
+
+done:
+	mark_buffer_dirty(bh);
+	affs_brelse(bh);
+	return retval;
+}
+
+static int
+affs_xrename(struct inode *old_dir, struct dentry *old_dentry,
+	     struct inode *new_dir, struct dentry *new_dentry)
+{
+
+	struct super_block *sb = old_dir->i_sb;
+	struct buffer_head *bh_old = NULL;
+	struct buffer_head *bh_new = NULL;
+	int retval;
+
+	bh_old = affs_bread(sb, d_inode(old_dentry)->i_ino);
+	if (!bh_old)
+		return -EIO;
+
+	bh_new = affs_bread(sb, d_inode(new_dentry)->i_ino);
+	if (!bh_new) {
+		affs_brelse(bh_old);
+		return -EIO;
+	}
+
+	/* Remove old header from its parent directory. */
+	affs_lock_dir(old_dir);
+	retval = affs_remove_hash(old_dir, bh_old);
+	affs_unlock_dir(old_dir);
+	if (retval)
+		goto done;
+
+	/* Remove new header from its parent directory. */
+	affs_lock_dir(new_dir);
+	retval = affs_remove_hash(new_dir, bh_new);
+	affs_unlock_dir(new_dir);
+	if (retval)
+		goto done;
+
+	/* Insert old into the new directory with the new name. */
+	affs_copy_name(AFFS_TAIL(sb, bh_old)->name, new_dentry);
+	affs_fix_checksum(sb, bh_old);
+	affs_lock_dir(new_dir);
+	retval = affs_insert_hash(new_dir, bh_old);
+	affs_unlock_dir(new_dir);
+
+	/* Insert new into the old directory with the old name. */
+	affs_copy_name(AFFS_TAIL(sb, bh_new)->name, old_dentry);
+	affs_fix_checksum(sb, bh_new);
+	affs_lock_dir(old_dir);
+	retval = affs_insert_hash(old_dir, bh_new);
+	affs_unlock_dir(old_dir);
+done:
+	mark_buffer_dirty(bh_old);
+	mark_buffer_dirty(bh_new);
+	affs_brelse(bh_old);
+	affs_brelse(bh_new);
+	return retval;
+}
+
+int affs_rename2(struct mnt_idmap *idmap, struct inode *old_dir,
+		 struct dentry *old_dentry, struct inode *new_dir,
+		 struct dentry *new_dentry, unsigned int flags)
+{
+
+	if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
+		return -EINVAL;
+
+	pr_debug("%s(old=%llu,\"%pd\" to new=%llu,\"%pd\")\n", __func__,
+		 old_dir->i_ino, old_dentry, new_dir->i_ino, new_dentry);
+
+	if (flags & RENAME_EXCHANGE)
+		return affs_xrename(old_dir, old_dentry, new_dir, new_dentry);
+
+	return affs_rename(old_dir, old_dentry, new_dir, new_dentry);
+}
+
+static struct dentry *affs_get_parent(struct dentry *child)
+{
+	struct inode *parent;
+	struct buffer_head *bh;
+
+	bh = affs_bread(child->d_sb, d_inode(child)->i_ino);
+	if (!bh)
+		return ERR_PTR(-EIO);
+
+	parent = affs_iget(child->d_sb,
+			   be32_to_cpu(AFFS_TAIL(child->d_sb, bh)->parent));
+	brelse(bh);
+	return d_obtain_alias(parent);
+}
+
+static struct inode *affs_nfs_get_inode(struct super_block *sb, u64 ino,
+					u32 generation)
+{
+	struct inode *inode;
+
+	if (!affs_validblock(sb, ino))
+		return ERR_PTR(-ESTALE);
+
+	inode = affs_iget(sb, ino);
+	if (IS_ERR(inode))
+		return ERR_CAST(inode);
+
+	return inode;
+}
+
+static struct dentry *affs_fh_to_dentry(struct super_block *sb, struct fid *fid,
+					int fh_len, int fh_type)
+{
+	return generic_fh_to_dentry(sb, fid, fh_len, fh_type,
+				    affs_nfs_get_inode);
+}
+
+static struct dentry *affs_fh_to_parent(struct super_block *sb, struct fid *fid,
+					int fh_len, int fh_type)
+{
+	return generic_fh_to_parent(sb, fid, fh_len, fh_type,
+				    affs_nfs_get_inode);
+}
+
+const struct export_operations affs_export_ops = {
+	.encode_fh = generic_encode_ino32_fh,
+	.fh_to_dentry = affs_fh_to_dentry,
+	.fh_to_parent = affs_fh_to_parent,
+	.get_parent = affs_get_parent,
+};
+
+const struct dentry_operations affs_dentry_operations = {
+	.d_hash		= affs_hash_dentry,
+	.d_compare	= affs_compare_dentry,
+};
+
+const struct dentry_operations affs_intl_dentry_operations = {
+	.d_hash		= affs_intl_hash_dentry,
+	.d_compare	= affs_intl_compare_dentry,
+};