Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 369 insertions, 0 deletions

diff --git a/fs/internal.h b/fs/internal.h
new file mode 100644
index 000000000..c658c8a5e
--- /dev/null
+++ b/fs/internal.h
@@ -0,0 +1,369 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* fs/ internal definitions
+ *
+ * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+struct super_block;
+struct file_system_type;
+struct iomap;
+struct iomap_ops;
+struct linux_binprm;
+struct path;
+struct mount;
+struct shrink_control;
+struct fs_context;
+struct pipe_inode_info;
+struct iov_iter;
+struct mnt_idmap;
+struct ns_common;
+
+/*
+ * block/bdev.c
+ */
+#ifdef CONFIG_BLOCK
+extern void __init bdev_cache_init(void);
+#else
+static inline void bdev_cache_init(void)
+{
+}
+#endif /* CONFIG_BLOCK */
+
+/*
+ * buffer.c
+ */
+int __block_write_begin_int(struct folio *folio, loff_t pos, unsigned len,
+		get_block_t *get_block, const struct iomap *iomap);
+
+/*
+ * char_dev.c
+ */
+extern void __init chrdev_init(void);
+
+/*
+ * fs_context.c
+ */
+extern int parse_monolithic_mount_data(struct fs_context *, void *);
+extern void vfs_clean_context(struct fs_context *fc);
+extern int finish_clean_context(struct fs_context *fc);
+
+/*
+ * namei.c
+ */
+extern int filename_lookup(int dfd, struct filename *name, unsigned flags,
+			   struct path *path, const struct path *root);
+int filename_rmdir(int dfd, struct filename *name);
+int filename_unlinkat(int dfd, struct filename *name);
+int may_linkat(struct mnt_idmap *idmap, const struct path *link);
+int filename_renameat2(int olddfd, struct filename *oldname, int newdfd,
+		 struct filename *newname, unsigned int flags);
+int filename_mkdirat(int dfd, struct filename *name, umode_t mode);
+int filename_mknodat(int dfd, struct filename *name, umode_t mode, unsigned int dev);
+int filename_symlinkat(struct filename *from, int newdfd, struct filename *to);
+int filename_linkat(int olddfd, struct filename *old, int newdfd,
+			struct filename *new, int flags);
+int vfs_tmpfile(struct mnt_idmap *idmap,
+		const struct path *parentpath,
+		struct file *file, umode_t mode);
+struct dentry *d_hash_and_lookup(struct dentry *, struct qstr *);
+struct dentry *start_dirop(struct dentry *parent, struct qstr *name,
+			   unsigned int lookup_flags);
+int lookup_noperm_common(struct qstr *qname, struct dentry *base);
+
+void __init filename_init(void);
+
+/*
+ * namespace.c
+ */
+extern struct vfsmount *lookup_mnt(const struct path *);
+extern int finish_automount(struct vfsmount *, const struct path *);
+
+extern int sb_prepare_remount_readonly(struct super_block *);
+
+extern void __init mnt_init(void);
+
+int mnt_get_write_access_file(struct file *file);
+void mnt_put_write_access_file(struct file *file);
+
+extern void dissolve_on_fput(struct vfsmount *);
+extern bool may_mount(void);
+
+int path_mount(const char *dev_name, const struct path *path,
+		const char *type_page, unsigned long flags, void *data_page);
+int path_umount(const struct path *path, int flags);
+int path_pivot_root(struct path *new, struct path *old);
+
+int show_path(struct seq_file *m, struct dentry *root);
+
+/*
+ * fs_struct.c
+ */
+extern void chroot_fs_refs(const struct path *, const struct path *);
+
+/*
+ * file_table.c
+ */
+struct file *alloc_empty_file(int flags, const struct cred *cred);
+struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred);
+struct file *alloc_empty_backing_file(int flags, const struct cred *cred,
+				      const struct file *user_file);
+void backing_file_set_user_path(struct file *f, const struct path *path);
+
+static inline void file_put_write_access(struct file *file)
+{
+	put_write_access(file->f_inode);
+	mnt_put_write_access(file->f_path.mnt);
+	if (unlikely(file->f_mode & FMODE_BACKING))
+		mnt_put_write_access(backing_file_user_path(file)->mnt);
+}
+
+static inline void put_file_access(struct file *file)
+{
+	if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
+		i_readcount_dec(file->f_inode);
+	} else if (file->f_mode & FMODE_WRITER) {
+		file_put_write_access(file);
+	}
+}
+
+void fput_close_sync(struct file *);
+void fput_close(struct file *);
+
+/*
+ * super.c
+ */
+extern int reconfigure_super(struct fs_context *);
+extern bool super_trylock_shared(struct super_block *sb);
+struct super_block *user_get_super(dev_t, bool excl);
+void put_super(struct super_block *sb);
+void __init super_dev_init(void);
+extern bool mount_capable(struct fs_context *);
+
+/*
+ * Prepare superblock for changing its read-only state (i.e., either remount
+ * read-write superblock read-only or vice versa). After this function returns
+ * mnt_is_readonly() will return true for any mount of the superblock if its
+ * caller is able to observe any changes done by the remount. This holds until
+ * sb_end_ro_state_change() is called.
+ */
+static inline void sb_start_ro_state_change(struct super_block *sb)
+{
+	WRITE_ONCE(sb->s_readonly_remount, 1);
+	/*
+	 * For RO->RW transition, the barrier pairs with the barrier in
+	 * mnt_is_readonly() making sure if mnt_is_readonly() sees SB_RDONLY
+	 * cleared, it will see s_readonly_remount set.
+	 * For RW->RO transition, the barrier pairs with the barrier in
+	 * mnt_get_write_access() before the mnt_is_readonly() check.
+	 * The barrier makes sure if mnt_get_write_access() sees MNT_WRITE_HOLD
+	 * already cleared, it will see s_readonly_remount set.
+	 */
+	smp_wmb();
+}
+
+/*
+ * Ends section changing read-only state of the superblock. After this function
+ * returns if mnt_is_readonly() returns false, the caller will be able to
+ * observe all the changes remount did to the superblock.
+ */
+static inline void sb_end_ro_state_change(struct super_block *sb)
+{
+	/*
+	 * This barrier provides release semantics that pairs with
+	 * the smp_rmb() acquire semantics in mnt_is_readonly().
+	 * This barrier pair ensure that when mnt_is_readonly() sees
+	 * 0 for sb->s_readonly_remount, it will also see all the
+	 * preceding flag changes that were made during the RO state
+	 * change.
+	 */
+	smp_wmb();
+	WRITE_ONCE(sb->s_readonly_remount, 0);
+}
+
+/*
+ * open.c
+ */
+struct open_flags {
+	int open_flag;
+	umode_t mode;
+	int acc_mode;
+	int intent;
+	int lookup_flags;
+};
+extern struct file *do_file_open(int dfd, struct filename *pathname,
+		const struct open_flags *op);
+extern struct file *do_file_open_root(const struct path *,
+		const char *, const struct open_flags *);
+extern struct open_how build_open_how(int flags, umode_t mode);
+extern int build_open_flags(const struct open_how *how, struct open_flags *op);
+struct file *file_close_fd_locked(struct files_struct *files, unsigned fd);
+
+int do_ftruncate(struct file *file, loff_t length, unsigned int flags);
+int chmod_common(const struct path *path, umode_t mode);
+int do_fchownat(int dfd, const char __user *filename, uid_t user, gid_t group,
+		int flag);
+int chown_common(const struct path *path, uid_t user, gid_t group);
+extern int vfs_open(const struct path *, struct file *);
+
+/*
+ * inode.c
+ */
+extern long prune_icache_sb(struct super_block *sb, struct shrink_control *sc);
+int dentry_needs_remove_privs(struct mnt_idmap *, struct dentry *dentry);
+bool in_group_or_capable(struct mnt_idmap *idmap,
+			 const struct inode *inode, vfsgid_t vfsgid);
+
+/*
+ * fs-writeback.c
+ */
+long get_nr_dirty_inodes(void);
+bool sync_lazytime(struct inode *inode);
+
+/*
+ * dcache.c
+ */
+extern int d_set_mounted(struct dentry *dentry);
+extern long prune_dcache_sb(struct super_block *sb, struct shrink_control *sc);
+extern struct dentry *d_alloc_cursor(struct dentry *);
+extern struct dentry * d_alloc_pseudo(struct super_block *, const struct qstr *);
+extern char *simple_dname(struct dentry *, char *, int);
+extern void dput_to_list(struct dentry *, struct list_head *);
+extern void shrink_dentry_list(struct list_head *);
+extern void shrink_dcache_for_umount(struct super_block *);
+extern struct dentry *__d_lookup(const struct dentry *, const struct qstr *);
+extern struct dentry *__d_lookup_rcu(const struct dentry *parent,
+				const struct qstr *name, unsigned *seq);
+
+/*
+ * pipe.c
+ */
+extern const struct file_operations pipefifo_fops;
+
+/*
+ * fs_pin.c
+ */
+extern void group_pin_kill(struct hlist_head *p);
+extern void mnt_pin_kill(struct mount *m);
+
+/*
+ * fs/nsfs.c
+ */
+extern const struct dentry_operations ns_dentry_operations;
+int open_namespace(struct ns_common *ns);
+struct file *open_namespace_file(struct ns_common *ns);
+
+/*
+ * fs/stat.c:
+ */
+
+int do_statx(int dfd, struct filename *filename, unsigned int flags,
+	     unsigned int mask, struct statx __user *buffer);
+int do_statx_fd(int fd, unsigned int flags, unsigned int mask,
+		struct statx __user *buffer);
+
+/*
+ * fs/splice.c:
+ */
+ssize_t splice_file_to_pipe(struct file *in,
+			    struct pipe_inode_info *opipe,
+			    loff_t *offset,
+			    size_t len, unsigned int flags);
+
+/*
+ * fs/xattr.c:
+ */
+struct xattr_name {
+	char name[XATTR_NAME_MAX + 1];
+};
+
+struct kernel_xattr_ctx {
+	/* Value of attribute */
+	union {
+		const void __user *cvalue;
+		void __user *value;
+	};
+	void *kvalue;
+	size_t size;
+	/* Attribute name */
+	struct xattr_name *kname;
+	unsigned int flags;
+};
+
+ssize_t file_getxattr(struct file *file, struct kernel_xattr_ctx *ctx);
+ssize_t filename_getxattr(int dfd, struct filename *filename,
+			  unsigned int lookup_flags, struct kernel_xattr_ctx *ctx);
+int file_setxattr(struct file *file, struct kernel_xattr_ctx *ctx);
+int filename_setxattr(int dfd, struct filename *filename,
+		      unsigned int lookup_flags, struct kernel_xattr_ctx *ctx);
+int setxattr_copy(const char __user *name, struct kernel_xattr_ctx *ctx);
+int import_xattr_name(struct xattr_name *kname, const char __user *name);
+
+int may_write_xattr(struct mnt_idmap *idmap, struct inode *inode);
+
+#ifdef CONFIG_FS_POSIX_ACL
+int do_set_acl(struct mnt_idmap *idmap, struct dentry *dentry,
+	       const char *acl_name, const void *kvalue, size_t size);
+ssize_t do_get_acl(struct mnt_idmap *idmap, struct dentry *dentry,
+		   const char *acl_name, void *kvalue, size_t size);
+#else
+static inline int do_set_acl(struct mnt_idmap *idmap,
+			     struct dentry *dentry, const char *acl_name,
+			     const void *kvalue, size_t size)
+{
+	return -EOPNOTSUPP;
+}
+static inline ssize_t do_get_acl(struct mnt_idmap *idmap,
+				 struct dentry *dentry, const char *acl_name,
+				 void *kvalue, size_t size)
+{
+	return -EOPNOTSUPP;
+}
+#endif
+
+ssize_t __kernel_write_iter(struct file *file, struct iov_iter *from, loff_t *pos);
+
+/*
+ * fs/attr.c
+ */
+struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns);
+struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap);
+void mnt_idmap_put(struct mnt_idmap *idmap);
+struct stashed_operations {
+	struct dentry *(*stash_dentry)(struct dentry **stashed,
+				       struct dentry *dentry);
+	void (*put_data)(void *data);
+	int (*init_inode)(struct inode *inode, void *data);
+};
+int path_from_stashed(struct dentry **stashed, struct vfsmount *mnt, void *data,
+		      struct path *path);
+void stashed_dentry_prune(struct dentry *dentry);
+struct dentry *stash_dentry(struct dentry **stashed, struct dentry *dentry);
+struct dentry *stashed_dentry_get(struct dentry **stashed);
+/**
+ * path_mounted - check whether path is mounted
+ * @path: path to check
+ *
+ * Determine whether @path refers to the root of a mount.
+ *
+ * Return: true if @path is the root of a mount, false if not.
+ */
+static inline bool path_mounted(const struct path *path)
+{
+	return path->mnt->mnt_root == path->dentry;
+}
+void file_f_owner_release(struct file *file);
+bool file_seek_cur_needs_f_lock(struct file *file);
+int statmount_mnt_idmap(struct mnt_idmap *idmap, struct seq_file *seq, bool uid_map);
+struct dentry *find_next_child(struct dentry *parent, struct dentry *prev);
+int anon_inode_getattr(struct mnt_idmap *idmap, const struct path *path,
+		       struct kstat *stat, u32 request_mask,
+		       unsigned int query_flags);
+int anon_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
+		       struct iattr *attr);
+void pidfs_get_root(struct path *path);
+void nsfs_get_root(struct path *path);
+void failfs_get_root(struct path *path);
+void __init failfs_init(void);
+bool failfs_mnt(const struct vfsmount *mnt);
+int failfs_current_chdir(void);