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, 231 insertions, 0 deletions

diff --git a/fs/ext4/xattr.h b/fs/ext4/xattr.h
new file mode 100644
index 000000000..821dc6a50
--- /dev/null
+++ b/fs/ext4/xattr.h
@@ -0,0 +1,231 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+  File: fs/ext4/xattr.h
+
+  On-disk format of extended attributes for the ext4 filesystem.
+
+  (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
+*/
+
+#include <linux/xattr.h>
+
+/* Magic value in attribute blocks */
+#define EXT4_XATTR_MAGIC		0xEA020000
+
+/* Maximum number of references to one attribute block */
+#define EXT4_XATTR_REFCOUNT_MAX		1024
+
+/* Name indexes */
+#define EXT4_XATTR_INDEX_USER			1
+#define EXT4_XATTR_INDEX_POSIX_ACL_ACCESS	2
+#define EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT	3
+#define EXT4_XATTR_INDEX_TRUSTED		4
+#define	EXT4_XATTR_INDEX_LUSTRE			5
+#define EXT4_XATTR_INDEX_SECURITY	        6
+#define EXT4_XATTR_INDEX_SYSTEM			7
+#define EXT4_XATTR_INDEX_RICHACL		8
+#define EXT4_XATTR_INDEX_ENCRYPTION		9
+#define EXT4_XATTR_INDEX_HURD			10 /* Reserved for Hurd */
+
+struct ext4_xattr_header {
+	__le32	h_magic;	/* magic number for identification */
+	__le32	h_refcount;	/* reference count */
+	__le32	h_blocks;	/* number of disk blocks used */
+	__le32	h_hash;		/* hash value of all attributes */
+	__le32	h_checksum;	/* crc32c(uuid+blknum+xattrblock) */
+	__u32	h_reserved[3];	/* zero right now */
+};
+
+struct ext4_xattr_ibody_header {
+	__le32	h_magic;	/* magic number for identification */
+};
+
+struct ext4_xattr_entry {
+	__u8	e_name_len;	/* length of name */
+	__u8	e_name_index;	/* attribute name index */
+	__le16	e_value_offs;	/* offset in disk block of value */
+	__le32	e_value_inum;	/* inode in which the value is stored */
+	__le32	e_value_size;	/* size of attribute value */
+	__le32	e_hash;		/* hash value of name and value */
+	char	e_name[];	/* attribute name */
+};
+
+#define EXT4_XATTR_PAD_BITS		2
+#define EXT4_XATTR_PAD		(1<<EXT4_XATTR_PAD_BITS)
+#define EXT4_XATTR_ROUND		(EXT4_XATTR_PAD-1)
+#define EXT4_XATTR_LEN(name_len) \
+	(((name_len) + EXT4_XATTR_ROUND + \
+	sizeof(struct ext4_xattr_entry)) & ~EXT4_XATTR_ROUND)
+#define EXT4_XATTR_NEXT(entry) \
+	((struct ext4_xattr_entry *)( \
+	 (char *)(entry) + EXT4_XATTR_LEN((entry)->e_name_len)))
+#define EXT4_XATTR_SIZE(size) \
+	(((size) + EXT4_XATTR_ROUND) & ~EXT4_XATTR_ROUND)
+
+#define IHDR(inode, raw_inode) \
+	((struct ext4_xattr_ibody_header *) \
+		((void *)raw_inode + \
+		EXT4_GOOD_OLD_INODE_SIZE + \
+		EXT4_I(inode)->i_extra_isize))
+#define ITAIL(inode, raw_inode) \
+	((void *)(raw_inode) + \
+	 EXT4_SB((inode)->i_sb)->s_inode_size)
+#define IFIRST(hdr) ((struct ext4_xattr_entry *)((hdr)+1))
+
+/*
+ * XATTR_SIZE_MAX is currently 64k, but for the purposes of checking
+ * for file system consistency errors, we use a somewhat bigger value.
+ * This allows XATTR_SIZE_MAX to grow in the future, but by using this
+ * instead of INT_MAX for certain consistency checks, we don't need to
+ * worry about arithmetic overflows.  (Actually XATTR_SIZE_MAX is
+ * defined in include/uapi/linux/limits.h, so changing it is going
+ * not going to be trivial....)
+ */
+#define EXT4_XATTR_SIZE_MAX (1 << 24)
+
+/*
+ * The minimum size of EA value when you start storing it in an external inode
+ * size of block - size of header - size of 1 entry - 4 null bytes
+ */
+#define EXT4_XATTR_MIN_LARGE_EA_SIZE(b)					\
+	((b) - EXT4_XATTR_LEN(3) - sizeof(struct ext4_xattr_header) - 4)
+
+#define BHDR(bh) ((struct ext4_xattr_header *)((bh)->b_data))
+#define ENTRY(ptr) ((struct ext4_xattr_entry *)(ptr))
+#define BFIRST(bh) ENTRY(BHDR(bh)+1)
+#define IS_LAST_ENTRY(entry) (*(__u32 *)(entry) == 0)
+
+#define EXT4_ZERO_XATTR_VALUE ((void *)-1)
+
+/*
+ * If we want to add an xattr to the inode, we should make sure that
+ * i_extra_isize is not 0 and that the inode size is not less than
+ * EXT4_GOOD_OLD_INODE_SIZE + extra_isize + pad.
+ *   EXT4_GOOD_OLD_INODE_SIZE   extra_isize header   entry   pad  data
+ * |--------------------------|------------|------|---------|---|-------|
+ */
+#define EXT4_INODE_HAS_XATTR_SPACE(inode)				\
+	((EXT4_I(inode)->i_extra_isize != 0) &&				\
+	 (EXT4_GOOD_OLD_INODE_SIZE + EXT4_I(inode)->i_extra_isize +	\
+	  sizeof(struct ext4_xattr_ibody_header) + EXT4_XATTR_PAD <=	\
+	  EXT4_INODE_SIZE((inode)->i_sb)))
+
+struct ext4_xattr_info {
+	const char *name;
+	const void *value;
+	size_t value_len;
+	int name_index;
+	int in_inode;
+};
+
+struct ext4_xattr_search {
+	struct ext4_xattr_entry *first;
+	void *base;
+	void *end;
+	struct ext4_xattr_entry *here;
+	int not_found;
+};
+
+struct ext4_xattr_ibody_find {
+	struct ext4_xattr_search s;
+	struct ext4_iloc iloc;
+};
+
+extern const struct xattr_handler ext4_xattr_user_handler;
+extern const struct xattr_handler ext4_xattr_trusted_handler;
+extern const struct xattr_handler ext4_xattr_security_handler;
+extern const struct xattr_handler ext4_xattr_hurd_handler;
+
+#define EXT4_XATTR_NAME_ENCRYPTION_CONTEXT "c"
+
+/*
+ * The EXT4_STATE_NO_EXPAND is overloaded and used for two purposes.
+ * The first is to signal that there the inline xattrs and data are
+ * taking up so much space that we might as well not keep trying to
+ * expand it.  The second is that xattr_sem is taken for writing, so
+ * we shouldn't try to recurse into the inode expansion.  For this
+ * second case, we need to make sure that we take save and restore the
+ * NO_EXPAND state flag appropriately.
+ */
+static inline void ext4_write_lock_xattr(struct inode *inode, int *save)
+{
+	down_write(&EXT4_I(inode)->xattr_sem);
+	*save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
+	ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
+}
+
+static inline int ext4_write_trylock_xattr(struct inode *inode, int *save)
+{
+	if (down_write_trylock(&EXT4_I(inode)->xattr_sem) == 0)
+		return 0;
+	*save = ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND);
+	ext4_set_inode_state(inode, EXT4_STATE_NO_EXPAND);
+	return 1;
+}
+
+static inline void ext4_write_unlock_xattr(struct inode *inode, int *save)
+{
+	if (*save == 0)
+		ext4_clear_inode_state(inode, EXT4_STATE_NO_EXPAND);
+	up_write(&EXT4_I(inode)->xattr_sem);
+}
+
+extern ssize_t ext4_listxattr(struct dentry *, char *, size_t);
+
+extern int ext4_xattr_get(struct inode *, int, const char *, void *, size_t);
+extern int ext4_xattr_set(struct inode *, int, const char *, const void *, size_t, int);
+extern int ext4_xattr_set_handle(handle_t *, struct inode *, int, const char *, const void *, size_t, int);
+extern int ext4_xattr_set_credits(struct inode *inode, size_t value_len,
+				  bool is_create, int *credits);
+extern int __ext4_xattr_set_credits(struct super_block *sb, struct inode *inode,
+				struct buffer_head *block_bh, size_t value_len,
+				bool is_create);
+
+extern int ext4_xattr_delete_inode(handle_t *handle, struct inode *inode,
+				   int extra_credits);
+extern void ext4_init_ea_inode_work(struct ext4_sb_info *sbi);
+extern void ext4_put_ea_inode(struct inode *inode);
+
+extern int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
+			    struct ext4_inode *raw_inode, handle_t *handle);
+extern void ext4_evict_ea_inode(struct inode *inode);
+
+extern const struct xattr_handler * const ext4_xattr_handlers[];
+
+extern int ext4_xattr_ibody_find(struct inode *inode, struct ext4_xattr_info *i,
+				 struct ext4_xattr_ibody_find *is);
+extern int ext4_xattr_ibody_get(struct inode *inode, int name_index,
+				const char *name,
+				void *buffer, size_t buffer_size);
+extern int ext4_xattr_ibody_set(handle_t *handle, struct inode *inode,
+				struct ext4_xattr_info *i,
+				struct ext4_xattr_ibody_find *is);
+
+extern struct mb_cache *ext4_xattr_create_cache(void);
+extern void ext4_xattr_destroy_cache(struct mb_cache *);
+
+extern int
+__xattr_check_inode(struct inode *inode, struct ext4_xattr_ibody_header *header,
+		    void *end, const char *function, unsigned int line);
+
+#define xattr_check_inode(inode, header, end) \
+	__xattr_check_inode((inode), (header), (end), __func__, __LINE__)
+
+#ifdef CONFIG_EXT4_FS_SECURITY
+extern int ext4_init_security(handle_t *handle, struct inode *inode,
+			      struct inode *dir, const struct qstr *qstr);
+#else
+static inline int ext4_init_security(handle_t *handle, struct inode *inode,
+				     struct inode *dir, const struct qstr *qstr)
+{
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_LOCKDEP
+extern void ext4_xattr_inode_set_class(struct inode *ea_inode);
+#else
+static inline void ext4_xattr_inode_set_class(struct inode *ea_inode) { }
+#endif
+
+extern int ext4_get_inode_usage(struct inode *inode, qsize_t *usage);