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, 232 insertions, 0 deletions

diff --git a/include/sound/info.h b/include/sound/info.h
new file mode 100644
index 000000000..adbc50686
--- /dev/null
+++ b/include/sound/info.h
@@ -0,0 +1,232 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef __SOUND_INFO_H
+#define __SOUND_INFO_H
+
+/*
+ *  Header file for info interface
+ *  Copyright (c) by Jaroslav Kysela <perex@perex.cz>
+ */
+
+#include <linux/poll.h>
+#include <linux/seq_file.h>
+#include <sound/core.h>
+
+/* buffer for information */
+struct snd_info_buffer {
+	char *buffer;		/* pointer to begin of buffer */
+	unsigned int curr;	/* current position in buffer */
+	unsigned int size;	/* current size */
+	unsigned int len;	/* total length of buffer */
+	int stop;		/* stop flag */
+	int error;		/* error code */
+};
+
+#define SNDRV_INFO_CONTENT_TEXT		0
+#define SNDRV_INFO_CONTENT_DATA		1
+
+struct snd_info_entry;
+
+struct snd_info_entry_text {
+	void (*read)(struct snd_info_entry *entry,
+		     struct snd_info_buffer *buffer);
+	void (*write)(struct snd_info_entry *entry,
+		      struct snd_info_buffer *buffer);
+};
+
+struct snd_info_entry_ops {
+	int (*open)(struct snd_info_entry *entry,
+		    unsigned short mode, void **file_private_data);
+	int (*release)(struct snd_info_entry *entry,
+		       unsigned short mode, void *file_private_data);
+	ssize_t (*read)(struct snd_info_entry *entry, void *file_private_data,
+			struct file *file, char __user *buf,
+			size_t count, loff_t pos);
+	ssize_t (*write)(struct snd_info_entry *entry, void *file_private_data,
+			 struct file *file, const char __user *buf,
+			 size_t count, loff_t pos);
+	loff_t (*llseek)(struct snd_info_entry *entry,
+			 void *file_private_data, struct file *file,
+			 loff_t offset, int orig);
+	__poll_t (*poll)(struct snd_info_entry *entry,
+			     void *file_private_data, struct file *file,
+			     poll_table *wait);
+	int (*ioctl)(struct snd_info_entry *entry, void *file_private_data,
+		     struct file *file, unsigned int cmd, unsigned long arg);
+	int (*mmap)(struct snd_info_entry *entry, void *file_private_data,
+		    struct inode *inode, struct file *file,
+		    struct vm_area_struct *vma);
+};
+
+struct snd_info_entry {
+	const char *name;
+	umode_t mode;
+	long size;
+	unsigned short content;
+	union {
+		struct snd_info_entry_text text;
+		const struct snd_info_entry_ops *ops;
+	} c;
+	struct snd_info_entry *parent;
+	struct module *module;
+	void *private_data;
+	void (*private_free)(struct snd_info_entry *entry);
+	struct proc_dir_entry *p;
+	struct mutex access;
+	struct list_head children;
+	struct list_head list;
+};
+
+#if defined(CONFIG_SND_OSSEMUL) && defined(CONFIG_SND_PROC_FS)
+int snd_info_minor_register(void);
+#else
+#define snd_info_minor_register()	0
+#endif
+
+
+#ifdef CONFIG_SND_PROC_FS
+
+extern struct snd_info_entry *snd_seq_root;
+#ifdef CONFIG_SND_OSSEMUL
+extern struct snd_info_entry *snd_oss_root;
+void snd_card_info_read_oss(struct snd_info_buffer *buffer);
+#else
+#define snd_oss_root NULL
+static inline void snd_card_info_read_oss(struct snd_info_buffer *buffer) {}
+#endif
+
+/**
+ * snd_iprintf - printf on the procfs buffer
+ * @buf: the procfs buffer
+ * @fmt: the printf format
+ *
+ * Outputs the string on the procfs buffer just like printf().
+ *
+ * Return: zero for success, or a negative error code.
+ */
+#define snd_iprintf(buf, fmt, args...) \
+	seq_printf((struct seq_file *)(buf)->buffer, fmt, ##args)
+
+int snd_info_init(void);
+int snd_info_done(void);
+
+int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len);
+const char *snd_info_get_str(char *dest, const char *src, int len);
+struct snd_info_entry *snd_info_create_module_entry(struct module *module,
+					       const char *name,
+					       struct snd_info_entry *parent);
+struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card,
+					     const char *name,
+					     struct snd_info_entry *parent);
+void snd_info_free_entry(struct snd_info_entry *entry);
+
+int snd_info_card_create(struct snd_card *card);
+int snd_info_card_register(struct snd_card *card);
+int snd_info_card_free(struct snd_card *card);
+void snd_info_card_disconnect(struct snd_card *card);
+void snd_info_card_id_change(struct snd_card *card);
+int snd_info_register(struct snd_info_entry *entry);
+
+/* for card drivers */
+static inline int snd_card_proc_new(struct snd_card *card, const char *name,
+				    struct snd_info_entry **entryp)
+{
+	*entryp = snd_info_create_card_entry(card, name, card->proc_root);
+	return *entryp ? 0 : -ENOMEM;
+}
+
+static inline void snd_info_set_text_ops(struct snd_info_entry *entry, 
+	void *private_data,
+	void (*read)(struct snd_info_entry *, struct snd_info_buffer *))
+{
+	entry->private_data = private_data;
+	entry->c.text.read = read;
+}
+
+int snd_card_rw_proc_new(struct snd_card *card, const char *name,
+			 void *private_data,
+			 void (*read)(struct snd_info_entry *,
+				      struct snd_info_buffer *),
+			 void (*write)(struct snd_info_entry *entry,
+				       struct snd_info_buffer *buffer));
+
+int snd_info_check_reserved_words(const char *str);
+
+#else
+
+#define snd_seq_root NULL
+#define snd_oss_root NULL
+
+static inline int snd_iprintf(struct snd_info_buffer *buffer, char *fmt, ...) { return 0; }
+static inline int snd_info_init(void) { return 0; }
+static inline int snd_info_done(void) { return 0; }
+
+static inline int snd_info_get_line(struct snd_info_buffer *buffer, char *line, int len) { return 0; }
+static inline char *snd_info_get_str(char *dest, char *src, int len) { return NULL; }
+static inline struct snd_info_entry *snd_info_create_module_entry(struct module *module, const char *name, struct snd_info_entry *parent) { return NULL; }
+static inline struct snd_info_entry *snd_info_create_card_entry(struct snd_card *card, const char *name, struct snd_info_entry *parent) { return NULL; }
+static inline void snd_info_free_entry(struct snd_info_entry *entry) { ; }
+
+static inline int snd_info_card_create(struct snd_card *card) { return 0; }
+static inline int snd_info_card_register(struct snd_card *card) { return 0; }
+static inline int snd_info_card_free(struct snd_card *card) { return 0; }
+static inline void snd_info_card_disconnect(struct snd_card *card) { }
+static inline void snd_info_card_id_change(struct snd_card *card) { }
+static inline int snd_info_register(struct snd_info_entry *entry) { return 0; }
+
+static inline int snd_card_proc_new(struct snd_card *card, const char *name,
+				    struct snd_info_entry **entryp) { return -EINVAL; }
+static inline void snd_info_set_text_ops(struct snd_info_entry *entry __attribute__((unused)),
+					 void *private_data,
+					 void (*read)(struct snd_info_entry *, struct snd_info_buffer *)) {}
+static inline int snd_card_rw_proc_new(struct snd_card *card, const char *name,
+				       void *private_data,
+				       void (*read)(struct snd_info_entry *,
+						    struct snd_info_buffer *),
+				       void (*write)(struct snd_info_entry *entry,
+						     struct snd_info_buffer *buffer))
+{
+	return 0;
+}
+static inline int snd_info_check_reserved_words(const char *str) { return 1; }
+
+#endif
+
+/**
+ * snd_card_ro_proc_new - Create a read-only text proc file entry for the card
+ * @card: the card instance
+ * @name: the file name
+ * @private_data: the arbitrary private data
+ * @read: the read callback
+ *
+ * This proc file entry will be registered via snd_card_register() call, and
+ * it will be removed automatically at the card removal, too.
+ */
+static inline int
+snd_card_ro_proc_new(struct snd_card *card, const char *name,
+		     void *private_data,
+		     void (*read)(struct snd_info_entry *,
+				  struct snd_info_buffer *))
+{
+	return snd_card_rw_proc_new(card, name, private_data, read, NULL);
+}
+
+/*
+ * OSS info part
+ */
+
+#if defined(CONFIG_SND_OSSEMUL) && defined(CONFIG_SND_PROC_FS)
+
+#define SNDRV_OSS_INFO_DEV_AUDIO	0
+#define SNDRV_OSS_INFO_DEV_SYNTH	1
+#define SNDRV_OSS_INFO_DEV_MIDI		2
+#define SNDRV_OSS_INFO_DEV_TIMERS	4
+#define SNDRV_OSS_INFO_DEV_MIXERS	5
+
+#define SNDRV_OSS_INFO_DEV_COUNT	6
+
+int snd_oss_info_register(int dev, int num, char *string);
+#define snd_oss_info_unregister(dev, num) snd_oss_info_register(dev, num, NULL)
+
+#endif /* CONFIG_SND_OSSEMUL && CONFIG_SND_PROC_FS */
+
+#endif /* __SOUND_INFO_H */