Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   1) // SPDX-License-Identifier: GPL-2.0
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   3)  * Infrastructure for statistic tracing (histogram output).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   5)  * Copyright (C) 2008-2009 Frederic Weisbecker <fweisbec@gmail.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   7)  * Based on the code from trace_branch.c which is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   8)  * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300   9)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  10)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  12) #include <linux/security.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  13) #include <linux/list.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  14) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  15) #include <linux/rbtree.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  16) #include <linux/tracefs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  17) #include "trace_stat.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  18) #include "trace.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  21) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  22)  * List of stat red-black nodes from a tracer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  23)  * We use a such tree to sort quickly the stat
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  24)  * entries from the tracer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  25)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  26) struct stat_node {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  27) 	struct rb_node		node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  28) 	void			*stat;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  29) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  30) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  31) /* A stat session is the stats output in one file */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  32) struct stat_session {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  33) 	struct list_head	session_list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  34) 	struct tracer_stat	*ts;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  35) 	struct rb_root		stat_root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  36) 	struct mutex		stat_mutex;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  37) 	struct dentry		*file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  38) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  39) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  40) /* All of the sessions currently in use. Each stat file embed one session */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  41) static LIST_HEAD(all_stat_sessions);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  42) static DEFINE_MUTEX(all_stat_sessions_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  43) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  44) /* The root directory for all stat files */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  45) static struct dentry		*stat_dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  46) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  47) static void __reset_stat_session(struct stat_session *session)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  48) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  49) 	struct stat_node *snode, *n;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  50) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  51) 	rbtree_postorder_for_each_entry_safe(snode, n, &session->stat_root, node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  52) 		if (session->ts->stat_release)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  53) 			session->ts->stat_release(snode->stat);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  54) 		kfree(snode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  55) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  56) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  57) 	session->stat_root = RB_ROOT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  58) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  59) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  60) static void reset_stat_session(struct stat_session *session)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  61) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  62) 	mutex_lock(&session->stat_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  63) 	__reset_stat_session(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  64) 	mutex_unlock(&session->stat_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  65) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  66) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  67) static void destroy_session(struct stat_session *session)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  68) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  69) 	tracefs_remove(session->file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  70) 	__reset_stat_session(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  71) 	mutex_destroy(&session->stat_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  72) 	kfree(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  73) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  75) static int insert_stat(struct rb_root *root, void *stat, cmp_func_t cmp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  76) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  77) 	struct rb_node **new = &(root->rb_node), *parent = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  78) 	struct stat_node *data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  79) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  80) 	data = kzalloc(sizeof(*data), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  81) 	if (!data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  82) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  83) 	data->stat = stat;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  84) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  85) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  86) 	 * Figure out where to put new node
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  87) 	 * This is a descendent sorting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  88) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  89) 	while (*new) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  90) 		struct stat_node *this;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  91) 		int result;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  92) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  93) 		this = container_of(*new, struct stat_node, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  94) 		result = cmp(data->stat, this->stat);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  95) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  96) 		parent = *new;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  97) 		if (result >= 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  98) 			new = &((*new)->rb_left);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  99) 		else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) 			new = &((*new)->rb_right);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) 	rb_link_node(&data->node, parent, new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) 	rb_insert_color(&data->node, root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)  * For tracers that don't provide a stat_cmp callback.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)  * This one will force an insertion as right-most node
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111)  * in the rbtree.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) static int dummy_cmp(const void *p1, const void *p2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) 	return -1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)  * Initialize the stat rbtree at each trace_stat file opening.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)  * All of these copies and sorting are required on all opening
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121)  * since the stats could have changed between two file sessions.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) static int stat_seq_init(struct stat_session *session)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) 	struct tracer_stat *ts = session->ts;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) 	struct rb_root *root = &session->stat_root;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) 	void *stat;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) 	int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) 	int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) 	mutex_lock(&session->stat_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) 	__reset_stat_session(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) 	if (!ts->stat_cmp)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) 		ts->stat_cmp = dummy_cmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) 	stat = ts->stat_start(ts);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) 	if (!stat)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) 		goto exit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) 	ret = insert_stat(root, stat, ts->stat_cmp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) 		goto exit;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) 	/*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) 	 * Iterate over the tracer stat entries and store them in an rbtree.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) 	 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) 	for (i = 1; ; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) 		stat = ts->stat_next(stat, i);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) 		/* End of insertion */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) 		if (!stat)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) 		ret = insert_stat(root, stat, ts->stat_cmp);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) 		if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) 			goto exit_free_rbtree;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) exit:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) 	mutex_unlock(&session->stat_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) exit_free_rbtree:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) 	__reset_stat_session(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) 	mutex_unlock(&session->stat_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) static void *stat_seq_start(struct seq_file *s, loff_t *pos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) 	struct stat_session *session = s->private;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) 	struct rb_node *node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) 	int n = *pos;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) 	int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) 	/* Prevent from tracer switch or rbtree modification */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) 	mutex_lock(&session->stat_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) 	/* If we are in the beginning of the file, print the headers */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) 	if (session->ts->stat_headers) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) 		if (n == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) 			return SEQ_START_TOKEN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) 		n--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) 	node = rb_first(&session->stat_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) 	for (i = 0; node && i < n; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) 		node = rb_next(node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) 	return node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) static void *stat_seq_next(struct seq_file *s, void *p, loff_t *pos)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) 	struct stat_session *session = s->private;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) 	struct rb_node *node = p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) 	(*pos)++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) 	if (p == SEQ_START_TOKEN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203) 		return rb_first(&session->stat_root);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) 	return rb_next(node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) static void stat_seq_stop(struct seq_file *s, void *p)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210) 	struct stat_session *session = s->private;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) 	mutex_unlock(&session->stat_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) static int stat_seq_show(struct seq_file *s, void *v)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) 	struct stat_session *session = s->private;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) 	struct stat_node *l = container_of(v, struct stat_node, node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) 	if (v == SEQ_START_TOKEN)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) 		return session->ts->stat_headers(s);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) 	return session->ts->stat_show(s, l->stat);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) static const struct seq_operations trace_stat_seq_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) 	.start		= stat_seq_start,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) 	.next		= stat_seq_next,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) 	.stop		= stat_seq_stop,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) 	.show		= stat_seq_show
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) /* The session stat is refilled and resorted at each stat file opening */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) static int tracing_stat_open(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) 	struct seq_file *m;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) 	struct stat_session *session = inode->i_private;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) 	ret = security_locked_down(LOCKDOWN_TRACEFS);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) 	ret = stat_seq_init(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247) 	ret = seq_open(file, &trace_stat_seq_ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) 	if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) 		reset_stat_session(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) 	m = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) 	m->private = session;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259)  * Avoid consuming memory with our now useless rbtree.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) static int tracing_stat_release(struct inode *i, struct file *f)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) 	struct stat_session *session = i->i_private;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) 	reset_stat_session(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) 	return seq_release(i, f);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) static const struct file_operations tracing_stat_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) 	.open		= tracing_stat_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) 	.read		= seq_read,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) 	.llseek		= seq_lseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) 	.release	= tracing_stat_release
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) static int tracing_stat_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) 	ret = tracing_init_dentry();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) 	if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) 		return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) 	stat_dir = tracefs_create_dir("trace_stat", NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) 	if (!stat_dir) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) 		pr_warn("Could not create tracefs 'trace_stat' entry\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) static int init_stat_file(struct stat_session *session)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) 	int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) 	if (!stat_dir && (ret = tracing_stat_init()))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) 		return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) 	session->file = tracefs_create_file(session->ts->name, 0644,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301) 					    stat_dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) 					    session, &tracing_stat_fops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) 	if (!session->file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) 		return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) int register_stat_tracer(struct tracer_stat *trace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) 	struct stat_session *session, *node;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) 	int ret = -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) 	if (!trace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) 	if (!trace->stat_start || !trace->stat_next || !trace->stat_show)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) 		return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) 	/* Already registered? */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) 	mutex_lock(&all_stat_sessions_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) 	list_for_each_entry(node, &all_stat_sessions, session_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) 		if (node->ts == trace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) 			goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) 	ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) 	/* Init the session */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) 	session = kzalloc(sizeof(*session), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) 	if (!session)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) 	session->ts = trace;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) 	INIT_LIST_HEAD(&session->session_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) 	mutex_init(&session->stat_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) 	ret = init_stat_file(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337) 	if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) 		destroy_session(session);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) 		goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) 	ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) 	/* Register */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) 	list_add_tail(&session->session_list, &all_stat_sessions);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345)  out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) 	mutex_unlock(&all_stat_sessions_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) 	return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) void unregister_stat_tracer(struct tracer_stat *trace)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) 	struct stat_session *node, *tmp;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) 	mutex_lock(&all_stat_sessions_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) 	list_for_each_entry_safe(node, tmp, &all_stat_sessions, session_list) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) 		if (node->ts == trace) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) 			list_del(&node->session_list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) 			destroy_session(node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) 		}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) 	mutex_unlock(&all_stat_sessions_mutex);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) }