Merge tag 'trace-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing updates from Steven Rostedt:
 "This release has no new tracing features, just clean ups, minor fixes
  and small optimizations"

* tag 'trace-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (25 commits)
  tracing: Remove outdated ring buffer comment
  tracing/probes: Fix a warning message to show correct maximum length
  tracing: Fix return value check in trace_benchmark_reg()
  tracing: Use modern function declaration
  jump_label: Reduce the size of struct static_key
  tracing/probe: Show subsystem name in messages
  tracing/hwlat: Update old comment about migration
  timers: Make flags output in the timer_start tracepoint useful
  tracing: Have traceprobe_probes_write() not access userspace unnecessarily
  tracing: Have COMM event filter key be treated as a string
  ftrace: Have set_graph_function handle multiple functions in one write
  ftrace: Do not hold references of ftrace_graph_{notrace_}hash out of graph_lock
  tracing: Reset parser->buffer to allow multiple "puts"
  ftrace: Have set_graph_functions handle write with RDWR
  ftrace: Reset fgd->hash in ftrace_graph_write()
  ftrace: Replace (void *)1 with a meaningful macro name FTRACE_GRAPH_EMPTY
  ftrace: Create a slight optimization on searching the ftrace_hash
  tracing: Add ftrace_hash_key() helper function
  ftrace: Convert graph filter to use hash tables
  ftrace: Expose ftrace_hash_empty and ftrace_lookup_ip
  ...

Documentation/static-keys.txt

@@ -155,7 +155,9 @@ or:
 
 There are a few functions and macros that architectures must implement in order
 to take advantage of this optimization. If there is no architecture support, we
-simply fall back to a traditional, load, test, and jump sequence.
+simply fall back to a traditional, load, test, and jump sequence. Also, the
+struct jump_entry table must be at least 4-byte aligned because the
+static_key->entry field makes use of the two least significant bits.
 
 * select HAVE_ARCH_JUMP_LABEL, see: arch/x86/Kconfig
 

include/linux/compiler.h

@@ -105,29 +105,36 @@ struct ftrace_branch_data {
 	};
 };
 
+struct ftrace_likely_data {
+	struct ftrace_branch_data	data;
+	unsigned long			constant;
+};
+
 /*
  * Note: DISABLE_BRANCH_PROFILING can be used by special lowlevel code
  * to disable branch tracing on a per file basis.
  */
 #if defined(CONFIG_TRACE_BRANCH_PROFILING) \
     && !defined(DISABLE_BRANCH_PROFILING) && !defined(__CHECKER__)
-void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
+void ftrace_likely_update(struct ftrace_likely_data *f, int val,
+			  int expect, int is_constant);
 
 #define likely_notrace(x)	__builtin_expect(!!(x), 1)
 #define unlikely_notrace(x)	__builtin_expect(!!(x), 0)
 
-#define __branch_check__(x, expect) ({					\
+#define __branch_check__(x, expect, is_constant) ({			\
 			int ______r;					\
-			static struct ftrace_branch_data		\
+			static struct ftrace_likely_data		\
 				__attribute__((__aligned__(4)))		\
 				__attribute__((section("_ftrace_annotated_branch"))) \
 				______f = {				\
-				.func = __func__,			\
-				.file = __FILE__,			\
-				.line = __LINE__,			\
+				.data.func = __func__,			\
+				.data.file = __FILE__,			\
+				.data.line = __LINE__,			\
 			};						\
-			______r = likely_notrace(x);			\
-			ftrace_likely_update(&______f, ______r, expect); \
+			______r = __builtin_expect(!!(x), expect);	\
+			ftrace_likely_update(&______f, ______r,		\
+					     expect, is_constant);	\
 			______r;					\
 		})
 
@@ -137,10 +144,10 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect);
  * written by Daniel Walker.
  */
 # ifndef likely
-#  define likely(x)	(__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 1))
+#  define likely(x)	(__branch_check__(x, 1, __builtin_constant_p(x)))
 # endif
 # ifndef unlikely
-#  define unlikely(x)	(__builtin_constant_p(x) ? !!(x) : __branch_check__(x, 0))
+#  define unlikely(x)	(__branch_check__(x, 0, __builtin_constant_p(x)))
 # endif
 
 #ifdef CONFIG_PROFILE_ALL_BRANCHES

include/linux/jump_label.h

@@ -89,11 +89,17 @@ extern bool static_key_initialized;
 
 struct static_key {
 	atomic_t enabled;
-/* Set lsb bit to 1 if branch is default true, 0 ot */
+/*
+ * bit 0 => 1 if key is initially true
+ *	    0 if initially false
+ * bit 1 => 1 if points to struct static_key_mod
+ *	    0 if points to struct jump_entry
+ */
+	union {
+		unsigned long type;
 		struct jump_entry *entries;
-#ifdef CONFIG_MODULES
 		struct static_key_mod *next;
-#endif
+	};
 };
 
 #else
@@ -120,7 +126,8 @@ struct module;
 
 #define JUMP_TYPE_FALSE		0UL
 #define JUMP_TYPE_TRUE		1UL
-#define JUMP_TYPE_MASK	1UL
+#define JUMP_TYPE_LINKED	2UL
+#define JUMP_TYPE_MASK		3UL
 
 static __always_inline bool static_key_false(struct static_key *key)
 {

include/linux/timer.h

@@ -61,6 +61,8 @@ struct timer_list {
 #define TIMER_ARRAYSHIFT	22
 #define TIMER_ARRAYMASK		0xFFC00000
 
+#define TIMER_TRACE_FLAGMASK	(TIMER_MIGRATING | TIMER_DEFERRABLE | TIMER_PINNED | TIMER_IRQSAFE)
+
 #define __TIMER_INITIALIZER(_function, _expires, _data, _flags) { \
 		.entry = { .next = TIMER_ENTRY_STATIC },	\
 		.function = (_function),			\

include/trace/events/timer.h

@@ -36,6 +36,13 @@ DEFINE_EVENT(timer_class, timer_init,
 	TP_ARGS(timer)
 );
 
+#define decode_timer_flags(flags)			\
+	__print_flags(flags, "|",			\
+		{  TIMER_MIGRATING,	"M" },		\
+		{  TIMER_DEFERRABLE,	"D" },		\
+		{  TIMER_PINNED,	"P" },		\
+		{  TIMER_IRQSAFE,	"I" })
+
 /**
  * timer_start - called when the timer is started
  * @timer:	pointer to struct timer_list
@@ -65,9 +72,12 @@ TRACE_EVENT(timer_start,
 		__entry->flags		= flags;
 	),
 
-	TP_printk("timer=%p function=%pf expires=%lu [timeout=%ld] flags=0x%08x",
+	TP_printk("timer=%p function=%pf expires=%lu [timeout=%ld] cpu=%u idx=%u flags=%s",
 		  __entry->timer, __entry->function, __entry->expires,
-		  (long)__entry->expires - __entry->now, __entry->flags)
+		  (long)__entry->expires - __entry->now,
+		  __entry->flags & TIMER_CPUMASK,
+		  __entry->flags >> TIMER_ARRAYSHIFT,
+		  decode_timer_flags(__entry->flags & TIMER_TRACE_FLAGMASK))
 );
 
 /**

kernel/jump_label.c

@@ -236,12 +236,28 @@ void __weak __init_or_module arch_jump_label_transform_static(struct jump_entry
 
 static inline struct jump_entry *static_key_entries(struct static_key *key)
 {
-	return (struct jump_entry *)((unsigned long)key->entries & ~JUMP_TYPE_MASK);
+	WARN_ON_ONCE(key->type & JUMP_TYPE_LINKED);
+	return (struct jump_entry *)(key->type & ~JUMP_TYPE_MASK);
 }
 
 static inline bool static_key_type(struct static_key *key)
 {
-	return (unsigned long)key->entries & JUMP_TYPE_MASK;
+	return key->type & JUMP_TYPE_TRUE;
+}
+
+static inline bool static_key_linked(struct static_key *key)
+{
+	return key->type & JUMP_TYPE_LINKED;
+}
+
+static inline void static_key_clear_linked(struct static_key *key)
+{
+	key->type &= ~JUMP_TYPE_LINKED;
+}
+
+static inline void static_key_set_linked(struct static_key *key)
+{
+	key->type |= JUMP_TYPE_LINKED;
 }
 
 static inline struct static_key *jump_entry_key(struct jump_entry *entry)
@@ -254,6 +270,26 @@ static bool jump_entry_branch(struct jump_entry *entry)
 	return (unsigned long)entry->key & 1UL;
 }
 
+/***
+ * A 'struct static_key' uses a union such that it either points directly
+ * to a table of 'struct jump_entry' or to a linked list of modules which in
+ * turn point to 'struct jump_entry' tables.
+ *
+ * The two lower bits of the pointer are used to keep track of which pointer
+ * type is in use and to store the initial branch direction, we use an access
+ * function which preserves these bits.
+ */
+static void static_key_set_entries(struct static_key *key,
+				   struct jump_entry *entries)
+{
+	unsigned long type;
+
+	WARN_ON_ONCE((unsigned long)entries & JUMP_TYPE_MASK);
+	type = key->type & JUMP_TYPE_MASK;
+	key->entries = entries;
+	key->type |= type;
+}
+
 static enum jump_label_type jump_label_type(struct jump_entry *entry)
 {
 	struct static_key *key = jump_entry_key(entry);
@@ -313,13 +349,7 @@ void __init jump_label_init(void)
 			continue;
 
 		key = iterk;
-		/*
-		 * Set key->entries to iter, but preserve JUMP_LABEL_TRUE_BRANCH.
-		 */
-		*((unsigned long *)&key->entries) += (unsigned long)iter;
-#ifdef CONFIG_MODULES
-		key->next = NULL;
-#endif
+		static_key_set_entries(key, iter);
 	}
 	static_key_initialized = true;
 	jump_label_unlock();
@@ -343,6 +373,29 @@ struct static_key_mod {
 	struct module *mod;
 };
 
+static inline struct static_key_mod *static_key_mod(struct static_key *key)
+{
+	WARN_ON_ONCE(!(key->type & JUMP_TYPE_LINKED));
+	return (struct static_key_mod *)(key->type & ~JUMP_TYPE_MASK);
+}
+
+/***
+ * key->type and key->next are the same via union.
+ * This sets key->next and preserves the type bits.
+ *
+ * See additional comments above static_key_set_entries().
+ */
+static void static_key_set_mod(struct static_key *key,
+			       struct static_key_mod *mod)
+{
+	unsigned long type;
+
+	WARN_ON_ONCE((unsigned long)mod & JUMP_TYPE_MASK);
+	type = key->type & JUMP_TYPE_MASK;
+	key->next = mod;
+	key->type |= type;
+}
+
 static int __jump_label_mod_text_reserved(void *start, void *end)
 {
 	struct module *mod;
@@ -365,11 +418,23 @@ static void __jump_label_mod_update(struct static_key *key)
 {
 	struct static_key_mod *mod;
 
-	for (mod = key->next; mod; mod = mod->next) {
-		struct module *m = mod->mod;
+	for (mod = static_key_mod(key); mod; mod = mod->next) {
+		struct jump_entry *stop;
+		struct module *m;
+
+		/*
+		 * NULL if the static_key is defined in a module
+		 * that does not use it
+		 */
+		if (!mod->entries)
+			continue;
 
-		__jump_label_update(key, mod->entries,
-				    m->jump_entries + m->num_jump_entries);
+		m = mod->mod;
+		if (!m)
+			stop = __stop___jump_table;
+		else
+			stop = m->jump_entries + m->num_jump_entries;
+		__jump_label_update(key, mod->entries, stop);
 	}
 }
 
@@ -404,7 +469,7 @@ static int jump_label_add_module(struct module *mod)
 	struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
 	struct jump_entry *iter;
 	struct static_key *key = NULL;
-	struct static_key_mod *jlm;
+	struct static_key_mod *jlm, *jlm2;
 
 	/* if the module doesn't have jump label entries, just return */
 	if (iter_start == iter_stop)
@@ -421,20 +486,32 @@ static int jump_label_add_module(struct module *mod)
 
 		key = iterk;
 		if (within_module(iter->key, mod)) {
-			/*
-			 * Set key->entries to iter, but preserve JUMP_LABEL_TRUE_BRANCH.
-			 */
-			*((unsigned long *)&key->entries) += (unsigned long)iter;
-			key->next = NULL;
+			static_key_set_entries(key, iter);
 			continue;
 		}
 		jlm = kzalloc(sizeof(struct static_key_mod), GFP_KERNEL);
 		if (!jlm)
 			return -ENOMEM;
+		if (!static_key_linked(key)) {
+			jlm2 = kzalloc(sizeof(struct static_key_mod),
+				       GFP_KERNEL);
+			if (!jlm2) {
+				kfree(jlm);
+				return -ENOMEM;
+			}
+			preempt_disable();
+			jlm2->mod = __module_address((unsigned long)key);
+			preempt_enable();
+			jlm2->entries = static_key_entries(key);
+			jlm2->next = NULL;
+			static_key_set_mod(key, jlm2);
+			static_key_set_linked(key);
+		}
 		jlm->mod = mod;
 		jlm->entries = iter;
-		jlm->next = key->next;
-		key->next = jlm;
+		jlm->next = static_key_mod(key);
+		static_key_set_mod(key, jlm);
+		static_key_set_linked(key);
 
 		/* Only update if we've changed from our initial state */
 		if (jump_label_type(iter) != jump_label_init_type(iter))
@@ -461,16 +538,34 @@ static void jump_label_del_module(struct module *mod)
 		if (within_module(iter->key, mod))
 			continue;
 
+		/* No memory during module load */
+		if (WARN_ON(!static_key_linked(key)))
+			continue;
+
 		prev = &key->next;
-		jlm = key->next;
+		jlm = static_key_mod(key);
 
 		while (jlm && jlm->mod != mod) {
 			prev = &jlm->next;
 			jlm = jlm->next;
 		}
 
-		if (jlm) {
+		/* No memory during module load */
+		if (WARN_ON(!jlm))
+			continue;
+
+		if (prev == &key->next)
+			static_key_set_mod(key, jlm->next);
+		else
 			*prev = jlm->next;
+
+		kfree(jlm);
+
+		jlm = static_key_mod(key);
+		/* if only one etry is left, fold it back into the static_key */
+		if (jlm->next == NULL) {
+			static_key_set_entries(key, jlm->entries);
+			static_key_clear_linked(key);
 			kfree(jlm);
 		}
 	}
@@ -499,8 +594,10 @@ jump_label_module_notify(struct notifier_block *self, unsigned long val,
 	case MODULE_STATE_COMING:
 		jump_label_lock();
 		ret = jump_label_add_module(mod);
-		if (ret)
+		if (ret) {
+			WARN(1, "Failed to allocatote memory: jump_label may not work properly.\n");
 			jump_label_del_module(mod);
+		}
 		jump_label_unlock();
 		break;
 	case MODULE_STATE_GOING:
@@ -561,11 +658,14 @@ int jump_label_text_reserved(void *start, void *end)
 static void jump_label_update(struct static_key *key)
 {
 	struct jump_entry *stop = __stop___jump_table;
-	struct jump_entry *entry = static_key_entries(key);
+	struct jump_entry *entry;
 #ifdef CONFIG_MODULES
 	struct module *mod;
 
+	if (static_key_linked(key)) {
 		__jump_label_mod_update(key);
+		return;
+	}
 
 	preempt_disable();
 	mod = __module_address((unsigned long)key);
@@ -573,6 +673,7 @@ static void jump_label_update(struct static_key *key)
 		stop = mod->jump_entries + mod->num_jump_entries;
 	preempt_enable();
 #endif
+	entry = static_key_entries(key);
 	/* if there are no users, entry can be NULL */
 	if (entry)
 		__jump_label_update(key, entry, stop);

kernel/trace/ftrace.c

@@ -1110,13 +1110,6 @@ struct ftrace_func_entry {
 	unsigned long ip;
 };
 
-struct ftrace_hash {
-	unsigned long		size_bits;
-	struct hlist_head	*buckets;
-	unsigned long		count;
-	struct rcu_head		rcu;
-};
-
 /*
  * We make these constant because no one should touch them,
  * but they are used as the default "empty hash", to avoid allocating
@@ -1192,26 +1185,24 @@ struct ftrace_page {
 static struct ftrace_page	*ftrace_pages_start;
 static struct ftrace_page	*ftrace_pages;
 
-static bool __always_inline ftrace_hash_empty(struct ftrace_hash *hash)
+static __always_inline unsigned long
+ftrace_hash_key(struct ftrace_hash *hash, unsigned long ip)
 {
-	return !hash || !hash->count;
+	if (hash->size_bits > 0)
+		return hash_long(ip, hash->size_bits);
+
+	return 0;
 }
 
-static struct ftrace_func_entry *
-ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
+/* Only use this function if ftrace_hash_empty() has already been tested */
+static __always_inline struct ftrace_func_entry *
+__ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
 {
 	unsigned long key;
 	struct ftrace_func_entry *entry;
 	struct hlist_head *hhd;
 
-	if (ftrace_hash_empty(hash))
-		return NULL;
-
-	if (hash->size_bits > 0)
-		key = hash_long(ip, hash->size_bits);
-	else
-		key = 0;
-
+	key = ftrace_hash_key(hash, ip);
 	hhd = &hash->buckets[key];
 
 	hlist_for_each_entry_rcu_notrace(entry, hhd, hlist) {
@@ -1221,17 +1212,32 @@ ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
 	return NULL;
 }
 
+/**
+ * ftrace_lookup_ip - Test to see if an ip exists in an ftrace_hash
+ * @hash: The hash to look at
+ * @ip: The instruction pointer to test
+ *
+ * Search a given @hash to see if a given instruction pointer (@ip)
+ * exists in it.
+ *
+ * Returns the entry that holds the @ip if found. NULL otherwise.
+ */
+struct ftrace_func_entry *
+ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip)
+{
+	if (ftrace_hash_empty(hash))
+		return NULL;
+
+	return __ftrace_lookup_ip(hash, ip);
+}
+
 static void __add_hash_entry(struct ftrace_hash *hash,
 			     struct ftrace_func_entry *entry)
 {
 	struct hlist_head *hhd;
 	unsigned long key;
 
-	if (hash->size_bits)
-		key = hash_long(entry->ip, hash->size_bits);
-	else
-		key = 0;
-
+	key = ftrace_hash_key(hash, entry->ip);
 	hhd = &hash->buckets[key];
 	hlist_add_head(&entry->hlist, hhd);
 	hash->count++;
@@ -1383,9 +1389,8 @@ ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, int filter_hash);
 static int ftrace_hash_ipmodify_update(struct ftrace_ops *ops,
 				       struct ftrace_hash *new_hash);
 
-static int
-ftrace_hash_move(struct ftrace_ops *ops, int enable,
-		 struct ftrace_hash **dst, struct ftrace_hash *src)
+static struct ftrace_hash *
+__ftrace_hash_move(struct ftrace_hash *src)
 {
 	struct ftrace_func_entry *entry;
 	struct hlist_node *tn;
@@ -1393,21 +1398,13 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
 	struct ftrace_hash *new_hash;
 	int size = src->count;
 	int bits = 0;
-	int ret;
 	int i;
 
-	/* Reject setting notrace hash on IPMODIFY ftrace_ops */
-	if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
-		return -EINVAL;
-
 	/*
-	 * If the new source is empty, just free dst and assign it
-	 * the empty_hash.
+	 * If the new source is empty, just return the empty_hash.
 	 */
-	if (!src->count) {
-		new_hash = EMPTY_HASH;
-		goto update;
-	}
+	if (!src->count)
+		return EMPTY_HASH;
 
 	/*
 	 * Make the hash size about 1/2 the # found
@@ -1421,7 +1418,7 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
 
 	new_hash = alloc_ftrace_hash(bits);
 	if (!new_hash)
-		return -ENOMEM;
+		return NULL;
 
 	size = 1 << src->size_bits;
 	for (i = 0; i < size; i++) {
@@ -1432,7 +1429,24 @@ ftrace_hash_move(struct ftrace_ops *ops, int enable,
 		}
 	}
 
-update:
+	return new_hash;
+}
+
+static int
+ftrace_hash_move(struct ftrace_ops *ops, int enable,
+		 struct ftrace_hash **dst, struct ftrace_hash *src)
+{
+	struct ftrace_hash *new_hash;
+	int ret;
+
+	/* Reject setting notrace hash on IPMODIFY ftrace_ops */
+	if (ops->flags & FTRACE_OPS_FL_IPMODIFY && !enable)
+		return -EINVAL;
+
+	new_hash = __ftrace_hash_move(src);
+	if (!new_hash)
+		return -ENOMEM;
+
 	/* Make sure this can be applied if it is IPMODIFY ftrace_ops */
 	if (enable) {
 		/* IPMODIFY should be updated only when filter_hash updating */
@@ -1466,9 +1480,9 @@ static bool hash_contains_ip(unsigned long ip,
 	 * notrace hash is considered not in the notrace hash.
 	 */
 	return (ftrace_hash_empty(hash->filter_hash) ||
-		ftrace_lookup_ip(hash->filter_hash, ip)) &&
+		__ftrace_lookup_ip(hash->filter_hash, ip)) &&
 		(ftrace_hash_empty(hash->notrace_hash) ||
-		 !ftrace_lookup_ip(hash->notrace_hash, ip));
+		 !__ftrace_lookup_ip(hash->notrace_hash, ip));
 }
 
 /*
@@ -2880,7 +2894,7 @@ ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)
 
 	/* The function must be in the filter */
 	if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&
-	    !ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
+	    !__ftrace_lookup_ip(ops->func_hash->filter_hash, rec->ip))
 		return 0;
 
 	/* If in notrace hash, we ignore it too */
@@ -4382,7 +4396,7 @@ __setup("ftrace_filter=", set_ftrace_filter);
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 static char ftrace_graph_buf[FTRACE_FILTER_SIZE] __initdata;
 static char ftrace_graph_notrace_buf[FTRACE_FILTER_SIZE] __initdata;
-static int ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer);
+static int ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer);
 
 static unsigned long save_global_trampoline;
 static unsigned long save_global_flags;
@@ -4405,18 +4419,17 @@ static void __init set_ftrace_early_graph(char *buf, int enable)
 {
 	int ret;
 	char *func;
-	unsigned long *table = ftrace_graph_funcs;
-	int *count = &ftrace_graph_count;
+	struct ftrace_hash *hash;
 
-	if (!enable) {
-		table = ftrace_graph_notrace_funcs;
-		count = &ftrace_graph_notrace_count;
-	}
+	if (enable)
+		hash = ftrace_graph_hash;
+	else
+		hash = ftrace_graph_notrace_hash;
 
 	while (buf) {
 		func = strsep(&buf, ",");
 		/* we allow only one expression at a time */
-		ret = ftrace_set_func(table, count, FTRACE_GRAPH_MAX_FUNCS, func);
+		ret = ftrace_graph_set_hash(hash, func);
 		if (ret)
 			printk(KERN_DEBUG "ftrace: function %s not "
 					  "traceable\n", func);
@@ -4540,26 +4553,55 @@ static const struct file_operations ftrace_notrace_fops = {
 
 static DEFINE_MUTEX(graph_lock);
 
-int ftrace_graph_count;
-int ftrace_graph_notrace_count;
-unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
-unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS] __read_mostly;
+struct ftrace_hash *ftrace_graph_hash = EMPTY_HASH;
+struct ftrace_hash *ftrace_graph_notrace_hash = EMPTY_HASH;
+
+enum graph_filter_type {
+	GRAPH_FILTER_NOTRACE	= 0,
+	GRAPH_FILTER_FUNCTION,
+};
+
+#define FTRACE_GRAPH_EMPTY	((void *)1)
 
 struct ftrace_graph_data {
-	unsigned long *table;
-	size_t size;
-	int *count;
+	struct ftrace_hash		*hash;
+	struct ftrace_func_entry	*entry;
+	int				idx;   /* for hash table iteration */
+	enum graph_filter_type		type;
+	struct ftrace_hash		*new_hash;
 	const struct seq_operations	*seq_ops;
+	struct trace_parser		parser;
 };
 
 static void *
 __g_next(struct seq_file *m, loff_t *pos)
 {
 	struct ftrace_graph_data *fgd = m->private;
+	struct ftrace_func_entry *entry = fgd->entry;
+	struct hlist_head *head;
+	int i, idx = fgd->idx;
 
-	if (*pos >= *fgd->count)
+	if (*pos >= fgd->hash->count)
+		return NULL;
+
+	if (entry) {
+		hlist_for_each_entry_continue(entry, hlist) {
+			fgd->entry = entry;
+			return entry;
+		}
+
+		idx++;
+	}
+
+	for (i = idx; i < 1 << fgd->hash->size_bits; i++) {
+		head = &fgd->hash->buckets[i];
+		hlist_for_each_entry(entry, head, hlist) {
+			fgd->entry = entry;
+			fgd->idx = i;
+			return entry;
+		}
+	}
 	return NULL;
-	return &fgd->table[*pos];
 }
 
 static void *
@@ -4575,10 +4617,19 @@ static void *g_start(struct seq_file *m, loff_t *pos)
 
 	mutex_lock(&graph_lock);
 
+	if (fgd->type == GRAPH_FILTER_FUNCTION)
+		fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
+					lockdep_is_held(&graph_lock));
+	else
+		fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
+					lockdep_is_held(&graph_lock));
+
 	/* Nothing, tell g_show to print all functions are enabled */
-	if (!*fgd->count && !*pos)
-		return (void *)1;
+	if (ftrace_hash_empty(fgd->hash) && !*pos)
+		return FTRACE_GRAPH_EMPTY;
 
+	fgd->idx = 0;
+	fgd->entry = NULL;
 	return __g_next(m, pos);
 }
 
@@ -4589,22 +4640,22 @@ static void g_stop(struct seq_file *m, void *p)
 
 static int g_show(struct seq_file *m, void *v)
 {
-	unsigned long *ptr = v;
+	struct ftrace_func_entry *entry = v;
 
-	if (!ptr)
+	if (!entry)
 		return 0;
 
-	if (ptr == (unsigned long *)1) {
+	if (entry == FTRACE_GRAPH_EMPTY) {
 		struct ftrace_graph_data *fgd = m->private;
 
-		if (fgd->table == ftrace_graph_funcs)
+		if (fgd->type == GRAPH_FILTER_FUNCTION)
 			seq_puts(m, "#### all functions enabled ####\n");
 		else
 			seq_puts(m, "#### no functions disabled ####\n");
 		return 0;
 	}
 
-	seq_printf(m, "%ps\n", (void *)*ptr);
+	seq_printf(m, "%ps\n", (void *)entry->ip);
 
 	return 0;
 }
@@ -4621,24 +4672,51 @@ __ftrace_graph_open(struct inode *inode, struct file *file,
 		    struct ftrace_graph_data *fgd)
 {
 	int ret = 0;
+	struct ftrace_hash *new_hash = NULL;
 
-	mutex_lock(&graph_lock);
-	if ((file->f_mode & FMODE_WRITE) &&
-	    (file->f_flags & O_TRUNC)) {
-		*fgd->count = 0;
-		memset(fgd->table, 0, fgd->size * sizeof(*fgd->table));
+	if (file->f_mode & FMODE_WRITE) {
+		const int size_bits = FTRACE_HASH_DEFAULT_BITS;
+
+		if (trace_parser_get_init(&fgd->parser, FTRACE_BUFF_MAX))
+			return -ENOMEM;
+
+		if (file->f_flags & O_TRUNC)
+			new_hash = alloc_ftrace_hash(size_bits);
+		else
+			new_hash = alloc_and_copy_ftrace_hash(size_bits,
+							      fgd->hash);
+		if (!new_hash) {
+			ret = -ENOMEM;
+			goto out;
+		}
 	}
-	mutex_unlock(&graph_lock);
 
 	if (file->f_mode & FMODE_READ) {
-		ret = seq_open(file, fgd->seq_ops);
+		ret = seq_open(file, &ftrace_graph_seq_ops);
 		if (!ret) {
 			struct seq_file *m = file->private_data;
 			m->private = fgd;
+		} else {
+			/* Failed */
+			free_ftrace_hash(new_hash);
+			new_hash = NULL;
 		}
 	} else
 		file->private_data = fgd;
 
+out:
+	if (ret < 0 && file->f_mode & FMODE_WRITE)
+		trace_parser_put(&fgd->parser);
+
+	fgd->new_hash = new_hash;
+
+	/*
+	 * All uses of fgd->hash must be taken with the graph_lock
+	 * held. The graph_lock is going to be released, so force
+	 * fgd->hash to be reinitialized when it is taken again.
+	 */
+	fgd->hash = NULL;
+
 	return ret;
 }
 
@@ -4646,6 +4724,7 @@ static int
 ftrace_graph_open(struct inode *inode, struct file *file)
 {
 	struct ftrace_graph_data *fgd;
+	int ret;
 
 	if (unlikely(ftrace_disabled))
 		return -ENODEV;
@@ -4654,18 +4733,26 @@ ftrace_graph_open(struct inode *inode, struct file *file)
 	if (fgd == NULL)
 		return -ENOMEM;
 
-	fgd->table = ftrace_graph_funcs;
-	fgd->size = FTRACE_GRAPH_MAX_FUNCS;
-	fgd->count = &ftrace_graph_count;
+	mutex_lock(&graph_lock);
+
+	fgd->hash = rcu_dereference_protected(ftrace_graph_hash,
+					lockdep_is_held(&graph_lock));
+	fgd->type = GRAPH_FILTER_FUNCTION;
 	fgd->seq_ops = &ftrace_graph_seq_ops;
 
-	return __ftrace_graph_open(inode, file, fgd);
+	ret = __ftrace_graph_open(inode, file, fgd);
+	if (ret < 0)
+		kfree(fgd);
+
+	mutex_unlock(&graph_lock);
+	return ret;
 }
 
 static int
 ftrace_graph_notrace_open(struct inode *inode, struct file *file)
 {
 	struct ftrace_graph_data *fgd;
+	int ret;
 
 	if (unlikely(ftrace_disabled))
 		return -ENODEV;
@@ -4674,45 +4761,97 @@ ftrace_graph_notrace_open(struct inode *inode, struct file *file)
 	if (fgd == NULL)
 		return -ENOMEM;
 
-	fgd->table = ftrace_graph_notrace_funcs;
-	fgd->size = FTRACE_GRAPH_MAX_FUNCS;
-	fgd->count = &ftrace_graph_notrace_count;
+	mutex_lock(&graph_lock);
+
+	fgd->hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
+					lockdep_is_held(&graph_lock));
+	fgd->type = GRAPH_FILTER_NOTRACE;
 	fgd->seq_ops = &ftrace_graph_seq_ops;
 
-	return __ftrace_graph_open(inode, file, fgd);
+	ret = __ftrace_graph_open(inode, file, fgd);
+	if (ret < 0)
+		kfree(fgd);
+
+	mutex_unlock(&graph_lock);
+	return ret;
 }
 
 static int
 ftrace_graph_release(struct inode *inode, struct file *file)
 {
+	struct ftrace_graph_data *fgd;
+	struct ftrace_hash *old_hash, *new_hash;
+	struct trace_parser *parser;
+	int ret = 0;
+
 	if (file->f_mode & FMODE_READ) {
 		struct seq_file *m = file->private_data;
 
-		kfree(m->private);
+		fgd = m->private;
 		seq_release(inode, file);
 	} else {
-		kfree(file->private_data);
+		fgd = file->private_data;
 	}
 
-	return 0;
+
+	if (file->f_mode & FMODE_WRITE) {
+
+		parser = &fgd->parser;
+
+		if (trace_parser_loaded((parser))) {
+			parser->buffer[parser->idx] = 0;
+			ret = ftrace_graph_set_hash(fgd->new_hash,
+						    parser->buffer);
+		}
+
+		trace_parser_put(parser);
+
+		new_hash = __ftrace_hash_move(fgd->new_hash);
+		if (!new_hash) {
+			ret = -ENOMEM;
+			goto out;
+		}
+
+		mutex_lock(&graph_lock);
+
+		if (fgd->type == GRAPH_FILTER_FUNCTION) {
+			old_hash = rcu_dereference_protected(ftrace_graph_hash,
+					lockdep_is_held(&graph_lock));
+			rcu_assign_pointer(ftrace_graph_hash, new_hash);
+		} else {
+			old_hash = rcu_dereference_protected(ftrace_graph_notrace_hash,
+					lockdep_is_held(&graph_lock));
+			rcu_assign_pointer(ftrace_graph_notrace_hash, new_hash);
+		}
+
+		mutex_unlock(&graph_lock);
+
+		/* Wait till all users are no longer using the old hash */
+		synchronize_sched();
+
+		free_ftrace_hash(old_hash);
+	}
+
+ out:
+	kfree(fgd->new_hash);
+	kfree(fgd);
+
+	return ret;
 }
 
 static int
-ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)
+ftrace_graph_set_hash(struct ftrace_hash *hash, char *buffer)
 {
 	struct ftrace_glob func_g;
 	struct dyn_ftrace *rec;
 	struct ftrace_page *pg;
+	struct ftrace_func_entry *entry;
 	int fail = 1;
 	int not;
-	bool exists;
-	int i;
 
 	/* decode regex */
 	func_g.type = filter_parse_regex(buffer, strlen(buffer),
 					 &func_g.search, &not);
-	if (!not && *idx >= size)
-		return -EBUSY;
 
 	func_g.len = strlen(func_g.search);
 
@@ -4729,26 +4868,18 @@ ftrace_set_func(unsigned long *array, int *idx, int size, char *buffer)
 			continue;
 
 		if (ftrace_match_record(rec, &func_g, NULL, 0)) {
-			/* if it is in the array */
-			exists = false;
-			for (i = 0; i < *idx; i++) {
-				if (array[i] == rec->ip) {
-					exists = true;
-					break;
-				}
-			}
+			entry = ftrace_lookup_ip(hash, rec->ip);
 
 			if (!not) {
 				fail = 0;
-				if (!exists) {
-					array[(*idx)++] = rec->ip;
-					if (*idx >= size)
+
+				if (entry)
+					continue;
+				if (add_hash_entry(hash, rec->ip) < 0)
 					goto out;
-				}
 			} else {
-				if (exists) {
-					array[i] = array[--(*idx)];
-					array[*idx] = 0;
+				if (entry) {
+					free_hash_entry(hash, entry);
 					fail = 0;
 				}
 			}
@@ -4767,35 +4898,34 @@ static ssize_t
 ftrace_graph_write(struct file *file, const char __user *ubuf,
 		   size_t cnt, loff_t *ppos)
 {
-	struct trace_parser parser;
 	ssize_t read, ret = 0;
 	struct ftrace_graph_data *fgd = file->private_data;
+	struct trace_parser *parser;
 
 	if (!cnt)
 		return 0;
 
-	if (trace_parser_get_init(&parser, FTRACE_BUFF_MAX))
-		return -ENOMEM;
-
-	read = trace_get_user(&parser, ubuf, cnt, ppos);
+	/* Read mode uses seq functions */
+	if (file->f_mode & FMODE_READ) {
+		struct seq_file *m = file->private_data;
+		fgd = m->private;
+	}
 
-	if (read >= 0 && trace_parser_loaded((&parser))) {
-		parser.buffer[parser.idx] = 0;
+	parser = &fgd->parser;
 
-		mutex_lock(&graph_lock);
+	read = trace_get_user(parser, ubuf, cnt, ppos);
 
-		/* we allow only one expression at a time */
-		ret = ftrace_set_func(fgd->table, fgd->count, fgd->size,
-				      parser.buffer);
+	if (read >= 0 && trace_parser_loaded(parser) &&
+	    !trace_parser_cont(parser)) {
 
-		mutex_unlock(&graph_lock);
+		ret = ftrace_graph_set_hash(fgd->new_hash,
+					    parser->buffer);
+		trace_parser_clear(parser);
 	}
 
 	if (!ret)
 		ret = read;
 
-	trace_parser_put(&parser);
-
 	return ret;
 }
 

kernel/trace/trace.c

@@ -260,16 +260,8 @@ unsigned long long ns2usecs(u64 nsec)
 	TRACE_ITER_EVENT_FORK
 
 /*
- * The global_trace is the descriptor that holds the tracing
- * buffers for the live tracing. For each CPU, it contains
- * a link list of pages that will store trace entries. The
- * page descriptor of the pages in the memory is used to hold
- * the link list by linking the lru item in the page descriptor
- * to each of the pages in the buffer per CPU.
- *
- * For each active CPU there is a data field that holds the
- * pages for the buffer for that CPU. Each CPU has the same number
- * of pages allocated for its buffer.
+ * The global_trace is the descriptor that holds the top-level tracing
+ * buffers for the live tracing.
  */
 static struct trace_array global_trace = {
 	.trace_flags = TRACE_DEFAULT_FLAGS,
@@ -1193,6 +1185,7 @@ int trace_parser_get_init(struct trace_parser *parser, int size)
 void trace_parser_put(struct trace_parser *parser)
 {
 	kfree(parser->buffer);
+	parser->buffer = NULL;
 }
 
 /*

kernel/trace/trace.h

@@ -753,6 +753,21 @@ enum print_line_t print_trace_line(struct trace_iterator *iter);
 
 extern char trace_find_mark(unsigned long long duration);
 
+struct ftrace_hash {
+	unsigned long		size_bits;
+	struct hlist_head	*buckets;
+	unsigned long		count;
+	struct rcu_head		rcu;
+};
+
+struct ftrace_func_entry *
+ftrace_lookup_ip(struct ftrace_hash *hash, unsigned long ip);
+
+static __always_inline bool ftrace_hash_empty(struct ftrace_hash *hash)
+{
+	return !hash || !hash->count;
+}
+
 /* Standard output formatting function used for function return traces */
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
@@ -787,24 +802,22 @@ extern void __trace_graph_return(struct trace_array *tr,
 				 struct ftrace_graph_ret *trace,
 				 unsigned long flags, int pc);
 
-
 #ifdef CONFIG_DYNAMIC_FTRACE
-/* TODO: make this variable */
-#define FTRACE_GRAPH_MAX_FUNCS		32
-extern int ftrace_graph_count;
-extern unsigned long ftrace_graph_funcs[FTRACE_GRAPH_MAX_FUNCS];
-extern int ftrace_graph_notrace_count;
-extern unsigned long ftrace_graph_notrace_funcs[FTRACE_GRAPH_MAX_FUNCS];
+extern struct ftrace_hash *ftrace_graph_hash;
+extern struct ftrace_hash *ftrace_graph_notrace_hash;
 
 static inline int ftrace_graph_addr(unsigned long addr)
 {
-	int i;
+	int ret = 0;
 
-	if (!ftrace_graph_count)
-		return 1;
+	preempt_disable_notrace();
 
-	for (i = 0; i < ftrace_graph_count; i++) {
-		if (addr == ftrace_graph_funcs[i]) {
+	if (ftrace_hash_empty(ftrace_graph_hash)) {
+		ret = 1;
+		goto out;
+	}
+
+	if (ftrace_lookup_ip(ftrace_graph_hash, addr)) {
 		/*
 		 * If no irqs are to be traced, but a set_graph_function
 		 * is set, and called by an interrupt handler, we still
@@ -814,26 +827,25 @@ static inline int ftrace_graph_addr(unsigned long addr)
 			trace_recursion_set(TRACE_IRQ_BIT);
 		else
 			trace_recursion_clear(TRACE_IRQ_BIT);
-			return 1;
-		}
+		ret = 1;
 	}
 
-	return 0;
+out:
+	preempt_enable_notrace();
+	return ret;
 }
 
 static inline int ftrace_graph_notrace_addr(unsigned long addr)
 {
-	int i;
+	int ret = 0;
 
-	if (!ftrace_graph_notrace_count)
-		return 0;
+	preempt_disable_notrace();
 
-	for (i = 0; i < ftrace_graph_notrace_count; i++) {
-		if (addr == ftrace_graph_notrace_funcs[i])
-			return 1;
-	}
+	if (ftrace_lookup_ip(ftrace_graph_notrace_hash, addr))
+		ret = 1;
 
-	return 0;
+	preempt_enable_notrace();
+	return ret;
 }
 #else
 static inline int ftrace_graph_addr(unsigned long addr)
@@ -1300,7 +1312,8 @@ static inline bool is_string_field(struct ftrace_event_field *field)
 {
 	return field->filter_type == FILTER_DYN_STRING ||
 	       field->filter_type == FILTER_STATIC_STRING ||
-	       field->filter_type == FILTER_PTR_STRING;
+	       field->filter_type == FILTER_PTR_STRING ||
+	       field->filter_type == FILTER_COMM;
 }
 
 static inline bool is_function_field(struct ftrace_event_field *field)

kernel/trace/trace_benchmark.c

@@ -175,9 +175,9 @@ int trace_benchmark_reg(void)
 
 	bm_event_thread = kthread_run(benchmark_event_kthread,
 				      NULL, "event_benchmark");
-	if (!bm_event_thread) {
+	if (IS_ERR(bm_event_thread)) {
 		pr_warning("trace benchmark failed to create kernel thread\n");
-		return -ENOMEM;
+		return PTR_ERR(bm_event_thread);
 	}
 
 	return 0;

kernel/trace/trace_branch.c

@@ -27,7 +27,7 @@ static DEFINE_MUTEX(branch_tracing_mutex);
 static struct trace_array *branch_tracer;
 
 static void
-probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
+probe_likely_condition(struct ftrace_likely_data *f, int val, int expect)
 {
 	struct trace_event_call *call = &event_branch;
 	struct trace_array *tr = branch_tracer;
@@ -68,16 +68,17 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
 	entry	= ring_buffer_event_data(event);
 
 	/* Strip off the path, only save the file */
-	p = f->file + strlen(f->file);
-	while (p >= f->file && *p != '/')
+	p = f->data.file + strlen(f->data.file);
+	while (p >= f->data.file && *p != '/')
 		p--;
 	p++;
 
-	strncpy(entry->func, f->func, TRACE_FUNC_SIZE);
+	strncpy(entry->func, f->data.func, TRACE_FUNC_SIZE);
 	strncpy(entry->file, p, TRACE_FILE_SIZE);
 	entry->func[TRACE_FUNC_SIZE] = 0;
 	entry->file[TRACE_FILE_SIZE] = 0;
-	entry->line = f->line;
+	entry->constant = f->constant;
+	entry->line = f->data.line;
 	entry->correct = val == expect;
 
 	if (!call_filter_check_discard(call, entry, buffer, event))
@@ -89,7 +90,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
 }
 
 static inline
-void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
+void trace_likely_condition(struct ftrace_likely_data *f, int val, int expect)
 {
 	if (!branch_tracing_enabled)
 		return;
@@ -195,13 +196,19 @@ core_initcall(init_branch_tracer);
 
 #else
 static inline
-void trace_likely_condition(struct ftrace_branch_data *f, int val, int expect)
+void trace_likely_condition(struct ftrace_likely_data *f, int val, int expect)
 {
 }
 #endif /* CONFIG_BRANCH_TRACER */
 
-void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect)
+void ftrace_likely_update(struct ftrace_likely_data *f, int val,
+			  int expect, int is_constant)
 {
+	/* A constant is always correct */
+	if (is_constant) {
+		f->constant++;
+		val = expect;
+	}
 	/*
 	 * I would love to have a trace point here instead, but the
 	 * trace point code is so inundated with unlikely and likely
@@ -212,9 +219,9 @@ void ftrace_likely_update(struct ftrace_branch_data *f, int val, int expect)
 
 	/* FIXME: Make this atomic! */
 	if (val == expect)
-		f->correct++;
+		f->data.correct++;
 	else
-		f->incorrect++;
+		f->data.incorrect++;
 }
 EXPORT_SYMBOL(ftrace_likely_update);
 
@@ -245,29 +252,60 @@ static inline long get_incorrect_percent(struct ftrace_branch_data *p)
 	return percent;
 }
 
-static int branch_stat_show(struct seq_file *m, void *v)
+static const char *branch_stat_process_file(struct ftrace_branch_data *p)
 {
-	struct ftrace_branch_data *p = v;
 	const char *f;
-	long percent;
 
 	/* Only print the file, not the path */
 	f = p->file + strlen(p->file);
 	while (f >= p->file && *f != '/')
 		f--;
-	f++;
+	return ++f;
+}
+
+static void branch_stat_show(struct seq_file *m,
+			     struct ftrace_branch_data *p, const char *f)
+{
+	long percent;
 
 	/*
 	 * The miss is overlayed on correct, and hit on incorrect.
 	 */
 	percent = get_incorrect_percent(p);
 
-	seq_printf(m, "%8lu %8lu ",  p->correct, p->incorrect);
 	if (percent < 0)
 		seq_puts(m, "  X ");
 	else
 		seq_printf(m, "%3ld ", percent);
+
 	seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line);
+}
+
+static int branch_stat_show_normal(struct seq_file *m,
+				   struct ftrace_branch_data *p, const char *f)
+{
+	seq_printf(m, "%8lu %8lu ",  p->correct, p->incorrect);
+	branch_stat_show(m, p, f);
+	return 0;
+}
+
+static int annotate_branch_stat_show(struct seq_file *m, void *v)
+{
+	struct ftrace_likely_data *p = v;
+	const char *f;
+	int l;
+
+	f = branch_stat_process_file(&p->data);
+
+	if (!p->constant)
+		return branch_stat_show_normal(m, &p->data, f);
+
+	l = snprintf(NULL, 0, "/%lu", p->constant);
+	l = l > 8 ? 0 : 8 - l;
+
+	seq_printf(m, "%8lu/%lu %*lu ",
+		   p->data.correct, p->constant, l, p->data.incorrect);
+	branch_stat_show(m, &p->data, f);
 	return 0;
 }
 
@@ -279,7 +317,7 @@ static void *annotated_branch_stat_start(struct tracer_stat *trace)
 static void *
 annotated_branch_stat_next(void *v, int idx)
 {
-	struct ftrace_branch_data *p = v;
+	struct ftrace_likely_data *p = v;
 
 	++p;
 
@@ -328,7 +366,7 @@ static struct tracer_stat annotated_branch_stats = {
 	.stat_next = annotated_branch_stat_next,
 	.stat_cmp = annotated_branch_stat_cmp,
 	.stat_headers = annotated_branch_stat_headers,
-	.stat_show = branch_stat_show
+	.stat_show = annotate_branch_stat_show
 };
 
 __init static int init_annotated_branch_stats(void)
@@ -379,12 +417,21 @@ all_branch_stat_next(void *v, int idx)
 	return p;
 }
 
+static int all_branch_stat_show(struct seq_file *m, void *v)
+{
+	struct ftrace_branch_data *p = v;
+	const char *f;
+
+	f = branch_stat_process_file(p);
+	return branch_stat_show_normal(m, p, f);
+}
+
 static struct tracer_stat all_branch_stats = {
 	.name = "branch_all",
 	.stat_start = all_branch_stat_start,
 	.stat_next = all_branch_stat_next,
 	.stat_headers = all_branch_stat_headers,
-	.stat_show = branch_stat_show
+	.stat_show = all_branch_stat_show
 };
 
 __init static int all_annotated_branch_stats(void)

kernel/trace/trace_entries.h

@@ -328,11 +328,13 @@ FTRACE_ENTRY(branch, trace_branch,
 		__array(	char,		func,	TRACE_FUNC_SIZE+1	)
 		__array(	char,		file,	TRACE_FILE_SIZE+1	)
 		__field(	char,		correct				)
+		__field(	char,		constant			)
 	),
 
-	F_printk("%u:%s:%s (%u)",
+	F_printk("%u:%s:%s (%u)%s",
 		 __entry->line,
-		 __entry->func, __entry->file, __entry->correct),
+		 __entry->func, __entry->file, __entry->correct,
+		 __entry->constant ? " CONSTANT" : ""),
 
 	FILTER_OTHER
 );

kernel/trace/trace_hwlat.c

@@ -322,10 +322,7 @@ static void move_to_next_cpu(bool initmask)
  * need to ensure nothing else might be running (and thus preempting).
  * Obviously this should never be used in production environments.
  *
- * Currently this runs on which ever CPU it was scheduled on, but most
- * real-world hardware latency situations occur across several CPUs,
- * but we might later generalize this if we find there are any actualy
- * systems with alternate SMI delivery or other hardware latencies.
+ * Executes one loop interaction on each CPU in tracing_cpumask sysfs file.
  */
 static int kthread_fn(void *data)
 {

kernel/trace/trace_kprobe.c

@@ -16,6 +16,7 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
+#define pr_fmt(fmt)	"trace_kprobe: " fmt
 
 #include <linux/module.h>
 #include <linux/uaccess.h>

kernel/trace/trace_probe.c

@@ -21,6 +21,7 @@
  * Copyright (C) IBM Corporation, 2010-2011
  * Author:     Srikar Dronamraju
  */
+#define pr_fmt(fmt)	"trace_probe: " fmt
 
 #include "trace_probe.h"
 
@@ -647,7 +648,7 @@ ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
 				size_t count, loff_t *ppos,
 				int (*createfn)(int, char **))
 {
-	char *kbuf, *tmp;
+	char *kbuf, *buf, *tmp;
 	int ret = 0;
 	size_t done = 0;
 	size_t size;
@@ -667,27 +668,38 @@ ssize_t traceprobe_probes_write(struct file *file, const char __user *buffer,
 			goto out;
 		}
 		kbuf[size] = '\0';
-		tmp = strchr(kbuf, '\n');
-
+		buf = kbuf;
+		do {
+			tmp = strchr(buf, '\n');
 			if (tmp) {
 				*tmp = '\0';
-			size = tmp - kbuf + 1;
-		} else if (done + size < count) {
+				size = tmp - buf + 1;
+			} else {
+				size = strlen(buf);
+				if (done + size < count) {
+					if (buf != kbuf)
+						break;
+					/* This can accept WRITE_BUFSIZE - 2 ('\n' + '\0') */
 					pr_warn("Line length is too long: Should be less than %d\n",
-				WRITE_BUFSIZE);
+						WRITE_BUFSIZE - 2);
 					ret = -EINVAL;
 					goto out;
 				}
+			}
 			done += size;
+
 			/* Remove comments */
-		tmp = strchr(kbuf, '#');
+			tmp = strchr(buf, '#');
 
 			if (tmp)
 				*tmp = '\0';
 
-		ret = traceprobe_command(kbuf, createfn);
+			ret = traceprobe_command(buf, createfn);
 			if (ret)
 				goto out;
+			buf += size;
+
+		} while (done < count);
 	}
 	ret = done;
 

kernel/trace/trace_uprobe.c

@@ -17,6 +17,7 @@
  * Copyright (C) IBM Corporation, 2010-2012
  * Author:	Srikar Dronamraju <srikar@linux.vnet.ibm.com>
  */
+#define pr_fmt(fmt)	"trace_kprobe: " fmt
 
 #include <linux/module.h>
 #include <linux/uaccess.h>
@@ -431,7 +432,8 @@ static int create_trace_uprobe(int argc, char **argv)
 		pr_info("Probe point is not specified.\n");
 		return -EINVAL;
 	}
-	arg = strchr(argv[1], ':');
+	/* Find the last occurrence, in case the path contains ':' too. */
+	arg = strrchr(argv[1], ':');
 	if (!arg) {
 		ret = -EINVAL;
 		goto fail_address_parse;