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authorLinus Torvalds <torvalds@linux-foundation.org>2017-02-27 13:26:17 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-27 13:26:17 -0800
commit79b17ea740d9fab178d6a1aa15d848b5e6c01b82 (patch)
treeb0c18df8713999e16bcc6e5a32cbef880efb3b10 /kernel
parente5d56efc97f8240d0b5d66c03949382b6d7e5570 (diff)
parent67d04bb2bcbd3e99f4c4daa58599c90a83ad314a (diff)
downloadlinux-79b17ea740d9fab178d6a1aa15d848b5e6c01b82.tar.gz
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* tag 'trace-v4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (25 commits) tracing: Remove outdated ring buffer comment tracing/probes: Fix a warning message to show correct maximum length tracing: Fix return value check in trace_benchmark_reg() tracing: Use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 ...
Diffstat (limited to 'kernel')
-rw-r--r--kernel/jump_label.c153
-rw-r--r--kernel/trace/ftrace.c372
-rw-r--r--kernel/trace/trace.c13
-rw-r--r--kernel/trace/trace.h83
-rw-r--r--kernel/trace/trace_benchmark.c4
-rw-r--r--kernel/trace/trace_branch.c83
-rw-r--r--kernel/trace/trace_entries.h6
-rw-r--r--kernel/trace/trace_hwlat.c5
-rw-r--r--kernel/trace/trace_kprobe.c1
-rw-r--r--kernel/trace/trace_probe.c50
-rw-r--r--kernel/trace/trace_uprobe.c4
11 files changed, 536 insertions, 238 deletions
diff --git a/kernel/jump_label.c b/kernel/jump_label.c
index a9b8cf5..6c9cb20 100644
--- a/kernel/jump_label.c
+++ b/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;
- __jump_label_mod_update(key);
+ 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);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index eb230f0..0c06093 100644
--- a/kernel/trace/ftrace.c
+++ b/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;
- const struct seq_operations *seq_ops;
+ 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;
- return &fgd->table[*pos];
+
+ 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;
}
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)
- goto out;
- }
+
+ 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;
}
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 310f0ea..707445c 100644
--- a/kernel/trace/trace.c
+++ b/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;
}
/*
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 1ea51ab..ae1cce9 100644
--- a/kernel/trace/trace.h
+++ b/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
@@ -787,53 +802,50 @@ 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;
-
- if (!ftrace_graph_count)
- return 1;
-
- for (i = 0; i < ftrace_graph_count; i++) {
- if (addr == ftrace_graph_funcs[i]) {
- /*
- * If no irqs are to be traced, but a set_graph_function
- * is set, and called by an interrupt handler, we still
- * want to trace it.
- */
- if (in_irq())
- trace_recursion_set(TRACE_IRQ_BIT);
- else
- trace_recursion_clear(TRACE_IRQ_BIT);
- return 1;
- }
+ int ret = 0;
+
+ preempt_disable_notrace();
+
+ if (ftrace_hash_empty(ftrace_graph_hash)) {
+ ret = 1;
+ goto out;
}
- return 0;
+ 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
+ * want to trace it.
+ */
+ if (in_irq())
+ trace_recursion_set(TRACE_IRQ_BIT);
+ else
+ trace_recursion_clear(TRACE_IRQ_BIT);
+ ret = 1;
+ }
+
+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)
diff --git a/kernel/trace/trace_benchmark.c b/kernel/trace/trace_benchmark.c
index e3b4888..e49fbe9 100644
--- a/kernel/trace/trace_benchmark.c
+++ b/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;
diff --git a/kernel/trace/trace_branch.c b/kernel/trace/trace_branch.c
index 75489de..4d8fdf3 100644
--- a/kernel/trace/trace_branch.c
+++ b/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)
diff --git a/kernel/trace/trace_entries.h b/kernel/trace/trace_entries.h
index eb7396b..c203ac4 100644
--- a/kernel/trace/trace_entries.h
+++ b/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
);
diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c
index af344a1b..1199fe1 100644
--- a/kernel/trace/trace_hwlat.c
+++ b/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)
{
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 7ad9e53..eadd96e 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/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>
diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 8c0553d..52478f0 100644
--- a/kernel/trace/trace_probe.c
+++ b/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 - 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 - 2);
+ ret = -EINVAL;
+ goto out;
+ }
+ }
+ done += size;
- if (tmp) {
- *tmp = '\0';
- size = tmp - kbuf + 1;
- } else if (done + size < count) {
- pr_warn("Line length is too long: Should be less than %d\n",
- WRITE_BUFSIZE);
- ret = -EINVAL;
- goto out;
- }
- done += size;
- /* Remove comments */
- tmp = strchr(kbuf, '#');
+ /* Remove comments */
+ tmp = strchr(buf, '#');
- if (tmp)
- *tmp = '\0';
+ if (tmp)
+ *tmp = '\0';
- ret = traceprobe_command(kbuf, createfn);
- if (ret)
- goto out;
+ ret = traceprobe_command(buf, createfn);
+ if (ret)
+ goto out;
+ buf += size;
+
+ } while (done < count);
}
ret = done;
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 0913693..f4379e7 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/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;