summaryrefslogtreecommitdiffstats
path: root/kernel/trace/ftrace.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace/ftrace.c')
-rw-r--r--kernel/trace/ftrace.c176
1 files changed, 150 insertions, 26 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index d3406346ced..04c002a491f 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -57,6 +57,7 @@
/* hash bits for specific function selection */
#define FTRACE_HASH_BITS 7
#define FTRACE_FUNC_HASHSIZE (1 << FTRACE_HASH_BITS)
+#define FTRACE_HASH_MAX_BITS 10
/* ftrace_enabled is a method to turn ftrace on or off */
int ftrace_enabled __read_mostly;
@@ -865,6 +866,22 @@ enum {
FTRACE_START_FUNC_RET = (1 << 3),
FTRACE_STOP_FUNC_RET = (1 << 4),
};
+struct ftrace_func_entry {
+ struct hlist_node hlist;
+ unsigned long ip;
+};
+
+struct ftrace_hash {
+ unsigned long size_bits;
+ struct hlist_head *buckets;
+ unsigned long count;
+};
+
+static struct hlist_head notrace_buckets[1 << FTRACE_HASH_MAX_BITS];
+static struct ftrace_hash notrace_hash = {
+ .size_bits = FTRACE_HASH_MAX_BITS,
+ .buckets = notrace_buckets,
+};
static int ftrace_filtered;
@@ -889,6 +906,79 @@ static struct ftrace_page *ftrace_pages;
static struct dyn_ftrace *ftrace_free_records;
+static 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;
+ struct hlist_node *n;
+
+ if (!hash->count)
+ return NULL;
+
+ if (hash->size_bits > 0)
+ key = hash_long(ip, hash->size_bits);
+ else
+ key = 0;
+
+ hhd = &hash->buckets[key];
+
+ hlist_for_each_entry_rcu(entry, n, hhd, hlist) {
+ if (entry->ip == ip)
+ return entry;
+ }
+ return NULL;
+}
+
+static int add_hash_entry(struct ftrace_hash *hash, unsigned long ip)
+{
+ struct ftrace_func_entry *entry;
+ struct hlist_head *hhd;
+ unsigned long key;
+
+ entry = kmalloc(sizeof(*entry), GFP_KERNEL);
+ if (!entry)
+ return -ENOMEM;
+
+ if (hash->size_bits)
+ key = hash_long(ip, hash->size_bits);
+ else
+ key = 0;
+
+ entry->ip = ip;
+ hhd = &hash->buckets[key];
+ hlist_add_head(&entry->hlist, hhd);
+ hash->count++;
+
+ return 0;
+}
+
+static void
+remove_hash_entry(struct ftrace_hash *hash,
+ struct ftrace_func_entry *entry)
+{
+ hlist_del(&entry->hlist);
+ kfree(entry);
+ hash->count--;
+}
+
+static void ftrace_hash_clear(struct ftrace_hash *hash)
+{
+ struct hlist_head *hhd;
+ struct hlist_node *tp, *tn;
+ struct ftrace_func_entry *entry;
+ int size = 1 << hash->size_bits;
+ int i;
+
+ for (i = 0; i < size; i++) {
+ hhd = &hash->buckets[i];
+ hlist_for_each_entry_safe(entry, tp, tn, hhd, hlist)
+ remove_hash_entry(hash, entry);
+ }
+ FTRACE_WARN_ON(hash->count);
+}
+
/*
* This is a double for. Do not use 'break' to break out of the loop,
* you must use a goto.
@@ -1032,7 +1122,7 @@ __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
* If we want to enable it and filtering is on, enable it only if
* it's filtered
*/
- if (enable && !(rec->flags & FTRACE_FL_NOTRACE)) {
+ if (enable && !ftrace_lookup_ip(&notrace_hash, rec->ip)) {
if (!ftrace_filtered || (rec->flags & FTRACE_FL_FILTER))
flag = FTRACE_FL_ENABLED;
}
@@ -1465,7 +1555,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos)
!(rec->flags & FTRACE_FL_FILTER)) ||
((iter->flags & FTRACE_ITER_NOTRACE) &&
- !(rec->flags & FTRACE_FL_NOTRACE))) {
+ !ftrace_lookup_ip(&notrace_hash, rec->ip))) {
rec = NULL;
goto retry;
}
@@ -1609,14 +1699,15 @@ static void ftrace_filter_reset(int enable)
{
struct ftrace_page *pg;
struct dyn_ftrace *rec;
- unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
mutex_lock(&ftrace_lock);
- if (enable)
+ if (enable) {
ftrace_filtered = 0;
- do_for_each_ftrace_rec(pg, rec) {
- rec->flags &= ~type;
- } while_for_each_ftrace_rec();
+ do_for_each_ftrace_rec(pg, rec) {
+ rec->flags &= ~FTRACE_FL_FILTER;
+ } while_for_each_ftrace_rec();
+ } else
+ ftrace_hash_clear(&notrace_hash);
mutex_unlock(&ftrace_lock);
}
@@ -1716,13 +1807,36 @@ static int ftrace_match(char *str, char *regex, int len, int type)
return matched;
}
-static void
-update_record(struct dyn_ftrace *rec, unsigned long flag, int not)
+static int
+update_record(struct dyn_ftrace *rec, int enable, int not)
{
- if (not)
- rec->flags &= ~flag;
- else
- rec->flags |= flag;
+ struct ftrace_func_entry *entry;
+ struct ftrace_hash *hash = &notrace_hash;
+ int ret = 0;
+
+ if (enable) {
+ if (not)
+ rec->flags &= ~FTRACE_FL_FILTER;
+ else
+ rec->flags |= FTRACE_FL_FILTER;
+ } else {
+ if (not) {
+ /* Do nothing if it doesn't exist */
+ entry = ftrace_lookup_ip(hash, rec->ip);
+ if (!entry)
+ return 0;
+
+ remove_hash_entry(hash, entry);
+ } else {
+ /* Do nothing if it exists */
+ entry = ftrace_lookup_ip(hash, rec->ip);
+ if (entry)
+ return 0;
+
+ ret = add_hash_entry(hash, rec->ip);
+ }
+ }
+ return ret;
}
static int
@@ -1754,16 +1868,14 @@ static int match_records(char *buff, int len, char *mod, int enable, int not)
struct dyn_ftrace *rec;
int type = MATCH_FULL;
char *search = buff;
- unsigned long flag;
int found = 0;
+ int ret;
if (len) {
type = filter_parse_regex(buff, len, &search, &not);
search_len = strlen(search);
}
- flag = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
-
mutex_lock(&ftrace_lock);
if (unlikely(ftrace_disabled))
@@ -1772,7 +1884,11 @@ static int match_records(char *buff, int len, char *mod, int enable, int not)
do_for_each_ftrace_rec(pg, rec) {
if (ftrace_match_record(rec, mod, search, search_len, type)) {
- update_record(rec, flag, not);
+ ret = update_record(rec, enable, not);
+ if (ret < 0) {
+ found = ret;
+ goto out_unlock;
+ }
found = 1;
}
/*
@@ -1821,6 +1937,7 @@ static int
ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
{
char *mod;
+ int ret = -EINVAL;
/*
* cmd == 'mod' because we only registered this func
@@ -1832,15 +1949,19 @@ ftrace_mod_callback(char *func, char *cmd, char *param, int enable)
/* we must have a module name */
if (!param)
- return -EINVAL;
+ return ret;
mod = strsep(&param, ":");
if (!strlen(mod))
- return -EINVAL;
+ return ret;
- if (ftrace_match_module_records(func, mod, enable))
- return 0;
- return -EINVAL;
+ ret = ftrace_match_module_records(func, mod, enable);
+ if (!ret)
+ ret = -EINVAL;
+ if (ret < 0)
+ return ret;
+
+ return 0;
}
static struct ftrace_func_command ftrace_mod_cmd = {
@@ -2132,14 +2253,17 @@ static int ftrace_process_regex(char *buff, int len, int enable)
{
char *func, *command, *next = buff;
struct ftrace_func_command *p;
- int ret = -EINVAL;
+ int ret;
func = strsep(&next, ":");
if (!next) {
- if (ftrace_match_records(func, len, enable))
- return 0;
- return ret;
+ ret = ftrace_match_records(func, len, enable);
+ if (!ret)
+ ret = -EINVAL;
+ if (ret < 0)
+ return ret;
+ return 0;
}
/* command found */
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-24 19:41:47 +0000