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-rw-r--r--kernel/trace/ftrace.c141
-rw-r--r--kernel/trace/trace.h14
-rw-r--r--kernel/trace/trace_events.c70
3 files changed, 210 insertions, 15 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index d8873079bed4..ac47d1845fdb 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -3808,6 +3808,147 @@ static void ftrace_free_entry(struct ftrace_func_probe *entry)
kfree(entry);
}
+struct ftrace_func_map {
+ struct ftrace_func_entry entry;
+ void *data;
+};
+
+struct ftrace_func_mapper {
+ struct ftrace_hash hash;
+};
+
+/**
+ * allocate_ftrace_func_mapper - allocate a new ftrace_func_mapper
+ *
+ * Returns a ftrace_func_mapper descriptor that can be used to map ips to data.
+ */
+struct ftrace_func_mapper *allocate_ftrace_func_mapper(void)
+{
+ struct ftrace_hash *hash;
+
+ /*
+ * The mapper is simply a ftrace_hash, but since the entries
+ * in the hash are not ftrace_func_entry type, we define it
+ * as a separate structure.
+ */
+ hash = alloc_ftrace_hash(FTRACE_HASH_DEFAULT_BITS);
+ return (struct ftrace_func_mapper *)hash;
+}
+
+/**
+ * ftrace_func_mapper_find_ip - Find some data mapped to an ip
+ * @mapper: The mapper that has the ip maps
+ * @ip: the instruction pointer to find the data for
+ *
+ * Returns the data mapped to @ip if found otherwise NULL. The return
+ * is actually the address of the mapper data pointer. The address is
+ * returned for use cases where the data is no bigger than a long, and
+ * the user can use the data pointer as its data instead of having to
+ * allocate more memory for the reference.
+ */
+void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
+ unsigned long ip)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_func_map *map;
+
+ entry = ftrace_lookup_ip(&mapper->hash, ip);
+ if (!entry)
+ return NULL;
+
+ map = (struct ftrace_func_map *)entry;
+ return &map->data;
+}
+
+/**
+ * ftrace_func_mapper_add_ip - Map some data to an ip
+ * @mapper: The mapper that has the ip maps
+ * @ip: The instruction pointer address to map @data to
+ * @data: The data to map to @ip
+ *
+ * Returns 0 on succes otherwise an error.
+ */
+int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
+ unsigned long ip, void *data)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_func_map *map;
+
+ entry = ftrace_lookup_ip(&mapper->hash, ip);
+ if (entry)
+ return -EBUSY;
+
+ map = kmalloc(sizeof(*map), GFP_KERNEL);
+ if (!map)
+ return -ENOMEM;
+
+ map->entry.ip = ip;
+ map->data = data;
+
+ __add_hash_entry(&mapper->hash, &map->entry);
+
+ return 0;
+}
+
+/**
+ * ftrace_func_mapper_remove_ip - Remove an ip from the mapping
+ * @mapper: The mapper that has the ip maps
+ * @ip: The instruction pointer address to remove the data from
+ *
+ * Returns the data if it is found, otherwise NULL.
+ * Note, if the data pointer is used as the data itself, (see
+ * ftrace_func_mapper_find_ip(), then the return value may be meaningless,
+ * if the data pointer was set to zero.
+ */
+void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
+ unsigned long ip)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_func_map *map;
+ void *data;
+
+ entry = ftrace_lookup_ip(&mapper->hash, ip);
+ if (!entry)
+ return NULL;
+
+ map = (struct ftrace_func_map *)entry;
+ data = map->data;
+
+ remove_hash_entry(&mapper->hash, entry);
+ kfree(entry);
+
+ return data;
+}
+
+/**
+ * free_ftrace_func_mapper - free a mapping of ips and data
+ * @mapper: The mapper that has the ip maps
+ * @free_func: A function to be called on each data item.
+ *
+ * This is used to free the function mapper. The @free_func is optional
+ * and can be used if the data needs to be freed as well.
+ */
+void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
+ ftrace_mapper_func free_func)
+{
+ struct ftrace_func_entry *entry;
+ struct ftrace_func_map *map;
+ struct hlist_head *hhd;
+ int size = 1 << mapper->hash.size_bits;
+ int i;
+
+ if (free_func && mapper->hash.count) {
+ for (i = 0; i < size; i++) {
+ hhd = &mapper->hash.buckets[i];
+ hlist_for_each_entry(entry, hhd, hlist) {
+ map = (struct ftrace_func_map *)entry;
+ free_func(map);
+ }
+ }
+ }
+ free_ftrace_hash(&mapper->hash);
+}
+
int
register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
void *data)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 0f915c264c19..dbbdee21bcc4 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -944,8 +944,22 @@ struct ftrace_probe_ops {
unsigned long ip,
struct ftrace_probe_ops *ops,
void *data);
+ void *private_data;
};
+struct ftrace_func_mapper;
+typedef int (*ftrace_mapper_func)(void *data);
+
+struct ftrace_func_mapper *allocate_ftrace_func_mapper(void);
+void **ftrace_func_mapper_find_ip(struct ftrace_func_mapper *mapper,
+ unsigned long ip);
+int ftrace_func_mapper_add_ip(struct ftrace_func_mapper *mapper,
+ unsigned long ip, void *data);
+void *ftrace_func_mapper_remove_ip(struct ftrace_func_mapper *mapper,
+ unsigned long ip);
+void free_ftrace_func_mapper(struct ftrace_func_mapper *mapper,
+ ftrace_mapper_func free_func);
+
extern int
register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
void *data);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 9dbac1881b03..ee308312fe87 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -2460,32 +2460,44 @@ struct event_probe_data {
bool enable;
};
+static void update_event_probe(struct event_probe_data *data)
+{
+ if (data->enable)
+ clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
+ else
+ set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
+}
+
static void
event_enable_probe(unsigned long ip, unsigned long parent_ip,
struct ftrace_probe_ops *ops, void **_data)
{
- struct event_probe_data **pdata = (struct event_probe_data **)_data;
- struct event_probe_data *data = *pdata;
+ struct ftrace_func_mapper *mapper = ops->private_data;
+ struct event_probe_data *data;
+ void **pdata;
- if (!data)
+ pdata = ftrace_func_mapper_find_ip(mapper, ip);
+ if (!pdata || !*pdata)
return;
- if (data->enable)
- clear_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
- else
- set_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &data->file->flags);
+ data = *pdata;
+ update_event_probe(data);
}
static void
event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
struct ftrace_probe_ops *ops, void **_data)
{
- struct event_probe_data **pdata = (struct event_probe_data **)_data;
- struct event_probe_data *data = *pdata;
+ struct ftrace_func_mapper *mapper = ops->private_data;
+ struct event_probe_data *data;
+ void **pdata;
- if (!data)
+ pdata = ftrace_func_mapper_find_ip(mapper, ip);
+ if (!pdata || !*pdata)
return;
+ data = *pdata;
+
if (!data->count)
return;
@@ -2496,14 +2508,23 @@ event_enable_count_probe(unsigned long ip, unsigned long parent_ip,
if (data->count != -1)
(data->count)--;
- event_enable_probe(ip, parent_ip, ops, _data);
+ update_event_probe(data);
}
static int
event_enable_print(struct seq_file *m, unsigned long ip,
struct ftrace_probe_ops *ops, void *_data)
{
- struct event_probe_data *data = _data;
+ struct ftrace_func_mapper *mapper = ops->private_data;
+ struct event_probe_data *data;
+ void **pdata;
+
+ pdata = ftrace_func_mapper_find_ip(mapper, ip);
+
+ if (WARN_ON_ONCE(!pdata || !*pdata))
+ return 0;
+
+ data = *pdata;
seq_printf(m, "%ps:", (void *)ip);
@@ -2524,10 +2545,17 @@ static int
event_enable_init(struct ftrace_probe_ops *ops, unsigned long ip,
void **_data)
{
+ struct ftrace_func_mapper *mapper = ops->private_data;
struct event_probe_data **pdata = (struct event_probe_data **)_data;
struct event_probe_data *data = *pdata;
+ int ret;
+
+ ret = ftrace_func_mapper_add_ip(mapper, ip, data);
+ if (ret < 0)
+ return ret;
data->ref++;
+
return 0;
}
@@ -2535,8 +2563,13 @@ static void
event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
void **_data)
{
- struct event_probe_data **pdata = (struct event_probe_data **)_data;
- struct event_probe_data *data = *pdata;
+ struct ftrace_func_mapper *mapper = ops->private_data;
+ struct event_probe_data *data;
+
+ data = ftrace_func_mapper_remove_ip(mapper, ip);
+
+ if (WARN_ON_ONCE(!data))
+ return;
if (WARN_ON_ONCE(data->ref <= 0))
return;
@@ -2548,7 +2581,6 @@ event_enable_free(struct ftrace_probe_ops *ops, unsigned long ip,
module_put(data->file->event_call->mod);
kfree(data);
}
- *pdata = NULL;
}
static struct ftrace_probe_ops event_enable_probe_ops = {
@@ -2627,6 +2659,13 @@ event_enable_func(struct ftrace_hash *hash,
}
ret = -ENOMEM;
+
+ if (!ops->private_data) {
+ ops->private_data = allocate_ftrace_func_mapper();
+ if (!ops->private_data)
+ goto out;
+ }
+
data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
goto out;
@@ -2663,6 +2702,7 @@ event_enable_func(struct ftrace_hash *hash,
ret = __ftrace_event_enable_disable(file, 1, 1);
if (ret < 0)
goto out_put;
+
ret = register_ftrace_function_probe(glob, ops, data);
/*
* The above returns on success the # of functions enabled,
generated by cgit (git 2.34.1) at 2024-06-12 12:06:38 +0000