Commit 4f554e95 authored by Jiri Olsa's avatar Jiri Olsa Committed by Alexei Starovoitov
Browse files

ftrace: Add ftrace_set_filter_ips function 



Adding ftrace_set_filter_ips function to be able to set filter on
multiple ip addresses at once.

With the kprobe multi attach interface we have cases where we need to
initialize ftrace_ops object with thousands of functions, so having
single function diving into ftrace_hash_move_and_update_ops with
ftrace_lock is faster.

The functions ips are passed as unsigned long array with count.

Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Tested-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/164735282673.1084943.18310504594134769804.stgit@devnote2
parent e0999c8e

include/linux/ftrace.h

+3 −0
Original line number Diff line number Diff line
@@ -512,6 +512,8 @@ struct dyn_ftrace { 


int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,

			 int remove, int reset);

int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,

			  unsigned int cnt, int remove, int reset);

int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,

		       int len, int reset);

int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
@@ -802,6 +804,7 @@ static inline unsigned long ftrace_location(unsigned long ip) 
#define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })

#define ftrace_set_early_filter(ops, buf, enable) do { } while (0)

#define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })

#define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; })

#define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })

#define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })

#define ftrace_free_filter(ops) do { } while (0)

kernel/trace/ftrace.c

+49 −9
Original line number Diff line number Diff line
@@ -4958,7 +4958,7 @@ ftrace_notrace_write(struct file *file, const char __user *ubuf, 
}



static int

ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)

__ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove)

{

	struct ftrace_func_entry *entry;
@@ -4976,9 +4976,30 @@ ftrace_match_addr(struct ftrace_hash *hash, unsigned long ip, int remove) 
	return add_hash_entry(hash, ip);

}



static int

ftrace_match_addr(struct ftrace_hash *hash, unsigned long *ips,

		  unsigned int cnt, int remove)

{

	unsigned int i;

	int err;



	for (i = 0; i < cnt; i++) {

		err = __ftrace_match_addr(hash, ips[i], remove);

		if (err) {

			/*

			 * This expects the @hash is a temporary hash and if this

			 * fails the caller must free the @hash.

			 */

			return err;

		}

	}

	return 0;

}



static int

ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len,

		unsigned long ip, int remove, int reset, int enable)

		unsigned long *ips, unsigned int cnt,

		int remove, int reset, int enable)

{

	struct ftrace_hash **orig_hash;

	struct ftrace_hash *hash;
@@ -5008,8 +5029,8 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, 
		ret = -EINVAL;

		goto out_regex_unlock;

	}

	if (ip) {

		ret = ftrace_match_addr(hash, ip, remove);

	if (ips) {

		ret = ftrace_match_addr(hash, ips, cnt, remove);

		if (ret < 0)

			goto out_regex_unlock;

	}
@@ -5026,10 +5047,10 @@ ftrace_set_hash(struct ftrace_ops *ops, unsigned char *buf, int len, 
}



static int

ftrace_set_addr(struct ftrace_ops *ops, unsigned long ip, int remove,

		int reset, int enable)

ftrace_set_addr(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt,

		int remove, int reset, int enable)

{

	return ftrace_set_hash(ops, NULL, 0, ip, remove, reset, enable);

	return ftrace_set_hash(ops, NULL, 0, ips, cnt, remove, reset, enable);

}



#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
@@ -5634,10 +5655,29 @@ int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 
			 int remove, int reset)

{

	ftrace_ops_init(ops);

	return ftrace_set_addr(ops, ip, remove, reset, 1);

	return ftrace_set_addr(ops, &ip, 1, remove, reset, 1);

}

EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);



/**

 * ftrace_set_filter_ips - set functions to filter on in ftrace by addresses

 * @ops - the ops to set the filter with

 * @ips - the array of addresses to add to or remove from the filter.

 * @cnt - the number of addresses in @ips

 * @remove - non zero to remove ips from the filter

 * @reset - non zero to reset all filters before applying this filter.

 *

 * Filters denote which functions should be enabled when tracing is enabled

 * If @ips array or any ip specified within is NULL , it fails to update filter.

 */

int ftrace_set_filter_ips(struct ftrace_ops *ops, unsigned long *ips,

			  unsigned int cnt, int remove, int reset)

{

	ftrace_ops_init(ops);

	return ftrace_set_addr(ops, ips, cnt, remove, reset, 1);

}

EXPORT_SYMBOL_GPL(ftrace_set_filter_ips);



/**

 * ftrace_ops_set_global_filter - setup ops to use global filters

 * @ops - the ops which will use the global filters
@@ -5659,7 +5699,7 @@ static int 
ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len,

		 int reset, int enable)

{

	return ftrace_set_hash(ops, buf, len, 0, 0, reset, enable);

	return ftrace_set_hash(ops, buf, len, NULL, 0, 0, reset, enable);

}



/**