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Commit 647664ea authored by Masami Hiramatsu's avatar Masami Hiramatsu Committed by Steven Rostedt
Browse files

ftrace: add ftrace_set_filter_ip() for address based filter 

Add a new filter update interface ftrace_set_filter_ip()
to set ftrace filter by ip address, not only glob pattern.

Link: http://lkml.kernel.org/r/20120605102808.27845.67952.stgit@localhost.localdomain



Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: default avatarMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent ad97772a

include/linux/ftrace.h

+3 −0
Original line number Diff line number Diff line
@@ -317,6 +317,8 @@ struct dyn_ftrace { 
};



int ftrace_force_update(void);

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

			 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,
@@ -544,6 +546,7 @@ static inline int ftrace_text_reserved(void *start, void *end) 
 */

#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(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

+57 −2
Original line number Diff line number Diff line
@@ -3242,8 +3242,27 @@ ftrace_notrace_write(struct file *file, const char __user *ubuf, 
}



static int

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

		 int reset, int enable)

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

{

	struct ftrace_func_entry *entry;



	if (!ftrace_location(ip))

		return -EINVAL;



	if (remove) {

		entry = ftrace_lookup_ip(hash, ip);

		if (!entry)

			return -ENOENT;

		free_hash_entry(hash, entry);

		return 0;

	}



	return add_hash_entry(hash, ip);

}



static int

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

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

{

	struct ftrace_hash **orig_hash;

	struct ftrace_hash *hash;
@@ -3272,6 +3291,11 @@ ftrace_set_regex(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 (ret < 0)

			goto out_regex_unlock;

	}



	mutex_lock(&ftrace_lock);

	ret = ftrace_hash_move(ops, enable, orig_hash, hash);
@@ -3288,6 +3312,37 @@ ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, 
	return ret;

}



static int

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

		int reset, int enable)

{

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

}



/**

 * ftrace_set_filter_ip - set a function to filter on in ftrace by address

 * @ops - the ops to set the filter with

 * @ip - the address to add to or remove from the filter.

 * @remove - non zero to remove the ip 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 @ip is NULL, it failes to update filter.

 */

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

			 int remove, int reset)

{

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

}

EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);



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);

}



/**

 * ftrace_set_filter - set a function to filter on in ftrace

 * @ops - the ops to set the filter with