Commit d032ae89 authored by Joel Fernandes's avatar Joel Fernandes Committed by Kees Cook
Browse files

ftrace: Provide API to use global filtering for ftrace ops 



Currently the global_ops filtering hash is not available to outside users
registering for function tracing. Provide an API for those users to be
able to choose global filtering.

This is in preparation for pstore's ftrace feature to be able to
use the global filters.

Suggested-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: default avatarJoel Fernandes <joelaf@google.com>
Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
parent a5d23b95

include/linux/ftrace.h

+2 −0
Original line number Diff line number Diff line
@@ -398,6 +398,7 @@ int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, 
void ftrace_set_global_filter(unsigned char *buf, int len, int reset);

void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);

void ftrace_free_filter(struct ftrace_ops *ops);

void ftrace_ops_set_global_filter(struct ftrace_ops *ops);



int register_ftrace_command(struct ftrace_func_command *cmd);

int unregister_ftrace_command(struct ftrace_func_command *cmd);
@@ -645,6 +646,7 @@ static inline unsigned long ftrace_location(unsigned long ip) 
#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)

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



static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,

			    size_t cnt, loff_t *ppos) { return -ENODEV; }

kernel/trace/ftrace.c

+17 −0
Original line number Diff line number Diff line
@@ -4239,6 +4239,23 @@ int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, 
}

EXPORT_SYMBOL_GPL(ftrace_set_filter_ip);



/**

 * ftrace_ops_set_global_filter - setup ops to use global filters

 * @ops - the ops which will use the global filters

 *

 * ftrace users who need global function trace filtering should call this.

 * It can set the global filter only if ops were not initialized before.

 */

void ftrace_ops_set_global_filter(struct ftrace_ops *ops)

{

	if (ops->flags & FTRACE_OPS_FL_INITIALIZED)

		return;



	ftrace_ops_init(ops);

	ops->func_hash = &global_ops.local_hash;

}

EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter);



static int

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

		 int reset, int enable)

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