linux/kernel/trace/trace_output.h
Steven Rostedt (Red Hat) 19a7fe2062 tracing: Add trace_seq_has_overflowed() and trace_handle_return()
Adding a trace_seq_has_overflowed() which returns true if the trace_seq
had too much written into it allows us to simplify the code.

Instead of checking the return value of every call to trace_seq_printf()
and friends, they can all be called normally, and at the end we can
return !trace_seq_has_overflowed() instead.

Several functions also return TRACE_TYPE_PARTIAL_LINE when the trace_seq
overflowed and TRACE_TYPE_HANDLED otherwise. Another helper function
was created called trace_handle_return() which takes a trace_seq and
returns these enums. Using this helper function also simplifies the
code.

This change also makes it possible to remove the return values of
trace_seq_printf() and friends. They should instead just be
void functions.

Link: http://lkml.kernel.org/r/20141114011410.365183157@goodmis.org

Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19 15:25:39 -05:00

46 lines
1.4 KiB
C

#ifndef __TRACE_EVENTS_H
#define __TRACE_EVENTS_H
#include <linux/trace_seq.h>
#include "trace.h"
extern enum print_line_t
trace_print_bputs_msg_only(struct trace_iterator *iter);
extern enum print_line_t
trace_print_bprintk_msg_only(struct trace_iterator *iter);
extern enum print_line_t
trace_print_printk_msg_only(struct trace_iterator *iter);
extern int
seq_print_ip_sym(struct trace_seq *s, unsigned long ip,
unsigned long sym_flags);
extern int seq_print_userip_objs(const struct userstack_entry *entry,
struct trace_seq *s, unsigned long sym_flags);
extern int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
unsigned long ip, unsigned long sym_flags);
extern int trace_print_context(struct trace_iterator *iter);
extern int trace_print_lat_context(struct trace_iterator *iter);
extern void trace_event_read_lock(void);
extern void trace_event_read_unlock(void);
extern struct trace_event *ftrace_find_event(int type);
extern enum print_line_t trace_nop_print(struct trace_iterator *iter,
int flags, struct trace_event *event);
extern int
trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry);
/* used by module unregistering */
extern int __unregister_ftrace_event(struct trace_event *event);
extern struct rw_semaphore trace_event_sem;
#define SEQ_PUT_FIELD(s, x) \
trace_seq_putmem(s, &(x), sizeof(x))
#define SEQ_PUT_HEX_FIELD(s, x) \
trace_seq_putmem_hex(s, &(x), sizeof(x))
#endif