linux/kernel/trace/trace_output.h
Steven Rostedt 110bf2b764 tracing: add protection around module events unload
When reading the trace buffer, there is a race that when a module
is unloaded it removes events that is stilled referenced in the buffers.
This patch adds the protection around the unloading of the events
from modules and the reading of the trace buffers.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-09 17:29:07 -04:00

52 lines
1.5 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_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);
/* used by module unregistering */
extern int __unregister_ftrace_event(struct trace_event *event);
extern struct rw_semaphore trace_event_mutex;
#define MAX_MEMHEX_BYTES 8
#define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1)
#define SEQ_PUT_FIELD_RET(s, x) \
do { \
if (!trace_seq_putmem(s, &(x), sizeof(x))) \
return TRACE_TYPE_PARTIAL_LINE; \
} while (0)
#define SEQ_PUT_HEX_FIELD_RET(s, x) \
do { \
BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES); \
if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \
return TRACE_TYPE_PARTIAL_LINE; \
} while (0)
#endif