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linux-next/include/linux/trace_seq.h
Johannes Berg d184b31c0e tracing: Add full state to trace_seq
The trace_seq buffer might fill up, and right now one needs to check the
return value of each printf into the buffer to check for that.

Instead, have the buffer keep track of whether it is full or not, and
reject more input if it is full or would have overflowed with an input
that wasn't added.

Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-12-09 14:05:49 -05:00

98 lines
2.5 KiB
C

#ifndef _LINUX_TRACE_SEQ_H
#define _LINUX_TRACE_SEQ_H
#include <linux/fs.h>
#include <asm/page.h>
/*
* Trace sequences are used to allow a function to call several other functions
* to create a string of data to use (up to a max of PAGE_SIZE).
*/
struct trace_seq {
unsigned char buffer[PAGE_SIZE];
unsigned int len;
unsigned int readpos;
int full;
};
static inline void
trace_seq_init(struct trace_seq *s)
{
s->len = 0;
s->readpos = 0;
s->full = 0;
}
/*
* Currently only defined when tracing is enabled.
*/
#ifdef CONFIG_TRACING
extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
__attribute__ ((format (printf, 2, 3)));
extern int trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
__attribute__ ((format (printf, 2, 0)));
extern int
trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary);
extern int trace_print_seq(struct seq_file *m, struct trace_seq *s);
extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
size_t cnt);
extern int trace_seq_puts(struct trace_seq *s, const char *str);
extern int trace_seq_putc(struct trace_seq *s, unsigned char c);
extern int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len);
extern int trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
size_t len);
extern void *trace_seq_reserve(struct trace_seq *s, size_t len);
extern int trace_seq_path(struct trace_seq *s, struct path *path);
#else /* CONFIG_TRACING */
static inline int trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
{
return 0;
}
static inline int
trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
{
return 0;
}
static inline int trace_print_seq(struct seq_file *m, struct trace_seq *s)
{
return 0;
}
static inline ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
size_t cnt)
{
return 0;
}
static inline int trace_seq_puts(struct trace_seq *s, const char *str)
{
return 0;
}
static inline int trace_seq_putc(struct trace_seq *s, unsigned char c)
{
return 0;
}
static inline int
trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
{
return 0;
}
static inline int trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
size_t len)
{
return 0;
}
static inline void *trace_seq_reserve(struct trace_seq *s, size_t len)
{
return NULL;
}
static inline int trace_seq_path(struct trace_seq *s, struct path *path)
{
return 0;
}
#endif /* CONFIG_TRACING */
#endif /* _LINUX_TRACE_SEQ_H */