mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-25 13:43:55 +08:00
5ac4837841
As the seq_buf->len will soon be +1 size when there's an overflow, we must use trace_seq_used() or seq_buf_used() methods to get the real length. This will prevent buffer overflow issues if just the len of the seq_buf descriptor is used to copy memory. Link: http://lkml.kernel.org/r/20141114121911.09ba3d38@gandalf.local.home Reported-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
139 lines
3.7 KiB
C
139 lines
3.7 KiB
C
#ifndef _LINUX_TRACE_SEQ_H
|
|
#define _LINUX_TRACE_SEQ_H
|
|
|
|
#include <linux/seq_buf.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];
|
|
struct seq_buf seq;
|
|
int full;
|
|
};
|
|
|
|
static inline void
|
|
trace_seq_init(struct trace_seq *s)
|
|
{
|
|
seq_buf_init(&s->seq, s->buffer, PAGE_SIZE);
|
|
s->full = 0;
|
|
}
|
|
|
|
/**
|
|
* trace_seq_used - amount of actual data written to buffer
|
|
* @s: trace sequence descriptor
|
|
*
|
|
* Returns the amount of data written to the buffer.
|
|
*
|
|
* IMPORTANT!
|
|
*
|
|
* Use this instead of @s->seq.len if you need to pass the amount
|
|
* of data from the buffer to another buffer (userspace, or what not).
|
|
* The @s->seq.len on overflow is bigger than the buffer size and
|
|
* using it can cause access to undefined memory.
|
|
*/
|
|
static inline int trace_seq_used(struct trace_seq *s)
|
|
{
|
|
return seq_buf_used(&s->seq);
|
|
}
|
|
|
|
/**
|
|
* trace_seq_buffer_ptr - return pointer to next location in buffer
|
|
* @s: trace sequence descriptor
|
|
*
|
|
* Returns the pointer to the buffer where the next write to
|
|
* the buffer will happen. This is useful to save the location
|
|
* that is about to be written to and then return the result
|
|
* of that write.
|
|
*/
|
|
static inline unsigned char *
|
|
trace_seq_buffer_ptr(struct trace_seq *s)
|
|
{
|
|
return s->buffer + seq_buf_used(&s->seq);
|
|
}
|
|
|
|
/**
|
|
* trace_seq_has_overflowed - return true if the trace_seq took too much
|
|
* @s: trace sequence descriptor
|
|
*
|
|
* Returns true if too much data was added to the trace_seq and it is
|
|
* now full and will not take anymore.
|
|
*/
|
|
static inline bool trace_seq_has_overflowed(struct trace_seq *s)
|
|
{
|
|
return s->full || seq_buf_has_overflowed(&s->seq);
|
|
}
|
|
|
|
/*
|
|
* Currently only defined when tracing is enabled.
|
|
*/
|
|
#ifdef CONFIG_TRACING
|
|
extern __printf(2, 3)
|
|
void trace_seq_printf(struct trace_seq *s, const char *fmt, ...);
|
|
extern __printf(2, 0)
|
|
void trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args);
|
|
extern void
|
|
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 int trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
|
|
int cnt);
|
|
extern void trace_seq_puts(struct trace_seq *s, const char *str);
|
|
extern void trace_seq_putc(struct trace_seq *s, unsigned char c);
|
|
extern void trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len);
|
|
extern void trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
|
|
unsigned int len);
|
|
extern int trace_seq_path(struct trace_seq *s, const struct path *path);
|
|
|
|
extern void trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
|
|
int nmaskbits);
|
|
|
|
#else /* CONFIG_TRACING */
|
|
static inline void trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
|
|
{
|
|
}
|
|
static inline void
|
|
trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
|
|
{
|
|
}
|
|
|
|
static inline void
|
|
trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
|
|
int nmaskbits)
|
|
{
|
|
}
|
|
|
|
static inline int trace_print_seq(struct seq_file *m, struct trace_seq *s)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline int trace_seq_to_user(struct trace_seq *s, char __user *ubuf,
|
|
int cnt)
|
|
{
|
|
return 0;
|
|
}
|
|
static inline void trace_seq_puts(struct trace_seq *s, const char *str)
|
|
{
|
|
}
|
|
static inline void trace_seq_putc(struct trace_seq *s, unsigned char c)
|
|
{
|
|
}
|
|
static inline void
|
|
trace_seq_putmem(struct trace_seq *s, const void *mem, unsigned int len)
|
|
{
|
|
}
|
|
static inline void trace_seq_putmem_hex(struct trace_seq *s, const void *mem,
|
|
unsigned int len)
|
|
{
|
|
}
|
|
static inline int trace_seq_path(struct trace_seq *s, const struct path *path)
|
|
{
|
|
return 0;
|
|
}
|
|
#endif /* CONFIG_TRACING */
|
|
|
|
#endif /* _LINUX_TRACE_SEQ_H */
|