/*
* trace_seq.c
*
* Copyright (C) 2008-2014 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
*
*/
#include <linux/uaccess.h>
#include <linux/seq_file.h>
#include <linux/trace_seq.h>
int trace_print_seq(struct seq_file *m, struct trace_seq *s)
{
int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
int ret;
ret = seq_write(m, s->buffer, len);
/*
* Only reset this buffer if we successfully wrote to the
* seq_file buffer.
*/
if (!ret)
trace_seq_init(s);
return ret;
}
/**
* trace_seq_printf - sequence printing of trace information
* @s: trace sequence descriptor
* @fmt: printf format string
*
* It returns 0 if the trace oversizes the buffer's free
* space, 1 otherwise.
*
* The tracer may use either sequence operations or its own
* copy to user routines. To simplify formating of a trace
* trace_seq_printf is used to store strings into a special
* buffer (@s). Then the output may be either used by
* the sequencer or pulled into another buffer.
*/
int
trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
{
int len = (PAGE_SIZE - 1) - s->len;
va_list ap;
int ret;
if (s->full || !len)
return 0;
va_start(ap, fmt);
ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
va_end(ap);
/* If we can't write it all, don't bother writing anything */
if (ret >= len) {
s->full = 1;
return 0;
}
s->len += ret;
return 1;
}
EXPORT_SYMBOL_GPL(trace_seq_printf);
/**
* trace_seq_bitmask - put a list of longs as a bitmask print output
* @s: trace sequence descriptor
* @maskp: points to an array of unsigned longs that represent a bitmask
* @nmaskbits: The number of bits that are valid in @maskp
*
* It returns 0 if the trace oversizes the buffer's free
* space, 1 otherwise.
*
* Writes a ASCII representation of a bitmask string into @s.
*/
int
trace_seq_bitmask(struct trace_seq *s, const unsigned long *maskp,
int nmaskbits)
{
int len = (PAGE_SIZE - 1) - s->len;
int ret;
if (s->full || !len)
return 0;
ret = bitmap_scnprintf(s->buffer, len, maskp, nmaskbits);
s->len += ret;
return 1;
}
EXPORT_SYMBOL_GPL(trace_seq_bitmask);
/**
* trace_seq_vprintf - sequence printing of trace information
* @s: trace sequence descriptor
* @fmt: printf format string
*
* The tracer may use either sequence operations or its own
* copy to user routines. To simplify formating of a trace
* trace_seq_printf is used to store strings into a special
* buffer (@s). Then the output may be either used by
* the sequencer or pulled into another buffer.
*/
int
trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
{
int len = (PAGE_SIZE - 1) - s->len;
int ret;
if (s->full || !len)
return 0;
ret = vsnprintf(s->buffer + s->len, len, fmt, args);
/* If we can't write it all, don't bother writing anything */
if (ret >= len) {
s->full = 1;
return 0;
}
s->len += ret;
return len;
}
EXPORT_SYMBOL_GPL(trace_seq_vprintf);
int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary)
{
int len = (PAGE_SIZE - 1) - s->len;
int ret;
if (s->full || !len)
return 0;
ret = bstr_printf(s->buffer + s->len, len, fmt, binary);
/* If we can't write it all, don't bother writing anything */
if (ret >= len) {
s->full = 1;
return 0;
}
s->len += ret;
return len;
}
/**
* trace_seq_puts - trace sequence printing of simple string
* @s: trace sequence descriptor
* @str: simple string to record
*
* The tracer may use either the sequence operations or its own
* copy to user routines. This function records a simple string
* into a special buffer (@s) for later retrieval by a sequencer
* or other mechanism.
*/
int trace_seq_puts(struct trace_seq *s, const char *str)
{
int len = strlen(str);
if (s->full)
return 0;
if (len > ((PAGE_SIZE - 1) - s->len)) {
s->full = 1;
return 0;
}
memcpy(s->buffer + s->len, str, len);
s->len += len;
return len;
}
int trace_seq_putc(struct trace_seq *s, unsigned char c)
{
if (s->full)
return 0;
if (s->len >= (PAGE_SIZE - 1)) {
s->full = 1;
return 0;
}
s->buffer[s->len++] = c;
return 1;
}
EXPORT_SYMBOL(trace_seq_putc);
int trace_seq_putmem(struct trace_seq *s, const void *mem, size_t len)
{
if (s->full)
return 0;
if (len > ((PAGE_SIZE - 1) - s->len)) {
s->full = 1;
return 0;
}
memcpy(s->buffer + s->len, mem, len);
s->len += len;
return len;
}
#define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1)
int trace_seq_putmem_hex(struct trace_seq *s, const void *mem, size_t len)
{
unsigned char hex[HEX_CHARS];
const unsigned char *data = mem;
int i, j;
if (s->full)
return 0;
#ifdef __BIG_ENDIAN
for (i = 0, j = 0; i < len; i++) {
#else
for (i = len-1, j = 0; i >= 0; i--) {
#endif
hex[j++] = hex_asc_hi(data[i]);
hex[j++] = hex_asc_lo(data[i]);
}
hex[j++] = ' ';
return trace_seq_putmem(s, hex, j);
}
void *trace_seq_reserve(struct trace_seq *s, size_t len)
{
void *ret;
if (s->full)
return NULL;
if (len > ((PAGE_SIZE - 1) - s->len)) {
s->full = 1;
return NULL;
}
ret = s->buffer + s->len;
s->len += len;
return ret;
}
int trace_seq_path(struct trace_seq *s, const struct path *path)
{
unsigned char *p;
if (s->full)
return 0;
if (s->len >= (PAGE_SIZE - 1)) {
s->full = 1;
return 0;
}
p = d_path(path, s->buffer + s->len, PAGE_SIZE - s->len);
if (!IS_ERR(p)) {
p = mangle_path(s->buffer + s->len, p, "\n");
if (p) {
s->len = p - s->buffer;
return 1;
}
} else {
s->buffer[s->len++] = '?';
return 1;
}
s->full = 1;
return 0;
}
ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt)
{
int len;
int ret;
if (!cnt)
return 0;
if (s->len <= s->readpos)
return -EBUSY;
len = s->len - s->readpos;
if (cnt > len)
cnt = len;
ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);
if (ret == cnt)
return -EFAULT;
cnt -= ret;
s->readpos += cnt;
return cnt;
}
