1/*
2 *  linux/lib/kasprintf.c
3 *
4 *  Copyright (C) 1991, 1992  Linus Torvalds
5 */
6
7#include <stdarg.h>
8#include <linux/export.h>
9#include <linux/slab.h>
10#include <linux/types.h>
11#include <linux/string.h>
12
13/* Simplified asprintf. */
14char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
15{
16	unsigned int len;
17	char *p;
18	va_list aq;
19
20	va_copy(aq, ap);
21	len = vsnprintf(NULL, 0, fmt, aq);
22	va_end(aq);
23
24	p = kmalloc_track_caller(len+1, gfp);
25	if (!p)
26		return NULL;
27
28	vsnprintf(p, len+1, fmt, ap);
29
30	return p;
31}
32EXPORT_SYMBOL(kvasprintf);
33
34/*
35 * If fmt contains no % (or is exactly %s), use kstrdup_const. If fmt
36 * (or the sole vararg) points to rodata, we will then save a memory
37 * allocation and string copy. In any case, the return value should be
38 * freed using kfree_const().
39 */
40const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list ap)
41{
42	if (!strchr(fmt, '%'))
43		return kstrdup_const(fmt, gfp);
44	if (!strcmp(fmt, "%s"))
45		return kstrdup_const(va_arg(ap, const char*), gfp);
46	return kvasprintf(gfp, fmt, ap);
47}
48EXPORT_SYMBOL(kvasprintf_const);
49
50char *kasprintf(gfp_t gfp, const char *fmt, ...)
51{
52	va_list ap;
53	char *p;
54
55	va_start(ap, fmt);
56	p = kvasprintf(gfp, fmt, ap);
57	va_end(ap);
58
59	return p;
60}
61EXPORT_SYMBOL(kasprintf);
62