1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 *  linux/lib/kasprintf.c
 4 *
 5 *  Copyright (C) 1991, 1992  Linus Torvalds
 6 */
 7
 8#include <stdarg.h>
 9#include <linux/export.h>
10#include <linux/slab.h>
11#include <linux/types.h>
12#include <linux/string.h>
13
14/* Simplified asprintf. */
15char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
16{
17	unsigned int first, second;
18	char *p;
19	va_list aq;
20
21	va_copy(aq, ap);
22	first = vsnprintf(NULL, 0, fmt, aq);
23	va_end(aq);
24
25	p = kmalloc_track_caller(first+1, gfp);
26	if (!p)
27		return NULL;
28
29	second = vsnprintf(p, first+1, fmt, ap);
30	WARN(first != second, "different return values (%u and %u) from vsnprintf(\"%s\", ...)",
31	     first, second, fmt);
32
33	return p;
34}
35EXPORT_SYMBOL(kvasprintf);
36
37/*
38 * If fmt contains no % (or is exactly %s), use kstrdup_const. If fmt
39 * (or the sole vararg) points to rodata, we will then save a memory
40 * allocation and string copy. In any case, the return value should be
41 * freed using kfree_const().
42 */
43const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list ap)
44{
45	if (!strchr(fmt, '%'))
46		return kstrdup_const(fmt, gfp);
47	if (!strcmp(fmt, "%s"))
48		return kstrdup_const(va_arg(ap, const char*), gfp);
49	return kvasprintf(gfp, fmt, ap);
50}
51EXPORT_SYMBOL(kvasprintf_const);
52
53char *kasprintf(gfp_t gfp, const char *fmt, ...)
54{
55	va_list ap;
56	char *p;
57
58	va_start(ap, fmt);
59	p = kvasprintf(gfp, fmt, ap);
60	va_end(ap);
61
62	return p;
63}
64EXPORT_SYMBOL(kasprintf);

 
 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 first, second;
17	char *p;
18	va_list aq;
19
20	va_copy(aq, ap);
21	first = vsnprintf(NULL, 0, fmt, aq);
22	va_end(aq);
23
24	p = kmalloc_track_caller(first+1, gfp);
25	if (!p)
26		return NULL;
27
28	second = vsnprintf(p, first+1, fmt, ap);
29	WARN(first != second, "different return values (%u and %u) from vsnprintf(\"%s\", ...)",
30	     first, second, fmt);
31
32	return p;
33}
34EXPORT_SYMBOL(kvasprintf);
35
36/*
37 * If fmt contains no % (or is exactly %s), use kstrdup_const. If fmt
38 * (or the sole vararg) points to rodata, we will then save a memory
39 * allocation and string copy. In any case, the return value should be
40 * freed using kfree_const().
41 */
42const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list ap)
43{
44	if (!strchr(fmt, '%'))
45		return kstrdup_const(fmt, gfp);
46	if (!strcmp(fmt, "%s"))
47		return kstrdup_const(va_arg(ap, const char*), gfp);
48	return kvasprintf(gfp, fmt, ap);
49}
50EXPORT_SYMBOL(kvasprintf_const);
51
52char *kasprintf(gfp_t gfp, const char *fmt, ...)
53{
54	va_list ap;
55	char *p;
56
57	va_start(ap, fmt);
58	p = kvasprintf(gfp, fmt, ap);
59	va_end(ap);
60
61	return p;
62}
63EXPORT_SYMBOL(kasprintf);