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. */
kvasprintf(gfp_t gfp,const char * fmt,va_list ap)14 char *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 }
32 EXPORT_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 */
kvasprintf_const(gfp_t gfp,const char * fmt,va_list ap)40 const 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 }
48 EXPORT_SYMBOL(kvasprintf_const);
49
kasprintf(gfp_t gfp,const char * fmt,...)50 char *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 }
61 EXPORT_SYMBOL(kasprintf);
62