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Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[mirror_ubuntu-artful-kernel.git] / lib / kasprintf.c
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. */
14 char *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 }
34 EXPORT_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 */
42 const 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 }
50 EXPORT_SYMBOL(kvasprintf_const);
51
52 char *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 }
63 EXPORT_SYMBOL(kasprintf);