blob: 7f6c506a494226479af1152f13f99f1870f554d1
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); |
64 |