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// SPDX-License-Identifier: GPL-2.0
/*
* linux/lib/kasprintf.c
*
* Copyright (C) 1991, 1992 Linus Torvalds
*/
#include <linux/stdarg.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/string.h>
/* Simplified asprintf. */
char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
{
unsigned int first, second;
char *p;
va_list aq;
va_copy(aq, ap);
first = vsnprintf(NULL, 0, fmt, aq);
va_end(aq);
p = kmalloc_track_caller(first+1, gfp);
if (!p)
return NULL;
second = vsnprintf(p, first+1, fmt, ap);
WARN(first != second, "different return values (%u and %u) from vsnprintf(\"%s\", ...)",
first, second, fmt);
return p;
}
EXPORT_SYMBOL(kvasprintf);
/*
* If fmt contains no % (or is exactly %s), use kstrdup_const. If fmt
* (or the sole vararg) points to rodata, we will then save a memory
* allocation and string copy. In any case, the return value should be
* freed using kfree_const().
*/
const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list ap)
{
if (!strchr(fmt, '%'))
return kstrdup_const(fmt, gfp);
if (!strcmp(fmt, "%s"))
return kstrdup_const(va_arg(ap, const char*), gfp);
return kvasprintf(gfp, fmt, ap);
}
EXPORT_SYMBOL(kvasprintf_const);
char *kasprintf(gfp_t gfp, const char *fmt, ...)
{
va_list ap;
char *p;
va_start(ap, fmt);
p = kvasprintf(gfp, fmt, ap);
va_end(ap);
return p;
}
EXPORT_SYMBOL(kasprintf);
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