mirror of
https://github.com/torvalds/linux.git
synced 2024-11-23 20:51:44 +00:00
6cb8f91320
Define ZERO_OR_NULL_PTR macro to be able to remove the checks from the allocators. Move ZERO_SIZE_PTR related stuff into slab.h. Make ZERO_SIZE_PTR work for all slab allocators and get rid of the WARN_ON_ONCE(size == 0) that is still remaining in SLAB. Make slub return NULL like the other allocators if a too large memory segment is requested via __kmalloc. Signed-off-by: Christoph Lameter <clameter@sgi.com> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
129 lines
2.5 KiB
C
129 lines
2.5 KiB
C
#include <linux/slab.h>
|
|
#include <linux/string.h>
|
|
#include <linux/module.h>
|
|
#include <linux/err.h>
|
|
#include <asm/uaccess.h>
|
|
|
|
/**
|
|
* __kzalloc - allocate memory. The memory is set to zero.
|
|
* @size: how many bytes of memory are required.
|
|
* @flags: the type of memory to allocate.
|
|
*/
|
|
void *__kzalloc(size_t size, gfp_t flags)
|
|
{
|
|
void *ret = kmalloc_track_caller(size, flags);
|
|
if (ret)
|
|
memset(ret, 0, size);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(__kzalloc);
|
|
|
|
/*
|
|
* kstrdup - allocate space for and copy an existing string
|
|
*
|
|
* @s: the string to duplicate
|
|
* @gfp: the GFP mask used in the kmalloc() call when allocating memory
|
|
*/
|
|
char *kstrdup(const char *s, gfp_t gfp)
|
|
{
|
|
size_t len;
|
|
char *buf;
|
|
|
|
if (!s)
|
|
return NULL;
|
|
|
|
len = strlen(s) + 1;
|
|
buf = kmalloc_track_caller(len, gfp);
|
|
if (buf)
|
|
memcpy(buf, s, len);
|
|
return buf;
|
|
}
|
|
EXPORT_SYMBOL(kstrdup);
|
|
|
|
/**
|
|
* kmemdup - duplicate region of memory
|
|
*
|
|
* @src: memory region to duplicate
|
|
* @len: memory region length
|
|
* @gfp: GFP mask to use
|
|
*/
|
|
void *kmemdup(const void *src, size_t len, gfp_t gfp)
|
|
{
|
|
void *p;
|
|
|
|
p = kmalloc_track_caller(len, gfp);
|
|
if (p)
|
|
memcpy(p, src, len);
|
|
return p;
|
|
}
|
|
EXPORT_SYMBOL(kmemdup);
|
|
|
|
/**
|
|
* krealloc - reallocate memory. The contents will remain unchanged.
|
|
* @p: object to reallocate memory for.
|
|
* @new_size: how many bytes of memory are required.
|
|
* @flags: the type of memory to allocate.
|
|
*
|
|
* The contents of the object pointed to are preserved up to the
|
|
* lesser of the new and old sizes. If @p is %NULL, krealloc()
|
|
* behaves exactly like kmalloc(). If @size is 0 and @p is not a
|
|
* %NULL pointer, the object pointed to is freed.
|
|
*/
|
|
void *krealloc(const void *p, size_t new_size, gfp_t flags)
|
|
{
|
|
void *ret;
|
|
size_t ks;
|
|
|
|
if (unlikely(!new_size)) {
|
|
kfree(p);
|
|
return ZERO_SIZE_PTR;
|
|
}
|
|
|
|
ks = ksize(p);
|
|
if (ks >= new_size)
|
|
return (void *)p;
|
|
|
|
ret = kmalloc_track_caller(new_size, flags);
|
|
if (ret) {
|
|
memcpy(ret, p, min(new_size, ks));
|
|
kfree(p);
|
|
}
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(krealloc);
|
|
|
|
/*
|
|
* strndup_user - duplicate an existing string from user space
|
|
*
|
|
* @s: The string to duplicate
|
|
* @n: Maximum number of bytes to copy, including the trailing NUL.
|
|
*/
|
|
char *strndup_user(const char __user *s, long n)
|
|
{
|
|
char *p;
|
|
long length;
|
|
|
|
length = strnlen_user(s, n);
|
|
|
|
if (!length)
|
|
return ERR_PTR(-EFAULT);
|
|
|
|
if (length > n)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
p = kmalloc(length, GFP_KERNEL);
|
|
|
|
if (!p)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
if (copy_from_user(p, s, length)) {
|
|
kfree(p);
|
|
return ERR_PTR(-EFAULT);
|
|
}
|
|
|
|
p[length - 1] = '\0';
|
|
|
|
return p;
|
|
}
|
|
EXPORT_SYMBOL(strndup_user);
|