diff options
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 47 |
1 files changed, 42 insertions, 5 deletions
diff --git a/mm/util.c b/mm/util.c index 5f4bb59da63..7368479220b 100644 --- a/mm/util.c +++ b/mm/util.c @@ -1,20 +1,22 @@ #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. + * __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 *__kzalloc(size_t size, gfp_t flags) { - void *ret = kmalloc(size, flags); + void *ret = ____kmalloc(size, flags); if (ret) memset(ret, 0, size); return ret; } -EXPORT_SYMBOL(kzalloc); +EXPORT_SYMBOL(__kzalloc); /* * kstrdup - allocate space for and copy an existing string @@ -31,9 +33,44 @@ char *kstrdup(const char *s, gfp_t gfp) return NULL; len = strlen(s) + 1; - buf = kmalloc(len, gfp); + buf = ____kmalloc(len, gfp); if (buf) memcpy(buf, s, len); return buf; } EXPORT_SYMBOL(kstrdup); + +/* + * 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); |