diff options
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 36 |
1 files changed, 29 insertions, 7 deletions
diff --git a/mm/util.c b/mm/util.c index 34e57fae959d..c1250501364f 100644 --- a/mm/util.c +++ b/mm/util.c @@ -150,18 +150,14 @@ EXPORT_SYMBOL(kmemdup_nul); * @src: source address in user space * @len: number of bytes to copy * - * Returns an ERR_PTR() on failure. + * Returns an ERR_PTR() on failure. Result is physically + * contiguous, to be freed by kfree(). */ void *memdup_user(const void __user *src, size_t len) { void *p; - /* - * Always use GFP_KERNEL, since copy_from_user() can sleep and - * cause pagefault, which makes it pointless to use GFP_NOFS - * or GFP_ATOMIC. - */ - p = kmalloc_track_caller(len, GFP_KERNEL); + p = kmalloc_track_caller(len, GFP_USER); if (!p) return ERR_PTR(-ENOMEM); @@ -174,6 +170,32 @@ void *memdup_user(const void __user *src, size_t len) } EXPORT_SYMBOL(memdup_user); +/** + * vmemdup_user - duplicate memory region from user space + * + * @src: source address in user space + * @len: number of bytes to copy + * + * Returns an ERR_PTR() on failure. Result may be not + * physically contiguous. Use kvfree() to free. + */ +void *vmemdup_user(const void __user *src, size_t len) +{ + void *p; + + p = kvmalloc(len, GFP_USER); + if (!p) + return ERR_PTR(-ENOMEM); + + if (copy_from_user(p, src, len)) { + kvfree(p); + return ERR_PTR(-EFAULT); + } + + return p; +} +EXPORT_SYMBOL(vmemdup_user); + /* * strndup_user - duplicate an existing string from user space * @s: The string to duplicate |