projects / linux-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 1a59d1b8 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
| fdd374b6 | 2 | /* |
| fdd374b6 AB |
3 | * |
| 4 | * Copyright (C) IBM Corporation, 2010 | |
| 5 | * | |
| 6 | * Author: Anton Blanchard <anton@au.ibm.com> | |
| 7 | */ | |
| 4b16f8e2 | 8 | #include <linux/export.h> |
| fdd374b6 AB |
9 | #include <linux/compiler.h> |
| 10 | #include <linux/types.h> | |
| 11 | #include <asm/checksum.h> | |
| 7c0f6ba6 | 12 | #include <linux/uaccess.h> |
| fdd374b6 AB |
13 | |
| 14 | __wsum csum_and_copy_from_user(const void __user *src, void *dst, | |
| 15 | int len, __wsum sum, int *err_ptr) | |
| 16 | { | |
| 17 | unsigned int csum; | |
| 18 | ||
| 19 | might_sleep(); | |
| de78a9c4 | 20 | allow_read_from_user(src, len); |
| fdd374b6 AB |
21 | |
| 22 | *err_ptr = 0; | |
| 23 | ||
| 24 | if (!len) { | |
| 25 | csum = 0; | |
| 26 | goto out; | |
| 27 | } | |
| 28 | ||
| 96d4f267 | 29 | if (unlikely((len < 0) || !access_ok(src, len))) { |
| fdd374b6 AB |
30 | *err_ptr = -EFAULT; |
| 31 | csum = (__force unsigned int)sum; | |
| 32 | goto out; | |
| 33 | } | |
| 34 | ||
| 35 | csum = csum_partial_copy_generic((void __force *)src, dst, | |
| 36 | len, sum, err_ptr, NULL); | |
| 37 | ||
| 38 | if (unlikely(*err_ptr)) { | |
| 39 | int missing = __copy_from_user(dst, src, len); | |
| 40 | ||
| 41 | if (missing) { | |
| 42 | memset(dst + len - missing, 0, missing); | |
| 43 | *err_ptr = -EFAULT; | |
| 44 | } else { | |
| 45 | *err_ptr = 0; | |
| 46 | } | |
| 47 | ||
| 48 | csum = csum_partial(dst, len, sum); | |
| 49 | } | |
| 50 | ||
| 51 | out: | |
| de78a9c4 | 52 | prevent_read_from_user(src, len); |
| fdd374b6 AB |
53 | return (__force __wsum)csum; |
| 54 | } | |
| 55 | EXPORT_SYMBOL(csum_and_copy_from_user); | |
| 8c773914 AB |
56 | |
| 57 | __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len, | |
| 58 | __wsum sum, int *err_ptr) | |
| 59 | { | |
| 60 | unsigned int csum; | |
| 61 | ||
| 62 | might_sleep(); | |
| de78a9c4 | 63 | allow_write_to_user(dst, len); |
| 8c773914 AB |
64 | |
| 65 | *err_ptr = 0; | |
| 66 | ||
| 67 | if (!len) { | |
| 68 | csum = 0; | |
| 69 | goto out; | |
| 70 | } | |
| 71 | ||
| 96d4f267 | 72 | if (unlikely((len < 0) || !access_ok(dst, len))) { |
| 8c773914 AB |
73 | *err_ptr = -EFAULT; |
| 74 | csum = -1; /* invalid checksum */ | |
| 75 | goto out; | |
| 76 | } | |
| 77 | ||
| 78 | csum = csum_partial_copy_generic(src, (void __force *)dst, | |
| 79 | len, sum, NULL, err_ptr); | |
| 80 | ||
| 81 | if (unlikely(*err_ptr)) { | |
| 82 | csum = csum_partial(src, len, sum); | |
| 83 | ||
| 84 | if (copy_to_user(dst, src, len)) { | |
| 85 | *err_ptr = -EFAULT; | |
| 86 | csum = -1; /* invalid checksum */ | |
| 87 | } | |
| 88 | } | |
| 89 | ||
| 90 | out: | |
| de78a9c4 | 91 | prevent_write_to_user(dst, len); |
| 8c773914 AB |
92 | return (__force __wsum)csum; |
| 93 | } | |
| 94 | EXPORT_SYMBOL(csum_and_copy_to_user); |