| Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame^] | 1 | /* |
| 2 | * This program is free software; you can redistribute it and/or modify |
| 3 | * it under the terms of the GNU General Public License as published by |
| 4 | * the Free Software Foundation; either version 2 of the License, or |
| 5 | * (at your option) any later version. |
| 6 | * |
| 7 | * This program is distributed in the hope that it will be useful, |
| 8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 10 | * GNU General Public License for more details. |
| 11 | * |
| 12 | * You should have received a copy of the GNU General Public License |
| 13 | * along with this program; if not, write to the Free Software |
| 14 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| 15 | * |
| 16 | * Copyright (C) IBM Corporation, 2010 |
| 17 | * |
| 18 | * Author: Anton Blanchard <anton@au.ibm.com> |
| 19 | */ |
| 20 | #include <linux/export.h> |
| 21 | #include <linux/compiler.h> |
| 22 | #include <linux/types.h> |
| 23 | #include <asm/checksum.h> |
| 24 | #include <asm/uaccess.h> |
| 25 | |
| 26 | __wsum csum_and_copy_from_user(const void __user *src, void *dst, |
| 27 | int len, __wsum sum, int *err_ptr) |
| 28 | { |
| 29 | unsigned int csum; |
| 30 | |
| 31 | might_sleep(); |
| 32 | |
| 33 | *err_ptr = 0; |
| 34 | |
| 35 | if (!len) { |
| 36 | csum = 0; |
| 37 | goto out; |
| 38 | } |
| 39 | |
| 40 | if (unlikely((len < 0) || !access_ok(VERIFY_READ, src, len))) { |
| 41 | *err_ptr = -EFAULT; |
| 42 | csum = (__force unsigned int)sum; |
| 43 | goto out; |
| 44 | } |
| 45 | |
| 46 | csum = csum_partial_copy_generic((void __force *)src, dst, |
| 47 | len, sum, err_ptr, NULL); |
| 48 | |
| 49 | if (unlikely(*err_ptr)) { |
| 50 | int missing = __copy_from_user(dst, src, len); |
| 51 | |
| 52 | if (missing) { |
| 53 | memset(dst + len - missing, 0, missing); |
| 54 | *err_ptr = -EFAULT; |
| 55 | } else { |
| 56 | *err_ptr = 0; |
| 57 | } |
| 58 | |
| 59 | csum = csum_partial(dst, len, sum); |
| 60 | } |
| 61 | |
| 62 | out: |
| 63 | return (__force __wsum)csum; |
| 64 | } |
| 65 | EXPORT_SYMBOL(csum_and_copy_from_user); |
| 66 | |
| 67 | __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len, |
| 68 | __wsum sum, int *err_ptr) |
| 69 | { |
| 70 | unsigned int csum; |
| 71 | |
| 72 | might_sleep(); |
| 73 | |
| 74 | *err_ptr = 0; |
| 75 | |
| 76 | if (!len) { |
| 77 | csum = 0; |
| 78 | goto out; |
| 79 | } |
| 80 | |
| 81 | if (unlikely((len < 0) || !access_ok(VERIFY_WRITE, dst, len))) { |
| 82 | *err_ptr = -EFAULT; |
| 83 | csum = -1; /* invalid checksum */ |
| 84 | goto out; |
| 85 | } |
| 86 | |
| 87 | csum = csum_partial_copy_generic(src, (void __force *)dst, |
| 88 | len, sum, NULL, err_ptr); |
| 89 | |
| 90 | if (unlikely(*err_ptr)) { |
| 91 | csum = csum_partial(src, len, sum); |
| 92 | |
| 93 | if (copy_to_user(dst, src, len)) { |
| 94 | *err_ptr = -EFAULT; |
| 95 | csum = -1; /* invalid checksum */ |
| 96 | } |
| 97 | } |
| 98 | |
| 99 | out: |
| 100 | return (__force __wsum)csum; |
| 101 | } |
| 102 | EXPORT_SYMBOL(csum_and_copy_to_user); |