| Rusty Russell | d2f83e9 | 2013-05-17 09:05:21 +0930 | [diff] [blame] | 1 | #include <linux/uaccess.h> |
| 2 | #include <linux/export.h> |
| 3 | #include <linux/uio.h> |
| 4 | |
| 5 | /* |
| 6 | * Copy iovec to kernel. Returns -EFAULT on error. |
| 7 | * |
| 8 | * Note: this modifies the original iovec. |
| 9 | */ |
| 10 | |
| 11 | int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len) |
| 12 | { |
| 13 | while (len > 0) { |
| 14 | if (iov->iov_len) { |
| 15 | int copy = min_t(unsigned int, len, iov->iov_len); |
| 16 | if (copy_from_user(kdata, iov->iov_base, copy)) |
| 17 | return -EFAULT; |
| 18 | len -= copy; |
| 19 | kdata += copy; |
| 20 | iov->iov_base += copy; |
| 21 | iov->iov_len -= copy; |
| 22 | } |
| 23 | iov++; |
| 24 | } |
| 25 | |
| 26 | return 0; |
| 27 | } |
| 28 | EXPORT_SYMBOL(memcpy_fromiovec); |
| 29 | |
| 30 | /* |
| 31 | * Copy kernel to iovec. Returns -EFAULT on error. |
| 32 | * |
| 33 | * Note: this modifies the original iovec. |
| 34 | */ |
| 35 | |
| 36 | int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len) |
| 37 | { |
| 38 | while (len > 0) { |
| 39 | if (iov->iov_len) { |
| 40 | int copy = min_t(unsigned int, iov->iov_len, len); |
| 41 | if (copy_to_user(iov->iov_base, kdata, copy)) |
| 42 | return -EFAULT; |
| 43 | kdata += copy; |
| 44 | len -= copy; |
| 45 | iov->iov_len -= copy; |
| 46 | iov->iov_base += copy; |
| 47 | } |
| 48 | iov++; |
| 49 | } |
| 50 | |
| 51 | return 0; |
| 52 | } |
| 53 | EXPORT_SYMBOL(memcpy_toiovec); |
| Michael S. Tsirkin | ac5ccdb | 2014-06-19 21:22:56 +0300 | [diff] [blame] | 54 | |
| 55 | /* |
| 56 | * Copy kernel to iovec. Returns -EFAULT on error. |
| 57 | */ |
| 58 | |
| 59 | int memcpy_toiovecend(const struct iovec *iov, unsigned char *kdata, |
| 60 | int offset, int len) |
| 61 | { |
| 62 | int copy; |
| 63 | for (; len > 0; ++iov) { |
| 64 | /* Skip over the finished iovecs */ |
| 65 | if (unlikely(offset >= iov->iov_len)) { |
| 66 | offset -= iov->iov_len; |
| 67 | continue; |
| 68 | } |
| 69 | copy = min_t(unsigned int, iov->iov_len - offset, len); |
| 70 | if (copy_to_user(iov->iov_base + offset, kdata, copy)) |
| 71 | return -EFAULT; |
| 72 | offset = 0; |
| 73 | kdata += copy; |
| 74 | len -= copy; |
| 75 | } |
| 76 | |
| 77 | return 0; |
| 78 | } |
| 79 | EXPORT_SYMBOL(memcpy_toiovecend); |
| 80 | |
| 81 | /* |
| 82 | * Copy iovec to kernel. Returns -EFAULT on error. |
| 83 | */ |
| 84 | |
| 85 | int memcpy_fromiovecend(unsigned char *kdata, const struct iovec *iov, |
| 86 | int offset, int len) |
| 87 | { |
| Sasha Levin | 06ebb06 | 2014-07-31 23:00:35 -0400 | [diff] [blame] | 88 | /* No data? Done! */ |
| 89 | if (len == 0) |
| 90 | return 0; |
| 91 | |
| Michael S. Tsirkin | ac5ccdb | 2014-06-19 21:22:56 +0300 | [diff] [blame] | 92 | /* Skip over the finished iovecs */ |
| 93 | while (offset >= iov->iov_len) { |
| 94 | offset -= iov->iov_len; |
| 95 | iov++; |
| 96 | } |
| 97 | |
| 98 | while (len > 0) { |
| 99 | u8 __user *base = iov->iov_base + offset; |
| 100 | int copy = min_t(unsigned int, len, iov->iov_len - offset); |
| 101 | |
| 102 | offset = 0; |
| 103 | if (copy_from_user(kdata, base, copy)) |
| 104 | return -EFAULT; |
| 105 | len -= copy; |
| 106 | kdata += copy; |
| 107 | iov++; |
| 108 | } |
| 109 | |
| 110 | return 0; |
| 111 | } |
| 112 | EXPORT_SYMBOL(memcpy_fromiovecend); |