Christopher Ferris | 12e1f28 | 2016-02-04 12:35:07 -0800 | [diff] [blame] | 1 | /* |
| 2 | * include/linux/userfaultfd.h |
| 3 | * |
| 4 | * Copyright (C) 2007 Davide Libenzi <davidel@xmailserver.org> |
| 5 | * Copyright (C) 2015 Red Hat, Inc. |
| 6 | * |
| 7 | */ |
| 8 | |
| 9 | #ifndef _LINUX_USERFAULTFD_H |
| 10 | #define _LINUX_USERFAULTFD_H |
| 11 | |
| 12 | #include <linux/types.h> |
| 13 | |
Christopher Ferris | 12e1f28 | 2016-02-04 12:35:07 -0800 | [diff] [blame] | 14 | /* |
Christopher Ferris | 0543f74 | 2017-07-26 13:09:46 -0700 | [diff] [blame] | 15 | * If the UFFDIO_API is upgraded someday, the UFFDIO_UNREGISTER and |
| 16 | * UFFDIO_WAKE ioctls should be defined as _IOW and not as _IOR. In |
| 17 | * userfaultfd.h we assumed the kernel was reading (instead _IOC_READ |
| 18 | * means the userland is reading). |
Christopher Ferris | 12e1f28 | 2016-02-04 12:35:07 -0800 | [diff] [blame] | 19 | */ |
Christopher Ferris | 0543f74 | 2017-07-26 13:09:46 -0700 | [diff] [blame] | 20 | #define UFFD_API ((__u64)0xAA) |
| 21 | #define UFFD_API_FEATURES (UFFD_FEATURE_EVENT_FORK | \ |
| 22 | UFFD_FEATURE_EVENT_REMAP | \ |
| 23 | UFFD_FEATURE_EVENT_REMOVE | \ |
| 24 | UFFD_FEATURE_EVENT_UNMAP | \ |
| 25 | UFFD_FEATURE_MISSING_HUGETLBFS | \ |
| 26 | UFFD_FEATURE_MISSING_SHMEM) |
Christopher Ferris | 12e1f28 | 2016-02-04 12:35:07 -0800 | [diff] [blame] | 27 | #define UFFD_API_IOCTLS \ |
| 28 | ((__u64)1 << _UFFDIO_REGISTER | \ |
| 29 | (__u64)1 << _UFFDIO_UNREGISTER | \ |
| 30 | (__u64)1 << _UFFDIO_API) |
| 31 | #define UFFD_API_RANGE_IOCTLS \ |
| 32 | ((__u64)1 << _UFFDIO_WAKE | \ |
| 33 | (__u64)1 << _UFFDIO_COPY | \ |
| 34 | (__u64)1 << _UFFDIO_ZEROPAGE) |
Christopher Ferris | 0543f74 | 2017-07-26 13:09:46 -0700 | [diff] [blame] | 35 | #define UFFD_API_RANGE_IOCTLS_BASIC \ |
| 36 | ((__u64)1 << _UFFDIO_WAKE | \ |
| 37 | (__u64)1 << _UFFDIO_COPY) |
Christopher Ferris | 12e1f28 | 2016-02-04 12:35:07 -0800 | [diff] [blame] | 38 | |
| 39 | /* |
| 40 | * Valid ioctl command number range with this API is from 0x00 to |
| 41 | * 0x3F. UFFDIO_API is the fixed number, everything else can be |
| 42 | * changed by implementing a different UFFD_API. If sticking to the |
| 43 | * same UFFD_API more ioctl can be added and userland will be aware of |
| 44 | * which ioctl the running kernel implements through the ioctl command |
| 45 | * bitmask written by the UFFDIO_API. |
| 46 | */ |
| 47 | #define _UFFDIO_REGISTER (0x00) |
| 48 | #define _UFFDIO_UNREGISTER (0x01) |
| 49 | #define _UFFDIO_WAKE (0x02) |
| 50 | #define _UFFDIO_COPY (0x03) |
| 51 | #define _UFFDIO_ZEROPAGE (0x04) |
| 52 | #define _UFFDIO_API (0x3F) |
| 53 | |
| 54 | /* userfaultfd ioctl ids */ |
| 55 | #define UFFDIO 0xAA |
| 56 | #define UFFDIO_API _IOWR(UFFDIO, _UFFDIO_API, \ |
| 57 | struct uffdio_api) |
| 58 | #define UFFDIO_REGISTER _IOWR(UFFDIO, _UFFDIO_REGISTER, \ |
| 59 | struct uffdio_register) |
| 60 | #define UFFDIO_UNREGISTER _IOR(UFFDIO, _UFFDIO_UNREGISTER, \ |
| 61 | struct uffdio_range) |
| 62 | #define UFFDIO_WAKE _IOR(UFFDIO, _UFFDIO_WAKE, \ |
| 63 | struct uffdio_range) |
| 64 | #define UFFDIO_COPY _IOWR(UFFDIO, _UFFDIO_COPY, \ |
| 65 | struct uffdio_copy) |
| 66 | #define UFFDIO_ZEROPAGE _IOWR(UFFDIO, _UFFDIO_ZEROPAGE, \ |
| 67 | struct uffdio_zeropage) |
| 68 | |
| 69 | /* read() structure */ |
| 70 | struct uffd_msg { |
| 71 | __u8 event; |
| 72 | |
| 73 | __u8 reserved1; |
| 74 | __u16 reserved2; |
| 75 | __u32 reserved3; |
| 76 | |
| 77 | union { |
| 78 | struct { |
| 79 | __u64 flags; |
| 80 | __u64 address; |
| 81 | } pagefault; |
| 82 | |
| 83 | struct { |
Christopher Ferris | 0543f74 | 2017-07-26 13:09:46 -0700 | [diff] [blame] | 84 | __u32 ufd; |
| 85 | } fork; |
| 86 | |
| 87 | struct { |
| 88 | __u64 from; |
| 89 | __u64 to; |
| 90 | __u64 len; |
| 91 | } remap; |
| 92 | |
| 93 | struct { |
| 94 | __u64 start; |
| 95 | __u64 end; |
| 96 | } remove; |
| 97 | |
| 98 | struct { |
Christopher Ferris | 12e1f28 | 2016-02-04 12:35:07 -0800 | [diff] [blame] | 99 | /* unused reserved fields */ |
| 100 | __u64 reserved1; |
| 101 | __u64 reserved2; |
| 102 | __u64 reserved3; |
| 103 | } reserved; |
| 104 | } arg; |
| 105 | } __packed; |
| 106 | |
| 107 | /* |
| 108 | * Start at 0x12 and not at 0 to be more strict against bugs. |
| 109 | */ |
| 110 | #define UFFD_EVENT_PAGEFAULT 0x12 |
Christopher Ferris | 12e1f28 | 2016-02-04 12:35:07 -0800 | [diff] [blame] | 111 | #define UFFD_EVENT_FORK 0x13 |
Christopher Ferris | 0543f74 | 2017-07-26 13:09:46 -0700 | [diff] [blame] | 112 | #define UFFD_EVENT_REMAP 0x14 |
| 113 | #define UFFD_EVENT_REMOVE 0x15 |
| 114 | #define UFFD_EVENT_UNMAP 0x16 |
Christopher Ferris | 12e1f28 | 2016-02-04 12:35:07 -0800 | [diff] [blame] | 115 | |
| 116 | /* flags for UFFD_EVENT_PAGEFAULT */ |
| 117 | #define UFFD_PAGEFAULT_FLAG_WRITE (1<<0) /* If this was a write fault */ |
| 118 | #define UFFD_PAGEFAULT_FLAG_WP (1<<1) /* If reason is VM_UFFD_WP */ |
| 119 | |
| 120 | struct uffdio_api { |
| 121 | /* userland asks for an API number and the features to enable */ |
| 122 | __u64 api; |
| 123 | /* |
| 124 | * Kernel answers below with the all available features for |
| 125 | * the API, this notifies userland of which events and/or |
| 126 | * which flags for each event are enabled in the current |
| 127 | * kernel. |
| 128 | * |
| 129 | * Note: UFFD_EVENT_PAGEFAULT and UFFD_PAGEFAULT_FLAG_WRITE |
| 130 | * are to be considered implicitly always enabled in all kernels as |
| 131 | * long as the uffdio_api.api requested matches UFFD_API. |
Christopher Ferris | 0543f74 | 2017-07-26 13:09:46 -0700 | [diff] [blame] | 132 | * |
| 133 | * UFFD_FEATURE_MISSING_HUGETLBFS means an UFFDIO_REGISTER |
| 134 | * with UFFDIO_REGISTER_MODE_MISSING mode will succeed on |
| 135 | * hugetlbfs virtual memory ranges. Adding or not adding |
| 136 | * UFFD_FEATURE_MISSING_HUGETLBFS to uffdio_api.features has |
| 137 | * no real functional effect after UFFDIO_API returns, but |
| 138 | * it's only useful for an initial feature set probe at |
| 139 | * UFFDIO_API time. There are two ways to use it: |
| 140 | * |
| 141 | * 1) by adding UFFD_FEATURE_MISSING_HUGETLBFS to the |
| 142 | * uffdio_api.features before calling UFFDIO_API, an error |
| 143 | * will be returned by UFFDIO_API on a kernel without |
| 144 | * hugetlbfs missing support |
| 145 | * |
| 146 | * 2) the UFFD_FEATURE_MISSING_HUGETLBFS can not be added in |
| 147 | * uffdio_api.features and instead it will be set by the |
| 148 | * kernel in the uffdio_api.features if the kernel supports |
| 149 | * it, so userland can later check if the feature flag is |
| 150 | * present in uffdio_api.features after UFFDIO_API |
| 151 | * succeeded. |
| 152 | * |
| 153 | * UFFD_FEATURE_MISSING_SHMEM works the same as |
| 154 | * UFFD_FEATURE_MISSING_HUGETLBFS, but it applies to shmem |
| 155 | * (i.e. tmpfs and other shmem based APIs). |
Christopher Ferris | 12e1f28 | 2016-02-04 12:35:07 -0800 | [diff] [blame] | 156 | */ |
Christopher Ferris | 12e1f28 | 2016-02-04 12:35:07 -0800 | [diff] [blame] | 157 | #define UFFD_FEATURE_PAGEFAULT_FLAG_WP (1<<0) |
| 158 | #define UFFD_FEATURE_EVENT_FORK (1<<1) |
Christopher Ferris | 0543f74 | 2017-07-26 13:09:46 -0700 | [diff] [blame] | 159 | #define UFFD_FEATURE_EVENT_REMAP (1<<2) |
| 160 | #define UFFD_FEATURE_EVENT_REMOVE (1<<3) |
| 161 | #define UFFD_FEATURE_MISSING_HUGETLBFS (1<<4) |
| 162 | #define UFFD_FEATURE_MISSING_SHMEM (1<<5) |
| 163 | #define UFFD_FEATURE_EVENT_UNMAP (1<<6) |
Christopher Ferris | 12e1f28 | 2016-02-04 12:35:07 -0800 | [diff] [blame] | 164 | __u64 features; |
| 165 | |
| 166 | __u64 ioctls; |
| 167 | }; |
| 168 | |
| 169 | struct uffdio_range { |
| 170 | __u64 start; |
| 171 | __u64 len; |
| 172 | }; |
| 173 | |
| 174 | struct uffdio_register { |
| 175 | struct uffdio_range range; |
| 176 | #define UFFDIO_REGISTER_MODE_MISSING ((__u64)1<<0) |
| 177 | #define UFFDIO_REGISTER_MODE_WP ((__u64)1<<1) |
| 178 | __u64 mode; |
| 179 | |
| 180 | /* |
| 181 | * kernel answers which ioctl commands are available for the |
| 182 | * range, keep at the end as the last 8 bytes aren't read. |
| 183 | */ |
| 184 | __u64 ioctls; |
| 185 | }; |
| 186 | |
| 187 | struct uffdio_copy { |
| 188 | __u64 dst; |
| 189 | __u64 src; |
| 190 | __u64 len; |
| 191 | /* |
| 192 | * There will be a wrprotection flag later that allows to map |
| 193 | * pages wrprotected on the fly. And such a flag will be |
| 194 | * available if the wrprotection ioctl are implemented for the |
| 195 | * range according to the uffdio_register.ioctls. |
| 196 | */ |
| 197 | #define UFFDIO_COPY_MODE_DONTWAKE ((__u64)1<<0) |
| 198 | __u64 mode; |
| 199 | |
| 200 | /* |
| 201 | * "copy" is written by the ioctl and must be at the end: the |
| 202 | * copy_from_user will not read the last 8 bytes. |
| 203 | */ |
| 204 | __s64 copy; |
| 205 | }; |
| 206 | |
| 207 | struct uffdio_zeropage { |
| 208 | struct uffdio_range range; |
| 209 | #define UFFDIO_ZEROPAGE_MODE_DONTWAKE ((__u64)1<<0) |
| 210 | __u64 mode; |
| 211 | |
| 212 | /* |
| 213 | * "zeropage" is written by the ioctl and must be at the end: |
| 214 | * the copy_from_user will not read the last 8 bytes. |
| 215 | */ |
| 216 | __s64 zeropage; |
| 217 | }; |
| 218 | |
| 219 | #endif /* _LINUX_USERFAULTFD_H */ |