Greg Kroah-Hartman | b244131 | 2017-11-01 15:07:57 +0100 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | /* |
| 3 | * linux/mm/mlock.c |
| 4 | * |
| 5 | * (C) Copyright 1995 Linus Torvalds |
| 6 | * (C) Copyright 2002 Christoph Hellwig |
| 7 | */ |
| 8 | |
Randy.Dunlap | c59ede7 | 2006-01-11 12:17:46 -0800 | [diff] [blame] | 9 | #include <linux/capability.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 10 | #include <linux/mman.h> |
| 11 | #include <linux/mm.h> |
Ingo Molnar | 8703e8a | 2017-02-08 18:51:30 +0100 | [diff] [blame] | 12 | #include <linux/sched/user.h> |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 13 | #include <linux/swap.h> |
| 14 | #include <linux/swapops.h> |
| 15 | #include <linux/pagemap.h> |
Vlastimil Babka | 7225522 | 2013-09-11 14:22:29 -0700 | [diff] [blame] | 16 | #include <linux/pagevec.h> |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 17 | #include <linux/pagewalk.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 18 | #include <linux/mempolicy.h> |
| 19 | #include <linux/syscalls.h> |
Alexey Dobriyan | e8edc6e | 2007-05-21 01:22:52 +0400 | [diff] [blame] | 20 | #include <linux/sched.h> |
Paul Gortmaker | b95f1b31 | 2011-10-16 02:01:52 -0400 | [diff] [blame] | 21 | #include <linux/export.h> |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 22 | #include <linux/rmap.h> |
| 23 | #include <linux/mmzone.h> |
| 24 | #include <linux/hugetlb.h> |
Vlastimil Babka | 7225522 | 2013-09-11 14:22:29 -0700 | [diff] [blame] | 25 | #include <linux/memcontrol.h> |
| 26 | #include <linux/mm_inline.h> |
Mike Rapoport | 1507f51 | 2021-07-07 18:08:03 -0700 | [diff] [blame] | 27 | #include <linux/secretmem.h> |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 28 | |
| 29 | #include "internal.h" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 30 | |
Sebastian Andrzej Siewior | adb11e7 | 2022-04-01 11:28:33 -0700 | [diff] [blame] | 31 | struct mlock_pvec { |
| 32 | local_lock_t lock; |
| 33 | struct pagevec vec; |
| 34 | }; |
| 35 | |
| 36 | static DEFINE_PER_CPU(struct mlock_pvec, mlock_pvec) = { |
| 37 | .lock = INIT_LOCAL_LOCK(lock), |
| 38 | }; |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 39 | |
Wang Xiaoqiang | 7f43add | 2016-01-15 16:57:22 -0800 | [diff] [blame] | 40 | bool can_do_mlock(void) |
Alexey Dobriyan | e8edc6e | 2007-05-21 01:22:52 +0400 | [diff] [blame] | 41 | { |
Jiri Slaby | 59e99e5 | 2010-03-05 13:41:44 -0800 | [diff] [blame] | 42 | if (rlimit(RLIMIT_MEMLOCK) != 0) |
Wang Xiaoqiang | 7f43add | 2016-01-15 16:57:22 -0800 | [diff] [blame] | 43 | return true; |
Jeff Vander Stoep | a5a6579 | 2015-03-12 16:26:17 -0700 | [diff] [blame] | 44 | if (capable(CAP_IPC_LOCK)) |
Wang Xiaoqiang | 7f43add | 2016-01-15 16:57:22 -0800 | [diff] [blame] | 45 | return true; |
| 46 | return false; |
Alexey Dobriyan | e8edc6e | 2007-05-21 01:22:52 +0400 | [diff] [blame] | 47 | } |
| 48 | EXPORT_SYMBOL(can_do_mlock); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 50 | /* |
| 51 | * Mlocked pages are marked with PageMlocked() flag for efficient testing |
| 52 | * in vmscan and, possibly, the fault path; and to support semi-accurate |
| 53 | * statistics. |
| 54 | * |
| 55 | * An mlocked page [PageMlocked(page)] is unevictable. As such, it will |
| 56 | * be placed on the LRU "unevictable" list, rather than the [in]active lists. |
| 57 | * The unevictable list is an LRU sibling list to the [in]active lists. |
| 58 | * PageUnevictable is set to indicate the unevictable state. |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 59 | */ |
| 60 | |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 61 | static struct lruvec *__mlock_page(struct page *page, struct lruvec *lruvec) |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 62 | { |
Hugh Dickins | 07ca760 | 2022-02-14 18:29:54 -0800 | [diff] [blame] | 63 | /* There is nothing more we can do while it's off LRU */ |
| 64 | if (!TestClearPageLRU(page)) |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 65 | return lruvec; |
Hugh Dickins | 0964730 | 2020-09-18 21:20:15 -0700 | [diff] [blame] | 66 | |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 67 | lruvec = folio_lruvec_relock_irq(page_folio(page), lruvec); |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 68 | |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 69 | if (unlikely(page_evictable(page))) { |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 70 | /* |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 71 | * This is a little surprising, but quite possible: |
| 72 | * PageMlocked must have got cleared already by another CPU. |
| 73 | * Could this page be on the Unevictable LRU? I'm not sure, |
| 74 | * but move it now if so. |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 75 | */ |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 76 | if (PageUnevictable(page)) { |
| 77 | del_page_from_lru_list(page, lruvec); |
| 78 | ClearPageUnevictable(page); |
| 79 | add_page_to_lru_list(page, lruvec); |
| 80 | __count_vm_events(UNEVICTABLE_PGRESCUED, |
| 81 | thp_nr_pages(page)); |
| 82 | } |
| 83 | goto out; |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 84 | } |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 85 | |
Hugh Dickins | 07ca760 | 2022-02-14 18:29:54 -0800 | [diff] [blame] | 86 | if (PageUnevictable(page)) { |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 87 | if (PageMlocked(page)) |
| 88 | page->mlock_count++; |
Hugh Dickins | 07ca760 | 2022-02-14 18:29:54 -0800 | [diff] [blame] | 89 | goto out; |
Nick Piggin | 5344b7e | 2008-10-18 20:26:51 -0700 | [diff] [blame] | 90 | } |
Hugh Dickins | 07ca760 | 2022-02-14 18:29:54 -0800 | [diff] [blame] | 91 | |
| 92 | del_page_from_lru_list(page, lruvec); |
| 93 | ClearPageActive(page); |
| 94 | SetPageUnevictable(page); |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 95 | page->mlock_count = !!PageMlocked(page); |
Hugh Dickins | 07ca760 | 2022-02-14 18:29:54 -0800 | [diff] [blame] | 96 | add_page_to_lru_list(page, lruvec); |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 97 | __count_vm_events(UNEVICTABLE_PGCULLED, thp_nr_pages(page)); |
Hugh Dickins | 07ca760 | 2022-02-14 18:29:54 -0800 | [diff] [blame] | 98 | out: |
| 99 | SetPageLRU(page); |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 100 | return lruvec; |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 101 | } |
| 102 | |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 103 | static struct lruvec *__mlock_new_page(struct page *page, struct lruvec *lruvec) |
Vlastimil Babka | 7225522 | 2013-09-11 14:22:29 -0700 | [diff] [blame] | 104 | { |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 105 | VM_BUG_ON_PAGE(PageLRU(page), page); |
Vlastimil Babka | 7225522 | 2013-09-11 14:22:29 -0700 | [diff] [blame] | 106 | |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 107 | lruvec = folio_lruvec_relock_irq(page_folio(page), lruvec); |
Vlastimil Babka | 7225522 | 2013-09-11 14:22:29 -0700 | [diff] [blame] | 108 | |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 109 | /* As above, this is a little surprising, but possible */ |
| 110 | if (unlikely(page_evictable(page))) |
| 111 | goto out; |
| 112 | |
| 113 | SetPageUnevictable(page); |
| 114 | page->mlock_count = !!PageMlocked(page); |
| 115 | __count_vm_events(UNEVICTABLE_PGCULLED, thp_nr_pages(page)); |
| 116 | out: |
| 117 | add_page_to_lru_list(page, lruvec); |
| 118 | SetPageLRU(page); |
| 119 | return lruvec; |
Vlastimil Babka | 7225522 | 2013-09-11 14:22:29 -0700 | [diff] [blame] | 120 | } |
| 121 | |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 122 | static struct lruvec *__munlock_page(struct page *page, struct lruvec *lruvec) |
Vlastimil Babka | 7225522 | 2013-09-11 14:22:29 -0700 | [diff] [blame] | 123 | { |
Hugh Dickins | 0964730 | 2020-09-18 21:20:15 -0700 | [diff] [blame] | 124 | int nr_pages = thp_nr_pages(page); |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 125 | bool isolated = false; |
Hugh Dickins | 0964730 | 2020-09-18 21:20:15 -0700 | [diff] [blame] | 126 | |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 127 | if (!TestClearPageLRU(page)) |
| 128 | goto munlock; |
Kirill A. Shutemov | e90309c | 2016-01-15 16:54:33 -0800 | [diff] [blame] | 129 | |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 130 | isolated = true; |
| 131 | lruvec = folio_lruvec_relock_irq(page_folio(page), lruvec); |
| 132 | |
| 133 | if (PageUnevictable(page)) { |
Hugh Dickins | 07ca760 | 2022-02-14 18:29:54 -0800 | [diff] [blame] | 134 | /* Then mlock_count is maintained, but might undercount */ |
| 135 | if (page->mlock_count) |
| 136 | page->mlock_count--; |
| 137 | if (page->mlock_count) |
| 138 | goto out; |
Vlastimil Babka | 7225522 | 2013-09-11 14:22:29 -0700 | [diff] [blame] | 139 | } |
Hugh Dickins | 07ca760 | 2022-02-14 18:29:54 -0800 | [diff] [blame] | 140 | /* else assume that was the last mlock: reclaim will fix it if not */ |
| 141 | |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 142 | munlock: |
Hugh Dickins | 07ca760 | 2022-02-14 18:29:54 -0800 | [diff] [blame] | 143 | if (TestClearPageMlocked(page)) { |
| 144 | __mod_zone_page_state(page_zone(page), NR_MLOCK, -nr_pages); |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 145 | if (isolated || !PageUnevictable(page)) |
Hugh Dickins | 07ca760 | 2022-02-14 18:29:54 -0800 | [diff] [blame] | 146 | __count_vm_events(UNEVICTABLE_PGMUNLOCKED, nr_pages); |
| 147 | else |
| 148 | __count_vm_events(UNEVICTABLE_PGSTRANDED, nr_pages); |
| 149 | } |
| 150 | |
| 151 | /* page_evictable() has to be checked *after* clearing Mlocked */ |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 152 | if (isolated && PageUnevictable(page) && page_evictable(page)) { |
Hugh Dickins | 07ca760 | 2022-02-14 18:29:54 -0800 | [diff] [blame] | 153 | del_page_from_lru_list(page, lruvec); |
| 154 | ClearPageUnevictable(page); |
| 155 | add_page_to_lru_list(page, lruvec); |
| 156 | __count_vm_events(UNEVICTABLE_PGRESCUED, nr_pages); |
| 157 | } |
| 158 | out: |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 159 | if (isolated) |
| 160 | SetPageLRU(page); |
| 161 | return lruvec; |
| 162 | } |
| 163 | |
| 164 | /* |
| 165 | * Flags held in the low bits of a struct page pointer on the mlock_pvec. |
| 166 | */ |
| 167 | #define LRU_PAGE 0x1 |
| 168 | #define NEW_PAGE 0x2 |
| 169 | static inline struct page *mlock_lru(struct page *page) |
| 170 | { |
| 171 | return (struct page *)((unsigned long)page + LRU_PAGE); |
| 172 | } |
| 173 | |
| 174 | static inline struct page *mlock_new(struct page *page) |
| 175 | { |
| 176 | return (struct page *)((unsigned long)page + NEW_PAGE); |
| 177 | } |
| 178 | |
| 179 | /* |
| 180 | * mlock_pagevec() is derived from pagevec_lru_move_fn(): |
| 181 | * perhaps that can make use of such page pointer flags in future, |
| 182 | * but for now just keep it for mlock. We could use three separate |
| 183 | * pagevecs instead, but one feels better (munlocking a full pagevec |
| 184 | * does not need to drain mlocking pagevecs first). |
| 185 | */ |
| 186 | static void mlock_pagevec(struct pagevec *pvec) |
| 187 | { |
| 188 | struct lruvec *lruvec = NULL; |
| 189 | unsigned long mlock; |
| 190 | struct page *page; |
| 191 | int i; |
| 192 | |
| 193 | for (i = 0; i < pagevec_count(pvec); i++) { |
| 194 | page = pvec->pages[i]; |
| 195 | mlock = (unsigned long)page & (LRU_PAGE | NEW_PAGE); |
| 196 | page = (struct page *)((unsigned long)page - mlock); |
| 197 | pvec->pages[i] = page; |
| 198 | |
| 199 | if (mlock & LRU_PAGE) |
| 200 | lruvec = __mlock_page(page, lruvec); |
| 201 | else if (mlock & NEW_PAGE) |
| 202 | lruvec = __mlock_new_page(page, lruvec); |
| 203 | else |
| 204 | lruvec = __munlock_page(page, lruvec); |
| 205 | } |
| 206 | |
| 207 | if (lruvec) |
| 208 | unlock_page_lruvec_irq(lruvec); |
| 209 | release_pages(pvec->pages, pvec->nr); |
| 210 | pagevec_reinit(pvec); |
| 211 | } |
| 212 | |
Sebastian Andrzej Siewior | adb11e7 | 2022-04-01 11:28:33 -0700 | [diff] [blame] | 213 | void mlock_page_drain_local(void) |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 214 | { |
| 215 | struct pagevec *pvec; |
| 216 | |
Sebastian Andrzej Siewior | adb11e7 | 2022-04-01 11:28:33 -0700 | [diff] [blame] | 217 | local_lock(&mlock_pvec.lock); |
| 218 | pvec = this_cpu_ptr(&mlock_pvec.vec); |
| 219 | if (pagevec_count(pvec)) |
| 220 | mlock_pagevec(pvec); |
| 221 | local_unlock(&mlock_pvec.lock); |
| 222 | } |
| 223 | |
| 224 | void mlock_page_drain_remote(int cpu) |
| 225 | { |
| 226 | struct pagevec *pvec; |
| 227 | |
| 228 | WARN_ON_ONCE(cpu_online(cpu)); |
| 229 | pvec = &per_cpu(mlock_pvec.vec, cpu); |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 230 | if (pagevec_count(pvec)) |
| 231 | mlock_pagevec(pvec); |
| 232 | } |
| 233 | |
| 234 | bool need_mlock_page_drain(int cpu) |
| 235 | { |
Sebastian Andrzej Siewior | adb11e7 | 2022-04-01 11:28:33 -0700 | [diff] [blame] | 236 | return pagevec_count(&per_cpu(mlock_pvec.vec, cpu)); |
Lee Schermerhorn | 6927c1d | 2009-12-14 17:59:55 -0800 | [diff] [blame] | 237 | } |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 238 | |
Michel Lespinasse | ff6a6da | 2013-02-27 17:02:44 -0800 | [diff] [blame] | 239 | /** |
Matthew Wilcox (Oracle) | dcc5d33 | 2022-02-15 13:33:59 -0500 | [diff] [blame] | 240 | * mlock_folio - mlock a folio already on (or temporarily off) LRU |
| 241 | * @folio: folio to be mlocked. |
Hugh Dickins | 3d470fc | 2011-10-31 17:09:43 -0700 | [diff] [blame] | 242 | */ |
Matthew Wilcox (Oracle) | dcc5d33 | 2022-02-15 13:33:59 -0500 | [diff] [blame] | 243 | void mlock_folio(struct folio *folio) |
Hugh Dickins | 3d470fc | 2011-10-31 17:09:43 -0700 | [diff] [blame] | 244 | { |
Sebastian Andrzej Siewior | adb11e7 | 2022-04-01 11:28:33 -0700 | [diff] [blame] | 245 | struct pagevec *pvec; |
| 246 | |
| 247 | local_lock(&mlock_pvec.lock); |
| 248 | pvec = this_cpu_ptr(&mlock_pvec.vec); |
Hugh Dickins | 3d470fc | 2011-10-31 17:09:43 -0700 | [diff] [blame] | 249 | |
Matthew Wilcox (Oracle) | dcc5d33 | 2022-02-15 13:33:59 -0500 | [diff] [blame] | 250 | if (!folio_test_set_mlocked(folio)) { |
| 251 | int nr_pages = folio_nr_pages(folio); |
Hugh Dickins | 3d470fc | 2011-10-31 17:09:43 -0700 | [diff] [blame] | 252 | |
Matthew Wilcox (Oracle) | dcc5d33 | 2022-02-15 13:33:59 -0500 | [diff] [blame] | 253 | zone_stat_mod_folio(folio, NR_MLOCK, nr_pages); |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 254 | __count_vm_events(UNEVICTABLE_PGMLOCKED, nr_pages); |
Hugh Dickins | 53f79ac | 2009-12-14 17:58:58 -0800 | [diff] [blame] | 255 | } |
Nick Piggin | 5344b7e | 2008-10-18 20:26:51 -0700 | [diff] [blame] | 256 | |
Matthew Wilcox (Oracle) | dcc5d33 | 2022-02-15 13:33:59 -0500 | [diff] [blame] | 257 | folio_get(folio); |
| 258 | if (!pagevec_add(pvec, mlock_lru(&folio->page)) || |
| 259 | folio_test_large(folio) || lru_cache_disabled()) |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 260 | mlock_pagevec(pvec); |
Sebastian Andrzej Siewior | adb11e7 | 2022-04-01 11:28:33 -0700 | [diff] [blame] | 261 | local_unlock(&mlock_pvec.lock); |
Nick Piggin | 5344b7e | 2008-10-18 20:26:51 -0700 | [diff] [blame] | 262 | } |
| 263 | |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 264 | /** |
| 265 | * mlock_new_page - mlock a newly allocated page not yet on LRU |
| 266 | * @page: page to be mlocked, either a normal page or a THP head. |
Lee Schermerhorn | 6927c1d | 2009-12-14 17:59:55 -0800 | [diff] [blame] | 267 | */ |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 268 | void mlock_new_page(struct page *page) |
Lee Schermerhorn | 6927c1d | 2009-12-14 17:59:55 -0800 | [diff] [blame] | 269 | { |
Sebastian Andrzej Siewior | adb11e7 | 2022-04-01 11:28:33 -0700 | [diff] [blame] | 270 | struct pagevec *pvec; |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 271 | int nr_pages = thp_nr_pages(page); |
| 272 | |
Sebastian Andrzej Siewior | adb11e7 | 2022-04-01 11:28:33 -0700 | [diff] [blame] | 273 | local_lock(&mlock_pvec.lock); |
| 274 | pvec = this_cpu_ptr(&mlock_pvec.vec); |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 275 | SetPageMlocked(page); |
| 276 | mod_zone_page_state(page_zone(page), NR_MLOCK, nr_pages); |
| 277 | __count_vm_events(UNEVICTABLE_PGMLOCKED, nr_pages); |
| 278 | |
| 279 | get_page(page); |
| 280 | if (!pagevec_add(pvec, mlock_new(page)) || |
| 281 | PageHead(page) || lru_cache_disabled()) |
| 282 | mlock_pagevec(pvec); |
Sebastian Andrzej Siewior | adb11e7 | 2022-04-01 11:28:33 -0700 | [diff] [blame] | 283 | local_unlock(&mlock_pvec.lock); |
Nick Piggin | 5344b7e | 2008-10-18 20:26:51 -0700 | [diff] [blame] | 284 | } |
| 285 | |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 286 | /** |
| 287 | * munlock_page - munlock a page |
| 288 | * @page: page to be munlocked, either a normal page or a THP head. |
Rik van Riel | ba470de | 2008-10-18 20:26:50 -0700 | [diff] [blame] | 289 | */ |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 290 | void munlock_page(struct page *page) |
Hugh Dickins | 408e82b | 2009-09-21 17:03:23 -0700 | [diff] [blame] | 291 | { |
Sebastian Andrzej Siewior | adb11e7 | 2022-04-01 11:28:33 -0700 | [diff] [blame] | 292 | struct pagevec *pvec; |
Vlastimil Babka | 56afe477d | 2013-09-11 14:22:32 -0700 | [diff] [blame] | 293 | |
Sebastian Andrzej Siewior | adb11e7 | 2022-04-01 11:28:33 -0700 | [diff] [blame] | 294 | local_lock(&mlock_pvec.lock); |
| 295 | pvec = this_cpu_ptr(&mlock_pvec.vec); |
Vlastimil Babka | 5b40998 | 2013-09-11 14:22:33 -0700 | [diff] [blame] | 296 | /* |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 297 | * TestClearPageMlocked(page) must be left to __munlock_page(), |
| 298 | * which will check whether the page is multiply mlocked. |
Vlastimil Babka | 5b40998 | 2013-09-11 14:22:33 -0700 | [diff] [blame] | 299 | */ |
Hugh Dickins | 2fbb0c1 | 2022-02-14 18:37:29 -0800 | [diff] [blame] | 300 | |
| 301 | get_page(page); |
| 302 | if (!pagevec_add(pvec, page) || |
| 303 | PageHead(page) || lru_cache_disabled()) |
| 304 | mlock_pagevec(pvec); |
Sebastian Andrzej Siewior | adb11e7 | 2022-04-01 11:28:33 -0700 | [diff] [blame] | 305 | local_unlock(&mlock_pvec.lock); |
Vlastimil Babka | 7a8010c | 2013-09-11 14:22:35 -0700 | [diff] [blame] | 306 | } |
Vlastimil Babka | 56afe477d | 2013-09-11 14:22:32 -0700 | [diff] [blame] | 307 | |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 308 | static int mlock_pte_range(pmd_t *pmd, unsigned long addr, |
| 309 | unsigned long end, struct mm_walk *walk) |
Hugh Dickins | 408e82b | 2009-09-21 17:03:23 -0700 | [diff] [blame] | 310 | |
Hugh Dickins | 408e82b | 2009-09-21 17:03:23 -0700 | [diff] [blame] | 311 | { |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 312 | struct vm_area_struct *vma = walk->vma; |
Hugh Dickins | 6e91971 | 2009-09-21 17:03:32 -0700 | [diff] [blame] | 313 | spinlock_t *ptl; |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 314 | pte_t *start_pte, *pte; |
| 315 | struct page *page; |
Michel Lespinasse | ff6a6da | 2013-02-27 17:02:44 -0800 | [diff] [blame] | 316 | |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 317 | ptl = pmd_trans_huge_lock(pmd, vma); |
| 318 | if (ptl) { |
| 319 | if (!pmd_present(*pmd)) |
| 320 | goto out; |
| 321 | if (is_huge_zero_pmd(*pmd)) |
| 322 | goto out; |
| 323 | page = pmd_page(*pmd); |
| 324 | if (vma->vm_flags & VM_LOCKED) |
Matthew Wilcox (Oracle) | dcc5d33 | 2022-02-15 13:33:59 -0500 | [diff] [blame] | 325 | mlock_folio(page_folio(page)); |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 326 | else |
| 327 | munlock_page(page); |
| 328 | goto out; |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 329 | } |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 330 | |
| 331 | start_pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl); |
| 332 | for (pte = start_pte; addr != end; pte++, addr += PAGE_SIZE) { |
| 333 | if (!pte_present(*pte)) |
| 334 | continue; |
| 335 | page = vm_normal_page(vma, addr, *pte); |
| 336 | if (!page) |
| 337 | continue; |
| 338 | if (PageTransCompound(page)) |
| 339 | continue; |
| 340 | if (vma->vm_flags & VM_LOCKED) |
Matthew Wilcox (Oracle) | dcc5d33 | 2022-02-15 13:33:59 -0500 | [diff] [blame] | 341 | mlock_folio(page_folio(page)); |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 342 | else |
| 343 | munlock_page(page); |
| 344 | } |
| 345 | pte_unmap(start_pte); |
| 346 | out: |
| 347 | spin_unlock(ptl); |
| 348 | cond_resched(); |
| 349 | return 0; |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 350 | } |
| 351 | |
| 352 | /* |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 353 | * mlock_vma_pages_range() - mlock any pages already in the range, |
| 354 | * or munlock all pages in the range. |
| 355 | * @vma - vma containing range to be mlock()ed or munlock()ed |
Rik van Riel | ba470de | 2008-10-18 20:26:50 -0700 | [diff] [blame] | 356 | * @start - start address in @vma of the range |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 357 | * @end - end of range in @vma |
| 358 | * @newflags - the new set of flags for @vma. |
Rik van Riel | ba470de | 2008-10-18 20:26:50 -0700 | [diff] [blame] | 359 | * |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 360 | * Called for mlock(), mlock2() and mlockall(), to set @vma VM_LOCKED; |
| 361 | * called for munlock() and munlockall(), to clear VM_LOCKED from @vma. |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 362 | */ |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 363 | static void mlock_vma_pages_range(struct vm_area_struct *vma, |
| 364 | unsigned long start, unsigned long end, vm_flags_t newflags) |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 365 | { |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 366 | static const struct mm_walk_ops mlock_walk_ops = { |
| 367 | .pmd_entry = mlock_pte_range, |
| 368 | }; |
Hugh Dickins | 408e82b | 2009-09-21 17:03:23 -0700 | [diff] [blame] | 369 | |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 370 | /* |
| 371 | * There is a slight chance that concurrent page migration, |
| 372 | * or page reclaim finding a page of this now-VM_LOCKED vma, |
| 373 | * will call mlock_vma_page() and raise page's mlock_count: |
| 374 | * double counting, leaving the page unevictable indefinitely. |
| 375 | * Communicate this danger to mlock_vma_page() with VM_IO, |
| 376 | * which is a VM_SPECIAL flag not allowed on VM_LOCKED vmas. |
| 377 | * mmap_lock is held in write mode here, so this weird |
| 378 | * combination should not be visible to other mmap_lock users; |
| 379 | * but WRITE_ONCE so rmap walkers must see VM_IO if VM_LOCKED. |
| 380 | */ |
| 381 | if (newflags & VM_LOCKED) |
| 382 | newflags |= VM_IO; |
| 383 | WRITE_ONCE(vma->vm_flags, newflags); |
Michel Lespinasse | ff6a6da | 2013-02-27 17:02:44 -0800 | [diff] [blame] | 384 | |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 385 | lru_add_drain(); |
| 386 | walk_page_range(vma->vm_mm, start, end, &mlock_walk_ops, NULL); |
| 387 | lru_add_drain(); |
Vlastimil Babka | 7a8010c | 2013-09-11 14:22:35 -0700 | [diff] [blame] | 388 | |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 389 | if (newflags & VM_IO) { |
| 390 | newflags &= ~VM_IO; |
| 391 | WRITE_ONCE(vma->vm_flags, newflags); |
Hugh Dickins | 408e82b | 2009-09-21 17:03:23 -0700 | [diff] [blame] | 392 | } |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 393 | } |
| 394 | |
| 395 | /* |
| 396 | * mlock_fixup - handle mlock[all]/munlock[all] requests. |
| 397 | * |
| 398 | * Filters out "special" vmas -- VM_LOCKED never gets set for these, and |
| 399 | * munlock is a no-op. However, for some special vmas, we go ahead and |
Michel Lespinasse | cea10a1 | 2013-02-22 16:32:44 -0800 | [diff] [blame] | 400 | * populate the ptes. |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 401 | * |
| 402 | * For vmas that pass the filters, merge/split as appropriate. |
| 403 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 404 | static int mlock_fixup(struct vm_area_struct *vma, struct vm_area_struct **prev, |
KOSAKI Motohiro | ca16d14 | 2011-05-26 19:16:19 +0900 | [diff] [blame] | 405 | unsigned long start, unsigned long end, vm_flags_t newflags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 406 | { |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 407 | struct mm_struct *mm = vma->vm_mm; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 408 | pgoff_t pgoff; |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 409 | int nr_pages; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 410 | int ret = 0; |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 411 | vm_flags_t oldflags = vma->vm_flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 412 | |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 413 | if (newflags == oldflags || (oldflags & VM_SPECIAL) || |
Dave Jiang | e1fb4a0 | 2018-08-17 15:43:40 -0700 | [diff] [blame] | 414 | is_vm_hugetlb_page(vma) || vma == get_gate_vma(current->mm) || |
Mike Rapoport | 1507f51 | 2021-07-07 18:08:03 -0700 | [diff] [blame] | 415 | vma_is_dax(vma) || vma_is_secretmem(vma)) |
Eric B Munson | b0f205c | 2015-11-05 18:51:39 -0800 | [diff] [blame] | 416 | /* don't set VM_LOCKED or VM_LOCKONFAULT and don't count */ |
| 417 | goto out; |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 418 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 419 | pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT); |
| 420 | *prev = vma_merge(mm, *prev, start, end, newflags, vma->anon_vma, |
Andrea Arcangeli | 19a809a | 2015-09-04 15:46:24 -0700 | [diff] [blame] | 421 | vma->vm_file, pgoff, vma_policy(vma), |
Suren Baghdasaryan | 5c26f6a | 2022-03-04 20:28:51 -0800 | [diff] [blame] | 422 | vma->vm_userfaultfd_ctx, anon_vma_name(vma)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 423 | if (*prev) { |
| 424 | vma = *prev; |
| 425 | goto success; |
| 426 | } |
| 427 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 428 | if (start != vma->vm_start) { |
| 429 | ret = split_vma(mm, vma, start, 1); |
| 430 | if (ret) |
| 431 | goto out; |
| 432 | } |
| 433 | |
| 434 | if (end != vma->vm_end) { |
| 435 | ret = split_vma(mm, vma, end, 0); |
| 436 | if (ret) |
| 437 | goto out; |
| 438 | } |
| 439 | |
| 440 | success: |
| 441 | /* |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 442 | * Keep track of amount of locked VM. |
| 443 | */ |
| 444 | nr_pages = (end - start) >> PAGE_SHIFT; |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 445 | if (!(newflags & VM_LOCKED)) |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 446 | nr_pages = -nr_pages; |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 447 | else if (oldflags & VM_LOCKED) |
Simon Guo | b155b4f | 2016-10-07 16:59:40 -0700 | [diff] [blame] | 448 | nr_pages = 0; |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 449 | mm->locked_vm += nr_pages; |
| 450 | |
| 451 | /* |
Michel Lespinasse | c1e8d7c | 2020-06-08 21:33:54 -0700 | [diff] [blame] | 452 | * vm_flags is protected by the mmap_lock held in write mode. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 453 | * It's okay if try_to_unmap_one unmaps a page just after we |
Kirill A. Shutemov | fc05f56 | 2015-04-14 15:44:39 -0700 | [diff] [blame] | 454 | * set VM_LOCKED, populate_vma_page_range will bring it back. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 455 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 456 | |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 457 | if ((newflags & VM_LOCKED) && (oldflags & VM_LOCKED)) { |
| 458 | /* No work to do, and mlocking twice would be wrong */ |
Hugh Dickins | 408e82b | 2009-09-21 17:03:23 -0700 | [diff] [blame] | 459 | vma->vm_flags = newflags; |
Hugh Dickins | 34b6792 | 2022-02-14 18:31:48 -0800 | [diff] [blame] | 460 | } else { |
| 461 | mlock_vma_pages_range(vma, start, end, newflags); |
| 462 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 463 | out: |
Nick Piggin | b291f00 | 2008-10-18 20:26:44 -0700 | [diff] [blame] | 464 | *prev = vma; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 465 | return ret; |
| 466 | } |
| 467 | |
Eric B Munson | 1aab92ec | 2015-11-05 18:51:29 -0800 | [diff] [blame] | 468 | static int apply_vma_lock_flags(unsigned long start, size_t len, |
| 469 | vm_flags_t flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 470 | { |
| 471 | unsigned long nstart, end, tmp; |
Zhiyuan Dai | 68d68ff | 2021-05-04 18:40:12 -0700 | [diff] [blame] | 472 | struct vm_area_struct *vma, *prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 473 | int error; |
| 474 | |
Alexander Kuleshov | 8fd9e48 | 2015-11-05 18:46:49 -0800 | [diff] [blame] | 475 | VM_BUG_ON(offset_in_page(start)); |
Michel Lespinasse | fed067d | 2011-01-13 15:46:10 -0800 | [diff] [blame] | 476 | VM_BUG_ON(len != PAGE_ALIGN(len)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 477 | end = start + len; |
| 478 | if (end < start) |
| 479 | return -EINVAL; |
| 480 | if (end == start) |
| 481 | return 0; |
Linus Torvalds | 097d591 | 2012-03-06 18:23:36 -0800 | [diff] [blame] | 482 | vma = find_vma(current->mm, start); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 483 | if (!vma || vma->vm_start > start) |
| 484 | return -ENOMEM; |
| 485 | |
Linus Torvalds | 097d591 | 2012-03-06 18:23:36 -0800 | [diff] [blame] | 486 | prev = vma->vm_prev; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 487 | if (start > vma->vm_start) |
| 488 | prev = vma; |
| 489 | |
| 490 | for (nstart = start ; ; ) { |
Eric B Munson | b0f205c | 2015-11-05 18:51:39 -0800 | [diff] [blame] | 491 | vm_flags_t newflags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; |
Eric B Munson | 1aab92ec | 2015-11-05 18:51:29 -0800 | [diff] [blame] | 492 | |
| 493 | newflags |= flags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | |
| 495 | /* Here we know that vma->vm_start <= nstart < vma->vm_end. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 496 | tmp = vma->vm_end; |
| 497 | if (tmp > end) |
| 498 | tmp = end; |
| 499 | error = mlock_fixup(vma, &prev, nstart, tmp, newflags); |
| 500 | if (error) |
| 501 | break; |
| 502 | nstart = tmp; |
| 503 | if (nstart < prev->vm_end) |
| 504 | nstart = prev->vm_end; |
| 505 | if (nstart >= end) |
| 506 | break; |
| 507 | |
| 508 | vma = prev->vm_next; |
| 509 | if (!vma || vma->vm_start != nstart) { |
| 510 | error = -ENOMEM; |
| 511 | break; |
| 512 | } |
| 513 | } |
| 514 | return error; |
| 515 | } |
| 516 | |
Simon Guo | 0cf2f6f | 2016-10-07 16:59:36 -0700 | [diff] [blame] | 517 | /* |
| 518 | * Go through vma areas and sum size of mlocked |
| 519 | * vma pages, as return value. |
| 520 | * Note deferred memory locking case(mlock2(,,MLOCK_ONFAULT) |
| 521 | * is also counted. |
| 522 | * Return value: previously mlocked page counts |
| 523 | */ |
swkhack | 0874bb4 | 2019-06-13 15:56:08 -0700 | [diff] [blame] | 524 | static unsigned long count_mm_mlocked_page_nr(struct mm_struct *mm, |
Simon Guo | 0cf2f6f | 2016-10-07 16:59:36 -0700 | [diff] [blame] | 525 | unsigned long start, size_t len) |
| 526 | { |
| 527 | struct vm_area_struct *vma; |
swkhack | 0874bb4 | 2019-06-13 15:56:08 -0700 | [diff] [blame] | 528 | unsigned long count = 0; |
Simon Guo | 0cf2f6f | 2016-10-07 16:59:36 -0700 | [diff] [blame] | 529 | |
| 530 | if (mm == NULL) |
| 531 | mm = current->mm; |
| 532 | |
| 533 | vma = find_vma(mm, start); |
| 534 | if (vma == NULL) |
Miaohe Lin | 48b03ee | 2021-02-25 17:17:49 -0800 | [diff] [blame] | 535 | return 0; |
Simon Guo | 0cf2f6f | 2016-10-07 16:59:36 -0700 | [diff] [blame] | 536 | |
| 537 | for (; vma ; vma = vma->vm_next) { |
| 538 | if (start >= vma->vm_end) |
| 539 | continue; |
| 540 | if (start + len <= vma->vm_start) |
| 541 | break; |
| 542 | if (vma->vm_flags & VM_LOCKED) { |
| 543 | if (start > vma->vm_start) |
| 544 | count -= (start - vma->vm_start); |
| 545 | if (start + len < vma->vm_end) { |
| 546 | count += start + len - vma->vm_start; |
| 547 | break; |
| 548 | } |
| 549 | count += vma->vm_end - vma->vm_start; |
| 550 | } |
| 551 | } |
| 552 | |
| 553 | return count >> PAGE_SHIFT; |
| 554 | } |
| 555 | |
Hugh Dickins | ebcbc6e | 2022-02-14 18:20:24 -0800 | [diff] [blame] | 556 | /* |
| 557 | * convert get_user_pages() return value to posix mlock() error |
| 558 | */ |
| 559 | static int __mlock_posix_error_return(long retval) |
| 560 | { |
| 561 | if (retval == -EFAULT) |
| 562 | retval = -ENOMEM; |
| 563 | else if (retval == -ENOMEM) |
| 564 | retval = -EAGAIN; |
| 565 | return retval; |
| 566 | } |
| 567 | |
Michal Hocko | dc0ef0d | 2016-05-23 16:25:27 -0700 | [diff] [blame] | 568 | static __must_check int do_mlock(unsigned long start, size_t len, vm_flags_t flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 569 | { |
| 570 | unsigned long locked; |
| 571 | unsigned long lock_limit; |
| 572 | int error = -ENOMEM; |
| 573 | |
Andrey Konovalov | 057d3389 | 2019-09-25 16:48:30 -0700 | [diff] [blame] | 574 | start = untagged_addr(start); |
| 575 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 576 | if (!can_do_mlock()) |
| 577 | return -EPERM; |
| 578 | |
Alexander Kuleshov | 8fd9e48 | 2015-11-05 18:46:49 -0800 | [diff] [blame] | 579 | len = PAGE_ALIGN(len + (offset_in_page(start))); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 580 | start &= PAGE_MASK; |
| 581 | |
Jiri Slaby | 59e99e5 | 2010-03-05 13:41:44 -0800 | [diff] [blame] | 582 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 583 | lock_limit >>= PAGE_SHIFT; |
Davidlohr Bueso | 1f1cd70 | 2014-01-21 15:49:16 -0800 | [diff] [blame] | 584 | locked = len >> PAGE_SHIFT; |
| 585 | |
Michel Lespinasse | d8ed45c | 2020-06-08 21:33:25 -0700 | [diff] [blame] | 586 | if (mmap_write_lock_killable(current->mm)) |
Michal Hocko | dc0ef0d | 2016-05-23 16:25:27 -0700 | [diff] [blame] | 587 | return -EINTR; |
Davidlohr Bueso | 1f1cd70 | 2014-01-21 15:49:16 -0800 | [diff] [blame] | 588 | |
| 589 | locked += current->mm->locked_vm; |
Simon Guo | 0cf2f6f | 2016-10-07 16:59:36 -0700 | [diff] [blame] | 590 | if ((locked > lock_limit) && (!capable(CAP_IPC_LOCK))) { |
| 591 | /* |
| 592 | * It is possible that the regions requested intersect with |
| 593 | * previously mlocked areas, that part area in "mm->locked_vm" |
| 594 | * should not be counted to new mlock increment count. So check |
| 595 | * and adjust locked count if necessary. |
| 596 | */ |
| 597 | locked -= count_mm_mlocked_page_nr(current->mm, |
| 598 | start, len); |
| 599 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 600 | |
| 601 | /* check against resource limits */ |
| 602 | if ((locked <= lock_limit) || capable(CAP_IPC_LOCK)) |
Eric B Munson | 1aab92ec | 2015-11-05 18:51:29 -0800 | [diff] [blame] | 603 | error = apply_vma_lock_flags(start, len, flags); |
Davidlohr Bueso | 1f1cd70 | 2014-01-21 15:49:16 -0800 | [diff] [blame] | 604 | |
Michel Lespinasse | d8ed45c | 2020-06-08 21:33:25 -0700 | [diff] [blame] | 605 | mmap_write_unlock(current->mm); |
Kirill A. Shutemov | c561259 | 2015-04-14 15:44:42 -0700 | [diff] [blame] | 606 | if (error) |
| 607 | return error; |
| 608 | |
| 609 | error = __mm_populate(start, len, 0); |
| 610 | if (error) |
| 611 | return __mlock_posix_error_return(error); |
| 612 | return 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 613 | } |
| 614 | |
Eric B Munson | 1aab92ec | 2015-11-05 18:51:29 -0800 | [diff] [blame] | 615 | SYSCALL_DEFINE2(mlock, unsigned long, start, size_t, len) |
| 616 | { |
| 617 | return do_mlock(start, len, VM_LOCKED); |
| 618 | } |
| 619 | |
Eric B Munson | a8ca5d0 | 2015-11-05 18:51:33 -0800 | [diff] [blame] | 620 | SYSCALL_DEFINE3(mlock2, unsigned long, start, size_t, len, int, flags) |
| 621 | { |
Eric B Munson | b0f205c | 2015-11-05 18:51:39 -0800 | [diff] [blame] | 622 | vm_flags_t vm_flags = VM_LOCKED; |
| 623 | |
| 624 | if (flags & ~MLOCK_ONFAULT) |
Eric B Munson | a8ca5d0 | 2015-11-05 18:51:33 -0800 | [diff] [blame] | 625 | return -EINVAL; |
| 626 | |
Eric B Munson | b0f205c | 2015-11-05 18:51:39 -0800 | [diff] [blame] | 627 | if (flags & MLOCK_ONFAULT) |
| 628 | vm_flags |= VM_LOCKONFAULT; |
| 629 | |
| 630 | return do_mlock(start, len, vm_flags); |
Eric B Munson | a8ca5d0 | 2015-11-05 18:51:33 -0800 | [diff] [blame] | 631 | } |
| 632 | |
Heiko Carstens | 6a6160a | 2009-01-14 14:14:15 +0100 | [diff] [blame] | 633 | SYSCALL_DEFINE2(munlock, unsigned long, start, size_t, len) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 634 | { |
| 635 | int ret; |
| 636 | |
Andrey Konovalov | 057d3389 | 2019-09-25 16:48:30 -0700 | [diff] [blame] | 637 | start = untagged_addr(start); |
| 638 | |
Alexander Kuleshov | 8fd9e48 | 2015-11-05 18:46:49 -0800 | [diff] [blame] | 639 | len = PAGE_ALIGN(len + (offset_in_page(start))); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 640 | start &= PAGE_MASK; |
Davidlohr Bueso | 1f1cd70 | 2014-01-21 15:49:16 -0800 | [diff] [blame] | 641 | |
Michel Lespinasse | d8ed45c | 2020-06-08 21:33:25 -0700 | [diff] [blame] | 642 | if (mmap_write_lock_killable(current->mm)) |
Michal Hocko | dc0ef0d | 2016-05-23 16:25:27 -0700 | [diff] [blame] | 643 | return -EINTR; |
Eric B Munson | 1aab92ec | 2015-11-05 18:51:29 -0800 | [diff] [blame] | 644 | ret = apply_vma_lock_flags(start, len, 0); |
Michel Lespinasse | d8ed45c | 2020-06-08 21:33:25 -0700 | [diff] [blame] | 645 | mmap_write_unlock(current->mm); |
Davidlohr Bueso | 1f1cd70 | 2014-01-21 15:49:16 -0800 | [diff] [blame] | 646 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 647 | return ret; |
| 648 | } |
| 649 | |
Eric B Munson | b0f205c | 2015-11-05 18:51:39 -0800 | [diff] [blame] | 650 | /* |
| 651 | * Take the MCL_* flags passed into mlockall (or 0 if called from munlockall) |
| 652 | * and translate into the appropriate modifications to mm->def_flags and/or the |
| 653 | * flags for all current VMAs. |
| 654 | * |
| 655 | * There are a couple of subtleties with this. If mlockall() is called multiple |
| 656 | * times with different flags, the values do not necessarily stack. If mlockall |
| 657 | * is called once including the MCL_FUTURE flag and then a second time without |
| 658 | * it, VM_LOCKED and VM_LOCKONFAULT will be cleared from mm->def_flags. |
| 659 | */ |
Eric B Munson | 1aab92ec | 2015-11-05 18:51:29 -0800 | [diff] [blame] | 660 | static int apply_mlockall_flags(int flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 661 | { |
Zhiyuan Dai | 68d68ff | 2021-05-04 18:40:12 -0700 | [diff] [blame] | 662 | struct vm_area_struct *vma, *prev = NULL; |
Eric B Munson | b0f205c | 2015-11-05 18:51:39 -0800 | [diff] [blame] | 663 | vm_flags_t to_add = 0; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 664 | |
Eric B Munson | b0f205c | 2015-11-05 18:51:39 -0800 | [diff] [blame] | 665 | current->mm->def_flags &= VM_LOCKED_CLEAR_MASK; |
| 666 | if (flags & MCL_FUTURE) { |
Michel Lespinasse | 09a9f1d | 2013-03-28 16:26:23 -0700 | [diff] [blame] | 667 | current->mm->def_flags |= VM_LOCKED; |
Eric B Munson | 1aab92ec | 2015-11-05 18:51:29 -0800 | [diff] [blame] | 668 | |
Eric B Munson | b0f205c | 2015-11-05 18:51:39 -0800 | [diff] [blame] | 669 | if (flags & MCL_ONFAULT) |
| 670 | current->mm->def_flags |= VM_LOCKONFAULT; |
| 671 | |
| 672 | if (!(flags & MCL_CURRENT)) |
| 673 | goto out; |
| 674 | } |
| 675 | |
| 676 | if (flags & MCL_CURRENT) { |
| 677 | to_add |= VM_LOCKED; |
| 678 | if (flags & MCL_ONFAULT) |
| 679 | to_add |= VM_LOCKONFAULT; |
| 680 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 681 | |
| 682 | for (vma = current->mm->mmap; vma ; vma = prev->vm_next) { |
KOSAKI Motohiro | ca16d14 | 2011-05-26 19:16:19 +0900 | [diff] [blame] | 683 | vm_flags_t newflags; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 684 | |
Eric B Munson | b0f205c | 2015-11-05 18:51:39 -0800 | [diff] [blame] | 685 | newflags = vma->vm_flags & VM_LOCKED_CLEAR_MASK; |
| 686 | newflags |= to_add; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 687 | |
| 688 | /* Ignore errors */ |
| 689 | mlock_fixup(vma, &prev, vma->vm_start, vma->vm_end, newflags); |
Paul E. McKenney | 50d4fb7 | 2017-10-24 08:22:18 -0700 | [diff] [blame] | 690 | cond_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 691 | } |
| 692 | out: |
| 693 | return 0; |
| 694 | } |
| 695 | |
Heiko Carstens | 3480b25 | 2009-01-14 14:14:16 +0100 | [diff] [blame] | 696 | SYSCALL_DEFINE1(mlockall, int, flags) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 697 | { |
| 698 | unsigned long lock_limit; |
Alexey Klimov | 86d2adcc | 2015-11-05 18:46:00 -0800 | [diff] [blame] | 699 | int ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | |
Potyra, Stefan | dedca63 | 2019-06-13 15:55:55 -0700 | [diff] [blame] | 701 | if (!flags || (flags & ~(MCL_CURRENT | MCL_FUTURE | MCL_ONFAULT)) || |
| 702 | flags == MCL_ONFAULT) |
Alexey Klimov | 86d2adcc | 2015-11-05 18:46:00 -0800 | [diff] [blame] | 703 | return -EINVAL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 704 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 705 | if (!can_do_mlock()) |
Alexey Klimov | 86d2adcc | 2015-11-05 18:46:00 -0800 | [diff] [blame] | 706 | return -EPERM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 707 | |
Jiri Slaby | 59e99e5 | 2010-03-05 13:41:44 -0800 | [diff] [blame] | 708 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 709 | lock_limit >>= PAGE_SHIFT; |
| 710 | |
Michel Lespinasse | d8ed45c | 2020-06-08 21:33:25 -0700 | [diff] [blame] | 711 | if (mmap_write_lock_killable(current->mm)) |
Michal Hocko | dc0ef0d | 2016-05-23 16:25:27 -0700 | [diff] [blame] | 712 | return -EINTR; |
Davidlohr Bueso | 1f1cd70 | 2014-01-21 15:49:16 -0800 | [diff] [blame] | 713 | |
Michal Hocko | dc0ef0d | 2016-05-23 16:25:27 -0700 | [diff] [blame] | 714 | ret = -ENOMEM; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 715 | if (!(flags & MCL_CURRENT) || (current->mm->total_vm <= lock_limit) || |
| 716 | capable(CAP_IPC_LOCK)) |
Eric B Munson | 1aab92ec | 2015-11-05 18:51:29 -0800 | [diff] [blame] | 717 | ret = apply_mlockall_flags(flags); |
Michel Lespinasse | d8ed45c | 2020-06-08 21:33:25 -0700 | [diff] [blame] | 718 | mmap_write_unlock(current->mm); |
Michel Lespinasse | bebeb3d | 2013-02-22 16:32:37 -0800 | [diff] [blame] | 719 | if (!ret && (flags & MCL_CURRENT)) |
| 720 | mm_populate(0, TASK_SIZE); |
Alexey Klimov | 86d2adcc | 2015-11-05 18:46:00 -0800 | [diff] [blame] | 721 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 722 | return ret; |
| 723 | } |
| 724 | |
Heiko Carstens | 3480b25 | 2009-01-14 14:14:16 +0100 | [diff] [blame] | 725 | SYSCALL_DEFINE0(munlockall) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 726 | { |
| 727 | int ret; |
| 728 | |
Michel Lespinasse | d8ed45c | 2020-06-08 21:33:25 -0700 | [diff] [blame] | 729 | if (mmap_write_lock_killable(current->mm)) |
Michal Hocko | dc0ef0d | 2016-05-23 16:25:27 -0700 | [diff] [blame] | 730 | return -EINTR; |
Eric B Munson | 1aab92ec | 2015-11-05 18:51:29 -0800 | [diff] [blame] | 731 | ret = apply_mlockall_flags(0); |
Michel Lespinasse | d8ed45c | 2020-06-08 21:33:25 -0700 | [diff] [blame] | 732 | mmap_write_unlock(current->mm); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 733 | return ret; |
| 734 | } |
| 735 | |
| 736 | /* |
| 737 | * Objects with different lifetime than processes (SHM_LOCK and SHM_HUGETLB |
| 738 | * shm segments) get accounted against the user_struct instead. |
| 739 | */ |
| 740 | static DEFINE_SPINLOCK(shmlock_user_lock); |
| 741 | |
Alexey Gladkov | d7c9e99 | 2021-04-22 14:27:14 +0200 | [diff] [blame] | 742 | int user_shm_lock(size_t size, struct ucounts *ucounts) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 743 | { |
| 744 | unsigned long lock_limit, locked; |
Alexey Gladkov | d7c9e99 | 2021-04-22 14:27:14 +0200 | [diff] [blame] | 745 | long memlock; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 746 | int allowed = 0; |
| 747 | |
| 748 | locked = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
Jiri Slaby | 59e99e5 | 2010-03-05 13:41:44 -0800 | [diff] [blame] | 749 | lock_limit = rlimit(RLIMIT_MEMLOCK); |
Miaohe Lin | e97824f | 2022-03-22 16:09:18 +0800 | [diff] [blame] | 750 | if (lock_limit != RLIM_INFINITY) |
| 751 | lock_limit >>= PAGE_SHIFT; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 752 | spin_lock(&shmlock_user_lock); |
Alexey Gladkov | d7c9e99 | 2021-04-22 14:27:14 +0200 | [diff] [blame] | 753 | memlock = inc_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_MEMLOCK, locked); |
| 754 | |
Miaohe Lin | e97824f | 2022-03-22 16:09:18 +0800 | [diff] [blame] | 755 | if ((memlock == LONG_MAX || memlock > lock_limit) && !capable(CAP_IPC_LOCK)) { |
Alexey Gladkov | d7c9e99 | 2021-04-22 14:27:14 +0200 | [diff] [blame] | 756 | dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_MEMLOCK, locked); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | goto out; |
Alexey Gladkov | d7c9e99 | 2021-04-22 14:27:14 +0200 | [diff] [blame] | 758 | } |
| 759 | if (!get_ucounts(ucounts)) { |
| 760 | dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_MEMLOCK, locked); |
Miaohe Lin | 5c2a956 | 2022-03-22 14:44:56 -0700 | [diff] [blame] | 761 | allowed = 0; |
Alexey Gladkov | d7c9e99 | 2021-04-22 14:27:14 +0200 | [diff] [blame] | 762 | goto out; |
| 763 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 764 | allowed = 1; |
| 765 | out: |
| 766 | spin_unlock(&shmlock_user_lock); |
| 767 | return allowed; |
| 768 | } |
| 769 | |
Alexey Gladkov | d7c9e99 | 2021-04-22 14:27:14 +0200 | [diff] [blame] | 770 | void user_shm_unlock(size_t size, struct ucounts *ucounts) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 771 | { |
| 772 | spin_lock(&shmlock_user_lock); |
Alexey Gladkov | d7c9e99 | 2021-04-22 14:27:14 +0200 | [diff] [blame] | 773 | dec_rlimit_ucounts(ucounts, UCOUNT_RLIMIT_MEMLOCK, (size + PAGE_SIZE - 1) >> PAGE_SHIFT); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 774 | spin_unlock(&shmlock_user_lock); |
Alexey Gladkov | d7c9e99 | 2021-04-22 14:27:14 +0200 | [diff] [blame] | 775 | put_ucounts(ucounts); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 776 | } |