File: | uvm/uvm_fault.c |
Warning: | line 922, column 33 Array access (from variable 'anons') results in a null pointer dereference |
Press '?' to see keyboard shortcuts
Keyboard shortcuts:
1 | /* $OpenBSD: uvm_fault.c,v 1.135 2023/09/05 05:08:26 guenther Exp $ */ | ||||
2 | /* $NetBSD: uvm_fault.c,v 1.51 2000/08/06 00:22:53 thorpej Exp $ */ | ||||
3 | |||||
4 | /* | ||||
5 | * Copyright (c) 1997 Charles D. Cranor and Washington University. | ||||
6 | * All rights reserved. | ||||
7 | * | ||||
8 | * Redistribution and use in source and binary forms, with or without | ||||
9 | * modification, are permitted provided that the following conditions | ||||
10 | * are met: | ||||
11 | * 1. Redistributions of source code must retain the above copyright | ||||
12 | * notice, this list of conditions and the following disclaimer. | ||||
13 | * 2. Redistributions in binary form must reproduce the above copyright | ||||
14 | * notice, this list of conditions and the following disclaimer in the | ||||
15 | * documentation and/or other materials provided with the distribution. | ||||
16 | * | ||||
17 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | ||||
18 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | ||||
19 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | ||||
20 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | ||||
21 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | ||||
22 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | ||||
23 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | ||||
24 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | ||||
25 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | ||||
26 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | ||||
27 | * | ||||
28 | * from: Id: uvm_fault.c,v 1.1.2.23 1998/02/06 05:29:05 chs Exp | ||||
29 | */ | ||||
30 | |||||
31 | /* | ||||
32 | * uvm_fault.c: fault handler | ||||
33 | */ | ||||
34 | |||||
35 | #include <sys/param.h> | ||||
36 | #include <sys/systm.h> | ||||
37 | #include <sys/kernel.h> | ||||
38 | #include <sys/percpu.h> | ||||
39 | #include <sys/proc.h> | ||||
40 | #include <sys/malloc.h> | ||||
41 | #include <sys/mman.h> | ||||
42 | #include <sys/tracepoint.h> | ||||
43 | |||||
44 | #include <uvm/uvm.h> | ||||
45 | |||||
46 | /* | ||||
47 | * | ||||
48 | * a word on page faults: | ||||
49 | * | ||||
50 | * types of page faults we handle: | ||||
51 | * | ||||
52 | * CASE 1: upper layer faults CASE 2: lower layer faults | ||||
53 | * | ||||
54 | * CASE 1A CASE 1B CASE 2A CASE 2B | ||||
55 | * read/write1 write>1 read/write +-cow_write/zero | ||||
56 | * | | | | | ||||
57 | * +--|--+ +--|--+ +-----+ + | + | +-----+ | ||||
58 | * amap | V | | ---------> new | | | | ^ | | ||||
59 | * +-----+ +-----+ +-----+ + | + | +--|--+ | ||||
60 | * | | | | ||||
61 | * +-----+ +-----+ +--|--+ | +--|--+ | ||||
62 | * uobj | d/c | | d/c | | V | +----+ | | ||||
63 | * +-----+ +-----+ +-----+ +-----+ | ||||
64 | * | ||||
65 | * d/c = don't care | ||||
66 | * | ||||
67 | * case [0]: layerless fault | ||||
68 | * no amap or uobj is present. this is an error. | ||||
69 | * | ||||
70 | * case [1]: upper layer fault [anon active] | ||||
71 | * 1A: [read] or [write with anon->an_ref == 1] | ||||
72 | * I/O takes place in upper level anon and uobj is not touched. | ||||
73 | * 1B: [write with anon->an_ref > 1] | ||||
74 | * new anon is alloc'd and data is copied off ["COW"] | ||||
75 | * | ||||
76 | * case [2]: lower layer fault [uobj] | ||||
77 | * 2A: [read on non-NULL uobj] or [write to non-copy_on_write area] | ||||
78 | * I/O takes place directly in object. | ||||
79 | * 2B: [write to copy_on_write] or [read on NULL uobj] | ||||
80 | * data is "promoted" from uobj to a new anon. | ||||
81 | * if uobj is null, then we zero fill. | ||||
82 | * | ||||
83 | * we follow the standard UVM locking protocol ordering: | ||||
84 | * | ||||
85 | * MAPS => AMAP => UOBJ => ANON => PAGE QUEUES (PQ) | ||||
86 | * we hold a PG_BUSY page if we unlock for I/O | ||||
87 | * | ||||
88 | * | ||||
89 | * the code is structured as follows: | ||||
90 | * | ||||
91 | * - init the "IN" params in the ufi structure | ||||
92 | * ReFault: (ERESTART returned to the loop in uvm_fault) | ||||
93 | * - do lookups [locks maps], check protection, handle needs_copy | ||||
94 | * - check for case 0 fault (error) | ||||
95 | * - establish "range" of fault | ||||
96 | * - if we have an amap lock it and extract the anons | ||||
97 | * - if sequential advice deactivate pages behind us | ||||
98 | * - at the same time check pmap for unmapped areas and anon for pages | ||||
99 | * that we could map in (and do map it if found) | ||||
100 | * - check object for resident pages that we could map in | ||||
101 | * - if (case 2) goto Case2 | ||||
102 | * - >>> handle case 1 | ||||
103 | * - ensure source anon is resident in RAM | ||||
104 | * - if case 1B alloc new anon and copy from source | ||||
105 | * - map the correct page in | ||||
106 | * Case2: | ||||
107 | * - >>> handle case 2 | ||||
108 | * - ensure source page is resident (if uobj) | ||||
109 | * - if case 2B alloc new anon and copy from source (could be zero | ||||
110 | * fill if uobj == NULL) | ||||
111 | * - map the correct page in | ||||
112 | * - done! | ||||
113 | * | ||||
114 | * note on paging: | ||||
115 | * if we have to do I/O we place a PG_BUSY page in the correct object, | ||||
116 | * unlock everything, and do the I/O. when I/O is done we must reverify | ||||
117 | * the state of the world before assuming that our data structures are | ||||
118 | * valid. [because mappings could change while the map is unlocked] | ||||
119 | * | ||||
120 | * alternative 1: unbusy the page in question and restart the page fault | ||||
121 | * from the top (ReFault). this is easy but does not take advantage | ||||
122 | * of the information that we already have from our previous lookup, | ||||
123 | * although it is possible that the "hints" in the vm_map will help here. | ||||
124 | * | ||||
125 | * alternative 2: the system already keeps track of a "version" number of | ||||
126 | * a map. [i.e. every time you write-lock a map (e.g. to change a | ||||
127 | * mapping) you bump the version number up by one...] so, we can save | ||||
128 | * the version number of the map before we release the lock and start I/O. | ||||
129 | * then when I/O is done we can relock and check the version numbers | ||||
130 | * to see if anything changed. this might save us some over 1 because | ||||
131 | * we don't have to unbusy the page and may be less compares(?). | ||||
132 | * | ||||
133 | * alternative 3: put in backpointers or a way to "hold" part of a map | ||||
134 | * in place while I/O is in progress. this could be complex to | ||||
135 | * implement (especially with structures like amap that can be referenced | ||||
136 | * by multiple map entries, and figuring out what should wait could be | ||||
137 | * complex as well...). | ||||
138 | * | ||||
139 | * we use alternative 2. given that we are multi-threaded now we may want | ||||
140 | * to reconsider the choice. | ||||
141 | */ | ||||
142 | |||||
143 | /* | ||||
144 | * local data structures | ||||
145 | */ | ||||
146 | struct uvm_advice { | ||||
147 | int nback; | ||||
148 | int nforw; | ||||
149 | }; | ||||
150 | |||||
151 | /* | ||||
152 | * page range array: set up in uvmfault_init(). | ||||
153 | */ | ||||
154 | static struct uvm_advice uvmadvice[MADV_MASK0x7 + 1]; | ||||
155 | |||||
156 | #define UVM_MAXRANGE16 16 /* must be max() of nback+nforw+1 */ | ||||
157 | |||||
158 | /* | ||||
159 | * private prototypes | ||||
160 | */ | ||||
161 | static void uvmfault_amapcopy(struct uvm_faultinfo *); | ||||
162 | static inline void uvmfault_anonflush(struct vm_anon **, int); | ||||
163 | void uvmfault_unlockmaps(struct uvm_faultinfo *, boolean_t); | ||||
164 | void uvmfault_update_stats(struct uvm_faultinfo *); | ||||
165 | |||||
166 | /* | ||||
167 | * inline functions | ||||
168 | */ | ||||
169 | /* | ||||
170 | * uvmfault_anonflush: try and deactivate pages in specified anons | ||||
171 | * | ||||
172 | * => does not have to deactivate page if it is busy | ||||
173 | */ | ||||
174 | static inline void | ||||
175 | uvmfault_anonflush(struct vm_anon **anons, int n) | ||||
176 | { | ||||
177 | int lcv; | ||||
178 | struct vm_page *pg; | ||||
179 | |||||
180 | for (lcv = 0; lcv < n; lcv++) { | ||||
181 | if (anons[lcv] == NULL((void *)0)) | ||||
182 | continue; | ||||
183 | KASSERT(rw_lock_held(anons[lcv]->an_lock))((rw_lock_held(anons[lcv]->an_lock)) ? (void)0 : __assert( "diagnostic ", "/usr/src/sys/uvm/uvm_fault.c", 183, "rw_lock_held(anons[lcv]->an_lock)" )); | ||||
184 | pg = anons[lcv]->an_page; | ||||
185 | if (pg && (pg->pg_flags & PG_BUSY0x00000001) == 0) { | ||||
186 | uvm_lock_pageq()mtx_enter(&uvm.pageqlock); | ||||
187 | if (pg->wire_count == 0) { | ||||
188 | pmap_page_protect(pg, PROT_NONE0x00); | ||||
189 | uvm_pagedeactivate(pg); | ||||
190 | } | ||||
191 | uvm_unlock_pageq()mtx_leave(&uvm.pageqlock); | ||||
192 | } | ||||
193 | } | ||||
194 | } | ||||
195 | |||||
196 | /* | ||||
197 | * normal functions | ||||
198 | */ | ||||
199 | /* | ||||
200 | * uvmfault_init: compute proper values for the uvmadvice[] array. | ||||
201 | */ | ||||
202 | void | ||||
203 | uvmfault_init(void) | ||||
204 | { | ||||
205 | int npages; | ||||
206 | |||||
207 | npages = atop(16384)((16384) >> 12); | ||||
208 | if (npages > 0) { | ||||
209 | KASSERT(npages <= UVM_MAXRANGE / 2)((npages <= 16 / 2) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 209, "npages <= UVM_MAXRANGE / 2")); | ||||
210 | uvmadvice[MADV_NORMAL0].nforw = npages; | ||||
211 | uvmadvice[MADV_NORMAL0].nback = npages - 1; | ||||
212 | } | ||||
213 | |||||
214 | npages = atop(32768)((32768) >> 12); | ||||
215 | if (npages > 0) { | ||||
216 | KASSERT(npages <= UVM_MAXRANGE / 2)((npages <= 16 / 2) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 216, "npages <= UVM_MAXRANGE / 2")); | ||||
217 | uvmadvice[MADV_SEQUENTIAL2].nforw = npages - 1; | ||||
218 | uvmadvice[MADV_SEQUENTIAL2].nback = npages; | ||||
219 | } | ||||
220 | } | ||||
221 | |||||
222 | /* | ||||
223 | * uvmfault_amapcopy: clear "needs_copy" in a map. | ||||
224 | * | ||||
225 | * => called with VM data structures unlocked (usually, see below) | ||||
226 | * => we get a write lock on the maps and clear needs_copy for a VA | ||||
227 | * => if we are out of RAM we sleep (waiting for more) | ||||
228 | */ | ||||
229 | static void | ||||
230 | uvmfault_amapcopy(struct uvm_faultinfo *ufi) | ||||
231 | { | ||||
232 | for (;;) { | ||||
233 | /* | ||||
234 | * no mapping? give up. | ||||
235 | */ | ||||
236 | if (uvmfault_lookup(ufi, TRUE1) == FALSE0) | ||||
237 | return; | ||||
238 | |||||
239 | /* | ||||
240 | * copy if needed. | ||||
241 | */ | ||||
242 | if (UVM_ET_ISNEEDSCOPY(ufi->entry)(((ufi->entry)->etype & 0x0008) != 0)) | ||||
243 | amap_copy(ufi->map, ufi->entry, M_NOWAIT0x0002, | ||||
244 | UVM_ET_ISSTACK(ufi->entry)(((ufi->entry)->etype & 0x0040) != 0) ? FALSE0 : TRUE1, | ||||
245 | ufi->orig_rvaddr, ufi->orig_rvaddr + 1); | ||||
246 | |||||
247 | /* | ||||
248 | * didn't work? must be out of RAM. unlock and sleep. | ||||
249 | */ | ||||
250 | if (UVM_ET_ISNEEDSCOPY(ufi->entry)(((ufi->entry)->etype & 0x0008) != 0)) { | ||||
251 | uvmfault_unlockmaps(ufi, TRUE1); | ||||
252 | uvm_wait("fltamapcopy"); | ||||
253 | continue; | ||||
254 | } | ||||
255 | |||||
256 | /* | ||||
257 | * got it! unlock and return. | ||||
258 | */ | ||||
259 | uvmfault_unlockmaps(ufi, TRUE1); | ||||
260 | return; | ||||
261 | } | ||||
262 | /*NOTREACHED*/ | ||||
263 | } | ||||
264 | |||||
265 | /* | ||||
266 | * uvmfault_anonget: get data in an anon into a non-busy, non-released | ||||
267 | * page in that anon. | ||||
268 | * | ||||
269 | * => Map, amap and thus anon should be locked by caller. | ||||
270 | * => If we fail, we unlock everything and error is returned. | ||||
271 | * => If we are successful, return with everything still locked. | ||||
272 | * => We do not move the page on the queues [gets moved later]. If we | ||||
273 | * allocate a new page [we_own], it gets put on the queues. Either way, | ||||
274 | * the result is that the page is on the queues at return time | ||||
275 | */ | ||||
276 | int | ||||
277 | uvmfault_anonget(struct uvm_faultinfo *ufi, struct vm_amap *amap, | ||||
278 | struct vm_anon *anon) | ||||
279 | { | ||||
280 | struct vm_page *pg; | ||||
281 | int error; | ||||
282 | |||||
283 | KASSERT(rw_lock_held(anon->an_lock))((rw_lock_held(anon->an_lock)) ? (void)0 : __assert("diagnostic " , "/usr/src/sys/uvm/uvm_fault.c", 283, "rw_lock_held(anon->an_lock)" )); | ||||
284 | KASSERT(anon->an_lock == amap->am_lock)((anon->an_lock == amap->am_lock) ? (void)0 : __assert( "diagnostic ", "/usr/src/sys/uvm/uvm_fault.c", 284, "anon->an_lock == amap->am_lock" )); | ||||
285 | |||||
286 | /* Increment the counters.*/ | ||||
287 | counters_inc(uvmexp_counters, flt_anget); | ||||
288 | if (anon->an_page) { | ||||
289 | curproc({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc->p_ru.ru_minflt++; | ||||
290 | } else { | ||||
291 | curproc({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc->p_ru.ru_majflt++; | ||||
292 | } | ||||
293 | error = 0; | ||||
294 | |||||
295 | /* | ||||
296 | * Loop until we get the anon data, or fail. | ||||
297 | */ | ||||
298 | for (;;) { | ||||
299 | boolean_t we_own, locked; | ||||
300 | /* | ||||
301 | * Note: 'we_own' will become true if we set PG_BUSY on a page. | ||||
302 | */ | ||||
303 | we_own = FALSE0; | ||||
304 | pg = anon->an_page; | ||||
305 | |||||
306 | /* | ||||
307 | * Is page resident? Make sure it is not busy/released. | ||||
308 | */ | ||||
309 | if (pg) { | ||||
310 | KASSERT(pg->pg_flags & PQ_ANON)((pg->pg_flags & 0x00100000) ? (void)0 : __assert("diagnostic " , "/usr/src/sys/uvm/uvm_fault.c", 310, "pg->pg_flags & PQ_ANON" )); | ||||
311 | KASSERT(pg->uanon == anon)((pg->uanon == anon) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 311, "pg->uanon == anon")); | ||||
312 | |||||
313 | /* | ||||
314 | * if the page is busy, we drop all the locks and | ||||
315 | * try again. | ||||
316 | */ | ||||
317 | if ((pg->pg_flags & (PG_BUSY0x00000001|PG_RELEASED0x00000020)) == 0) | ||||
318 | return (VM_PAGER_OK0); | ||||
319 | atomic_setbits_intx86_atomic_setbits_u32(&pg->pg_flags, PG_WANTED0x00000002); | ||||
320 | counters_inc(uvmexp_counters, flt_pgwait); | ||||
321 | |||||
322 | /* | ||||
323 | * The last unlock must be an atomic unlock and wait | ||||
324 | * on the owner of page. | ||||
325 | */ | ||||
326 | if (pg->uobject) { | ||||
327 | /* Owner of page is UVM object. */ | ||||
328 | uvmfault_unlockall(ufi, amap, NULL((void *)0)); | ||||
329 | rwsleep_nsec(pg, pg->uobject->vmobjlock, | ||||
330 | PVM4 | PNORELOCK0x200, "anonget1", INFSLP0xffffffffffffffffULL); | ||||
331 | } else { | ||||
332 | /* Owner of page is anon. */ | ||||
333 | uvmfault_unlockall(ufi, NULL((void *)0), NULL((void *)0)); | ||||
334 | rwsleep_nsec(pg, anon->an_lock, PVM4 | PNORELOCK0x200, | ||||
335 | "anonget2", INFSLP0xffffffffffffffffULL); | ||||
336 | } | ||||
337 | } else { | ||||
338 | /* | ||||
339 | * No page, therefore allocate one. | ||||
340 | */ | ||||
341 | pg = uvm_pagealloc(NULL((void *)0), 0, anon, 0); | ||||
342 | if (pg == NULL((void *)0)) { | ||||
343 | /* Out of memory. Wait a little. */ | ||||
344 | uvmfault_unlockall(ufi, amap, NULL((void *)0)); | ||||
345 | counters_inc(uvmexp_counters, flt_noram); | ||||
346 | uvm_wait("flt_noram1"); | ||||
347 | } else { | ||||
348 | /* PG_BUSY bit is set. */ | ||||
349 | we_own = TRUE1; | ||||
350 | uvmfault_unlockall(ufi, amap, NULL((void *)0)); | ||||
351 | |||||
352 | /* | ||||
353 | * Pass a PG_BUSY+PG_FAKE+PG_CLEAN page into | ||||
354 | * the uvm_swap_get() function with all data | ||||
355 | * structures unlocked. Note that it is OK | ||||
356 | * to read an_swslot here, because we hold | ||||
357 | * PG_BUSY on the page. | ||||
358 | */ | ||||
359 | counters_inc(uvmexp_counters, pageins); | ||||
360 | error = uvm_swap_get(pg, anon->an_swslot, | ||||
361 | PGO_SYNCIO0x002); | ||||
362 | |||||
363 | /* | ||||
364 | * We clean up after the I/O below in the | ||||
365 | * 'we_own' case. | ||||
366 | */ | ||||
367 | } | ||||
368 | } | ||||
369 | |||||
370 | /* | ||||
371 | * Re-lock the map and anon. | ||||
372 | */ | ||||
373 | locked = uvmfault_relock(ufi); | ||||
374 | if (locked || we_own) { | ||||
375 | rw_enter(anon->an_lock, RW_WRITE0x0001UL); | ||||
376 | } | ||||
377 | |||||
378 | /* | ||||
379 | * If we own the page (i.e. we set PG_BUSY), then we need | ||||
380 | * to clean up after the I/O. There are three cases to | ||||
381 | * consider: | ||||
382 | * | ||||
383 | * 1) Page was released during I/O: free anon and ReFault. | ||||
384 | * 2) I/O not OK. Free the page and cause the fault to fail. | ||||
385 | * 3) I/O OK! Activate the page and sync with the non-we_own | ||||
386 | * case (i.e. drop anon lock if not locked). | ||||
387 | */ | ||||
388 | if (we_own) { | ||||
389 | if (pg->pg_flags & PG_WANTED0x00000002) { | ||||
390 | wakeup(pg); | ||||
391 | } | ||||
392 | |||||
393 | /* | ||||
394 | * if we were RELEASED during I/O, then our anon is | ||||
395 | * no longer part of an amap. we need to free the | ||||
396 | * anon and try again. | ||||
397 | */ | ||||
398 | if (pg->pg_flags & PG_RELEASED0x00000020) { | ||||
399 | KASSERT(anon->an_ref == 0)((anon->an_ref == 0) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 399, "anon->an_ref == 0")); | ||||
400 | /* | ||||
401 | * Released while we had unlocked amap. | ||||
402 | */ | ||||
403 | if (locked) | ||||
404 | uvmfault_unlockall(ufi, NULL((void *)0), NULL((void *)0)); | ||||
405 | uvm_anon_release(anon); /* frees page for us */ | ||||
406 | counters_inc(uvmexp_counters, flt_pgrele); | ||||
407 | return (VM_PAGER_REFAULT7); /* refault! */ | ||||
408 | } | ||||
409 | |||||
410 | if (error != VM_PAGER_OK0) { | ||||
411 | KASSERT(error != VM_PAGER_PEND)((error != 3) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 411, "error != VM_PAGER_PEND")); | ||||
412 | |||||
413 | /* remove page from anon */ | ||||
414 | anon->an_page = NULL((void *)0); | ||||
415 | |||||
416 | /* | ||||
417 | * Remove the swap slot from the anon and | ||||
418 | * mark the anon as having no real slot. | ||||
419 | * Do not free the swap slot, thus preventing | ||||
420 | * it from being used again. | ||||
421 | */ | ||||
422 | uvm_swap_markbad(anon->an_swslot, 1); | ||||
423 | anon->an_swslot = SWSLOT_BAD(-1); | ||||
424 | |||||
425 | /* | ||||
426 | * Note: page was never !PG_BUSY, so it | ||||
427 | * cannot be mapped and thus no need to | ||||
428 | * pmap_page_protect() it. | ||||
429 | */ | ||||
430 | uvm_lock_pageq()mtx_enter(&uvm.pageqlock); | ||||
431 | uvm_pagefree(pg); | ||||
432 | uvm_unlock_pageq()mtx_leave(&uvm.pageqlock); | ||||
433 | |||||
434 | if (locked) { | ||||
435 | uvmfault_unlockall(ufi, NULL((void *)0), NULL((void *)0)); | ||||
436 | } | ||||
437 | rw_exit(anon->an_lock); | ||||
438 | return (VM_PAGER_ERROR4); | ||||
439 | } | ||||
440 | |||||
441 | /* | ||||
442 | * We have successfully read the page, activate it. | ||||
443 | */ | ||||
444 | pmap_clear_modify(pg)pmap_clear_attrs(pg, 0x0000000000000040UL); | ||||
445 | uvm_lock_pageq()mtx_enter(&uvm.pageqlock); | ||||
446 | uvm_pageactivate(pg); | ||||
447 | uvm_unlock_pageq()mtx_leave(&uvm.pageqlock); | ||||
448 | atomic_clearbits_intx86_atomic_clearbits_u32(&pg->pg_flags, | ||||
449 | PG_WANTED0x00000002|PG_BUSY0x00000001|PG_FAKE0x00000040); | ||||
450 | UVM_PAGE_OWN(pg, NULL); | ||||
451 | } | ||||
452 | |||||
453 | /* | ||||
454 | * We were not able to re-lock the map - restart the fault. | ||||
455 | */ | ||||
456 | if (!locked) { | ||||
457 | if (we_own) { | ||||
458 | rw_exit(anon->an_lock); | ||||
459 | } | ||||
460 | return (VM_PAGER_REFAULT7); | ||||
461 | } | ||||
462 | |||||
463 | /* | ||||
464 | * Verify that no one has touched the amap and moved | ||||
465 | * the anon on us. | ||||
466 | */ | ||||
467 | if (ufi != NULL((void *)0) && amap_lookup(&ufi->entry->aref, | ||||
468 | ufi->orig_rvaddr - ufi->entry->start) != anon) { | ||||
469 | |||||
470 | uvmfault_unlockall(ufi, amap, NULL((void *)0)); | ||||
471 | return (VM_PAGER_REFAULT7); | ||||
472 | } | ||||
473 | |||||
474 | /* | ||||
475 | * Retry.. | ||||
476 | */ | ||||
477 | counters_inc(uvmexp_counters, flt_anretry); | ||||
478 | continue; | ||||
479 | |||||
480 | } | ||||
481 | /*NOTREACHED*/ | ||||
482 | } | ||||
483 | |||||
484 | /* | ||||
485 | * Update statistics after fault resolution. | ||||
486 | * - maxrss | ||||
487 | */ | ||||
488 | void | ||||
489 | uvmfault_update_stats(struct uvm_faultinfo *ufi) | ||||
490 | { | ||||
491 | struct vm_map *map; | ||||
492 | struct proc *p; | ||||
493 | vsize_t res; | ||||
494 | |||||
495 | map = ufi->orig_map; | ||||
496 | |||||
497 | /* | ||||
498 | * If this is a nested pmap (eg, a virtual machine pmap managed | ||||
499 | * by vmm(4) on amd64/i386), don't do any updating, just return. | ||||
500 | * | ||||
501 | * pmap_nested() on other archs is #defined to 0, so this is a | ||||
502 | * no-op. | ||||
503 | */ | ||||
504 | if (pmap_nested(map->pmap)((map->pmap)->pm_type != 1)) | ||||
505 | return; | ||||
506 | |||||
507 | /* Update the maxrss for the process. */ | ||||
508 | if (map->flags & VM_MAP_ISVMSPACE0x40) { | ||||
509 | p = curproc({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc; | ||||
510 | KASSERT(p != NULL && &p->p_vmspace->vm_map == map)((p != ((void *)0) && &p->p_vmspace->vm_map == map) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 510, "p != NULL && &p->p_vmspace->vm_map == map" )); | ||||
511 | |||||
512 | res = pmap_resident_count(map->pmap)((map->pmap)->pm_stats.resident_count); | ||||
513 | /* Convert res from pages to kilobytes. */ | ||||
514 | res <<= (PAGE_SHIFT12 - 10); | ||||
515 | |||||
516 | if (p->p_ru.ru_maxrss < res) | ||||
517 | p->p_ru.ru_maxrss = res; | ||||
518 | } | ||||
519 | } | ||||
520 | |||||
521 | /* | ||||
522 | * F A U L T - m a i n e n t r y p o i n t | ||||
523 | */ | ||||
524 | |||||
525 | /* | ||||
526 | * uvm_fault: page fault handler | ||||
527 | * | ||||
528 | * => called from MD code to resolve a page fault | ||||
529 | * => VM data structures usually should be unlocked. however, it is | ||||
530 | * possible to call here with the main map locked if the caller | ||||
531 | * gets a write lock, sets it recursive, and then calls us (c.f. | ||||
532 | * uvm_map_pageable). this should be avoided because it keeps | ||||
533 | * the map locked off during I/O. | ||||
534 | * => MUST NEVER BE CALLED IN INTERRUPT CONTEXT | ||||
535 | */ | ||||
536 | #define MASK(entry)((((entry)->etype & 0x0004) != 0) ? ~0x02 : (0x01 | 0x02 | 0x04)) (UVM_ET_ISCOPYONWRITE(entry)(((entry)->etype & 0x0004) != 0) ? \ | ||||
537 | ~PROT_WRITE0x02 : PROT_MASK(0x01 | 0x02 | 0x04)) | ||||
538 | struct uvm_faultctx { | ||||
539 | /* | ||||
540 | * the following members are set up by uvm_fault_check() and | ||||
541 | * read-only after that. | ||||
542 | */ | ||||
543 | vm_prot_t enter_prot; | ||||
544 | vm_prot_t access_type; | ||||
545 | vaddr_t startva; | ||||
546 | int npages; | ||||
547 | int centeridx; | ||||
548 | boolean_t narrow; | ||||
549 | boolean_t wired; | ||||
550 | paddr_t pa_flags; | ||||
551 | }; | ||||
552 | |||||
553 | int uvm_fault_check( | ||||
554 | struct uvm_faultinfo *, struct uvm_faultctx *, | ||||
555 | struct vm_anon ***); | ||||
556 | |||||
557 | int uvm_fault_upper( | ||||
558 | struct uvm_faultinfo *, struct uvm_faultctx *, | ||||
559 | struct vm_anon **, vm_fault_t); | ||||
560 | boolean_t uvm_fault_upper_lookup( | ||||
561 | struct uvm_faultinfo *, const struct uvm_faultctx *, | ||||
562 | struct vm_anon **, struct vm_page **); | ||||
563 | |||||
564 | int uvm_fault_lower( | ||||
565 | struct uvm_faultinfo *, struct uvm_faultctx *, | ||||
566 | struct vm_page **, vm_fault_t); | ||||
567 | |||||
568 | int | ||||
569 | uvm_fault(vm_map_t orig_map, vaddr_t vaddr, vm_fault_t fault_type, | ||||
570 | vm_prot_t access_type) | ||||
571 | { | ||||
572 | struct uvm_faultinfo ufi; | ||||
573 | struct uvm_faultctx flt; | ||||
574 | boolean_t shadowed; | ||||
575 | struct vm_anon *anons_store[UVM_MAXRANGE16], **anons; | ||||
576 | struct vm_page *pages[UVM_MAXRANGE16]; | ||||
577 | int error; | ||||
578 | |||||
579 | counters_inc(uvmexp_counters, faults); | ||||
580 | TRACEPOINT(uvm, fault, vaddr, fault_type, access_type, NULL)do { extern struct dt_probe (dt_static_uvm_fault); struct dt_probe *dtp = &(dt_static_uvm_fault); if (__builtin_expect(((dt_tracing ) != 0), 0) && __builtin_expect(((dtp->dtp_recording ) != 0), 0)) { struct dt_provider *dtpv = dtp->dtp_prov; dtpv ->dtpv_enter(dtpv, dtp, vaddr, fault_type, access_type, (( void *)0)); } } while (0); | ||||
581 | |||||
582 | /* | ||||
583 | * init the IN parameters in the ufi | ||||
584 | */ | ||||
585 | ufi.orig_map = orig_map; | ||||
586 | ufi.orig_rvaddr = trunc_page(vaddr)((vaddr) & ~((1 << 12) - 1)); | ||||
587 | ufi.orig_size = PAGE_SIZE(1 << 12); /* can't get any smaller than this */ | ||||
588 | if (fault_type
| ||||
589 | flt.narrow = TRUE1; /* don't look for neighborhood | ||||
590 | * pages on wire */ | ||||
591 | else | ||||
592 | flt.narrow = FALSE0; /* normal fault */ | ||||
593 | flt.access_type = access_type; | ||||
594 | |||||
595 | |||||
596 | error = ERESTART-1; | ||||
597 | while (error == ERESTART-1) { /* ReFault: */ | ||||
598 | anons = anons_store; | ||||
599 | |||||
600 | error = uvm_fault_check(&ufi, &flt, &anons); | ||||
601 | if (error
| ||||
602 | continue; | ||||
603 | |||||
604 | /* True if there is an anon at the faulting address */ | ||||
605 | shadowed = uvm_fault_upper_lookup(&ufi, &flt, anons, pages); | ||||
606 | if (shadowed == TRUE1) { | ||||
607 | /* case 1: fault on an anon in our amap */ | ||||
608 | error = uvm_fault_upper(&ufi, &flt, anons, fault_type); | ||||
609 | } else { | ||||
610 | struct uvm_object *uobj = ufi.entry->object.uvm_obj; | ||||
611 | |||||
612 | /* | ||||
613 | * if the desired page is not shadowed by the amap and | ||||
614 | * we have a backing object, then we check to see if | ||||
615 | * the backing object would prefer to handle the fault | ||||
616 | * itself (rather than letting us do it with the usual | ||||
617 | * pgo_get hook). the backing object signals this by | ||||
618 | * providing a pgo_fault routine. | ||||
619 | */ | ||||
620 | if (uobj != NULL((void *)0) && uobj->pgops->pgo_fault != NULL((void *)0)) { | ||||
621 | KERNEL_LOCK()_kernel_lock(); | ||||
622 | rw_enter(uobj->vmobjlock, RW_WRITE0x0001UL); | ||||
623 | error = uobj->pgops->pgo_fault(&ufi, | ||||
624 | flt.startva, pages, flt.npages, | ||||
625 | flt.centeridx, fault_type, flt.access_type, | ||||
626 | PGO_LOCKED0x040); | ||||
627 | KERNEL_UNLOCK()_kernel_unlock(); | ||||
628 | |||||
629 | if (error == VM_PAGER_OK0) | ||||
630 | error = 0; | ||||
631 | else if (error == VM_PAGER_REFAULT7) | ||||
632 | error = ERESTART-1; | ||||
633 | else | ||||
634 | error = EACCES13; | ||||
635 | } else { | ||||
636 | /* case 2: fault on backing obj or zero fill */ | ||||
637 | error = uvm_fault_lower(&ufi, &flt, pages, | ||||
638 | fault_type); | ||||
639 | } | ||||
640 | } | ||||
641 | } | ||||
642 | |||||
643 | return error; | ||||
644 | } | ||||
645 | |||||
646 | /* | ||||
647 | * uvm_fault_check: check prot, handle needs-copy, etc. | ||||
648 | * | ||||
649 | * 1. lookup entry. | ||||
650 | * 2. check protection. | ||||
651 | * 3. adjust fault condition (mainly for simulated fault). | ||||
652 | * 4. handle needs-copy (lazy amap copy). | ||||
653 | * 5. establish range of interest for neighbor fault (aka pre-fault). | ||||
654 | * 6. look up anons (if amap exists). | ||||
655 | * 7. flush pages (if MADV_SEQUENTIAL) | ||||
656 | * | ||||
657 | * => called with nothing locked. | ||||
658 | * => if we fail (result != 0) we unlock everything. | ||||
659 | * => initialize/adjust many members of flt. | ||||
660 | */ | ||||
661 | int | ||||
662 | uvm_fault_check(struct uvm_faultinfo *ufi, struct uvm_faultctx *flt, | ||||
663 | struct vm_anon ***ranons) | ||||
664 | { | ||||
665 | struct vm_amap *amap; | ||||
666 | struct uvm_object *uobj; | ||||
667 | int nback, nforw; | ||||
668 | |||||
669 | /* | ||||
670 | * lookup and lock the maps | ||||
671 | */ | ||||
672 | if (uvmfault_lookup(ufi, FALSE0) == FALSE0) { | ||||
673 | return EFAULT14; | ||||
674 | } | ||||
675 | /* locked: maps(read) */ | ||||
676 | |||||
677 | #ifdef DIAGNOSTIC1 | ||||
678 | if ((ufi->map->flags & VM_MAP_PAGEABLE0x01) == 0) | ||||
679 | panic("uvm_fault: fault on non-pageable map (%p, 0x%lx)", | ||||
680 | ufi->map, ufi->orig_rvaddr); | ||||
681 | #endif | ||||
682 | |||||
683 | /* | ||||
684 | * check protection | ||||
685 | */ | ||||
686 | if ((ufi->entry->protection & flt->access_type) != flt->access_type) { | ||||
687 | uvmfault_unlockmaps(ufi, FALSE0); | ||||
688 | return EACCES13; | ||||
689 | } | ||||
690 | |||||
691 | /* | ||||
692 | * "enter_prot" is the protection we want to enter the page in at. | ||||
693 | * for certain pages (e.g. copy-on-write pages) this protection can | ||||
694 | * be more strict than ufi->entry->protection. "wired" means either | ||||
695 | * the entry is wired or we are fault-wiring the pg. | ||||
696 | */ | ||||
697 | |||||
698 | flt->enter_prot = ufi->entry->protection; | ||||
699 | flt->pa_flags = UVM_ET_ISWC(ufi->entry)(((ufi->entry)->etype & 0x0080) != 0) ? PMAP_WC0x2 : 0; | ||||
700 | flt->wired = VM_MAPENT_ISWIRED(ufi->entry)((ufi->entry)->wired_count != 0) || (flt->narrow == TRUE1); | ||||
701 | if (flt->wired
| ||||
702 | flt->access_type = flt->enter_prot; /* full access for wired */ | ||||
703 | |||||
704 | /* handle "needs_copy" case. */ | ||||
705 | if (UVM_ET_ISNEEDSCOPY(ufi->entry)(((ufi->entry)->etype & 0x0008) != 0)) { | ||||
706 | if ((flt->access_type & PROT_WRITE0x02) || | ||||
707 | (ufi->entry->object.uvm_obj == NULL((void *)0))) { | ||||
708 | /* need to clear */ | ||||
709 | uvmfault_unlockmaps(ufi, FALSE0); | ||||
710 | uvmfault_amapcopy(ufi); | ||||
711 | counters_inc(uvmexp_counters, flt_amcopy); | ||||
712 | return ERESTART-1; | ||||
713 | } else { | ||||
714 | /* | ||||
715 | * ensure that we pmap_enter page R/O since | ||||
716 | * needs_copy is still true | ||||
717 | */ | ||||
718 | flt->enter_prot &= ~PROT_WRITE0x02; | ||||
719 | } | ||||
720 | } | ||||
721 | |||||
722 | /* | ||||
723 | * identify the players | ||||
724 | */ | ||||
725 | amap = ufi->entry->aref.ar_amap; /* upper layer */ | ||||
726 | uobj = ufi->entry->object.uvm_obj; /* lower layer */ | ||||
727 | |||||
728 | /* | ||||
729 | * check for a case 0 fault. if nothing backing the entry then | ||||
730 | * error now. | ||||
731 | */ | ||||
732 | if (amap == NULL((void *)0) && uobj == NULL((void *)0)) { | ||||
733 | uvmfault_unlockmaps(ufi, FALSE0); | ||||
734 | return EFAULT14; | ||||
735 | } | ||||
736 | |||||
737 | /* | ||||
738 | * for a case 2B fault waste no time on adjacent pages because | ||||
739 | * they are likely already entered. | ||||
740 | */ | ||||
741 | if (uobj
| ||||
742 | (flt->access_type & PROT_WRITE0x02) != 0) { | ||||
743 | /* wide fault (!narrow) */ | ||||
744 | flt->narrow = TRUE1; | ||||
745 | } | ||||
746 | |||||
747 | /* | ||||
748 | * establish range of interest based on advice from mapper | ||||
749 | * and then clip to fit map entry. note that we only want | ||||
750 | * to do this the first time through the fault. if we | ||||
751 | * ReFault we will disable this by setting "narrow" to true. | ||||
752 | */ | ||||
753 | if (flt->narrow
| ||||
754 | |||||
755 | /* wide fault (!narrow) */ | ||||
756 | nback = min(uvmadvice[ufi->entry->advice].nback, | ||||
757 | (ufi->orig_rvaddr - ufi->entry->start) >> PAGE_SHIFT12); | ||||
758 | flt->startva = ufi->orig_rvaddr - ((vsize_t)nback << PAGE_SHIFT12); | ||||
759 | nforw = min(uvmadvice[ufi->entry->advice].nforw, | ||||
760 | ((ufi->entry->end - ufi->orig_rvaddr) >> PAGE_SHIFT12) - 1); | ||||
761 | /* | ||||
762 | * note: "-1" because we don't want to count the | ||||
763 | * faulting page as forw | ||||
764 | */ | ||||
765 | flt->npages = nback + nforw + 1; | ||||
766 | flt->centeridx = nback; | ||||
767 | |||||
768 | flt->narrow = TRUE1; /* ensure only once per-fault */ | ||||
769 | } else { | ||||
770 | /* narrow fault! */ | ||||
771 | nback = nforw = 0; | ||||
772 | flt->startva = ufi->orig_rvaddr; | ||||
773 | flt->npages = 1; | ||||
774 | flt->centeridx = 0; | ||||
775 | } | ||||
776 | |||||
777 | /* | ||||
778 | * if we've got an amap then lock it and extract current anons. | ||||
779 | */ | ||||
780 | if (amap
| ||||
781 | amap_lock(amap)rw_enter_write((amap)->am_lock); | ||||
782 | amap_lookups(&ufi->entry->aref, | ||||
783 | flt->startva - ufi->entry->start, *ranons, flt->npages); | ||||
784 | } else { | ||||
785 | *ranons = NULL((void *)0); /* to be safe */ | ||||
786 | } | ||||
787 | |||||
788 | /* | ||||
789 | * for MADV_SEQUENTIAL mappings we want to deactivate the back pages | ||||
790 | * now and then forget about them (for the rest of the fault). | ||||
791 | */ | ||||
792 | if (ufi->entry->advice == MADV_SEQUENTIAL2 && nback != 0) { | ||||
793 | /* flush back-page anons? */ | ||||
794 | if (amap) | ||||
795 | uvmfault_anonflush(*ranons, nback); | ||||
796 | |||||
797 | /* | ||||
798 | * flush object? | ||||
799 | */ | ||||
800 | if (uobj) { | ||||
801 | voff_t uoff; | ||||
802 | |||||
803 | uoff = (flt->startva - ufi->entry->start) + ufi->entry->offset; | ||||
804 | rw_enter(uobj->vmobjlock, RW_WRITE0x0001UL); | ||||
805 | (void) uobj->pgops->pgo_flush(uobj, uoff, uoff + | ||||
806 | ((vsize_t)nback << PAGE_SHIFT12), PGO_DEACTIVATE0x004); | ||||
807 | rw_exit(uobj->vmobjlock); | ||||
808 | } | ||||
809 | |||||
810 | /* now forget about the backpages */ | ||||
811 | if (amap) | ||||
812 | *ranons += nback; | ||||
813 | flt->startva += ((vsize_t)nback << PAGE_SHIFT12); | ||||
814 | flt->npages -= nback; | ||||
815 | flt->centeridx = 0; | ||||
816 | } | ||||
817 | |||||
818 | return 0; | ||||
819 | } | ||||
820 | |||||
821 | /* | ||||
822 | * uvm_fault_upper_lookup: look up existing h/w mapping and amap. | ||||
823 | * | ||||
824 | * iterate range of interest: | ||||
825 | * 1. check if h/w mapping exists. if yes, we don't care | ||||
826 | * 2. check if anon exists. if not, page is lower. | ||||
827 | * 3. if anon exists, enter h/w mapping for neighbors. | ||||
828 | * | ||||
829 | * => called with amap locked (if exists). | ||||
830 | */ | ||||
831 | boolean_t | ||||
832 | uvm_fault_upper_lookup(struct uvm_faultinfo *ufi, | ||||
833 | const struct uvm_faultctx *flt, struct vm_anon **anons, | ||||
834 | struct vm_page **pages) | ||||
835 | { | ||||
836 | struct vm_amap *amap = ufi->entry->aref.ar_amap; | ||||
837 | struct vm_anon *anon; | ||||
838 | boolean_t shadowed; | ||||
839 | vaddr_t currva; | ||||
840 | paddr_t pa; | ||||
841 | int lcv; | ||||
842 | |||||
843 | /* locked: maps(read), amap(if there) */ | ||||
844 | KASSERT(amap == NULL ||((amap == ((void *)0) || rw_write_held(amap->am_lock)) ? ( void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 845, "amap == NULL || rw_write_held(amap->am_lock)")) | ||||
845 | rw_write_held(amap->am_lock))((amap == ((void *)0) || rw_write_held(amap->am_lock)) ? ( void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 845, "amap == NULL || rw_write_held(amap->am_lock)")); | ||||
846 | |||||
847 | /* | ||||
848 | * map in the backpages and frontpages we found in the amap in hopes | ||||
849 | * of preventing future faults. we also init the pages[] array as | ||||
850 | * we go. | ||||
851 | */ | ||||
852 | currva = flt->startva; | ||||
853 | shadowed = FALSE0; | ||||
854 | for (lcv = 0; lcv < flt->npages; lcv++, currva += PAGE_SIZE(1 << 12)) { | ||||
855 | /* | ||||
856 | * dont play with VAs that are already mapped | ||||
857 | * except for center) | ||||
858 | */ | ||||
859 | if (lcv != flt->centeridx && | ||||
860 | pmap_extract(ufi->orig_map->pmap, currva, &pa)) { | ||||
861 | pages[lcv] = PGO_DONTCARE((struct vm_page *) -1L); | ||||
862 | continue; | ||||
863 | } | ||||
864 | |||||
865 | /* | ||||
866 | * unmapped or center page. check if any anon at this level. | ||||
867 | */ | ||||
868 | if (amap == NULL((void *)0) || anons[lcv] == NULL((void *)0)) { | ||||
869 | pages[lcv] = NULL((void *)0); | ||||
870 | continue; | ||||
871 | } | ||||
872 | |||||
873 | /* | ||||
874 | * check for present page and map if possible. | ||||
875 | */ | ||||
876 | pages[lcv] = PGO_DONTCARE((struct vm_page *) -1L); | ||||
877 | if (lcv == flt->centeridx) { /* save center for later! */ | ||||
878 | shadowed = TRUE1; | ||||
879 | continue; | ||||
880 | } | ||||
881 | anon = anons[lcv]; | ||||
882 | KASSERT(anon->an_lock == amap->am_lock)((anon->an_lock == amap->am_lock) ? (void)0 : __assert( "diagnostic ", "/usr/src/sys/uvm/uvm_fault.c", 882, "anon->an_lock == amap->am_lock" )); | ||||
883 | if (anon->an_page && | ||||
884 | (anon->an_page->pg_flags & (PG_RELEASED0x00000020|PG_BUSY0x00000001)) == 0) { | ||||
885 | uvm_lock_pageq()mtx_enter(&uvm.pageqlock); | ||||
886 | uvm_pageactivate(anon->an_page); /* reactivate */ | ||||
887 | uvm_unlock_pageq()mtx_leave(&uvm.pageqlock); | ||||
888 | counters_inc(uvmexp_counters, flt_namap); | ||||
889 | |||||
890 | /* | ||||
891 | * Since this isn't the page that's actually faulting, | ||||
892 | * ignore pmap_enter() failures; it's not critical | ||||
893 | * that we enter these right now. | ||||
894 | */ | ||||
895 | (void) pmap_enter(ufi->orig_map->pmap, currva, | ||||
896 | VM_PAGE_TO_PHYS(anon->an_page)((anon->an_page)->phys_addr) | flt->pa_flags, | ||||
897 | (anon->an_ref > 1) ? | ||||
898 | (flt->enter_prot & ~PROT_WRITE0x02) : flt->enter_prot, | ||||
899 | PMAP_CANFAIL0x00000020 | | ||||
900 | (VM_MAPENT_ISWIRED(ufi->entry)((ufi->entry)->wired_count != 0) ? PMAP_WIRED0x00000010 : 0)); | ||||
901 | } | ||||
902 | } | ||||
903 | if (flt->npages > 1) | ||||
904 | pmap_update(ufi->orig_map->pmap); | ||||
905 | |||||
906 | return shadowed; | ||||
907 | } | ||||
908 | |||||
909 | /* | ||||
910 | * uvm_fault_upper: handle upper fault. | ||||
911 | * | ||||
912 | * 1. acquire anon lock. | ||||
913 | * 2. get anon. let uvmfault_anonget do the dirty work. | ||||
914 | * 3. if COW, promote data to new anon | ||||
915 | * 4. enter h/w mapping | ||||
916 | */ | ||||
917 | int | ||||
918 | uvm_fault_upper(struct uvm_faultinfo *ufi, struct uvm_faultctx *flt, | ||||
919 | struct vm_anon **anons, vm_fault_t fault_type) | ||||
920 | { | ||||
921 | struct vm_amap *amap = ufi->entry->aref.ar_amap; | ||||
922 | struct vm_anon *oanon, *anon = anons[flt->centeridx]; | ||||
| |||||
923 | struct vm_page *pg = NULL((void *)0); | ||||
924 | int error, ret; | ||||
925 | |||||
926 | /* locked: maps(read), amap, anon */ | ||||
927 | KASSERT(rw_write_held(amap->am_lock))((rw_write_held(amap->am_lock)) ? (void)0 : __assert("diagnostic " , "/usr/src/sys/uvm/uvm_fault.c", 927, "rw_write_held(amap->am_lock)" )); | ||||
928 | KASSERT(anon->an_lock == amap->am_lock)((anon->an_lock == amap->am_lock) ? (void)0 : __assert( "diagnostic ", "/usr/src/sys/uvm/uvm_fault.c", 928, "anon->an_lock == amap->am_lock" )); | ||||
929 | |||||
930 | /* | ||||
931 | * no matter if we have case 1A or case 1B we are going to need to | ||||
932 | * have the anon's memory resident. ensure that now. | ||||
933 | */ | ||||
934 | /* | ||||
935 | * let uvmfault_anonget do the dirty work. | ||||
936 | * if it fails (!OK) it will unlock everything for us. | ||||
937 | * if it succeeds, locks are still valid and locked. | ||||
938 | * also, if it is OK, then the anon's page is on the queues. | ||||
939 | * if the page is on loan from a uvm_object, then anonget will | ||||
940 | * lock that object for us if it does not fail. | ||||
941 | */ | ||||
942 | error = uvmfault_anonget(ufi, amap, anon); | ||||
943 | switch (error) { | ||||
944 | case VM_PAGER_OK0: | ||||
945 | break; | ||||
946 | |||||
947 | case VM_PAGER_REFAULT7: | ||||
948 | return ERESTART-1; | ||||
949 | |||||
950 | case VM_PAGER_ERROR4: | ||||
951 | /* | ||||
952 | * An error occurred while trying to bring in the | ||||
953 | * page -- this is the only error we return right | ||||
954 | * now. | ||||
955 | */ | ||||
956 | return EACCES13; /* XXX */ | ||||
957 | default: | ||||
958 | #ifdef DIAGNOSTIC1 | ||||
959 | panic("uvm_fault: uvmfault_anonget -> %d", error); | ||||
960 | #else | ||||
961 | return EACCES13; | ||||
962 | #endif | ||||
963 | } | ||||
964 | |||||
965 | KASSERT(rw_write_held(amap->am_lock))((rw_write_held(amap->am_lock)) ? (void)0 : __assert("diagnostic " , "/usr/src/sys/uvm/uvm_fault.c", 965, "rw_write_held(amap->am_lock)" )); | ||||
966 | KASSERT(anon->an_lock == amap->am_lock)((anon->an_lock == amap->am_lock) ? (void)0 : __assert( "diagnostic ", "/usr/src/sys/uvm/uvm_fault.c", 966, "anon->an_lock == amap->am_lock" )); | ||||
967 | |||||
968 | /* | ||||
969 | * if we are case 1B then we will need to allocate a new blank | ||||
970 | * anon to transfer the data into. note that we have a lock | ||||
971 | * on anon, so no one can busy or release the page until we are done. | ||||
972 | * also note that the ref count can't drop to zero here because | ||||
973 | * it is > 1 and we are only dropping one ref. | ||||
974 | * | ||||
975 | * in the (hopefully very rare) case that we are out of RAM we | ||||
976 | * will unlock, wait for more RAM, and refault. | ||||
977 | * | ||||
978 | * if we are out of anon VM we wait for RAM to become available. | ||||
979 | */ | ||||
980 | |||||
981 | if ((flt->access_type & PROT_WRITE0x02) != 0 && anon->an_ref > 1) { | ||||
982 | counters_inc(uvmexp_counters, flt_acow); | ||||
983 | oanon = anon; /* oanon = old */ | ||||
984 | anon = uvm_analloc(); | ||||
985 | if (anon) { | ||||
986 | anon->an_lock = amap->am_lock; | ||||
987 | pg = uvm_pagealloc(NULL((void *)0), 0, anon, 0); | ||||
988 | } | ||||
989 | |||||
990 | /* check for out of RAM */ | ||||
991 | if (anon == NULL((void *)0) || pg == NULL((void *)0)) { | ||||
992 | uvmfault_unlockall(ufi, amap, NULL((void *)0)); | ||||
993 | if (anon == NULL((void *)0)) | ||||
994 | counters_inc(uvmexp_counters, flt_noanon); | ||||
995 | else { | ||||
996 | anon->an_lock = NULL((void *)0); | ||||
997 | anon->an_ref--; | ||||
998 | uvm_anfree(anon)uvm_anfree_list((anon), ((void *)0)); | ||||
999 | counters_inc(uvmexp_counters, flt_noram); | ||||
1000 | } | ||||
1001 | |||||
1002 | if (uvm_swapisfull()) | ||||
1003 | return ENOMEM12; | ||||
1004 | |||||
1005 | /* out of RAM, wait for more */ | ||||
1006 | if (anon == NULL((void *)0)) | ||||
1007 | uvm_anwait(); | ||||
1008 | else | ||||
1009 | uvm_wait("flt_noram3"); | ||||
1010 | return ERESTART-1; | ||||
1011 | } | ||||
1012 | |||||
1013 | /* got all resources, replace anon with nanon */ | ||||
1014 | uvm_pagecopy(oanon->an_page, pg); /* pg now !PG_CLEAN */ | ||||
1015 | /* un-busy! new page */ | ||||
1016 | atomic_clearbits_intx86_atomic_clearbits_u32(&pg->pg_flags, PG_BUSY0x00000001|PG_FAKE0x00000040); | ||||
1017 | UVM_PAGE_OWN(pg, NULL); | ||||
1018 | ret = amap_add(&ufi->entry->aref, | ||||
1019 | ufi->orig_rvaddr - ufi->entry->start, anon, 1); | ||||
1020 | KASSERT(ret == 0)((ret == 0) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 1020, "ret == 0")); | ||||
1021 | |||||
1022 | /* deref: can not drop to zero here by defn! */ | ||||
1023 | oanon->an_ref--; | ||||
1024 | |||||
1025 | #if defined(MULTIPROCESSOR1) && !defined(__HAVE_PMAP_MPSAFE_ENTER_COW) | ||||
1026 | /* | ||||
1027 | * If there are multiple threads, either uvm or the | ||||
1028 | * pmap has to make sure no threads see the old RO | ||||
1029 | * mapping once any have seen the new RW mapping. | ||||
1030 | * uvm does it by inserting the new mapping RO and | ||||
1031 | * letting it fault again. | ||||
1032 | * This is only a problem on MP systems. | ||||
1033 | */ | ||||
1034 | if (P_HASSIBLING(curproc)((({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc)->p_p->ps_threadcnt > 1)) { | ||||
1035 | flt->enter_prot &= ~PROT_WRITE0x02; | ||||
1036 | flt->access_type &= ~PROT_WRITE0x02; | ||||
1037 | } | ||||
1038 | #endif | ||||
1039 | |||||
1040 | /* | ||||
1041 | * note: anon is _not_ locked, but we have the sole references | ||||
1042 | * to in from amap. | ||||
1043 | * thus, no one can get at it until we are done with it. | ||||
1044 | */ | ||||
1045 | } else { | ||||
1046 | counters_inc(uvmexp_counters, flt_anon); | ||||
1047 | oanon = anon; | ||||
1048 | pg = anon->an_page; | ||||
1049 | if (anon->an_ref > 1) /* disallow writes to ref > 1 anons */ | ||||
1050 | flt->enter_prot = flt->enter_prot & ~PROT_WRITE0x02; | ||||
1051 | } | ||||
1052 | |||||
1053 | /* | ||||
1054 | * now map the page in . | ||||
1055 | */ | ||||
1056 | if (pmap_enter(ufi->orig_map->pmap, ufi->orig_rvaddr, | ||||
1057 | VM_PAGE_TO_PHYS(pg)((pg)->phys_addr) | flt->pa_flags, flt->enter_prot, | ||||
1058 | flt->access_type | PMAP_CANFAIL0x00000020 | (flt->wired ? PMAP_WIRED0x00000010 : 0)) != 0) { | ||||
1059 | /* | ||||
1060 | * No need to undo what we did; we can simply think of | ||||
1061 | * this as the pmap throwing away the mapping information. | ||||
1062 | * | ||||
1063 | * We do, however, have to go through the ReFault path, | ||||
1064 | * as the map may change while we're asleep. | ||||
1065 | */ | ||||
1066 | uvmfault_unlockall(ufi, amap, NULL((void *)0)); | ||||
1067 | if (uvm_swapisfull()) { | ||||
1068 | /* XXX instrumentation */ | ||||
1069 | return ENOMEM12; | ||||
1070 | } | ||||
1071 | /* XXX instrumentation */ | ||||
1072 | uvm_wait("flt_pmfail1"); | ||||
1073 | return ERESTART-1; | ||||
1074 | } | ||||
1075 | |||||
1076 | /* | ||||
1077 | * ... update the page queues. | ||||
1078 | */ | ||||
1079 | uvm_lock_pageq()mtx_enter(&uvm.pageqlock); | ||||
1080 | |||||
1081 | if (fault_type == VM_FAULT_WIRE((vm_fault_t) 0x2)) { | ||||
1082 | uvm_pagewire(pg); | ||||
1083 | /* | ||||
1084 | * since the now-wired page cannot be paged out, | ||||
1085 | * release its swap resources for others to use. | ||||
1086 | * since an anon with no swap cannot be PG_CLEAN, | ||||
1087 | * clear its clean flag now. | ||||
1088 | */ | ||||
1089 | atomic_clearbits_intx86_atomic_clearbits_u32(&pg->pg_flags, PG_CLEAN0x00000008); | ||||
1090 | uvm_anon_dropswap(anon); | ||||
1091 | } else { | ||||
1092 | /* activate it */ | ||||
1093 | uvm_pageactivate(pg); | ||||
1094 | } | ||||
1095 | |||||
1096 | uvm_unlock_pageq()mtx_leave(&uvm.pageqlock); | ||||
1097 | |||||
1098 | /* | ||||
1099 | * done case 1! finish up by unlocking everything and returning success | ||||
1100 | */ | ||||
1101 | uvmfault_unlockall(ufi, amap, NULL((void *)0)); | ||||
1102 | pmap_update(ufi->orig_map->pmap); | ||||
1103 | return 0; | ||||
1104 | } | ||||
1105 | |||||
1106 | /* | ||||
1107 | * uvm_fault_lower_lookup: look up on-memory uobj pages. | ||||
1108 | * | ||||
1109 | * 1. get on-memory pages. | ||||
1110 | * 2. if failed, give up (get only center page later). | ||||
1111 | * 3. if succeeded, enter h/w mapping of neighbor pages. | ||||
1112 | */ | ||||
1113 | |||||
1114 | struct vm_page * | ||||
1115 | uvm_fault_lower_lookup( | ||||
1116 | struct uvm_faultinfo *ufi, const struct uvm_faultctx *flt, | ||||
1117 | struct vm_page **pages) | ||||
1118 | { | ||||
1119 | struct uvm_object *uobj = ufi->entry->object.uvm_obj; | ||||
1120 | struct vm_page *uobjpage = NULL((void *)0); | ||||
1121 | int lcv, gotpages; | ||||
1122 | vaddr_t currva; | ||||
1123 | |||||
1124 | rw_enter(uobj->vmobjlock, RW_WRITE0x0001UL); | ||||
1125 | |||||
1126 | counters_inc(uvmexp_counters, flt_lget); | ||||
1127 | gotpages = flt->npages; | ||||
1128 | (void) uobj->pgops->pgo_get(uobj, | ||||
1129 | ufi->entry->offset + (flt->startva - ufi->entry->start), | ||||
1130 | pages, &gotpages, flt->centeridx, | ||||
1131 | flt->access_type & MASK(ufi->entry)((((ufi->entry)->etype & 0x0004) != 0) ? ~0x02 : (0x01 | 0x02 | 0x04)), ufi->entry->advice, | ||||
1132 | PGO_LOCKED0x040); | ||||
1133 | |||||
1134 | /* | ||||
1135 | * check for pages to map, if we got any | ||||
1136 | */ | ||||
1137 | if (gotpages == 0) { | ||||
1138 | return NULL((void *)0); | ||||
1139 | } | ||||
1140 | |||||
1141 | currva = flt->startva; | ||||
1142 | for (lcv = 0; lcv < flt->npages; lcv++, currva += PAGE_SIZE(1 << 12)) { | ||||
1143 | if (pages[lcv] == NULL((void *)0) || | ||||
1144 | pages[lcv] == PGO_DONTCARE((struct vm_page *) -1L)) | ||||
1145 | continue; | ||||
1146 | |||||
1147 | KASSERT((pages[lcv]->pg_flags & PG_RELEASED) == 0)(((pages[lcv]->pg_flags & 0x00000020) == 0) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c", 1147 , "(pages[lcv]->pg_flags & PG_RELEASED) == 0")); | ||||
1148 | |||||
1149 | /* | ||||
1150 | * if center page is resident and not | ||||
1151 | * PG_BUSY, then pgo_get made it PG_BUSY | ||||
1152 | * for us and gave us a handle to it. | ||||
1153 | * remember this page as "uobjpage." | ||||
1154 | * (for later use). | ||||
1155 | */ | ||||
1156 | if (lcv == flt->centeridx) { | ||||
1157 | uobjpage = pages[lcv]; | ||||
1158 | continue; | ||||
1159 | } | ||||
1160 | |||||
1161 | /* | ||||
1162 | * note: calling pgo_get with locked data | ||||
1163 | * structures returns us pages which are | ||||
1164 | * neither busy nor released, so we don't | ||||
1165 | * need to check for this. we can just | ||||
1166 | * directly enter the page (after moving it | ||||
1167 | * to the head of the active queue [useful?]). | ||||
1168 | */ | ||||
1169 | |||||
1170 | uvm_lock_pageq()mtx_enter(&uvm.pageqlock); | ||||
1171 | uvm_pageactivate(pages[lcv]); /* reactivate */ | ||||
1172 | uvm_unlock_pageq()mtx_leave(&uvm.pageqlock); | ||||
1173 | counters_inc(uvmexp_counters, flt_nomap); | ||||
1174 | |||||
1175 | /* | ||||
1176 | * Since this page isn't the page that's | ||||
1177 | * actually faulting, ignore pmap_enter() | ||||
1178 | * failures; it's not critical that we | ||||
1179 | * enter these right now. | ||||
1180 | */ | ||||
1181 | (void) pmap_enter(ufi->orig_map->pmap, currva, | ||||
1182 | VM_PAGE_TO_PHYS(pages[lcv])((pages[lcv])->phys_addr) | flt->pa_flags, | ||||
1183 | flt->enter_prot & MASK(ufi->entry)((((ufi->entry)->etype & 0x0004) != 0) ? ~0x02 : (0x01 | 0x02 | 0x04)), | ||||
1184 | PMAP_CANFAIL0x00000020 | | ||||
1185 | (flt->wired ? PMAP_WIRED0x00000010 : 0)); | ||||
1186 | |||||
1187 | /* | ||||
1188 | * NOTE: page can't be PG_WANTED because | ||||
1189 | * we've held the lock the whole time | ||||
1190 | * we've had the handle. | ||||
1191 | */ | ||||
1192 | atomic_clearbits_intx86_atomic_clearbits_u32(&pages[lcv]->pg_flags, PG_BUSY0x00000001); | ||||
1193 | UVM_PAGE_OWN(pages[lcv], NULL); | ||||
1194 | } | ||||
1195 | pmap_update(ufi->orig_map->pmap); | ||||
1196 | |||||
1197 | return uobjpage; | ||||
1198 | } | ||||
1199 | |||||
1200 | /* | ||||
1201 | * uvm_fault_lower: handle lower fault. | ||||
1202 | * | ||||
1203 | */ | ||||
1204 | int | ||||
1205 | uvm_fault_lower(struct uvm_faultinfo *ufi, struct uvm_faultctx *flt, | ||||
1206 | struct vm_page **pages, vm_fault_t fault_type) | ||||
1207 | { | ||||
1208 | struct vm_amap *amap = ufi->entry->aref.ar_amap; | ||||
1209 | struct uvm_object *uobj = ufi->entry->object.uvm_obj; | ||||
1210 | boolean_t promote, locked; | ||||
1211 | int result; | ||||
1212 | struct vm_page *uobjpage, *pg = NULL((void *)0); | ||||
1213 | struct vm_anon *anon = NULL((void *)0); | ||||
1214 | voff_t uoff; | ||||
1215 | |||||
1216 | /* | ||||
1217 | * now, if the desired page is not shadowed by the amap and we have | ||||
1218 | * a backing object that does not have a special fault routine, then | ||||
1219 | * we ask (with pgo_get) the object for resident pages that we care | ||||
1220 | * about and attempt to map them in. we do not let pgo_get block | ||||
1221 | * (PGO_LOCKED). | ||||
1222 | */ | ||||
1223 | if (uobj == NULL((void *)0)) { | ||||
1224 | /* zero fill; don't care neighbor pages */ | ||||
1225 | uobjpage = NULL((void *)0); | ||||
1226 | } else { | ||||
1227 | uobjpage = uvm_fault_lower_lookup(ufi, flt, pages); | ||||
1228 | } | ||||
1229 | |||||
1230 | /* | ||||
1231 | * note that at this point we are done with any front or back pages. | ||||
1232 | * we are now going to focus on the center page (i.e. the one we've | ||||
1233 | * faulted on). if we have faulted on the bottom (uobj) | ||||
1234 | * layer [i.e. case 2] and the page was both present and available, | ||||
1235 | * then we've got a pointer to it as "uobjpage" and we've already | ||||
1236 | * made it BUSY. | ||||
1237 | */ | ||||
1238 | |||||
1239 | /* | ||||
1240 | * locked: | ||||
1241 | */ | ||||
1242 | KASSERT(amap == NULL ||((amap == ((void *)0) || rw_write_held(amap->am_lock)) ? ( void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 1243, "amap == NULL || rw_write_held(amap->am_lock)")) | ||||
1243 | rw_write_held(amap->am_lock))((amap == ((void *)0) || rw_write_held(amap->am_lock)) ? ( void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 1243, "amap == NULL || rw_write_held(amap->am_lock)")); | ||||
1244 | KASSERT(uobj == NULL ||((uobj == ((void *)0) || rw_write_held(uobj->vmobjlock)) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 1245, "uobj == NULL || rw_write_held(uobj->vmobjlock)")) | ||||
1245 | rw_write_held(uobj->vmobjlock))((uobj == ((void *)0) || rw_write_held(uobj->vmobjlock)) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 1245, "uobj == NULL || rw_write_held(uobj->vmobjlock)")); | ||||
1246 | |||||
1247 | /* | ||||
1248 | * note that uobjpage can not be PGO_DONTCARE at this point. we now | ||||
1249 | * set uobjpage to PGO_DONTCARE if we are doing a zero fill. if we | ||||
1250 | * have a backing object, check and see if we are going to promote | ||||
1251 | * the data up to an anon during the fault. | ||||
1252 | */ | ||||
1253 | if (uobj == NULL((void *)0)) { | ||||
1254 | uobjpage = PGO_DONTCARE((struct vm_page *) -1L); | ||||
1255 | promote = TRUE1; /* always need anon here */ | ||||
1256 | } else { | ||||
1257 | KASSERT(uobjpage != PGO_DONTCARE)((uobjpage != ((struct vm_page *) -1L)) ? (void)0 : __assert( "diagnostic ", "/usr/src/sys/uvm/uvm_fault.c", 1257, "uobjpage != PGO_DONTCARE" )); | ||||
1258 | promote = (flt->access_type & PROT_WRITE0x02) && | ||||
1259 | UVM_ET_ISCOPYONWRITE(ufi->entry)(((ufi->entry)->etype & 0x0004) != 0); | ||||
1260 | } | ||||
1261 | |||||
1262 | /* | ||||
1263 | * if uobjpage is not null then we do not need to do I/O to get the | ||||
1264 | * uobjpage. | ||||
1265 | * | ||||
1266 | * if uobjpage is null, then we need to ask the pager to | ||||
1267 | * get the data for us. once we have the data, we need to reverify | ||||
1268 | * the state the world. we are currently not holding any resources. | ||||
1269 | */ | ||||
1270 | if (uobjpage) { | ||||
1271 | /* update rusage counters */ | ||||
1272 | curproc({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc->p_ru.ru_minflt++; | ||||
1273 | } else { | ||||
1274 | int gotpages; | ||||
1275 | |||||
1276 | /* update rusage counters */ | ||||
1277 | curproc({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc->p_ru.ru_majflt++; | ||||
1278 | |||||
1279 | uvmfault_unlockall(ufi, amap, NULL((void *)0)); | ||||
1280 | |||||
1281 | counters_inc(uvmexp_counters, flt_get); | ||||
1282 | gotpages = 1; | ||||
1283 | uoff = (ufi->orig_rvaddr - ufi->entry->start) + ufi->entry->offset; | ||||
1284 | result = uobj->pgops->pgo_get(uobj, uoff, &uobjpage, &gotpages, | ||||
1285 | 0, flt->access_type & MASK(ufi->entry)((((ufi->entry)->etype & 0x0004) != 0) ? ~0x02 : (0x01 | 0x02 | 0x04)), ufi->entry->advice, | ||||
1286 | PGO_SYNCIO0x002); | ||||
1287 | |||||
1288 | /* | ||||
1289 | * recover from I/O | ||||
1290 | */ | ||||
1291 | if (result != VM_PAGER_OK0) { | ||||
1292 | KASSERT(result != VM_PAGER_PEND)((result != 3) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 1292, "result != VM_PAGER_PEND")); | ||||
1293 | |||||
1294 | if (result == VM_PAGER_AGAIN5) { | ||||
1295 | tsleep_nsec(&nowake, PVM4, "fltagain2", | ||||
1296 | MSEC_TO_NSEC(5)); | ||||
1297 | return ERESTART-1; | ||||
1298 | } | ||||
1299 | |||||
1300 | if (!UVM_ET_ISNOFAULT(ufi->entry)(((ufi->entry)->etype & 0x0020) != 0)) | ||||
1301 | return (EIO5); | ||||
1302 | |||||
1303 | uobjpage = PGO_DONTCARE((struct vm_page *) -1L); | ||||
1304 | uobj = NULL((void *)0); | ||||
1305 | promote = TRUE1; | ||||
1306 | } | ||||
1307 | |||||
1308 | /* re-verify the state of the world. */ | ||||
1309 | locked = uvmfault_relock(ufi); | ||||
1310 | if (locked && amap != NULL((void *)0)) | ||||
1311 | amap_lock(amap)rw_enter_write((amap)->am_lock); | ||||
1312 | |||||
1313 | /* might be changed */ | ||||
1314 | if (uobjpage != PGO_DONTCARE((struct vm_page *) -1L)) { | ||||
1315 | uobj = uobjpage->uobject; | ||||
1316 | rw_enter(uobj->vmobjlock, RW_WRITE0x0001UL); | ||||
1317 | } | ||||
1318 | |||||
1319 | /* | ||||
1320 | * Re-verify that amap slot is still free. if there is | ||||
1321 | * a problem, we clean up. | ||||
1322 | */ | ||||
1323 | if (locked && amap && amap_lookup(&ufi->entry->aref, | ||||
1324 | ufi->orig_rvaddr - ufi->entry->start)) { | ||||
1325 | if (locked) | ||||
1326 | uvmfault_unlockall(ufi, amap, NULL((void *)0)); | ||||
1327 | locked = FALSE0; | ||||
1328 | } | ||||
1329 | |||||
1330 | /* didn't get the lock? release the page and retry. */ | ||||
1331 | if (locked == FALSE0 && uobjpage != PGO_DONTCARE((struct vm_page *) -1L)) { | ||||
1332 | uvm_lock_pageq()mtx_enter(&uvm.pageqlock); | ||||
1333 | /* make sure it is in queues */ | ||||
1334 | uvm_pageactivate(uobjpage); | ||||
1335 | uvm_unlock_pageq()mtx_leave(&uvm.pageqlock); | ||||
1336 | |||||
1337 | if (uobjpage->pg_flags & PG_WANTED0x00000002) | ||||
1338 | /* still holding object lock */ | ||||
1339 | wakeup(uobjpage); | ||||
1340 | atomic_clearbits_intx86_atomic_clearbits_u32(&uobjpage->pg_flags, | ||||
1341 | PG_BUSY0x00000001|PG_WANTED0x00000002); | ||||
1342 | UVM_PAGE_OWN(uobjpage, NULL); | ||||
1343 | } | ||||
1344 | |||||
1345 | if (locked == FALSE0) { | ||||
1346 | if (uobjpage != PGO_DONTCARE((struct vm_page *) -1L)) | ||||
1347 | rw_exit(uobj->vmobjlock); | ||||
1348 | return ERESTART-1; | ||||
1349 | } | ||||
1350 | |||||
1351 | /* | ||||
1352 | * we have the data in uobjpage which is PG_BUSY | ||||
1353 | */ | ||||
1354 | } | ||||
1355 | |||||
1356 | /* | ||||
1357 | * notes: | ||||
1358 | * - at this point uobjpage can not be NULL | ||||
1359 | * - at this point uobjpage could be PG_WANTED (handle later) | ||||
1360 | */ | ||||
1361 | if (promote == FALSE0) { | ||||
1362 | /* | ||||
1363 | * we are not promoting. if the mapping is COW ensure that we | ||||
1364 | * don't give more access than we should (e.g. when doing a read | ||||
1365 | * fault on a COPYONWRITE mapping we want to map the COW page in | ||||
1366 | * R/O even though the entry protection could be R/W). | ||||
1367 | * | ||||
1368 | * set "pg" to the page we want to map in (uobjpage, usually) | ||||
1369 | */ | ||||
1370 | counters_inc(uvmexp_counters, flt_obj); | ||||
1371 | if (UVM_ET_ISCOPYONWRITE(ufi->entry)(((ufi->entry)->etype & 0x0004) != 0)) | ||||
1372 | flt->enter_prot &= ~PROT_WRITE0x02; | ||||
1373 | pg = uobjpage; /* map in the actual object */ | ||||
1374 | |||||
1375 | /* assert(uobjpage != PGO_DONTCARE) */ | ||||
1376 | |||||
1377 | /* | ||||
1378 | * we are faulting directly on the page. | ||||
1379 | */ | ||||
1380 | } else { | ||||
1381 | /* | ||||
1382 | * if we are going to promote the data to an anon we | ||||
1383 | * allocate a blank anon here and plug it into our amap. | ||||
1384 | */ | ||||
1385 | #ifdef DIAGNOSTIC1 | ||||
1386 | if (amap == NULL((void *)0)) | ||||
1387 | panic("uvm_fault: want to promote data, but no anon"); | ||||
1388 | #endif | ||||
1389 | |||||
1390 | anon = uvm_analloc(); | ||||
1391 | if (anon) { | ||||
1392 | /* | ||||
1393 | * In `Fill in data...' below, if | ||||
1394 | * uobjpage == PGO_DONTCARE, we want | ||||
1395 | * a zero'd, dirty page, so have | ||||
1396 | * uvm_pagealloc() do that for us. | ||||
1397 | */ | ||||
1398 | anon->an_lock = amap->am_lock; | ||||
1399 | pg = uvm_pagealloc(NULL((void *)0), 0, anon, | ||||
1400 | (uobjpage == PGO_DONTCARE((struct vm_page *) -1L)) ? UVM_PGA_ZERO0x0002 : 0); | ||||
1401 | } | ||||
1402 | |||||
1403 | /* | ||||
1404 | * out of memory resources? | ||||
1405 | */ | ||||
1406 | if (anon == NULL((void *)0) || pg == NULL((void *)0)) { | ||||
1407 | /* | ||||
1408 | * arg! must unbusy our page and fail or sleep. | ||||
1409 | */ | ||||
1410 | if (uobjpage != PGO_DONTCARE((struct vm_page *) -1L)) { | ||||
1411 | uvm_lock_pageq()mtx_enter(&uvm.pageqlock); | ||||
1412 | uvm_pageactivate(uobjpage); | ||||
1413 | uvm_unlock_pageq()mtx_leave(&uvm.pageqlock); | ||||
1414 | |||||
1415 | if (uobjpage->pg_flags & PG_WANTED0x00000002) | ||||
1416 | wakeup(uobjpage); | ||||
1417 | atomic_clearbits_intx86_atomic_clearbits_u32(&uobjpage->pg_flags, | ||||
1418 | PG_BUSY0x00000001|PG_WANTED0x00000002); | ||||
1419 | UVM_PAGE_OWN(uobjpage, NULL); | ||||
1420 | } | ||||
1421 | |||||
1422 | /* unlock and fail ... */ | ||||
1423 | uvmfault_unlockall(ufi, amap, uobj); | ||||
1424 | if (anon == NULL((void *)0)) | ||||
1425 | counters_inc(uvmexp_counters, flt_noanon); | ||||
1426 | else { | ||||
1427 | anon->an_lock = NULL((void *)0); | ||||
1428 | anon->an_ref--; | ||||
1429 | uvm_anfree(anon)uvm_anfree_list((anon), ((void *)0)); | ||||
1430 | counters_inc(uvmexp_counters, flt_noram); | ||||
1431 | } | ||||
1432 | |||||
1433 | if (uvm_swapisfull()) | ||||
1434 | return (ENOMEM12); | ||||
1435 | |||||
1436 | /* out of RAM, wait for more */ | ||||
1437 | if (anon == NULL((void *)0)) | ||||
1438 | uvm_anwait(); | ||||
1439 | else | ||||
1440 | uvm_wait("flt_noram5"); | ||||
1441 | return ERESTART-1; | ||||
1442 | } | ||||
1443 | |||||
1444 | /* | ||||
1445 | * fill in the data | ||||
1446 | */ | ||||
1447 | if (uobjpage != PGO_DONTCARE((struct vm_page *) -1L)) { | ||||
1448 | counters_inc(uvmexp_counters, flt_prcopy); | ||||
1449 | /* copy page [pg now dirty] */ | ||||
1450 | uvm_pagecopy(uobjpage, pg); | ||||
1451 | |||||
1452 | /* | ||||
1453 | * promote to shared amap? make sure all sharing | ||||
1454 | * procs see it | ||||
1455 | */ | ||||
1456 | if ((amap_flags(amap)((amap)->am_flags) & AMAP_SHARED0x1) != 0) { | ||||
1457 | pmap_page_protect(uobjpage, PROT_NONE0x00); | ||||
1458 | } | ||||
1459 | #if defined(MULTIPROCESSOR1) && !defined(__HAVE_PMAP_MPSAFE_ENTER_COW) | ||||
1460 | /* | ||||
1461 | * Otherwise: | ||||
1462 | * If there are multiple threads, either uvm or the | ||||
1463 | * pmap has to make sure no threads see the old RO | ||||
1464 | * mapping once any have seen the new RW mapping. | ||||
1465 | * uvm does it here by forcing it to PROT_NONE before | ||||
1466 | * inserting the new mapping. | ||||
1467 | */ | ||||
1468 | else if (P_HASSIBLING(curproc)((({struct cpu_info *__ci; asm volatile("movq %%gs:%P1,%0" : "=r" (__ci) :"n" (__builtin_offsetof(struct cpu_info, ci_self))); __ci;})->ci_curproc)->p_p->ps_threadcnt > 1)) { | ||||
1469 | pmap_page_protect(uobjpage, PROT_NONE0x00); | ||||
1470 | } | ||||
1471 | #endif | ||||
1472 | |||||
1473 | /* dispose of uobjpage. drop handle to uobj as well. */ | ||||
1474 | if (uobjpage->pg_flags & PG_WANTED0x00000002) | ||||
1475 | wakeup(uobjpage); | ||||
1476 | atomic_clearbits_intx86_atomic_clearbits_u32(&uobjpage->pg_flags, | ||||
1477 | PG_BUSY0x00000001|PG_WANTED0x00000002); | ||||
1478 | UVM_PAGE_OWN(uobjpage, NULL); | ||||
1479 | uvm_lock_pageq()mtx_enter(&uvm.pageqlock); | ||||
1480 | uvm_pageactivate(uobjpage); | ||||
1481 | uvm_unlock_pageq()mtx_leave(&uvm.pageqlock); | ||||
1482 | rw_exit(uobj->vmobjlock); | ||||
1483 | uobj = NULL((void *)0); | ||||
1484 | } else { | ||||
1485 | counters_inc(uvmexp_counters, flt_przero); | ||||
1486 | /* | ||||
1487 | * Page is zero'd and marked dirty by uvm_pagealloc() | ||||
1488 | * above. | ||||
1489 | */ | ||||
1490 | } | ||||
1491 | |||||
1492 | if (amap_add(&ufi->entry->aref, | ||||
1493 | ufi->orig_rvaddr - ufi->entry->start, anon, 0)) { | ||||
1494 | uvmfault_unlockall(ufi, amap, uobj); | ||||
1495 | uvm_anfree(anon)uvm_anfree_list((anon), ((void *)0)); | ||||
1496 | counters_inc(uvmexp_counters, flt_noamap); | ||||
1497 | |||||
1498 | if (uvm_swapisfull()) | ||||
1499 | return (ENOMEM12); | ||||
1500 | |||||
1501 | amap_populate(&ufi->entry->aref, | ||||
1502 | ufi->orig_rvaddr - ufi->entry->start); | ||||
1503 | return ERESTART-1; | ||||
1504 | } | ||||
1505 | } | ||||
1506 | |||||
1507 | /* note: pg is either the uobjpage or the new page in the new anon */ | ||||
1508 | /* | ||||
1509 | * all resources are present. we can now map it in and free our | ||||
1510 | * resources. | ||||
1511 | */ | ||||
1512 | if (amap == NULL((void *)0)) | ||||
1513 | KASSERT(anon == NULL)((anon == ((void *)0)) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 1513, "anon == NULL")); | ||||
1514 | else { | ||||
1515 | KASSERT(rw_write_held(amap->am_lock))((rw_write_held(amap->am_lock)) ? (void)0 : __assert("diagnostic " , "/usr/src/sys/uvm/uvm_fault.c", 1515, "rw_write_held(amap->am_lock)" )); | ||||
1516 | KASSERT(anon == NULL || anon->an_lock == amap->am_lock)((anon == ((void *)0) || anon->an_lock == amap->am_lock ) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 1516, "anon == NULL || anon->an_lock == amap->am_lock" )); | ||||
1517 | } | ||||
1518 | if (pmap_enter(ufi->orig_map->pmap, ufi->orig_rvaddr, | ||||
1519 | VM_PAGE_TO_PHYS(pg)((pg)->phys_addr) | flt->pa_flags, flt->enter_prot, | ||||
1520 | flt->access_type | PMAP_CANFAIL0x00000020 | (flt->wired ? PMAP_WIRED0x00000010 : 0)) != 0) { | ||||
1521 | /* | ||||
1522 | * No need to undo what we did; we can simply think of | ||||
1523 | * this as the pmap throwing away the mapping information. | ||||
1524 | * | ||||
1525 | * We do, however, have to go through the ReFault path, | ||||
1526 | * as the map may change while we're asleep. | ||||
1527 | */ | ||||
1528 | if (pg->pg_flags & PG_WANTED0x00000002) | ||||
1529 | wakeup(pg); | ||||
1530 | |||||
1531 | atomic_clearbits_intx86_atomic_clearbits_u32(&pg->pg_flags, PG_BUSY0x00000001|PG_FAKE0x00000040|PG_WANTED0x00000002); | ||||
1532 | UVM_PAGE_OWN(pg, NULL); | ||||
1533 | uvmfault_unlockall(ufi, amap, uobj); | ||||
1534 | if (uvm_swapisfull()) { | ||||
1535 | /* XXX instrumentation */ | ||||
1536 | return (ENOMEM12); | ||||
1537 | } | ||||
1538 | /* XXX instrumentation */ | ||||
1539 | uvm_wait("flt_pmfail2"); | ||||
1540 | return ERESTART-1; | ||||
1541 | } | ||||
1542 | |||||
1543 | if (fault_type == VM_FAULT_WIRE((vm_fault_t) 0x2)) { | ||||
1544 | uvm_lock_pageq()mtx_enter(&uvm.pageqlock); | ||||
1545 | uvm_pagewire(pg); | ||||
1546 | uvm_unlock_pageq()mtx_leave(&uvm.pageqlock); | ||||
1547 | if (pg->pg_flags & PQ_AOBJ0x00200000) { | ||||
1548 | /* | ||||
1549 | * since the now-wired page cannot be paged out, | ||||
1550 | * release its swap resources for others to use. | ||||
1551 | * since an aobj page with no swap cannot be clean, | ||||
1552 | * mark it dirty now. | ||||
1553 | * | ||||
1554 | * use pg->uobject here. if the page is from a | ||||
1555 | * tmpfs vnode, the pages are backed by its UAO and | ||||
1556 | * not the vnode. | ||||
1557 | */ | ||||
1558 | KASSERT(uobj != NULL)((uobj != ((void *)0)) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 1558, "uobj != NULL")); | ||||
1559 | KASSERT(uobj->vmobjlock == pg->uobject->vmobjlock)((uobj->vmobjlock == pg->uobject->vmobjlock) ? (void )0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c", 1559 , "uobj->vmobjlock == pg->uobject->vmobjlock")); | ||||
1560 | atomic_clearbits_intx86_atomic_clearbits_u32(&pg->pg_flags, PG_CLEAN0x00000008); | ||||
1561 | uao_dropswap(uobj, pg->offset >> PAGE_SHIFT12); | ||||
1562 | } | ||||
1563 | } else { | ||||
1564 | /* activate it */ | ||||
1565 | uvm_lock_pageq()mtx_enter(&uvm.pageqlock); | ||||
1566 | uvm_pageactivate(pg); | ||||
1567 | uvm_unlock_pageq()mtx_leave(&uvm.pageqlock); | ||||
1568 | } | ||||
1569 | |||||
1570 | if (pg->pg_flags & PG_WANTED0x00000002) | ||||
1571 | wakeup(pg); | ||||
1572 | |||||
1573 | atomic_clearbits_intx86_atomic_clearbits_u32(&pg->pg_flags, PG_BUSY0x00000001|PG_FAKE0x00000040|PG_WANTED0x00000002); | ||||
1574 | UVM_PAGE_OWN(pg, NULL); | ||||
1575 | uvmfault_unlockall(ufi, amap, uobj); | ||||
1576 | pmap_update(ufi->orig_map->pmap); | ||||
1577 | |||||
1578 | return (0); | ||||
1579 | } | ||||
1580 | |||||
1581 | |||||
1582 | /* | ||||
1583 | * uvm_fault_wire: wire down a range of virtual addresses in a map. | ||||
1584 | * | ||||
1585 | * => map may be read-locked by caller, but MUST NOT be write-locked. | ||||
1586 | * => if map is read-locked, any operations which may cause map to | ||||
1587 | * be write-locked in uvm_fault() must be taken care of by | ||||
1588 | * the caller. See uvm_map_pageable(). | ||||
1589 | */ | ||||
1590 | int | ||||
1591 | uvm_fault_wire(vm_map_t map, vaddr_t start, vaddr_t end, vm_prot_t access_type) | ||||
1592 | { | ||||
1593 | vaddr_t va; | ||||
1594 | int rv; | ||||
1595 | |||||
1596 | /* | ||||
1597 | * now fault it in a page at a time. if the fault fails then we have | ||||
1598 | * to undo what we have done. note that in uvm_fault PROT_NONE | ||||
1599 | * is replaced with the max protection if fault_type is VM_FAULT_WIRE. | ||||
1600 | */ | ||||
1601 | for (va = start ; va < end ; va += PAGE_SIZE(1 << 12)) { | ||||
| |||||
1602 | rv = uvm_fault(map, va, VM_FAULT_WIRE((vm_fault_t) 0x2), access_type); | ||||
1603 | if (rv) { | ||||
1604 | if (va != start) { | ||||
1605 | uvm_fault_unwire(map, start, va); | ||||
1606 | } | ||||
1607 | return (rv); | ||||
1608 | } | ||||
1609 | } | ||||
1610 | |||||
1611 | return (0); | ||||
1612 | } | ||||
1613 | |||||
1614 | /* | ||||
1615 | * uvm_fault_unwire(): unwire range of virtual space. | ||||
1616 | */ | ||||
1617 | void | ||||
1618 | uvm_fault_unwire(vm_map_t map, vaddr_t start, vaddr_t end) | ||||
1619 | { | ||||
1620 | |||||
1621 | vm_map_lock_read(map)vm_map_lock_read_ln(map, "/usr/src/sys/uvm/uvm_fault.c", 1621 ); | ||||
1622 | uvm_fault_unwire_locked(map, start, end); | ||||
1623 | vm_map_unlock_read(map)vm_map_unlock_read_ln(map, "/usr/src/sys/uvm/uvm_fault.c", 1623 ); | ||||
1624 | } | ||||
1625 | |||||
1626 | /* | ||||
1627 | * uvm_fault_unwire_locked(): the guts of uvm_fault_unwire(). | ||||
1628 | * | ||||
1629 | * => map must be at least read-locked. | ||||
1630 | */ | ||||
1631 | void | ||||
1632 | uvm_fault_unwire_locked(vm_map_t map, vaddr_t start, vaddr_t end) | ||||
1633 | { | ||||
1634 | vm_map_entry_t entry, oentry = NULL((void *)0), next; | ||||
1635 | pmap_t pmap = vm_map_pmap(map)((map)->pmap); | ||||
1636 | vaddr_t va; | ||||
1637 | paddr_t pa; | ||||
1638 | struct vm_page *pg; | ||||
1639 | |||||
1640 | KASSERT((map->flags & VM_MAP_INTRSAFE) == 0)(((map->flags & 0x02) == 0) ? (void)0 : __assert("diagnostic " , "/usr/src/sys/uvm/uvm_fault.c", 1640, "(map->flags & VM_MAP_INTRSAFE) == 0" )); | ||||
1641 | vm_map_assert_anylock(map)vm_map_assert_anylock_ln(map, "/usr/src/sys/uvm/uvm_fault.c", 1641); | ||||
1642 | |||||
1643 | /* | ||||
1644 | * we assume that the area we are unwiring has actually been wired | ||||
1645 | * in the first place. this means that we should be able to extract | ||||
1646 | * the PAs from the pmap. | ||||
1647 | */ | ||||
1648 | |||||
1649 | /* | ||||
1650 | * find the beginning map entry for the region. | ||||
1651 | */ | ||||
1652 | KASSERT(start >= vm_map_min(map) && end <= vm_map_max(map))((start >= ((map)->min_offset) && end <= ((map )->max_offset)) ? (void)0 : __assert("diagnostic ", "/usr/src/sys/uvm/uvm_fault.c" , 1652, "start >= vm_map_min(map) && end <= vm_map_max(map)" )); | ||||
1653 | if (uvm_map_lookup_entry(map, start, &entry) == FALSE0) | ||||
1654 | panic("uvm_fault_unwire_locked: address not in map"); | ||||
1655 | |||||
1656 | for (va = start; va < end ; va += PAGE_SIZE(1 << 12)) { | ||||
1657 | if (pmap_extract(pmap, va, &pa) == FALSE0) | ||||
1658 | continue; | ||||
1659 | |||||
1660 | /* | ||||
1661 | * find the map entry for the current address. | ||||
1662 | */ | ||||
1663 | KASSERT(va >= entry->start)((va >= entry->start) ? (void)0 : __assert("diagnostic " , "/usr/src/sys/uvm/uvm_fault.c", 1663, "va >= entry->start" )); | ||||
1664 | while (entry && va >= entry->end) { | ||||
1665 | next = RBT_NEXT(uvm_map_addr, entry)uvm_map_addr_RBT_NEXT(entry); | ||||
1666 | entry = next; | ||||
1667 | } | ||||
1668 | |||||
1669 | if (entry == NULL((void *)0)) | ||||
1670 | return; | ||||
1671 | if (va < entry->start) | ||||
1672 | continue; | ||||
1673 | |||||
1674 | /* | ||||
1675 | * lock it. | ||||
1676 | */ | ||||
1677 | if (entry != oentry) { | ||||
1678 | if (oentry != NULL((void *)0)) { | ||||
1679 | uvm_map_unlock_entry(oentry); | ||||
1680 | } | ||||
1681 | uvm_map_lock_entry(entry); | ||||
1682 | oentry = entry; | ||||
1683 | } | ||||
1684 | |||||
1685 | /* | ||||
1686 | * if the entry is no longer wired, tell the pmap. | ||||
1687 | */ | ||||
1688 | if (VM_MAPENT_ISWIRED(entry)((entry)->wired_count != 0) == 0) | ||||
1689 | pmap_unwire(pmap, va); | ||||
1690 | |||||
1691 | pg = PHYS_TO_VM_PAGE(pa); | ||||
1692 | if (pg) { | ||||
1693 | uvm_lock_pageq()mtx_enter(&uvm.pageqlock); | ||||
1694 | uvm_pageunwire(pg); | ||||
1695 | uvm_unlock_pageq()mtx_leave(&uvm.pageqlock); | ||||
1696 | } | ||||
1697 | } | ||||
1698 | |||||
1699 | if (oentry != NULL((void *)0)) { | ||||
1700 | uvm_map_unlock_entry(oentry); | ||||
1701 | } | ||||
1702 | } | ||||
1703 | |||||
1704 | /* | ||||
1705 | * uvmfault_unlockmaps: unlock the maps | ||||
1706 | */ | ||||
1707 | void | ||||
1708 | uvmfault_unlockmaps(struct uvm_faultinfo *ufi, boolean_t write_locked) | ||||
1709 | { | ||||
1710 | /* | ||||
1711 | * ufi can be NULL when this isn't really a fault, | ||||
1712 | * but merely paging in anon data. | ||||
1713 | */ | ||||
1714 | if (ufi == NULL((void *)0)) { | ||||
1715 | return; | ||||
1716 | } | ||||
1717 | |||||
1718 | uvmfault_update_stats(ufi); | ||||
1719 | if (write_locked) { | ||||
1720 | vm_map_unlock(ufi->map)vm_map_unlock_ln(ufi->map, "/usr/src/sys/uvm/uvm_fault.c", 1720); | ||||
1721 | } else { | ||||
1722 | vm_map_unlock_read(ufi->map)vm_map_unlock_read_ln(ufi->map, "/usr/src/sys/uvm/uvm_fault.c" , 1722); | ||||
1723 | } | ||||
1724 | } | ||||
1725 | |||||
1726 | /* | ||||
1727 | * uvmfault_unlockall: unlock everything passed in. | ||||
1728 | * | ||||
1729 | * => maps must be read-locked (not write-locked). | ||||
1730 | */ | ||||
1731 | void | ||||
1732 | uvmfault_unlockall(struct uvm_faultinfo *ufi, struct vm_amap *amap, | ||||
1733 | struct uvm_object *uobj) | ||||
1734 | { | ||||
1735 | if (uobj) | ||||
1736 | rw_exit(uobj->vmobjlock); | ||||
1737 | if (amap != NULL((void *)0)) | ||||
1738 | amap_unlock(amap)rw_exit_write((amap)->am_lock); | ||||
1739 | uvmfault_unlockmaps(ufi, FALSE0); | ||||
1740 | } | ||||
1741 | |||||
1742 | /* | ||||
1743 | * uvmfault_lookup: lookup a virtual address in a map | ||||
1744 | * | ||||
1745 | * => caller must provide a uvm_faultinfo structure with the IN | ||||
1746 | * params properly filled in | ||||
1747 | * => we will lookup the map entry (handling submaps) as we go | ||||
1748 | * => if the lookup is a success we will return with the maps locked | ||||
1749 | * => if "write_lock" is TRUE, we write_lock the map, otherwise we only | ||||
1750 | * get a read lock. | ||||
1751 | * => note that submaps can only appear in the kernel and they are | ||||
1752 | * required to use the same virtual addresses as the map they | ||||
1753 | * are referenced by (thus address translation between the main | ||||
1754 | * map and the submap is unnecessary). | ||||
1755 | */ | ||||
1756 | |||||
1757 | boolean_t | ||||
1758 | uvmfault_lookup(struct uvm_faultinfo *ufi, boolean_t write_lock) | ||||
1759 | { | ||||
1760 | vm_map_t tmpmap; | ||||
1761 | |||||
1762 | /* | ||||
1763 | * init ufi values for lookup. | ||||
1764 | */ | ||||
1765 | ufi->map = ufi->orig_map; | ||||
1766 | ufi->size = ufi->orig_size; | ||||
1767 | |||||
1768 | /* | ||||
1769 | * keep going down levels until we are done. note that there can | ||||
1770 | * only be two levels so we won't loop very long. | ||||
1771 | */ | ||||
1772 | while (1) { | ||||
1773 | if (ufi->orig_rvaddr < ufi->map->min_offset || | ||||
1774 | ufi->orig_rvaddr >= ufi->map->max_offset) | ||||
1775 | return FALSE0; | ||||
1776 | |||||
1777 | /* lock map */ | ||||
1778 | if (write_lock) { | ||||
1779 | vm_map_lock(ufi->map)vm_map_lock_ln(ufi->map, "/usr/src/sys/uvm/uvm_fault.c", 1779 ); | ||||
1780 | } else { | ||||
1781 | vm_map_lock_read(ufi->map)vm_map_lock_read_ln(ufi->map, "/usr/src/sys/uvm/uvm_fault.c" , 1781); | ||||
1782 | } | ||||
1783 | |||||
1784 | /* lookup */ | ||||
1785 | if (!uvm_map_lookup_entry(ufi->map, ufi->orig_rvaddr, | ||||
1786 | &ufi->entry)) { | ||||
1787 | uvmfault_unlockmaps(ufi, write_lock); | ||||
1788 | return FALSE0; | ||||
1789 | } | ||||
1790 | |||||
1791 | /* reduce size if necessary */ | ||||
1792 | if (ufi->entry->end - ufi->orig_rvaddr < ufi->size) | ||||
1793 | ufi->size = ufi->entry->end - ufi->orig_rvaddr; | ||||
1794 | |||||
1795 | /* | ||||
1796 | * submap? replace map with the submap and lookup again. | ||||
1797 | * note: VAs in submaps must match VAs in main map. | ||||
1798 | */ | ||||
1799 | if (UVM_ET_ISSUBMAP(ufi->entry)(((ufi->entry)->etype & 0x0002) != 0)) { | ||||
1800 | tmpmap = ufi->entry->object.sub_map; | ||||
1801 | uvmfault_unlockmaps(ufi, write_lock); | ||||
1802 | ufi->map = tmpmap; | ||||
1803 | continue; | ||||
1804 | } | ||||
1805 | |||||
1806 | /* | ||||
1807 | * got it! | ||||
1808 | */ | ||||
1809 | ufi->mapv = ufi->map->timestamp; | ||||
1810 | return TRUE1; | ||||
1811 | |||||
1812 | } /* while loop */ | ||||
1813 | |||||
1814 | /*NOTREACHED*/ | ||||
1815 | } | ||||
1816 | |||||
1817 | /* | ||||
1818 | * uvmfault_relock: attempt to relock the same version of the map | ||||
1819 | * | ||||
1820 | * => fault data structures should be unlocked before calling. | ||||
1821 | * => if a success (TRUE) maps will be locked after call. | ||||
1822 | */ | ||||
1823 | boolean_t | ||||
1824 | uvmfault_relock(struct uvm_faultinfo *ufi) | ||||
1825 | { | ||||
1826 | /* | ||||
1827 | * ufi can be NULL when this isn't really a fault, | ||||
1828 | * but merely paging in anon data. | ||||
1829 | */ | ||||
1830 | if (ufi == NULL((void *)0)) { | ||||
1831 | return TRUE1; | ||||
1832 | } | ||||
1833 | |||||
1834 | counters_inc(uvmexp_counters, flt_relck); | ||||
1835 | |||||
1836 | /* | ||||
1837 | * relock map. fail if version mismatch (in which case nothing | ||||
1838 | * gets locked). | ||||
1839 | */ | ||||
1840 | vm_map_lock_read(ufi->map)vm_map_lock_read_ln(ufi->map, "/usr/src/sys/uvm/uvm_fault.c" , 1840); | ||||
1841 | if (ufi->mapv != ufi->map->timestamp) { | ||||
1842 | vm_map_unlock_read(ufi->map)vm_map_unlock_read_ln(ufi->map, "/usr/src/sys/uvm/uvm_fault.c" , 1842); | ||||
1843 | return FALSE0; | ||||
1844 | } | ||||
1845 | |||||
1846 | counters_inc(uvmexp_counters, flt_relckok); | ||||
1847 | return TRUE1; /* got it! */ | ||||
1848 | } |