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9c92ab61 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
0c972a05 TK |
2 | /* binder_alloc.c |
3 | * | |
4 | * Android IPC Subsystem | |
5 | * | |
6 | * Copyright (C) 2007-2017 Google, Inc. | |
0c972a05 TK |
7 | */ |
8 | ||
9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
10 | ||
0c972a05 TK |
11 | #include <linux/list.h> |
12 | #include <linux/sched/mm.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/rtmutex.h> | |
15 | #include <linux/rbtree.h> | |
16 | #include <linux/seq_file.h> | |
17 | #include <linux/vmalloc.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/sched.h> | |
f2517eb7 | 20 | #include <linux/list_lru.h> |
128f3804 | 21 | #include <linux/ratelimit.h> |
1e81c57b | 22 | #include <asm/cacheflush.h> |
1a7c3d9b TK |
23 | #include <linux/uaccess.h> |
24 | #include <linux/highmem.h> | |
45d02f79 | 25 | #include <linux/sizes.h> |
0c972a05 TK |
26 | #include "binder_alloc.h" |
27 | #include "binder_trace.h" | |
28 | ||
f2517eb7 SY |
29 | struct list_lru binder_alloc_lru; |
30 | ||
0c972a05 TK |
31 | static DEFINE_MUTEX(binder_alloc_mmap_lock); |
32 | ||
33 | enum { | |
128f3804 | 34 | BINDER_DEBUG_USER_ERROR = 1U << 0, |
0c972a05 TK |
35 | BINDER_DEBUG_OPEN_CLOSE = 1U << 1, |
36 | BINDER_DEBUG_BUFFER_ALLOC = 1U << 2, | |
37 | BINDER_DEBUG_BUFFER_ALLOC_ASYNC = 1U << 3, | |
38 | }; | |
128f3804 | 39 | static uint32_t binder_alloc_debug_mask = BINDER_DEBUG_USER_ERROR; |
0c972a05 TK |
40 | |
41 | module_param_named(debug_mask, binder_alloc_debug_mask, | |
42 | uint, 0644); | |
43 | ||
44 | #define binder_alloc_debug(mask, x...) \ | |
45 | do { \ | |
46 | if (binder_alloc_debug_mask & mask) \ | |
128f3804 | 47 | pr_info_ratelimited(x); \ |
0c972a05 TK |
48 | } while (0) |
49 | ||
e2176219 SY |
50 | static struct binder_buffer *binder_buffer_next(struct binder_buffer *buffer) |
51 | { | |
52 | return list_entry(buffer->entry.next, struct binder_buffer, entry); | |
53 | } | |
54 | ||
55 | static struct binder_buffer *binder_buffer_prev(struct binder_buffer *buffer) | |
56 | { | |
57 | return list_entry(buffer->entry.prev, struct binder_buffer, entry); | |
58 | } | |
59 | ||
0c972a05 TK |
60 | static size_t binder_alloc_buffer_size(struct binder_alloc *alloc, |
61 | struct binder_buffer *buffer) | |
62 | { | |
63 | if (list_is_last(&buffer->entry, &alloc->buffers)) | |
bde4a19f TK |
64 | return alloc->buffer + alloc->buffer_size - buffer->user_data; |
65 | return binder_buffer_next(buffer)->user_data - buffer->user_data; | |
0c972a05 TK |
66 | } |
67 | ||
68 | static void binder_insert_free_buffer(struct binder_alloc *alloc, | |
69 | struct binder_buffer *new_buffer) | |
70 | { | |
71 | struct rb_node **p = &alloc->free_buffers.rb_node; | |
72 | struct rb_node *parent = NULL; | |
73 | struct binder_buffer *buffer; | |
74 | size_t buffer_size; | |
75 | size_t new_buffer_size; | |
76 | ||
77 | BUG_ON(!new_buffer->free); | |
78 | ||
79 | new_buffer_size = binder_alloc_buffer_size(alloc, new_buffer); | |
80 | ||
81 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, | |
82 | "%d: add free buffer, size %zd, at %pK\n", | |
83 | alloc->pid, new_buffer_size, new_buffer); | |
84 | ||
85 | while (*p) { | |
86 | parent = *p; | |
87 | buffer = rb_entry(parent, struct binder_buffer, rb_node); | |
88 | BUG_ON(!buffer->free); | |
89 | ||
90 | buffer_size = binder_alloc_buffer_size(alloc, buffer); | |
91 | ||
92 | if (new_buffer_size < buffer_size) | |
93 | p = &parent->rb_left; | |
94 | else | |
95 | p = &parent->rb_right; | |
96 | } | |
97 | rb_link_node(&new_buffer->rb_node, parent, p); | |
98 | rb_insert_color(&new_buffer->rb_node, &alloc->free_buffers); | |
99 | } | |
100 | ||
101 | static void binder_insert_allocated_buffer_locked( | |
102 | struct binder_alloc *alloc, struct binder_buffer *new_buffer) | |
103 | { | |
104 | struct rb_node **p = &alloc->allocated_buffers.rb_node; | |
105 | struct rb_node *parent = NULL; | |
106 | struct binder_buffer *buffer; | |
107 | ||
108 | BUG_ON(new_buffer->free); | |
109 | ||
110 | while (*p) { | |
111 | parent = *p; | |
112 | buffer = rb_entry(parent, struct binder_buffer, rb_node); | |
113 | BUG_ON(buffer->free); | |
114 | ||
bde4a19f | 115 | if (new_buffer->user_data < buffer->user_data) |
0c972a05 | 116 | p = &parent->rb_left; |
bde4a19f | 117 | else if (new_buffer->user_data > buffer->user_data) |
0c972a05 TK |
118 | p = &parent->rb_right; |
119 | else | |
120 | BUG(); | |
121 | } | |
122 | rb_link_node(&new_buffer->rb_node, parent, p); | |
123 | rb_insert_color(&new_buffer->rb_node, &alloc->allocated_buffers); | |
124 | } | |
125 | ||
53d311cf | 126 | static struct binder_buffer *binder_alloc_prepare_to_free_locked( |
0c972a05 TK |
127 | struct binder_alloc *alloc, |
128 | uintptr_t user_ptr) | |
129 | { | |
130 | struct rb_node *n = alloc->allocated_buffers.rb_node; | |
131 | struct binder_buffer *buffer; | |
bde4a19f | 132 | void __user *uptr; |
0c972a05 | 133 | |
bde4a19f | 134 | uptr = (void __user *)user_ptr; |
0c972a05 TK |
135 | |
136 | while (n) { | |
137 | buffer = rb_entry(n, struct binder_buffer, rb_node); | |
138 | BUG_ON(buffer->free); | |
139 | ||
bde4a19f | 140 | if (uptr < buffer->user_data) |
0c972a05 | 141 | n = n->rb_left; |
bde4a19f | 142 | else if (uptr > buffer->user_data) |
0c972a05 | 143 | n = n->rb_right; |
53d311cf TK |
144 | else { |
145 | /* | |
146 | * Guard against user threads attempting to | |
7bada55a TK |
147 | * free the buffer when in use by kernel or |
148 | * after it's already been freed. | |
53d311cf | 149 | */ |
7bada55a TK |
150 | if (!buffer->allow_user_free) |
151 | return ERR_PTR(-EPERM); | |
152 | buffer->allow_user_free = 0; | |
0c972a05 | 153 | return buffer; |
53d311cf | 154 | } |
0c972a05 TK |
155 | } |
156 | return NULL; | |
157 | } | |
158 | ||
159 | /** | |
5dc54a06 | 160 | * binder_alloc_prepare_to_free() - get buffer given user ptr |
0c972a05 TK |
161 | * @alloc: binder_alloc for this proc |
162 | * @user_ptr: User pointer to buffer data | |
163 | * | |
164 | * Validate userspace pointer to buffer data and return buffer corresponding to | |
165 | * that user pointer. Search the rb tree for buffer that matches user data | |
166 | * pointer. | |
167 | * | |
168 | * Return: Pointer to buffer or NULL | |
169 | */ | |
53d311cf TK |
170 | struct binder_buffer *binder_alloc_prepare_to_free(struct binder_alloc *alloc, |
171 | uintptr_t user_ptr) | |
0c972a05 TK |
172 | { |
173 | struct binder_buffer *buffer; | |
174 | ||
175 | mutex_lock(&alloc->mutex); | |
53d311cf | 176 | buffer = binder_alloc_prepare_to_free_locked(alloc, user_ptr); |
0c972a05 TK |
177 | mutex_unlock(&alloc->mutex); |
178 | return buffer; | |
179 | } | |
180 | ||
181 | static int binder_update_page_range(struct binder_alloc *alloc, int allocate, | |
bde4a19f | 182 | void __user *start, void __user *end) |
0c972a05 | 183 | { |
bde4a19f | 184 | void __user *page_addr; |
0c972a05 | 185 | unsigned long user_page_addr; |
f2517eb7 | 186 | struct binder_lru_page *page; |
6ae33b9c | 187 | struct vm_area_struct *vma = NULL; |
f2517eb7 SY |
188 | struct mm_struct *mm = NULL; |
189 | bool need_mm = false; | |
0c972a05 TK |
190 | |
191 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, | |
192 | "%d: %s pages %pK-%pK\n", alloc->pid, | |
193 | allocate ? "allocate" : "free", start, end); | |
194 | ||
195 | if (end <= start) | |
196 | return 0; | |
197 | ||
198 | trace_binder_update_page_range(alloc, allocate, start, end); | |
199 | ||
f2517eb7 SY |
200 | if (allocate == 0) |
201 | goto free_range; | |
202 | ||
203 | for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) { | |
204 | page = &alloc->pages[(page_addr - alloc->buffer) / PAGE_SIZE]; | |
205 | if (!page->page_ptr) { | |
206 | need_mm = true; | |
207 | break; | |
208 | } | |
209 | } | |
210 | ||
6fbf248a | 211 | if (need_mm && mmget_not_zero(alloc->vma_vm_mm)) |
a0c2baaf | 212 | mm = alloc->vma_vm_mm; |
0c972a05 TK |
213 | |
214 | if (mm) { | |
720c2419 | 215 | down_read(&mm->mmap_sem); |
0c972a05 | 216 | vma = alloc->vma; |
0c972a05 TK |
217 | } |
218 | ||
f2517eb7 | 219 | if (!vma && need_mm) { |
128f3804 SY |
220 | binder_alloc_debug(BINDER_DEBUG_USER_ERROR, |
221 | "%d: binder_alloc_buf failed to map pages in userspace, no vma\n", | |
222 | alloc->pid); | |
0c972a05 TK |
223 | goto err_no_vma; |
224 | } | |
225 | ||
226 | for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) { | |
227 | int ret; | |
f2517eb7 | 228 | bool on_lru; |
e41e164c | 229 | size_t index; |
0c972a05 | 230 | |
e41e164c SY |
231 | index = (page_addr - alloc->buffer) / PAGE_SIZE; |
232 | page = &alloc->pages[index]; | |
0c972a05 | 233 | |
f2517eb7 | 234 | if (page->page_ptr) { |
e41e164c SY |
235 | trace_binder_alloc_lru_start(alloc, index); |
236 | ||
f2517eb7 SY |
237 | on_lru = list_lru_del(&binder_alloc_lru, &page->lru); |
238 | WARN_ON(!on_lru); | |
e41e164c SY |
239 | |
240 | trace_binder_alloc_lru_end(alloc, index); | |
f2517eb7 SY |
241 | continue; |
242 | } | |
243 | ||
244 | if (WARN_ON(!vma)) | |
245 | goto err_page_ptr_cleared; | |
246 | ||
e41e164c | 247 | trace_binder_alloc_page_start(alloc, index); |
f2517eb7 SY |
248 | page->page_ptr = alloc_page(GFP_KERNEL | |
249 | __GFP_HIGHMEM | | |
250 | __GFP_ZERO); | |
251 | if (!page->page_ptr) { | |
0c972a05 TK |
252 | pr_err("%d: binder_alloc_buf failed for page at %pK\n", |
253 | alloc->pid, page_addr); | |
254 | goto err_alloc_page_failed; | |
255 | } | |
f2517eb7 SY |
256 | page->alloc = alloc; |
257 | INIT_LIST_HEAD(&page->lru); | |
258 | ||
c41358a5 | 259 | user_page_addr = (uintptr_t)page_addr; |
f2517eb7 | 260 | ret = vm_insert_page(vma, user_page_addr, page[0].page_ptr); |
0c972a05 TK |
261 | if (ret) { |
262 | pr_err("%d: binder_alloc_buf failed to map page at %lx in userspace\n", | |
263 | alloc->pid, user_page_addr); | |
264 | goto err_vm_insert_page_failed; | |
265 | } | |
e41e164c | 266 | |
8d9a3ab6 MC |
267 | if (index + 1 > alloc->pages_high) |
268 | alloc->pages_high = index + 1; | |
269 | ||
e41e164c | 270 | trace_binder_alloc_page_end(alloc, index); |
0c972a05 TK |
271 | /* vm_insert_page does not seem to increment the refcount */ |
272 | } | |
273 | if (mm) { | |
720c2419 | 274 | up_read(&mm->mmap_sem); |
0c972a05 TK |
275 | mmput(mm); |
276 | } | |
277 | return 0; | |
278 | ||
279 | free_range: | |
280 | for (page_addr = end - PAGE_SIZE; page_addr >= start; | |
281 | page_addr -= PAGE_SIZE) { | |
f2517eb7 | 282 | bool ret; |
e41e164c | 283 | size_t index; |
f2517eb7 | 284 | |
e41e164c SY |
285 | index = (page_addr - alloc->buffer) / PAGE_SIZE; |
286 | page = &alloc->pages[index]; | |
287 | ||
288 | trace_binder_free_lru_start(alloc, index); | |
f2517eb7 SY |
289 | |
290 | ret = list_lru_add(&binder_alloc_lru, &page->lru); | |
291 | WARN_ON(!ret); | |
e41e164c SY |
292 | |
293 | trace_binder_free_lru_end(alloc, index); | |
f2517eb7 SY |
294 | continue; |
295 | ||
0c972a05 | 296 | err_vm_insert_page_failed: |
f2517eb7 SY |
297 | __free_page(page->page_ptr); |
298 | page->page_ptr = NULL; | |
0c972a05 | 299 | err_alloc_page_failed: |
f2517eb7 | 300 | err_page_ptr_cleared: |
0c972a05 TK |
301 | ; |
302 | } | |
303 | err_no_vma: | |
304 | if (mm) { | |
720c2419 | 305 | up_read(&mm->mmap_sem); |
0c972a05 TK |
306 | mmput(mm); |
307 | } | |
57ada2fb | 308 | return vma ? -ENOMEM : -ESRCH; |
0c972a05 TK |
309 | } |
310 | ||
da1b9564 MK |
311 | |
312 | static inline void binder_alloc_set_vma(struct binder_alloc *alloc, | |
313 | struct vm_area_struct *vma) | |
314 | { | |
315 | if (vma) | |
316 | alloc->vma_vm_mm = vma->vm_mm; | |
317 | /* | |
318 | * If we see alloc->vma is not NULL, buffer data structures set up | |
319 | * completely. Look at smp_rmb side binder_alloc_get_vma. | |
320 | * We also want to guarantee new alloc->vma_vm_mm is always visible | |
321 | * if alloc->vma is set. | |
322 | */ | |
323 | smp_wmb(); | |
324 | alloc->vma = vma; | |
325 | } | |
326 | ||
327 | static inline struct vm_area_struct *binder_alloc_get_vma( | |
328 | struct binder_alloc *alloc) | |
329 | { | |
330 | struct vm_area_struct *vma = NULL; | |
331 | ||
332 | if (alloc->vma) { | |
333 | /* Look at description in binder_alloc_set_vma */ | |
334 | smp_rmb(); | |
335 | vma = alloc->vma; | |
336 | } | |
337 | return vma; | |
338 | } | |
339 | ||
3f827245 XS |
340 | static struct binder_buffer *binder_alloc_new_buf_locked( |
341 | struct binder_alloc *alloc, | |
342 | size_t data_size, | |
343 | size_t offsets_size, | |
344 | size_t extra_buffers_size, | |
345 | int is_async) | |
0c972a05 TK |
346 | { |
347 | struct rb_node *n = alloc->free_buffers.rb_node; | |
348 | struct binder_buffer *buffer; | |
349 | size_t buffer_size; | |
350 | struct rb_node *best_fit = NULL; | |
bde4a19f TK |
351 | void __user *has_page_addr; |
352 | void __user *end_page_addr; | |
0c972a05 | 353 | size_t size, data_offsets_size; |
57ada2fb | 354 | int ret; |
0c972a05 | 355 | |
da1b9564 | 356 | if (!binder_alloc_get_vma(alloc)) { |
128f3804 SY |
357 | binder_alloc_debug(BINDER_DEBUG_USER_ERROR, |
358 | "%d: binder_alloc_buf, no vma\n", | |
359 | alloc->pid); | |
57ada2fb | 360 | return ERR_PTR(-ESRCH); |
0c972a05 TK |
361 | } |
362 | ||
363 | data_offsets_size = ALIGN(data_size, sizeof(void *)) + | |
364 | ALIGN(offsets_size, sizeof(void *)); | |
365 | ||
366 | if (data_offsets_size < data_size || data_offsets_size < offsets_size) { | |
367 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, | |
368 | "%d: got transaction with invalid size %zd-%zd\n", | |
369 | alloc->pid, data_size, offsets_size); | |
57ada2fb | 370 | return ERR_PTR(-EINVAL); |
0c972a05 TK |
371 | } |
372 | size = data_offsets_size + ALIGN(extra_buffers_size, sizeof(void *)); | |
373 | if (size < data_offsets_size || size < extra_buffers_size) { | |
374 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, | |
375 | "%d: got transaction with invalid extra_buffers_size %zd\n", | |
376 | alloc->pid, extra_buffers_size); | |
57ada2fb | 377 | return ERR_PTR(-EINVAL); |
0c972a05 TK |
378 | } |
379 | if (is_async && | |
380 | alloc->free_async_space < size + sizeof(struct binder_buffer)) { | |
381 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, | |
382 | "%d: binder_alloc_buf size %zd failed, no async space left\n", | |
383 | alloc->pid, size); | |
57ada2fb | 384 | return ERR_PTR(-ENOSPC); |
0c972a05 TK |
385 | } |
386 | ||
74310e06 SY |
387 | /* Pad 0-size buffers so they get assigned unique addresses */ |
388 | size = max(size, sizeof(void *)); | |
389 | ||
0c972a05 TK |
390 | while (n) { |
391 | buffer = rb_entry(n, struct binder_buffer, rb_node); | |
392 | BUG_ON(!buffer->free); | |
393 | buffer_size = binder_alloc_buffer_size(alloc, buffer); | |
394 | ||
395 | if (size < buffer_size) { | |
396 | best_fit = n; | |
397 | n = n->rb_left; | |
398 | } else if (size > buffer_size) | |
399 | n = n->rb_right; | |
400 | else { | |
401 | best_fit = n; | |
402 | break; | |
403 | } | |
404 | } | |
405 | if (best_fit == NULL) { | |
b05a68e9 MC |
406 | size_t allocated_buffers = 0; |
407 | size_t largest_alloc_size = 0; | |
408 | size_t total_alloc_size = 0; | |
409 | size_t free_buffers = 0; | |
410 | size_t largest_free_size = 0; | |
411 | size_t total_free_size = 0; | |
412 | ||
413 | for (n = rb_first(&alloc->allocated_buffers); n != NULL; | |
414 | n = rb_next(n)) { | |
415 | buffer = rb_entry(n, struct binder_buffer, rb_node); | |
416 | buffer_size = binder_alloc_buffer_size(alloc, buffer); | |
417 | allocated_buffers++; | |
418 | total_alloc_size += buffer_size; | |
419 | if (buffer_size > largest_alloc_size) | |
420 | largest_alloc_size = buffer_size; | |
421 | } | |
422 | for (n = rb_first(&alloc->free_buffers); n != NULL; | |
423 | n = rb_next(n)) { | |
424 | buffer = rb_entry(n, struct binder_buffer, rb_node); | |
425 | buffer_size = binder_alloc_buffer_size(alloc, buffer); | |
426 | free_buffers++; | |
427 | total_free_size += buffer_size; | |
428 | if (buffer_size > largest_free_size) | |
429 | largest_free_size = buffer_size; | |
430 | } | |
128f3804 SY |
431 | binder_alloc_debug(BINDER_DEBUG_USER_ERROR, |
432 | "%d: binder_alloc_buf size %zd failed, no address space\n", | |
433 | alloc->pid, size); | |
434 | binder_alloc_debug(BINDER_DEBUG_USER_ERROR, | |
435 | "allocated: %zd (num: %zd largest: %zd), free: %zd (num: %zd largest: %zd)\n", | |
436 | total_alloc_size, allocated_buffers, | |
437 | largest_alloc_size, total_free_size, | |
438 | free_buffers, largest_free_size); | |
57ada2fb | 439 | return ERR_PTR(-ENOSPC); |
0c972a05 TK |
440 | } |
441 | if (n == NULL) { | |
442 | buffer = rb_entry(best_fit, struct binder_buffer, rb_node); | |
443 | buffer_size = binder_alloc_buffer_size(alloc, buffer); | |
444 | } | |
445 | ||
446 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, | |
447 | "%d: binder_alloc_buf size %zd got buffer %pK size %zd\n", | |
448 | alloc->pid, size, buffer, buffer_size); | |
449 | ||
bde4a19f TK |
450 | has_page_addr = (void __user *) |
451 | (((uintptr_t)buffer->user_data + buffer_size) & PAGE_MASK); | |
74310e06 | 452 | WARN_ON(n && buffer_size != size); |
0c972a05 | 453 | end_page_addr = |
bde4a19f | 454 | (void __user *)PAGE_ALIGN((uintptr_t)buffer->user_data + size); |
0c972a05 TK |
455 | if (end_page_addr > has_page_addr) |
456 | end_page_addr = has_page_addr; | |
bde4a19f TK |
457 | ret = binder_update_page_range(alloc, 1, (void __user *) |
458 | PAGE_ALIGN((uintptr_t)buffer->user_data), end_page_addr); | |
57ada2fb TK |
459 | if (ret) |
460 | return ERR_PTR(ret); | |
0c972a05 | 461 | |
0c972a05 | 462 | if (buffer_size != size) { |
74310e06 | 463 | struct binder_buffer *new_buffer; |
0c972a05 | 464 | |
74310e06 SY |
465 | new_buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); |
466 | if (!new_buffer) { | |
467 | pr_err("%s: %d failed to alloc new buffer struct\n", | |
468 | __func__, alloc->pid); | |
469 | goto err_alloc_buf_struct_failed; | |
470 | } | |
bde4a19f | 471 | new_buffer->user_data = (u8 __user *)buffer->user_data + size; |
0c972a05 TK |
472 | list_add(&new_buffer->entry, &buffer->entry); |
473 | new_buffer->free = 1; | |
474 | binder_insert_free_buffer(alloc, new_buffer); | |
475 | } | |
74310e06 SY |
476 | |
477 | rb_erase(best_fit, &alloc->free_buffers); | |
478 | buffer->free = 0; | |
7bada55a | 479 | buffer->allow_user_free = 0; |
74310e06 | 480 | binder_insert_allocated_buffer_locked(alloc, buffer); |
0c972a05 TK |
481 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, |
482 | "%d: binder_alloc_buf size %zd got %pK\n", | |
483 | alloc->pid, size, buffer); | |
484 | buffer->data_size = data_size; | |
485 | buffer->offsets_size = offsets_size; | |
486 | buffer->async_transaction = is_async; | |
487 | buffer->extra_buffers_size = extra_buffers_size; | |
488 | if (is_async) { | |
489 | alloc->free_async_space -= size + sizeof(struct binder_buffer); | |
490 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC, | |
491 | "%d: binder_alloc_buf size %zd async free %zd\n", | |
492 | alloc->pid, size, alloc->free_async_space); | |
493 | } | |
494 | return buffer; | |
74310e06 SY |
495 | |
496 | err_alloc_buf_struct_failed: | |
bde4a19f TK |
497 | binder_update_page_range(alloc, 0, (void __user *) |
498 | PAGE_ALIGN((uintptr_t)buffer->user_data), | |
6ae33b9c | 499 | end_page_addr); |
74310e06 | 500 | return ERR_PTR(-ENOMEM); |
0c972a05 TK |
501 | } |
502 | ||
503 | /** | |
504 | * binder_alloc_new_buf() - Allocate a new binder buffer | |
505 | * @alloc: binder_alloc for this proc | |
506 | * @data_size: size of user data buffer | |
507 | * @offsets_size: user specified buffer offset | |
508 | * @extra_buffers_size: size of extra space for meta-data (eg, security context) | |
509 | * @is_async: buffer for async transaction | |
510 | * | |
511 | * Allocate a new buffer given the requested sizes. Returns | |
512 | * the kernel version of the buffer pointer. The size allocated | |
513 | * is the sum of the three given sizes (each rounded up to | |
514 | * pointer-sized boundary) | |
515 | * | |
516 | * Return: The allocated buffer or %NULL if error | |
517 | */ | |
518 | struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc, | |
519 | size_t data_size, | |
520 | size_t offsets_size, | |
521 | size_t extra_buffers_size, | |
522 | int is_async) | |
523 | { | |
524 | struct binder_buffer *buffer; | |
525 | ||
526 | mutex_lock(&alloc->mutex); | |
527 | buffer = binder_alloc_new_buf_locked(alloc, data_size, offsets_size, | |
528 | extra_buffers_size, is_async); | |
529 | mutex_unlock(&alloc->mutex); | |
530 | return buffer; | |
531 | } | |
532 | ||
bde4a19f | 533 | static void __user *buffer_start_page(struct binder_buffer *buffer) |
0c972a05 | 534 | { |
bde4a19f | 535 | return (void __user *)((uintptr_t)buffer->user_data & PAGE_MASK); |
0c972a05 TK |
536 | } |
537 | ||
bde4a19f | 538 | static void __user *prev_buffer_end_page(struct binder_buffer *buffer) |
0c972a05 | 539 | { |
bde4a19f TK |
540 | return (void __user *) |
541 | (((uintptr_t)(buffer->user_data) - 1) & PAGE_MASK); | |
0c972a05 TK |
542 | } |
543 | ||
544 | static void binder_delete_free_buffer(struct binder_alloc *alloc, | |
545 | struct binder_buffer *buffer) | |
546 | { | |
547 | struct binder_buffer *prev, *next = NULL; | |
74310e06 | 548 | bool to_free = true; |
0c972a05 | 549 | BUG_ON(alloc->buffers.next == &buffer->entry); |
e2176219 | 550 | prev = binder_buffer_prev(buffer); |
0c972a05 | 551 | BUG_ON(!prev->free); |
74310e06 SY |
552 | if (prev_buffer_end_page(prev) == buffer_start_page(buffer)) { |
553 | to_free = false; | |
0c972a05 | 554 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, |
74310e06 | 555 | "%d: merge free, buffer %pK share page with %pK\n", |
bde4a19f TK |
556 | alloc->pid, buffer->user_data, |
557 | prev->user_data); | |
0c972a05 TK |
558 | } |
559 | ||
560 | if (!list_is_last(&buffer->entry, &alloc->buffers)) { | |
e2176219 | 561 | next = binder_buffer_next(buffer); |
74310e06 SY |
562 | if (buffer_start_page(next) == buffer_start_page(buffer)) { |
563 | to_free = false; | |
0c972a05 | 564 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, |
74310e06 SY |
565 | "%d: merge free, buffer %pK share page with %pK\n", |
566 | alloc->pid, | |
bde4a19f TK |
567 | buffer->user_data, |
568 | next->user_data); | |
0c972a05 TK |
569 | } |
570 | } | |
74310e06 | 571 | |
bde4a19f | 572 | if (PAGE_ALIGNED(buffer->user_data)) { |
74310e06 SY |
573 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, |
574 | "%d: merge free, buffer start %pK is page aligned\n", | |
bde4a19f | 575 | alloc->pid, buffer->user_data); |
74310e06 SY |
576 | to_free = false; |
577 | } | |
578 | ||
579 | if (to_free) { | |
0c972a05 | 580 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, |
74310e06 | 581 | "%d: merge free, buffer %pK do not share page with %pK or %pK\n", |
bde4a19f TK |
582 | alloc->pid, buffer->user_data, |
583 | prev->user_data, | |
584 | next ? next->user_data : NULL); | |
74310e06 | 585 | binder_update_page_range(alloc, 0, buffer_start_page(buffer), |
6ae33b9c | 586 | buffer_start_page(buffer) + PAGE_SIZE); |
0c972a05 | 587 | } |
74310e06 SY |
588 | list_del(&buffer->entry); |
589 | kfree(buffer); | |
0c972a05 TK |
590 | } |
591 | ||
592 | static void binder_free_buf_locked(struct binder_alloc *alloc, | |
593 | struct binder_buffer *buffer) | |
594 | { | |
595 | size_t size, buffer_size; | |
596 | ||
597 | buffer_size = binder_alloc_buffer_size(alloc, buffer); | |
598 | ||
599 | size = ALIGN(buffer->data_size, sizeof(void *)) + | |
600 | ALIGN(buffer->offsets_size, sizeof(void *)) + | |
601 | ALIGN(buffer->extra_buffers_size, sizeof(void *)); | |
602 | ||
603 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, | |
604 | "%d: binder_free_buf %pK size %zd buffer_size %zd\n", | |
605 | alloc->pid, buffer, size, buffer_size); | |
606 | ||
607 | BUG_ON(buffer->free); | |
608 | BUG_ON(size > buffer_size); | |
609 | BUG_ON(buffer->transaction != NULL); | |
bde4a19f TK |
610 | BUG_ON(buffer->user_data < alloc->buffer); |
611 | BUG_ON(buffer->user_data > alloc->buffer + alloc->buffer_size); | |
0c972a05 TK |
612 | |
613 | if (buffer->async_transaction) { | |
614 | alloc->free_async_space += size + sizeof(struct binder_buffer); | |
615 | ||
616 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC, | |
617 | "%d: binder_free_buf size %zd async free %zd\n", | |
618 | alloc->pid, size, alloc->free_async_space); | |
619 | } | |
620 | ||
621 | binder_update_page_range(alloc, 0, | |
bde4a19f TK |
622 | (void __user *)PAGE_ALIGN((uintptr_t)buffer->user_data), |
623 | (void __user *)(((uintptr_t) | |
624 | buffer->user_data + buffer_size) & PAGE_MASK)); | |
0c972a05 TK |
625 | |
626 | rb_erase(&buffer->rb_node, &alloc->allocated_buffers); | |
627 | buffer->free = 1; | |
628 | if (!list_is_last(&buffer->entry, &alloc->buffers)) { | |
e2176219 | 629 | struct binder_buffer *next = binder_buffer_next(buffer); |
0c972a05 TK |
630 | |
631 | if (next->free) { | |
632 | rb_erase(&next->rb_node, &alloc->free_buffers); | |
633 | binder_delete_free_buffer(alloc, next); | |
634 | } | |
635 | } | |
636 | if (alloc->buffers.next != &buffer->entry) { | |
e2176219 | 637 | struct binder_buffer *prev = binder_buffer_prev(buffer); |
0c972a05 TK |
638 | |
639 | if (prev->free) { | |
640 | binder_delete_free_buffer(alloc, buffer); | |
641 | rb_erase(&prev->rb_node, &alloc->free_buffers); | |
642 | buffer = prev; | |
643 | } | |
644 | } | |
645 | binder_insert_free_buffer(alloc, buffer); | |
646 | } | |
647 | ||
648 | /** | |
649 | * binder_alloc_free_buf() - free a binder buffer | |
650 | * @alloc: binder_alloc for this proc | |
651 | * @buffer: kernel pointer to buffer | |
652 | * | |
653 | * Free the buffer allocated via binder_alloc_new_buffer() | |
654 | */ | |
655 | void binder_alloc_free_buf(struct binder_alloc *alloc, | |
656 | struct binder_buffer *buffer) | |
657 | { | |
658 | mutex_lock(&alloc->mutex); | |
659 | binder_free_buf_locked(alloc, buffer); | |
660 | mutex_unlock(&alloc->mutex); | |
661 | } | |
662 | ||
663 | /** | |
664 | * binder_alloc_mmap_handler() - map virtual address space for proc | |
665 | * @alloc: alloc structure for this proc | |
666 | * @vma: vma passed to mmap() | |
667 | * | |
668 | * Called by binder_mmap() to initialize the space specified in | |
669 | * vma for allocating binder buffers | |
670 | * | |
671 | * Return: | |
672 | * 0 = success | |
673 | * -EBUSY = address space already mapped | |
674 | * -ENOMEM = failed to map memory to given address space | |
675 | */ | |
676 | int binder_alloc_mmap_handler(struct binder_alloc *alloc, | |
677 | struct vm_area_struct *vma) | |
678 | { | |
679 | int ret; | |
0c972a05 TK |
680 | const char *failure_string; |
681 | struct binder_buffer *buffer; | |
682 | ||
683 | mutex_lock(&binder_alloc_mmap_lock); | |
684 | if (alloc->buffer) { | |
685 | ret = -EBUSY; | |
686 | failure_string = "already mapped"; | |
687 | goto err_already_mapped; | |
688 | } | |
689 | ||
bde4a19f | 690 | alloc->buffer = (void __user *)vma->vm_start; |
0c972a05 TK |
691 | mutex_unlock(&binder_alloc_mmap_lock); |
692 | ||
45d02f79 JH |
693 | alloc->buffer_size = min_t(unsigned long, vma->vm_end - vma->vm_start, |
694 | SZ_4M); | |
695 | alloc->pages = kcalloc(alloc->buffer_size / PAGE_SIZE, | |
6396bb22 | 696 | sizeof(alloc->pages[0]), |
0c972a05 TK |
697 | GFP_KERNEL); |
698 | if (alloc->pages == NULL) { | |
699 | ret = -ENOMEM; | |
700 | failure_string = "alloc page array"; | |
701 | goto err_alloc_pages_failed; | |
702 | } | |
0c972a05 | 703 | |
74310e06 SY |
704 | buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); |
705 | if (!buffer) { | |
0c972a05 | 706 | ret = -ENOMEM; |
74310e06 SY |
707 | failure_string = "alloc buffer struct"; |
708 | goto err_alloc_buf_struct_failed; | |
0c972a05 | 709 | } |
74310e06 | 710 | |
bde4a19f | 711 | buffer->user_data = alloc->buffer; |
0c972a05 TK |
712 | list_add(&buffer->entry, &alloc->buffers); |
713 | buffer->free = 1; | |
714 | binder_insert_free_buffer(alloc, buffer); | |
715 | alloc->free_async_space = alloc->buffer_size / 2; | |
da1b9564 | 716 | binder_alloc_set_vma(alloc, vma); |
a0c2baaf | 717 | mmgrab(alloc->vma_vm_mm); |
0c972a05 TK |
718 | |
719 | return 0; | |
720 | ||
74310e06 | 721 | err_alloc_buf_struct_failed: |
0c972a05 TK |
722 | kfree(alloc->pages); |
723 | alloc->pages = NULL; | |
724 | err_alloc_pages_failed: | |
725 | mutex_lock(&binder_alloc_mmap_lock); | |
0c972a05 | 726 | alloc->buffer = NULL; |
0c972a05 TK |
727 | err_already_mapped: |
728 | mutex_unlock(&binder_alloc_mmap_lock); | |
128f3804 SY |
729 | binder_alloc_debug(BINDER_DEBUG_USER_ERROR, |
730 | "%s: %d %lx-%lx %s failed %d\n", __func__, | |
731 | alloc->pid, vma->vm_start, vma->vm_end, | |
732 | failure_string, ret); | |
0c972a05 TK |
733 | return ret; |
734 | } | |
735 | ||
736 | ||
737 | void binder_alloc_deferred_release(struct binder_alloc *alloc) | |
738 | { | |
739 | struct rb_node *n; | |
740 | int buffers, page_count; | |
74310e06 | 741 | struct binder_buffer *buffer; |
0c972a05 | 742 | |
0c972a05 TK |
743 | buffers = 0; |
744 | mutex_lock(&alloc->mutex); | |
da1b9564 MK |
745 | BUG_ON(alloc->vma); |
746 | ||
0c972a05 | 747 | while ((n = rb_first(&alloc->allocated_buffers))) { |
0c972a05 TK |
748 | buffer = rb_entry(n, struct binder_buffer, rb_node); |
749 | ||
750 | /* Transaction should already have been freed */ | |
751 | BUG_ON(buffer->transaction); | |
752 | ||
753 | binder_free_buf_locked(alloc, buffer); | |
754 | buffers++; | |
755 | } | |
756 | ||
74310e06 SY |
757 | while (!list_empty(&alloc->buffers)) { |
758 | buffer = list_first_entry(&alloc->buffers, | |
759 | struct binder_buffer, entry); | |
760 | WARN_ON(!buffer->free); | |
761 | ||
762 | list_del(&buffer->entry); | |
763 | WARN_ON_ONCE(!list_empty(&alloc->buffers)); | |
764 | kfree(buffer); | |
765 | } | |
766 | ||
0c972a05 TK |
767 | page_count = 0; |
768 | if (alloc->pages) { | |
769 | int i; | |
770 | ||
771 | for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) { | |
bde4a19f | 772 | void __user *page_addr; |
f2517eb7 | 773 | bool on_lru; |
0c972a05 | 774 | |
f2517eb7 | 775 | if (!alloc->pages[i].page_ptr) |
0c972a05 TK |
776 | continue; |
777 | ||
f2517eb7 SY |
778 | on_lru = list_lru_del(&binder_alloc_lru, |
779 | &alloc->pages[i].lru); | |
0c972a05 TK |
780 | page_addr = alloc->buffer + i * PAGE_SIZE; |
781 | binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC, | |
f2517eb7 SY |
782 | "%s: %d: page %d at %pK %s\n", |
783 | __func__, alloc->pid, i, page_addr, | |
784 | on_lru ? "on lru" : "active"); | |
f2517eb7 | 785 | __free_page(alloc->pages[i].page_ptr); |
0c972a05 TK |
786 | page_count++; |
787 | } | |
788 | kfree(alloc->pages); | |
0c972a05 TK |
789 | } |
790 | mutex_unlock(&alloc->mutex); | |
a0c2baaf SY |
791 | if (alloc->vma_vm_mm) |
792 | mmdrop(alloc->vma_vm_mm); | |
0c972a05 TK |
793 | |
794 | binder_alloc_debug(BINDER_DEBUG_OPEN_CLOSE, | |
795 | "%s: %d buffers %d, pages %d\n", | |
796 | __func__, alloc->pid, buffers, page_count); | |
797 | } | |
798 | ||
799 | static void print_binder_buffer(struct seq_file *m, const char *prefix, | |
800 | struct binder_buffer *buffer) | |
801 | { | |
b05a68e9 | 802 | seq_printf(m, "%s %d: %pK size %zd:%zd:%zd %s\n", |
bde4a19f | 803 | prefix, buffer->debug_id, buffer->user_data, |
0c972a05 | 804 | buffer->data_size, buffer->offsets_size, |
b05a68e9 | 805 | buffer->extra_buffers_size, |
0c972a05 TK |
806 | buffer->transaction ? "active" : "delivered"); |
807 | } | |
808 | ||
809 | /** | |
810 | * binder_alloc_print_allocated() - print buffer info | |
811 | * @m: seq_file for output via seq_printf() | |
812 | * @alloc: binder_alloc for this proc | |
813 | * | |
814 | * Prints information about every buffer associated with | |
815 | * the binder_alloc state to the given seq_file | |
816 | */ | |
817 | void binder_alloc_print_allocated(struct seq_file *m, | |
818 | struct binder_alloc *alloc) | |
819 | { | |
820 | struct rb_node *n; | |
821 | ||
822 | mutex_lock(&alloc->mutex); | |
823 | for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n)) | |
824 | print_binder_buffer(m, " buffer", | |
825 | rb_entry(n, struct binder_buffer, rb_node)); | |
826 | mutex_unlock(&alloc->mutex); | |
827 | } | |
828 | ||
8ef4665a SY |
829 | /** |
830 | * binder_alloc_print_pages() - print page usage | |
831 | * @m: seq_file for output via seq_printf() | |
832 | * @alloc: binder_alloc for this proc | |
833 | */ | |
834 | void binder_alloc_print_pages(struct seq_file *m, | |
835 | struct binder_alloc *alloc) | |
836 | { | |
837 | struct binder_lru_page *page; | |
838 | int i; | |
839 | int active = 0; | |
840 | int lru = 0; | |
841 | int free = 0; | |
842 | ||
843 | mutex_lock(&alloc->mutex); | |
844 | for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) { | |
845 | page = &alloc->pages[i]; | |
846 | if (!page->page_ptr) | |
847 | free++; | |
848 | else if (list_empty(&page->lru)) | |
849 | active++; | |
850 | else | |
851 | lru++; | |
852 | } | |
853 | mutex_unlock(&alloc->mutex); | |
854 | seq_printf(m, " pages: %d:%d:%d\n", active, lru, free); | |
8d9a3ab6 | 855 | seq_printf(m, " pages high watermark: %zu\n", alloc->pages_high); |
8ef4665a SY |
856 | } |
857 | ||
0c972a05 TK |
858 | /** |
859 | * binder_alloc_get_allocated_count() - return count of buffers | |
860 | * @alloc: binder_alloc for this proc | |
861 | * | |
862 | * Return: count of allocated buffers | |
863 | */ | |
864 | int binder_alloc_get_allocated_count(struct binder_alloc *alloc) | |
865 | { | |
866 | struct rb_node *n; | |
867 | int count = 0; | |
868 | ||
869 | mutex_lock(&alloc->mutex); | |
870 | for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n)) | |
871 | count++; | |
872 | mutex_unlock(&alloc->mutex); | |
873 | return count; | |
874 | } | |
875 | ||
876 | ||
877 | /** | |
878 | * binder_alloc_vma_close() - invalidate address space | |
879 | * @alloc: binder_alloc for this proc | |
880 | * | |
881 | * Called from binder_vma_close() when releasing address space. | |
882 | * Clears alloc->vma to prevent new incoming transactions from | |
883 | * allocating more buffers. | |
884 | */ | |
885 | void binder_alloc_vma_close(struct binder_alloc *alloc) | |
886 | { | |
da1b9564 | 887 | binder_alloc_set_vma(alloc, NULL); |
0c972a05 TK |
888 | } |
889 | ||
f2517eb7 SY |
890 | /** |
891 | * binder_alloc_free_page() - shrinker callback to free pages | |
892 | * @item: item to free | |
893 | * @lock: lock protecting the item | |
894 | * @cb_arg: callback argument | |
895 | * | |
896 | * Called from list_lru_walk() in binder_shrink_scan() to free | |
897 | * up pages when the system is under memory pressure. | |
898 | */ | |
899 | enum lru_status binder_alloc_free_page(struct list_head *item, | |
900 | struct list_lru_one *lru, | |
901 | spinlock_t *lock, | |
902 | void *cb_arg) | |
324fa64c | 903 | __must_hold(lock) |
f2517eb7 SY |
904 | { |
905 | struct mm_struct *mm = NULL; | |
906 | struct binder_lru_page *page = container_of(item, | |
907 | struct binder_lru_page, | |
908 | lru); | |
909 | struct binder_alloc *alloc; | |
910 | uintptr_t page_addr; | |
911 | size_t index; | |
a1b2289c | 912 | struct vm_area_struct *vma; |
f2517eb7 SY |
913 | |
914 | alloc = page->alloc; | |
915 | if (!mutex_trylock(&alloc->mutex)) | |
916 | goto err_get_alloc_mutex_failed; | |
917 | ||
918 | if (!page->page_ptr) | |
919 | goto err_page_already_freed; | |
920 | ||
921 | index = page - alloc->pages; | |
922 | page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE; | |
5cec2d2e TK |
923 | |
924 | mm = alloc->vma_vm_mm; | |
925 | if (!mmget_not_zero(mm)) | |
926 | goto err_mmget; | |
60d48857 TH |
927 | if (!down_read_trylock(&mm->mmap_sem)) |
928 | goto err_down_read_mmap_sem_failed; | |
da1b9564 | 929 | vma = binder_alloc_get_vma(alloc); |
a1b2289c SY |
930 | |
931 | list_lru_isolate(lru, item); | |
932 | spin_unlock(lock); | |
f2517eb7 | 933 | |
a1b2289c | 934 | if (vma) { |
e41e164c SY |
935 | trace_binder_unmap_user_start(alloc, index); |
936 | ||
c41358a5 | 937 | zap_page_range(vma, page_addr, PAGE_SIZE); |
f2517eb7 | 938 | |
e41e164c | 939 | trace_binder_unmap_user_end(alloc, index); |
f2517eb7 | 940 | } |
60d48857 | 941 | up_read(&mm->mmap_sem); |
5cec2d2e | 942 | mmput(mm); |
f2517eb7 | 943 | |
e41e164c SY |
944 | trace_binder_unmap_kernel_start(alloc, index); |
945 | ||
f2517eb7 SY |
946 | __free_page(page->page_ptr); |
947 | page->page_ptr = NULL; | |
948 | ||
e41e164c SY |
949 | trace_binder_unmap_kernel_end(alloc, index); |
950 | ||
a1b2289c | 951 | spin_lock(lock); |
f2517eb7 | 952 | mutex_unlock(&alloc->mutex); |
a1b2289c | 953 | return LRU_REMOVED_RETRY; |
f2517eb7 | 954 | |
60d48857 | 955 | err_down_read_mmap_sem_failed: |
a1b2289c | 956 | mmput_async(mm); |
a0c2baaf | 957 | err_mmget: |
f2517eb7 SY |
958 | err_page_already_freed: |
959 | mutex_unlock(&alloc->mutex); | |
960 | err_get_alloc_mutex_failed: | |
961 | return LRU_SKIP; | |
962 | } | |
963 | ||
964 | static unsigned long | |
965 | binder_shrink_count(struct shrinker *shrink, struct shrink_control *sc) | |
966 | { | |
967 | unsigned long ret = list_lru_count(&binder_alloc_lru); | |
968 | return ret; | |
969 | } | |
970 | ||
971 | static unsigned long | |
972 | binder_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) | |
973 | { | |
974 | unsigned long ret; | |
975 | ||
976 | ret = list_lru_walk(&binder_alloc_lru, binder_alloc_free_page, | |
977 | NULL, sc->nr_to_scan); | |
978 | return ret; | |
979 | } | |
980 | ||
de7bbe3d | 981 | static struct shrinker binder_shrinker = { |
f2517eb7 SY |
982 | .count_objects = binder_shrink_count, |
983 | .scan_objects = binder_shrink_scan, | |
984 | .seeks = DEFAULT_SEEKS, | |
985 | }; | |
986 | ||
0c972a05 TK |
987 | /** |
988 | * binder_alloc_init() - called by binder_open() for per-proc initialization | |
989 | * @alloc: binder_alloc for this proc | |
990 | * | |
991 | * Called from binder_open() to initialize binder_alloc fields for | |
992 | * new binder proc | |
993 | */ | |
994 | void binder_alloc_init(struct binder_alloc *alloc) | |
995 | { | |
0c972a05 TK |
996 | alloc->pid = current->group_leader->pid; |
997 | mutex_init(&alloc->mutex); | |
957ccc2b | 998 | INIT_LIST_HEAD(&alloc->buffers); |
0c972a05 TK |
999 | } |
1000 | ||
533dfb25 | 1001 | int binder_alloc_shrinker_init(void) |
f2517eb7 | 1002 | { |
533dfb25 TH |
1003 | int ret = list_lru_init(&binder_alloc_lru); |
1004 | ||
1005 | if (ret == 0) { | |
1006 | ret = register_shrinker(&binder_shrinker); | |
1007 | if (ret) | |
1008 | list_lru_destroy(&binder_alloc_lru); | |
1009 | } | |
1010 | return ret; | |
f2517eb7 | 1011 | } |
1a7c3d9b TK |
1012 | |
1013 | /** | |
1014 | * check_buffer() - verify that buffer/offset is safe to access | |
1015 | * @alloc: binder_alloc for this proc | |
1016 | * @buffer: binder buffer to be accessed | |
1017 | * @offset: offset into @buffer data | |
1018 | * @bytes: bytes to access from offset | |
1019 | * | |
1020 | * Check that the @offset/@bytes are within the size of the given | |
1021 | * @buffer and that the buffer is currently active and not freeable. | |
1022 | * Offsets must also be multiples of sizeof(u32). The kernel is | |
1023 | * allowed to touch the buffer in two cases: | |
1024 | * | |
1025 | * 1) when the buffer is being created: | |
1026 | * (buffer->free == 0 && buffer->allow_user_free == 0) | |
1027 | * 2) when the buffer is being torn down: | |
1028 | * (buffer->free == 0 && buffer->transaction == NULL). | |
1029 | * | |
1030 | * Return: true if the buffer is safe to access | |
1031 | */ | |
1032 | static inline bool check_buffer(struct binder_alloc *alloc, | |
1033 | struct binder_buffer *buffer, | |
1034 | binder_size_t offset, size_t bytes) | |
1035 | { | |
1036 | size_t buffer_size = binder_alloc_buffer_size(alloc, buffer); | |
1037 | ||
1038 | return buffer_size >= bytes && | |
1039 | offset <= buffer_size - bytes && | |
1040 | IS_ALIGNED(offset, sizeof(u32)) && | |
1041 | !buffer->free && | |
1042 | (!buffer->allow_user_free || !buffer->transaction); | |
1043 | } | |
1044 | ||
1045 | /** | |
1046 | * binder_alloc_get_page() - get kernel pointer for given buffer offset | |
1047 | * @alloc: binder_alloc for this proc | |
1048 | * @buffer: binder buffer to be accessed | |
1049 | * @buffer_offset: offset into @buffer data | |
1050 | * @pgoffp: address to copy final page offset to | |
1051 | * | |
1052 | * Lookup the struct page corresponding to the address | |
bde4a19f | 1053 | * at @buffer_offset into @buffer->user_data. If @pgoffp is not |
1a7c3d9b TK |
1054 | * NULL, the byte-offset into the page is written there. |
1055 | * | |
1056 | * The caller is responsible to ensure that the offset points | |
1057 | * to a valid address within the @buffer and that @buffer is | |
1058 | * not freeable by the user. Since it can't be freed, we are | |
1059 | * guaranteed that the corresponding elements of @alloc->pages[] | |
1060 | * cannot change. | |
1061 | * | |
1062 | * Return: struct page | |
1063 | */ | |
1064 | static struct page *binder_alloc_get_page(struct binder_alloc *alloc, | |
1065 | struct binder_buffer *buffer, | |
1066 | binder_size_t buffer_offset, | |
1067 | pgoff_t *pgoffp) | |
1068 | { | |
1069 | binder_size_t buffer_space_offset = buffer_offset + | |
bde4a19f | 1070 | (buffer->user_data - alloc->buffer); |
1a7c3d9b TK |
1071 | pgoff_t pgoff = buffer_space_offset & ~PAGE_MASK; |
1072 | size_t index = buffer_space_offset >> PAGE_SHIFT; | |
1073 | struct binder_lru_page *lru_page; | |
1074 | ||
1075 | lru_page = &alloc->pages[index]; | |
1076 | *pgoffp = pgoff; | |
1077 | return lru_page->page_ptr; | |
1078 | } | |
1079 | ||
1080 | /** | |
1081 | * binder_alloc_copy_user_to_buffer() - copy src user to tgt user | |
1082 | * @alloc: binder_alloc for this proc | |
1083 | * @buffer: binder buffer to be accessed | |
1084 | * @buffer_offset: offset into @buffer data | |
1085 | * @from: userspace pointer to source buffer | |
1086 | * @bytes: bytes to copy | |
1087 | * | |
1088 | * Copy bytes from source userspace to target buffer. | |
1089 | * | |
1090 | * Return: bytes remaining to be copied | |
1091 | */ | |
1092 | unsigned long | |
1093 | binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc, | |
1094 | struct binder_buffer *buffer, | |
1095 | binder_size_t buffer_offset, | |
1096 | const void __user *from, | |
1097 | size_t bytes) | |
1098 | { | |
1099 | if (!check_buffer(alloc, buffer, buffer_offset, bytes)) | |
1100 | return bytes; | |
1101 | ||
1102 | while (bytes) { | |
1103 | unsigned long size; | |
1104 | unsigned long ret; | |
1105 | struct page *page; | |
1106 | pgoff_t pgoff; | |
1107 | void *kptr; | |
1108 | ||
1109 | page = binder_alloc_get_page(alloc, buffer, | |
1110 | buffer_offset, &pgoff); | |
1111 | size = min_t(size_t, bytes, PAGE_SIZE - pgoff); | |
1112 | kptr = kmap(page) + pgoff; | |
1113 | ret = copy_from_user(kptr, from, size); | |
1114 | kunmap(page); | |
1115 | if (ret) | |
1116 | return bytes - size + ret; | |
1117 | bytes -= size; | |
1118 | from += size; | |
1119 | buffer_offset += size; | |
1120 | } | |
1121 | return 0; | |
1122 | } | |
8ced0c62 | 1123 | |
bb4a2e48 TK |
1124 | static int binder_alloc_do_buffer_copy(struct binder_alloc *alloc, |
1125 | bool to_buffer, | |
1126 | struct binder_buffer *buffer, | |
1127 | binder_size_t buffer_offset, | |
1128 | void *ptr, | |
1129 | size_t bytes) | |
8ced0c62 TK |
1130 | { |
1131 | /* All copies must be 32-bit aligned and 32-bit size */ | |
bb4a2e48 TK |
1132 | if (!check_buffer(alloc, buffer, buffer_offset, bytes)) |
1133 | return -EINVAL; | |
8ced0c62 TK |
1134 | |
1135 | while (bytes) { | |
1136 | unsigned long size; | |
1137 | struct page *page; | |
1138 | pgoff_t pgoff; | |
1139 | void *tmpptr; | |
1140 | void *base_ptr; | |
1141 | ||
1142 | page = binder_alloc_get_page(alloc, buffer, | |
1143 | buffer_offset, &pgoff); | |
1144 | size = min_t(size_t, bytes, PAGE_SIZE - pgoff); | |
1145 | base_ptr = kmap_atomic(page); | |
1146 | tmpptr = base_ptr + pgoff; | |
1147 | if (to_buffer) | |
1148 | memcpy(tmpptr, ptr, size); | |
1149 | else | |
1150 | memcpy(ptr, tmpptr, size); | |
1151 | /* | |
1152 | * kunmap_atomic() takes care of flushing the cache | |
1153 | * if this device has VIVT cache arch | |
1154 | */ | |
1155 | kunmap_atomic(base_ptr); | |
1156 | bytes -= size; | |
1157 | pgoff = 0; | |
1158 | ptr = ptr + size; | |
1159 | buffer_offset += size; | |
1160 | } | |
bb4a2e48 | 1161 | return 0; |
8ced0c62 TK |
1162 | } |
1163 | ||
bb4a2e48 TK |
1164 | int binder_alloc_copy_to_buffer(struct binder_alloc *alloc, |
1165 | struct binder_buffer *buffer, | |
1166 | binder_size_t buffer_offset, | |
1167 | void *src, | |
1168 | size_t bytes) | |
8ced0c62 | 1169 | { |
bb4a2e48 TK |
1170 | return binder_alloc_do_buffer_copy(alloc, true, buffer, buffer_offset, |
1171 | src, bytes); | |
8ced0c62 TK |
1172 | } |
1173 | ||
bb4a2e48 TK |
1174 | int binder_alloc_copy_from_buffer(struct binder_alloc *alloc, |
1175 | void *dest, | |
1176 | struct binder_buffer *buffer, | |
1177 | binder_size_t buffer_offset, | |
1178 | size_t bytes) | |
8ced0c62 | 1179 | { |
bb4a2e48 TK |
1180 | return binder_alloc_do_buffer_copy(alloc, false, buffer, buffer_offset, |
1181 | dest, bytes); | |
8ced0c62 TK |
1182 | } |
1183 |