blob: 3cfad638db638001593fde4eb233740c4adec37c [file] [log] [blame]
Thomas Gleixner9c92ab62019-05-29 07:17:56 -07001// SPDX-License-Identifier: GPL-2.0-only
Todd Kjos0c972a02017-06-29 12:01:41 -07002/* binder_alloc.c
3 *
4 * Android IPC Subsystem
5 *
6 * Copyright (C) 2007-2017 Google, Inc.
Todd Kjos0c972a02017-06-29 12:01:41 -07007 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
Todd Kjos0c972a02017-06-29 12:01:41 -070011#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>
Sherry Yangf2517eb2017-08-23 08:46:42 -070020#include <linux/list_lru.h>
Sherry Yang128f3802018-08-07 12:57:13 -070021#include <linux/ratelimit.h>
Guenter Roeck1e81c572018-07-23 14:47:23 -070022#include <asm/cacheflush.h>
Todd Kjos1a7c3d92019-02-08 10:35:14 -080023#include <linux/uaccess.h>
24#include <linux/highmem.h>
Jann Horn45d02f72019-10-16 17:01:18 +020025#include <linux/sizes.h>
Todd Kjos0c972a02017-06-29 12:01:41 -070026#include "binder_alloc.h"
27#include "binder_trace.h"
28
Sherry Yangf2517eb2017-08-23 08:46:42 -070029struct list_lru binder_alloc_lru;
30
Todd Kjos0c972a02017-06-29 12:01:41 -070031static DEFINE_MUTEX(binder_alloc_mmap_lock);
32
33enum {
Sherry Yang128f3802018-08-07 12:57:13 -070034 BINDER_DEBUG_USER_ERROR = 1U << 0,
Todd Kjos0c972a02017-06-29 12:01:41 -070035 BINDER_DEBUG_OPEN_CLOSE = 1U << 1,
36 BINDER_DEBUG_BUFFER_ALLOC = 1U << 2,
37 BINDER_DEBUG_BUFFER_ALLOC_ASYNC = 1U << 3,
38};
Sherry Yang128f3802018-08-07 12:57:13 -070039static uint32_t binder_alloc_debug_mask = BINDER_DEBUG_USER_ERROR;
Todd Kjos0c972a02017-06-29 12:01:41 -070040
41module_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) \
Sherry Yang128f3802018-08-07 12:57:13 -070047 pr_info_ratelimited(x); \
Todd Kjos0c972a02017-06-29 12:01:41 -070048 } while (0)
49
Sherry Yange21762192017-08-23 08:46:39 -070050static struct binder_buffer *binder_buffer_next(struct binder_buffer *buffer)
51{
52 return list_entry(buffer->entry.next, struct binder_buffer, entry);
53}
54
55static struct binder_buffer *binder_buffer_prev(struct binder_buffer *buffer)
56{
57 return list_entry(buffer->entry.prev, struct binder_buffer, entry);
58}
59
Todd Kjos0c972a02017-06-29 12:01:41 -070060static 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))
Todd Kjosbde4a192019-02-08 10:35:20 -080064 return alloc->buffer + alloc->buffer_size - buffer->user_data;
65 return binder_buffer_next(buffer)->user_data - buffer->user_data;
Todd Kjos0c972a02017-06-29 12:01:41 -070066}
67
68static 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
101static 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
Todd Kjosbde4a192019-02-08 10:35:20 -0800115 if (new_buffer->user_data < buffer->user_data)
Todd Kjos0c972a02017-06-29 12:01:41 -0700116 p = &parent->rb_left;
Todd Kjosbde4a192019-02-08 10:35:20 -0800117 else if (new_buffer->user_data > buffer->user_data)
Todd Kjos0c972a02017-06-29 12:01:41 -0700118 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
Todd Kjos53d311cf2017-06-29 12:01:51 -0700126static struct binder_buffer *binder_alloc_prepare_to_free_locked(
Todd Kjos0c972a02017-06-29 12:01:41 -0700127 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;
Todd Kjosbde4a192019-02-08 10:35:20 -0800132 void __user *uptr;
Todd Kjos0c972a02017-06-29 12:01:41 -0700133
Todd Kjosbde4a192019-02-08 10:35:20 -0800134 uptr = (void __user *)user_ptr;
Todd Kjos0c972a02017-06-29 12:01:41 -0700135
136 while (n) {
137 buffer = rb_entry(n, struct binder_buffer, rb_node);
138 BUG_ON(buffer->free);
139
Todd Kjosbde4a192019-02-08 10:35:20 -0800140 if (uptr < buffer->user_data)
Todd Kjos0c972a02017-06-29 12:01:41 -0700141 n = n->rb_left;
Todd Kjosbde4a192019-02-08 10:35:20 -0800142 else if (uptr > buffer->user_data)
Todd Kjos0c972a02017-06-29 12:01:41 -0700143 n = n->rb_right;
Todd Kjos53d311cf2017-06-29 12:01:51 -0700144 else {
145 /*
146 * Guard against user threads attempting to
Todd Kjos7bada552018-11-06 15:55:32 -0800147 * free the buffer when in use by kernel or
148 * after it's already been freed.
Todd Kjos53d311cf2017-06-29 12:01:51 -0700149 */
Todd Kjos7bada552018-11-06 15:55:32 -0800150 if (!buffer->allow_user_free)
151 return ERR_PTR(-EPERM);
152 buffer->allow_user_free = 0;
Todd Kjos0c972a02017-06-29 12:01:41 -0700153 return buffer;
Todd Kjos53d311cf2017-06-29 12:01:51 -0700154 }
Todd Kjos0c972a02017-06-29 12:01:41 -0700155 }
156 return NULL;
157}
158
159/**
Joel Fernandes (Google)5dc54a02019-09-30 16:12:50 -0400160 * binder_alloc_prepare_to_free() - get buffer given user ptr
Todd Kjos0c972a02017-06-29 12:01:41 -0700161 * @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 */
Todd Kjos53d311cf2017-06-29 12:01:51 -0700170struct binder_buffer *binder_alloc_prepare_to_free(struct binder_alloc *alloc,
171 uintptr_t user_ptr)
Todd Kjos0c972a02017-06-29 12:01:41 -0700172{
173 struct binder_buffer *buffer;
174
175 mutex_lock(&alloc->mutex);
Todd Kjos53d311cf2017-06-29 12:01:51 -0700176 buffer = binder_alloc_prepare_to_free_locked(alloc, user_ptr);
Todd Kjos0c972a02017-06-29 12:01:41 -0700177 mutex_unlock(&alloc->mutex);
178 return buffer;
179}
180
181static int binder_update_page_range(struct binder_alloc *alloc, int allocate,
Todd Kjosbde4a192019-02-08 10:35:20 -0800182 void __user *start, void __user *end)
Todd Kjos0c972a02017-06-29 12:01:41 -0700183{
Todd Kjosbde4a192019-02-08 10:35:20 -0800184 void __user *page_addr;
Todd Kjos0c972a02017-06-29 12:01:41 -0700185 unsigned long user_page_addr;
Sherry Yangf2517eb2017-08-23 08:46:42 -0700186 struct binder_lru_page *page;
Sherry Yang6ae33b92017-09-16 01:11:56 -0400187 struct vm_area_struct *vma = NULL;
Sherry Yangf2517eb2017-08-23 08:46:42 -0700188 struct mm_struct *mm = NULL;
189 bool need_mm = false;
Todd Kjos0c972a02017-06-29 12:01:41 -0700190
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
Sherry Yangf2517eb2017-08-23 08:46:42 -0700200 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
Greg Kroah-Hartman6fbf2482017-10-23 17:21:44 +0200211 if (need_mm && mmget_not_zero(alloc->vma_vm_mm))
Sherry Yanga0c2baa2017-10-20 20:58:58 -0400212 mm = alloc->vma_vm_mm;
Todd Kjos0c972a02017-06-29 12:01:41 -0700213
214 if (mm) {
Michel Lespinassed8ed45c2020-06-08 21:33:25 -0700215 mmap_read_lock(mm);
Carlos Llamasdd7aff42023-05-30 19:43:36 +0000216 vma = alloc->vma;
Todd Kjos0c972a02017-06-29 12:01:41 -0700217 }
218
Sherry Yangf2517eb2017-08-23 08:46:42 -0700219 if (!vma && need_mm) {
Sherry Yang128f3802018-08-07 12:57:13 -0700220 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
221 "%d: binder_alloc_buf failed to map pages in userspace, no vma\n",
222 alloc->pid);
Todd Kjos0c972a02017-06-29 12:01:41 -0700223 goto err_no_vma;
224 }
225
226 for (page_addr = start; page_addr < end; page_addr += PAGE_SIZE) {
227 int ret;
Sherry Yangf2517eb2017-08-23 08:46:42 -0700228 bool on_lru;
Sherry Yange41e1642017-08-23 08:46:43 -0700229 size_t index;
Todd Kjos0c972a02017-06-29 12:01:41 -0700230
Sherry Yange41e1642017-08-23 08:46:43 -0700231 index = (page_addr - alloc->buffer) / PAGE_SIZE;
232 page = &alloc->pages[index];
Todd Kjos0c972a02017-06-29 12:01:41 -0700233
Sherry Yangf2517eb2017-08-23 08:46:42 -0700234 if (page->page_ptr) {
Sherry Yange41e1642017-08-23 08:46:43 -0700235 trace_binder_alloc_lru_start(alloc, index);
236
Sherry Yangf2517eb2017-08-23 08:46:42 -0700237 on_lru = list_lru_del(&binder_alloc_lru, &page->lru);
238 WARN_ON(!on_lru);
Sherry Yange41e1642017-08-23 08:46:43 -0700239
240 trace_binder_alloc_lru_end(alloc, index);
Sherry Yangf2517eb2017-08-23 08:46:42 -0700241 continue;
242 }
243
244 if (WARN_ON(!vma))
245 goto err_page_ptr_cleared;
246
Sherry Yange41e1642017-08-23 08:46:43 -0700247 trace_binder_alloc_page_start(alloc, index);
Sherry Yangf2517eb2017-08-23 08:46:42 -0700248 page->page_ptr = alloc_page(GFP_KERNEL |
249 __GFP_HIGHMEM |
250 __GFP_ZERO);
251 if (!page->page_ptr) {
Todd Kjos0c972a02017-06-29 12:01:41 -0700252 pr_err("%d: binder_alloc_buf failed for page at %pK\n",
253 alloc->pid, page_addr);
254 goto err_alloc_page_failed;
255 }
Sherry Yangf2517eb2017-08-23 08:46:42 -0700256 page->alloc = alloc;
257 INIT_LIST_HEAD(&page->lru);
258
Todd Kjosc41358a2019-02-08 10:35:19 -0800259 user_page_addr = (uintptr_t)page_addr;
Sherry Yangf2517eb2017-08-23 08:46:42 -0700260 ret = vm_insert_page(vma, user_page_addr, page[0].page_ptr);
Todd Kjos0c972a02017-06-29 12:01:41 -0700261 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 }
Sherry Yange41e1642017-08-23 08:46:43 -0700266
Martijn Coenen8d9a3ab62017-11-13 10:06:56 +0100267 if (index + 1 > alloc->pages_high)
268 alloc->pages_high = index + 1;
269
Sherry Yange41e1642017-08-23 08:46:43 -0700270 trace_binder_alloc_page_end(alloc, index);
Todd Kjos0c972a02017-06-29 12:01:41 -0700271 }
272 if (mm) {
Michel Lespinassed8ed45c2020-06-08 21:33:25 -0700273 mmap_read_unlock(mm);
Todd Kjos0c972a02017-06-29 12:01:41 -0700274 mmput(mm);
275 }
276 return 0;
277
278free_range:
Jann Horn2a9edd02019-10-18 22:56:31 +0200279 for (page_addr = end - PAGE_SIZE; 1; page_addr -= PAGE_SIZE) {
Sherry Yangf2517eb2017-08-23 08:46:42 -0700280 bool ret;
Sherry Yange41e1642017-08-23 08:46:43 -0700281 size_t index;
Sherry Yangf2517eb2017-08-23 08:46:42 -0700282
Sherry Yange41e1642017-08-23 08:46:43 -0700283 index = (page_addr - alloc->buffer) / PAGE_SIZE;
284 page = &alloc->pages[index];
285
286 trace_binder_free_lru_start(alloc, index);
Sherry Yangf2517eb2017-08-23 08:46:42 -0700287
288 ret = list_lru_add(&binder_alloc_lru, &page->lru);
289 WARN_ON(!ret);
Sherry Yange41e1642017-08-23 08:46:43 -0700290
291 trace_binder_free_lru_end(alloc, index);
Jann Horn2a9edd02019-10-18 22:56:31 +0200292 if (page_addr == start)
293 break;
Sherry Yangf2517eb2017-08-23 08:46:42 -0700294 continue;
295
Todd Kjos0c972a02017-06-29 12:01:41 -0700296err_vm_insert_page_failed:
Sherry Yangf2517eb2017-08-23 08:46:42 -0700297 __free_page(page->page_ptr);
298 page->page_ptr = NULL;
Todd Kjos0c972a02017-06-29 12:01:41 -0700299err_alloc_page_failed:
Sherry Yangf2517eb2017-08-23 08:46:42 -0700300err_page_ptr_cleared:
Jann Horn2a9edd02019-10-18 22:56:31 +0200301 if (page_addr == start)
302 break;
Todd Kjos0c972a02017-06-29 12:01:41 -0700303 }
304err_no_vma:
305 if (mm) {
Michel Lespinassed8ed45c2020-06-08 21:33:25 -0700306 mmap_read_unlock(mm);
Todd Kjos0c972a02017-06-29 12:01:41 -0700307 mmput(mm);
308 }
Todd Kjos57ada2f2017-06-29 12:01:46 -0700309 return vma ? -ENOMEM : -ESRCH;
Todd Kjos0c972a02017-06-29 12:01:41 -0700310}
311
Minchan Kimda1b9562018-08-23 14:29:56 +0900312
313static inline void binder_alloc_set_vma(struct binder_alloc *alloc,
314 struct vm_area_struct *vma)
315{
Carlos Llamasdd7aff42023-05-30 19:43:36 +0000316 /*
317 * If we see alloc->vma is not NULL, buffer data structures set up
318 * completely. Look at smp_rmb side binder_alloc_get_vma.
319 */
320 smp_wmb();
321 alloc->vma = vma;
Minchan Kimda1b9562018-08-23 14:29:56 +0900322}
323
324static inline struct vm_area_struct *binder_alloc_get_vma(
325 struct binder_alloc *alloc)
326{
327 struct vm_area_struct *vma = NULL;
328
Carlos Llamasdd7aff42023-05-30 19:43:36 +0000329 if (alloc->vma) {
330 /* Look at description in binder_alloc_set_vma */
331 smp_rmb();
332 vma = alloc->vma;
333 }
Minchan Kimda1b9562018-08-23 14:29:56 +0900334 return vma;
335}
336
Hang Lua7dc1e62021-04-09 17:40:46 +0800337static bool debug_low_async_space_locked(struct binder_alloc *alloc, int pid)
Martijn Coenen261e7812020-08-21 14:25:44 +0200338{
339 /*
340 * Find the amount and size of buffers allocated by the current caller;
341 * The idea is that once we cross the threshold, whoever is responsible
342 * for the low async space is likely to try to send another async txn,
343 * and at some point we'll catch them in the act. This is more efficient
344 * than keeping a map per pid.
345 */
Colin Ian King7369fa42020-09-10 16:12:21 +0100346 struct rb_node *n;
Martijn Coenen261e7812020-08-21 14:25:44 +0200347 struct binder_buffer *buffer;
348 size_t total_alloc_size = 0;
349 size_t num_buffers = 0;
350
351 for (n = rb_first(&alloc->allocated_buffers); n != NULL;
352 n = rb_next(n)) {
353 buffer = rb_entry(n, struct binder_buffer, rb_node);
354 if (buffer->pid != pid)
355 continue;
356 if (!buffer->async_transaction)
357 continue;
358 total_alloc_size += binder_alloc_buffer_size(alloc, buffer)
359 + sizeof(struct binder_buffer);
360 num_buffers++;
361 }
362
363 /*
364 * Warn if this pid has more than 50 transactions, or more than 50% of
Hang Lua7dc1e62021-04-09 17:40:46 +0800365 * async space (which is 25% of total buffer size). Oneway spam is only
366 * detected when the threshold is exceeded.
Martijn Coenen261e7812020-08-21 14:25:44 +0200367 */
368 if (num_buffers > 50 || total_alloc_size > alloc->buffer_size / 4) {
369 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
370 "%d: pid %d spamming oneway? %zd buffers allocated for a total size of %zd\n",
371 alloc->pid, pid, num_buffers, total_alloc_size);
Hang Lua7dc1e62021-04-09 17:40:46 +0800372 if (!alloc->oneway_spam_detected) {
373 alloc->oneway_spam_detected = true;
374 return true;
375 }
Martijn Coenen261e7812020-08-21 14:25:44 +0200376 }
Hang Lua7dc1e62021-04-09 17:40:46 +0800377 return false;
Martijn Coenen261e7812020-08-21 14:25:44 +0200378}
379
Xiongwei Song3f827242017-12-14 12:15:42 +0800380static struct binder_buffer *binder_alloc_new_buf_locked(
381 struct binder_alloc *alloc,
382 size_t data_size,
383 size_t offsets_size,
384 size_t extra_buffers_size,
Martijn Coenen261e7812020-08-21 14:25:44 +0200385 int is_async,
386 int pid)
Todd Kjos0c972a02017-06-29 12:01:41 -0700387{
388 struct rb_node *n = alloc->free_buffers.rb_node;
389 struct binder_buffer *buffer;
390 size_t buffer_size;
391 struct rb_node *best_fit = NULL;
Todd Kjosbde4a192019-02-08 10:35:20 -0800392 void __user *has_page_addr;
393 void __user *end_page_addr;
Todd Kjos0c972a02017-06-29 12:01:41 -0700394 size_t size, data_offsets_size;
Todd Kjos57ada2f2017-06-29 12:01:46 -0700395 int ret;
Todd Kjos0c972a02017-06-29 12:01:41 -0700396
Minchan Kimda1b9562018-08-23 14:29:56 +0900397 if (!binder_alloc_get_vma(alloc)) {
Sherry Yang128f3802018-08-07 12:57:13 -0700398 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
399 "%d: binder_alloc_buf, no vma\n",
400 alloc->pid);
Todd Kjos57ada2f2017-06-29 12:01:46 -0700401 return ERR_PTR(-ESRCH);
Todd Kjos0c972a02017-06-29 12:01:41 -0700402 }
403
404 data_offsets_size = ALIGN(data_size, sizeof(void *)) +
405 ALIGN(offsets_size, sizeof(void *));
406
407 if (data_offsets_size < data_size || data_offsets_size < offsets_size) {
408 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
409 "%d: got transaction with invalid size %zd-%zd\n",
410 alloc->pid, data_size, offsets_size);
Todd Kjos57ada2f2017-06-29 12:01:46 -0700411 return ERR_PTR(-EINVAL);
Todd Kjos0c972a02017-06-29 12:01:41 -0700412 }
413 size = data_offsets_size + ALIGN(extra_buffers_size, sizeof(void *));
414 if (size < data_offsets_size || size < extra_buffers_size) {
415 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
416 "%d: got transaction with invalid extra_buffers_size %zd\n",
417 alloc->pid, extra_buffers_size);
Todd Kjos57ada2f2017-06-29 12:01:46 -0700418 return ERR_PTR(-EINVAL);
Todd Kjos0c972a02017-06-29 12:01:41 -0700419 }
420 if (is_async &&
421 alloc->free_async_space < size + sizeof(struct binder_buffer)) {
422 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
423 "%d: binder_alloc_buf size %zd failed, no async space left\n",
424 alloc->pid, size);
Todd Kjos57ada2f2017-06-29 12:01:46 -0700425 return ERR_PTR(-ENOSPC);
Todd Kjos0c972a02017-06-29 12:01:41 -0700426 }
427
Sherry Yang74310e02017-08-23 08:46:41 -0700428 /* Pad 0-size buffers so they get assigned unique addresses */
429 size = max(size, sizeof(void *));
430
Todd Kjos0c972a02017-06-29 12:01:41 -0700431 while (n) {
432 buffer = rb_entry(n, struct binder_buffer, rb_node);
433 BUG_ON(!buffer->free);
434 buffer_size = binder_alloc_buffer_size(alloc, buffer);
435
436 if (size < buffer_size) {
437 best_fit = n;
438 n = n->rb_left;
439 } else if (size > buffer_size)
440 n = n->rb_right;
441 else {
442 best_fit = n;
443 break;
444 }
445 }
446 if (best_fit == NULL) {
Martijn Coenenb05a68e2017-06-29 12:01:52 -0700447 size_t allocated_buffers = 0;
448 size_t largest_alloc_size = 0;
449 size_t total_alloc_size = 0;
450 size_t free_buffers = 0;
451 size_t largest_free_size = 0;
452 size_t total_free_size = 0;
453
454 for (n = rb_first(&alloc->allocated_buffers); n != NULL;
455 n = rb_next(n)) {
456 buffer = rb_entry(n, struct binder_buffer, rb_node);
457 buffer_size = binder_alloc_buffer_size(alloc, buffer);
458 allocated_buffers++;
459 total_alloc_size += buffer_size;
460 if (buffer_size > largest_alloc_size)
461 largest_alloc_size = buffer_size;
462 }
463 for (n = rb_first(&alloc->free_buffers); n != NULL;
464 n = rb_next(n)) {
465 buffer = rb_entry(n, struct binder_buffer, rb_node);
466 buffer_size = binder_alloc_buffer_size(alloc, buffer);
467 free_buffers++;
468 total_free_size += buffer_size;
469 if (buffer_size > largest_free_size)
470 largest_free_size = buffer_size;
471 }
Sherry Yang128f3802018-08-07 12:57:13 -0700472 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
473 "%d: binder_alloc_buf size %zd failed, no address space\n",
474 alloc->pid, size);
475 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
476 "allocated: %zd (num: %zd largest: %zd), free: %zd (num: %zd largest: %zd)\n",
477 total_alloc_size, allocated_buffers,
478 largest_alloc_size, total_free_size,
479 free_buffers, largest_free_size);
Todd Kjos57ada2f2017-06-29 12:01:46 -0700480 return ERR_PTR(-ENOSPC);
Todd Kjos0c972a02017-06-29 12:01:41 -0700481 }
482 if (n == NULL) {
483 buffer = rb_entry(best_fit, struct binder_buffer, rb_node);
484 buffer_size = binder_alloc_buffer_size(alloc, buffer);
485 }
486
487 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
488 "%d: binder_alloc_buf size %zd got buffer %pK size %zd\n",
489 alloc->pid, size, buffer, buffer_size);
490
Todd Kjosbde4a192019-02-08 10:35:20 -0800491 has_page_addr = (void __user *)
492 (((uintptr_t)buffer->user_data + buffer_size) & PAGE_MASK);
Sherry Yang74310e02017-08-23 08:46:41 -0700493 WARN_ON(n && buffer_size != size);
Todd Kjos0c972a02017-06-29 12:01:41 -0700494 end_page_addr =
Todd Kjosbde4a192019-02-08 10:35:20 -0800495 (void __user *)PAGE_ALIGN((uintptr_t)buffer->user_data + size);
Todd Kjos0c972a02017-06-29 12:01:41 -0700496 if (end_page_addr > has_page_addr)
497 end_page_addr = has_page_addr;
Todd Kjosbde4a192019-02-08 10:35:20 -0800498 ret = binder_update_page_range(alloc, 1, (void __user *)
499 PAGE_ALIGN((uintptr_t)buffer->user_data), end_page_addr);
Todd Kjos57ada2f2017-06-29 12:01:46 -0700500 if (ret)
501 return ERR_PTR(ret);
Todd Kjos0c972a02017-06-29 12:01:41 -0700502
Todd Kjos0c972a02017-06-29 12:01:41 -0700503 if (buffer_size != size) {
Sherry Yang74310e02017-08-23 08:46:41 -0700504 struct binder_buffer *new_buffer;
Todd Kjos0c972a02017-06-29 12:01:41 -0700505
Sherry Yang74310e02017-08-23 08:46:41 -0700506 new_buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
507 if (!new_buffer) {
508 pr_err("%s: %d failed to alloc new buffer struct\n",
509 __func__, alloc->pid);
510 goto err_alloc_buf_struct_failed;
511 }
Todd Kjosbde4a192019-02-08 10:35:20 -0800512 new_buffer->user_data = (u8 __user *)buffer->user_data + size;
Todd Kjos0c972a02017-06-29 12:01:41 -0700513 list_add(&new_buffer->entry, &buffer->entry);
514 new_buffer->free = 1;
515 binder_insert_free_buffer(alloc, new_buffer);
516 }
Sherry Yang74310e02017-08-23 08:46:41 -0700517
518 rb_erase(best_fit, &alloc->free_buffers);
519 buffer->free = 0;
Todd Kjos7bada552018-11-06 15:55:32 -0800520 buffer->allow_user_free = 0;
Sherry Yang74310e02017-08-23 08:46:41 -0700521 binder_insert_allocated_buffer_locked(alloc, buffer);
Todd Kjos0c972a02017-06-29 12:01:41 -0700522 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
523 "%d: binder_alloc_buf size %zd got %pK\n",
524 alloc->pid, size, buffer);
525 buffer->data_size = data_size;
526 buffer->offsets_size = offsets_size;
527 buffer->async_transaction = is_async;
528 buffer->extra_buffers_size = extra_buffers_size;
Martijn Coenen261e7812020-08-21 14:25:44 +0200529 buffer->pid = pid;
Hang Lua7dc1e62021-04-09 17:40:46 +0800530 buffer->oneway_spam_suspect = false;
Todd Kjos0c972a02017-06-29 12:01:41 -0700531 if (is_async) {
532 alloc->free_async_space -= size + sizeof(struct binder_buffer);
533 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
534 "%d: binder_alloc_buf size %zd async free %zd\n",
535 alloc->pid, size, alloc->free_async_space);
Martijn Coenen261e7812020-08-21 14:25:44 +0200536 if (alloc->free_async_space < alloc->buffer_size / 10) {
537 /*
538 * Start detecting spammers once we have less than 20%
539 * of async space left (which is less than 10% of total
540 * buffer size).
541 */
Hang Lua7dc1e62021-04-09 17:40:46 +0800542 buffer->oneway_spam_suspect = debug_low_async_space_locked(alloc, pid);
543 } else {
544 alloc->oneway_spam_detected = false;
Martijn Coenen261e7812020-08-21 14:25:44 +0200545 }
Todd Kjos0c972a02017-06-29 12:01:41 -0700546 }
547 return buffer;
Sherry Yang74310e02017-08-23 08:46:41 -0700548
549err_alloc_buf_struct_failed:
Todd Kjosbde4a192019-02-08 10:35:20 -0800550 binder_update_page_range(alloc, 0, (void __user *)
551 PAGE_ALIGN((uintptr_t)buffer->user_data),
Sherry Yang6ae33b92017-09-16 01:11:56 -0400552 end_page_addr);
Sherry Yang74310e02017-08-23 08:46:41 -0700553 return ERR_PTR(-ENOMEM);
Todd Kjos0c972a02017-06-29 12:01:41 -0700554}
555
556/**
557 * binder_alloc_new_buf() - Allocate a new binder buffer
558 * @alloc: binder_alloc for this proc
559 * @data_size: size of user data buffer
560 * @offsets_size: user specified buffer offset
561 * @extra_buffers_size: size of extra space for meta-data (eg, security context)
562 * @is_async: buffer for async transaction
Martijn Coenen261e7812020-08-21 14:25:44 +0200563 * @pid: pid to attribute allocation to (used for debugging)
Todd Kjos0c972a02017-06-29 12:01:41 -0700564 *
565 * Allocate a new buffer given the requested sizes. Returns
566 * the kernel version of the buffer pointer. The size allocated
567 * is the sum of the three given sizes (each rounded up to
568 * pointer-sized boundary)
569 *
570 * Return: The allocated buffer or %NULL if error
571 */
572struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc,
573 size_t data_size,
574 size_t offsets_size,
575 size_t extra_buffers_size,
Martijn Coenen261e7812020-08-21 14:25:44 +0200576 int is_async,
577 int pid)
Todd Kjos0c972a02017-06-29 12:01:41 -0700578{
579 struct binder_buffer *buffer;
580
581 mutex_lock(&alloc->mutex);
582 buffer = binder_alloc_new_buf_locked(alloc, data_size, offsets_size,
Martijn Coenen261e7812020-08-21 14:25:44 +0200583 extra_buffers_size, is_async, pid);
Todd Kjos0c972a02017-06-29 12:01:41 -0700584 mutex_unlock(&alloc->mutex);
585 return buffer;
586}
587
Todd Kjosbde4a192019-02-08 10:35:20 -0800588static void __user *buffer_start_page(struct binder_buffer *buffer)
Todd Kjos0c972a02017-06-29 12:01:41 -0700589{
Todd Kjosbde4a192019-02-08 10:35:20 -0800590 return (void __user *)((uintptr_t)buffer->user_data & PAGE_MASK);
Todd Kjos0c972a02017-06-29 12:01:41 -0700591}
592
Todd Kjosbde4a192019-02-08 10:35:20 -0800593static void __user *prev_buffer_end_page(struct binder_buffer *buffer)
Todd Kjos0c972a02017-06-29 12:01:41 -0700594{
Todd Kjosbde4a192019-02-08 10:35:20 -0800595 return (void __user *)
596 (((uintptr_t)(buffer->user_data) - 1) & PAGE_MASK);
Todd Kjos0c972a02017-06-29 12:01:41 -0700597}
598
599static void binder_delete_free_buffer(struct binder_alloc *alloc,
600 struct binder_buffer *buffer)
601{
602 struct binder_buffer *prev, *next = NULL;
Sherry Yang74310e02017-08-23 08:46:41 -0700603 bool to_free = true;
Mrinal Pandey4df97722020-07-24 18:42:54 +0530604
Todd Kjos0c972a02017-06-29 12:01:41 -0700605 BUG_ON(alloc->buffers.next == &buffer->entry);
Sherry Yange21762192017-08-23 08:46:39 -0700606 prev = binder_buffer_prev(buffer);
Todd Kjos0c972a02017-06-29 12:01:41 -0700607 BUG_ON(!prev->free);
Sherry Yang74310e02017-08-23 08:46:41 -0700608 if (prev_buffer_end_page(prev) == buffer_start_page(buffer)) {
609 to_free = false;
Todd Kjos0c972a02017-06-29 12:01:41 -0700610 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
Sherry Yang74310e02017-08-23 08:46:41 -0700611 "%d: merge free, buffer %pK share page with %pK\n",
Todd Kjosbde4a192019-02-08 10:35:20 -0800612 alloc->pid, buffer->user_data,
613 prev->user_data);
Todd Kjos0c972a02017-06-29 12:01:41 -0700614 }
615
616 if (!list_is_last(&buffer->entry, &alloc->buffers)) {
Sherry Yange21762192017-08-23 08:46:39 -0700617 next = binder_buffer_next(buffer);
Sherry Yang74310e02017-08-23 08:46:41 -0700618 if (buffer_start_page(next) == buffer_start_page(buffer)) {
619 to_free = false;
Todd Kjos0c972a02017-06-29 12:01:41 -0700620 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
Sherry Yang74310e02017-08-23 08:46:41 -0700621 "%d: merge free, buffer %pK share page with %pK\n",
622 alloc->pid,
Todd Kjosbde4a192019-02-08 10:35:20 -0800623 buffer->user_data,
624 next->user_data);
Todd Kjos0c972a02017-06-29 12:01:41 -0700625 }
626 }
Sherry Yang74310e02017-08-23 08:46:41 -0700627
Todd Kjosbde4a192019-02-08 10:35:20 -0800628 if (PAGE_ALIGNED(buffer->user_data)) {
Todd Kjos0c972a02017-06-29 12:01:41 -0700629 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
Sherry Yang74310e02017-08-23 08:46:41 -0700630 "%d: merge free, buffer start %pK is page aligned\n",
Todd Kjosbde4a192019-02-08 10:35:20 -0800631 alloc->pid, buffer->user_data);
Sherry Yang74310e02017-08-23 08:46:41 -0700632 to_free = false;
Todd Kjos0c972a02017-06-29 12:01:41 -0700633 }
Sherry Yang74310e02017-08-23 08:46:41 -0700634
635 if (to_free) {
636 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
637 "%d: merge free, buffer %pK do not share page with %pK or %pK\n",
Todd Kjosbde4a192019-02-08 10:35:20 -0800638 alloc->pid, buffer->user_data,
639 prev->user_data,
640 next ? next->user_data : NULL);
Sherry Yang74310e02017-08-23 08:46:41 -0700641 binder_update_page_range(alloc, 0, buffer_start_page(buffer),
Sherry Yang6ae33b92017-09-16 01:11:56 -0400642 buffer_start_page(buffer) + PAGE_SIZE);
Sherry Yang74310e02017-08-23 08:46:41 -0700643 }
644 list_del(&buffer->entry);
645 kfree(buffer);
Todd Kjos0c972a02017-06-29 12:01:41 -0700646}
647
648static void binder_free_buf_locked(struct binder_alloc *alloc,
649 struct binder_buffer *buffer)
650{
651 size_t size, buffer_size;
652
653 buffer_size = binder_alloc_buffer_size(alloc, buffer);
654
655 size = ALIGN(buffer->data_size, sizeof(void *)) +
656 ALIGN(buffer->offsets_size, sizeof(void *)) +
657 ALIGN(buffer->extra_buffers_size, sizeof(void *));
658
659 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
660 "%d: binder_free_buf %pK size %zd buffer_size %zd\n",
661 alloc->pid, buffer, size, buffer_size);
662
663 BUG_ON(buffer->free);
664 BUG_ON(size > buffer_size);
665 BUG_ON(buffer->transaction != NULL);
Todd Kjosbde4a192019-02-08 10:35:20 -0800666 BUG_ON(buffer->user_data < alloc->buffer);
667 BUG_ON(buffer->user_data > alloc->buffer + alloc->buffer_size);
Todd Kjos0c972a02017-06-29 12:01:41 -0700668
669 if (buffer->async_transaction) {
Todd Kjos17691ba2021-12-20 11:01:50 -0800670 alloc->free_async_space += buffer_size + sizeof(struct binder_buffer);
Todd Kjos0c972a02017-06-29 12:01:41 -0700671
672 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC,
673 "%d: binder_free_buf size %zd async free %zd\n",
674 alloc->pid, size, alloc->free_async_space);
675 }
676
677 binder_update_page_range(alloc, 0,
Todd Kjosbde4a192019-02-08 10:35:20 -0800678 (void __user *)PAGE_ALIGN((uintptr_t)buffer->user_data),
679 (void __user *)(((uintptr_t)
680 buffer->user_data + buffer_size) & PAGE_MASK));
Todd Kjos0c972a02017-06-29 12:01:41 -0700681
682 rb_erase(&buffer->rb_node, &alloc->allocated_buffers);
683 buffer->free = 1;
684 if (!list_is_last(&buffer->entry, &alloc->buffers)) {
Sherry Yange21762192017-08-23 08:46:39 -0700685 struct binder_buffer *next = binder_buffer_next(buffer);
Todd Kjos0c972a02017-06-29 12:01:41 -0700686
687 if (next->free) {
688 rb_erase(&next->rb_node, &alloc->free_buffers);
689 binder_delete_free_buffer(alloc, next);
690 }
691 }
692 if (alloc->buffers.next != &buffer->entry) {
Sherry Yange21762192017-08-23 08:46:39 -0700693 struct binder_buffer *prev = binder_buffer_prev(buffer);
Todd Kjos0c972a02017-06-29 12:01:41 -0700694
695 if (prev->free) {
696 binder_delete_free_buffer(alloc, buffer);
697 rb_erase(&prev->rb_node, &alloc->free_buffers);
698 buffer = prev;
699 }
700 }
701 binder_insert_free_buffer(alloc, buffer);
702}
703
Todd Kjos0f966cb2020-11-20 15:37:43 -0800704static void binder_alloc_clear_buf(struct binder_alloc *alloc,
705 struct binder_buffer *buffer);
Todd Kjos0c972a02017-06-29 12:01:41 -0700706/**
707 * binder_alloc_free_buf() - free a binder buffer
708 * @alloc: binder_alloc for this proc
709 * @buffer: kernel pointer to buffer
710 *
YangHui4b463822020-08-18 09:34:04 +0800711 * Free the buffer allocated via binder_alloc_new_buf()
Todd Kjos0c972a02017-06-29 12:01:41 -0700712 */
713void binder_alloc_free_buf(struct binder_alloc *alloc,
714 struct binder_buffer *buffer)
715{
Todd Kjos0f966cb2020-11-20 15:37:43 -0800716 /*
717 * We could eliminate the call to binder_alloc_clear_buf()
718 * from binder_alloc_deferred_release() by moving this to
719 * binder_alloc_free_buf_locked(). However, that could
720 * increase contention for the alloc mutex if clear_on_free
721 * is used frequently for large buffers. The mutex is not
722 * needed for correctness here.
723 */
724 if (buffer->clear_on_free) {
725 binder_alloc_clear_buf(alloc, buffer);
726 buffer->clear_on_free = false;
727 }
Todd Kjos0c972a02017-06-29 12:01:41 -0700728 mutex_lock(&alloc->mutex);
729 binder_free_buf_locked(alloc, buffer);
730 mutex_unlock(&alloc->mutex);
731}
732
733/**
734 * binder_alloc_mmap_handler() - map virtual address space for proc
735 * @alloc: alloc structure for this proc
736 * @vma: vma passed to mmap()
737 *
738 * Called by binder_mmap() to initialize the space specified in
739 * vma for allocating binder buffers
740 *
741 * Return:
742 * 0 = success
743 * -EBUSY = address space already mapped
744 * -ENOMEM = failed to map memory to given address space
745 */
746int binder_alloc_mmap_handler(struct binder_alloc *alloc,
747 struct vm_area_struct *vma)
748{
749 int ret;
Todd Kjos0c972a02017-06-29 12:01:41 -0700750 const char *failure_string;
751 struct binder_buffer *buffer;
752
Carlos Llamasd276fb42022-11-04 23:12:35 +0000753 if (unlikely(vma->vm_mm != alloc->vma_vm_mm)) {
754 ret = -EINVAL;
755 failure_string = "invalid vma->vm_mm";
756 goto err_invalid_mm;
757 }
758
Todd Kjos0c972a02017-06-29 12:01:41 -0700759 mutex_lock(&binder_alloc_mmap_lock);
Jann Horna7a74d72019-10-18 22:56:30 +0200760 if (alloc->buffer_size) {
Todd Kjos0c972a02017-06-29 12:01:41 -0700761 ret = -EBUSY;
762 failure_string = "already mapped";
763 goto err_already_mapped;
764 }
Jann Horn45d02f72019-10-16 17:01:18 +0200765 alloc->buffer_size = min_t(unsigned long, vma->vm_end - vma->vm_start,
766 SZ_4M);
Jann Horna7a74d72019-10-18 22:56:30 +0200767 mutex_unlock(&binder_alloc_mmap_lock);
768
769 alloc->buffer = (void __user *)vma->vm_start;
770
Jann Horn45d02f72019-10-16 17:01:18 +0200771 alloc->pages = kcalloc(alloc->buffer_size / PAGE_SIZE,
Kees Cook6396bb22018-06-12 14:03:40 -0700772 sizeof(alloc->pages[0]),
Todd Kjos0c972a02017-06-29 12:01:41 -0700773 GFP_KERNEL);
774 if (alloc->pages == NULL) {
775 ret = -ENOMEM;
776 failure_string = "alloc page array";
777 goto err_alloc_pages_failed;
778 }
Todd Kjos0c972a02017-06-29 12:01:41 -0700779
Sherry Yang74310e02017-08-23 08:46:41 -0700780 buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
781 if (!buffer) {
Todd Kjos0c972a02017-06-29 12:01:41 -0700782 ret = -ENOMEM;
Sherry Yang74310e02017-08-23 08:46:41 -0700783 failure_string = "alloc buffer struct";
784 goto err_alloc_buf_struct_failed;
Todd Kjos0c972a02017-06-29 12:01:41 -0700785 }
Sherry Yang74310e02017-08-23 08:46:41 -0700786
Todd Kjosbde4a192019-02-08 10:35:20 -0800787 buffer->user_data = alloc->buffer;
Todd Kjos0c972a02017-06-29 12:01:41 -0700788 list_add(&buffer->entry, &alloc->buffers);
789 buffer->free = 1;
790 binder_insert_free_buffer(alloc, buffer);
791 alloc->free_async_space = alloc->buffer_size / 2;
Minchan Kimda1b9562018-08-23 14:29:56 +0900792 binder_alloc_set_vma(alloc, vma);
Todd Kjos0c972a02017-06-29 12:01:41 -0700793
794 return 0;
795
Sherry Yang74310e02017-08-23 08:46:41 -0700796err_alloc_buf_struct_failed:
Todd Kjos0c972a02017-06-29 12:01:41 -0700797 kfree(alloc->pages);
798 alloc->pages = NULL;
799err_alloc_pages_failed:
Todd Kjos0c972a02017-06-29 12:01:41 -0700800 alloc->buffer = NULL;
Jann Horna7a74d72019-10-18 22:56:30 +0200801 mutex_lock(&binder_alloc_mmap_lock);
802 alloc->buffer_size = 0;
Todd Kjos0c972a02017-06-29 12:01:41 -0700803err_already_mapped:
804 mutex_unlock(&binder_alloc_mmap_lock);
Carlos Llamasd276fb42022-11-04 23:12:35 +0000805err_invalid_mm:
Sherry Yang128f3802018-08-07 12:57:13 -0700806 binder_alloc_debug(BINDER_DEBUG_USER_ERROR,
807 "%s: %d %lx-%lx %s failed %d\n", __func__,
808 alloc->pid, vma->vm_start, vma->vm_end,
809 failure_string, ret);
Todd Kjos0c972a02017-06-29 12:01:41 -0700810 return ret;
811}
812
813
814void binder_alloc_deferred_release(struct binder_alloc *alloc)
815{
816 struct rb_node *n;
817 int buffers, page_count;
Sherry Yang74310e02017-08-23 08:46:41 -0700818 struct binder_buffer *buffer;
Todd Kjos0c972a02017-06-29 12:01:41 -0700819
Todd Kjos0c972a02017-06-29 12:01:41 -0700820 buffers = 0;
821 mutex_lock(&alloc->mutex);
Carlos Llamasdd7aff42023-05-30 19:43:36 +0000822 BUG_ON(alloc->vma);
Minchan Kimda1b9562018-08-23 14:29:56 +0900823
Todd Kjos0c972a02017-06-29 12:01:41 -0700824 while ((n = rb_first(&alloc->allocated_buffers))) {
Todd Kjos0c972a02017-06-29 12:01:41 -0700825 buffer = rb_entry(n, struct binder_buffer, rb_node);
826
827 /* Transaction should already have been freed */
828 BUG_ON(buffer->transaction);
829
Todd Kjos0f966cb2020-11-20 15:37:43 -0800830 if (buffer->clear_on_free) {
831 binder_alloc_clear_buf(alloc, buffer);
832 buffer->clear_on_free = false;
833 }
Todd Kjos0c972a02017-06-29 12:01:41 -0700834 binder_free_buf_locked(alloc, buffer);
835 buffers++;
836 }
837
Sherry Yang74310e02017-08-23 08:46:41 -0700838 while (!list_empty(&alloc->buffers)) {
839 buffer = list_first_entry(&alloc->buffers,
840 struct binder_buffer, entry);
841 WARN_ON(!buffer->free);
842
843 list_del(&buffer->entry);
844 WARN_ON_ONCE(!list_empty(&alloc->buffers));
845 kfree(buffer);
846 }
847
Todd Kjos0c972a02017-06-29 12:01:41 -0700848 page_count = 0;
849 if (alloc->pages) {
850 int i;
851
852 for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
Todd Kjosbde4a192019-02-08 10:35:20 -0800853 void __user *page_addr;
Sherry Yangf2517eb2017-08-23 08:46:42 -0700854 bool on_lru;
Todd Kjos0c972a02017-06-29 12:01:41 -0700855
Sherry Yangf2517eb2017-08-23 08:46:42 -0700856 if (!alloc->pages[i].page_ptr)
Todd Kjos0c972a02017-06-29 12:01:41 -0700857 continue;
858
Sherry Yangf2517eb2017-08-23 08:46:42 -0700859 on_lru = list_lru_del(&binder_alloc_lru,
860 &alloc->pages[i].lru);
Todd Kjos0c972a02017-06-29 12:01:41 -0700861 page_addr = alloc->buffer + i * PAGE_SIZE;
862 binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC,
Sherry Yangf2517eb2017-08-23 08:46:42 -0700863 "%s: %d: page %d at %pK %s\n",
864 __func__, alloc->pid, i, page_addr,
865 on_lru ? "on lru" : "active");
Sherry Yangf2517eb2017-08-23 08:46:42 -0700866 __free_page(alloc->pages[i].page_ptr);
Todd Kjos0c972a02017-06-29 12:01:41 -0700867 page_count++;
868 }
869 kfree(alloc->pages);
Todd Kjos0c972a02017-06-29 12:01:41 -0700870 }
871 mutex_unlock(&alloc->mutex);
Sherry Yanga0c2baa2017-10-20 20:58:58 -0400872 if (alloc->vma_vm_mm)
873 mmdrop(alloc->vma_vm_mm);
Todd Kjos0c972a02017-06-29 12:01:41 -0700874
875 binder_alloc_debug(BINDER_DEBUG_OPEN_CLOSE,
876 "%s: %d buffers %d, pages %d\n",
877 __func__, alloc->pid, buffers, page_count);
878}
879
880static void print_binder_buffer(struct seq_file *m, const char *prefix,
881 struct binder_buffer *buffer)
882{
Martijn Coenenb05a68e2017-06-29 12:01:52 -0700883 seq_printf(m, "%s %d: %pK size %zd:%zd:%zd %s\n",
Todd Kjosbde4a192019-02-08 10:35:20 -0800884 prefix, buffer->debug_id, buffer->user_data,
Todd Kjos0c972a02017-06-29 12:01:41 -0700885 buffer->data_size, buffer->offsets_size,
Martijn Coenenb05a68e2017-06-29 12:01:52 -0700886 buffer->extra_buffers_size,
Todd Kjos0c972a02017-06-29 12:01:41 -0700887 buffer->transaction ? "active" : "delivered");
888}
889
890/**
891 * binder_alloc_print_allocated() - print buffer info
892 * @m: seq_file for output via seq_printf()
893 * @alloc: binder_alloc for this proc
894 *
895 * Prints information about every buffer associated with
896 * the binder_alloc state to the given seq_file
897 */
898void binder_alloc_print_allocated(struct seq_file *m,
899 struct binder_alloc *alloc)
900{
901 struct rb_node *n;
902
903 mutex_lock(&alloc->mutex);
904 for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
905 print_binder_buffer(m, " buffer",
906 rb_entry(n, struct binder_buffer, rb_node));
907 mutex_unlock(&alloc->mutex);
908}
909
910/**
Sherry Yang8ef46652017-08-31 11:56:36 -0700911 * binder_alloc_print_pages() - print page usage
912 * @m: seq_file for output via seq_printf()
913 * @alloc: binder_alloc for this proc
914 */
915void binder_alloc_print_pages(struct seq_file *m,
916 struct binder_alloc *alloc)
917{
918 struct binder_lru_page *page;
919 int i;
920 int active = 0;
921 int lru = 0;
922 int free = 0;
923
924 mutex_lock(&alloc->mutex);
Jann Horn8eb52a12019-10-18 22:56:29 +0200925 /*
926 * Make sure the binder_alloc is fully initialized, otherwise we might
927 * read inconsistent state.
928 */
Carlos Llamas6802c702023-05-30 19:43:35 +0000929 if (binder_alloc_get_vma(alloc) != NULL) {
930 for (i = 0; i < alloc->buffer_size / PAGE_SIZE; i++) {
931 page = &alloc->pages[i];
932 if (!page->page_ptr)
933 free++;
934 else if (list_empty(&page->lru))
935 active++;
936 else
937 lru++;
938 }
Sherry Yang8ef46652017-08-31 11:56:36 -0700939 }
940 mutex_unlock(&alloc->mutex);
941 seq_printf(m, " pages: %d:%d:%d\n", active, lru, free);
Martijn Coenen8d9a3ab62017-11-13 10:06:56 +0100942 seq_printf(m, " pages high watermark: %zu\n", alloc->pages_high);
Sherry Yang8ef46652017-08-31 11:56:36 -0700943}
944
945/**
Todd Kjos0c972a02017-06-29 12:01:41 -0700946 * binder_alloc_get_allocated_count() - return count of buffers
947 * @alloc: binder_alloc for this proc
948 *
949 * Return: count of allocated buffers
950 */
951int binder_alloc_get_allocated_count(struct binder_alloc *alloc)
952{
953 struct rb_node *n;
954 int count = 0;
955
956 mutex_lock(&alloc->mutex);
957 for (n = rb_first(&alloc->allocated_buffers); n != NULL; n = rb_next(n))
958 count++;
959 mutex_unlock(&alloc->mutex);
960 return count;
961}
962
963
964/**
965 * binder_alloc_vma_close() - invalidate address space
966 * @alloc: binder_alloc for this proc
967 *
968 * Called from binder_vma_close() when releasing address space.
969 * Clears alloc->vma to prevent new incoming transactions from
970 * allocating more buffers.
971 */
972void binder_alloc_vma_close(struct binder_alloc *alloc)
973{
Minchan Kimda1b9562018-08-23 14:29:56 +0900974 binder_alloc_set_vma(alloc, NULL);
Todd Kjos0c972a02017-06-29 12:01:41 -0700975}
976
977/**
Sherry Yangf2517eb2017-08-23 08:46:42 -0700978 * binder_alloc_free_page() - shrinker callback to free pages
979 * @item: item to free
980 * @lock: lock protecting the item
981 * @cb_arg: callback argument
982 *
983 * Called from list_lru_walk() in binder_shrink_scan() to free
984 * up pages when the system is under memory pressure.
985 */
986enum lru_status binder_alloc_free_page(struct list_head *item,
987 struct list_lru_one *lru,
988 spinlock_t *lock,
989 void *cb_arg)
Todd Kjos324fa642018-11-06 15:56:31 -0800990 __must_hold(lock)
Sherry Yangf2517eb2017-08-23 08:46:42 -0700991{
992 struct mm_struct *mm = NULL;
993 struct binder_lru_page *page = container_of(item,
994 struct binder_lru_page,
995 lru);
996 struct binder_alloc *alloc;
997 uintptr_t page_addr;
998 size_t index;
Sherry Yanga1b22892017-10-03 16:15:00 -0700999 struct vm_area_struct *vma;
Sherry Yangf2517eb2017-08-23 08:46:42 -07001000
1001 alloc = page->alloc;
1002 if (!mutex_trylock(&alloc->mutex))
1003 goto err_get_alloc_mutex_failed;
1004
1005 if (!page->page_ptr)
1006 goto err_page_already_freed;
1007
1008 index = page - alloc->pages;
1009 page_addr = (uintptr_t)alloc->buffer + index * PAGE_SIZE;
Todd Kjos5cec2d22019-03-01 15:06:06 -08001010
1011 mm = alloc->vma_vm_mm;
1012 if (!mmget_not_zero(mm))
1013 goto err_mmget;
Michel Lespinassed8ed45c2020-06-08 21:33:25 -07001014 if (!mmap_read_trylock(mm))
Michel Lespinasse3e4e28c2020-06-08 21:33:51 -07001015 goto err_mmap_read_lock_failed;
Minchan Kimda1b9562018-08-23 14:29:56 +09001016 vma = binder_alloc_get_vma(alloc);
Sherry Yangf2517eb2017-08-23 08:46:42 -07001017
Sherry Yanga1b22892017-10-03 16:15:00 -07001018 list_lru_isolate(lru, item);
1019 spin_unlock(lock);
1020
1021 if (vma) {
Sherry Yange41e1642017-08-23 08:46:43 -07001022 trace_binder_unmap_user_start(alloc, index);
1023
Todd Kjosc41358a2019-02-08 10:35:19 -08001024 zap_page_range(vma, page_addr, PAGE_SIZE);
Sherry Yangf2517eb2017-08-23 08:46:42 -07001025
Sherry Yange41e1642017-08-23 08:46:43 -07001026 trace_binder_unmap_user_end(alloc, index);
Sherry Yangf2517eb2017-08-23 08:46:42 -07001027 }
Michel Lespinassed8ed45c2020-06-08 21:33:25 -07001028 mmap_read_unlock(mm);
Tetsuo Handaf867c772020-07-17 00:12:15 +09001029 mmput_async(mm);
Sherry Yangf2517eb2017-08-23 08:46:42 -07001030
Sherry Yange41e1642017-08-23 08:46:43 -07001031 trace_binder_unmap_kernel_start(alloc, index);
1032
Sherry Yangf2517eb2017-08-23 08:46:42 -07001033 __free_page(page->page_ptr);
1034 page->page_ptr = NULL;
1035
Sherry Yange41e1642017-08-23 08:46:43 -07001036 trace_binder_unmap_kernel_end(alloc, index);
1037
Sherry Yanga1b22892017-10-03 16:15:00 -07001038 spin_lock(lock);
Sherry Yangf2517eb2017-08-23 08:46:42 -07001039 mutex_unlock(&alloc->mutex);
Sherry Yanga1b22892017-10-03 16:15:00 -07001040 return LRU_REMOVED_RETRY;
Sherry Yangf2517eb2017-08-23 08:46:42 -07001041
Michel Lespinasse3e4e28c2020-06-08 21:33:51 -07001042err_mmap_read_lock_failed:
Sherry Yanga1b22892017-10-03 16:15:00 -07001043 mmput_async(mm);
Sherry Yanga0c2baa2017-10-20 20:58:58 -04001044err_mmget:
Sherry Yangf2517eb2017-08-23 08:46:42 -07001045err_page_already_freed:
1046 mutex_unlock(&alloc->mutex);
1047err_get_alloc_mutex_failed:
1048 return LRU_SKIP;
1049}
1050
1051static unsigned long
1052binder_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
1053{
1054 unsigned long ret = list_lru_count(&binder_alloc_lru);
1055 return ret;
1056}
1057
1058static unsigned long
1059binder_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
1060{
1061 unsigned long ret;
1062
1063 ret = list_lru_walk(&binder_alloc_lru, binder_alloc_free_page,
1064 NULL, sc->nr_to_scan);
1065 return ret;
1066}
1067
Sherry Yangde7bbe32017-10-06 16:12:05 -04001068static struct shrinker binder_shrinker = {
Sherry Yangf2517eb2017-08-23 08:46:42 -07001069 .count_objects = binder_shrink_count,
1070 .scan_objects = binder_shrink_scan,
1071 .seeks = DEFAULT_SEEKS,
1072};
1073
1074/**
Todd Kjos0c972a02017-06-29 12:01:41 -07001075 * binder_alloc_init() - called by binder_open() for per-proc initialization
1076 * @alloc: binder_alloc for this proc
1077 *
1078 * Called from binder_open() to initialize binder_alloc fields for
1079 * new binder proc
1080 */
1081void binder_alloc_init(struct binder_alloc *alloc)
1082{
Todd Kjos0c972a02017-06-29 12:01:41 -07001083 alloc->pid = current->group_leader->pid;
Carlos Llamas81203ab2022-08-29 20:12:48 +00001084 alloc->vma_vm_mm = current->mm;
1085 mmgrab(alloc->vma_vm_mm);
Todd Kjos0c972a02017-06-29 12:01:41 -07001086 mutex_init(&alloc->mutex);
Sherry Yang957ccc22017-08-31 10:26:06 -07001087 INIT_LIST_HEAD(&alloc->buffers);
Todd Kjos0c972a02017-06-29 12:01:41 -07001088}
1089
Tetsuo Handa533dfb22017-11-29 22:29:47 +09001090int binder_alloc_shrinker_init(void)
Sherry Yangf2517eb2017-08-23 08:46:42 -07001091{
Tetsuo Handa533dfb22017-11-29 22:29:47 +09001092 int ret = list_lru_init(&binder_alloc_lru);
1093
1094 if (ret == 0) {
1095 ret = register_shrinker(&binder_shrinker);
1096 if (ret)
1097 list_lru_destroy(&binder_alloc_lru);
1098 }
1099 return ret;
Sherry Yangf2517eb2017-08-23 08:46:42 -07001100}
Todd Kjos1a7c3d92019-02-08 10:35:14 -08001101
1102/**
1103 * check_buffer() - verify that buffer/offset is safe to access
1104 * @alloc: binder_alloc for this proc
1105 * @buffer: binder buffer to be accessed
1106 * @offset: offset into @buffer data
1107 * @bytes: bytes to access from offset
1108 *
1109 * Check that the @offset/@bytes are within the size of the given
1110 * @buffer and that the buffer is currently active and not freeable.
1111 * Offsets must also be multiples of sizeof(u32). The kernel is
1112 * allowed to touch the buffer in two cases:
1113 *
1114 * 1) when the buffer is being created:
1115 * (buffer->free == 0 && buffer->allow_user_free == 0)
1116 * 2) when the buffer is being torn down:
1117 * (buffer->free == 0 && buffer->transaction == NULL).
1118 *
1119 * Return: true if the buffer is safe to access
1120 */
1121static inline bool check_buffer(struct binder_alloc *alloc,
1122 struct binder_buffer *buffer,
1123 binder_size_t offset, size_t bytes)
1124{
1125 size_t buffer_size = binder_alloc_buffer_size(alloc, buffer);
1126
1127 return buffer_size >= bytes &&
1128 offset <= buffer_size - bytes &&
1129 IS_ALIGNED(offset, sizeof(u32)) &&
1130 !buffer->free &&
1131 (!buffer->allow_user_free || !buffer->transaction);
1132}
1133
1134/**
1135 * binder_alloc_get_page() - get kernel pointer for given buffer offset
1136 * @alloc: binder_alloc for this proc
1137 * @buffer: binder buffer to be accessed
1138 * @buffer_offset: offset into @buffer data
1139 * @pgoffp: address to copy final page offset to
1140 *
1141 * Lookup the struct page corresponding to the address
Todd Kjosbde4a192019-02-08 10:35:20 -08001142 * at @buffer_offset into @buffer->user_data. If @pgoffp is not
Todd Kjos1a7c3d92019-02-08 10:35:14 -08001143 * NULL, the byte-offset into the page is written there.
1144 *
1145 * The caller is responsible to ensure that the offset points
1146 * to a valid address within the @buffer and that @buffer is
1147 * not freeable by the user. Since it can't be freed, we are
1148 * guaranteed that the corresponding elements of @alloc->pages[]
1149 * cannot change.
1150 *
1151 * Return: struct page
1152 */
1153static struct page *binder_alloc_get_page(struct binder_alloc *alloc,
1154 struct binder_buffer *buffer,
1155 binder_size_t buffer_offset,
1156 pgoff_t *pgoffp)
1157{
1158 binder_size_t buffer_space_offset = buffer_offset +
Todd Kjosbde4a192019-02-08 10:35:20 -08001159 (buffer->user_data - alloc->buffer);
Todd Kjos1a7c3d92019-02-08 10:35:14 -08001160 pgoff_t pgoff = buffer_space_offset & ~PAGE_MASK;
1161 size_t index = buffer_space_offset >> PAGE_SHIFT;
1162 struct binder_lru_page *lru_page;
1163
1164 lru_page = &alloc->pages[index];
1165 *pgoffp = pgoff;
1166 return lru_page->page_ptr;
1167}
1168
1169/**
Todd Kjos0f966cb2020-11-20 15:37:43 -08001170 * binder_alloc_clear_buf() - zero out buffer
1171 * @alloc: binder_alloc for this proc
1172 * @buffer: binder buffer to be cleared
1173 *
1174 * memset the given buffer to 0
1175 */
1176static void binder_alloc_clear_buf(struct binder_alloc *alloc,
1177 struct binder_buffer *buffer)
1178{
1179 size_t bytes = binder_alloc_buffer_size(alloc, buffer);
1180 binder_size_t buffer_offset = 0;
1181
1182 while (bytes) {
1183 unsigned long size;
1184 struct page *page;
1185 pgoff_t pgoff;
1186 void *kptr;
1187
1188 page = binder_alloc_get_page(alloc, buffer,
1189 buffer_offset, &pgoff);
1190 size = min_t(size_t, bytes, PAGE_SIZE - pgoff);
1191 kptr = kmap(page) + pgoff;
1192 memset(kptr, 0, size);
1193 kunmap(page);
1194 bytes -= size;
1195 buffer_offset += size;
1196 }
1197}
1198
1199/**
Todd Kjos1a7c3d92019-02-08 10:35:14 -08001200 * binder_alloc_copy_user_to_buffer() - copy src user to tgt user
1201 * @alloc: binder_alloc for this proc
1202 * @buffer: binder buffer to be accessed
1203 * @buffer_offset: offset into @buffer data
1204 * @from: userspace pointer to source buffer
1205 * @bytes: bytes to copy
1206 *
1207 * Copy bytes from source userspace to target buffer.
1208 *
1209 * Return: bytes remaining to be copied
1210 */
1211unsigned long
1212binder_alloc_copy_user_to_buffer(struct binder_alloc *alloc,
1213 struct binder_buffer *buffer,
1214 binder_size_t buffer_offset,
1215 const void __user *from,
1216 size_t bytes)
1217{
1218 if (!check_buffer(alloc, buffer, buffer_offset, bytes))
1219 return bytes;
1220
1221 while (bytes) {
1222 unsigned long size;
1223 unsigned long ret;
1224 struct page *page;
1225 pgoff_t pgoff;
1226 void *kptr;
1227
1228 page = binder_alloc_get_page(alloc, buffer,
1229 buffer_offset, &pgoff);
1230 size = min_t(size_t, bytes, PAGE_SIZE - pgoff);
1231 kptr = kmap(page) + pgoff;
1232 ret = copy_from_user(kptr, from, size);
1233 kunmap(page);
1234 if (ret)
1235 return bytes - size + ret;
1236 bytes -= size;
1237 from += size;
1238 buffer_offset += size;
1239 }
1240 return 0;
1241}
Todd Kjos8ced0c62019-02-08 10:35:15 -08001242
Todd Kjosbb4a2e482019-06-28 09:50:12 -07001243static int binder_alloc_do_buffer_copy(struct binder_alloc *alloc,
1244 bool to_buffer,
1245 struct binder_buffer *buffer,
1246 binder_size_t buffer_offset,
1247 void *ptr,
1248 size_t bytes)
Todd Kjos8ced0c62019-02-08 10:35:15 -08001249{
1250 /* All copies must be 32-bit aligned and 32-bit size */
Todd Kjosbb4a2e482019-06-28 09:50:12 -07001251 if (!check_buffer(alloc, buffer, buffer_offset, bytes))
1252 return -EINVAL;
Todd Kjos8ced0c62019-02-08 10:35:15 -08001253
1254 while (bytes) {
1255 unsigned long size;
1256 struct page *page;
1257 pgoff_t pgoff;
1258 void *tmpptr;
1259 void *base_ptr;
1260
1261 page = binder_alloc_get_page(alloc, buffer,
1262 buffer_offset, &pgoff);
1263 size = min_t(size_t, bytes, PAGE_SIZE - pgoff);
1264 base_ptr = kmap_atomic(page);
1265 tmpptr = base_ptr + pgoff;
1266 if (to_buffer)
1267 memcpy(tmpptr, ptr, size);
1268 else
1269 memcpy(ptr, tmpptr, size);
1270 /*
1271 * kunmap_atomic() takes care of flushing the cache
1272 * if this device has VIVT cache arch
1273 */
1274 kunmap_atomic(base_ptr);
1275 bytes -= size;
1276 pgoff = 0;
1277 ptr = ptr + size;
1278 buffer_offset += size;
1279 }
Todd Kjosbb4a2e482019-06-28 09:50:12 -07001280 return 0;
Todd Kjos8ced0c62019-02-08 10:35:15 -08001281}
1282
Todd Kjosbb4a2e482019-06-28 09:50:12 -07001283int binder_alloc_copy_to_buffer(struct binder_alloc *alloc,
1284 struct binder_buffer *buffer,
1285 binder_size_t buffer_offset,
1286 void *src,
1287 size_t bytes)
Todd Kjos8ced0c62019-02-08 10:35:15 -08001288{
Todd Kjosbb4a2e482019-06-28 09:50:12 -07001289 return binder_alloc_do_buffer_copy(alloc, true, buffer, buffer_offset,
1290 src, bytes);
Todd Kjos8ced0c62019-02-08 10:35:15 -08001291}
1292
Todd Kjosbb4a2e482019-06-28 09:50:12 -07001293int binder_alloc_copy_from_buffer(struct binder_alloc *alloc,
1294 void *dest,
1295 struct binder_buffer *buffer,
1296 binder_size_t buffer_offset,
1297 size_t bytes)
Todd Kjos8ced0c62019-02-08 10:35:15 -08001298{
Todd Kjosbb4a2e482019-06-28 09:50:12 -07001299 return binder_alloc_do_buffer_copy(alloc, false, buffer, buffer_offset,
1300 dest, bytes);
Todd Kjos8ced0c62019-02-08 10:35:15 -08001301}
1302