ashmem.c revision 781114ced258bac3cff00342c9dafda1afe93c6d
111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* mm/ashmem.c 22258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * 32258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * Anonymous Shared Memory Subsystem, ashmem 42258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * 52258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * Copyright (C) 2008 Google, Inc. 62258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * 72258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * Robert Love <rlove@google.com> 82258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * 92258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * This software is licensed under the terms of the GNU General Public 102258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * License version 2, as published by the Free Software Foundation, and 112258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * may be copied, distributed, and modified under those terms. 122258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * 132258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * This program is distributed in the hope that it will be useful, 142258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * but WITHOUT ANY WARRANTY; without even the implied warranty of 152258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 162258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop * GNU General Public License for more details. 172258937b2137214bae796ec929394a282f531ed7Cruz Julian Bishop */ 1811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 19c810a399798022d545191e2daaca0368623c15d3Sachin Kamat#define pr_fmt(fmt) "ashmem: " fmt 20c810a399798022d545191e2daaca0368623c15d3Sachin Kamat 2111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include <linux/module.h> 2211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include <linux/file.h> 2311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include <linux/fs.h> 243f31d07571eeea18a7d34db9af21d2285b807a17Hugh Dickins#include <linux/falloc.h> 2511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include <linux/miscdevice.h> 2611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include <linux/security.h> 2711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include <linux/mm.h> 2811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include <linux/mman.h> 2911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include <linux/uaccess.h> 3011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include <linux/personality.h> 3111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include <linux/bitops.h> 3211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include <linux/mutex.h> 3311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include <linux/shmem_fs.h> 3411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#include "ashmem.h" 3511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 3611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define ASHMEM_NAME_PREFIX "dev/ashmem/" 3711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define ASHMEM_NAME_PREFIX_LEN (sizeof(ASHMEM_NAME_PREFIX) - 1) 3811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define ASHMEM_FULL_NAME_LEN (ASHMEM_NAME_LEN + ASHMEM_NAME_PREFIX_LEN) 3911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 404d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop/** 414d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * struct ashmem_area - The anonymous shared memory area 424d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @name: The optional name in /proc/pid/maps 434d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @unpinned_list: The list of all ashmem areas 444d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @file: The shmem-based backing file 454d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @size: The size of the mapping, in bytes 464d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @prot_masks: The allowed protection bits, as vm_flags 474d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * 484d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * The lifecycle of this structure is from our parent file's open() until 494d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * its release(). It is also protected by 'ashmem_mutex' 504d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * 514d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * Warning: Mappings do NOT pin this structure; It dies on close() 5211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 5311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestruct ashmem_area { 544d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop char name[ASHMEM_FULL_NAME_LEN]; 554d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop struct list_head unpinned_list; 564d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop struct file *file; 574d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop size_t size; 584d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop unsigned long prot_mask; 5911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love}; 6011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 614d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop/** 624d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * struct ashmem_range - A range of unpinned/evictable pages 634d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @lru: The entry in the LRU list 644d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @unpinned: The entry in its area's unpinned list 654d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @asma: The associated anonymous shared memory area. 664d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @pgstart: The starting page (inclusive) 674d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @pgend: The ending page (inclusive) 684d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @purged: The purge status (ASHMEM_NOT or ASHMEM_WAS_PURGED) 694d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * 704d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * The lifecycle of this structure is from unpin to pin. 714d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * It is protected by 'ashmem_mutex' 7211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 7311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestruct ashmem_range { 744d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop struct list_head lru; 754d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop struct list_head unpinned; 764d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop struct ashmem_area *asma; 774d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop size_t pgstart; 784d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop size_t pgend; 794d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop unsigned int purged; 8011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love}; 8111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 8211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* LRU list of unpinned pages, protected by ashmem_mutex */ 8311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic LIST_HEAD(ashmem_lru_list); 8411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 854d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop/** 864d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * long lru_count - The count of pages on our LRU list. 874d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * 884d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * This is protected by ashmem_mutex. 894d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop */ 9011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic unsigned long lru_count; 9111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 924d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop/** 9311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * ashmem_mutex - protects the list of and each individual ashmem_area 9411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 9511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Lock Ordering: ashmex_mutex -> i_mutex -> i_alloc_sem 9611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 9711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic DEFINE_MUTEX(ashmem_mutex); 9811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 9911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic struct kmem_cache *ashmem_area_cachep __read_mostly; 10011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic struct kmem_cache *ashmem_range_cachep __read_mostly; 10111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 10211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define range_size(range) \ 1031efb34394a694b458d66f25072318c375e22afe2John Stultz ((range)->pgend - (range)->pgstart + 1) 10411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 10511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define range_on_lru(range) \ 1061efb34394a694b458d66f25072318c375e22afe2John Stultz ((range)->purged == ASHMEM_NOT_PURGED) 10711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 10811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define page_range_subsumes_range(range, start, end) \ 1091efb34394a694b458d66f25072318c375e22afe2John Stultz (((range)->pgstart >= (start)) && ((range)->pgend <= (end))) 11011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 11111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define page_range_subsumed_by_range(range, start, end) \ 1121efb34394a694b458d66f25072318c375e22afe2John Stultz (((range)->pgstart <= (start)) && ((range)->pgend >= (end))) 11311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 11411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define page_in_range(range, page) \ 1151efb34394a694b458d66f25072318c375e22afe2John Stultz (((range)->pgstart <= (page)) && ((range)->pgend >= (page))) 11611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 11711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define page_range_in_range(range, start, end) \ 1181efb34394a694b458d66f25072318c375e22afe2John Stultz (page_in_range(range, start) || page_in_range(range, end) || \ 1191efb34394a694b458d66f25072318c375e22afe2John Stultz page_range_subsumes_range(range, start, end)) 12011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 12111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define range_before_page(range, page) \ 1221efb34394a694b458d66f25072318c375e22afe2John Stultz ((range)->pgend < (page)) 12311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 12411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define PROT_MASK (PROT_EXEC | PROT_READ | PROT_WRITE) 12511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 1264d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop/** 1274d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * lru_add() - Adds a range of memory to the LRU list 1284d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @range: The memory range being added. 1294d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * 1304d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * The range is first added to the end (tail) of the LRU list. 1314d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * After this, the size of the range is added to @lru_count 1324d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop */ 13311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic inline void lru_add(struct ashmem_range *range) 13411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 13511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_add_tail(&range->lru, &ashmem_lru_list); 13611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love lru_count += range_size(range); 13711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 13811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 1394d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop/** 1404d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * lru_del() - Removes a range of memory from the LRU list 1414d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @range: The memory range being removed 1424d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * 1434d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * The range is first deleted from the LRU list. 1444d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * After this, the size of the range is removed from @lru_count 1454d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop */ 14611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic inline void lru_del(struct ashmem_range *range) 14711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 14811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_del(&range->lru); 14911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love lru_count -= range_size(range); 15011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 15111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 1524d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop/** 1534d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * range_alloc() - Allocates and initializes a new ashmem_range structure 1544d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @asma: The associated ashmem_area 1554d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @prev_range: The previous ashmem_range in the sorted asma->unpinned list 1564d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @purged: Initial purge status (ASMEM_NOT_PURGED or ASHMEM_WAS_PURGED) 1574d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @start: The starting page (inclusive) 1584d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @end: The ending page (inclusive) 15911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 1604d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * This function is protected by ashmem_mutex. 16111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 1624d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * Return: 0 if successful, or -ENOMEM if there is an error 16311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 16411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int range_alloc(struct ashmem_area *asma, 16511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *prev_range, unsigned int purged, 16611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love size_t start, size_t end) 16711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 16811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *range; 16911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 17011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range = kmem_cache_zalloc(ashmem_range_cachep, GFP_KERNEL); 17111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(!range)) 17211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -ENOMEM; 17311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 17411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->asma = asma; 17511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->pgstart = start; 17611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->pgend = end; 17711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->purged = purged; 17811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 17911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_add_tail(&range->unpinned, &prev_range->unpinned); 18011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 18111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range_on_lru(range)) 18211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love lru_add(range); 18311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 18411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return 0; 18511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 18611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 1874d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop/** 1884d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * range_del() - Deletes and dealloctes an ashmem_range structure 1894d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop * @range: The associated ashmem_range that has previously been allocated 1904d2c9d5ddc3a38abb12253b4fd6ac05bfc3b4462Cruz Julian Bishop */ 19111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic void range_del(struct ashmem_range *range) 19211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 19311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_del(&range->unpinned); 19411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range_on_lru(range)) 19511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love lru_del(range); 19611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love kmem_cache_free(ashmem_range_cachep, range); 19711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 19811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 199781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop/** 200781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * range_shrink() - Shrinks an ashmem_range 201781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * @range: The associated ashmem_range being shrunk 202781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * @start: The starting byte of the new range 203781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * @end: The ending byte of the new range 204781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * 205781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * This does not modify the data inside the existing range in any way - It 206781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * simply shrinks the boundaries of the range. 20711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 208781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * Theoretically, with a little tweaking, this could eventually be changed 209781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * to range_resize, and expand the lru_count if the new range is larger. 21011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 21111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic inline void range_shrink(struct ashmem_range *range, 21211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love size_t start, size_t end) 21311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 21411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love size_t pre = range_size(range); 21511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 21611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->pgstart = start; 21711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->pgend = end; 21811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 21911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range_on_lru(range)) 22011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love lru_count -= pre - range_size(range); 22111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 22211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 223781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop/** 224781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * ashmem_open() - Opens an Anonymous Shared Memory structure 225781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * @inode: The backing file's index node(?) 226781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * @file: The backing file 227781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * 228781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * Please note that the ashmem_area is not returned by this function - It is 229781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * instead written to "file->private_data". 230781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * 231781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * Return: 0 if successful, or another code if unsuccessful. 232781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop */ 23311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_open(struct inode *inode, struct file *file) 23411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 23511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_area *asma; 23611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret; 23711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 2385154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert ret = generic_file_open(inode, file); 23911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(ret)) 24011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 24111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 24211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love asma = kmem_cache_zalloc(ashmem_area_cachep, GFP_KERNEL); 24311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(!asma)) 24411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -ENOMEM; 24511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 24611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love INIT_LIST_HEAD(&asma->unpinned_list); 24711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love memcpy(asma->name, ASHMEM_NAME_PREFIX, ASHMEM_NAME_PREFIX_LEN); 24811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love asma->prot_mask = PROT_MASK; 24911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love file->private_data = asma; 25011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 25111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return 0; 25211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 25311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 254781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop/** 255781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * ashmem_release() - Releases an Anonymous Shared Memory structure 256781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * @ignored: The backing file's Index Node(?) - It is ignored here. 257781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * @file: The backing file 258781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * 259781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * Return: 0 if successful. If it is anything else, go have a coffee and 260781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * try again. 261781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop */ 26211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_release(struct inode *ignored, struct file *file) 26311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 26411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_area *asma = file->private_data; 26511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *range, *next; 26611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 26711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_lock(&ashmem_mutex); 26811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) 26911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_del(range); 27011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 27111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 27211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (asma->file) 27311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love fput(asma->file); 27411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love kmem_cache_free(ashmem_area_cachep, asma); 27511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 27611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return 0; 27711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 27811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 279781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop/** 280781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * ashmem_read() - Reads a set of bytes from an Ashmem-enabled file 281781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * @file: The associated backing file. 282781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * @buf: The buffer of data being written to 283781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * @len: The number of bytes being read 284781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * @pos: The position of the first byte to read. 285781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * 286781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop * Return: 0 if successful, or another return code if not. 287781114ced258bac3cff00342c9dafda1afe93c6dCruz Julian Bishop */ 288853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringertstatic ssize_t ashmem_read(struct file *file, char __user *buf, 289853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert size_t len, loff_t *pos) 290853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert{ 291853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert struct ashmem_area *asma = file->private_data; 292853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert int ret = 0; 293853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 294853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert mutex_lock(&ashmem_mutex); 295853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 296853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert /* If size is not set, or set to 0, always return EOF. */ 2971efb34394a694b458d66f25072318c375e22afe2John Stultz if (asma->size == 0) 298853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert goto out; 299853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 300853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert if (!asma->file) { 301853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert ret = -EBADF; 302853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert goto out; 303853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert } 304853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 305853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert ret = asma->file->f_op->read(asma->file, buf, len, pos); 3061efb34394a694b458d66f25072318c375e22afe2John Stultz if (ret < 0) 3075154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert goto out; 3085154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 3095154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert /** Update backing file pos, since f_ops->read() doesn't */ 3105154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert asma->file->f_pos = *pos; 3115154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 3125154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringertout: 3135154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert mutex_unlock(&ashmem_mutex); 3145154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert return ret; 3155154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert} 3165154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 3175154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringertstatic loff_t ashmem_llseek(struct file *file, loff_t offset, int origin) 3185154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert{ 3195154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert struct ashmem_area *asma = file->private_data; 3205154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert int ret; 3215154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 3225154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert mutex_lock(&ashmem_mutex); 3235154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 3245154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert if (asma->size == 0) { 3255154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert ret = -EINVAL; 3265154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert goto out; 3275154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert } 3285154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 3295154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert if (!asma->file) { 3305154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert ret = -EBADF; 3315154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert goto out; 3325154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert } 3335154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 3345154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert ret = asma->file->f_op->llseek(asma->file, offset, origin); 3351efb34394a694b458d66f25072318c375e22afe2John Stultz if (ret < 0) 3365154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert goto out; 3375154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 3385154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert /** Copy f_pos from backing file, since f_ops->llseek() sets it */ 3395154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert file->f_pos = asma->file->f_pos; 340853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 341853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringertout: 342853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert mutex_unlock(&ashmem_mutex); 343853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert return ret; 344853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert} 345853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 3467cfce77d779f43299c1cfeddd72462fed596c168Konstantin Khlebnikovstatic inline vm_flags_t calc_vm_may_flags(unsigned long prot) 34756f76fc68492af718fff88927bc296635d634b78Arve Hjønnevåg{ 3481efb34394a694b458d66f25072318c375e22afe2John Stultz return _calc_vm_trans(prot, PROT_READ, VM_MAYREAD) | 34956f76fc68492af718fff88927bc296635d634b78Arve Hjønnevåg _calc_vm_trans(prot, PROT_WRITE, VM_MAYWRITE) | 35056f76fc68492af718fff88927bc296635d634b78Arve Hjønnevåg _calc_vm_trans(prot, PROT_EXEC, VM_MAYEXEC); 35156f76fc68492af718fff88927bc296635d634b78Arve Hjønnevåg} 352853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 35311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_mmap(struct file *file, struct vm_area_struct *vma) 35411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 35511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_area *asma = file->private_data; 35611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = 0; 35711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 35811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_lock(&ashmem_mutex); 35911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 36011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* user needs to SET_SIZE before mapping */ 36111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(!asma->size)) { 36211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = -EINVAL; 36311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto out; 36411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 36511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 36611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* requested protection bits must match our allowed protection mask */ 36756f76fc68492af718fff88927bc296635d634b78Arve Hjønnevåg if (unlikely((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask)) & 3681efb34394a694b458d66f25072318c375e22afe2John Stultz calc_vm_prot_bits(PROT_MASK))) { 36911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = -EPERM; 37011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto out; 37111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 37256f76fc68492af718fff88927bc296635d634b78Arve Hjønnevåg vma->vm_flags &= ~calc_vm_may_flags(~asma->prot_mask); 37311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 37411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (!asma->file) { 37511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love char *name = ASHMEM_NAME_DEF; 37611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct file *vmfile; 37711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 37811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0') 37911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love name = asma->name; 38011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 38111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* ... and allocate the backing shmem file */ 38211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love vmfile = shmem_file_setup(name, asma->size, vma->vm_flags); 38311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(IS_ERR(vmfile))) { 38411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = PTR_ERR(vmfile); 38511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto out; 38611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 38711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love asma->file = vmfile; 38811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 38911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love get_file(asma->file); 39011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 39111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* 392aa5af974127d317071d6225a0f3678c5f520e7ceTracey Dent * XXX - Reworked to use shmem_zero_setup() instead of 39311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * shmem_set_file while we're in staging. -jstultz 39411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 39511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (vma->vm_flags & VM_SHARED) { 39611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = shmem_zero_setup(vma); 39711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (ret) { 39811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love fput(asma->file); 39911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto out; 40011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 40111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 40211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 40311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (vma->vm_file) 40411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love fput(vma->vm_file); 40511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love vma->vm_file = asma->file; 40611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 40711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Loveout: 40811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 40911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 41011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 41111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 41211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 41311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * ashmem_shrink - our cache shrinker, called from mm/vmscan.c :: shrink_slab 41411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 4157dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner * 'nr_to_scan' is the number of objects to scan for freeing. 41611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 41711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 'gfp_mask' is the mask of the allocation that got us into this mess. 41811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 4197dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner * Return value is the number of objects freed or -1 if we cannot 42011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * proceed without risk of deadlock (due to gfp_mask). 42111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 42211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * We approximate LRU via least-recently-unpinned, jettisoning unpinned partial 42311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * chunks of ashmem regions LRU-wise one-at-a-time until we hit 'nr_to_scan' 42411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * pages freed. 42511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 4267dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinnerstatic unsigned long 4277dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinnerashmem_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) 42811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 42911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *range, *next; 4307dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner unsigned long freed = 0; 43111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 43211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* We might recurse into filesystem code, so bail out if necessary */ 4337dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner if (!(sc->gfp_mask & __GFP_FS)) 4347dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner return SHRINK_STOP; 43511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 43611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_lock(&ashmem_mutex); 43711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_for_each_entry_safe(range, next, &ashmem_lru_list, lru) { 43811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love loff_t start = range->pgstart * PAGE_SIZE; 4393f31d07571eeea18a7d34db9af21d2285b807a17Hugh Dickins loff_t end = (range->pgend + 1) * PAGE_SIZE; 44011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 4413f31d07571eeea18a7d34db9af21d2285b807a17Hugh Dickins do_fallocate(range->asma->file, 4423f31d07571eeea18a7d34db9af21d2285b807a17Hugh Dickins FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, 4433f31d07571eeea18a7d34db9af21d2285b807a17Hugh Dickins start, end - start); 44411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->purged = ASHMEM_WAS_PURGED; 44511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love lru_del(range); 44611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 4477dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner freed += range_size(range); 4487dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner if (--sc->nr_to_scan <= 0) 44911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 45011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 45111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 4527dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner return freed; 4537dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner} 45411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 4557dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinnerstatic unsigned long 4567dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinnerashmem_shrink_count(struct shrinker *shrink, struct shrink_control *sc) 4577dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner{ 4587dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner /* 4597dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner * note that lru_count is count of pages on the lru, not a count of 4607dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner * objects on the list. This means the scan function needs to return the 4617dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner * number of pages freed, not the number of objects scanned. 4627dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner */ 46311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return lru_count; 46411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 46511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 46611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic struct shrinker ashmem_shrinker = { 4677dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner .count_objects = ashmem_shrink_count, 4687dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner .scan_objects = ashmem_shrink_scan, 4697dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner /* 4707dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner * XXX (dchinner): I wish people would comment on why they need on 4717dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner * significant changes to the default value here 4727dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner */ 47311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .seeks = DEFAULT_SEEKS * 4, 47411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love}; 47511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 47611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int set_prot_mask(struct ashmem_area *asma, unsigned long prot) 47711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 47811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = 0; 47911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 48011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_lock(&ashmem_mutex); 48111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 48211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* the user can only remove, not add, protection bits */ 48311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely((asma->prot_mask & prot) != prot)) { 48411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = -EINVAL; 48511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto out; 48611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 48711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 48811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* does the application expect PROT_READ to imply PROT_EXEC? */ 48911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC)) 49011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love prot |= PROT_EXEC; 49111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 49211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love asma->prot_mask = prot; 49311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 49411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Loveout: 49511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 49611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 49711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 49811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 49911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int set_name(struct ashmem_area *asma, void __user *name) 50011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 50111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = 0; 502e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran char local_name[ASHMEM_NAME_LEN]; 50311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 504e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran /* 505e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * Holding the ashmem_mutex while doing a copy_from_user might cause 506e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * an data abort which would try to access mmap_sem. If another 507e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * thread has invoked ashmem_mmap then it will be holding the 508e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * semaphore and will be waiting for ashmem_mutex, there by leading to 509e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * deadlock. We'll release the mutex and take the name to a local 510e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * variable that does not need protection and later copy the local 511e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * variable to the structure member with lock held. 512e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran */ 513e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran if (copy_from_user(local_name, name, ASHMEM_NAME_LEN)) 514e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran return -EFAULT; 51511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 516e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran mutex_lock(&ashmem_mutex); 51711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* cannot change an existing mapping's name */ 51811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(asma->file)) { 51911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = -EINVAL; 52011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto out; 52111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 522e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran memcpy(asma->name + ASHMEM_NAME_PREFIX_LEN, 523e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran local_name, ASHMEM_NAME_LEN); 52411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love asma->name[ASHMEM_FULL_NAME_LEN-1] = '\0'; 52511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Loveout: 52611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 52711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 52811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 52911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 53011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 53111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int get_name(struct ashmem_area *asma, void __user *name) 53211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 53311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = 0; 534e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran size_t len; 535e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran /* 536e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * Have a local variable to which we'll copy the content 537e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * from asma with the lock held. Later we can copy this to the user 538e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * space safely without holding any locks. So even if we proceed to 539e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * wait for mmap_sem, it won't lead to deadlock. 540e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran */ 541e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran char local_name[ASHMEM_NAME_LEN]; 54211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 54311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_lock(&ashmem_mutex); 54411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0') { 54511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 54611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* 54711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Copying only `len', instead of ASHMEM_NAME_LEN, bytes 54811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * prevents us from revealing one user's stack to another. 54911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 55011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love len = strlen(asma->name + ASHMEM_NAME_PREFIX_LEN) + 1; 551e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran memcpy(local_name, asma->name + ASHMEM_NAME_PREFIX_LEN, len); 55211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } else { 553e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran len = sizeof(ASHMEM_NAME_DEF); 554e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran memcpy(local_name, ASHMEM_NAME_DEF, len); 55511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 55611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 55711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 558e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran /* 559e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * Now we are just copying from the stack variable to userland 560e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * No lock held 561e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran */ 562e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran if (unlikely(copy_to_user(name, local_name, len))) 563e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran ret = -EFAULT; 56411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 56511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 56611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 56711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 56811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * ashmem_pin - pin the given ashmem region, returning whether it was 56911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * previously purged (ASHMEM_WAS_PURGED) or not (ASHMEM_NOT_PURGED). 57011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 57111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Caller must hold ashmem_mutex. 57211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 57311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_pin(struct ashmem_area *asma, size_t pgstart, size_t pgend) 57411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 57511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *range, *next; 57611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = ASHMEM_NOT_PURGED; 57711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 57811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) { 57911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* moved past last applicable page; we can short circuit */ 58011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range_before_page(range, pgstart)) 58111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 58211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 58311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* 58411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * The user can ask us to pin pages that span multiple ranges, 58511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * or to pin pages that aren't even unpinned, so this is messy. 58611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 58711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Four cases: 58811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 1. The requested range subsumes an existing range, so we 58911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * just remove the entire matching range. 59011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 2. The requested range overlaps the start of an existing 59111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * range, so we just update that range. 59211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 3. The requested range overlaps the end of an existing 59311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * range, so we just update that range. 59411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 4. The requested range punches a hole in an existing range, 59511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * so we have to update one side of the range and then 59611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * create a new range for the other side. 59711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 59811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (page_range_in_range(range, pgstart, pgend)) { 59911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret |= range->purged; 60011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 60111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* Case #1: Easy. Just nuke the whole thing. */ 60211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (page_range_subsumes_range(range, pgstart, pgend)) { 60311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_del(range); 60411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love continue; 60511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 60611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 60711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* Case #2: We overlap from the start, so adjust it */ 60811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range->pgstart >= pgstart) { 60911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_shrink(range, pgend + 1, range->pgend); 61011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love continue; 61111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 61211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 61311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* Case #3: We overlap from the rear, so adjust it */ 61411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range->pgend <= pgend) { 61511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_shrink(range, range->pgstart, pgstart-1); 61611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love continue; 61711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 61811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 61911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* 62011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Case #4: We eat a chunk out of the middle. A bit 62111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * more complicated, we allocate a new range for the 62211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * second half and adjust the first chunk's endpoint. 62311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 62411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_alloc(asma, range, range->purged, 62511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love pgend + 1, range->pgend); 62611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_shrink(range, range->pgstart, pgstart - 1); 62711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 62811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 62911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 63011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 63111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 63211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 63311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 63411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 63511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * ashmem_unpin - unpin the given range of pages. Returns zero on success. 63611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 63711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Caller must hold ashmem_mutex. 63811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 63911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_unpin(struct ashmem_area *asma, size_t pgstart, size_t pgend) 64011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 64111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *range, *next; 64211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love unsigned int purged = ASHMEM_NOT_PURGED; 64311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 64411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Loverestart: 64511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) { 64611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* short circuit: this is our insertion point */ 64711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range_before_page(range, pgstart)) 64811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 64911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 65011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* 65111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * The user can ask us to unpin pages that are already entirely 65211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * or partially pinned. We handle those two cases here. 65311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 65411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (page_range_subsumed_by_range(range, pgstart, pgend)) 65511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return 0; 65611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (page_range_in_range(range, pgstart, pgend)) { 65711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love pgstart = min_t(size_t, range->pgstart, pgstart), 65811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love pgend = max_t(size_t, range->pgend, pgend); 65911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love purged |= range->purged; 66011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_del(range); 66111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto restart; 66211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 66311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 66411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 66511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return range_alloc(asma, range, purged, pgstart, pgend); 66611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 66711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 66811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 66911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * ashmem_get_pin_status - Returns ASHMEM_IS_UNPINNED if _any_ pages in the 67011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * given interval are unpinned and ASHMEM_IS_PINNED otherwise. 67111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 67211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Caller must hold ashmem_mutex. 67311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 67411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_get_pin_status(struct ashmem_area *asma, size_t pgstart, 67511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love size_t pgend) 67611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 67711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *range; 67811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = ASHMEM_IS_PINNED; 67911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 68011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_for_each_entry(range, &asma->unpinned_list, unpinned) { 68111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range_before_page(range, pgstart)) 68211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 68311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (page_range_in_range(range, pgstart, pgend)) { 68411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = ASHMEM_IS_UNPINNED; 68511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 68611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 68711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 68811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 68911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 69011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 69111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 69211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_pin_unpin(struct ashmem_area *asma, unsigned long cmd, 69311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love void __user *p) 69411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 69511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_pin pin; 69611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love size_t pgstart, pgend; 69711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = -EINVAL; 69811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 69911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(!asma->file)) 70011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -EINVAL; 70111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 70211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(copy_from_user(&pin, p, sizeof(pin)))) 70311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -EFAULT; 70411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 70511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* per custom, you can pass zero for len to mean "everything onward" */ 70611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (!pin.len) 70711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love pin.len = PAGE_ALIGN(asma->size) - pin.offset; 70811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 70911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely((pin.offset | pin.len) & ~PAGE_MASK)) 71011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -EINVAL; 71111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 71211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(((__u32) -1) - pin.offset < pin.len)) 71311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -EINVAL; 71411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 71511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(PAGE_ALIGN(asma->size) < pin.offset + pin.len)) 71611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -EINVAL; 71711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 71811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love pgstart = pin.offset / PAGE_SIZE; 71911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love pgend = pgstart + (pin.len / PAGE_SIZE) - 1; 72011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 72111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_lock(&ashmem_mutex); 72211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 72311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love switch (cmd) { 72411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_PIN: 72511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = ashmem_pin(asma, pgstart, pgend); 72611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 72711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_UNPIN: 72811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = ashmem_unpin(asma, pgstart, pgend); 72911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 73011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_GET_PIN_STATUS: 73111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = ashmem_get_pin_status(asma, pgstart, pgend); 73211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 73311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 73411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 73511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 73611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 73711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 73811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 73911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 74011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 74111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 74211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_area *asma = file->private_data; 74311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love long ret = -ENOTTY; 74411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 74511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love switch (cmd) { 74611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_SET_NAME: 74711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = set_name(asma, (void __user *) arg); 74811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 74911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_GET_NAME: 75011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = get_name(asma, (void __user *) arg); 75111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 75211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_SET_SIZE: 75311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = -EINVAL; 75411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (!asma->file) { 75511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = 0; 75611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love asma->size = (size_t) arg; 75711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 75811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 75911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_GET_SIZE: 76011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = asma->size; 76111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 76211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_SET_PROT_MASK: 76311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = set_prot_mask(asma, arg); 76411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 76511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_GET_PROT_MASK: 76611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = asma->prot_mask; 76711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 76811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_PIN: 76911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_UNPIN: 77011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_GET_PIN_STATUS: 77111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = ashmem_pin_unpin(asma, cmd, (void __user *) arg); 77211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 77311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_PURGE_ALL_CACHES: 77411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = -EPERM; 77511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (capable(CAP_SYS_ADMIN)) { 77633e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross struct shrink_control sc = { 77733e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross .gfp_mask = GFP_KERNEL, 7787dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner .nr_to_scan = LONG_MAX, 77933e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross }; 7800ce3d74450815500e31f16a0b65f6bab687985c3Dave Chinner 7810ce3d74450815500e31f16a0b65f6bab687985c3Dave Chinner nodes_setall(sc.nodes_to_scan); 7827dc19d5affd71370754a2c3d36b485810eaee7a1Dave Chinner ashmem_shrink_scan(&ashmem_shrinker, &sc); 78311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 78411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 78511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 78611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 78711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 78811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 78911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 790e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu/* support of 32bit userspace on 64bit platforms */ 791e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu#ifdef CONFIG_COMPAT 792017ca3bf4aa28871a5a19830ca27e1f4726c26ecMarlies Ruckstatic long compat_ashmem_ioctl(struct file *file, unsigned int cmd, 793017ca3bf4aa28871a5a19830ca27e1f4726c26ecMarlies Ruck unsigned long arg) 794e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu{ 795e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu 796e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu switch (cmd) { 797e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu case COMPAT_ASHMEM_SET_SIZE: 798e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu cmd = ASHMEM_SET_SIZE; 799e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu break; 800e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu case COMPAT_ASHMEM_SET_PROT_MASK: 801e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu cmd = ASHMEM_SET_PROT_MASK; 802e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu break; 803e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu } 804e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu return ashmem_ioctl(file, cmd, arg); 805e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu} 806e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu#endif 807e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu 808aa5af974127d317071d6225a0f3678c5f520e7ceTracey Dentstatic const struct file_operations ashmem_fops = { 80911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .owner = THIS_MODULE, 81011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .open = ashmem_open, 81111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .release = ashmem_release, 8121efb34394a694b458d66f25072318c375e22afe2John Stultz .read = ashmem_read, 8131efb34394a694b458d66f25072318c375e22afe2John Stultz .llseek = ashmem_llseek, 81411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .mmap = ashmem_mmap, 81511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .unlocked_ioctl = ashmem_ioctl, 816e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu#ifdef CONFIG_COMPAT 817e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu .compat_ioctl = compat_ashmem_ioctl, 818e9f5b8145af9a0ee34e98cf01dcd3afb87225538Serban Constantinescu#endif 81911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love}; 82011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 82111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic struct miscdevice ashmem_misc = { 82211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .minor = MISC_DYNAMIC_MINOR, 82311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .name = "ashmem", 82411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .fops = &ashmem_fops, 82511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love}; 82611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 82711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int __init ashmem_init(void) 82811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 82911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret; 83011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 83111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ashmem_area_cachep = kmem_cache_create("ashmem_area_cache", 83211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love sizeof(struct ashmem_area), 83311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 0, 0, NULL); 83411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(!ashmem_area_cachep)) { 835c810a399798022d545191e2daaca0368623c15d3Sachin Kamat pr_err("failed to create slab cache\n"); 83611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -ENOMEM; 83711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 83811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 83911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ashmem_range_cachep = kmem_cache_create("ashmem_range_cache", 84011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love sizeof(struct ashmem_range), 84111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 0, 0, NULL); 84211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(!ashmem_range_cachep)) { 843c810a399798022d545191e2daaca0368623c15d3Sachin Kamat pr_err("failed to create slab cache\n"); 84411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -ENOMEM; 84511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 84611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 84711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = misc_register(&ashmem_misc); 84811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(ret)) { 849c810a399798022d545191e2daaca0368623c15d3Sachin Kamat pr_err("failed to register misc device!\n"); 85011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 85111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 85211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 85311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love register_shrinker(&ashmem_shrinker); 85411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 855c810a399798022d545191e2daaca0368623c15d3Sachin Kamat pr_info("initialized\n"); 85611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 85711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return 0; 85811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 85911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 86011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic void __exit ashmem_exit(void) 86111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 86211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret; 86311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 86411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love unregister_shrinker(&ashmem_shrinker); 86511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 86611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = misc_deregister(&ashmem_misc); 86711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(ret)) 868c810a399798022d545191e2daaca0368623c15d3Sachin Kamat pr_err("failed to unregister misc device!\n"); 86911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 87011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love kmem_cache_destroy(ashmem_range_cachep); 87111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love kmem_cache_destroy(ashmem_area_cachep); 87211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 873c810a399798022d545191e2daaca0368623c15d3Sachin Kamat pr_info("unloaded\n"); 87411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 87511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 87611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovemodule_init(ashmem_init); 87711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovemodule_exit(ashmem_exit); 87811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 87911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert LoveMODULE_LICENSE("GPL"); 880