ashmem.c revision e5834d620d61d01444c41958f1816d688a96433c
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 4011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 4111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * ashmem_area - anonymous shared memory area 4211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Lifecycle: From our parent file's open() until its release() 4311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Locking: Protected by `ashmem_mutex' 4411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Big Note: Mappings do NOT pin this structure; it dies on close() 4511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 4611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestruct ashmem_area { 471efb34394a694b458d66f25072318c375e22afe2John Stultz char name[ASHMEM_FULL_NAME_LEN]; /* optional name in /proc/pid/maps */ 481efb34394a694b458d66f25072318c375e22afe2John Stultz struct list_head unpinned_list; /* list of all ashmem areas */ 491efb34394a694b458d66f25072318c375e22afe2John Stultz struct file *file; /* the shmem-based backing file */ 501efb34394a694b458d66f25072318c375e22afe2John Stultz size_t size; /* size of the mapping, in bytes */ 511efb34394a694b458d66f25072318c375e22afe2John Stultz unsigned long prot_mask; /* allowed prot bits, as vm_flags */ 5211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love}; 5311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 5411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 5511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * ashmem_range - represents an interval of unpinned (evictable) pages 5611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Lifecycle: From unpin to pin 5711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Locking: Protected by `ashmem_mutex' 5811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 5911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestruct ashmem_range { 6011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct list_head lru; /* entry in LRU list */ 6111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct list_head unpinned; /* entry in its area's unpinned list */ 6211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_area *asma; /* associated area */ 6311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love size_t pgstart; /* starting page, inclusive */ 6411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love size_t pgend; /* ending page, inclusive */ 6511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love unsigned int purged; /* ASHMEM_NOT or ASHMEM_WAS_PURGED */ 6611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love}; 6711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 6811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* LRU list of unpinned pages, protected by ashmem_mutex */ 6911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic LIST_HEAD(ashmem_lru_list); 7011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 7111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* Count of pages on our LRU list, protected by ashmem_mutex */ 7211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic unsigned long lru_count; 7311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 7411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 7511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * ashmem_mutex - protects the list of and each individual ashmem_area 7611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 7711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Lock Ordering: ashmex_mutex -> i_mutex -> i_alloc_sem 7811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 7911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic DEFINE_MUTEX(ashmem_mutex); 8011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 8111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic struct kmem_cache *ashmem_area_cachep __read_mostly; 8211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic struct kmem_cache *ashmem_range_cachep __read_mostly; 8311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 8411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define range_size(range) \ 851efb34394a694b458d66f25072318c375e22afe2John Stultz ((range)->pgend - (range)->pgstart + 1) 8611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 8711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define range_on_lru(range) \ 881efb34394a694b458d66f25072318c375e22afe2John Stultz ((range)->purged == ASHMEM_NOT_PURGED) 8911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 9011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define page_range_subsumes_range(range, start, end) \ 911efb34394a694b458d66f25072318c375e22afe2John Stultz (((range)->pgstart >= (start)) && ((range)->pgend <= (end))) 9211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 9311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define page_range_subsumed_by_range(range, start, end) \ 941efb34394a694b458d66f25072318c375e22afe2John Stultz (((range)->pgstart <= (start)) && ((range)->pgend >= (end))) 9511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 9611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define page_in_range(range, page) \ 971efb34394a694b458d66f25072318c375e22afe2John Stultz (((range)->pgstart <= (page)) && ((range)->pgend >= (page))) 9811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 9911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define page_range_in_range(range, start, end) \ 1001efb34394a694b458d66f25072318c375e22afe2John Stultz (page_in_range(range, start) || page_in_range(range, end) || \ 1011efb34394a694b458d66f25072318c375e22afe2John Stultz page_range_subsumes_range(range, start, end)) 10211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 10311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define range_before_page(range, page) \ 1041efb34394a694b458d66f25072318c375e22afe2John Stultz ((range)->pgend < (page)) 10511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 10611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love#define PROT_MASK (PROT_EXEC | PROT_READ | PROT_WRITE) 10711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 10811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic inline void lru_add(struct ashmem_range *range) 10911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 11011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_add_tail(&range->lru, &ashmem_lru_list); 11111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love lru_count += range_size(range); 11211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 11311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 11411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic inline void lru_del(struct ashmem_range *range) 11511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 11611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_del(&range->lru); 11711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love lru_count -= range_size(range); 11811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 11911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 12011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 12111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * range_alloc - allocate and initialize a new ashmem_range structure 12211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 12311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 'asma' - associated ashmem_area 12411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 'prev_range' - the previous ashmem_range in the sorted asma->unpinned list 12511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 'purged' - initial purge value (ASMEM_NOT_PURGED or ASHMEM_WAS_PURGED) 12611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 'start' - starting page, inclusive 12711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 'end' - ending page, inclusive 12811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 12911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Caller must hold ashmem_mutex. 13011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 13111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int range_alloc(struct ashmem_area *asma, 13211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *prev_range, unsigned int purged, 13311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love size_t start, size_t end) 13411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 13511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *range; 13611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 13711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range = kmem_cache_zalloc(ashmem_range_cachep, GFP_KERNEL); 13811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(!range)) 13911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -ENOMEM; 14011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 14111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->asma = asma; 14211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->pgstart = start; 14311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->pgend = end; 14411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->purged = purged; 14511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 14611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_add_tail(&range->unpinned, &prev_range->unpinned); 14711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 14811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range_on_lru(range)) 14911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love lru_add(range); 15011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 15111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return 0; 15211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 15311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 15411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic void range_del(struct ashmem_range *range) 15511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 15611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_del(&range->unpinned); 15711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range_on_lru(range)) 15811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love lru_del(range); 15911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love kmem_cache_free(ashmem_range_cachep, range); 16011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 16111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 16211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 16311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * range_shrink - shrinks a range 16411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 16511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Caller must hold ashmem_mutex. 16611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 16711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic inline void range_shrink(struct ashmem_range *range, 16811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love size_t start, size_t end) 16911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 17011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love size_t pre = range_size(range); 17111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 17211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->pgstart = start; 17311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->pgend = end; 17411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 17511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range_on_lru(range)) 17611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love lru_count -= pre - range_size(range); 17711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 17811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 17911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_open(struct inode *inode, struct file *file) 18011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 18111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_area *asma; 18211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret; 18311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 1845154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert ret = generic_file_open(inode, file); 18511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(ret)) 18611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 18711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 18811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love asma = kmem_cache_zalloc(ashmem_area_cachep, GFP_KERNEL); 18911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(!asma)) 19011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -ENOMEM; 19111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 19211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love INIT_LIST_HEAD(&asma->unpinned_list); 19311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love memcpy(asma->name, ASHMEM_NAME_PREFIX, ASHMEM_NAME_PREFIX_LEN); 19411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love asma->prot_mask = PROT_MASK; 19511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love file->private_data = asma; 19611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 19711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return 0; 19811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 19911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 20011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_release(struct inode *ignored, struct file *file) 20111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 20211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_area *asma = file->private_data; 20311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *range, *next; 20411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 20511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_lock(&ashmem_mutex); 20611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) 20711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_del(range); 20811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 20911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 21011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (asma->file) 21111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love fput(asma->file); 21211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love kmem_cache_free(ashmem_area_cachep, asma); 21311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 21411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return 0; 21511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 21611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 217853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringertstatic ssize_t ashmem_read(struct file *file, char __user *buf, 218853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert size_t len, loff_t *pos) 219853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert{ 220853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert struct ashmem_area *asma = file->private_data; 221853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert int ret = 0; 222853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 223853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert mutex_lock(&ashmem_mutex); 224853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 225853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert /* If size is not set, or set to 0, always return EOF. */ 2261efb34394a694b458d66f25072318c375e22afe2John Stultz if (asma->size == 0) 227853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert goto out; 228853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 229853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert if (!asma->file) { 230853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert ret = -EBADF; 231853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert goto out; 232853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert } 233853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 234853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert ret = asma->file->f_op->read(asma->file, buf, len, pos); 2351efb34394a694b458d66f25072318c375e22afe2John Stultz if (ret < 0) 2365154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert goto out; 2375154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 2385154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert /** Update backing file pos, since f_ops->read() doesn't */ 2395154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert asma->file->f_pos = *pos; 2405154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 2415154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringertout: 2425154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert mutex_unlock(&ashmem_mutex); 2435154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert return ret; 2445154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert} 2455154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 2465154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringertstatic loff_t ashmem_llseek(struct file *file, loff_t offset, int origin) 2475154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert{ 2485154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert struct ashmem_area *asma = file->private_data; 2495154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert int ret; 2505154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 2515154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert mutex_lock(&ashmem_mutex); 2525154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 2535154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert if (asma->size == 0) { 2545154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert ret = -EINVAL; 2555154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert goto out; 2565154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert } 2575154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 2585154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert if (!asma->file) { 2595154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert ret = -EBADF; 2605154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert goto out; 2615154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert } 2625154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 2635154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert ret = asma->file->f_op->llseek(asma->file, offset, origin); 2641efb34394a694b458d66f25072318c375e22afe2John Stultz if (ret < 0) 2655154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert goto out; 2665154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert 2675154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert /** Copy f_pos from backing file, since f_ops->llseek() sets it */ 2685154b93b8eceb57bdab4e77030bf21ead15b42e4Bjorn Bringert file->f_pos = asma->file->f_pos; 269853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 270853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringertout: 271853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert mutex_unlock(&ashmem_mutex); 272853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert return ret; 273853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert} 274853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 2757cfce77d779f43299c1cfeddd72462fed596c168Konstantin Khlebnikovstatic inline vm_flags_t calc_vm_may_flags(unsigned long prot) 27656f76fc68492af718fff88927bc296635d634b78Arve Hjønnevåg{ 2771efb34394a694b458d66f25072318c375e22afe2John Stultz return _calc_vm_trans(prot, PROT_READ, VM_MAYREAD) | 27856f76fc68492af718fff88927bc296635d634b78Arve Hjønnevåg _calc_vm_trans(prot, PROT_WRITE, VM_MAYWRITE) | 27956f76fc68492af718fff88927bc296635d634b78Arve Hjønnevåg _calc_vm_trans(prot, PROT_EXEC, VM_MAYEXEC); 28056f76fc68492af718fff88927bc296635d634b78Arve Hjønnevåg} 281853ca7ae292f9c4809e1e42914e81453eaa15367Bjorn Bringert 28211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_mmap(struct file *file, struct vm_area_struct *vma) 28311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 28411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_area *asma = file->private_data; 28511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = 0; 28611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 28711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_lock(&ashmem_mutex); 28811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 28911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* user needs to SET_SIZE before mapping */ 29011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(!asma->size)) { 29111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = -EINVAL; 29211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto out; 29311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 29411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 29511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* requested protection bits must match our allowed protection mask */ 29656f76fc68492af718fff88927bc296635d634b78Arve Hjønnevåg if (unlikely((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask)) & 2971efb34394a694b458d66f25072318c375e22afe2John Stultz calc_vm_prot_bits(PROT_MASK))) { 29811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = -EPERM; 29911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto out; 30011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 30156f76fc68492af718fff88927bc296635d634b78Arve Hjønnevåg vma->vm_flags &= ~calc_vm_may_flags(~asma->prot_mask); 30211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 30311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (!asma->file) { 30411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love char *name = ASHMEM_NAME_DEF; 30511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct file *vmfile; 30611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 30711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0') 30811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love name = asma->name; 30911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 31011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* ... and allocate the backing shmem file */ 31111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love vmfile = shmem_file_setup(name, asma->size, vma->vm_flags); 31211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(IS_ERR(vmfile))) { 31311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = PTR_ERR(vmfile); 31411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto out; 31511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 31611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love asma->file = vmfile; 31711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 31811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love get_file(asma->file); 31911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 32011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* 321aa5af974127d317071d6225a0f3678c5f520e7ceTracey Dent * XXX - Reworked to use shmem_zero_setup() instead of 32211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * shmem_set_file while we're in staging. -jstultz 32311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 32411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (vma->vm_flags & VM_SHARED) { 32511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = shmem_zero_setup(vma); 32611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (ret) { 32711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love fput(asma->file); 32811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto out; 32911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 33011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 33111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 33211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (vma->vm_file) 33311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love fput(vma->vm_file); 33411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love vma->vm_file = asma->file; 33511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 33611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Loveout: 33711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 33811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 33911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 34011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 34111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 34211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * ashmem_shrink - our cache shrinker, called from mm/vmscan.c :: shrink_slab 34311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 34411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 'nr_to_scan' is the number of objects (pages) to prune, or 0 to query how 34511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * many objects (pages) we have in total. 34611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 34711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 'gfp_mask' is the mask of the allocation that got us into this mess. 34811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 34911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Return value is the number of objects (pages) remaining, or -1 if we cannot 35011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * proceed without risk of deadlock (due to gfp_mask). 35111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 35211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * We approximate LRU via least-recently-unpinned, jettisoning unpinned partial 35311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * chunks of ashmem regions LRU-wise one-at-a-time until we hit 'nr_to_scan' 35411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * pages freed. 35511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 35633e8fc463eeec29227282e4bd2082f5928d629a5Colin Crossstatic int ashmem_shrink(struct shrinker *s, struct shrink_control *sc) 35711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 35811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *range, *next; 35911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 36011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* We might recurse into filesystem code, so bail out if necessary */ 36133e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross if (sc->nr_to_scan && !(sc->gfp_mask & __GFP_FS)) 36211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -1; 36333e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross if (!sc->nr_to_scan) 36411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return lru_count; 36511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 36611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_lock(&ashmem_mutex); 36711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_for_each_entry_safe(range, next, &ashmem_lru_list, lru) { 36811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love loff_t start = range->pgstart * PAGE_SIZE; 3693f31d07571eeea18a7d34db9af21d2285b807a17Hugh Dickins loff_t end = (range->pgend + 1) * PAGE_SIZE; 37011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 3713f31d07571eeea18a7d34db9af21d2285b807a17Hugh Dickins do_fallocate(range->asma->file, 3723f31d07571eeea18a7d34db9af21d2285b807a17Hugh Dickins FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, 3733f31d07571eeea18a7d34db9af21d2285b807a17Hugh Dickins start, end - start); 37411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range->purged = ASHMEM_WAS_PURGED; 37511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love lru_del(range); 37611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 37733e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross sc->nr_to_scan -= range_size(range); 37833e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross if (sc->nr_to_scan <= 0) 37911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 38011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 38111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 38211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 38311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return lru_count; 38411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 38511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 38611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic struct shrinker ashmem_shrinker = { 38711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .shrink = ashmem_shrink, 38811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .seeks = DEFAULT_SEEKS * 4, 38911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love}; 39011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 39111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int set_prot_mask(struct ashmem_area *asma, unsigned long prot) 39211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 39311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = 0; 39411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 39511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_lock(&ashmem_mutex); 39611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 39711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* the user can only remove, not add, protection bits */ 39811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely((asma->prot_mask & prot) != prot)) { 39911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = -EINVAL; 40011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto out; 40111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 40211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 40311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* does the application expect PROT_READ to imply PROT_EXEC? */ 40411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC)) 40511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love prot |= PROT_EXEC; 40611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 40711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love asma->prot_mask = prot; 40811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 40911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Loveout: 41011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 41111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 41211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 41311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 41411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int set_name(struct ashmem_area *asma, void __user *name) 41511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 41611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = 0; 417e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran char local_name[ASHMEM_NAME_LEN]; 41811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 419e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran /* 420e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * Holding the ashmem_mutex while doing a copy_from_user might cause 421e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * an data abort which would try to access mmap_sem. If another 422e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * thread has invoked ashmem_mmap then it will be holding the 423e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * semaphore and will be waiting for ashmem_mutex, there by leading to 424e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * deadlock. We'll release the mutex and take the name to a local 425e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * variable that does not need protection and later copy the local 426e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * variable to the structure member with lock held. 427e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran */ 428e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran if (copy_from_user(local_name, name, ASHMEM_NAME_LEN)) 429e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran return -EFAULT; 43011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 431e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran mutex_lock(&ashmem_mutex); 43211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* cannot change an existing mapping's name */ 43311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(asma->file)) { 43411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = -EINVAL; 43511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto out; 43611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 437e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran memcpy(asma->name + ASHMEM_NAME_PREFIX_LEN, 438e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran local_name, ASHMEM_NAME_LEN); 43911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love asma->name[ASHMEM_FULL_NAME_LEN-1] = '\0'; 44011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Loveout: 44111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 44211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 44311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 44411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 44511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 44611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int get_name(struct ashmem_area *asma, void __user *name) 44711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 44811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = 0; 449e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran size_t len; 450e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran /* 451e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * Have a local variable to which we'll copy the content 452e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * from asma with the lock held. Later we can copy this to the user 453e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * space safely without holding any locks. So even if we proceed to 454e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * wait for mmap_sem, it won't lead to deadlock. 455e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran */ 456e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran char local_name[ASHMEM_NAME_LEN]; 45711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 45811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_lock(&ashmem_mutex); 45911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0') { 46011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 46111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* 46211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Copying only `len', instead of ASHMEM_NAME_LEN, bytes 46311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * prevents us from revealing one user's stack to another. 46411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 46511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love len = strlen(asma->name + ASHMEM_NAME_PREFIX_LEN) + 1; 466e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran memcpy(local_name, asma->name + ASHMEM_NAME_PREFIX_LEN, len); 46711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } else { 468e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran len = sizeof(ASHMEM_NAME_DEF); 469e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran memcpy(local_name, ASHMEM_NAME_DEF, len); 47011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 47111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 47211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 473e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran /* 474e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * Now we are just copying from the stack variable to userland 475e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran * No lock held 476e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran */ 477e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran if (unlikely(copy_to_user(name, local_name, len))) 478e5834d620d61d01444c41958f1816d688a96433cShankar Brahadeeswaran ret = -EFAULT; 47911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 48011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 48111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 48211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 48311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * ashmem_pin - pin the given ashmem region, returning whether it was 48411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * previously purged (ASHMEM_WAS_PURGED) or not (ASHMEM_NOT_PURGED). 48511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 48611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Caller must hold ashmem_mutex. 48711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 48811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_pin(struct ashmem_area *asma, size_t pgstart, size_t pgend) 48911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 49011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *range, *next; 49111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = ASHMEM_NOT_PURGED; 49211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 49311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) { 49411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* moved past last applicable page; we can short circuit */ 49511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range_before_page(range, pgstart)) 49611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 49711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 49811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* 49911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * The user can ask us to pin pages that span multiple ranges, 50011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * or to pin pages that aren't even unpinned, so this is messy. 50111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 50211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Four cases: 50311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 1. The requested range subsumes an existing range, so we 50411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * just remove the entire matching range. 50511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 2. The requested range overlaps the start of an existing 50611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * range, so we just update that range. 50711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 3. The requested range overlaps the end of an existing 50811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * range, so we just update that range. 50911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 4. The requested range punches a hole in an existing range, 51011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * so we have to update one side of the range and then 51111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * create a new range for the other side. 51211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 51311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (page_range_in_range(range, pgstart, pgend)) { 51411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret |= range->purged; 51511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 51611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* Case #1: Easy. Just nuke the whole thing. */ 51711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (page_range_subsumes_range(range, pgstart, pgend)) { 51811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_del(range); 51911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love continue; 52011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 52111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 52211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* Case #2: We overlap from the start, so adjust it */ 52311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range->pgstart >= pgstart) { 52411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_shrink(range, pgend + 1, range->pgend); 52511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love continue; 52611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 52711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 52811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* Case #3: We overlap from the rear, so adjust it */ 52911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range->pgend <= pgend) { 53011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_shrink(range, range->pgstart, pgstart-1); 53111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love continue; 53211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 53311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 53411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* 53511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Case #4: We eat a chunk out of the middle. A bit 53611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * more complicated, we allocate a new range for the 53711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * second half and adjust the first chunk's endpoint. 53811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 53911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_alloc(asma, range, range->purged, 54011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love pgend + 1, range->pgend); 54111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_shrink(range, range->pgstart, pgstart - 1); 54211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 54311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 54411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 54511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 54611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 54711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 54811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 54911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 55011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * ashmem_unpin - unpin the given range of pages. Returns zero on success. 55111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 55211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Caller must hold ashmem_mutex. 55311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 55411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_unpin(struct ashmem_area *asma, size_t pgstart, size_t pgend) 55511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 55611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *range, *next; 55711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love unsigned int purged = ASHMEM_NOT_PURGED; 55811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 55911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Loverestart: 56011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) { 56111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* short circuit: this is our insertion point */ 56211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range_before_page(range, pgstart)) 56311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 56411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 56511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* 56611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * The user can ask us to unpin pages that are already entirely 56711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * or partially pinned. We handle those two cases here. 56811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 56911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (page_range_subsumed_by_range(range, pgstart, pgend)) 57011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return 0; 57111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (page_range_in_range(range, pgstart, pgend)) { 57211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love pgstart = min_t(size_t, range->pgstart, pgstart), 57311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love pgend = max_t(size_t, range->pgend, pgend); 57411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love purged |= range->purged; 57511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love range_del(range); 57611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love goto restart; 57711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 57811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 57911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 58011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return range_alloc(asma, range, purged, pgstart, pgend); 58111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 58211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 58311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love/* 58411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * ashmem_get_pin_status - Returns ASHMEM_IS_UNPINNED if _any_ pages in the 58511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * given interval are unpinned and ASHMEM_IS_PINNED otherwise. 58611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * 58711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love * Caller must hold ashmem_mutex. 58811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love */ 58911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_get_pin_status(struct ashmem_area *asma, size_t pgstart, 59011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love size_t pgend) 59111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 59211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_range *range; 59311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = ASHMEM_IS_PINNED; 59411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 59511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love list_for_each_entry(range, &asma->unpinned_list, unpinned) { 59611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (range_before_page(range, pgstart)) 59711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 59811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (page_range_in_range(range, pgstart, pgend)) { 59911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = ASHMEM_IS_UNPINNED; 60011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 60111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 60211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 60311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 60411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 60511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 60611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 60711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int ashmem_pin_unpin(struct ashmem_area *asma, unsigned long cmd, 60811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love void __user *p) 60911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 61011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_pin pin; 61111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love size_t pgstart, pgend; 61211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret = -EINVAL; 61311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 61411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(!asma->file)) 61511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -EINVAL; 61611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 61711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(copy_from_user(&pin, p, sizeof(pin)))) 61811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -EFAULT; 61911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 62011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love /* per custom, you can pass zero for len to mean "everything onward" */ 62111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (!pin.len) 62211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love pin.len = PAGE_ALIGN(asma->size) - pin.offset; 62311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 62411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely((pin.offset | pin.len) & ~PAGE_MASK)) 62511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -EINVAL; 62611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 62711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(((__u32) -1) - pin.offset < pin.len)) 62811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -EINVAL; 62911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 63011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(PAGE_ALIGN(asma->size) < pin.offset + pin.len)) 63111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -EINVAL; 63211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 63311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love pgstart = pin.offset / PAGE_SIZE; 63411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love pgend = pgstart + (pin.len / PAGE_SIZE) - 1; 63511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 63611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_lock(&ashmem_mutex); 63711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 63811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love switch (cmd) { 63911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_PIN: 64011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = ashmem_pin(asma, pgstart, pgend); 64111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 64211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_UNPIN: 64311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = ashmem_unpin(asma, pgstart, pgend); 64411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 64511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_GET_PIN_STATUS: 64611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = ashmem_get_pin_status(asma, pgstart, pgend); 64711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 64811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 64911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 65011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love mutex_unlock(&ashmem_mutex); 65111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 65211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 65311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 65411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 65511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 65611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 65711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love struct ashmem_area *asma = file->private_data; 65811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love long ret = -ENOTTY; 65911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 66011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love switch (cmd) { 66111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_SET_NAME: 66211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = set_name(asma, (void __user *) arg); 66311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 66411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_GET_NAME: 66511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = get_name(asma, (void __user *) arg); 66611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 66711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_SET_SIZE: 66811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = -EINVAL; 66911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (!asma->file) { 67011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = 0; 67111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love asma->size = (size_t) arg; 67211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 67311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 67411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_GET_SIZE: 67511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = asma->size; 67611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 67711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_SET_PROT_MASK: 67811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = set_prot_mask(asma, arg); 67911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 68011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_GET_PROT_MASK: 68111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = asma->prot_mask; 68211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 68311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_PIN: 68411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_UNPIN: 68511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_GET_PIN_STATUS: 68611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = ashmem_pin_unpin(asma, cmd, (void __user *) arg); 68711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 68811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love case ASHMEM_PURGE_ALL_CACHES: 68911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = -EPERM; 69011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (capable(CAP_SYS_ADMIN)) { 69133e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross struct shrink_control sc = { 69233e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross .gfp_mask = GFP_KERNEL, 69333e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross .nr_to_scan = 0, 69433e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross }; 69533e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross ret = ashmem_shrink(&ashmem_shrinker, &sc); 69633e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross sc.nr_to_scan = ret; 69733e8fc463eeec29227282e4bd2082f5928d629a5Colin Cross ashmem_shrink(&ashmem_shrinker, &sc); 69811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 69911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love break; 70011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 70111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 70211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 70311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 70411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 705aa5af974127d317071d6225a0f3678c5f520e7ceTracey Dentstatic const struct file_operations ashmem_fops = { 70611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .owner = THIS_MODULE, 70711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .open = ashmem_open, 70811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .release = ashmem_release, 7091efb34394a694b458d66f25072318c375e22afe2John Stultz .read = ashmem_read, 7101efb34394a694b458d66f25072318c375e22afe2John Stultz .llseek = ashmem_llseek, 71111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .mmap = ashmem_mmap, 71211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .unlocked_ioctl = ashmem_ioctl, 71311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .compat_ioctl = ashmem_ioctl, 71411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love}; 71511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 71611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic struct miscdevice ashmem_misc = { 71711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .minor = MISC_DYNAMIC_MINOR, 71811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .name = "ashmem", 71911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love .fops = &ashmem_fops, 72011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love}; 72111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 72211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic int __init ashmem_init(void) 72311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 72411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret; 72511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 72611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ashmem_area_cachep = kmem_cache_create("ashmem_area_cache", 72711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love sizeof(struct ashmem_area), 72811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 0, 0, NULL); 72911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(!ashmem_area_cachep)) { 730c810a399798022d545191e2daaca0368623c15d3Sachin Kamat pr_err("failed to create slab cache\n"); 73111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -ENOMEM; 73211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 73311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 73411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ashmem_range_cachep = kmem_cache_create("ashmem_range_cache", 73511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love sizeof(struct ashmem_range), 73611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 0, 0, NULL); 73711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(!ashmem_range_cachep)) { 738c810a399798022d545191e2daaca0368623c15d3Sachin Kamat pr_err("failed to create slab cache\n"); 73911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return -ENOMEM; 74011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 74111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 74211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = misc_register(&ashmem_misc); 74311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(ret)) { 744c810a399798022d545191e2daaca0368623c15d3Sachin Kamat pr_err("failed to register misc device!\n"); 74511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return ret; 74611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love } 74711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 74811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love register_shrinker(&ashmem_shrinker); 74911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 750c810a399798022d545191e2daaca0368623c15d3Sachin Kamat pr_info("initialized\n"); 75111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 75211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love return 0; 75311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 75411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 75511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovestatic void __exit ashmem_exit(void) 75611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love{ 75711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love int ret; 75811980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 75911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love unregister_shrinker(&ashmem_shrinker); 76011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 76111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love ret = misc_deregister(&ashmem_misc); 76211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love if (unlikely(ret)) 763c810a399798022d545191e2daaca0368623c15d3Sachin Kamat pr_err("failed to unregister misc device!\n"); 76411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 76511980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love kmem_cache_destroy(ashmem_range_cachep); 76611980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love kmem_cache_destroy(ashmem_area_cachep); 76711980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 768c810a399798022d545191e2daaca0368623c15d3Sachin Kamat pr_info("unloaded\n"); 76911980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love} 77011980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 77111980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovemodule_init(ashmem_init); 77211980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Lovemodule_exit(ashmem_exit); 77311980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert Love 77411980c2ac4ccfad21a5f8ee9e12059f1e687bb40Robert LoveMODULE_LICENSE("GPL"); 775