From patchwork Fri Dec 9 04:45:01 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: John Stultz X-Patchwork-Id: 5546 Return-Path: X-Original-To: patchwork@peony.canonical.com Delivered-To: patchwork@peony.canonical.com Received: from fiordland.canonical.com (fiordland.canonical.com [91.189.94.145]) by peony.canonical.com (Postfix) with ESMTP id 9026823E03 for ; Fri, 9 Dec 2011 04:45:51 +0000 (UTC) Received: from mail-bw0-f52.google.com (mail-bw0-f52.google.com [209.85.214.52]) by fiordland.canonical.com (Postfix) with ESMTP id 7319EA18024 for ; Fri, 9 Dec 2011 04:45:51 +0000 (UTC) Received: by mail-bw0-f52.google.com with SMTP id 17so3421035bke.11 for ; Thu, 08 Dec 2011 20:45:51 -0800 (PST) Received: by 10.204.156.141 with SMTP id x13mr2844839bkw.54.1323405951207; Thu, 08 Dec 2011 20:45:51 -0800 (PST) X-Forwarded-To: linaro-patchwork@canonical.com X-Forwarded-For: patch@linaro.org linaro-patchwork@canonical.com Delivered-To: patches@linaro.org Received: by 10.205.129.2 with SMTP id hg2cs106998bkc; Thu, 8 Dec 2011 20:45:50 -0800 (PST) Received: by 10.68.73.65 with SMTP id j1mr2289635pbv.80.1323405948238; Thu, 08 Dec 2011 20:45:48 -0800 (PST) Received: from e34.co.us.ibm.com (e34.co.us.ibm.com. 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Violators will be prosecuted; Thu, 8 Dec 2011 21:45:43 -0700 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by d03relay01.boulder.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id pB94jgCE110858; Thu, 8 Dec 2011 21:45:42 -0700 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id pB94jgdw017389; Thu, 8 Dec 2011 21:45:42 -0700 Received: from kernel.beaverton.ibm.com (kernel.beaverton.ibm.com [9.47.67.96]) by d03av03.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVin) with ESMTP id pB94jgW0017331; Thu, 8 Dec 2011 21:45:42 -0700 Received: by kernel.beaverton.ibm.com (Postfix, from userid 1056) id 480E81E74FD; Thu, 8 Dec 2011 20:45:41 -0800 (PST) From: John Stultz To: Brian Swetland Cc: John Stultz , Brian Swetland , Colin Cross , =?UTF-8?q?Arve=20Hj=C3=B8nnev=C3=A5g?= , Dima Zavin , Robert Love , Greg KH Subject: [PATCH 2/9] ashmem: Move ashmem to staging Date: Thu, 8 Dec 2011 20:45:01 -0800 Message-Id: <1323405908-26046-3-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.7.3.2.146.gca209 In-Reply-To: <1323405908-26046-1-git-send-email-john.stultz@linaro.org> References: <1323405908-26046-1-git-send-email-john.stultz@linaro.org> MIME-Version: 1.0 x-cbid: 11120904-1780-0000-0000-0000018351E0 X-IBM-ISS-SpamDetectors: X-IBM-ISS-DetailInfo: BY=3.00000239; HX=3.00000179; KW=3.00000007; PH=3.00000001; SC=3.00000001; SDB=6.00094509; UDB=6.00024807; UTC=2011-12-09 04:45:44 Move ashmem code under the drivers/staging/android dir. NOTE: This patch will be folded into the previous before I submit the queue to staging. CC: Brian Swetland CC: Colin Cross CC: Arve Hjønnevåg CC: Dima Zavin CC: Robert Love CC: Greg KH Signed-off-by: John Stultz --- drivers/staging/android/Kconfig | 9 + drivers/staging/android/Makefile | 1 + drivers/staging/android/ashmem.c | 670 ++++++++++++++++++++++++++++++++++++++ drivers/staging/android/ashmem.h | 48 +++ include/linux/ashmem.h | 48 --- init/Kconfig | 9 - mm/Makefile | 1 - mm/ashmem.c | 670 -------------------------------------- 8 files changed, 728 insertions(+), 728 deletions(-) create mode 100644 drivers/staging/android/ashmem.c create mode 100644 drivers/staging/android/ashmem.h delete mode 100644 include/linux/ashmem.h delete mode 100644 mm/ashmem.c diff --git a/drivers/staging/android/Kconfig b/drivers/staging/android/Kconfig index 2471949..a72142d 100644 --- a/drivers/staging/android/Kconfig +++ b/drivers/staging/android/Kconfig @@ -12,6 +12,15 @@ config ANDROID_BINDER_IPC bool "Android Binder IPC Driver" default n +config ASHMEM + bool "Enable the Anonymous Shared Memory Subsystem" + default n + depends on SHMEM || TINY_SHMEM + help + The ashmem subsystem is a new shared memory allocator, similar to + POSIX SHM but with different behavior and sporting a simpler + file-based API. + config ANDROID_LOGGER tristate "Android log driver" default n diff --git a/drivers/staging/android/Makefile b/drivers/staging/android/Makefile index 8e057e6..206e70c 100644 --- a/drivers/staging/android/Makefile +++ b/drivers/staging/android/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_ANDROID_BINDER_IPC) += binder.o +obj-$(CONFIG_ASHMEM) += ashmem.o obj-$(CONFIG_ANDROID_LOGGER) += logger.o obj-$(CONFIG_ANDROID_RAM_CONSOLE) += ram_console.o obj-$(CONFIG_ANDROID_TIMED_OUTPUT) += timed_output.o diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c new file mode 100644 index 0000000..34a5f8b --- /dev/null +++ b/drivers/staging/android/ashmem.c @@ -0,0 +1,670 @@ +/* mm/ashmem.c +** +** Anonymous Shared Memory Subsystem, ashmem +** +** Copyright (C) 2008 Google, Inc. +** +** Robert Love +** +** This software is licensed under the terms of the GNU General Public +** License version 2, as published by the Free Software Foundation, and +** may be copied, distributed, and modified under those terms. +** +** This program is distributed in the hope that it will be useful, +** but WITHOUT ANY WARRANTY; without even the implied warranty of +** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +** GNU General Public License for more details. +*/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "ashmem.h" + +#define ASHMEM_NAME_PREFIX "dev/ashmem/" +#define ASHMEM_NAME_PREFIX_LEN (sizeof(ASHMEM_NAME_PREFIX) - 1) +#define ASHMEM_FULL_NAME_LEN (ASHMEM_NAME_LEN + ASHMEM_NAME_PREFIX_LEN) + +/* + * ashmem_area - anonymous shared memory area + * Lifecycle: From our parent file's open() until its release() + * Locking: Protected by `ashmem_mutex' + * Big Note: Mappings do NOT pin this structure; it dies on close() + */ +struct ashmem_area { + char name[ASHMEM_FULL_NAME_LEN];/* optional name for /proc/pid/maps */ + struct list_head unpinned_list; /* list of all ashmem areas */ + struct file *file; /* the shmem-based backing file */ + size_t size; /* size of the mapping, in bytes */ + unsigned long prot_mask; /* allowed prot bits, as vm_flags */ +}; + +/* + * ashmem_range - represents an interval of unpinned (evictable) pages + * Lifecycle: From unpin to pin + * Locking: Protected by `ashmem_mutex' + */ +struct ashmem_range { + struct list_head lru; /* entry in LRU list */ + struct list_head unpinned; /* entry in its area's unpinned list */ + struct ashmem_area *asma; /* associated area */ + size_t pgstart; /* starting page, inclusive */ + size_t pgend; /* ending page, inclusive */ + unsigned int purged; /* ASHMEM_NOT or ASHMEM_WAS_PURGED */ +}; + +/* LRU list of unpinned pages, protected by ashmem_mutex */ +static LIST_HEAD(ashmem_lru_list); + +/* Count of pages on our LRU list, protected by ashmem_mutex */ +static unsigned long lru_count; + +/* + * ashmem_mutex - protects the list of and each individual ashmem_area + * + * Lock Ordering: ashmex_mutex -> i_mutex -> i_alloc_sem + */ +static DEFINE_MUTEX(ashmem_mutex); + +static struct kmem_cache *ashmem_area_cachep __read_mostly; +static struct kmem_cache *ashmem_range_cachep __read_mostly; + +#define range_size(range) \ + ((range)->pgend - (range)->pgstart + 1) + +#define range_on_lru(range) \ + ((range)->purged == ASHMEM_NOT_PURGED) + +#define page_range_subsumes_range(range, start, end) \ + (((range)->pgstart >= (start)) && ((range)->pgend <= (end))) + +#define page_range_subsumed_by_range(range, start, end) \ + (((range)->pgstart <= (start)) && ((range)->pgend >= (end))) + +#define page_in_range(range, page) \ + (((range)->pgstart <= (page)) && ((range)->pgend >= (page))) + +#define page_range_in_range(range, start, end) \ + (page_in_range(range, start) || page_in_range(range, end) || \ + page_range_subsumes_range(range, start, end)) + +#define range_before_page(range, page) \ + ((range)->pgend < (page)) + +#define PROT_MASK (PROT_EXEC | PROT_READ | PROT_WRITE) + +static inline void lru_add(struct ashmem_range *range) +{ + list_add_tail(&range->lru, &ashmem_lru_list); + lru_count += range_size(range); +} + +static inline void lru_del(struct ashmem_range *range) +{ + list_del(&range->lru); + lru_count -= range_size(range); +} + +/* + * range_alloc - allocate and initialize a new ashmem_range structure + * + * 'asma' - associated ashmem_area + * 'prev_range' - the previous ashmem_range in the sorted asma->unpinned list + * 'purged' - initial purge value (ASMEM_NOT_PURGED or ASHMEM_WAS_PURGED) + * 'start' - starting page, inclusive + * 'end' - ending page, inclusive + * + * Caller must hold ashmem_mutex. + */ +static int range_alloc(struct ashmem_area *asma, + struct ashmem_range *prev_range, unsigned int purged, + size_t start, size_t end) +{ + struct ashmem_range *range; + + range = kmem_cache_zalloc(ashmem_range_cachep, GFP_KERNEL); + if (unlikely(!range)) + return -ENOMEM; + + range->asma = asma; + range->pgstart = start; + range->pgend = end; + range->purged = purged; + + list_add_tail(&range->unpinned, &prev_range->unpinned); + + if (range_on_lru(range)) + lru_add(range); + + return 0; +} + +static void range_del(struct ashmem_range *range) +{ + list_del(&range->unpinned); + if (range_on_lru(range)) + lru_del(range); + kmem_cache_free(ashmem_range_cachep, range); +} + +/* + * range_shrink - shrinks a range + * + * Caller must hold ashmem_mutex. + */ +static inline void range_shrink(struct ashmem_range *range, + size_t start, size_t end) +{ + size_t pre = range_size(range); + + range->pgstart = start; + range->pgend = end; + + if (range_on_lru(range)) + lru_count -= pre - range_size(range); +} + +static int ashmem_open(struct inode *inode, struct file *file) +{ + struct ashmem_area *asma; + int ret; + + ret = nonseekable_open(inode, file); + if (unlikely(ret)) + return ret; + + asma = kmem_cache_zalloc(ashmem_area_cachep, GFP_KERNEL); + if (unlikely(!asma)) + return -ENOMEM; + + INIT_LIST_HEAD(&asma->unpinned_list); + memcpy(asma->name, ASHMEM_NAME_PREFIX, ASHMEM_NAME_PREFIX_LEN); + asma->prot_mask = PROT_MASK; + file->private_data = asma; + + return 0; +} + +static int ashmem_release(struct inode *ignored, struct file *file) +{ + struct ashmem_area *asma = file->private_data; + struct ashmem_range *range, *next; + + mutex_lock(&ashmem_mutex); + list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) + range_del(range); + mutex_unlock(&ashmem_mutex); + + if (asma->file) + fput(asma->file); + kmem_cache_free(ashmem_area_cachep, asma); + + return 0; +} + +static int ashmem_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct ashmem_area *asma = file->private_data; + int ret = 0; + + mutex_lock(&ashmem_mutex); + + /* user needs to SET_SIZE before mapping */ + if (unlikely(!asma->size)) { + ret = -EINVAL; + goto out; + } + + /* requested protection bits must match our allowed protection mask */ + if (unlikely((vma->vm_flags & ~asma->prot_mask) & PROT_MASK)) { + ret = -EPERM; + goto out; + } + + if (!asma->file) { + char *name = ASHMEM_NAME_DEF; + struct file *vmfile; + + if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0') + name = asma->name; + + /* ... and allocate the backing shmem file */ + vmfile = shmem_file_setup(name, asma->size, vma->vm_flags); + if (unlikely(IS_ERR(vmfile))) { + ret = PTR_ERR(vmfile); + goto out; + } + asma->file = vmfile; + } + get_file(asma->file); + + if (vma->vm_flags & VM_SHARED) + shmem_set_file(vma, asma->file); + else { + if (vma->vm_file) + fput(vma->vm_file); + vma->vm_file = asma->file; + } + vma->vm_flags |= VM_CAN_NONLINEAR; + +out: + mutex_unlock(&ashmem_mutex); + return ret; +} + +/* + * ashmem_shrink - our cache shrinker, called from mm/vmscan.c :: shrink_slab + * + * 'nr_to_scan' is the number of objects (pages) to prune, or 0 to query how + * many objects (pages) we have in total. + * + * 'gfp_mask' is the mask of the allocation that got us into this mess. + * + * Return value is the number of objects (pages) remaining, or -1 if we cannot + * proceed without risk of deadlock (due to gfp_mask). + * + * We approximate LRU via least-recently-unpinned, jettisoning unpinned partial + * chunks of ashmem regions LRU-wise one-at-a-time until we hit 'nr_to_scan' + * pages freed. + */ +static int ashmem_shrink(int nr_to_scan, gfp_t gfp_mask) +{ + struct ashmem_range *range, *next; + + /* We might recurse into filesystem code, so bail out if necessary */ + if (nr_to_scan && !(gfp_mask & __GFP_FS)) + return -1; + if (!nr_to_scan) + return lru_count; + + mutex_lock(&ashmem_mutex); + list_for_each_entry_safe(range, next, &ashmem_lru_list, lru) { + struct inode *inode = range->asma->file->f_dentry->d_inode; + loff_t start = range->pgstart * PAGE_SIZE; + loff_t end = (range->pgend + 1) * PAGE_SIZE - 1; + + vmtruncate_range(inode, start, end); + range->purged = ASHMEM_WAS_PURGED; + lru_del(range); + + nr_to_scan -= range_size(range); + if (nr_to_scan <= 0) + break; + } + mutex_unlock(&ashmem_mutex); + + return lru_count; +} + +static struct shrinker ashmem_shrinker = { + .shrink = ashmem_shrink, + .seeks = DEFAULT_SEEKS * 4, +}; + +static int set_prot_mask(struct ashmem_area *asma, unsigned long prot) +{ + int ret = 0; + + mutex_lock(&ashmem_mutex); + + /* the user can only remove, not add, protection bits */ + if (unlikely((asma->prot_mask & prot) != prot)) { + ret = -EINVAL; + goto out; + } + + /* does the application expect PROT_READ to imply PROT_EXEC? */ + if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC)) + prot |= PROT_EXEC; + + asma->prot_mask = prot; + +out: + mutex_unlock(&ashmem_mutex); + return ret; +} + +static int set_name(struct ashmem_area *asma, void __user *name) +{ + int ret = 0; + + mutex_lock(&ashmem_mutex); + + /* cannot change an existing mapping's name */ + if (unlikely(asma->file)) { + ret = -EINVAL; + goto out; + } + + if (unlikely(copy_from_user(asma->name + ASHMEM_NAME_PREFIX_LEN, + name, ASHMEM_NAME_LEN))) + ret = -EFAULT; + asma->name[ASHMEM_FULL_NAME_LEN-1] = '\0'; + +out: + mutex_unlock(&ashmem_mutex); + + return ret; +} + +static int get_name(struct ashmem_area *asma, void __user *name) +{ + int ret = 0; + + mutex_lock(&ashmem_mutex); + if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0') { + size_t len; + + /* + * Copying only `len', instead of ASHMEM_NAME_LEN, bytes + * prevents us from revealing one user's stack to another. + */ + len = strlen(asma->name + ASHMEM_NAME_PREFIX_LEN) + 1; + if (unlikely(copy_to_user(name, + asma->name + ASHMEM_NAME_PREFIX_LEN, len))) + ret = -EFAULT; + } else { + if (unlikely(copy_to_user(name, ASHMEM_NAME_DEF, + sizeof(ASHMEM_NAME_DEF)))) + ret = -EFAULT; + } + mutex_unlock(&ashmem_mutex); + + return ret; +} + +/* + * ashmem_pin - pin the given ashmem region, returning whether it was + * previously purged (ASHMEM_WAS_PURGED) or not (ASHMEM_NOT_PURGED). + * + * Caller must hold ashmem_mutex. + */ +static int ashmem_pin(struct ashmem_area *asma, size_t pgstart, size_t pgend) +{ + struct ashmem_range *range, *next; + int ret = ASHMEM_NOT_PURGED; + + list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) { + /* moved past last applicable page; we can short circuit */ + if (range_before_page(range, pgstart)) + break; + + /* + * The user can ask us to pin pages that span multiple ranges, + * or to pin pages that aren't even unpinned, so this is messy. + * + * Four cases: + * 1. The requested range subsumes an existing range, so we + * just remove the entire matching range. + * 2. The requested range overlaps the start of an existing + * range, so we just update that range. + * 3. The requested range overlaps the end of an existing + * range, so we just update that range. + * 4. The requested range punches a hole in an existing range, + * so we have to update one side of the range and then + * create a new range for the other side. + */ + if (page_range_in_range(range, pgstart, pgend)) { + ret |= range->purged; + + /* Case #1: Easy. Just nuke the whole thing. */ + if (page_range_subsumes_range(range, pgstart, pgend)) { + range_del(range); + continue; + } + + /* Case #2: We overlap from the start, so adjust it */ + if (range->pgstart >= pgstart) { + range_shrink(range, pgend + 1, range->pgend); + continue; + } + + /* Case #3: We overlap from the rear, so adjust it */ + if (range->pgend <= pgend) { + range_shrink(range, range->pgstart, pgstart-1); + continue; + } + + /* + * Case #4: We eat a chunk out of the middle. A bit + * more complicated, we allocate a new range for the + * second half and adjust the first chunk's endpoint. + */ + range_alloc(asma, range, range->purged, + pgend + 1, range->pgend); + range_shrink(range, range->pgstart, pgstart - 1); + break; + } + } + + return ret; +} + +/* + * ashmem_unpin - unpin the given range of pages. Returns zero on success. + * + * Caller must hold ashmem_mutex. + */ +static int ashmem_unpin(struct ashmem_area *asma, size_t pgstart, size_t pgend) +{ + struct ashmem_range *range, *next; + unsigned int purged = ASHMEM_NOT_PURGED; + +restart: + list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) { + /* short circuit: this is our insertion point */ + if (range_before_page(range, pgstart)) + break; + + /* + * The user can ask us to unpin pages that are already entirely + * or partially pinned. We handle those two cases here. + */ + if (page_range_subsumed_by_range(range, pgstart, pgend)) + return 0; + if (page_range_in_range(range, pgstart, pgend)) { + pgstart = min_t(size_t, range->pgstart, pgstart), + pgend = max_t(size_t, range->pgend, pgend); + purged |= range->purged; + range_del(range); + goto restart; + } + } + + return range_alloc(asma, range, purged, pgstart, pgend); +} + +/* + * ashmem_get_pin_status - Returns ASHMEM_IS_UNPINNED if _any_ pages in the + * given interval are unpinned and ASHMEM_IS_PINNED otherwise. + * + * Caller must hold ashmem_mutex. + */ +static int ashmem_get_pin_status(struct ashmem_area *asma, size_t pgstart, + size_t pgend) +{ + struct ashmem_range *range; + int ret = ASHMEM_IS_PINNED; + + list_for_each_entry(range, &asma->unpinned_list, unpinned) { + if (range_before_page(range, pgstart)) + break; + if (page_range_in_range(range, pgstart, pgend)) { + ret = ASHMEM_IS_UNPINNED; + break; + } + } + + return ret; +} + +static int ashmem_pin_unpin(struct ashmem_area *asma, unsigned long cmd, + void __user *p) +{ + struct ashmem_pin pin; + size_t pgstart, pgend; + int ret = -EINVAL; + + if (unlikely(!asma->file)) + return -EINVAL; + + if (unlikely(copy_from_user(&pin, p, sizeof(pin)))) + return -EFAULT; + + /* per custom, you can pass zero for len to mean "everything onward" */ + if (!pin.len) + pin.len = PAGE_ALIGN(asma->size) - pin.offset; + + if (unlikely((pin.offset | pin.len) & ~PAGE_MASK)) + return -EINVAL; + + if (unlikely(((__u32) -1) - pin.offset < pin.len)) + return -EINVAL; + + if (unlikely(PAGE_ALIGN(asma->size) < pin.offset + pin.len)) + return -EINVAL; + + pgstart = pin.offset / PAGE_SIZE; + pgend = pgstart + (pin.len / PAGE_SIZE) - 1; + + mutex_lock(&ashmem_mutex); + + switch (cmd) { + case ASHMEM_PIN: + ret = ashmem_pin(asma, pgstart, pgend); + break; + case ASHMEM_UNPIN: + ret = ashmem_unpin(asma, pgstart, pgend); + break; + case ASHMEM_GET_PIN_STATUS: + ret = ashmem_get_pin_status(asma, pgstart, pgend); + break; + } + + mutex_unlock(&ashmem_mutex); + + return ret; +} + +static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg) +{ + struct ashmem_area *asma = file->private_data; + long ret = -ENOTTY; + + switch (cmd) { + case ASHMEM_SET_NAME: + ret = set_name(asma, (void __user *) arg); + break; + case ASHMEM_GET_NAME: + ret = get_name(asma, (void __user *) arg); + break; + case ASHMEM_SET_SIZE: + ret = -EINVAL; + if (!asma->file) { + ret = 0; + asma->size = (size_t) arg; + } + break; + case ASHMEM_GET_SIZE: + ret = asma->size; + break; + case ASHMEM_SET_PROT_MASK: + ret = set_prot_mask(asma, arg); + break; + case ASHMEM_GET_PROT_MASK: + ret = asma->prot_mask; + break; + case ASHMEM_PIN: + case ASHMEM_UNPIN: + case ASHMEM_GET_PIN_STATUS: + ret = ashmem_pin_unpin(asma, cmd, (void __user *) arg); + break; + case ASHMEM_PURGE_ALL_CACHES: + ret = -EPERM; + if (capable(CAP_SYS_ADMIN)) { + ret = ashmem_shrink(0, GFP_KERNEL); + ashmem_shrink(ret, GFP_KERNEL); + } + break; + } + + return ret; +} + +static struct file_operations ashmem_fops = { + .owner = THIS_MODULE, + .open = ashmem_open, + .release = ashmem_release, + .mmap = ashmem_mmap, + .unlocked_ioctl = ashmem_ioctl, + .compat_ioctl = ashmem_ioctl, +}; + +static struct miscdevice ashmem_misc = { + .minor = MISC_DYNAMIC_MINOR, + .name = "ashmem", + .fops = &ashmem_fops, +}; + +static int __init ashmem_init(void) +{ + int ret; + + ashmem_area_cachep = kmem_cache_create("ashmem_area_cache", + sizeof(struct ashmem_area), + 0, 0, NULL); + if (unlikely(!ashmem_area_cachep)) { + printk(KERN_ERR "ashmem: failed to create slab cache\n"); + return -ENOMEM; + } + + ashmem_range_cachep = kmem_cache_create("ashmem_range_cache", + sizeof(struct ashmem_range), + 0, 0, NULL); + if (unlikely(!ashmem_range_cachep)) { + printk(KERN_ERR "ashmem: failed to create slab cache\n"); + return -ENOMEM; + } + + ret = misc_register(&ashmem_misc); + if (unlikely(ret)) { + printk(KERN_ERR "ashmem: failed to register misc device!\n"); + return ret; + } + + register_shrinker(&ashmem_shrinker); + + printk(KERN_INFO "ashmem: initialized\n"); + + return 0; +} + +static void __exit ashmem_exit(void) +{ + int ret; + + unregister_shrinker(&ashmem_shrinker); + + ret = misc_deregister(&ashmem_misc); + if (unlikely(ret)) + printk(KERN_ERR "ashmem: failed to unregister misc device!\n"); + + kmem_cache_destroy(ashmem_range_cachep); + kmem_cache_destroy(ashmem_area_cachep); + + printk(KERN_INFO "ashmem: unloaded\n"); +} + +module_init(ashmem_init); +module_exit(ashmem_exit); + +MODULE_LICENSE("GPL"); diff --git a/drivers/staging/android/ashmem.h b/drivers/staging/android/ashmem.h new file mode 100644 index 0000000..1976b10 --- /dev/null +++ b/drivers/staging/android/ashmem.h @@ -0,0 +1,48 @@ +/* + * include/linux/ashmem.h + * + * Copyright 2008 Google Inc. + * Author: Robert Love + * + * This file is dual licensed. It may be redistributed and/or modified + * under the terms of the Apache 2.0 License OR version 2 of the GNU + * General Public License. + */ + +#ifndef _LINUX_ASHMEM_H +#define _LINUX_ASHMEM_H + +#include +#include + +#define ASHMEM_NAME_LEN 256 + +#define ASHMEM_NAME_DEF "dev/ashmem" + +/* Return values from ASHMEM_PIN: Was the mapping purged while unpinned? */ +#define ASHMEM_NOT_PURGED 0 +#define ASHMEM_WAS_PURGED 1 + +/* Return values from ASHMEM_GET_PIN_STATUS: Is the mapping pinned? */ +#define ASHMEM_IS_UNPINNED 0 +#define ASHMEM_IS_PINNED 1 + +struct ashmem_pin { + __u32 offset; /* offset into region, in bytes, page-aligned */ + __u32 len; /* length forward from offset, in bytes, page-aligned */ +}; + +#define __ASHMEMIOC 0x77 + +#define ASHMEM_SET_NAME _IOW(__ASHMEMIOC, 1, char[ASHMEM_NAME_LEN]) +#define ASHMEM_GET_NAME _IOR(__ASHMEMIOC, 2, char[ASHMEM_NAME_LEN]) +#define ASHMEM_SET_SIZE _IOW(__ASHMEMIOC, 3, size_t) +#define ASHMEM_GET_SIZE _IO(__ASHMEMIOC, 4) +#define ASHMEM_SET_PROT_MASK _IOW(__ASHMEMIOC, 5, unsigned long) +#define ASHMEM_GET_PROT_MASK _IO(__ASHMEMIOC, 6) +#define ASHMEM_PIN _IOW(__ASHMEMIOC, 7, struct ashmem_pin) +#define ASHMEM_UNPIN _IOW(__ASHMEMIOC, 8, struct ashmem_pin) +#define ASHMEM_GET_PIN_STATUS _IO(__ASHMEMIOC, 9) +#define ASHMEM_PURGE_ALL_CACHES _IO(__ASHMEMIOC, 10) + +#endif /* _LINUX_ASHMEM_H */ diff --git a/include/linux/ashmem.h b/include/linux/ashmem.h deleted file mode 100644 index 1976b10..0000000 --- a/include/linux/ashmem.h +++ /dev/null @@ -1,48 +0,0 @@ -/* - * include/linux/ashmem.h - * - * Copyright 2008 Google Inc. - * Author: Robert Love - * - * This file is dual licensed. It may be redistributed and/or modified - * under the terms of the Apache 2.0 License OR version 2 of the GNU - * General Public License. - */ - -#ifndef _LINUX_ASHMEM_H -#define _LINUX_ASHMEM_H - -#include -#include - -#define ASHMEM_NAME_LEN 256 - -#define ASHMEM_NAME_DEF "dev/ashmem" - -/* Return values from ASHMEM_PIN: Was the mapping purged while unpinned? */ -#define ASHMEM_NOT_PURGED 0 -#define ASHMEM_WAS_PURGED 1 - -/* Return values from ASHMEM_GET_PIN_STATUS: Is the mapping pinned? */ -#define ASHMEM_IS_UNPINNED 0 -#define ASHMEM_IS_PINNED 1 - -struct ashmem_pin { - __u32 offset; /* offset into region, in bytes, page-aligned */ - __u32 len; /* length forward from offset, in bytes, page-aligned */ -}; - -#define __ASHMEMIOC 0x77 - -#define ASHMEM_SET_NAME _IOW(__ASHMEMIOC, 1, char[ASHMEM_NAME_LEN]) -#define ASHMEM_GET_NAME _IOR(__ASHMEMIOC, 2, char[ASHMEM_NAME_LEN]) -#define ASHMEM_SET_SIZE _IOW(__ASHMEMIOC, 3, size_t) -#define ASHMEM_GET_SIZE _IO(__ASHMEMIOC, 4) -#define ASHMEM_SET_PROT_MASK _IOW(__ASHMEMIOC, 5, unsigned long) -#define ASHMEM_GET_PROT_MASK _IO(__ASHMEMIOC, 6) -#define ASHMEM_PIN _IOW(__ASHMEMIOC, 7, struct ashmem_pin) -#define ASHMEM_UNPIN _IOW(__ASHMEMIOC, 8, struct ashmem_pin) -#define ASHMEM_GET_PIN_STATUS _IO(__ASHMEMIOC, 9) -#define ASHMEM_PURGE_ALL_CACHES _IO(__ASHMEMIOC, 10) - -#endif /* _LINUX_ASHMEM_H */ diff --git a/init/Kconfig b/init/Kconfig index 4dbd8da..43298f9 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1100,15 +1100,6 @@ config SHMEM option replaces shmem and tmpfs with the much simpler ramfs code, which may be appropriate on small systems without swap. -config ASHMEM - bool "Enable the Anonymous Shared Memory Subsystem" - default n - depends on SHMEM || TINY_SHMEM - help - The ashmem subsystem is a new shared memory allocator, similar to - POSIX SHM but with different behavior and sporting a simpler - file-based API. - config AIO bool "Enable AIO support" if EXPERT default y diff --git a/mm/Makefile b/mm/Makefile index b48c3cf..50ec00e 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -31,7 +31,6 @@ obj-$(CONFIG_HUGETLBFS) += hugetlb.o obj-$(CONFIG_NUMA) += mempolicy.o obj-$(CONFIG_SPARSEMEM) += sparse.o obj-$(CONFIG_SPARSEMEM_VMEMMAP) += sparse-vmemmap.o -obj-$(CONFIG_ASHMEM) += ashmem.o obj-$(CONFIG_SLOB) += slob.o obj-$(CONFIG_COMPACTION) += compaction.o obj-$(CONFIG_MMU_NOTIFIER) += mmu_notifier.o diff --git a/mm/ashmem.c b/mm/ashmem.c deleted file mode 100644 index 230810f..0000000 --- a/mm/ashmem.c +++ /dev/null @@ -1,670 +0,0 @@ -/* mm/ashmem.c -** -** Anonymous Shared Memory Subsystem, ashmem -** -** Copyright (C) 2008 Google, Inc. -** -** Robert Love -** -** This software is licensed under the terms of the GNU General Public -** License version 2, as published by the Free Software Foundation, and -** may be copied, distributed, and modified under those terms. -** -** This program is distributed in the hope that it will be useful, -** but WITHOUT ANY WARRANTY; without even the implied warranty of -** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -** GNU General Public License for more details. -*/ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#define ASHMEM_NAME_PREFIX "dev/ashmem/" -#define ASHMEM_NAME_PREFIX_LEN (sizeof(ASHMEM_NAME_PREFIX) - 1) -#define ASHMEM_FULL_NAME_LEN (ASHMEM_NAME_LEN + ASHMEM_NAME_PREFIX_LEN) - -/* - * ashmem_area - anonymous shared memory area - * Lifecycle: From our parent file's open() until its release() - * Locking: Protected by `ashmem_mutex' - * Big Note: Mappings do NOT pin this structure; it dies on close() - */ -struct ashmem_area { - char name[ASHMEM_FULL_NAME_LEN];/* optional name for /proc/pid/maps */ - struct list_head unpinned_list; /* list of all ashmem areas */ - struct file *file; /* the shmem-based backing file */ - size_t size; /* size of the mapping, in bytes */ - unsigned long prot_mask; /* allowed prot bits, as vm_flags */ -}; - -/* - * ashmem_range - represents an interval of unpinned (evictable) pages - * Lifecycle: From unpin to pin - * Locking: Protected by `ashmem_mutex' - */ -struct ashmem_range { - struct list_head lru; /* entry in LRU list */ - struct list_head unpinned; /* entry in its area's unpinned list */ - struct ashmem_area *asma; /* associated area */ - size_t pgstart; /* starting page, inclusive */ - size_t pgend; /* ending page, inclusive */ - unsigned int purged; /* ASHMEM_NOT or ASHMEM_WAS_PURGED */ -}; - -/* LRU list of unpinned pages, protected by ashmem_mutex */ -static LIST_HEAD(ashmem_lru_list); - -/* Count of pages on our LRU list, protected by ashmem_mutex */ -static unsigned long lru_count; - -/* - * ashmem_mutex - protects the list of and each individual ashmem_area - * - * Lock Ordering: ashmex_mutex -> i_mutex -> i_alloc_sem - */ -static DEFINE_MUTEX(ashmem_mutex); - -static struct kmem_cache *ashmem_area_cachep __read_mostly; -static struct kmem_cache *ashmem_range_cachep __read_mostly; - -#define range_size(range) \ - ((range)->pgend - (range)->pgstart + 1) - -#define range_on_lru(range) \ - ((range)->purged == ASHMEM_NOT_PURGED) - -#define page_range_subsumes_range(range, start, end) \ - (((range)->pgstart >= (start)) && ((range)->pgend <= (end))) - -#define page_range_subsumed_by_range(range, start, end) \ - (((range)->pgstart <= (start)) && ((range)->pgend >= (end))) - -#define page_in_range(range, page) \ - (((range)->pgstart <= (page)) && ((range)->pgend >= (page))) - -#define page_range_in_range(range, start, end) \ - (page_in_range(range, start) || page_in_range(range, end) || \ - page_range_subsumes_range(range, start, end)) - -#define range_before_page(range, page) \ - ((range)->pgend < (page)) - -#define PROT_MASK (PROT_EXEC | PROT_READ | PROT_WRITE) - -static inline void lru_add(struct ashmem_range *range) -{ - list_add_tail(&range->lru, &ashmem_lru_list); - lru_count += range_size(range); -} - -static inline void lru_del(struct ashmem_range *range) -{ - list_del(&range->lru); - lru_count -= range_size(range); -} - -/* - * range_alloc - allocate and initialize a new ashmem_range structure - * - * 'asma' - associated ashmem_area - * 'prev_range' - the previous ashmem_range in the sorted asma->unpinned list - * 'purged' - initial purge value (ASMEM_NOT_PURGED or ASHMEM_WAS_PURGED) - * 'start' - starting page, inclusive - * 'end' - ending page, inclusive - * - * Caller must hold ashmem_mutex. - */ -static int range_alloc(struct ashmem_area *asma, - struct ashmem_range *prev_range, unsigned int purged, - size_t start, size_t end) -{ - struct ashmem_range *range; - - range = kmem_cache_zalloc(ashmem_range_cachep, GFP_KERNEL); - if (unlikely(!range)) - return -ENOMEM; - - range->asma = asma; - range->pgstart = start; - range->pgend = end; - range->purged = purged; - - list_add_tail(&range->unpinned, &prev_range->unpinned); - - if (range_on_lru(range)) - lru_add(range); - - return 0; -} - -static void range_del(struct ashmem_range *range) -{ - list_del(&range->unpinned); - if (range_on_lru(range)) - lru_del(range); - kmem_cache_free(ashmem_range_cachep, range); -} - -/* - * range_shrink - shrinks a range - * - * Caller must hold ashmem_mutex. - */ -static inline void range_shrink(struct ashmem_range *range, - size_t start, size_t end) -{ - size_t pre = range_size(range); - - range->pgstart = start; - range->pgend = end; - - if (range_on_lru(range)) - lru_count -= pre - range_size(range); -} - -static int ashmem_open(struct inode *inode, struct file *file) -{ - struct ashmem_area *asma; - int ret; - - ret = nonseekable_open(inode, file); - if (unlikely(ret)) - return ret; - - asma = kmem_cache_zalloc(ashmem_area_cachep, GFP_KERNEL); - if (unlikely(!asma)) - return -ENOMEM; - - INIT_LIST_HEAD(&asma->unpinned_list); - memcpy(asma->name, ASHMEM_NAME_PREFIX, ASHMEM_NAME_PREFIX_LEN); - asma->prot_mask = PROT_MASK; - file->private_data = asma; - - return 0; -} - -static int ashmem_release(struct inode *ignored, struct file *file) -{ - struct ashmem_area *asma = file->private_data; - struct ashmem_range *range, *next; - - mutex_lock(&ashmem_mutex); - list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) - range_del(range); - mutex_unlock(&ashmem_mutex); - - if (asma->file) - fput(asma->file); - kmem_cache_free(ashmem_area_cachep, asma); - - return 0; -} - -static int ashmem_mmap(struct file *file, struct vm_area_struct *vma) -{ - struct ashmem_area *asma = file->private_data; - int ret = 0; - - mutex_lock(&ashmem_mutex); - - /* user needs to SET_SIZE before mapping */ - if (unlikely(!asma->size)) { - ret = -EINVAL; - goto out; - } - - /* requested protection bits must match our allowed protection mask */ - if (unlikely((vma->vm_flags & ~asma->prot_mask) & PROT_MASK)) { - ret = -EPERM; - goto out; - } - - if (!asma->file) { - char *name = ASHMEM_NAME_DEF; - struct file *vmfile; - - if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0') - name = asma->name; - - /* ... and allocate the backing shmem file */ - vmfile = shmem_file_setup(name, asma->size, vma->vm_flags); - if (unlikely(IS_ERR(vmfile))) { - ret = PTR_ERR(vmfile); - goto out; - } - asma->file = vmfile; - } - get_file(asma->file); - - if (vma->vm_flags & VM_SHARED) - shmem_set_file(vma, asma->file); - else { - if (vma->vm_file) - fput(vma->vm_file); - vma->vm_file = asma->file; - } - vma->vm_flags |= VM_CAN_NONLINEAR; - -out: - mutex_unlock(&ashmem_mutex); - return ret; -} - -/* - * ashmem_shrink - our cache shrinker, called from mm/vmscan.c :: shrink_slab - * - * 'nr_to_scan' is the number of objects (pages) to prune, or 0 to query how - * many objects (pages) we have in total. - * - * 'gfp_mask' is the mask of the allocation that got us into this mess. - * - * Return value is the number of objects (pages) remaining, or -1 if we cannot - * proceed without risk of deadlock (due to gfp_mask). - * - * We approximate LRU via least-recently-unpinned, jettisoning unpinned partial - * chunks of ashmem regions LRU-wise one-at-a-time until we hit 'nr_to_scan' - * pages freed. - */ -static int ashmem_shrink(int nr_to_scan, gfp_t gfp_mask) -{ - struct ashmem_range *range, *next; - - /* We might recurse into filesystem code, so bail out if necessary */ - if (nr_to_scan && !(gfp_mask & __GFP_FS)) - return -1; - if (!nr_to_scan) - return lru_count; - - mutex_lock(&ashmem_mutex); - list_for_each_entry_safe(range, next, &ashmem_lru_list, lru) { - struct inode *inode = range->asma->file->f_dentry->d_inode; - loff_t start = range->pgstart * PAGE_SIZE; - loff_t end = (range->pgend + 1) * PAGE_SIZE - 1; - - vmtruncate_range(inode, start, end); - range->purged = ASHMEM_WAS_PURGED; - lru_del(range); - - nr_to_scan -= range_size(range); - if (nr_to_scan <= 0) - break; - } - mutex_unlock(&ashmem_mutex); - - return lru_count; -} - -static struct shrinker ashmem_shrinker = { - .shrink = ashmem_shrink, - .seeks = DEFAULT_SEEKS * 4, -}; - -static int set_prot_mask(struct ashmem_area *asma, unsigned long prot) -{ - int ret = 0; - - mutex_lock(&ashmem_mutex); - - /* the user can only remove, not add, protection bits */ - if (unlikely((asma->prot_mask & prot) != prot)) { - ret = -EINVAL; - goto out; - } - - /* does the application expect PROT_READ to imply PROT_EXEC? */ - if ((prot & PROT_READ) && (current->personality & READ_IMPLIES_EXEC)) - prot |= PROT_EXEC; - - asma->prot_mask = prot; - -out: - mutex_unlock(&ashmem_mutex); - return ret; -} - -static int set_name(struct ashmem_area *asma, void __user *name) -{ - int ret = 0; - - mutex_lock(&ashmem_mutex); - - /* cannot change an existing mapping's name */ - if (unlikely(asma->file)) { - ret = -EINVAL; - goto out; - } - - if (unlikely(copy_from_user(asma->name + ASHMEM_NAME_PREFIX_LEN, - name, ASHMEM_NAME_LEN))) - ret = -EFAULT; - asma->name[ASHMEM_FULL_NAME_LEN-1] = '\0'; - -out: - mutex_unlock(&ashmem_mutex); - - return ret; -} - -static int get_name(struct ashmem_area *asma, void __user *name) -{ - int ret = 0; - - mutex_lock(&ashmem_mutex); - if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0') { - size_t len; - - /* - * Copying only `len', instead of ASHMEM_NAME_LEN, bytes - * prevents us from revealing one user's stack to another. - */ - len = strlen(asma->name + ASHMEM_NAME_PREFIX_LEN) + 1; - if (unlikely(copy_to_user(name, - asma->name + ASHMEM_NAME_PREFIX_LEN, len))) - ret = -EFAULT; - } else { - if (unlikely(copy_to_user(name, ASHMEM_NAME_DEF, - sizeof(ASHMEM_NAME_DEF)))) - ret = -EFAULT; - } - mutex_unlock(&ashmem_mutex); - - return ret; -} - -/* - * ashmem_pin - pin the given ashmem region, returning whether it was - * previously purged (ASHMEM_WAS_PURGED) or not (ASHMEM_NOT_PURGED). - * - * Caller must hold ashmem_mutex. - */ -static int ashmem_pin(struct ashmem_area *asma, size_t pgstart, size_t pgend) -{ - struct ashmem_range *range, *next; - int ret = ASHMEM_NOT_PURGED; - - list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) { - /* moved past last applicable page; we can short circuit */ - if (range_before_page(range, pgstart)) - break; - - /* - * The user can ask us to pin pages that span multiple ranges, - * or to pin pages that aren't even unpinned, so this is messy. - * - * Four cases: - * 1. The requested range subsumes an existing range, so we - * just remove the entire matching range. - * 2. The requested range overlaps the start of an existing - * range, so we just update that range. - * 3. The requested range overlaps the end of an existing - * range, so we just update that range. - * 4. The requested range punches a hole in an existing range, - * so we have to update one side of the range and then - * create a new range for the other side. - */ - if (page_range_in_range(range, pgstart, pgend)) { - ret |= range->purged; - - /* Case #1: Easy. Just nuke the whole thing. */ - if (page_range_subsumes_range(range, pgstart, pgend)) { - range_del(range); - continue; - } - - /* Case #2: We overlap from the start, so adjust it */ - if (range->pgstart >= pgstart) { - range_shrink(range, pgend + 1, range->pgend); - continue; - } - - /* Case #3: We overlap from the rear, so adjust it */ - if (range->pgend <= pgend) { - range_shrink(range, range->pgstart, pgstart-1); - continue; - } - - /* - * Case #4: We eat a chunk out of the middle. A bit - * more complicated, we allocate a new range for the - * second half and adjust the first chunk's endpoint. - */ - range_alloc(asma, range, range->purged, - pgend + 1, range->pgend); - range_shrink(range, range->pgstart, pgstart - 1); - break; - } - } - - return ret; -} - -/* - * ashmem_unpin - unpin the given range of pages. Returns zero on success. - * - * Caller must hold ashmem_mutex. - */ -static int ashmem_unpin(struct ashmem_area *asma, size_t pgstart, size_t pgend) -{ - struct ashmem_range *range, *next; - unsigned int purged = ASHMEM_NOT_PURGED; - -restart: - list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) { - /* short circuit: this is our insertion point */ - if (range_before_page(range, pgstart)) - break; - - /* - * The user can ask us to unpin pages that are already entirely - * or partially pinned. We handle those two cases here. - */ - if (page_range_subsumed_by_range(range, pgstart, pgend)) - return 0; - if (page_range_in_range(range, pgstart, pgend)) { - pgstart = min_t(size_t, range->pgstart, pgstart), - pgend = max_t(size_t, range->pgend, pgend); - purged |= range->purged; - range_del(range); - goto restart; - } - } - - return range_alloc(asma, range, purged, pgstart, pgend); -} - -/* - * ashmem_get_pin_status - Returns ASHMEM_IS_UNPINNED if _any_ pages in the - * given interval are unpinned and ASHMEM_IS_PINNED otherwise. - * - * Caller must hold ashmem_mutex. - */ -static int ashmem_get_pin_status(struct ashmem_area *asma, size_t pgstart, - size_t pgend) -{ - struct ashmem_range *range; - int ret = ASHMEM_IS_PINNED; - - list_for_each_entry(range, &asma->unpinned_list, unpinned) { - if (range_before_page(range, pgstart)) - break; - if (page_range_in_range(range, pgstart, pgend)) { - ret = ASHMEM_IS_UNPINNED; - break; - } - } - - return ret; -} - -static int ashmem_pin_unpin(struct ashmem_area *asma, unsigned long cmd, - void __user *p) -{ - struct ashmem_pin pin; - size_t pgstart, pgend; - int ret = -EINVAL; - - if (unlikely(!asma->file)) - return -EINVAL; - - if (unlikely(copy_from_user(&pin, p, sizeof(pin)))) - return -EFAULT; - - /* per custom, you can pass zero for len to mean "everything onward" */ - if (!pin.len) - pin.len = PAGE_ALIGN(asma->size) - pin.offset; - - if (unlikely((pin.offset | pin.len) & ~PAGE_MASK)) - return -EINVAL; - - if (unlikely(((__u32) -1) - pin.offset < pin.len)) - return -EINVAL; - - if (unlikely(PAGE_ALIGN(asma->size) < pin.offset + pin.len)) - return -EINVAL; - - pgstart = pin.offset / PAGE_SIZE; - pgend = pgstart + (pin.len / PAGE_SIZE) - 1; - - mutex_lock(&ashmem_mutex); - - switch (cmd) { - case ASHMEM_PIN: - ret = ashmem_pin(asma, pgstart, pgend); - break; - case ASHMEM_UNPIN: - ret = ashmem_unpin(asma, pgstart, pgend); - break; - case ASHMEM_GET_PIN_STATUS: - ret = ashmem_get_pin_status(asma, pgstart, pgend); - break; - } - - mutex_unlock(&ashmem_mutex); - - return ret; -} - -static long ashmem_ioctl(struct file *file, unsigned int cmd, unsigned long arg) -{ - struct ashmem_area *asma = file->private_data; - long ret = -ENOTTY; - - switch (cmd) { - case ASHMEM_SET_NAME: - ret = set_name(asma, (void __user *) arg); - break; - case ASHMEM_GET_NAME: - ret = get_name(asma, (void __user *) arg); - break; - case ASHMEM_SET_SIZE: - ret = -EINVAL; - if (!asma->file) { - ret = 0; - asma->size = (size_t) arg; - } - break; - case ASHMEM_GET_SIZE: - ret = asma->size; - break; - case ASHMEM_SET_PROT_MASK: - ret = set_prot_mask(asma, arg); - break; - case ASHMEM_GET_PROT_MASK: - ret = asma->prot_mask; - break; - case ASHMEM_PIN: - case ASHMEM_UNPIN: - case ASHMEM_GET_PIN_STATUS: - ret = ashmem_pin_unpin(asma, cmd, (void __user *) arg); - break; - case ASHMEM_PURGE_ALL_CACHES: - ret = -EPERM; - if (capable(CAP_SYS_ADMIN)) { - ret = ashmem_shrink(0, GFP_KERNEL); - ashmem_shrink(ret, GFP_KERNEL); - } - break; - } - - return ret; -} - -static struct file_operations ashmem_fops = { - .owner = THIS_MODULE, - .open = ashmem_open, - .release = ashmem_release, - .mmap = ashmem_mmap, - .unlocked_ioctl = ashmem_ioctl, - .compat_ioctl = ashmem_ioctl, -}; - -static struct miscdevice ashmem_misc = { - .minor = MISC_DYNAMIC_MINOR, - .name = "ashmem", - .fops = &ashmem_fops, -}; - -static int __init ashmem_init(void) -{ - int ret; - - ashmem_area_cachep = kmem_cache_create("ashmem_area_cache", - sizeof(struct ashmem_area), - 0, 0, NULL); - if (unlikely(!ashmem_area_cachep)) { - printk(KERN_ERR "ashmem: failed to create slab cache\n"); - return -ENOMEM; - } - - ashmem_range_cachep = kmem_cache_create("ashmem_range_cache", - sizeof(struct ashmem_range), - 0, 0, NULL); - if (unlikely(!ashmem_range_cachep)) { - printk(KERN_ERR "ashmem: failed to create slab cache\n"); - return -ENOMEM; - } - - ret = misc_register(&ashmem_misc); - if (unlikely(ret)) { - printk(KERN_ERR "ashmem: failed to register misc device!\n"); - return ret; - } - - register_shrinker(&ashmem_shrinker); - - printk(KERN_INFO "ashmem: initialized\n"); - - return 0; -} - -static void __exit ashmem_exit(void) -{ - int ret; - - unregister_shrinker(&ashmem_shrinker); - - ret = misc_deregister(&ashmem_misc); - if (unlikely(ret)) - printk(KERN_ERR "ashmem: failed to unregister misc device!\n"); - - kmem_cache_destroy(ashmem_range_cachep); - kmem_cache_destroy(ashmem_area_cachep); - - printk(KERN_INFO "ashmem: unloaded\n"); -} - -module_init(ashmem_init); -module_exit(ashmem_exit); - -MODULE_LICENSE("GPL");