diff options
Diffstat (limited to 'drivers/staging/android')
| -rw-r--r-- | drivers/staging/android/Kconfig | 19 | ||||
| -rw-r--r-- | drivers/staging/android/Makefile | 4 | ||||
| -rw-r--r-- | drivers/staging/android/TODO | 8 | ||||
| -rw-r--r-- | drivers/staging/android/ashmem.c | 970 | ||||
| -rw-r--r-- | drivers/staging/android/ashmem.h | 24 | ||||
| -rw-r--r-- | drivers/staging/android/uapi/ashmem.h | 43 |
6 files changed, 0 insertions, 1068 deletions
diff --git a/drivers/staging/android/Kconfig b/drivers/staging/android/Kconfig deleted file mode 100644 index 70498adb1575..000000000000 --- a/drivers/staging/android/Kconfig +++ /dev/null @@ -1,19 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0 -menu "Android" - -if ANDROID - -config ASHMEM - bool "Enable the Anonymous Shared Memory Subsystem" - depends on 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. - - It is, in theory, a good memory allocator for low-memory devices, - because it can discard shared memory units when under memory pressure. - -endif # if ANDROID - -endmenu diff --git a/drivers/staging/android/Makefile b/drivers/staging/android/Makefile deleted file mode 100644 index e9a55a5e6529..000000000000 --- a/drivers/staging/android/Makefile +++ /dev/null @@ -1,4 +0,0 @@ -# SPDX-License-Identifier: GPL-2.0 -ccflags-y += -I$(src) # needed for trace events - -obj-$(CONFIG_ASHMEM) += ashmem.o diff --git a/drivers/staging/android/TODO b/drivers/staging/android/TODO deleted file mode 100644 index f74eb44d8e45..000000000000 --- a/drivers/staging/android/TODO +++ /dev/null @@ -1,8 +0,0 @@ -TODO: - - sparse fixes - - rename files to be not so "generic" - - add proper arch dependencies as needed - - audit userspace interfaces to make sure they are sane - -Please send patches to Greg Kroah-Hartman <greg@kroah.com> and Cc: -Arve Hjønnevåg <arve@android.com> and Riley Andrews <riandrews@android.com> diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c deleted file mode 100644 index ddbde3f8430e..000000000000 --- a/drivers/staging/android/ashmem.c +++ /dev/null @@ -1,970 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* mm/ashmem.c - * - * Anonymous Shared Memory Subsystem, ashmem - * - * Copyright (C) 2008 Google, Inc. - * - * Robert Love <rlove@google.com> - */ - -#define pr_fmt(fmt) "ashmem: " fmt - -#include <linux/init.h> -#include <linux/export.h> -#include <linux/file.h> -#include <linux/fs.h> -#include <linux/falloc.h> -#include <linux/miscdevice.h> -#include <linux/security.h> -#include <linux/mm.h> -#include <linux/mman.h> -#include <linux/uaccess.h> -#include <linux/personality.h> -#include <linux/bitops.h> -#include <linux/mutex.h> -#include <linux/shmem_fs.h> -#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) - -/** - * struct ashmem_area - The anonymous shared memory area - * @name: The optional name in /proc/pid/maps - * @unpinned_list: The list of all ashmem areas - * @file: The shmem-based backing file - * @size: The size of the mapping, in bytes - * @prot_mask: The allowed protection bits, as vm_flags - * - * The lifecycle of this structure is from our parent file's open() until - * its release(). It is also protected by 'ashmem_mutex' - * - * Warning: Mappings do NOT pin this structure; It dies on close() - */ -struct ashmem_area { - char name[ASHMEM_FULL_NAME_LEN]; - struct list_head unpinned_list; - struct file *file; - size_t size; - unsigned long prot_mask; -}; - -/** - * struct ashmem_range - A range of unpinned/evictable pages - * @lru: The entry in the LRU list - * @unpinned: The entry in its area's unpinned list - * @asma: The associated anonymous shared memory area. - * @pgstart: The starting page (inclusive) - * @pgend: The ending page (inclusive) - * @purged: The purge status (ASHMEM_NOT or ASHMEM_WAS_PURGED) - * - * The lifecycle of this structure is from unpin to pin. - * It is protected by 'ashmem_mutex' - */ -struct ashmem_range { - struct list_head lru; - struct list_head unpinned; - struct ashmem_area *asma; - size_t pgstart; - size_t pgend; - unsigned int purged; -}; - -/* LRU list of unpinned pages, protected by ashmem_mutex */ -static LIST_HEAD(ashmem_lru_list); - -static atomic_t ashmem_shrink_inflight = ATOMIC_INIT(0); -static DECLARE_WAIT_QUEUE_HEAD(ashmem_shrink_wait); - -/* - * long lru_count - The count of pages on our LRU list. - * - * This is 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; - -/* - * A separate lockdep class for the backing shmem inodes to resolve the lockdep - * warning about the race between kswapd taking fs_reclaim before inode_lock - * and write syscall taking inode_lock and then fs_reclaim. - * Note that such race is impossible because ashmem does not support write - * syscalls operating on the backing shmem. - */ -static struct lock_class_key backing_shmem_inode_class; - -static inline unsigned long range_size(struct ashmem_range *range) -{ - return range->pgend - range->pgstart + 1; -} - -static inline bool range_on_lru(struct ashmem_range *range) -{ - return range->purged == ASHMEM_NOT_PURGED; -} - -static inline bool page_range_subsumes_range(struct ashmem_range *range, - size_t start, size_t end) -{ - return (range->pgstart >= start) && (range->pgend <= end); -} - -static inline bool page_range_subsumed_by_range(struct ashmem_range *range, - size_t start, size_t end) -{ - return (range->pgstart <= start) && (range->pgend >= end); -} - -static inline bool page_in_range(struct ashmem_range *range, size_t page) -{ - return (range->pgstart <= page) && (range->pgend >= page); -} - -static inline bool page_range_in_range(struct ashmem_range *range, - size_t start, size_t end) -{ - return page_in_range(range, start) || page_in_range(range, end) || - page_range_subsumes_range(range, start, end); -} - -static inline bool range_before_page(struct ashmem_range *range, - size_t page) -{ - return range->pgend < page; -} - -#define PROT_MASK (PROT_EXEC | PROT_READ | PROT_WRITE) - -/** - * lru_add() - Adds a range of memory to the LRU list - * @range: The memory range being added. - * - * The range is first added to the end (tail) of the LRU list. - * After this, the size of the range is added to @lru_count - */ -static inline void lru_add(struct ashmem_range *range) -{ - list_add_tail(&range->lru, &ashmem_lru_list); - lru_count += range_size(range); -} - -/** - * lru_del() - Removes a range of memory from the LRU list - * @range: The memory range being removed - * - * The range is first deleted from the LRU list. - * After this, the size of the range is removed from @lru_count - */ -static inline void lru_del(struct ashmem_range *range) -{ - list_del(&range->lru); - lru_count -= range_size(range); -} - -/** - * range_alloc() - Allocates and initializes a new ashmem_range structure - * @asma: The associated ashmem_area - * @prev_range: The previous ashmem_range in the sorted asma->unpinned list - * @purged: Initial purge status (ASMEM_NOT_PURGED or ASHMEM_WAS_PURGED) - * @start: The starting page (inclusive) - * @end: The ending page (inclusive) - * @new_range: The placeholder for the new range - * - * This function is protected by ashmem_mutex. - */ -static void range_alloc(struct ashmem_area *asma, - struct ashmem_range *prev_range, unsigned int purged, - size_t start, size_t end, - struct ashmem_range **new_range) -{ - struct ashmem_range *range = *new_range; - - *new_range = NULL; - 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); -} - -/** - * range_del() - Deletes and deallocates an ashmem_range structure - * @range: The associated ashmem_range that has previously been allocated - */ -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 an ashmem_range - * @range: The associated ashmem_range being shrunk - * @start: The starting byte of the new range - * @end: The ending byte of the new range - * - * This does not modify the data inside the existing range in any way - It - * simply shrinks the boundaries of the range. - * - * Theoretically, with a little tweaking, this could eventually be changed - * to range_resize, and expand the lru_count if the new range is larger. - */ -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); -} - -/** - * ashmem_open() - Opens an Anonymous Shared Memory structure - * @inode: The backing file's index node(?) - * @file: The backing file - * - * Please note that the ashmem_area is not returned by this function - It is - * instead written to "file->private_data". - * - * Return: 0 if successful, or another code if unsuccessful. - */ -static int ashmem_open(struct inode *inode, struct file *file) -{ - struct ashmem_area *asma; - int ret; - - ret = generic_file_open(inode, file); - if (ret) - return ret; - - asma = kmem_cache_zalloc(ashmem_area_cachep, GFP_KERNEL); - if (!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; -} - -/** - * ashmem_release() - Releases an Anonymous Shared Memory structure - * @ignored: The backing file's Index Node(?) - It is ignored here. - * @file: The backing file - * - * Return: 0 if successful. If it is anything else, go have a coffee and - * try again. - */ -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 ssize_t ashmem_read_iter(struct kiocb *iocb, struct iov_iter *iter) -{ - struct ashmem_area *asma = iocb->ki_filp->private_data; - int ret = 0; - - mutex_lock(&ashmem_mutex); - - /* If size is not set, or set to 0, always return EOF. */ - if (asma->size == 0) - goto out_unlock; - - if (!asma->file) { - ret = -EBADF; - goto out_unlock; - } - - /* - * asma and asma->file are used outside the lock here. We assume - * once asma->file is set it will never be changed, and will not - * be destroyed until all references to the file are dropped and - * ashmem_release is called. - */ - mutex_unlock(&ashmem_mutex); - ret = vfs_iter_read(asma->file, iter, &iocb->ki_pos, 0); - mutex_lock(&ashmem_mutex); - if (ret > 0) - asma->file->f_pos = iocb->ki_pos; -out_unlock: - mutex_unlock(&ashmem_mutex); - return ret; -} - -static loff_t ashmem_llseek(struct file *file, loff_t offset, int origin) -{ - struct ashmem_area *asma = file->private_data; - loff_t ret; - - mutex_lock(&ashmem_mutex); - - if (asma->size == 0) { - mutex_unlock(&ashmem_mutex); - return -EINVAL; - } - - if (!asma->file) { - mutex_unlock(&ashmem_mutex); - return -EBADF; - } - - mutex_unlock(&ashmem_mutex); - - ret = vfs_llseek(asma->file, offset, origin); - if (ret < 0) - return ret; - - /** Copy f_pos from backing file, since f_ops->llseek() sets it */ - file->f_pos = asma->file->f_pos; - return ret; -} - -static inline vm_flags_t calc_vm_may_flags(unsigned long prot) -{ - return _calc_vm_trans(prot, PROT_READ, VM_MAYREAD) | - _calc_vm_trans(prot, PROT_WRITE, VM_MAYWRITE) | - _calc_vm_trans(prot, PROT_EXEC, VM_MAYEXEC); -} - -static int ashmem_vmfile_mmap(struct file *file, struct vm_area_struct *vma) -{ - /* do not allow to mmap ashmem backing shmem file directly */ - return -EPERM; -} - -static unsigned long -ashmem_vmfile_get_unmapped_area(struct file *file, unsigned long addr, - unsigned long len, unsigned long pgoff, - unsigned long flags) -{ - return current->mm->get_unmapped_area(file, addr, len, pgoff, flags); -} - -static int ashmem_mmap(struct file *file, struct vm_area_struct *vma) -{ - static struct file_operations vmfile_fops; - struct ashmem_area *asma = file->private_data; - int ret = 0; - - mutex_lock(&ashmem_mutex); - - /* user needs to SET_SIZE before mapping */ - if (!asma->size) { - ret = -EINVAL; - goto out; - } - - /* requested mapping size larger than object size */ - if (vma->vm_end - vma->vm_start > PAGE_ALIGN(asma->size)) { - ret = -EINVAL; - goto out; - } - - /* requested protection bits must match our allowed protection mask */ - if ((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask, 0)) & - calc_vm_prot_bits(PROT_MASK, 0)) { - ret = -EPERM; - goto out; - } - vma->vm_flags &= ~calc_vm_may_flags(~asma->prot_mask); - - if (!asma->file) { - char *name = ASHMEM_NAME_DEF; - struct file *vmfile; - struct inode *inode; - - 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 (IS_ERR(vmfile)) { - ret = PTR_ERR(vmfile); - goto out; - } - vmfile->f_mode |= FMODE_LSEEK; - inode = file_inode(vmfile); - lockdep_set_class(&inode->i_rwsem, &backing_shmem_inode_class); - asma->file = vmfile; - /* - * override mmap operation of the vmfile so that it can't be - * remapped which would lead to creation of a new vma with no - * asma permission checks. Have to override get_unmapped_area - * as well to prevent VM_BUG_ON check for f_ops modification. - */ - if (!vmfile_fops.mmap) { - vmfile_fops = *vmfile->f_op; - vmfile_fops.mmap = ashmem_vmfile_mmap; - vmfile_fops.get_unmapped_area = - ashmem_vmfile_get_unmapped_area; - } - vmfile->f_op = &vmfile_fops; - } - get_file(asma->file); - - /* - * XXX - Reworked to use shmem_zero_setup() instead of - * shmem_set_file while we're in staging. -jstultz - */ - if (vma->vm_flags & VM_SHARED) { - ret = shmem_zero_setup(vma); - if (ret) { - fput(asma->file); - goto out; - } - } else { - vma_set_anonymous(vma); - } - - vma_set_file(vma, asma->file); - /* XXX: merge this with the get_file() above if possible */ - fput(asma->file); - -out: - mutex_unlock(&ashmem_mutex); - return ret; -} - -/* - * ashmem_shrink - our cache shrinker, called from mm/vmscan.c - * - * 'nr_to_scan' is the number of objects to scan for freeing. - * - * 'gfp_mask' is the mask of the allocation that got us into this mess. - * - * Return value is the number of objects freed 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 unsigned long -ashmem_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) -{ - unsigned long freed = 0; - - /* We might recurse into filesystem code, so bail out if necessary */ - if (!(sc->gfp_mask & __GFP_FS)) - return SHRINK_STOP; - - if (!mutex_trylock(&ashmem_mutex)) - return -1; - - while (!list_empty(&ashmem_lru_list)) { - struct ashmem_range *range = - list_first_entry(&ashmem_lru_list, typeof(*range), lru); - loff_t start = range->pgstart * PAGE_SIZE; - loff_t end = (range->pgend + 1) * PAGE_SIZE; - struct file *f = range->asma->file; - - get_file(f); - atomic_inc(&ashmem_shrink_inflight); - range->purged = ASHMEM_WAS_PURGED; - lru_del(range); - - freed += range_size(range); - mutex_unlock(&ashmem_mutex); - f->f_op->fallocate(f, - FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, - start, end - start); - fput(f); - if (atomic_dec_and_test(&ashmem_shrink_inflight)) - wake_up_all(&ashmem_shrink_wait); - if (!mutex_trylock(&ashmem_mutex)) - goto out; - if (--sc->nr_to_scan <= 0) - break; - } - mutex_unlock(&ashmem_mutex); -out: - return freed; -} - -static unsigned long -ashmem_shrink_count(struct shrinker *shrink, struct shrink_control *sc) -{ - /* - * note that lru_count is count of pages on the lru, not a count of - * objects on the list. This means the scan function needs to return the - * number of pages freed, not the number of objects scanned. - */ - return lru_count; -} - -static struct shrinker ashmem_shrinker = { - .count_objects = ashmem_shrink_count, - .scan_objects = ashmem_shrink_scan, - /* - * XXX (dchinner): I wish people would comment on why they need on - * significant changes to the default value here - */ - .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 ((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 len; - int ret = 0; - char local_name[ASHMEM_NAME_LEN]; - - /* - * Holding the ashmem_mutex while doing a copy_from_user might cause - * an data abort which would try to access mmap_lock. If another - * thread has invoked ashmem_mmap then it will be holding the - * semaphore and will be waiting for ashmem_mutex, there by leading to - * deadlock. We'll release the mutex and take the name to a local - * variable that does not need protection and later copy the local - * variable to the structure member with lock held. - */ - len = strncpy_from_user(local_name, name, ASHMEM_NAME_LEN); - if (len < 0) - return len; - - mutex_lock(&ashmem_mutex); - /* cannot change an existing mapping's name */ - if (asma->file) - ret = -EINVAL; - else - strscpy(asma->name + ASHMEM_NAME_PREFIX_LEN, local_name, - ASHMEM_NAME_LEN); - - mutex_unlock(&ashmem_mutex); - return ret; -} - -static int get_name(struct ashmem_area *asma, void __user *name) -{ - int ret = 0; - size_t len; - /* - * Have a local variable to which we'll copy the content - * from asma with the lock held. Later we can copy this to the user - * space safely without holding any locks. So even if we proceed to - * wait for mmap_lock, it won't lead to deadlock. - */ - char local_name[ASHMEM_NAME_LEN]; - - mutex_lock(&ashmem_mutex); - if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0') { - /* - * 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; - memcpy(local_name, asma->name + ASHMEM_NAME_PREFIX_LEN, len); - } else { - len = sizeof(ASHMEM_NAME_DEF); - memcpy(local_name, ASHMEM_NAME_DEF, len); - } - mutex_unlock(&ashmem_mutex); - - /* - * Now we are just copying from the stack variable to userland - * No lock held - */ - if (copy_to_user(name, local_name, len)) - ret = -EFAULT; - 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 **new_range) -{ - 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, new_range); - 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 **new_range) -{ - 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(range->pgstart, pgstart); - pgend = max(range->pgend, pgend); - purged |= range->purged; - range_del(range); - goto restart; - } - } - - range_alloc(asma, range, purged, pgstart, pgend, new_range); - return 0; -} - -/* - * 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; - struct ashmem_range *range = NULL; - - if (copy_from_user(&pin, p, sizeof(pin))) - return -EFAULT; - - if (cmd == ASHMEM_PIN || cmd == ASHMEM_UNPIN) { - range = kmem_cache_zalloc(ashmem_range_cachep, GFP_KERNEL); - if (!range) - return -ENOMEM; - } - - mutex_lock(&ashmem_mutex); - wait_event(ashmem_shrink_wait, !atomic_read(&ashmem_shrink_inflight)); - - if (!asma->file) - goto out_unlock; - - /* per custom, you can pass zero for len to mean "everything onward" */ - if (!pin.len) - pin.len = PAGE_ALIGN(asma->size) - pin.offset; - - if ((pin.offset | pin.len) & ~PAGE_MASK) - goto out_unlock; - - if (((__u32)-1) - pin.offset < pin.len) - goto out_unlock; - - if (PAGE_ALIGN(asma->size) < pin.offset + pin.len) - goto out_unlock; - - pgstart = pin.offset / PAGE_SIZE; - pgend = pgstart + (pin.len / PAGE_SIZE) - 1; - - switch (cmd) { - case ASHMEM_PIN: - ret = ashmem_pin(asma, pgstart, pgend, &range); - break; - case ASHMEM_UNPIN: - ret = ashmem_unpin(asma, pgstart, pgend, &range); - break; - case ASHMEM_GET_PIN_STATUS: - ret = ashmem_get_pin_status(asma, pgstart, pgend); - break; - } - -out_unlock: - mutex_unlock(&ashmem_mutex); - if (range) - kmem_cache_free(ashmem_range_cachep, range); - - 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; - mutex_lock(&ashmem_mutex); - if (!asma->file) { - ret = 0; - asma->size = (size_t)arg; - } - mutex_unlock(&ashmem_mutex); - 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)) { - struct shrink_control sc = { - .gfp_mask = GFP_KERNEL, - .nr_to_scan = LONG_MAX, - }; - ret = ashmem_shrink_count(&ashmem_shrinker, &sc); - ashmem_shrink_scan(&ashmem_shrinker, &sc); - } - break; - } - - return ret; -} - -/* support of 32bit userspace on 64bit platforms */ -#ifdef CONFIG_COMPAT -static long compat_ashmem_ioctl(struct file *file, unsigned int cmd, - unsigned long arg) -{ - switch (cmd) { - case COMPAT_ASHMEM_SET_SIZE: - cmd = ASHMEM_SET_SIZE; - break; - case COMPAT_ASHMEM_SET_PROT_MASK: - cmd = ASHMEM_SET_PROT_MASK; - break; - } - return ashmem_ioctl(file, cmd, arg); -} -#endif -#ifdef CONFIG_PROC_FS -static void ashmem_show_fdinfo(struct seq_file *m, struct file *file) -{ - struct ashmem_area *asma = file->private_data; - - mutex_lock(&ashmem_mutex); - - if (asma->file) - seq_printf(m, "inode:\t%ld\n", file_inode(asma->file)->i_ino); - - if (asma->name[ASHMEM_NAME_PREFIX_LEN] != '\0') - seq_printf(m, "name:\t%s\n", - asma->name + ASHMEM_NAME_PREFIX_LEN); - - seq_printf(m, "size:\t%zu\n", asma->size); - - mutex_unlock(&ashmem_mutex); -} -#endif -static const struct file_operations ashmem_fops = { - .owner = THIS_MODULE, - .open = ashmem_open, - .release = ashmem_release, - .read_iter = ashmem_read_iter, - .llseek = ashmem_llseek, - .mmap = ashmem_mmap, - .unlocked_ioctl = ashmem_ioctl, -#ifdef CONFIG_COMPAT - .compat_ioctl = compat_ashmem_ioctl, -#endif -#ifdef CONFIG_PROC_FS - .show_fdinfo = ashmem_show_fdinfo, -#endif -}; - -static struct miscdevice ashmem_misc = { - .minor = MISC_DYNAMIC_MINOR, - .name = "ashmem", - .fops = &ashmem_fops, -}; - -static int __init ashmem_init(void) -{ - int ret = -ENOMEM; - - ashmem_area_cachep = kmem_cache_create("ashmem_area_cache", - sizeof(struct ashmem_area), - 0, 0, NULL); - if (!ashmem_area_cachep) { - pr_err("failed to create slab cache\n"); - goto out; - } - - ashmem_range_cachep = kmem_cache_create("ashmem_range_cache", - sizeof(struct ashmem_range), - 0, SLAB_RECLAIM_ACCOUNT, NULL); - if (!ashmem_range_cachep) { - pr_err("failed to create slab cache\n"); - goto out_free1; - } - - ret = misc_register(&ashmem_misc); - if (ret) { - pr_err("failed to register misc device!\n"); - goto out_free2; - } - - ret = register_shrinker(&ashmem_shrinker); - if (ret) { - pr_err("failed to register shrinker!\n"); - goto out_demisc; - } - - pr_info("initialized\n"); - - return 0; - -out_demisc: - misc_deregister(&ashmem_misc); -out_free2: - kmem_cache_destroy(ashmem_range_cachep); -out_free1: - kmem_cache_destroy(ashmem_area_cachep); -out: - return ret; -} -device_initcall(ashmem_init); diff --git a/drivers/staging/android/ashmem.h b/drivers/staging/android/ashmem.h deleted file mode 100644 index 1a478173cd21..000000000000 --- a/drivers/staging/android/ashmem.h +++ /dev/null @@ -1,24 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 OR Apache-2.0 */ -/* - * include/linux/ashmem.h - * - * Copyright 2008 Google Inc. - * Author: Robert Love - */ - -#ifndef _LINUX_ASHMEM_H -#define _LINUX_ASHMEM_H - -#include <linux/limits.h> -#include <linux/ioctl.h> -#include <linux/compat.h> - -#include "uapi/ashmem.h" - -/* support of 32bit userspace on 64bit platforms */ -#ifdef CONFIG_COMPAT -#define COMPAT_ASHMEM_SET_SIZE _IOW(__ASHMEMIOC, 3, compat_size_t) -#define COMPAT_ASHMEM_SET_PROT_MASK _IOW(__ASHMEMIOC, 5, unsigned int) -#endif - -#endif /* _LINUX_ASHMEM_H */ diff --git a/drivers/staging/android/uapi/ashmem.h b/drivers/staging/android/uapi/ashmem.h deleted file mode 100644 index 134efacb3219..000000000000 --- a/drivers/staging/android/uapi/ashmem.h +++ /dev/null @@ -1,43 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 OR Apache-2.0 */ -/* - * Copyright 2008 Google Inc. - * Author: Robert Love - */ - -#ifndef _UAPI_LINUX_ASHMEM_H -#define _UAPI_LINUX_ASHMEM_H - -#include <linux/ioctl.h> -#include <linux/types.h> - -#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 /* _UAPI_LINUX_ASHMEM_H */ |