diff options
| author | spkal01 <kalligeross@gmail.com> | 2021-05-17 02:37:28 +0530 |
|---|---|---|
| committer | spkal01 <kalligeross@gmail.com> | 2021-05-17 02:37:28 +0530 |
| commit | 93b265ae2eba8d93d0ffa406958547232f3114c8 (patch) | |
| tree | c2f093aa144f732b5cf7bd8a0b45bf35eda42e1c /drivers/android | |
| parent | 0a82617b8fce8994076b518064e7d420af290ea8 (diff) | |
| parent | 016f4ba70bffb6d02725e778c3989fa542e6d12a (diff) | |
Diffstat (limited to 'drivers/android')
| -rw-r--r-- | drivers/android/binder.c | 212 | ||||
| -rw-r--r-- | drivers/android/binder_alloc.c | 106 | ||||
| -rw-r--r-- | drivers/android/binder_alloc.h | 9 | ||||
| -rw-r--r-- | drivers/android/binder_alloc_selftest.c | 2 |
4 files changed, 310 insertions, 19 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index afb4675d65f3..632308c48bf7 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -459,9 +459,19 @@ struct binder_priority { * (protected by binder_deferred_lock) * @deferred_work: bitmap of deferred work to perform * (protected by binder_deferred_lock) + * @outstanding_txns: number of transactions to be transmitted before + * processes in freeze_wait are woken up + * (protected by @inner_lock) * @is_dead: process is dead and awaiting free * when outstanding transactions are cleaned up * (protected by @inner_lock) + * @sync_recv: process received sync transactions since last frozen + * (protected by @inner_lock) + * @async_recv: process received async transactions since last frozen + * (protected by @inner_lock) + * @freeze_wait: waitqueue of processes waiting for all outstanding + * transactions to be processed + * (protected by @inner_lock) * @todo: list of work for this process * (protected by @inner_lock) * @stats: per-process binder statistics @@ -505,7 +515,12 @@ struct binder_proc { struct mutex files_lock; struct hlist_node deferred_work_node; int deferred_work; + int outstanding_txns; bool is_dead; + bool is_frozen; + bool sync_recv; + bool async_recv; + wait_queue_head_t freeze_wait; struct list_head todo; struct binder_stats stats; @@ -2076,6 +2091,10 @@ static void binder_free_transaction(struct binder_transaction *t) spin_unlock(&t->lock); binder_inner_proc_lock(target_proc); + target_proc->outstanding_txns--; + BUG_ON(target_proc->outstanding_txns < 0); + if (!target_proc->outstanding_txns && target_proc->is_frozen) + wake_up_interruptible_all(&target_proc->freeze_wait); if (t->buffer) t->buffer->transaction = NULL; binder_inner_proc_unlock(target_proc); @@ -2829,10 +2848,11 @@ static int binder_fixup_parent(struct binder_transaction *t, * If the @thread parameter is not NULL, the transaction is always queued * to the waitlist of that specific thread. * - * Return: true if the transactions was successfully queued - * false if the target process or thread is dead + * Return: 0 if the transaction was successfully queued + * BR_DEAD_REPLY if the target process or thread is dead + * BR_FROZEN_REPLY if the target process or thread is frozen */ -static bool binder_proc_transaction(struct binder_transaction *t, +static int binder_proc_transaction(struct binder_transaction *t, struct binder_proc *proc, struct binder_thread *thread) { @@ -2856,11 +2876,18 @@ static bool binder_proc_transaction(struct binder_transaction *t, } binder_inner_proc_lock(proc); + if (proc->is_frozen) { + proc->sync_recv |= !oneway; + proc->async_recv |= oneway; + } - if (proc->is_dead || (thread && thread->is_dead)) { + if ((proc->is_frozen && !oneway) || proc->is_dead || + (thread && thread->is_dead)) { + bool proc_is_dead = proc->is_dead + || (thread && thread->is_dead); binder_inner_proc_unlock(proc); binder_node_unlock(node); - return false; + return proc_is_dead ? BR_DEAD_REPLY : BR_FROZEN_REPLY; } if (!thread && !pending_async) @@ -2879,10 +2906,11 @@ static bool binder_proc_transaction(struct binder_transaction *t, if (!pending_async) binder_wakeup_thread_ilocked(proc, thread, !oneway /* sync */); + proc->outstanding_txns++; binder_inner_proc_unlock(proc); binder_node_unlock(node); - return true; + return 0; } /** @@ -3203,7 +3231,7 @@ static void binder_transaction(struct binder_proc *proc, t->buffer = binder_alloc_new_buf(&target_proc->alloc, tr->data_size, tr->offsets_size, extra_buffers_size, - !reply && (t->flags & TF_ONE_WAY)); + !reply && (t->flags & TF_ONE_WAY), current->tgid); if (IS_ERR(t->buffer)) { /* * -ESRCH indicates VMA cleared. The target is dying. @@ -3231,6 +3259,7 @@ static void binder_transaction(struct binder_proc *proc, t->buffer->debug_id = t->debug_id; t->buffer->transaction = t; t->buffer->target_node = target_node; + t->buffer->clear_on_free = !!(t->flags & TF_CLEAR_BUF); trace_binder_transaction_alloc_buf(t->buffer); if (binder_alloc_copy_user_to_buffer( @@ -3476,13 +3505,16 @@ static void binder_transaction(struct binder_proc *proc, if (reply) { binder_enqueue_thread_work(thread, tcomplete); binder_inner_proc_lock(target_proc); - if (target_thread->is_dead) { + if (target_thread->is_dead || target_proc->is_frozen) { + return_error = target_thread->is_dead ? + BR_DEAD_REPLY : BR_FROZEN_REPLY; binder_inner_proc_unlock(target_proc); goto err_dead_proc_or_thread; } BUG_ON(t->buffer->async_transaction != 0); binder_pop_transaction_ilocked(target_thread, in_reply_to); binder_enqueue_thread_work_ilocked(target_thread, &t->work); + target_proc->outstanding_txns++; binder_inner_proc_unlock(target_proc); wake_up_interruptible_sync(&target_thread->wait); binder_restore_priority(current, in_reply_to->saved_priority); @@ -3502,7 +3534,9 @@ static void binder_transaction(struct binder_proc *proc, t->from_parent = thread->transaction_stack; thread->transaction_stack = t; binder_inner_proc_unlock(proc); - if (!binder_proc_transaction(t, target_proc, target_thread)) { + return_error = binder_proc_transaction(t, + target_proc, target_thread); + if (return_error) { binder_inner_proc_lock(proc); binder_pop_transaction_ilocked(thread, t); binder_inner_proc_unlock(proc); @@ -3512,7 +3546,8 @@ static void binder_transaction(struct binder_proc *proc, BUG_ON(target_node == NULL); BUG_ON(t->buffer->async_transaction != 1); binder_enqueue_thread_work(thread, tcomplete); - if (!binder_proc_transaction(t, target_proc, NULL)) + return_error = binder_proc_transaction(t, target_proc, NULL); + if (return_error) goto err_dead_proc_or_thread; } if (target_thread) @@ -3529,7 +3564,6 @@ static void binder_transaction(struct binder_proc *proc, return; err_dead_proc_or_thread: - return_error = BR_DEAD_REPLY; return_error_line = __LINE__; binder_dequeue_work(proc, tcomplete); err_translate_failed: @@ -4134,7 +4168,7 @@ static int binder_wait_for_work(struct binder_thread *thread, binder_inner_proc_lock(proc); list_del_init(&thread->waiting_thread_node); if (signal_pending(current)) { - ret = -ERESTARTSYS; + ret = -EINTR; break; } } @@ -4638,6 +4672,7 @@ static void binder_free_proc(struct binder_proc *proc) BUG_ON(!list_empty(&proc->todo)); BUG_ON(!list_empty(&proc->delivered_death)); + WARN_ON(proc->outstanding_txns); device = container_of(proc->context, struct binder_device, context); if (refcount_dec_and_test(&device->ref)) { kfree(proc->context->name); @@ -4698,6 +4733,7 @@ static int binder_thread_release(struct binder_proc *proc, (t->to_thread == thread) ? "in" : "out"); if (t->to_thread == thread) { + t->to_proc->outstanding_txns--; t->to_proc = NULL; t->to_thread = NULL; if (t->buffer) { @@ -4944,6 +4980,76 @@ static int binder_ioctl_get_node_debug_info(struct binder_proc *proc, return 0; } +static int binder_ioctl_freeze(struct binder_freeze_info *info, + struct binder_proc *target_proc) +{ + int ret = 0; + + if (!info->enable) { + binder_inner_proc_lock(target_proc); + target_proc->sync_recv = false; + target_proc->async_recv = false; + target_proc->is_frozen = false; + binder_inner_proc_unlock(target_proc); + return 0; + } + + /* + * Freezing the target. Prevent new transactions by + * setting frozen state. If timeout specified, wait + * for transactions to drain. + */ + binder_inner_proc_lock(target_proc); + target_proc->sync_recv = false; + target_proc->async_recv = false; + target_proc->is_frozen = true; + binder_inner_proc_unlock(target_proc); + + if (info->timeout_ms > 0) + ret = wait_event_interruptible_timeout( + target_proc->freeze_wait, + (!target_proc->outstanding_txns), + msecs_to_jiffies(info->timeout_ms)); + + if (!ret && target_proc->outstanding_txns) + ret = -EAGAIN; + + if (ret < 0) { + binder_inner_proc_lock(target_proc); + target_proc->is_frozen = false; + binder_inner_proc_unlock(target_proc); + } + + return ret; +} + +static int binder_ioctl_get_freezer_info( + struct binder_frozen_status_info *info) +{ + struct binder_proc *target_proc; + bool found = false; + + info->sync_recv = 0; + info->async_recv = 0; + + mutex_lock(&binder_procs_lock); + hlist_for_each_entry(target_proc, &binder_procs, proc_node) { + if (target_proc->pid == info->pid) { + found = true; + binder_inner_proc_lock(target_proc); + info->sync_recv |= target_proc->sync_recv; + info->async_recv |= target_proc->async_recv; + binder_inner_proc_unlock(target_proc); + } + } + mutex_unlock(&binder_procs_lock); + + if (!found) + return -EINVAL; + + return 0; +} + static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { int ret; @@ -5062,6 +5168,84 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) } break; } + case BINDER_FREEZE: { + struct binder_freeze_info info; + struct binder_proc **target_procs = NULL, *target_proc; + int target_procs_count = 0, i = 0; + + ret = 0; + + if (copy_from_user(&info, ubuf, sizeof(info))) { + ret = -EFAULT; + goto err; + } + + mutex_lock(&binder_procs_lock); + hlist_for_each_entry(target_proc, &binder_procs, proc_node) { + if (target_proc->pid == info.pid) + target_procs_count++; + } + + if (target_procs_count == 0) { + mutex_unlock(&binder_procs_lock); + ret = -EINVAL; + goto err; + } + + target_procs = kmalloc(sizeof(struct binder_proc *) * + target_procs_count, + GFP_KERNEL); + + if (!target_procs) { + mutex_unlock(&binder_procs_lock); + ret = -ENOMEM; + goto err; + } + + hlist_for_each_entry(target_proc, &binder_procs, proc_node) { + if (target_proc->pid != info.pid) + continue; + + binder_inner_proc_lock(target_proc); + atomic_inc(&target_proc->tmp_ref); + binder_inner_proc_unlock(target_proc); + + target_procs[i++] = target_proc; + } + mutex_unlock(&binder_procs_lock); + + for (i = 0; i < target_procs_count; i++) { + if (ret >= 0) + ret = binder_ioctl_freeze(&info, + target_procs[i]); + + binder_proc_dec_tmpref(target_procs[i]); + } + + kfree(target_procs); + + if (ret < 0) + goto err; + break; + } + case BINDER_GET_FROZEN_INFO: { + struct binder_frozen_status_info info; + + if (copy_from_user(&info, ubuf, sizeof(info))) { + ret = -EFAULT; + goto err; + } + + ret = binder_ioctl_get_freezer_info(&info); + if (ret < 0) + goto err; + + if (copy_to_user(ubuf, &info, sizeof(info))) { + ret = -EFAULT; + goto err; + } + break; + } default: ret = -EINVAL; goto err; @@ -5176,6 +5360,7 @@ static int binder_open(struct inode *nodp, struct file *filp) proc->tsk = current->group_leader; mutex_init(&proc->files_lock); INIT_LIST_HEAD(&proc->todo); + init_waitqueue_head(&proc->freeze_wait); if (binder_supported_policy(current->policy)) { proc->default_priority.sched_policy = current->policy; proc->default_priority.prio = current->normal_prio; @@ -5397,6 +5582,9 @@ static void binder_deferred_release(struct binder_proc *proc) atomic_inc(&proc->tmp_ref); proc->is_dead = true; + proc->is_frozen = false; + proc->sync_recv = false; + proc->async_recv = false; threads = 0; active_transactions = 0; while ((n = rb_first(&proc->threads))) { diff --git a/drivers/android/binder_alloc.c b/drivers/android/binder_alloc.c index 1b5a131278bc..a0856e920b2b 100644 --- a/drivers/android/binder_alloc.c +++ b/drivers/android/binder_alloc.c @@ -38,11 +38,12 @@ struct list_lru binder_alloc_lru; static DEFINE_MUTEX(binder_alloc_mmap_lock); enum { + BINDER_DEBUG_USER_ERROR = 1U << 0, BINDER_DEBUG_OPEN_CLOSE = 1U << 1, BINDER_DEBUG_BUFFER_ALLOC = 1U << 2, BINDER_DEBUG_BUFFER_ALLOC_ASYNC = 1U << 3, }; -static uint32_t binder_alloc_debug_mask; +static uint32_t binder_alloc_debug_mask = 0; module_param_named(debug_mask, binder_alloc_debug_mask, uint, 0644); @@ -343,12 +344,50 @@ static inline struct vm_area_struct *binder_alloc_get_vma( return vma; } +static void debug_low_async_space_locked(struct binder_alloc *alloc, int pid) +{ + /* + * Find the amount and size of buffers allocated by the current caller; + * The idea is that once we cross the threshold, whoever is responsible + * for the low async space is likely to try to send another async txn, + * and at some point we'll catch them in the act. This is more efficient + * than keeping a map per pid. + */ + struct rb_node *n = alloc->free_buffers.rb_node; + struct binder_buffer *buffer; + size_t total_alloc_size = 0; + size_t num_buffers = 0; + + for (n = rb_first(&alloc->allocated_buffers); n != NULL; + n = rb_next(n)) { + buffer = rb_entry(n, struct binder_buffer, rb_node); + if (buffer->pid != pid) + continue; + if (!buffer->async_transaction) + continue; + total_alloc_size += binder_alloc_buffer_size(alloc, buffer) + + sizeof(struct binder_buffer); + num_buffers++; + } + + /* + * Warn if this pid has more than 50 transactions, or more than 50% of + * async space (which is 25% of total buffer size). + */ + if (num_buffers > 50 || total_alloc_size > alloc->buffer_size / 4) { + binder_alloc_debug(BINDER_DEBUG_USER_ERROR, + "%d: pid %d spamming oneway? %zd buffers allocated for a total size of %zd\n", + alloc->pid, pid, num_buffers, total_alloc_size); + } +} + static struct binder_buffer *binder_alloc_new_buf_locked( struct binder_alloc *alloc, size_t data_size, size_t offsets_size, size_t extra_buffers_size, - int is_async) + int is_async, + int pid) { struct rb_node *n = alloc->free_buffers.rb_node; struct binder_buffer *buffer; @@ -487,11 +526,20 @@ static struct binder_buffer *binder_alloc_new_buf_locked( buffer->offsets_size = offsets_size; buffer->async_transaction = is_async; buffer->extra_buffers_size = extra_buffers_size; + buffer->pid = pid; if (is_async) { alloc->free_async_space -= size + sizeof(struct binder_buffer); binder_alloc_debug(BINDER_DEBUG_BUFFER_ALLOC_ASYNC, "%d: binder_alloc_buf size %zd async free %zd\n", alloc->pid, size, alloc->free_async_space); + if (alloc->free_async_space < alloc->buffer_size / 10) { + /* + * Start detecting spammers once we have less than 20% + * of async space left (which is less than 10% of total + * buffer size). + */ + debug_low_async_space_locked(alloc, pid); + } } return buffer; @@ -509,6 +557,7 @@ err_alloc_buf_struct_failed: * @offsets_size: user specified buffer offset * @extra_buffers_size: size of extra space for meta-data (eg, security context) * @is_async: buffer for async transaction + * @pid: pid to attribute allocation to (used for debugging) * * Allocate a new buffer given the requested sizes. Returns * the kernel version of the buffer pointer. The size allocated @@ -521,13 +570,14 @@ struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc, size_t data_size, size_t offsets_size, size_t extra_buffers_size, - int is_async) + int is_async, + int pid) { struct binder_buffer *buffer; mutex_lock(&alloc->mutex); buffer = binder_alloc_new_buf_locked(alloc, data_size, offsets_size, - extra_buffers_size, is_async); + extra_buffers_size, is_async, pid); mutex_unlock(&alloc->mutex); return buffer; } @@ -647,6 +697,8 @@ static void binder_free_buf_locked(struct binder_alloc *alloc, binder_insert_free_buffer(alloc, buffer); } +static void binder_alloc_clear_buf(struct binder_alloc *alloc, + struct binder_buffer *buffer); /** * binder_alloc_free_buf() - free a binder buffer * @alloc: binder_alloc for this proc @@ -657,6 +709,18 @@ static void binder_free_buf_locked(struct binder_alloc *alloc, void binder_alloc_free_buf(struct binder_alloc *alloc, struct binder_buffer *buffer) { + /* + * We could eliminate the call to binder_alloc_clear_buf() + * from binder_alloc_deferred_release() by moving this to + * binder_alloc_free_buf_locked(). However, that could + * increase contention for the alloc mutex if clear_on_free + * is used frequently for large buffers. The mutex is not + * needed for correctness here. + */ + if (buffer->clear_on_free) { + binder_alloc_clear_buf(alloc, buffer); + buffer->clear_on_free = false; + } mutex_lock(&alloc->mutex); binder_free_buf_locked(alloc, buffer); mutex_unlock(&alloc->mutex); @@ -749,6 +813,10 @@ void binder_alloc_deferred_release(struct binder_alloc *alloc) /* Transaction should already have been freed */ BUG_ON(buffer->transaction); + if (buffer->clear_on_free) { + binder_alloc_clear_buf(alloc, buffer); + buffer->clear_on_free = false; + } binder_free_buf_locked(alloc, buffer); buffers++; } @@ -1076,6 +1144,36 @@ static struct page *binder_alloc_get_page(struct binder_alloc *alloc, } /** + * binder_alloc_clear_buf() - zero out buffer + * @alloc: binder_alloc for this proc + * @buffer: binder buffer to be cleared + * + * memset the given buffer to 0 + */ +static void binder_alloc_clear_buf(struct binder_alloc *alloc, + struct binder_buffer *buffer) +{ + size_t bytes = binder_alloc_buffer_size(alloc, buffer); + binder_size_t buffer_offset = 0; + + while (bytes) { + unsigned long size; + struct page *page; + pgoff_t pgoff; + void *kptr; + + page = binder_alloc_get_page(alloc, buffer, + buffer_offset, &pgoff); + size = min_t(size_t, bytes, PAGE_SIZE - pgoff); + kptr = kmap(page) + pgoff; + memset(kptr, 0, size); + kunmap(page); + bytes -= size; + buffer_offset += size; + } +} + +/** * binder_alloc_copy_user_to_buffer() - copy src user to tgt user * @alloc: binder_alloc for this proc * @buffer: binder buffer to be accessed diff --git a/drivers/android/binder_alloc.h b/drivers/android/binder_alloc.h index b60d161b7a7a..fdb220eb55d1 100644 --- a/drivers/android/binder_alloc.h +++ b/drivers/android/binder_alloc.h @@ -32,6 +32,7 @@ struct binder_transaction; * @entry: entry alloc->buffers * @rb_node: node for allocated_buffers/free_buffers rb trees * @free: %true if buffer is free + * @clear_on_free: %true if buffer must be zeroed after use * @allow_user_free: %true if user is allowed to free buffer * @async_transaction: %true if buffer is in use for an async txn * @debug_id: unique ID for debugging @@ -41,6 +42,7 @@ struct binder_transaction; * @offsets_size: size of array of offsets * @extra_buffers_size: size of space for other objects (like sg lists) * @user_data: user pointer to base of buffer space + * @pid: pid to attribute the buffer to (caller) * * Bookkeeping structure for binder transaction buffers */ @@ -49,9 +51,10 @@ struct binder_buffer { struct rb_node rb_node; /* free entry by size or allocated entry */ /* by address */ unsigned free:1; + unsigned clear_on_free:1; unsigned allow_user_free:1; unsigned async_transaction:1; - unsigned debug_id:29; + unsigned debug_id:28; struct binder_transaction *transaction; @@ -60,6 +63,7 @@ struct binder_buffer { size_t offsets_size; size_t extra_buffers_size; void __user *user_data; + int pid; }; /** @@ -126,7 +130,8 @@ extern struct binder_buffer *binder_alloc_new_buf(struct binder_alloc *alloc, size_t data_size, size_t offsets_size, size_t extra_buffers_size, - int is_async); + int is_async, + int pid); extern void binder_alloc_init(struct binder_alloc *alloc); extern int binder_alloc_shrinker_init(void); extern void binder_alloc_vma_close(struct binder_alloc *alloc); diff --git a/drivers/android/binder_alloc_selftest.c b/drivers/android/binder_alloc_selftest.c index b72708918b06..c839c490fde3 100644 --- a/drivers/android/binder_alloc_selftest.c +++ b/drivers/android/binder_alloc_selftest.c @@ -128,7 +128,7 @@ static void binder_selftest_alloc_buf(struct binder_alloc *alloc, int i; for (i = 0; i < BUFFER_NUM; i++) { - buffers[i] = binder_alloc_new_buf(alloc, sizes[i], 0, 0, 0); + buffers[i] = binder_alloc_new_buf(alloc, sizes[i], 0, 0, 0, 0); if (IS_ERR(buffers[i]) || !check_buffer_pages_allocated(alloc, buffers[i], sizes[i])) { |
