mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-04 09:59:32 +00:00
Staging: binder: Defer flush and release operations to avoid deadlocks.
If a transaction that contains a file descriptor fails on a later object, the new file descriptor needs to be closed. If this is a binder file descriptor we would deadlock in flush. If there were no other references to the file at this point release would also be called. Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
parent
0cf24a7dc9
commit
861a0dcc39
1 changed files with 88 additions and 61 deletions
|
@ -41,8 +41,8 @@ static int binder_last_id;
|
|||
static struct proc_dir_entry *binder_proc_dir_entry_root;
|
||||
static struct proc_dir_entry *binder_proc_dir_entry_proc;
|
||||
static struct hlist_head binder_dead_nodes;
|
||||
static HLIST_HEAD(binder_release_files_list);
|
||||
static DEFINE_MUTEX(binder_release_files_lock);
|
||||
static HLIST_HEAD(binder_deferred_list);
|
||||
static DEFINE_MUTEX(binder_deferred_lock);
|
||||
|
||||
static int binder_read_proc_proc(
|
||||
char *page, char **start, off_t off, int count, int *eof, void *data);
|
||||
|
@ -234,6 +234,12 @@ struct binder_buffer {
|
|||
uint8_t data[0];
|
||||
};
|
||||
|
||||
enum {
|
||||
BINDER_DEFERRED_PUT_FILES = 0x01,
|
||||
BINDER_DEFERRED_FLUSH = 0x02,
|
||||
BINDER_DEFERRED_RELEASE = 0x04,
|
||||
};
|
||||
|
||||
struct binder_proc {
|
||||
struct hlist_node proc_node;
|
||||
struct rb_root threads;
|
||||
|
@ -244,7 +250,8 @@ struct binder_proc {
|
|||
struct vm_area_struct *vma;
|
||||
struct task_struct *tsk;
|
||||
struct files_struct *files;
|
||||
struct hlist_node release_files_node;
|
||||
struct hlist_node deferred_work_node;
|
||||
int deferred_work;
|
||||
void *buffer;
|
||||
ptrdiff_t user_buffer_offset;
|
||||
|
||||
|
@ -310,6 +317,8 @@ struct binder_transaction {
|
|||
uid_t sender_euid;
|
||||
};
|
||||
|
||||
static void binder_defer_work(struct binder_proc *proc, int defer);
|
||||
|
||||
/*
|
||||
* copied from get_unused_fd_flags
|
||||
*/
|
||||
|
@ -2677,33 +2686,6 @@ static void binder_vma_open(struct vm_area_struct *vma)
|
|||
dump_stack();
|
||||
}
|
||||
|
||||
static void binder_release_files(struct work_struct *work)
|
||||
{
|
||||
struct binder_proc *proc;
|
||||
struct files_struct *files;
|
||||
do {
|
||||
mutex_lock(&binder_lock);
|
||||
mutex_lock(&binder_release_files_lock);
|
||||
if (!hlist_empty(&binder_release_files_list)) {
|
||||
proc = hlist_entry(binder_release_files_list.first,
|
||||
struct binder_proc, release_files_node);
|
||||
hlist_del_init(&proc->release_files_node);
|
||||
files = proc->files;
|
||||
if (files)
|
||||
proc->files = NULL;
|
||||
} else {
|
||||
proc = NULL;
|
||||
files = NULL;
|
||||
}
|
||||
mutex_unlock(&binder_release_files_lock);
|
||||
mutex_unlock(&binder_lock);
|
||||
if (files)
|
||||
put_files_struct(files);
|
||||
} while (proc);
|
||||
}
|
||||
|
||||
static DECLARE_WORK(binder_release_files_work, binder_release_files);
|
||||
|
||||
static void binder_vma_close(struct vm_area_struct *vma)
|
||||
{
|
||||
struct binder_proc *proc = vma->vm_private_data;
|
||||
|
@ -2714,13 +2696,7 @@ static void binder_vma_close(struct vm_area_struct *vma)
|
|||
(vma->vm_end - vma->vm_start) / SZ_1K, vma->vm_flags,
|
||||
(unsigned long)pgprot_val(vma->vm_page_prot));
|
||||
proc->vma = NULL;
|
||||
mutex_lock(&binder_release_files_lock);
|
||||
if (proc->files) {
|
||||
hlist_add_head(&proc->release_files_node,
|
||||
&binder_release_files_list);
|
||||
schedule_work(&binder_release_files_work);
|
||||
}
|
||||
mutex_unlock(&binder_release_files_lock);
|
||||
binder_defer_work(proc, BINDER_DEFERRED_PUT_FILES);
|
||||
}
|
||||
|
||||
static struct vm_operations_struct binder_vm_ops = {
|
||||
|
@ -2853,11 +2829,17 @@ static int binder_open(struct inode *nodp, struct file *filp)
|
|||
|
||||
static int binder_flush(struct file *filp, fl_owner_t id)
|
||||
{
|
||||
struct rb_node *n;
|
||||
struct binder_proc *proc = filp->private_data;
|
||||
int wake_count = 0;
|
||||
|
||||
mutex_lock(&binder_lock);
|
||||
binder_defer_work(proc, BINDER_DEFERRED_FLUSH);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void binder_deferred_flush(struct binder_proc *proc)
|
||||
{
|
||||
struct rb_node *n;
|
||||
int wake_count = 0;
|
||||
for (n = rb_first(&proc->threads); n != NULL; n = rb_next(n)) {
|
||||
struct binder_thread *thread = rb_entry(n, struct binder_thread, rb_node);
|
||||
thread->looper |= BINDER_LOOPER_STATE_NEED_RETURN;
|
||||
|
@ -2867,36 +2849,34 @@ static int binder_flush(struct file *filp, fl_owner_t id)
|
|||
}
|
||||
}
|
||||
wake_up_interruptible_all(&proc->wait);
|
||||
mutex_unlock(&binder_lock);
|
||||
|
||||
if (binder_debug_mask & BINDER_DEBUG_OPEN_CLOSE)
|
||||
printk(KERN_INFO "binder_flush: %d woke %d threads\n", proc->pid, wake_count);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int binder_release(struct inode *nodp, struct file *filp)
|
||||
{
|
||||
struct hlist_node *pos;
|
||||
struct binder_transaction *t;
|
||||
struct rb_node *n;
|
||||
struct files_struct *files;
|
||||
struct binder_proc *proc = filp->private_data;
|
||||
int threads, nodes, incoming_refs, outgoing_refs, buffers, active_transactions, page_count;
|
||||
|
||||
if (binder_proc_dir_entry_proc) {
|
||||
char strbuf[11];
|
||||
snprintf(strbuf, sizeof(strbuf), "%u", proc->pid);
|
||||
remove_proc_entry(strbuf, binder_proc_dir_entry_proc);
|
||||
}
|
||||
mutex_lock(&binder_lock);
|
||||
mutex_lock(&binder_release_files_lock);
|
||||
if (!hlist_unhashed(&proc->release_files_node))
|
||||
hlist_del(&proc->release_files_node);
|
||||
files = proc->files;
|
||||
if (files)
|
||||
proc->files = NULL;
|
||||
mutex_unlock(&binder_release_files_lock);
|
||||
|
||||
binder_defer_work(proc, BINDER_DEFERRED_RELEASE);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void binder_deferred_release(struct binder_proc *proc)
|
||||
{
|
||||
struct hlist_node *pos;
|
||||
struct binder_transaction *t;
|
||||
struct rb_node *n;
|
||||
int threads, nodes, incoming_refs, outgoing_refs, buffers, active_transactions, page_count;
|
||||
|
||||
BUG_ON(proc->vma);
|
||||
BUG_ON(proc->files);
|
||||
|
||||
hlist_del(&proc->proc_node);
|
||||
if (binder_context_mgr_node && binder_context_mgr_node->proc == proc) {
|
||||
|
@ -2971,7 +2951,6 @@ static int binder_release(struct inode *nodp, struct file *filp)
|
|||
}
|
||||
|
||||
binder_stats.obj_deleted[BINDER_STAT_PROC]++;
|
||||
mutex_unlock(&binder_lock);
|
||||
|
||||
page_count = 0;
|
||||
if (proc->pages) {
|
||||
|
@ -2995,9 +2974,57 @@ static int binder_release(struct inode *nodp, struct file *filp)
|
|||
proc->pid, threads, nodes, incoming_refs, outgoing_refs, active_transactions, buffers, page_count);
|
||||
|
||||
kfree(proc);
|
||||
if (files)
|
||||
put_files_struct(files);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static void binder_deferred_func(struct work_struct *work)
|
||||
{
|
||||
struct binder_proc *proc;
|
||||
struct files_struct *files;
|
||||
|
||||
int defer;
|
||||
do {
|
||||
mutex_lock(&binder_lock);
|
||||
mutex_lock(&binder_deferred_lock);
|
||||
if (!hlist_empty(&binder_deferred_list)) {
|
||||
proc = hlist_entry(binder_deferred_list.first,
|
||||
struct binder_proc, deferred_work_node);
|
||||
hlist_del_init(&proc->deferred_work_node);
|
||||
defer = proc->deferred_work;
|
||||
proc->deferred_work = 0;
|
||||
} else {
|
||||
proc = NULL;
|
||||
defer = 0;
|
||||
}
|
||||
mutex_unlock(&binder_deferred_lock);
|
||||
|
||||
files = NULL;
|
||||
if (defer & BINDER_DEFERRED_PUT_FILES)
|
||||
if ((files = proc->files))
|
||||
proc->files = NULL;
|
||||
|
||||
if (defer & BINDER_DEFERRED_FLUSH)
|
||||
binder_deferred_flush(proc);
|
||||
|
||||
if (defer & BINDER_DEFERRED_RELEASE)
|
||||
binder_deferred_release(proc); /* frees proc */
|
||||
|
||||
mutex_unlock(&binder_lock);
|
||||
if (files)
|
||||
put_files_struct(files);
|
||||
} while (proc);
|
||||
}
|
||||
static DECLARE_WORK(binder_deferred_work, binder_deferred_func);
|
||||
|
||||
static void binder_defer_work(struct binder_proc *proc, int defer)
|
||||
{
|
||||
mutex_lock(&binder_deferred_lock);
|
||||
proc->deferred_work |= defer;
|
||||
if (hlist_unhashed(&proc->deferred_work_node)) {
|
||||
hlist_add_head(&proc->deferred_work_node,
|
||||
&binder_deferred_list);
|
||||
schedule_work(&binder_deferred_work);
|
||||
}
|
||||
mutex_unlock(&binder_deferred_lock);
|
||||
}
|
||||
|
||||
static char *print_binder_transaction(char *buf, char *end, const char *prefix, struct binder_transaction *t)
|
||||
|
|
Loading…
Reference in a new issue