diff options
Diffstat (limited to 'drivers/android')
| -rw-r--r-- | drivers/android/binder.c | 84 |
1 files changed, 62 insertions, 22 deletions
diff --git a/drivers/android/binder.c b/drivers/android/binder.c index fdc951083b07..cc89d0d2b965 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -482,7 +482,8 @@ enum binder_deferred_state { * @tsk task_struct for group_leader of process * (invariant after initialized) * @files files_struct for process - * (invariant after initialized) + * (protected by @files_lock) + * @files_lock mutex to protect @files * @deferred_work_node: element for binder_deferred_list * (protected by binder_deferred_lock) * @deferred_work: bitmap of deferred work to perform @@ -530,6 +531,7 @@ struct binder_proc { int pid; struct task_struct *tsk; struct files_struct *files; + struct mutex files_lock; struct hlist_node deferred_work_node; int deferred_work; bool is_dead; @@ -877,20 +879,26 @@ static void binder_inc_node_tmpref_ilocked(struct binder_node *node); static int task_get_unused_fd_flags(struct binder_proc *proc, int flags) { - struct files_struct *files = proc->files; unsigned long rlim_cur; unsigned long irqs; + int ret; - if (files == NULL) - return -ESRCH; - - if (!lock_task_sighand(proc->tsk, &irqs)) - return -EMFILE; - + mutex_lock(&proc->files_lock); + if (proc->files == NULL) { + ret = -ESRCH; + goto err; + } + if (!lock_task_sighand(proc->tsk, &irqs)) { + ret = -EMFILE; + goto err; + } rlim_cur = task_rlimit(proc->tsk, RLIMIT_NOFILE); unlock_task_sighand(proc->tsk, &irqs); - return __alloc_fd(files, 0, rlim_cur, flags); + ret = __alloc_fd(proc->files, 0, rlim_cur, flags); +err: + mutex_unlock(&proc->files_lock); + return ret; } /* @@ -899,8 +907,10 @@ static int task_get_unused_fd_flags(struct binder_proc *proc, int flags) static void task_fd_install( struct binder_proc *proc, unsigned int fd, struct file *file) { + mutex_lock(&proc->files_lock); if (proc->files) __fd_install(proc->files, fd, file); + mutex_unlock(&proc->files_lock); } /* @@ -910,9 +920,11 @@ static long task_close_fd(struct binder_proc *proc, unsigned int fd) { int retval; - if (proc->files == NULL) - return -ESRCH; - + mutex_lock(&proc->files_lock); + if (proc->files == NULL) { + retval = -ESRCH; + goto err; + } retval = __close_fd(proc->files, fd); /* can't restart close syscall because file table entry was cleared */ if (unlikely(retval == -ERESTARTSYS || @@ -920,7 +932,8 @@ static long task_close_fd(struct binder_proc *proc, unsigned int fd) retval == -ERESTARTNOHAND || retval == -ERESTART_RESTARTBLOCK)) retval = -EINTR; - +err: + mutex_unlock(&proc->files_lock); return retval; } @@ -1948,6 +1961,26 @@ static void binder_send_failed_reply(struct binder_transaction *t, } /** + * binder_cleanup_transaction() - cleans up undelivered transaction + * @t: transaction that needs to be cleaned up + * @reason: reason the transaction wasn't delivered + * @error_code: error to return to caller (if synchronous call) + */ +static void binder_cleanup_transaction(struct binder_transaction *t, + const char *reason, + uint32_t error_code) +{ + if (t->buffer->target_node && !(t->flags & TF_ONE_WAY)) { + binder_send_failed_reply(t, error_code); + } else { + binder_debug(BINDER_DEBUG_DEAD_TRANSACTION, + "undelivered transaction %d, %s\n", + t->debug_id, reason); + binder_free_transaction(t); + } +} + +/** * binder_validate_object() - checks for a valid metadata object in a buffer. * @buffer: binder_buffer that we're parsing. * @offset: offset in the buffer at which to validate an object. @@ -4015,12 +4048,20 @@ retry: if (put_user(cmd, (uint32_t __user *)ptr)) { if (t_from) binder_thread_dec_tmpref(t_from); + + binder_cleanup_transaction(t, "put_user failed", + BR_FAILED_REPLY); + return -EFAULT; } ptr += sizeof(uint32_t); if (copy_to_user(ptr, &tr, sizeof(tr))) { if (t_from) binder_thread_dec_tmpref(t_from); + + binder_cleanup_transaction(t, "copy_to_user failed", + BR_FAILED_REPLY); + return -EFAULT; } ptr += sizeof(tr); @@ -4090,15 +4131,9 @@ static void binder_release_work(struct binder_proc *proc, struct binder_transaction *t; t = container_of(w, struct binder_transaction, work); - if (t->buffer->target_node && - !(t->flags & TF_ONE_WAY)) { - binder_send_failed_reply(t, BR_DEAD_REPLY); - } else { - binder_debug(BINDER_DEBUG_DEAD_TRANSACTION, - "undelivered transaction %d\n", - t->debug_id); - binder_free_transaction(t); - } + + binder_cleanup_transaction(t, "process died.", + BR_DEAD_REPLY); } break; case BINDER_WORK_RETURN_ERROR: { struct binder_error *e = container_of( @@ -4605,7 +4640,9 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma) ret = binder_alloc_mmap_handler(&proc->alloc, vma); if (ret) return ret; + mutex_lock(&proc->files_lock); proc->files = get_files_struct(current); + mutex_unlock(&proc->files_lock); return 0; err_bad_arg: @@ -4629,6 +4666,7 @@ static int binder_open(struct inode *nodp, struct file *filp) spin_lock_init(&proc->outer_lock); get_task_struct(current->group_leader); proc->tsk = current->group_leader; + mutex_init(&proc->files_lock); INIT_LIST_HEAD(&proc->todo); proc->default_priority = task_nice(current); binder_dev = container_of(filp->private_data, struct binder_device, @@ -4881,9 +4919,11 @@ static void binder_deferred_func(struct work_struct *work) files = NULL; if (defer & BINDER_DEFERRED_PUT_FILES) { + mutex_lock(&proc->files_lock); files = proc->files; if (files) proc->files = NULL; + mutex_unlock(&proc->files_lock); } if (defer & BINDER_DEFERRED_FLUSH) |