Re: [PATCH] Staging: android: binder: Fix over-80-char lines

[NeilBrown]

On Fri, 30 May 2014 22:31:20 -0600 Daniel Dressler
<danieru.dressler@xxxxxxxxx> wrote:

> From: danieru <danieru.dressler@xxxxxxxxx>
> 
> Following Greg Kroah-Hartman's newbie guide to hacking
> the linux kernel this patch addresses only coding style
> issues.
> 
> Binder still has many too-long lines but I'm worried
> doing too much work in a single patch is unfair to the
> reviewers. So this patch address 20% of the file's
> issues.
> 
> There is one change to take notice of: it merges two if
> statement's conditionals together. Then it removes a
> redundant else clause.
> 
> Signed-off-by: Daniel Dressler <danieru.dressler@xxxxxxxxx>
> ---
>  drivers/staging/android/binder.c | 89 ++++++++++++++++++++++++----------------
>  1 file changed, 54 insertions(+), 35 deletions(-)
> 
> diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
> index cfe4bc8..6e80861a 100644
> --- a/drivers/staging/android/binder.c
> +++ b/drivers/staging/android/binder.c
> @@ -2211,11 +2211,14 @@ retry:
>  			binder_stats_deleted(BINDER_STAT_TRANSACTION_COMPLETE);
>  		} break;
>  		case BINDER_WORK_NODE: {
> -			struct binder_node *node = container_of(w, struct binder_node, work);
> +			struct binder_node *node = container_of(w,
> +						struct binder_node, work);
>  			uint32_t cmd = BR_NOOP;
>  			const char *cmd_name;
> -			int strong = node->internal_strong_refs || node->local_strong_refs;
> -			int weak = !hlist_empty(&node->refs) || node->local_weak_refs || strong;
> +			int strong = node->internal_strong_refs ||
> +						node->local_strong_refs;
> +			int weak = !hlist_empty(&node->refs) ||
> +					node->local_weak_refs || strong;
>  			if (weak && !node->has_weak_ref) {
>  				cmd = BR_INCREFS;
>  				cmd_name = "BR_INCREFS";
> @@ -2311,8 +2314,10 @@ retry:
>  				binder_stats_deleted(BINDER_STAT_DEATH);
>  			} else
>  				list_move(&w->entry, &proc->delivered_death);
> +
> +			/* DEAD_BINDER notifications can cause transactions */
>  			if (cmd == BR_DEAD_BINDER)
> -				goto done; /* DEAD_BINDER notifications can cause transactions */
> +				goto done;
>  		} break;
>  		}
>  
> @@ -2321,7 +2326,8 @@ retry:
>  
>  		BUG_ON(t->buffer == NULL);
>  		if (t->buffer->target_node) {
> -			struct binder_node *target_node = t->buffer->target_node;
> +			struct binder_node *target_node =
> +							t->buffer->target_node;
>  			tr.target.ptr = target_node->ptr;
>  			tr.cookie =  target_node->cookie;
>  			t->saved_priority = task_nice(current);
> @@ -2344,7 +2350,7 @@ retry:
>  		if (t->from) {
>  			struct task_struct *sender = t->from->proc->tsk;
>  			tr.sender_pid = task_tgid_nr_ns(sender,
> -							task_active_pid_ns(current));
> +						task_active_pid_ns(current));

If it were my code, I'd say the cure is much worse than the disease.

Stuff inside brackets (any sort) should always be to the right of the opening
bracket, unless that bracket is at the end of the line.  Then the stuff
inside the brackets should be indented a single tab.

So the only alternative to the original here (which I don't personally think
is worth fixing) is:

>  			tr.sender_pid = task_tgid_nr_ns(
>                               sender,	task_active_pid_ns(current));

That way the full list of arguments is still a well defined block that is
easy to see.



>  		} else {
>  			tr.sender_pid = 0;
>  		}
> @@ -2575,11 +2581,13 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  	unsigned int size = _IOC_SIZE(cmd);
>  	void __user *ubuf = (void __user *)arg;
>  
> -	/*pr_info("binder_ioctl: %d:%d %x %lx\n", proc->pid, current->pid, cmd, arg);*/
> +	/*pr_info("binder_ioctl: %d:%d %x %lx\n",
> +					proc->pid, current->pid, cmd, arg);*/
>  
>  	trace_binder_ioctl(cmd, arg);
>  
> -	ret = wait_event_interruptible(binder_user_error_wait, binder_stop_on_user_error < 2);
> +	ret = wait_event_interruptible(binder_user_error_wait,
> +						binder_stop_on_user_error < 2);
>  	if (ret)
>  		goto err_unlocked;
>  
> @@ -2602,10 +2610,10 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  			goto err;
>  		}
>  		binder_debug(BINDER_DEBUG_READ_WRITE,
> -			     "%d:%d write %lld at %016llx, read %lld at %016llx\n",
> -			     proc->pid, thread->pid,
> -			     (u64)bwr.write_size, (u64)bwr.write_buffer,
> -			     (u64)bwr.read_size, (u64)bwr.read_buffer);
> +			"%d:%d write %lld at %016llx, read %lld at %016llx\n",
> +			proc->pid, thread->pid,
> +			(u64)bwr.write_size, (u64)bwr.write_buffer,
> +			(u64)bwr.read_size, (u64)bwr.read_buffer);
>  
>  		if (bwr.write_size > 0) {
>  			ret = binder_thread_write(proc, thread,
> @@ -2635,10 +2643,10 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  			}
>  		}
>  		binder_debug(BINDER_DEBUG_READ_WRITE,
> -			     "%d:%d wrote %lld of %lld, read return %lld of %lld\n",
> -			     proc->pid, thread->pid,
> -			     (u64)bwr.write_consumed, (u64)bwr.write_size,
> -			     (u64)bwr.read_consumed, (u64)bwr.read_size);
> +			"%d:%d wrote %lld of %lld, read return %lld of %lld\n",
> +			proc->pid, thread->pid,
> +			(u64)bwr.write_consumed, (u64)bwr.write_size,
> +			(u64)bwr.read_consumed, (u64)bwr.read_size);
>  		if (copy_to_user(ubuf, &bwr, sizeof(bwr))) {
>  			ret = -EFAULT;
>  			goto err;
> @@ -2646,7 +2654,8 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  		break;
>  	}
>  	case BINDER_SET_MAX_THREADS:
> -		if (copy_from_user(&proc->max_threads, ubuf, sizeof(proc->max_threads))) {
> +		if (copy_from_user(&proc->max_threads, ubuf,
> +						sizeof(proc->max_threads))) {
>  			ret = -EINVAL;
>  			goto err;
>  		}
> @@ -2657,16 +2666,16 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  			ret = -EBUSY;
>  			goto err;
>  		}
> -		if (uid_valid(binder_context_mgr_uid)) {
> -			if (!uid_eq(binder_context_mgr_uid, current->cred->euid)) {
> -				pr_err("BINDER_SET_CONTEXT_MGR bad uid %d != %d\n",
> -				       from_kuid(&init_user_ns, current->cred->euid),
> -				       from_kuid(&init_user_ns, binder_context_mgr_uid));
> -				ret = -EPERM;
> -				goto err;
> -			}
> -		} else
> -			binder_context_mgr_uid = current->cred->euid;
> +		if (uid_valid(binder_context_mgr_uid) &&
> +			!uid_eq(binder_context_mgr_uid, current->cred->euid)) {

This also looks wrong.  visually, the second line above links with the line
below, but conceptually it links with the next line above.
So:
> +		if (uid_valid(binder_context_mgr_uid) &&
> +		    !uid_eq(binder_context_mgr_uid, current->cred->euid)) {

is much more visually consistent.

Apply these rules throughout the patch and, for me at least, the patch will be much better for it.

(I use emacs C-mode with (c-set-style "K&R"), and it always gets the indenting right)

Thanks,
NeilBrown



> +			pr_err("BINDER_SET_CONTEXT_MGR bad uid %d != %d\n",
> +			       from_kuid(&init_user_ns, current->cred->euid),
> +			       from_kuid(&init_user_ns, binder_context_mgr_uid)
> +			       );
> +			ret = -EPERM;
> +			goto err;
> +		}
> +		binder_context_mgr_uid = current->cred->euid;
>  		binder_context_mgr_node = binder_new_node(proc, 0, 0);
>  		if (binder_context_mgr_node == NULL) {
>  			ret = -ENOMEM;
> @@ -2688,7 +2697,8 @@ static long binder_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
>  			ret = -EINVAL;
>  			goto err;
>  		}
> -		if (put_user(BINDER_CURRENT_PROTOCOL_VERSION, &((struct binder_version *)ubuf)->protocol_version)) {
> +		if (put_user(BINDER_CURRENT_PROTOCOL_VERSION,
> +			&((struct binder_version *)ubuf)->protocol_version)) {
>  			ret = -EINVAL;
>  			goto err;
>  		}
> @@ -2702,9 +2712,11 @@ err:
>  	if (thread)
>  		thread->looper &= ~BINDER_LOOPER_STATE_NEED_RETURN;
>  	binder_unlock(__func__);
> -	wait_event_interruptible(binder_user_error_wait, binder_stop_on_user_error < 2);
> +	wait_event_interruptible(binder_user_error_wait,
> +						binder_stop_on_user_error < 2);
>  	if (ret && ret != -ERESTARTSYS)
> -		pr_info("%d:%d ioctl %x %lx returned %d\n", proc->pid, current->pid, cmd, arg, ret);
> +		pr_info("%d:%d ioctl %x %lx returned %d\n", proc->pid,
> +						current->pid, cmd, arg, ret);
>  err_unlocked:
>  	trace_binder_ioctl_done(ret);
>  	return ret;
> @@ -2784,13 +2796,18 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
>  
>  #ifdef CONFIG_CPU_CACHE_VIPT
>  	if (cache_is_vipt_aliasing()) {
> -		while (CACHE_COLOUR((vma->vm_start ^ (uint32_t)proc->buffer))) {
> -			pr_info("binder_mmap: %d %lx-%lx maps %p bad alignment\n", proc->pid, vma->vm_start, vma->vm_end, proc->buffer);
> +		uint32_t proc_buffer = (uint32_t)proc->buffer;
> +		while (CACHE_COLOUR((vma->vm_start ^ proc_buffer))) {
> +			pr_info(
> +			"binder_mmap: %d %lx-%lx maps %p bad alignment\n",
> +						proc->pid, vma->vm_start,
> +						vma->vm_end, proc->buffer);
>  			vma->vm_start += PAGE_SIZE;
>  		}
>  	}
>  #endif
> -	proc->pages = kzalloc(sizeof(proc->pages[0]) * ((vma->vm_end - vma->vm_start) / PAGE_SIZE), GFP_KERNEL);
> +	size_t num_pages = (vma->vm_end - vma->vm_start) / PAGE_SIZE;
> +	proc->pages = kzalloc(sizeof(proc->pages[0]) * num_pages, GFP_KERNEL);
>  	if (proc->pages == NULL) {
>  		ret = -ENOMEM;
>  		failure_string = "alloc page array";
> @@ -2801,7 +2818,8 @@ static int binder_mmap(struct file *filp, struct vm_area_struct *vma)
>  	vma->vm_ops = &binder_vm_ops;
>  	vma->vm_private_data = proc;
>  
> -	if (binder_update_page_range(proc, 1, proc->buffer, proc->buffer + PAGE_SIZE, vma)) {
> +	if (binder_update_page_range(proc, 1, proc->buffer,
> +					proc->buffer + PAGE_SIZE, vma)) {
>  		ret = -ENOMEM;
>  		failure_string = "alloc small buf";
>  		goto err_alloc_small_buf_failed;
> @@ -2887,7 +2905,8 @@ 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);
> +		struct binder_thread *thread = rb_entry(n, struct binder_thread,
> +								rb_node);
>  		thread->looper |= BINDER_LOOPER_STATE_NEED_RETURN;
>  		if (thread->looper & BINDER_LOOPER_STATE_WAITING) {
>  			wake_up_interruptible(&thread->wait);

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