lkml.org 
[lkml]   [2018]   [Dec]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] binder: fix sparse warnings on locking context
On Mon, Dec 03, 2018 at 12:24:54PM -0800, Todd Kjos wrote:
> Add __acquire()/__release() annnotations to fix warnings
> in sparse context checking
>
> There is one case where the warning was due to a lack of
> a "default:" case in a switch statement where a lock was
> being released in each of the cases, so the default
> case was added.
>
> Signed-off-by: Todd Kjos <tkjos@google.com>
> ---
> drivers/android/binder.c | 43 +++++++++++++++++++++++++++++++++-
> drivers/android/binder_alloc.c | 1 +
> 2 files changed, 43 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/android/binder.c b/drivers/android/binder.c
> index 9f1000d2a40c7..9f2059d24ae2d 100644
> --- a/drivers/android/binder.c
> +++ b/drivers/android/binder.c
> @@ -751,12 +757,16 @@ _binder_node_unlock(struct binder_node *node, int line)
> #define binder_node_inner_lock(node) _binder_node_inner_lock(node, __LINE__)
> static void
> _binder_node_inner_lock(struct binder_node *node, int line)
> + __acquires(&node->lock) __acquires(&node->proc->inner_lock)
> {
> binder_debug(BINDER_DEBUG_SPINLOCKS,
> "%s: line=%d\n", __func__, line);
> spin_lock(&node->lock);
> if (node->proc)
> binder_inner_proc_lock(node->proc);
> + else
> + /* annotation for sparse */
> + __acquire(&node->proc->inner_lock);

This one is questionnable because:
1) if !node->proc, then '&node->proc->inner_lock' is not acquired
since it doesn't even exist.
2) OTOH, the function can't have the annotation 100% right because
it semantics allows unbalanced locking depending on node->proc
being null or not.
But I see very well the intent and maybe it's a right solution.
I dunno.

Same for most of the following ones.


Best regards,
-- Luc Van Oostenryck

\
 
 \ /
  Last update: 2018-12-03 23:31    [W:0.073 / U:11.324 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site