On Wed, Mar 31, 2021 at 03:34:16PM +0800, Hang Lu wrote: > When async binder buffer got exhausted, some normal oneway transaction > will also be discarded and finally caused system/app stop. By that time, > the binder debug information we dump may not relevant to the root cause. > And this issue is difficult to debug if without the backtrace of thread > sending spam. > > This change will send BR_ONEWAY_SPAM_SUSPECT to userspace when detecting > oneway spamming, request to dump current backtrace. The detection will > happened only once when exceeding the threshold (target process dips > below 80% of its oneway space, and current process is responsible for > either more than 50 transactions, or more than 50% of the oneway space). > And the detection will restart when the async buffer has returned to a > healthy state. > > Signed-off-by: Hang Lu <ha...@codeaurora.org> > --- > drivers/android/binder.c | 25 ++++++++++++++++++++++--- > drivers/android/binder_alloc.c | 15 ++++++++++++--- > drivers/android/binder_alloc.h | 8 +++++++- > drivers/android/binder_internal.h | 1 + > include/uapi/linux/android/binder.h | 8 ++++++++ > 5 files changed, 50 insertions(+), 7 deletions(-) > > diff --git a/drivers/android/binder.c b/drivers/android/binder.c > index c119736..28ceaf9 100644 > --- a/drivers/android/binder.c > +++ b/drivers/android/binder.c > @@ -87,6 +87,7 @@ static DEFINE_SPINLOCK(binder_dead_nodes_lock); > static struct dentry *binder_debugfs_dir_entry_root; > static struct dentry *binder_debugfs_dir_entry_proc; > static atomic_t binder_last_id; > +static bool oneway_spam_detection_enabled;
Why is this a "whole system" value and not a "per binder instance" value? You just allowed one binder instance to affect another one, which does not seem like a good idea to me :( thanks, greg k-h
