[PATCH v2 0/2] Proxy Execution fixes for v7.1-rc

[John Stultz <jstultz@google.com>]

Hey All,
  So in testing with the full Proxy Execution series,
Vineeth Pillai managed to trip some interesting bugs which
initially looked to be KVM or RCU related[1], which he later
diagnosed as Proxy Execution related and created a useful test
driver to reproduce.

I found these same issues could be triggered with the upstream
portions of Proxy Execution, so I wanted to send along these
fixes for 7.1-rc

Again, a huge thanks to Vineeth for uncovering these issues
that have evaded all my stress testing so far!

New in this version:
* Peter didn't like the change modifying task __state in
  schedule() and so I've reworked this to use an extra bit flag
  in the low bit of the blocked_on pointer. This does make the
  change a little larger then I'd like for a fix, but I think
  minimizing it further would create a bit of a mess.

Anyway, any feedback would be greatly appreciated!

Thanks
-john

[1]: https://lore.kernel.org/lkml/20260320125633.2290675-1-vineeth@bitbyteword.org/

Cc: Vineeth Pillai <vineethrp@google.com>
Cc: Sonam Sanju <sonam.sanju@intel.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Kunwu Chan <kunwu.chan@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: Joel Fernandes <joelagnelf@nvidia.com>
Cc: Qais Yousef <qyousef@layalina.io>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Vincent Guittot <vincent.guittot@linaro.org>
Cc: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Valentin Schneider <vschneid@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Deacon <will@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Metin Kaya <Metin.Kaya@arm.com>
Cc: Xuewen Yan <xuewen.yan94@gmail.com>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Suleiman Souhlal <suleiman@google.com>
Cc: kuyo chang <kuyo.chang@mediatek.com>
Cc: hupu <hupu.gm@gmail.com>
Cc: kernel-team@android.com

John Stultz (2):
  sched: proxy-exec: Close race causing workqueue work being delayed
  locking: mutex: Fix proxy-exec potentially deactivating tasks marked
    TASK_RUNNING

 include/linux/sched.h  | 64 ++++++++++++++++++++++++++++++++++--------
 kernel/locking/mutex.c |  1 +
 kernel/sched/core.c    | 15 ++++++----
 3 files changed, 64 insertions(+), 16 deletions(-)

-- 
2.54.0.545.g6539524ca2-goog