diff options
Diffstat (limited to 'debian/patches-rt/0023-sched-core-Add-missing-completion-for-affine_move_ta.patch')
| -rw-r--r-- | debian/patches-rt/0023-sched-core-Add-missing-completion-for-affine_move_ta.patch | 79 |
1 files changed, 0 insertions, 79 deletions
diff --git a/debian/patches-rt/0023-sched-core-Add-missing-completion-for-affine_move_ta.patch b/debian/patches-rt/0023-sched-core-Add-missing-completion-for-affine_move_ta.patch deleted file mode 100644 index e1458ff9d..000000000 --- a/debian/patches-rt/0023-sched-core-Add-missing-completion-for-affine_move_ta.patch +++ /dev/null @@ -1,79 +0,0 @@ -From 5cde0b8f5457c33119a117fc1ca5faf7efc7ed59 Mon Sep 17 00:00:00 2001 -From: Valentin Schneider <valentin.schneider@arm.com> -Date: Fri, 13 Nov 2020 11:24:14 +0000 -Subject: [PATCH 023/296] sched/core: Add missing completion for - affine_move_task() waiters -Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.35-rt39.tar.xz - -Qian reported that some fuzzer issuing sched_setaffinity() ends up stuck on -a wait_for_completion(). The problematic pattern seems to be: - - affine_move_task() - // task_running() case - stop_one_cpu(); - wait_for_completion(&pending->done); - -Combined with, on the stopper side: - - migration_cpu_stop() - // Task moved between unlocks and scheduling the stopper - task_rq(p) != rq && - // task_running() case - dest_cpu >= 0 - - => no complete_all() - -This can happen with both PREEMPT and !PREEMPT, although !PREEMPT should -be more likely to see this given the targeted task has a much bigger window -to block and be woken up elsewhere before the stopper runs. - -Make migration_cpu_stop() always look at pending affinity requests; signal -their completion if the stopper hits a rq mismatch but the task is -still within its allowed mask. When Migrate-Disable isn't involved, this -matches the previous set_cpus_allowed_ptr() vs migration_cpu_stop() -behaviour. - -Fixes: 6d337eab041d ("sched: Fix migrate_disable() vs set_cpus_allowed_ptr()") -Reported-by: Qian Cai <cai@redhat.com> -Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> -Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> -Link: https://lore.kernel.org/lkml/8b62fd1ad1b18def27f18e2ee2df3ff5b36d0762.camel@redhat.com -Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> ---- - kernel/sched/core.c | 13 ++++++++++++- - 1 file changed, 12 insertions(+), 1 deletion(-) - -diff --git a/kernel/sched/core.c b/kernel/sched/core.c -index ac6704de36d3..9429059d96e3 100644 ---- a/kernel/sched/core.c -+++ b/kernel/sched/core.c -@@ -1925,7 +1925,7 @@ static int migration_cpu_stop(void *data) - else - p->wake_cpu = dest_cpu; - -- } else if (dest_cpu < 0) { -+ } else if (dest_cpu < 0 || pending) { - /* - * This happens when we get migrated between migrate_enable()'s - * preempt_enable() and scheduling the stopper task. At that -@@ -1935,6 +1935,17 @@ static int migration_cpu_stop(void *data) - * more likely. - */ - -+ /* -+ * The task moved before the stopper got to run. We're holding -+ * ->pi_lock, so the allowed mask is stable - if it got -+ * somewhere allowed, we're done. -+ */ -+ if (pending && cpumask_test_cpu(task_cpu(p), p->cpus_ptr)) { -+ p->migration_pending = NULL; -+ complete = true; -+ goto out; -+ } -+ - /* - * When this was migrate_enable() but we no longer have an - * @pending, a concurrent SCA 'fixed' things and we should be --- -2.30.2 - |