diff options
Diffstat (limited to 'features/rt/kernel-sched-move-stack-kprobe-clean-up-to-__put_tas.patch')
-rw-r--r-- | features/rt/kernel-sched-move-stack-kprobe-clean-up-to-__put_tas.patch | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/features/rt/kernel-sched-move-stack-kprobe-clean-up-to-__put_tas.patch b/features/rt/kernel-sched-move-stack-kprobe-clean-up-to-__put_tas.patch new file mode 100644 index 00000000..085edde5 --- /dev/null +++ b/features/rt/kernel-sched-move-stack-kprobe-clean-up-to-__put_tas.patch @@ -0,0 +1,80 @@ +From cb9ddd5eec36831a80572aa3d33be62eff791e74 Mon Sep 17 00:00:00 2001 +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Mon, 21 Nov 2016 19:31:08 +0100 +Subject: [PATCH 121/191] kernel/sched: move stack + kprobe clean up to + __put_task_struct() + +There is no need to free the stack before the task struct (except for reasons +mentioned in commit 68f24b08ee89 ("sched/core: Free the stack early if +CONFIG_THREAD_INFO_IN_TASK")). This also comes handy on -RT because we can't +free memory in preempt disabled region. +vfree_atomic() delays the memory cleanup to a worker. Since we move everything +to the RCU callback, we can also free it immediately. + +Cc: stable-rt@vger.kernel.org #for kprobe_flush_task() +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + kernel/fork.c | 12 +++++++++++- + kernel/sched/core.c | 9 --------- + 2 files changed, 11 insertions(+), 10 deletions(-) + +diff --git a/kernel/fork.c b/kernel/fork.c +index da1b307cbf73..5fdb0a1bbad8 100644 +--- a/kernel/fork.c ++++ b/kernel/fork.c +@@ -42,6 +42,7 @@ + #include <linux/mmu_notifier.h> + #include <linux/fs.h> + #include <linux/mm.h> ++#include <linux/kprobes.h> + #include <linux/vmacache.h> + #include <linux/nsproxy.h> + #include <linux/capability.h> +@@ -288,7 +289,7 @@ static inline void free_thread_stack(struct task_struct *tsk) + return; + } + +- vfree_atomic(tsk->stack); ++ vfree(tsk->stack); + return; + } + #endif +@@ -743,6 +744,15 @@ void __put_task_struct(struct task_struct *tsk) + WARN_ON(refcount_read(&tsk->usage)); + WARN_ON(tsk == current); + ++ /* ++ * Remove function-return probe instances associated with this ++ * task and put them back on the free list. ++ */ ++ kprobe_flush_task(tsk); ++ ++ /* Task is done with its stack. */ ++ put_task_stack(tsk); ++ + io_uring_free(tsk); + cgroup_free(tsk); + task_numa_free(tsk, true); +diff --git a/kernel/sched/core.c b/kernel/sched/core.c +index 9ec24e4188f4..2069022bdce5 100644 +--- a/kernel/sched/core.c ++++ b/kernel/sched/core.c +@@ -4282,15 +4282,6 @@ static struct rq *finish_task_switch(struct task_struct *prev) + if (prev->sched_class->task_dead) + prev->sched_class->task_dead(prev); + +- /* +- * Remove function-return probe instances associated with this +- * task and put them back on the free list. +- */ +- kprobe_flush_task(prev); +- +- /* Task is done with its stack. */ +- put_task_stack(prev); +- + put_task_struct_rcu_user(prev); + } + +-- +2.19.1 + |