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-rw-r--r--include/linux/sched.h4
-rw-r--r--kernel/sched/core.c23
2 files changed, 25 insertions, 2 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 6f342d8e31a9..f29134712284 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1655,6 +1655,10 @@ struct task_struct {
int kmap_idx;
pte_t kmap_pte[KM_TYPE_NR];
#endif
+
+#ifdef CONFIG_DEBUG_PREEMPT
+ unsigned long preempt_disable_ip;
+#endif
};
#ifdef CONFIG_PREEMPT_RT_FULL
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 49ba251af88e..1f9d6f5184e5 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3215,8 +3215,13 @@ void __kprobes add_preempt_count(int val)
DEBUG_LOCKS_WARN_ON((preempt_count() & PREEMPT_MASK) >=
PREEMPT_MASK - 10);
#endif
- if (preempt_count() == val)
- trace_preempt_off(CALLER_ADDR0, get_parent_ip(CALLER_ADDR1));
+ if (preempt_count() == val) {
+ unsigned long ip = get_parent_ip(CALLER_ADDR1);
+#ifdef CONFIG_DEBUG_PREEMPT
+ current->preempt_disable_ip = ip;
+#endif
+ trace_preempt_off(CALLER_ADDR0, ip);
+ }
}
EXPORT_SYMBOL(add_preempt_count);
@@ -3259,6 +3264,13 @@ static noinline void __schedule_bug(struct task_struct *prev)
print_modules();
if (irqs_disabled())
print_irqtrace_events(prev);
+#ifdef DEBUG_PREEMPT
+ if (in_atomic_preempt_off()) {
+ pr_err("Preemption disabled at:");
+ print_ip_sym(current->preempt_disable_ip);
+ pr_cont("\n");
+ }
+#endif
dump_stack();
}
@@ -7511,6 +7523,13 @@ void __might_sleep(const char *file, int line, int preempt_offset)
debug_show_held_locks(current);
if (irqs_disabled())
print_irqtrace_events(current);
+#ifdef DEBUG_PREEMPT
+ if (!preempt_count_equals(preempt_offset)) {
+ pr_err("Preemption disabled at:");
+ print_ip_sym(current->preempt_disable_ip);
+ pr_cont("\n");
+ }
+#endif
dump_stack();
}
EXPORT_SYMBOL(__might_sleep);