[PATCH 4.14 070/217] locking/lockdep: Do not record IRQ state within lockdep code

Greg Kroah-Hartman
2018-08-23T08:21:55Z

From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>

[ Upstream commit fcc784be837714a9173b372ff9fb9b514590dad9 ]

While debugging where things were going wrong with mapping
enabling/disabling interrupts with the lockdep state and actual real
enabling and disabling interrupts, I had to silent the IRQ
disabling/enabling in debug_check_no_locks_freed() because it was
always showing up as it was called before the splat was.

Use raw_local_irq_save/restore() for not only debug_check_no_locks_freed()
but for all internal lockdep functions, as they hide useful information
about where interrupts were used incorrectly last.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/lkml/20180404140630.3f4f4c7a@gandalf.local.home
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
kernel/locking/lockdep.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -1296,11 +1296,11 @@ unsigned long lockdep_count_forward_deps
this.parent = NULL;
this.class = class;

- local_irq_save(flags);
+ raw_local_irq_save(flags);
arch_spin_lock(&lockdep_lock);
ret = __lockdep_count_forward_deps(&this);
arch_spin_unlock(&lockdep_lock);
- local_irq_restore(flags);
+ raw_local_irq_restore(flags);

return ret;
}
@@ -1323,11 +1323,11 @@ unsigned long lockdep_count_backward_dep
this.parent = NULL;
this.class = class;

- local_irq_save(flags);
+ raw_local_irq_save(flags);
arch_spin_lock(&lockdep_lock);
ret = __lockdep_count_backward_deps(&this);
arch_spin_unlock(&lockdep_lock);
- local_irq_restore(flags);
+ raw_local_irq_restore(flags);

return ret;
}
@@ -4478,7 +4478,7 @@ void debug_check_no_locks_freed(const vo
if (unlikely(!debug_locks))
return;

- local_irq_save(flags);
+ raw_local_irq_save(flags);
for (i = 0; i < curr->lockdep_depth; i++) {
hlock = curr->held_locks + i;

@@ -4489,7 +4489,7 @@ void debug_check_no_locks_freed(const vo
print_freed_lock_bug(curr, mem_from, mem_from + mem_len, hlock);
break;
}
- local_irq_restore(flags);
+ raw_local_irq_restore(flags);
}
EXPORT_SYMBOL_GPL(debug_check_no_locks_freed);