queue-4.4/locking-lockdep-do-not-record-irq-state-within-lockdep-code.patch

   1 From foo@baz Wed Aug 22 10:28:26 CEST 2018
   2 From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
   3 Date: Wed, 4 Apr 2018 14:06:30 -0400
   4 Subject: locking/lockdep: Do not record IRQ state within lockdep code
   5
   6 From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
   7
   8 [ Upstream commit fcc784be837714a9173b372ff9fb9b514590dad9 ]
   9
  10 While debugging where things were going wrong with mapping
  11 enabling/disabling interrupts with the lockdep state and actual real
  12 enabling and disabling interrupts, I had to silent the IRQ
  13 disabling/enabling in debug_check_no_locks_freed() because it was
  14 always showing up as it was called before the splat was.
  15
  16 Use raw_local_irq_save/restore() for not only debug_check_no_locks_freed()
  17 but for all internal lockdep functions, as they hide useful information
  18 about where interrupts were used incorrectly last.
  19
  20 Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
  21 Cc: Andrew Morton <akpm@linux-foundation.org>
  22 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  23 Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
  24 Cc: Peter Zijlstra <peterz@infradead.org>
  25 Cc: Thomas Gleixner <tglx@linutronix.de>
  26 Cc: Will Deacon <will.deacon@arm.com>
  27 Link: https://lkml.kernel.org/lkml/20180404140630.3f4f4c7a@gandalf.local.home
  28 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  29 Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
  30 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  31 ---
  32  kernel/locking/lockdep.c |   12 ++++++------
  33  1 file changed, 6 insertions(+), 6 deletions(-)
  34
  35 --- a/kernel/locking/lockdep.c
  36 +++ b/kernel/locking/lockdep.c
  37 @@ -1264,11 +1264,11 @@ unsigned long lockdep_count_forward_deps
  38         this.parent = NULL;
  39         this.class = class;
  40
  41 -       local_irq_save(flags);
  42 +       raw_local_irq_save(flags);
  43         arch_spin_lock(&lockdep_lock);
  44         ret = __lockdep_count_forward_deps(&this);
  45         arch_spin_unlock(&lockdep_lock);
  46 -       local_irq_restore(flags);
  47 +       raw_local_irq_restore(flags);
  48
  49         return ret;
  50  }
  51 @@ -1291,11 +1291,11 @@ unsigned long lockdep_count_backward_dep
  52         this.parent = NULL;
  53         this.class = class;
  54
  55 -       local_irq_save(flags);
  56 +       raw_local_irq_save(flags);
  57         arch_spin_lock(&lockdep_lock);
  58         ret = __lockdep_count_backward_deps(&this);
  59         arch_spin_unlock(&lockdep_lock);
  60 -       local_irq_restore(flags);
  61 +       raw_local_irq_restore(flags);
  62
  63         return ret;
  64  }
  65 @@ -4123,7 +4123,7 @@ void debug_check_no_locks_freed(const vo
  66         if (unlikely(!debug_locks))
  67                 return;
  68
  69 -       local_irq_save(flags);
  70 +       raw_local_irq_save(flags);
  71         for (i = 0; i < curr->lockdep_depth; i++) {
  72                 hlock = curr->held_locks + i;
  73
  74 @@ -4134,7 +4134,7 @@ void debug_check_no_locks_freed(const vo
  75                 print_freed_lock_bug(curr, mem_from, mem_from + mem_len, hlock);
  76                 break;
  77         }
  78 -       local_irq_restore(flags);
  79 +       raw_local_irq_restore(flags);
  80  }
  81  EXPORT_SYMBOL_GPL(debug_check_no_locks_freed);
  82