locking/lockdep: Do not record IRQ state within lockdep code (fcc784be) · Commits · 戴 / test

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>

kernel/locking/lockdep.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -1265,11 +1265,11 @@ unsigned long lockdep_count_forward_deps(struct lock_class *class)
		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;
		}
		@@ -1292,11 +1292,11 @@ unsigned long lockdep_count_backward_deps(struct lock_class *class)
		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;
		}
		@@ -4411,7 +4411,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
		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;

		@@ -4422,7 +4422,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len)
		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);

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