locking/lockdep: Adjust new bit cases in mark_lock (4d56330d) · Commits · 戴 / test

The new bit can be any possible lock usage except it is garbage, so the cases in switch can be made simpler. Warn early on if wrong usage bit is passed without taking locks. No functional change. Signed-off-by:

Yuyang Du <duyuyang@gmail.com> Signed-off-by:

Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: bvanassche@acm.org Cc: frederic@kernel.org Cc: ming.lei@redhat.com Cc: will.deacon@arm.com Link: https://lkml.kernel.org/r/20190506081939.74287-23-duyuyang@gmail.com Signed-off-by:

Ingo Molnar <mingo@kernel.org>

kernel/locking/lockdep.c

+7 −14

Original line number	Diff line number	Diff line
		@@ -3582,6 +3582,11 @@ static int mark_lock(struct task_struct curr, struct held_lock this,
		{
		unsigned int new_mask = 1 << new_bit, ret = 1;

		if (new_bit >= LOCK_USAGE_STATES) {
		DEBUG_LOCKS_WARN_ON(1);
		return 0;
		}

		/*
		* If already set then do not dirty the cacheline,
		* nor do any checks:
		@@ -3605,24 +3610,12 @@ static int mark_lock(struct task_struct curr, struct held_lock this,
		return 0;

		switch (new_bit) {
		#define LOCKDEP_STATE(__STATE) \
		case LOCK_USED_IN_##__STATE: \
		case LOCK_USED_IN_##__STATE##_READ: \
		case LOCK_ENABLED_##__STATE: \
		case LOCK_ENABLED_##__STATE##_READ:
		#include "lockdep_states.h"
		#undef LOCKDEP_STATE
		ret = mark_lock_irq(curr, this, new_bit);
		if (!ret)
		return 0;
		break;
		case LOCK_USED:
		debug_atomic_dec(nr_unused_locks);
		break;
		default:
		if (!debug_locks_off_graph_unlock())
		return 0;
		WARN_ON(1);
		ret = mark_lock_irq(curr, this, new_bit);
		if (!ret)
		return 0;
		}

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