Commit 8b023acc authored by Nick Desaulniers's avatar Nick Desaulniers Committed by Peter Zijlstra
Browse files

lockdep: Fix -Wunused-parameter for _THIS_IP_ 



While looking into a bug related to the compiler's handling of addresses
of labels, I noticed some uses of _THIS_IP_ seemed unused in lockdep.
Drive by cleanup.

-Wunused-parameter:
kernel/locking/lockdep.c:1383:22: warning: unused parameter 'ip'
kernel/locking/lockdep.c:4246:48: warning: unused parameter 'ip'
kernel/locking/lockdep.c:4844:19: warning: unused parameter 'ip'

Signed-off-by: default avatarNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarWaiman Long <longman@redhat.com>
Link: https://lore.kernel.org/r/20220314221909.2027027-1-ndesaulniers@google.com
parent ace1a985

arch/arm64/kernel/entry-common.c

+4 −4
Original line number Diff line number Diff line
@@ -75,7 +75,7 @@ static __always_inline void __exit_to_kernel_mode(struct pt_regs *regs) 
	if (interrupts_enabled(regs)) {

		if (regs->exit_rcu) {

			trace_hardirqs_on_prepare();

			lockdep_hardirqs_on_prepare(CALLER_ADDR0);

			lockdep_hardirqs_on_prepare();

			rcu_irq_exit();

			lockdep_hardirqs_on(CALLER_ADDR0);

			return;
@@ -121,7 +121,7 @@ static __always_inline void enter_from_user_mode(struct pt_regs *regs) 
static __always_inline void __exit_to_user_mode(void)

{

	trace_hardirqs_on_prepare();

	lockdep_hardirqs_on_prepare(CALLER_ADDR0);

	lockdep_hardirqs_on_prepare();

	user_enter_irqoff();

	lockdep_hardirqs_on(CALLER_ADDR0);

}
@@ -179,7 +179,7 @@ static void noinstr arm64_exit_nmi(struct pt_regs *regs) 
	ftrace_nmi_exit();

	if (restore) {

		trace_hardirqs_on_prepare();

		lockdep_hardirqs_on_prepare(CALLER_ADDR0);

		lockdep_hardirqs_on_prepare();

	}



	rcu_nmi_exit();
@@ -215,7 +215,7 @@ static void noinstr arm64_exit_el1_dbg(struct pt_regs *regs) 


	if (restore) {

		trace_hardirqs_on_prepare();

		lockdep_hardirqs_on_prepare(CALLER_ADDR0);

		lockdep_hardirqs_on_prepare();

	}



	rcu_nmi_exit();

include/linux/irqflags.h

+2 −2
Original line number Diff line number Diff line
@@ -20,13 +20,13 @@ 
#ifdef CONFIG_PROVE_LOCKING

  extern void lockdep_softirqs_on(unsigned long ip);

  extern void lockdep_softirqs_off(unsigned long ip);

  extern void lockdep_hardirqs_on_prepare(unsigned long ip);

  extern void lockdep_hardirqs_on_prepare(void);

  extern void lockdep_hardirqs_on(unsigned long ip);

  extern void lockdep_hardirqs_off(unsigned long ip);

#else

  static inline void lockdep_softirqs_on(unsigned long ip) { }

  static inline void lockdep_softirqs_off(unsigned long ip) { }

  static inline void lockdep_hardirqs_on_prepare(unsigned long ip) { }

  static inline void lockdep_hardirqs_on_prepare(void) { }

  static inline void lockdep_hardirqs_on(unsigned long ip) { }

  static inline void lockdep_hardirqs_off(unsigned long ip) { }

#endif

include/linux/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -450,7 +450,7 @@ static __always_inline void guest_state_enter_irqoff(void) 
{

	instrumentation_begin();

	trace_hardirqs_on_prepare();

	lockdep_hardirqs_on_prepare(CALLER_ADDR0);

	lockdep_hardirqs_on_prepare();

	instrumentation_end();



	guest_context_enter_irqoff();

kernel/entry/common.c

+3 −3
Original line number Diff line number Diff line
@@ -126,7 +126,7 @@ static __always_inline void __exit_to_user_mode(void) 
{

	instrumentation_begin();

	trace_hardirqs_on_prepare();

	lockdep_hardirqs_on_prepare(CALLER_ADDR0);

	lockdep_hardirqs_on_prepare();

	instrumentation_end();



	user_enter_irqoff();
@@ -416,7 +416,7 @@ noinstr void irqentry_exit(struct pt_regs *regs, irqentry_state_t state) 
			instrumentation_begin();

			/* Tell the tracer that IRET will enable interrupts */

			trace_hardirqs_on_prepare();

			lockdep_hardirqs_on_prepare(CALLER_ADDR0);

			lockdep_hardirqs_on_prepare();

			instrumentation_end();

			rcu_irq_exit();

			lockdep_hardirqs_on(CALLER_ADDR0);
@@ -465,7 +465,7 @@ void noinstr irqentry_nmi_exit(struct pt_regs *regs, irqentry_state_t irq_state) 
	ftrace_nmi_exit();

	if (irq_state.lockdep) {

		trace_hardirqs_on_prepare();

		lockdep_hardirqs_on_prepare(CALLER_ADDR0);

		lockdep_hardirqs_on_prepare();

	}

	instrumentation_end();

kernel/locking/lockdep.c

+8 −14
Original line number Diff line number Diff line
@@ -1380,7 +1380,7 @@ static struct lock_list *alloc_list_entry(void) 
 */

static int add_lock_to_list(struct lock_class *this,

			    struct lock_class *links_to, struct list_head *head,

			    unsigned long ip, u16 distance, u8 dep,

			    u16 distance, u8 dep,

			    const struct lock_trace *trace)

{

	struct lock_list *entry;
@@ -3133,19 +3133,15 @@ check_prev_add(struct task_struct *curr, struct held_lock *prev, 
	 * to the previous lock's dependency list:

	 */

	ret = add_lock_to_list(hlock_class(next), hlock_class(prev),

			       &hlock_class(prev)->locks_after,

			       next->acquire_ip, distance,

			       calc_dep(prev, next),

			       *trace);

			       &hlock_class(prev)->locks_after, distance,

			       calc_dep(prev, next), *trace);



	if (!ret)

		return 0;



	ret = add_lock_to_list(hlock_class(prev), hlock_class(next),

			       &hlock_class(next)->locks_before,

			       next->acquire_ip, distance,

			       calc_depb(prev, next),

			       *trace);

			       &hlock_class(next)->locks_before, distance,

			       calc_depb(prev, next), *trace);

	if (!ret)

		return 0;
@@ -4236,14 +4232,13 @@ static void __trace_hardirqs_on_caller(void) 


/**

 * lockdep_hardirqs_on_prepare - Prepare for enabling interrupts

 * @ip:		Caller address

 *

 * Invoked before a possible transition to RCU idle from exit to user or

 * guest mode. This ensures that all RCU operations are done before RCU

 * stops watching. After the RCU transition lockdep_hardirqs_on() has to be

 * invoked to set the final state.

 */

void lockdep_hardirqs_on_prepare(unsigned long ip)

void lockdep_hardirqs_on_prepare(void)

{

	if (unlikely(!debug_locks))

		return;
@@ -4840,8 +4835,7 @@ EXPORT_SYMBOL_GPL(__lockdep_no_validate__); 


static void

print_lock_nested_lock_not_held(struct task_struct *curr,

				struct held_lock *hlock,

				unsigned long ip)

				struct held_lock *hlock)

{

	if (!debug_locks_off())

		return;
@@ -5017,7 +5011,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass, 
	chain_key = iterate_chain_key(chain_key, hlock_id(hlock));



	if (nest_lock && !__lock_is_held(nest_lock, -1)) {

		print_lock_nested_lock_not_held(curr, hlock, ip);

		print_lock_nested_lock_not_held(curr, hlock);

		return 0;

	}