Re: drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse: sparse: incorrect type in argument 1 (different address spaces)

[Robin Murphy]

On 2023-11-12 1:38 am, kernel test robot wrote:
> Hi Robin,
>
> First bad commit (maybe != root cause):
>
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   3ca112b71f35dd5d99fc4571a56b5fc6f0c15814
> commit: f9bd34e3753ea8f1433a3ba70f03a165a1416f98 perf/arm_cspmu: Clean up ACPI dependency
> date:   5 months ago
> config: loongarch-randconfig-r133-20231107 (https://download.01.org/0day-ci/archive/20231112/202311120926.cjYHyoYw-lkp@xxxxxxxxx/config)
> compiler: loongarch64-linux-gcc (GCC) 13.2.0
> reproduce: (https://download.01.org/0day-ci/archive/20231112/202311120926.cjYHyoYw-lkp@xxxxxxxxx/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202311120926.cjYHyoYw-lkp@xxxxxxxxx/
>
> sparse warnings: (new ones prefixed by >>)
> > > drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got unsigned int [noderef] __percpu * @@
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     expected void *ptr
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     got unsigned int [noderef] __percpu *

Unpicking the macros, I guess this must stem from:

for_each_sibling_event()
 -> lockdep_assert_event_ctx()
    ->this_cpu_read(hardirqs_enabled)

which appears to be the only obvious place to involve a __percpu pointer 
in this area.

From there it would seem to be a preexisting Loongarch bug - AFAICS 
__percpu_read() (and presumably at least __percpu_write() as well) 
should not be expecting a raw void * argument, but still the __percpu 
pointer, since the final dereference is done right down in the asm using 
the per-cpu offset stashed in r21?

Thanks,
Robin.

> > > drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got unsigned int [noderef] __percpu * @@
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     expected void *ptr
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     got unsigned int [noderef] __percpu *
> > > drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got unsigned int [noderef] __percpu * @@
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     expected void *ptr
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     got unsigned int [noderef] __percpu *
> > > drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got unsigned int [noderef] __percpu * @@
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     expected void *ptr
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     got unsigned int [noderef] __percpu *
> > > drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got int [noderef] __percpu * @@
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     expected void *ptr
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     got int [noderef] __percpu *
> > > drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got int [noderef] __percpu * @@
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     expected void *ptr
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     got int [noderef] __percpu *
> > > drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got int [noderef] __percpu * @@
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     expected void *ptr
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     got int [noderef] __percpu *
> > > drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse: sparse: incorrect type in argument 1 (different address spaces) @@     expected void *ptr @@     got int [noderef] __percpu * @@
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     expected void *ptr
>     drivers/perf/arm_cspmu/arm_cspmu.c:627:9: sparse:     got int [noderef] __percpu *
>
> vim +627 drivers/perf/arm_cspmu/arm_cspmu.c
>
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  609
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  610  /*
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  611   * Make sure the group of events can be scheduled at once
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  612   * on the PMU.
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  613   */
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  614  static bool arm_cspmu_validate_group(struct perf_event *event)
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  615  {
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  616  	struct perf_event *sibling, *leader = event->group_leader;
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  617  	struct arm_cspmu_hw_events fake_hw_events;
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  618
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  619  	if (event->group_leader == event)
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  620  		return true;
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  621
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  622  	memset(&fake_hw_events, 0, sizeof(fake_hw_events));
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  623
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  624  	if (!arm_cspmu_validate_event(event->pmu, &fake_hw_events, leader))
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  625  		return false;
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  626
> e37dfd65731dc4f Besar Wicaksono 2022-11-11 @627  	for_each_sibling_event(sibling, leader) {
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  628  		if (!arm_cspmu_validate_event(event->pmu, &fake_hw_events,
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  629  						  sibling))
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  630  			return false;
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  631  	}
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  632
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  633  	return arm_cspmu_validate_event(event->pmu, &fake_hw_events, event);
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  634  }
> e37dfd65731dc4f Besar Wicaksono 2022-11-11  635
>
> :::::: The code at line 627 was first introduced by commit
> :::::: e37dfd65731dc4f001fa7dfa7f705e6840017d5a perf: arm_cspmu: Add support for ARM CoreSight PMU driver
>
> :::::: TO: Besar Wicaksono <bwicaksono@xxxxxxxxxx>
> :::::: CC: Will Deacon <will@xxxxxxxxxx>