From: Madhuparna Bhowmik <[email protected]>
This patch fixes the following sparse errors in events/core.c
and events/ring_buffer.c by adding RCU Annotation to struct
ring_buffer in perf_event:
kernel/events/core.c:5597:9: error: incompatible types in comparison expression
kernel/events/core.c:5303:22: error: incompatible types in comparison expression
kernel/events/core.c:5439:14: error: incompatible types in comparison expression
kernel/events/core.c:5472:14: error: incompatible types in comparison expression
kernel/events/core.c:5529:14: error: incompatible types in comparison expression
kernel/events/core.c:5615:14: error: incompatible types in comparison expression
kernel/events/core.c:5615:14: error: incompatible types in comparison expression
kernel/events/core.c:7183:13: error: incompatible types in comparison expression
kernel/events/ring_buffer.c:169:14: error: incompatible types in comparison expression
Signed-off-by: Madhuparna Bhowmik <[email protected]>
---
include/linux/perf_event.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 6d4c22aee384..1691107d2800 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -694,7 +694,7 @@ struct perf_event {
struct mutex mmap_mutex;
atomic_t mmap_count;
- struct ring_buffer *rb;
+ struct ring_buffer __rcu *rb;
struct list_head rb_entry;
unsigned long rcu_batches;
int rcu_pending;
--
2.17.1
Hi,
Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on tip/perf/core]
[also build test WARNING on v5.5]
[cannot apply to next-20200130]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]
url: https://github.com/0day-ci/linux/commits/madhuparnabhowmik10-gmail-com/perf_event-h-Add-RCU-Annotation-to-struct-ring_buffer-in-perf_event/20200202-163053
base: https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 0cc4bd8f70d1ea2940295f1050508c663fe9eff9
reproduce:
# apt-get install sparse
# sparse version: v0.6.1-154-g1dc00f87-dirty
make ARCH=x86_64 allmodconfig
make C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'
If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <[email protected]>
sparse warnings: (new ones prefixed by >>)
kernel/events/core.c:571:26: sparse: sparse: function 'perf_pmu_name' with external linkage has definition
kernel/events/core.c:1384:15: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:1384:15: sparse: struct perf_event_context [noderef] <asn:4> *
kernel/events/core.c:1384:15: sparse: struct perf_event_context *
kernel/events/core.c:1397:28: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:1397:28: sparse: struct perf_event_context [noderef] <asn:4> *
kernel/events/core.c:1397:28: sparse: struct perf_event_context *
kernel/events/core.c:3221:18: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:3221:18: sparse: struct perf_event_context [noderef] <asn:4> *
kernel/events/core.c:3221:18: sparse: struct perf_event_context *
kernel/events/core.c:3222:23: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:3222:23: sparse: struct perf_event_context [noderef] <asn:4> *
kernel/events/core.c:3222:23: sparse: struct perf_event_context *
kernel/events/core.c:3264:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:3264:25: sparse: struct perf_event_context [noderef] <asn:4> *
kernel/events/core.c:3264:25: sparse: struct perf_event_context *
kernel/events/core.c:3265:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:3265:25: sparse: struct perf_event_context [noderef] <asn:4> *
kernel/events/core.c:3265:25: sparse: struct perf_event_context *
kernel/events/core.c:4340:25: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:4340:25: sparse: struct perf_event_context [noderef] <asn:4> *
kernel/events/core.c:4340:25: sparse: struct perf_event_context *
kernel/events/core.c:5563:24: sparse: sparse: incorrect type in assignment (different address spaces)
>> kernel/events/core.c:5563:24: sparse: expected struct ring_buffer *old_rb
>> kernel/events/core.c:5563:24: sparse: got struct ring_buffer [noderef] <asn:4> *rb
kernel/events/core.c:5070:12: sparse: sparse: incorrect type in assignment (different address spaces)
>> kernel/events/core.c:5070:12: sparse: expected struct ring_buffer *rb
kernel/events/core.c:5070:12: sparse: got struct ring_buffer [noderef] <asn:4> *rb
kernel/events/core.c:5072:24: sparse: sparse: incorrect type in assignment (different base types)
kernel/events/core.c:5072:24: sparse: expected restricted __poll_t [usertype] events
kernel/events/core.c:5072:24: sparse: got int
kernel/events/core.c:5652:26: sparse: sparse: incorrect type in argument 1 (different address spaces)
>> kernel/events/core.c:5652:26: sparse: expected struct atomic_t [usertype] *v
>> kernel/events/core.c:5652:26: sparse: got struct atomic_t [noderef] <asn:4> *
kernel/events/core.c:5655:34: sparse: sparse: incorrect type in argument 1 (different address spaces)
kernel/events/core.c:5655:34: sparse: expected struct atomic_t [usertype] *v
kernel/events/core.c:5655:34: sparse: got struct atomic_t [noderef] <asn:4> *
kernel/events/core.c:7212:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
>> kernel/events/core.c:7212:9: sparse: struct list_head *
>> kernel/events/core.c:7212:9: sparse: struct list_head [noderef] <asn:4> *
kernel/events/core.c:5749:31: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:5749:31: sparse: struct ring_buffer [noderef] <asn:4> *
kernel/events/core.c:5749:31: sparse: struct ring_buffer *
kernel/events/core.c:5835:20: sparse: sparse: incorrect type in assignment (different address spaces)
kernel/events/core.c:5835:20: sparse: expected struct ring_buffer *rb
kernel/events/core.c:5835:20: sparse: got struct ring_buffer [noderef] <asn:4> *rb
kernel/events/core.c:5896:48: sparse: sparse: incorrect type in argument 1 (different address spaces)
kernel/events/core.c:5896:48: sparse: expected struct atomic_t [usertype] *v
kernel/events/core.c:5896:48: sparse: got struct atomic_t [noderef] <asn:4> *
kernel/events/internal.h:204:1: sparse: sparse: incorrect type in argument 2 (different address spaces)
kernel/events/internal.h:204:1: sparse: expected void const [noderef] <asn:1> *from
kernel/events/internal.h:204:1: sparse: got void const *buf
kernel/events/core.c:6302:6: sparse: sparse: symbol 'perf_pmu_snapshot_aux' was not declared. Should it be static?
kernel/events/core.c:7091:23: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:7091:23: sparse: struct perf_event_context [noderef] <asn:4> *
kernel/events/core.c:7091:23: sparse: struct perf_event_context *
kernel/events/core.c:7192:32: sparse: sparse: incorrect type in initializer (different address spaces)
kernel/events/core.c:7192:32: sparse: expected struct ring_buffer *rb
kernel/events/core.c:7192:32: sparse: got struct ring_buffer [noderef] <asn:4> *rb
kernel/events/core.c:7870:23: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:7870:23: sparse: struct perf_event_context [noderef] <asn:4> *
kernel/events/core.c:7870:23: sparse: struct perf_event_context *
kernel/events/core.c:8600:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:8600:17: sparse: struct swevent_hlist [noderef] <asn:4> *
kernel/events/core.c:8600:17: sparse: struct swevent_hlist *
kernel/events/core.c:8620:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:8620:17: sparse: struct swevent_hlist [noderef] <asn:4> *
kernel/events/core.c:8620:17: sparse: struct swevent_hlist *
kernel/events/core.c:8740:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:8740:16: sparse: struct swevent_hlist [noderef] <asn:4> *
kernel/events/core.c:8740:16: sparse: struct swevent_hlist *
kernel/events/core.c:8751:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:8751:9: sparse: struct swevent_hlist [noderef] <asn:4> *
kernel/events/core.c:8751:9: sparse: struct swevent_hlist *
kernel/events/core.c:8740:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:8740:16: sparse: struct swevent_hlist [noderef] <asn:4> *
kernel/events/core.c:8740:16: sparse: struct swevent_hlist *
kernel/events/core.c:8790:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:8790:17: sparse: struct swevent_hlist [noderef] <asn:4> *
kernel/events/core.c:8790:17: sparse: struct swevent_hlist *
kernel/events/core.c:8971:23: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:8971:23: sparse: struct perf_event_context [noderef] <asn:4> *
kernel/events/core.c:8971:23: sparse: struct perf_event_context *
kernel/events/core.c:10142:1: sparse: sparse: symbol 'dev_attr_nr_addr_filters' was not declared. Should it be static?
kernel/events/core.c:11865:9: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:11865:9: sparse: struct perf_event_context [noderef] <asn:4> *
kernel/events/core.c:11865:9: sparse: struct perf_event_context *
kernel/events/core.c:11975:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:11975:17: sparse: struct perf_event_context [noderef] <asn:4> *
kernel/events/core.c:11975:17: sparse: struct perf_event_context *
kernel/events/core.c:8740:16: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:8740:16: sparse: struct swevent_hlist [noderef] <asn:4> *
kernel/events/core.c:8740:16: sparse: struct swevent_hlist *
kernel/events/core.c:12399:17: sparse: sparse: incompatible types in comparison expression (different address spaces):
kernel/events/core.c:12399:17: sparse: struct swevent_hlist [noderef] <asn:4> *
kernel/events/core.c:12399:17: sparse: struct swevent_hlist *
kernel/events/core.c:155:9: sparse: sparse: context imbalance in 'perf_ctx_lock' - wrong count at exit
kernel/events/core.c:163:17: sparse: sparse: context imbalance in 'perf_ctx_unlock' - unexpected unlock
kernel/events/core.c:1404:17: sparse: sparse: context imbalance in 'perf_lock_task_context' - different lock contexts for basic block
kernel/events/core.c:1431:17: sparse: sparse: context imbalance in 'perf_pin_task_context' - unexpected unlock
kernel/events/core.c:2651:9: sparse: sparse: context imbalance in '__perf_install_in_context' - wrong count at exit
kernel/events/core.c:4312:17: sparse: sparse: context imbalance in 'find_get_context' - unexpected unlock
kernel/events/core.c:5891:26: sparse: sparse: dereference of noderef expression
vim +5563 kernel/events/core.c
fa7315871046b9 kernel/events/core.c Peter Zijlstra 2013-09-19 5453
c1317ec2b90644 kernel/events/core.c Andy Lutomirski 2014-10-24 @5454 void __weak arch_perf_update_userpage(
c1317ec2b90644 kernel/events/core.c Andy Lutomirski 2014-10-24 5455 struct perf_event *event, struct perf_event_mmap_page *userpg, u64 now)
e3f3541c19c89a kernel/events/core.c Peter Zijlstra 2011-11-21 5456 {
e3f3541c19c89a kernel/events/core.c Peter Zijlstra 2011-11-21 5457 }
e3f3541c19c89a kernel/events/core.c Peter Zijlstra 2011-11-21 5458
38ff667b321b00 kernel/perf_counter.c Peter Zijlstra 2009-03-30 5459 /*
38ff667b321b00 kernel/perf_counter.c Peter Zijlstra 2009-03-30 5460 * Callers need to ensure there can be no nesting of this function, otherwise
38ff667b321b00 kernel/perf_counter.c Peter Zijlstra 2009-03-30 5461 * the seqlock logic goes bad. We can not serialize this because the arch
38ff667b321b00 kernel/perf_counter.c Peter Zijlstra 2009-03-30 5462 * code calls this from NMI context.
38ff667b321b00 kernel/perf_counter.c Peter Zijlstra 2009-03-30 5463 */
cdd6c482c9ff9c kernel/perf_event.c Ingo Molnar 2009-09-21 5464 void perf_event_update_userpage(struct perf_event *event)
37d81828385f8f kernel/perf_counter.c Paul Mackerras 2009-03-23 5465 {
cdd6c482c9ff9c kernel/perf_event.c Ingo Molnar 2009-09-21 5466 struct perf_event_mmap_page *userpg;
76369139ceb955 kernel/events/core.c Frederic Weisbecker 2011-05-19 5467 struct ring_buffer *rb;
e3f3541c19c89a kernel/events/core.c Peter Zijlstra 2011-11-21 5468 u64 enabled, running, now;
38ff667b321b00 kernel/perf_counter.c Peter Zijlstra 2009-03-30 5469
38ff667b321b00 kernel/perf_counter.c Peter Zijlstra 2009-03-30 5470 rcu_read_lock();
5ec4c599a52362 kernel/events/core.c Peter Zijlstra 2013-08-02 5471 rb = rcu_dereference(event->rb);
5ec4c599a52362 kernel/events/core.c Peter Zijlstra 2013-08-02 5472 if (!rb)
5ec4c599a52362 kernel/events/core.c Peter Zijlstra 2013-08-02 5473 goto unlock;
5ec4c599a52362 kernel/events/core.c Peter Zijlstra 2013-08-02 5474
0d6412085b7ff5 kernel/events/core.c Eric B Munson 2011-06-24 5475 /*
0d6412085b7ff5 kernel/events/core.c Eric B Munson 2011-06-24 5476 * compute total_time_enabled, total_time_running
0d6412085b7ff5 kernel/events/core.c Eric B Munson 2011-06-24 5477 * based on snapshot values taken when the event
0d6412085b7ff5 kernel/events/core.c Eric B Munson 2011-06-24 5478 * was last scheduled in.
0d6412085b7ff5 kernel/events/core.c Eric B Munson 2011-06-24 5479 *
0d6412085b7ff5 kernel/events/core.c Eric B Munson 2011-06-24 5480 * we cannot simply called update_context_time()
0d6412085b7ff5 kernel/events/core.c Eric B Munson 2011-06-24 5481 * because of locking issue as we can be called in
0d6412085b7ff5 kernel/events/core.c Eric B Munson 2011-06-24 5482 * NMI context
0d6412085b7ff5 kernel/events/core.c Eric B Munson 2011-06-24 5483 */
e3f3541c19c89a kernel/events/core.c Peter Zijlstra 2011-11-21 5484 calc_timer_values(event, &now, &enabled, &running);
38ff667b321b00 kernel/perf_counter.c Peter Zijlstra 2009-03-30 5485
76369139ceb955 kernel/events/core.c Frederic Weisbecker 2011-05-19 5486 userpg = rb->user_page;
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5487 /*
9d2dcc8fc66087 kernel/events/core.c Michael O'Farrell 2018-07-30 5488 * Disable preemption to guarantee consistent time stamps are stored to
9d2dcc8fc66087 kernel/events/core.c Michael O'Farrell 2018-07-30 5489 * the user page.
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5490 */
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5491 preempt_disable();
37d81828385f8f kernel/perf_counter.c Paul Mackerras 2009-03-23 5492 ++userpg->lock;
92f22a3865abe8 kernel/perf_counter.c Peter Zijlstra 2009-04-02 5493 barrier();
cdd6c482c9ff9c kernel/perf_event.c Ingo Molnar 2009-09-21 5494 userpg->index = perf_event_index(event);
b5e58793c7a8ec kernel/perf_event.c Peter Zijlstra 2010-05-21 5495 userpg->offset = perf_event_count(event);
365a4038486b57 kernel/events/core.c Peter Zijlstra 2011-11-21 5496 if (userpg->index)
e78505958cf123 kernel/perf_event.c Peter Zijlstra 2010-05-21 5497 userpg->offset -= local64_read(&event->hw.prev_count);
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5498
0d6412085b7ff5 kernel/events/core.c Eric B Munson 2011-06-24 5499 userpg->time_enabled = enabled +
cdd6c482c9ff9c kernel/perf_event.c Ingo Molnar 2009-09-21 5500 atomic64_read(&event->child_total_time_enabled);
7f8b4e4e0988da kernel/perf_counter.c Peter Zijlstra 2009-06-22 5501
0d6412085b7ff5 kernel/events/core.c Eric B Munson 2011-06-24 5502 userpg->time_running = running +
cdd6c482c9ff9c kernel/perf_event.c Ingo Molnar 2009-09-21 5503 atomic64_read(&event->child_total_time_running);
7f8b4e4e0988da kernel/perf_counter.c Peter Zijlstra 2009-06-22 5504
c1317ec2b90644 kernel/events/core.c Andy Lutomirski 2014-10-24 5505 arch_perf_update_userpage(event, userpg, now);
e3f3541c19c89a kernel/events/core.c Peter Zijlstra 2011-11-21 5506
92f22a3865abe8 kernel/perf_counter.c Peter Zijlstra 2009-04-02 5507 barrier();
37d81828385f8f kernel/perf_counter.c Paul Mackerras 2009-03-23 5508 ++userpg->lock;
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5509 preempt_enable();
38ff667b321b00 kernel/perf_counter.c Peter Zijlstra 2009-03-30 5510 unlock:
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5511 rcu_read_unlock();
37d81828385f8f kernel/perf_counter.c Paul Mackerras 2009-03-23 5512 }
82975c46da8275 kernel/events/core.c Suzuki K Poulose 2018-01-02 5513 EXPORT_SYMBOL_GPL(perf_event_update_userpage);
37d81828385f8f kernel/perf_counter.c Paul Mackerras 2009-03-23 5514
9e3ed2d7597ccb kernel/events/core.c Souptick Joarder 2018-05-21 5515 static vm_fault_t perf_mmap_fault(struct vm_fault *vmf)
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5516 {
11bac80004499e kernel/events/core.c Dave Jiang 2017-02-24 5517 struct perf_event *event = vmf->vma->vm_file->private_data;
76369139ceb955 kernel/events/core.c Frederic Weisbecker 2011-05-19 5518 struct ring_buffer *rb;
9e3ed2d7597ccb kernel/events/core.c Souptick Joarder 2018-05-21 5519 vm_fault_t ret = VM_FAULT_SIGBUS;
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5520
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5521 if (vmf->flags & FAULT_FLAG_MKWRITE) {
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5522 if (vmf->pgoff == 0)
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5523 ret = 0;
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5524 return ret;
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5525 }
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5526
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5527 rcu_read_lock();
76369139ceb955 kernel/events/core.c Frederic Weisbecker 2011-05-19 5528 rb = rcu_dereference(event->rb);
76369139ceb955 kernel/events/core.c Frederic Weisbecker 2011-05-19 5529 if (!rb)
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5530 goto unlock;
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5531
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5532 if (vmf->pgoff && (vmf->flags & FAULT_FLAG_WRITE))
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5533 goto unlock;
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5534
76369139ceb955 kernel/events/core.c Frederic Weisbecker 2011-05-19 5535 vmf->page = perf_mmap_to_page(rb, vmf->pgoff);
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5536 if (!vmf->page)
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5537 goto unlock;
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5538
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5539 get_page(vmf->page);
11bac80004499e kernel/events/core.c Dave Jiang 2017-02-24 5540 vmf->page->mapping = vmf->vma->vm_file->f_mapping;
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5541 vmf->page->index = vmf->pgoff;
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5542
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5543 ret = 0;
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5544 unlock:
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5545 rcu_read_unlock();
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5546
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5547 return ret;
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5548 }
906010b2134e14 kernel/perf_event.c Peter Zijlstra 2009-09-21 5549
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5550 static void ring_buffer_attach(struct perf_event *event,
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5551 struct ring_buffer *rb)
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5552 {
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5553 struct ring_buffer *old_rb = NULL;
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5554 unsigned long flags;
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5555
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5556 if (event->rb) {
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5557 /*
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5558 * Should be impossible, we set this when removing
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5559 * event->rb_entry and wait/clear when adding event->rb_entry.
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5560 */
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5561 WARN_ON_ONCE(event->rcu_pending);
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5562
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 @5563 old_rb = event->rb;
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5564 spin_lock_irqsave(&old_rb->event_lock, flags);
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5565 list_del_rcu(&event->rb_entry);
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5566 spin_unlock_irqrestore(&old_rb->event_lock, flags);
2f993cf093643b kernel/events/core.c Oleg Nesterov 2015-05-30 5567
2f993cf093643b kernel/events/core.c Oleg Nesterov 2015-05-30 5568 event->rcu_batches = get_state_synchronize_rcu();
2f993cf093643b kernel/events/core.c Oleg Nesterov 2015-05-30 5569 event->rcu_pending = 1;
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5570 }
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5571
2f993cf093643b kernel/events/core.c Oleg Nesterov 2015-05-30 5572 if (rb) {
2f993cf093643b kernel/events/core.c Oleg Nesterov 2015-05-30 5573 if (event->rcu_pending) {
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5574 cond_synchronize_rcu(event->rcu_batches);
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5575 event->rcu_pending = 0;
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5576 }
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5577
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5578 spin_lock_irqsave(&rb->event_lock, flags);
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5579 list_add_rcu(&event->rb_entry, &rb->event_list);
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5580 spin_unlock_irqrestore(&rb->event_lock, flags);
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5581 }
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5582
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5583 /*
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5584 * Avoid racing with perf_mmap_close(AUX): stop the event
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5585 * before swizzling the event::rb pointer; if it's getting
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5586 * unmapped, its aux_mmap_count will be 0 and it won't
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5587 * restart. See the comment in __perf_pmu_output_stop().
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5588 *
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5589 * Data will inevitably be lost when set_output is done in
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5590 * mid-air, but then again, whoever does it like this is
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5591 * not in for the data anyway.
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5592 */
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5593 if (has_aux(event))
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5594 perf_event_stop(event, 0);
767ae08678c2c7 kernel/events/core.c Alexander Shishkin 2016-09-06 5595
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5596 rcu_assign_pointer(event->rb, rb);
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5597
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5598 if (old_rb) {
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5599 ring_buffer_put(old_rb);
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5600 /*
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5601 * Since we detached before setting the new rb, so that we
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5602 * could attach the new rb, we could have missed a wakeup.
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5603 * Provide it now.
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5604 */
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5605 wake_up_all(&event->waitq);
b69cf53640da2b kernel/events/core.c Peter Zijlstra 2014-03-14 5606 }
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5607 }
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5608
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5609 static void ring_buffer_wakeup(struct perf_event *event)
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5610 {
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5611 struct ring_buffer *rb;
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5612
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5613 rcu_read_lock();
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5614 rb = rcu_dereference(event->rb);
9bb5d40cd93c9d kernel/events/core.c Peter Zijlstra 2013-06-04 5615 if (rb) {
44b7f4b98d8877 kernel/events/core.c Will Deacon 2011-12-13 5616 list_for_each_entry_rcu(event, &rb->event_list, rb_entry)
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5617 wake_up_all(&event->waitq);
9bb5d40cd93c9d kernel/events/core.c Peter Zijlstra 2013-06-04 5618 }
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5619 rcu_read_unlock();
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5620 }
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5621
fdc2670666f40a kernel/events/core.c Alexander Shishkin 2015-01-14 5622 struct ring_buffer *ring_buffer_get(struct perf_event *event)
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5623 {
76369139ceb955 kernel/events/core.c Frederic Weisbecker 2011-05-19 5624 struct ring_buffer *rb;
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5625
ac9721f3f54b27 kernel/perf_event.c Peter Zijlstra 2010-05-27 5626 rcu_read_lock();
76369139ceb955 kernel/events/core.c Frederic Weisbecker 2011-05-19 5627 rb = rcu_dereference(event->rb);
76369139ceb955 kernel/events/core.c Frederic Weisbecker 2011-05-19 5628 if (rb) {
fecb8ed2ce7010 kernel/events/core.c Elena Reshetova 2019-01-28 5629 if (!refcount_inc_not_zero(&rb->refcount))
76369139ceb955 kernel/events/core.c Frederic Weisbecker 2011-05-19 5630 rb = NULL;
ac9721f3f54b27 kernel/perf_event.c Peter Zijlstra 2010-05-27 5631 }
ac9721f3f54b27 kernel/perf_event.c Peter Zijlstra 2010-05-27 5632 rcu_read_unlock();
ac9721f3f54b27 kernel/perf_event.c Peter Zijlstra 2010-05-27 5633
76369139ceb955 kernel/events/core.c Frederic Weisbecker 2011-05-19 5634 return rb;
ac9721f3f54b27 kernel/perf_event.c Peter Zijlstra 2010-05-27 5635 }
ac9721f3f54b27 kernel/perf_event.c Peter Zijlstra 2010-05-27 5636
fdc2670666f40a kernel/events/core.c Alexander Shishkin 2015-01-14 5637 void ring_buffer_put(struct ring_buffer *rb)
ac9721f3f54b27 kernel/perf_event.c Peter Zijlstra 2010-05-27 5638 {
fecb8ed2ce7010 kernel/events/core.c Elena Reshetova 2019-01-28 5639 if (!refcount_dec_and_test(&rb->refcount))
ac9721f3f54b27 kernel/perf_event.c Peter Zijlstra 2010-05-27 5640 return;
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5641
9bb5d40cd93c9d kernel/events/core.c Peter Zijlstra 2013-06-04 5642 WARN_ON_ONCE(!list_empty(&rb->event_list));
10c6db110d0eb4 kernel/events/core.c Peter Zijlstra 2011-11-26 5643
76369139ceb955 kernel/events/core.c Frederic Weisbecker 2011-05-19 5644 call_rcu(&rb->rcu_head, rb_free_rcu);
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5645 }
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5646
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5647 static void perf_mmap_open(struct vm_area_struct *vma)
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5648 {
cdd6c482c9ff9c kernel/perf_event.c Ingo Molnar 2009-09-21 5649 struct perf_event *event = vma->vm_file->private_data;
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5650
cdd6c482c9ff9c kernel/perf_event.c Ingo Molnar 2009-09-21 5651 atomic_inc(&event->mmap_count);
9bb5d40cd93c9d kernel/events/core.c Peter Zijlstra 2013-06-04 @5652 atomic_inc(&event->rb->mmap_count);
1e0fb9ec679c92 kernel/events/core.c Andy Lutomirski 2014-10-24 5653
45bfb2e50471ab kernel/events/core.c Peter Zijlstra 2015-01-14 5654 if (vma->vm_pgoff)
45bfb2e50471ab kernel/events/core.c Peter Zijlstra 2015-01-14 5655 atomic_inc(&event->rb->aux_mmap_count);
45bfb2e50471ab kernel/events/core.c Peter Zijlstra 2015-01-14 5656
1e0fb9ec679c92 kernel/events/core.c Andy Lutomirski 2014-10-24 5657 if (event->pmu->event_mapped)
bfe334924ccd9f kernel/events/core.c Peter Zijlstra 2017-08-02 5658 event->pmu->event_mapped(event, vma->vm_mm);
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5659 }
7b732a75047738 kernel/perf_counter.c Peter Zijlstra 2009-03-23 5660
:::::: The code at line 5563 was first introduced by commit
:::::: b69cf53640da2b86439596118cfa95233154ee76 perf: Fix a race between ring_buffer_detach() and ring_buffer_attach()
:::::: TO: Peter Zijlstra <[email protected]>
:::::: CC: Thomas Gleixner <[email protected]>
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/hyperkitty/list/[email protected] Intel Corporation