Eric Lee / smarc-ti-linux-kernel

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Commit 44ee63587dce85593c22497140db16f4e5027860

Authored by Tejun Heo
Committed by Frederic Weisbecker
1 parent 018cbffe68
Exists in master and in 20 other branches dlt-processor-sdk-linux-03.00.00.04, newt-ti-linux-3.12.y, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.12.10, smarc-ti-linux-3.12.y, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.12.y, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

percpu: Add __percpu sparse annotations to hw_breakpoint 

Add __percpu sparse annotations to hw_breakpoint.

These annotations are to make sparse consider percpu variables to be
in a different address space and warn if accessed without going
through percpu accessors.  This patch doesn't affect normal builds.

In kernel/hw_breakpoint.c, per_cpu(nr_task_bp_pinned, cpu)'s will
trigger spurious noderef related warnings from sparse.  Changing it to
&per_cpu(nr_task_bp_pinned[0], cpu) will work around the problem but
deemed to ugly by the maintainer.  Leave it alone until better
solution can be found.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
LKML-Reference: <4B7B4B7A.9050902@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

Showing 3 changed files with 12 additions and 12 deletions Side-by-side Diff

include/linux/hw_breakpoint.h
Diff comments   View file @ 44ee635
... ... @@ -66,14 +66,14 @@
66 66 perf_overflow_handler_t triggered,
67 67 int cpu);
68 68  
69   -extern struct perf_event **
  69 +extern struct perf_event * __percpu *
70 70 register_wide_hw_breakpoint(struct perf_event_attr *attr,
71 71 perf_overflow_handler_t triggered);
72 72  
73 73 extern int register_perf_hw_breakpoint(struct perf_event *bp);
74 74 extern int __register_perf_hw_breakpoint(struct perf_event *bp);
75 75 extern void unregister_hw_breakpoint(struct perf_event *bp);
76   -extern void unregister_wide_hw_breakpoint(struct perf_event **cpu_events);
  76 +extern void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events);
77 77  
78 78 extern int dbg_reserve_bp_slot(struct perf_event *bp);
79 79 extern int dbg_release_bp_slot(struct perf_event *bp);
... ... @@ -100,7 +100,7 @@
100 100 register_wide_hw_breakpoint_cpu(struct perf_event_attr *attr,
101 101 perf_overflow_handler_t triggered,
102 102 int cpu) { return NULL; }
103   -static inline struct perf_event **
  103 +static inline struct perf_event * __percpu *
104 104 register_wide_hw_breakpoint(struct perf_event_attr *attr,
105 105 perf_overflow_handler_t triggered) { return NULL; }
106 106 static inline int
... ... @@ -109,7 +109,7 @@
109 109 __register_perf_hw_breakpoint(struct perf_event *bp) { return -ENOSYS; }
110 110 static inline void unregister_hw_breakpoint(struct perf_event *bp) { }
111 111 static inline void
112   -unregister_wide_hw_breakpoint(struct perf_event **cpu_events) { }
  112 +unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events) { }
113 113 static inline int
114 114 reserve_bp_slot(struct perf_event *bp) {return -ENOSYS; }
115 115 static inline void release_bp_slot(struct perf_event *bp) { }
kernel/hw_breakpoint.c
Diff comments   View file @ 44ee635
... ... @@ -413,17 +413,17 @@
413 413 *
414 414 * @return a set of per_cpu pointers to perf events
415 415 */
416   -struct perf_event **
  416 +struct perf_event * __percpu *
417 417 register_wide_hw_breakpoint(struct perf_event_attr *attr,
418 418 perf_overflow_handler_t triggered)
419 419 {
420   - struct perf_event **cpu_events, **pevent, *bp;
  420 + struct perf_event * __percpu *cpu_events, **pevent, *bp;
421 421 long err;
422 422 int cpu;
423 423  
424 424 cpu_events = alloc_percpu(typeof(*cpu_events));
425 425 if (!cpu_events)
426   - return ERR_PTR(-ENOMEM);
  426 + return (void __percpu __force *)ERR_PTR(-ENOMEM);
427 427  
428 428 get_online_cpus();
429 429 for_each_online_cpu(cpu) {
... ... @@ -451,7 +451,7 @@
451 451 put_online_cpus();
452 452  
453 453 free_percpu(cpu_events);
454   - return ERR_PTR(err);
  454 + return (void __percpu __force *)ERR_PTR(err);
455 455 }
456 456 EXPORT_SYMBOL_GPL(register_wide_hw_breakpoint);
457 457  
... ... @@ -459,7 +459,7 @@
459 459 * unregister_wide_hw_breakpoint - unregister a wide breakpoint in the kernel
460 460 * @cpu_events: the per cpu set of events to unregister
461 461 */
462   -void unregister_wide_hw_breakpoint(struct perf_event **cpu_events)
  462 +void unregister_wide_hw_breakpoint(struct perf_event * __percpu *cpu_events)
463 463 {
464 464 int cpu;
465 465 struct perf_event **pevent;
samples/hw_breakpoint/data_breakpoint.c
Diff comments   View file @ 44ee635
... ... @@ -34,7 +34,7 @@
34 34 #include <linux/perf_event.h>
35 35 #include <linux/hw_breakpoint.h>
36 36  
37   -struct perf_event **sample_hbp;
  37 +struct perf_event * __percpu *sample_hbp;
38 38  
39 39 static char ksym_name[KSYM_NAME_LEN] = "pid_max";
40 40 module_param_string(ksym, ksym_name, KSYM_NAME_LEN, S_IRUGO);
... ... @@ -61,8 +61,8 @@
61 61 attr.bp_type = HW_BREAKPOINT_W | HW_BREAKPOINT_R;
62 62  
63 63 sample_hbp = register_wide_hw_breakpoint(&attr, sample_hbp_handler);
64   - if (IS_ERR(sample_hbp)) {
65   - ret = PTR_ERR(sample_hbp);
  64 + if (IS_ERR((void __force *)sample_hbp)) {
  65 + ret = PTR_ERR((void __force *)sample_hbp);
66 66 goto fail;
67 67 }
68 68