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perf/x86/intel: Add cpu_(prepare|starting|dying) for core_pmu 

The core_pmu does not define cpu_* callbacks, which handles
allocation of 'struct cpu_hw_events::shared_regs' data,
initialization of debug store and PMU_FL_EXCL_CNTRS counters.

While this probably won't happen on bare metal, virtual CPU can
define x86_pmu.extra_regs together with PMU version 1 and thus
be using core_pmu -> using shared_regs data without it being
allocated. That could could leave to following panic:

	BUG: unable to handle kernel NULL pointer dereference at (null)
	IP: [<ffffffff8152cd4f>] _spin_lock_irqsave+0x1f/0x40

	SNIP

	 [<ffffffff81024bd9>] __intel_shared_reg_get_constraints+0x69/0x1e0
	 [<ffffffff81024deb>] intel_get_event_constraints+0x9b/0x180
	 [<ffffffff8101e815>] x86_schedule_events+0x75/0x1d0
	 [<ffffffff810586dc>] ? check_preempt_curr+0x7c/0x90
	 [<ffffffff810649fe>] ? try_to_wake_up+0x24e/0x3e0
	 [<ffffffff81064ba2>] ? default_wake_function+0x12/0x20
	 [<ffffffff8109eb16>] ? autoremove_wake_function+0x16/0x40
	 [<ffffffff810577e9>] ? __wake_up_common+0x59/0x90
	 [<ffffffff811a9517>] ? __d_lookup+0xa7/0x150
	 [<ffffffff8119db5f>] ? do_lookup+0x9f/0x230
	 [<ffffffff811a993a>] ? dput+0x9a/0x150
	 [<ffffffff8119c8f5>] ? path_to_nameidata+0x25/0x60
	 [<ffffffff8119e90a>] ? __link_path_walk+0x7da/0x1000
	 [<ffffffff8101d8f9>] ? x86_pmu_add+0xb9/0x170
	 [<ffffffff8101d7a7>] x86_pmu_commit_txn+0x67/0xc0
	 [<ffffffff811b07b0>] ? mntput_no_expire+0x30/0x110
	 [<ffffffff8119c731>] ? path_put+0x31/0x40
	 [<ffffffff8107c297>] ? current_fs_time+0x27/0x30
	 [<ffffffff8117d170>] ? mem_cgroup_get_reclaim_stat_from_page+0x20/0x70
	 [<ffffffff8111b7aa>] group_sched_in+0x13a/0x170
	 [<ffffffff81014a29>] ? sched_clock+0x9/0x10
	 [<ffffffff8111bac8>] ctx_sched_in+0x2e8/0x330
	 [<ffffffff8111bb7b>] perf_event_sched_in+0x6b/0xb0
	 [<ffffffff8111bc36>] perf_event_context_sched_in+0x76/0xc0
	 [<ffffffff8111eb3b>] perf_event_comm+0x1bb/0x2e0
	 [<ffffffff81195ee9>] set_task_comm+0x69/0x80
	 [<ffffffff81195fe1>] setup_new_exec+0xe1/0x2e0
	 [<ffffffff811ea68e>] load_elf_binary+0x3ce/0x1ab0

Adding cpu_(prepare|starting|dying) for core_pmu to have
shared_regs data allocated for core_pmu. AFAICS there's no harm
to initialize debug store and PMU_FL_EXCL_CNTRS either for
core_pmu.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20150421152623.GC13169@krava.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
hifive-unleashed-5.1
Jiri Olsa 2015-04-21 17:26:23 +02:00 committed by Ingo Molnar
parent 0c99241c93
commit 3b6e042188
1 changed files with 38 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

66
arch/x86/kernel/cpu/perf_event_intel.c
View File

@ -2533,34 +2533,6 @@ ssize_t intel_event_sysfs_show(char *page, u64 config)
return x86_event_sysfs_show(page, config, event);
}
static __initconst const struct x86_pmu core_pmu = {
.name = "core",
.handle_irq = x86_pmu_handle_irq,
.disable_all = x86_pmu_disable_all,
.enable_all = core_pmu_enable_all,
.enable = core_pmu_enable_event,
.disable = x86_pmu_disable_event,
.hw_config = x86_pmu_hw_config,
.schedule_events = x86_schedule_events,
.eventsel = MSR_ARCH_PERFMON_EVENTSEL0,
.perfctr = MSR_ARCH_PERFMON_PERFCTR0,
.event_map = intel_pmu_event_map,
.max_events = ARRAY_SIZE(intel_perfmon_event_map),
.apic = 1,
/*
* Intel PMCs cannot be accessed sanely above 32 bit width,
* so we install an artificial 1<<31 period regardless of
* the generic event period:
*/
.max_period = (1ULL << 31) - 1,
.get_event_constraints = intel_get_event_constraints,
.put_event_constraints = intel_put_event_constraints,
.event_constraints = intel_core_event_constraints,
.guest_get_msrs = core_guest_get_msrs,
.format_attrs = intel_arch_formats_attr,
.events_sysfs_show = intel_event_sysfs_show,
};
struct intel_shared_regs *allocate_shared_regs(int cpu)
{
struct intel_shared_regs *regs;
@ -2743,6 +2715,44 @@ static struct attribute *intel_arch3_formats_attr[] = {
NULL,
};
static __initconst const struct x86_pmu core_pmu = {
.name = "core",
.handle_irq = x86_pmu_handle_irq,
.disable_all = x86_pmu_disable_all,
.enable_all = core_pmu_enable_all,
.enable = core_pmu_enable_event,
.disable = x86_pmu_disable_event,
.hw_config = x86_pmu_hw_config,
.schedule_events = x86_schedule_events,
.eventsel = MSR_ARCH_PERFMON_EVENTSEL0,
.perfctr = MSR_ARCH_PERFMON_PERFCTR0,
.event_map = intel_pmu_event_map,
.max_events = ARRAY_SIZE(intel_perfmon_event_map),
.apic = 1,
/*
* Intel PMCs cannot be accessed sanely above 32-bit width,
* so we install an artificial 1<<31 period regardless of
* the generic event period:
*/
.max_period = (1ULL<<31) - 1,
.get_event_constraints = intel_get_event_constraints,
.put_event_constraints = intel_put_event_constraints,
.event_constraints = intel_core_event_constraints,
.guest_get_msrs = core_guest_get_msrs,
.format_attrs = intel_arch_formats_attr,
.events_sysfs_show = intel_event_sysfs_show,
/*
* Virtual (or funny metal) CPU can define x86_pmu.extra_regs
* together with PMU version 1 and thus be using core_pmu with
* shared_regs. We need following callbacks here to allocate
* it properly.
*/
.cpu_prepare = intel_pmu_cpu_prepare,
.cpu_starting = intel_pmu_cpu_starting,
.cpu_dying = intel_pmu_cpu_dying,
};
static __initconst const struct x86_pmu intel_pmu = {
.name = "Intel",
.handle_irq = intel_pmu_handle_irq,