diff options
author | Jiri Olsa <jolsa@redhat.com> | 2015-04-21 15:26:23 (GMT) |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2015-04-22 06:24:33 (GMT) |
commit | 3b6e042188994466ec257b71296b5f85b894dcd9 (patch) | |
tree | 58a3bafd4bfe1a26345afbb4f98ab1c8b617694c /arch/x86/kernel | |
parent | 0c99241c93b8060441f3c8434848e54b5338f922 (diff) | |
download | linux-3b6e042188994466ec257b71296b5f85b894dcd9.tar.xz |
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>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r-- | arch/x86/kernel/cpu/perf_event_intel.c | 66 |
1 files changed, 38 insertions, 28 deletions
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 219d3fb..960e85d 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -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, |