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    drivers/perf: hisi: Don't migrate perf to the CPU going to teardown · 37b891ca
    Junhao He 提交于
    driver inclusion
    category: bugfix
    bugzilla: https://gitee.com/openeuler/kernel/issues/I7BUN2
    CVE: NA
    
    ----------------------------------------------------------------------
    
    The driver needs to migrate the perf context if the current using CPU going
    to teardown. By the time calling the cpuhp::teardown() callback the
    cpu_online_mask() hasn't updated yet and still includes the CPU going to
    teardown. In current driver's implementation we may migrate the context
    to the teardown CPU and leads to the below calltrace:
    
    ...
    [  368.104662][  T932] task:cpuhp/0         state:D stack:    0 pid:   15 ppid:     2 flags:0x00000008
    [  368.113699][  T932] Call trace:
    [  368.116834][  T932]  __switch_to+0x7c/0xbc
    [  368.120924][  T932]  __schedule+0x338/0x6f0
    [  368.125098][  T932]  schedule+0x50/0xe0
    [  368.128926][  T932]  schedule_preempt_disabled+0x18/0x24
    [  368.134229][  T932]  __mutex_lock.constprop.0+0x1d4/0x5dc
    [  368.139617][  T932]  __mutex_lock_slowpath+0x1c/0x30
    [  368.144573][  T932]  mutex_lock+0x50/0x60
    [  368.148579][  T932]  perf_pmu_migrate_context+0x84/0x2b0
    [  368.153884][  T932]  hisi_pcie_pmu_offline_cpu+0x90/0xe0 [hisi_pcie_pmu]
    [  368.160579][  T932]  cpuhp_invoke_callback+0x2a0/0x650
    [  368.165707][  T932]  cpuhp_thread_fun+0xe4/0x190
    [  368.170316][  T932]  smpboot_thread_fn+0x15c/0x1a0
    [  368.175099][  T932]  kthread+0x108/0x13c
    [  368.179012][  T932]  ret_from_fork+0x10/0x18
    ...
    
    Use function cpumask_any_but() to find one correct active cpu to fixes
    this issue.
    
    Fixes: 8404b0fb ("drivers/perf: hisi: Add driver for HiSilicon PCIe PMU")
    Signed-off-by: NJunhao He <hejunhao3@huawei.com>
    37b891ca
hisi_pcie_pmu.c 25.6 KB