From: Qian Cai cai@lca.pw
commit e278af89f1ba0a9ef20947db6afc2c9afa37e85b upstream.
A system that supports resource monitoring may have multiple resources while not all of these resources are capable of monitoring. Monitoring related state is initialized only for resources that are capable of monitoring and correspondingly this state should subsequently only be removed from these resources that are capable of monitoring.
domain_add_cpu() calls domain_setup_mon_state() only when r->mon_capable is true where it will initialize d->mbm_over. However, domain_remove_cpu() calls cancel_delayed_work(&d->mbm_over) without checking r->mon_capable resulting in an attempt to cancel d->mbm_over on all resources, even those that never initialized d->mbm_over because they are not capable of monitoring. Hence, it triggers a debugobjects warning when offlining CPUs because those timer debugobjects are never initialized:
ODEBUG: assert_init not available (active state 0) object type: timer_list hint: 0x0 WARNING: CPU: 143 PID: 789 at lib/debugobjects.c:484 debug_print_object Hardware name: HP Synergy 680 Gen9/Synergy 680 Gen9 Compute Module, BIOS I40 05/23/2018 RIP: 0010:debug_print_object Call Trace: debug_object_assert_init del_timer try_to_grab_pending cancel_delayed_work resctrl_offline_cpu cpuhp_invoke_callback cpuhp_thread_fun smpboot_thread_fn kthread ret_from_fork
Fixes: e33026831bdb ("x86/intel_rdt/mbm: Handle counter overflow") Signed-off-by: Qian Cai cai@lca.pw Signed-off-by: Borislav Petkov bp@suse.de Acked-by: Reinette Chatre reinette.chatre@intel.com Cc: Fenghua Yu fenghua.yu@intel.com Cc: "H. Peter Anvin" hpa@zytor.com Cc: Ingo Molnar mingo@redhat.com Cc: john.stultz@linaro.org Cc: sboyd@kernel.org Cc: stable@vger.kernel.org Cc: Thomas Gleixner tglx@linutronix.de Cc: tj@kernel.org Cc: Tony Luck tony.luck@intel.com Cc: Vikas Shivappa vikas.shivappa@linux.intel.com Cc: x86-ml x86@kernel.org Link: https://lkml.kernel.org/r/20191211033042.2188-1-cai@lca.pw Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kernel/cpu/intel_rdt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/x86/kernel/cpu/intel_rdt.c +++ b/arch/x86/kernel/cpu/intel_rdt.c @@ -526,7 +526,7 @@ static void domain_remove_cpu(int cpu, s if (static_branch_unlikely(&rdt_mon_enable_key)) rmdir_mondata_subdir_allrdtgrp(r, d->id); list_del(&d->list); - if (is_mbm_enabled()) + if (r->mon_capable && is_mbm_enabled()) cancel_delayed_work(&d->mbm_over); if (is_llc_occupancy_enabled() && has_busy_rmid(r, d)) { /*