From f163ffa9df918f41f2faf1b0fda19842c84b02ce Mon Sep 17 00:00:00 2001 From: Qian Cai Date: Tue, 10 Dec 2019 22:30:42 -0500 Subject: [PATCH] x86/resctrl: Fix an imbalance in domain_remove_cpu() 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 Signed-off-by: Borislav Petkov Acked-by: Reinette Chatre Cc: Fenghua Yu Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: john.stultz@linaro.org Cc: sboyd@kernel.org Cc: Cc: Thomas Gleixner Cc: tj@kernel.org Cc: Tony Luck Cc: Vikas Shivappa Cc: x86-ml Link: https://lkml.kernel.org/r/20191211033042.2188-1-cai@lca.pw Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/resctrl/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/resctrl/core.c b/arch/x86/kernel/cpu/resctrl/core.c index 03eb90d..89049b3 100644 --- a/arch/x86/kernel/cpu/resctrl/core.c +++ b/arch/x86/kernel/cpu/resctrl/core.c @@ -618,7 +618,7 @@ static void domain_remove_cpu(int cpu, struct rdt_resource *r) 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)) { /* -- 2.7.4