From 8735728ef8dc935c4fb351f913758fdbb62c308d Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 22 Aug 2008 22:23:09 +0200 Subject: [PATCH] x86 MCE: Fix CPU hotplug problem with multiple multicore AMD CPUs During CPU hot-remove the sysfs directory created by threshold_create_bank(), defined in arch/x86/kernel/cpu/mcheck/mce_amd_64.c, has to be removed before its parent directory, created by mce_create_device(), defined in arch/x86/kernel/cpu/mcheck/mce_64.c . Moreover, when the CPU in question is hotplugged again, obviously the latter has to be created before the former. At present, the right ordering is not enforced, because all of these operations are carried out by CPU hotplug notifiers which are not appropriately ordered with respect to each other. This leads to serious problems on systems with two or more multicore AMD CPUs, among other things during suspend and hibernation. Fix the problem by placing threshold bank CPU hotplug callbacks in mce_cpu_callback(), so that they are invoked at the right places, if defined. Additionally, use kobject_del() to remove the sysfs directory associated with the kobject created by kobject_create_and_add() in threshold_create_bank(), to prevent the kernel from crashing during CPU hotplug operations on systems with two or more multicore AMD CPUs. This patch fixes bug #11337. Signed-off-by: Rafael J. Wysocki Acked-by: Andi Kleen Tested-by: Mark Langsdorf Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/mcheck/mce_64.c | 5 +++++ arch/x86/kernel/cpu/mcheck/mce_amd_64.c | 18 +++++------------- include/asm-x86/mce.h | 1 + 3 files changed, 11 insertions(+), 13 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce_64.c b/arch/x86/kernel/cpu/mcheck/mce_64.c index 65a339678e..726a5fcdf3 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_64.c +++ b/arch/x86/kernel/cpu/mcheck/mce_64.c @@ -759,6 +759,7 @@ static struct sysdev_class mce_sysclass = { }; DEFINE_PER_CPU(struct sys_device, device_mce); +void (*threshold_cpu_callback)(unsigned long action, unsigned int cpu) __cpuinitdata; /* Why are there no generic functions for this? */ #define ACCESSOR(name, var, start) \ @@ -883,9 +884,13 @@ static int __cpuinit mce_cpu_callback(struct notifier_block *nfb, case CPU_ONLINE: case CPU_ONLINE_FROZEN: mce_create_device(cpu); + if (threshold_cpu_callback) + threshold_cpu_callback(action, cpu); break; case CPU_DEAD: case CPU_DEAD_FROZEN: + if (threshold_cpu_callback) + threshold_cpu_callback(action, cpu); mce_remove_device(cpu); break; } diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd_64.c b/arch/x86/kernel/cpu/mcheck/mce_amd_64.c index 88736cadba..5eb390a4b2 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_amd_64.c +++ b/arch/x86/kernel/cpu/mcheck/mce_amd_64.c @@ -628,6 +628,7 @@ static void threshold_remove_bank(unsigned int cpu, int bank) deallocate_threshold_block(cpu, bank); free_out: + kobject_del(b->kobj); kobject_put(b->kobj); kfree(b); per_cpu(threshold_banks, cpu)[bank] = NULL; @@ -645,14 +646,11 @@ static void threshold_remove_device(unsigned int cpu) } /* get notified when a cpu comes on/off */ -static int __cpuinit threshold_cpu_callback(struct notifier_block *nfb, - unsigned long action, void *hcpu) +static void __cpuinit amd_64_threshold_cpu_callback(unsigned long action, + unsigned int cpu) { - /* cpu was unsigned int to begin with */ - unsigned int cpu = (unsigned long)hcpu; - if (cpu >= NR_CPUS) - goto out; + return; switch (action) { case CPU_ONLINE: @@ -666,14 +664,8 @@ static int __cpuinit threshold_cpu_callback(struct notifier_block *nfb, default: break; } - out: - return NOTIFY_OK; } -static struct notifier_block threshold_cpu_notifier __cpuinitdata = { - .notifier_call = threshold_cpu_callback, -}; - static __init int threshold_init_device(void) { unsigned lcpu = 0; @@ -684,7 +676,7 @@ static __init int threshold_init_device(void) if (err) return err; } - register_hotcpu_notifier(&threshold_cpu_notifier); + threshold_cpu_callback = amd_64_threshold_cpu_callback; return 0; } diff --git a/include/asm-x86/mce.h b/include/asm-x86/mce.h index 94f1fd79e2..531eaa5874 100644 --- a/include/asm-x86/mce.h +++ b/include/asm-x86/mce.h @@ -92,6 +92,7 @@ extern int mce_disabled; void mce_log(struct mce *m); DECLARE_PER_CPU(struct sys_device, device_mce); +extern void (*threshold_cpu_callback)(unsigned long action, unsigned int cpu); #ifdef CONFIG_X86_MCE_INTEL void mce_intel_feature_init(struct cpuinfo_x86 *c); -- 2.39.5