diff options
Diffstat (limited to 'arch/x86/kernel/cpu/bus_lock.c')
| -rw-r--r-- | arch/x86/kernel/cpu/bus_lock.c | 54 |
1 files changed, 40 insertions, 14 deletions
diff --git a/arch/x86/kernel/cpu/bus_lock.c b/arch/x86/kernel/cpu/bus_lock.c index 6cba85c79d42..981f8b1f0792 100644 --- a/arch/x86/kernel/cpu/bus_lock.c +++ b/arch/x86/kernel/cpu/bus_lock.c @@ -10,6 +10,7 @@ #include <asm/cmdline.h> #include <asm/traps.h> #include <asm/cpu.h> +#include <asm/msr.h> enum split_lock_detect_state { sld_off = 0, @@ -95,15 +96,15 @@ static bool split_lock_verify_msr(bool on) { u64 ctrl, tmp; - if (rdmsrl_safe(MSR_TEST_CTRL, &ctrl)) + if (rdmsrq_safe(MSR_TEST_CTRL, &ctrl)) return false; if (on) ctrl |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT; else ctrl &= ~MSR_TEST_CTRL_SPLIT_LOCK_DETECT; - if (wrmsrl_safe(MSR_TEST_CTRL, ctrl)) + if (wrmsrq_safe(MSR_TEST_CTRL, ctrl)) return false; - rdmsrl(MSR_TEST_CTRL, tmp); + rdmsrq(MSR_TEST_CTRL, tmp); return ctrl == tmp; } @@ -137,7 +138,7 @@ static void __init __split_lock_setup(void) return; } - rdmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache); + rdmsrq(MSR_TEST_CTRL, msr_test_ctrl_cache); if (!split_lock_verify_msr(true)) { pr_info("MSR access failed: Disabled\n"); @@ -145,7 +146,7 @@ static void __init __split_lock_setup(void) } /* Restore the MSR to its cached value. */ - wrmsrl(MSR_TEST_CTRL, msr_test_ctrl_cache); + wrmsrq(MSR_TEST_CTRL, msr_test_ctrl_cache); setup_force_cpu_cap(X86_FEATURE_SPLIT_LOCK_DETECT); } @@ -162,7 +163,7 @@ static void sld_update_msr(bool on) if (on) test_ctrl_val |= MSR_TEST_CTRL_SPLIT_LOCK_DETECT; - wrmsrl(MSR_TEST_CTRL, test_ctrl_val); + wrmsrq(MSR_TEST_CTRL, test_ctrl_val); } void split_lock_init(void) @@ -192,7 +193,33 @@ static void __split_lock_reenable(struct work_struct *work) { sld_update_msr(true); } -static DECLARE_DELAYED_WORK(sl_reenable, __split_lock_reenable); +/* + * In order for each CPU to schedule its delayed work independently of the + * others, delayed work struct must be per-CPU. This is not required when + * sysctl_sld_mitigate is enabled because of the semaphore that limits + * the number of simultaneously scheduled delayed works to 1. + */ +static DEFINE_PER_CPU(struct delayed_work, sl_reenable); + +/* + * Per-CPU delayed_work can't be statically initialized properly because + * the struct address is unknown. Thus per-CPU delayed_work structures + * have to be initialized during kernel initialization and after calling + * setup_per_cpu_areas(). + */ +static int __init setup_split_lock_delayed_work(void) +{ + unsigned int cpu; + + for_each_possible_cpu(cpu) { + struct delayed_work *work = per_cpu_ptr(&sl_reenable, cpu); + + INIT_DELAYED_WORK(work, __split_lock_reenable); + } + + return 0; +} +pure_initcall(setup_split_lock_delayed_work); /* * If a CPU goes offline with pending delayed work to re-enable split lock @@ -215,13 +242,14 @@ static void split_lock_warn(unsigned long ip) { struct delayed_work *work; int cpu; + unsigned int saved_sld_mitigate = READ_ONCE(sysctl_sld_mitigate); if (!current->reported_split_lock) pr_warn_ratelimited("#AC: %s/%d took a split_lock trap at address: 0x%lx\n", current->comm, current->pid, ip); current->reported_split_lock = 1; - if (sysctl_sld_mitigate) { + if (saved_sld_mitigate) { /* * misery factor #1: * sleep 10ms before trying to execute split lock. @@ -234,12 +262,10 @@ static void split_lock_warn(unsigned long ip) */ if (down_interruptible(&buslock_sem) == -EINTR) return; - work = &sl_reenable_unlock; - } else { - work = &sl_reenable; } cpu = get_cpu(); + work = saved_sld_mitigate ? &sl_reenable_unlock : per_cpu_ptr(&sl_reenable, cpu); schedule_delayed_work_on(cpu, work, 2); /* Disable split lock detection on this CPU to make progress */ @@ -272,7 +298,7 @@ void bus_lock_init(void) if (!boot_cpu_has(X86_FEATURE_BUS_LOCK_DETECT)) return; - rdmsrl(MSR_IA32_DEBUGCTLMSR, val); + rdmsrq(MSR_IA32_DEBUGCTLMSR, val); if ((boot_cpu_has(X86_FEATURE_SPLIT_LOCK_DETECT) && (sld_state == sld_warn || sld_state == sld_fatal)) || @@ -286,7 +312,7 @@ void bus_lock_init(void) val |= DEBUGCTLMSR_BUS_LOCK_DETECT; } - wrmsrl(MSR_IA32_DEBUGCTLMSR, val); + wrmsrq(MSR_IA32_DEBUGCTLMSR, val); } bool handle_user_split_lock(struct pt_regs *regs, long error_code) @@ -350,7 +376,7 @@ static void __init split_lock_setup(struct cpuinfo_x86 *c) * MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT is. All CPUs that set * it have split lock detection. */ - rdmsrl(MSR_IA32_CORE_CAPS, ia32_core_caps); + rdmsrq(MSR_IA32_CORE_CAPS, ia32_core_caps); if (ia32_core_caps & MSR_IA32_CORE_CAPS_SPLIT_LOCK_DETECT) goto supported; |