Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756966Ab0HFOZV (ORCPT ); Fri, 6 Aug 2010 10:25:21 -0400 Received: from s15228384.onlinehome-server.info ([87.106.30.177]:40112 "EHLO mail.x86-64.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752727Ab0HFOZP (ORCPT ); Fri, 6 Aug 2010 10:25:15 -0400 From: Borislav Petkov To: , , , , Cc: , Borislav Petkov Subject: [RFC PATCH 4/9] mce: Add persistent events Date: Fri, 6 Aug 2010 16:25:08 +0200 Message-Id: <1281104713-23141-5-git-send-email-bp@amd64.org> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1281104713-23141-1-git-send-email-bp@amd64.org> References: <1281104713-23141-1-git-send-email-bp@amd64.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5083 Lines: 194 From: Borislav Petkov Add the required glue to enable the mce_record tracepoint on boot thus simulating a persistent event with allocated buffers. Userspace daemon will hook into it later when booting is done. Export mce buffer read-only through debugfs. Signed-off-by: Borislav Petkov --- arch/x86/kernel/cpu/mcheck/mce.c | 135 ++++++++++++++++++++++++++++++++++++++ 1 files changed, 135 insertions(+), 0 deletions(-) diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 1970ef9..cdff254 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -95,6 +95,7 @@ static char *mce_helper_argv[2] = { mce_helper, NULL }; static DECLARE_WAIT_QUEUE_HEAD(mce_wait); static DEFINE_PER_CPU(struct mce, mces_seen); +static DEFINE_PER_CPU(struct perf_event *, mce_event); static int cpu_missing; /* @@ -2064,6 +2065,137 @@ static void __cpuinit mce_reenable_cpu(void *h) } } +struct perf_event_attr pattr = { + .type = PERF_TYPE_TRACEPOINT, + .size = sizeof(pattr), + .sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_CPU | PERF_SAMPLE_TIME, +}; + +static int mce_enable_perf_event_on_cpu(int cpu) +{ + struct perf_event *event; + struct perf_buffer *buffer; + + if (!event_mce_record.event.type) { + printk(KERN_ERR "mce: Tracepoint not enumerated yet!\n"); + return -EINVAL; + } + pattr.config = event_mce_record.event.type; + pattr.sample_period = ULLONG_MAX; + + event = perf_event_create_kernel_counter(&pattr, cpu, -1, NULL); + if (IS_ERR(event)) + return -EINVAL; + + buffer = perf_buffer_alloc(128, 0, cpu, 0); + if (IS_ERR(buffer)) + goto err; + + rcu_assign_pointer(event->buffer, buffer); + per_cpu(mce_event, cpu) = event; + + perf_event_enable(event); + + return 0; + +err: + perf_event_release_kernel(event); + return -EINVAL; +} + +static void mce_disable_perf_event_on_cpu(int cpu) +{ + struct perf_event *event = per_cpu(mce_event, cpu); + + if (!event) + return; + + perf_event_disable(event); + + if (event->buffer) { + perf_buffer_put(event->buffer); + rcu_assign_pointer(event->buffer, NULL); + } + + per_cpu(mce_event, cpu) = NULL; + + perf_event_release_kernel(event); +} + +static int mce_perf_open(struct inode *inode, struct file *file) +{ + file->private_data = inode->i_private; + + return 0; +} + +static const struct file_operations perf_mce_fops = { + .llseek = no_llseek, + .open = mce_perf_open, + .poll = perf_poll, + .unlocked_ioctl = perf_ioctl, + .compat_ioctl = perf_ioctl, + .mmap = perf_mmap, + .fasync = perf_fasync, + .release = perf_release, +}; + +static int mce_add_perf_debugfs_entry(struct dentry *dmce, int cpu) +{ + struct dentry *fmce_record; + char buf[14]; + + sprintf(buf, "mce_record%d", cpu); + + fmce_record = debugfs_create_file(buf, S_IRUGO, dmce, + per_cpu(mce_event, cpu), + &perf_mce_fops); + + if (!fmce_record) + return -ENOMEM; + + return 0; +} + +static int mcheck_init_perf_event(void) +{ + int cpu, err = 0; + + get_online_cpus(); + + for_each_online_cpu(cpu) { + err = mce_enable_perf_event_on_cpu(cpu); + if (err) { + printk(KERN_ERR "mce: error initializing mce tracepoint" + " on cpu %d\n", cpu); + goto unwind; + } + + err = mce_add_perf_debugfs_entry(mce_get_debugfs_dir(), cpu); + if (err) { + printk(KERN_ERR "mce: error adding debugfs entry" + "on cpu %d\n", cpu); + goto unwind; + } + } + goto unlock; + +unwind: + for (--cpu; cpu >= 0; cpu--) + mce_disable_perf_event_on_cpu(cpu); + +unlock: + put_online_cpus(); + + return err; +} + +/* + * This has to run after after event_trace_init() which is an fs_initcall() + * currently + */ +device_initcall(mcheck_init_perf_event); + /* Get notified when a cpu comes on/off. Be hotplug friendly. */ static int __cpuinit mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) @@ -2077,6 +2209,7 @@ mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) mce_create_device(cpu); if (threshold_cpu_callback) threshold_cpu_callback(action, cpu); + mce_enable_perf_event_on_cpu(cpu); break; case CPU_DEAD: case CPU_DEAD_FROZEN: @@ -2088,6 +2221,7 @@ mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) case CPU_DOWN_PREPARE_FROZEN: del_timer_sync(t); smp_call_function_single(cpu, mce_disable_cpu, &action, 1); + mce_disable_perf_event_on_cpu(cpu); break; case CPU_DOWN_FAILED: case CPU_DOWN_FAILED_FROZEN: @@ -2097,6 +2231,7 @@ mce_cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) add_timer_on(t, cpu); } smp_call_function_single(cpu, mce_reenable_cpu, &action, 1); + mce_enable_perf_event_on_cpu(cpu); break; case CPU_POST_DEAD: /* intentionally ignoring frozen here */ -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/