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87121ca504
Oprofile may crash in a KVM guest while unlaoding modules. This happens if oprofile_arch_init() fails and oprofile switches to the hr timer mode as a fallback. In this case oprofile_arch_exit() is called, but it never was initialized properly which causes the crash. This patch fixes this. oprofile: using timer interrupt. BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: [<ffffffff8123c226>] unregister_syscore_ops+0x41/0x58 PGD 41da3f067 PUD 41d80e067 PMD 0 Oops: 0002 [#1] PREEMPT SMP CPU 5 Modules linked in: oprofile(-) Pid: 2382, comm: modprobe Not tainted 3.1.0-rc7-00018-g709a39d #18 Advanced Micro Device Anaheim/Anaheim RIP: 0010:[<ffffffff8123c226>] [<ffffffff8123c226>] unregister_syscore_ops+0x41/0x58 RSP: 0018:ffff88041de1de98 EFLAGS: 00010296 RAX: 0000000000000000 RBX: ffffffffa00060e0 RCX: dead000000200200 RDX: 0000000000000000 RSI: dead000000100100 RDI: ffffffff8178c620 RBP: ffff88041de1dea8 R08: 0000000000000001 R09: 0000000000000082 R10: 0000000000000000 R11: ffff88041de1dde8 R12: 0000000000000080 R13: fffffffffffffff5 R14: 0000000000000001 R15: 0000000000610210 FS: 00007f9ae5bef700(0000) GS:ffff88042fd40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000008 CR3: 000000041ca44000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process modprobe (pid: 2382, threadinfo ffff88041de1c000, task ffff88042db6d040) Stack: ffff88041de1deb8 ffffffffa0006770 ffff88041de1deb8 ffffffffa000251e ffff88041de1dec8 ffffffffa00022c2 ffff88041de1ded8 ffffffffa0004993 ffff88041de1df78 ffffffff81073115 656c69666f72706f 0000000000610200 Call Trace: [<ffffffffa000251e>] op_nmi_exit+0x15/0x17 [oprofile] [<ffffffffa00022c2>] oprofile_arch_exit+0xe/0x10 [oprofile] [<ffffffffa0004993>] oprofile_exit+0x13/0x15 [oprofile] [<ffffffff81073115>] sys_delete_module+0x1c3/0x22f [<ffffffff811bf09e>] ? trace_hardirqs_on_thunk+0x3a/0x3f [<ffffffff8148070b>] system_call_fastpath+0x16/0x1b Code: 20 c6 78 81 e8 c5 cc 23 00 48 8b 13 48 8b 43 08 48 be 00 01 10 00 00 00 ad de 48 b9 00 02 20 00 00 00 ad de 48 c7 c7 20 c6 78 81 89 42 08 48 89 10 48 89 33 48 89 4b 08 e8 a6 c0 23 00 5a 5b RIP [<ffffffff8123c226>] unregister_syscore_ops+0x41/0x58 RSP <ffff88041de1de98> CR2: 0000000000000008 ---[ end trace 06d4e95b6aa3b437 ]--- CC: stable@kernel.org # 2.6.37+ Signed-off-by: Robert Richter <robert.richter@amd.com>
121 lines
2.5 KiB
C
121 lines
2.5 KiB
C
/**
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* @file timer_int.c
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*
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* @remark Copyright 2002 OProfile authors
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* @remark Read the file COPYING
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*
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* @author John Levon <levon@movementarian.org>
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*/
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#include <linux/kernel.h>
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#include <linux/notifier.h>
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#include <linux/smp.h>
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#include <linux/oprofile.h>
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#include <linux/profile.h>
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#include <linux/init.h>
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#include <linux/cpu.h>
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#include <linux/hrtimer.h>
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#include <asm/irq_regs.h>
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#include <asm/ptrace.h>
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#include "oprof.h"
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static DEFINE_PER_CPU(struct hrtimer, oprofile_hrtimer);
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static int ctr_running;
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static enum hrtimer_restart oprofile_hrtimer_notify(struct hrtimer *hrtimer)
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{
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oprofile_add_sample(get_irq_regs(), 0);
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hrtimer_forward_now(hrtimer, ns_to_ktime(TICK_NSEC));
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return HRTIMER_RESTART;
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}
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static void __oprofile_hrtimer_start(void *unused)
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{
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struct hrtimer *hrtimer = &__get_cpu_var(oprofile_hrtimer);
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if (!ctr_running)
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return;
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hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
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hrtimer->function = oprofile_hrtimer_notify;
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hrtimer_start(hrtimer, ns_to_ktime(TICK_NSEC),
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HRTIMER_MODE_REL_PINNED);
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}
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static int oprofile_hrtimer_start(void)
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{
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get_online_cpus();
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ctr_running = 1;
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on_each_cpu(__oprofile_hrtimer_start, NULL, 1);
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put_online_cpus();
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return 0;
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}
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static void __oprofile_hrtimer_stop(int cpu)
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{
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struct hrtimer *hrtimer = &per_cpu(oprofile_hrtimer, cpu);
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if (!ctr_running)
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return;
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hrtimer_cancel(hrtimer);
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}
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static void oprofile_hrtimer_stop(void)
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{
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int cpu;
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get_online_cpus();
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for_each_online_cpu(cpu)
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__oprofile_hrtimer_stop(cpu);
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ctr_running = 0;
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put_online_cpus();
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}
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static int __cpuinit oprofile_cpu_notify(struct notifier_block *self,
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unsigned long action, void *hcpu)
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{
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long cpu = (long) hcpu;
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switch (action) {
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case CPU_ONLINE:
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case CPU_ONLINE_FROZEN:
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smp_call_function_single(cpu, __oprofile_hrtimer_start,
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NULL, 1);
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break;
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case CPU_DEAD:
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case CPU_DEAD_FROZEN:
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__oprofile_hrtimer_stop(cpu);
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break;
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}
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return NOTIFY_OK;
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}
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static struct notifier_block __refdata oprofile_cpu_notifier = {
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.notifier_call = oprofile_cpu_notify,
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};
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int oprofile_timer_init(struct oprofile_operations *ops)
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{
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int rc;
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rc = register_hotcpu_notifier(&oprofile_cpu_notifier);
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if (rc)
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return rc;
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ops->create_files = NULL;
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ops->setup = NULL;
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ops->shutdown = NULL;
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ops->start = oprofile_hrtimer_start;
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ops->stop = oprofile_hrtimer_stop;
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ops->cpu_type = "timer";
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printk(KERN_INFO "oprofile: using timer interrupt.\n");
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return 0;
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}
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void oprofile_timer_exit(void)
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{
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unregister_hotcpu_notifier(&oprofile_cpu_notifier);
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}
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