Re: Linux 4.9.6 ( Restore IO-APIC irq_chip retrigger callback , breaks my box )

[Borislav Petkov]

On Sun, Feb 12, 2017 at 11:21:13PM +0100, Gabriel C wrote:
> http://ftp.frugalware.org/pub/other/people/crazy/kernel/t/crash_initcall_debug.mp4
> http://ftp.frugalware.org/pub/other/people/crazy/kernel/t/crash_intcall_debug_ucode_off.mp4

Thanks and interesting. In both cases, mcheck_init_device() doesn't
return or we don't see the "initcall returned" message.

Ok, let's try a silly sprinkling of printks in that function and try to
pinpoint how far we manage to come.

Apply, build, boot and shoot video again :-)

Thanks.

---
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 8e9725c607ea..70268867cb33 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -2565,37 +2565,57 @@ static __init int mcheck_init_device(void)
        enum cpuhp_state hp_online;
        int err;
 
+       pr_err("%s: entry\n", __func__);
+
        if (!mce_available(&boot_cpu_data)) {
                err = -EIO;
                goto err_out;
        }
 
+       pr_err("%s: mce_available\n", __func__);
+
        if (!zalloc_cpumask_var(&mce_device_initialized, GFP_KERNEL)) {
                err = -ENOMEM;
                goto err_out;
        }
 
+       pr_err("%s: zalloc_cpumask_var\n", __func__);
+
        mce_init_banks();
 
+       pr_err("%s: mce_init_banks\n", __func__);
+
        err = subsys_system_register(&mce_subsys, NULL);
        if (err)
                goto err_out_mem;
 
+       pr_err("%s: subsys_system_register\n", __func__);
+
        err = cpuhp_setup_state(CPUHP_X86_MCE_DEAD, "x86/mce:dead", NULL,
                                mce_cpu_dead);
        if (err)
                goto err_out_mem;
 
+       pr_err("%s: x86/mce:dead\n", __func__);
+
        err = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/mce:online",
                                mce_cpu_online, mce_cpu_pre_down);
        if (err < 0)
                goto err_out_online;
+
+       pr_err("%s: x86/mce:online\n", __func__);
+
        hp_online = err;
 
        register_syscore_ops(&mce_syscore_ops);
 
+       pr_err("%s: register_syscore_ops\n", __func__);
+
        /* register character device /dev/mcelog */
        err = misc_register(&mce_chrdev_device);
+
+       pr_err("%s: misc_register, err: 0x%x\n", __func__, err);
+
        if (err)
                goto err_register;
 

-- 
Regards/Gruss,
    Boris.

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