linux-kernel - Re: 4.15.17 regression: bisected: timeout during microcode update

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Message-ID: <20180419121840.GF3896@pd.tnic>
Date:   Thu, 19 Apr 2018 14:18:41 +0200
From:   Borislav Petkov <bp@...e.de>
To:     Vitezslav Samel <vitezslav@...el.cz>
Cc:     "Raj, Ashok" <ashok.raj@...el.com>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        linux-kernel@...r.kernel.org
Subject: Re: 4.15.17 regression: bisected: timeout during microcode update

On Thu, Apr 19, 2018 at 02:02:39PM +0200, Vitezslav Samel wrote:
>   Here it is:

Thanks!

> -------------------------------------------------------------
> microcode: __reload_late: CPU1
> microcode: __reload_late: CPU3
> microcode: __reload_late: CPU2
> microcode: __reload_late: CPU0
> microcode: __reload_late: CPU1 reloading
> microcode: __reload_late: CPU3 reloading
> microcode: __reload_late: CPU2 reloading
> microcode: __reload_late: CPU0 reloading
> microcode: __reload_late: CPU3 returning 0x0

Aaaha, there it is.

Ok, debug patch v2, please do the same.

Thx.

---
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index 10c4fc2c91f8..737f93422d0b 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -553,6 +553,8 @@ static int __reload_late(void *info)
 	enum ucode_state err;
 	int ret = 0;
 
+	pr_info("%s: CPU%d\n", __func__, cpu);
+
 	/*
 	 * Wait for all CPUs to arrive. A load will not be attempted unless all
 	 * CPUs show up.
@@ -560,6 +562,8 @@ static int __reload_late(void *info)
 	if (__wait_for_cpus(&late_cpus_in, NSEC_PER_SEC))
 		return -1;
 
+	pr_info("%s: CPU%d reloading\n", __func__, cpu);
+
 	spin_lock(&update_lock);
 	apply_microcode_local(&err);
 	spin_unlock(&update_lock);
@@ -571,9 +575,12 @@ static int __reload_late(void *info)
 	} else if (err == UCODE_UPDATED || err == UCODE_OK) {
 		ret = 1;
 	} else {
+		pr_info("%s: CPU%d returning 0x%x\n", __func__, cpu, err);
 		return ret;
 	}
 
+	pr_info("%s: CPU%d waiting to exit\n", __func__, cpu);
+
 	/*
 	 * Increase the wait timeout to a safe value here since we're
 	 * serializing the microcode update and that could take a while on a
diff --git a/arch/x86/kernel/cpu/microcode/intel.c b/arch/x86/kernel/cpu/microcode/intel.c
index 32b8e5724f96..ad0a19154c40 100644
--- a/arch/x86/kernel/cpu/microcode/intel.c
+++ b/arch/x86/kernel/cpu/microcode/intel.c
@@ -727,21 +727,32 @@ static struct microcode_intel *find_patch(struct ucode_cpu_info *uci)
 {
 	struct microcode_header_intel *phdr;
 	struct ucode_patch *iter, *tmp;
+	int cpu = smp_processor_id();
 
 	list_for_each_entry_safe(iter, tmp, &microcode_cache, plist) {
 
 		phdr = (struct microcode_header_intel *)iter->data;
 
+		pr_info("%s: CPU%d, phdr: 0x%x, uci: 0x%x\n",
+			__func__, cpu, phdr->rev, uci->cpu_sig.rev);
+
 		if (phdr->rev <= uci->cpu_sig.rev)
 			continue;
 
+		pr_info("%s: CPU%d, find_matching_signature: sig: 0x%x, pf: 0x%x\n",
+			__func__, cpu, uci->cpu_sig.sig, uci->cpu_sig.pf);
+
 		if (!find_matching_signature(phdr,
 					     uci->cpu_sig.sig,
 					     uci->cpu_sig.pf))
 			continue;
 
+
+		pr_info("%s: CPU%d, found phdr: 0x%x\n", __func__, cpu, phdr->rev);
 		return iter->data;
 	}
+
+	pr_info("%s: CPU%d, NADA\n", __func__, cpu);
 	return NULL;
 }
 
@@ -805,8 +816,10 @@ static enum ucode_state apply_microcode_intel(int cpu)
 	mc = find_patch(uci);
 	if (!mc) {
 		mc = uci->mc;
-		if (!mc)
+		if (!mc) {
+			pr_info("%s: CPU%d, NFOUND\n", __func__, cpu);
 			return UCODE_NFOUND;
+		}
 	}
 
 	/*

-- 
Regards/Gruss,
    Boris.

SUSE Linux GmbH, GF: Felix Imendörffer, Jane Smithard, Graham Norton, HRB 21284 (AG Nürnberg)
--