linux-kernel - [PATCH v1 Part2 1/5] x86/microcode: Move late load warning to the same function that taints kernel

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Date:   Fri, 13 Jan 2023 09:29:16 -0800
From:   Ashok Raj <ashok.raj@...el.com>
To:     Borislav Petkov <bp@...en8.de>,
        Thomas Gleixner <tglx@...utronix.de>
Cc:     Ashok Raj <ashok.raj@...el.com>, Tony Luck <tony.luck@...el.com>,
        LKML <linux-kernel@...r.kernel.org>, x86 <x86@...nel.org>,
        Ingo Molnar <mingo@...nel.org>,
        Dave Hansen <dave.hansen@...el.com>,
        Alison Schofield <alison.schofield@...el.com>,
        Reinette Chatre <reinette.chatre@...el.com>,
        Tom Lendacky <thomas.lendacky@....com>,
        Stefan Talpalaru <stefantalpalaru@...oo.com>,
        David Woodhouse <dwmw2@...radead.org>,
        Benjamin Herrenschmidt <benh@...nel.crashing.org>,
        Jonathan Corbet <corbet@....net>,
        "Rafael J . Wysocki" <rafael@...nel.org>,
        Peter Zilstra <peterz@...radead.org>,
        Andy Lutomirski <luto@...nel.org>,
        Andrew Cooper <Andrew.Cooper3@...rix.com>
Subject: [PATCH v1 Part2 1/5] x86/microcode: Move late load warning to the same function that taints kernel

Currently the warning about late loading and tainting are issued from two
different functions.

Later patches will re-enable microcode late-loading.

Having both messages in the same function helps issuing warnings only
when required.

Move the warning from microcode_reload_late() -> reload_store() where the
kernel tainting also happens.

No functional changes.

Signed-off-by: Ashok Raj <ashok.raj@...el.com>
Reviewed-by: Tony Luck <tony.luck@...el.com>
Cc: LKML <linux-kernel@...r.kernel.org>
Cc: x86 <x86@...nel.org>
Cc: Ingo Molnar <mingo@...nel.org>
Cc: Tony Luck <tony.luck@...el.com>
Cc: Dave Hansen <dave.hansen@...el.com>
Cc: Alison Schofield <alison.schofield@...el.com>
Cc: Reinette Chatre <reinette.chatre@...el.com>
Cc: Thomas Gleixner (Intel) <tglx@...utronix.de>
Cc: Tom Lendacky <thomas.lendacky@....com>
Cc: Stefan Talpalaru <stefantalpalaru@...oo.com>
Cc: David Woodhouse <dwmw2@...radead.org>
Cc: Benjamin Herrenschmidt <benh@...nel.crashing.org>
Cc: Jonathan Corbet <corbet@....net>
Cc: Rafael J. Wysocki <rafael@...nel.org>
Cc: Peter Zilstra (Intel) <peterz@...radead.org>
Cc: Andy Lutomirski <luto@...nel.org>
Cc: Andrew Cooper <Andrew.Cooper3@...rix.com>
---
 arch/x86/kernel/cpu/microcode/core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index d7cbc83df9b6..c361882baf63 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -441,9 +441,6 @@ static int microcode_reload_late(void)
 	int old = boot_cpu_data.microcode, ret;
 	struct cpuinfo_x86 prev_info;
 
-	pr_err("Attempting late microcode loading - it is dangerous and taints the kernel.\n");
-	pr_err("You should switch to early loading, if possible.\n");
-
 	atomic_set(&late_cpus_in,  0);
 	atomic_set(&late_cpus_out, 0);
 
@@ -494,6 +491,9 @@ static ssize_t reload_store(struct device *dev,
 	if (tmp_ret != UCODE_NEW)
 		goto put;
 
+	pr_err("Attempting late microcode loading - it is dangerous and taints the kernel.\n");
+	pr_err("You should switch to early loading, if possible.\n");
+
 	mutex_lock(&microcode_mutex);
 	ret = microcode_reload_late();
 	mutex_unlock(&microcode_mutex);
-- 
2.34.1