linux-kernel - [PATCH 4.19 174/276] x86/microcode: Fix the ancient deprecated microcode loading method

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Message-Id: <20190530030536.226687991@linuxfoundation.org>
Date:   Wed, 29 May 2019 20:05:32 -0700
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Borislav Petkov <bp@...e.de>,
        Thomas Gleixner <tglx@...utronix.de>,
        Jann Horn <jannh@...gle.com>, Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.19 174/276] x86/microcode: Fix the ancient deprecated microcode loading method

[ Upstream commit 24613a04ad1c0588c10f4b5403ca60a73d164051 ]

Commit

  2613f36ed965 ("x86/microcode: Attempt late loading only when new microcode is present")

added the new define UCODE_NEW to denote that an update should happen
only when newer microcode (than installed on the system) has been found.

But it missed adjusting that for the old /dev/cpu/microcode loading
interface. Fix it.

Fixes: 2613f36ed965 ("x86/microcode: Attempt late loading only when new microcode is present")
Signed-off-by: Borislav Petkov <bp@...e.de>
Reviewed-by: Thomas Gleixner <tglx@...utronix.de>
Cc: Jann Horn <jannh@...gle.com>
Link: https://lkml.kernel.org/r/20190405133010.24249-3-bp@alien8.de
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 arch/x86/kernel/cpu/microcode/core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c
index b9bc8a1a584e3..b43ddefd77f45 100644
--- a/arch/x86/kernel/cpu/microcode/core.c
+++ b/arch/x86/kernel/cpu/microcode/core.c
@@ -418,8 +418,9 @@ static int do_microcode_update(const void __user *buf, size_t size)
 		if (ustate == UCODE_ERROR) {
 			error = -1;
 			break;
-		} else if (ustate == UCODE_OK)
+		} else if (ustate == UCODE_NEW) {
 			apply_microcode_on_target(cpu);
+		}
 	}
 
 	return error;
-- 
2.20.1