linux-kernel - [tip: x86/misc] x86/msr: Do not allow writes to MSR_IA32_ENERGY_PERF

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Date:   Mon, 16 Nov 2020 20:08:27 -0000
From:   "tip-bot2 for Borislav Petkov" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Borislav Petkov <bp@...e.de>,
        Shuah Khan <skhan@...uxfoundation.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/misc] x86/msr: Do not allow writes to MSR_IA32_ENERGY_PERF_BIAS

The following commit has been merged into the x86/misc branch of tip:

Commit-ID:     18741a5251d018094536a2dffe284d269ebb07fe
Gitweb:        https://git.kernel.org/tip/18741a5251d018094536a2dffe284d269ebb07fe
Author:        Borislav Petkov <bp@...e.de>
AuthorDate:    Thu, 15 Oct 2020 15:00:31 +02:00
Committer:     Borislav Petkov <bp@...e.de>
CommitterDate: Mon, 16 Nov 2020 17:44:04 +01:00

x86/msr: Do not allow writes to MSR_IA32_ENERGY_PERF_BIAS

Now that all in-kernel-tree users are converted to using the sysfs file,
remove the MSR from the "allowlist".

Signed-off-by: Borislav Petkov <bp@...e.de>
Reviewed-by: Shuah Khan <skhan@...uxfoundation.org>
Link: https://lkml.kernel.org/r/20201029190259.3476-5-bp@alien8.de
---
 arch/x86/kernel/msr.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
index c0d4098..b114786 100644
--- a/arch/x86/kernel/msr.c
+++ b/arch/x86/kernel/msr.c
@@ -99,9 +99,6 @@ static int filter_write(u32 reg)
 	if (!__ratelimit(&fw_rs))
 		return 0;
 
-	if (reg == MSR_IA32_ENERGY_PERF_BIAS)
-		return 0;
-
 	pr_err("Write to unrecognized MSR 0x%x by %s (pid: %d). Please report to x86@...nel.org.\n",
 	       reg, current->comm, current->pid);