Patch "perf/x86/amd/power: Do not load AMD power module on !AMD platforms" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    perf/x86/amd/power: Do not load AMD power module on !AMD platforms

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     perf-x86-amd-power-do-not-load-amd-power-module-on-amd-platforms.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 40d4071ce2d20840d224b4a77b5dc6f752c9ab15 Mon Sep 17 00:00:00 2001
From: Xiao Liang <xiliang@redhat.com>
Date: Mon, 22 Jan 2018 14:12:52 +0800
Subject: perf/x86/amd/power: Do not load AMD power module on !AMD platforms

From: Xiao Liang <xiliang@redhat.com>

commit 40d4071ce2d20840d224b4a77b5dc6f752c9ab15 upstream.

The AMD power module can be loaded on non AMD platforms, but unload fails
with the following Oops:

 BUG: unable to handle kernel NULL pointer dereference at           (null)
 IP: __list_del_entry_valid+0x29/0x90
 Call Trace:
  perf_pmu_unregister+0x25/0xf0
  amd_power_pmu_exit+0x1c/0xd23 [power]
  SyS_delete_module+0x1a8/0x2b0
  ? exit_to_usermode_loop+0x8f/0xb0
  entry_SYSCALL_64_fastpath+0x20/0x83

Return -ENODEV instead of 0 from the module init function if the CPU does
not match.

Fixes: c7ab62bfbe0e ("perf/x86/amd/power: Add AMD accumulated power reporting mechanism")
Signed-off-by: Xiao Liang <xiliang@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20180122061252.6394-1-xiliang@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/x86/events/amd/power.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/events/amd/power.c
+++ b/arch/x86/events/amd/power.c
@@ -277,7 +277,7 @@ static int __init amd_power_pmu_init(voi
 	int ret;
 
 	if (!x86_match_cpu(cpu_match))
-		return 0;
+		return -ENODEV;
 
 	if (!boot_cpu_has(X86_FEATURE_ACC_POWER))
 		return -ENODEV;


Patches currently in stable-queue which might be from xiliang@redhat.com are

queue-4.9/perf-x86-amd-power-do-not-load-amd-power-module-on-amd-platforms.patch