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From: tip-bot for Reinette Chatre <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: mingo@kernel.org, fenghua.yu@intel.com, hpa@zytor.com,
	xiaochen.shen@intel.com, yu.c.chen@intel.com,
	linux-kernel@vger.kernel.org, reinette.chatre@intel.com,
	tony.luck@intel.com, tglx@linutronix.de
Subject: [tip:x86/urgent] x86/intel_rdt: Fix unchecked MSR access
Date: Tue, 18 Sep 2018 14:45:07 -0700	[thread overview]
Message-ID: <tip-70479c012b67b89e219c40eddc5dc338b7c447a3@git.kernel.org> (raw)
In-Reply-To: <1537048707-76280-6-git-send-email-fenghua.yu@intel.com>

Commit-ID:  70479c012b67b89e219c40eddc5dc338b7c447a3
Gitweb:     https://git.kernel.org/tip/70479c012b67b89e219c40eddc5dc338b7c447a3
Author:     Reinette Chatre <reinette.chatre@intel.com>
AuthorDate: Sat, 15 Sep 2018 14:58:23 -0700
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Tue, 18 Sep 2018 23:38:06 +0200

x86/intel_rdt: Fix unchecked MSR access

When a new resource group is created, it is initialized with sane
defaults that currently assume the resource being initialized is a CAT
resource. This code path is also followed by a MBA resource that is not
allocated the same as a CAT resource and as a result we encounter the
following unchecked MSR access error:

unchecked MSR access error: WRMSR to 0xd51 (tried to write 0x0000
000000000064) at rIP: 0xffffffffae059994 (native_write_msr+0x4/0x20)
Call Trace:
mba_wrmsr+0x41/0x80
update_domains+0x125/0x130
rdtgroup_mkdir+0x270/0x500

Fix the above by ensuring the initial allocation is only attempted on a
CAT resource.

Fixes: 95f0b77ef ("x86/intel_rdt: Initialize new resource group with sane defaults")
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "H Peter Anvin" <hpa@zytor.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Xiaochen Shen" <xiaochen.shen@intel.com>
Cc: "Chen Yu" <yu.c.chen@intel.com>
Link: https://lkml.kernel.org/r/1537048707-76280-6-git-send-email-fenghua.yu@intel.com

---
 arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index ea91750ba27f..74821bc457c0 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -2349,6 +2349,12 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
 	u32 *ctrl;
 
 	for_each_alloc_enabled_rdt_resource(r) {
+		/*
+		 * Only initialize default allocations for CBM cache
+		 * resources
+		 */
+		if (r->rid == RDT_RESOURCE_MBA)
+			continue;
 		list_for_each_entry(d, &r->domains, list) {
 			d->have_new_ctrl = false;
 			d->new_ctrl = r->cache.shareable_bits;
@@ -2386,6 +2392,12 @@ static int rdtgroup_init_alloc(struct rdtgroup *rdtgrp)
 	}
 
 	for_each_alloc_enabled_rdt_resource(r) {
+		/*
+		 * Only initialize default allocations for CBM cache
+		 * resources
+		 */
+		if (r->rid == RDT_RESOURCE_MBA)
+			continue;
 		ret = update_domains(r, rdtgrp->closid);
 		if (ret < 0) {
 			rdt_last_cmd_puts("failed to initialize allocations\n");

  reply	other threads:[~2018-09-18 21:45 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-15 21:58 [PATCH V2 0/9] x86/intel_rdt: MBA integration fixes Fenghua Yu
2018-09-15 21:58 ` [PATCH V2 1/9] x86/intel_rdt: Fix data type in parsing callbacks Fenghua Yu
2018-09-18 21:42   ` [tip:x86/urgent] " tip-bot for Xiaochen Shen
2018-09-15 21:58 ` [PATCH V2 2/9] x86/intel_rdt: Fix size reporting of MBA resource Fenghua Yu
2018-09-18 21:43   ` [tip:x86/urgent] " tip-bot for Reinette Chatre
2018-09-15 21:58 ` [PATCH V2 3/9] x86/intel_rdt: Global closid helper to support future fixes Fenghua Yu
2018-09-18 21:43   ` [tip:x86/urgent] " tip-bot for Reinette Chatre
2018-09-15 21:58 ` [PATCH V2 4/9] x86/intel_rdt: Fix invalid mode warning when multiple resources are managed Fenghua Yu
2018-09-18 21:44   ` [tip:x86/urgent] " tip-bot for Reinette Chatre
2018-09-15 21:58 ` [PATCH V2 5/9] x86/intel_rdt: Fix unchecked MSR access Fenghua Yu
2018-09-18 21:45   ` tip-bot for Reinette Chatre [this message]
2018-09-15 21:58 ` [PATCH V2 6/9] x86/intel_rdt: Do not allow pseudo-locking of MBA resource Fenghua Yu
2018-09-18 21:45   ` [tip:x86/urgent] " tip-bot for Reinette Chatre
2018-09-15 21:58 ` [PATCH V2 7/9] x86/intel_rdt: Fix incorrect loop end condition Fenghua Yu
2018-09-18 21:46   ` [tip:x86/urgent] " tip-bot for Reinette Chatre
2018-09-15 21:58 ` [PATCH V2 8/9] x86/intel_rdt: Fix exclusive mode handling of MBA resource Fenghua Yu
2018-09-18 21:46   ` [tip:x86/urgent] " tip-bot for Reinette Chatre
2018-09-15 21:58 ` [PATCH V2 9/9] x86/intel_rdt: Fix incorrect loop end condition Fenghua Yu
2018-09-18 21:47   ` [tip:x86/urgent] " tip-bot for Reinette Chatre
  -- strict thread matches above, loose matches on Subject: below --
2018-09-04 17:46 [PATCH][RFC] x86/intel_rdt: Do not display size for non-CAT resource Chen Yu
2018-09-04 20:24 ` Reinette Chatre
2018-09-04 22:36   ` Reinette Chatre
2018-09-05  6:28     ` Yu Chen
2018-09-05 20:52       ` Reinette Chatre

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