Commit-ID: 70479c012b67b89e219c40eddc5dc338b7c447a3
Gitweb: https://git.kernel.org/tip/70479c012b67b89e219c40eddc5dc338b7c447a3
Author: Reinette Chatre <reinette.cha...@intel.com>
AuthorDate: Sat, 15 Sep 2018 14:58:23 -0700
Committer: Thomas Gleixner <t...@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.cha...@intel.com>
Signed-off-by: Fenghua Yu <fenghua...@intel.com>
Signed-off-by: Thomas Gleixner <t...@linutronix.de>
Cc: "H Peter Anvin" <h...@zytor.com>
Cc: "Tony Luck" <tony.l...@intel.com>
Cc: "Xiaochen Shen" <xiaochen.s...@intel.com>
Cc: "Chen Yu" <yu.c.c...@intel.com>
Link:
https://lkml.kernel.org/r/1537048707-76280-6-git-send-email-fenghua...@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");
