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| author | Reinette Chatre <reinette.chatre@intel.com> | 2018-09-15 14:58:23 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-09-18 23:38:06 +0200 |
| commit | 70479c012b67b89e219c40eddc5dc338b7c447a3 (patch) | |
| tree | a3fa0666a409cfb6dcac5ef9bcaea7cf3c10cef2 | |
| parent | 47d53b184aee983ab9492503da11b0a81b19145b (diff) | |
| download | linux-70479c012b67b89e219c40eddc5dc338b7c447a3.tar.bz2 | |
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
| -rw-r--r-- | arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 12 |
1 files changed, 12 insertions, 0 deletions
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"); |