Messages in this thread Patch in this message | | | From | Fenghua Yu <> | Subject | [PATCH V2 5/9] x86/intel_rdt: Fix unchecked MSR access | Date | Sat, 15 Sep 2018 14:58:23 -0700 |
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From: Reinette Chatre <reinette.chatre@intel.com>
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> --- 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"); -- 2.19.0
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