From: Fenghua Yu <fenghua.yu@intel.com>
To: "Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>, "H Peter Anvin" <hpa@zytor.com>,
"Tony Luck" <tony.luck@intel.com>
Cc: "Chatre, Reinette" <reinette.chatre@intel.com>,
"Xiaochen Shen" <xiaochen.shen@intel.com>,
"Chen Yu" <yu.c.chen@intel.com>,
"linux-kernel" <linux-kernel@vger.kernel.org>,
"x86" <x86@kernel.org>, "Fenghua Yu" <fenghua.yu@intel.com>
Subject: [PATCH 5/9] x86/intel_rdt: Fix unchecked MSR access
Date: Fri, 14 Sep 2018 13:32:05 -0700 [thread overview]
Message-ID: <1536957129-70380-6-git-send-email-fenghua.yu@intel.com> (raw)
In-Reply-To: <1536957129-70380-1-git-send-email-fenghua.yu@intel.com>
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:
[ 6944.864724] unchecked MSR access error: WRMSR to 0xd51 (tried to write 0x0000
000000000064) at rIP: 0xffffffffae059994 (native_write_msr+0x4/0x20)
[ 6944.877967] Call Trace:
[ 6944.880472] mba_wrmsr+0x41/0x80
[ 6944.883762] update_domains+0x125/0x130
[ 6944.887667] rdtgroup_mkdir+0x270/0x500
[ 6944.891572] kernfs_iop_mkdir+0x5d/0x80
[ 6944.895475] vfs_mkdir+0x101/0x1b0
[ 6944.898934] do_mkdirat+0x7b/0xf0
[ 6944.902308] do_syscall_64+0x5b/0x180
[ 6944.906036] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 6944.911171] RIP: 0033:0x7f5a452b5377
[ 6944.914803] Code: 00 b8 ff ff ff ff c3 0f 1f 40 00 48 8b 05 21 9b 2c 00 64 c7
00 5f 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0
ff ff 73 01 c3 48 8b 0d f9 9a 2c 00 f7 d8 64 89 01 48
[ 6944.933942] RSP: 002b:00007ffe18172f78 EFLAGS: 00000246 ORIG_RAX: 00000000000
00053
[ 6944.941628] RAX: ffffffffffffffda RBX: 00007ffe18174cff RCX: 00007f5a452b5377
[ 6944.948929] RDX: 0000000000000001 RSI: 00000000000001ff RDI: 00007ffe18174cff
[ 6944.956168] RBP: 00007ffe18174cff R08: 00000000000001ff R09: 000056126dad8d30
[ 6944.963407] R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000001ff
[ 6944.970651] R13: 00007ffe181730f0 R14: 0000000000000000 R15: 00007ffe18173140
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
next prev parent reply other threads:[~2018-09-14 20:35 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-14 20:32 [PATCH 0/9] x86/intel_rdt: MBA integration fixes Fenghua Yu
2018-09-14 20:32 ` [PATCH 1/9] x86/intel_rdt: Fix MBA parsing callback Fenghua Yu
2018-09-15 10:13 ` Thomas Gleixner
2018-09-15 22:27 ` Fenghua Yu
2018-09-14 20:32 ` [PATCH 2/9] x86/intel_rdt: Fix size reporting of MBA resource Fenghua Yu
2018-09-14 20:32 ` [PATCH 3/9] x86/intel_rdt: Global closid helper to support future fixes Fenghua Yu
2018-09-14 20:32 ` [PATCH 4/9] x86/intel_rdt: Fix invalid mode warning when Fenghua Yu
2018-09-15 4:36 ` Reinette Chatre
2018-09-15 4:47 ` Reinette Chatre
2018-09-15 10:22 ` Thomas Gleixner
2018-09-14 20:32 ` Fenghua Yu [this message]
2018-09-14 20:32 ` [PATCH 6/9] x86/intel_rdt: Do not allow pseudo-locking of MBA resource Fenghua Yu
2018-09-14 20:32 ` [PATCH 7/9] x86/intel_rdt: Fix incorrect loop end condition Fenghua Yu
2018-09-14 20:32 ` [PATCH 8/9] x86/intel_rdt: Fix exclusive mode handling of MBA resource Fenghua Yu
2018-09-14 20:32 ` [PATCH 9/9] x86/intel_rdt: Fix incorrect loop end condition Fenghua Yu
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