Hello stable-list,
I think this subjected patch [1] missed the below fixes tag.
I guess the subjected patch is only picked for 5.7. And
AFAIU, this patch will be needed for 5.6 as well.
Could you please do the needful.
Fixes: 244adf6426ee31a (ext4: make dioread_nolock the default)
[1]:
https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git/commit/?h=de…
-ritesh
On 3/29/20 7:47 AM, Theodore Y. Ts'o wrote:
> On Sat, Mar 28, 2020 at 01:37:44AM +0530, Ritesh Harjani wrote:
>> Currently on calling echo 3 > drop_caches on host machine, we see
>> FS corruption in the guest. This happens on Power machine where
>> blocksize < pagesize.
>>
>> So as a temporary workaound don't enable dioread_nolock by default
>> for blocksize < pagesize until we identify the root cause.
>>
>> Also emit a warning msg in case if this mount option is manually
>> enabled for blocksize < pagesize.
>>
>> Reported-by: Aneesh Kumar K.V <aneesh.kumar(a)linux.ibm.com>
>> Signed-off-by: Ritesh Harjani <riteshh(a)linux.ibm.com>
>
> Thanks, applied.
>
> - Ted
>
From: Yasunori Goto <y-goto(a)jp.fujitsu.com>
commit a117699c6c4a4b1b4e90ed51e393590986567cb4 upstream
The root cause of panic is the num_pm of nfit_test1 is wrong.
Though 1 is specified for num_pm at nfit_test_init(), it must be 2,
because nfit_test1->spa_set[] array has 2 elements.
Since the array is smaller than expected, the driver breaks other area.
(it is often the link list of devres).
As a result, panic occurs like the following example.
CPU: 4 PID: 2233 Comm: lt-libndctl Tainted: G O 4.12.0-rc1+ #12
RIP: 0010:__list_del_entry_valid+0x6c/0xa0
Call Trace:
release_nodes+0x76/0x260
devres_release_all+0x3c/0x50
device_release_driver_internal+0x159/0x200
device_release_driver+0x12/0x20
bus_remove_device+0xfd/0x170
device_del+0x1e8/0x330
platform_device_del+0x28/0x90
platform_device_unregister+0x12/0x30
nfit_test_exit+0x2a/0x93b [nfit_test]
Cc: <stable(a)vger.kernel.org>
Signed-off-by: Yasunori Goto <y-goto(a)jp.fujitsu.com>
Signed-off-by: Dan Williams <dan.j.williams(a)intel.com>
---
tools/testing/nvdimm/test/nfit.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/nvdimm/test/nfit.c b/tools/testing/nvdimm/test/nfit.c
index 47ab1ab..ffdb7d0 100644
--- a/tools/testing/nvdimm/test/nfit.c
+++ b/tools/testing/nvdimm/test/nfit.c
@@ -2388,7 +2388,7 @@ static __init int nfit_test_init(void)
nfit_test->setup = nfit_test0_setup;
break;
case 1:
- nfit_test->num_pm = 1;
+ nfit_test->num_pm = 2;
nfit_test->dcr_idx = NUM_DCR;
nfit_test->num_dcr = 2;
nfit_test->alloc = nfit_test1_alloc;
--
1.8.3.1
The patch below does not apply to the 5.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 6bd87eec23cbc9ed222bed0f5b5b02bf300e9a8d Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch(a)lst.de>
Date: Mon, 4 May 2020 14:47:56 +0200
Subject: [PATCH] bdi: add a ->dev_name field to struct backing_dev_info
Cache a copy of the name for the life time of the backing_dev_info
structure so that we can reference it even after unregistering.
Fixes: 68f23b89067f ("memcg: fix a crash in wb_workfn when a device disappears")
Reported-by: Yufen Yu <yuyufen(a)huawei.com>
Signed-off-by: Christoph Hellwig <hch(a)lst.de>
Reviewed-by: Jan Kara <jack(a)suse.cz>
Reviewed-by: Bart Van Assche <bvanassche(a)acm.org>
Signed-off-by: Jens Axboe <axboe(a)kernel.dk>
diff --git a/include/linux/backing-dev-defs.h b/include/linux/backing-dev-defs.h
index ee577a83cfe6..7367150f962a 100644
--- a/include/linux/backing-dev-defs.h
+++ b/include/linux/backing-dev-defs.h
@@ -219,6 +219,7 @@ struct backing_dev_info {
wait_queue_head_t wb_waitq;
struct device *dev;
+ char dev_name[64];
struct device *owner;
struct timer_list laptop_mode_wb_timer;
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index c2c44c89ee5d..efc5b83acd2d 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -938,7 +938,8 @@ int bdi_register_va(struct backing_dev_info *bdi, const char *fmt, va_list args)
if (bdi->dev) /* The driver needs to use separate queues per device */
return 0;
- dev = device_create_vargs(bdi_class, NULL, MKDEV(0, 0), bdi, fmt, args);
+ vsnprintf(bdi->dev_name, sizeof(bdi->dev_name), fmt, args);
+ dev = device_create(bdi_class, NULL, MKDEV(0, 0), bdi, bdi->dev_name);
if (IS_ERR(dev))
return PTR_ERR(dev);
@@ -1047,7 +1048,7 @@ const char *bdi_dev_name(struct backing_dev_info *bdi)
{
if (!bdi || !bdi->dev)
return bdi_unknown_name;
- return dev_name(bdi->dev);
+ return bdi->dev_name;
}
EXPORT_SYMBOL_GPL(bdi_dev_name);
The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 027d0c7101f50cf03aeea9eebf484afd4920c8d3 Mon Sep 17 00:00:00 2001
From: Mark Rutland <mark.rutland(a)arm.com>
Date: Tue, 5 May 2020 13:59:30 +0100
Subject: [PATCH] arm64: hugetlb: avoid potential NULL dereference
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
The static analyzer in GCC 10 spotted that in huge_pte_alloc() we may
pass a NULL pmdp into pte_alloc_map() when pmd_alloc() returns NULL:
| CC arch/arm64/mm/pageattr.o
| CC arch/arm64/mm/hugetlbpage.o
| from arch/arm64/mm/hugetlbpage.c:10:
| arch/arm64/mm/hugetlbpage.c: In function ‘huge_pte_alloc’:
| ./arch/arm64/include/asm/pgtable-types.h:28:24: warning: dereference of NULL ‘pmdp’ [CWE-690] [-Wanalyzer-null-dereference]
| ./arch/arm64/include/asm/pgtable.h:436:26: note: in expansion of macro ‘pmd_val’
| arch/arm64/mm/hugetlbpage.c:242:10: note: in expansion of macro ‘pte_alloc_map’
| |arch/arm64/mm/hugetlbpage.c:232:10:
| |./arch/arm64/include/asm/pgtable-types.h:28:24:
| ./arch/arm64/include/asm/pgtable.h:436:26: note: in expansion of macro ‘pmd_val’
| arch/arm64/mm/hugetlbpage.c:242:10: note: in expansion of macro ‘pte_alloc_map’
This can only occur when the kernel cannot allocate a page, and so is
unlikely to happen in practice before other systems start failing.
We can avoid this by bailing out if pmd_alloc() fails, as we do earlier
in the function if pud_alloc() fails.
Fixes: 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit")
Signed-off-by: Mark Rutland <mark.rutland(a)arm.com>
Reported-by: Kyrill Tkachov <kyrylo.tkachov(a)arm.com>
Cc: <stable(a)vger.kernel.org> # 4.5.x-
Cc: Will Deacon <will(a)kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas(a)arm.com>
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index bbeb6a5a6ba6..0be3355e3499 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -230,6 +230,8 @@ pte_t *huge_pte_alloc(struct mm_struct *mm,
ptep = (pte_t *)pudp;
} else if (sz == (CONT_PTE_SIZE)) {
pmdp = pmd_alloc(mm, pudp, addr);
+ if (!pmdp)
+ return NULL;
WARN_ON(addr & (sz - 1));
/*
From: "Steven Rostedt (VMware)" <rostedt(a)goodmis.org>
A bug report was posted that running the preempt irq delay module on a slow
machine, and removing it quickly could lead to the thread created by the
modlue to execute after the module is removed, and this could cause the
kernel to crash. The fix for this was to call kthread_stop() after creating
the thread to make sure it finishes before allowing the module to be
removed.
Now this caused the opposite problem on fast machines. What now happens is
the kthread_stop() can cause the kthread never to execute and the test never
to run. To fix this, add a completion and wait for the kthread to execute,
then wait for it to end.
This issue caused the ftracetest selftests to fail on the preemptirq tests.
Link: https://lore.kernel.org/r/20200510114210.15d9e4af@oasis.local.home
Cc: stable(a)vger.kernel.org
Fixes: d16a8c31077e ("tracing: Wait for preempt irq delay thread to finish")
Reviewed-by: Joel Fernandes (Google) <joel(a)joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt(a)goodmis.org>
---
kernel/trace/preemptirq_delay_test.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/preemptirq_delay_test.c b/kernel/trace/preemptirq_delay_test.c
index c4c86de63cf9..312d1a0ca3b6 100644
--- a/kernel/trace/preemptirq_delay_test.c
+++ b/kernel/trace/preemptirq_delay_test.c
@@ -16,6 +16,7 @@
#include <linux/printk.h>
#include <linux/string.h>
#include <linux/sysfs.h>
+#include <linux/completion.h>
static ulong delay = 100;
static char test_mode[12] = "irq";
@@ -28,6 +29,8 @@ MODULE_PARM_DESC(delay, "Period in microseconds (100 us default)");
MODULE_PARM_DESC(test_mode, "Mode of the test such as preempt, irq, or alternate (default irq)");
MODULE_PARM_DESC(burst_size, "The size of a burst (default 1)");
+static struct completion done;
+
#define MIN(x, y) ((x) < (y) ? (x) : (y))
static void busy_wait(ulong time)
@@ -114,6 +117,8 @@ static int preemptirq_delay_run(void *data)
for (i = 0; i < s; i++)
(testfuncs[i])(i);
+ complete(&done);
+
set_current_state(TASK_INTERRUPTIBLE);
while (!kthread_should_stop()) {
schedule();
@@ -128,15 +133,18 @@ static int preemptirq_delay_run(void *data)
static int preemptirq_run_test(void)
{
struct task_struct *task;
-
char task_name[50];
+ init_completion(&done);
+
snprintf(task_name, sizeof(task_name), "%s_test", test_mode);
task = kthread_run(preemptirq_delay_run, NULL, task_name);
if (IS_ERR(task))
return PTR_ERR(task);
- if (task)
+ if (task) {
+ wait_for_completion(&done);
kthread_stop(task);
+ }
return 0;
}
--
2.26.2
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 139f7425fdf54f054463e7524b9f54c41af8407f Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini(a)redhat.com>
Date: Tue, 5 May 2020 09:40:46 -0400
Subject: [PATCH] kvm: x86: Use KVM CPU capabilities to determine CR4 reserved
bits
Using CPUID data can be useful for the processor compatibility
check, but that's it. Using it to compute guest-reserved bits
can have both false positives (such as LA57 and UMIP which we
are already handling) and false negatives: in particular, with
this patch we don't allow anymore a KVM guest to set CR4.PKE
when CR4.PKE is clear on the host.
Fixes: b9dd21e104bc ("KVM: x86: simplify handling of PKRU")
Reported-by: Jim Mattson <jmattson(a)google.com>
Tested-by: Jim Mattson <jmattson(a)google.com>
Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c5835f9cb9ad..8d296e3d0d56 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -926,19 +926,6 @@ EXPORT_SYMBOL_GPL(kvm_set_xcr);
__reserved_bits; \
})
-static u64 kvm_host_cr4_reserved_bits(struct cpuinfo_x86 *c)
-{
- u64 reserved_bits = __cr4_reserved_bits(cpu_has, c);
-
- if (kvm_cpu_cap_has(X86_FEATURE_LA57))
- reserved_bits &= ~X86_CR4_LA57;
-
- if (kvm_cpu_cap_has(X86_FEATURE_UMIP))
- reserved_bits &= ~X86_CR4_UMIP;
-
- return reserved_bits;
-}
-
static int kvm_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
if (cr4 & cr4_reserved_bits)
@@ -9675,7 +9662,9 @@ int kvm_arch_hardware_setup(void *opaque)
if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
supported_xss = 0;
- cr4_reserved_bits = kvm_host_cr4_reserved_bits(&boot_cpu_data);
+#define __kvm_cpu_cap_has(UNUSED_, f) kvm_cpu_cap_has(f)
+ cr4_reserved_bits = __cr4_reserved_bits(__kvm_cpu_cap_has, UNUSED_);
+#undef __kvm_cpu_cap_has
if (kvm_has_tsc_control) {
/*
@@ -9707,7 +9696,8 @@ int kvm_arch_check_processor_compat(void *opaque)
WARN_ON(!irqs_disabled());
- if (kvm_host_cr4_reserved_bits(c) != cr4_reserved_bits)
+ if (__cr4_reserved_bits(cpu_has, c) !=
+ __cr4_reserved_bits(cpu_has, &boot_cpu_data))
return -EIO;
return ops->check_processor_compatibility();
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 139f7425fdf54f054463e7524b9f54c41af8407f Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini(a)redhat.com>
Date: Tue, 5 May 2020 09:40:46 -0400
Subject: [PATCH] kvm: x86: Use KVM CPU capabilities to determine CR4 reserved
bits
Using CPUID data can be useful for the processor compatibility
check, but that's it. Using it to compute guest-reserved bits
can have both false positives (such as LA57 and UMIP which we
are already handling) and false negatives: in particular, with
this patch we don't allow anymore a KVM guest to set CR4.PKE
when CR4.PKE is clear on the host.
Fixes: b9dd21e104bc ("KVM: x86: simplify handling of PKRU")
Reported-by: Jim Mattson <jmattson(a)google.com>
Tested-by: Jim Mattson <jmattson(a)google.com>
Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c5835f9cb9ad..8d296e3d0d56 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -926,19 +926,6 @@ EXPORT_SYMBOL_GPL(kvm_set_xcr);
__reserved_bits; \
})
-static u64 kvm_host_cr4_reserved_bits(struct cpuinfo_x86 *c)
-{
- u64 reserved_bits = __cr4_reserved_bits(cpu_has, c);
-
- if (kvm_cpu_cap_has(X86_FEATURE_LA57))
- reserved_bits &= ~X86_CR4_LA57;
-
- if (kvm_cpu_cap_has(X86_FEATURE_UMIP))
- reserved_bits &= ~X86_CR4_UMIP;
-
- return reserved_bits;
-}
-
static int kvm_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
if (cr4 & cr4_reserved_bits)
@@ -9675,7 +9662,9 @@ int kvm_arch_hardware_setup(void *opaque)
if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
supported_xss = 0;
- cr4_reserved_bits = kvm_host_cr4_reserved_bits(&boot_cpu_data);
+#define __kvm_cpu_cap_has(UNUSED_, f) kvm_cpu_cap_has(f)
+ cr4_reserved_bits = __cr4_reserved_bits(__kvm_cpu_cap_has, UNUSED_);
+#undef __kvm_cpu_cap_has
if (kvm_has_tsc_control) {
/*
@@ -9707,7 +9696,8 @@ int kvm_arch_check_processor_compat(void *opaque)
WARN_ON(!irqs_disabled());
- if (kvm_host_cr4_reserved_bits(c) != cr4_reserved_bits)
+ if (__cr4_reserved_bits(cpu_has, c) !=
+ __cr4_reserved_bits(cpu_has, &boot_cpu_data))
return -EIO;
return ops->check_processor_compatibility();
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 139f7425fdf54f054463e7524b9f54c41af8407f Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini(a)redhat.com>
Date: Tue, 5 May 2020 09:40:46 -0400
Subject: [PATCH] kvm: x86: Use KVM CPU capabilities to determine CR4 reserved
bits
Using CPUID data can be useful for the processor compatibility
check, but that's it. Using it to compute guest-reserved bits
can have both false positives (such as LA57 and UMIP which we
are already handling) and false negatives: in particular, with
this patch we don't allow anymore a KVM guest to set CR4.PKE
when CR4.PKE is clear on the host.
Fixes: b9dd21e104bc ("KVM: x86: simplify handling of PKRU")
Reported-by: Jim Mattson <jmattson(a)google.com>
Tested-by: Jim Mattson <jmattson(a)google.com>
Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c5835f9cb9ad..8d296e3d0d56 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -926,19 +926,6 @@ EXPORT_SYMBOL_GPL(kvm_set_xcr);
__reserved_bits; \
})
-static u64 kvm_host_cr4_reserved_bits(struct cpuinfo_x86 *c)
-{
- u64 reserved_bits = __cr4_reserved_bits(cpu_has, c);
-
- if (kvm_cpu_cap_has(X86_FEATURE_LA57))
- reserved_bits &= ~X86_CR4_LA57;
-
- if (kvm_cpu_cap_has(X86_FEATURE_UMIP))
- reserved_bits &= ~X86_CR4_UMIP;
-
- return reserved_bits;
-}
-
static int kvm_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
if (cr4 & cr4_reserved_bits)
@@ -9675,7 +9662,9 @@ int kvm_arch_hardware_setup(void *opaque)
if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
supported_xss = 0;
- cr4_reserved_bits = kvm_host_cr4_reserved_bits(&boot_cpu_data);
+#define __kvm_cpu_cap_has(UNUSED_, f) kvm_cpu_cap_has(f)
+ cr4_reserved_bits = __cr4_reserved_bits(__kvm_cpu_cap_has, UNUSED_);
+#undef __kvm_cpu_cap_has
if (kvm_has_tsc_control) {
/*
@@ -9707,7 +9696,8 @@ int kvm_arch_check_processor_compat(void *opaque)
WARN_ON(!irqs_disabled());
- if (kvm_host_cr4_reserved_bits(c) != cr4_reserved_bits)
+ if (__cr4_reserved_bits(cpu_has, c) !=
+ __cr4_reserved_bits(cpu_has, &boot_cpu_data))
return -EIO;
return ops->check_processor_compatibility();
The patch below does not apply to the 5.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 139f7425fdf54f054463e7524b9f54c41af8407f Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini(a)redhat.com>
Date: Tue, 5 May 2020 09:40:46 -0400
Subject: [PATCH] kvm: x86: Use KVM CPU capabilities to determine CR4 reserved
bits
Using CPUID data can be useful for the processor compatibility
check, but that's it. Using it to compute guest-reserved bits
can have both false positives (such as LA57 and UMIP which we
are already handling) and false negatives: in particular, with
this patch we don't allow anymore a KVM guest to set CR4.PKE
when CR4.PKE is clear on the host.
Fixes: b9dd21e104bc ("KVM: x86: simplify handling of PKRU")
Reported-by: Jim Mattson <jmattson(a)google.com>
Tested-by: Jim Mattson <jmattson(a)google.com>
Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c5835f9cb9ad..8d296e3d0d56 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -926,19 +926,6 @@ EXPORT_SYMBOL_GPL(kvm_set_xcr);
__reserved_bits; \
})
-static u64 kvm_host_cr4_reserved_bits(struct cpuinfo_x86 *c)
-{
- u64 reserved_bits = __cr4_reserved_bits(cpu_has, c);
-
- if (kvm_cpu_cap_has(X86_FEATURE_LA57))
- reserved_bits &= ~X86_CR4_LA57;
-
- if (kvm_cpu_cap_has(X86_FEATURE_UMIP))
- reserved_bits &= ~X86_CR4_UMIP;
-
- return reserved_bits;
-}
-
static int kvm_valid_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
{
if (cr4 & cr4_reserved_bits)
@@ -9675,7 +9662,9 @@ int kvm_arch_hardware_setup(void *opaque)
if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
supported_xss = 0;
- cr4_reserved_bits = kvm_host_cr4_reserved_bits(&boot_cpu_data);
+#define __kvm_cpu_cap_has(UNUSED_, f) kvm_cpu_cap_has(f)
+ cr4_reserved_bits = __cr4_reserved_bits(__kvm_cpu_cap_has, UNUSED_);
+#undef __kvm_cpu_cap_has
if (kvm_has_tsc_control) {
/*
@@ -9707,7 +9696,8 @@ int kvm_arch_check_processor_compat(void *opaque)
WARN_ON(!irqs_disabled());
- if (kvm_host_cr4_reserved_bits(c) != cr4_reserved_bits)
+ if (__cr4_reserved_bits(cpu_has, c) !=
+ __cr4_reserved_bits(cpu_has, &boot_cpu_data))
return -EIO;
return ops->check_processor_compatibility();