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 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 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();
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 5.4-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 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);
A simple fix for a null pointer dereference in vmx_vcpu_run() with an
ugly-but-safe prereq patch.
The even uglier ASM_CALL_CONSTRAINT is gone in v2 as I finally figured
out why vmx_return was undefined: GCC dropped the entire asm blob because
all outputs were deemed unused.
v2:
- Document why there is no exact upstream commit for the fix, with
--verbose. [Greg]
- Tag the asm blob as volatile and drop the ASM_CALL_CONSTRAINT hack.
Sean Christopherson (2):
KVM: VMX: Explicitly reference RCX as the vmx_vcpu pointer in asm
blobs
KVM: VMX: Mark RCX, RDX and RSI as clobbered in vmx_vcpu_run()'s asm
blob
arch/x86/kvm/vmx.c | 91 +++++++++++++++++++++++++---------------------
1 file changed, 50 insertions(+), 41 deletions(-)
--
2.26.0
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 63ff822358b276137059520cf16e587e8073e80f Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe(a)kernel.dk>
Date: Thu, 7 May 2020 14:56:15 -0600
Subject: [PATCH] io_uring: don't use 'fd' for openat/openat2/statx
We currently make some guesses as when to open this fd, but in reality
we have no business (or need) to do so at all. In fact, it makes certain
things fail, like O_PATH.
Remove the fd lookup from these opcodes, we're just passing the 'fd' to
generic helpers anyway. With that, we can also remove the special casing
of fd values in io_req_needs_file(), and the 'fd_non_neg' check that
we have. And we can ensure that we only read sqe->fd once.
This fixes O_PATH usage with openat/openat2, and ditto statx path side
oddities.
Cc: stable(a)vger.kernel.org: # v5.6
Reported-by: Max Kellermann <mk(a)cm4all.com>
Signed-off-by: Jens Axboe <axboe(a)kernel.dk>
diff --git a/fs/io_uring.c b/fs/io_uring.c
index dd680eb153cb..979d9f977409 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -680,8 +680,6 @@ struct io_op_def {
unsigned needs_mm : 1;
/* needs req->file assigned */
unsigned needs_file : 1;
- /* needs req->file assigned IFF fd is >= 0 */
- unsigned fd_non_neg : 1;
/* hash wq insertion if file is a regular file */
unsigned hash_reg_file : 1;
/* unbound wq insertion if file is a non-regular file */
@@ -784,8 +782,6 @@ static const struct io_op_def io_op_defs[] = {
.needs_file = 1,
},
[IORING_OP_OPENAT] = {
- .needs_file = 1,
- .fd_non_neg = 1,
.file_table = 1,
.needs_fs = 1,
},
@@ -799,8 +795,6 @@ static const struct io_op_def io_op_defs[] = {
},
[IORING_OP_STATX] = {
.needs_mm = 1,
- .needs_file = 1,
- .fd_non_neg = 1,
.needs_fs = 1,
.file_table = 1,
},
@@ -837,8 +831,6 @@ static const struct io_op_def io_op_defs[] = {
.buffer_select = 1,
},
[IORING_OP_OPENAT2] = {
- .needs_file = 1,
- .fd_non_neg = 1,
.file_table = 1,
.needs_fs = 1,
},
@@ -5368,15 +5360,6 @@ static void io_wq_submit_work(struct io_wq_work **workptr)
io_steal_work(req, workptr);
}
-static int io_req_needs_file(struct io_kiocb *req, int fd)
-{
- if (!io_op_defs[req->opcode].needs_file)
- return 0;
- if ((fd == -1 || fd == AT_FDCWD) && io_op_defs[req->opcode].fd_non_neg)
- return 0;
- return 1;
-}
-
static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
int index)
{
@@ -5414,14 +5397,11 @@ static int io_file_get(struct io_submit_state *state, struct io_kiocb *req,
}
static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
- int fd, unsigned int flags)
+ int fd)
{
bool fixed;
- if (!io_req_needs_file(req, fd))
- return 0;
-
- fixed = (flags & IOSQE_FIXED_FILE);
+ fixed = (req->flags & REQ_F_FIXED_FILE) != 0;
if (unlikely(!fixed && req->needs_fixed_file))
return -EBADF;
@@ -5798,7 +5778,7 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
struct io_submit_state *state, bool async)
{
unsigned int sqe_flags;
- int id, fd;
+ int id;
/*
* All io need record the previous position, if LINK vs DARIN,
@@ -5850,8 +5830,10 @@ static int io_init_req(struct io_ring_ctx *ctx, struct io_kiocb *req,
IOSQE_ASYNC | IOSQE_FIXED_FILE |
IOSQE_BUFFER_SELECT | IOSQE_IO_LINK);
- fd = READ_ONCE(sqe->fd);
- return io_req_set_file(state, req, fd, sqe_flags);
+ if (!io_op_defs[req->opcode].needs_file)
+ return 0;
+
+ return io_req_set_file(state, req, READ_ONCE(sqe->fd));
}
static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,