Cover the essential functionality of the iommufd with a directed test from
userspace. This aims to achieve reasonable functional coverage using the
in-kernel self test framework.
A second test does a failure injection sweep of the success paths to study
error unwind behaviors.
This allows achieving high coverage of the corner cases in pages.c.
The selftest requires CONFIG_IOMMUFD_TEST to be enabled, and several huge
pages which may require:
echo 4 > /proc/sys/vm/nr_hugepages
Link: https://lore.kernel.org/r/19-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> # s390
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Eric Auger <eric.auger@redhat.com> # aarch64
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
These are on performance paths so we protect them using the
CONFIG_IOMMUFD_TEST to not take a hit during normal operation.
These are useful when running the test suite and syzkaller to find data
structure inconsistencies early.
Link: https://lore.kernel.org/r/18-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> # s390
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Provide a mock kernel module for the iommu_domain that allows it to run
without any HW and the mocking provides a way to directly validate that
the PFNs loaded into the iommu_domain are correct. This exposes the access
kAPI toward userspace to allow userspace to explore the functionality of
pages.c and io_pagetable.c
The mock also simulates the rare case of PAGE_SIZE > iommu page size as
the mock will operate at a 2K iommu page size. This allows exercising all
of the calculations to support this mismatch.
This is also intended to support syzkaller exploring the same space.
However, it is an unusually invasive config option to enable all of
this. The config option should not be enabled in a production kernel.
Link: https://lore.kernel.org/r/16-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com> # s390
Tested-by: Eric Auger <eric.auger@redhat.com> # aarch64
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
iommufd can directly implement the /dev/vfio/vfio container IOCTLs by
mapping them into io_pagetable operations.
A userspace application can test against iommufd and confirm compatibility
then simply make a small change to open /dev/iommu instead of
/dev/vfio/vfio.
For testing purposes /dev/vfio/vfio can be symlinked to /dev/iommu and
then all applications will use the compatibility path with no code
changes. A later series allows /dev/vfio/vfio to be directly provided by
iommufd, which allows the rlimit mode to work the same as well.
This series just provides the iommufd side of compatibility. Actually
linking this to VFIO_SET_CONTAINER is a followup series, with a link in
the cover letter.
Internally the compatibility API uses a normal IOAS object that, like
vfio, is automatically allocated when the first device is
attached.
Userspace can also query or set this IOAS object directly using the
IOMMU_VFIO_IOAS ioctl. This allows mixing and matching new iommufd only
features while still using the VFIO style map/unmap ioctls.
While this is enough to operate qemu, it has a few differences:
- Resource limits rely on memory cgroups to bound what userspace can do
instead of the module parameter dma_entry_limit.
- VFIO P2P is not implemented. The DMABUF patches for vfio are a start at
a solution where iommufd would import a special DMABUF. This is to avoid
further propogating the follow_pfn() security problem.
- A full audit for pedantic compatibility details (eg errnos, etc) has
not yet been done
- powerpc SPAPR is left out, as it is not connected to the iommu_domain
framework. It seems interest in SPAPR is minimal as it is currently
non-working in v6.1-rc1. They will have to convert to the iommu
subsystem framework to enjoy iommfd.
The following are not going to be implemented and we expect to remove them
from VFIO type1:
- SW access 'dirty tracking'. As discussed in the cover letter this will
be done in VFIO.
- VFIO_TYPE1_NESTING_IOMMU
https://lore.kernel.org/all/0-v1-0093c9b0e345+19-vfio_no_nesting_jgg@nvidia.com/
- VFIO_DMA_MAP_FLAG_VADDR
https://lore.kernel.org/all/Yz777bJZjTyLrHEQ@nvidia.com/
Link: https://lore.kernel.org/r/15-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Kernel access is the mode that VFIO "mdevs" use. In this case there is no
struct device and no IOMMU connection. iommufd acts as a record keeper for
accesses and returns the actual struct pages back to the caller to use
however they need. eg with kmap or the DMA API.
Each caller must create a struct iommufd_access with
iommufd_access_create(), similar to how iommufd_device_bind() works. Using
this struct the caller can access blocks of IOVA using
iommufd_access_pin_pages() or iommufd_access_rw().
Callers must provide a callback that immediately unpins any IOVA being
used within a range. This happens if userspace unmaps the IOVA under the
pin.
The implementation forwards the access requests directly to the iopt
infrastructure that manages the iopt_pages_access.
Link: https://lore.kernel.org/r/14-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Add the four functions external drivers need to connect physical DMA to
the IOMMUFD:
iommufd_device_bind() / iommufd_device_unbind()
Register the device with iommufd and establish security isolation.
iommufd_device_attach() / iommufd_device_detach()
Connect a bound device to a page table
Binding a device creates a device object ID in the uAPI, however the
generic API does not yet provide any IOCTLs to manipulate them.
Link: https://lore.kernel.org/r/13-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The hw_pagetable object exposes the internal struct iommu_domain's to
userspace. An iommu_domain is required when any DMA device attaches to an
IOAS to control the io page table through the iommu driver.
For compatibility with VFIO the hw_pagetable is automatically created when
a DMA device is attached to the IOAS. If a compatible iommu_domain already
exists then the hw_pagetable associated with it is used for the
attachment.
In the initial series there is no iommufd uAPI for the hw_pagetable
object. The next patch provides driver facing APIs for IO page table
attachment that allows drivers to accept either an IOAS or a hw_pagetable
ID and for the driver to return the hw_pagetable ID that was auto-selected
from an IOAS. The expectation is the driver will provide uAPI through its
own FD for attaching its device to iommufd. This allows userspace to learn
the mapping of devices to iommu_domains and to override the automatic
attachment.
The future HW specific interface will allow userspace to create
hw_pagetable objects using iommu_domains with IOMMU driver specific
parameters. This infrastructure will allow linking those domains to IOAS's
and devices.
Link: https://lore.kernel.org/r/12-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Connect the IOAS to its IOCTL interface. This exposes most of the
functionality in the io_pagetable to userspace.
This is intended to be the core of the generic interface that IOMMUFD will
provide. Every IOMMU driver should be able to implement an iommu_domain
that is compatible with this generic mechanism.
It is also designed to be easy to use for simple non virtual machine
monitor users, like DPDK:
- Universal simple support for all IOMMUs (no PPC special path)
- An IOVA allocator that considers the aperture and the allowed/reserved
ranges
- io_pagetable allows any number of iommu_domains to be connected to the
IOAS
- Automatic allocation and re-use of iommu_domains
Along with room in the design to add non-generic features to cater to
specific HW functionality.
Link: https://lore.kernel.org/r/11-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
This is the remainder of the IOAS data structure. Provide an object called
an io_pagetable that is composed of iopt_areas pointing at iopt_pages,
along with a list of iommu_domains that mirror the IOVA to PFN map.
At the top this is a simple interval tree of iopt_areas indicating the map
of IOVA to iopt_pages. An xarray keeps track of a list of domains. Based
on the attached domains there is a minimum alignment for areas (which may
be smaller than PAGE_SIZE), an interval tree of reserved IOVA that can't
be mapped and an IOVA of allowed IOVA that can always be mappable.
The concept of an 'access' refers to something like a VFIO mdev that is
accessing the IOVA and using a 'struct page *' for CPU based access.
Externally an API is provided that matches the requirements of the IOCTL
interface for map/unmap and domain attachment.
The API provides a 'copy' primitive to establish a new IOVA map in a
different IOAS from an existing mapping by re-using the iopt_pages. This
is the basic mechanism to provide single pinning.
This is designed to support a pre-registration flow where userspace would
setup an dummy IOAS with no domains, map in memory and then establish an
access to pin all PFNs into the xarray.
Copy can then be used to create new IOVA mappings in a different IOAS,
with iommu_domains attached. Upon copy the PFNs will be read out of the
xarray and mapped into the iommu_domains, avoiding any pin_user_pages()
overheads.
Link: https://lore.kernel.org/r/10-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The iopt_pages which represents a logical linear list of full PFNs held in
different storage tiers. Each area points to a slice of exactly one
iopt_pages, and each iopt_pages can have multiple areas and accesses.
The three storage tiers are managed to meet these objectives:
- If no iommu_domain or in-kerenel access exists then minimal memory
should be consumed by iomufd
- If a page has been pinned then an iopt_pages will not pin it again
- If an in-kernel access exists then the xarray must provide the backing
storage to avoid allocations on domain removals
- Otherwise any iommu_domain will be used for storage
In a common configuration with only an iommu_domain the iopt_pages does
not allocate significant memory itself.
The external interface for pages has several logical operations:
iopt_area_fill_domain() will load the PFNs from storage into a single
domain. This is used when attaching a new domain to an existing IOAS.
iopt_area_fill_domains() will load the PFNs from storage into multiple
domains. This is used when creating a new IOVA map in an existing IOAS
iopt_pages_add_access() creates an iopt_pages_access that tracks an
in-kernel access of PFNs. This is some external driver that might be
accessing the IOVA using the CPU, or programming PFNs with the DMA
API. ie a VFIO mdev.
iopt_pages_rw_access() directly perform a memcpy on the PFNs, without
the overhead of iopt_pages_add_access()
iopt_pages_fill_xarray() will load PFNs into the xarray and return a
'struct page *' array. It is used by iopt_pages_access's to extract PFNs
for in-kernel use. iopt_pages_fill_from_xarray() is a fast path when it
is known the xarray is already filled.
As an iopt_pages can be referred to in slices by many areas and accesses
it uses interval trees to keep track of which storage tiers currently hold
the PFNs. On a page-by-page basis any request for a PFN will be satisfied
from one of the storage tiers and the PFN copied to target domain/array.
Unfill actions are similar, on a page by page basis domains are unmapped,
xarray entries freed or struct pages fully put back.
Significant complexity is required to fully optimize all of these data
motions. The implementation calculates the largest consecutive range of
same-storage indexes and operates in blocks. The accumulation of PFNs
always generates the largest contiguous PFN range possible to optimize and
this gathering can cross storage tier boundaries. For cases like 'fill
domains' care is taken to avoid duplicated work and PFNs are read once and
pushed into all domains.
The map/unmap interaction with the iommu_domain always works in contiguous
PFN blocks. The implementation does not require or benefit from any
split/merge optimization in the iommu_domain driver.
This design suggests several possible improvements in the IOMMU API that
would greatly help performance, particularly a way for the driver to map
and read the pfns lists instead of working with one driver call per page
to read, and one driver call per contiguous range to store.
Link: https://lore.kernel.org/r/9-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
The top of the data structure provides an IO Address Space (IOAS) that is
similar to a VFIO container. The IOAS allows map/unmap of memory into
ranges of IOVA called iopt_areas. Multiple IOMMU domains (IO page tables)
and in-kernel accesses (like VFIO mdevs) can be attached to the IOAS to
access the PFNs that those IOVA areas cover.
The IO Address Space (IOAS) datastructure is composed of:
- struct io_pagetable holding the IOVA map
- struct iopt_areas representing populated portions of IOVA
- struct iopt_pages representing the storage of PFNs
- struct iommu_domain representing each IO page table in the system IOMMU
- struct iopt_pages_access representing in-kernel accesses of PFNs (ie
VFIO mdevs)
- struct xarray pinned_pfns holding a list of pages pinned by in-kernel
accesses
This patch introduces the lowest part of the datastructure - the movement
of PFNs in a tiered storage scheme:
1) iopt_pages::pinned_pfns xarray
2) Multiple iommu_domains
3) The origin of the PFNs, i.e. the userspace pointer
PFN have to be copied between all combinations of tiers, depending on the
configuration.
The interface is an iterator called a 'pfn_reader' which determines which
tier each PFN is stored and loads it into a list of PFNs held in a struct
pfn_batch.
Each step of the iterator will fill up the pfn_batch, then the caller can
use the pfn_batch to send the PFNs to the required destination. Repeating
this loop will read all the PFNs in an IOVA range.
The pfn_reader and pfn_batch also keep track of the pinned page accounting.
While PFNs are always stored and accessed as full PAGE_SIZE units the
iommu_domain tier can store with a sub-page offset/length to support
IOMMUs with a smaller IOPTE size than PAGE_SIZE.
Link: https://lore.kernel.org/r/8-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Following the pattern of io_uring, perf, skb, and bpf, iommfd will use
user->locked_vm for accounting pinned pages. Ensure the value is included
in the struct and export free_uid() as iommufd is modular.
user->locked_vm is the good accounting to use for ulimit because it is
per-user, and the security sandboxing of locked pages is not supposed to
be per-process. Other places (vfio, vdpa and infiniband) have used
mm->pinned_vm and/or mm->locked_vm for accounting pinned pages, but this
is only per-process and inconsistent with the new FOLL_LONGTERM users in
the kernel.
Concurrent work is underway to try to put this in a cgroup, so everything
can be consistent and the kernel can provide a FOLL_LONGTERM limit that
actually provides security.
Link: https://lore.kernel.org/r/7-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
This is the basic infrastructure of a new miscdevice to hold the iommufd
IOCTL API.
It provides:
- A miscdevice to create file descriptors to run the IOCTL interface over
- A table based ioctl dispatch and centralized extendable pre-validation
step
- An xarray mapping userspace ID's to kernel objects. The design has
multiple inter-related objects held within in a single IOMMUFD fd
- A simple usage count to build a graph of object relations and protect
against hostile userspace racing ioctls
The only IOCTL provided in this patch is the generic 'destroy any object
by handle' operation.
Link: https://lore.kernel.org/r/6-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Lixiao Yang <lixiao.yang@intel.com>
Tested-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Add iommufd into the documentation tree, and supply initial documentation.
Much of this is linked from code comments by kdoc.
Link: https://lore.kernel.org/r/5-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
According to Intel's document on Indirect Branch Restricted
Speculation, "Enabling IBRS does not prevent software from controlling
the predicted targets of indirect branches of unrelated software
executed later at the same predictor mode (for example, between two
different user applications, or two different virtual machines). Such
isolation can be ensured through use of the Indirect Branch Predictor
Barrier (IBPB) command." This applies to both basic and enhanced IBRS.
Since L1 and L2 VMs share hardware predictor modes (guest-user and
guest-kernel), hardware IBRS is not sufficient to virtualize
IBRS. (The way that basic IBRS is implemented on pre-eIBRS parts,
hardware IBRS is actually sufficient in practice, even though it isn't
sufficient architecturally.)
For virtual CPUs that support IBRS, add an indirect branch prediction
barrier on emulated VM-exit, to ensure that the predicted targets of
indirect branches executed in L1 cannot be controlled by software that
was executed in L2.
Since we typically don't intercept guest writes to IA32_SPEC_CTRL,
perform the IBPB at emulated VM-exit regardless of the current
IA32_SPEC_CTRL.IBRS value, even though the IBPB could technically be
deferred until L1 sets IA32_SPEC_CTRL.IBRS, if IA32_SPEC_CTRL.IBRS is
clear at emulated VM-exit.
This is CVE-2022-2196.
Fixes: 5c911beff2 ("KVM: nVMX: Skip IBPB when switching between vmcs01 and vmcs02")
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221019213620.1953281-3-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
At this point in time, most guests (in the default, out-of-the-box
configuration) are likely to use IA32_SPEC_CTRL. Therefore, drop the
compiler hint that it is unlikely for KVM to be intercepting WRMSR of
IA32_SPEC_CTRL.
Signed-off-by: Jim Mattson <jmattson@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221019213620.1953281-2-jmattson@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Inject #GP for if VMXON is attempting with a CR0/CR4 that fails the
generic "is CRx valid" check, but passes the CR4.VMXE check, and do the
generic checks _after_ handling the post-VMXON VM-Fail.
The CR4.VMXE check, and all other #UD cases, are special pre-conditions
that are enforced prior to pivoting on the current VMX mode, i.e. occur
before interception if VMXON is attempted in VMX non-root mode.
All other CR0/CR4 checks generate #GP and effectively have lower priority
than the post-VMXON check.
Per the SDM:
IF (register operand) or (CR0.PE = 0) or (CR4.VMXE = 0) or ...
THEN #UD;
ELSIF not in VMX operation
THEN
IF (CPL > 0) or (in A20M mode) or
(the values of CR0 and CR4 are not supported in VMX operation)
THEN #GP(0);
ELSIF in VMX non-root operation
THEN VMexit;
ELSIF CPL > 0
THEN #GP(0);
ELSE VMfail("VMXON executed in VMX root operation");
FI;
which, if re-written without ELSIF, yields:
IF (register operand) or (CR0.PE = 0) or (CR4.VMXE = 0) or ...
THEN #UD
IF in VMX non-root operation
THEN VMexit;
IF CPL > 0
THEN #GP(0)
IF in VMX operation
THEN VMfail("VMXON executed in VMX root operation");
IF (in A20M mode) or
(the values of CR0 and CR4 are not supported in VMX operation)
THEN #GP(0);
Note, KVM unconditionally forwards VMXON VM-Exits that occur in L2 to L1,
i.e. there is no need to check the vCPU is not in VMX non-root mode. Add
a comment to explain why unconditionally forwarding such exits is
functionally correct.
Reported-by: Eric Li <ercli@ucdavis.edu>
Fixes: c7d855c2af ("KVM: nVMX: Inject #UD if VMXON is attempted with incompatible CR0/CR4")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20221006001956.329314-1-seanjc@google.com
In current form, FORCE_NR_CPUS is visible to all users building their
kernels, even not experts. It is also set in allmodconfig or
allyesconfig, which is not a correct behavior.
This patch fixes it. It also changes the parameter short description:
removes implementation details and highlights the effect of the change.
Link: https://lkml.kernel.org/r/20221116172451.274938-1-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Suggested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Cc: Alexey Klimov <klimov.linux@gmail.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sander Vanheule <sander@svanheule.net>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The integer overflow is descripted with following codes:
> 317 static comp_t encode_comp_t(u64 value)
> 318 {
> 319 int exp, rnd;
......
> 341 exp <<= MANTSIZE;
> 342 exp += value;
> 343 return exp;
> 344 }
Currently comp_t is defined as type of '__u16', but the variable 'exp' is
type of 'int', so overflow would happen when variable 'exp' in line 343 is
greater than 65535.
Link: https://lkml.kernel.org/r/20210515140631.369106-3-zhengyejian1@huawei.com
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhang Jinhao <zhangjinhao2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "Fix encode_comp_t()".
Type conversion in encode_comp_t() may look a bit problematic.
This patch (of 2):
See calculation of ac_{u,s}time in fill_ac():
> ac->ac_utime = encode_comp_t(nsec_to_AHZ(pacct->ac_utime));
> ac->ac_stime = encode_comp_t(nsec_to_AHZ(pacct->ac_stime));
Return value of nsec_to_AHZ() is always type of 'u64', but it is handled
as type of 'unsigned long' in encode_comp_t, and accuracy loss would
happen on 32-bit platform when 'unsigned long' value is 32-bit-width.
So 'u64' value of encode_comp_t() may look better.
Link: https://lkml.kernel.org/r/20210515140631.369106-1-zhengyejian1@huawei.com
Link: https://lkml.kernel.org/r/20210515140631.369106-2-zhengyejian1@huawei.com
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Cc: Hanjun Guo <guohanjun@huawei.com>
Cc: Randy Dunlap <rdunlap@infradead.org> # build-tested
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zhang Jinhao <zhangjinhao2@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
With CONFIG_HAVE_ARCH_PREL32_RELOCATIONS=y, the following code fails to
build:
---------------->8----------------
#include <linux/init.h>
int foo(void) { return 0; }
core_initcall(foo);
---------------->8----------------
Include <linux/build_bug.h> for static_assert() and <linux/stringify.h>
for __stringify().
Link: https://lkml.kernel.org/r/20221113110802.3760705-1-masahiroy@kernel.org
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Cc: Jiangshan Yi <yijiangshan@kylinos.cn>
Cc: Kees Cook <keescook@chromium.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org> # build-tested
Cc: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If device_register() returns error, the name allocated by dev_set_name()
need be freed. It should use put_device() to give up the reference in the
error path, so that the name can be freed in kobject_cleanup(), and
list_del() is called to delete the port from rio_mports.
Link: https://lkml.kernel.org/r/20221114152636.2939035-3-yangyingliang@huawei.com
Fixes: 2aaf308b95 ("rapidio: rework device hierarchy and introduce mport class of devices")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "rapidio: fix three possible memory leaks".
This patchset fixes three name leaks in error handling.
- patch #1 fixes two name leaks while rio_add_device() fails.
- patch #2 fixes a name leak while rio_register_mport() fails.
This patch (of 2):
If rio_add_device() returns error, the name allocated by dev_set_name()
need be freed. It should use put_device() to give up the reference in the
error path, so that the name can be freed in kobject_cleanup(), and the
'rdev' can be freed in rio_release_dev().
Link: https://lkml.kernel.org/r/20221114152636.2939035-1-yangyingliang@huawei.com
Link: https://lkml.kernel.org/r/20221114152636.2939035-2-yangyingliang@huawei.com
Fixes: e8de370188 ("rapidio: add mport char device driver")
Fixes: 1fa5ae857b ("driver core: get rid of struct device's bus_id string array")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Fix the following W=1 kernel build warning(s):
fs/fat/nfs.c:21: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
fs/fat/nfs.c:139: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst
Link: https://lkml.kernel.org/r/20221111075648.4005-1-liubo03@inspur.com
Signed-off-by: Bo Liu <liubo03@inspur.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There is a memory leak reported by kmemleak:
unreferenced object 0xffff88810cc65e60 (size 32):
comm "mount.ocfs2", pid 23753, jiffies 4302528942 (age 34735.105s)
hex dump (first 32 bytes):
10 00 00 00 00 00 00 00 00 01 01 01 01 01 01 01 ................
01 01 01 01 01 01 01 01 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff8170f73d>] __kmalloc+0x4d/0x150
[<ffffffffa0ac3f51>] ocfs2_compute_replay_slots+0x121/0x330 [ocfs2]
[<ffffffffa0b65165>] ocfs2_check_volume+0x485/0x900 [ocfs2]
[<ffffffffa0b68129>] ocfs2_mount_volume.isra.0+0x1e9/0x650 [ocfs2]
[<ffffffffa0b7160b>] ocfs2_fill_super+0xe0b/0x1740 [ocfs2]
[<ffffffff818e1fe2>] mount_bdev+0x312/0x400
[<ffffffff819a086d>] legacy_get_tree+0xed/0x1d0
[<ffffffff818de82d>] vfs_get_tree+0x7d/0x230
[<ffffffff81957f92>] path_mount+0xd62/0x1760
[<ffffffff81958a5a>] do_mount+0xca/0xe0
[<ffffffff81958d3c>] __x64_sys_mount+0x12c/0x1a0
[<ffffffff82f26f15>] do_syscall_64+0x35/0x80
[<ffffffff8300006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
This call stack is related to two problems. Firstly, the ocfs2 super uses
"replay_map" to trace online/offline slots, in order to recover offline
slots during recovery and mount. But when ocfs2_truncate_log_init()
returns an error in ocfs2_mount_volume(), the memory of "replay_map" will
not be freed in error handling path. Secondly, the memory of "replay_map"
will not be freed if d_make_root() returns an error in ocfs2_fill_super().
But the memory of "replay_map" will be freed normally when completing
recovery and mount in ocfs2_complete_mount_recovery().
Fix the first problem by adding error handling path to free "replay_map"
when ocfs2_truncate_log_init() fails. And fix the second problem by
calling ocfs2_free_replay_slots(osb) in the error handling path
"out_dismount". In addition, since ocfs2_free_replay_slots() is static,
it is necessary to remove its static attribute and declare it in header
file.
Link: https://lkml.kernel.org/r/20221109074627.2303950-1-lizetao1@huawei.com
Fixes: 9140db04ef ("ocfs2: recover orphans in offline slots during recovery and mount")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We need to set an initial value for offset to eliminate compilation
warning.
How to reproduce warning:
$ make -C tools/testing/radix-tree
radix-tree.c: In function `radix_tree_tag_clear':
radix-tree.c:1046:17: warning: `offset' may be used uninitialized in this function [-Wmaybe-uninitialized]
1046 | node_tag_clear(root, parent, tag, offset);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Link: https://lkml.kernel.org/r/tencent_DF74099967595DCEA93CBDC28D062026180A@qq.com
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Though vmcoreinfo is intended to be small, at just one page, useful
information is still added to it, so we risk running out of space.
Currently there is no runtime check to see whether the vmcoreinfo buffer
has been exhausted. Add a warning for this case.
Currently, my static checking tool[1] indicates that a good upper bound
for vmcoreinfo size is currently 3415 bytes, but the best time to add
warnings is before the risk becomes too high.
[1] https://github.com/brenns10/kernel_stuff/blob/master/vmcoreinfosize/vmcoreinfosize.py
Link: https://lkml.kernel.org/r/20221027205008.312534-1-stephen.s.brennan@oracle.com
Signed-off-by: Stephen Brennan <stephen.s.brennan@oracle.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
These array allocator family are sometimes misused with the first and
second arguments switched.
Same issue with calloc, kvcalloc, kvmalloc_array etc.
Bleat if sizeof is the first argument.
Link: https://lore.kernel.org/lkml/5374345c-7973-6a3c-d559-73bf4ac15079@redhat.com/
Link: https://lkml.kernel.org/r/20221104070523.60296-1-liaochang1@huawei.com
Signed-off-by: Liao Chang <liaochang1@huawei.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
On some platforms, `char` is unsigned, but this driver, for the most part,
assumed it was signed. In other places, it uses `char` to mean an
unsigned number, but only in cases when the values are small. And in
still other places, `char` is used as a boolean. Put an end to this
confusion by declaring explicit types, depending on the context.
Link: https://lkml.kernel.org/r/20221019155541.3410813-1-Jason@zx2c4.com
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The simple attribute files do not accept a negative value since the commit
488dac0c92 ("libfs: fix error cast of negative value in
simple_attr_write()"), so we have to use a 64-bit value to write a
negative value for a debugfs file created by debugfs_create_atomic_t().
This restores the previous behaviour by introducing
DEFINE_DEBUGFS_ATTRIBUTE_SIGNED for a signed value.
Link: https://lkml.kernel.org/r/20220919172418.45257-4-akinobu.mita@gmail.com
Fixes: 488dac0c92 ("libfs: fix error cast of negative value in simple_attr_write()")
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reported-by: Zhao Gongyi <zhaogongyi@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The simple attribute files do not accept a negative value since the commit
488dac0c92 ("libfs: fix error cast of negative value in
simple_attr_write()").
This restores the previous behaviour by using newly introduced
DEFINE_SIMPLE_ATTRIBUTE_SIGNED instead of DEFINE_SIMPLE_ATTRIBUTE.
Link: https://lkml.kernel.org/r/20220919172418.45257-3-akinobu.mita@gmail.com
Fixes: 488dac0c92 ("libfs: fix error cast of negative value in simple_attr_write()")
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reported-by: Zhao Gongyi <zhaogongyi@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "fix error when writing negative value to simple attribute
files".
The simple attribute files do not accept a negative value since the commit
488dac0c92 ("libfs: fix error cast of negative value in
simple_attr_write()"), but some attribute files want to accept a negative
value.
This patch (of 3):
The simple attribute files do not accept a negative value since the commit
488dac0c92 ("libfs: fix error cast of negative value in
simple_attr_write()"), so we have to use a 64-bit value to write a
negative value.
This adds DEFINE_SIMPLE_ATTRIBUTE_SIGNED for a signed value.
Link: https://lkml.kernel.org/r/20220919172418.45257-1-akinobu.mita@gmail.com
Link: https://lkml.kernel.org/r/20220919172418.45257-2-akinobu.mita@gmail.com
Fixes: 488dac0c92 ("libfs: fix error cast of negative value in simple_attr_write()")
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Reported-by: Zhao Gongyi <zhaogongyi@huawei.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The use of kmap_atomic() is being deprecated in favor of
kmap_local_page()[1].
The main difference between atomic and local mappings is that local
mappings don't disable page faults or preemption.
There're 2 reasons we can use kmap_local_page() here:
1. SEV is 64-bit only and kmap_local_page() doesn't disable migration in
this case, but here the function clflush_cache_range() uses CLFLUSHOPT
instruction to flush, and on x86 CLFLUSHOPT is not CPU-local and flushes
the page out of the entire cache hierarchy on all CPUs (APM volume 3,
chapter 3, CLFLUSHOPT). So there's no need to disable preemption to ensure
CPU-local.
2. clflush_cache_range() doesn't need to disable pagefault and the mapping
is still valid even if sleeps. This is also true for sched out/in when
preempted.
In addition, though kmap_local_page() is a thin wrapper around
page_address() on 64-bit, kmap_local_page() should still be used here in
preference to page_address() since page_address() isn't suitable to be used
in a generic function (like sev_clflush_pages()) where the page passed in
is not easy to determine the source of allocation. Keeping the kmap* API in
place means it can be used for things other than highmem mappings[2].
Therefore, sev_clflush_pages() is a function that should use
kmap_local_page() in place of kmap_atomic().
Convert the calls of kmap_atomic() / kunmap_atomic() to kmap_local_page() /
kunmap_local().
[1]: https://lore.kernel.org/all/20220813220034.806698-1-ira.weiny@intel.com
[2]: https://lore.kernel.org/lkml/5d667258-b58b-3d28-3609-e7914c99b31b@intel.com/
Suggested-by: Dave Hansen <dave.hansen@intel.com>
Suggested-by: Ira Weiny <ira.weiny@intel.com>
Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220928092748.463631-1-zhao1.liu@linux.intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Skip the WRMSR fastpath in SVM's VM-Exit handler if the next RIP isn't
valid, e.g. because KVM is running with nrips=false. SVM must decode and
emulate to skip the WRMSR if the CPU doesn't provide the next RIP.
Getting the instruction bytes to decode the WRMSR requires reading guest
memory, which in turn means dereferencing memslots, and that isn't safe
because KVM doesn't hold SRCU when the fastpath runs.
Don't bother trying to enable the fastpath for this case, e.g. by doing
only the WRMSR and leaving the "skip" until later. NRIPS is supported on
all modern CPUs (KVM has considered making it mandatory), and the next
RIP will be valid the vast, vast majority of the time.
=============================
WARNING: suspicious RCU usage
6.0.0-smp--4e557fcd3d80-skip #13 Tainted: G O
-----------------------------
include/linux/kvm_host.h:954 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by stable/206475:
#0: ffff9d9dfebcc0f0 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x8b/0x620 [kvm]
stack backtrace:
CPU: 152 PID: 206475 Comm: stable Tainted: G O 6.0.0-smp--4e557fcd3d80-skip #13
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 10.48.0 01/27/2022
Call Trace:
<TASK>
dump_stack_lvl+0x69/0xaa
dump_stack+0x10/0x12
lockdep_rcu_suspicious+0x11e/0x130
kvm_vcpu_gfn_to_memslot+0x155/0x190 [kvm]
kvm_vcpu_gfn_to_hva_prot+0x18/0x80 [kvm]
paging64_walk_addr_generic+0x183/0x450 [kvm]
paging64_gva_to_gpa+0x63/0xd0 [kvm]
kvm_fetch_guest_virt+0x53/0xc0 [kvm]
__do_insn_fetch_bytes+0x18b/0x1c0 [kvm]
x86_decode_insn+0xf0/0xef0 [kvm]
x86_emulate_instruction+0xba/0x790 [kvm]
kvm_emulate_instruction+0x17/0x20 [kvm]
__svm_skip_emulated_instruction+0x85/0x100 [kvm_amd]
svm_skip_emulated_instruction+0x13/0x20 [kvm_amd]
handle_fastpath_set_msr_irqoff+0xae/0x180 [kvm]
svm_vcpu_run+0x4b8/0x5a0 [kvm_amd]
vcpu_enter_guest+0x16ca/0x22f0 [kvm]
kvm_arch_vcpu_ioctl_run+0x39d/0x900 [kvm]
kvm_vcpu_ioctl+0x538/0x620 [kvm]
__se_sys_ioctl+0x77/0xc0
__x64_sys_ioctl+0x1d/0x20
do_syscall_64+0x3d/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fixes: 404d5d7bff ("KVM: X86: Introduce more exit_fastpath_completion enum values")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220930234031.1732249-1-seanjc@google.com
Treat any exception during instruction decode for EMULTYPE_SKIP as a
"full" emulation failure, i.e. signal failure instead of queuing the
exception. When decoding purely to skip an instruction, KVM and/or the
CPU has already done some amount of emulation that cannot be unwound,
e.g. on an EPT misconfig VM-Exit KVM has already processeed the emulated
MMIO. KVM already does this if a #UD is encountered, but not for other
exceptions, e.g. if a #PF is encountered during fetch.
In SVM's soft-injection use case, queueing the exception is particularly
problematic as queueing exceptions while injecting events can put KVM
into an infinite loop due to bailing from VM-Enter to service the newly
pending exception. E.g. multiple warnings to detect such behavior fire:
------------[ cut here ]------------
WARNING: CPU: 3 PID: 1017 at arch/x86/kvm/x86.c:9873 kvm_arch_vcpu_ioctl_run+0x1de5/0x20a0 [kvm]
Modules linked in: kvm_amd ccp kvm irqbypass
CPU: 3 PID: 1017 Comm: svm_nested_soft Not tainted 6.0.0-rc1+ #220
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:kvm_arch_vcpu_ioctl_run+0x1de5/0x20a0 [kvm]
Call Trace:
kvm_vcpu_ioctl+0x223/0x6d0 [kvm]
__x64_sys_ioctl+0x85/0xc0
do_syscall_64+0x2b/0x50
entry_SYSCALL_64_after_hwframe+0x46/0xb0
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 3 PID: 1017 at arch/x86/kvm/x86.c:9987 kvm_arch_vcpu_ioctl_run+0x12a3/0x20a0 [kvm]
Modules linked in: kvm_amd ccp kvm irqbypass
CPU: 3 PID: 1017 Comm: svm_nested_soft Tainted: G W 6.0.0-rc1+ #220
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
RIP: 0010:kvm_arch_vcpu_ioctl_run+0x12a3/0x20a0 [kvm]
Call Trace:
kvm_vcpu_ioctl+0x223/0x6d0 [kvm]
__x64_sys_ioctl+0x85/0xc0
do_syscall_64+0x2b/0x50
entry_SYSCALL_64_after_hwframe+0x46/0xb0
---[ end trace 0000000000000000 ]---
Fixes: 6ea6e84309 ("KVM: x86: inject exceptions produced by x86_decode_insn")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20220930233632.1725475-1-seanjc@google.com
Use apply_bytes on ingress redirect, when apply_bytes is less than
the length of msg data, some data may be skipped and lost in
bpf_tcp_ingress().
If there is still data in the scatterlist that has not been consumed,
we cannot move the msg iter.
Fixes: 604326b41a ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/1669718441-2654-4-git-send-email-yangpc@wangsu.com
When redirecting, we use sk_msg_to_ingress() to get the BPF_F_INGRESS
flag from the msg->flags. If apply_bytes is used and it is larger than
the current data being processed, sk_psock_msg_verdict() will not be
called when sendmsg() is called again. At this time, the msg->flags is 0,
and we lost the BPF_F_INGRESS flag.
So we need to save the BPF_F_INGRESS flag in sk_psock and use it when
redirection.
Fixes: 8934ce2fd0 ("bpf: sockmap redirect ingress support")
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/1669718441-2654-3-git-send-email-yangpc@wangsu.com
In tcp_bpf_send_verdict() redirection, the eval variable is assigned to
__SK_REDIRECT after the apply_bytes data is sent, if msg has more_data,
sock_put() will be called multiple times.
We should reset the eval variable to __SK_NONE every time more_data
starts.
This causes:
IPv4: Attempt to release TCP socket in state 1 00000000b4c925d7
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 5 PID: 4482 at lib/refcount.c:25 refcount_warn_saturate+0x7d/0x110
Modules linked in:
CPU: 5 PID: 4482 Comm: sockhash_bypass Kdump: loaded Not tainted 6.0.0 #1
Hardware name: Red Hat KVM, BIOS 1.11.0-2.el7 04/01/2014
Call Trace:
<TASK>
__tcp_transmit_skb+0xa1b/0xb90
? __alloc_skb+0x8c/0x1a0
? __kmalloc_node_track_caller+0x184/0x320
tcp_write_xmit+0x22a/0x1110
__tcp_push_pending_frames+0x32/0xf0
do_tcp_sendpages+0x62d/0x640
tcp_bpf_push+0xae/0x2c0
tcp_bpf_sendmsg_redir+0x260/0x410
? preempt_count_add+0x70/0xa0
tcp_bpf_send_verdict+0x386/0x4b0
tcp_bpf_sendmsg+0x21b/0x3b0
sock_sendmsg+0x58/0x70
__sys_sendto+0xfa/0x170
? xfd_validate_state+0x1d/0x80
? switch_fpu_return+0x59/0xe0
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x37/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fixes: cd9733f5d7 ("tcp_bpf: Fix one concurrency problem in the tcp_bpf_send_verdict function")
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/1669718441-2654-2-git-send-email-yangpc@wangsu.com
Acquire SRCU before taking the gpc spinlock in wait_pending_event() so as
to be consistent with all other functions that acquire both locks. It's
not illegal to acquire SRCU inside a spinlock, nor is there deadlock
potential, but in general it's preferable to order locks from least
restrictive to most restrictive, e.g. if wait_pending_event() needed to
sleep for whatever reason, it could do so while holding SRCU, but would
need to drop the spinlock.
Signed-off-by: Peng Hao <flyingpeng@tencent.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/CAPm50a++Cb=QfnjMZ2EnCj-Sb9Y4UM-=uOEtHAcjnNLCAAf-dQ@mail.gmail.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
If freeit is true, the value of ret must be zero, there is no need to
check the value of freeit after label unlock_mutex.
We can drop variable freeit to do this cleanup.
Link: https://lkml.kernel.org/r/20221125065444.3462681-1-mawupeng1@huawei.com
Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: zhenwei pi <pizhenwei@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
We used to have 624a2c94f5 (Partly revert "mm/thp: carry over dirty bit
when thp splits on pmd") fixing the regression reported here by Anatoly
Pugachev on sparc64:
https://lore.kernel.org/r/20221021160603.GA23307@u164.east.ru
Where we temporarily ignored the dirty bit for small pages.
Then, Hev also reported similar issue on loongarch:
(the original mail was private, but Anatoly copied the list here)
https://lore.kernel.org/r/CADxRZqxqb7f_WhMh=jweZP+ynf_JwGd-0VwbYgp4P+T0-AXosw@mail.gmail.com
Hev pointed out that the issue is having HW write bit set within the
pte_mkdirty() so the split pte can be written after split even if e.g.
they were shared by more than one processes, causing data corrupt.
Hev also tried to explain why loongarch set HW write bit in mkdirty:
https://lore.kernel.org/r/CAHirt9itKO_K_HPboXh5AyJtt16Zf0cD73PtHvM=na39u_ztxA@mail.gmail.com
One way to fix it is as what Huacai proposed here for loongarch (then we
can re-apply the dirty bit in thp split):
https://lore.kernel.org/r/20221117042532.4064448-1-chenhuacai@loongson.cnn
We may need similar thing for sparc64, though.
For now since we've found the root cause of the dirty bit issue the
simpler solution (which won't lose the dirty bit for small) that will work
for both is we wr-protect after pte_mkdirty(), so the HW write bit can be
persistent after thp split.
Add a comment for wrprotect, so we will not mess up the ordering later.
With 624a2c94f5 (Partly revert "mm/thp: carry over dirty bit when thp
splits on pmd") this is not a fix anymore, but just brings back the dirty
bit for thp split safely, so we re-apply the optimization but in safe way.
Provide a Tested-by credit to Hev too (not the exact same patch but the
same outcome) for loongarch.
Link: https://lkml.kernel.org/r/20221125185857.3110155-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Tested-by: Hev <r@hev.cc> # loongarch
Cc: Anatoly Pugachev <matorola@gmail.com>
Cc: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Replace open-coded snprintf() with sysfs_emit() to simplify the code.
Link: https://lkml.kernel.org/r/202211241929015476424@zte.com.cn
Signed-off-by: Xu Panda <xu.panda@zte.com.cn>
Signed-off-by: Yang Yang <yang.yang29@zte.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In __gmap_segment_gaddr() pmd level page table page is being extracted
from the pmd pointer, similar to pmd_pgtable_page() implementation. This
reduces some redundancy by directly using pmd_pgtable_page() instead,
though first making it available.
Link: https://lkml.kernel.org/r/20221125034502.1559986-1-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Current pmd_to_page(), which derives the page table page containing the
pmd address has a very misleading name. The problem being, it sounds
similar to pmd_page() which derives page embedded in a given pmd entry
either for next level page or a mapped huge page. Rename it as
pmd_pgtable_page() instead.
Link: https://lkml.kernel.org/r/20221124131641.1523772-1-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
zswap_frontswap_load() should be called from preemptible context (we even
call mutex_lock() there) and it does not look like we need to do
GFP_ATOMIC allocaion for temp buffer. The same applies to
zswap_writeback_entry().
Use GFP_KERNEL for temporary buffer allocation in both cases.
Link: https://lkml.kernel.org/r/Y3xCTr6ikbtcUr/y@google.com
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Nhat Pham <nphamcs@gmail.com>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Dan Streetman <ddstreet@ieee.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Although pmd_present() might seem to indicate a valid and mapped pmd
entry, in reality it returns true when pmd_page() points to a valid page
in memory , regardless whether the pmd entry is mapped or not. Andrea
Arcangeli had earlier explained [1] the required semantics for
pmd_present(). This just updates the documentation for pmd_present() as
required.
[1] https://lore.kernel.org/lkml/20181017020930.GN30832@redhat.com/
Link: https://lkml.kernel.org/r/20221123051319.1312582-1-anshuman.khandual@arm.com
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Depending on the memory configuration, isolate_freepages_block() may scan
pages out of the target range and causes panic.
Panic can occur on systems with multiple zones in a single pageblock.
The reason it is rare is that it only happens in special
configurations. Depending on how many similar systems there are, it
may be a good idea to fix this problem for older kernels as well.
The problem is that pfn as argument of fast_isolate_around() could be out
of the target range. Therefore we should consider the case where pfn <
start_pfn, and also the case where end_pfn < pfn.
This problem should have been addressd by the commit 6e2b7044c1 ("mm,
compaction: make fast_isolate_freepages() stay within zone") but there was
an oversight.
Case1: pfn < start_pfn
<at memory compaction for node Y>
| node X's zone | node Y's zone
+-----------------+------------------------------...
pageblock ^ ^ ^
+-----------+-----------+-----------+-----------+...
^ ^ ^
^ ^ end_pfn
^ start_pfn = cc->zone->zone_start_pfn
pfn
<---------> scanned range by "Scan After"
Case2: end_pfn < pfn
<at memory compaction for node X>
| node X's zone | node Y's zone
+-----------------+------------------------------...
pageblock ^ ^ ^
+-----------+-----------+-----------+-----------+...
^ ^ ^
^ ^ pfn
^ end_pfn
start_pfn
<---------> scanned range by "Scan Before"
It seems that there is no good reason to skip nr_isolated pages just after
given pfn. So let perform simple scan from start to end instead of
dividing the scan into "Before" and "After".
Link: https://lkml.kernel.org/r/20221026112438.236336-1-a.naribayashi@fujitsu.com
Fixes: 6e2b7044c1 ("mm, compaction: make fast_isolate_freepages() stay within zone").
Signed-off-by: NARIBAYASHI Akira <a.naribayashi@fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This documents the new /sys/class/bdi/<bdi>/max_ratio_fine knob.
[akpm@linux-foundation.org: fix htmldocs warnings]
Link: https://lkml.kernel.org/r/20221119005215.3052436-21-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Cc: Chris Mason <clm@meta.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
