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The whole point of SGX is to create a hardware protected place to do
“stuff”. But, before someone is willing to hand over the keys to
the castle , an enclave must often prove that it is running on an
SGX-protected processor. Provisioning enclaves play a key role in
providing proof.
There are actually three different enclaves in play in order to make this
happen:
1. The application enclave. The familiar one we know and love that runs
the actual code that’s doing real work. There can be many of these on
a single system, or even in a single application.
2. The quoting enclave (QE). The QE is mentioned in lots of silly
whitepapers, but, for the purposes of kernel enabling, just pretend they
do not exist.
3. The provisioning enclave. There is typically only one of these
enclaves per system. Provisioning enclaves have access to a special
hardware key.
They can use this key to help to generate certificates which serve as
proof that enclaves are running on trusted SGX hardware. These
certificates can be passed around without revealing the special key.
Any user who can create a provisioning enclave can access the
processor-unique Provisioning Certificate Key which has privacy and
fingerprinting implications. Even if a user is permitted to create
normal application enclaves (via /dev/sgx_enclave), they should not be
able to create provisioning enclaves. That means a separate permissions
scheme is needed to control provisioning enclave privileges.
Implement a separate device file (/dev/sgx_provision) which allows
creating provisioning enclaves. This device will typically have more
strict permissions than the plain enclave device.
The actual device “driver” is an empty stub. Open file descriptors for
this device will represent a token which allows provisioning enclave duty.
This file descriptor can be passed around and ultimately given as an
argument to the /dev/sgx_enclave driver ioctl().
[ bp: Touchups. ]
Suggested-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: linux-security-module@vger.kernel.org
Link: https://lkml.kernel.org/r/20201112220135.165028-16-jarkko@kernel.org
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Enclaves have two basic states. They are either being built and are
malleable and can be modified by doing things like adding pages. Or,
they are locked down and not accepting changes. They can only be run
after they have been locked down. The ENCLS[EINIT] function induces the
transition from being malleable to locked-down.
Add an ioctl() that performs ENCLS[EINIT]. After this, new pages can
no longer be added with ENCLS[EADD]. This is also the time where the
enclave can be measured to verify its integrity.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-15-jarkko@kernel.org
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SGX enclave pages are inaccessible to normal software. They must be
populated with data by copying from normal memory with the help of the
EADD and EEXTEND functions of the ENCLS instruction.
Add an ioctl() which performs EADD that adds new data to an enclave, and
optionally EEXTEND functions that hash the page contents and use the
hash as part of enclave “measurement” to ensure enclave integrity.
The enclave author gets to decide which pages will be included in the
enclave measurement with EEXTEND. Measurement is very slow and has
sometimes has very little value. For instance, an enclave _could_
measure every page of data and code, but would be slow to initialize.
Or, it might just measure its code and then trust that code to
initialize the bulk of its data after it starts running.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-14-jarkko@kernel.org
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Add an ioctl() that performs the ECREATE function of the ENCLS
instruction, which creates an SGX Enclave Control Structure (SECS).
Although the SECS is an in-memory data structure, it is present in
enclave memory and is not directly accessible by software.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-13-jarkko@kernel.org
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Intel(R) SGX is a new hardware functionality that can be used by
applications to set aside private regions of code and data called
enclaves. New hardware protects enclave code and data from outside
access and modification.
Add a driver that presents a device file and ioctl API to build and
manage enclaves.
[ bp: Small touchups, remove unused encl variable in sgx_encl_find() as
Reported-by: kernel test robot <lkp@intel.com> ]
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-12-jarkko@kernel.org
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Background
==========
1. SGX enclave pages are populated with data by copying from normal memory
via ioctl() (SGX_IOC_ENCLAVE_ADD_PAGES), which will be added later in
this series.
2. It is desirable to be able to restrict those normal memory data sources.
For instance, to ensure that the source data is executable before
copying data to an executable enclave page.
3. Enclave page permissions are dynamic (just like normal permissions) and
can be adjusted at runtime with mprotect().
This creates a problem because the original data source may have long since
vanished at the time when enclave page permissions are established (mmap()
or mprotect()).
The solution (elsewhere in this series) is to force enclave creators to
declare their paging permission *intent* up front to the ioctl(). This
intent can be immediately compared to the source data’s mapping and
rejected if necessary.
The “intent” is also stashed off for later comparison with enclave
PTEs. This ensures that any future mmap()/mprotect() operations
performed by the enclave creator or done on behalf of the enclave
can be compared with the earlier declared permissions.
Problem
=======
There is an existing mmap() hook which allows SGX to perform this
permission comparison at mmap() time. However, there is no corresponding
->mprotect() hook.
Solution
========
Add a vm_ops->mprotect() hook so that mprotect() operations which are
inconsistent with any page's stashed intent can be rejected by the driver.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Hillf Danton <hdanton@sina.com>
Cc: linux-mm@kvack.org
Link: https://lkml.kernel.org/r/20201112220135.165028-11-jarkko@kernel.org
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Add functions for runtime allocation and free.
This allocator and its algorithms are as simple as it gets. They do a
linear search across all EPC sections and find the first free page. They
are not NUMA-aware and only hand out individual pages. The SGX hardware
does not support large pages, so something more complicated like a buddy
allocator is unwarranted.
The free function (sgx_free_epc_page()) implicitly calls ENCLS[EREMOVE],
which returns the page to the uninitialized state. This ensures that the
page is ready for use at the next allocation.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-10-jarkko@kernel.org
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Add a kernel parameter to disable SGX kernel support and document it.
[ bp: Massage. ]
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Tested-by: Sean Christopherson <sean.j.christopherson@intel.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-9-jarkko@kernel.org
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Kernel support for SGX is ultimately decided by the state of the launch
control bits in the feature control MSR (MSR_IA32_FEAT_CTL). If the
hardware supports SGX, but neglects to support flexible launch control, the
kernel will not enable SGX.
Enable SGX at feature control MSR initialization and update the associated
X86_FEATURE flags accordingly. Disable X86_FEATURE_SGX (and all
derivatives) if the kernel is not able to establish itself as the authority
over SGX Launch Control.
All checks are performed for each logical CPU (not just boot CPU) in order
to verify that MSR_IA32_FEATURE_CONTROL is correctly configured on all
CPUs. All SGX code in this series expects the same configuration from all
CPUs.
This differs from VMX where X86_FEATURE_VMX is intentionally cleared only
for the current CPU so that KVM can provide additional information if KVM
fails to load like which CPU doesn't support VMX. There’s not much the
kernel or an administrator can do to fix the situation, so SGX neglects to
convey additional details about these kinds of failures if they occur.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-8-jarkko@kernel.org
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The x86 architecture has a set of page fault error codes. These indicate
things like whether the fault occurred from a write, or whether it
originated in userspace.
The SGX hardware architecture has its own per-page memory management
metadata (EPCM) [*] and hardware which is separate from the normal x86 MMU.
The architecture has a new page fault error code: PF_SGX. This new error
code bit is set whenever a page fault occurs as the result of the SGX MMU.
These faults occur for a variety of reasons. For instance, an access
attempt to enclave memory from outside the enclave causes a PF_SGX fault.
PF_SGX would also be set for permission conflicts, such as if a write to an
enclave page occurs and the page is marked read-write in the x86 page
tables but is read-only in the EPCM.
These faults do not always indicate errors, though. SGX pages are
encrypted with a key that is destroyed at hardware reset, including
suspend. Throwing a SIGSEGV allows user space software to react and recover
when these events occur.
Include PF_SGX in the PF error codes list and throw SIGSEGV when it is
encountered.
[*] Intel SDM: 36.5.1 Enclave Page Cache Map (EPCM)
[ bp: Add bit 15 to the comment above enum x86_pf_error_code too. ]
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-7-jarkko@kernel.org
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Although carved out of normal DRAM, enclave memory is marked in the
system memory map as reserved and is not managed by the core mm. There
may be several regions spread across the system. Each contiguous region
is called an Enclave Page Cache (EPC) section. EPC sections are
enumerated via CPUID
Enclave pages can only be accessed when they are mapped as part of an
enclave, by a hardware thread running inside the enclave.
Parse CPUID data, create metadata for EPC pages and populate a simple
EPC page allocator. Although much smaller, ‘struct sgx_epc_page’
metadata is the SGX analog of the core mm ‘struct page’.
Similar to how the core mm’s page->flags encode zone and NUMA
information, embed the EPC section index to the first eight bits of
sgx_epc_page->desc. This allows a quick reverse lookup from EPC page to
EPC section. Existing client hardware supports only a single section,
while upcoming server hardware will support at most eight sections.
Thus, eight bits should be enough for long term needs.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Serge Ayoun <serge.ayoun@intel.com>
Signed-off-by: Serge Ayoun <serge.ayoun@intel.com>
Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-6-jarkko@kernel.org
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The SGX Launch Control hardware helps restrict which enclaves the
hardware will run. Launch control is intended to restrict what software
can run with enclave protections, which helps protect the overall system
from bad enclaves.
For the kernel's purposes, there are effectively two modes in which the
launch control hardware can operate: rigid and flexible. In its rigid
mode, an entity other than the kernel has ultimate authority over which
enclaves can be run (firmware, Intel, etc...). In its flexible mode, the
kernel has ultimate authority over which enclaves can run.
Enable X86_FEATURE_SGX_LC to enumerate when the CPU supports SGX Launch
Control in general.
Add MSR_IA32_SGXLEPUBKEYHASH{0, 1, 2, 3}, which when combined contain a
SHA256 hash of a 3072-bit RSA public key. The hardware allows SGX enclaves
signed with this public key to initialize and run [*]. Enclaves not signed
with this key can not initialize and run.
Add FEAT_CTL_SGX_LC_ENABLED, which informs whether the SGXLEPUBKEYHASH MSRs
can be written by the kernel.
If the MSRs do not exist or are read-only, the launch control hardware is
operating in rigid mode. Linux does not and will not support creating
enclaves when hardware is configured in rigid mode because it takes away
the authority for launch decisions from the kernel. Note, this does not
preclude KVM from virtualizing/exposing SGX to a KVM guest when launch
control hardware is operating in rigid mode.
[*] Intel SDM: 38.1.4 Intel SGX Launch Control Configuration
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-5-jarkko@kernel.org
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Populate X86_FEATURE_SGX feature from CPUID and tie it to the Kconfig
option with disabled-features.h.
IA32_FEATURE_CONTROL.SGX_ENABLE must be examined in addition to the CPUID
bits to enable full SGX support. The BIOS must both set this bit and lock
IA32_FEATURE_CONTROL for SGX to be supported (Intel SDM section 36.7.1).
The setting or clearing of this bit has no impact on the CPUID bits above,
which is why it needs to be detected separately.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Co-developed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-4-jarkko@kernel.org
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ENCLS is the userspace instruction which wraps virtually all
unprivileged SGX functionality for managing enclaves. It is essentially
the ioctl() of instructions with each function implementing different
SGX-related functionality.
Add macros to wrap the ENCLS functionality. There are two main groups,
one for functions which do not return error codes and a “ret_” set for
those that do.
ENCLS functions are documented in Intel SDM section 36.6.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-3-jarkko@kernel.org
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Define the SGX architectural data structures used by various SGX
functions. This is not an exhaustive representation of all SGX data
structures but only those needed by the kernel.
The goal is to sequester hardware structures in "sgx/arch.h" and keep
them separate from kernel-internal or uapi structures.
The data structures are described in Intel SDM section 37.6.
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Jethro Beekman <jethro@fortanix.com>
Link: https://lkml.kernel.org/r/20201112220135.165028-2-jarkko@kernel.org
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Pull drm fixes from Dave Airlie:
"Nouveau fixes:
- atomic modesetting regression fix
- ttm pre-nv50 fix
- connector NULL ptr deref fix"
* tag 'drm-fixes-2020-11-16' of git://anongit.freedesktop.org/drm/drm:
drm/nouveau/kms/nv50-: Use atomic encoder callbacks everywhere
drm/nouveau/ttm: avoid using nouveau_drm.ttm.type_vram prior to nv50
drm/nouveau/kms: Fix NULL pointer dereference in nouveau_connector_detect_depth
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- atomic modesetting regression fix
- ttm pre-nv50 fix
- connector NULL ptr deref fix
Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Ben Skeggs <skeggsb@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/CACAvsv5D9p78MNN0OxVeRZxN8LDqcadJEGUEFCgWJQ6+_rjPuw@mail.gmail.com
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH:
"Here are some small char/misc/whatever driver fixes for 5.10-rc4.
Nothing huge, lots of small fixes for reported issues:
- habanalabs driver fixes
- speakup driver fixes
- uio driver fixes
- virtio driver fix
- other tiny driver fixes
Full details are in the shortlog.
All of these have been in linux-next for a full week with no reported
issues"
* tag 'char-misc-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
uio: Fix use-after-free in uio_unregister_device()
firmware: xilinx: fix out-of-bounds access
nitro_enclaves: Fixup type and simplify logic of the poll mask setup
speakup ttyio: Do not schedule() in ttyio_in_nowait
speakup: Fix clearing selection in safe context
speakup: Fix var_id_t values and thus keymap
virtio: virtio_console: fix DMA memory allocation for rproc serial
habanalabs/gaudi: mask WDT error in QMAN
habanalabs/gaudi: move coresight mmu config
habanalabs: fix kernel pointer type
mei: protect mei_cl_mtu from null dereference
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB and Thunderbolt fixes from Greg KH:
"Here are some small Thunderbolt and USB driver fixes for 5.10-rc4 to
solve some reported issues.
Nothing huge in here, just small things:
- thunderbolt memory leaks fixed and new device ids added
- revert of problem patch for the musb driver
- new quirks added for USB devices
- typec power supply fixes to resolve much reported problems about
charging notifications not working anymore
All except the cdc-acm driver quirk addition have been in linux-next
with no reported issues (the quirk patch was applied on Friday, and is
self-contained)"
* tag 'usb-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
usb: cdc-acm: Add DISABLE_ECHO for Renesas USB Download mode
MAINTAINERS: add usb raw gadget entry
usb: typec: ucsi: Report power supply changes
xhci: hisilicon: fix refercence leak in xhci_histb_probe
Revert "usb: musb: convert to devm_platform_ioremap_resource_byname"
thunderbolt: Add support for Intel Tiger Lake-H
thunderbolt: Only configure USB4 wake for lane 0 adapters
thunderbolt: Add uaccess dependency to debugfs interface
thunderbolt: Fix memory leak if ida_simple_get() fails in enumerate_services()
thunderbolt: Add the missed ida_simple_remove() in ring_request_msix()
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Pull kvm fixes from Paolo Bonzini:
"Fixes for ARM and x86, the latter especially for old processors
without two-dimensional paging (EPT/NPT)"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
kvm: mmu: fix is_tdp_mmu_check when the TDP MMU is not in use
KVM: SVM: Update cr3_lm_rsvd_bits for AMD SEV guests
KVM: x86: Introduce cr3_lm_rsvd_bits in kvm_vcpu_arch
KVM: x86: clflushopt should be treated as a no-op by emulation
KVM: arm64: Handle SCXTNUM_ELx traps
KVM: arm64: Unify trap handlers injecting an UNDEF
KVM: arm64: Allow setting of ID_AA64PFR0_EL1.CSV2 from userspace
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Thomas Gleixner:
"A small set of fixes for x86:
- Cure the fallout from the MSI irqdomain overhaul which missed that
the Intel IOMMU does not register virtual function devices and
therefore never reaches the point where the MSI interrupt domain is
assigned. This made the VF devices use the non-remapped MSI domain
which is trapped by the IOMMU/remap unit
- Remove an extra space in the SGI_UV architecture type procfs output
for UV5
- Remove a unused function which was missed when removing the UV BAU
TLB shootdown handler"
* tag 'x86-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
iommu/vt-d: Cure VF irqdomain hickup
x86/platform/uv: Fix copied UV5 output archtype
x86/platform/uv: Drop last traces of uv_flush_tlb_others
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Thomas Gleixner:
"A set of fixes for perf:
- A set of commits which reduce the stack usage of various perf
event handling functions which allocated large data structs on
stack causing stack overflows in the worst case
- Use the proper mechanism for detecting soft interrupts in the
recursion protection
- Make the resursion protection simpler and more robust
- Simplify the scheduling of event groups to make the code more
robust and prepare for fixing the issues vs. scheduling of
exclusive event groups
- Prevent event multiplexing and rotation for exclusive event groups
- Correct the perf event attribute exclusive semantics to take
pinned events, e.g. the PMU watchdog, into account
- Make the anythread filtering conditional for Intel's generic PMU
counters as it is not longer guaranteed to be supported on newer
CPUs. Check the corresponding CPUID leaf to make sure
- Fixup a duplicate initialization in an array which was probably
caused by the usual 'copy & paste - forgot to edit' mishap"
* tag 'perf-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/uncore: Fix Add BW copypasta
perf/x86/intel: Make anythread filter support conditional
perf: Tweak perf_event_attr::exclusive semantics
perf: Fix event multiplexing for exclusive groups
perf: Simplify group_sched_in()
perf: Simplify group_sched_out()
perf/x86: Make dummy_iregs static
perf/arch: Remove perf_sample_data::regs_user_copy
perf: Optimize get_recursion_context()
perf: Fix get_recursion_context()
perf/x86: Reduce stack usage for x86_pmu::drain_pebs()
perf: Reduce stack usage of perf_output_begin()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Thomas Gleixner:
"A set of scheduler fixes:
- Address a load balancer regression by making the load balancer use
the same logic as the wakeup path to spread tasks in the LLC domain
- Prefer the CPU on which a task run last over the local CPU in the
fast wakeup path for asymmetric CPU capacity systems to align with
the symmetric case. This ensures more locality and prevents massive
migration overhead on those asymetric systems
- Fix a memory corruption bug in the scheduler debug code caused by
handing a modified buffer pointer to kfree()"
* tag 'sched-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/debug: Fix memory corruption caused by multiple small reads of flags
sched/fair: Prefer prev cpu in asymmetric wakeup path
sched/fair: Ensure tasks spreading in LLC during LB
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Thomas Gleixner:
"Two fixes for the locking subsystem:
- Prevent an unconditional interrupt enable in a futex helper
function which can be called from contexts which expect interrupts
to stay disabled across the call
- Don't modify lockdep chain keys in the validation process as that
causes chain inconsistency"
* tag 'locking-urgent-2020-11-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
lockdep: Avoid to modify chain keys in validate_chain()
futex: Don't enable IRQs unconditionally in put_pi_state()
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git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu
Pull percpu fix and cleanup from Dennis Zhou:
"A fix for a Wshadow warning in the asm-generic percpu macros came in
and then I tacked on the removal of flexible array initializers in the
percpu allocator"
* 'for-5.10-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dennis/percpu:
percpu: convert flexible array initializers to use struct_size()
asm-generic: percpu: avoid Wshadow warning
|
|
In some cases where shadow paging is in use, the root page will
be either mmu->pae_root or vcpu->arch.mmu->lm_root. Then it will
not have an associated struct kvm_mmu_page, because it is allocated
with alloc_page instead of kvm_mmu_alloc_page.
Just return false quickly from is_tdp_mmu_root if the TDP MMU is
not in use, which also includes the case where shadow paging is
enabled.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
Merge fixes from Andrew Morton:
"14 patches.
Subsystems affected by this patch series: mm (migration, vmscan, slub,
gup, memcg, hugetlbfs), mailmap, kbuild, reboot, watchdog, panic, and
ocfs2"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
ocfs2: initialize ip_next_orphan
panic: don't dump stack twice on warn
hugetlbfs: fix anon huge page migration race
mm: memcontrol: fix missing wakeup polling thread
kernel/watchdog: fix watchdog_allowed_mask not used warning
reboot: fix overflow parsing reboot cpu number
Revert "kernel/reboot.c: convert simple_strtoul to kstrtoint"
compiler.h: fix barrier_data() on clang
mm/gup: use unpin_user_pages() in __gup_longterm_locked()
mm/slub: fix panic in slab_alloc_node()
mailmap: fix entry for Dmitry Baryshkov/Eremin-Solenikov
mm/vmscan: fix NR_ISOLATED_FILE corruption on 64-bit
mm/compaction: stop isolation if too many pages are isolated and we have pages to migrate
mm/compaction: count pages and stop correctly during page isolation
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk fixes from Stephen Boyd:
"Two small clk driver fixes:
- Make to_clk_regmap() inline to avoid compiler annoyance
- Fix critical clks on i.MX imx8m SoCs"
* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: imx8m: fix bus critical clk registration
clk: define to_clk_regmap() as inline function
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon fixes from Guenter Roeck:
- Fix potential bufer overflow in pmbus/max20730 driver
- Fix locking issue in pmbus core
- Fix regression causing timeouts in applesmc driver
- Fix RPM calculation in pwm-fan driver
- Restrict counter visibility in amd_energy driver
* tag 'hwmon-for-v5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (amd_energy) modify the visibility of the counters
hwmon: (applesmc) Re-work SMC comms
hwmon: (pwm-fan) Fix RPM calculation
hwmon: (pmbus) Add mutex locking for sysfs reads
hwmon: (pmbus/max20730) use scnprintf() instead of snprintf()
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"Three small fixes, all in the embedded ufs driver subsystem"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: ufshcd: Fix missing destroy_workqueue()
scsi: ufs: Try to save power mode change and UIC cmd completion timeout
scsi: ufs: Fix unbalanced scsi_block_reqs_cnt caused by ufshcd_hold()
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux fix from Paul Moore:
"One small SELinux patch to make sure we return an error code when an
allocation fails. It passes all of our tests, but given the nature of
the patch that isn't surprising"
* tag 'selinux-pr-20201113' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: Fix error return code in sel_ib_pkey_sid_slow()
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml
Pull uml fix from Richard Weinberger:
"Call PMD destructor in __pmd_free_tlb()"
* tag 'for-linus-5.10-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
um: Call pgtable_pmd_page_dtor() in __pmd_free_tlb()
|
|
When afs_write_end() is called with copied == 0, it tries to set the
dirty region, but there's no way to actually encode a 0-length region in
the encoding in page->private.
"0,0", for example, indicates a 1-byte region at offset 0. The maths
miscalculates this and sets it incorrectly.
Fix it to just do nothing but unlock and put the page in this case. We
don't actually need to mark the page dirty as nothing presumably
changed.
Fixes: 65dd2d6072d3 ("afs: Alter dirty range encoding in page->private")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Though problem if found on a lower 4.1.12 kernel, I think upstream has
same issue.
In one node in the cluster, there is the following callback trace:
# cat /proc/21473/stack
__ocfs2_cluster_lock.isra.36+0x336/0x9e0 [ocfs2]
ocfs2_inode_lock_full_nested+0x121/0x520 [ocfs2]
ocfs2_evict_inode+0x152/0x820 [ocfs2]
evict+0xae/0x1a0
iput+0x1c6/0x230
ocfs2_orphan_filldir+0x5d/0x100 [ocfs2]
ocfs2_dir_foreach_blk+0x490/0x4f0 [ocfs2]
ocfs2_dir_foreach+0x29/0x30 [ocfs2]
ocfs2_recover_orphans+0x1b6/0x9a0 [ocfs2]
ocfs2_complete_recovery+0x1de/0x5c0 [ocfs2]
process_one_work+0x169/0x4a0
worker_thread+0x5b/0x560
kthread+0xcb/0xf0
ret_from_fork+0x61/0x90
The above stack is not reasonable, the final iput shouldn't happen in
ocfs2_orphan_filldir() function. Looking at the code,
2067 /* Skip inodes which are already added to recover list, since dio may
2068 * happen concurrently with unlink/rename */
2069 if (OCFS2_I(iter)->ip_next_orphan) {
2070 iput(iter);
2071 return 0;
2072 }
2073
The logic thinks the inode is already in recover list on seeing
ip_next_orphan is non-NULL, so it skip this inode after dropping a
reference which incremented in ocfs2_iget().
While, if the inode is already in recover list, it should have another
reference and the iput() at line 2070 should not be the final iput
(dropping the last reference). So I don't think the inode is really in
the recover list (no vmcore to confirm).
Note that ocfs2_queue_orphans(), though not shown up in the call back
trace, is holding cluster lock on the orphan directory when looking up
for unlinked inodes. The on disk inode eviction could involve a lot of
IOs which may need long time to finish. That means this node could hold
the cluster lock for very long time, that can lead to the lock requests
(from other nodes) to the orhpan directory hang for long time.
Looking at more on ip_next_orphan, I found it's not initialized when
allocating a new ocfs2_inode_info structure.
This causes te reflink operations from some nodes hang for very long
time waiting for the cluster lock on the orphan directory.
Fix: initialize ip_next_orphan as NULL.
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201109171746.27884-1-wen.gang.wang@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Before commit 3f388f28639f ("panic: dump registers on panic_on_warn"),
__warn() was calling show_regs() when regs was not NULL, and show_stack()
otherwise.
After that commit, show_stack() is called regardless of whether
show_regs() has been called or not, leading to duplicated Call Trace:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1 at arch/powerpc/mm/nohash/8xx.c:186 mmu_mark_initmem_nx+0x24/0x94
CPU: 0 PID: 1 Comm: swapper Not tainted 5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty #4092
NIP: c00128b4 LR: c0010228 CTR: 00000000
REGS: c9023e40 TRAP: 0700 Not tainted (5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty)
MSR: 00029032 <EE,ME,IR,DR,RI> CR: 24000424 XER: 00000000
GPR00: c0010228 c9023ef8 c2100000 0074c000 ffffffff 00000000 c2151000 c07b3880
GPR08: ff000900 0074c000 c8000000 c33b53a8 24000822 00000000 c0003a20 00000000
GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
GPR24: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00800000
NIP [c00128b4] mmu_mark_initmem_nx+0x24/0x94
LR [c0010228] free_initmem+0x20/0x58
Call Trace:
free_initmem+0x20/0x58
kernel_init+0x1c/0x114
ret_from_kernel_thread+0x14/0x1c
Instruction dump:
7d291850 7d234b78 4e800020 9421ffe0 7c0802a6 bfc10018 3fe0c060 3bff0000
3fff4080 3bffffff 90010024 57ff0010 <0fe00000> 392001cd 7c3e0b78 953e0008
CPU: 0 PID: 1 Comm: swapper Not tainted 5.10.0-rc2-s3k-dev-01375-gf46ec0d3ecbd-dirty #4092
Call Trace:
__warn+0x8c/0xd8 (unreliable)
report_bug+0x11c/0x154
program_check_exception+0x1dc/0x6e0
ret_from_except_full+0x0/0x4
--- interrupt: 700 at mmu_mark_initmem_nx+0x24/0x94
LR = free_initmem+0x20/0x58
free_initmem+0x20/0x58
kernel_init+0x1c/0x114
ret_from_kernel_thread+0x14/0x1c
---[ end trace 31702cd2a9570752 ]---
Only call show_stack() when regs is NULL.
Fixes: 3f388f28639f ("panic: dump registers on panic_on_warn")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Link: https://lkml.kernel.org/r/e8c055458b080707f1bc1a98ff8bea79d0cec445.1604748361.git.christophe.leroy@csgroup.eu
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Qian Cai reported the following BUG in [1]
LTP: starting move_pages12
BUG: unable to handle page fault for address: ffffffffffffffe0
...
RIP: 0010:anon_vma_interval_tree_iter_first+0xa2/0x170 avc_start_pgoff at mm/interval_tree.c:63
Call Trace:
rmap_walk_anon+0x141/0xa30 rmap_walk_anon at mm/rmap.c:1864
try_to_unmap+0x209/0x2d0 try_to_unmap at mm/rmap.c:1763
migrate_pages+0x1005/0x1fb0
move_pages_and_store_status.isra.47+0xd7/0x1a0
__x64_sys_move_pages+0xa5c/0x1100
do_syscall_64+0x5f/0x310
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Hugh Dickins diagnosed this as a migration bug caused by code introduced
to use i_mmap_rwsem for pmd sharing synchronization. Specifically, the
routine unmap_and_move_huge_page() is always passing the TTU_RMAP_LOCKED
flag to try_to_unmap() while holding i_mmap_rwsem. This is wrong for
anon pages as the anon_vma_lock should be held in this case. Further
analysis suggested that i_mmap_rwsem was not required to he held at all
when calling try_to_unmap for anon pages as an anon page could never be
part of a shared pmd mapping.
Discussion also revealed that the hack in hugetlb_page_mapping_lock_write
to drop page lock and acquire i_mmap_rwsem is wrong. There is no way to
keep mapping valid while dropping page lock.
This patch does the following:
- Do not take i_mmap_rwsem and set TTU_RMAP_LOCKED for anon pages when
calling try_to_unmap.
- Remove the hacky code in hugetlb_page_mapping_lock_write. The routine
will now simply do a 'trylock' while still holding the page lock. If
the trylock fails, it will return NULL. This could impact the
callers:
- migration calling code will receive -EAGAIN and retry up to the
hard coded limit (10).
- memory error code will treat the page as BUSY. This will force
killing (SIGKILL) instead of SIGBUS any mapping tasks.
Do note that this change in behavior only happens when there is a
race. None of the standard kernel testing suites actually hit this
race, but it is possible.
[1] https://lore.kernel.org/lkml/20200708012044.GC992@lca.pw/
[2] https://lore.kernel.org/linux-mm/alpine.LSU.2.11.2010071833100.2214@eggly.anvils/
Fixes: c0d0381ade79 ("hugetlbfs: use i_mmap_rwsem for more pmd sharing synchronization")
Reported-by: Qian Cai <cai@lca.pw>
Suggested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201105195058.78401-1-mike.kravetz@oracle.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
When we poll the swap.events, we can miss being woken up when the swap
event occurs. Because we didn't notify.
Fixes: f3a53a3a1e5b ("mm, memcontrol: implement memory.swap.events")
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Yafang Shao <laoar.shao@gmail.com>
Cc: Chris Down <chris@chrisdown.name>
Cc: Tejun Heo <tj@kernel.org>
Link: https://lkml.kernel.org/r/20201105161936.98312-1-songmuchun@bytedance.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Define watchdog_allowed_mask only when SOFTLOCKUP_DETECTOR is enabled.
Fixes: 7feeb9cd4f5b ("watchdog/sysctl: Clean up sysctl variable name space")
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20201106015025.1281561-1-santosh@fossix.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Limit the CPU number to num_possible_cpus(), because setting it to a
value lower than INT_MAX but higher than NR_CPUS produces the following
error on reboot and shutdown:
BUG: unable to handle page fault for address: ffffffff90ab1bb0
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 1c09067 P4D 1c09067 PUD 1c0a063 PMD 0
Oops: 0000 [#1] SMP
CPU: 1 PID: 1 Comm: systemd-shutdow Not tainted 5.9.0-rc8-kvm #110
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
RIP: 0010:migrate_to_reboot_cpu+0xe/0x60
Code: ea ea 00 48 89 fa 48 c7 c7 30 57 f1 81 e9 fa ef ff ff 66 2e 0f 1f 84 00 00 00 00 00 53 8b 1d d5 ea ea 00 e8 14 33 fe ff 89 da <48> 0f a3 15 ea fc bd 00 48 89 d0 73 29 89 c2 c1 e8 06 65 48 8b 3c
RSP: 0018:ffffc90000013e08 EFLAGS: 00010246
RAX: ffff88801f0a0000 RBX: 0000000077359400 RCX: 0000000000000000
RDX: 0000000077359400 RSI: 0000000000000002 RDI: ffffffff81c199e0
RBP: ffffffff81c1e3c0 R08: ffff88801f41f000 R09: ffffffff81c1e348
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 00007f32bedf8830 R14: 00000000fee1dead R15: 0000000000000000
FS: 00007f32bedf8980(0000) GS:ffff88801f480000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffff90ab1bb0 CR3: 000000001d057000 CR4: 00000000000006a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__do_sys_reboot.cold+0x34/0x5b
do_syscall_64+0x2d/0x40
Fixes: 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic kernel")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201103214025.116799-3-mcroce@linux.microsoft.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Patch series "fix parsing of reboot= cmdline", v3.
The parsing of the reboot= cmdline has two major errors:
- a missing bound check can crash the system on reboot
- parsing of the cpu number only works if specified last
Fix both.
This patch (of 2):
This reverts commit 616feab753972b97.
kstrtoint() and simple_strtoul() have a subtle difference which makes
them non interchangeable: if a non digit character is found amid the
parsing, the former will return an error, while the latter will just
stop parsing, e.g. simple_strtoul("123xyx") = 123.
The kernel cmdline reboot= argument allows to specify the CPU used for
rebooting, with the syntax `s####` among the other flags, e.g.
"reboot=warm,s31,force", so if this flag is not the last given, it's
silently ignored as well as the subsequent ones.
Fixes: 616feab75397 ("kernel/reboot.c: convert simple_strtoul to kstrtoint")
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Pavel Tatashin <pasha.tatashin@soleen.com>
Cc: Robin Holt <robinmholt@gmail.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201103214025.116799-2-mcroce@linux.microsoft.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Commit 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h
mutually exclusive") neglected to copy barrier_data() from
compiler-gcc.h into compiler-clang.h.
The definition in compiler-gcc.h was really to work around clang's more
aggressive optimization, so this broke barrier_data() on clang, and
consequently memzero_explicit() as well.
For example, this results in at least the memzero_explicit() call in
lib/crypto/sha256.c:sha256_transform() being optimized away by clang.
Fix this by moving the definition of barrier_data() into compiler.h.
Also move the gcc/clang definition of barrier() into compiler.h,
__memory_barrier() is icc-specific (and barrier() is already defined
using it in compiler-intel.h) and doesn't belong in compiler.h.
[rdunlap@infradead.org: fix ALPHA builds when SMP is not enabled]
Link: https://lkml.kernel.org/r/20201101231835.4589-1-rdunlap@infradead.org
Fixes: 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive")
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201014212631.207844-1-nivedita@alum.mit.edu
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
When FOLL_PIN is passed to __get_user_pages() the page list must be put
back using unpin_user_pages() otherwise the page pin reference persists
in a corrupted state.
There are two places in the unwind of __gup_longterm_locked() that put
the pages back without checking. Normally on error this function would
return the partial page list making this the caller's responsibility,
but in these two cases the caller is not allowed to see these pages at
all.
Fixes: 3faa52c03f44 ("mm/gup: track FOLL_PIN pages")
Reported-by: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/0-v2-3ae7d9d162e2+2a7-gup_cma_fix_jgg@nvidia.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
While doing memory hot-unplug operation on a PowerPC VM running 1024 CPUs
with 11TB of ram, I hit the following panic:
BUG: Kernel NULL pointer dereference on read at 0x00000007
Faulting instruction address: 0xc000000000456048
Oops: Kernel access of bad area, sig: 11 [#2]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS= 2048 NUMA pSeries
Modules linked in: rpadlpar_io rpaphp
CPU: 160 PID: 1 Comm: systemd Tainted: G D 5.9.0 #1
NIP: c000000000456048 LR: c000000000455fd4 CTR: c00000000047b350
REGS: c00006028d1b77a0 TRAP: 0300 Tainted: G D (5.9.0)
MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 24004228 XER: 00000000
CFAR: c00000000000f1b0 DAR: 0000000000000007 DSISR: 40000000 IRQMASK: 0
GPR00: c000000000455fd4 c00006028d1b7a30 c000000001bec800 0000000000000000
GPR04: 0000000000000dc0 0000000000000000 00000000000374ef c00007c53df99320
GPR08: 000007c53c980000 0000000000000000 000007c53c980000 0000000000000000
GPR12: 0000000000004400 c00000001e8e4400 0000000000000000 0000000000000f6a
GPR16: 0000000000000000 c000000001c25930 c000000001d62528 00000000000000c1
GPR20: c000000001d62538 c00006be469e9000 0000000fffffffe0 c0000000003c0ff8
GPR24: 0000000000000018 0000000000000000 0000000000000dc0 0000000000000000
GPR28: c00007c513755700 c000000001c236a4 c00007bc4001f800 0000000000000001
NIP [c000000000456048] __kmalloc_node+0x108/0x790
LR [c000000000455fd4] __kmalloc_node+0x94/0x790
Call Trace:
kvmalloc_node+0x58/0x110
mem_cgroup_css_online+0x10c/0x270
online_css+0x48/0xd0
cgroup_apply_control_enable+0x2c4/0x470
cgroup_mkdir+0x408/0x5f0
kernfs_iop_mkdir+0x90/0x100
vfs_mkdir+0x138/0x250
do_mkdirat+0x154/0x1c0
system_call_exception+0xf8/0x200
system_call_common+0xf0/0x27c
Instruction dump:
e93e0000 e90d0030 39290008 7cc9402a e94d0030 e93e0000 7ce95214 7f89502a
2fbc0000 419e0018 41920230 e9270010 <89290007> 7f994800 419e0220 7ee6bb78
This pointing to the following code:
mm/slub.c:2851
if (unlikely(!object || !node_match(page, node))) {
c000000000456038: 00 00 bc 2f cmpdi cr7,r28,0
c00000000045603c: 18 00 9e 41 beq cr7,c000000000456054 <__kmalloc_node+0x114>
node_match():
mm/slub.c:2491
if (node != NUMA_NO_NODE && page_to_nid(page) != node)
c000000000456040: 30 02 92 41 beq cr4,c000000000456270 <__kmalloc_node+0x330>
page_to_nid():
include/linux/mm.h:1294
c000000000456044: 10 00 27 e9 ld r9,16(r7)
c000000000456048: 07 00 29 89 lbz r9,7(r9) <<<< r9 = NULL
node_match():
mm/slub.c:2491
c00000000045604c: 00 48 99 7f cmpw cr7,r25,r9
c000000000456050: 20 02 9e 41 beq cr7,c000000000456270 <__kmalloc_node+0x330>
The panic occurred in slab_alloc_node() when checking for the page's node:
object = c->freelist;
page = c->page;
if (unlikely(!object || !node_match(page, node))) {
object = __slab_alloc(s, gfpflags, node, addr, c);
stat(s, ALLOC_SLOWPATH);
The issue is that object is not NULL while page is NULL which is odd but
may happen if the cache flush happened after loading object but before
loading page. Thus checking for the page pointer is required too.
The cache flush is done through an inter processor interrupt when a
piece of memory is off-lined. That interrupt is triggered when a memory
hot-unplug operation is initiated and offline_pages() is calling the
slub's MEM_GOING_OFFLINE callback slab_mem_going_offline_callback()
which is calling flush_cpu_slab(). If that interrupt is caught between
the reading of c->freelist and the reading of c->page, this could lead
to such a situation. That situation is expected and the later call to
this_cpu_cmpxchg_double() will detect the change to c->freelist and redo
the whole operation.
In commit 6159d0f5c03e ("mm/slub.c: page is always non-NULL in
node_match()") check on the page pointer has been removed assuming that
page is always valid when it is called. It happens that this is not
true in that particular case, so check for page before calling
node_match() here.
Fixes: 6159d0f5c03e ("mm/slub.c: page is always non-NULL in node_match()")
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Cc: Scott Cheloha <cheloha@linux.ibm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201027190406.33283-1-ldufour@linux.ibm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Change back surname to new (old) one. Dmitry Baryshkov -> Dmitry
Eremin-Solenikov -> Dmitry Baryshkov. Map several odd entries to main
identity.
Signed-off-by: Dmitry Baryshkov <dbaryshkov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20201103005158.1181426-1-dmitry.baryshkov@linaro.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Previously the negated unsigned long would be cast back to signed long
which would have the correct negative value. After commit 730ec8c01a2b
("mm/vmscan.c: change prototype for shrink_page_list"), the large
unsigned int converts to a large positive signed long.
Symptoms include CMA allocations hanging forever holding the cma_mutex
due to alloc_contig_range->...->isolate_migratepages_block waiting
forever in "while (unlikely(too_many_isolated(pgdat)))".
[akpm@linux-foundation.org: fix -stat.nr_lazyfree_fail as well, per Michal]
Fixes: 730ec8c01a2b ("mm/vmscan.c: change prototype for shrink_page_list")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Vaneet Narang <v.narang@samsung.com>
Cc: Maninder Singh <maninder1.s@samsung.com>
Cc: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201029032320.1448441-1-npiggin@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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pages to migrate
In isolate_migratepages_block, if we have too many isolated pages and
nr_migratepages is not zero, we should try to migrate what we have
without wasting time on isolating.
In theory it's possible that multiple parallel compactions will cause
too_many_isolated() to become true even if each has isolated less than
COMPACT_CLUSTER_MAX, and loop forever in the while loop. Bailing
immediately prevents that.
[vbabka@suse.cz: changelog addition]
Fixes: 1da2f328fa64 (“mm,thp,compaction,cma: allow THP migration for CMA allocations”)
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Yang Shi <shy828301@gmail.com>
Link: https://lkml.kernel.org/r/20201030183809.3616803-2-zi.yan@sent.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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In isolate_migratepages_block, when cc->alloc_contig is true, we are
able to isolate compound pages. But nr_migratepages and nr_isolated did
not count compound pages correctly, causing us to isolate more pages
than we thought.
So count compound pages as the number of base pages they contain.
Otherwise, we might be trapped in too_many_isolated while loop, since
the actual isolated pages can go up to COMPACT_CLUSTER_MAX*512=16384,
where COMPACT_CLUSTER_MAX is 32, since we stop isolation after
cc->nr_migratepages reaches to COMPACT_CLUSTER_MAX.
In addition, after we fix the issue above, cc->nr_migratepages could
never be equal to COMPACT_CLUSTER_MAX if compound pages are isolated,
thus page isolation could not stop as we intended. Change the isolation
stop condition to '>='.
The issue can be triggered as follows:
In a system with 16GB memory and an 8GB CMA region reserved by
hugetlb_cma, if we first allocate 10GB THPs and mlock them (so some THPs
are allocated in the CMA region and mlocked), reserving 6 1GB hugetlb
pages via /sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages will
get stuck (looping in too_many_isolated function) until we kill either
task. With the patch applied, oom will kill the application with 10GB
THPs and let hugetlb page reservation finish.
[ziy@nvidia.com: v3]
Link: https://lkml.kernel.org/r/20201030183809.3616803-1-zi.yan@sent.com
Fixes: 1da2f328fa64 ("cmm,thp,compaction,cma: allow THP migration for CMA allocations")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Rik van Riel <riel@surriel.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201029200435.3386066-1-zi.yan@sent.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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It turns out that I forgot to go through and make sure that I converted all
encoder callbacks to use atomic_enable/atomic_disable(), so let's go and
actually do that.
Signed-off-by: Lyude Paul <lyude@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Fixes: 09838c4efe9a ("drm/nouveau/kms: Search for encoders' connectors properly")
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
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Pre-NV50 chipsets don't currently use the MMU subsystem that later
chipsets use, and type_vram is negative here, leading to an OOB memory
access.
This was previously guarded by a chipset check, restore that.
Reported-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: 5839172f0980 ("drm/nouveau: explicitly specify caching to use")
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
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