When mremap is called with MREMAP_FIXED it unmaps memory at the
destination address without notifying userfaultfd monitor.
If the destination were registered with userfaultfd, the monitor has no
way to distinguish between the old and new ranges and to properly relate
the page faults that would occur in the destination region.
Fixes: 897ab3e0c4 ("userfaultfd: non-cooperative: add event for memory unmaps")
Link: http://lkml.kernel.org/r/1500276876-3350-1-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Acked-by: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Nadav Amit identified a theoritical race between page reclaim and
mprotect due to TLB flushes being batched outside of the PTL being held.
He described the race as follows:
CPU0 CPU1
---- ----
user accesses memory using RW PTE
[PTE now cached in TLB]
try_to_unmap_one()
==> ptep_get_and_clear()
==> set_tlb_ubc_flush_pending()
mprotect(addr, PROT_READ)
==> change_pte_range()
==> [ PTE non-present - no flush ]
user writes using cached RW PTE
...
try_to_unmap_flush()
The same type of race exists for reads when protecting for PROT_NONE and
also exists for operations that can leave an old TLB entry behind such
as munmap, mremap and madvise.
For some operations like mprotect, it's not necessarily a data integrity
issue but it is a correctness issue as there is a window where an
mprotect that limits access still allows access. For munmap, it's
potentially a data integrity issue although the race is massive as an
munmap, mmap and return to userspace must all complete between the
window when reclaim drops the PTL and flushes the TLB. However, it's
theoritically possible so handle this issue by flushing the mm if
reclaim is potentially currently batching TLB flushes.
Other instances where a flush is required for a present pte should be ok
as either the page lock is held preventing parallel reclaim or a page
reference count is elevated preventing a parallel free leading to
corruption. In the case of page_mkclean there isn't an obvious path
that userspace could take advantage of without using the operations that
are guarded by this patch. Other users such as gup as a race with
reclaim looks just at PTEs. huge page variants should be ok as they
don't race with reclaim. mincore only looks at PTEs. userfault also
should be ok as if a parallel reclaim takes place, it will either fault
the page back in or read some of the data before the flush occurs
triggering a fault.
Note that a variant of this patch was acked by Andy Lutomirski but this
was for the x86 parts on top of his PCID work which didn't make the 4.13
merge window as expected. His ack is dropped from this version and
there will be a follow-on patch on top of PCID that will include his
ack.
[akpm@linux-foundation.org: tweak comments]
[akpm@linux-foundation.org: fix spello]
Link: http://lkml.kernel.org/r/20170717155523.emckq2esjro6hf3z@suse.de
Reported-by: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: <stable@vger.kernel.org> [v4.4+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit 3d375d7859 ("mm: update callers to use HASH_ZERO flag"),
drop unused pidhash_size in pidhash_init().
Link: http://lkml.kernel.org/r/1500389267-49222-1-git-send-email-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Pavel Tatashin <Pasha.Tatashin@Oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 9a291a7c94 ("mm/hugetlb: report -EHWPOISON not -EFAULT when
FOLL_HWPOISON is specified") causes __get_user_pages to ignore certain
errors from follow_hugetlb_page. After such error, __get_user_pages
subsequently calls faultin_page on the same VMA and start address that
follow_hugetlb_page failed on instead of returning the error immediately
as it should.
In follow_hugetlb_page, when hugetlb_fault returns a value covered under
VM_FAULT_ERROR, follow_hugetlb_page returns it without setting nr_pages
to 0 as __get_user_pages expects in this case, which causes the
following to happen in __get_user_pages: the "while (nr_pages)" check
succeeds, we skip the "if (!vma..." check because we got a VMA the last
time around, we find no page with follow_page_mask, and we call
faultin_page, which calls hugetlb_fault for the second time.
This issue also slightly changes how __get_user_pages works. Before, it
only returned error if it had made no progress (i = 0). But now,
follow_hugetlb_page can clobber "i" with an error code since its new
return path doesn't check for progress. So if "i" is nonzero before a
failing call to follow_hugetlb_page, that indication of progress is lost
and __get_user_pages can return error even if some pages were
successfully pinned.
To fix this, change follow_hugetlb_page so that it updates nr_pages,
allowing __get_user_pages to fail immediately and restoring the "error
only if no progress" behavior to __get_user_pages.
Tested that __get_user_pages returns when expected on error from
hugetlb_fault in follow_hugetlb_page.
Fixes: 9a291a7c94 ("mm/hugetlb: report -EHWPOISON not -EFAULT when FOLL_HWPOISON is specified")
Link: http://lkml.kernel.org/r/1500406795-58462-1-git-send-email-daniel.m.jordan@oracle.com
Signed-off-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Acked-by: Punit Agrawal <punit.agrawal@arm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: James Morse <james.morse@arm.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: zhong jiang <zhongjiang@huawei.com>
Cc: <stable@vger.kernel.org> [4.12.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Each css_set directly points to the default cgroup it belongs to, so
there's no reason to walk the cgrp_links list on the default
hierarchy.
Signed-off-by: Tejun Heo <tj@kernel.org>
The Raspberry Pi Zero W has the same components like the Zero plus
a Cypress CYW43438 wireless chip (wifi + bl).
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Eric Anholt <eric@anholt.net>
This adds the root properties for the Raspberry Pi Zero W.
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Eric Anholt <eric@anholt.net>
Until RPI 3 and Zero W the pl011 (uart0) was always on pin 14/15. So in
order to take care of them and other boards in the future,
we need to define UART pinmuxing on board level.
This work based on Eric Anholt's patch "ARM: bcm2385: Don't force pl011
onto pins 14/15." and Fabian Vogt's patch "ARM64: dts: bcm2837: assign
uart0 to BT and uart1 to pin headers".
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Eric Anholt <eric@anholt.net>
An SHPC may generate MSIs to notify software about slot or controller
events (SHPC spec r1.0, sec 4.7). A PCI device can only generate an MSI if
it has bus mastering enabled.
Enable bus mastering if the bridge contains an SHPC that uses MSI for event
notifications.
Signed-off-by: Aleksandr Bezzubikov <zuban32s@gmail.com>
[bhelgaas: changelog]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: stable@vger.kernel.org
The ATU CTRL2 register is 32 bits, and bits other than the enable bit may
be set. To check whether the ATU is enabled or not, we should test the
enable bit specifically.
Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Joao Pinto <jpinto@synopsys.com>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
Helper functions dw_pcie_prog_*_atu_unroll() don't need to be in global
scope, so make them static.
Cleans up sparse warnings:
- symbol 'dw_pcie_prog_outbound_atu_unroll' was not declared. Should it be static?
- symbol 'dw_pcie_prog_inbound_atu_unroll' was not declared. Should it be static?
Signed-off-by: Carlos Palminha <palminha@synopsys.com>
[bhelgaas: rewrap to fit in 80 columns]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Joao Pinto <jpinto@synopsys.com>
Acked-by: Jingoo Han <jingoohan1@gmail.com>
The gpiod API checks for NULL descriptors, so there is no need to duplicate
the check in the driver.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com
Convert the test to use TAP13 ksft framework for test output. Converting
error paths using err() and errx() will be done in another patch to make
it easier for review and change management.
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
do_tests() runs sgidnonroot test without fork_wait(). As a result the
last test "Non-root +ia, sgidroot => i test" is left out. Fix it.
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Add the usr/include subdirectory of the top-level tree to the include
path to fix build when cross compiling for ARM.
testptp.c: In function 'main':
testptp.c:289:15: error: 'struct ptp_clock_caps' has no member named 'cross_timestamping'
caps.cross_timestamping);
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Currently we expect that clock driver produces the exact same value
as we are requiring. There can, and will, be some deviation
however so we need to take that into account instead of just
rejecting the mode.
According to the HDMI spec we have a max of +-0.5% for the pixel clock
frequency deviation. Lets take that into an advantage and use it to
calculate how much deviation we can support.
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Acked-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Carlos Palminha <palminha@synopsys.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
At module unload we are expecting a struct drm_device but at
probing we are not setting it right. Fix this and correct the
arcpgu module unload.
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Fixes: 0c4250e7b1 ("drm: Add support of ARC PGU display controller")
Cc: Carlos Palminha <palminha@synopsys.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Now that ARC properly supports DMA mmap() we can use the standard
CMA helper to map dumb buffers. This makes ARC PGU works with
standard DRM consumer applications like, for example, mpv/mplayer
via DRM. While at it, use the DEFINE_DRM_GEM_CMA_FOPS() helper.
This fixes the use of dumb buffers.
Signed-off-by: Jose Abreu <joabreu@synopsys.com>
Fixes: 0c4250e7b1 ("drm: Add support of ARC PGU display controller")
Cc: Carlos Palminha <palminha@synopsys.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Dave Airlie <airlied@gmail.com>
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
This very minor change is still useful because it aligns
ARC PGU driver name with other DRM drivers and makes usage of
that driver name a bit easier.
For example in libdrm's test app we'll use "arcpgu" instead of
a bit more ugly "drm-arcpgu".
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
This change adopts debugfs usage for outputting useful data.
As of today we print:
* Mode and real HW clock values
* Standard FB info
Code is heavily borrowed from ARM's HDLCD thus adding Liviu in Cc.
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Reviewed-by: Liviu Dudau <Liviu.Dudau@arm.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@linux.ie>
Cc: Jose Abreu <joabreu@synopsys.com>
The host physical addresses of L1's Virtual APIC Page and Posted
Interrupt descriptor are loaded into the VMCS02. The CPU may write
to these pages via their host physical address while L2 is running,
bypassing address-translation-based dirty tracking (e.g. EPT write
protection). Mark them dirty on every exit from L2 to prevent them
from getting out of sync with dirty tracking.
Also mark the virtual APIC page and the posted interrupt descriptor
dirty when KVM is virtualizing posted interrupt processing.
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
According to the Intel SDM, software cannot rely on the current VMCS to be
coherent after a VMXOFF or shutdown. So this is a valid way to handle VMCS12
flushes.
24.11.1 Software Use of Virtual-Machine Control Structures
...
If a logical processor leaves VMX operation, any VMCSs active on
that logical processor may be corrupted (see below). To prevent
such corruption of a VMCS that may be used either after a return
to VMX operation or on another logical processor, software should
execute VMCLEAR for that VMCS before executing the VMXOFF instruction
or removing power from the processor (e.g., as part of a transition
to the S3 and S4 power states).
...
This fixes a "suspicious rcu_dereference_check() usage!" warning during
kvm_vm_release() because nested_release_vmcs12() calls
kvm_vcpu_write_guest_page() without holding kvm->srcu.
Signed-off-by: David Matlack <dmatlack@google.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Since the current implementation of VMCS12 does a memcpy in and out
of guest memory, we do not need current_vmcs12 and current_vmcs12_page
anymore. current_vmptr is enough to read and write the VMCS12.
And David Matlack noted:
This patch also fixes dirty tracking (memslot->dirty_bitmap) of the
VMCS12 page by using kvm_write_guest. nested_release_page() only marks
the struct page dirty.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
[Added David Matlack's note and nested_release_page_clean() fix.]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
During teardown, accesses to memslots and buses are using
rcu_dereference_protected with an always-true condition because
these accesses are done outside the usual mutexes. This
is because the last reference is gone and there cannot be any
concurrent modifications, but rcu_dereference_protected is
ugly and unobvious.
Instead, check the refcount in kvm_get_bus and __kvm_memslots.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
'lapic_irq' is a local variable and its 'level' field isn't
initialized, so 'level' is random, it doesn't matter but
makes UBSAN unhappy:
UBSAN: Undefined behaviour in .../lapic.c:...
load of value 10 is not a valid value for type '_Bool'
...
Call Trace:
[<ffffffff81f030b6>] dump_stack+0x1e/0x20
[<ffffffff81f03173>] ubsan_epilogue+0x12/0x55
[<ffffffff81f03b96>] __ubsan_handle_load_invalid_value+0x118/0x162
[<ffffffffa1575173>] kvm_apic_set_irq+0xc3/0xf0 [kvm]
[<ffffffffa1575b20>] kvm_irq_delivery_to_apic_fast+0x450/0x910 [kvm]
[<ffffffffa15858ea>] kvm_irq_delivery_to_apic+0xfa/0x7a0 [kvm]
[<ffffffffa1517f4e>] kvm_emulate_hypercall+0x62e/0x760 [kvm]
[<ffffffffa113141a>] handle_vmcall+0x1a/0x30 [kvm_intel]
[<ffffffffa114e592>] vmx_handle_exit+0x7a2/0x1fa0 [kvm_intel]
...
Signed-off-by: Longpeng(Mike) <longpeng2@huawei.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
When SMP VM start, AP may lost INIT because of receiving INIT between
kvm_vcpu_ioctl_x86_get/set_vcpu_events.
vcpu 0 vcpu 1
kvm_vcpu_ioctl_x86_get_vcpu_events
events->smi.latched_init = 0
send INIT to vcpu1
set vcpu1's pending_events
kvm_vcpu_ioctl_x86_set_vcpu_events
if (events->smi.latched_init == 0)
clear INIT in pending_events
This patch fixes it by just update SMM related flags if we are in SMM.
Thanks Peng Hao for the report and original commit message.
Reported-by: Peng Hao <peng.hao2@zte.com.cn>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
As systemd ramps up enabling NNP (NoNewPrivileges) for system services,
it is increasingly breaking SELinux domain transitions for those services
and their descendants. systemd enables NNP not only for services whose
unit files explicitly specify NoNewPrivileges=yes but also for services
whose unit files specify any of the following options in combination with
running without CAP_SYS_ADMIN (e.g. specifying User= or a
CapabilityBoundingSet= without CAP_SYS_ADMIN): SystemCallFilter=,
SystemCallArchitectures=, RestrictAddressFamilies=, RestrictNamespaces=,
PrivateDevices=, ProtectKernelTunables=, ProtectKernelModules=,
MemoryDenyWriteExecute=, or RestrictRealtime= as per the systemd.exec(5)
man page.
The end result is bad for the security of both SELinux-disabled and
SELinux-enabled systems. Packagers have to turn off these
options in the unit files to preserve SELinux domain transitions. For
users who choose to disable SELinux, this means that they miss out on
at least having the systemd-supported protections. For users who keep
SELinux enabled, they may still be missing out on some protections
because it isn't necessarily guaranteed that the SELinux policy for
that service provides the same protections in all cases.
commit 7b0d0b40cd ("selinux: Permit bounded transitions under
NO_NEW_PRIVS or NOSUID.") allowed bounded transitions under NNP in
order to support limited usage for sandboxing programs. However,
defining typebounds for all of the affected service domains
is impractical to implement in policy, since typebounds requires us
to ensure that each domain is allowed everything all of its descendant
domains are allowed, and this has to be repeated for the entire chain
of domain transitions. There is no way to clone all allow rules from
descendants to their ancestors in policy currently, and doing so would
be undesirable even if it were practical, as it requires leaking
permissions to objects and operations into ancestor domains that could
weaken their own security in order to allow them to the descendants
(e.g. if a descendant requires execmem permission, then so do all of
its ancestors; if a descendant requires execute permission to a file,
then so do all of its ancestors; if a descendant requires read to a
symbolic link or temporary file, then so do all of its ancestors...).
SELinux domains are intentionally not hierarchical / bounded in this
manner normally, and making them so would undermine their protections
and least privilege.
We have long had a similar tension with SELinux transitions and nosuid
mounts, albeit not as severe. Users often have had to choose between
retaining nosuid on a mount and allowing SELinux domain transitions on
files within those mounts. This likewise leads to unfortunate tradeoffs
in security.
Decouple NNP/nosuid from SELinux transitions, so that we don't have to
make a choice between them. Introduce a nnp_nosuid_transition policy
capability that enables transitions under NNP/nosuid to be based on
a permission (nnp_transition for NNP; nosuid_transition for nosuid)
between the old and new contexts in addition to the current support
for bounded transitions. Domain transitions can then be allowed in
policy without requiring the parent to be a strict superset of all of
its children.
With this change, systemd unit files can be left unmodified from upstream.
SELinux-disabled and SELinux-enabled users will benefit from retaining any
of the systemd-provided protections. SELinux policy will only need to
be adapted to enable the new policy capability and to allow the
new permissions between domain pairs as appropriate.
NB: Allowing nnp_transition between two contexts opens up the potential
for the old context to subvert the new context by installing seccomp
filters before the execve. Allowing nosuid_transition between two contexts
opens up the potential for a context transition to occur on a file from
an untrusted filesystem (e.g. removable media or remote filesystem). Use
with care.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Multiple architectures define this as a trivial function, and I'm adding
another one as part of the RISC-V port. Add a __weak version of
pcibios_align_resource() and delete the now-obselete ones in a handful of
ports.
The only functional change should be that a handful of ports used to export
pcibios_fixup_bus(). Only some architectures export this, so I just
dropped it.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Multiple architectures define this as an empty function, and I'm adding
another one as part of the RISC-V port. Add a __weak version of
pcibios_fixup_bus() and delete the now-obselete ones in a handful of
ports.
The only functional change should be that microblaze used to export
pcibios_fixup_bus(). None of the other architectures exports this, so I
just dropped it.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This driver register as a subsystem restart notifier and will send out
notifications to remote processors that has opened the "glink_ssr" GLINK
channel.
This mechanism is used to signal any GLINK participants that a 3rd party
is gone and that the communication state has to be reset; i.e. that read
and write pointers of the GLINK FIFOs are stale.
Acked-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
This adds the remoteproc part of subsystem restart, which is responsible
for emitting notifications to other processors in the system about a
dying remoteproc instance.
These notifications are propagated to the various communication systems
in the various remote processors to shut down communication links that
was left in a dangling state as the remoteproc was stopped (or crashed).
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
As we already have a pointer to the parent cgroup in
cgroup_destroy_locked(), we don't need to calculate it again
to pass as an argument for cgroup1_check_for_release().
Signed-off-by: Roman Gushchin <guro@fb.com>
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: kernel-team@fb.com
Cc: linux-kernel@vger.kernel.org
A cgroup can consume resources even after being deleted by a user.
For example, writing back dirty pages should be accounted and
limited, despite the corresponding cgroup might contain no processes
and being deleted by a user.
In the current implementation a cgroup can remain in such "dying" state
for an undefined amount of time. For instance, if a memory cgroup
contains a pge, mlocked by a process belonging to an other cgroup.
Although the lifecycle of a dying cgroup is out of user's control,
it's important to have some insight of what's going on under the hood.
In particular, it's handy to have a counter which will allow
to detect css leaks.
To solve this problem, add a cgroup.stat interface to
the base cgroup control files with the following metrics:
nr_descendants total number of visible descendant cgroups
nr_dying_descendants total number of dying descendant cgroups
Signed-off-by: Roman Gushchin <guro@fb.com>
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: kernel-team@fb.com
Cc: cgroups@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Creating cgroup hierearchies of unreasonable size can affect
overall system performance. A user might want to limit the
size of cgroup hierarchy. This is especially important if a user
is delegating some cgroup sub-tree.
To address this issue, introduce an ability to control
the size of cgroup hierarchy.
The cgroup.max.descendants control file allows to set the maximum
allowed number of descendant cgroups.
The cgroup.max.depth file controls the maximum depth of the cgroup
tree. Both are single value r/w files, with "max" default value.
The control files exist on each hierarchy level (including root).
When a new cgroup is created, we check the total descendants
and depth limits on each level, and if none of them are exceeded,
a new cgroup is created.
Only alive cgroups are counted, removed (dying) cgroups are
ignored.
Signed-off-by: Roman Gushchin <guro@fb.com>
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: kernel-team@fb.com
Cc: cgroups@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Keep track of the number of online and dying descent cgroups.
This data will be used later to add an ability to control cgroup
hierarchy (limit the depth and the number of descent cgroups)
and display hierarchy stats.
Signed-off-by: Roman Gushchin <guro@fb.com>
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: kernel-team@fb.com
Cc: cgroups@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Otherwise bo->shadow_list (which is aliased by bo->mn_list) will not
appear empty in amdgpu_ttm_bo_destroy and cause an oops when freeing
former userptr BOs.
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
As I was staring at the si_init_golden_registers code, I noticed that
the Pitcairn initialization silently falls through the Cape Verde
initialization, and the Oland initialization falls through the Hainan
initialization. However there is no comment stating that this is
intentional, and the radeon driver doesn't have any such fallthrough,
so I suspect this is not supposed to happen.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: 62a3755341 ("drm/amdgpu: add si implementation v10")
Cc: Ken Wang <Qingqing.Wang@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Marek Olšák" <maraeo@gmail.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Flora Cui <Flora.Cui@amd.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Chunyu Hu reported:
"per_cpu trace directories and files are created for all possible cpus,
but only the cpus which have ever been on-lined have their own per cpu
ring buffer (allocated by cpuhp threads). While trace_buffers_open, the
open handler for trace file 'trace_pipe_raw' is always trying to access
field of ring_buffer_per_cpu, and would panic with the NULL pointer.
Align the behavior of trace_pipe_raw with trace_pipe, that returns -NODEV
when openning it if that cpu does not have trace ring buffer.
Reproduce:
cat /sys/kernel/debug/tracing/per_cpu/cpu31/trace_pipe_raw
(cpu31 is never on-lined, this is a 16 cores x86_64 box)
Tested with:
1) boot with maxcpus=14, read trace_pipe_raw of cpu15.
Got -NODEV.
2) oneline cpu15, read trace_pipe_raw of cpu15.
Get the raw trace data.
Call trace:
[ 5760.950995] RIP: 0010:ring_buffer_alloc_read_page+0x32/0xe0
[ 5760.961678] tracing_buffers_read+0x1f6/0x230
[ 5760.962695] __vfs_read+0x37/0x160
[ 5760.963498] ? __vfs_read+0x5/0x160
[ 5760.964339] ? security_file_permission+0x9d/0xc0
[ 5760.965451] ? __vfs_read+0x5/0x160
[ 5760.966280] vfs_read+0x8c/0x130
[ 5760.967070] SyS_read+0x55/0xc0
[ 5760.967779] do_syscall_64+0x67/0x150
[ 5760.968687] entry_SYSCALL64_slow_path+0x25/0x25"
This was introduced by the addition of the feature to reuse reader pages
instead of re-allocating them. The problem is that the allocation of a
reader page (which is per cpu) does not check if the cpu is online and set
up for the ring buffer.
Link: http://lkml.kernel.org/r/1500880866-1177-1-git-send-email-chuhu@redhat.com
Cc: stable@vger.kernel.org
Fixes: 73a757e631 ("ring-buffer: Return reader page back into existing ring buffer")
Reported-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If ring_buffer_alloc() or one of the next couple function calls fail
then we should return -ENOMEM but the current code returns success.
Link: http://lkml.kernel.org/r/20170801110201.ajdkct7vwzixahvx@mwanda
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: b32614c034 ('tracing/rb: Convert to hotplug state machine')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The clear_boot_tracer function is used to reset the default_bootup_tracer
string to prevent it from being accessed after boot, as it originally points
to init data. But since clear_boot_tracer() is called via the
init_lateinit() call, it races with the initcall for registering the hwlat
tracer. If someone adds "ftrace=hwlat" to the kernel command line, depending
on how the linker sets up the text, the saved command line may be cleared,
and the hwlat tracer never is initialized.
Simply have the clear_boot_tracer() be called by initcall_lateinit_sync() as
that's for tasks to be called after lateinit.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=196551
Cc: stable@vger.kernel.org
Fixes: e7c15cd8a ("tracing: Added hardware latency tracer")
Reported-by: Zamir SUN <sztsian@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If the sender switches the congestion control during ECN-triggered
cwnd-reduction state (CA_CWR), upon exiting recovery cwnd is set to
the ssthresh value calculated by the previous congestion control. If
the previous congestion control is BBR that always keep ssthresh
to TCP_INIFINITE_SSTHRESH, cwnd ends up being infinite. The safe
step is to avoid assigning invalid ssthresh value when recovery ends.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
They are introduced by commit f70ea018da
("net: Add functions to get skb->hash based on flow structures")
but never gets used in tree.
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
SCRQ resources are freed during renegotiation, but they are not
re-allocated afterwards due to some changes in the initialization
process. Fix that by re-allocating the memory after renegotation.
SCRQ's can also be freed if a server capabilities request fails.
If this were encountered during a device reset for example,
SCRQ's may not be re-allocated. This operation is not necessary
anymore so remove it.
Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit c13ee2a4f0 ("tcp: reindent two spots after prequeue removal")
removed code in tcp_data_queue().
We can go a little farther, removing an always true test,
and removing initializers for fragstolen and eaten variables.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
