Compilation fails when KVM is selected and ARM64_SVE isn't.
The root cause is that sve_cond_update_zcr_vq is not defined when
ARM64_SVE is not selected. Fix it by adding an empty definition
when CONFIG_ARM64_SVE=n.
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
[maz: simplified commit message, fleshed out dummy #define]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/1617183879-48748-1-git-send-email-tanxiaofei@huawei.com
(cherry picked from commit a9f8696d4b)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 190594147
Change-Id: I55b8027a6025262e3921561d37d73d2199625be4
Although the SMCCC specification provides some limited functionality for
describing the presence of hypervisor and firmware services, this is
generally applicable only to functions designated as "Arm Architecture
Service Functions" and no portable discovery mechanism is provided for
standard hypervisor services, despite having a designated range of
function identifiers reserved by the specification.
In an attempt to avoid the need for additional firmware changes every
time a new function is added, introduce a UID to identify the service
provider as being compatible with KVM. Once this has been established,
additional services can be discovered via a feature bitmap.
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
[maz: move code to its own file, plug it into PSCI]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201209060932.212364-2-jianyong.wu@arm.com
(cherry picked from commit 6e085e0ac9)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 190594147
Change-Id: I820ef716a2316a928d7cc8e5dda5befa543432d5
When reseeding the CRNG periodically, arch_get_random_seed_long() is
called to obtain entropy from an architecture specific source if one
is implemented. In most cases, these are special instructions, but in
some cases, such as on ARM, we may want to back this using firmware
calls, which are considerably more expensive.
Another call to arch_get_random_seed_long() exists in the CRNG driver,
in add_interrupt_randomness(), which collects entropy by capturing
inter-interrupt timing and relying on interrupt jitter to provide
random bits. This is done by keeping a per-CPU state, and mixing in
the IRQ number, the cycle counter and the return address every time an
interrupt is taken, and mixing this per-CPU state into the entropy pool
every 64 invocations, or at least once per second. The entropy that is
gathered this way is credited as 1 bit of entropy. Every time this
happens, arch_get_random_seed_long() is invoked, and the result is
mixed in as well, and also credited with 1 bit of entropy.
This means that arch_get_random_seed_long() is called at least once
per second on every CPU, which seems excessive, and doesn't really
scale, especially in a virtualization scenario where CPUs may be
oversubscribed: in cases where arch_get_random_seed_long() is backed
by an instruction that actually goes back to a shared hardware entropy
source (such as RNDRRS on ARM), we will end up hitting it hundreds of
times per second.
So let's drop the call to arch_get_random_seed_long() from
add_interrupt_randomness(), and instead, rely on crng_reseed() to call
the arch hook to get random seed material from the platform.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20201105152944.16953-1-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
(cherry picked from commit 390596c995)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 190594147
Change-Id: I03ef9372cf464a8b5de0e09e93cad1baa059ae40
The ARM architected TRNG firmware interface, described in ARM spec
DEN0098, defines an ARM SMCCC based interface to a true random number
generator, provided by firmware.
This can be discovered via the SMCCC >=v1.1 interface, and provides
up to 192 bits of entropy per call.
Hook this SMC call into arm64's arch_get_random_*() implementation,
coming to the rescue when the CPU does not implement the ARM v8.5 RNG
system registers.
For the detection, we piggy back on the PSCI/SMCCC discovery (which gives
us the conduit to use (hvc/smc)), then try to call the
ARM_SMCCC_TRNG_VERSION function, which returns -1 if this interface is
not implemented.
Reviewed-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
(cherry picked from commit 38db987316)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 190594147
Change-Id: I0c0cedbd7053cd322e119cb00ec5c05684458b7e
The ARM DEN0098 document describe an SMCCC based firmware service to
deliver hardware generated random numbers. Its existence is advertised
according to the SMCCC v1.1 specification.
Add a (dummy) call to probe functions implemented in each architecture
(ARM and arm64), to determine the existence of this interface.
For now this return false, but this will be overwritten by each
architecture's support patch.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
(cherry picked from commit a37e31fc97)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 190594147
Change-Id: I3e91678706efdaa992c2d52a9bcbf1bb994e93e4
Before GICv4.1, we don't have direct access to the VLPI state. So
we simply let it fail early when encountering any VLPI in saving.
But now we don't have to return -EACCES directly if on GICv4.1. Let’s
change the hard code and give a chance to save the VLPI state (and
preserve the UAPI).
Signed-off-by: Shenming Lu <lushenming@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210322060158.1584-7-lushenming@huawei.com
(cherry picked from commit 8082d50f48)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 190594147
Change-Id: I5f878c088b42772774d5189d32bf74814e932521
When setting the forwarding path of a VLPI (switch to the HW mode),
we can also transfer the pending state from irq->pending_latch to
VPT (especially in migration, the pending states of VLPIs are restored
into kvm’s vgic first). And we currently send "INT+VSYNC" to trigger
a VLPI to pending.
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Shenming Lu <lushenming@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210322060158.1584-6-lushenming@huawei.com
(cherry picked from commit 12df742921)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 190594147
Change-Id: I7eb7e5db5d6e251c0f65f00c814a887ef44e260f
After pausing all vCPUs and devices capable of interrupting, in order
to save the states of all interrupts, besides flushing the states in
kvm’s vgic, we also try to flush the states of VLPIs in the virtual
pending tables into guest RAM, but we need to have GICv4.1 and safely
unmap the vPEs first.
As for the saving of VSGIs, which needs the vPEs to be mapped and might
conflict with the saving of VLPIs, but since we will map the vPEs back
at the end of save_pending_tables and both savings require the kvm->lock
to be held (thus only happen serially), it will work fine.
Signed-off-by: Shenming Lu <lushenming@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210322060158.1584-5-lushenming@huawei.com
(cherry picked from commit f66b7b151e)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 190594147
Change-Id: Ia375c8400861ef93cded852c05e4fe169445fe13
GICv4.1 gives a way to get the VLPI state, which needs to map the
vPE first, and after the state read, we may remap the vPE back while
the VPT is not empty. So we can't assume that the VPT is empty at
the first map. Besides, the optimization of PTZ is probably limited
since the HW should be fairly efficient to parse the empty VPT. Let's
drop the setting of PTZ altogether.
Signed-off-by: Shenming Lu <lushenming@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210322060158.1584-3-lushenming@huawei.com
(cherry picked from commit c21bc068cd)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 190594147
Change-Id: I599b10b7b196fba5515d835b340721b23990387c
Changes in 5.10.47
module: limit enabling module.sig_enforce
Revert "drm/amdgpu/gfx9: fix the doorbell missing when in CGPG issue."
Revert "drm/amdgpu/gfx10: enlarge CP_MEC_DOORBELL_RANGE_UPPER to cover full doorbell."
drm: add a locked version of drm_is_current_master
drm/nouveau: wait for moving fence after pinning v2
drm/radeon: wait for moving fence after pinning
drm/amdgpu: wait for moving fence after pinning
ARM: 9081/1: fix gcc-10 thumb2-kernel regression
mmc: meson-gx: use memcpy_to/fromio for dram-access-quirk
MIPS: generic: Update node names to avoid unit addresses
arm64: Ignore any DMA offsets in the max_zone_phys() calculation
arm64: Force NO_BLOCK_MAPPINGS if crashkernel reservation is required
spi: spi-nxp-fspi: move the register operation after the clock enable
Revert "PCI: PM: Do not read power state in pci_enable_device_flags()"
drm/vc4: hdmi: Move the HSM clock enable to runtime_pm
drm/vc4: hdmi: Make sure the controller is powered in detect
x86/entry: Fix noinstr fail in __do_fast_syscall_32()
x86/xen: Fix noinstr fail in exc_xen_unknown_trap()
locking/lockdep: Improve noinstr vs errors
perf/x86/lbr: Remove cpuc->lbr_xsave allocation from atomic context
perf/x86/intel/lbr: Zero the xstate buffer on allocation
dmaengine: zynqmp_dma: Fix PM reference leak in zynqmp_dma_alloc_chan_resourc()
dmaengine: stm32-mdma: fix PM reference leak in stm32_mdma_alloc_chan_resourc()
dmaengine: xilinx: dpdma: Add missing dependencies to Kconfig
dmaengine: xilinx: dpdma: Limit descriptor IDs to 16 bits
mac80211: remove warning in ieee80211_get_sband()
mac80211_hwsim: drop pending frames on stop
cfg80211: call cfg80211_leave_ocb when switching away from OCB
dmaengine: rcar-dmac: Fix PM reference leak in rcar_dmac_probe()
dmaengine: mediatek: free the proper desc in desc_free handler
dmaengine: mediatek: do not issue a new desc if one is still current
dmaengine: mediatek: use GFP_NOWAIT instead of GFP_ATOMIC in prep_dma
net: ipv4: Remove unneed BUG() function
mac80211: drop multicast fragments
net: ethtool: clear heap allocations for ethtool function
inet: annotate data race in inet_send_prepare() and inet_dgram_connect()
ping: Check return value of function 'ping_queue_rcv_skb'
net: annotate data race in sock_error()
inet: annotate date races around sk->sk_txhash
net/packet: annotate data race in packet_sendmsg()
net: phy: dp83867: perform soft reset and retain established link
riscv32: Use medany C model for modules
net: caif: fix memory leak in ldisc_open
net/packet: annotate accesses to po->bind
net/packet: annotate accesses to po->ifindex
r8152: Avoid memcpy() over-reading of ETH_SS_STATS
sh_eth: Avoid memcpy() over-reading of ETH_SS_STATS
r8169: Avoid memcpy() over-reading of ETH_SS_STATS
KVM: selftests: Fix kvm_check_cap() assertion
net: qed: Fix memcpy() overflow of qed_dcbx_params()
mac80211: reset profile_periodicity/ema_ap
mac80211: handle various extensible elements correctly
recordmcount: Correct st_shndx handling
PCI: Add AMD RS690 quirk to enable 64-bit DMA
net: ll_temac: Add memory-barriers for TX BD access
net: ll_temac: Avoid ndo_start_xmit returning NETDEV_TX_BUSY
perf/x86: Track pmu in per-CPU cpu_hw_events
pinctrl: stm32: fix the reported number of GPIO lines per bank
i2c: i801: Ensure that SMBHSTSTS_INUSE_STS is cleared when leaving i801_access
gpiolib: cdev: zero padding during conversion to gpioline_info_changed
scsi: sd: Call sd_revalidate_disk() for ioctl(BLKRRPART)
nilfs2: fix memory leak in nilfs_sysfs_delete_device_group
s390/stack: fix possible register corruption with stack switch helper
KVM: do not allow mapping valid but non-reference-counted pages
i2c: robotfuzz-osif: fix control-request directions
ceph: must hold snap_rwsem when filling inode for async create
kthread_worker: split code for canceling the delayed work timer
kthread: prevent deadlock when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync()
x86/fpu: Preserve supervisor states in sanitize_restored_user_xstate()
x86/fpu: Make init_fpstate correct with optimized XSAVE
mm: add VM_WARN_ON_ONCE_PAGE() macro
mm/rmap: remove unneeded semicolon in page_not_mapped()
mm/rmap: use page_not_mapped in try_to_unmap()
mm, thp: use head page in __migration_entry_wait()
mm/thp: fix __split_huge_pmd_locked() on shmem migration entry
mm/thp: make is_huge_zero_pmd() safe and quicker
mm/thp: try_to_unmap() use TTU_SYNC for safe splitting
mm/thp: fix vma_address() if virtual address below file offset
mm/thp: fix page_address_in_vma() on file THP tails
mm/thp: unmap_mapping_page() to fix THP truncate_cleanup_page()
mm: thp: replace DEBUG_VM BUG with VM_WARN when unmap fails for split
mm: page_vma_mapped_walk(): use page for pvmw->page
mm: page_vma_mapped_walk(): settle PageHuge on entry
mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd
mm: page_vma_mapped_walk(): prettify PVMW_MIGRATION block
mm: page_vma_mapped_walk(): crossing page table boundary
mm: page_vma_mapped_walk(): add a level of indentation
mm: page_vma_mapped_walk(): use goto instead of while (1)
mm: page_vma_mapped_walk(): get vma_address_end() earlier
mm/thp: fix page_vma_mapped_walk() if THP mapped by ptes
mm/thp: another PVMW_SYNC fix in page_vma_mapped_walk()
mm, futex: fix shared futex pgoff on shmem huge page
KVM: SVM: Call SEV Guest Decommission if ASID binding fails
swiotlb: manipulate orig_addr when tlb_addr has offset
netfs: fix test for whether we can skip read when writing beyond EOF
Revert "drm: add a locked version of drm_is_current_master"
certs: Add EFI_CERT_X509_GUID support for dbx entries
certs: Move load_system_certificate_list to a common function
certs: Add ability to preload revocation certs
integrity: Load mokx variables into the blacklist keyring
Linux 5.10.47
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I48fc1e94475e27da558c2cbedcd253a3d06e535e
commit 5f89468e2f upstream.
in case of driver wants to sync part of ranges with offset,
swiotlb_tbl_sync_single() copies from orig_addr base to tlb_addr with
offset and ends up with data mismatch.
It was removed from
"swiotlb: don't modify orig_addr in swiotlb_tbl_sync_single",
but said logic has to be added back in.
From Linus's email:
"That commit which the removed the offset calculation entirely, because the old
(unsigned long)tlb_addr & (IO_TLB_SIZE - 1)
was wrong, but instead of removing it, I think it should have just
fixed it to be
(tlb_addr - mem->start) & (IO_TLB_SIZE - 1);
instead. That way the slot offset always matches the slot index calculation."
(Unfortunatly that broke NVMe).
The use-case that drivers are hitting is as follow:
1. Get dma_addr_t from dma_map_single()
dma_addr_t tlb_addr = dma_map_single(dev, vaddr, vsize, DMA_TO_DEVICE);
|<---------------vsize------------->|
+-----------------------------------+
| | original buffer
+-----------------------------------+
vaddr
swiotlb_align_offset
|<----->|<---------------vsize------------->|
+-------+-----------------------------------+
| | | swiotlb buffer
+-------+-----------------------------------+
tlb_addr
2. Do something
3. Sync dma_addr_t through dma_sync_single_for_device(..)
dma_sync_single_for_device(dev, tlb_addr + offset, size, DMA_TO_DEVICE);
Error case.
Copy data to original buffer but it is from base addr (instead of
base addr + offset) in original buffer:
swiotlb_align_offset
|<----->|<- offset ->|<- size ->|
+-------+-----------------------------------+
| | |##########| | swiotlb buffer
+-------+-----------------------------------+
tlb_addr
|<- size ->|
+-----------------------------------+
|##########| | original buffer
+-----------------------------------+
vaddr
The fix is to copy the data to the original buffer and take into
account the offset, like so:
swiotlb_align_offset
|<----->|<- offset ->|<- size ->|
+-------+-----------------------------------+
| | |##########| | swiotlb buffer
+-------+-----------------------------------+
tlb_addr
|<- offset ->|<- size ->|
+-----------------------------------+
| |##########| | original buffer
+-----------------------------------+
vaddr
[One fix which was Linus's that made more sense to as it created a
symmetry would break NVMe. The reason for that is the:
unsigned int offset = (tlb_addr - mem->start) & (IO_TLB_SIZE - 1);
would come up with the proper offset, but it would lose the
alignment (which this patch contains).]
Fixes: 16fc3cef33 ("swiotlb: don't modify orig_addr in swiotlb_tbl_sync_single")
Signed-off-by: Bumyong Lee <bumyong.lee@samsung.com>
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reported-by: Dominique MARTINET <dominique.martinet@atmark-techno.com>
Reported-by: Horia Geantă <horia.geanta@nxp.com>
Tested-by: Horia Geantă <horia.geanta@nxp.com>
CC: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 934002cd66 upstream.
Send SEV_CMD_DECOMMISSION command to PSP firmware if ASID binding
fails. If a failure happens after a successful LAUNCH_START command,
a decommission command should be executed. Otherwise, guest context
will be unfreed inside the AMD SP. After the firmware will not have
memory to allocate more SEV guest context, LAUNCH_START command will
begin to fail with SEV_RET_RESOURCE_LIMIT error.
The existing code calls decommission inside sev_unbind_asid, but it is
not called if a failure happens before guest activation succeeds. If
sev_bind_asid fails, decommission is never called. PSP firmware has a
limit for the number of guests. If sev_asid_binding fails many times,
PSP firmware will not have resources to create another guest context.
Cc: stable@vger.kernel.org
Fixes: 59414c9892 ("KVM: SVM: Add support for KVM_SEV_LAUNCH_START command")
Reported-by: Peter Gonda <pgonda@google.com>
Signed-off-by: Alper Gun <alpergun@google.com>
Reviewed-by: Marc Orr <marcorr@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210610174604.2554090-1-alpergun@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fe19bd3dae upstream.
If more than one futex is placed on a shmem huge page, it can happen
that waking the second wakes the first instead, and leaves the second
waiting: the key's shared.pgoff is wrong.
When 3.11 commit 13d60f4b6a ("futex: Take hugepages into account when
generating futex_key"), the only shared huge pages came from hugetlbfs,
and the code added to deal with its exceptional page->index was put into
hugetlb source. Then that was missed when 4.8 added shmem huge pages.
page_to_pgoff() is what others use for this nowadays: except that, as
currently written, it gives the right answer on hugetlbfs head, but
nonsense on hugetlbfs tails. Fix that by calling hugetlbfs-specific
hugetlb_basepage_index() on PageHuge tails as well as on head.
Yes, it's unconventional to declare hugetlb_basepage_index() there in
pagemap.h, rather than in hugetlb.h; but I do not expect anything but
page_to_pgoff() ever to need it.
[akpm@linux-foundation.org: give hugetlb_basepage_index() prototype the correct scope]
Link: https://lkml.kernel.org/r/b17d946b-d09-326e-b42a-52884c36df32@google.com
Fixes: 800d8c63b2 ("shmem: add huge pages support")
Reported-by: Neel Natu <neelnatu@google.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Zhang Yi <wetpzy@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a9a7504d9b upstream.
Running certain tests with a DEBUG_VM kernel would crash within hours,
on the total_mapcount BUG() in split_huge_page_to_list(), while trying
to free up some memory by punching a hole in a shmem huge page: split's
try_to_unmap() was unable to find all the mappings of the page (which,
on a !DEBUG_VM kernel, would then keep the huge page pinned in memory).
Crash dumps showed two tail pages of a shmem huge page remained mapped
by pte: ptes in a non-huge-aligned vma of a gVisor process, at the end
of a long unmapped range; and no page table had yet been allocated for
the head of the huge page to be mapped into.
Although designed to handle these odd misaligned huge-page-mapped-by-pte
cases, page_vma_mapped_walk() falls short by returning false prematurely
when !pmd_present or !pud_present or !p4d_present or !pgd_present: there
are cases when a huge page may span the boundary, with ptes present in
the next.
Restructure page_vma_mapped_walk() as a loop to continue in these cases,
while keeping its layout much as before. Add a step_forward() helper to
advance pvmw->address across those boundaries: originally I tried to use
mm's standard p?d_addr_end() macros, but hit the same crash 512 times
less often: because of the way redundant levels are folded together, but
folded differently in different configurations, it was just too
difficult to use them correctly; and step_forward() is simpler anyway.
Link: https://lkml.kernel.org/r/fedb8632-1798-de42-f39e-873551d5bc81@google.com
Fixes: ace71a19ce ("mm: introduce page_vma_mapped_walk()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Will Deacon <will@kernel.org>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 22061a1ffa ]
There is a race between THP unmapping and truncation, when truncate sees
pmd_none() and skips the entry, after munmap's zap_huge_pmd() cleared
it, but before its page_remove_rmap() gets to decrement
compound_mapcount: generating false "BUG: Bad page cache" reports that
the page is still mapped when deleted. This commit fixes that, but not
in the way I hoped.
The first attempt used try_to_unmap(page, TTU_SYNC|TTU_IGNORE_MLOCK)
instead of unmap_mapping_range() in truncate_cleanup_page(): it has
often been an annoyance that we usually call unmap_mapping_range() with
no pages locked, but there apply it to a single locked page.
try_to_unmap() looks more suitable for a single locked page.
However, try_to_unmap_one() contains a VM_BUG_ON_PAGE(!pvmw.pte,page):
it is used to insert THP migration entries, but not used to unmap THPs.
Copy zap_huge_pmd() and add THP handling now? Perhaps, but their TLB
needs are different, I'm too ignorant of the DAX cases, and couldn't
decide how far to go for anon+swap. Set that aside.
The second attempt took a different tack: make no change in truncate.c,
but modify zap_huge_pmd() to insert an invalidated huge pmd instead of
clearing it initially, then pmd_clear() between page_remove_rmap() and
unlocking at the end. Nice. But powerpc blows that approach out of the
water, with its serialize_against_pte_lookup(), and interesting pgtable
usage. It would need serious help to get working on powerpc (with a
minor optimization issue on s390 too). Set that aside.
Just add an "if (page_mapped(page)) synchronize_rcu();" or other such
delay, after unmapping in truncate_cleanup_page()? Perhaps, but though
that's likely to reduce or eliminate the number of incidents, it would
give less assurance of whether we had identified the problem correctly.
This successful iteration introduces "unmap_mapping_page(page)" instead
of try_to_unmap(), and goes the usual unmap_mapping_range_tree() route,
with an addition to details. Then zap_pmd_range() watches for this
case, and does spin_unlock(pmd_lock) if so - just like
page_vma_mapped_walk() now does in the PVMW_SYNC case. Not pretty, but
safe.
Note that unmap_mapping_page() is doing a VM_BUG_ON(!PageLocked) to
assert its interface; but currently that's only used to make sure that
page->mapping is stable, and zap_pmd_range() doesn't care if the page is
locked or not. Along these lines, in invalidate_inode_pages2_range()
move the initial unmap_mapping_range() out from under page lock, before
then calling unmap_mapping_page() under page lock if still mapped.
Link: https://lkml.kernel.org/r/a2a4a148-cdd8-942c-4ef8-51b77f643dbe@google.com
Fixes: fc127da085 ("truncate: handle file thp")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jue Wang <juew@google.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Note on stable backport: fixed up call to truncate_cleanup_page()
in truncate_inode_pages_range().
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 494334e43c upstream.
Running certain tests with a DEBUG_VM kernel would crash within hours,
on the total_mapcount BUG() in split_huge_page_to_list(), while trying
to free up some memory by punching a hole in a shmem huge page: split's
try_to_unmap() was unable to find all the mappings of the page (which,
on a !DEBUG_VM kernel, would then keep the huge page pinned in memory).
When that BUG() was changed to a WARN(), it would later crash on the
VM_BUG_ON_VMA(end < vma->vm_start || start >= vma->vm_end, vma) in
mm/internal.h:vma_address(), used by rmap_walk_file() for
try_to_unmap().
vma_address() is usually correct, but there's a wraparound case when the
vm_start address is unusually low, but vm_pgoff not so low:
vma_address() chooses max(start, vma->vm_start), but that decides on the
wrong address, because start has become almost ULONG_MAX.
Rewrite vma_address() to be more careful about vm_pgoff; move the
VM_BUG_ON_VMA() out of it, returning -EFAULT for errors, so that it can
be safely used from page_mapped_in_vma() and page_address_in_vma() too.
Add vma_address_end() to apply similar care to end address calculation,
in page_vma_mapped_walk() and page_mkclean_one() and try_to_unmap_one();
though it raises a question of whether callers would do better to supply
pvmw->end to page_vma_mapped_walk() - I chose not, for a smaller patch.
An irritation is that their apparent generality breaks down on KSM
pages, which cannot be located by the page->index that page_to_pgoff()
uses: as commit 4b0ece6fa0 ("mm: migrate: fix remove_migration_pte()
for ksm pages") once discovered. I dithered over the best thing to do
about that, and have ended up with a VM_BUG_ON_PAGE(PageKsm) in both
vma_address() and vma_address_end(); though the only place in danger of
using it on them was try_to_unmap_one().
Sidenote: vma_address() and vma_address_end() now use compound_nr() on a
head page, instead of thp_size(): to make the right calculation on a
hugetlbfs page, whether or not THPs are configured. try_to_unmap() is
used on hugetlbfs pages, but perhaps the wrong calculation never
mattered.
Link: https://lkml.kernel.org/r/caf1c1a3-7cfb-7f8f-1beb-ba816e932825@google.com
Fixes: a8fa41ad2f ("mm, rmap: check all VMAs that PTE-mapped THP can be part of")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jue Wang <juew@google.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 732ed55823 upstream.
Stressing huge tmpfs often crashed on unmap_page()'s VM_BUG_ON_PAGE
(!unmap_success): with dump_page() showing mapcount:1, but then its raw
struct page output showing _mapcount ffffffff i.e. mapcount 0.
And even if that particular VM_BUG_ON_PAGE(!unmap_success) is removed,
it is immediately followed by a VM_BUG_ON_PAGE(compound_mapcount(head)),
and further down an IS_ENABLED(CONFIG_DEBUG_VM) total_mapcount BUG():
all indicative of some mapcount difficulty in development here perhaps.
But the !CONFIG_DEBUG_VM path handles the failures correctly and
silently.
I believe the problem is that once a racing unmap has cleared pte or
pmd, try_to_unmap_one() may skip taking the page table lock, and emerge
from try_to_unmap() before the racing task has reached decrementing
mapcount.
Instead of abandoning the unsafe VM_BUG_ON_PAGE(), and the ones that
follow, use PVMW_SYNC in try_to_unmap_one() in this case: adding
TTU_SYNC to the options, and passing that from unmap_page().
When CONFIG_DEBUG_VM, or for non-debug too? Consensus is to do the same
for both: the slight overhead added should rarely matter, except perhaps
if splitting sparsely-populated multiply-mapped shmem. Once confident
that bugs are fixed, TTU_SYNC here can be removed, and the race
tolerated.
Link: https://lkml.kernel.org/r/c1e95853-8bcd-d8fd-55fa-e7f2488e78f@google.com
Fixes: fec89c109f ("thp: rewrite freeze_page()/unfreeze_page() with generic rmap walkers")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jue Wang <juew@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 99fa8a4820 ]
Patch series "mm/thp: fix THP splitting unmap BUGs and related", v10.
Here is v2 batch of long-standing THP bug fixes that I had not got
around to sending before, but prompted now by Wang Yugui's report
https://lore.kernel.org/linux-mm/20210412180659.B9E3.409509F4@e16-tech.com/
Wang Yugui has tested a rollup of these fixes applied to 5.10.39, and
they have done no harm, but have *not* fixed that issue: something more
is needed and I have no idea of what.
This patch (of 7):
Stressing huge tmpfs page migration racing hole punch often crashed on
the VM_BUG_ON(!pmd_present) in pmdp_huge_clear_flush(), with DEBUG_VM=y
kernel; or shortly afterwards, on a bad dereference in
__split_huge_pmd_locked() when DEBUG_VM=n. They forgot to allow for pmd
migration entries in the non-anonymous case.
Full disclosure: those particular experiments were on a kernel with more
relaxed mmap_lock and i_mmap_rwsem locking, and were not repeated on the
vanilla kernel: it is conceivable that stricter locking happens to avoid
those cases, or makes them less likely; but __split_huge_pmd_locked()
already allowed for pmd migration entries when handling anonymous THPs,
so this commit brings the shmem and file THP handling into line.
And while there: use old_pmd rather than _pmd, as in the following
blocks; and make it clearer to the eye that the !vma_is_anonymous()
block is self-contained, making an early return after accounting for
unmapping.
Link: https://lkml.kernel.org/r/af88612-1473-2eaa-903-8d1a448b26@google.com
Link: https://lkml.kernel.org/r/dd221a99-efb3-cd1d-6256-7e646af29314@google.com
Fixes: e71769ae52 ("mm: enable thp migration for shmem thp")
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Wang Yugui <wangyugui@e16-tech.com>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Jue Wang <juew@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Note on stable backport: this commit made intervening cleanups in
pmdp_huge_clear_flush() redundant: here it's rediffed to skip them.
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ffc90cbb29 upstream.
We notice that hung task happens in a corner but practical scenario when
CONFIG_PREEMPT_NONE is enabled, as follows.
Process 0 Process 1 Process 2..Inf
split_huge_page_to_list
unmap_page
split_huge_pmd_address
__migration_entry_wait(head)
__migration_entry_wait(tail)
remap_page (roll back)
remove_migration_ptes
rmap_walk_anon
cond_resched
Where __migration_entry_wait(tail) is occurred in kernel space, e.g.,
copy_to_user in fstat, which will immediately fault again without
rescheduling, and thus occupy the cpu fully.
When there are too many processes performing __migration_entry_wait on
tail page, remap_page will never be done after cond_resched.
This makes __migration_entry_wait operate on the compound head page,
thus waits for remap_page to complete, whether the THP is split
successfully or roll back.
Note that put_and_wait_on_page_locked helps to drop the page reference
acquired with get_page_unless_zero, as soon as the page is on the wait
queue, before actually waiting. So splitting the THP is only prevented
for a brief interval.
Link: https://lkml.kernel.org/r/b9836c1dd522e903891760af9f0c86a2cce987eb.1623144009.git.xuyu@linux.alibaba.com
Fixes: ba98828088 ("thp: add option to setup migration entries during PMD split")
Suggested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Gang Deng <gavin.dg@linux.alibaba.com>
Signed-off-by: Xu Yu <xuyu@linux.alibaba.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b7e188ec98 ]
page_mapcount_is_zero() calculates accurately how many mappings a hugepage
has in order to check against 0 only. This is a waste of cpu time. We
can do this via page_not_mapped() to save some possible atomic_read
cycles. Remove the function page_mapcount_is_zero() as it's not used
anymore and move page_not_mapped() above try_to_unmap() to avoid
identifier undeclared compilation error.
Link: https://lkml.kernel.org/r/20210130084904.35307-1-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f9dfb5e390 upstream.
The XSAVE init code initializes all enabled and supported components with
XRSTOR(S) to init state. Then it XSAVEs the state of the components back
into init_fpstate which is used in several places to fill in the init state
of components.
This works correctly with XSAVE, but not with XSAVEOPT and XSAVES because
those use the init optimization and skip writing state of components which
are in init state. So init_fpstate.xsave still contains all zeroes after
this operation.
There are two ways to solve that:
1) Use XSAVE unconditionally, but that requires to reshuffle the buffer when
XSAVES is enabled because XSAVES uses compacted format.
2) Save the components which are known to have a non-zero init state by other
means.
Looking deeper, #2 is the right thing to do because all components the
kernel supports have all-zeroes init state except the legacy features (FP,
SSE). Those cannot be hard coded because the states are not identical on all
CPUs, but they can be saved with FXSAVE which avoids all conditionals.
Use FXSAVE to save the legacy FP/SSE components in init_fpstate along with
a BUILD_BUG_ON() which reminds developers to validate that a newly added
component has all zeroes init state. As a bonus remove the now unused
copy_xregs_to_kernel_booting() crutch.
The XSAVE and reshuffle method can still be implemented in the unlikely
case that components are added which have a non-zero init state and no
other means to save them. For now, FXSAVE is just simple and good enough.
[ bp: Fix a typo or two in the text. ]
Fixes: 6bad06b768 ("x86, xsave: Use xsaveopt in context-switch path when supported")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20210618143444.587311343@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
