As in kvm_ioctl and _kvm_ioctl, add
the respective _vm_ioctl for vm_ioctl.
_vm_ioctl invokes an ioctl using the vm fd,
leaving the caller to test the result.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Message-Id: <20210318151624.490861-1-eesposit@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Introduce a new selftest for Hyper-V clocksources (MSR-based reference TSC
and TSC page). As a starting point, test the following:
1) Reference TSC is 1Ghz clock.
2) Reference TSC and TSC page give the same reading.
3) TSC page gets updated upon KVM_SET_CLOCK call.
4) TSC page does not get updated when guest opted for reenlightenment.
5) Disabled TSC page doesn't get updated.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210318140949.1065740-1-vkuznets@redhat.com>
[Add a host-side test using TSC + KVM_GET_MSR too. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When guest opts for re-enlightenment notifications upon migration, it is
in its right to assume that TSC page values never change (as they're only
supposed to change upon migration and the host has to keep things as they
are before it receives confirmation from the guest). This is mostly true
until the guest is migrated somewhere. KVM userspace (e.g. QEMU) will
trigger masterclock update by writing to HV_X64_MSR_REFERENCE_TSC, by
calling KVM_SET_CLOCK,... and as TSC value and kvmclock reading drift
apart (even slightly), the update causes TSC page values to change.
The issue at hand is that when Hyper-V is migrated, it uses stale (cached)
TSC page values to compute the difference between its own clocksource
(provided by KVM) and its guests' TSC pages to program synthetic timers
and in some cases, when TSC page is updated, this puts all stimer
expirations in the past. This, in its turn, causes an interrupt storm
and L2 guests not making much forward progress.
Note, KVM doesn't fully implement re-enlightenment notification. Basically,
the support for reenlightenment MSRs is just a stub and userspace is only
expected to expose the feature when TSC scaling on the expected destination
hosts is available. With TSC scaling, no real re-enlightenment is needed
as TSC frequency doesn't change. With TSC scaling becoming ubiquitous, it
likely makes little sense to fully implement re-enlightenment in KVM.
Prevent TSC page from being updated after migration. In case it's not the
guest who's initiating the change and when TSC page is already enabled,
just keep it as it is: TSC value is supposed to be preserved across
migration and TSC frequency can't change with re-enlightenment enabled.
The guest is doomed anyway if any of this is not true.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210316143736.964151-5-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Create an infrastructure for tracking Hyper-V TSC page status, i.e. if it
was updated from guest/host side or if we've failed to set it up (because
e.g. guest wrote some garbage to HV_X64_MSR_REFERENCE_TSC) and there's no
need to retry.
Also, in a hypothetical situation when we are in 'always catchup' mode for
TSC we can now avoid contending 'hv->hv_lock' on every guest enter by
setting the state to HV_TSC_PAGE_BROKEN after compute_tsc_page_parameters()
returns false.
Check for HV_TSC_PAGE_SET state instead of '!hv->tsc_ref.tsc_sequence' in
get_time_ref_counter() to properly handle the situation when we failed to
write the updated TSC page values to the guest.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210316143736.964151-4-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When KVM_REQ_MASTERCLOCK_UPDATE request is issued (e.g. after migration)
we need to make sure no vCPU sees stale values in PV clock structures and
thus all vCPUs are kicked with KVM_REQ_CLOCK_UPDATE. Hyper-V TSC page
clocksource is global and kvm_guest_time_update() only updates in on vCPU0
but this is not entirely correct: nothing blocks some other vCPU from
entering the guest before we finish the update on CPU0 and it can read
stale values from the page.
Invalidate TSC page in kvm_gen_update_masterclock() to switch all vCPUs
to using MSR based clocksource (HV_X64_MSR_TIME_REF_COUNT).
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210316143736.964151-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
HV_X64_MSR_TSC_EMULATION_STATUS indicates whether TSC accesses are emulated
after migration (to accommodate for a different host TSC frequency when TSC
scaling is not supported; we don't implement this in KVM). Guest can use
the same MSR to stop TSC access emulation by writing zero. Writing anything
else is forbidden.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20210316143736.964151-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Store the address space ID in the TDP iterator so that it can be
retrieved without having to bounce through the root shadow page. This
streamlines the code and fixes a Sparse warning about not properly using
rcu_dereference() when grabbing the ID from the root on the fly.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210315233803.2706477-5-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
In tdp_mmu_iter_cond_resched there is a call to tdp_iter_start which
causes the iterator to continue its walk over the paging structure from
the root. This is needed after a yield as paging structure could have
been freed in the interim.
The tdp_iter_start call is not very clear and something of a hack. It
requires exposing tdp_iter fields not used elsewhere in tdp_mmu.c and
the effect is not obvious from the function name. Factor a more aptly
named function out of tdp_iter_start and call it from
tdp_mmu_iter_cond_resched and tdp_iter_start.
No functional change intended.
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210315233803.2706477-4-bgardon@google.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
The pt passed into handle_removed_tdp_mmu_page does not need RCU
protection, as it is not at any risk of being freed by another thread at
that point. However, the implicit cast from tdp_sptep_t to u64 * dropped
the __rcu annotation without a proper rcu_derefrence. Fix this by
passing the pt as a tdp_ptep_t and then rcu_dereferencing it in
the function.
Suggested-by: Sean Christopherson <seanjc@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Ben Gardon <bgardon@google.com>
Message-Id: <20210315233803.2706477-2-bgardon@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Doing a
prctl(PR_SET_MM, PR_SET_MM_AUXV, addr, 1);
will copy 1 byte from userspace to (quite big) on-stack array
and then stash everything to mm->saved_auxv.
AT_NULL terminator will be inserted at the very end.
/proc/*/auxv handler will find that AT_NULL terminator
and copy original stack contents to userspace.
This devious scheme requires CAP_SYS_RESOURCE.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull irq fixes from Thomas Gleixner:
"A set of irqchip updates:
- Make the GENERIC_IRQ_MULTI_HANDLER configuration correct
- Add a missing DT compatible string for the Ingenic driver
- Remove the pointless debugfs_file pointer from struct irqdomain"
* tag 'irq-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
irqchip/ingenic: Add support for the JZ4760
dt-bindings/irq: Add compatible string for the JZ4760B
irqchip: Do not blindly select CONFIG_GENERIC_IRQ_MULTI_HANDLER
ARM: ep93xx: Select GENERIC_IRQ_MULTI_HANDLER directly
irqdomain: Remove debugfs_file from struct irq_domain
Pull timer fix from Thomas Gleixner:
"A single fix in for hrtimers to prevent an interrupt storm caused by
the lack of reevaluation of the timers which expire in softirq context
under certain circumstances, e.g. when the clock was set"
* tag 'timers-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hrtimer: Update softirq_expires_next correctly after __hrtimer_get_next_event()
Pull scheduler fixes from Thomas Gleixner:
"A set of scheduler updates:
- Prevent a NULL pointer dereference in the migration_stop_cpu()
mechanims
- Prevent self concurrency of affine_move_task()
- Small fixes and cleanups related to task migration/affinity setting
- Ensure that sync_runqueues_membarrier_state() is invoked on the
current CPU when it is in the cpu mask"
* tag 'sched-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/membarrier: fix missing local execution of ipi_sync_rq_state()
sched: Simplify set_affinity_pending refcounts
sched: Fix affine_move_task() self-concurrency
sched: Optimize migration_cpu_stop()
sched: Collate affine_move_task() stoppers
sched: Simplify migration_cpu_stop()
sched: Fix migration_cpu_stop() requeueing
Pull objtool fix from Thomas Gleixner:
"A single objtool fix to handle the PUSHF/POPF validation correctly for
the paravirt changes which modified arch_local_irq_restore not to use
popf"
* tag 'objtool-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
objtool,x86: Fix uaccess PUSHF/POPF validation
Pull locking fixes from Thomas Gleixner:
"A couple of locking fixes:
- A fix for the static_call mechanism so it handles unaligned
addresses correctly.
- Make u64_stats_init() a macro so every instance gets a seperate
lockdep key.
- Make seqcount_latch_init() a macro as well to preserve the static
variable which is used for the lockdep key"
* tag 'locking-urgent-2021-03-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
seqlock,lockdep: Fix seqcount_latch_init()
u64_stats,lockdep: Fix u64_stats_init() vs lockdep
static_call: Fix the module key fixup
Pull perf fixes from Borislav Petkov:
- Make sure PMU internal buffers are flushed for per-CPU events too and
properly handle PID/TID for large PEBS.
- Handle the case properly when there's no PMU and therefore return an
empty list of perf MSRs for VMX to switch instead of reading random
garbage from the stack.
* tag 'perf_urgent_for_v5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/perf: Use RET0 as default for guest_get_msrs to handle "no PMU" case
perf/x86/intel: Set PERF_ATTACH_SCHED_CB for large PEBS and LBR
perf/core: Flush PMU internal buffers for per-CPU events
Pull EFI fix from Ard Biesheuvel via Borislav Petkov:
"Fix an oversight in the handling of EFI_RT_PROPERTIES_TABLE, which was
added v5.10, but failed to take the SetVirtualAddressMap() RT service
into account"
* tag 'efi-urgent-for-v5.12-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi: stub: omit SetVirtualAddressMap() if marked unsupported in RT_PROP table
Pull x86 fixes from Borislav Petkov:
- A couple of SEV-ES fixes and robustifications: verify usermode stack
pointer in NMI is not coming from the syscall gap, correctly track
IRQ states in the #VC handler and access user insn bytes atomically
in same handler as latter cannot sleep.
- Balance 32-bit fast syscall exit path to do the proper work on exit
and thus not confuse audit and ptrace frameworks.
- Two fixes for the ORC unwinder going "off the rails" into KASAN
redzones and when ORC data is missing.
* tag 'x86_urgent_for_v5.12_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/sev-es: Use __copy_from_user_inatomic()
x86/sev-es: Correctly track IRQ states in runtime #VC handler
x86/sev-es: Check regs->sp is trusted before adjusting #VC IST stack
x86/sev-es: Introduce ip_within_syscall_gap() helper
x86/entry: Fix entry/exit mismatch on failed fast 32-bit syscalls
x86/unwind/orc: Silence warnings caused by missing ORC data
x86/unwind/orc: Disable KASAN checking in the ORC unwinder, part 2
Pull powerpc fixes from Michael Ellerman:
"Some more powerpc fixes for 5.12:
- Fix wrong instruction encoding for lis in ppc_function_entry(),
which could potentially lead to missed kprobes.
- Fix SET_FULL_REGS on 32-bit and 64e, which prevented ptrace of
non-volatile GPRs immediately after exec.
- Clean up a missed SRR specifier in the recent interrupt rework.
- Don't treat unrecoverable_exception() as an interrupt handler, it's
called from other handlers so shouldn't do the interrupt entry/exit
accounting itself.
- Fix build errors caused by missing declarations for
[en/dis]able_kernel_vsx().
Thanks to Christophe Leroy, Daniel Axtens, Geert Uytterhoeven, Jiri
Olsa, Naveen N. Rao, and Nicholas Piggin"
* tag 'powerpc-5.12-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/traps: unrecoverable_exception() is not an interrupt handler
powerpc: Fix missing declaration of [en/dis]able_kernel_vsx()
powerpc/64s/exception: Clean up a missed SRR specifier
powerpc: Fix inverted SET_FULL_REGS bitop
powerpc/64s: Use symbolic macros for function entry encoding
powerpc/64s: Fix instruction encoding for lis in ppc_function_entry()
Pull KVM fixes from Paolo Bonzini:
"More fixes for ARM and x86"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: LAPIC: Advancing the timer expiration on guest initiated write
KVM: x86/mmu: Skip !MMU-present SPTEs when removing SP in exclusive mode
KVM: kvmclock: Fix vCPUs > 64 can't be online/hotpluged
kvm: x86: annotate RCU pointers
KVM: arm64: Fix exclusive limit for IPA size
KVM: arm64: Reject VM creation when the default IPA size is unsupported
KVM: arm64: Ensure I-cache isolation between vcpus of a same VM
KVM: arm64: Don't use cbz/adr with external symbols
KVM: arm64: Fix range alignment when walking page tables
KVM: arm64: Workaround firmware wrongly advertising GICv2-on-v3 compatibility
KVM: arm64: Rename __vgic_v3_get_ich_vtr_el2() to __vgic_v3_get_gic_config()
KVM: arm64: Don't access PMSELR_EL0/PMUSERENR_EL0 when no PMU is available
KVM: arm64: Turn kvm_arm_support_pmu_v3() into a static key
KVM: arm64: Fix nVHE hyp panic host context restore
KVM: arm64: Avoid corrupting vCPU context register in guest exit
KVM: arm64: nvhe: Save the SPE context early
kvm: x86: use NULL instead of using plain integer as pointer
KVM: SVM: Connect 'npt' module param to KVM's internal 'npt_enabled'
KVM: x86: Ensure deadline timer has truly expired before posting its IRQ
Merge misc fixes from Andrew Morton:
"28 patches.
Subsystems affected by this series: mm (memblock, pagealloc, hugetlb,
highmem, kfence, oom-kill, madvise, kasan, userfaultfd, memcg, and
zram), core-kernel, kconfig, fork, binfmt, MAINTAINERS, kbuild, and
ia64"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (28 commits)
zram: fix broken page writeback
zram: fix return value on writeback_store
mm/memcg: set memcg when splitting page
mm/memcg: rename mem_cgroup_split_huge_fixup to split_page_memcg and add nr_pages argument
ia64: fix ptrace(PTRACE_SYSCALL_INFO_EXIT) sign
ia64: fix ia64_syscall_get_set_arguments() for break-based syscalls
mm/userfaultfd: fix memory corruption due to writeprotect
kasan: fix KASAN_STACK dependency for HW_TAGS
kasan, mm: fix crash with HW_TAGS and DEBUG_PAGEALLOC
mm/madvise: replace ptrace attach requirement for process_madvise
include/linux/sched/mm.h: use rcu_dereference in in_vfork()
kfence: fix reports if constant function prefixes exist
kfence, slab: fix cache_alloc_debugcheck_after() for bulk allocations
kfence: fix printk format for ptrdiff_t
linux/compiler-clang.h: define HAVE_BUILTIN_BSWAP*
MAINTAINERS: exclude uapi directories in API/ABI section
binfmt_misc: fix possible deadlock in bm_register_write
mm/highmem.c: fix zero_user_segments() with start > end
hugetlb: do early cow when page pinned on src mm
mm: use is_cow_mapping() across tree where proper
...
Pull irqchip fixes from Marc Zyngier:
- More compatible strings for the Ingenic irqchip (introducing the
JZ4760B SoC)
- Select GENERIC_IRQ_MULTI_HANDLER on the ARM ep93xx platform
- Drop all GENERIC_IRQ_MULTI_HANDLER selections from the irqchip
Kconfig, now relying on the architecture to get it right
- Drop the debugfs_file field from struct irq_domain, now that
debugfs can track things on its own
Pull char/misc driver fixes from Greg KH:
"Here are some small misc/char driver fixes to resolve some reported
problems:
- habanalabs driver fixes
- Acrn build fixes (reported many times)
- pvpanic module table export fix
All of these have been in linux-next for a while with no reported
issues"
* tag 'char-misc-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
misc/pvpanic: Export module FDT device table
misc: fastrpc: restrict user apps from sending kernel RPC messages
virt: acrn: Correct type casting of argument of copy_from_user()
virt: acrn: Use EPOLLIN instead of POLLIN
virt: acrn: Use vfs_poll() instead of f_op->poll()
virt: acrn: Make remove_cpu sysfs invisible with !CONFIG_HOTPLUG_CPU
cpu/hotplug: Fix build error of using {add,remove}_cpu() with !CONFIG_SMP
habanalabs: fix debugfs address translation
habanalabs: Disable file operations after device is removed
habanalabs: Call put_pid() when releasing control device
drivers: habanalabs: remove unused dentry pointer for debugfs files
habanalabs: mark hl_eq_inc_ptr() as static
Pull staging driver fixes from Greg KH:
"Here are some small staging driver fixes for reported problems. They
include:
- wfx header file cleanup patch reverted as it could cause problems
- comedi driver endian fixes
- buffer overflow problems for staging wifi drivers
- build dependency issue for rtl8192e driver
All have been in linux-next for a while with no reported problems"
* tag 'staging-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (23 commits)
Revert "staging: wfx: remove unused included header files"
staging: rtl8188eu: prevent ->ssid overflow in rtw_wx_set_scan()
staging: rtl8188eu: fix potential memory corruption in rtw_check_beacon_data()
staging: rtl8192u: fix ->ssid overflow in r8192_wx_set_scan()
staging: comedi: pcl726: Use 16-bit 0 for interrupt data
staging: comedi: ni_65xx: Use 16-bit 0 for interrupt data
staging: comedi: ni_6527: Use 16-bit 0 for interrupt data
staging: comedi: comedi_parport: Use 16-bit 0 for interrupt data
staging: comedi: amplc_pc236_common: Use 16-bit 0 for interrupt data
staging: comedi: pcl818: Fix endian problem for AI command data
staging: comedi: pcl711: Fix endian problem for AI command data
staging: comedi: me4000: Fix endian problem for AI command data
staging: comedi: dmm32at: Fix endian problem for AI command data
staging: comedi: das800: Fix endian problem for AI command data
staging: comedi: das6402: Fix endian problem for AI command data
staging: comedi: adv_pci1710: Fix endian problem for AI command data
staging: comedi: addi_apci_1500: Fix endian problem for command sample
staging: comedi: addi_apci_1032: Fix endian problem for COS sample
staging: ks7010: prevent buffer overflow in ks_wlan_set_scan()
staging: rtl8712: Fix possible buffer overflow in r8712_sitesurvey_cmd
...
Pull tty/serial fixes from Greg KH:
"Here are some small tty and serial driver fixes to resolve some
reported problems:
- led tty trigger fixes based on review and were acked by the led
maintainer
- revert a max310x serial driver patch as it was causing problems
- revert a pty change as it was also causing problems
All of these have been in linux-next for a while with no reported
problems"
* tag 'tty-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
Revert "drivers:tty:pty: Fix a race causing data loss on close"
Revert "serial: max310x: rework RX interrupt handling"
leds: trigger/tty: Use led_set_brightness_sync() from workqueue
leds: trigger: Fix error path to not unlock the unlocked mutex
Pull USB fixes from Greg KH:
"Here are a small number of USB fixes for 5.12-rc3 to resolve a bunch
of reported issues:
- usbip fixups for issues found by syzbot
- xhci driver fixes and quirk additions
- gadget driver fixes
- dwc3 QCOM driver fix
- usb-serial new ids and fixes
- usblp fix for a long-time issue
- cdc-acm quirk addition
- other tiny fixes for reported problems
All of these have been in linux-next for a while with no reported
issues"
* tag 'usb-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (25 commits)
xhci: Fix repeated xhci wake after suspend due to uncleared internal wake state
usb: xhci: Fix ASMedia ASM1042A and ASM3242 DMA addressing
xhci: Improve detection of device initiated wake signal.
usb: xhci: do not perform Soft Retry for some xHCI hosts
usbip: fix vudc usbip_sockfd_store races leading to gpf
usbip: fix vhci_hcd attach_store() races leading to gpf
usbip: fix stub_dev usbip_sockfd_store() races leading to gpf
usbip: fix vudc to check for stream socket
usbip: fix vhci_hcd to check for stream socket
usbip: fix stub_dev to check for stream socket
usb: dwc3: qcom: Add missing DWC3 OF node refcount decrement
USB: usblp: fix a hang in poll() if disconnected
USB: gadget: udc: s3c2410_udc: fix return value check in s3c2410_udc_probe()
usb: renesas_usbhs: Clear PIPECFG for re-enabling pipe with other EPNUM
usb: dwc3: qcom: Honor wakeup enabled/disabled state
usb: gadget: f_uac1: stop playback on function disable
usb: gadget: f_uac2: always increase endpoint max_packet_size by one audio slot
USB: gadget: u_ether: Fix a configfs return code
usb: dwc3: qcom: add ACPI device id for sc8180x
Goodix Fingerprint device is not a modem
...
Pull erofs fix from Gao Xiang:
"Fix an urgent regression introduced by commit baa2c7c971 ("block:
set .bi_max_vecs as actual allocated vector number"), which could
cause unexpected hung since linux 5.12-rc1.
Resolve it by avoiding using bio->bi_max_vecs completely"
* tag 'erofs-for-5.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
erofs: fix bio->bi_max_vecs behavior change
Pull Kbuild fixes from Masahiro Yamada:
- avoid 'make image_name' invoking syncconfig
- fix a couple of bugs in scripts/dummy-tools
- fix LLD_VENDOR and locale issues in scripts/ld-version.sh
- rebuild GCC plugins when the compiler is upgraded
- allow LTO to be enabled with KASAN_HW_TAGS
- allow LTO to be enabled without LLVM=1
* tag 'kbuild-fixes-v5.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
kbuild: fix ld-version.sh to not be affected by locale
kbuild: remove meaningless parameter to $(call if_changed_rule,dtc)
kbuild: remove LLVM=1 test from HAS_LTO_CLANG
kbuild: remove unneeded -O option to dtc
kbuild: dummy-tools: adjust to scripts/cc-version.sh
kbuild: Allow LTO to be selected with KASAN_HW_TAGS
kbuild: dummy-tools: support MPROFILE_KERNEL checks for ppc
kbuild: rebuild GCC plugins when the compiler is upgraded
kbuild: Fix ld-version.sh script if LLD was built with LLD_VENDOR
kbuild: dummy-tools: fix inverted tests for gcc
kbuild: add image_name to no-sync-config-targets
commit 0d8359620d ("zram: support page writeback") introduced two
problems. It overwrites writeback_store's return value as kstrtol's
return value, which makes return value zero so user could see zero as
return value of write syscall even though it wrote data successfully.
It also breaks index value in the loop in that it doesn't increase the
index any longer. It means it can write only first starting block index
so user couldn't write all idle pages in the zram so lose memory saving
chance.
This patch fixes those issues.
Link: https://lkml.kernel.org/r/20210312173949.2197662-2-minchan@kernel.org
Fixes: 0d8359620d9b("zram: support page writeback")
Signed-off-by: Minchan Kim <minchan@kernel.org>
Reported-by: Amos Bianchi <amosbianchi@google.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: John Dias <joaodias@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In https://bugs.gentoo.org/769614 Dmitry noticed that
`ptrace(PTRACE_GET_SYSCALL_INFO)` does not work for syscalls called via
glibc's syscall() wrapper.
ia64 has two ways to call syscalls from userspace: via `break` and via
`eps` instructions.
The difference is in stack layout:
1. `eps` creates simple stack frame: no locals, in{0..7} == out{0..8}
2. `break` uses userspace stack frame: may be locals (glibc provides
one), in{0..7} == out{0..8}.
Both work fine in syscall handling cde itself.
But `ptrace(PTRACE_GET_SYSCALL_INFO)` uses unwind mechanism to
re-extract syscall arguments but it does not account for locals.
The change always skips locals registers. It should not change `eps`
path as kernel's handler already enforces locals=0 and fixes `break`.
Tested on v5.10 on rx3600 machine (ia64 9040 CPU).
Link: https://lkml.kernel.org/r/20210221002554.333076-1-slyfox@gentoo.org
Link: https://bugs.gentoo.org/769614
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
Reported-by: Dmitry V. Levin <ldv@altlinux.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Userfaultfd self-test fails occasionally, indicating a memory corruption.
Analyzing this problem indicates that there is a real bug since mmap_lock
is only taken for read in mwriteprotect_range() and defers flushes, and
since there is insufficient consideration of concurrent deferred TLB
flushes in wp_page_copy(). Although the PTE is flushed from the TLBs in
wp_page_copy(), this flush takes place after the copy has already been
performed, and therefore changes of the page are possible between the time
of the copy and the time in which the PTE is flushed.
To make matters worse, memory-unprotection using userfaultfd also poses a
problem. Although memory unprotection is logically a promotion of PTE
permissions, and therefore should not require a TLB flush, the current
userrfaultfd code might actually cause a demotion of the architectural PTE
permission: when userfaultfd_writeprotect() unprotects memory region, it
unintentionally *clears* the RW-bit if it was already set. Note that this
unprotecting a PTE that is not write-protected is a valid use-case: the
userfaultfd monitor might ask to unprotect a region that holds both
write-protected and write-unprotected PTEs.
The scenario that happens in selftests/vm/userfaultfd is as follows:
cpu0 cpu1 cpu2
---- ---- ----
[ Writable PTE
cached in TLB ]
userfaultfd_writeprotect()
[ write-*unprotect* ]
mwriteprotect_range()
mmap_read_lock()
change_protection()
change_protection_range()
...
change_pte_range()
[ *clear* “write”-bit ]
[ defer TLB flushes ]
[ page-fault ]
...
wp_page_copy()
cow_user_page()
[ copy page ]
[ write to old
page ]
...
set_pte_at_notify()
A similar scenario can happen:
cpu0 cpu1 cpu2 cpu3
---- ---- ---- ----
[ Writable PTE
cached in TLB ]
userfaultfd_writeprotect()
[ write-protect ]
[ deferred TLB flush ]
userfaultfd_writeprotect()
[ write-unprotect ]
[ deferred TLB flush]
[ page-fault ]
wp_page_copy()
cow_user_page()
[ copy page ]
... [ write to page ]
set_pte_at_notify()
This race exists since commit 292924b260 ("userfaultfd: wp: apply
_PAGE_UFFD_WP bit"). Yet, as Yu Zhao pointed, these races became apparent
since commit 09854ba94c ("mm: do_wp_page() simplification") which made
wp_page_copy() more likely to take place, specifically if page_count(page)
> 1.
To resolve the aforementioned races, check whether there are pending
flushes on uffd-write-protected VMAs, and if there are, perform a flush
before doing the COW.
Further optimizations will follow to avoid during uffd-write-unprotect
unnecassary PTE write-protection and TLB flushes.
Link: https://lkml.kernel.org/r/20210304095423.3825684-1-namit@vmware.com
Fixes: 09854ba94c ("mm: do_wp_page() simplification")
Signed-off-by: Nadav Amit <namit@vmware.com>
Suggested-by: Yu Zhao <yuzhao@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Peter Xu <peterx@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org> [5.9+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
process_madvise currently requires ptrace attach capability.
PTRACE_MODE_ATTACH gives one process complete control over another
process. It effectively removes the security boundary between the two
processes (in one direction). Granting ptrace attach capability even to a
system process is considered dangerous since it creates an attack surface.
This severely limits the usage of this API.
The operations process_madvise can perform do not affect the correctness
of the operation of the target process; they only affect where the data is
physically located (and therefore, how fast it can be accessed). What we
want is the ability for one process to influence another process in order
to optimize performance across the entire system while leaving the
security boundary intact.
Replace PTRACE_MODE_ATTACH with a combination of PTRACE_MODE_READ and
CAP_SYS_NICE. PTRACE_MODE_READ to prevent leaking ASLR metadata and
CAP_SYS_NICE for influencing process performance.
Link: https://lkml.kernel.org/r/20210303185807.2160264-1-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tim Murray <timmurray@google.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: <stable@vger.kernel.org> [5.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Separating compiler-clang.h from compiler-gcc.h inadventently dropped the
definitions of the three HAVE_BUILTIN_BSWAP macros, which requires falling
back to the open-coded version and hoping that the compiler detects it.
Since all versions of clang support the __builtin_bswap interfaces, add
back the flags and have the headers pick these up automatically.
This results in a 4% improvement of compilation speed for arm defconfig.
Note: it might also be worth revisiting which architectures set
CONFIG_ARCH_USE_BUILTIN_BSWAP for one compiler or the other, today this is
set on six architectures (arm32, csky, mips, powerpc, s390, x86), while
another ten architectures define custom helpers (alpha, arc, ia64, m68k,
mips, nios2, parisc, sh, sparc, xtensa), and the rest (arm64, h8300,
hexagon, microblaze, nds32, openrisc, riscv) just get the unoptimized
version and rely on the compiler to detect it.
A long time ago, the compiler builtins were architecture specific, but
nowadays, all compilers that are able to build the kernel have correct
implementations of them, though some may not be as optimized as the inline
asm versions.
The patch that dropped the optimization landed in v4.19, so as discussed
it would be fairly safe to backport this revert to stable kernels to the
4.19/5.4/5.10 stable kernels, but there is a remaining risk for
regressions, and it has no known side-effects besides compile speed.
Link: https://lkml.kernel.org/r/20210226161151.2629097-1-arnd@kernel.org
Link: https://lore.kernel.org/lkml/20210225164513.3667778-1-arnd@kernel.org/
Fixes: 815f0ddb34 ("include/linux/compiler*.h: make compiler-*.h mutually exclusive")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Guo Ren <guoren@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 7b4693e644 ("MAINTAINERS: add uapi directories to API/ABI
section") added include/uapi/ and arch/*/include/uapi/ so that patches
modifying them CC linux-api. However that was already done in the past
and resulted in too much noise and thus later removed, as explained in
b14fd334ff ("MAINTAINERS: trim the file triggers for ABI/API")
To prevent another round of addition and removal in the future, change the
entries to X: (explicit exclusion) for documentation purposes, although
they are not subdirectories of broader included directories, as there is
apparently no defined way to add plain comments in subsystem sections.
Link: https://lkml.kernel.org/r/20210301100255.25229-1-vbabka@suse.cz
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reported-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Acked-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a deadlock in bm_register_write:
First, in the begining of the function, a lock is taken on the binfmt_misc
root inode with inode_lock(d_inode(root)).
Then, if the user used the MISC_FMT_OPEN_FILE flag, the function will call
open_exec on the user-provided interpreter.
open_exec will call a path lookup, and if the path lookup process includes
the root of binfmt_misc, it will try to take a shared lock on its inode
again, but it is already locked, and the code will get stuck in a deadlock
To reproduce the bug:
$ echo ":iiiii:E::ii::/proc/sys/fs/binfmt_misc/bla:F" > /proc/sys/fs/binfmt_misc/register
backtrace of where the lock occurs (#5):
0 schedule () at ./arch/x86/include/asm/current.h:15
1 0xffffffff81b51237 in rwsem_down_read_slowpath (sem=0xffff888003b202e0, count=<optimized out>, state=state@entry=2) at kernel/locking/rwsem.c:992
2 0xffffffff81b5150a in __down_read_common (state=2, sem=<optimized out>) at kernel/locking/rwsem.c:1213
3 __down_read (sem=<optimized out>) at kernel/locking/rwsem.c:1222
4 down_read (sem=<optimized out>) at kernel/locking/rwsem.c:1355
5 0xffffffff811ee22a in inode_lock_shared (inode=<optimized out>) at ./include/linux/fs.h:783
6 open_last_lookups (op=0xffffc9000022fe34, file=0xffff888004098600, nd=0xffffc9000022fd10) at fs/namei.c:3177
7 path_openat (nd=nd@entry=0xffffc9000022fd10, op=op@entry=0xffffc9000022fe34, flags=flags@entry=65) at fs/namei.c:3366
8 0xffffffff811efe1c in do_filp_open (dfd=<optimized out>, pathname=pathname@entry=0xffff8880031b9000, op=op@entry=0xffffc9000022fe34) at fs/namei.c:3396
9 0xffffffff811e493f in do_open_execat (fd=fd@entry=-100, name=name@entry=0xffff8880031b9000, flags=<optimized out>, flags@entry=0) at fs/exec.c:913
10 0xffffffff811e4a92 in open_exec (name=<optimized out>) at fs/exec.c:948
11 0xffffffff8124aa84 in bm_register_write (file=<optimized out>, buffer=<optimized out>, count=19, ppos=<optimized out>) at fs/binfmt_misc.c:682
12 0xffffffff811decd2 in vfs_write (file=file@entry=0xffff888004098500, buf=buf@entry=0xa758d0 ":iiiii:E::ii::i:CF
", count=count@entry=19, pos=pos@entry=0xffffc9000022ff10) at fs/read_write.c:603
13 0xffffffff811defda in ksys_write (fd=<optimized out>, buf=0xa758d0 ":iiiii:E::ii::i:CF
", count=19) at fs/read_write.c:658
14 0xffffffff81b49813 in do_syscall_64 (nr=<optimized out>, regs=0xffffc9000022ff58) at arch/x86/entry/common.c:46
15 0xffffffff81c0007c in entry_SYSCALL_64 () at arch/x86/entry/entry_64.S:120
To solve the issue, the open_exec call is moved to before the write
lock is taken by bm_register_write
Link: https://lkml.kernel.org/r/20210228224414.95962-1-liorribak@gmail.com
Fixes: 948b701a60 ("binfmt_misc: add persistent opened binary handler for containers")
Signed-off-by: Lior Ribak <liorribak@gmail.com>
Acked-by: Helge Deller <deller@gmx.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
zero_user_segments() is used from __block_write_begin_int(), for example
like the following
zero_user_segments(page, 4096, 1024, 512, 918)
But new the zero_user_segments() implementation for for HIGHMEM +
TRANSPARENT_HUGEPAGE doesn't handle "start > end" case correctly, and hits
BUG_ON(). (we can fix __block_write_begin_int() instead though, it is the
old and multiple usage)
Also it calls kmap_atomic() unnecessarily while start == end == 0.
Link: https://lkml.kernel.org/r/87v9ab60r4.fsf@mail.parknet.co.jp
Fixes: 0060ef3b4e ("mm: support THPs in zero_user_segments")
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
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>
