On s390 systems (aka mainframes), it has classic channel devices for
networking and permanent storage that are currently even more common than
PCI devices.  Hence it could have a fully functional s390 kernel with
CONFIG_PCI=n, then the relevant iomem mapping functions [including
ioremap(), devm_ioremap(), etc.] are not available.

Here let AL_FIC depend on HAS_IOMEM so that it won't be built
to cause below compiling error if PCI is unset:

------
ld: drivers/irqchip/irq-al-fic.o: in function `al_fic_init_dt':
irq-al-fic.c:(.init.text+0x76): undefined reference to `of_iomap'
ld: irq-al-fic.c:(.init.text+0x4ce): undefined reference to `iounmap'
------

Link: https://lkml.kernel.org/r/20230707135852.24292-7-bhe@redhat.comReported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202306211329.ticOJCSv-lkp@intel.com/Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

On s390 systems (aka mainframes), it has classic channel devices for
networking and permanent storage that are currently even more common than
PCI devices.  Hence it could have a fully functional s390 kernel with
CONFIG_PCI=n, then the relevant iomem mapping functions [including
ioremap(), devm_ioremap(), etc.] are not available.

Here let ALTERA_TSE depend on HAS_IOMEM so that it won't be built to cause
below compiling error if PCI is unset:

------
ERROR: modpost: "devm_ioremap" [drivers/net/ethernet/altera/altera_tse.ko] undefined!
------

Link: https://lkml.kernel.org/r/20230707135852.24292-6-bhe@redhat.comReported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202306211329.ticOJCSv-lkp@intel.com/Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: Joyce Ooi <joyce.ooi@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Turn 'semadj' in 'struct sem_undo' into a flexible array.

The advantages are:
   - save the size of a pointer when the new undo structure is allocated
   - avoid some always ugly pointer arithmetic to get the address of semadj
   - avoid an indirection when the array is accessed

While at it, use struct_size() to compute the size of the new undo
structure.

Link: https://lkml.kernel.org/r/1ba993d443ad7e16ac2b1902adab1f05ebdfa454.1688918791.git.christophe.jaillet@wanadoo.frSigned-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Manfred Spraul <manfred@colorfullife.com>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Jann Horn <jannh@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

strlcpy() reads the entire source buffer first.  This read may exceed the
destination size limit.  This is both inefficient and can lead to linear
read overflows if a source string is not NUL-terminated [1].  In an effort
to remove strlcpy() completely [2], replace strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Link: https://lkml.kernel.org/r/20230710011748.3538624-1-azeemshaikh38@gmail.comSigned-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Make the print-fatal-signals message more useful by printing the comm
and the exe name for the process which received the fatal signal:

Before:

 potentially unexpected fatal signal 4
 potentially unexpected fatal signal 11

After:

 buggy-program: pool: potentially unexpected fatal signal 4
 some-daemon: gdbus: potentially unexpected fatal signal 11

comm used to be present but was removed in commit 681a90ff
("arc, print-fatal-signals: reduce duplicated information") because it's
also included as part of the later stack trace.  Having the comm as part
of the main "unexpected fatal..." print is rather useful though when
analysing logs, and the exe name is also valuable as shown in the
examples above where the comm ends up having some generic name like
"pool".

[akpm@linux-foundation.org: don't include linux/file.h twice]
Link: https://lkml.kernel.org/r/20230707-fatal-comm-v1-1-400363905d5e@axis.comSigned-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

CONFIG_* switches should not be exposed in uapi headers.  The macros that
are defined here are also only useful for the kernel code, so let's move
them to asm/cmpxchg.h instead.

The only two files that are using these macros are the headers
arch/ia64/include/asm/bitops.h and arch/ia64/include/asm/atomic.h and
these include asm/cmpxchg.h via asm/intrinsics.h, so this movement should
not cause any trouble.

Link: https://lkml.kernel.org/r/20230426065032.517693-1-thuth@redhat.comSigned-off-by: Thomas Huth <thuth@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

kmap() has been deprecated in favor of the kmap_local_page() due to high
cost, restricted mapping space, the overhead of a global lock for
synchronization, and making the process sleep in the absence of free
slots.

kmap_local_page() is faster than kmap() and offers thread-local and
CPU-local mappings, take pagefaults in a local kmap region and preserves
preemption by saving the mappings of outgoing tasks and restoring those of
the incoming one during a context switch.

The mappings are kept thread local in the functions “dmirror_do_read”
and “dmirror_do_write” in test_hmm.c

Therefore, replace kmap() with kmap_local_page() and use
mempcy_from/to_page() to avoid open coding kmap_local_page() + memcpy() +
kunmap_local().

Remove the unused variable “tmp”.

Link: https://lkml.kernel.org/r/20230610175712.GA348514@sumitra.comSigned-off-by: Sumitra Sharma <sumitraartsy@gmail.com>
Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Fabio M. De Francesco <fmdefrancesco@gmail.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Cc: Deepak R Varma <drv@mailo.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

This test is arch specific, requires "munmap everything" primitive.

Link: https://lkml.kernel.org/r/20230630183434.17434-2-adobriyan@gmail.comSigned-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Björn Töpel <bjorn@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Unmap everything starting from 4GB length until it unmaps, otherwise test
has to detect which virtual memory split kernel is using.

Link: https://lkml.kernel.org/r/20230630183434.17434-1-adobriyan@gmail.comSigned-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Björn Töpel <bjorn@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Use current logging style.

Link: https://lkml.kernel.org/r/20230625033452.GA22858@didi-ThinkCentre-M930t-N000Signed-off-by: tiozhang <tiozhang@didiglobal.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Joe Perches <joe@perches.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Paulo Alcantara <pc@cjr.nz>
Cc: Weiping Zhang <zwp10758@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Pull spi fixes from Mark Brown:
 "A bunch of fixes for the Qualcomm QSPI driver, fixing multiple issues
  with the newly added DMA mode - it had a number of issues exposed when
  tested in a wider range of use cases, both race condition style issues
  and issues with different inputs to those that had been used in test"

* tag 'spi-fix-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: spi-qcom-qspi: Add mem_ops to avoid PIO for badly sized reads
  spi: spi-qcom-qspi: Fallback to PIO for xfers that aren't multiples of 4 bytes
  spi: spi-qcom-qspi: Add DMA_CHAIN_DONE to ALL_IRQS
  spi: spi-qcom-qspi: Call dma_wmb() after setting up descriptors
  spi: spi-qcom-qspi: Use GFP_ATOMIC flag while allocating for descriptor
  spi: spi-qcom-qspi: Ignore disabled interrupts' status in isr

Merge tag 'regulator-fix-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Pull regulator fixes from Mark Brown:
 "A couple of small fixes for the the mt6358 driver, fixing error
  reporting and a bootstrapping issue"

* tag 'regulator-fix-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator:
  regulator: mt6358: Fix incorrect VCN33 sync error message
  regulator: mt6358: Sync VCN33_* enable status after checking ID

Pull USB fixes from Greg KH:
 "Here are a set of USB driver fixes for 6.5-rc4. Include in here are:

   - new USB serial device ids

   - dwc3 driver fixes for reported issues

   - typec driver fixes for reported problems

   - gadget driver fixes

   - reverts of some problematic USB changes that went into -rc1

  All of these have been in linux-next with no reported problems"

* tag 'usb-6.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (24 commits)
  usb: misc: ehset: fix wrong if condition
  usb: dwc3: pci: skip BYT GPIO lookup table for hardwired phy
  usb: cdns3: fix incorrect calculation of ep_buf_size when more than one config
  usb: gadget: call usb_gadget_check_config() to verify UDC capability
  usb: typec: Use sysfs_emit_at when concatenating the string
  usb: typec: Iterate pds array when showing the pd list
  usb: typec: Set port->pd before adding device for typec_port
  usb: typec: qcom: fix return value check in qcom_pmic_typec_probe()
  Revert "usb: gadget: tegra-xudc: Fix error check in tegra_xudc_powerdomain_init()"
  Revert "usb: xhci: tegra: Fix error check"
  USB: gadget: Fix the memory leak in raw_gadget driver
  usb: gadget: core: remove unbalanced mutex_unlock in usb_gadget_activate
  Revert "usb: dwc3: core: Enable AutoRetry feature in the controller"
  Revert "xhci: add quirk for host controllers that don't update endpoint DCS"
  USB: quirks: add quirk for Focusrite Scarlett
  usb: xhci-mtk: set the dma max_seg_size
  MAINTAINERS: drop invalid usb/cdns3 Reviewer e-mail
  usb: dwc3: don't reset device side if dwc3 was configured as host-only
  usb: typec: ucsi: move typec_set_mode(TYPEC_STATE_SAFE) to ucsi_unregister_partner()
  usb: ohci-at91: Fix the unhandle interrupt when resume
  ...

Pull tty/serial fixes from Greg KH:
 "Here are some small TTY and serial driver fixes for 6.5-rc4 for some
  reported problems. Included in here is:

   - TIOCSTI fix for braille readers

   - documentation fix for minor numbers

   - MAINTAINERS update for new serial files in -rc1

   - minor serial driver fixes for reported problems

  All of these have been in linux-next with no reported problems"

* tag 'tty-6.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  serial: 8250_dw: Preserve original value of DLF register
  tty: serial: sh-sci: Fix sleeping in atomic context
  serial: sifive: Fix sifive_serial_console_setup() section
  Documentation: devices.txt: reconcile serial/ucc_uart minor numers
  MAINTAINERS: Update TTY layer for lists and recently added files
  tty: n_gsm: fix UAF in gsm_cleanup_mux
  TIOCSTI: always enable for CAP_SYS_ADMIN

Pull staging driver fixes from Greg KH:
 "Here are three small staging driver fixes for 6.5-rc4 that resolve
  some reported problems. These fixes are:

   - fix for an old bug in the r8712 driver

   - fbtft driver fix for a spi device

   - potential overflow fix in the ks7010 driver

  All of these have been in linux-next with no reported problems"

* tag 'staging-6.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
  staging: ks7010: potential buffer overflow in ks_wlan_set_encode_ext()
  staging: fbtft: ili9341: use macro FBTFT_REGISTER_SPI_DRIVER
  staging: r8712: Fix memory leak in _r8712_init_xmit_priv()

Pull char driver and Documentation fixes from Greg KH:
 "Here is a char driver fix and some documentation updates for 6.5-rc4
  that contain the following changes:

   - sram/genalloc bugfix for reported problem

   - security-bugs.rst update based on recent discussions

   - embargoed-hardware-issues minor cleanups and then partial revert
     for the project/company lists

  All of these have been in linux-next for a while with no reported
  problems, and the documentation updates have all been reviewed by the
  relevant developers"

* tag 'char-misc-6.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  misc/genalloc: Name subpools by of_node_full_name()
  Documentation: embargoed-hardware-issues.rst: add AMD to the list
  Documentation: embargoed-hardware-issues.rst: clean out empty and unused entries
  Documentation: security-bugs.rst: clarify CVE handling
  Documentation: security-bugs.rst: update preferences when dealing with the linux-distros group

Merge tag 'probes-fixes-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probe fixes from Masami Hiramatsu:

 - probe-events: add NULL check for some BTF API calls which can return
   error code and NULL.

 - ftrace selftests: check fprobe and kprobe event correctly. This fixes
   a miss condition of the test command.

 - kprobes: do not allow probing functions that start with "__cfi_" or
   "__pfx_" since those are auto generated for kernel CFI and not
   executed.

* tag 'probes-fixes-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  kprobes: Prohibit probing on CFI preamble symbol
  selftests/ftrace: Fix to check fprobe event eneblement
  tracing/probes: Fix to add NULL check for BTF APIs

Pull kvm fixes from Paolo Bonzini:
 "x86:

   - Do not register IRQ bypass consumer if posted interrupts not
     supported

   - Fix missed device interrupt due to non-atomic update of IRR

   - Use GFP_KERNEL_ACCOUNT for pid_table in ipiv

   - Make VMREAD error path play nice with noinstr

   - x86: Acquire SRCU read lock when handling fastpath MSR writes

   - Support linking rseq tests statically against glibc 2.35+

   - Fix reference count for stats file descriptors

   - Detect userspace setting invalid CR0

  Non-KVM:

   - Remove coccinelle script that has caused multiple confusion
     ("debugfs, coccinelle: check for obsolete DEFINE_SIMPLE_ATTRIBUTE()
     usage", acked by Greg)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (21 commits)
  KVM: selftests: Expand x86's sregs test to cover illegal CR0 values
  KVM: VMX: Don't fudge CR0 and CR4 for restricted L2 guest
  KVM: x86: Disallow KVM_SET_SREGS{2} if incoming CR0 is invalid
  Revert "debugfs, coccinelle: check for obsolete DEFINE_SIMPLE_ATTRIBUTE() usage"
  KVM: selftests: Verify stats fd is usable after VM fd has been closed
  KVM: selftests: Verify stats fd can be dup()'d and read
  KVM: selftests: Verify userspace can create "redundant" binary stats files
  KVM: selftests: Explicitly free vcpus array in binary stats test
  KVM: selftests: Clean up stats fd in common stats_test() helper
  KVM: selftests: Use pread() to read binary stats header
  KVM: Grab a reference to KVM for VM and vCPU stats file descriptors
  selftests/rseq: Play nice with binaries statically linked against glibc 2.35+
  Revert "KVM: SVM: Skip WRMSR fastpath on VM-Exit if next RIP isn't valid"
  KVM: x86: Acquire SRCU read lock when handling fastpath MSR writes
  KVM: VMX: Use vmread_error() to report VM-Fail in "goto" path
  KVM: VMX: Make VMREAD error path play nice with noinstr
  KVM: x86/irq: Conditionally register IRQ bypass consumer again
  KVM: X86: Use GFP_KERNEL_ACCOUNT for pid_table in ipiv
  KVM: x86: check the kvm_cpu_get_interrupt result before using it
  KVM: x86: VMX: set irr_pending in kvm_apic_update_irr
  ...

Pull locking fix from Borislav Petkov:

 - Fix a rtmutex race condition resulting from sharing of the sort key
   between the lock waiters and the PI chain tree (->pi_waiters) of a
   task by giving each tree their own sort key

* tag 'locking_urgent_for_v6.5_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rtmutex: Fix task->pi_waiters integrity

Pull x86 fixes from Borislav Petkov:

 - AMD's automatic IBRS doesn't enable cross-thread branch target
   injection protection (STIBP) for user processes. Enable STIBP on such
   systems.

 - Do not delete (but put the ref instead) of AMD MCE error thresholding
   sysfs kobjects when destroying them in order not to delete the kernfs
   pointer prematurely

 - Restore annotation in ret_from_fork_asm() in order to fix kthread
   stack unwinding from being marked as unreliable and thus breaking
   livepatching

* tag 'x86_urgent_for_v6.5_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Enable STIBP on AMD if Automatic IBRS is enabled
  x86/MCE/AMD: Decrement threshold_bank refcount when removing threshold blocks
  x86: Fix kthread unwind

Pull irq fixes from Borislav Petkov:

 - Work around an erratum on GIC700, where a race between a CPU handling
   a wake-up interrupt, a change of affinity, and another CPU going to
   sleep can result in a lack of wake-up event on the next interrupt

 - Fix the locking required on a VPE for GICv4

 - Enable Rockchip 3588001 erratum workaround for RK3588S

 - Fix the irq-bcm6345-l1 assumtions of the boot CPU always be the first
   CPU in the system

* tag 'irq_urgent_for_v6.5_rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3: Workaround for GIC-700 erratum 2941627
  irqchip/gic-v3: Enable Rockchip 3588001 erratum workaround for RK3588S
  irqchip/gic-v4.1: Properly lock VPEs when doing a directLPI invalidation
  irq-bcm6345-l1: Do not assume a fixed block to cpu mapping

Pull smb client fixes from Steve French:
 "Four small SMB3 client fixes:

   - two reconnect fixes (to address the case where non-default
     iocharset gets incorrectly overridden at reconnect with the
     default charset)

   - fix for NTLMSSP_AUTH request setting a flag incorrectly)

   - Add missing check for invalid tlink (tree connection) in ioctl"

* tag '6.5-rc3-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: add missing return value check for cifs_sb_tlink
  smb3: do not set NTLMSSP_VERSION flag for negotiate not auth request
  cifs: fix charset issue in reconnection
  fs/nls: make load_nls() take a const parameter

Pull tracing fixes from Steven Rostedt:

 - Fix to /sys/kernel/tracing/per_cpu/cpu*/stats read and entries.

   If a resize shrinks the buffer it clears the read count to notify
   readers that they need to reset. But the read count is also used for
   accounting and this causes the numbers to be off. Instead, create a
   separate variable to use to notify readers to reset.

 - Fix the ref counts of the "soft disable" mode. The wrong value was
   used for testing if soft disable mode should be enabled or disable,
   but instead, just change the logic to do the enable and disable in
   place when the SOFT_MODE is set or cleared.

 - Several kernel-doc fixes

 - Removal of unused external declarations

* tag 'trace-v6.5-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Fix warning in trace_buffered_event_disable()
  ftrace: Remove unused extern declarations
  tracing: Fix kernel-doc warnings in trace_seq.c
  tracing: Fix kernel-doc warnings in trace_events_trigger.c
  tracing/synthetic: Fix kernel-doc warnings in trace_events_synth.c
  ring-buffer: Fix kernel-doc warnings in ring_buffer.c
  ring-buffer: Fix wrong stat of cpu_buffer->read

Commit a2225d93 ("autofs: remove left-over autofs4 stubs")
promised the removal of the fs/autofs/Kconfig fragment for AUTOFS4_FS
within a couple of releases, but five years later this still has not
happened yet, and AUTOFS4_FS is still enabled in 63 defconfigs.

Get rid of it mechanically:

   git grep -l CONFIG_AUTOFS4_FS -- '*defconfig' |
       xargs sed -i 's/AUTOFS4_FS/AUTOFS_FS/'

Also just remove the AUTOFS4_FS config option stub.  Anybody who hasn't
regenerated their config file in the last five years will need to just
get the new name right when they do.
Signed-off-by: Sven Joachim <svenjoac@gmx.de>
Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'loongarch-fixes-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson

Pull LoongArch fixes from Huacai Chen:
 "Some bug fixes for build system, builtin cmdline handling, bpf and
  {copy, clear}_user, together with a trivial cleanup"

* tag 'loongarch-fixes-6.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson:
  LoongArch: Cleanup __builtin_constant_p() checking for cpu_has_*
  LoongArch: BPF: Fix check condition to call lu32id in move_imm()
  LoongArch: BPF: Enable bpf_probe_read{, str}() on LoongArch
  LoongArch: Fix return value underflow in exception path
  LoongArch: Fix CMDLINE_EXTEND and CMDLINE_BOOTLOADER handling
  LoongArch: Fix module relocation error with binutils 2.41
  LoongArch: Only fiddle with CHECKFLAGS if `need-compiler'

Add coverage to x86's set_sregs_test to verify KVM rejects vendor-agnostic
illegal CR0 values, i.e. CR0 values whose legality doesn't depend on the
current VMX mode.  KVM historically has neglected to reject bad CR0s from
userspace, i.e. would happily accept a completely bogus CR0 via
KVM_SET_SREGS{2}.

Punt VMX specific subtests to future work, as they would require quite a
bit more effort, and KVM gets coverage for CR0 checks in general through
other means, e.g. KVM-Unit-Tests.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230613203037.1968489-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Stuff CR0 and/or CR4 to be compliant with a restricted guest if and only
if KVM itself is not configured to utilize unrestricted guests, i.e. don't
stuff CR0/CR4 for a restricted L2 that is running as the guest of an
unrestricted L1.  Any attempt to VM-Enter a restricted guest with invalid
CR0/CR4 values should fail, i.e. in a nested scenario, KVM (as L0) should
never observe a restricted L2 with incompatible CR0/CR4, since nested
VM-Enter from L1 should have failed.

And if KVM does observe an active, restricted L2 with incompatible state,
e.g. due to a KVM bug, fudging CR0/CR4 instead of letting VM-Enter fail
does more harm than good, as KVM will often neglect to undo the side
effects, e.g. won't clear rmode.vm86_active on nested VM-Exit, and thus
the damage can easily spill over to L1.  On the other hand, letting
VM-Enter fail due to bad guest state is more likely to contain the damage
to L2 as KVM relies on hardware to perform most guest state consistency
checks, i.e. KVM needs to be able to reflect a failed nested VM-Enter into
L1 irrespective of (un)restricted guest behavior.

Cc: Jim Mattson <jmattson@google.com>
Cc: stable@vger.kernel.org
Fixes: bddd82d1 ("KVM: nVMX: KVM needs to unset "unrestricted guest" VM-execution control in vmcs02 if vmcs12 doesn't set it")
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230613203037.1968489-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Reject KVM_SET_SREGS{2} with -EINVAL if the incoming CR0 is invalid,
e.g. due to setting bits 63:32, illegal combinations, or to a value that
isn't allowed in VMX (non-)root mode.  The VMX checks in particular are
"fun" as failure to disallow Real Mode for an L2 that is configured with
unrestricted guest disabled, when KVM itself has unrestricted guest
enabled, will result in KVM forcing VM86 mode to virtual Real Mode for
L2, but then fail to unwind the related metadata when synthesizing a
nested VM-Exit back to L1 (which has unrestricted guest enabled).

Opportunistically fix a benign typo in the prototype for is_valid_cr4().

Cc: stable@vger.kernel.org
Reported-by: syzbot+5feef0b9ee9c8e9e5689@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000f316b705fdf6e2b4@google.comSigned-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230613203037.1968489-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Remove coccinelle's recommendation to use DEFINE_DEBUGFS_ATTRIBUTE()
instead of DEFINE_SIMPLE_ATTRIBUTE().  Regardless of whether or not the
"significant overhead" incurred by debugfs_create_file() is actually
meaningful, warnings from the script have led to a rash of low-quality
patches that have sowed confusion and consumed maintainer time for little
to no benefit.  There have been no less than four attempts to "fix" KVM,
and a quick search on lore shows that KVM is not alone.

This reverts commit 5103068e.

Link: https://lore.kernel.org/all/87tu2nbnz3.fsf@mpe.ellerman.id.au
Link: https://lore.kernel.org/all/c0b98151-16b6-6d8f-1765-0f7d46682d60@redhat.com
Link: https://lkml.kernel.org/r/20230706072954.4881-1-duminjie%40vivo.com
Link: https://lore.kernel.org/all/Y2FsbufV00jbyF0B@google.com
Link: https://lore.kernel.org/all/Y2ENJJ1YiSg5oHiy@orome
Link: https://lore.kernel.org/all/7560b350e7b23786ce712118a9a504356ff1cca4.camel@kernel.orgSuggested-by: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230726202920.507756-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Verify that VM and vCPU binary stats files are usable even after userspace
has put its last direct reference to the VM.  This is a regression test
for a UAF bug where KVM didn't gift the stats files a reference to the VM.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230711230131.648752-8-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Expand the binary stats test to verify that a stats fd can be dup()'d
and read, to (very) roughly simulate userspace passing around the file.
Adding the dup() test is primarily an intermediate step towards verifying
that userspace can read VM/vCPU stats before _and_ after userspace closes
its copy of the VM fd; the dup() test itself is only mildly interesting.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230711230131.648752-7-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Verify that KVM doesn't artificially limit KVM_GET_STATS_FD to a single
file per VM/vCPU.  There's no known use case for getting multiple stats
fds, but it should work, and more importantly creating multiple files will
make it easier to test that KVM correct manages VM refcounts for stats
files.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230711230131.648752-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Explicitly free the all-encompassing vcpus array in the binary stats test
so that the test is consistent with respect to freeing all dynamically
allocated resources (versus letting them be freed on exit).
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230711230131.648752-5-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Move the stats fd cleanup code into stats_test() and drop the
superfluous vm_stats_test() and vcpu_stats_test() helpers in order to
decouple creation of the stats file from consuming/testing the file
(deduping code is a bonus).  This will make it easier to test various
edge cases related to stats, e.g. that userspace can dup() a stats fd,
that userspace can have multiple stats files for a singleVM/vCPU, etc.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230711230131.648752-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Use pread() with an explicit offset when reading the header and the header
name for a binary stats fd so that the common helper and the binary stats
test don't subtly rely on the file effectively being untouched, e.g. to
allow multiple reads of the header, name, etc.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230711230131.648752-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Grab a reference to KVM prior to installing VM and vCPU stats file
descriptors to ensure the underlying VM and vCPU objects are not freed
until the last reference to any and all stats fds are dropped.

Note, the stats paths manually invoke fd_install() and so don't need to
grab a reference before creating the file.

Fixes: ce55c049 ("KVM: stats: Support binary stats retrieval for a VCPU")
Fixes: fcfe1bae ("KVM: stats: Support binary stats retrieval for a VM")
Reported-by: Zheng Zhang <zheng.zhang@email.ucr.edu>
Closes: https://lore.kernel.org/all/CAC_GQSr3xzZaeZt85k_RCBd5kfiOve8qXo7a81Cq53LuVQ5r=Q@mail.gmail.com
Cc: stable@vger.kernel.org
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Message-Id: <20230711230131.648752-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

To allow running rseq and KVM's rseq selftests as statically linked
binaries, initialize the various "trampoline" pointers to point directly
at the expect glibc symbols, and skip the dlysm() lookups if the rseq
size is non-zero, i.e. the binary is statically linked *and* the libc
registered its own rseq.

Define weak versions of the symbols so as not to break linking against
libc versions that don't support rseq in any capacity.

The KVM selftests in particular are often statically linked so that they
can be run on targets with very limited runtime environments, i.e. test
machines.

Fixes: 233e667e ("selftests/rseq: Uplift rseq selftests for compatibility with glibc-2.35")
Cc: Aaron Lewis <aaronlewis@google.com>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230721223352.2333911-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Now that handle_fastpath_set_msr_irqoff() acquires kvm->srcu, i.e. allows
dereferencing memslots during WRMSR emulation, drop the requirement that
"next RIP" is valid.  In hindsight, acquiring kvm->srcu would have been a
better fix than avoiding the pastpath, but at the time it was thought that
accessing SRCU-protected data in the fastpath was a one-off edge case.

This reverts commit 5c30e810.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230721224337.2335137-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Temporarily acquire kvm->srcu for read when potentially emulating WRMSR in
the VM-Exit fastpath handler, as several of the common helpers used during
emulation expect the caller to provide SRCU protection.  E.g. if the guest
is counting instructions retired, KVM will query the PMU event filter when
stepping over the WRMSR.

  dump_stack+0x85/0xdf
  lockdep_rcu_suspicious+0x109/0x120
  pmc_event_is_allowed+0x165/0x170
  kvm_pmu_trigger_event+0xa5/0x190
  handle_fastpath_set_msr_irqoff+0xca/0x1e0
  svm_vcpu_run+0x5c3/0x7b0 [kvm_amd]
  vcpu_enter_guest+0x2108/0x2580

Alternatively, check_pmu_event_filter() could acquire kvm->srcu, but this
isn't the first bug of this nature, e.g. see commit 5c30e810 ("KVM:
SVM: Skip WRMSR fastpath on VM-Exit if next RIP isn't valid").  Providing
protection for the entirety of WRMSR emulation will allow reverting the
aforementioned commit, and will avoid having to play whack-a-mole when new
uses of SRCU-protected structures are inevitably added in common emulation
helpers.

Fixes: dfdeda67 ("KVM: x86/pmu: Prevent the PMU from counting disallowed events")
Reported-by: Greg Thelen <gthelen@google.com>
Reported-by: Aaron Lewis <aaronlewis@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230721224337.2335137-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>