Make two nonfunctional changes to the vector get/set vector reg
functions and their supporting function for simplification and
readability. The first is to not pass KVM_REG_RISCV_VECTOR, but
rather integrate it directly into the masking. The second is to
rename reg_val to reg_addr where and address is used instead of
a value.

Also opportunistically touch up some of the code formatting for
a third nonfunctional change.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

The EBUSY errno is being used for KVM_SET_ONE_REG as a way to tell
userspace that a given reg can't be changed after the vcpu started.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

kvm_riscv_vcpu_(get/set)_reg_vector() now returns ENOENT if V is not
available, EINVAL if reg type is not of VECTOR type, and any error that
might be thrown by kvm_riscv_vcpu_vreg_addr().
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

riscv_vcpu_set_isa_ext_single() will prevent any write of isa_ext regs
if the vcpu already started spinning.

But if there's no extension state (enabled/disabled) made by the
userspace, there's no need to -EBUSY out - we can treat the operation as
a no-op.

zicbom/zicboz_block_size, ISA config reg and mvendorid/march/mimpid
already works in a more permissive manner w.r.t userspace writes being a
no-op, so let's do the same with isa_ext writes.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

Right now we do not allow any write in mvendorid/marchid/mimpid if the
vcpu already started, preventing these regs to be changed.

However, if userspace doesn't change them, an alternative is to consider
the reg write a no-op and avoid erroring out altogether. Userpace can
then be oblivious about KVM internals if no changes were intended in the
first place.

Allow the same form of 'lazy writing' that registers such as
zicbom/zicboz_block_size supports: avoid erroring out if userspace makes
no changes in mvendorid/marchid/mimpid during reg write.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

kvm_riscv_vcpu_set_reg_config() will return -EBUSY if the ISA config reg
is being written after the VCPU ran at least once.

The same restriction isn't placed in kvm_riscv_vcpu_get_reg_config(), so
there's a chance that we'll -EBUSY out on an ISA config reg write even
if the userspace intended no changes to it.

We'll allow the same form of 'lazy writing' that registers such as
zicbom/zicboz_block_size supports: avoid erroring out if userspace made
no changes to the ISA config reg.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

vcpu_set_reg_config() and vcpu_set_reg_isa_ext() is throwing an
EOPNOTSUPP error when !vcpu->arch.ran_atleast_once. In similar cases
we're throwing an EBUSY error, like in mvendorid/marchid/mimpid
set_reg().

EOPNOTSUPP has a conotation of finality. EBUSY is more adequate in this
case since its a condition/error related to the vcpu lifecycle.

Change these EOPNOTSUPP instances to EBUSY.
Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

The KVM_REG_RISCV_TIMER_REG can be read via get_one_reg(). But trying to
write anything in this reg via set_one_reg() results in an EOPNOTSUPP.

Change the API to behave like cbom_block_size: instead of always
erroring out with EOPNOTSUPP, allow userspace to write the same value
(riscv_timebase) back, throwing an EINVAL if a different value is
attempted.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

zicbom_block_size and zicboz_block_size have a peculiar API: they can be
read via get_one_reg() but any write will return a EOPNOTSUPP.

It makes sense to return a 'not supported' error since both values can't
be changed, but as far as userspace goes they're regs that are throwing
the same EOPNOTSUPP error even if they were read beforehand via
get_one_reg(), even if the same  read value is being written back.
EOPNOTSUPP is also returned even if ZICBOM/ZICBOZ aren't enabled in the
host.

Change both to work more like their counterparts in get_one_reg() and
return -ENOENT if their respective extensions aren't available. After
that, check if the userspace is written a valid value (i.e. the host
value). Throw an -EINVAL if that's not case, let it slide otherwise.

This allows both regs to be read/written by userspace in a 'lazy'
manner, as long as the userspace doesn't change the reg vals.
Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

Following a similar logic as the previous patch let's minimize the EINVAL
usage in *_one_reg() APIs by using ENOENT when an extension that
implements the reg is not available.

For consistency we're also replacing an EOPNOTSUPP instance that should
be an ENOENT since it's an "extension is not available" error.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

get_one_reg() and set_one_reg() are returning EINVAL errors for almost
everything: if a reg doesn't exist, if a reg ID is malformatted, if the
associated CPU extension that implements the reg isn't present in the
host, and for set_one_reg() if the value being written is invalid.

This isn't wrong according to the existing KVM API docs (EINVAL can be
used when there's no such register) but adding more ENOENT instances
will make easier for userspace to understand what went wrong.

Existing userspaces can be affected by this error code change. We
checked a few. As of current upstream code, crosvm doesn't check for any
particular errno code when using kvm_(get|set)_one_reg(). Neither does
QEMU. rust-vmm doesn't have kvm-riscv support yet. Thus we have a good
chance of changing these error codes now while the KVM RISC-V ecosystem
is still new, minimizing user impact.

Change all get_one_reg() and set_one_reg() implementations to return
-ENOENT at all "no such register" cases.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

KVM userspaces need to be aware of the host SATP to allow them to
advertise it back to the guest OS.

Since this information is used to build the guest FDT we can't wait for
the SATP reg to be readable. We just need to read the SATP mode, thus
we can use the existing 'satp_mode' global that represents the SATP reg
with MODE set and both ASID and PPN cleared. E.g. for a 32 bit host
running with sv32 satp_mode is 0x80000000, for a 64 bit host running
sv57 satp_mode is 0xa000000000000000, and so on.

Add a new userspace virtual config register 'satp_mode' to allow
userspace to read the current SATP mode the host is using with
GET_ONE_REG API before spinning the vcpu.

'satp_mode' can't be changed via KVM, so SET_ONE_REG is allowed as long
as userspace writes the existing 'satp_mode'.
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

Let us sort isa extensions alphabetically in kvm_isa_ext_arr[] and
kvm_riscv_vcpu_isa_disable_allowed() so that future insertions are
more predictable.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

We extend the KVM ISA extension ONE_REG interface to allow KVM
user space to detect and enable Zicntr, Zicsr, Zifencei, and Zihpm
extensions for Guest/VM.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

We extend the KVM ISA extension ONE_REG interface to allow KVM
user space to detect and enable Zba and Zbs extensions for Guest/VM.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

Currently, the ISA extension ONE_REG interface only allows enabling or
disabling one extension at a time. To improve this, we extend the ISA
extension ONE_REG interface (similar to SBI extension ONE_REG interface)
so that KVM user space can enable/disable multiple extensions in one
ioctl.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

The VCPU ONE_REG interface has grown over time and it will continue
to grow with new ISA extensions and other features. Let us move all
ONE_REG related code to its own source file so that vcpu.c only
focuses only on high-level VCPU functions.
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Anup Patel <anup@brainfault.org>

Pull vfs fixes from Christian Brauner:

 - Fix a wrong check for O_TMPFILE during RESOLVE_CACHED lookup

 - Clean up directory iterators and clarify file_needs_f_pos_lock()

* tag 'v6.5-rc5.vfs.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  fs: rely on ->iterate_shared to determine f_pos locking
  vfs: get rid of old '->iterate' directory operation
  proc: fix missing conversion to 'iterate_shared'
  open: make RESOLVE_CACHED correctly test for O_TMPFILE

Now that we removed ->iterate we don't need to check for either
->iterate or ->iterate_shared in file_needs_f_pos_lock(). Simply check
for ->iterate_shared instead. This will tell us whether we need to
unconditionally take the lock. Not just does it allow us to avoid
checking f_inode's mode it also actually clearly shows that we're
locking because of readdir.
Signed-off-by: Christian Brauner <brauner@kernel.org>

All users now just use '->iterate_shared()', which only takes the
directory inode lock for reading.

Filesystems that never got convered to shared mode now instead use a
wrapper that drops the lock, re-takes it in write mode, calls the old
function, and then downgrades the lock back to read mode.

This way the VFS layer and other callers no longer need to care about
filesystems that never got converted to the modern era.

The filesystems that use the new wrapper are ceph, coda, exfat, jfs,
ntfs, ocfs2, overlayfs, and vboxsf.

Honestly, several of them look like they really could just iterate their
directories in shared mode and skip the wrapper entirely, but the point
of this change is to not change semantics or fix filesystems that
haven't been fixed in the last 7+ years, but to finally get rid of the
dual iterators.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

I'm looking at the directory handling due to the discussion about f_pos
locking (see commit 79796425: "file: reinstate f_pos locking
optimization for regular files"), and wanting to clean that up.

And one source of ugliness is how we were supposed to move filesystems
over to the '->iterate_shared()' function that only takes the inode lock
for reading many many years ago, but several filesystems still use the
bad old '->iterate()' that takes the inode lock for exclusive access.

See commit 61922694 ("introduce a parallel variant of ->iterate()")
that also added some documentation stating

      Old method is only used if the new one is absent; eventually it will
      be removed.  Switch while you still can; the old one won't stay.

and that was back in April 2016.  Here we are, many years later, and the
old version is still clearly sadly alive and well.

Now, some of those old style iterators are probably just because the
filesystem may end up having per-inode mutable data that it uses for
iterating a directory, but at least one case is just a mistake.

Al switched over most filesystems to use '->iterate_shared()' back when
it was introduced.  In particular, the /proc filesystem was converted as
one of the first ones in commit f50752ea ("switch all procfs
directories ->iterate_shared()").

But then later one new user of '->iterate()' was then re-introduced by
commit 6d9c939d ("procfs: add smack subdir to attrs").

And that's clearly not what we wanted, since that new case just uses the
same 'proc_pident_readdir()' and 'proc_pident_lookup()' helper functions
that other /proc pident directories use, and they are most definitely
safe to use with the inode lock held shared.

So just fix it.

This still leaves a fair number of oddball filesystems using the
old-style directory iterator (ceph, coda, exfat, jfs, ntfs, ocfs2,
overlayfs, and vboxsf), but at least we don't have any remaining in the
core filesystems.

I'm going to add a wrapper function that just drops the read-lock and
takes it as a write lock, so that we can clean up the core vfs layer and
make all the ugly 'this filesystem needs exclusive inode locking' be
just filesystem-internal warts.

I just didn't want to make that conversion when we still had a core user
left.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>

O_TMPFILE is actually __O_TMPFILE|O_DIRECTORY. This means that the old
fast-path check for RESOLVE_CACHED would reject all users passing
O_DIRECTORY with -EAGAIN, when in fact the intended test was to check
for __O_TMPFILE.

Cc: stable@vger.kernel.org # v5.12+
Fixes: 99668f61 ("fs: expose LOOKUP_CACHED through openat2() RESOLVE_CACHED")
Signed-off-by: Aleksa Sarai <cyphar@cyphar.com>
Message-Id: <20230806-resolve_cached-o_tmpfile-v1-1-7ba16308465e@cyphar.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>

Pull rust fixes from Miguel Ojeda:

 - Allocator: prevent mis-aligned allocation

 - Types: delete 'ForeignOwnable::borrow_mut'. A sound replacement is
   planned for the merge window

 - Build: fix bindgen error with UBSAN_BOUNDS_STRICT

* tag 'rust-fixes-6.5-rc5' of https://github.com/Rust-for-Linux/linux:
  rust: fix bindgen build error with UBSAN_BOUNDS_STRICT
  rust: delete `ForeignOwnable::borrow_mut`
  rust: allocator: Prevent mis-aligned allocation

Pull ata fix from Damien Le Moal:

 - Prevent the scsi disk driver from issuing a START STOP UNIT command
   for ATA devices during system resume as this causes various issues
   reported by multiple users.

* tag 'ata-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/libata:
  ata,scsi: do not issue START STOP UNIT on resume

Pull smb client fix from Steve French:

 - Fix DFS interlink problem (different namespace)

* tag '6.5-rc4-smb3-client-fix' of git://git.samba.org/sfrench/cifs-2.6:
  smb: client: fix dfs link mount against w2k8

Pull powerpc fixes from Michael Ellerman:

 - Fix vmemmap altmap boundary check which could cause memory hotunplug
   failure

 - Create a dummy stackframe to fix ftrace stack unwind

 - Fix secondary thread bringup for Book3E ELFv2 kernels

 - Use early_ioremap/unmap() in via_calibrate_decr()

Thanks to Aneesh Kumar K.V, Benjamin Gray, Christophe Leroy, David
Hildenbrand, and Naveen N Rao.

* tag 'powerpc-6.5-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/powermac: Use early_* IO variants in via_calibrate_decr()
  powerpc/64e: Fix secondary thread bringup for ELFv2 kernels
  powerpc/ftrace: Create a dummy stackframe to fix stack unwind
  powerpc/mm/altmap: Fix altmap boundary check

Pull parisc architecture fixes from Helge Deller:

 - early fixmap preallocation to fix boot failures on kernel >= 6.4

 - remove DMA leftover code in parport_gsc

 - drop old comments and code style fixes

* tag 'parisc-for-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
  parisc: unaligned: Add required spaces after ','
  parport: gsc: remove DMA leftover code
  parisc: pci-dma: remove unused and dead EISA code and comment
  parisc/mm: preallocate fixmap page tables at init

Pull clk fixes from Stephen Boyd:
 "A few clk driver fixes for some SoC clk drivers:

   - Change a usleep() to udelay() to avoid scheduling while atomic in
     the Amlogic PLL code

   - Revert a patch to the Mediatek MT8183 driver that caused an
     out-of-bounds write

   - Return the right error value when devm_of_iomap() fails in
     imx93_clocks_probe()

   - Constrain the Kconfig for the fixed mmio clk so that it depends on
     HAS_IOMEM and can't be compiled on architectures such as s390"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: fixed-mmio: make COMMON_CLK_FIXED_MMIO depend on HAS_IOMEM
  clk: imx93: Propagate correct error in imx93_clocks_probe()
  clk: mediatek: mt8183: Add back SSPM related clocks
  clk: meson: change usleep_range() to udelay() for atomic context

Merge tag 'hyperv-fixes-signed-20230804' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:

 - Fix a bug in a python script for Hyper-V (Ani Sinha)

 - Workaround a bug in Hyper-V when IBT is enabled (Michael Kelley)

 - Fix an issue parsing MP table when Linux runs in VTL2 (Saurabh
   Sengar)

 - Several cleanup patches (Nischala Yelchuri, Kameron Carr, YueHaibing,
   ZhiHu)

* tag 'hyperv-fixes-signed-20230804' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Drivers: hv: vmbus: Remove unused extern declaration vmbus_ontimer()
  x86/hyperv: add noop functions to x86_init mpparse functions
  vmbus_testing: fix wrong python syntax for integer value comparison
  x86/hyperv: fix a warning in mshyperv.h
  x86/hyperv: Disable IBT when hypercall page lacks ENDBR instruction
  x86/hyperv: Improve code for referencing hyperv_pcpu_input_arg
  Drivers: hv: Change hv_free_hyperv_page() to take void * argument

Pull RISC-V fixes from Palmer Dabbelt:

 - A pair of fixes for build-related failures in the selftests

 - A fix for a sparse warning in acpi_os_ioremap()

 - A fix to restore the kernel PA offset in vmcoreinfo, to fix crash
   handling

* tag 'riscv-for-linus-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  Documentation: kdump: Add va_kernel_pa_offset for RISCV64
  riscv: Export va_kernel_pa_offset in vmcoreinfo
  RISC-V: ACPI: Fix acpi_os_ioremap to return iomem address
  selftests: riscv: Fix compilation error with vstate_exec_nolibc.c
  selftests/riscv: fix potential build failure during the "emit_tests" step

Pull power management fix from Rafael Wysocki:
 "Fix a sparse warning triggered by the TPMI interface recently added to
  the Intel RAPL power capping driver (Zhang Rui)"

* tag 'pm-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  powercap: intel_rapl: Fix a sparse warning in TPMI interface

Pull arm64 fixes from Catalin Marinas:
 "More SVE/SME fixes for ptrace() and for the (potentially future) case
  where SME is implemented in hardware without SVE support"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64/fpsimd: Sync and zero pad FPSIMD state for streaming SVE
  arm64/fpsimd: Sync FPSIMD state with SVE for SME only systems
  arm64/ptrace: Don't enable SVE when setting streaming SVE
  arm64/ptrace: Flush FP state when setting ZT0
  arm64/fpsimd: Clear SME state in the target task when setting the VL

Pull mtd fixes from Miquel Raynal:
 "Raw NAND fixes:
   - fsl_upm: Fix an off-by one test in fun_exec_op()
   - Rockchip:
       - Align hwecc vs. raw page helper layouts
       - Fix oobfree offset and description
   - Meson: Fix OOB available bytes for ECC
   - Omap ELM: Fix incorrect type in assignment

  SPI-NOR fix:
   - Avoid holes in struct spi_mem_op

  Hyperbus fix:
   - Add Tudor as reviewer in MAINTAINERS

  SPI-NAND fixes:
   - Winbond and Toshiba: Fix ecc_get_status"

* tag 'mtd/fixes-for-6.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
  mtd: rawnand: fsl_upm: Fix an off-by one test in fun_exec_op()
  mtd: spi-nor: avoid holes in struct spi_mem_op
  MAINTAINERS: Add myself as reviewer for HYPERBUS
  mtd: rawnand: rockchip: Align hwecc vs. raw page helper layouts
  mtd: rawnand: rockchip: fix oobfree offset and description
  mtd: rawnand: meson: fix OOB available bytes for ECC
  mtd: rawnand: omap_elm: Fix incorrect type in assignment
  mtd: spinand: winbond: Fix ecc_get_status
  mtd: spinand: toshiba: Fix ecc_get_status

Pull drm fixes from Dave Airlie:
 "Small set of fixes this week, i915 and a few misc ones. I didn't see
  an amd pull so maybe next week it'll have a few more on that driver.

  ttm:
   - NULL ptr deref fix

  panel:
   - add missing MODULE_DEVICE_TABLE

  imx/ipuv3:
   - timing fix

  i915:
   - Fix bug in getting msg length in AUX CH registers handler
   - Gen12 AUX invalidation fixes
   - Fix premature release of request's reusable memory"

* tag 'drm-fixes-2023-08-04' of git://anongit.freedesktop.org/drm/drm:
  drm/panel: samsung-s6d7aa0: Add MODULE_DEVICE_TABLE
  drm/i915: Fix premature release of request's reusable memory
  drm/i915/gt: Support aux invalidation on all engines
  drm/i915/gt: Poll aux invalidation register bit on invalidation
  drm/i915/gt: Enable the CCS_FLUSH bit in the pipe control and in the CS
  drm/i915/gt: Rename flags with bit_group_X according to the datasheet
  drm/i915/gt: Ensure memory quiesced before invalidation
  drm/i915: Add the gen12_needs_ccs_aux_inv helper
  drm/i915/gt: Cleanup aux invalidation registers
  drm/i915/gvt: Fix bug in getting msg length in AUX CH registers handler
  drm/imx/ipuv3: Fix front porch adjustment upon hactive aligning
  drm/ttm: check null pointer before accessing when swapping

Pull ceph fixes from Ilya Dryomov:
 "Two patches to improve RBD exclusive lock interaction with
  osd_request_timeout option and another fix to reduce the potential for
  erroneous blocklisting -- this time in CephFS. All going to stable"

* tag 'ceph-for-6.5-rc5' of https://github.com/ceph/ceph-client:
  libceph: fix potential hang in ceph_osdc_notify()
  rbd: prevent busy loop when requesting exclusive lock
  ceph: defer stopping mdsc delayed_work

In commit 20ea1e7d ("file: always lock position for
FMODE_ATOMIC_POS") we ended up always taking the file pos lock, because
pidfd_getfd() could get a reference to the file even when it didn't have
an elevated file count due to threading of other sharing cases.

But Mateusz Guzik reports that the extra locking is actually measurable,
so let's re-introduce the optimization, and only force the locking for
directory traversal.

Directories need the lock for correctness reasons, while regular files
only need it for "POSIX semantics".  Since pidfd_getfd() is about
debuggers etc special things that are _way_ outside of POSIX, we can
relax the rules for that case.
Reported-by: Mateusz Guzik <mjguzik@gmail.com>
Cc: Christian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/linux-fsdevel/20230803095311.ijpvhx3fyrbkasul@f/Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We have a function sve_sync_from_fpsimd_zeropad() which is used by the
ptrace code to update the SVE state when the user writes to the the
FPSIMD register set.  Currently this checks that the task has SVE
enabled but this will miss updates for tasks which have streaming SVE
enabled if SVE has not been enabled for the thread, also do the
conversion if the task has streaming SVE enabled.

Fixes: e12310a0 ("arm64/sme: Implement ptrace support for streaming mode SVE registers")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230803-arm64-fix-ptrace-ssve-no-sve-v1-3-49df214bfb3e@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Currently we guard FPSIMD/SVE state conversions with a check for the system
supporting SVE but SME only systems may need to sync streaming mode SVE
state so add a check for SME support too.  These functions are only used
by the ptrace code.

Fixes: e12310a0 ("arm64/sme: Implement ptrace support for streaming mode SVE registers")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230803-arm64-fix-ptrace-ssve-no-sve-v1-2-49df214bfb3e@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Systems which implement SME without also implementing SVE are
architecturally valid but were not initially supported by the kernel,
unfortunately we missed one issue in the ptrace code.

The SVE register setting code is shared between SVE and streaming mode
SVE. When we set full SVE register state we currently enable TIF_SVE
unconditionally, in the case where streaming SVE is being configured on a
system that supports vanilla SVE this is not an issue since we always
initialise enough state for both vector lengths but on a system which only
support SME it will result in us attempting to restore the SVE vector
length after having set streaming SVE registers.

Fix this by making the enabling of SVE conditional on setting SVE vector
state. If we set streaming SVE state and SVE was not already enabled this
will result in a SVE access trap on next use of normal SVE, this will cause
us to flush our register state but this is fine since the only way to
trigger a SVE access trap would be to exit streaming mode which will cause
the in register state to be flushed anyway.

Fixes: e12310a0 ("arm64/sme: Implement ptrace support for streaming mode SVE registers")
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230803-arm64-fix-ptrace-ssve-no-sve-v1-1-49df214bfb3e@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>