Make use of fpstate::size in various places which require the buffer size
information for sanity checks or memcpy() sizing.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.973518954@linutronix.de
Add state size and feature mask information to the fpstate container. This
will be used for runtime checks with the upcoming support for dynamically
enabled features and dynamically sized buffers. That avoids conditionals
all over the place as the required information is accessible for both
default and extended buffers.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.921388806@linutronix.de
In preparation for dynamically enabled FPU features move the function
out of line as the goal is to expose less and not more information.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.869001791@linutronix.de
If fork fails early then the copied task struct would carry the fpstate
pointer of the parent task.
Not a problem right now, but later when dynamically allocated buffers
are available, keeping the pointer might result in freeing the
parent's buffer. Set it to NULL which prevents that. If fork reaches
clone_thread(), the pointer will be correctly set to the new task
context.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.817101108@linutronix.de
Convert math emulation code to the new register storage
mechanism in preparation for dynamically sized buffers.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.711347464@linutronix.de
Convert the rest of the core code to the new register storage mechanism in
preparation for dynamically sized buffers.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.659456185@linutronix.de
Convert signal related code to the new register storage mechanism in
preparation for dynamically sized buffers.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.607370221@linutronix.de
Convert regset related code to the new register storage mechanism in
preparation for dynamically sized buffers.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.555239736@linutronix.de
Convert FPU tracing code to the new register storage mechanism in
preparation for dynamically sized buffers.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.503327333@linutronix.de
Convert KVM code to the new register storage mechanism in preparation for
dynamically sized buffers.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/20211013145322.451439983@linutronix.de
In order to prepare for the support of dynamically enabled FPU features,
move the clearing of xstate components to the FPU core code.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/20211013145322.399567049@linutronix.de
Convert restore_fpregs_from_fpstate() and related code to the new
register storage mechanism in preparation for dynamically sized buffers.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.347395546@linutronix.de
Convert fpstate_init() and related code to the new register storage
mechanism in preparation for dynamically sized buffers.
No functional change.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.292157401@linutronix.de
New xfeatures will not longer be automatically stored in the regular XSAVE
buffer in thread_struct::fpu.
The kernel will provide the default sized buffer for storing the regular
features up to AVX512 in thread_struct::fpu and if a task requests to use
one of the new features then the register storage has to be extended.
The state will be accessed via a pointer in thread_struct::fpu which
defaults to the builtin storage and can be switched when extended storage
is required.
To avoid conditionals all over the code, create a new container for the
register storage which will gain other information, e.g. size, feature
masks etc., later. For now it just contains the register storage, which
gives it exactly the same layout as the exiting fpu::state.
Stick fpu::state and the new fpu::__fpstate into an anonymous union and
initialize the pointer. Add build time checks to validate that both are
at the same place and have the same size.
This allows step by step conversion of all users.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145322.234458659@linutronix.de
Similar to the copy from user function the FPU core has this already
implemented with all bells and whistles.
Get rid of the duplicated code and use the core functionality.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/20211015011539.244101845@linutronix.de
To make upcoming changes for support of dynamically enabled features
simpler, provide a proper function for the exception handler which removes
exposure of FPU internals.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011540.053515012@linutronix.de
Now that the file is empty, fixup all references with the proper includes
and delete the former kitchen sink.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011540.001197214@linutronix.de
Include the header which only provides the XCR accessors. That's all what
is needed here.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.896573039@linutronix.de
In order to remove internal.h make signal.h independent of it.
Include asm/fpu/xstate.h to fix a missing update_regset_xstate_info()
prototype, which is
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.844565975@linutronix.de
Move function declarations which need to be globally available to api.h
where they belong.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.792363754@linutronix.de
Only used internally in the FPU core code.
While at it, convert to the percpu accessors which verify preemption is
disabled.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.686806639@linutronix.de
Further disintegration of internal.h:
Move the CPU feature tests to a core header and remove the unused one.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.401510559@linutronix.de
internal.h is a kitchen sink which needs to get out of the way to prepare
for the upcoming changes.
Move the context switch and exit to user inlines into a separate header,
which is all that code needs.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.349132461@linutronix.de
Prepare for replacing the KVM copy xstate to user function by extending
copy_xstate_to_uabi_buf() with a pkru argument which allows the caller to
hand in the pkru value, which is required for KVM because the guest PKRU is
not accessible via current. Fixup all callsites accordingly.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011539.191902137@linutronix.de
Copying a user space buffer to the memory buffer is already available in
the FPU core. The copy mechanism in KVM lacks sanity checks and needs to
use cpuid() to lookup the offset of each component, while the FPU core has
this information cached.
Make the FPU core variant accessible for KVM and replace the home brewed
mechanism.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/20211015011539.134065207@linutronix.de
Swapping the host/guest FPU is directly fiddling with FPU internals which
requires 5 exports. The upcoming support of dynamically enabled states
would even need more.
Implement a swap function in the FPU core code and export that instead.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/20211015011539.076072399@linutronix.de
These loops evaluating xfeature bits are really hard to read. Create an
iterator and use for_each_set_bit_from() inside which already does the right
thing.
No functional changes.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.958107505@linutronix.de
No point in having this duplicated all over the place with needlessly
different defines.
Provide a proper initialization function which initializes user buffers
properly and make KVM use it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.897664678@linutronix.de
There is no reason why kernel and IO worker threads need a full clone of
the parent's FPU state. Both are kernel threads which are not supposed to
use FPU. So copying a large state or doing XSAVE() is pointless. Just clean
out the minimally required state for those tasks.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.839822981@linutronix.de
There is no reason to clone FPU in arch_dup_task_struct(). Quite the
contrary - it prevents optimizations. Move it to copy_thread().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.780714235@linutronix.de
Zeroing the forked task's FPU registers buffer to avoid leaking init
optimized stale data into the clone is a pointless exercise for the case
where the current task has TIF_NEED_FPU_LOAD set. In that case, the FPU
registers state is copied from current's FPU register buffer which can
contain stale init optimized data as well.
The alledged information leak is non-existant because this stale init
optimized data is used nowhere and cannot leak anywhere.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.722854569@linutronix.de
These interfaces are really only valid for features which are independently
managed and not part of the task context state for various reasons.
Tighten the checks and adjust the misleading comments.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.608492174@linutronix.de
PKRU code does not need anything from FPU headers. Include cpufeature.h
instead and fixup the resulting fallout in perf.
This is a preparation for FPU changes in order to prevent recursive include
hell.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.551522694@linutronix.de
copy_fpstate_to_sigframe() does not have a slow path anymore. Neither does
the !ia32 restore in __fpu_restore_sig().
Update the comments accordingly.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211015011538.493570236@linutronix.de
Resolve the conflict between these commits:
x86/fpu: 1193f408cd ("x86/fpu/signal: Change return type of __fpu_restore_sig() to boolean")
x86/urgent: d298b03506 ("x86/fpu: Restore the masking out of reserved MXCSR bits")
b2381acd3f ("x86/fpu: Mask out the invalid MXCSR bits properly")
Conflicts:
arch/x86/kernel/fpu/signal.c
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This is a fix for the fix (yeah, /facepalm).
The correct mask to use is not the negation of the MXCSR_MASK but the
actual mask which contains the supported bits in the MXCSR register.
Reported and debugged by Ville Syrjälä <ville.syrjala@linux.intel.com>
Fixes: d298b03506 ("x86/fpu: Restore the masking out of reserved MXCSR bits")
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Tested-by: Ser Olmy <ser.olmy@protonmail.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/YWgYIYXLriayyezv@intel.com
This Kconfig option was added initially so that memory encryption is
enabled by default on machines which support it.
However, devices which have DMA masks that are less than the bit
position of the encryption bit, aka C-bit, require the use of an IOMMU
or the use of SWIOTLB.
If the IOMMU is disabled or in passthrough mode, the kernel would switch
to SWIOTLB bounce-buffering for those transfers.
In order to avoid that,
2cc13bb4f5 ("iommu: Disable passthrough mode when SME is active")
disables the default IOMMU passthrough mode so that devices for which the
default 256K DMA is insufficient, can use the IOMMU instead.
However 2, there are cases where the IOMMU is disabled in the BIOS, etc.
(think the usual hardware folk "oops, I dropped the ball there" cases) or a
driver doesn't properly use the DMA APIs or a device has a firmware or
hardware bug, e.g.:
ea68573d40 ("drm/amdgpu: Fail to load on RAVEN if SME is active")
However 3, in the above GPU use case, there are APIs like Vulkan and
some OpenGL/OpenCL extensions which are under the assumption that
user-allocated memory can be passed in to the kernel driver and both the
GPU and CPU can do coherent and concurrent access to the same memory.
That cannot work with SWIOTLB bounce buffers, of course.
So, in order for those devices to function, drop the "default y" for the
SME by default active option so that users who want to have SME enabled,
will need to either enable it in their config or use "mem_encrypt=on" on
the kernel command line.
[ tlendacky: Generalize commit message. ]
Fixes: 7744ccdbc1 ("x86/mm: Add Secure Memory Encryption (SME) support")
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/8bbacd0e-4580-3194-19d2-a0ecad7df09c@molgen.mpg.de
Fix a regression hit by the IPR SCSI driver, introduced by the recent addition of MSI
domains on pseries.
A big series including 8 BPF fixes, some with potential security impact and the rest
various code generation issues.
Fix our program check assembler entry path, which was accidentally jumping into a gas
macro and generating strange stack frames, which could confuse find_bug().
A couple of fixes, and related changes, to fix corner cases in our machine check handling.
Fix our DMA IOMMU ops, which were not always returning the optimal DMA mask, leading to
at least one device falling back to 32-bit DMA when it shouldn't.
A fix for KUAP handling on 32-bit Book3S.
Fix crashes seen when kdumping on some pseries systems.
Thanks to: Naveen N. Rao, Nicholas Piggin, Alexey Kardashevskiy, Cédric Le Goater,
Christophe Leroy, Mahesh Salgaonkar, Abdul Haleem, Christoph Hellwig, Johan Almbladh, Stan
Johnson.
-----BEGIN PGP SIGNATURE-----
iQJHBAABCAAxFiEEJFGtCPCthwEv2Y/bUevqPMjhpYAFAmFi044THG1wZUBlbGxl
cm1hbi5pZC5hdQAKCRBR6+o8yOGlgGtXD/0a8dy70W8lXq3k1Zz33vzp/NSnq5Cj
d1lTI6hgbow5KbMgoKi3f2RC1S1qd0Kenz4zDD+rljRg8xrUCswUB+al2mrkeaBm
9s82lWwemmdB8LUbWAV/SscaJ6Pc5ODmjwGpsB36gdBgaYnmedQky4knh1m0NNCS
nyY6ugQIP6GnAZ2mojKnWx84Gj8hIYs5rEqAeDhHGNvLKSt2yIQv5LzqGM423j2O
44nbMmEt8Jq6oJCSeMRf3j5rgc6RTkwnL/543faRe5BBNbuMU01oIhDrGALXY8Ip
gOjyRsQYy1s+dU1rypaP/rlE3hRAUGmShCYQXA6kcESgwZc+BMSSShM/FhvVx2C7
UnFiFHyWnrP3PrhDGW+WGhrUN2kyoZZ7V6x5bggW93pyVCmA9RW62J8HU8DwzucU
IBO7TBNoHsscKEw8dSwG6jBOfx30bEwD2tl2PjNaDFIk7WndMOT4MbjPTDlXj38u
PbLPlY1xEghUafAdLwWL46wQMc0pLHyAaiM/Wl8nUaES73tdtMTLtg7QH/+uBc+a
iS1ji1U9VOpRjtBOjQHmPtRiit9aL1UJ0PDMrJWQpKxALv139jdlhjdzexnPgNAe
8l/9bvTsCTn5j5C3m1XaUSSGM2AyawMEC0+9bJWMKuD0F8JmZfUYMSjSk0CWJFRG
e+xG8TGXClfTxg==
=q+1t
-----END PGP SIGNATURE-----
Merge tag 'powerpc-5.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman:
"A bit of a big batch, partly because I didn't send any last week, and
also just because the BPF fixes happened to land this week.
Summary:
- Fix a regression hit by the IPR SCSI driver, introduced by the
recent addition of MSI domains on pseries.
- A big series including 8 BPF fixes, some with potential security
impact and the rest various code generation issues.
- Fix our program check assembler entry path, which was accidentally
jumping into a gas macro and generating strange stack frames, which
could confuse find_bug().
- A couple of fixes, and related changes, to fix corner cases in our
machine check handling.
- Fix our DMA IOMMU ops, which were not always returning the optimal
DMA mask, leading to at least one device falling back to 32-bit DMA
when it shouldn't.
- A fix for KUAP handling on 32-bit Book3S.
- Fix crashes seen when kdumping on some pseries systems.
Thanks to Naveen N. Rao, Nicholas Piggin, Alexey Kardashevskiy, Cédric
Le Goater, Christophe Leroy, Mahesh Salgaonkar, Abdul Haleem,
Christoph Hellwig, Johan Almbladh, Stan Johnson"
* tag 'powerpc-5.15-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
pseries/eeh: Fix the kdump kernel crash during eeh_pseries_init
powerpc/32s: Fix kuap_kernel_restore()
powerpc/pseries/msi: Add an empty irq_write_msi_msg() handler
powerpc/64s: Fix unrecoverable MCE calling async handler from NMI
powerpc/64/interrupt: Reconcile soft-mask state in NMI and fix false BUG
powerpc/64: warn if local irqs are enabled in NMI or hardirq context
powerpc/traps: do not enable irqs in _exception
powerpc/64s: fix program check interrupt emergency stack path
powerpc/bpf ppc32: Fix BPF_SUB when imm == 0x80000000
powerpc/bpf ppc32: Do not emit zero extend instruction for 64-bit BPF_END
powerpc/bpf ppc32: Fix JMP32_JSET_K
powerpc/bpf ppc32: Fix ALU32 BPF_ARSH operation
powerpc/bpf: Emit stf barrier instruction sequences for BPF_NOSPEC
powerpc/security: Add a helper to query stf_barrier type
powerpc/bpf: Fix BPF_SUB when imm == 0x80000000
powerpc/bpf: Fix BPF_MOD when imm == 1
powerpc/bpf: Validate branch ranges
powerpc/lib: Add helper to check if offset is within conditional branch range
powerpc/iommu: Report the correct most efficient DMA mask for PCI devices
