- 20 Oct, 2021 33 commits
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Thomas Gleixner authored
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
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Thomas Gleixner authored
Convert fpstate_init() and related code to the new register storage mechanism in preparation for dynamically sized buffers. No functional change. Signed-off-by:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
Now that the file is empty, fixup all references with the proper includes and delete the former kitchen sink. Signed-off-by:
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Thomas Gleixner authored
Move the global interfaces to api.h and the rest into the core. Signed-off-by:
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Thomas Gleixner authored
Include the header which only provides the XCR accessors. That's all what is needed here. Signed-off-by:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
Move function declarations which need to be globally available to api.h where they belong. Signed-off-by:
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Thomas Gleixner authored
No need to expose that to code which only needs the XCR0 accessors. Signed-off-by:
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Thomas Gleixner authored
Only used internally in the FPU core code. While at it, convert to the percpu accessors which verify preemption is disabled. Signed-off-by:
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Thomas Gleixner authored
No point in being in global headers. Signed-off-by:
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Thomas Gleixner authored
Nothing outside the core code requires them. Signed-off-by:
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Thomas Gleixner authored
Nothing outside the core code needs these. Signed-off-by:
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Thomas Gleixner authored
It's only required in the xstate init code. Signed-off-by:
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Thomas Gleixner authored
Further disintegration of internal.h: Move the CPU feature tests to a core header and remove the unused one. Signed-off-by:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
No need to keep it around. Signed-off-by:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
Paolo Bonzini <pbonzini@redhat.com> Cc: kvm@vger.kernel.org Link: https://lkml.kernel.org/r/20211015011539.076072399@linutronix.de
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Thomas Gleixner authored
No point to keep them around after boot. Signed-off-by:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
Defensive programming is useful, but this on_boot_cpu debug is really silly. Signed-off-by:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
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:
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Thomas Gleixner authored
Unused since the FPU switching rework. Signed-off-by:
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- 16 Oct, 2021 2 commits
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Ingo Molnar authored
Resolve the conflict between these commits: x86/fpu: 1193f408 ("x86/fpu/signal: Change return type of __fpu_restore_sig() to boolean") x86/urgent: d298b035 ("x86/fpu: Restore the masking out of reserved MXCSR bits") b2381acd ("x86/fpu: Mask out the invalid MXCSR bits properly") Conflicts: arch/x86/kernel/fpu/signal.c Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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Borislav Petkov authored
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: d298b035 ("x86/fpu: Restore the masking out of reserved MXCSR bits") Signed-off-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
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- 11 Oct, 2021 2 commits
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Borislav Petkov authored
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, 2cc13bb4 ("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.: ea68573d ("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: 7744ccdb ("x86/mm: Add Secure Memory Encryption (SME) support") Reported-by:
Paul Menzel <pmenzel@molgen.mpg.de> Signed-off-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
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Linus Torvalds authored
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- 10 Oct, 2021 3 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
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 -
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull objtool fixes from Borislav Petkov: - Remove an extra section.len member in favour of section.sh_size - Align .altinstructions section creation with the kernel's by creating them with entry size of 0 - Fix objtool to convert a reloc symbol to a section offset and not to not warn about not knowing how * tag 'objtool_urgent_for_v5.15_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool: Remove redundant 'len' field from struct section objtool: Make .altinstructions section entry size consistent objtool: Remove reloc symbol type checks in get_alt_entry()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull x86 fixes from Borislav Petkov: - A FPU fix to properly handle invalid MXCSR values: 32-bit masks them out due to historical reasons and 64-bit kernels reject them - A fix to clear X86_FEATURE_SMAP when support for is not config-enabled - Three fixes correcting misspelled Kconfig symbols used in code - Two resctrl object cleanup fixes - Yet another attempt at fixing the neverending saga of botched x86 timers, this time because some incredibly smart hardware decides to turn off the HPET timer in a low power state - who cares if the OS is relying on it... - Check the full return value range of an SEV VMGEXIT call to determine whether it returned an error * tag 'x86_urgent_for_v5.15_rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/fpu: Restore the masking out of reserved MXCSR bits x86/Kconfig: Correct reference to MWINCHIP3D x86/platform/olpc: Correct ifdef symbol to intended CONFIG_OLPC_XO15_SCI x86/entry: Clear X86_FEATURE_SMAP when CONFIG_X86_SMAP=n x86/entry: Correct reference to intended CONFIG_64_BIT x86/resctrl: Fix kfree() of the wrong type in domain_add_cpu() x86/resctrl: Free the ctrlval arrays when domain_setup_mon_state() fails x86/hpet: Use another crystalball to evaluate HPET usability x86/sev: Return an error on a returned non-zero SW_EXITINFO1[31:0]
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