mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-12-27 11:06:41 -05:00
e2aa39b368
Pull misc x86 updates from Dave Hansen: "The most significant are some changes to ensure that symbols exported for KVM are used only by KVM modules themselves, along with some related cleanups. In true x86/misc fashion, the other patch is completely unrelated and just enhances an existing pr_warn() to make it clear to users how they have tainted their kernel when something is mucking with MSRs. Summary: - Make MSR-induced taint easier for users to track down - Restrict KVM-specific exports to KVM itself" * tag 'x86_misc_for_6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86: Restrict KVM-induced symbol exports to KVM modules where obvious/possible x86/mm: Drop unnecessary export of "ptdump_walk_pgd_level_debugfs" x86/mtrr: Drop unnecessary export of "mtrr_state" x86/bugs: Drop unnecessary export of "x86_spec_ctrl_base" x86/msr: Add CPU_OUT_OF_SPEC taint name to "unrecognized" pr_warn(msg)
78 lines
2.1 KiB
ArmAsm
78 lines
2.1 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Common place for both 32- and 64-bit entry routines.
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*/
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#include <linux/export.h>
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#include <linux/kvm_types.h>
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#include <linux/linkage.h>
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#include <linux/objtool.h>
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#include <asm/msr-index.h>
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#include <asm/unwind_hints.h>
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#include <asm/segment.h>
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#include <asm/cache.h>
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#include <asm/cpufeatures.h>
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#include <asm/nospec-branch.h>
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#include "calling.h"
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.pushsection .noinstr.text, "ax"
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/* Clobbers AX, CX, DX */
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SYM_FUNC_START(write_ibpb)
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ANNOTATE_NOENDBR
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movl $MSR_IA32_PRED_CMD, %ecx
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movl _ASM_RIP(x86_pred_cmd), %eax
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xorl %edx, %edx
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wrmsr
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/* Make sure IBPB clears return stack preductions too. */
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FILL_RETURN_BUFFER %rax, RSB_CLEAR_LOOPS, X86_BUG_IBPB_NO_RET
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RET
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SYM_FUNC_END(write_ibpb)
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EXPORT_SYMBOL_FOR_KVM(write_ibpb);
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SYM_FUNC_START(__WARN_trap)
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ANNOTATE_NOENDBR
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ANNOTATE_REACHABLE
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ud1 (%edx), %_ASM_ARG1
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RET
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SYM_FUNC_END(__WARN_trap)
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EXPORT_SYMBOL(__WARN_trap)
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.popsection
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/*
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* Define the VERW operand that is disguised as entry code so that
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* it can be referenced with KPTI enabled. This ensures VERW can be
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* used late in exit-to-user path after page tables are switched.
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*/
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.pushsection .entry.text, "ax"
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.align L1_CACHE_BYTES, 0xcc
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SYM_CODE_START_NOALIGN(x86_verw_sel)
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UNWIND_HINT_UNDEFINED
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ANNOTATE_NOENDBR
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.word __KERNEL_DS
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.align L1_CACHE_BYTES, 0xcc
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SYM_CODE_END(x86_verw_sel);
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EXPORT_SYMBOL_FOR_KVM(x86_verw_sel);
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.popsection
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THUNK warn_thunk_thunk, __warn_thunk
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/*
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* Clang's implementation of TLS stack cookies requires the variable in
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* question to be a TLS variable. If the variable happens to be defined as an
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* ordinary variable with external linkage in the same compilation unit (which
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* amounts to the whole of vmlinux with LTO enabled), Clang will drop the
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* segment register prefix from the references, resulting in broken code. Work
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* around this by avoiding the symbol used in -mstack-protector-guard-symbol=
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* entirely in the C code, and use an alias emitted by the linker script
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* instead.
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*/
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#if defined(CONFIG_STACKPROTECTOR) && defined(CONFIG_SMP)
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EXPORT_SYMBOL(__ref_stack_chk_guard);
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#endif
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