linux/arch/arm64/kernel/image-vars.h
James Morse 8979720ac6 arm64: Use the clearbhb instruction in mitigations
commit 228a26b912 upstream.

Future CPUs may implement a clearbhb instruction that is sufficient
to mitigate SpectreBHB. CPUs that implement this instruction, but
not CSV2.3 must be affected by Spectre-BHB.

Add support to use this instruction as the BHB mitigation on CPUs
that support it. The instruction is in the hint space, so it will
be treated by a NOP as older CPUs.

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-03-11 12:22:35 +01:00

144 lines
4.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Linker script variables to be set after section resolution, as
* ld.lld does not like variables assigned before SECTIONS is processed.
*/
#ifndef __ARM64_KERNEL_IMAGE_VARS_H
#define __ARM64_KERNEL_IMAGE_VARS_H
#ifndef LINKER_SCRIPT
#error This file should only be included in vmlinux.lds.S
#endif
#ifdef CONFIG_EFI
__efistub_kernel_size = _edata - _text;
__efistub_primary_entry_offset = primary_entry - _text;
/*
* The EFI stub has its own symbol namespace prefixed by __efistub_, to
* isolate it from the kernel proper. The following symbols are legally
* accessed by the stub, so provide some aliases to make them accessible.
* Only include data symbols here, or text symbols of functions that are
* guaranteed to be safe when executed at another offset than they were
* linked at. The routines below are all implemented in assembler in a
* position independent manner
*/
__efistub_memcmp = __pi_memcmp;
__efistub_memchr = __pi_memchr;
__efistub_memcpy = __pi_memcpy;
__efistub_memmove = __pi_memmove;
__efistub_memset = __pi_memset;
__efistub_strlen = __pi_strlen;
__efistub_strnlen = __pi_strnlen;
__efistub_strcmp = __pi_strcmp;
__efistub_strncmp = __pi_strncmp;
__efistub_strrchr = __pi_strrchr;
__efistub_dcache_clean_poc = __pi_dcache_clean_poc;
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
__efistub___memcpy = __pi_memcpy;
__efistub___memmove = __pi_memmove;
__efistub___memset = __pi_memset;
#endif
__efistub__text = _text;
__efistub__end = _end;
__efistub__edata = _edata;
__efistub_screen_info = screen_info;
__efistub__ctype = _ctype;
#endif
#ifdef CONFIG_KVM
/*
* KVM nVHE code has its own symbol namespace prefixed with __kvm_nvhe_, to
* separate it from the kernel proper. The following symbols are legally
* accessed by it, therefore provide aliases to make them linkable.
* Do not include symbols which may not be safely accessed under hypervisor
* memory mappings.
*/
/* Alternative callbacks for init-time patching of nVHE hyp code. */
KVM_NVHE_ALIAS(kvm_patch_vector_branch);
KVM_NVHE_ALIAS(kvm_update_va_mask);
KVM_NVHE_ALIAS(kvm_get_kimage_voffset);
KVM_NVHE_ALIAS(kvm_compute_final_ctr_el0);
KVM_NVHE_ALIAS(spectre_bhb_patch_loop_iter);
KVM_NVHE_ALIAS(spectre_bhb_patch_loop_mitigation_enable);
KVM_NVHE_ALIAS(spectre_bhb_patch_wa3);
KVM_NVHE_ALIAS(spectre_bhb_patch_clearbhb);
/* Global kernel state accessed by nVHE hyp code. */
KVM_NVHE_ALIAS(kvm_vgic_global_state);
/* Kernel symbols used to call panic() from nVHE hyp code (via ERET). */
KVM_NVHE_ALIAS(nvhe_hyp_panic_handler);
/* Vectors installed by hyp-init on reset HVC. */
KVM_NVHE_ALIAS(__hyp_stub_vectors);
/* Kernel symbol used by icache_is_vpipt(). */
KVM_NVHE_ALIAS(__icache_flags);
/* Kernel symbols needed for cpus_have_final/const_caps checks. */
KVM_NVHE_ALIAS(arm64_const_caps_ready);
KVM_NVHE_ALIAS(cpu_hwcap_keys);
/* Static keys which are set if a vGIC trap should be handled in hyp. */
KVM_NVHE_ALIAS(vgic_v2_cpuif_trap);
KVM_NVHE_ALIAS(vgic_v3_cpuif_trap);
/* Static key checked in pmr_sync(). */
#ifdef CONFIG_ARM64_PSEUDO_NMI
KVM_NVHE_ALIAS(gic_pmr_sync);
/* Static key checked in GIC_PRIO_IRQOFF. */
KVM_NVHE_ALIAS(gic_nonsecure_priorities);
#endif
/* EL2 exception handling */
KVM_NVHE_ALIAS(__start___kvm_ex_table);
KVM_NVHE_ALIAS(__stop___kvm_ex_table);
/* Array containing bases of nVHE per-CPU memory regions. */
KVM_NVHE_ALIAS(kvm_arm_hyp_percpu_base);
/* PMU available static key */
KVM_NVHE_ALIAS(kvm_arm_pmu_available);
/* Position-independent library routines */
KVM_NVHE_ALIAS_HYP(clear_page, __pi_clear_page);
KVM_NVHE_ALIAS_HYP(copy_page, __pi_copy_page);
KVM_NVHE_ALIAS_HYP(memcpy, __pi_memcpy);
KVM_NVHE_ALIAS_HYP(memset, __pi_memset);
#ifdef CONFIG_KASAN
KVM_NVHE_ALIAS_HYP(__memcpy, __pi_memcpy);
KVM_NVHE_ALIAS_HYP(__memset, __pi_memset);
#endif
/* Kernel memory sections */
KVM_NVHE_ALIAS(__start_rodata);
KVM_NVHE_ALIAS(__end_rodata);
KVM_NVHE_ALIAS(__bss_start);
KVM_NVHE_ALIAS(__bss_stop);
/* Hyp memory sections */
KVM_NVHE_ALIAS(__hyp_idmap_text_start);
KVM_NVHE_ALIAS(__hyp_idmap_text_end);
KVM_NVHE_ALIAS(__hyp_text_start);
KVM_NVHE_ALIAS(__hyp_text_end);
KVM_NVHE_ALIAS(__hyp_bss_start);
KVM_NVHE_ALIAS(__hyp_bss_end);
KVM_NVHE_ALIAS(__hyp_rodata_start);
KVM_NVHE_ALIAS(__hyp_rodata_end);
/* pKVM static key */
KVM_NVHE_ALIAS(kvm_protected_mode_initialized);
#endif /* CONFIG_KVM */
#endif /* __ARM64_KERNEL_IMAGE_VARS_H */