diff options
Diffstat (limited to 'arch/arm64/kernel')
| -rw-r--r-- | arch/arm64/kernel/Makefile | 4 | ||||
| -rw-r--r-- | arch/arm64/kernel/alternative.c | 43 | ||||
| -rw-r--r-- | arch/arm64/kernel/asm-offsets.c | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/bpi.S | 67 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpu_errata.c | 25 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 19 | ||||
| -rw-r--r-- | arch/arm64/kernel/head.S | 7 | ||||
| -rw-r--r-- | arch/arm64/kernel/insn.c | 190 |
8 files changed, 292 insertions, 64 deletions
diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 6a4bd80c75bd..9b55a3f24be7 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -55,9 +55,7 @@ arm64-reloc-test-y := reloc_test_core.o reloc_test_syms.o arm64-obj-$(CONFIG_CRASH_DUMP) += crash_dump.o arm64-obj-$(CONFIG_ARM_SDE_INTERFACE) += sdei.o -ifeq ($(CONFIG_KVM),y) -arm64-obj-$(CONFIG_HARDEN_BRANCH_PREDICTOR) += bpi.o -endif +arm64-obj-$(CONFIG_KVM_INDIRECT_VECTORS)+= bpi.o obj-y += $(arm64-obj-y) vdso/ probes/ obj-m += $(arm64-obj-m) diff --git a/arch/arm64/kernel/alternative.c b/arch/arm64/kernel/alternative.c index 414288a558c8..5c4bce4ac381 100644 --- a/arch/arm64/kernel/alternative.c +++ b/arch/arm64/kernel/alternative.c @@ -107,32 +107,53 @@ static u32 get_alt_insn(struct alt_instr *alt, __le32 *insnptr, __le32 *altinsnp return insn; } +static void patch_alternative(struct alt_instr *alt, + __le32 *origptr, __le32 *updptr, int nr_inst) +{ + __le32 *replptr; + int i; + + replptr = ALT_REPL_PTR(alt); + for (i = 0; i < nr_inst; i++) { + u32 insn; + + insn = get_alt_insn(alt, origptr + i, replptr + i); + updptr[i] = cpu_to_le32(insn); + } +} + static void __apply_alternatives(void *alt_region, bool use_linear_alias) { struct alt_instr *alt; struct alt_region *region = alt_region; - __le32 *origptr, *replptr, *updptr; + __le32 *origptr, *updptr; + alternative_cb_t alt_cb; for (alt = region->begin; alt < region->end; alt++) { - u32 insn; - int i, nr_inst; + int nr_inst; - if (!cpus_have_cap(alt->cpufeature)) + /* Use ARM64_CB_PATCH as an unconditional patch */ + if (alt->cpufeature < ARM64_CB_PATCH && + !cpus_have_cap(alt->cpufeature)) continue; - BUG_ON(alt->alt_len != alt->orig_len); + if (alt->cpufeature == ARM64_CB_PATCH) + BUG_ON(alt->alt_len != 0); + else + BUG_ON(alt->alt_len != alt->orig_len); pr_info_once("patching kernel code\n"); origptr = ALT_ORIG_PTR(alt); - replptr = ALT_REPL_PTR(alt); updptr = use_linear_alias ? lm_alias(origptr) : origptr; - nr_inst = alt->alt_len / sizeof(insn); + nr_inst = alt->orig_len / AARCH64_INSN_SIZE; - for (i = 0; i < nr_inst; i++) { - insn = get_alt_insn(alt, origptr + i, replptr + i); - updptr[i] = cpu_to_le32(insn); - } + if (alt->cpufeature < ARM64_CB_PATCH) + alt_cb = patch_alternative; + else + alt_cb = ALT_REPL_PTR(alt); + + alt_cb(alt, origptr, updptr, nr_inst); flush_icache_range((uintptr_t)origptr, (uintptr_t)(origptr + nr_inst)); diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index 1303e04110cd..78e1b0a70aaf 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -138,6 +138,7 @@ int main(void) DEFINE(CPU_FP_REGS, offsetof(struct kvm_regs, fp_regs)); DEFINE(VCPU_FPEXC32_EL2, offsetof(struct kvm_vcpu, arch.ctxt.sys_regs[FPEXC32_EL2])); DEFINE(VCPU_HOST_CONTEXT, offsetof(struct kvm_vcpu, arch.host_cpu_context)); + DEFINE(HOST_CONTEXT_VCPU, offsetof(struct kvm_cpu_context, __hyp_running_vcpu)); #endif #ifdef CONFIG_CPU_PM DEFINE(CPU_SUSPEND_SZ, sizeof(struct cpu_suspend_ctx)); diff --git a/arch/arm64/kernel/bpi.S b/arch/arm64/kernel/bpi.S index e5de33513b5d..bb0b67722e86 100644 --- a/arch/arm64/kernel/bpi.S +++ b/arch/arm64/kernel/bpi.S @@ -19,42 +19,61 @@ #include <linux/linkage.h> #include <linux/arm-smccc.h> -.macro ventry target - .rept 31 +#include <asm/alternative.h> +#include <asm/mmu.h> + +.macro hyp_ventry + .align 7 +1: .rept 27 nop .endr - b \target +/* + * The default sequence is to directly branch to the KVM vectors, + * using the computed offset. This applies for VHE as well as + * !ARM64_HARDEN_EL2_VECTORS. + * + * For ARM64_HARDEN_EL2_VECTORS configurations, this gets replaced + * with: + * + * stp x0, x1, [sp, #-16]! + * movz x0, #(addr & 0xffff) + * movk x0, #((addr >> 16) & 0xffff), lsl #16 + * movk x0, #((addr >> 32) & 0xffff), lsl #32 + * br x0 + * + * Where addr = kern_hyp_va(__kvm_hyp_vector) + vector-offset + 4. + * See kvm_patch_vector_branch for details. + */ +alternative_cb kvm_patch_vector_branch + b __kvm_hyp_vector + (1b - 0b) + nop + nop + nop + nop +alternative_cb_end .endm -.macro vectors target - ventry \target + 0x000 - ventry \target + 0x080 - ventry \target + 0x100 - ventry \target + 0x180 - - ventry \target + 0x200 - ventry \target + 0x280 - ventry \target + 0x300 - ventry \target + 0x380 +.macro generate_vectors +0: + .rept 16 + hyp_ventry + .endr + .org 0b + SZ_2K // Safety measure +.endm - ventry \target + 0x400 - ventry \target + 0x480 - ventry \target + 0x500 - ventry \target + 0x580 - ventry \target + 0x600 - ventry \target + 0x680 - ventry \target + 0x700 - ventry \target + 0x780 -.endm + .text + .pushsection .hyp.text, "ax" .align 11 ENTRY(__bp_harden_hyp_vecs_start) - .rept 4 - vectors __kvm_hyp_vector + .rept BP_HARDEN_EL2_SLOTS + generate_vectors .endr ENTRY(__bp_harden_hyp_vecs_end) + .popsection + ENTRY(__qcom_hyp_sanitize_link_stack_start) stp x29, x30, [sp, #-16]! .rept 16 diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 2df792771053..9262ec57f5ab 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -78,6 +78,8 @@ cpu_enable_trap_ctr_access(const struct arm64_cpu_capabilities *__unused) config_sctlr_el1(SCTLR_EL1_UCT, 0); } +atomic_t arm64_el2_vector_last_slot = ATOMIC_INIT(-1); + #ifdef CONFIG_HARDEN_BRANCH_PREDICTOR #include <asm/mmu_context.h> #include <asm/cacheflush.h> @@ -108,7 +110,6 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, const char *hyp_vecs_start, const char *hyp_vecs_end) { - static int last_slot = -1; static DEFINE_SPINLOCK(bp_lock); int cpu, slot = -1; @@ -121,10 +122,8 @@ static void __install_bp_hardening_cb(bp_hardening_cb_t fn, } if (slot == -1) { - last_slot++; - BUG_ON(((__bp_harden_hyp_vecs_end - __bp_harden_hyp_vecs_start) - / SZ_2K) <= last_slot); - slot = last_slot; + slot = atomic_inc_return(&arm64_el2_vector_last_slot); + BUG_ON(slot >= BP_HARDEN_EL2_SLOTS); __copy_hyp_vect_bpi(slot, hyp_vecs_start, hyp_vecs_end); } @@ -348,6 +347,10 @@ static const struct arm64_cpu_capabilities arm64_bp_harden_list[] = { #endif +#ifndef ERRATA_MIDR_ALL_VERSIONS +#define ERRATA_MIDR_ALL_VERSIONS(x) MIDR_ALL_VERSIONS(x) +#endif + const struct arm64_cpu_capabilities arm64_errata[] = { #if defined(CONFIG_ARM64_ERRATUM_826319) || \ defined(CONFIG_ARM64_ERRATUM_827319) || \ @@ -501,6 +504,18 @@ const struct arm64_cpu_capabilities arm64_errata[] = { ERRATA_MIDR_RANGE_LIST(qcom_bp_harden_cpus), }, #endif +#ifdef CONFIG_HARDEN_EL2_VECTORS + { + .desc = "Cortex-A57 EL2 vector hardening", + .capability = ARM64_HARDEN_EL2_VECTORS, + ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A57), + }, + { + .desc = "Cortex-A72 EL2 vector hardening", + .capability = ARM64_HARDEN_EL2_VECTORS, + ERRATA_MIDR_ALL_VERSIONS(MIDR_CORTEX_A72), + }, +#endif { } }; diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 96b15d7b10a8..536d572e5596 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -838,19 +838,6 @@ static bool has_no_hw_prefetch(const struct arm64_cpu_capabilities *entry, int _ MIDR_CPU_VAR_REV(1, MIDR_REVISION_MASK)); } -static bool hyp_offset_low(const struct arm64_cpu_capabilities *entry, - int __unused) -{ - phys_addr_t idmap_addr = __pa_symbol(__hyp_idmap_text_start); - - /* - * Activate the lower HYP offset only if: - * - the idmap doesn't clash with it, - * - the kernel is not running at EL2. - */ - return idmap_addr > GENMASK(VA_BITS - 2, 0) && !is_kernel_in_hyp_mode(); -} - static bool has_no_fpsimd(const struct arm64_cpu_capabilities *entry, int __unused) { u64 pfr0 = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); @@ -1121,12 +1108,6 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .field_pos = ID_AA64PFR0_EL0_SHIFT, .min_field_value = ID_AA64PFR0_EL0_32BIT_64BIT, }, - { - .desc = "Reduced HYP mapping offset", - .capability = ARM64_HYP_OFFSET_LOW, - .type = ARM64_CPUCAP_SYSTEM_FEATURE, - .matches = hyp_offset_low, - }, #ifdef CONFIG_UNMAP_KERNEL_AT_EL0 { .desc = "Kernel page table isolation (KPTI)", diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 2b6b8b24e5ab..b0853069702f 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -577,6 +577,13 @@ set_hcr: 7: msr mdcr_el2, x3 // Configure debug traps + /* LORegions */ + mrs x1, id_aa64mmfr1_el1 + ubfx x0, x1, #ID_AA64MMFR1_LOR_SHIFT, 4 + cbz x0, 1f + msr_s SYS_LORC_EL1, xzr +1: + /* Stage-2 translation */ msr vttbr_el2, xzr diff --git a/arch/arm64/kernel/insn.c b/arch/arm64/kernel/insn.c index 2718a77da165..816d03c4c913 100644 --- a/arch/arm64/kernel/insn.c +++ b/arch/arm64/kernel/insn.c @@ -35,6 +35,7 @@ #define AARCH64_INSN_SF_BIT BIT(31) #define AARCH64_INSN_N_BIT BIT(22) +#define AARCH64_INSN_LSL_12 BIT(22) static int aarch64_insn_encoding_class[] = { AARCH64_INSN_CLS_UNKNOWN, @@ -343,6 +344,10 @@ static int __kprobes aarch64_get_imm_shift_mask(enum aarch64_insn_imm_type type, mask = BIT(6) - 1; shift = 16; break; + case AARCH64_INSN_IMM_N: + mask = 1; + shift = 22; + break; default: return -EINVAL; } @@ -899,9 +904,18 @@ u32 aarch64_insn_gen_add_sub_imm(enum aarch64_insn_register dst, return AARCH64_BREAK_FAULT; } + /* We can't encode more than a 24bit value (12bit + 12bit shift) */ + if (imm & ~(BIT(24) - 1)) + goto out; + + /* If we have something in the top 12 bits... */ if (imm & ~(SZ_4K - 1)) { - pr_err("%s: invalid immediate encoding %d\n", __func__, imm); - return AARCH64_BREAK_FAULT; + /* ... and in the low 12 bits -> error */ + if (imm & (SZ_4K - 1)) + goto out; + + imm >>= 12; + insn |= AARCH64_INSN_LSL_12; } insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, dst); @@ -909,6 +923,10 @@ u32 aarch64_insn_gen_add_sub_imm(enum aarch64_insn_register dst, insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, src); return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_12, insn, imm); + +out: + pr_err("%s: invalid immediate encoding %d\n", __func__, imm); + return AARCH64_BREAK_FAULT; } u32 aarch64_insn_gen_bitfield(enum aarch64_insn_register dst, @@ -1481,3 +1499,171 @@ pstate_check_t * const aarch32_opcode_cond_checks[16] = { __check_hi, __check_ls, __check_ge, __check_lt, __check_gt, __check_le, __check_al, __check_al }; + +static bool range_of_ones(u64 val) +{ + /* Doesn't handle full ones or full zeroes */ + u64 sval = val >> __ffs64(val); + + /* One of Sean Eron Anderson's bithack tricks */ + return ((sval + 1) & (sval)) == 0; +} + +static u32 aarch64_encode_immediate(u64 imm, + enum aarch64_insn_variant variant, + u32 insn) +{ + unsigned int immr, imms, n, ones, ror, esz, tmp; + u64 mask = ~0UL; + + /* Can't encode full zeroes or full ones */ + if (!imm || !~imm) + return AARCH64_BREAK_FAULT; + + switch (variant) { + case AARCH64_INSN_VARIANT_32BIT: + if (upper_32_bits(imm)) + return AARCH64_BREAK_FAULT; + esz = 32; + break; + case AARCH64_INSN_VARIANT_64BIT: + insn |= AARCH64_INSN_SF_BIT; + esz = 64; + break; + default: + pr_err("%s: unknown variant encoding %d\n", __func__, variant); + return AARCH64_BREAK_FAULT; + } + + /* + * Inverse of Replicate(). Try to spot a repeating pattern + * with a pow2 stride. + */ + for (tmp = esz / 2; tmp >= 2; tmp /= 2) { + u64 emask = BIT(tmp) - 1; + + if ((imm & emask) != ((imm >> tmp) & emask)) + break; + + esz = tmp; + mask = emask; + } + + /* N is only set if we're encoding a 64bit value */ + n = esz == 64; + + /* Trim imm to the element size */ + imm &= mask; + + /* That's how many ones we need to encode */ + ones = hweight64(imm); + + /* + * imms is set to (ones - 1), prefixed with a string of ones + * and a zero if they fit. Cap it to 6 bits. + */ + imms = ones - 1; + imms |= 0xf << ffs(esz); + imms &= BIT(6) - 1; + + /* Compute the rotation */ + if (range_of_ones(imm)) { + /* + * Pattern: 0..01..10..0 + * + * Compute how many rotate we need to align it right + */ + ror = __ffs64(imm); + } else { + /* + * Pattern: 0..01..10..01..1 + * + * Fill the unused top bits with ones, and check if + * the result is a valid immediate (all ones with a + * contiguous ranges of zeroes). + */ + imm |= ~mask; + if (!range_of_ones(~imm)) + return AARCH64_BREAK_FAULT; + + /* + * Compute the rotation to get a continuous set of + * ones, with the first bit set at position 0 + */ + ror = fls(~imm); + } + + /* + * immr is the number of bits we need to rotate back to the + * original set of ones. Note that this is relative to the + * element size... + */ + immr = (esz - ror) % esz; + + insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_N, insn, n); + insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_R, insn, immr); + return aarch64_insn_encode_immediate(AARCH64_INSN_IMM_S, insn, imms); +} + +u32 aarch64_insn_gen_logical_immediate(enum aarch64_insn_logic_type type, + enum aarch64_insn_variant variant, + enum aarch64_insn_register Rn, + enum aarch64_insn_register Rd, + u64 imm) +{ + u32 insn; + + switch (type) { + case AARCH64_INSN_LOGIC_AND: + insn = aarch64_insn_get_and_imm_value(); + break; + case AARCH64_INSN_LOGIC_ORR: + insn = aarch64_insn_get_orr_imm_value(); + break; + case AARCH64_INSN_LOGIC_EOR: + insn = aarch64_insn_get_eor_imm_value(); + break; + case AARCH64_INSN_LOGIC_AND_SETFLAGS: + insn = aarch64_insn_get_ands_imm_value(); + break; + default: + pr_err("%s: unknown logical encoding %d\n", __func__, type); + return AARCH64_BREAK_FAULT; + } + + insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, Rd); + insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, Rn); + return aarch64_encode_immediate(imm, variant, insn); +} + +u32 aarch64_insn_gen_extr(enum aarch64_insn_variant variant, + enum aarch64_insn_register Rm, + enum aarch64_insn_register Rn, + enum aarch64_insn_register Rd, + u8 lsb) +{ + u32 insn; + + insn = aarch64_insn_get_extr_value(); + + switch (variant) { + case AARCH64_INSN_VARIANT_32BIT: + if (lsb > 31) + return AARCH64_BREAK_FAULT; + break; + case AARCH64_INSN_VARIANT_64BIT: + if (lsb > 63) + return AARCH64_BREAK_FAULT; + insn |= AARCH64_INSN_SF_BIT; + insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_N, insn, 1); + break; + default: + pr_err("%s: unknown variant encoding %d\n", __func__, variant); + return AARCH64_BREAK_FAULT; + } + + insn = aarch64_insn_encode_immediate(AARCH64_INSN_IMM_S, insn, lsb); + insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RD, insn, Rd); + insn = aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RN, insn, Rn); + return aarch64_insn_encode_register(AARCH64_INSN_REGTYPE_RM, insn, Rm); +} |