diff options
| -rw-r--r-- | Documentation/arm64/cpu-feature-registers.rst | 2 | ||||
| -rw-r--r-- | Documentation/arm64/elf_hwcaps.rst | 5 | ||||
| -rw-r--r-- | arch/arm64/include/asm/cpucaps.h | 3 | ||||
| -rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 6 | ||||
| -rw-r--r-- | arch/arm64/include/asm/esr.h | 2 | ||||
| -rw-r--r-- | arch/arm64/include/asm/exception.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/hwcap.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/mman.h | 37 | ||||
| -rw-r--r-- | arch/arm64/include/asm/pgtable-hwdef.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/pgtable.h | 2 | ||||
| -rw-r--r-- | arch/arm64/include/asm/ptrace.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/asm/sysreg.h | 4 | ||||
| -rw-r--r-- | arch/arm64/include/uapi/asm/hwcap.h | 1 | ||||
| -rw-r--r-- | arch/arm64/include/uapi/asm/mman.h | 9 | ||||
| -rw-r--r-- | arch/arm64/include/uapi/asm/ptrace.h | 9 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpufeature.c | 33 | ||||
| -rw-r--r-- | arch/arm64/kernel/cpuinfo.c | 1 | ||||
| -rw-r--r-- | arch/arm64/kernel/entry-common.c | 11 | ||||
| -rw-r--r-- | arch/arm64/kernel/ptrace.c | 2 | ||||
| -rw-r--r-- | arch/arm64/kernel/signal.c | 16 | ||||
| -rw-r--r-- | arch/arm64/kernel/syscall.c | 18 | ||||
| -rw-r--r-- | arch/arm64/kernel/traps.c | 8 | ||||
| -rw-r--r-- | include/linux/mm.h | 3 |
23 files changed, 172 insertions, 4 deletions
diff --git a/Documentation/arm64/cpu-feature-registers.rst b/Documentation/arm64/cpu-feature-registers.rst index 41937a8091aa..314fa5bc2655 100644 --- a/Documentation/arm64/cpu-feature-registers.rst +++ b/Documentation/arm64/cpu-feature-registers.rst @@ -176,6 +176,8 @@ infrastructure: +------------------------------+---------+---------+ | SSBS | [7-4] | y | +------------------------------+---------+---------+ + | BT | [3-0] | y | + +------------------------------+---------+---------+ 4) MIDR_EL1 - Main ID Register diff --git a/Documentation/arm64/elf_hwcaps.rst b/Documentation/arm64/elf_hwcaps.rst index 7dfb97dfe416..84a9fd2d41b4 100644 --- a/Documentation/arm64/elf_hwcaps.rst +++ b/Documentation/arm64/elf_hwcaps.rst @@ -236,6 +236,11 @@ HWCAP2_RNG Functionality implied by ID_AA64ISAR0_EL1.RNDR == 0b0001. +HWCAP2_BTI + + Functionality implied by ID_AA64PFR0_EL1.BT == 0b0001. + + 4. Unused AT_HWCAP bits ----------------------- diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index 865e0253fc1e..58e776c22aab 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -58,7 +58,8 @@ #define ARM64_WORKAROUND_SPECULATIVE_AT_NVHE 48 #define ARM64_HAS_E0PD 49 #define ARM64_HAS_RNG 50 +#define ARM64_BTI 51 -#define ARM64_NCAPS 51 +#define ARM64_NCAPS 52 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index 92ef9539874a..e3ebcc59e83b 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -613,6 +613,12 @@ static inline bool system_has_prio_mask_debugging(void) system_uses_irq_prio_masking(); } +static inline bool system_supports_bti(void) +{ + return IS_ENABLED(CONFIG_ARM64_BTI) && + cpus_have_const_cap(ARM64_BTI); +} + static inline bool system_capabilities_finalized(void) { return static_branch_likely(&arm64_const_caps_ready); diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h index cb29253ae86b..390b8ba67830 100644 --- a/arch/arm64/include/asm/esr.h +++ b/arch/arm64/include/asm/esr.h @@ -22,7 +22,7 @@ #define ESR_ELx_EC_PAC (0x09) /* EL2 and above */ /* Unallocated EC: 0x0A - 0x0B */ #define ESR_ELx_EC_CP14_64 (0x0C) -/* Unallocated EC: 0x0d */ +#define ESR_ELx_EC_BTI (0x0D) #define ESR_ELx_EC_ILL (0x0E) /* Unallocated EC: 0x0F - 0x10 */ #define ESR_ELx_EC_SVC32 (0x11) diff --git a/arch/arm64/include/asm/exception.h b/arch/arm64/include/asm/exception.h index 7a6e81ca23a8..7577a754d443 100644 --- a/arch/arm64/include/asm/exception.h +++ b/arch/arm64/include/asm/exception.h @@ -34,6 +34,7 @@ static inline u32 disr_to_esr(u64 disr) asmlinkage void enter_from_user_mode(void); void do_mem_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs); void do_undefinstr(struct pt_regs *regs); +void do_bti(struct pt_regs *regs); asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr); void do_debug_exception(unsigned long addr_if_watchpoint, unsigned int esr, struct pt_regs *regs); diff --git a/arch/arm64/include/asm/hwcap.h b/arch/arm64/include/asm/hwcap.h index 0f00265248b5..d683bcbf1e7c 100644 --- a/arch/arm64/include/asm/hwcap.h +++ b/arch/arm64/include/asm/hwcap.h @@ -94,6 +94,7 @@ #define KERNEL_HWCAP_BF16 __khwcap2_feature(BF16) #define KERNEL_HWCAP_DGH __khwcap2_feature(DGH) #define KERNEL_HWCAP_RNG __khwcap2_feature(RNG) +#define KERNEL_HWCAP_BTI __khwcap2_feature(BTI) /* * This yields a mask that user programs can use to figure out what diff --git a/arch/arm64/include/asm/mman.h b/arch/arm64/include/asm/mman.h new file mode 100644 index 000000000000..081ec8de9ea6 --- /dev/null +++ b/arch/arm64/include/asm/mman.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_MMAN_H__ +#define __ASM_MMAN_H__ + +#include <linux/compiler.h> +#include <linux/types.h> +#include <uapi/asm/mman.h> + +static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot, + unsigned long pkey __always_unused) +{ + if (system_supports_bti() && (prot & PROT_BTI)) + return VM_ARM64_BTI; + + return 0; +} +#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey) + +static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags) +{ + return (vm_flags & VM_ARM64_BTI) ? __pgprot(PTE_GP) : __pgprot(0); +} +#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags) + +static inline bool arch_validate_prot(unsigned long prot, + unsigned long addr __always_unused) +{ + unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM; + + if (system_supports_bti()) + supported |= PROT_BTI; + + return (prot & ~supported) == 0; +} +#define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr) + +#endif /* ! __ASM_MMAN_H__ */ diff --git a/arch/arm64/include/asm/pgtable-hwdef.h b/arch/arm64/include/asm/pgtable-hwdef.h index 6bf5e650da78..167f1d1d48aa 100644 --- a/arch/arm64/include/asm/pgtable-hwdef.h +++ b/arch/arm64/include/asm/pgtable-hwdef.h @@ -151,6 +151,7 @@ #define PTE_SHARED (_AT(pteval_t, 3) << 8) /* SH[1:0], inner shareable */ #define PTE_AF (_AT(pteval_t, 1) << 10) /* Access Flag */ #define PTE_NG (_AT(pteval_t, 1) << 11) /* nG */ +#define PTE_GP (_AT(pteval_t, 1) << 50) /* BTI guarded */ #define PTE_DBM (_AT(pteval_t, 1) << 51) /* Dirty Bit Management */ #define PTE_CONT (_AT(pteval_t, 1) << 52) /* Contiguous range */ #define PTE_PXN (_AT(pteval_t, 1) << 53) /* Privileged XN */ diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 538c85e62f86..4fbf516d8cb2 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -660,7 +660,7 @@ static inline phys_addr_t pgd_page_paddr(pgd_t pgd) static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY | - PTE_PROT_NONE | PTE_VALID | PTE_WRITE; + PTE_PROT_NONE | PTE_VALID | PTE_WRITE | PTE_GP; /* preserve the hardware dirty information */ if (pte_hw_dirty(pte)) pte = pte_mkdirty(pte); diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index bf57308fcd63..2172ec7594ba 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -35,6 +35,7 @@ #define GIC_PRIO_PSR_I_SET (1 << 4) /* Additional SPSR bits not exposed in the UABI */ + #define PSR_IL_BIT (1 << 20) /* AArch32-specific ptrace requests */ diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index b91570ff9db1..db08ceb4cc9a 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -514,6 +514,8 @@ #endif /* SCTLR_EL1 specific flags. */ +#define SCTLR_EL1_BT1 (BIT(36)) +#define SCTLR_EL1_BT0 (BIT(35)) #define SCTLR_EL1_UCI (BIT(26)) #define SCTLR_EL1_E0E (BIT(24)) #define SCTLR_EL1_SPAN (BIT(23)) @@ -620,10 +622,12 @@ /* id_aa64pfr1 */ #define ID_AA64PFR1_SSBS_SHIFT 4 +#define ID_AA64PFR1_BT_SHIFT 0 #define ID_AA64PFR1_SSBS_PSTATE_NI 0 #define ID_AA64PFR1_SSBS_PSTATE_ONLY 1 #define ID_AA64PFR1_SSBS_PSTATE_INSNS 2 +#define ID_AA64PFR1_BT_BTI 0x1 /* id_aa64zfr0 */ #define ID_AA64ZFR0_F64MM_SHIFT 56 diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h index 7752d93bb50f..2d6ba1c2592e 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -73,5 +73,6 @@ #define HWCAP2_BF16 (1 << 14) #define HWCAP2_DGH (1 << 15) #define HWCAP2_RNG (1 << 16) +#define HWCAP2_BTI (1 << 17) #endif /* _UAPI__ASM_HWCAP_H */ diff --git a/arch/arm64/include/uapi/asm/mman.h b/arch/arm64/include/uapi/asm/mman.h new file mode 100644 index 000000000000..6fdd71eb644f --- /dev/null +++ b/arch/arm64/include/uapi/asm/mman.h @@ -0,0 +1,9 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _UAPI__ASM_MMAN_H +#define _UAPI__ASM_MMAN_H + +#include <asm-generic/mman.h> + +#define PROT_BTI 0x10 /* BTI guarded page */ + +#endif /* ! _UAPI__ASM_MMAN_H */ diff --git a/arch/arm64/include/uapi/asm/ptrace.h b/arch/arm64/include/uapi/asm/ptrace.h index d1bb5b69f1ce..42cbe34d95ce 100644 --- a/arch/arm64/include/uapi/asm/ptrace.h +++ b/arch/arm64/include/uapi/asm/ptrace.h @@ -46,6 +46,7 @@ #define PSR_I_BIT 0x00000080 #define PSR_A_BIT 0x00000100 #define PSR_D_BIT 0x00000200 +#define PSR_BTYPE_MASK 0x00000c00 #define PSR_SSBS_BIT 0x00001000 #define PSR_PAN_BIT 0x00400000 #define PSR_UAO_BIT 0x00800000 @@ -55,6 +56,8 @@ #define PSR_Z_BIT 0x40000000 #define PSR_N_BIT 0x80000000 +#define PSR_BTYPE_SHIFT 10 + /* * Groups of PSR bits */ @@ -63,6 +66,12 @@ #define PSR_x 0x0000ff00 /* Extension */ #define PSR_c 0x000000ff /* Control */ +/* Convenience names for the values of PSTATE.BTYPE */ +#define PSR_BTYPE_NONE (0b00 << PSR_BTYPE_SHIFT) +#define PSR_BTYPE_JC (0b01 << PSR_BTYPE_SHIFT) +#define PSR_BTYPE_C (0b10 << PSR_BTYPE_SHIFT) +#define PSR_BTYPE_J (0b11 << PSR_BTYPE_SHIFT) + /* syscall emulation path in ptrace */ #define PTRACE_SYSEMU 31 #define PTRACE_SYSEMU_SINGLESTEP 32 diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 0b6715625cf6..e6d31776e49b 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -179,6 +179,8 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = { static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = { ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SSBS_SHIFT, 4, ID_AA64PFR1_SSBS_PSTATE_NI), + ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_BTI), + FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_BT_SHIFT, 4, 0), ARM64_FTR_END, }; @@ -1347,6 +1349,21 @@ static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry, } #endif +#ifdef CONFIG_ARM64_BTI +static void bti_enable(const struct arm64_cpu_capabilities *__unused) +{ + /* + * Use of X16/X17 for tail-calls and trampolines that jump to + * function entry points using BR is a requirement for + * marking binaries with GNU_PROPERTY_AARCH64_FEATURE_1_BTI. + * So, be strict and forbid other BRs using other registers to + * jump onto a PACIxSP instruction: + */ + sysreg_clear_set(sctlr_el1, 0, SCTLR_EL1_BT0 | SCTLR_EL1_BT1); + isb(); +} +#endif /* CONFIG_ARM64_BTI */ + static const struct arm64_cpu_capabilities arm64_features[] = { { .desc = "GIC system register CPU interface", @@ -1672,6 +1689,19 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .min_field_value = 1, }, #endif +#ifdef CONFIG_ARM64_BTI + { + .desc = "Branch Target Identification", + .capability = ARM64_BTI, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_cpuid_feature, + .cpu_enable = bti_enable, + .sys_reg = SYS_ID_AA64PFR1_EL1, + .field_pos = ID_AA64PFR1_BT_SHIFT, + .min_field_value = ID_AA64PFR1_BT_BTI, + .sign = FTR_UNSIGNED, + }, +#endif {}, }; @@ -1781,6 +1811,9 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = { HWCAP_CAP(SYS_ID_AA64ZFR0_EL1, ID_AA64ZFR0_F64MM_SHIFT, FTR_UNSIGNED, ID_AA64ZFR0_F64MM, CAP_HWCAP, KERNEL_HWCAP_SVEF64MM), #endif HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SSBS_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_SSBS_PSTATE_INSNS, CAP_HWCAP, KERNEL_HWCAP_SSBS), +#ifdef CONFIG_ARM64_BTI + HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_BT_SHIFT, FTR_UNSIGNED, ID_AA64PFR1_BT_BTI, CAP_HWCAP, KERNEL_HWCAP_BTI), +#endif #ifdef CONFIG_ARM64_PTR_AUTH HWCAP_MULTI_CAP(ptr_auth_hwcap_addr_matches, CAP_HWCAP, KERNEL_HWCAP_PACA), HWCAP_MULTI_CAP(ptr_auth_hwcap_gen_matches, CAP_HWCAP, KERNEL_HWCAP_PACG), diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c index 86136075ae41..5e47e93b5dc1 100644 --- a/arch/arm64/kernel/cpuinfo.c +++ b/arch/arm64/kernel/cpuinfo.c @@ -92,6 +92,7 @@ static const char *const hwcap_str[] = { "bf16", "dgh", "rng", + "bti", NULL }; diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index fde59981445c..55ec0627f5a7 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -188,6 +188,14 @@ static void notrace el0_undef(struct pt_regs *regs) } NOKPROBE_SYMBOL(el0_undef); +static void notrace el0_bti(struct pt_regs *regs) +{ + user_exit_irqoff(); + local_daif_restore(DAIF_PROCCTX); + do_bti(regs); +} +NOKPROBE_SYMBOL(el0_bti); + static void notrace el0_inv(struct pt_regs *regs, unsigned long esr) { user_exit_irqoff(); @@ -255,6 +263,9 @@ asmlinkage void notrace el0_sync_handler(struct pt_regs *regs) case ESR_ELx_EC_UNKNOWN: el0_undef(regs); break; + case ESR_ELx_EC_BTI: + el0_bti(regs); + break; case ESR_ELx_EC_BREAKPT_LOW: case ESR_ELx_EC_SOFTSTP_LOW: case ESR_ELx_EC_WATCHPT_LOW: diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index cd6e5fa48b9c..fd8ac7cf68e7 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -1874,7 +1874,7 @@ void syscall_trace_exit(struct pt_regs *regs) */ #define SPSR_EL1_AARCH64_RES0_BITS \ (GENMASK_ULL(63, 32) | GENMASK_ULL(27, 25) | GENMASK_ULL(23, 22) | \ - GENMASK_ULL(20, 13) | GENMASK_ULL(11, 10) | GENMASK_ULL(5, 5)) + GENMASK_ULL(20, 13) | GENMASK_ULL(5, 5)) #define SPSR_EL1_AARCH32_RES0_BITS \ (GENMASK_ULL(63, 32) | GENMASK_ULL(22, 22) | GENMASK_ULL(20, 20)) diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c index 339882db5a91..801d56cdf701 100644 --- a/arch/arm64/kernel/signal.c +++ b/arch/arm64/kernel/signal.c @@ -732,6 +732,22 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka, regs->regs[29] = (unsigned long)&user->next_frame->fp; regs->pc = (unsigned long)ka->sa.sa_handler; + /* + * Signal delivery is a (wacky) indirect function call in + * userspace, so simulate the same setting of BTYPE as a BLR + * <register containing the signal handler entry point>. + * Signal delivery to a location in a PROT_BTI guarded page + * that is not a function entry point will now trigger a + * SIGILL in userspace. + * + * If the signal handler entry point is not in a PROT_BTI + * guarded page, this is harmless. + */ + if (system_supports_bti()) { + regs->pstate &= ~PSR_BTYPE_MASK; + regs->pstate |= PSR_BTYPE_C; + } + if (ka->sa.sa_flags & SA_RESTORER) sigtramp = ka->sa.sa_restorer; else diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c index a12c0c88d345..5f5b868292f5 100644 --- a/arch/arm64/kernel/syscall.c +++ b/arch/arm64/kernel/syscall.c @@ -98,6 +98,24 @@ static void el0_svc_common(struct pt_regs *regs, int scno, int sc_nr, regs->orig_x0 = regs->regs[0]; regs->syscallno = scno; + /* + * BTI note: + * The architecture does not guarantee that SPSR.BTYPE is zero + * on taking an SVC, so we could return to userspace with a + * non-zero BTYPE after the syscall. + * + * This shouldn't matter except when userspace is explicitly + * doing something stupid, such as setting PROT_BTI on a page + * that lacks conforming BTI/PACIxSP instructions, falling + * through from one executable page to another with differing + * PROT_BTI, or messing with BTYPE via ptrace: in such cases, + * userspace should not be surprised if a SIGILL occurs on + * syscall return. + * + * So, don't touch regs->pstate & PSR_BTYPE_MASK here. + * (Similarly for HVC and SMC elsewhere.) + */ + cortex_a76_erratum_1463225_svc_handler(); local_daif_restore(DAIF_PROCCTX); user_exit(); diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index cf402be5c573..b8c714dda851 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -411,6 +411,13 @@ void do_undefinstr(struct pt_regs *regs) } NOKPROBE_SYMBOL(do_undefinstr); +void do_bti(struct pt_regs *regs) +{ + BUG_ON(!user_mode(regs)); + force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc); +} +NOKPROBE_SYMBOL(do_bti); + #define __user_cache_maint(insn, address, res) \ if (address >= user_addr_max()) { \ res = -EFAULT; \ @@ -753,6 +760,7 @@ static const char *esr_class_str[] = { [ESR_ELx_EC_CP10_ID] = "CP10 MRC/VMRS", [ESR_ELx_EC_PAC] = "PAC", [ESR_ELx_EC_CP14_64] = "CP14 MCRR/MRRC", + [ESR_ELx_EC_BTI] = "BTI", [ESR_ELx_EC_ILL] = "PSTATE.IL", [ESR_ELx_EC_SVC32] = "SVC (AArch32)", [ESR_ELx_EC_HVC32] = "HVC (AArch32)", diff --git a/include/linux/mm.h b/include/linux/mm.h index 52269e56c514..9e5fce1b2099 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -324,6 +324,9 @@ extern unsigned int kobjsize(const void *objp); #elif defined(CONFIG_SPARC64) # define VM_SPARC_ADI VM_ARCH_1 /* Uses ADI tag for access control */ # define VM_ARCH_CLEAR VM_SPARC_ADI +#elif defined(CONFIG_ARM64) +# define VM_ARM64_BTI VM_ARCH_1 /* BTI guarded page, a.k.a. GP bit */ +# define VM_ARCH_CLEAR VM_ARM64_BTI #elif !defined(CONFIG_MMU) # define VM_MAPPED_COPY VM_ARCH_1 /* T if mapped copy of data (nommu mmap) */ #endif |