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author | Catalin Marinas <catalin.marinas@arm.com> | 2020-03-25 11:11:08 +0000 |
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committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-03-25 11:11:08 +0000 |
commit | 44ca0e00b6a05ea9cf89d8a5290a225de19f4a2a (patch) | |
tree | 781fad5d055110645a037e61fa9d28d53e51572c /arch/arm64/include/asm | |
parent | 806dc825f01f1543f613b8195112ef06d04eb6d3 (diff) | |
parent | 3b446c7d27ddd06342901bb35211363f6944291a (diff) | |
download | linux-44ca0e00b6a05ea9cf89d8a5290a225de19f4a2a.tar.bz2 |
Merge branch 'for-next/kernel-ptrauth' into for-next/core
* for-next/kernel-ptrauth:
: Return address signing - in-kernel support
arm64: Kconfig: verify binutils support for ARM64_PTR_AUTH
lkdtm: arm64: test kernel pointer authentication
arm64: compile the kernel with ptrauth return address signing
kconfig: Add support for 'as-option'
arm64: suspend: restore the kernel ptrauth keys
arm64: __show_regs: strip PAC from lr in printk
arm64: unwind: strip PAC from kernel addresses
arm64: mask PAC bits of __builtin_return_address
arm64: initialize ptrauth keys for kernel booting task
arm64: initialize and switch ptrauth kernel keys
arm64: enable ptrauth earlier
arm64: cpufeature: handle conflicts based on capability
arm64: cpufeature: Move cpu capability helpers inside C file
arm64: ptrauth: Add bootup/runtime flags for __cpu_setup
arm64: install user ptrauth keys at kernel exit time
arm64: rename ptrauth key structures to be user-specific
arm64: cpufeature: add pointer auth meta-capabilities
arm64: cpufeature: Fix meta-capability cpufeature check
Diffstat (limited to 'arch/arm64/include/asm')
-rw-r--r-- | arch/arm64/include/asm/asm_pointer_auth.h | 65 | ||||
-rw-r--r-- | arch/arm64/include/asm/compiler.h | 24 | ||||
-rw-r--r-- | arch/arm64/include/asm/cpucaps.h | 4 | ||||
-rw-r--r-- | arch/arm64/include/asm/cpufeature.h | 39 | ||||
-rw-r--r-- | arch/arm64/include/asm/pointer_auth.h | 50 | ||||
-rw-r--r-- | arch/arm64/include/asm/processor.h | 3 | ||||
-rw-r--r-- | arch/arm64/include/asm/smp.h | 12 | ||||
-rw-r--r-- | arch/arm64/include/asm/stackprotector.h | 5 |
8 files changed, 154 insertions, 48 deletions
diff --git a/arch/arm64/include/asm/asm_pointer_auth.h b/arch/arm64/include/asm/asm_pointer_auth.h new file mode 100644 index 000000000000..ce2a8486992b --- /dev/null +++ b/arch/arm64/include/asm/asm_pointer_auth.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_ASM_POINTER_AUTH_H +#define __ASM_ASM_POINTER_AUTH_H + +#include <asm/alternative.h> +#include <asm/asm-offsets.h> +#include <asm/cpufeature.h> +#include <asm/sysreg.h> + +#ifdef CONFIG_ARM64_PTR_AUTH +/* + * thread.keys_user.ap* as offset exceeds the #imm offset range + * so use the base value of ldp as thread.keys_user and offset as + * thread.keys_user.ap*. + */ + .macro ptrauth_keys_install_user tsk, tmp1, tmp2, tmp3 + mov \tmp1, #THREAD_KEYS_USER + add \tmp1, \tsk, \tmp1 +alternative_if_not ARM64_HAS_ADDRESS_AUTH + b .Laddr_auth_skip_\@ +alternative_else_nop_endif + ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_USER_KEY_APIA] + msr_s SYS_APIAKEYLO_EL1, \tmp2 + msr_s SYS_APIAKEYHI_EL1, \tmp3 + ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_USER_KEY_APIB] + msr_s SYS_APIBKEYLO_EL1, \tmp2 + msr_s SYS_APIBKEYHI_EL1, \tmp3 + ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_USER_KEY_APDA] + msr_s SYS_APDAKEYLO_EL1, \tmp2 + msr_s SYS_APDAKEYHI_EL1, \tmp3 + ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_USER_KEY_APDB] + msr_s SYS_APDBKEYLO_EL1, \tmp2 + msr_s SYS_APDBKEYHI_EL1, \tmp3 +.Laddr_auth_skip_\@: +alternative_if ARM64_HAS_GENERIC_AUTH + ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_USER_KEY_APGA] + msr_s SYS_APGAKEYLO_EL1, \tmp2 + msr_s SYS_APGAKEYHI_EL1, \tmp3 +alternative_else_nop_endif + .endm + + .macro ptrauth_keys_install_kernel tsk, sync, tmp1, tmp2, tmp3 +alternative_if ARM64_HAS_ADDRESS_AUTH + mov \tmp1, #THREAD_KEYS_KERNEL + add \tmp1, \tsk, \tmp1 + ldp \tmp2, \tmp3, [\tmp1, #PTRAUTH_KERNEL_KEY_APIA] + msr_s SYS_APIAKEYLO_EL1, \tmp2 + msr_s SYS_APIAKEYHI_EL1, \tmp3 + .if \sync == 1 + isb + .endif +alternative_else_nop_endif + .endm + +#else /* CONFIG_ARM64_PTR_AUTH */ + + .macro ptrauth_keys_install_user tsk, tmp1, tmp2, tmp3 + .endm + + .macro ptrauth_keys_install_kernel tsk, sync, tmp1, tmp2, tmp3 + .endm + +#endif /* CONFIG_ARM64_PTR_AUTH */ + +#endif /* __ASM_ASM_POINTER_AUTH_H */ diff --git a/arch/arm64/include/asm/compiler.h b/arch/arm64/include/asm/compiler.h new file mode 100644 index 000000000000..eece20d2c55f --- /dev/null +++ b/arch/arm64/include/asm/compiler.h @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __ASM_COMPILER_H +#define __ASM_COMPILER_H + +#if defined(CONFIG_ARM64_PTR_AUTH) + +/* + * The EL0/EL1 pointer bits used by a pointer authentication code. + * This is dependent on TBI0/TBI1 being enabled, or bits 63:56 would also apply. + */ +#define ptrauth_user_pac_mask() GENMASK_ULL(54, vabits_actual) +#define ptrauth_kernel_pac_mask() GENMASK_ULL(63, vabits_actual) + +/* Valid for EL0 TTBR0 and EL1 TTBR1 instruction pointers */ +#define ptrauth_clear_pac(ptr) \ + ((ptr & BIT_ULL(55)) ? (ptr | ptrauth_kernel_pac_mask()) : \ + (ptr & ~ptrauth_user_pac_mask())) + +#define __builtin_return_address(val) \ + (void *)(ptrauth_clear_pac((unsigned long)__builtin_return_address(val))) + +#endif /* CONFIG_ARM64_PTR_AUTH */ + +#endif /* __ASM_COMPILER_H */ diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h index 185e44aa2713..8eb5a088ae65 100644 --- a/arch/arm64/include/asm/cpucaps.h +++ b/arch/arm64/include/asm/cpucaps.h @@ -59,7 +59,9 @@ #define ARM64_HAS_E0PD 49 #define ARM64_HAS_RNG 50 #define ARM64_HAS_AMU_EXTN 51 +#define ARM64_HAS_ADDRESS_AUTH 52 +#define ARM64_HAS_GENERIC_AUTH 53 -#define ARM64_NCAPS 52 +#define ARM64_NCAPS 54 #endif /* __ASM_CPUCAPS_H */ diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h index e75f7df746ba..09eb0dab66f8 100644 --- a/arch/arm64/include/asm/cpufeature.h +++ b/arch/arm64/include/asm/cpufeature.h @@ -208,6 +208,10 @@ extern struct arm64_ftr_reg arm64_ftr_reg_ctrel0; * In some non-typical cases either both (a) and (b), or neither, * should be permitted. This can be described by including neither * or both flags in the capability's type field. + * + * In case of a conflict, the CPU is prevented from booting. If the + * ARM64_CPUCAP_PANIC_ON_CONFLICT flag is specified for the capability, + * then a kernel panic is triggered. */ @@ -240,6 +244,8 @@ extern struct arm64_ftr_reg arm64_ftr_reg_ctrel0; #define ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU ((u16)BIT(4)) /* Is it safe for a late CPU to miss this capability when system has it */ #define ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU ((u16)BIT(5)) +/* Panic when a conflict is detected */ +#define ARM64_CPUCAP_PANIC_ON_CONFLICT ((u16)BIT(6)) /* * CPU errata workarounds that need to be enabled at boot time if one or @@ -279,9 +285,20 @@ extern struct arm64_ftr_reg arm64_ftr_reg_ctrel0; /* * CPU feature used early in the boot based on the boot CPU. All secondary - * CPUs must match the state of the capability as detected by the boot CPU. + * CPUs must match the state of the capability as detected by the boot CPU. In + * case of a conflict, a kernel panic is triggered. + */ +#define ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE \ + (ARM64_CPUCAP_SCOPE_BOOT_CPU | ARM64_CPUCAP_PANIC_ON_CONFLICT) + +/* + * CPU feature used early in the boot based on the boot CPU. It is safe for a + * late CPU to have this feature even though the boot CPU hasn't enabled it, + * although the feature will not be used by Linux in this case. If the boot CPU + * has enabled this feature already, then every late CPU must have it. */ -#define ARM64_CPUCAP_STRICT_BOOT_CPU_FEATURE ARM64_CPUCAP_SCOPE_BOOT_CPU +#define ARM64_CPUCAP_BOOT_CPU_FEATURE \ + (ARM64_CPUCAP_SCOPE_BOOT_CPU | ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU) struct arm64_cpu_capabilities { const char *desc; @@ -340,18 +357,6 @@ static inline int cpucap_default_scope(const struct arm64_cpu_capabilities *cap) return cap->type & ARM64_CPUCAP_SCOPE_MASK; } -static inline bool -cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap) -{ - return !!(cap->type & ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU); -} - -static inline bool -cpucap_late_cpu_permitted(const struct arm64_cpu_capabilities *cap) -{ - return !!(cap->type & ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU); -} - /* * Generic helper for handling capabilties with multiple (match,enable) pairs * of call backs, sharing the same capability bit. @@ -654,15 +659,13 @@ static inline bool system_supports_cnp(void) static inline bool system_supports_address_auth(void) { return IS_ENABLED(CONFIG_ARM64_PTR_AUTH) && - (cpus_have_const_cap(ARM64_HAS_ADDRESS_AUTH_ARCH) || - cpus_have_const_cap(ARM64_HAS_ADDRESS_AUTH_IMP_DEF)); + cpus_have_const_cap(ARM64_HAS_ADDRESS_AUTH); } static inline bool system_supports_generic_auth(void) { return IS_ENABLED(CONFIG_ARM64_PTR_AUTH) && - (cpus_have_const_cap(ARM64_HAS_GENERIC_AUTH_ARCH) || - cpus_have_const_cap(ARM64_HAS_GENERIC_AUTH_IMP_DEF)); + cpus_have_const_cap(ARM64_HAS_GENERIC_AUTH); } static inline bool system_uses_irq_prio_masking(void) diff --git a/arch/arm64/include/asm/pointer_auth.h b/arch/arm64/include/asm/pointer_auth.h index 7a24bad1a58b..70c47156e54b 100644 --- a/arch/arm64/include/asm/pointer_auth.h +++ b/arch/arm64/include/asm/pointer_auth.h @@ -22,7 +22,7 @@ struct ptrauth_key { * We give each process its own keys, which are shared by all threads. The keys * are inherited upon fork(), and reinitialised upon exec*(). */ -struct ptrauth_keys { +struct ptrauth_keys_user { struct ptrauth_key apia; struct ptrauth_key apib; struct ptrauth_key apda; @@ -30,7 +30,11 @@ struct ptrauth_keys { struct ptrauth_key apga; }; -static inline void ptrauth_keys_init(struct ptrauth_keys *keys) +struct ptrauth_keys_kernel { + struct ptrauth_key apia; +}; + +static inline void ptrauth_keys_init_user(struct ptrauth_keys_user *keys) { if (system_supports_address_auth()) { get_random_bytes(&keys->apia, sizeof(keys->apia)); @@ -50,48 +54,38 @@ do { \ write_sysreg_s(__pki_v.hi, SYS_ ## k ## KEYHI_EL1); \ } while (0) -static inline void ptrauth_keys_switch(struct ptrauth_keys *keys) +static __always_inline void ptrauth_keys_init_kernel(struct ptrauth_keys_kernel *keys) { - if (system_supports_address_auth()) { - __ptrauth_key_install(APIA, keys->apia); - __ptrauth_key_install(APIB, keys->apib); - __ptrauth_key_install(APDA, keys->apda); - __ptrauth_key_install(APDB, keys->apdb); - } + if (system_supports_address_auth()) + get_random_bytes(&keys->apia, sizeof(keys->apia)); +} - if (system_supports_generic_auth()) - __ptrauth_key_install(APGA, keys->apga); +static __always_inline void ptrauth_keys_switch_kernel(struct ptrauth_keys_kernel *keys) +{ + if (system_supports_address_auth()) + __ptrauth_key_install(APIA, keys->apia); } extern int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg); -/* - * The EL0 pointer bits used by a pointer authentication code. - * This is dependent on TBI0 being enabled, or bits 63:56 would also apply. - */ -#define ptrauth_user_pac_mask() GENMASK(54, vabits_actual) - -/* Only valid for EL0 TTBR0 instruction pointers */ static inline unsigned long ptrauth_strip_insn_pac(unsigned long ptr) { - return ptr & ~ptrauth_user_pac_mask(); + return ptrauth_clear_pac(ptr); } #define ptrauth_thread_init_user(tsk) \ -do { \ - struct task_struct *__ptiu_tsk = (tsk); \ - ptrauth_keys_init(&__ptiu_tsk->thread.keys_user); \ - ptrauth_keys_switch(&__ptiu_tsk->thread.keys_user); \ -} while (0) - -#define ptrauth_thread_switch(tsk) \ - ptrauth_keys_switch(&(tsk)->thread.keys_user) + ptrauth_keys_init_user(&(tsk)->thread.keys_user) +#define ptrauth_thread_init_kernel(tsk) \ + ptrauth_keys_init_kernel(&(tsk)->thread.keys_kernel) +#define ptrauth_thread_switch_kernel(tsk) \ + ptrauth_keys_switch_kernel(&(tsk)->thread.keys_kernel) #else /* CONFIG_ARM64_PTR_AUTH */ #define ptrauth_prctl_reset_keys(tsk, arg) (-EINVAL) #define ptrauth_strip_insn_pac(lr) (lr) #define ptrauth_thread_init_user(tsk) -#define ptrauth_thread_switch(tsk) +#define ptrauth_thread_init_kernel(tsk) +#define ptrauth_thread_switch_kernel(tsk) #endif /* CONFIG_ARM64_PTR_AUTH */ #endif /* __ASM_POINTER_AUTH_H */ diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h index 5ba63204d078..4c77da5dc819 100644 --- a/arch/arm64/include/asm/processor.h +++ b/arch/arm64/include/asm/processor.h @@ -146,7 +146,8 @@ struct thread_struct { unsigned long fault_code; /* ESR_EL1 value */ struct debug_info debug; /* debugging */ #ifdef CONFIG_ARM64_PTR_AUTH - struct ptrauth_keys keys_user; + struct ptrauth_keys_user keys_user; + struct ptrauth_keys_kernel keys_kernel; #endif }; diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h index a0c8a0b65259..40d5ba029615 100644 --- a/arch/arm64/include/asm/smp.h +++ b/arch/arm64/include/asm/smp.h @@ -23,6 +23,14 @@ #define CPU_STUCK_REASON_52_BIT_VA (UL(1) << CPU_STUCK_REASON_SHIFT) #define CPU_STUCK_REASON_NO_GRAN (UL(2) << CPU_STUCK_REASON_SHIFT) +/* Possible options for __cpu_setup */ +/* Option to setup primary cpu */ +#define ARM64_CPU_BOOT_PRIMARY (1) +/* Option to setup secondary cpus */ +#define ARM64_CPU_BOOT_SECONDARY (2) +/* Option to setup cpus for different cpu run time services */ +#define ARM64_CPU_RUNTIME (3) + #ifndef __ASSEMBLY__ #include <asm/percpu.h> @@ -30,6 +38,7 @@ #include <linux/threads.h> #include <linux/cpumask.h> #include <linux/thread_info.h> +#include <asm/pointer_auth.h> DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number); @@ -87,6 +96,9 @@ asmlinkage void secondary_start_kernel(void); struct secondary_data { void *stack; struct task_struct *task; +#ifdef CONFIG_ARM64_PTR_AUTH + struct ptrauth_keys_kernel ptrauth_key; +#endif long status; }; diff --git a/arch/arm64/include/asm/stackprotector.h b/arch/arm64/include/asm/stackprotector.h index 5884a2b02827..7263e0bac680 100644 --- a/arch/arm64/include/asm/stackprotector.h +++ b/arch/arm64/include/asm/stackprotector.h @@ -15,6 +15,7 @@ #include <linux/random.h> #include <linux/version.h> +#include <asm/pointer_auth.h> extern unsigned long __stack_chk_guard; @@ -26,6 +27,7 @@ extern unsigned long __stack_chk_guard; */ static __always_inline void boot_init_stack_canary(void) { +#if defined(CONFIG_STACKPROTECTOR) unsigned long canary; /* Try to get a semi random initial value. */ @@ -36,6 +38,9 @@ static __always_inline void boot_init_stack_canary(void) current->stack_canary = canary; if (!IS_ENABLED(CONFIG_STACKPROTECTOR_PER_TASK)) __stack_chk_guard = current->stack_canary; +#endif + ptrauth_thread_init_kernel(current); + ptrauth_thread_switch_kernel(current); } #endif /* _ASM_STACKPROTECTOR_H */ |