diff options
author | Catalin Marinas <catalin.marinas@arm.com> | 2020-03-25 11:11:08 +0000 |
---|---|---|
committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-03-25 11:11:08 +0000 |
commit | 44ca0e00b6a05ea9cf89d8a5290a225de19f4a2a (patch) | |
tree | 781fad5d055110645a037e61fa9d28d53e51572c /arch/arm64/kernel | |
parent | 806dc825f01f1543f613b8195112ef06d04eb6d3 (diff) | |
parent | 3b446c7d27ddd06342901bb35211363f6944291a (diff) |
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/kernel')
-rw-r--r-- | arch/arm64/kernel/asm-offsets.c | 16 | ||||
-rw-r--r-- | arch/arm64/kernel/cpufeature.c | 93 | ||||
-rw-r--r-- | arch/arm64/kernel/entry.S | 6 | ||||
-rw-r--r-- | arch/arm64/kernel/head.S | 2 | ||||
-rw-r--r-- | arch/arm64/kernel/pointer_auth.c | 7 | ||||
-rw-r--r-- | arch/arm64/kernel/process.c | 5 | ||||
-rw-r--r-- | arch/arm64/kernel/ptrace.c | 16 | ||||
-rw-r--r-- | arch/arm64/kernel/sleep.S | 2 | ||||
-rw-r--r-- | arch/arm64/kernel/smp.c | 8 | ||||
-rw-r--r-- | arch/arm64/kernel/stacktrace.c | 5 |
10 files changed, 122 insertions, 38 deletions
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c index a5bdce8af65b..9981a0a5a87f 100644 --- a/arch/arm64/kernel/asm-offsets.c +++ b/arch/arm64/kernel/asm-offsets.c @@ -40,6 +40,10 @@ int main(void) #endif BLANK(); DEFINE(THREAD_CPU_CONTEXT, offsetof(struct task_struct, thread.cpu_context)); +#ifdef CONFIG_ARM64_PTR_AUTH + DEFINE(THREAD_KEYS_USER, offsetof(struct task_struct, thread.keys_user)); + DEFINE(THREAD_KEYS_KERNEL, offsetof(struct task_struct, thread.keys_kernel)); +#endif BLANK(); DEFINE(S_X0, offsetof(struct pt_regs, regs[0])); DEFINE(S_X2, offsetof(struct pt_regs, regs[2])); @@ -88,6 +92,9 @@ int main(void) BLANK(); DEFINE(CPU_BOOT_STACK, offsetof(struct secondary_data, stack)); DEFINE(CPU_BOOT_TASK, offsetof(struct secondary_data, task)); +#ifdef CONFIG_ARM64_PTR_AUTH + DEFINE(CPU_BOOT_PTRAUTH_KEY, offsetof(struct secondary_data, ptrauth_key)); +#endif BLANK(); #ifdef CONFIG_KVM_ARM_HOST DEFINE(VCPU_CONTEXT, offsetof(struct kvm_vcpu, arch.ctxt)); @@ -128,5 +135,14 @@ int main(void) DEFINE(SDEI_EVENT_INTREGS, offsetof(struct sdei_registered_event, interrupted_regs)); DEFINE(SDEI_EVENT_PRIORITY, offsetof(struct sdei_registered_event, priority)); #endif +#ifdef CONFIG_ARM64_PTR_AUTH + DEFINE(PTRAUTH_USER_KEY_APIA, offsetof(struct ptrauth_keys_user, apia)); + DEFINE(PTRAUTH_USER_KEY_APIB, offsetof(struct ptrauth_keys_user, apib)); + DEFINE(PTRAUTH_USER_KEY_APDA, offsetof(struct ptrauth_keys_user, apda)); + DEFINE(PTRAUTH_USER_KEY_APDB, offsetof(struct ptrauth_keys_user, apdb)); + DEFINE(PTRAUTH_USER_KEY_APGA, offsetof(struct ptrauth_keys_user, apga)); + DEFINE(PTRAUTH_KERNEL_KEY_APIA, offsetof(struct ptrauth_keys_kernel, apia)); + BLANK(); +#endif return 0; } diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 38ebad880f5c..9fac745aa7bb 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -116,6 +116,8 @@ cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused) static void cpu_enable_cnp(struct arm64_cpu_capabilities const *cap); +static bool __system_matches_cap(unsigned int n); + /* * NOTE: Any changes to the visibility of features should be kept in * sync with the documentation of the CPU feature register ABI. @@ -1368,10 +1370,18 @@ static void cpu_clear_disr(const struct arm64_cpu_capabilities *__unused) #endif /* CONFIG_ARM64_RAS_EXTN */ #ifdef CONFIG_ARM64_PTR_AUTH -static void cpu_enable_address_auth(struct arm64_cpu_capabilities const *cap) +static bool has_address_auth(const struct arm64_cpu_capabilities *entry, + int __unused) +{ + return __system_matches_cap(ARM64_HAS_ADDRESS_AUTH_ARCH) || + __system_matches_cap(ARM64_HAS_ADDRESS_AUTH_IMP_DEF); +} + +static bool has_generic_auth(const struct arm64_cpu_capabilities *entry, + int __unused) { - sysreg_clear_set(sctlr_el1, 0, SCTLR_ELx_ENIA | SCTLR_ELx_ENIB | - SCTLR_ELx_ENDA | SCTLR_ELx_ENDB); + return __system_matches_cap(ARM64_HAS_GENERIC_AUTH_ARCH) || + __system_matches_cap(ARM64_HAS_GENERIC_AUTH_IMP_DEF); } #endif /* CONFIG_ARM64_PTR_AUTH */ @@ -1399,6 +1409,25 @@ static bool can_use_gic_priorities(const struct arm64_cpu_capabilities *entry, } #endif +/* Internal helper functions to match cpu capability type */ +static bool +cpucap_late_cpu_optional(const struct arm64_cpu_capabilities *cap) +{ + return !!(cap->type & ARM64_CPUCAP_OPTIONAL_FOR_LATE_CPU); +} + +static bool +cpucap_late_cpu_permitted(const struct arm64_cpu_capabilities *cap) +{ + return !!(cap->type & ARM64_CPUCAP_PERMITTED_FOR_LATE_CPU); +} + +static bool +cpucap_panic_on_conflict(const struct arm64_cpu_capabilities *cap) +{ + return !!(cap->type & ARM64_CPUCAP_PANIC_ON_CONFLICT); +} + static const struct arm64_cpu_capabilities arm64_features[] = { { .desc = "GIC system register CPU interface", @@ -1662,24 +1691,27 @@ static const struct arm64_cpu_capabilities arm64_features[] = { { .desc = "Address authentication (architected algorithm)", .capability = ARM64_HAS_ADDRESS_AUTH_ARCH, - .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .type = ARM64_CPUCAP_BOOT_CPU_FEATURE, .sys_reg = SYS_ID_AA64ISAR1_EL1, .sign = FTR_UNSIGNED, .field_pos = ID_AA64ISAR1_APA_SHIFT, .min_field_value = ID_AA64ISAR1_APA_ARCHITECTED, .matches = has_cpuid_feature, - .cpu_enable = cpu_enable_address_auth, }, { .desc = "Address authentication (IMP DEF algorithm)", .capability = ARM64_HAS_ADDRESS_AUTH_IMP_DEF, - .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .type = ARM64_CPUCAP_BOOT_CPU_FEATURE, .sys_reg = SYS_ID_AA64ISAR1_EL1, .sign = FTR_UNSIGNED, .field_pos = ID_AA64ISAR1_API_SHIFT, .min_field_value = ID_AA64ISAR1_API_IMP_DEF, .matches = has_cpuid_feature, - .cpu_enable = cpu_enable_address_auth, + }, + { + .capability = ARM64_HAS_ADDRESS_AUTH, + .type = ARM64_CPUCAP_BOOT_CPU_FEATURE, + .matches = has_address_auth, }, { .desc = "Generic authentication (architected algorithm)", @@ -1701,6 +1733,11 @@ static const struct arm64_cpu_capabilities arm64_features[] = { .min_field_value = ID_AA64ISAR1_GPI_IMP_DEF, .matches = has_cpuid_feature, }, + { + .capability = ARM64_HAS_GENERIC_AUTH, + .type = ARM64_CPUCAP_SYSTEM_FEATURE, + .matches = has_generic_auth, + }, #endif /* CONFIG_ARM64_PTR_AUTH */ #ifdef CONFIG_ARM64_PSEUDO_NMI { @@ -2050,10 +2087,8 @@ static void __init enable_cpu_capabilities(u16 scope_mask) * Run through the list of capabilities to check for conflicts. * If the system has already detected a capability, take necessary * action on this CPU. - * - * Returns "false" on conflicts. */ -static bool verify_local_cpu_caps(u16 scope_mask) +static void verify_local_cpu_caps(u16 scope_mask) { int i; bool cpu_has_cap, system_has_cap; @@ -2098,10 +2133,12 @@ static bool verify_local_cpu_caps(u16 scope_mask) pr_crit("CPU%d: Detected conflict for capability %d (%s), System: %d, CPU: %d\n", smp_processor_id(), caps->capability, caps->desc, system_has_cap, cpu_has_cap); - return false; - } - return true; + if (cpucap_panic_on_conflict(caps)) + cpu_panic_kernel(); + else + cpu_die_early(); + } } /* @@ -2111,12 +2148,8 @@ static bool verify_local_cpu_caps(u16 scope_mask) static void check_early_cpu_features(void) { verify_cpu_asid_bits(); - /* - * Early features are used by the kernel already. If there - * is a conflict, we cannot proceed further. - */ - if (!verify_local_cpu_caps(SCOPE_BOOT_CPU)) - cpu_panic_kernel(); + + verify_local_cpu_caps(SCOPE_BOOT_CPU); } static void @@ -2164,8 +2197,7 @@ static void verify_local_cpu_capabilities(void) * check_early_cpu_features(), as they need to be verified * on all secondary CPUs. */ - if (!verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU)) - cpu_die_early(); + verify_local_cpu_caps(SCOPE_ALL & ~SCOPE_BOOT_CPU); verify_local_elf_hwcaps(arm64_elf_hwcaps); @@ -2216,6 +2248,23 @@ bool this_cpu_has_cap(unsigned int n) return false; } +/* + * This helper function is used in a narrow window when, + * - The system wide safe registers are set with all the SMP CPUs and, + * - The SYSTEM_FEATURE cpu_hwcaps may not have been set. + * In all other cases cpus_have_{const_}cap() should be used. + */ +static bool __system_matches_cap(unsigned int n) +{ + if (n < ARM64_NCAPS) { + const struct arm64_cpu_capabilities *cap = cpu_hwcaps_ptrs[n]; + + if (cap) + return cap->matches(cap, SCOPE_SYSTEM); + } + return false; +} + void cpu_set_feature(unsigned int num) { WARN_ON(num >= MAX_CPU_FEATURES); @@ -2288,7 +2337,7 @@ void __init setup_cpu_features(void) static bool __maybe_unused cpufeature_pan_not_uao(const struct arm64_cpu_capabilities *entry, int __unused) { - return (cpus_have_const_cap(ARM64_HAS_PAN) && !cpus_have_const_cap(ARM64_HAS_UAO)); + return (__system_matches_cap(ARM64_HAS_PAN) && !__system_matches_cap(ARM64_HAS_UAO)); } static void __maybe_unused cpu_enable_cnp(struct arm64_cpu_capabilities const *cap) diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index e5d4e30ee242..ddcde093c433 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -14,6 +14,7 @@ #include <asm/alternative.h> #include <asm/assembler.h> #include <asm/asm-offsets.h> +#include <asm/asm_pointer_auth.h> #include <asm/cpufeature.h> #include <asm/errno.h> #include <asm/esr.h> @@ -177,6 +178,7 @@ alternative_cb_end apply_ssbd 1, x22, x23 + ptrauth_keys_install_kernel tsk, 1, x20, x22, x23 .else add x21, sp, #S_FRAME_SIZE get_current_task tsk @@ -341,6 +343,9 @@ alternative_else_nop_endif msr cntkctl_el1, x1 4: #endif + /* No kernel C function calls after this as user keys are set. */ + ptrauth_keys_install_user tsk, x0, x1, x2 + apply_ssbd 0, x0, x1 .endif @@ -895,6 +900,7 @@ SYM_FUNC_START(cpu_switch_to) ldr lr, [x8] mov sp, x9 msr sp_el0, x1 + ptrauth_keys_install_kernel x1, 1, x8, x9, x10 ret SYM_FUNC_END(cpu_switch_to) NOKPROBE(cpu_switch_to) diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S index 2f7ea6d8f5bf..57a91032b4c2 100644 --- a/arch/arm64/kernel/head.S +++ b/arch/arm64/kernel/head.S @@ -118,6 +118,7 @@ SYM_CODE_START(stext) * On return, the CPU will be ready for the MMU to be turned on and * the TCR will have been set. */ + mov x0, #ARM64_CPU_BOOT_PRIMARY bl __cpu_setup // initialise processor b __primary_switch SYM_CODE_END(stext) @@ -716,6 +717,7 @@ SYM_FUNC_START_LOCAL(secondary_startup) * Common entry point for secondary CPUs. */ bl __cpu_secondary_check52bitva + mov x0, #ARM64_CPU_BOOT_SECONDARY bl __cpu_setup // initialise processor adrp x1, swapper_pg_dir bl __enable_mmu diff --git a/arch/arm64/kernel/pointer_auth.c b/arch/arm64/kernel/pointer_auth.c index c507b584259d..1e77736a4f66 100644 --- a/arch/arm64/kernel/pointer_auth.c +++ b/arch/arm64/kernel/pointer_auth.c @@ -9,7 +9,7 @@ int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg) { - struct ptrauth_keys *keys = &tsk->thread.keys_user; + struct ptrauth_keys_user *keys = &tsk->thread.keys_user; unsigned long addr_key_mask = PR_PAC_APIAKEY | PR_PAC_APIBKEY | PR_PAC_APDAKEY | PR_PAC_APDBKEY; unsigned long key_mask = addr_key_mask | PR_PAC_APGAKEY; @@ -18,8 +18,7 @@ int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg) return -EINVAL; if (!arg) { - ptrauth_keys_init(keys); - ptrauth_keys_switch(keys); + ptrauth_keys_init_user(keys); return 0; } @@ -41,7 +40,5 @@ int ptrauth_prctl_reset_keys(struct task_struct *tsk, unsigned long arg) if (arg & PR_PAC_APGAKEY) get_random_bytes(&keys->apga, sizeof(keys->apga)); - ptrauth_keys_switch(keys); - return 0; } diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 00626057a384..cacae291ba27 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -262,7 +262,7 @@ void __show_regs(struct pt_regs *regs) if (!user_mode(regs)) { printk("pc : %pS\n", (void *)regs->pc); - printk("lr : %pS\n", (void *)lr); + printk("lr : %pS\n", (void *)ptrauth_strip_insn_pac(lr)); } else { printk("pc : %016llx\n", regs->pc); printk("lr : %016llx\n", lr); @@ -376,6 +376,8 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long stack_start, */ fpsimd_flush_task_state(p); + ptrauth_thread_init_kernel(p); + if (likely(!(p->flags & PF_KTHREAD))) { *childregs = *current_pt_regs(); childregs->regs[0] = 0; @@ -512,7 +514,6 @@ __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, contextidr_thread_switch(next); entry_task_switch(next); uao_thread_switch(next); - ptrauth_thread_switch(next); ssbs_thread_switch(next); /* diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index cd6e5fa48b9c..b3d3005d9515 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -999,7 +999,7 @@ static struct ptrauth_key pac_key_from_user(__uint128_t ukey) } static void pac_address_keys_to_user(struct user_pac_address_keys *ukeys, - const struct ptrauth_keys *keys) + const struct ptrauth_keys_user *keys) { ukeys->apiakey = pac_key_to_user(&keys->apia); ukeys->apibkey = pac_key_to_user(&keys->apib); @@ -1007,7 +1007,7 @@ static void pac_address_keys_to_user(struct user_pac_address_keys *ukeys, ukeys->apdbkey = pac_key_to_user(&keys->apdb); } -static void pac_address_keys_from_user(struct ptrauth_keys *keys, +static void pac_address_keys_from_user(struct ptrauth_keys_user *keys, const struct user_pac_address_keys *ukeys) { keys->apia = pac_key_from_user(ukeys->apiakey); @@ -1021,7 +1021,7 @@ static int pac_address_keys_get(struct task_struct *target, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { - struct ptrauth_keys *keys = &target->thread.keys_user; + struct ptrauth_keys_user *keys = &target->thread.keys_user; struct user_pac_address_keys user_keys; if (!system_supports_address_auth()) @@ -1038,7 +1038,7 @@ static int pac_address_keys_set(struct task_struct *target, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { - struct ptrauth_keys *keys = &target->thread.keys_user; + struct ptrauth_keys_user *keys = &target->thread.keys_user; struct user_pac_address_keys user_keys; int ret; @@ -1056,12 +1056,12 @@ static int pac_address_keys_set(struct task_struct *target, } static void pac_generic_keys_to_user(struct user_pac_generic_keys *ukeys, - const struct ptrauth_keys *keys) + const struct ptrauth_keys_user *keys) { ukeys->apgakey = pac_key_to_user(&keys->apga); } -static void pac_generic_keys_from_user(struct ptrauth_keys *keys, +static void pac_generic_keys_from_user(struct ptrauth_keys_user *keys, const struct user_pac_generic_keys *ukeys) { keys->apga = pac_key_from_user(ukeys->apgakey); @@ -1072,7 +1072,7 @@ static int pac_generic_keys_get(struct task_struct *target, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { - struct ptrauth_keys *keys = &target->thread.keys_user; + struct ptrauth_keys_user *keys = &target->thread.keys_user; struct user_pac_generic_keys user_keys; if (!system_supports_generic_auth()) @@ -1089,7 +1089,7 @@ static int pac_generic_keys_set(struct task_struct *target, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { - struct ptrauth_keys *keys = &target->thread.keys_user; + struct ptrauth_keys_user *keys = &target->thread.keys_user; struct user_pac_generic_keys user_keys; int ret; diff --git a/arch/arm64/kernel/sleep.S b/arch/arm64/kernel/sleep.S index f5b04dd8a710..7b2f2e650c44 100644 --- a/arch/arm64/kernel/sleep.S +++ b/arch/arm64/kernel/sleep.S @@ -3,6 +3,7 @@ #include <linux/linkage.h> #include <asm/asm-offsets.h> #include <asm/assembler.h> +#include <asm/smp.h> .text /* @@ -99,6 +100,7 @@ ENDPROC(__cpu_suspend_enter) .pushsection ".idmap.text", "awx" ENTRY(cpu_resume) bl el2_setup // if in EL2 drop to EL1 cleanly + mov x0, #ARM64_CPU_RUNTIME bl __cpu_setup /* enable the MMU early - so we can access sleep_save_stash by va */ adrp x1, swapper_pg_dir diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 034806725598..fd4b2ec3ddd5 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -114,6 +114,10 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) */ secondary_data.task = idle; secondary_data.stack = task_stack_page(idle) + THREAD_SIZE; +#if defined(CONFIG_ARM64_PTR_AUTH) + secondary_data.ptrauth_key.apia.lo = idle->thread.keys_kernel.apia.lo; + secondary_data.ptrauth_key.apia.hi = idle->thread.keys_kernel.apia.hi; +#endif update_cpu_boot_status(CPU_MMU_OFF); __flush_dcache_area(&secondary_data, sizeof(secondary_data)); @@ -136,6 +140,10 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle) pr_crit("CPU%u: failed to come online\n", cpu); secondary_data.task = NULL; secondary_data.stack = NULL; +#if defined(CONFIG_ARM64_PTR_AUTH) + secondary_data.ptrauth_key.apia.lo = 0; + secondary_data.ptrauth_key.apia.hi = 0; +#endif __flush_dcache_area(&secondary_data, sizeof(secondary_data)); status = READ_ONCE(secondary_data.status); if (status == CPU_MMU_OFF) diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index a336cb124320..139679c745bf 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -14,6 +14,7 @@ #include <linux/stacktrace.h> #include <asm/irq.h> +#include <asm/pointer_auth.h> #include <asm/stack_pointer.h> #include <asm/stacktrace.h> @@ -86,7 +87,7 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) #ifdef CONFIG_FUNCTION_GRAPH_TRACER if (tsk->ret_stack && - (frame->pc == (unsigned long)return_to_handler)) { + (ptrauth_strip_insn_pac(frame->pc) == (unsigned long)return_to_handler)) { struct ftrace_ret_stack *ret_stack; /* * This is a case where function graph tracer has @@ -101,6 +102,8 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + frame->pc = ptrauth_strip_insn_pac(frame->pc); + /* * Frames created upon entry from EL0 have NULL FP and PC values, so * don't bother reporting these. Frames created by __noreturn functions |