diff options
Diffstat (limited to 'arch/arm64/kernel/entry-common.c')
| -rw-r--r-- | arch/arm64/kernel/entry-common.c | 256 |
1 files changed, 238 insertions, 18 deletions
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 340d04e13617..12ce14a98b7c 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -6,7 +6,11 @@ */ #include <linux/context_tracking.h> +#include <linux/linkage.h> +#include <linux/lockdep.h> #include <linux/ptrace.h> +#include <linux/sched.h> +#include <linux/sched/debug.h> #include <linux/thread_info.h> #include <asm/cpufeature.h> @@ -15,7 +19,11 @@ #include <asm/exception.h> #include <asm/kprobes.h> #include <asm/mmu.h> +#include <asm/processor.h> +#include <asm/sdei.h> +#include <asm/stacktrace.h> #include <asm/sysreg.h> +#include <asm/system_misc.h> /* * This is intended to match the logic in irqentry_enter(), handling the kernel @@ -67,7 +75,7 @@ static void noinstr exit_to_kernel_mode(struct pt_regs *regs) } } -void noinstr arm64_enter_nmi(struct pt_regs *regs) +static void noinstr arm64_enter_nmi(struct pt_regs *regs) { regs->lockdep_hardirqs = lockdep_hardirqs_enabled(); @@ -80,7 +88,7 @@ void noinstr arm64_enter_nmi(struct pt_regs *regs) ftrace_nmi_enter(); } -void noinstr arm64_exit_nmi(struct pt_regs *regs) +static void noinstr arm64_exit_nmi(struct pt_regs *regs) { bool restore = regs->lockdep_hardirqs; @@ -97,7 +105,7 @@ void noinstr arm64_exit_nmi(struct pt_regs *regs) __nmi_exit(); } -asmlinkage void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs) +static void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs) { if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs)) arm64_enter_nmi(regs); @@ -105,7 +113,7 @@ asmlinkage void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs) enter_from_kernel_mode(regs); } -asmlinkage void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs) +static void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs) { if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs)) arm64_exit_nmi(regs); @@ -113,6 +121,65 @@ asmlinkage void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs) exit_to_kernel_mode(regs); } +static void __sched arm64_preempt_schedule_irq(void) +{ + lockdep_assert_irqs_disabled(); + + /* + * DAIF.DA are cleared at the start of IRQ/FIQ handling, and when GIC + * priority masking is used the GIC irqchip driver will clear DAIF.IF + * using gic_arch_enable_irqs() for normal IRQs. If anything is set in + * DAIF we must have handled an NMI, so skip preemption. + */ + if (system_uses_irq_prio_masking() && read_sysreg(daif)) + return; + + /* + * Preempting a task from an IRQ means we leave copies of PSTATE + * on the stack. cpufeature's enable calls may modify PSTATE, but + * resuming one of these preempted tasks would undo those changes. + * + * Only allow a task to be preempted once cpufeatures have been + * enabled. + */ + if (system_capabilities_finalized()) + preempt_schedule_irq(); +} + +static void do_interrupt_handler(struct pt_regs *regs, + void (*handler)(struct pt_regs *)) +{ + if (on_thread_stack()) + call_on_irq_stack(regs, handler); + else + handler(regs); +} + +extern void (*handle_arch_irq)(struct pt_regs *); +extern void (*handle_arch_fiq)(struct pt_regs *); + +static void noinstr __panic_unhandled(struct pt_regs *regs, const char *vector, + unsigned int esr) +{ + arm64_enter_nmi(regs); + + console_verbose(); + + pr_crit("Unhandled %s exception on CPU%d, ESR 0x%08x -- %s\n", + vector, smp_processor_id(), esr, + esr_get_class_string(esr)); + + __show_regs(regs); + panic("Unhandled exception"); +} + +#define UNHANDLED(el, regsize, vector) \ +asmlinkage void noinstr el##_##regsize##_##vector##_handler(struct pt_regs *regs) \ +{ \ + const char *desc = #regsize "-bit " #el " " #vector; \ + __panic_unhandled(regs, desc, read_sysreg(esr_el1)); \ +} + #ifdef CONFIG_ARM64_ERRATUM_1463225 static DEFINE_PER_CPU(int, __in_cortex_a76_erratum_1463225_wa); @@ -162,6 +229,11 @@ static bool cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs) } #endif /* CONFIG_ARM64_ERRATUM_1463225 */ +UNHANDLED(el1t, 64, sync) +UNHANDLED(el1t, 64, irq) +UNHANDLED(el1t, 64, fiq) +UNHANDLED(el1t, 64, error) + static void noinstr el1_abort(struct pt_regs *regs, unsigned long esr) { unsigned long far = read_sysreg(far_el1); @@ -193,15 +265,6 @@ static void noinstr el1_undef(struct pt_regs *regs) exit_to_kernel_mode(regs); } -static void noinstr el1_inv(struct pt_regs *regs, unsigned long esr) -{ - enter_from_kernel_mode(regs); - local_daif_inherit(regs); - bad_mode(regs, 0, esr); - local_daif_mask(); - exit_to_kernel_mode(regs); -} - static void noinstr arm64_enter_el1_dbg(struct pt_regs *regs) { regs->lockdep_hardirqs = lockdep_hardirqs_enabled(); @@ -245,7 +308,7 @@ static void noinstr el1_fpac(struct pt_regs *regs, unsigned long esr) exit_to_kernel_mode(regs); } -asmlinkage void noinstr el1_sync_handler(struct pt_regs *regs) +asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs) { unsigned long esr = read_sysreg(esr_el1); @@ -275,10 +338,50 @@ asmlinkage void noinstr el1_sync_handler(struct pt_regs *regs) el1_fpac(regs, esr); break; default: - el1_inv(regs, esr); + __panic_unhandled(regs, "64-bit el1h sync", esr); } } +static void noinstr el1_interrupt(struct pt_regs *regs, + void (*handler)(struct pt_regs *)) +{ + write_sysreg(DAIF_PROCCTX_NOIRQ, daif); + + enter_el1_irq_or_nmi(regs); + do_interrupt_handler(regs, handler); + + /* + * Note: thread_info::preempt_count includes both thread_info::count + * and thread_info::need_resched, and is not equivalent to + * preempt_count(). + */ + if (IS_ENABLED(CONFIG_PREEMPTION) && + READ_ONCE(current_thread_info()->preempt_count) == 0) + arm64_preempt_schedule_irq(); + + exit_el1_irq_or_nmi(regs); +} + +asmlinkage void noinstr el1h_64_irq_handler(struct pt_regs *regs) +{ + el1_interrupt(regs, handle_arch_irq); +} + +asmlinkage void noinstr el1h_64_fiq_handler(struct pt_regs *regs) +{ + el1_interrupt(regs, handle_arch_fiq); +} + +asmlinkage void noinstr el1h_64_error_handler(struct pt_regs *regs) +{ + unsigned long esr = read_sysreg(esr_el1); + + local_daif_restore(DAIF_ERRCTX); + arm64_enter_nmi(regs); + do_serror(regs, esr); + arm64_exit_nmi(regs); +} + asmlinkage void noinstr enter_from_user_mode(void) { lockdep_hardirqs_off(CALLER_ADDR0); @@ -398,7 +501,7 @@ static void noinstr el0_dbg(struct pt_regs *regs, unsigned long esr) enter_from_user_mode(); do_debug_exception(far, esr, regs); - local_daif_restore(DAIF_PROCCTX_NOIRQ); + local_daif_restore(DAIF_PROCCTX); } static void noinstr el0_svc(struct pt_regs *regs) @@ -415,7 +518,7 @@ static void noinstr el0_fpac(struct pt_regs *regs, unsigned long esr) do_ptrauth_fault(regs, esr); } -asmlinkage void noinstr el0_sync_handler(struct pt_regs *regs) +asmlinkage void noinstr el0t_64_sync_handler(struct pt_regs *regs) { unsigned long esr = read_sysreg(esr_el1); @@ -468,6 +571,56 @@ asmlinkage void noinstr el0_sync_handler(struct pt_regs *regs) } } +static void noinstr el0_interrupt(struct pt_regs *regs, + void (*handler)(struct pt_regs *)) +{ + enter_from_user_mode(); + + write_sysreg(DAIF_PROCCTX_NOIRQ, daif); + + if (regs->pc & BIT(55)) + arm64_apply_bp_hardening(); + + do_interrupt_handler(regs, handler); +} + +static void noinstr __el0_irq_handler_common(struct pt_regs *regs) +{ + el0_interrupt(regs, handle_arch_irq); +} + +asmlinkage void noinstr el0t_64_irq_handler(struct pt_regs *regs) +{ + __el0_irq_handler_common(regs); +} + +static void noinstr __el0_fiq_handler_common(struct pt_regs *regs) +{ + el0_interrupt(regs, handle_arch_fiq); +} + +asmlinkage void noinstr el0t_64_fiq_handler(struct pt_regs *regs) +{ + __el0_fiq_handler_common(regs); +} + +static void __el0_error_handler_common(struct pt_regs *regs) +{ + unsigned long esr = read_sysreg(esr_el1); + + enter_from_user_mode(); + local_daif_restore(DAIF_ERRCTX); + arm64_enter_nmi(regs); + do_serror(regs, esr); + arm64_exit_nmi(regs); + local_daif_restore(DAIF_PROCCTX); +} + +asmlinkage void noinstr el0t_64_error_handler(struct pt_regs *regs) +{ + __el0_error_handler_common(regs); +} + #ifdef CONFIG_COMPAT static void noinstr el0_cp15(struct pt_regs *regs, unsigned long esr) { @@ -483,7 +636,7 @@ static void noinstr el0_svc_compat(struct pt_regs *regs) do_el0_svc_compat(regs); } -asmlinkage void noinstr el0_sync_compat_handler(struct pt_regs *regs) +asmlinkage void noinstr el0t_32_sync_handler(struct pt_regs *regs) { unsigned long esr = read_sysreg(esr_el1); @@ -526,4 +679,71 @@ asmlinkage void noinstr el0_sync_compat_handler(struct pt_regs *regs) el0_inv(regs, esr); } } + +asmlinkage void noinstr el0t_32_irq_handler(struct pt_regs *regs) +{ + __el0_irq_handler_common(regs); +} + +asmlinkage void noinstr el0t_32_fiq_handler(struct pt_regs *regs) +{ + __el0_fiq_handler_common(regs); +} + +asmlinkage void noinstr el0t_32_error_handler(struct pt_regs *regs) +{ + __el0_error_handler_common(regs); +} +#else /* CONFIG_COMPAT */ +UNHANDLED(el0t, 32, sync) +UNHANDLED(el0t, 32, irq) +UNHANDLED(el0t, 32, fiq) +UNHANDLED(el0t, 32, error) #endif /* CONFIG_COMPAT */ + +#ifdef CONFIG_VMAP_STACK +asmlinkage void noinstr handle_bad_stack(struct pt_regs *regs) +{ + unsigned int esr = read_sysreg(esr_el1); + unsigned long far = read_sysreg(far_el1); + + arm64_enter_nmi(regs); + panic_bad_stack(regs, esr, far); +} +#endif /* CONFIG_VMAP_STACK */ + +#ifdef CONFIG_ARM_SDE_INTERFACE +asmlinkage noinstr unsigned long +__sdei_handler(struct pt_regs *regs, struct sdei_registered_event *arg) +{ + unsigned long ret; + + /* + * We didn't take an exception to get here, so the HW hasn't + * set/cleared bits in PSTATE that we may rely on. + * + * The original SDEI spec (ARM DEN 0054A) can be read ambiguously as to + * whether PSTATE bits are inherited unchanged or generated from + * scratch, and the TF-A implementation always clears PAN and always + * clears UAO. There are no other known implementations. + * + * Subsequent revisions (ARM DEN 0054B) follow the usual rules for how + * PSTATE is modified upon architectural exceptions, and so PAN is + * either inherited or set per SCTLR_ELx.SPAN, and UAO is always + * cleared. + * + * We must explicitly reset PAN to the expected state, including + * clearing it when the host isn't using it, in case a VM had it set. + */ + if (system_uses_hw_pan()) + set_pstate_pan(1); + else if (cpu_has_pan()) + set_pstate_pan(0); + + arm64_enter_nmi(regs); + ret = do_sdei_event(regs, arg); + arm64_exit_nmi(regs); + + return ret; +} +#endif /* CONFIG_ARM_SDE_INTERFACE */ |