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if (!IS_ENABLED(CONFIG_TINY_RCU) && is_idle_task(current)) { lockdep_hardirqs_off(CALLER_ADDR0); rcu_irq_enter(); trace_hardirqs_off_finish(); regs->exit_rcu = true; return; } lockdep_hardirqs_off(CALLER_ADDR0); rcu_irq_enter_check_tick(); trace_hardirqs_off_finish(); } static void noinstr enter_from_kernel_mode(struct pt_regs *regs) { __enter_from_kernel_mode(regs); mte_check_tfsr_entry(); } /* * Handle IRQ/context state management when exiting to kernel mode. * After this function returns it is not safe to call regular kernel code, * intrumentable code, or any code which may trigger an exception. * * This is intended to match the logic in irqentry_exit(), handling the kernel * mode transitions only, and with preemption handled elsewhere. */ static __always_inline void __exit_to_kernel_mode(struct pt_regs *regs) { lockdep_assert_irqs_disabled(); if (interrupts_enabled(regs)) { if (regs->exit_rcu) { trace_hardirqs_on_prepare(); lockdep_hardirqs_on_prepare(CALLER_ADDR0); rcu_irq_exit(); lockdep_hardirqs_on(CALLER_ADDR0); return; } trace_hardirqs_on(); } else { if (regs->exit_rcu) rcu_irq_exit(); } } static void noinstr exit_to_kernel_mode(struct pt_regs *regs) { mte_check_tfsr_exit(); __exit_to_kernel_mode(regs); } /* * Handle IRQ/context state management when entering from user mode. * Before this function is called it is not safe to call regular kernel code, * intrumentable code, or any code which may trigger an exception. */ static __always_inline void __enter_from_user_mode(void) { lockdep_hardirqs_off(CALLER_ADDR0); CT_WARN_ON(ct_state() != CONTEXT_USER); user_exit_irqoff(); trace_hardirqs_off_finish(); } static __always_inline void enter_from_user_mode(struct pt_regs *regs) { __enter_from_user_mode(); } /* * Handle IRQ/context state management when exiting to user mode. * After this function returns it is not safe to call regular kernel code, * intrumentable code, or any code which may trigger an exception. */ static __always_inline void __exit_to_user_mode(void) { trace_hardirqs_on_prepare(); lockdep_hardirqs_on_prepare(CALLER_ADDR0); user_enter_irqoff(); lockdep_hardirqs_on(CALLER_ADDR0); } static __always_inline void prepare_exit_to_user_mode(struct pt_regs *regs) { unsigned long flags; local_daif_mask(); flags = READ_ONCE(current_thread_info()->flags); if (unlikely(flags & _TIF_WORK_MASK)) do_notify_resume(regs, flags); } static __always_inline void exit_to_user_mode(struct pt_regs *regs) { prepare_exit_to_user_mode(regs); mte_check_tfsr_exit(); __exit_to_user_mode(); } asmlinkage void noinstr asm_exit_to_user_mode(struct pt_regs *regs) { exit_to_user_mode(regs); } /* * Handle IRQ/context state management when entering an NMI from user/kernel * mode. Before this function is called it is not safe to call regular kernel * code, intrumentable code, or any code which may trigger an exception. */ static void noinstr arm64_enter_nmi(struct pt_regs *regs) { regs->lockdep_hardirqs = lockdep_hardirqs_enabled(); __nmi_enter(); lockdep_hardirqs_off(CALLER_ADDR0); lockdep_hardirq_enter(); rcu_nmi_enter(); trace_hardirqs_off_finish(); ftrace_nmi_enter(); } /* * Handle IRQ/context state management when exiting an NMI from user/kernel * mode. After this function returns it is not safe to call regular kernel * code, intrumentable code, or any code which may trigger an exception. */ static void noinstr arm64_exit_nmi(struct pt_regs *regs) { bool restore = regs->lockdep_hardirqs; ftrace_nmi_exit(); if (restore) { trace_hardirqs_on_prepare(); lockdep_hardirqs_on_prepare(CALLER_ADDR0); } rcu_nmi_exit(); lockdep_hardirq_exit(); if (restore) lockdep_hardirqs_on(CALLER_ADDR0); __nmi_exit(); } /* * Handle IRQ/context state management when entering a debug exception from * kernel mode. Before this function is called it is not safe to call regular * kernel code, intrumentable code, or any code which may trigger an exception. */ static void noinstr arm64_enter_el1_dbg(struct pt_regs *regs) { regs->lockdep_hardirqs = lockdep_hardirqs_enabled(); lockdep_hardirqs_off(CALLER_ADDR0); rcu_nmi_enter(); trace_hardirqs_off_finish(); } /* * Handle IRQ/context state management when exiting a debug exception from * kernel mode. After this function returns it is not safe to call regular * kernel code, intrumentable code, or any code which may trigger an exception. */ static void noinstr arm64_exit_el1_dbg(struct pt_regs *regs) { bool restore = regs->lockdep_hardirqs; if (restore) { trace_hardirqs_on_prepare(); lockdep_hardirqs_on_prepare(CALLER_ADDR0); } rcu_nmi_exit(); if (restore) lockdep_hardirqs_on(CALLER_ADDR0); } 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 *)) { struct pt_regs *old_regs = set_irq_regs(regs); if (on_thread_stack()) call_on_irq_stack(regs, handler); else handler(regs); set_irq_regs(old_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); static void cortex_a76_erratum_1463225_svc_handler(void) { u32 reg, val; if (!unlikely(test_thread_flag(TIF_SINGLESTEP))) return; if (!unlikely(this_cpu_has_cap(ARM64_WORKAROUND_1463225))) return; __this_cpu_write(__in_cortex_a76_erratum_1463225_wa, 1); reg = read_sysreg(mdscr_el1); val = reg | DBG_MDSCR_SS | DBG_MDSCR_KDE; write_sysreg(val, mdscr_el1); asm volatile("msr daifclr, #8"); isb(); /* We will have taken a single-step exception by this point */ write_sysreg(reg, mdscr_el1); __this_cpu_write(__in_cortex_a76_erratum_1463225_wa, 0); } static bool cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs) { if (!__this_cpu_read(__in_cortex_a76_erratum_1463225_wa)) return false; /* * We've taken a dummy step exception from the kernel to ensure * that interrupts are re-enabled on the syscall path. Return back * to cortex_a76_erratum_1463225_svc_handler() with debug exceptions * masked so that we can safely restore the mdscr and get on with * handling the syscall. */ regs->pstate |= PSR_D_BIT; return true; } #else /* CONFIG_ARM64_ERRATUM_1463225 */ static void cortex_a76_erratum_1463225_svc_handler(void) { } static bool cortex_a76_erratum_1463225_debug_handler(struct pt_regs *regs) { return false; } #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); enter_from_kernel_mode(regs); local_daif_inherit(regs); do_mem_abort(far, esr, regs); local_daif_mask(); exit_to_kernel_mode(regs); } static void noinstr el1_pc(struct pt_regs *regs, unsigned long esr) { unsigned long far = read_sysreg(far_el1); enter_from_kernel_mode(regs); local_daif_inherit(regs); do_sp_pc_abort(far, esr, regs); local_daif_mask(); exit_to_kernel_mode(regs); } static void noinstr el1_undef(struct pt_regs *regs) { enter_from_kernel_mode(regs); local_daif_inherit(regs); do_undefinstr(regs); local_daif_mask(); exit_to_kernel_mode(regs); } static void noinstr el1_dbg(struct pt_regs *regs, unsigned long esr) { unsigned long far = read_sysreg(far_el1); arm64_enter_el1_dbg(regs); if (!cortex_a76_erratum_1463225_debug_handler(regs)) do_debug_exception(far, esr, regs); arm64_exit_el1_dbg(regs); } static void noinstr el1_fpac(struct pt_regs *regs, unsigned long esr) { enter_from_kernel_mode(regs); local_daif_inherit(regs); do_ptrauth_fault(regs, esr); local_daif_mask(); exit_to_kernel_mode(regs); } asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs) { unsigned long esr = read_sysreg(esr_el1); switch (ESR_ELx_EC(esr)) { case ESR_ELx_EC_DABT_CUR: case ESR_ELx_EC_IABT_CUR: el1_abort(regs, esr); break; /* * We don't handle ESR_ELx_EC_SP_ALIGN, since we will have hit a * recursive exception when trying to push the initial pt_regs. */ case ESR_ELx_EC_PC_ALIGN: el1_pc(regs, esr); break; case ESR_ELx_EC_SYS64: case ESR_ELx_EC_UNKNOWN: el1_undef(regs); break; case ESR_ELx_EC_BREAKPT_CUR: case ESR_ELx_EC_SOFTSTP_CUR: case ESR_ELx_EC_WATCHPT_CUR: case ESR_ELx_EC_BRK64: el1_dbg(regs, esr); break; case ESR_ELx_EC_FPAC: el1_fpac(regs, esr); break; default: __panic_unhandled(regs, "64-bit el1h sync", esr); } } static __always_inline void __el1_pnmi(struct pt_regs *regs, void (*handler)(struct pt_regs *)) { arm64_enter_nmi(regs); do_interrupt_handler(regs, handler); arm64_exit_nmi(regs); } static __always_inline void __el1_irq(struct pt_regs *regs, void (*handler)(struct pt_regs *)) { enter_from_kernel_mode(regs); irq_enter_rcu(); do_interrupt_handler(regs, handler); irq_exit_rcu(); /* * 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_to_kernel_mode(regs); } static void noinstr el1_interrupt(struct pt_regs *regs, void (*handler)(struct pt_regs *)) { write_sysreg(DAIF_PROCCTX_NOIRQ, daif); if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs)) __el1_pnmi(regs, handler); else __el1_irq(regs, handler); } 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); } static void noinstr el0_da(struct pt_regs *regs, unsigned long esr) { unsigned long far = read_sysreg(far_el1); enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); do_mem_abort(far, esr, regs); exit_to_user_mode(regs); } static void noinstr el0_ia(struct pt_regs *regs, unsigned long esr) { unsigned long far = read_sysreg(far_el1); /* * We've taken an instruction abort from userspace and not yet * re-enabled IRQs. If the address is a kernel address, apply * BP hardening prior to enabling IRQs and pre-emption. */ if (!is_ttbr0_addr(far)) arm64_apply_bp_hardening(); enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); do_mem_abort(far, esr, regs); exit_to_user_mode(regs); } static void noinstr el0_fpsimd_acc(struct pt_regs *regs, unsigned long esr) { enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); do_fpsimd_acc(esr, regs); exit_to_user_mode(regs); } static void noinstr el0_sve_acc(struct pt_regs *regs, unsigned long esr) { enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); do_sve_acc(esr, regs); exit_to_user_mode(regs); } static void noinstr el0_fpsimd_exc(struct pt_regs *regs, unsigned long esr) { enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); do_fpsimd_exc(esr, regs); exit_to_user_mode(regs); } static void noinstr el0_sys(struct pt_regs *regs, unsigned long esr) { enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); do_sysinstr(esr, regs); exit_to_user_mode(regs); } static void noinstr el0_pc(struct pt_regs *regs, unsigned long esr) { unsigned long far = read_sysreg(far_el1); if (!is_ttbr0_addr(instruction_pointer(regs))) arm64_apply_bp_hardening(); enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); do_sp_pc_abort(far, esr, regs); exit_to_user_mode(regs); } static void noinstr el0_sp(struct pt_regs *regs, unsigned long esr) { enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); do_sp_pc_abort(regs->sp, esr, regs); exit_to_user_mode(regs); } static void noinstr el0_undef(struct pt_regs *regs) { enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); do_undefinstr(regs); exit_to_user_mode(regs); } static void noinstr el0_bti(struct pt_regs *regs) { enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); do_bti(regs); exit_to_user_mode(regs); } static void noinstr el0_inv(struct pt_regs *regs, unsigned long esr) { enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); bad_el0_sync(regs, 0, esr); exit_to_user_mode(regs); } static void noinstr el0_dbg(struct pt_regs *regs, unsigned long esr) { /* Only watchpoints write FAR_EL1, otherwise its UNKNOWN */ unsigned long far = read_sysreg(far_el1); enter_from_user_mode(regs); do_debug_exception(far, esr, regs); local_daif_restore(DAIF_PROCCTX); exit_to_user_mode(regs); } static void noinstr el0_svc(struct pt_regs *regs) { enter_from_user_mode(regs); cortex_a76_erratum_1463225_svc_handler(); do_el0_svc(regs); exit_to_user_mode(regs); } static void noinstr el0_fpac(struct pt_regs *regs, unsigned long esr) { enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); do_ptrauth_fault(regs, esr); exit_to_user_mode(regs); } asmlinkage void noinstr el0t_64_sync_handler(struct pt_regs *regs) { unsigned long esr = read_sysreg(esr_el1); switch (ESR_ELx_EC(esr)) { case ESR_ELx_EC_SVC64: el0_svc(regs); break; case ESR_ELx_EC_DABT_LOW: el0_da(regs, esr); break; case ESR_ELx_EC_IABT_LOW: el0_ia(regs, esr); break; case ESR_ELx_EC_FP_ASIMD: el0_fpsimd_acc(regs, esr); break; case ESR_ELx_EC_SVE: el0_sve_acc(regs, esr); break; case ESR_ELx_EC_FP_EXC64: el0_fpsimd_exc(regs, esr); break; case ESR_ELx_EC_SYS64: case ESR_ELx_EC_WFx: el0_sys(regs, esr); break; case ESR_ELx_EC_SP_ALIGN: el0_sp(regs, esr); break; case ESR_ELx_EC_PC_ALIGN: el0_pc(regs, esr); break; 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: case ESR_ELx_EC_BRK64: el0_dbg(regs, esr); break; case ESR_ELx_EC_FPAC: el0_fpac(regs, esr); break; default: el0_inv(regs, esr); } } static void noinstr el0_interrupt(struct pt_regs *regs, void (*handler)(struct pt_regs *)) { enter_from_user_mode(regs); write_sysreg(DAIF_PROCCTX_NOIRQ, daif); if (regs->pc & BIT(55)) arm64_apply_bp_hardening(); irq_enter_rcu(); do_interrupt_handler(regs, handler); irq_exit_rcu(); exit_to_user_mode(regs); } 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 noinstr __el0_error_handler_common(struct pt_regs *regs) { unsigned long esr = read_sysreg(esr_el1); enter_from_user_mode(regs); local_daif_restore(DAIF_ERRCTX); arm64_enter_nmi(regs); do_serror(regs, esr); arm64_exit_nmi(regs); local_daif_restore(DAIF_PROCCTX); exit_to_user_mode(regs); } 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) { enter_from_user_mode(regs); local_daif_restore(DAIF_PROCCTX); do_cp15instr(esr, regs); exit_to_user_mode(regs); } static void noinstr el0_svc_compat(struct pt_regs *regs) { enter_from_user_mode(regs); cortex_a76_erratum_1463225_svc_handler(); do_el0_svc_compat(regs); exit_to_user_mode(regs); } asmlinkage void noinstr el0t_32_sync_handler(struct pt_regs *regs) { unsigned long esr = read_sysreg(esr_el1); switch (ESR_ELx_EC(esr)) { case ESR_ELx_EC_SVC32: el0_svc_compat(regs); break; case ESR_ELx_EC_DABT_LOW: el0_da(regs, esr); break; case ESR_ELx_EC_IABT_LOW: el0_ia(regs, esr); break; case ESR_ELx_EC_FP_ASIMD: el0_fpsimd_acc(regs, esr); break; case ESR_ELx_EC_FP_EXC32: el0_fpsimd_exc(regs, esr); break; case ESR_ELx_EC_PC_ALIGN: el0_pc(regs, esr); break; case ESR_ELx_EC_UNKNOWN: case ESR_ELx_EC_CP14_MR: case ESR_ELx_EC_CP14_LS: case ESR_ELx_EC_CP14_64: el0_undef(regs); break; case ESR_ELx_EC_CP15_32: case ESR_ELx_EC_CP15_64: el0_cp15(regs, esr); break; case ESR_ELx_EC_BREAKPT_LOW: case ESR_ELx_EC_SOFTSTP_LOW: case ESR_ELx_EC_WATCHPT_LOW: case ESR_ELx_EC_BKPT32: el0_dbg(regs, esr); break; default: 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 */ |