diff --git a/arch/arm64/include/asm/sdei.h b/arch/arm64/include/asm/sdei.h index 4292d9bafb9d2..484cb6972e99a 100644 --- a/arch/arm64/include/asm/sdei.h +++ b/arch/arm64/include/asm/sdei.h @@ -17,6 +17,9 @@ #include +DECLARE_PER_CPU(struct sdei_registered_event *, sdei_active_normal_event); +DECLARE_PER_CPU(struct sdei_registered_event *, sdei_active_critical_event); + extern unsigned long sdei_exit_mode; /* Software Delegated Exception entry point from firmware*/ @@ -29,6 +32,9 @@ asmlinkage void __sdei_asm_entry_trampoline(unsigned long event_num, unsigned long pc, unsigned long pstate); +/* Abort a running handler. Context is discarded. */ +void __sdei_handler_abort(void); + /* * The above entry point does the minimum to call C code. This function does * anything else, before calling the driver. diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 3671d9521d4f5..beb4db21c89c1 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -993,9 +993,13 @@ SYM_CODE_START(__sdei_asm_handler) mov x19, x1 -#if defined(CONFIG_VMAP_STACK) || defined(CONFIG_SHADOW_CALL_STACK) + /* Store the registered-event for crash_smp_send_stop() */ ldrb w4, [x19, #SDEI_EVENT_PRIORITY] -#endif + cbnz w4, 1f + adr_this_cpu dst=x5, sym=sdei_active_normal_event, tmp=x6 + b 2f +1: adr_this_cpu dst=x5, sym=sdei_active_critical_event, tmp=x6 +2: str x19, [x5] #ifdef CONFIG_VMAP_STACK /* @@ -1062,6 +1066,14 @@ SYM_CODE_START(__sdei_asm_handler) ldr_l x2, sdei_exit_mode + /* Clear the registered-event seen by crash_smp_send_stop() */ + ldrb w3, [x4, #SDEI_EVENT_PRIORITY] + cbnz w3, 1f + adr_this_cpu dst=x5, sym=sdei_active_normal_event, tmp=x6 + b 2f +1: adr_this_cpu dst=x5, sym=sdei_active_critical_event, tmp=x6 +2: str xzr, [x5] + alternative_if_not ARM64_UNMAP_KERNEL_AT_EL0 sdei_handler_exit exit_mode=x2 alternative_else_nop_endif @@ -1072,4 +1084,15 @@ alternative_else_nop_endif #endif SYM_CODE_END(__sdei_asm_handler) NOKPROBE(__sdei_asm_handler) + +SYM_CODE_START(__sdei_handler_abort) + mov_q x0, SDEI_1_0_FN_SDEI_EVENT_COMPLETE_AND_RESUME + adr x1, 1f + ldr_l x2, sdei_exit_mode + sdei_handler_exit exit_mode=x2 + // exit the handler and jump to the next instruction. + // Exit will stomp x0-x17, PSTATE, ELR_ELx, and SPSR_ELx. +1: ret +SYM_CODE_END(__sdei_handler_abort) +NOKPROBE(__sdei_handler_abort) #endif /* CONFIG_ARM_SDE_INTERFACE */ diff --git a/arch/arm64/kernel/sdei.c b/arch/arm64/kernel/sdei.c index d56e170e1ca7c..48c6457b67db8 100644 --- a/arch/arm64/kernel/sdei.c +++ b/arch/arm64/kernel/sdei.c @@ -47,6 +47,9 @@ DEFINE_PER_CPU(unsigned long *, sdei_shadow_call_stack_normal_ptr); DEFINE_PER_CPU(unsigned long *, sdei_shadow_call_stack_critical_ptr); #endif +DEFINE_PER_CPU(struct sdei_registered_event *, sdei_active_normal_event); +DEFINE_PER_CPU(struct sdei_registered_event *, sdei_active_critical_event); + static void _free_sdei_stack(unsigned long * __percpu *ptr, int cpu) { unsigned long *p; diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index ffc5d76cf6955..d323621d14a59 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -1047,10 +1047,8 @@ void crash_smp_send_stop(void) * If this cpu is the only one alive at this point in time, online or * not, there are no stop messages to be sent around, so just back out. */ - if (num_other_online_cpus() == 0) { - sdei_mask_local_cpu(); - return; - } + if (num_other_online_cpus() == 0) + goto skip_ipi; cpumask_copy(&mask, cpu_online_mask); cpumask_clear_cpu(smp_processor_id(), &mask); @@ -1069,7 +1067,9 @@ void crash_smp_send_stop(void) pr_warn("SMP: failed to stop secondary CPUs %*pbl\n", cpumask_pr_args(&mask)); +skip_ipi: sdei_mask_local_cpu(); + sdei_handler_abort(); } bool smp_crash_stop_failed(void) diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c index f9040bd610812..285fe7ad490d1 100644 --- a/drivers/firmware/arm_sdei.c +++ b/drivers/firmware/arm_sdei.c @@ -1095,3 +1095,22 @@ int sdei_event_handler(struct pt_regs *regs, return err; } NOKPROBE_SYMBOL(sdei_event_handler); + +void sdei_handler_abort(void) +{ + /* + * If the crash happened in an SDEI event handler then we need to + * finish the handler with the firmware so that we can have working + * interrupts in the crash kernel. + */ + if (__this_cpu_read(sdei_active_critical_event)) { + pr_warn("still in SDEI critical event context, attempting to finish handler.\n"); + __sdei_handler_abort(); + __this_cpu_write(sdei_active_critical_event, NULL); + } + if (__this_cpu_read(sdei_active_normal_event)) { + pr_warn("still in SDEI normal event context, attempting to finish handler.\n"); + __sdei_handler_abort(); + __this_cpu_write(sdei_active_normal_event, NULL); + } +} diff --git a/include/linux/arm_sdei.h b/include/linux/arm_sdei.h index 14dc461b0e829..255701e1251b4 100644 --- a/include/linux/arm_sdei.h +++ b/include/linux/arm_sdei.h @@ -47,10 +47,12 @@ int sdei_unregister_ghes(struct ghes *ghes); int sdei_mask_local_cpu(void); int sdei_unmask_local_cpu(void); void __init sdei_init(void); +void sdei_handler_abort(void); #else static inline int sdei_mask_local_cpu(void) { return 0; } static inline int sdei_unmask_local_cpu(void) { return 0; } static inline void sdei_init(void) { } +static inline void sdei_handler_abort(void) { } #endif /* CONFIG_ARM_SDE_INTERFACE */