The generic entry code uses irqentry_state_t to track lockdep and RCU state across exception entry and return. For historical reasons, arm64 embeds similar fields within its pt_regs structure. In preparation for moving arm64 over to the generic entry code, pull these fields out of arm64's pt_regs, and use a separate structure, matching the style of the generic entry code. No functional changes. Acked-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ada Couprie Diaz <ada.coupriediaz@arm.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com> --- arch/arm64/include/asm/ptrace.h | 4 - arch/arm64/kernel/entry-common.c | 163 ++++++++++++++++++++----------- 2 files changed, 106 insertions(+), 61 deletions(-) diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index 8b915d4a9d4b..65b053a24d82 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -169,10 +169,6 @@ struct pt_regs { u64 sdei_ttbr1; struct frame_record_meta stackframe; - - /* Only valid for some EL1 exceptions. */ - u64 lockdep_hardirqs; - u64 exit_rcu; }; /* For correct stack alignment, pt_regs has to be a multiple of 16 bytes. */ diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c index 8e798f46ad28..93c95fc51cc0 100644 --- a/arch/arm64/kernel/entry-common.c +++ b/arch/arm64/kernel/entry-common.c @@ -29,6 +29,13 @@ #include <asm/sysreg.h> #include <asm/system_misc.h> +typedef struct irqentry_state { + union { + bool exit_rcu; + bool lockdep; + }; +} arm64_irqentry_state_t; + /* * Handle IRQ/context state management when entering from kernel mode. * Before this function is called it is not safe to call regular kernel code, @@ -37,29 +44,37 @@ * This is intended to match the logic in irqentry_enter(), handling the kernel * mode transitions only. */ -static __always_inline void __enter_from_kernel_mode(struct pt_regs *regs) +static __always_inline arm64_irqentry_state_t __enter_from_kernel_mode(struct pt_regs *regs) { - regs->exit_rcu = false; + arm64_irqentry_state_t state = { + .exit_rcu = false, + }; if (!IS_ENABLED(CONFIG_TINY_RCU) && is_idle_task(current)) { lockdep_hardirqs_off(CALLER_ADDR0); ct_irq_enter(); trace_hardirqs_off_finish(); - regs->exit_rcu = true; - return; + state.exit_rcu = true; + return state; } lockdep_hardirqs_off(CALLER_ADDR0); rcu_irq_enter_check_tick(); trace_hardirqs_off_finish(); + + return state; } -static void noinstr enter_from_kernel_mode(struct pt_regs *regs) +static noinstr arm64_irqentry_state_t enter_from_kernel_mode(struct pt_regs *regs) { - __enter_from_kernel_mode(regs); + arm64_irqentry_state_t state; + + state = __enter_from_kernel_mode(regs); mte_check_tfsr_entry(); mte_disable_tco_entry(current); + + return state; } /* @@ -70,12 +85,13 @@ static void noinstr enter_from_kernel_mode(struct pt_regs *regs) * 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) +static __always_inline void __exit_to_kernel_mode(struct pt_regs *regs, + arm64_irqentry_state_t state) { lockdep_assert_irqs_disabled(); if (!regs_irqs_disabled(regs)) { - if (regs->exit_rcu) { + if (state.exit_rcu) { trace_hardirqs_on_prepare(); lockdep_hardirqs_on_prepare(); ct_irq_exit(); @@ -85,15 +101,16 @@ static __always_inline void __exit_to_kernel_mode(struct pt_regs *regs) trace_hardirqs_on(); } else { - if (regs->exit_rcu) + if (state.exit_rcu) ct_irq_exit(); } } -static void noinstr exit_to_kernel_mode(struct pt_regs *regs) +static void noinstr exit_to_kernel_mode(struct pt_regs *regs, + arm64_irqentry_state_t state) { mte_check_tfsr_exit(); - __exit_to_kernel_mode(regs); + __exit_to_kernel_mode(regs, state); } /* @@ -194,9 +211,11 @@ asmlinkage void noinstr asm_exit_to_user_mode(struct pt_regs *regs) * mode. Before this function is called it is not safe to call regular kernel * code, instrumentable code, or any code which may trigger an exception. */ -static void noinstr arm64_enter_nmi(struct pt_regs *regs) +static noinstr arm64_irqentry_state_t arm64_enter_nmi(struct pt_regs *regs) { - regs->lockdep_hardirqs = lockdep_hardirqs_enabled(); + arm64_irqentry_state_t state; + + state.lockdep = lockdep_hardirqs_enabled(); __nmi_enter(); lockdep_hardirqs_off(CALLER_ADDR0); @@ -205,6 +224,8 @@ static void noinstr arm64_enter_nmi(struct pt_regs *regs) trace_hardirqs_off_finish(); ftrace_nmi_enter(); + + return state; } /* @@ -212,19 +233,18 @@ static void noinstr arm64_enter_nmi(struct pt_regs *regs) * mode. After this function returns it is not safe to call regular kernel * code, instrumentable code, or any code which may trigger an exception. */ -static void noinstr arm64_exit_nmi(struct pt_regs *regs) +static void noinstr arm64_exit_nmi(struct pt_regs *regs, + arm64_irqentry_state_t state) { - bool restore = regs->lockdep_hardirqs; - ftrace_nmi_exit(); - if (restore) { + if (state.lockdep) { trace_hardirqs_on_prepare(); lockdep_hardirqs_on_prepare(); } ct_nmi_exit(); lockdep_hardirq_exit(); - if (restore) + if (state.lockdep) lockdep_hardirqs_on(CALLER_ADDR0); __nmi_exit(); } @@ -234,14 +254,18 @@ static void noinstr arm64_exit_nmi(struct pt_regs *regs) * kernel mode. Before this function is called it is not safe to call regular * kernel code, instrumentable code, or any code which may trigger an exception. */ -static void noinstr arm64_enter_el1_dbg(struct pt_regs *regs) +static noinstr arm64_irqentry_state_t arm64_enter_el1_dbg(struct pt_regs *regs) { - regs->lockdep_hardirqs = lockdep_hardirqs_enabled(); + arm64_irqentry_state_t state; + + state.lockdep = lockdep_hardirqs_enabled(); lockdep_hardirqs_off(CALLER_ADDR0); ct_nmi_enter(); trace_hardirqs_off_finish(); + + return state; } /* @@ -249,17 +273,16 @@ static void noinstr arm64_enter_el1_dbg(struct pt_regs *regs) * kernel mode. After this function returns it is not safe to call regular * kernel code, instrumentable code, or any code which may trigger an exception. */ -static void noinstr arm64_exit_el1_dbg(struct pt_regs *regs) +static void noinstr arm64_exit_el1_dbg(struct pt_regs *regs, + arm64_irqentry_state_t state) { - bool restore = regs->lockdep_hardirqs; - - if (restore) { + if (state.lockdep) { trace_hardirqs_on_prepare(); lockdep_hardirqs_on_prepare(); } ct_nmi_exit(); - if (restore) + if (state.lockdep) lockdep_hardirqs_on(CALLER_ADDR0); } @@ -475,73 +498,87 @@ UNHANDLED(el1t, 64, error) static void noinstr el1_abort(struct pt_regs *regs, unsigned long esr) { unsigned long far = read_sysreg(far_el1); + arm64_irqentry_state_t state; - enter_from_kernel_mode(regs); + state = enter_from_kernel_mode(regs); local_daif_inherit(regs); do_mem_abort(far, esr, regs); local_daif_mask(); - exit_to_kernel_mode(regs); + exit_to_kernel_mode(regs, state); } static void noinstr el1_pc(struct pt_regs *regs, unsigned long esr) { unsigned long far = read_sysreg(far_el1); + arm64_irqentry_state_t state; - enter_from_kernel_mode(regs); + state = enter_from_kernel_mode(regs); local_daif_inherit(regs); do_sp_pc_abort(far, esr, regs); local_daif_mask(); - exit_to_kernel_mode(regs); + exit_to_kernel_mode(regs, state); } static void noinstr el1_undef(struct pt_regs *regs, unsigned long esr) { - enter_from_kernel_mode(regs); + arm64_irqentry_state_t state; + + state = enter_from_kernel_mode(regs); local_daif_inherit(regs); do_el1_undef(regs, esr); local_daif_mask(); - exit_to_kernel_mode(regs); + exit_to_kernel_mode(regs, state); } static void noinstr el1_bti(struct pt_regs *regs, unsigned long esr) { - enter_from_kernel_mode(regs); + arm64_irqentry_state_t state; + + state = enter_from_kernel_mode(regs); local_daif_inherit(regs); do_el1_bti(regs, esr); local_daif_mask(); - exit_to_kernel_mode(regs); + exit_to_kernel_mode(regs, state); } static void noinstr el1_gcs(struct pt_regs *regs, unsigned long esr) { - enter_from_kernel_mode(regs); + arm64_irqentry_state_t state; + + state = enter_from_kernel_mode(regs); local_daif_inherit(regs); do_el1_gcs(regs, esr); local_daif_mask(); - exit_to_kernel_mode(regs); + exit_to_kernel_mode(regs, state); } static void noinstr el1_mops(struct pt_regs *regs, unsigned long esr) { - enter_from_kernel_mode(regs); + arm64_irqentry_state_t state; + + state = enter_from_kernel_mode(regs); local_daif_inherit(regs); do_el1_mops(regs, esr); local_daif_mask(); - exit_to_kernel_mode(regs); + exit_to_kernel_mode(regs, state); } static void noinstr el1_breakpt(struct pt_regs *regs, unsigned long esr) { - arm64_enter_el1_dbg(regs); + arm64_irqentry_state_t state; + + state = arm64_enter_el1_dbg(regs); debug_exception_enter(regs); do_breakpoint(esr, regs); debug_exception_exit(regs); - arm64_exit_el1_dbg(regs); + arm64_exit_el1_dbg(regs, state); } static void noinstr el1_softstp(struct pt_regs *regs, unsigned long esr) { - arm64_enter_el1_dbg(regs); + arm64_irqentry_state_t state; + + state = arm64_enter_el1_dbg(regs); if (!cortex_a76_erratum_1463225_debug_handler(regs)) { debug_exception_enter(regs); /* @@ -554,37 +591,42 @@ static void noinstr el1_softstp(struct pt_regs *regs, unsigned long esr) do_el1_softstep(esr, regs); debug_exception_exit(regs); } - arm64_exit_el1_dbg(regs); + arm64_exit_el1_dbg(regs, state); } static void noinstr el1_watchpt(struct pt_regs *regs, unsigned long esr) { /* Watchpoints are the only debug exception to write FAR_EL1 */ unsigned long far = read_sysreg(far_el1); + arm64_irqentry_state_t state; - arm64_enter_el1_dbg(regs); + state = arm64_enter_el1_dbg(regs); debug_exception_enter(regs); do_watchpoint(far, esr, regs); debug_exception_exit(regs); - arm64_exit_el1_dbg(regs); + arm64_exit_el1_dbg(regs, state); } static void noinstr el1_brk64(struct pt_regs *regs, unsigned long esr) { - arm64_enter_el1_dbg(regs); + arm64_irqentry_state_t state; + + state = arm64_enter_el1_dbg(regs); debug_exception_enter(regs); do_el1_brk64(esr, regs); debug_exception_exit(regs); - arm64_exit_el1_dbg(regs); + arm64_exit_el1_dbg(regs, state); } static void noinstr el1_fpac(struct pt_regs *regs, unsigned long esr) { - enter_from_kernel_mode(regs); + arm64_irqentry_state_t state; + + state = enter_from_kernel_mode(regs); local_daif_inherit(regs); do_el1_fpac(regs, esr); local_daif_mask(); - exit_to_kernel_mode(regs); + exit_to_kernel_mode(regs, state); } asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs) @@ -639,15 +681,19 @@ asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs) static __always_inline void __el1_pnmi(struct pt_regs *regs, void (*handler)(struct pt_regs *)) { - arm64_enter_nmi(regs); + arm64_irqentry_state_t state; + + state = arm64_enter_nmi(regs); do_interrupt_handler(regs, handler); - arm64_exit_nmi(regs); + arm64_exit_nmi(regs, state); } static __always_inline void __el1_irq(struct pt_regs *regs, void (*handler)(struct pt_regs *)) { - enter_from_kernel_mode(regs); + arm64_irqentry_state_t state; + + state = enter_from_kernel_mode(regs); irq_enter_rcu(); do_interrupt_handler(regs, handler); @@ -655,7 +701,7 @@ static __always_inline void __el1_irq(struct pt_regs *regs, arm64_preempt_schedule_irq(); - exit_to_kernel_mode(regs); + exit_to_kernel_mode(regs, state); } static void noinstr el1_interrupt(struct pt_regs *regs, void (*handler)(struct pt_regs *)) @@ -681,11 +727,12 @@ asmlinkage void noinstr el1h_64_fiq_handler(struct pt_regs *regs) asmlinkage void noinstr el1h_64_error_handler(struct pt_regs *regs) { unsigned long esr = read_sysreg(esr_el1); + arm64_irqentry_state_t state; local_daif_restore(DAIF_ERRCTX); - arm64_enter_nmi(regs); + state = arm64_enter_nmi(regs); do_serror(regs, esr); - arm64_exit_nmi(regs); + arm64_exit_nmi(regs, state); } static void noinstr el0_da(struct pt_regs *regs, unsigned long esr) @@ -997,12 +1044,13 @@ asmlinkage void noinstr el0t_64_fiq_handler(struct pt_regs *regs) static void noinstr __el0_error_handler_common(struct pt_regs *regs) { unsigned long esr = read_sysreg(esr_el1); + arm64_irqentry_state_t state; enter_from_user_mode(regs); local_daif_restore(DAIF_ERRCTX); - arm64_enter_nmi(regs); + state = arm64_enter_nmi(regs); do_serror(regs, esr); - arm64_exit_nmi(regs); + arm64_exit_nmi(regs, state); local_daif_restore(DAIF_PROCCTX); exit_to_user_mode(regs); } @@ -1122,6 +1170,7 @@ asmlinkage void noinstr __noreturn handle_bad_stack(struct pt_regs *regs) asmlinkage noinstr unsigned long __sdei_handler(struct pt_regs *regs, struct sdei_registered_event *arg) { + arm64_irqentry_state_t state; unsigned long ret; /* @@ -1146,9 +1195,9 @@ __sdei_handler(struct pt_regs *regs, struct sdei_registered_event *arg) else if (cpu_has_pan()) set_pstate_pan(0); - arm64_enter_nmi(regs); + state = arm64_enter_nmi(regs); ret = do_sdei_event(regs, arg); - arm64_exit_nmi(regs); + arm64_exit_nmi(regs, state); return ret; } -- 2.34.1