[RFC PATCH v2 15/45] arm64: entry: replace DAIF helpers with entry helpers
Jinjie Ruan
ruanjinjie at huawei.com
Tue Jul 28 02:53:58 PDT 2026
在 2026/7/28 0:34, Vladimir Murzin 写道:
> From: Ada Couprie Diaz <ada.coupriediaz at arm.com>
>
> Replace all uses of the `local_daif_...` helpers in `entry-common.c`
> with the new entry-specific exception masking helpers.
>
> Also replace `local_irq_disable()` with a switch to NOIRQ context
> using the new helpers. This provides:
>
> - consistency checks for hardware state
> - a unified style for managing exception context
>
> Now that both the irqflags API and entry code handle DAIF and PMR
> correctly, remove `GIC_PRIO_PSR_I_SET` from the PMR value set by
> `kernel_entry` in `entry.S` and by `init_gic_priority_masking()` in
> `kernel/smp.c`.
>
> The `local_daif_...` helpers and other specialized code still use
> `GIC_PRIO_PSR_I_SET` for now; this commit does not change their
> behavior.
>
> Signed-off-by: Ada Couprie Diaz <ada.coupriediaz at arm.com>
> Signed-off-by: Vladimir Murzin <vladimir.murzin at arm.com>
> ---
> arch/arm64/kernel/entry-common.c | 258 ++++++++++++++++++++-----------
> arch/arm64/kernel/entry.S | 2 +-
> arch/arm64/kernel/smp.c | 2 +-
> 3 files changed, 173 insertions(+), 89 deletions(-)
>
> diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
> index 72c03ccea59f..a409cd6159a4 100644
> --- a/arch/arm64/kernel/entry-common.c
> +++ b/arch/arm64/kernel/entry-common.c
> @@ -18,11 +18,11 @@
> #include <linux/thread_info.h>
>
> #include <asm/cpufeature.h>
> -#include <asm/daifflags.h>
> #include <asm/esr.h>
> #include <asm/exception.h>
> #include <asm/fpsimd.h>
> #include <asm/irq_regs.h>
> +#include <asm/interrupts/entry.h>
> #include <asm/kprobes.h>
> #include <asm/mmu.h>
> #include <asm/processor.h>
> @@ -53,9 +53,10 @@ static noinstr irqentry_state_t arm64_enter_from_kernel_mode(struct pt_regs *reg
> * instrumentable code, or any code which may trigger an exception.
> */
[...]
>
> asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs)
> @@ -506,16 +521,20 @@ asmlinkage void noinstr el1h_64_sync_handler(struct pt_regs *regs)
> default:
> __panic_unhandled(regs, "64-bit el1h sync", esr);
> }
> +
> + arm64_debug_exc_context(CRITICAL_CONTEXT);
> }
>
> static __always_inline void __el1_pnmi(struct pt_regs *regs,
> void (*handler)(struct pt_regs *))
> {
> + arm64_exc_hwstate_t hwstate;
> irqentry_state_t state;
>
> state = irqentry_nmi_enter(regs);
> + hwstate = arm64_unmask_exc_context(NONMI_CONTEXT);
> do_interrupt_handler(regs, handler);
> - local_daif_mask();
> + arm64_mask_exc_context(hwstate);
> irqentry_nmi_exit(regs, state);
> }
>
> @@ -526,21 +545,32 @@ static __always_inline void __el1_irq(struct pt_regs *regs,
>
> state = arm64_enter_from_kernel_mode(regs);
>
> + arm64_unmask_exc_context(NONMI_CONTEXT);
> +
> irq_enter_rcu();
> do_interrupt_handler(regs, handler);
> irq_exit_rcu();
>
> - arm64_exit_to_kernel_mode_preempt(regs, state);
> + /*
> + * If pseudo-NMIs are enabled and the interrupted context had
> + * IRQs unmasked, the interrupt handler will have cleared DAIF
> + * and switched to PMR masking in order to handle
> + * NMIs. Otherwise it would keep IF. In both cases on return
> + * we effectivly have NOIRQ_CONTEXT - keep track of it
> + */
> + arm64_debug_exc_context(NOIRQ_CONTEXT);
> + arm64_exit_to_kernel_mode(regs, state, arm64_exc_hwstate_of_context(NOIRQ_CONTEXT));
> }
Is this a typo?
arm64_exit_to_kernel_mode_preempt(regs,
arm64_exc_hwstate_of_context(NOIRQ_CONTEXT));
otherwise LGTM
Reviewed-by: Jinjie Ruan <ruanjinjie at huawei.com>
> +
> 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) && regs_irqs_disabled(regs))
> __el1_pnmi(regs, handler);
> else
> __el1_irq(regs, handler);
> +
> + arm64_debug_exc_context(CRITICAL_CONTEXT);
> }
>
> asmlinkage void noinstr el1h_64_irq_handler(struct pt_regs *regs)
> @@ -556,28 +586,31 @@ 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_exc_hwstate_t hwstate;
> irqentry_state_t state;
>
> - local_daif_restore(DAIF_ERRCTX);
> state = irqentry_nmi_enter(regs);
> + hwstate = arm64_unmask_exc_context(ERROR_CONTEXT);
> do_serror(regs, esr);
> - local_daif_mask();
> + arm64_mask_exc_context(hwstate);
> irqentry_nmi_exit(regs, state);
> }
>
> static void noinstr el0_da(struct pt_regs *regs, unsigned long esr)
> {
> unsigned long far = read_sysreg(far_el1);
> + arm64_exc_hwstate_t hwstate;
>
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_mem_abort(far, esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_ia(struct pt_regs *regs, unsigned long esr)
> {
> unsigned long far = read_sysreg(far_el1);
> + arm64_exc_hwstate_t hwstate;
>
> /*
> * We've taken an instruction abort from userspace and not yet
> @@ -588,114 +621,139 @@ static void noinstr el0_ia(struct pt_regs *regs, unsigned long esr)
> arm64_apply_bp_hardening();
>
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_mem_abort(far, esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_fpsimd_acc(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_fpsimd_acc(esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_sve_acc(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_sve_acc(esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_sme_acc(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_sme_acc(esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_fpsimd_exc(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_fpsimd_exc(esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_sys(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_el0_sys(esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_pc(struct pt_regs *regs, unsigned long esr)
> {
> unsigned long far = read_sysreg(far_el1);
> + arm64_exc_hwstate_t hwstate;
>
> if (!is_ttbr0_addr(instruction_pointer(regs)))
> arm64_apply_bp_hardening();
>
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_sp_pc_abort(far, esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_sp(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_sp_pc_abort(regs->sp, esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_undef(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_el0_undef(regs, esr);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_bti(struct pt_regs *regs)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_el0_bti(regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_mops(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_el0_mops(regs, esr);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_gcs(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_el0_gcs(regs, esr);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_inv(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> bad_el0_sync(regs, 0, esr);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_breakpt(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> if (!is_ttbr0_addr(regs->pc))
> arm64_apply_bp_hardening();
>
> @@ -703,12 +761,13 @@ static void noinstr el0_breakpt(struct pt_regs *regs, unsigned long esr)
> debug_exception_enter(regs);
> do_breakpoint(esr, regs);
> debug_exception_exit(regs);
> - local_daif_restore(DAIF_PROCCTX);
> - arm64_exit_to_user_mode(regs);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_softstp(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> bool step_done;
>
> if (!is_ttbr0_addr(regs->pc))
> @@ -722,50 +781,56 @@ static void noinstr el0_softstp(struct pt_regs *regs, unsigned long esr)
> * the single-step is complete.
> */
> step_done = try_step_suspended_breakpoints(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> if (!step_done)
> do_el0_softstep(esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_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_exc_hwstate_t hwstate;
>
> arm64_enter_from_user_mode(regs);
> debug_exception_enter(regs);
> do_watchpoint(far, esr, regs);
> debug_exception_exit(regs);
> - local_daif_restore(DAIF_PROCCTX);
> - arm64_exit_to_user_mode(regs);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_brk64(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_el0_brk64(esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_svc(struct pt_regs *regs)
> {
> + arm64_exc_hwstate_t hwstate;
> arm64_syscall_enter_from_user_mode(regs);
> cortex_a76_erratum_1463225_svc_handler();
> fpsimd_syscall_enter();
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_el0_svc(regs);
> - arm64_syscall_exit_to_user_mode(regs);
> + arm64_syscall_exit_to_user_mode(regs, hwstate);
> fpsimd_syscall_exit();
> }
>
> static void noinstr el0_fpac(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_el0_fpac(regs, esr);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> asmlinkage void noinstr el0t_64_sync_handler(struct pt_regs *regs)
> @@ -834,6 +899,8 @@ asmlinkage void noinstr el0t_64_sync_handler(struct pt_regs *regs)
> default:
> el0_inv(regs, esr);
> }
> +
> + arm64_debug_exc_context(CRITICAL_CONTEXT);
> }
>
> static void noinstr el0_interrupt(struct pt_regs *regs,
> @@ -841,7 +908,7 @@ static void noinstr el0_interrupt(struct pt_regs *regs,
> {
> arm64_enter_from_user_mode(regs);
>
> - write_sysreg(DAIF_PROCCTX_NOIRQ, daif);
> + arm64_unmask_exc_context(NONMI_CONTEXT);
>
> if (regs->pc & BIT(55))
> arm64_apply_bp_hardening();
> @@ -850,7 +917,14 @@ static void noinstr el0_interrupt(struct pt_regs *regs,
> do_interrupt_handler(regs, handler);
> irq_exit_rcu();
>
> - arm64_exit_to_user_mode(regs);
> + /*
> + * For the same reason as in el1_irq() we effectivly
> + * have NOIRQ_CONTEXT on return from handler - keep
> + * track of it
> + */
> + arm64_debug_exc_context(NOIRQ_CONTEXT);
> + arm64_exit_to_user_mode(regs, arm64_exc_hwstate_of_context(NOIRQ_CONTEXT));
> + arm64_debug_exc_context(CRITICAL_CONTEXT);
> }
>
> static void noinstr __el0_irq_handler_common(struct pt_regs *regs)
> @@ -876,15 +950,17 @@ 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_exc_hwstate_t hwstate;
> irqentry_state_t state;
>
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_ERRCTX);
> + hwstate = arm64_unmask_exc_context(ERROR_CONTEXT);
> state = irqentry_nmi_enter(regs);
> do_serror(regs, esr);
> irqentry_nmi_exit(regs, state);
> - local_daif_restore(DAIF_PROCCTX);
> - arm64_exit_to_user_mode(regs);
> + hwstate = arm64_drop_exc_context(hwstate, PROCESS_CONTEXT);
> + arm64_exit_to_user_mode(regs, hwstate);
> + arm64_debug_exc_context(CRITICAL_CONTEXT);
> }
>
> asmlinkage void noinstr el0t_64_error_handler(struct pt_regs *regs)
> @@ -895,27 +971,33 @@ asmlinkage void noinstr el0t_64_error_handler(struct pt_regs *regs)
> #ifdef CONFIG_COMPAT
> static void noinstr el0_cp15(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_el0_cp15(esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_svc_compat(struct pt_regs *regs)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_syscall_enter_from_user_mode(regs);
> cortex_a76_erratum_1463225_svc_handler();
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_el0_svc_compat(regs);
> - arm64_syscall_exit_to_user_mode(regs);
> + arm64_syscall_exit_to_user_mode(regs, hwstate);
> }
>
> static void noinstr el0_bkpt32(struct pt_regs *regs, unsigned long esr)
> {
> + arm64_exc_hwstate_t hwstate;
> +
> arm64_enter_from_user_mode(regs);
> - local_daif_restore(DAIF_PROCCTX);
> + hwstate = arm64_unmask_exc_context(PROCESS_CONTEXT);
> do_bkpt32(esr, regs);
> - arm64_exit_to_user_mode(regs);
> + arm64_exit_to_user_mode(regs, hwstate);
> }
>
> asmlinkage void noinstr el0t_32_sync_handler(struct pt_regs *regs)
> @@ -966,6 +1048,8 @@ asmlinkage void noinstr el0t_32_sync_handler(struct pt_regs *regs)
> default:
> el0_inv(regs, esr);
> }
> +
> + arm64_debug_exc_context(CRITICAL_CONTEXT);
> }
>
> asmlinkage void noinstr el0t_32_irq_handler(struct pt_regs *regs)
> diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
> index f63049ac32dc..cb3be770f2d0 100644
> --- a/arch/arm64/kernel/entry.S
> +++ b/arch/arm64/kernel/entry.S
> @@ -316,7 +316,7 @@ alternative_else_nop_endif
>
> mrs_s x20, SYS_ICC_PMR_EL1
> str w20, [sp, #S_PMR]
> - mov x20, #GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET
> + mov x20, #GIC_PRIO_IRQON
> msr_s SYS_ICC_PMR_EL1, x20
>
> .Lskip_pmr_save\@:
> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> index cdcdd160e5b6..1e08537df67b 100644
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
> @@ -185,7 +185,7 @@ static void init_gic_priority_masking(void)
> WARN_ON(!(cpuflags & PSR_I_BIT));
> WARN_ON(!(cpuflags & PSR_F_BIT));
>
> - gic_write_pmr(GIC_PRIO_IRQON | GIC_PRIO_PSR_I_SET);
> + gic_write_pmr(GIC_PRIO_IRQON);
> }
>
> /*
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