[RFC PATCH v2 37/45] arm64: kprobes: Disable NMIs
From: Vladimir Murzin <hidden>
Date: 2026-07-27 16:38:01
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
Kprobes masks all DAIF exceptions to keep things simple and avoid nested exceptions. With FEAT_NMI, that is no longer enough. Mask ALLINT as well to ensure things stay simple. Signed-off-by: Vladimir Murzin <redacted> Reviewed-by: Jinjie Ruan <redacted> --- arch/arm64/kernel/probes/kprobes.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/arch/arm64/kernel/probes/kprobes.c b/arch/arm64/kernel/probes/kprobes.c
index 68f4271ce02f..ac14022ff4aa 100644
--- a/arch/arm64/kernel/probes/kprobes.c
+++ b/arch/arm64/kernel/probes/kprobes.c@@ -208,17 +208,27 @@ static void __kprobes set_current_kprobe(struct kprobe *p) * the kprobe state is per-CPU and doesn't get migrated. */ static void __kprobes kprobes_save_local_irqflag(struct kprobe_ctlblk *kcb, - struct pt_regs *regs) + struct pt_regs *regs) { - kcb->saved_irqflag = regs->pstate & DAIF_MASK; - regs->pstate |= DAIF_MASK; + arm64_exc_hwstate_t next = arm64_exc_hwstate_of_context(CRITICAL_CONTEXT); + + kcb->saved_irqflag = arm64_inherit_exc_hwstate(regs).flags; + + regs->pstate &= ~(DAIF_MASK | PSR_ALLINT_BIT); + + regs->pstate |= next.daif; + regs->pstate |= next.allint; } static void __kprobes kprobes_restore_local_irqflag(struct kprobe_ctlblk *kcb, - struct pt_regs *regs) + struct pt_regs *regs) { - regs->pstate &= ~DAIF_MASK; - regs->pstate |= kcb->saved_irqflag; + arm64_exc_hwstate_t prev = {.flags = kcb->saved_irqflag}; + + regs->pstate &= ~(DAIF_MASK | PSR_ALLINT_BIT); + + regs->pstate |= prev.daif; + regs->pstate |= prev.allint; } static void __kprobes setup_singlestep(struct kprobe *p,
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2.34.1