arch_exit_to_user_mode(9)

okay so bestie, you're looking at arch_exit_to_user_mode(9) from the Kernel API Manual — it's the architecture-specific final-work-before-user-mode situation, and it's giving tiny but important ✨

🎀 NAME

arch_exit_to_user_mode — Architecture specific final work before exit to user mode. 💅

✨ SYNOPSIS

void arch_exit_to_user_mode (void );

🌸 ARGUMENTS

• void — no arguments. That's it. Nothing. Nada. 🫶

💅 DESCRIPTION

Invoked from exit_to_user_mode with interrupt disabled as the last function before return. Defaults to NOOP.

This needs to be __always_inline because it is non-instrumentable code invoked after context tracking switched to user mode. Like, it has to be __always_inline, no debate. 🔥

An architecture implementation must not do anything complex, no locking etc. Keep it simple, bestie. The main purpose is for speculation mitigations. 👑

🦋 SEE ALSO

Kernel file ./include/linux/irq-entry-common.h — yes, that's the one:

• arch_enter_from_user_mode(9)
• arch_in_rcu_eqs(9)
• enter_from_user_mode(9)
• arch_exit_to_user_mode_work(9)
• arch_exit_to_user_mode_prepare(9)
• arch_do_signal_or_restart(9)
• __exit_to_user_mode_prepare(9)
• syscall_exit_to_user_mode_prepare(9)
• irqentry_exit_to_user_mode_prepare(9)
• exit_to_user_mode(9)
• irqentry_enter_from_user_mode(9)
• irqentry_exit_to_user_mode(9)
• struct irqentry_state(9)
• irqentry_enter_from_kernel_mode(9)
• irqentry_exit_to_kernel_mode_preempt(9)
• irqentry_exit_to_kernel_mode_after_preempt(9)
• irqentry_exit_to_kernel_mode(9)
• irqentry_enter(9)
• irqentry_exit(9)
• irqentry_nmi_enter(9)
• irqentry_nmi_exit(9)

mwah 💖 that's the whole page: source/version ./include/linux, date October 2026, and the title is arch_exit_to_user_mode(9) from the Kernel API Manual. periodt. 🎀