On 7/8/2026 3:06 AM, Thomas Gleixner wrote:
> All architecture use either:
>
> nr = enter_from_user_mode_randomize_stack(regs, nr);
>
> or
>
> enter_from_user_mode_randomize_stack(regs);
> nr = syscall_enter_from_user_mode_work(regs, nr);
>
> Remove the now unused function.
>
> Signed-off-by: Thomas Gleixner <[email protected]>
> ---
> Documentation/core-api/entry.rst | 17 +++++++++-------
> include/linux/entry-common.h | 40
> +++------------------------------------
> include/linux/irq-entry-common.h | 6 ++---
> 3 files changed, 17 insertions(+), 46 deletions(-)
>
> --- a/Documentation/core-api/entry.rst
> +++ b/Documentation/core-api/entry.rst
> @@ -68,7 +68,7 @@ low-level C code must not be instrumente
> noinstr void syscall(struct pt_regs *regs, int nr)
> {
> arch_syscall_enter(regs);
> - nr = syscall_enter_from_user_mode(regs, nr);
> + nr = syscall_enter_from_user_mode_randomize_stack(regs, nr);
>
> instrumentation_begin();
> if (!invoke_syscall(regs, nr) && nr != -1)
> @@ -78,12 +78,14 @@ low-level C code must not be instrumente
> syscall_exit_to_user_mode(regs);
> }
>
> -syscall_enter_from_user_mode() first invokes enter_from_user_mode() which
> -establishes state in the following order:
> +syscall_enter_from_user_mode_randomize_stack() first invokes
> +enter_from_user_mode_randomize_stack() which establishes state in the
> +following order:
>
> * Lockdep
> * RCU / Context tracking
> * Tracing
> + * Apply stack randomization
>
> and then invokes the various entry work functions like ptrace, seccomp,
> audit,
> syscall tracing, etc. After all that is done, the instrumentable
> invoke_syscall
> @@ -99,10 +101,11 @@ that it invokes exit_to_user_mode() whic
> * RCU / Context tracking
> * Lockdep
>
> -syscall_enter_from_user_mode() and syscall_exit_to_user_mode() are also
> -available as fine grained subfunctions in cases where the architecture code
> -has to do extra work between the various steps. In such cases it has to
> -ensure that enter_from_user_mode() is called first on entry and
> +syscall_enter_from_user_mode_randomize_stack() and
> +syscall_exit_to_user_mode() are also available as fine grained subfunctions
> +in cases where the architecture code has to do extra work between the
> +various steps. In such cases it has to ensure that
> +enter_from_user_mode_randomize_stack() is called first on entry and
> exit_to_user_mode() is called last on exit.
>
> Do not nest syscalls. Nested syscalls will cause RCU and/or context tracking
> --- a/include/linux/entry-common.h
> +++ b/include/linux/entry-common.h
> @@ -19,7 +19,7 @@
> #endif
>
> /*
> - * SYSCALL_WORK flags handled in syscall_enter_from_user_mode()
> + * SYSCALL_WORK flags handled in syscall_enter_from_user_mode_work()
> */
> #define SYSCALL_WORK_ENTER (SYSCALL_WORK_SECCOMP | \
> SYSCALL_WORK_SYSCALL_TRACEPOINT | \
> @@ -205,42 +205,10 @@ do {
> \
> _ret; \
> })
>
> -/**
> - * syscall_enter_from_user_mode - Establish state and check and handle work
> - * before invoking a syscall
> - * @regs: Pointer to currents pt_regs
> - * @syscall: The syscall number
> - *
> - * Invoked from architecture specific syscall entry code with interrupts
> - * disabled. The calling code has to be non-instrumentable. When the
> - * function returns all state is correct, interrupts are enabled and the
> - * subsequent functions can be instrumented.
> - *
> - * This is the combination of enter_from_user_mode() and
> - * syscall_enter_from_user_mode_work() to be used when there is no
> - * architecture specific work to be done between the two.
> - *
> - * Returns: The original or a modified syscall number. See
> - * syscall_enter_from_user_mode_work() for further explanation.
> - */
> -static __always_inline long syscall_enter_from_user_mode(struct pt_regs
> *regs, long syscall)
> -{
> - long ret;
> -
> - enter_from_user_mode(regs);
> -
> - instrumentation_begin();
> - local_irq_enable();
> - ret = syscall_enter_from_user_mode_work(regs, syscall);
> - instrumentation_end();
> -
> - return ret;
> -}
> -
> /*
> - * If SYSCALL_EMU is set, then the only reason to report is when
> - * SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP). This syscall
> - * instruction has been already reported in syscall_enter_from_user_mode().
> + * If SYSCALL_EMU is set, then the only reason to report is when SINGLESTEP
> is
> + * set (i.e. PTRACE_SYSEMU_SINGLESTEP). This syscall instruction has been
> + * already reported in syscall_enter_from_user_mode_work().
> */
> static __always_inline bool report_single_step(unsigned long work)
> {
> --- a/include/linux/irq-entry-common.h
> +++ b/include/linux/irq-entry-common.h
> @@ -49,9 +49,9 @@
> * Defaults to an empty implementation. Can be replaced by architecture
> * specific code.
> *
> - * Invoked from syscall_enter_from_user_mode() in the non-instrumentable
> - * section. Use __always_inline so the compiler cannot push it out of line
> - * and make it instrumentable.
> + * Invoked from enter_from_user_mode_syscall_and_randomize_stack() in the
> + * non-instrumentable section. Use __always_inline so the compiler cannot
> push
> + * it out of line and make it instrumentable.
Reviewed-by: Jinjie Ruan <[email protected]>
> */
> static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs);
>
>
