On 7/13/2026 5:25 AM, Thomas Gleixner wrote:
> From: Thomas Gleixner <[email protected]>
>
> This prepares for changing the return types of
> syscall_enter_from_user_mode[_work]() to bool, which in turn separates the
> decision of invoking the syscall from the syscall number, which might have
> been changed in the call by ptrace, seccomp, tracing.
>
> Signed-off-by: Thomas Gleixner <[email protected]>
> ---
> include/linux/entry-common.h | 18 +++++++++++-------
> 1 file changed, 11 insertions(+), 7 deletions(-)
> --- a/include/linux/entry-common.h
> +++ b/include/linux/entry-common.h
> @@ -72,7 +72,7 @@ static __always_inline long syscall_trac
> */
> if (work & SYSCALL_WORK_SYSCALL_USER_DISPATCH) {
> if (syscall_user_dispatch(regs))
> - return -1L;
> + return false;
> }
>
> /*
> @@ -87,13 +87,13 @@ static __always_inline long syscall_trac
> if (work & (SYSCALL_WORK_SYSCALL_TRACE | SYSCALL_WORK_SYSCALL_EMU)) {
> if (!arch_ptrace_report_syscall_permit_entry(regs) ||
> (work & SYSCALL_WORK_SYSCALL_EMU))
> - return -1L;
> + return false;
> }
>
> /* Do seccomp after ptrace, to catch any tracer changes. */
> if (work & SYSCALL_WORK_SECCOMP) {
> if (!__seccomp_permit_syscall())
> - return -1L;
> + return false;
> }
>
> if (unlikely(work & SYSCALL_WORK_SYSCALL_TRACEPOINT))
> @@ -102,8 +102,7 @@ static __always_inline long syscall_trac
> if (unlikely(audit_context()))
> syscall_enter_audit(regs);
>
> - /* Either of the above might have changed the syscall number */
> - return syscall_get_nr(current, regs);
> + return true;
> }
>
> /**
> @@ -133,8 +132,13 @@ static __always_inline long syscall_ente
> {
> unsigned long work = READ_ONCE(current_thread_info()->syscall_work);
>
> - if (work & SYSCALL_WORK_ENTER)
> - syscall = syscall_trace_enter(regs, work, syscall);
> + if (work & SYSCALL_WORK_ENTER) {
> + if (!syscall_trace_enter(regs, work, syscall))
> + return -1L;
> +
> + /* Reread the syscall number as it might have been modified */
> + syscall = syscall_get_nr(current, regs);
> + }
Reviewed-by: Jinjie Ruan <[email protected]>
>
> return syscall;
> }
>
