From 54a5ab56242f96555999aaa41228f77b4a76e386 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Mon, 27 Oct 2025 09:44:38 +0100 Subject: [PATCH] entry: Remove syscall_enter_from_user_mode_prepare() Open code the only user in the x86 syscall code and reduce the zoo of functions. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Reviewed-by: Mathieu Desnoyers Link: https://patch.msgid.link/20251027084306.652839989@linutronix.de --- arch/x86/entry/syscall_32.c | 3 ++- include/linux/entry-common.h | 26 +++++--------------------- kernel/entry/syscall-common.c | 8 -------- 3 files changed, 7 insertions(+), 30 deletions(-) diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c index 2b15ea17bb7c5..a67a644d0cfe0 100644 --- a/arch/x86/entry/syscall_32.c +++ b/arch/x86/entry/syscall_32.c @@ -274,9 +274,10 @@ static noinstr bool __do_fast_syscall_32(struct pt_regs *regs) * fetch EBP before invoking any of the syscall entry work * functions. */ - syscall_enter_from_user_mode_prepare(regs); + enter_from_user_mode(regs); instrumentation_begin(); + local_irq_enable(); /* Fetch EBP from where the vDSO stashed it. */ if (IS_ENABLED(CONFIG_X86_64)) { /* diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h index c585221ff16b0..75b194c34e18d 100644 --- a/include/linux/entry-common.h +++ b/include/linux/entry-common.h @@ -45,23 +45,6 @@ SYSCALL_WORK_SYSCALL_EXIT_TRAP | \ ARCH_SYSCALL_WORK_EXIT) -/** - * syscall_enter_from_user_mode_prepare - Establish state and enable interrupts - * @regs: Pointer to currents pt_regs - * - * 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 handles lockdep, RCU (context tracking) and tracing state, i.e. - * the functionality provided by enter_from_user_mode(). - * - * This is invoked when there is extra architecture specific functionality - * to be done between establishing state and handling user mode entry work. - */ -void syscall_enter_from_user_mode_prepare(struct pt_regs *regs); - long syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long work); /** @@ -71,8 +54,8 @@ long syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long work) * @syscall: The syscall number * * Invoked from architecture specific syscall entry code with interrupts - * enabled after invoking syscall_enter_from_user_mode_prepare() and extra - * architecture specific work. + * enabled after invoking enter_from_user_mode(), enabling interrupts and + * extra architecture specific work. * * Returns: The original or a modified syscall number * @@ -108,8 +91,9 @@ static __always_inline long syscall_enter_from_user_mode_work(struct pt_regs *re * function returns all state is correct, interrupts are enabled and the * subsequent functions can be instrumented. * - * This is combination of syscall_enter_from_user_mode_prepare() and - * syscall_enter_from_user_mode_work(). + * 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. diff --git a/kernel/entry/syscall-common.c b/kernel/entry/syscall-common.c index 66e6ba7fa80c8..940a597ded40f 100644 --- a/kernel/entry/syscall-common.c +++ b/kernel/entry/syscall-common.c @@ -63,14 +63,6 @@ long syscall_trace_enter(struct pt_regs *regs, long syscall, return ret ? : syscall; } -noinstr void syscall_enter_from_user_mode_prepare(struct pt_regs *regs) -{ - enter_from_user_mode(regs); - instrumentation_begin(); - local_irq_enable(); - instrumentation_end(); -} - /* * If SYSCALL_EMU is set, then the only reason to report is when * SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP). This syscall -- 2.47.3