Commit 54a5ab56 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

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: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251027084306.652839989@linutronix.de
parent 5204be16

arch/x86/entry/syscall_32.c

+2 −1
Original line number Diff line number Diff line
@@ -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)) {

		/*

include/linux/entry-common.h

+5 −21
Original line number Diff line number Diff line
@@ -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.

kernel/entry/syscall-common.c

+0 −8
Original line number Diff line number Diff line
@@ -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