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 <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251027084306.652839989@linutronix.de

diff --git a/arch/x86/entry/syscall_32.c b/arch/x86/entry/syscall_32.c
index 2b15ea17bb7c5931a37db9100749e2d5de3810d6..a67a644d0cfe04288ec910d1b7c85520cfbe1734 100644 (file)
--- 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 c585221ff16b04166added852079347a78f8ead5..75b194c34e18d41b3a95580694b6d5a140a74bd8 100644 (file)
--- 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 66e6ba7fa80c8ed13177b00c3dc66ef2f0de029f..940a597ded40fbdb708c3116504c5c663df4b37f 100644 (file)
--- 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