1 files changed, 43 insertions, 10 deletions

diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h
index c7bfac45f951..b9711e813ec2 100644
--- a/include/linux/entry-common.h
+++ b/include/linux/entry-common.h
@@ -42,7 +42,7 @@
 #endif
 
 /*
- * TIF flags handled in syscall_enter_from_usermode()
+ * TIF flags handled in syscall_enter_from_user_mode()
  */
 #ifndef ARCH_SYSCALL_ENTER_WORK
 # define ARCH_SYSCALL_ENTER_WORK	(0)
@@ -114,15 +114,30 @@ static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs
 #endif
 
 /**
- * syscall_enter_from_user_mode - Check and handle work before invoking
- *				 a syscall
+ * syscall_enter_from_user_mode_prepare - Establish state and enable interrupts
  * @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 and the subsequent functions can be
- * instrumented.
+ * 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.
+ *
+ * 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);
+
+/**
+ * syscall_enter_from_user_mode_work - 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
+ * enabled after invoking syscall_enter_from_user_mode_prepare() and extra
+ * architecture specific work.
  *
  * Returns: The original or a modified syscall number
  *
@@ -131,12 +146,30 @@ static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs
  * syscall_set_return_value() first.  If neither of those are called and -1
  * is returned, then the syscall will fail with ENOSYS.
  *
- * The following functionality is handled here:
+ * It handles the following work items:
  *
- *  1) Establish state (lockdep, RCU (context tracking), tracing)
- *  2) TIF flag dependent invocations of arch_syscall_enter_tracehook(),
+ *  1) TIF flag dependent invocations of arch_syscall_enter_tracehook(),
  *     __secure_computing(), trace_sys_enter()
- *  3) Invocation of audit_syscall_entry()
+ *  2) Invocation of audit_syscall_entry()
+ */
+long syscall_enter_from_user_mode_work(struct pt_regs *regs, long syscall);
+
+/**
+ * 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 combination of syscall_enter_from_user_mode_prepare() and
+ * syscall_enter_from_user_mode_work().
+ *
+ * Returns: The original or a modified syscall number. See
+ * syscall_enter_from_user_mode_work() for further explanation.
  */
 long syscall_enter_from_user_mode(struct pt_regs *regs, long syscall);