ptrace: Remove arch_syscall_{enter,exit}_tracehook

These functions are alwasy one-to-one wrappers around
ptrace_report_syscall_entry and ptrace_report_syscall_exit.
So directly call the functions they are wrapping instead.

Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20220309162454.123006-4-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

include/linux/entry-common.h

@@ -79,26 +79,6 @@ static __always_inline void arch_check_user_regs(struct pt_regs *regs);
 static __always_inline void arch_check_user_regs(struct pt_regs *regs) {}
 #endif
 
-/**
- * arch_syscall_enter_tracehook - Wrapper around tracehook_report_syscall_entry()
- * @regs:	Pointer to currents pt_regs
- *
- * Returns: 0 on success or an error code to skip the syscall.
- *
- * Defaults to tracehook_report_syscall_entry(). Can be replaced by
- * architecture specific code.
- *
- * Invoked from syscall_enter_from_user_mode()
- */
-static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs);
-
-#ifndef arch_syscall_enter_tracehook
-static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs)
-{
-	return ptrace_report_syscall_entry(regs);
-}
-#endif
-
 /**
  * enter_from_user_mode - Establish state when coming from user mode
  *
@@ -157,7 +137,7 @@ void syscall_enter_from_user_mode_prepare(struct pt_regs *regs);
  * It handles the following work items:
  *
  *  1) syscall_work flag dependent invocations of
- *     arch_syscall_enter_tracehook(), __secure_computing(), trace_sys_enter()
+ *     ptrace_report_syscall_entry(), __secure_computing(), trace_sys_enter()
  *  2) Invocation of audit_syscall_entry()
  */
 long syscall_enter_from_user_mode_work(struct pt_regs *regs, long syscall);
@@ -279,25 +259,6 @@ static __always_inline void arch_exit_to_user_mode(void) { }
  */
 void arch_do_signal_or_restart(struct pt_regs *regs, bool has_signal);
 
-/**
- * arch_syscall_exit_tracehook - Wrapper around tracehook_report_syscall_exit()
- * @regs:	Pointer to currents pt_regs
- * @step:	Indicator for single step
- *
- * Defaults to tracehook_report_syscall_exit(). Can be replaced by
- * architecture specific code.
- *
- * Invoked from syscall_exit_to_user_mode()
- */
-static inline void arch_syscall_exit_tracehook(struct pt_regs *regs, bool step);
-
-#ifndef arch_syscall_exit_tracehook
-static inline void arch_syscall_exit_tracehook(struct pt_regs *regs, bool step)
-{
-	ptrace_report_syscall_exit(regs, step);
-}
-#endif
-
 /**
  * exit_to_user_mode - Fixup state when exiting to user mode
  *
@@ -347,7 +308,7 @@ void syscall_exit_to_user_mode_work(struct pt_regs *regs);
  *	- rseq syscall exit
  *      - audit
  *	- syscall tracing
- *	- tracehook (single stepping)
+ *	- ptrace (single stepping)
  *
  *  2) Preparatory work
  *	- Exit to user mode loop (common TIF handling). Invokes

kernel/entry/common.c

@@ -59,7 +59,7 @@ static long syscall_trace_enter(struct pt_regs *regs, long syscall,
 
 	/* Handle ptrace */
 	if (work & (SYSCALL_WORK_SYSCALL_TRACE | SYSCALL_WORK_SYSCALL_EMU)) {
-		ret = arch_syscall_enter_tracehook(regs);
+		ret = ptrace_report_syscall_entry(regs);
 		if (ret || (work & SYSCALL_WORK_SYSCALL_EMU))
 			return -1L;
 	}
@@ -253,7 +253,7 @@ static void syscall_exit_work(struct pt_regs *regs, unsigned long work)
 
 	step = report_single_step(work);
 	if (step || work & SYSCALL_WORK_SYSCALL_TRACE)
-		arch_syscall_exit_tracehook(regs, step);
+		ptrace_report_syscall_exit(regs, step);
 }
 
 /*