[PATCH -next v5 19/22] arm64/ptrace: Use syscall_get_arguments() heleper

[Jinjie Ruan <ruanjinjie@xxxxxxxxxx>]

The generic entry check audit context first and use
syscall_get_arguments() helper.

In order to switch to the generic entry for arm64,

- Also use the helper.

- Extract the syscall_enter_audit() helper to make it clear.

- Check audit context for syscall_enter_audit(), which only adds
  one additional check without any other differences as
  audit_syscall_entry() check it first otherwise do nothing.

No functional changes.

Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
---
 arch/arm64/kernel/ptrace.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index c0c00e173f61..3a7a1eaca0a9 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -2357,6 +2357,17 @@ static void report_syscall_exit(struct pt_regs *regs)
        }
 }
 
+static inline void syscall_enter_audit(struct pt_regs *regs, long syscall)
+{
+       if (unlikely(audit_context())) {
+               unsigned long args[6];
+
+               syscall_get_arguments(current, regs, args);
+               audit_syscall_entry(syscall, args[0], args[1], args[2], 
args[3]);
+       }
+
+}
+
 int syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long 
flags)
 {
        int ret;
@@ -2387,8 +2398,7 @@ int syscall_trace_enter(struct pt_regs *regs, long 
syscall, unsigned long flags)
                 syscall = syscall_get_nr(current, regs);
        }
 
-       audit_syscall_entry(syscall, regs->orig_x0, regs->regs[1],
-                           regs->regs[2], regs->regs[3]);
+       syscall_enter_audit(regs, syscall);
 
        return regs->syscallno;
 }
-- 
2.34.1