[PATCH -next v5 17/22] arm64/ptrace: Return early for ptrace_report_syscall_entry() error

[Jinjie Ruan <ruanjinjie@xxxxxxxxxx>]

As the comment said, the calling arch code should abort the system
call and must prevent normal entry so no system call is
made if ptrace_report_syscall_entry() return nonzero.

As the generic entry check error for ptrace_report_syscall_entry(), in
preparation for moving arm64 over to the generic entry code, also return
early if it returns error.

Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
---
 arch/arm64/kernel/ptrace.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 23df2e558fe9..b53d3759baf8 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -2298,10 +2298,10 @@ enum ptrace_syscall_dir {
        PTRACE_SYSCALL_EXIT,
 };
 
-static void report_syscall_enter(struct pt_regs *regs)
+static int report_syscall_enter(struct pt_regs *regs)
 {
-       int regno;
        unsigned long saved_reg;
+       int regno, ret;
 
        /*
         * We have some ABI weirdness here in the way that we handle syscall
@@ -2323,9 +2323,13 @@ static void report_syscall_enter(struct pt_regs *regs)
        saved_reg = regs->regs[regno];
        regs->regs[regno] = PTRACE_SYSCALL_ENTER;
 
-       if (ptrace_report_syscall_entry(regs))
+       ret = ptrace_report_syscall_entry(regs);
+       if (ret)
                forget_syscall(regs);
+
        regs->regs[regno] = saved_reg;
+
+       return ret;
 }
 
 static void report_syscall_exit(struct pt_regs *regs)
@@ -2355,9 +2359,11 @@ static void report_syscall_exit(struct pt_regs *regs)
 
 int syscall_trace_enter(struct pt_regs *regs, long syscall, unsigned long 
flags)
 {
+       int ret;
+
        if (flags & (_TIF_SYSCALL_EMU | _TIF_SYSCALL_TRACE)) {
-               report_syscall_enter(regs);
-               if (flags & _TIF_SYSCALL_EMU)
+               ret = report_syscall_enter(regs);
+               if (ret || (flags & _TIF_SYSCALL_EMU))
                        return NO_SYSCALL;
        }
 
-- 
2.34.1