[PATCH 08/17] ptrace/m68k: Stop open coding ptrace_report_syscall

Eric W. Biederman
2022-01-03T21:33:58Z

The generic function ptrace_report_syscall does a little more
than syscall_trace on m68k. The function ptrace_report_syscall
stops early if PT_TRACED is not set, it sets ptrace_message,
and returns the result of fatal_signal_pending.

Setting ptrace_message to a passed in value of 0 is effectively not
setting ptrace_message, making that additional work a noop.

Returning the result of fatal_signal_pending and letting the caller
ignore the result becomes a noop in this change.

When a process is ptraced, the flag PT_PTRACED is always set in
current->ptrace. Testing for PT_PTRACED in ptrace_report_syscall is
just an optimization to fail early if the process is not ptraced.
Later on in ptrace_notify, ptrace_stop will test current->ptrace under
tasklist_lock and skip performing any work if the task is not ptraced.

Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
---
arch/m68k/kernel/ptrace.c | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/arch/m68k/kernel/ptrace.c b/arch/m68k/kernel/ptrace.c
index 94b3b274186d..aa3a0b8d07e9 100644
--- a/arch/m68k/kernel/ptrace.c
+++ b/arch/m68k/kernel/ptrace.c
@@ -273,17 +273,7 @@ long arch_ptrace(struct task_struct *child, long request,

asmlinkage void syscall_trace(void)
{
- ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
- ? 0x80 : 0));
- /*
- * this isn't the same as continuing with a signal, but it will do
- * for normal use. strace only continues with a signal if the
- * stopping signal is not SIGTRAP. -brl
- */
- if (current->exit_code) {
- send_sig(current->exit_code, current, 1);
- current->exit_code = 0;
- }
+ ptrace_report_syscall(0);
}

#if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
--
2.29.2