Re: [PATCH 1/3] [gdb/tdep] Add syscall number cache

[Tom de Vries <tdevries@suse.de>]

On 11/27/23 16:52, Simon Marchi wrote:
> On 11/24/23 17:19, Tom de Vries wrote:
>>> If we're going to use lp->syscall_number (if it is not -1) and it
>>> disagrees with gdbarch_get_syscall_number, what's the point in calling
>>> gdbarch_get_syscall_number in the first place?
>>
>> The debug printf that notes the override of gdbarch_get_syscall_number by the cached syscall number.
>>
>>> Should the logic be:
>>>
>>>     if (new_syscall_state == TARGET_WAITKIND_SYSCALL_RETURN
>>>         && lp->syscall_number != -1)
>>>       // use lp->syscall_number
>>>     else
>>>       // call gdbarch_get_syscall_number
>>>
>>> ?
>>
>> If we don't care about that particular type of debug printf, then yes.
> 
> In my opinion it doesn't add any value to call
> gdbarch_get_syscall_number just to be able to make that debug printf.

OK, fixed in a v2 ( 
https://sourceware.org/pipermail/gdb-patches/2023-November/204553.html ).

I've also added another case in linux_handle_syscall_trap of syscall 
cache invalidation:
...
@@ -1791,6 +1826,7 @@ linux_handle_syscall_trap (struct lwp_info *lp, 
int stopping)
  	 "PTRACE_CONT for SIGSTOP", syscall_number, lp->ptid.lwp ());

        lp->syscall_state = TARGET_WAITKIND_IGNORE;
+      lp->syscall_number = -1;
        ptrace (PTRACE_CONT, lp->ptid.lwp (), 0, 0);
        lp->stopped = 0;
        return 1;
...

Thanks,
- Tom