Re: [PATCH] Disable get_ptrace_pid for NetBSD

Simon Marchi
2020-03-18T21:15:21Z

On 2020-03-18 12:29 p.m., Kamil Rytarowski wrote:
> Unlike most other Operating Systems, NetBSD tracks both pid and lwp.
> The process id on NetBSD is stored always in the pid field of ptid.
>
> gdb/ChangeLog:
>
> * inf-ptrace.h: Disable get_ptrace_pid on NetBSD.
> * inf-ptrace.c: Likewise.
> * (inf_ptrace_target::resume): Update.
> * (inf_ptrace_target::xfer_partial): Likewise.
> ---
> gdb/ChangeLog | 7 +++++++
> gdb/inf-ptrace.c | 19 +++++++++++++++++--
> gdb/inf-ptrace.h | 2 ++
> 3 files changed, 26 insertions(+), 2 deletions(-)
>
> diff --git a/gdb/ChangeLog b/gdb/ChangeLog
> index 84964dc00ac..36e333ec8ba 100644
> --- a/gdb/ChangeLog
> +++ b/gdb/ChangeLog
> @@ -1,3 +1,10 @@
> +2020-03-18 Kamil Rytarowski <n54@gmx.com>
> +
> + * inf-ptrace.h: Disable get_ptrace_pid on NetBSD.
> + * inf-ptrace.c: Likewise.
> + * (inf_ptrace_target::resume): Update.
> + * (inf_ptrace_target::xfer_partial): Likewise.
> +
> 2020-03-17 Kamil Rytarowski <n54@gmx.com>
>
> * regformats/regdef.h: Put reg in gdb namespace.
> diff --git a/gdb/inf-ptrace.c b/gdb/inf-ptrace.c
> index db17a76d946..e8bf66ed45f 100644
> --- a/gdb/inf-ptrace.c
> +++ b/gdb/inf-ptrace.c
> @@ -313,8 +313,12 @@ inf_ptrace_target::kill ()
> target_mourn_inferior (inferior_ptid);
> }
>
> +#ifndef __NetBSD__
> /* Return which PID to pass to ptrace in order to observe/control the
> - tracee identified by PTID. */
> + tracee identified by PTID.
> +
> + Unlike most other Operating Systems, NetBSD tracks both pid and lwp
> + and avoids this function. */
>
> pid_t
> get_ptrace_pid (ptid_t ptid)
> @@ -328,6 +332,7 @@ get_ptrace_pid (ptid_t ptid)
> pid = ptid.pid ();
> return pid;
> }
> +#endif
>
> /* Resume execution of thread PTID, or all threads if PTID is -1. If
> STEP is nonzero, single-step it. If SIGNAL is nonzero, give it
> @@ -344,7 +349,13 @@ inf_ptrace_target::resume (ptid_t ptid, int step, enum gdb_signal signal)
> single-threaded processes, so simply resume the inferior. */
> pid = inferior_ptid.pid ();
> else
> - pid = get_ptrace_pid (ptid);
> + {
> +#ifdef __NetBSD__
> + pid = ptid. pid();
> +#else
> + pid = get_ptrace_pid (ptid);
> +#endif
> + }

To avoid the ifdefs in this more complex code, can't you use a gdb_ptrace function like in
the other patches? This time, it would look like:

static int
gdb_ptrace (PTRACE_TYPE_ARG1 request, ptid_t ptid, PTRACE_TYPE_ARG3 addr,
PTRACE_TYPE_ARG4 data)
{
#ifdef __NetBSD__
return ptrace (request, ptid.pid (), addr, data);
#else
pid_t pid = get_ptrace_pid (ptid);
return ptrace (request, pid, addr, data);
#endif
}

Simon