Re: [PATCH] Disable get_ptrace_pid for NetBSD

[Kamil Rytarowski <n54@gmx.com>]

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On 18.03.2020 22:49, 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.
> 

There is is one bug.

I'm going to fix and submit a new version.

> gdb/ChangeLog:
> 
> 	* inf-ptrace.h: Disable get_ptrace_pid on NetBSD.
> 	* inf-ptrace.c: Likewise.
> 	* (gdb_ptrace): Add.
> 	* (inf_ptrace_target::resume): Update.
> 	* (inf_ptrace_target::xfer_partial): Likewise.
> ---
>  gdb/ChangeLog    |  8 ++++++++
>  gdb/inf-ptrace.c | 32 +++++++++++++++++++++++---------
>  gdb/inf-ptrace.h |  2 ++
>  3 files changed, 33 insertions(+), 9 deletions(-)
> 
> diff --git a/gdb/ChangeLog b/gdb/ChangeLog
> index 84964dc00ac..406414cee76 100644
> --- a/gdb/ChangeLog
> +++ b/gdb/ChangeLog
> @@ -1,3 +1,11 @@
> +2020-03-18  Kamil Rytarowski  <n54@gmx.com>
> +
> +	* inf-ptrace.h: Disable get_ptrace_pid on NetBSD.
> +	* inf-ptrace.c: Likewise.
> +	* (gdb_ptrace): Add.
> +	* (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..304a749f3f3 100644
> --- a/gdb/inf-ptrace.c
> +++ b/gdb/inf-ptrace.c
> @@ -37,6 +37,18 @@
> 
>  \f
> 
> +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
> +}
> +
>  /* A unique_ptr helper to unpush a target.  */
> 
>  struct target_unpusher
> @@ -313,8 +325,12 @@ 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 +344,7 @@ 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
> @@ -336,15 +353,12 @@ get_ptrace_pid (ptid_t ptid)
>  void
>  inf_ptrace_target::resume (ptid_t ptid, int step, enum gdb_signal signal)
>  {
> -  pid_t pid;
>    int request;
> 
>    if (minus_one_ptid == ptid)
>      /* Resume all threads.  Traditionally ptrace() only supports
>         single-threaded processes, so simply resume the inferior.  */
> -    pid = inferior_ptid.pid ();
> -  else
> -    pid = get_ptrace_pid (ptid);
> +    ptid = inferior_ptid;
> 
>    if (catch_syscall_enabled () > 0)
>      request = PT_SYSCALL;
> @@ -365,7 +379,7 @@ inf_ptrace_target::resume (ptid_t ptid, int step, enum gdb_signal signal)
>       where it was.  If GDB wanted it to start some other way, we have
>       already written a new program counter value to the child.  */
>    errno = 0;
> -  ptrace (request, pid, (PTRACE_TYPE_ARG3)1, gdb_signal_to_host (signal));
> +  gdb_ptrace (request, ptid, (PTRACE_TYPE_ARG3)1, gdb_signal_to_host (signal));
>    if (errno != 0)
>      perror_with_name (("ptrace"));
>  }
> @@ -528,7 +542,7 @@ inf_ptrace_target::xfer_partial (enum target_object object,
>  				 const gdb_byte *writebuf,
>  				 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
>  {
> -  pid_t pid = get_ptrace_pid (inferior_ptid);
> +  ptid_t ptid = inferior_ptid;
> 
>    switch (object)
>      {
> @@ -552,7 +566,7 @@ inf_ptrace_target::xfer_partial (enum target_object object,
>  	piod.piod_len = len;
> 
>  	errno = 0;
> -	if (ptrace (PT_IO, pid, (caddr_t)&piod, 0) == 0)
> +	if (gdb_ptrace (PT_IO, ptid, (caddr_t)&piod, 0) == 0)
>  	  {
>  	    /* Return the actual number of bytes read or written.  */
>  	    *xfered_len = piod.piod_len;
> @@ -588,7 +602,7 @@ inf_ptrace_target::xfer_partial (enum target_object object,
>  	piod.piod_len = len;
> 
>  	errno = 0;
> -	if (ptrace (PT_IO, pid, (caddr_t)&piod, 0) == 0)
> +	if (gdb_ptrace (PT_IO, ptid, (caddr_t)&piod, 0) == 0)
>  	  {
>  	    /* Return the actual number of bytes read or written.  */
>  	    *xfered_len = piod.piod_len;
> diff --git a/gdb/inf-ptrace.h b/gdb/inf-ptrace.h
> index dd0733736f2..340d41d8beb 100644
> --- a/gdb/inf-ptrace.h
> +++ b/gdb/inf-ptrace.h
> @@ -78,9 +78,11 @@ struct inf_ptrace_target : public inf_child_target
>    void detach_success (inferior *inf);
>  };
> 
> +#ifndef __NetBSD__
>  /* Return which PID to pass to ptrace in order to observe/control the
>     tracee identified by PTID.  */
> 
>  extern pid_t get_ptrace_pid (ptid_t);
> +#endif
> 
>  #endif
> --
> 2.25.0
> 



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