[PATCH] Disable get_ptrace_pid for NetBSD

[Kamil Rytarowski <n54@gmx.com>]

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.
	* (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