Add support for NetBSD threads in i386-bsd-nat.c

NetBSD ptrace(2) accepts thread id (LWP) as the 4th argument for threads.

Define gdb_ptrace() a wrapper function for ptrace(2) that properly passes
the pid,lwp pair on NetBSD and the result of get_ptrace_pid() for others.

gdb/ChangeLog:

	* i386-bsd-nat.c (gdb_ptrace): New.
	* (i386bsd_fetch_inferior_registers,
	i386bsd_store_inferior_registers) Switch from pid_t to ptid_t.
	* (i386bsd_fetch_inferior_registers,
	i386bsd_store_inferior_registers) Use gdb_ptrace.

2 files changed, 50 insertions, 21 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index f4f7b79..a89267f 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,13 @@
 2020-03-17  Kamil Rytarowski  <n54@gmx.com>
 
+	* i386-bsd-nat.c (gdb_ptrace): New.
+	* (i386bsd_fetch_inferior_registers,
+	i386bsd_store_inferior_registers) Switch from pid_t to ptid_t.
+	* (i386bsd_fetch_inferior_registers,
+	i386bsd_store_inferior_registers) Use gdb_ptrace.
+
+2020-03-17  Kamil Rytarowski  <n54@gmx.com>
+
 	* amd64-bsd-nat.c (gdb_ptrace): New.
 	* (amd64bsd_fetch_inferior_registers,
 	amd64bsd_store_inferior_registers) Switch from pid_t to ptid_t.
diff --git a/gdb/i386-bsd-nat.c b/gdb/i386-bsd-nat.c
index 4e22013..3250dab 100644
--- a/gdb/i386-bsd-nat.c
+++ b/gdb/i386-bsd-nat.c
@@ -34,6 +34,21 @@
 #include "inf-ptrace.h"
 
 
+static int
+gdb_ptrace (PTRACE_TYPE_ARG1 request, ptid_t ptid, PTRACE_TYPE_ARG3 addr,
+	    PTRACE_TYPE_ARG4 data)
+{
+#ifdef __NetBSD__
+  gdb_assert (data == 0);
+  /* Support for NetBSD threads: unlike other ptrace implementations in this
+     file, NetBSD requires that we pass both the pid and lwp.  */
+  return ptrace (request, ptid.pid (), addr, ptid.lwp ());
+#else
+  pid_t pid = get_ptrace_pid (ptid);
+  return ptrace (request, pid, addr, data);
+#endif
+}
+
 /* In older BSD versions we cannot get at some of the segment
    registers.  FreeBSD for example didn't support the %fs and %gs
    registers until the 3.0 release.  We have autoconf checks for their
@@ -130,13 +145,13 @@ i386bsd_collect_gregset (const struct regcache *regcache,
 void
 i386bsd_fetch_inferior_registers (struct regcache *regcache, int regnum)
 {
-  pid_t pid = get_ptrace_pid (regcache->ptid ());
+  ptid_t ptid = regcache->ptid ();
 
   if (regnum == -1 || GETREGS_SUPPLIES (regnum))
     {
       struct reg regs;
 
-      if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
+      if (gdb_ptrace (PT_GETREGS, ptid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
 	perror_with_name (_("Couldn't get registers"));
 
       i386bsd_supply_gregset (regcache, &regs);
@@ -149,7 +164,7 @@ i386bsd_fetch_inferior_registers (struct regcache *regcache, int regnum)
     {
       register_t base;
 
-      if (ptrace (PT_GETFSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
+      if (gdb_ptrace (PT_GETFSBASE, ptid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
 	perror_with_name (_("Couldn't get segment register fs_base"));
 
       regcache->raw_supply (I386_FSBASE_REGNUM, &base);
@@ -162,7 +177,7 @@ i386bsd_fetch_inferior_registers (struct regcache *regcache, int regnum)
     {
       register_t base;
 
-      if (ptrace (PT_GETGSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
+      if (gdb_ptrace (PT_GETGSBASE, ptid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
 	perror_with_name (_("Couldn't get segment register gs_base"));
 
       regcache->raw_supply (I386_GSBASE_REGNUM, &base);
@@ -184,8 +199,8 @@ i386bsd_fetch_inferior_registers (struct regcache *regcache, int regnum)
 	  void *xstateregs;
 
 	  xstateregs = alloca (x86bsd_xsave_len);
-	  if (ptrace (PT_GETXSTATE, pid,
-		      (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
+	  if (gdb_ptrace (PT_GETXSTATE, ptid,
+			  (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
 	    perror_with_name (_("Couldn't get extended state status"));
 
 	  i387_supply_xsave (regcache, -1, xstateregs);
@@ -195,7 +210,8 @@ i386bsd_fetch_inferior_registers (struct regcache *regcache, int regnum)
       
 #ifdef HAVE_PT_GETXMMREGS
       if (have_ptrace_xmmregs != 0
-	  && ptrace(PT_GETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, 0) == 0)
+	  && gdb_ptrace(PT_GETXMMREGS, ptid,
+			(PTRACE_TYPE_ARG3) xmmregs, 0) == 0)
 	{
 	  have_ptrace_xmmregs = 1;
 	  i387_supply_fxsave (regcache, -1, xmmregs);
@@ -204,7 +220,8 @@ i386bsd_fetch_inferior_registers (struct regcache *regcache, int regnum)
 	{
 	  have_ptrace_xmmregs = 0;
 #endif
-          if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
+          if (gdb_ptrace (PT_GETFPREGS, ptid,
+			  (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 	    perror_with_name (_("Couldn't get floating point status"));
 
 	  i387_supply_fsave (regcache, -1, &fpregs);
@@ -220,18 +237,18 @@ i386bsd_fetch_inferior_registers (struct regcache *regcache, int regnum)
 void
 i386bsd_store_inferior_registers (struct regcache *regcache, int regnum)
 {
-  pid_t pid = get_ptrace_pid (regcache->ptid ());
+  ptid_t ptid = regcache->ptid ();
 
   if (regnum == -1 || GETREGS_SUPPLIES (regnum))
     {
       struct reg regs;
 
-      if (ptrace (PT_GETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
+      if (gdb_ptrace (PT_GETREGS, ptid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
         perror_with_name (_("Couldn't get registers"));
 
       i386bsd_collect_gregset (regcache, &regs, regnum);
 
-      if (ptrace (PT_SETREGS, pid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
+      if (gdb_ptrace (PT_SETREGS, ptid, (PTRACE_TYPE_ARG3) &regs, 0) == -1)
         perror_with_name (_("Couldn't write registers"));
 
       if (regnum != -1)
@@ -245,7 +262,7 @@ i386bsd_store_inferior_registers (struct regcache *regcache, int regnum)
 
       regcache->raw_collect (I386_FSBASE_REGNUM, &base);
 
-      if (ptrace (PT_SETFSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
+      if (gdb_ptrace (PT_SETFSBASE, ptid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
 	perror_with_name (_("Couldn't write segment register fs_base"));
       if (regnum != -1)
 	return;
@@ -258,7 +275,7 @@ i386bsd_store_inferior_registers (struct regcache *regcache, int regnum)
 
       regcache->raw_collect (I386_GSBASE_REGNUM, &base);
 
-      if (ptrace (PT_SETGSBASE, pid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
+      if (gdb_ptrace (PT_SETGSBASE, ptid, (PTRACE_TYPE_ARG3) &base, 0) == -1)
 	perror_with_name (_("Couldn't write segment register gs_base"));
       if (regnum != -1)
 	return;
@@ -278,14 +295,14 @@ i386bsd_store_inferior_registers (struct regcache *regcache, int regnum)
 	  void *xstateregs;
 
 	  xstateregs = alloca (x86bsd_xsave_len);
-	  if (ptrace (PT_GETXSTATE, pid,
-		      (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
+	  if (gdb_ptrace (PT_GETXSTATE, ptid,
+			  (PTRACE_TYPE_ARG3) xstateregs, 0) == -1)
 	    perror_with_name (_("Couldn't get extended state status"));
 
 	  i387_collect_xsave (regcache, -1, xstateregs, 0);
 
-	  if (ptrace (PT_SETXSTATE, pid,
-		      (PTRACE_TYPE_ARG3) xstateregs, x86bsd_xsave_len) == -1)
+	  if (gdb_ptrace (PT_SETXSTATE, ptid, (PTRACE_TYPE_ARG3) xstateregs,
+			  x86bsd_xsave_len) == -1)
 	    perror_with_name (_("Couldn't write extended state status"));
 	  return;
 	}
@@ -293,25 +310,29 @@ i386bsd_store_inferior_registers (struct regcache *regcache, int regnum)
 
 #ifdef HAVE_PT_GETXMMREGS
       if (have_ptrace_xmmregs != 0
-	  && ptrace(PT_GETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, 0) == 0)
+	  && gdb_ptrace(PT_GETXMMREGS, ptid,
+			(PTRACE_TYPE_ARG3) xmmregs, 0) == 0)
 	{
 	  have_ptrace_xmmregs = 1;
 
 	  i387_collect_fxsave (regcache, regnum, xmmregs);
 
-	  if (ptrace (PT_SETXMMREGS, pid, (PTRACE_TYPE_ARG3) xmmregs, 0) == -1)
+	  if (gdb_ptrace (PT_SETXMMREGS, ptid,
+			  (PTRACE_TYPE_ARG3) xmmregs, 0) == -1)
             perror_with_name (_("Couldn't write XMM registers"));
 	}
       else
 	{
 	  have_ptrace_xmmregs = 0;
 #endif
-          if (ptrace (PT_GETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
+          if (gdb_ptrace (PT_GETFPREGS, ptid,
+			  (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 	    perror_with_name (_("Couldn't get floating point status"));
 
           i387_collect_fsave (regcache, regnum, &fpregs);
 
-          if (ptrace (PT_SETFPREGS, pid, (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
+          if (gdb_ptrace (PT_SETFPREGS, ptid,
+			  (PTRACE_TYPE_ARG3) &fpregs, 0) == -1)
 	    perror_with_name (_("Couldn't write floating point status"));
 #ifdef HAVE_PT_GETXMMREGS
         }