Fix s390 GNU/Linux build after enum __ptrace_request changes

The buildbot noticed that the enum __ptrace_request series broke the
s390 GNU/Linux build:

../../binutils-gdb/gdb/s390-linux-nat.c: In function 'fetch_regs':
../../binutils-gdb/gdb/s390-linux-nat.c:226:54: error: macro "ptrace" requires 4 arguments, but only 3 given
   if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea) < 0)
                                                      ^
../../binutils-gdb/gdb/s390-linux-nat.c: In function 'store_regs':
../../binutils-gdb/gdb/s390-linux-nat.c:243:54: error: macro "ptrace" requires 4 arguments, but only 3 given
   if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea) < 0)
                                                      ^

Fix this the same way it's handled everywhere else -- just pass 0 as
forth argument, which also handles non-varargs ptrace prototypes in
non-glibc libcs, e.g., Bionic (if it ever gets a s390 port...).

gdb/ChangeLog:
2015-07-24  Pedro Alves  <palves@redhat.com>

	* s390-linux-nat.c (fetch_regs, store_regs, fetch_fpregs)
	(s390_stopped_by_watchpoint, s390_prepare_to_resume): Pass 0 as
	forth argument to ptrace PTRACE_PEEKUSR_AREA/PTRACE_POKEUSR_AREA.

2 files changed, 16 insertions, 10 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index b781698..0061bff 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,11 @@
 2015-07-24  Pedro Alves  <palves@redhat.com>
 
+	* s390-linux-nat.c (fetch_regs, store_regs, fetch_fpregs)
+	(s390_stopped_by_watchpoint, s390_prepare_to_resume): Pass 0 as
+	forth argument to ptrace PTRACE_PEEKUSR_AREA/PTRACE_POKEUSR_AREA.
+
+2015-07-24  Pedro Alves  <palves@redhat.com>
+
 	PR gdb/18717
 	* linux-nat.c (linux_nat_filter_event): Don't assert that the lwp
 	is resumed, and extend the debug log.
diff --git a/gdb/s390-linux-nat.c b/gdb/s390-linux-nat.c
index 94edce8..360d761 100644
--- a/gdb/s390-linux-nat.c
+++ b/gdb/s390-linux-nat.c
@@ -223,7 +223,7 @@ fetch_regs (struct regcache *regcache, int tid)
   parea.len = sizeof (regs);
   parea.process_addr = (addr_t) &regs;
   parea.kernel_addr = offsetof (struct user_regs_struct, psw);
-  if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea) < 0)
+  if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea, 0) < 0)
     perror_with_name (_("Couldn't get registers"));
 
   supply_gregset (regcache, (const gregset_t *) &regs);
@@ -240,12 +240,12 @@ store_regs (const struct regcache *regcache, int tid, int regnum)
   parea.len = sizeof (regs);
   parea.process_addr = (addr_t) &regs;
   parea.kernel_addr = offsetof (struct user_regs_struct, psw);
-  if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea) < 0)
+  if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea, 0) < 0)
     perror_with_name (_("Couldn't get registers"));
 
   fill_gregset (regcache, &regs, regnum);
 
-  if (ptrace (PTRACE_POKEUSR_AREA, tid, (long) &parea) < 0)
+  if (ptrace (PTRACE_POKEUSR_AREA, tid, (long) &parea, 0) < 0)
     perror_with_name (_("Couldn't write registers"));
 }
 
@@ -260,7 +260,7 @@ fetch_fpregs (struct regcache *regcache, int tid)
   parea.len = sizeof (fpregs);
   parea.process_addr = (addr_t) &fpregs;
   parea.kernel_addr = offsetof (struct user_regs_struct, fp_regs);
-  if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea) < 0)
+  if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea, 0) < 0)
     perror_with_name (_("Couldn't get floating point status"));
 
   supply_fpregset (regcache, (const fpregset_t *) &fpregs);
@@ -277,12 +277,12 @@ store_fpregs (const struct regcache *regcache, int tid, int regnum)
   parea.len = sizeof (fpregs);
   parea.process_addr = (addr_t) &fpregs;
   parea.kernel_addr = offsetof (struct user_regs_struct, fp_regs);
-  if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea) < 0)
+  if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea, 0) < 0)
     perror_with_name (_("Couldn't get floating point status"));
 
   fill_fpregset (regcache, &fpregs, regnum);
 
-  if (ptrace (PTRACE_POKEUSR_AREA, tid, (long) &parea) < 0)
+  if (ptrace (PTRACE_POKEUSR_AREA, tid, (long) &parea, 0) < 0)
     perror_with_name (_("Couldn't write floating point status"));
 }
 
@@ -459,7 +459,7 @@ s390_stopped_by_watchpoint (struct target_ops *ops)
   parea.len = sizeof (per_lowcore);
   parea.process_addr = (addr_t) & per_lowcore;
   parea.kernel_addr = offsetof (struct user_regs_struct, per_info.lowcore);
-  if (ptrace (PTRACE_PEEKUSR_AREA, s390_inferior_tid (), &parea) < 0)
+  if (ptrace (PTRACE_PEEKUSR_AREA, s390_inferior_tid (), &parea, 0) < 0)
     perror_with_name (_("Couldn't retrieve watchpoint status"));
 
   result = (per_lowcore.perc_storage_alteration == 1
@@ -469,7 +469,7 @@ s390_stopped_by_watchpoint (struct target_ops *ops)
     {
       /* Do not report this watchpoint again.  */
       memset (&per_lowcore, 0, sizeof (per_lowcore));
-      if (ptrace (PTRACE_POKEUSR_AREA, s390_inferior_tid (), &parea) < 0)
+      if (ptrace (PTRACE_POKEUSR_AREA, s390_inferior_tid (), &parea, 0) < 0)
 	perror_with_name (_("Couldn't clear watchpoint status"));
     }
 
@@ -508,7 +508,7 @@ s390_prepare_to_resume (struct lwp_info *lp)
   parea.len = sizeof (per_info);
   parea.process_addr = (addr_t) & per_info;
   parea.kernel_addr = offsetof (struct user_regs_struct, per_info);
-  if (ptrace (PTRACE_PEEKUSR_AREA, tid, &parea) < 0)
+  if (ptrace (PTRACE_PEEKUSR_AREA, tid, &parea, 0) < 0)
     perror_with_name (_("Couldn't retrieve watchpoint status"));
 
   if (watch_base)
@@ -524,7 +524,7 @@ s390_prepare_to_resume (struct lwp_info *lp)
   per_info.starting_addr = watch_lo_addr;
   per_info.ending_addr = watch_hi_addr;
 
-  if (ptrace (PTRACE_POKEUSR_AREA, tid, &parea) < 0)
+  if (ptrace (PTRACE_POKEUSR_AREA, tid, &parea, 0) < 0)
     perror_with_name (_("Couldn't modify watchpoint status"));
 }