Re: make inferior calls work on ia64 even when syscall is pending

[David Mosberger <davidm@napali.hpl.hp.com>]

>>>>> On Fri, 13 Feb 2004 10:12:21 -0500, Andrew Cagney <cagney@gnu.org> said:

  >> Looks good, except for the "extern" function proptotypes.  But I
  >> guess we can't blame you for following the bad example set by
  >> ia64-tdep.c.

  Andrew> Fixing, that by creating "ia64-tdep.h", is "obvious".

Oh, man, you do know how to suck me into doing extra work...

How is this one?  Caveat: I know nothing about the gdb build
environment, so someone may want to double-check the Makefile changes.

Thanks,

	--david

ChangeLog

2004-02-13  David Mosberger  <davidm@hpl.hp.com>

	* Makefile.in (ia64_tdep_h): New macro.
	(ia64-linux-tdep.o): Mention $(ia64_tdep_h).
	(ia64-tdep.o): Likewise.

	* ia64-tdep.h (ia64_linux_write_pc): New file.
	* ia64-tdep.c: Update copyright notice.
	Include "ia64-tdep.h".
	(ia64_linux_sigcontext_register_address): Move decl to ia64-tdep.h.
	(ia64_aix_sigcontext_register_address): Likewise.
	(ia64_linux_getunwind_table): Likewise.
	* ia64-linux-tdep.c: Likewise.
	Include "regcache.h" to get write_register_pid() declared.

2004-02-12  David Mosberger  <davidm@hpl.hp.com>

	* ia64-tdep.c (ia64_linux_write_pc): Declare as extern.
	(ia64_write_pc): Make it a global function.
	(ia64_gdbarch_init): For Linux targets, use ia64_linux_write_pc()
	instead of ia64_write_pc().

	* ia64-linux-tdep.c (ia64_write_pc): Declare as extern.
	(ia64_linux_write_pc): New function.  Works like ia64_write_pc(),
	except that it also clears r10 afterwards to prevent the kernel
	from attempting to restart an interrupt system call.

Index: Makefile.in
--- Makefile.in
+++ Makefile.in
@@ -683,6 +683,7 @@
 i386_linux_tdep_h = i386-linux-tdep.h
 i386_tdep_h = i386-tdep.h
 i387_tdep_h = i387-tdep.h
+ia64_tdep_h = ia64-tdep.h
 infcall_h = infcall.h
 inferior_h = inferior.h $(breakpoint_h) $(target_h) $(frame_h)
 inf_loop_h = inf-loop.h
@@ -1916,13 +1917,14 @@
 ia64-aix-tdep.o: ia64-aix-tdep.c $(defs_h)
 ia64-linux-nat.o: ia64-linux-nat.c $(defs_h) $(gdb_string_h) $(inferior_h) \
 	$(target_h) $(gdbcore_h) $(regcache_h) $(gdb_wait_h) $(gregset_h)
-ia64-linux-tdep.o: ia64-linux-tdep.c $(defs_h) $(arch_utils_h) $(gdbcore_h)
+ia64-linux-tdep.o: ia64-linux-tdep.c $(defs_h) $(arch_utils_h) $(gdbcore_h) \
+	$(ia64_tdep_h)
 ia64-tdep.o: ia64-tdep.c $(defs_h) $(inferior_h) $(symfile_h) $(gdbcore_h) \
 	$(arch_utils_h) $(floatformat_h) $(regcache_h) $(reggroups_h) \
 	$(frame_h) $(frame_base_h) $(frame_unwind_h) $(doublest_h) \
 	$(value_h) $(gdb_assert_h) $(objfiles_h) $(elf_common_h) \
 	$(elf_bfd_h) $(elf_h) $(dis_asm_h) $(libunwind_frame_h) \
-	$(libunwind_ia64_h)
+	$(libunwind_ia64_h) $(ia64_tdep_h)
 infcall.o: infcall.c $(defs_h) $(breakpoint_h) $(target_h) $(regcache_h) \
 	$(inferior_h) $(gdb_assert_h) $(block_h) $(gdbcore_h) $(language_h) \
 	$(symfile_h) $(gdbcmd_h) $(command_h) $(gdb_string_h) $(infcall_h)
Index: ia64-linux-tdep.c
--- ia64-linux-tdep.c
+++ ia64-linux-tdep.c
@@ -20,8 +20,10 @@
    Boston, MA 02111-1307, USA.  */
 
 #include "defs.h"
+#include "ia64-tdep.h"
 #include "arch-utils.h"
 #include "gdbcore.h"
+#include "regcache.h"
 
 /* The sigtramp code is in a non-readable (executable-only) region
    of memory called the ``gate page''.  The addresses in question
@@ -93,3 +95,20 @@
 	return 0;
       }
 }
+
+void
+ia64_linux_write_pc (CORE_ADDR pc, ptid_t ptid)
+{
+  ia64_write_pc (pc, ptid);
+
+  /* We must be careful with modifying the instruction-pointer: if we
+     just interrupt a system call, the kernel would ordinarily try to
+     restart it when we resume the inferior, which typically results
+     in SIGSEGV or SIGILL.  We prevent this by clearing r10, which
+     will tell the kernel that r8 does NOT contain a valid error code
+     and hence it will skip system-call restart.
+
+     The clearing of r10 is safe as long as ia64_write_pc() is only
+     called as part of setting up an inferior call.  */
+  write_register_pid (IA64_GR10_REGNUM, 0, ptid);
+}
Index: ia64-tdep.c
--- ia64-tdep.c
+++ ia64-tdep.c
@@ -1,6 +1,6 @@
 /* Target-dependent code for the IA-64 for GDB, the GNU debugger.
 
-   Copyright 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+   Copyright 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -38,6 +38,7 @@
 #include "elf-bfd.h"
 #include "elf.h"                /* for PT_IA64_UNWIND value */
 #include "dis-asm.h"
+#include "ia64-tdep.h"
 
 #ifdef HAVE_LIBUNWIND_IA64_H
 #include "libunwind-frame.h"
@@ -90,11 +91,6 @@
 
 #define BUNDLE_LEN 16
 
-/* FIXME: These extern declarations should go in ia64-tdep.h.  */
-extern CORE_ADDR ia64_linux_sigcontext_register_address (CORE_ADDR, int);
-extern CORE_ADDR ia64_aix_sigcontext_register_address (CORE_ADDR, int);
-extern unsigned long ia64_linux_getunwind_table (void *, size_t);
-
 static gdbarch_init_ftype ia64_gdbarch_init;
 
 static gdbarch_register_name_ftype ia64_register_name;
@@ -632,7 +628,7 @@
   return pc_value | (slot_num * SLOT_MULTIPLIER);
 }
 
-static void
+void
 ia64_write_pc (CORE_ADDR new_pc, ptid_t ptid)
 {
   int slot_num = (int) (new_pc & 0xf) / SLOT_MULTIPLIER;
@@ -3339,7 +3343,10 @@
   set_gdbarch_memory_remove_breakpoint (gdbarch, ia64_memory_remove_breakpoint);
   set_gdbarch_breakpoint_from_pc (gdbarch, ia64_breakpoint_from_pc);
   set_gdbarch_read_pc (gdbarch, ia64_read_pc);
-  set_gdbarch_write_pc (gdbarch, ia64_write_pc);
+  if (info.osabi == GDB_OSABI_LINUX)
+    set_gdbarch_write_pc (gdbarch, ia64_linux_write_pc);
+  else
+    set_gdbarch_write_pc (gdbarch, ia64_write_pc);
 
   /* Settings for calling functions in the inferior.  */
   set_gdbarch_push_dummy_call (gdbarch, ia64_push_dummy_call);
Index: ia64-tdep.h
--- /dev/null
+++ ia64-tdep.h
@@ -0,0 +1,32 @@
+/* Target-dependent code for the ia64.
+
+   Copyright 2004
+   Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#ifndef IA64_TDEP_H
+#define IA64_TDEP_H
+
+extern CORE_ADDR ia64_linux_sigcontext_register_address (CORE_ADDR, int);
+extern CORE_ADDR ia64_aix_sigcontext_register_address (CORE_ADDR, int);
+extern unsigned long ia64_linux_getunwind_table (void *, size_t);
+extern void ia64_write_pc (CORE_ADDR, ptid_t);
+extern void ia64_linux_write_pc (CORE_ADDR, ptid_t);
+
+#endif /* IA64_TDEP_H */