gdbserver support for Linux on sparc64

[Daniel Gutson <dgutson at codesourcery dot com>]

Hi,
 this patch adds gdbserver support for sparc64 on Linux.

I was able to test a hello world application, placing breakpoints, do 
step-by-step, single stepping, and stepping into glibc calls.

Additionally, I ran the gdb dejagnu test suite, finding basically stuff 
that fails on sparc native or other gsbserver ports.

This patch provides 64-bits support only; v8plus is not supported, since 
it would have required bi-arch support, thus undesirably extending the 
change scope to gdb as well.
Background: v8plus is a 32-bits binary type that has some insns which 
modify the upper half of the 64-bits registers, therefore involving a 
32/64 variable size registers in terms of gdb/gdbserver communication.
Please refer to 
http://sourceware.org/ml/gdb-patches/2006-05/msg00268.html for further 
background information.

Watchpoints are not supported by this patch.
-------------

2008-10-31  Daniel Gutson  <dgutson@codesourcery.com>

      * configure.tgt (sparc64-*-linux*): added gdbserver support.

      * regformats/reg-sparc64.dat: New file.

      * gdbserver/Makefile.in (SFILES,CLEAN): Added sparc64 files.
      (reg-sparc64.o,reg-sparc64.c): New.

      * gdbserver/configure.srv (sparc*-*-linux*): New configuration.

      * gdbserver/linux-low.c (regsets_fetch_inferior_registers): 
ptrace syscall args.
      (regsets_store_inferior_registers): Likewise.

      * gdbserver/linux-sparc-low.c: New file.


--
Daniel Gutson

diff -Naurp gdb_original/configure.tgt gdb_dfg/configure.tgt
--- gdb_original/configure.tgt  2008-10-02 08:48:06.000000000 -0700
+++ gdb_dfg/configure.tgt       2008-10-28 11:32:22.000000000 -0700
@@ -411,6 +411,7 @@ sparc64-*-linux*)
        gdb_target_obs="sparc64-tdep.o sparc64-sol2-tdep.o sol2-tdep.o \
                        sparc64-linux-tdep.o sparc-tdep.o sparc-sol2-tdep.o \
                        sparc-linux-tdep.o solib.o solib-svr4.o"
+       build_gdbserver=yes
        ;;
 sparc*-*-freebsd* | sparc*-*-kfreebsd*-gnu)
        # Target: FreeBSD/sparc64
diff -Naurp gdb_original/gdbserver/configure.srv gdb_dfg/gdbserver/configure.srv
--- gdb_original/gdbserver/configure.srv	2008-09-04 10:05:24.000000000 -0700
+++ gdb_dfg/gdbserver/configure.srv	2008-10-28 11:35:28.000000000 -0700
@@ -139,6 +139,11 @@ case "${target}" in
 			srv_linux_regsets=yes
 			srv_linux_thread_db=yes
 			;;
+  sparc*-*-linux*)	srv_regobj=reg-sparc64.o
+			srv_tgtobj="linux-low.o linux-sparc-low.o"
+			srv_linux_regsets=yes
+			srv_linux_thread_db=yes
+			;;
   spu*-*-*)		srv_regobj=reg-spu.o
 			srv_tgtobj="spu-low.o"
 			;;
diff -Naurp gdb_original/gdbserver/linux-low.c gdb_dfg/gdbserver/linux-low.c
--- gdb_original/gdbserver/linux-low.c	2008-08-05 15:13:23.000000000 -0700
+++ gdb_dfg/gdbserver/linux-low.c	2008-10-28 11:35:28.000000000 -0700
@@ -1523,7 +1523,11 @@ regsets_fetch_inferior_registers ()
 	}
 
       buf = malloc (regset->size);
+#ifndef __sparc__
       res = ptrace (regset->get_request, inferior_pid, 0, buf);
+#else
+      res = ptrace (regset->get_request, inferior_pid, buf, 0);
+#endif
       if (res < 0)
 	{
 	  if (errno == EIO)
@@ -1576,7 +1580,11 @@ regsets_store_inferior_registers ()
       /* First fill the buffer with the current register set contents,
 	 in case there are any items in the kernel's regset that are
 	 not in gdbserver's regcache.  */
+#ifndef __sparc__
       res = ptrace (regset->get_request, inferior_pid, 0, buf);
+#else
+      res = ptrace (regset->get_request, inferior_pid, buf, 0);
+#endif
 
       if (res == 0)
 	{
@@ -1584,7 +1592,11 @@ regsets_store_inferior_registers ()
 	  regset->fill_function (buf);
 
 	  /* Only now do we write the register set.  */
-	  res = ptrace (regset->set_request, inferior_pid, 0, buf);
+#ifndef __sparc__
+          res = ptrace (regset->set_request, inferior_pid, 0, buf);
+#else
+          res = ptrace (regset->set_request, inferior_pid, buf, 0);
+#endif
 	}
 
       if (res < 0)
diff -Naurp gdb_original/gdbserver/linux-sparc-low.c gdb_dfg/gdbserver/linux-sparc-low.c
--- gdb_original/gdbserver/linux-sparc-low.c	1969-12-31 16:00:00.000000000 -0800
+++ gdb_dfg/gdbserver/linux-sparc-low.c	2008-10-28 11:35:28.000000000 -0700
@@ -0,0 +1,287 @@
+/* Low level interface to ptrace, for the remote server for GDB.
+   Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
+   2006, 2007, 2008 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 3 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, see <http://www.gnu.org/licenses/>.  */
+
+#include "server.h"
+#include "linux-low.h"
+
+#include <sys/ptrace.h>
+
+#include "gdb_proc_service.h"
+
+/* The stack pointer is offset from the stack frame by a BIAS of 2047
+   (0x7ff) for 64-bit code.  BIAS is likely to be defined on SPARC
+   hosts, so undefine it first.  */
+#undef BIAS
+#define BIAS 2047
+
+#ifdef HAVE_SYS_REG_H
+#include <sys/reg.h>
+#endif
+
+#define INSN_SIZE 4
+
+#define SPARC_R_REGS_NUM 32
+#define SPARC_F_REGS_NUM 48
+#define SPARC_CONTROL_REGS_NUM 6
+
+#define sparc_num_regs (SPARC_R_REGS_NUM + SPARC_F_REGS_NUM + SPARC_CONTROL_REGS_NUM)
+
+/* Each offset is multiplied by 8, because of the register size.
+   These offsets apply to the buffer sent/filled by ptrace.
+   Additionally, the array elements order corresponds to the .dat file, and the
+   gdb's registers enumeration order.  */
+
+static int sparc_regmap[] = {
+  /* These offsets correspond to GET/SETREGSET.  */
+         -1,  0*8,  1*8,  2*8,  3*8,  4*8,  5*8,  6*8, 	   /* g0 .. g7 */
+        7*8,  8*8,  9*8, 10*8, 11*8, 12*8, 13*8, 14*8,	   /* o0 .. o5, sp, o7 */
+         -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,     /* l0 .. l7 */
+         -1,   -1,   -1,   -1,   -1,   -1,   -1,   -1,     /* i0 .. i5, fp, i7 */
+
+  /* Floating point registers offsets correspond to GET/SETFPREGSET.  */
+    0*4,  1*4,  2*4,  3*4,  4*4,  5*4,  6*4,  7*4,	   /*  f0 ..  f7 */
+    8*4,  9*4, 10*4, 11*4, 12*4, 13*4, 14*4, 15*4,	   /*  f8 .. f15 */
+   16*4, 17*4, 18*4, 19*4, 20*4, 21*4, 22*4, 23*4,	   /* f16 .. f23 */
+   24*4, 25*4, 26*4, 27*4, 28*4, 29*4, 30*4, 31*4,	   /* f24 .. f31 */
+
+  /* F32 offset starts next to f31: 31*4+4 = 16 * 8.  */
+   16*8, 17*8, 18*8, 19*8, 20*8, 21*8, 22*8, 23*8, 	   /* f32 .. f46 */
+   24*8, 25*8, 26*8, 27*8, 28*8, 29*8, 30*8, 31*8, 	   /* f48 .. f62 */
+
+   17 *8, /*    pc */
+   18 *8, /*   npc */
+   16 *8, /* state */
+  /* FSR offset also corresponds to GET/SETFPREGSET, ans is placed next to f62.  */
+   32 *8, /*   fsr */
+      -1, /*  fprs */
+  /* Y register is 32-bits length, but gdb takes care of that.  */
+   19 *8, /*     y */
+
+};
+
+
+struct regs_range_t
+{
+  int regno_start;
+  int regno_end;
+};
+
+static const struct regs_range_t gregs_ranges[] = {
+ {  0, 31 }, /*   g0 .. i7  */
+ { 80, 82 }, /*   pc .. state */
+ { 84, 85 }  /* fprs .. y */
+};
+
+#define N_GREGS_RANGES (sizeof (gregs_ranges) / sizeof (struct regs_range_t))
+
+static const struct regs_range_t fpregs_ranges[] = {
+ { 32, 79 }, /* f0 .. f62  */
+ { 83, 83 }  /* fsr */
+};
+
+#define N_FPREGS_RANGES (sizeof (fpregs_ranges) / sizeof (struct regs_range_t))
+
+/* Defined in auto-generated file reg-sparc64.c.  */
+void init_registers_sparc64 (void);
+
+static int
+sparc_cannot_store_register (int regno)
+{
+  return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
+}
+
+static int
+sparc_cannot_fetch_register (int regno)
+{
+  return (regno >= sparc_num_regs || sparc_regmap[regno] == -1);
+}
+
+static void
+sparc_fill_gregset_to_stack (const void *buf)
+{
+  int i;
+  CORE_ADDR addr = 0;
+  unsigned char tmp_reg_buf[8];
+  const int l0_regno = find_regno("l0");
+  const int i7_regno = l0_regno + 15;
+
+  /* These registers have to be stored in the stack.  */
+  memcpy(&addr, ((char *) buf) + sparc_regmap[find_regno("sp")], sizeof(addr));
+
+  addr += BIAS;
+  
+  for (i = l0_regno; i <= i7_regno; i++)
+    {
+      collect_register (i, tmp_reg_buf);
+      (*the_target->write_memory) (addr, tmp_reg_buf, sizeof(tmp_reg_buf));
+      addr += sizeof(tmp_reg_buf);
+    }
+}
+
+static void
+sparc_fill_gregset (void *buf)
+{
+  int i;
+  int range;
+  
+  for (range = 0; range < N_GREGS_RANGES; range++)
+    for (i = gregs_ranges[range].regno_start; i <= gregs_ranges[range].regno_end; i++)
+      if (sparc_regmap[i] != -1)
+        collect_register (i, ((char *) buf) + sparc_regmap[i]);
+      
+  sparc_fill_gregset_to_stack (buf);
+}
+
+static void
+sparc_fill_fpregset (void *buf)
+{
+  int i;
+  int range;
+  
+  for (range = 0; range < N_FPREGS_RANGES; range++)
+    for (i = fpregs_ranges[range].regno_start; i <= fpregs_ranges[range].regno_end; i++)
+      collect_register (i, ((char *) buf) + sparc_regmap[i]);
+      
+}
+
+static void
+sparc_store_gregset_from_stack (const void *buf)
+{
+  int i;
+  CORE_ADDR addr = 0;
+  unsigned char tmp_reg_buf[8];
+  const int l0_regno = find_regno("l0");
+  const int i7_regno = l0_regno + 15;
+
+  /* These registers have to be obtained from the stack.  */
+  memcpy(&addr, ((char *) buf) + sparc_regmap[find_regno("sp")], sizeof(addr));
+
+  addr += BIAS;
+  
+  for (i = l0_regno; i <= i7_regno; i++)
+    {
+      (*the_target->read_memory) (addr, tmp_reg_buf, sizeof(tmp_reg_buf));
+      supply_register (i, tmp_reg_buf);
+      addr += sizeof(tmp_reg_buf);
+    }
+}
+
+static void
+sparc_store_gregset (const void *buf)
+{
+  int i;
+  char zerobuf[8];
+  int range;
+
+  memset (zerobuf, 0, sizeof(zerobuf));
+  
+  for (range = 0; range < N_GREGS_RANGES; range++)
+    for (i = gregs_ranges[range].regno_start; i <= gregs_ranges[range].regno_end; i++)
+      if (sparc_regmap[i] != -1)
+        supply_register (i, ((char *) buf) + sparc_regmap[i]);
+      else
+        supply_register (i, zerobuf);
+      
+  sparc_store_gregset_from_stack (buf);
+}
+
+static void
+sparc_store_fpregset (const void *buf)
+{
+  int i;
+  int range;
+  
+  for (range = 0; range < N_FPREGS_RANGES; range++)
+    for (i = fpregs_ranges[range].regno_start; i <= fpregs_ranges[range].regno_end; i++)
+      supply_register (i, ((char *) buf) + sparc_regmap[i]);
+}
+
+extern int debug_threads;
+
+static CORE_ADDR
+sparc_get_pc ()
+{
+  CORE_ADDR pc;
+  collect_register_by_name ("pc", &pc);
+  if (debug_threads)
+    fprintf (stderr, "stop pc is %08lx\n", pc);
+  return pc;
+}
+
+static const unsigned char sparc_breakpoint[INSN_SIZE] = { 0x91, 0xd0, 0x20, 0x01 };
+#define sparc_breakpoint_len INSN_SIZE
+
+
+static int
+sparc_breakpoint_at (CORE_ADDR where)
+{
+  unsigned char insn[INSN_SIZE];
+
+  (*the_target->read_memory) (where, (unsigned char *) insn, sizeof(insn));
+  
+  if (memcmp(sparc_breakpoint, insn, sizeof(insn)) == 0)
+    return 1;
+
+  /* If necessary, recognize more trap instructions here.  GDB only uses TRAP Always.  */
+
+  return 0;
+}
+
+/* We only place breakpoints in empty marker functions, and thread locking
+   is outside of the function.  So rather than importing software single-step,
+   we can just run until exit.  */
+static CORE_ADDR
+sparc_reinsert_addr ()
+{
+  CORE_ADDR lr;
+  /* O7 is the equivalent to the 'lr' of other archs.  */
+  collect_register_by_name ("o7", &lr);
+  return lr;
+}
+
+
+struct regset_info target_regsets[] = {
+  { PTRACE_GETREGS, PTRACE_SETREGS, sizeof (elf_gregset_t),
+    GENERAL_REGS,
+    sparc_fill_gregset, sparc_store_gregset },
+  { PTRACE_GETFPREGS, PTRACE_SETFPREGS, sizeof (fpregset_t),
+    FP_REGS,
+    sparc_fill_fpregset, sparc_store_fpregset },
+  { 0, 0, -1, -1, NULL, NULL }
+};
+
+struct linux_target_ops the_low_target = {
+  init_registers_sparc64,
+  sparc_num_regs,
+  /* No regmap needs to be provided since this impl. doesn't use USRREGS.  */
+  NULL,
+  sparc_cannot_fetch_register,
+  sparc_cannot_store_register,
+  sparc_get_pc,
+  /* No sparc_set_pc is needed.  */
+  NULL,
+  (const unsigned char *) sparc_breakpoint,
+  sparc_breakpoint_len,
+  sparc_reinsert_addr,
+  0,
+  sparc_breakpoint_at,
+  NULL, NULL, NULL, NULL,
+  NULL, NULL
+};
+
diff -Naurp gdb_original/gdbserver/Makefile.in gdb_dfg/gdbserver/Makefile.in
--- gdb_original/gdbserver/Makefile.in	2008-10-21 14:22:53.000000000 -0700
+++ gdb_dfg/gdbserver/Makefile.in	2008-10-28 11:35:28.000000000 -0700
@@ -117,7 +117,8 @@ SFILES=	$(srcdir)/gdbreplay.c $(srcdir)/
 	$(srcdir)/linux-m68k-low.c $(srcdir)/linux-mips-low.c \
 	$(srcdir)/linux-ppc-low.c \
 	$(srcdir)/linux-s390-low.c \
-	$(srcdir)/linux-sh-low.c $(srcdir)/linux-x86-64-low.c \
+	$(srcdir)/linux-sh-low.c $(srcdir)/linux-sparc-low.c \
+	$(srcdir)/linux-x86-64-low.c \
 	$(srcdir)/linux-xtensa-low.c \
 	$(srcdir)/win32-arm-low.c $(srcdir)/win32-i386-low.c \
 	$(srcdir)/win32-low.c $(srcdir)/wincecompat.c \
@@ -209,7 +210,7 @@ clean:
 	rm -f version.c
 	rm -f gdbserver$(EXEEXT) gdbreplay$(EXEEXT) core make.log
 	rm -f reg-arm.c reg-i386.c reg-ia64.c reg-m32r.c reg-m68k.c
-	rm -f reg-sh.c reg-spu.c reg-x86-64.c reg-i386-linux.c
+	rm -f reg-sh.c reg-sparc.c reg-spu.c reg-x86-64.c reg-i386-linux.c
 	rm -f reg-cris.c reg-crisv32.c reg-x86-64-linux.c reg-xtensa.c
 	rm -f arm-with-iwmmxt.c mips-linux.c mips64-linux.c
 	rm -f powerpc-32l.c powerpc-64l.c powerpc-e500l.c
@@ -382,6 +383,9 @@ reg-s390x.c : $(srcdir)/../regformats/re
 reg-sh.o : reg-sh.c $(regdef_h)
 reg-sh.c : $(srcdir)/../regformats/reg-sh.dat $(regdat_sh)
 	$(SHELL) $(regdat_sh) $(srcdir)/../regformats/reg-sh.dat reg-sh.c
+reg-sparc64.o : reg-sparc64.c $(regdef_h)
+reg-sparc64.c : $(srcdir)/../regformats/reg-sparc64.dat $(regdat_sh)
+	$(SHELL) $(regdat_sh) $(srcdir)/../regformats/reg-sparc64.dat reg-sparc64.c
 reg-spu.o : reg-spu.c $(regdef_h)
 reg-spu.c : $(srcdir)/../regformats/reg-spu.dat $(regdat_sh)
 	$(SHELL) $(regdat_sh) $(srcdir)/../regformats/reg-spu.dat reg-spu.c
diff -Naurp gdb_original/regformats/reg-sparc64.dat gdb_dfg/regformats/reg-sparc64.dat
--- gdb_original/regformats/reg-sparc64.dat	1969-12-31 16:00:00.000000000 -0800
+++ gdb_dfg/regformats/reg-sparc64.dat	2008-10-28 11:35:28.000000000 -0700
@@ -0,0 +1,91 @@
+name:sparc64
+expedite:sp,fp,pc,npc,o7
+64:g0
+64:g1
+64:g2
+64:g3
+64:g4
+64:g5
+64:g6
+64:g7
+64:o0
+64:o1
+64:o2
+64:o3
+64:o4
+64:o5
+64:sp
+64:o7
+64:l0
+64:l1
+64:l2
+64:l3
+64:l4
+64:l5
+64:l6
+64:l7
+64:i0
+64:i1
+64:i2
+64:i3
+64:i4
+64:i5
+64:fp
+64:i7
+
+32:f0
+32:f1
+32:f2
+32:f3
+32:f4
+32:f5
+32:f6
+32:f7
+32:f8
+32:f9
+32:f10
+32:f11
+32:f12
+32:f13
+32:f14
+32:f15
+32:f16
+32:f17
+32:f18
+32:f19
+32:f20
+32:f21
+32:f22
+32:f23
+32:f24
+32:f25
+32:f26
+32:f27
+32:f28
+32:f29
+32:f30
+32:f31
+
+64:f32
+64:f34
+64:f36
+64:f38
+64:f40
+64:f42
+64:f44
+64:f46
+64:f48
+64:f50
+64:f52
+64:f54
+64:f56
+64:f58
+64:f60
+64:f62
+
+64:pc
+64:npc
+64:state
+64:fsr
+64:fprs
+64:y