Re: [gdbserver] MIPS64 gdbserver port

[Daniel Jacobowitz <drow at false dot org>]

On Thu, Nov 09, 2006 at 04:17:13PM -0500, Daniel Jacobowitz wrote:
> Been meaning to do this for ages.  This is a fairly straightforward port of
> gdbserver to mips64-none-linux-gnu.  It works no matter which ABI it's
> configured for.  It's hairy in places, but all the hair is the same as
> in the native mips64-linux GDB.

Oh, I forgot to mention one thing: like native mips64 GDB, to get good
behavior from this be sure to have a recent kernel and glibc.  There
have been a number of fixes to n32 and n64 ptrace.

Committed this, with only minor changes to resolve a merge conflict.

-- 
Daniel Jacobowitz
CodeSourcery

2006-11-28  Daniel Jacobowitz  <dan@codesourcery.com>

	* Makefile.in (clean): Remove reg-mips64.c.
	(reg-mips64.c, reg-mips64.o): New rules.
	* configure.srv: Handle mips64.  Include regset support for mips.
	* linux-mips-low.c (union mips_register): New.
	(mips_get_pc, mips_set_pc, mips_reinsert_addr): Use it.
	(mips_breakpoint, mips_breakpoint_at): Use int.
	(mips_collect_register, mips_supply_register)
	(mips_collect_register_32bit, mips_supply_register_32bit)
	(mips_fill_gregset, mips_store_gregset, mips_fill_fpregset)
	(mips_store_fpregset, target_regsets): New.
	* thread-db.c (thread_db_get_tls_address): Use uintptr_t.

2006-11-28  Daniel Jacobowitz  <dan@codesourcery.com>

	* regformats/reg-mips64.dat: New file.

---
 gdb/gdbserver/Makefile.in      |    5 -
 gdb/gdbserver/configure.srv    |    7 +
 gdb/gdbserver/linux-mips-low.c |  184 ++++++++++++++++++++++++++++++++++++++---
 gdb/gdbserver/thread-db.c      |   11 +-
 gdb/regformats/reg-mips64.dat  |  112 ++++++++++++++++++++++++
 5 files changed, 305 insertions(+), 14 deletions(-)

Index: src/gdb/gdbserver/Makefile.in
===================================================================
--- src.orig/gdb/gdbserver/Makefile.in	2006-11-28 13:50:50.000000000 -0500
+++ src/gdb/gdbserver/Makefile.in	2006-11-28 13:53:59.000000000 -0500
@@ -206,7 +206,7 @@ clean:
 	rm -f gdbserver gdbreplay core make.log
 	rm -f reg-arm.c reg-i386.c reg-ia64.c reg-m32r.c reg-m68k.c reg-mips.c
 	rm -f reg-ppc.c reg-sh.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
+	rm -f reg-cris.c reg-crisv32.c reg-x86-64-linux.c reg-mips64.c
 
 maintainer-clean realclean distclean: clean
 	rm -f nm.h tm.h xm.h config.status config.h stamp-h config.log
@@ -318,6 +318,9 @@ reg-m68k.c : $(srcdir)/../regformats/reg
 reg-mips.o : reg-mips.c $(regdef_h)
 reg-mips.c : $(srcdir)/../regformats/reg-mips.dat $(regdat_sh)
 	sh $(regdat_sh) $(srcdir)/../regformats/reg-mips.dat reg-mips.c
+reg-mips64.o : reg-mips64.c $(regdef_h)
+reg-mips64.c : $(srcdir)/../regformats/reg-mips64.dat $(regdat_sh)
+	sh $(regdat_sh) $(srcdir)/../regformats/reg-mips64.dat reg-mips64.c
 reg-ppc.o : reg-ppc.c $(regdef_h)
 reg-ppc.c : $(srcdir)/../regformats/reg-ppc.dat $(regdat_sh)
 	sh $(regdat_sh) $(srcdir)/../regformats/reg-ppc.dat reg-ppc.c
Index: src/gdb/gdbserver/configure.srv
===================================================================
--- src.orig/gdb/gdbserver/configure.srv	2006-11-28 13:50:50.000000000 -0500
+++ src/gdb/gdbserver/configure.srv	2006-11-28 13:53:36.000000000 -0500
@@ -67,8 +67,15 @@ case "${target}" in
 			srv_linux_regsets=yes
 			srv_linux_thread_db=yes
 			;;
+  mips*64*-*-linux*)	srv_regobj=reg-mips64.o
+			srv_tgtobj="linux-low.o linux-mips-low.o"
+			srv_linux_regsets=yes
+			srv_linux_usrregs=yes
+			srv_linux_thread_db=yes
+			;;
   mips*-*-linux*)	srv_regobj=reg-mips.o
 			srv_tgtobj="linux-low.o linux-mips-low.o"
+			srv_linux_regsets=yes
 			srv_linux_usrregs=yes
 			srv_linux_thread_db=yes
 			;;
Index: src/gdb/gdbserver/linux-mips-low.c
===================================================================
--- src.orig/gdb/gdbserver/linux-mips-low.c	2006-11-09 14:07:10.000000000 -0500
+++ src/gdb/gdbserver/linux-mips-low.c	2006-11-28 13:53:36.000000000 -0500
@@ -23,6 +23,7 @@
 #include "linux-low.h"
 
 #include <sys/ptrace.h>
+#include <endian.h>
 
 #include "gdb_proc_service.h"
 
@@ -38,6 +39,15 @@
 
 #include <asm/ptrace.h>
 
+union mips_register
+{
+  unsigned char buf[8];
+
+  /* Deliberately signed, for proper sign extension.  */
+  int reg32;
+  long long reg64;
+};
+
 /* Return the ptrace ``address'' of register REGNO. */
 
 /* Matches mips_generic32_regs */
@@ -107,20 +117,25 @@ mips_cannot_store_register (int regno)
 static CORE_ADDR
 mips_get_pc ()
 {
-  unsigned long pc;
-  collect_register_by_name ("pc", &pc);
-  return pc;
+  union mips_register pc;
+  collect_register_by_name ("pc", pc.buf);
+  return register_size (0) == 4 ? pc.reg32 : pc.reg64;
 }
 
 static void
 mips_set_pc (CORE_ADDR pc)
 {
-  unsigned long newpc = pc;
-  supply_register_by_name ("pc", &newpc);
+  union mips_register newpc;
+  if (register_size (0) == 4)
+    newpc.reg32 = pc;
+  else
+    newpc.reg64 = pc;
+
+  supply_register_by_name ("pc", newpc.buf);
 }
 
 /* Correct in either endianness.  */
-static const unsigned long mips_breakpoint = 0x0005000d;
+static const unsigned int mips_breakpoint = 0x0005000d;
 #define mips_breakpoint_len 4
 
 /* We only place breakpoints in empty marker functions, and thread locking
@@ -129,15 +144,15 @@ static const unsigned long mips_breakpoi
 static CORE_ADDR
 mips_reinsert_addr ()
 {
-  unsigned long pc;
-  collect_register_by_name ("ra", &pc);
-  return pc;
+  union mips_register ra;
+  collect_register_by_name ("ra", ra.buf);
+  return register_size (0) == 4 ? ra.reg32 : ra.reg64;
 }
 
 static int
 mips_breakpoint_at (CORE_ADDR where)
 {
-  unsigned long insn;
+  unsigned int insn;
 
   (*the_target->read_memory) (where, (unsigned char *) &insn, 4);
   if (insn == mips_breakpoint)
@@ -165,6 +180,155 @@ ps_get_thread_area (const struct ps_proc
   return PS_OK;
 }
 
+#ifdef HAVE_PTRACE_GETREGS
+
+static void
+mips_collect_register (int use_64bit, int regno, union mips_register *reg)
+{
+  union mips_register tmp_reg;
+
+  if (use_64bit)
+    {
+      collect_register (regno, &tmp_reg.reg64);
+      *reg = tmp_reg;
+    }
+  else
+    {
+      collect_register (regno, &tmp_reg.reg32);
+      reg->reg64 = tmp_reg.reg32;
+    }
+}
+
+static void
+mips_supply_register (int use_64bit, int regno, const union mips_register *reg)
+{
+  int offset = 0;
+
+  /* For big-endian 32-bit targets, ignore the high four bytes of each
+     eight-byte slot.  */
+  if (__BYTE_ORDER == __BIG_ENDIAN && !use_64bit)
+    offset = 4;
+
+  supply_register (regno, reg->buf + offset);
+}
+
+static void
+mips_collect_register_32bit (int use_64bit, int regno, unsigned char *buf)
+{
+  union mips_register tmp_reg;
+  int reg32;
+
+  mips_collect_register (use_64bit, regno, &tmp_reg);
+  reg32 = tmp_reg.reg64;
+  memcpy (buf, &reg32, 4);
+}
+
+static void
+mips_supply_register_32bit (int use_64bit, int regno, const unsigned char *buf)
+{
+  union mips_register tmp_reg;
+  int reg32;
+
+  memcpy (&reg32, buf, 4);
+  tmp_reg.reg64 = reg32;
+  mips_supply_register (use_64bit, regno, &tmp_reg);
+}
+
+static void
+mips_fill_gregset (void *buf)
+{
+  union mips_register *regset = buf;
+  int i, use_64bit;
+
+  use_64bit = (register_size (0) == 8);
+
+  for (i = 0; i < 32; i++)
+    mips_collect_register (use_64bit, i, regset + i);
+
+  mips_collect_register (use_64bit, find_regno ("lo"), regset + 32);
+  mips_collect_register (use_64bit, find_regno ("hi"), regset + 33);
+  mips_collect_register (use_64bit, find_regno ("pc"), regset + 34);
+  mips_collect_register (use_64bit, find_regno ("bad"), regset + 35);
+  mips_collect_register (use_64bit, find_regno ("sr"), regset + 36);
+  mips_collect_register (use_64bit, find_regno ("cause"), regset + 37);
+}
+
+static void
+mips_store_gregset (const void *buf)
+{
+  const union mips_register *regset = buf;
+  int i, use_64bit;
+
+  use_64bit = (register_size (0) == 8);
+
+  for (i = 0; i < 32; i++)
+    mips_supply_register (use_64bit, i, regset + i);
+
+  mips_supply_register (use_64bit, find_regno ("lo"), regset + 32);
+  mips_supply_register (use_64bit, find_regno ("hi"), regset + 33);
+  mips_supply_register (use_64bit, find_regno ("pc"), regset + 34);
+  mips_supply_register (use_64bit, find_regno ("bad"), regset + 35);
+  mips_supply_register (use_64bit, find_regno ("sr"), regset + 36);
+  mips_supply_register (use_64bit, find_regno ("cause"), regset + 37);
+}
+
+static void
+mips_fill_fpregset (void *buf)
+{
+  union mips_register *regset = buf;
+  int i, use_64bit, first_fp, big_endian;
+
+  use_64bit = (register_size (0) == 8);
+  first_fp = find_regno ("f0");
+  big_endian = (__BYTE_ORDER == __BIG_ENDIAN);
+
+  /* See GDB for a discussion of this peculiar layout.  */
+  for (i = 0; i < 32; i++)
+    if (use_64bit)
+      collect_register (first_fp + i, regset[i].buf);
+    else
+      collect_register (first_fp + i,
+			regset[i & ~1].buf + 4 * (big_endian != (i & 1)));
+
+  mips_collect_register_32bit (use_64bit, find_regno ("fsr"), regset[32].buf);
+  mips_collect_register_32bit (use_64bit, find_regno ("fir"),
+			       regset[32].buf + 4);
+}
+
+static void
+mips_store_fpregset (const void *buf)
+{
+  const union mips_register *regset = buf;
+  int i, use_64bit, first_fp, big_endian;
+
+  use_64bit = (register_size (0) == 8);
+  first_fp = find_regno ("f0");
+  big_endian = (__BYTE_ORDER == __BIG_ENDIAN);
+
+  /* See GDB for a discussion of this peculiar layout.  */
+  for (i = 0; i < 32; i++)
+    if (use_64bit)
+      supply_register (first_fp + i, regset[i].buf);
+    else
+      supply_register (first_fp + i,
+		       regset[i & ~1].buf + 4 * (big_endian != (i & 1)));
+
+  mips_supply_register_32bit (use_64bit, find_regno ("fsr"), regset[32].buf);
+  mips_supply_register_32bit (use_64bit, find_regno ("fir"),
+			      regset[32].buf + 4);
+}
+#endif /* HAVE_PTRACE_GETREGS */
+
+struct regset_info target_regsets[] = {
+#ifdef HAVE_PTRACE_GETREGS
+  { PTRACE_GETREGS, PTRACE_SETREGS, 38 * 8, GENERAL_REGS,
+    mips_fill_gregset, mips_store_gregset },
+  { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 33 * 8, FP_REGS,
+    mips_fill_fpregset, mips_store_fpregset },
+#endif /* HAVE_PTRACE_GETREGS */
+  { 0, 0, -1, -1, NULL, NULL }
+};
+
 struct linux_target_ops the_low_target = {
   mips_num_regs,
   mips_regmap,
Index: src/gdb/gdbserver/thread-db.c
===================================================================
--- src.orig/gdb/gdbserver/thread-db.c	2006-11-09 14:07:10.000000000 -0500
+++ src/gdb/gdbserver/thread-db.c	2006-11-28 13:53:36.000000000 -0500
@@ -33,6 +33,8 @@ extern int debug_threads;
 
 #include "gdb_proc_service.h"
 
+#include <stdint.h>
+
 /* Structure that identifies the child process for the
    <proc_service.h> interface.  */
 static struct ps_prochandle proc_handle;
@@ -333,11 +335,14 @@ thread_db_get_tls_address (struct thread
   if (!process->thread_known)
     return TD_NOTHR;
 
-  err = td_thr_tls_get_addr (&process->th, (psaddr_t) load_module, offset,
-			     &addr);
+  /* Note the cast through uintptr_t: this interface only works if
+     a target address fits in a psaddr_t, which is a host pointer.
+     So a 32-bit debugger can not access 64-bit TLS through this.  */
+  err = td_thr_tls_get_addr (&process->th, (psaddr_t) (uintptr_t) load_module,
+			     offset, &addr);
   if (err == TD_OK)
     {
-      *address = (CORE_ADDR) addr;
+      *address = (CORE_ADDR) (uintptr_t) addr;
       return 0;
     }
   else
Index: src/gdb/regformats/reg-mips64.dat
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ src/gdb/regformats/reg-mips64.dat	2006-11-28 13:53:36.000000000 -0500
@@ -0,0 +1,112 @@
+name:mips
+expedite:pc,sp
+64:zero
+64:at
+64:v0
+64:v1
+
+64:a0
+64:a1
+64:a2
+64:a3
+
+64:t0
+64:t1
+64:t2
+64:t3
+
+64:t4
+64:t5
+64:t6
+64:t7
+
+64:s0
+64:s1
+64:s2
+64:s3
+
+64:s4
+64:s5
+64:s6
+64:s7
+
+64:t8
+64:t9
+64:k0
+64:k1
+
+64:gp
+64:sp
+64:s8
+64:ra
+
+64:sr
+64:lo
+64:hi
+64:bad
+
+64:cause
+64:pc
+
+64:f0
+64:f1
+64:f2
+64:f3
+
+64:f4
+64:f5
+64:f6
+64:f7
+
+64:f8
+64:f9
+64:f10
+64:f11
+
+64:f12
+64:f13
+64:f14
+64:f15
+
+64:f16
+64:f17
+64:f18
+64:f19
+
+64:f20
+64:f21
+64:f22
+64:f23
+
+64:f24
+64:f25
+64:f26
+64:f27
+
+64:f28
+64:f29
+64:f30
+64:f31
+
+64:fsr
+64:fir
+
+64:fp
+64:
+
+64:
+64:
+64:
+64:
+64:
+64:
+64:
+64:
+64:
+64:
+64:
+64:
+64:
+64:
+64:
+64: