X-Git-Url: http://drtracing.org/?a=blobdiff_plain;f=gdb%2Fppcobsd-tdep.c;h=2cc62a0db3ba58dbf1fa1266d873eb39a1cfd54b;hb=21002a635bf3da33367592e3a3ab3cce24fe5299;hp=94cea38b7887f12d42aaade6e242b1dbc8f503eb;hpb=5d6210f04389cc54d1937e309ea48e979a352e54;p=deliverable%2Fbinutils-gdb.git

diff --git a/gdb/ppcobsd-tdep.c b/gdb/ppcobsd-tdep.c
index 94cea38b78..2cc62a0db3 100644
--- a/gdb/ppcobsd-tdep.c
+++ b/gdb/ppcobsd-tdep.c
@@ -1,12 +1,12 @@
 /* Target-dependent code for OpenBSD/powerpc.
 
-   Copyright 2004, 2005 Free Software Foundation, Inc.
+   Copyright (C) 2004-2016 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
+   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,
@@ -15,20 +15,18 @@
    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.  */
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "defs.h"
 #include "arch-utils.h"
+#include "frame.h"
+#include "frame-unwind.h"
+#include "gdbtypes.h"
 #include "osabi.h"
 #include "regcache.h"
 #include "regset.h"
+#include "symtab.h"
 #include "trad-frame.h"
-#include "tramp-frame.h"
-
-#include "gdb_assert.h"
-#include "gdb_string.h"
 
 #include "ppc-tdep.h"
 #include "ppcobsd-tdep.h"
@@ -36,6 +34,7 @@
 
 /* Register offsets from <machine/reg.h>.  */
 struct ppc_reg_offsets ppcobsd_reg_offsets;
+struct ppc_reg_offsets ppcobsd_fpreg_offsets;
 
 
 /* Core file support.  */
@@ -49,24 +48,12 @@ ppcobsd_supply_gregset (const struct regset *regset,
 			struct regcache *regcache, int regnum,
 			const void *gregs, size_t len)
 {
-  /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
-     point registers.  Traditionally, GDB's register set has still
-     listed the floating point registers for such machines, so this
-     code is harmless.  However, the new E500 port actually omits the
-     floating point registers entirely from the register set --- they
-     don't even have register numbers assigned to them.
-
-     It's not clear to me how best to update this code, so this assert
-     will alert the first person to encounter the OpenBSD/E500
-     combination to the problem.  */
-  gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
-
   ppc_supply_gregset (regset, regcache, regnum, gregs, len);
   ppc_supply_fpregset (regset, regcache, regnum, gregs, len);
 }
 
 /* Collect register REGNUM in the general-purpose register set
-   REGSET. from register cache REGCACHE into the buffer specified by
+   REGSET, from register cache REGCACHE into the buffer specified by
    GREGS and LEN.  If REGNUM is -1, do this for all registers in
    REGSET.  */
 
@@ -75,108 +62,203 @@ ppcobsd_collect_gregset (const struct regset *regset,
 			 const struct regcache *regcache, int regnum,
 			 void *gregs, size_t len)
 {
-  /* FIXME: jimb/2004-05-05: Some PPC variants don't have floating
-     point registers.  Traditionally, GDB's register set has still
-     listed the floating point registers for such machines, so this
-     code is harmless.  However, the new E500 port actually omits the
-     floating point registers entirely from the register set --- they
-     don't even have register numbers assigned to them.
-
-     It's not clear to me how best to update this code, so this assert
-     will alert the first person to encounter the OpenBSD/E500
-     combination to the problem.  */
-  gdb_assert (ppc_floating_point_unit_p (current_gdbarch));
-
   ppc_collect_gregset (regset, regcache, regnum, gregs, len);
   ppc_collect_fpregset (regset, regcache, regnum, gregs, len);
 }
 
 /* OpenBSD/powerpc register set.  */
 
-struct regset ppcobsd_gregset =
+const struct regset ppcobsd_gregset =
 {
   &ppcobsd_reg_offsets,
   ppcobsd_supply_gregset
 };
 
-/* Return the appropriate register set for the core section identified
-   by SECT_NAME and SECT_SIZE.  */
-
-static const struct regset *
-ppcobsd_regset_from_core_section (struct gdbarch *gdbarch,
-				  const char *sect_name, size_t sect_size)
+const struct regset ppcobsd_fpregset =
 {
-  if (strcmp (sect_name, ".reg") == 0 && sect_size >= 412)
-    return &ppcobsd_gregset;
+  &ppcobsd_fpreg_offsets,
+  ppc_supply_fpregset
+};
 
-  return NULL;
+/* Iterate over core file register note sections.  */
+
+static void
+ppcobsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
+				      iterate_over_regset_sections_cb *cb,
+				      void *cb_data,
+				      const struct regcache *regcache)
+{
+  cb (".reg", 412, &ppcobsd_gregset, NULL, cb_data);
 }
 
 
 /* Signal trampolines.  */
 
-static void
-ppcobsd_sigtramp_cache_init (const struct tramp_frame *self,
-			     struct frame_info *next_frame,
-			     struct trad_frame_cache *this_cache,
-			     CORE_ADDR func)
+/* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page
+   in virtual memory.  The randomness makes it somewhat tricky to
+   detect it, but fortunately we can rely on the fact that the start
+   of the sigtramp routine is page-aligned.  We recognize the
+   trampoline by looking for the code that invokes the sigreturn
+   system call.  The offset where we can find that code varies from
+   release to release.
+
+   By the way, the mapping mentioned above is read-only, so you cannot
+   place a breakpoint in the signal trampoline.  */
+
+/* Default page size.  */
+static const int ppcobsd_page_size = 4096;
+
+/* Offset for sigreturn(2).  */
+static const int ppcobsd_sigreturn_offset[] = {
+  0x98,				/* OpenBSD 3.8 */
+  0x0c,				/* OpenBSD 3.2 */
+  -1
+};
+
+static int
+ppcobsd_sigtramp_frame_sniffer (const struct frame_unwind *self,
+				struct frame_info *this_frame,
+				void **this_cache)
+{
+  struct gdbarch *gdbarch = get_frame_arch (this_frame);
+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+  CORE_ADDR pc = get_frame_pc (this_frame);
+  CORE_ADDR start_pc = (pc & ~(ppcobsd_page_size - 1));
+  const int *offset;
+  const char *name;
+
+  find_pc_partial_function (pc, &name, NULL, NULL);
+  if (name)
+    return 0;
+
+  for (offset = ppcobsd_sigreturn_offset; *offset != -1; offset++)
+    {
+      gdb_byte buf[2 * PPC_INSN_SIZE];
+      unsigned long insn;
+
+      if (!safe_frame_unwind_memory (this_frame, start_pc + *offset,
+				     buf, sizeof buf))
+	continue;
+
+      /* Check for "li r0,SYS_sigreturn".  */
+      insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
+      if (insn != 0x38000067)
+	continue;
+
+      /* Check for "sc".  */
+      insn = extract_unsigned_integer (buf + PPC_INSN_SIZE,
+				       PPC_INSN_SIZE, byte_order);
+      if (insn != 0x44000002)
+	continue;
+
+      return 1;
+    }
+
+  return 0;
+}
+
+static struct trad_frame_cache *
+ppcobsd_sigtramp_frame_cache (struct frame_info *this_frame, void **this_cache)
 {
-  struct gdbarch *gdbarch = get_frame_arch (next_frame);
+  struct gdbarch *gdbarch = get_frame_arch (this_frame);
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
-  CORE_ADDR addr, base;
+  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+  struct trad_frame_cache *cache;
+  CORE_ADDR addr, base, func;
+  gdb_byte buf[PPC_INSN_SIZE];
+  unsigned long insn, sigcontext_offset;
   int i;
 
-  base = frame_unwind_register_unsigned (next_frame, SP_REGNUM);
-  addr = base + 0x18 + 2 * tdep->wordsize;
+  if (*this_cache)
+    return (struct trad_frame_cache *) *this_cache;
+
+  cache = trad_frame_cache_zalloc (this_frame);
+  *this_cache = cache;
+
+  func = get_frame_pc (this_frame);
+  func &= ~(ppcobsd_page_size - 1);
+  if (!safe_frame_unwind_memory (this_frame, func, buf, sizeof buf))
+    return cache;
+
+  /* Calculate the offset where we can find `struct sigcontext'.  We
+     base our calculation on the amount of stack space reserved by the
+     first instruction of the signal trampoline.  */
+  insn = extract_unsigned_integer (buf, PPC_INSN_SIZE, byte_order);
+  sigcontext_offset = (0x10000 - (insn & 0x0000ffff)) + 8;
+
+  base = get_frame_register_unsigned (this_frame, gdbarch_sp_regnum (gdbarch));
+  addr = base + sigcontext_offset + 2 * tdep->wordsize;
   for (i = 0; i < ppc_num_gprs; i++, addr += tdep->wordsize)
     {
       int regnum = i + tdep->ppc_gp0_regnum;
-      trad_frame_set_reg_addr (this_cache, regnum, addr);
+      trad_frame_set_reg_addr (cache, regnum, addr);
     }
-  trad_frame_set_reg_addr (this_cache, tdep->ppc_lr_regnum, addr);
+  trad_frame_set_reg_addr (cache, tdep->ppc_lr_regnum, addr);
   addr += tdep->wordsize;
-  trad_frame_set_reg_addr (this_cache, tdep->ppc_cr_regnum, addr);
+  trad_frame_set_reg_addr (cache, tdep->ppc_cr_regnum, addr);
   addr += tdep->wordsize;
-  trad_frame_set_reg_addr (this_cache, tdep->ppc_xer_regnum, addr);
+  trad_frame_set_reg_addr (cache, tdep->ppc_xer_regnum, addr);
   addr += tdep->wordsize;
-  trad_frame_set_reg_addr (this_cache, tdep->ppc_ctr_regnum, addr);
+  trad_frame_set_reg_addr (cache, tdep->ppc_ctr_regnum, addr);
   addr += tdep->wordsize;
-  trad_frame_set_reg_addr (this_cache, PC_REGNUM, addr); /* SRR0? */
+  trad_frame_set_reg_addr (cache, gdbarch_pc_regnum (gdbarch), addr);
+  /* SRR0?  */
   addr += tdep->wordsize;
 
   /* Construct the frame ID using the function start.  */
-  trad_frame_set_id (this_cache, frame_id_build (base, func));
+  trad_frame_set_id (cache, frame_id_build (base, func));
+
+  return cache;
+}
+
+static void
+ppcobsd_sigtramp_frame_this_id (struct frame_info *this_frame,
+				void **this_cache, struct frame_id *this_id)
+{
+  struct trad_frame_cache *cache =
+    ppcobsd_sigtramp_frame_cache (this_frame, this_cache);
+
+  trad_frame_get_id (cache, this_id);
 }
 
-static const struct tramp_frame ppcobsd_sigtramp =
+static struct value *
+ppcobsd_sigtramp_frame_prev_register (struct frame_info *this_frame,
+				      void **this_cache, int regnum)
 {
+  struct trad_frame_cache *cache =
+    ppcobsd_sigtramp_frame_cache (this_frame, this_cache);
+
+  return trad_frame_get_register (cache, this_frame, regnum);
+}
+
+static const struct frame_unwind ppcobsd_sigtramp_frame_unwind = {
   SIGTRAMP_FRAME,
-  4,
-  {
-    { 0x3821fff0, -1 },		/* add r1,r1,-16 */
-    { 0x4e800021, -1 },		/* blrl */
-    { 0x38610018, -1 },		/* addi r3,r1,24 */
-    { 0x38000067, -1 },		/* li r0,103 */
-    { 0x44000002, -1 },		/* sc */
-    { 0x38000001, -1 },		/* li r0,1 */
-    { 0x44000002, -1 },		/* sc */
-    { TRAMP_SENTINEL_INSN, -1 }
-  },
-  ppcobsd_sigtramp_cache_init
+  default_frame_unwind_stop_reason,
+  ppcobsd_sigtramp_frame_this_id,
+  ppcobsd_sigtramp_frame_prev_register,
+  NULL,
+  ppcobsd_sigtramp_frame_sniffer
 };
 
 
 static void
 ppcobsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
+  /* OpenBSD doesn't support the 128-bit `long double' from the psABI.  */
+  set_gdbarch_long_double_bit (gdbarch, 64);
+  set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
+
+  /* OpenBSD currently uses a broken GCC.  */
+  set_gdbarch_return_value (gdbarch, ppc_sysv_abi_broken_return_value);
+
   /* OpenBSD uses SVR4-style shared libraries.  */
   set_solib_svr4_fetch_link_map_offsets
     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 
-  set_gdbarch_regset_from_core_section
-    (gdbarch, ppcobsd_regset_from_core_section);
+  set_gdbarch_iterate_over_regset_sections
+    (gdbarch, ppcobsd_iterate_over_regset_sections);
 
-  tramp_frame_prepend_unwinder (gdbarch, &ppcobsd_sigtramp);
+  frame_unwind_append_unwinder (gdbarch, &ppcobsd_sigtramp_frame_unwind);
 }
 
 
@@ -215,6 +297,8 @@ _initialize_ppcobsd_tdep (void)
     {
       /* General-purpose registers.  */
       ppcobsd_reg_offsets.r0_offset = 0;
+      ppcobsd_reg_offsets.gpr_size = 4;
+      ppcobsd_reg_offsets.xr_size = 4;
       ppcobsd_reg_offsets.pc_offset = 384;
       ppcobsd_reg_offsets.ps_offset = 388;
       ppcobsd_reg_offsets.cr_offset = 392;
@@ -232,4 +316,12 @@ _initialize_ppcobsd_tdep (void)
       ppcobsd_reg_offsets.vscr_offset = 512;
       ppcobsd_reg_offsets.vrsave_offset = 520;
     }
+
+  if (ppcobsd_fpreg_offsets.fpscr_offset == 0)
+    {
+      /* Floating-point registers.  */
+      ppcobsd_reg_offsets.f0_offset = 0;
+      ppcobsd_reg_offsets.fpscr_offset = 256;
+      ppcobsd_reg_offsets.fpscr_size = 4;
+    }
 }