[patch 3/4] unwinder: ppc and ppc64

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

Hi Mark,

jankratochvil/ynonx86base-attach-firstreg-ppc

I have left ebl API extensions together with ppc and ppc64 all in one.


Thanks,
Jan


unwinder: ppc and ppc64

backends/
2013-11-10  Jan Kratochvil  <jan.kratochvil@redhat.com>

	unwinder: ppc and ppc64
	* Makefile.am (ppc_SRCS, ppc64_SRCS): Add ppc_initreg.c.
	* ppc64_init.c (ppc64_init): Initialize also frame_nregs,
	core_pc_offset, set_initial_registers_tid and dwarf_to_regno.
	* ppc_init.c (ppc64_init): Initialize also frame_nregs,
	core_pc_offset, set_initial_registers_tid and dwarf_to_regno.
	* ppc_initreg.c: New file.

libdwfl/
2013-11-10  Jan Kratochvil  <jan.kratochvil@redhat.com>

	unwinder: ppc and ppc64
	* frame_unwind.c (__libdwfl_frame_reg_get, __libdwfl_frame_reg_set):
	Call ebl_dwarf_to_regno.
	* linux-core-attach.c (core_set_initial_registers): Keep DESC intact.
	Implement ebl_core_pc_offset support.
	* linux-pid-attach.c (pid_thread_state_registers_cb): Implement
	FIRSTREG -1.

libebl/
2013-11-10  Jan Kratochvil  <jan.kratochvil@redhat.com>

	unwinder: ppc and ppc64
	* Makefile.am (gen_SOURCES): Add ebldwarftoregno.c.
	* ebl-hooks.h (dwarf_to_regno): New.
	* ebldwarftoregno.c: New file.
	* eblinitreg.c (ebl_core_pc_offset): New.
	* libebl.h (ebl_tid_registers_t): Add FIRSTREG -1 to the comment.
	(ebl_core_pc_offset, ebl_dwarf_to_regno): New.
	* libeblP.h (struct ebl): New field core_pc_offset.

tests/
2013-11-10  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* Makefile.am (EXTRA_DIST): Add backtrace.ppc.core.bz2,
	backtrace.ppc.exec.bz2, backtrace.ppc64.core.bz2 and
	backtrace.ppc64.exec.bz2.
	* backtrace.ppc.core.bz2: New file.
	* backtrace.ppc.exec.bz2: New file.
	* backtrace.ppc64.core.bz2: New file.
	* backtrace.ppc64.exec.bz2: New file.
	* run-backtrace.sh: Add tests for ppc and ppc64.

Signed-off-by: Jan Kratochvil <jan.kratochvil@redhat.com>

--- a/backends/Makefile.am
+++ b/backends/Makefile.am
@@ -88,13 +88,13 @@ am_libebl_sparc_pic_a_OBJECTS = $(sparc_SRCS:.c=.os)
 
 ppc_SRCS = ppc_init.c ppc_symbol.c ppc_retval.c ppc_regs.c \
 	   ppc_corenote.c ppc_auxv.c ppc_attrs.c ppc_syscall.c \
-	   ppc_cfi.c
+	   ppc_cfi.c ppc_initreg.c
 libebl_ppc_pic_a_SOURCES = $(ppc_SRCS)
 am_libebl_ppc_pic_a_OBJECTS = $(ppc_SRCS:.c=.os)
 
 ppc64_SRCS = ppc64_init.c ppc64_symbol.c ppc64_retval.c \
 	     ppc64_corenote.c ppc_regs.c ppc_auxv.c ppc_attrs.c ppc_syscall.c \
-	     ppc_cfi.c ppc64_get_symbol.c
+	     ppc_cfi.c ppc64_get_symbol.c ppc_initreg.c
 libebl_ppc64_pic_a_SOURCES = $(ppc64_SRCS)
 am_libebl_ppc64_pic_a_OBJECTS = $(ppc64_SRCS:.c=.os)
 
--- a/backends/ppc64_init.c
+++ b/backends/ppc64_init.c
@@ -68,6 +68,11 @@ ppc64_init (elf, machine, eh, ehlen)
   HOOK (eh, init_symbols);
   HOOK (eh, get_symbol);
   HOOK (eh, destr);
+  /* gcc/config/ #define DWARF_FRAME_REGISTERS.  */
+  eh->frame_nregs = (114 - 1) + 32;
+  eh->core_pc_offset = 0x170;
+  HOOK (eh, set_initial_registers_tid);
+  HOOK (eh, dwarf_to_regno);
 
   return MODVERSION;
 }
--- a/backends/ppc_init.c
+++ b/backends/ppc_init.c
@@ -65,6 +65,11 @@ ppc_init (elf, machine, eh, ehlen)
   HOOK (eh, auxv_info);
   HOOK (eh, check_object_attribute);
   HOOK (eh, abi_cfi);
+  /* gcc/config/ #define DWARF_FRAME_REGISTERS.  */
+  eh->frame_nregs = (114 - 1) + 32;
+  eh->core_pc_offset = 0xc8;
+  HOOK (eh, set_initial_registers_tid);
+  HOOK (eh, dwarf_to_regno);
 
   return MODVERSION;
 }
--- /dev/null
+++ b/backends/ppc_initreg.c
@@ -0,0 +1,111 @@
+/* Fetch live process registers from TID.
+   Copyright (C) 2013 Red Hat, Inc.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * 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
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <stdlib.h>
+#ifdef __powerpc__
+# include <sys/user.h>
+# include <sys/ptrace.h>
+#endif
+
+#define BACKEND ppc_
+#include "libebl_CPU.h"
+
+bool
+ppc_dwarf_to_regno (Ebl *ebl __attribute__ ((unused)), unsigned *regno)
+{
+  switch (*regno)
+  {
+    case 108:
+      *regno = 65;
+      return true;
+    case 0 ... 107:
+    case 109 ... (114 - 1) -1:
+      return true;
+    case 1200 ... 1231:
+      *regno = *regno - 1200 + (114 - 1);
+      return true;
+    default:
+      return false;
+  }
+  abort ();
+}
+
+__typeof (ppc_dwarf_to_regno)
+     ppc64_dwarf_to_regno
+     __attribute__ ((alias ("ppc_dwarf_to_regno")));
+
+bool
+ppc_set_initial_registers_tid (pid_t tid __attribute__ ((unused)),
+			  ebl_tid_registers_t *setfunc __attribute__ ((unused)),
+			       void *arg __attribute__ ((unused)))
+{
+#ifndef __powerpc__
+  return false;
+#else /* __powerpc__ */
+  union
+    {
+      struct pt_regs r;
+      long l[sizeof (struct pt_regs) / sizeof (long)];
+    }
+  user_regs;
+  eu_static_assert (sizeof (struct pt_regs) % sizeof (long) == 0);
+  /* PTRACE_GETREGS is EIO on kernel-2.6.18-308.el5.ppc64.  */
+  errno = 0;
+  for (unsigned regno = 0; regno < sizeof (user_regs) / sizeof (long);
+       regno++)
+    {
+      user_regs.l[regno] = ptrace (PTRACE_PEEKUSER, tid,
+				   (void *) (uintptr_t) (regno
+							 * sizeof (long)),
+				   NULL);
+      if (errno != 0)
+	return false;
+    }
+  const size_t gprs = sizeof (user_regs.r.gpr) / sizeof (*user_regs.r.gpr);
+  Dwarf_Word dwarf_regs[gprs];
+  for (unsigned gpr = 0; gpr < gprs; gpr++)
+    dwarf_regs[gprs] = user_regs.r.gpr[gpr];
+  if (! setfunc (0, gprs, dwarf_regs, arg))
+    return false;
+  dwarf_regs[0] = user_regs.r.link;
+  if (! setfunc (65, 1, dwarf_regs, arg)) // or 108
+    return false;
+  /* Registers like msr, ctr, xer, dar, dsisr etc. are probably irrelevant
+     for CFI.  */
+  dwarf_regs[0] = user_regs.r.nip;
+  return setfunc (-1, 1, dwarf_regs, arg);
+#endif /* __powerpc__ */
+}
+
+__typeof (ppc_set_initial_registers_tid)
+     ppc64_set_initial_registers_tid
+     __attribute__ ((alias ("ppc_set_initial_registers_tid")));
--- a/libdwfl/frame_unwind.c
+++ b/libdwfl/frame_unwind.c
@@ -52,6 +52,8 @@ internal_function
 __libdwfl_frame_reg_get (Dwfl_Frame *state, unsigned regno, Dwarf_Addr *val)
 {
   Ebl *ebl = state->thread->process->ebl;
+  if (! ebl_dwarf_to_regno (ebl, &regno))
+    return false;
   if (regno >= ebl_frame_nregs (ebl))
     return false;
   if ((state->regs_set[regno / sizeof (*state->regs_set) / 8]
@@ -67,6 +69,8 @@ internal_function
 __libdwfl_frame_reg_set (Dwfl_Frame *state, unsigned regno, Dwarf_Addr val)
 {
   Ebl *ebl = state->thread->process->ebl;
+  if (! ebl_dwarf_to_regno (ebl, &regno))
+    return false;
   if (regno >= ebl_frame_nregs (ebl))
     return false;
   /* For example i386 user_regs_struct has signed fields.  */
--- a/libdwfl/linux-core-attach.c
+++ b/libdwfl/linux-core-attach.c
@@ -198,14 +198,13 @@ core_set_initial_registers (Dwfl_Thread *thread, void *thread_arg_voidp)
   }
   /* core_next_thread already found this TID there.  */
   assert (tid == INTUSE(dwfl_thread_tid) (thread));
-  desc += regs_offset;
   for (size_t regloci = 0; regloci < nregloc; regloci++)
     {
       const Ebl_Register_Location *regloc = reglocs + regloci;
       if (regloc->regno >= nregs)
 	continue;
       assert (regloc->bits == 32 || regloc->bits == 64);
-      const char *reg_desc = desc + regloc->offset;
+      const char *reg_desc = desc + regs_offset + regloc->offset;
       for (unsigned regno = regloc->regno;
 	   regno < MIN (regloc->regno + (regloc->count ?: 1U), nregs);
 	   regno++)
@@ -244,6 +243,30 @@ core_set_initial_registers (Dwfl_Thread *thread, void *thread_arg_voidp)
 	  reg_desc += regloc->pad;
 	}
     }
+  size_t core_pc_offset = ebl_core_pc_offset (core_arg->ebl);
+  if (core_pc_offset)
+    {
+      Dwarf_Word pc;
+      switch (gelf_getclass (core) == ELFCLASS32 ? 32 : 64)
+      {
+	case 32:;
+	  uint32_t val32 = *(const uint32_t *) (desc + core_pc_offset);
+	  val32 = (elf_getident (core, NULL)[EI_DATA] == ELFDATA2MSB
+		   ? be32toh (val32) : le32toh (val32));
+	  /* Do a host width conversion.  */
+	  pc = val32;
+	  break;
+	case 64:;
+	  uint64_t val64 = *(const uint64_t *) (desc + core_pc_offset);
+	  val64 = (elf_getident (core, NULL)[EI_DATA] == ELFDATA2MSB
+		   ? be64toh (val64) : le64toh (val64));
+	  pc = val64;
+	  break;
+	default:
+	  abort ();
+      }
+      INTUSE(dwfl_thread_state_register_pc) (thread, pc);
+    }
   return true;
 }
 
--- a/libdwfl/linux-pid-attach.c
+++ b/libdwfl/linux-pid-attach.c
@@ -202,6 +202,17 @@ pid_thread_state_registers_cb (int firstreg, unsigned nregs,
 			       const Dwarf_Word *regs, void *arg)
 {
   Dwfl_Thread *thread = (Dwfl_Thread *) arg;
+  if (firstreg < 0)
+    {
+      assert (firstreg == -1);
+      assert (nregs > 0);
+      INTUSE(dwfl_thread_state_register_pc) (thread, *regs);
+      firstreg++;
+      nregs--;
+      regs++;
+    }
+  if (! nregs)
+    return true;
   return INTUSE(dwfl_thread_state_registers) (thread, firstreg, nregs, regs);
 }
 
--- a/libebl/Makefile.am
+++ b/libebl/Makefile.am
@@ -54,7 +54,7 @@ gen_SOURCES = eblopenbackend.c eblclosebackend.c eblstrtab.c \
 	      eblreginfo.c eblnonerelocp.c eblrelativerelocp.c \
 	      eblsysvhashentrysize.c eblauxvinfo.c eblcheckobjattr.c \
 	      ebl_check_special_section.c ebl_syscall_abi.c eblabicfi.c \
-	      eblstother.c eblinitreg.c eblgetsymbol.c
+	      eblstother.c eblinitreg.c eblgetsymbol.c ebldwarftoregno.c
 
 libebl_a_SOURCES = $(gen_SOURCES)
 
--- a/libebl/ebl-hooks.h
+++ b/libebl/ebl-hooks.h
@@ -180,5 +180,9 @@ void EBLHOOK(init_symbols) (Ebl *ebl, size_t syments, int first_global,
 const char *EBLHOOK(get_symbol) (Ebl *ebl, size_t ndx, GElf_Sym *symp,
 				 GElf_Word *shndxp, void **filep);
 
+/* Convert *REGNO as is in DWARF to a lower range suitable for
+   Dwarf_Frame->REGS indexing.  */
+bool EBLHOOK(dwarf_to_regno) (Ebl *ebl, unsigned *regno);
+
 /* Destructor for ELF backend handle.  */
 void EBLHOOK(destr) (struct ebl *);
--- /dev/null
+++ b/libebl/ebldwarftoregno.c
@@ -0,0 +1,41 @@
+/* Convert *REGNO as is in DWARF to a lower range.
+   Copyright (C) 2013 Red Hat, Inc.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * 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
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include <libeblP.h>
+
+bool
+ebl_dwarf_to_regno (Ebl *ebl, unsigned *regno)
+{
+  if (ebl == NULL)
+    return false;
+  return ebl->dwarf_to_regno == NULL ? true : ebl->dwarf_to_regno (ebl, regno);
+}
--- a/libebl/eblinitreg.c
+++ b/libebl/eblinitreg.c
@@ -49,3 +49,9 @@ ebl_frame_nregs (Ebl *ebl)
 {
   return ebl == NULL ? 0 : ebl->frame_nregs;
 }
+
+size_t
+ebl_core_pc_offset (Ebl *ebl)
+{
+  return ebl == NULL ? 0 : ebl->core_pc_offset;
+}
--- a/libebl/libebl.h
+++ b/libebl/libebl.h
@@ -383,7 +383,8 @@ extern int ebl_auxv_info (Ebl *ebl, GElf_Xword a_type,
 			  const char **name, const char **format)
   __nonnull_attribute__ (1, 3, 4);
 
-/* Callback type for ebl_set_initial_registers_tid.  */
+/* Callback type for ebl_set_initial_registers_tid.
+   Register -1 is mapped to PC (if arch PC has no DWARF number).  */
 typedef bool (ebl_tid_registers_t) (int firstreg, unsigned nregs,
 				    const Dwarf_Word *regs, void *arg)
   __nonnull_attribute__ (3);
@@ -402,6 +403,11 @@ extern bool ebl_set_initial_registers_tid (Ebl *ebl,
 extern size_t ebl_frame_nregs (Ebl *ebl)
   __nonnull_attribute__ (1);
 
+/* PC register location stored in core file.  It is a number of bytes from
+   descriptor of NT_PRSTATUS core note.  It is 0 if unused.  */
+extern size_t ebl_core_pc_offset (Ebl *ebl)
+  __nonnull_attribute__ (1);
+
 /* Callback type for ebl_init_symbols,
    it is forwarded to __libdwfl_module_getsym.  */
 typedef const char *(ebl_getsym_t) (void *arg, int ndx, GElf_Sym *symp,
@@ -422,6 +428,11 @@ extern const char *ebl_get_symbol (Ebl *ebl, size_t ndx, GElf_Sym *symp,
 				   GElf_Word *shndxp, void **filep)
   __nonnull_attribute__ (1, 3);
 
+/* Convert *REGNO as is in DWARF to a lower range suitable for
+   Dwarf_Frame->REGS indexing.  */
+extern bool ebl_dwarf_to_regno (Ebl *ebl, unsigned *regno)
+  __nonnull_attribute__ (1, 2);
+
 #ifdef __cplusplus
 }
 #endif
--- a/libebl/libeblP.h
+++ b/libebl/libeblP.h
@@ -64,6 +64,10 @@ struct ebl
      Ebl architecture can unwind iff FRAME_NREGS > 0.  */
   size_t frame_nregs;
 
+  /* PC register location stored in core file.  It is a number of bytes from
+     descriptor of NT_PRSTATUS core note.  It is 0 if unused.  */
+  size_t core_pc_offset;
+
   /* Internal data.  */
   void *dlhandle;
 
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -229,7 +229,9 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh \
 	     testfile_parameter_ref.c testfile_parameter_ref.bz2 \
 	     testfile_entry_value.c testfile_entry_value.bz2 \
 	     testfile_implicit_value.c testfile_implicit_value.bz2 \
-	     testfile66.bz2 run-backtrace.sh
+	     testfile66.bz2 run-backtrace.sh \
+	     backtrace.ppc.core.bz2 backtrace.ppc.exec.bz2 \
+	     backtrace.ppc64.core.bz2 backtrace.ppc64.exec.bz2
 
 if USE_VALGRIND
 valgrind_cmd='valgrind -q --trace-children=yes --error-exitcode=1 --run-libc-freeres=no'
Binary files /dev/null and b/tests/backtrace.ppc.core.bz2 differ
Binary files /dev/null and b/tests/backtrace.ppc.exec.bz2 differ
Binary files /dev/null and b/tests/backtrace.ppc64.core.bz2 differ
Binary files /dev/null and b/tests/backtrace.ppc64.exec.bz2 differ
--- a/tests/run-backtrace.sh
+++ b/tests/run-backtrace.sh
@@ -91,4 +91,12 @@ for child in backtrace-child{,-biarch}; do
 
 done
 
+for arch in ppc ppc64; do
+  testfiles backtrace.$arch.{exec,core}
+  tempfiles backtrace.$arch.{bt,err}
+  echo ./backtrace ./backtrace.$arch.{exec,core}
+  testrun ${abs_builddir}/backtrace ./backtrace.$arch.{exec,core} 1>backtrace.$arch.bt 2>backtrace.$arch.err || true
+  check_all backtrace.$arch.{bt,err} backtrace.$arch.core
+done
+
 exit 0