src/ia64/tables-ia64.c

/* libunwind - a platform-independent unwind library
   Copyright (C) 2001-2003 Hewlett-Packard Co
	Contributed by David Mosberger-Tang <davidm@hpl.hp.com>

This file is part of libunwind.  */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include <assert.h>
#include <stdlib.h>
#include <stddef.h>
#ifdef HAVE_IA64INTRIN_H
# include <ia64intrin.h>
#endif

#include "unwind_i.h"

extern unw_addr_space_t _ULia64_local_addr_space;

struct ia64_table_entry
  {
    uint64_t start_offset;
    uint64_t end_offset;
    uint64_t info_offset;
  };

static inline const struct ia64_table_entry *
lookup (struct ia64_table_entry *table, size_t table_size, unw_word_t rel_ip)
{
  const struct ia64_table_entry *e = 0;
  unsigned long lo, hi, mid;

  /* do a binary search for right entry: */
  for (lo = 0, hi = table_size / sizeof (struct ia64_table_entry); lo < hi;)
    {
      mid = (lo + hi) / 2;
      e = table + mid;
      if (rel_ip < e->start_offset)
	hi = mid;
      else if (rel_ip >= e->end_offset)
	lo = mid + 1;
      else
	break;
    }
  if (rel_ip < e->start_offset || rel_ip >= e->end_offset)
    return NULL;
  return e;
}

/* Helper macro for reading an ia64_table_entry from remote memory.  */
#define remote_read(addr, member)					     \
	(*a->access_mem) (as, (addr) + offsetof (struct ia64_table_entry,    \
						 member), &member, 0, arg)

/* Lookup an unwind-table entry in remote memory.  Returns 1 if an
   entry is found, 0 if no entry is found, negative if an error
   occurred reading remote memory.  */
static int
remote_lookup (unw_addr_space_t as,
	       unw_word_t table, size_t table_size, unw_word_t rel_ip,
	       struct ia64_table_entry *e, void *arg)
{
  unw_word_t e_addr = 0, start_offset, end_offset, info_offset;
  unw_accessors_t *a = unw_get_accessors (as);
  unsigned long lo, hi, mid;
  int ret;

  /* do a binary search for right entry: */
  for (lo = 0, hi = table_size / sizeof (struct ia64_table_entry); lo < hi;)
    {
      mid = (lo + hi) / 2;
      e_addr = table + mid * sizeof (struct ia64_table_entry);
      if ((ret = remote_read (e_addr, start_offset)) < 0)
	return ret;

      if (rel_ip < start_offset)
	hi = mid;
      else
	{
	  if ((ret = remote_read (e_addr, end_offset)) < 0)
	    return ret;

	  if (rel_ip >= end_offset)
	    lo = mid + 1;
	  else
	    break;
	}
    }
  if (rel_ip < start_offset || rel_ip >= end_offset)
    return 0;
  e->start_offset = start_offset;
  e->end_offset = end_offset;

  if ((ret = remote_read (e_addr, info_offset)) < 0)
    return ret;
  e->info_offset = info_offset;
  return 1;
}

static inline int
is_local_addr_space (unw_addr_space_t as)
{
#ifdef UNW_REMOTE_ONLY
  return 0;
#else
  return (as == _Uia64_local_addr_space
# ifndef UNW_GENERIC_ONLY
	  || as == _ULia64_local_addr_space
# endif
	  );
#endif
}

int
_Uia64_search_unwind_table (unw_addr_space_t as, unw_word_t ip,
			    unw_dyn_info_t *di, unw_proc_info_t *pi,
			    int need_unwind_info, void *arg)
{
  unw_word_t addr, hdr_addr, info_addr, info_end_addr, hdr, *wp;
  unw_word_t handler_offset, segbase;
  const struct ia64_table_entry *e;
  struct ia64_table_entry ent;
  unw_accessors_t *a = unw_get_accessors (as);
  int ret;

  assert ((di->format == UNW_INFO_FORMAT_TABLE
	   || di->format == UNW_INFO_FORMAT_REMOTE_TABLE)
	  && (ip >= di->start_ip && ip < di->end_ip));

  pi->flags = 0;
  pi->unwind_info = 0;
  pi->handler = 0;

  if (likely (di->format == UNW_INFO_FORMAT_TABLE))
    {
      segbase = di->u.ti.segbase;
      e = lookup ((struct ia64_table_entry *) di->u.ti.table_data,
		  di->u.ti.table_len * sizeof (unw_word_t),
		  ip - segbase);
    }
  else
    {
      segbase = di->u.rti.segbase;
      if ((ret = remote_lookup (as, di->u.rti.table_data,
				di->u.rti.table_len * sizeof (unw_word_t),
				ip - segbase, &ent, arg)) < 0)
	return ret;
      if (ret)
	e = &ent;
      else
	e = NULL;	/* no info found */
    }
  if (!e)
    {
      /* IP is inside this table's range, but there is no explicit
	 unwind info => use default conventions (i.e., this is NOT an
	 error).  */
      memset (pi, 0, sizeof (*pi));
      pi->start_ip = 0;
      pi->end_ip = 0;
      pi->gp = di->gp;
      pi->lsda = 0;
      return 0;
    }

  pi->start_ip = e->start_offset + segbase;
  pi->end_ip = e->end_offset + segbase;

  hdr_addr = e->info_offset + segbase;
  info_addr = hdr_addr + 8;

  /* read the header word: */
  ret = (*a->access_mem) (as, hdr_addr, &hdr, 0, arg);
  if (ret < 0)
    return ret;

  if (IA64_UNW_VER (hdr) != 1)
    return -UNW_EBADVERSION;

  info_end_addr = info_addr + 8 * IA64_UNW_LENGTH (hdr);

  if (need_unwind_info)
    {
      pi->unwind_info_size = 8 * IA64_UNW_LENGTH (hdr);

      if (is_local_addr_space (as))
	pi->unwind_info = (void *) (uintptr_t) info_addr;
      else
	{
	  /* Internalize unwind info.  Note: since we're doing this
	     only for non-local address spaces, there is no
	     signal-safety issue and it is OK to use malloc()/free().  */
	  pi->unwind_info = malloc (8 * IA64_UNW_LENGTH (hdr));
	  if (!pi->unwind_info)
	    return -UNW_ENOMEM;

	  wp = (unw_word_t *) pi->unwind_info;
	  for (addr = info_addr; addr < info_end_addr; addr += 8, ++wp)
	    {
	      ret = (*a->access_mem) (as, addr, wp, 0, arg);
	      if (ret < 0)
		{
		  free (pi->unwind_info);
		  return ret;
		}
	    }
	}
    }

  if (IA64_UNW_FLAG_EHANDLER (hdr) || IA64_UNW_FLAG_UHANDLER (hdr))
    {
      /* read the personality routine address (address is gp-relative): */
      ret = (*a->access_mem) (as, info_end_addr, &handler_offset, 0, arg);
      if (ret < 0)
	return ret;
      debug (50, "%s: handler ptr @ offset=%lx, gp=%lx\n",
	     __FUNCTION__, handler_offset, di->gp);
      ret = (*a->access_mem) (as, handler_offset + di->gp, &pi->handler,
			      0, arg);
      if (ret < 0)
	return ret;
    }
  pi->lsda = info_end_addr + 8;
  pi->gp = di->gp;
  pi->format = di->format;
  return 0;
}

HIDDEN void
tdep_put_unwind_info (unw_addr_space_t as, unw_proc_info_t *pi, void *arg)
{
  if (!pi->unwind_info)
    return;

  if (!is_local_addr_space (as))
    {
      free (pi->unwind_info);
      pi->unwind_info = NULL;
    }
}

unw_word_t
_Uia64_find_dyn_list (unw_addr_space_t as, unw_dyn_info_t *di, void *arg)
{
  unw_word_t hdr_addr, info_addr, hdr, directives, pers, cookie, off;
  unw_word_t start_offset, end_offset, info_offset, e_addr, segbase;
  unw_accessors_t *a = unw_get_accessors (as);
  struct ia64_table_entry *e;
  size_t table_size;
  unw_word_t gp = di->gp;
  int ret;

  switch (di->format)
    {
    case UNW_INFO_FORMAT_DYNAMIC:
    default:
      return 0;

    case UNW_INFO_FORMAT_TABLE:
      e = (struct ia64_table_entry *) di->u.ti.table_data;
      table_size = di->u.ti.table_len * sizeof (di->u.ti.table_data[0]);
      segbase = di->u.ti.segbase;
      if (table_size < sizeof (struct ia64_table_entry))
	return 0;
      start_offset = e[0].start_offset;
      end_offset = e[0].end_offset;
      info_offset = e[0].info_offset;
      break;

    case UNW_INFO_FORMAT_REMOTE_TABLE:
      e_addr = di->u.rti.table_data;
      table_size = di->u.rti.table_len * sizeof (unw_word_t);
      segbase = di->u.rti.segbase;
      if (table_size < sizeof (struct ia64_table_entry))
	return 0;

      if ((ret = remote_read (e_addr, start_offset) < 0)
	  || (ret = remote_read (e_addr, end_offset) < 0)
	  || (ret = remote_read (e_addr, info_offset) < 0))
	return ret;
      break;
    }


  if (start_offset != end_offset)
    /* dyn-list entry cover a zero-length "procedure" and should be
       first entry (note: technically a binary could contain code
       below the segment base, but this doesn't happen for normal
       binaries and certainly doesn't happen when libunwind is a
       separate shared object.  For weird cases, the application may
       have to provide its own (slower) version of this routine.  */
    return 0;

  hdr_addr = info_offset + segbase;
  info_addr = hdr_addr + 8;

  /* read the header word: */
  ret = (*a->access_mem) (as, hdr_addr, &hdr, 0, arg);
  if (ret < 0)
    return ret;

  if (IA64_UNW_VER (hdr) != 1
      || IA64_UNW_FLAG_EHANDLER (hdr) || IA64_UNW_FLAG_UHANDLER (hdr))
    /* dyn-list entry must be version 1 and doesn't have ehandler
       or uhandler */
    return 0;

  if (IA64_UNW_LENGTH (hdr) != 1)
    /* dyn-list entry must consist of a single word of NOP directives */
    return 0;

  if (((ret = (*a->access_mem) (as, info_addr, &directives, 0, arg)) < 0)
      || ((ret = (*a->access_mem) (as, info_addr + 0x08, &pers, 0, arg)) < 0)
      || ((ret = (*a->access_mem) (as, info_addr + 0x10, &cookie, 0, arg)) < 0)
      || ((ret = (*a->access_mem) (as, info_addr + 0x18, &off, 0, arg)) < 0))
    return 0;

  if (directives != 0 || pers != 0
      || (!as->big_endian && cookie != 0x7473696c2d6e7964)
      || ( as->big_endian && cookie != 0x64796e2d6c697374))
    return 0;

  /* OK, we ran the gauntlet and found it: */
  return off + gp;
}

#ifndef UNW_REMOTE_ONLY

#if defined(HAVE_DL_ITERATE_PHDR)

#include <link.h>
#include <stdlib.h>

#if __GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ < 2) \
    || (__GLIBC__ == 2 && __GLIBC_MINOR__ == 2 && !defined(DT_CONFIG))
# error You need GLIBC 2.2.4 or later on IA-64 Linux
#endif

#if defined(HAVE_GETUNWIND)

extern unsigned long getunwind (void *buf, size_t len);

#else /* HAVE_GETUNWIND */

#include <unistd.h>
#include <sys/syscall.h>

# ifndef __NR_getunwind
#  define __NR_getunwind	1215
# endif

static unsigned long
getunwind (void *buf, size_t len)
{
  return syscall (SYS_getunwind, buf, len);
}

#endif /* HAVE_GETUNWIND */

static unw_dyn_info_t kernel_table;

int
_Uia64_get_kernel_table (unw_dyn_info_t *di)
{
  struct ia64_table_entry *ktab, *etab;
  size_t size;

  debug (100, "unwind: getting kernel table");

  size = getunwind (NULL, 0);
  ktab = sos_alloc (size);
  if (!ktab)
    {
      dprintf (__FILE__".%s: failed to allocate %Zu bytes",
	       __FUNCTION__, size);
      return -UNW_ENOMEM;
    }
  getunwind (ktab, size);

  /* Determine length of kernel's unwind table & relocate its entries.  */
  for (etab = ktab; etab->start_offset; ++etab)
    etab->info_offset += (uint64_t) ktab;

  di->format = UNW_INFO_FORMAT_TABLE;
  di->gp = 0;
  di->start_ip = ktab[0].start_offset;
  di->end_ip = etab[-1].end_offset;
  di->u.ti.name_ptr = (unw_word_t) "<kernel>";
  di->u.ti.segbase = 0;
  di->u.ti.table_len = ((char *) etab - (char *) ktab) / sizeof (unw_word_t);
  di->u.ti.table_data = (unw_word_t *) ktab;

  debug (100, "unwind: found table `%s': [%lx-%lx) segbase=%lx len=%lu\n",
	 (char *) di->u.ti.name_ptr, di->start_ip, di->end_ip,
	 di->u.ti.segbase, di->u.ti.table_len);
  return 0;
}

static inline unsigned long
current_gp (void)
{
#ifdef __GNUC__
      register unsigned long gp __asm__("gp");
      return gp;
#elif HAVE_IA64INTRIN_H
      return __getReg(_IA64_REG_GP);
#else
# error Implement me.
#endif
}

static int
callback (struct dl_phdr_info *info, size_t size, void *ptr)
{
  unw_dyn_info_t *di = ptr;
  const Elf64_Phdr *phdr, *p_unwind, *p_dynamic, *p_text;
  long n;
  Elf64_Addr load_base, segbase = 0;

  /* Make sure struct dl_phdr_info is at least as big as we need.  */
  if (size < offsetof (struct dl_phdr_info, dlpi_phnum)
	     + sizeof (info->dlpi_phnum))
    return -1;

  debug (100, "unwind: checking `%s' (load_base=%lx)\n",
	 info->dlpi_name, info->dlpi_addr);

  phdr = info->dlpi_phdr;
  load_base = info->dlpi_addr;
  p_text = NULL;
  p_unwind = NULL;
  p_dynamic = NULL;

  /* See if PC falls into one of the loaded segments.  Find the unwind
     segment at the same time.  */
  for (n = info->dlpi_phnum; --n >= 0; phdr++)
    {
      if (phdr->p_type == PT_LOAD)
	{
	  Elf64_Addr vaddr = phdr->p_vaddr + load_base;
	  if (di->u.ti.segbase >= vaddr
	      && di->u.ti.segbase < vaddr + phdr->p_memsz)
	    p_text = phdr;
	}
      else if (phdr->p_type == PT_IA_64_UNWIND)
	p_unwind = phdr;
      else if (phdr->p_type == PT_DYNAMIC)
	p_dynamic = phdr;
    }
  if (!p_text || !p_unwind)
    return 0;

  if (likely (p_unwind->p_vaddr >= p_text->p_vaddr
	      && p_unwind->p_vaddr < p_text->p_vaddr + p_text->p_memsz))
    /* normal case: unwind table is inside text segment */
    segbase = p_text->p_vaddr + load_base;
  else
    {
      /* Special case: unwind table is in some other segment; this
	 happens for the Linux kernel's gate DSO, for example.  */
      phdr = info->dlpi_phdr;
      for (n = info->dlpi_phnum; --n >= 0; phdr++)
	{
	  if (phdr->p_type == PT_LOAD && p_unwind->p_vaddr >= phdr->p_vaddr
	      && p_unwind->p_vaddr < phdr->p_vaddr + phdr->p_memsz)
	    {
	      segbase = phdr->p_vaddr + load_base;
	      break;
	    }
	}
    }

  if (p_dynamic)
    {
      /* For dynamicly linked executables and shared libraries,
	 DT_PLTGOT is the gp value for that object.  */
      Elf64_Dyn *dyn = (Elf64_Dyn *)(p_dynamic->p_vaddr + load_base);
      for (; dyn->d_tag != DT_NULL; ++dyn)
	if (dyn->d_tag == DT_PLTGOT)
	  {
	    /* On IA-64, _DYNAMIC is writable and GLIBC has relocated it.  */
	    di->gp = dyn->d_un.d_ptr;
	    break;
	  }
    }
  else
    /* Otherwise this is a static executable with no _DYNAMIC.
       The gp is constant program-wide.  */
    di->gp = current_gp();
  di->format = UNW_INFO_FORMAT_TABLE;
  di->start_ip = p_text->p_vaddr + load_base;
  di->end_ip = p_text->p_vaddr + load_base + p_text->p_memsz;
  di->u.ti.name_ptr = (unw_word_t) info->dlpi_name;
  di->u.ti.table_data = (void *) (p_unwind->p_vaddr + load_base);
  di->u.ti.table_len = p_unwind->p_memsz / sizeof (unw_word_t);
  di->u.ti.segbase = segbase;

  debug (100, "unwind: found table `%s': segbase=%lx, len=%lu, gp=%lx, "
	 "table_data=%p\n", (char *) di->u.ti.name_ptr, di->u.ti.segbase,
	 di->u.ti.table_len, di->gp, di->u.ti.table_data);
  return 1;
}

#elif defined(HAVE_DLMODINFO)
  /* Support for HP-UX-style dlmodinfo() */
# include <dlfcn.h>
#endif

HIDDEN int
tdep_find_proc_info (unw_addr_space_t as, unw_word_t ip,
		     unw_proc_info_t *pi, int need_unwind_info, void *arg)
{
#if defined(HAVE_DL_ITERATE_PHDR)
  unw_dyn_info_t di, *dip = &di;
  int ret;

  di.u.ti.segbase = ip;	/* this is cheap... */

  if (dl_iterate_phdr (callback, &di) <= 0)
    {
      if (!kernel_table.u.ti.table_data)
	{
	  ret = _Uia64_get_kernel_table (&kernel_table);
	  if (ret < 0)
	    return ret;
	}
      if (ip < kernel_table.start_ip || ip >= kernel_table.end_ip)
	return -UNW_ENOINFO;
      dip = &kernel_table;
    }
#elif defined(HAVE_DLMODINFO)
# define UNWIND_TBL_32BIT	0x8000000000000000
  struct load_module_desc lmd;
  unw_dyn_info_t di, *dip = &di;
  struct unwind_header
    {
      uint64_t header_version;
      uint64_t start_offset;
      uint64_t end_offset;
    }
  *uhdr;

  if (!dlmodinfo (ip, &lmd, sizeof (lmd), NULL, 0, 0))
    return -UNW_ENOINFO;

  di.format = UNW_INFO_FORMAT_TABLE;
  di.start_ip = lmd.text_base;
  di.end_ip = lmd.text_base + lmd.text_size;
  di.gp = lmd.linkage_ptr;
  di.u.ti.name_ptr = 0;	/* no obvious table-name available */
  di.u.ti.segbase = lmd.text_base;

  uhdr = (struct unwind_header *) lmd.unwind_base;

  if ((uhdr->header_version & ~UNWIND_TBL_32BIT) != 1
      && (uhdr->header_version & ~UNWIND_TBL_32BIT) != 2)
    {
      debug (1, "%s: encountered unknown unwind header version %ld\n",
 	     __FUNCTION__, (long) (uhdr->header_version & ~UNWIND_TBL_32BIT));
      return -UNW_EBADVERSION;
    }
  if (uhdr->header_version & UNWIND_TBL_32BIT)
    {
      debug (1, "%s: 32-bit unwind tables are not supported yet\n",
 	     __FUNCTION__);
      return -UNW_EINVAL;
    }

  di.u.ti.table_data = (unw_word_t *) (di.u.ti.segbase + uhdr->start_offset);
  di.u.ti.table_len = ((uhdr->end_offset - uhdr->start_offset)
		       / sizeof (unw_word_t));

  debug (100, "unwind: found table `%s': segbase=%lx, len=%lu, gp=%lx, "
 	 "table_data=%p\n", (char *) di.u.ti.name_ptr, di.u.ti.segbase,
 	 di.u.ti.table_len, di.gp, di.u.ti.table_data);
#endif

  /* now search the table: */
  return tdep_search_unwind_table (as, ip, dip, pi, need_unwind_info, arg);
}

#endif /* !UNW_REMOTE_ONLY */