2004-12-07 Randolph Chung <tausq@debian.org>

	* solib-som.c: New file.
	* solib-som.h: New file.
	* solib-pa64.c: New file.
	* solib-pa64.h: New file.

1 files changed, 653 insertions, 0 deletions

diff --git a/gdb/solib-pa64.c b/gdb/solib-pa64.c
new file mode 100644
index 0000000..9f54104
--- /dev/null
+++ b/gdb/solib-pa64.c
@@ -0,0 +1,653 @@
+/* Handle PA64 shared libraries for GDB, the GNU Debugger.
+
+   Copyright 2004 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
+   (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, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  
+   
+   HP in their infinite stupidity choose not to use standard ELF dynamic
+   linker interfaces.  They also choose not to make their ELF dymamic
+   linker interfaces compatible with the SOM dynamic linker.  The
+   net result is we can not use either of the existing somsolib.c or
+   solib.c.  What a crock.
+
+   Even more disgusting.  This file depends on functions provided only
+   in certain PA64 libraries.  Thus this file is supposed to only be
+   used native.  When will HP ever learn that they need to provide the
+   same functionality in all their libraries!  */
+
+#include "defs.h"
+#include <dlfcn.h>
+#include <elf.h>
+#include <elf_hp.h>
+#include "symtab.h"
+#include "bfd.h"
+#include "symfile.h"
+#include "objfiles.h"
+#include "gdbcore.h"
+#include "target.h"
+#include "inferior.h"
+
+#include "hppa-tdep.h"
+#include "solist.h"
+#include "solib-pa64.h"
+
+#undef SOLIB_PA64_DBG
+
+/* If we are building for a SOM-only target, then we don't need this.  */
+#ifndef PA_SOM_ONLY
+
+struct lm_info {
+  struct load_module_desc desc;
+  CORE_ADDR desc_addr;
+};
+
+/* When adding fields, be sure to clear them in _initialize_pa64_solib. */
+typedef struct
+  {
+    CORE_ADDR dld_flags_addr;
+    LONGEST dld_flags;
+    struct bfd_section *dyninfo_sect;
+    int have_read_dld_descriptor;
+    int is_valid;
+    CORE_ADDR load_map;
+    CORE_ADDR load_map_addr;
+    struct load_module_desc dld_desc;
+  }
+dld_cache_t;
+
+static dld_cache_t dld_cache;
+
+static int
+read_dynamic_info (asection *dyninfo_sect, dld_cache_t *dld_cache_p);
+
+static void
+pa64_relocate_section_addresses (struct so_list *so,
+				 struct section_table *sec)
+{
+}
+
+static void
+pa64_free_so (struct so_list *so)
+{
+  xfree (so->lm_info);
+}
+
+static void
+pa64_clear_solib (void)
+{
+}
+
+/* Wrapper for target_read_memory for dlgetmodinfo.  */
+
+static void *
+pa64_target_read_memory (void *buffer, CORE_ADDR ptr, size_t bufsiz, int ident)
+{
+  if (target_read_memory (ptr, buffer, bufsiz) != 0)
+    return 0;
+  return buffer;
+}
+
+/* Read the dynamic linker's internal shared library descriptor.
+
+   This must happen after dld starts running, so we can't do it in
+   read_dynamic_info.  Record the fact that we have loaded the
+   descriptor.  If the library is archive bound, then return zero, else
+   return nonzero.  */
+
+static int
+read_dld_descriptor (void)
+{
+  char *dll_path;
+  asection *dyninfo_sect;
+
+  /* If necessary call read_dynamic_info to extract the contents of the
+     .dynamic section from the shared library.  */
+  if (!dld_cache.is_valid) 
+    {
+      if (symfile_objfile == NULL)
+	error ("No object file symbols.");
+
+      dyninfo_sect = bfd_get_section_by_name (symfile_objfile->obfd, 
+					      ".dynamic");
+      if (!dyninfo_sect) 
+	{
+	  return 0;
+	}
+
+      if (!read_dynamic_info (dyninfo_sect, &dld_cache))
+	error ("Unable to read in .dynamic section information.");
+    }
+
+  /* Read the load map pointer.  */
+  if (target_read_memory (dld_cache.load_map_addr,
+			  (char *) &dld_cache.load_map,
+			  sizeof (dld_cache.load_map))
+      != 0)
+    {
+      error ("Error while reading in load map pointer.");
+    }
+
+  /* Read in the dld load module descriptor */
+  if (dlgetmodinfo (-1, 
+		    &dld_cache.dld_desc,
+		    sizeof (dld_cache.dld_desc), 
+		    pa64_target_read_memory, 
+		    0, 
+		    dld_cache.load_map)
+      == 0)
+    {
+      error ("Error trying to get information about dynamic linker.");
+    }
+
+  /* Indicate that we have loaded the dld descriptor.  */
+  dld_cache.have_read_dld_descriptor = 1;
+
+  return 1;
+}
+
+
+/* Read the .dynamic section and extract the information of interest,
+   which is stored in dld_cache.  The routine elf_locate_base in solib.c 
+   was used as a model for this.  */
+
+static int
+read_dynamic_info (asection *dyninfo_sect, dld_cache_t *dld_cache_p)
+{
+  char *buf;
+  char *bufend;
+  CORE_ADDR dyninfo_addr;
+  int dyninfo_sect_size;
+  CORE_ADDR entry_addr;
+
+  /* Read in .dynamic section, silently ignore errors.  */
+  dyninfo_addr = bfd_section_vma (symfile_objfile->obfd, dyninfo_sect);
+  dyninfo_sect_size = bfd_section_size (exec_bfd, dyninfo_sect);
+  buf = alloca (dyninfo_sect_size);
+  if (target_read_memory (dyninfo_addr, buf, dyninfo_sect_size))
+    return 0;
+
+  /* Scan the .dynamic section and record the items of interest. 
+     In particular, DT_HP_DLD_FLAGS */
+  for (bufend = buf + dyninfo_sect_size, entry_addr = dyninfo_addr;
+       buf < bufend;
+       buf += sizeof (Elf64_Dyn), entry_addr += sizeof (Elf64_Dyn))
+    {
+      Elf64_Dyn *x_dynp = (Elf64_Dyn*)buf;
+      Elf64_Sxword dyn_tag;
+      CORE_ADDR	dyn_ptr;
+      char *pbuf;
+
+      pbuf = alloca (TARGET_PTR_BIT / HOST_CHAR_BIT);
+      dyn_tag = bfd_h_get_64 (symfile_objfile->obfd, 
+			      (bfd_byte*) &x_dynp->d_tag);
+
+      /* We can't use a switch here because dyn_tag is 64 bits and HP's
+	 lame comiler does not handle 64bit items in switch statements.  */
+      if (dyn_tag == DT_NULL)
+	break;
+      else if (dyn_tag == DT_HP_DLD_FLAGS)
+	{
+	  /* Set dld_flags_addr and dld_flags in *dld_cache_p */
+	  dld_cache_p->dld_flags_addr = entry_addr + offsetof(Elf64_Dyn, d_un);
+	  if (target_read_memory (dld_cache_p->dld_flags_addr,
+	  			  (char*) &dld_cache_p->dld_flags, 
+				  sizeof (dld_cache_p->dld_flags))
+	      != 0)
+	    {
+	      error ("Error while reading in .dynamic section of the program.");
+	    }
+	}
+      else if (dyn_tag == DT_HP_LOAD_MAP)
+	{
+	  /* Dld will place the address of the load map at load_map_addr
+	     after it starts running.  */
+	  if (target_read_memory (entry_addr + offsetof(Elf64_Dyn, 
+							d_un.d_ptr),
+				  (char*) &dld_cache_p->load_map_addr,
+				  sizeof (dld_cache_p->load_map_addr))
+	      != 0)
+	    {
+	      error ("Error while reading in .dynamic section of the program.");
+	    }
+	}
+      else 
+	{
+	  /* tag is not of interest */
+	}
+    }
+
+  /* Record other information and set is_valid to 1. */
+  dld_cache_p->dyninfo_sect = dyninfo_sect;
+
+  /* Verify that we read in required info.  These fields are re-set to zero
+     in pa64_solib_restart.  */
+
+  if (dld_cache_p->dld_flags_addr != 0 && dld_cache_p->load_map_addr != 0) 
+    dld_cache_p->is_valid = 1;
+  else 
+    return 0;
+
+  return 1;
+}
+
+/*
+   bfd_lookup_symbol -- lookup the value for a specific symbol
+
+   An expensive way to lookup the value of a single symbol for
+   bfd's that are only temporary anyway.  This is used by the
+   shared library support to find the address of the debugger
+   interface structures in the shared library.
+
+   Note that 0 is specifically allowed as an error return (no
+   such symbol).
+ */
+
+static CORE_ADDR
+bfd_lookup_symbol (bfd *abfd, char *symname)
+{
+  unsigned int storage_needed;
+  asymbol *sym;
+  asymbol **symbol_table;
+  unsigned int number_of_symbols;
+  unsigned int i;
+  struct cleanup *back_to;
+  CORE_ADDR symaddr = 0;
+
+  storage_needed = bfd_get_symtab_upper_bound (abfd);
+
+  if (storage_needed > 0)
+    {
+      symbol_table = (asymbol **) xmalloc (storage_needed);
+      back_to = make_cleanup (xfree, symbol_table);
+      number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
+
+      for (i = 0; i < number_of_symbols; i++)
+	{
+	  sym = *symbol_table++;
+	  if (strcmp (sym->name, symname) == 0)
+	    {
+	      /* Bfd symbols are section relative. */
+	      symaddr = sym->value + sym->section->vma;
+	      break;
+	    }
+	}
+      do_cleanups (back_to);
+    }
+  return (symaddr);
+}
+
+
+/* This hook gets called just before the first instruction in the
+   inferior process is executed.
+
+   This is our opportunity to set magic flags in the inferior so
+   that GDB can be notified when a shared library is mapped in and
+   to tell the dynamic linker that a private copy of the library is
+   needed (so GDB can set breakpoints in the library).
+
+   We need to set two flag bits in this routine.
+
+     DT_HP_DEBUG_PRIVATE to indicate that shared libraries should be
+     mapped private.
+
+     DT_HP_DEBUG_CALLBACK to indicate that we want the dynamic linker to
+     call the breakpoint routine for significant events.  */
+
+static void
+pa64_solib_create_inferior_hook (void)
+{
+  struct minimal_symbol *msymbol;
+  unsigned int dld_flags, status;
+  asection *shlib_info, *interp_sect;
+  char buf[4];
+  struct objfile *objfile;
+  CORE_ADDR anaddr;
+
+  /* First, remove all the solib event breakpoints.  Their addresses
+     may have changed since the last time we ran the program.  */
+  remove_solib_event_breakpoints ();
+
+  if (symfile_objfile == NULL)
+    return;
+
+  /* First see if the objfile was dynamically linked.  */
+  shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, ".dynamic");
+  if (!shlib_info)
+    return;
+
+  /* It's got a .dynamic section, make sure it's not empty.  */
+  if (bfd_section_size (symfile_objfile->obfd, shlib_info) == 0)
+    return;
+
+  /* Read in the .dynamic section.  */
+  if (! read_dynamic_info (shlib_info, &dld_cache))
+    error ("Unable to read the .dynamic section.");
+
+  /* Turn on the flags we care about.  */
+  dld_cache.dld_flags |= DT_HP_DEBUG_PRIVATE;
+  dld_cache.dld_flags |= DT_HP_DEBUG_CALLBACK;
+  status = target_write_memory (dld_cache.dld_flags_addr,
+				(char *) &dld_cache.dld_flags,
+				sizeof (dld_cache.dld_flags));
+  if (status != 0)
+    error ("Unable to modify dynamic linker flags.");
+
+  /* Now we have to create a shared library breakpoint in the dynamic
+     linker.  This can be somewhat tricky since the symbol is inside
+     the dynamic linker (for which we do not have symbols or a base
+     load address!   Luckily I wrote this code for solib.c years ago.  */
+  interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
+  if (interp_sect)
+    {
+      unsigned int interp_sect_size;
+      char *buf;
+      CORE_ADDR load_addr;
+      bfd *tmp_bfd;
+      CORE_ADDR sym_addr = 0;
+
+      /* Read the contents of the .interp section into a local buffer;
+	 the contents specify the dynamic linker this program uses.  */
+      interp_sect_size = bfd_section_size (exec_bfd, interp_sect);
+      buf = alloca (interp_sect_size);
+      bfd_get_section_contents (exec_bfd, interp_sect,
+				buf, 0, interp_sect_size);
+
+      /* Now we need to figure out where the dynamic linker was
+	 loaded so that we can load its symbols and place a breakpoint
+	 in the dynamic linker itself.
+
+	 This address is stored on the stack.  However, I've been unable
+	 to find any magic formula to find it for Solaris (appears to
+	 be trivial on GNU/Linux).  Therefore, we have to try an alternate
+	 mechanism to find the dynamic linker's base address.  */
+      tmp_bfd = bfd_openr (buf, gnutarget);
+      if (tmp_bfd == NULL)
+	return;
+
+      /* Make sure the dynamic linker's really a useful object.  */
+      if (!bfd_check_format (tmp_bfd, bfd_object))
+	{
+	  warning ("Unable to grok dynamic linker %s as an object file", buf);
+	  bfd_close (tmp_bfd);
+	  return;
+	}
+
+      /* We find the dynamic linker's base address by examining the
+	 current pc (which point at the entry point for the dynamic
+	 linker) and subtracting the offset of the entry point. 
+
+	 Also note the breakpoint is the second instruction in the
+	 routine.  */
+      load_addr = read_pc () - tmp_bfd->start_address;
+      sym_addr = bfd_lookup_symbol (tmp_bfd, "__dld_break");
+      sym_addr = load_addr + sym_addr + 4;
+      
+      /* Create the shared library breakpoint.  */
+      {
+	struct breakpoint *b
+	  = create_solib_event_breakpoint (sym_addr);
+
+	/* The breakpoint is actually hard-coded into the dynamic linker,
+	   so we don't need to actually insert a breakpoint instruction
+	   there.  In fact, the dynamic linker's code is immutable, even to
+	   ttrace, so we shouldn't even try to do that.  For cases like
+	   this, we have "permanent" breakpoints.  */
+	make_breakpoint_permanent (b);
+      }
+
+      /* We're done with the temporary bfd.  */
+      bfd_close (tmp_bfd);
+    }
+}
+
+static void
+pa64_special_symbol_handling (void)
+{
+}
+
+static struct so_list *
+pa64_current_sos (void)
+{
+  struct so_list *head = 0;
+  struct so_list **link_ptr = &head;
+  int dll_index;
+
+  /* Read in the load map pointer if we have not done so already.  */
+  if (! dld_cache.have_read_dld_descriptor)
+    if (! read_dld_descriptor ())
+      return NULL;
+
+  /* If the libraries were not mapped private, warn the user.  */
+  if ((dld_cache.dld_flags & DT_HP_DEBUG_PRIVATE) == 0)
+    warning ("The shared libraries were not privately mapped; setting a\n"
+    	     "breakpoint in a shared library will not work until you rerun "
+	     "the program.\n");
+
+  for (dll_index = 1; ; dll_index++)
+    {
+      struct load_module_desc dll_desc;
+      char *dll_path;
+      struct so_list *new;
+      struct cleanup *old_chain;
+
+      /* Read in the load module descriptor.  */
+      if (dlgetmodinfo (dll_index, &dll_desc, sizeof (dll_desc),
+			pa64_target_read_memory, 0, dld_cache.load_map)
+	  == 0)
+	break;
+
+      /* Get the name of the shared library.  */
+      dll_path = (char *)dlgetname (&dll_desc, sizeof (dll_desc),
+			    pa64_target_read_memory,
+			    0, dld_cache.load_map);
+
+      if (dll_path == NULL)
+        dll_path = "";
+
+      new = (struct so_list *) xmalloc (sizeof (struct so_list));
+      memset (new, 0, sizeof (struct so_list));
+      new->lm_info = (struct lm_info *) xmalloc (sizeof (struct lm_info));
+      memset (new->lm_info, 0, sizeof (struct lm_info));
+
+      strncpy (new->so_name, dll_path, SO_NAME_MAX_PATH_SIZE - 1);
+      new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
+      strcpy (new->so_original_name, new->so_name);
+
+      memcpy (&new->lm_info->desc, &dll_desc, sizeof (dll_desc));
+
+#ifdef SOLIB_PA64_DBG
+      {
+        struct load_module_desc *d = &new->lm_info->desc;
+	printf ("\n+ library \"%s\" is described at index %d\n", new->so_name, 
+		dll_index);
+	printf ("    text_base = 0x%llx\n", d->text_base); 
+	printf ("    text_size = 0x%llx\n", d->text_size); 
+	printf ("    data_base = 0x%llx\n", d->data_base); 
+	printf ("    data_size = 0x%llx\n", d->data_size); 
+	printf ("    unwind_base = 0x%llx\n", d->unwind_base); 
+	printf ("    linkage_ptr = 0x%llx\n", d->linkage_ptr); 
+	printf ("    phdr_base = 0x%llx\n", d->phdr_base); 
+	printf ("    tls_size = 0x%llx\n", d->tls_size); 
+	printf ("    tls_start_addr = 0x%llx\n", d->tls_start_addr); 
+	printf ("    unwind_size = 0x%llx\n", d->unwind_size); 
+	printf ("    tls_index = 0x%llx\n", d->tls_index); 
+      }
+#endif
+
+      /* Link the new object onto the list.  */
+      new->next = NULL;
+      *link_ptr = new;
+      link_ptr = &new->next;
+    }
+
+  return head;
+}
+
+static int
+pa64_open_symbol_file_object (void *from_ttyp)
+{
+  int from_tty = *(int *)from_ttyp;
+  char buf[4];
+  struct load_module_desc dll_desc;
+  char *dll_path;
+
+  if (symfile_objfile)
+    if (!query ("Attempt to reload symbols from process? "))
+      return 0;
+
+  /* Read in the load map pointer if we have not done so already.  */
+  if (! dld_cache.have_read_dld_descriptor)
+    if (! read_dld_descriptor ())
+      return 0;
+
+  /* Read in the load module descriptor.  */
+  if (dlgetmodinfo (0, &dll_desc, sizeof (dll_desc),
+		    pa64_target_read_memory, 0, dld_cache.load_map) == 0)
+    return 0;
+
+  /* Get the name of the shared library.  */
+  dll_path = (char *)dlgetname (&dll_desc, sizeof (dll_desc),
+				pa64_target_read_memory,
+				0, dld_cache.load_map);
+
+  /* Have a pathname: read the symbol file.  */
+  symbol_file_add_main (dll_path, from_tty);
+
+  return 1;
+}
+
+/* Return nonzero if PC is an address inside the dynamic linker.  */
+static int
+pa64_in_dynsym_resolve_code (CORE_ADDR pc)
+{
+  asection *shlib_info;
+
+  if (symfile_objfile == NULL)
+    return 0;
+
+  if (!dld_cache.have_read_dld_descriptor)
+    if (!read_dld_descriptor ())
+      return 0;
+
+  return (pc >= dld_cache.dld_desc.text_base
+	  && pc < dld_cache.dld_desc.text_base + dld_cache.dld_desc.text_size);
+}
+
+
+/* Return the GOT value for the shared library in which ADDR belongs.  If
+   ADDR isn't in any known shared library, return zero.  */
+
+static CORE_ADDR
+pa64_solib_get_got_by_pc (CORE_ADDR addr)
+{
+  struct so_list *so_list = master_so_list ();
+  CORE_ADDR got_value = 0;
+
+  while (so_list)
+    {
+      if (so_list->lm_info->desc.text_base <= addr
+	  && ((so_list->lm_info->desc.text_base
+	       + so_list->lm_info->desc.text_size)
+	      > addr))
+	{
+	  got_value = so_list->lm_info->desc.linkage_ptr;
+	  break;
+	}
+      so_list = so_list->next;
+    }
+  return got_value;
+}
+
+/* Get some HPUX-specific data from a shared lib.  */
+static CORE_ADDR
+pa64_solib_thread_start_addr (struct so_list *so)
+{
+  return so->lm_info->desc.tls_start_addr;
+}
+
+
+/* Return the address of the handle of the shared library in which ADDR
+   belongs.  If ADDR isn't in any known shared library, return zero. 
+
+   This function is used in hppa_fix_call_dummy in hppa-tdep.c.  */
+
+static CORE_ADDR
+pa64_solib_get_solib_by_pc (CORE_ADDR addr)
+{
+  struct so_list *so_list = master_so_list ();
+  CORE_ADDR retval = 0;
+
+  while (so_list)
+    {
+      if (so_list->lm_info->desc.text_base <= addr
+	  && ((so_list->lm_info->desc.text_base
+	       + so_list->lm_info->desc.text_size)
+	      > addr))
+	{
+	  retval = so_list->lm_info->desc_addr;
+	  break;
+	}
+      so_list = so_list->next;
+    }
+  return retval;
+}
+
+static struct target_so_ops pa64_so_ops;
+
+extern initialize_file_ftype _initialize_pa64_solib; /* -Wmissing-prototypes */
+
+void
+_initialize_pa64_solib (void)
+{
+  pa64_so_ops.relocate_section_addresses = pa64_relocate_section_addresses;
+  pa64_so_ops.free_so = pa64_free_so;
+  pa64_so_ops.clear_solib = pa64_clear_solib;
+  pa64_so_ops.solib_create_inferior_hook = pa64_solib_create_inferior_hook;
+  pa64_so_ops.special_symbol_handling = pa64_special_symbol_handling;
+  pa64_so_ops.current_sos = pa64_current_sos;
+  pa64_so_ops.open_symbol_file_object = pa64_open_symbol_file_object;
+  pa64_so_ops.in_dynsym_resolve_code = pa64_in_dynsym_resolve_code;
+
+  memset (&dld_cache, 0, sizeof (dld_cache));
+}
+
+void pa64_solib_select (struct gdbarch_tdep *tdep)
+{
+  current_target_so_ops = &pa64_so_ops;
+
+  tdep->solib_thread_start_addr = pa64_solib_thread_start_addr;
+  tdep->solib_get_got_by_pc = pa64_solib_get_got_by_pc;
+  tdep->solib_get_solib_by_pc = pa64_solib_get_solib_by_pc;
+}
+
+#else /* PA_SOM_ONLY */
+
+extern initialize_file_ftype _initialize_pa64_solib; /* -Wmissing-prototypes */
+
+void
+_initialize_pa64_solib (void)
+{
+}
+
+void pa64_solib_select (struct gdbarch_tdep *tdep)
+{
+  /* For a SOM-only target, there is no pa64 solib support.  This is needed
+     for hppa-hpux-tdep.c to build.  */
+  error ("Cannot select pa64 solib support for this configuration.\n");
+}
+#endif