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- /* Handle HP SOM shared libraries for GDB, the GNU Debugger.
- Copyright 1993 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., 675 Mass Ave, Cambridge, MA 02139, USA.
-
- Written by the Center for Software Science at the Univerity of Utah
- and by Cygnus Support. */
-
-
- #include "defs.h"
-
- #include "frame.h"
- #include "bfd.h"
- #include "som.h"
- #include "libhppa.h"
- #include "gdbcore.h"
- #include "symtab.h"
- #include "breakpoint.h"
- #include "symfile.h"
- #include "objfiles.h"
- #include "inferior.h"
-
- /* TODO:
-
- * Relocate data addresses in the shared library.
-
- * Most of this code should work for hp300 shared libraries. Does
- anyone care enough to weed out any SOM-isms.
-
- * Do we need/want a command to load a shared library?
-
- * Support for hpux8 dynamic linker.
-
- * Support for tracking user calls to dld_load, dld_unload. */
-
- /* The basic structure which describes a dynamically loaded object. This
- data structure is private to the dynamic linker and isn't found in
- any HPUX include file. */
-
- struct som_solib_mapped_entry
- {
- /* The name of the library. */
- char *name;
-
- /* Version of this structure (it is expected to change again in hpux10). */
- unsigned char struct_version;
-
- /* Binding mode for this library. */
- unsigned char bind_mode;
-
- /* Version of this library. */
- short library_version;
-
- /* Start of text address, link-time text location, end of text address. */
- CORE_ADDR text_addr;
- CORE_ADDR text_link_addr;
- CORE_ADDR text_end;
-
- /* Start of data, start of bss and end of data. */
- CORE_ADDR data_start;
- CORE_ADDR bss_start;
- CORE_ADDR data_end;
-
- /* Value of linkage pointer (%r19). */
- CORE_ADDR got_value;
-
- /* Next entry. */
- struct som_solib_mapped_entry *next;
-
- /* There are other fields, but I don't have information as to what is
- contained in them. */
- };
-
- /* A structure to keep track of all the known shared objects. */
- struct so_list
- {
- struct som_solib_mapped_entry som_solib;
- struct objfile *objfile;
- bfd *abfd;
- struct section_table *sections;
- struct section_table *sections_end;
- struct so_list *next;
- };
-
- static struct so_list *so_list_head;
-
- static void som_sharedlibrary_info_command PARAMS ((char *, int));
-
- /* Add symbols from shared libraries into the symtab list. */
-
- void
- som_solib_add (arg_string, from_tty, target)
- char *arg_string;
- int from_tty;
- struct target_ops *target;
- {
- struct minimal_symbol *msymbol;
- struct so_list *so_list_tail;
- CORE_ADDR addr;
- asection *shlib_info;
- int status;
- unsigned int dld_flags;
- char buf[4];
-
- /* If we're debugging a core file, or have attached to a running
- process, then som_solib_create_inferior_hook will not have been
- called.
-
- We need to first determine if we're dealing with a dynamically
- linked executable. If not, then return without an error or warning.
-
- We also need to examine __dld_flags to determine if the shared library
- list is valid and to determine if the libraries have been privately
- mapped. */
- if (symfile_objfile == NULL)
- return;
-
- /* First see if the objfile was dynamically linked. */
- shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, "$SHLIB_INFO$");
- if (!shlib_info)
- return;
-
- /* It's got a $SHLIB_INFO$ section, make sure it's not empty. */
- if (bfd_section_size (symfile_objfile->obfd, shlib_info) == 0)
- return;
-
- msymbol = lookup_minimal_symbol ("__dld_flags", NULL, NULL);
- if (msymbol == NULL)
- {
- error ("Unable to find __dld_flags symbol in object file.\n");
- return;
- }
-
- addr = SYMBOL_VALUE_ADDRESS (msymbol);
- /* Read the current contents. */
- status = target_read_memory (addr, buf, 4);
- if (status != 0)
- {
- error ("Unable to read __dld_flags\n");
- return;
- }
- dld_flags = extract_unsigned_integer (buf, 4);
-
- /* __dld_list may not be valid. If it's not valid tell the user. */
- if ((dld_flags & 4) == 0)
- {
- error ("__dld_list is not valid according to __dld_flags.\n");
- return;
- }
-
- /* If the libraries were not mapped private, warn the user. */
- if ((dld_flags & 1) == 0)
- warning ("The shared libraries were not privately mapped; setting a\nbreakpoint in a shared library will not work until you rerun the program.\n");
-
- msymbol = lookup_minimal_symbol ("__dld_list", NULL, NULL);
- if (!msymbol)
- {
- /* Older crt0.o files (hpux8) don't have __dld_list as a symbol,
- but the data is still available if you know where to look. */
- msymbol = lookup_minimal_symbol ("__dld_flags", NULL, NULL);
- if (!msymbol)
- {
- error ("Unable to find dynamic library list.\n");
- return;
- }
- addr = SYMBOL_VALUE_ADDRESS (msymbol) - 8;
- }
- else
- addr = SYMBOL_VALUE_ADDRESS (msymbol);
-
- status = target_read_memory (addr, buf, 4);
- if (status != 0)
- {
- error ("Unable to find dynamic library list.\n");
- return;
- }
-
- addr = extract_unsigned_integer (buf, 4);
-
- /* If addr is zero, then we're using an old dynamic loader which
- doesn't maintain __dld_list. We'll have to use a completely
- different approach to get shared library information. */
- if (addr == 0)
- goto old_dld;
-
- /* Using the information in __dld_list is the preferred method
- to get at shared library information. It doesn't depend on
- any functions in /usr/lib/end.o and has a chance of working
- with hpux10 when it is released. */
- status = target_read_memory (addr, buf, 4);
- if (status != 0)
- {
- error ("Unable to find dynamic library list.\n");
- return;
- }
-
- /* addr now holds the address of the first entry in the dynamic
- library list. */
- addr = extract_unsigned_integer (buf, 4);
-
- /* Now that we have a pointer to the dynamic library list, walk
- through it and add the symbols for each library.
-
- Skip the first entry since it's our executable. */
- status = target_read_memory (addr + 36, buf, 4);
- if (status != 0)
- goto err;
-
- addr = extract_unsigned_integer (buf, 4);
-
- so_list_tail = so_list_head;
- /* Find the end of the list of shared objects. */
- while (so_list_tail && so_list_tail->next)
- so_list_tail = so_list_tail->next;
-
- while (1)
- {
- CORE_ADDR name_addr, text_addr;
- unsigned int name_len;
- char *name;
- struct so_list *new_so;
- struct section_table *p;
-
- if (addr == 0)
- break;
-
- /* Get a pointer to the name of this library. */
- status = target_read_memory (addr, buf, 4);
- if (status != 0)
- goto err;
-
- name_addr = extract_unsigned_integer (buf, 4);
- name_len = 0;
- while (1)
- {
- target_read_memory (name_addr + name_len, buf, 1);
- if (status != 0)
- goto err;
-
- name_len++;
- if (*buf == '\0')
- break;
- }
- name = alloca (name_len);
- status = target_read_memory (name_addr, name, name_len);
- if (status != 0)
- goto err;
-
- name = obsavestring (name, name_len - 1,
- &symfile_objfile->symbol_obstack);
-
- status = target_read_memory (addr + 8, buf, 4);
- if (status != 0)
- goto err;
-
- text_addr = extract_unsigned_integer (buf, 4);
-
-
- new_so = (struct so_list *) malloc (sizeof (struct so_list));
- memset ((char *)new_so, 0, sizeof (struct so_list));
- if (so_list_head == NULL)
- {
- so_list_head = new_so;
- so_list_tail = new_so;
- }
- else
- {
- so_list_tail->next = new_so;
- so_list_tail = new_so;
- }
-
- /* Fill in all the entries in GDB's shared library list. */
- new_so->som_solib.name = name;
- status = target_read_memory (addr + 4, buf, 4);
- if (status != 0)
- goto err;
-
- new_so->som_solib.struct_version = extract_unsigned_integer (buf + 3, 1);
- new_so->som_solib.bind_mode = extract_unsigned_integer (buf + 2, 1);
- new_so->som_solib.library_version = extract_unsigned_integer (buf, 2);
- new_so->som_solib.text_addr = text_addr;
-
- status = target_read_memory (addr + 12, buf, 4);
- if (status != 0)
- goto err;
-
- new_so->som_solib.text_link_addr = extract_unsigned_integer (buf, 4);
-
- status = target_read_memory (addr + 16, buf, 4);
- if (status != 0)
- goto err;
-
- new_so->som_solib.text_end = extract_unsigned_integer (buf, 4);
-
- status = target_read_memory (addr + 20, buf, 4);
- if (status != 0)
- goto err;
-
- new_so->som_solib.data_start = extract_unsigned_integer (buf, 4);
-
- status = target_read_memory (addr + 24, buf, 4);
- if (status != 0)
- goto err;
-
- new_so->som_solib.bss_start = extract_unsigned_integer (buf, 4);
-
- status = target_read_memory (addr + 28, buf, 4);
- if (status != 0)
- goto err;
-
- new_so->som_solib.data_end = extract_unsigned_integer (buf, 4);
-
- status = target_read_memory (addr + 32, buf, 4);
- if (status != 0)
- goto err;
-
- new_so->som_solib.got_value = extract_unsigned_integer (buf, 4);
-
- status = target_read_memory (addr + 36, buf, 4);
- if (status != 0)
- goto err;
-
- new_so->som_solib.next = (void *)extract_unsigned_integer (buf, 4);
- addr = (CORE_ADDR)new_so->som_solib.next;
-
- new_so->objfile = symbol_file_add (name, from_tty, text_addr, 0, 0, 0);
- new_so->abfd = new_so->objfile->obfd;
-
- if (!bfd_check_format (new_so->abfd, bfd_object))
- {
- error ("\"%s\": not in executable format: %s.",
- name, bfd_errmsg (bfd_get_error ()));
- }
-
- /* Now we need to build a section table for this library since
- we might be debugging a core file from a dynamically linked
- executable in which the libraries were not privately mapped. */
- if (build_section_table (new_so->abfd,
- &new_so->sections,
- &new_so->sections_end))
- {
- error ("Unable to build section table for shared library\n.");
- return;
- }
-
- /* Relocate all the sections based on where they got loaded. */
- for (p = new_so->sections; p < new_so->sections_end; p++)
- {
- if (p->the_bfd_section->flags & SEC_CODE)
- {
- p->addr += text_addr - new_so->som_solib.text_link_addr;
- p->endaddr += text_addr - new_so->som_solib.text_link_addr;
- }
- else if (p->the_bfd_section->flags & SEC_DATA)
- {
- p->addr += new_so->som_solib.data_start;
- p->endaddr += new_so->som_solib.data_start;
- }
- }
-
- /* Now see if we need to map in the text and data for this shared
- library (for example debugging a core file which does not use
- private shared libraries.).
-
- Carefully peek at the first text address in the library. If the
- read succeeds, then the libraries were privately mapped and were
- included in the core dump file.
-
- If the peek failed, then the libraries were not privately mapped
- and are not in the core file, we'll have to read them in ourselves. */
- status = target_read_memory (text_addr, buf, 4);
- if (status != 0)
- {
- int old;
-
- /* Add sections from the shared library to the core target. */
- if (target->to_sections)
- {
- old = target->to_sections_end - target->to_sections;
- target->to_sections = (struct section_table *)
- xrealloc ((char *)target->to_sections,
- ((sizeof (struct section_table))
- * (old + bfd_count_sections (new_so->abfd))));
- }
- else
- {
- old = 0;
- target->to_sections = (struct section_table *)
- xmalloc ((sizeof (struct section_table))
- * bfd_count_sections (new_so->abfd));
- }
- target->to_sections_end = (target->to_sections
- + old + bfd_count_sections (new_so->abfd));
- memcpy ((char *)(target->to_sections + old),
- new_so->sections,
- ((sizeof (struct section_table))
- * bfd_count_sections (new_so->abfd)));
- }
- }
-
- /* Getting new symbols may change our opinion about what is
- frameless. */
- reinit_frame_cache ();
- return;
-
- old_dld:
- error ("Debugging dynamic executables loaded via the hpux8 dld.sl is not supported.\n");
- return;
-
- err:
- error ("Error while reading dynamic library list.\n");
- return;
- }
-
-
- /* 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).
-
- __dld_flags is the location of the magic flags; as of this implementation
- there are 3 flags of interest:
-
- bit 0 when set indicates that private copies of the libraries are needed
- bit 1 when set indicates that the callback hook routine is valid
- bit 2 when set indicates that the dynamic linker should maintain the
- __dld_list structure when loading/unloading libraries.
-
- Note that shared libraries are not mapped in at this time, so we have
- run the inferior until the libraries are mapped in. Typically this
- means running until the "_start" is called. */
-
- void
- som_solib_create_inferior_hook()
- {
- struct minimal_symbol *msymbol;
- unsigned int dld_flags, status;
- asection *shlib_info;
- char shadow_contents[BREAKPOINT_MAX], buf[4];
- CORE_ADDR anaddr;
-
- if (symfile_objfile == NULL)
- return;
-
- /* First see if the objfile was dynamically linked. */
- shlib_info = bfd_get_section_by_name (symfile_objfile->obfd, "$SHLIB_INFO$");
- if (!shlib_info)
- return;
-
- /* It's got a $SHLIB_INFO$ section, make sure it's not empty. */
- if (bfd_section_size (symfile_objfile->obfd, shlib_info) == 0)
- return;
-
- /* Get the address of __dld_flags, if no such symbol exists, then we can
- not debug the shared code. */
- msymbol = lookup_minimal_symbol ("__dld_flags", NULL, NULL);
- if (msymbol == NULL)
- {
- error ("Unable to find __dld_flags symbol in object file.\n");
- return;
- }
-
- anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
- /* Read the current contents. */
- status = target_read_memory (anaddr, buf, 4);
- if (status != 0)
- {
- error ("Unable to read __dld_flags\n");
- return;
- }
- dld_flags = extract_unsigned_integer (buf, 4);
-
- /* Turn on the flags we care about. */
- dld_flags |= 0x5;
- store_unsigned_integer (buf, 4, dld_flags);
- status = target_write_memory (anaddr, buf, 4);
- if (status != 0)
- {
- error ("Unable to write __dld_flags\n");
- return;
- }
-
- /* Now find the address of _start and set a breakpoint there. */
- msymbol = lookup_minimal_symbol ("_start", NULL, symfile_objfile);
- if (msymbol == NULL)
- {
- error ("Unable to find _start symbol in object file.\n");
- return;
- }
-
- anaddr = SYMBOL_VALUE_ADDRESS (msymbol);
- if (target_insert_breakpoint (anaddr, shadow_contents))
- {
- error ("Unable to set breakpoint at _start.\n");
- return;
- }
-
- /* Wipe out all knowledge of old shared libraries since their
- mapping can change from one exec to another! */
- while (so_list_head)
- {
- struct so_list *temp;
-
- free_objfile (so_list_head->objfile);
- temp = so_list_head;
- free (so_list_head);
- so_list_head = temp->next;
- }
-
- /* Start the process again and wait for it to hit our breakpoint. */
- clear_proceed_status ();
- stop_soon_quietly = 1;
- stop_signal = TARGET_SIGNAL_0;
- do
- {
- target_resume (-1, 0, stop_signal);
- wait_for_inferior ();
- }
- while (stop_signal != TARGET_SIGNAL_TRAP);
- stop_soon_quietly = 0;
-
- /* All the libraries should be mapped in now. Remove our breakpoint and
- read in the symbol tables from the shared libraries. */
- if (target_remove_breakpoint (anaddr, shadow_contents))
- {
- error ("Unable to remove breakpoint at _start.\n");
- return;
- }
-
- som_solib_add ((char *) 0, 0, (struct target_ops *) 0);
- }
-
- /* Return the GOT value for the shared library in which ADDR belongs. If
- ADDR isn't in any known shared library, return zero. */
-
- CORE_ADDR
- som_solib_get_got_by_pc (addr)
- CORE_ADDR addr;
- {
- struct so_list *so_list = so_list_head;
- CORE_ADDR got_value = 0;
-
- while (so_list)
- {
- if (so_list->som_solib.text_addr <= addr
- && so_list->som_solib.text_end > addr)
- {
- got_value = so_list->som_solib.got_value;
- break;
- }
- so_list = so_list->next;
- }
- return got_value;
- }
-
- int
- som_solib_section_offsets (objfile, offsets)
- struct objfile *objfile;
- struct section_offsets *offsets;
- {
- struct so_list *so_list = so_list_head;
-
- while (so_list)
- {
- /* Oh what a pain! We need the offsets before so_list->objfile
- is valid. The BFDs will never match. Make a best guess. */
- if (!strcmp (so_list->som_solib.name, objfile->name))
- {
- asection *private_section;
-
- /* The text offset is easy. */
- ANOFFSET (offsets, 0) = so_list->som_solib.text_addr;
-
- /* We should look at presumed_dp in the SOM header, but
- that's not easily available. This should be OK though. */
- private_section = bfd_get_section_by_name (objfile->obfd,
- "$PRIVATE$");
- if (!private_section)
- {
- warning ("Unable to find $PRIVATE$ in shared library!");
- ANOFFSET (offsets, 1) = 0;
- return 1;
- }
- ANOFFSET (offsets, 1) = (so_list->som_solib.data_start
- - private_section->vma);
- return 1;
- }
- so_list = so_list->next;
- }
- return 0;
- }
-
- /* Dump information about all the currently loaded shared libraries. */
-
- static void
- som_sharedlibrary_info_command (ignore, from_tty)
- char *ignore;
- int from_tty;
- {
- struct so_list *so_list = so_list_head;
-
- if (exec_bfd == NULL)
- {
- printf_unfiltered ("no exec file.\n");
- return;
- }
-
- if (so_list == NULL)
- {
- printf_unfiltered ("No shared libraries loaded at this time.\n");
- return;
- }
-
- printf_unfiltered ("Shared Object Libraries\n");
- printf_unfiltered (" %-12s%-12s%-12s%-12s%-12s%-12s\n",
- " flags", " tstart", " tend", " dstart", " dend", " dlt");
- while (so_list)
- {
- unsigned int flags;
-
- flags = so_list->som_solib.struct_version << 24;
- flags |= so_list->som_solib.bind_mode << 16;
- flags |= so_list->som_solib.library_version;
- printf_unfiltered ("%s\n", so_list->som_solib.name);
- printf_unfiltered (" %-12s", local_hex_string_custom (flags, "08l"));
- printf_unfiltered ("%-12s",
- local_hex_string_custom (so_list->som_solib.text_addr, "08l"));
- printf_unfiltered ("%-12s",
- local_hex_string_custom (so_list->som_solib.text_end, "08l"));
- printf_unfiltered ("%-12s",
- local_hex_string_custom (so_list->som_solib.data_start, "08l"));
- printf_unfiltered ("%-12s",
- local_hex_string_custom (so_list->som_solib.data_end, "08l"));
- printf_unfiltered ("%-12s\n",
- local_hex_string_custom (so_list->som_solib.got_value, "08l"));
- so_list = so_list->next;
- }
- }
-
- void
- _initialize_som_solib ()
- {
- add_info ("sharedlibrary", som_sharedlibrary_info_command,
- "Status of loaded shared object libraries.");
- }
-