1533 lines
48 KiB
C
1533 lines
48 KiB
C
/* Handle SVR4 shared libraries for GDB, the GNU Debugger.
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Copyright 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1998, 1999,
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2000, 2001, 2003 Free Software Foundation, Inc.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "elf/external.h"
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#include "elf/common.h"
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#include "elf/mips.h"
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#include "symtab.h"
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#include "bfd.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "gdbcore.h"
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#include "target.h"
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#include "inferior.h"
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#include "solist.h"
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#include "solib-svr4.h"
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#include "bfd-target.h"
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#include "exec.h"
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#ifndef SVR4_FETCH_LINK_MAP_OFFSETS
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#define SVR4_FETCH_LINK_MAP_OFFSETS() svr4_fetch_link_map_offsets ()
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#endif
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static struct link_map_offsets *svr4_fetch_link_map_offsets (void);
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static struct link_map_offsets *legacy_fetch_link_map_offsets (void);
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static int svr4_have_link_map_offsets (void);
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/* fetch_link_map_offsets_gdbarch_data is a handle used to obtain the
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architecture specific link map offsets fetching function. */
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static struct gdbarch_data *fetch_link_map_offsets_gdbarch_data;
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/* legacy_svr4_fetch_link_map_offsets_hook is a pointer to a function
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which is used to fetch link map offsets. It will only be set
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by solib-legacy.c, if at all. */
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struct link_map_offsets *(*legacy_svr4_fetch_link_map_offsets_hook)(void) = 0;
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/* Link map info to include in an allocated so_list entry */
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struct lm_info
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{
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/* Pointer to copy of link map from inferior. The type is char *
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rather than void *, so that we may use byte offsets to find the
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various fields without the need for a cast. */
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char *lm;
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};
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/* On SVR4 systems, a list of symbols in the dynamic linker where
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GDB can try to place a breakpoint to monitor shared library
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events.
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If none of these symbols are found, or other errors occur, then
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SVR4 systems will fall back to using a symbol as the "startup
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mapping complete" breakpoint address. */
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static char *solib_break_names[] =
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{
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"r_debug_state",
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"_r_debug_state",
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"_dl_debug_state",
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"rtld_db_dlactivity",
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"_rtld_debug_state",
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/* On the 64-bit PowerPC, the linker symbol with the same name as
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the C function points to a function descriptor, not to the entry
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point. The linker symbol whose name is the C function name
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prefixed with a '.' points to the function's entry point. So
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when we look through this table, we ignore symbols that point
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into the data section (thus skipping the descriptor's symbol),
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and eventually try this one, giving us the real entry point
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address. */
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"._dl_debug_state",
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NULL
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};
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#define BKPT_AT_SYMBOL 1
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#if defined (BKPT_AT_SYMBOL)
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static char *bkpt_names[] =
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{
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#ifdef SOLIB_BKPT_NAME
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SOLIB_BKPT_NAME, /* Prefer configured name if it exists. */
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#endif
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"_start",
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"__start",
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"main",
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NULL
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};
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#endif
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static char *main_name_list[] =
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{
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"main_$main",
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NULL
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};
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/* Macro to extract an address from a solib structure. When GDB is
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configured for some 32-bit targets (e.g. Solaris 2.7 sparc), BFD is
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configured to handle 64-bit targets, so CORE_ADDR is 64 bits. We
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have to extract only the significant bits of addresses to get the
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right address when accessing the core file BFD.
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Assume that the address is unsigned. */
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#define SOLIB_EXTRACT_ADDRESS(MEMBER) \
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extract_unsigned_integer (&(MEMBER), sizeof (MEMBER))
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/* local data declarations */
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/* link map access functions */
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static CORE_ADDR
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LM_ADDR (struct so_list *so)
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{
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struct link_map_offsets *lmo = SVR4_FETCH_LINK_MAP_OFFSETS ();
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return (CORE_ADDR) extract_signed_integer (so->lm_info->lm + lmo->l_addr_offset,
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lmo->l_addr_size);
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}
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static CORE_ADDR
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LM_NEXT (struct so_list *so)
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{
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struct link_map_offsets *lmo = SVR4_FETCH_LINK_MAP_OFFSETS ();
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/* Assume that the address is unsigned. */
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return extract_unsigned_integer (so->lm_info->lm + lmo->l_next_offset,
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lmo->l_next_size);
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}
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static CORE_ADDR
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LM_NAME (struct so_list *so)
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{
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struct link_map_offsets *lmo = SVR4_FETCH_LINK_MAP_OFFSETS ();
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/* Assume that the address is unsigned. */
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return extract_unsigned_integer (so->lm_info->lm + lmo->l_name_offset,
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lmo->l_name_size);
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}
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static int
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IGNORE_FIRST_LINK_MAP_ENTRY (struct so_list *so)
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{
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struct link_map_offsets *lmo = SVR4_FETCH_LINK_MAP_OFFSETS ();
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/* Assume that the address is unsigned. */
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return extract_unsigned_integer (so->lm_info->lm + lmo->l_prev_offset,
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lmo->l_prev_size) == 0;
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}
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static CORE_ADDR debug_base; /* Base of dynamic linker structures */
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static CORE_ADDR breakpoint_addr; /* Address where end bkpt is set */
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/* Local function prototypes */
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static int match_main (char *);
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static CORE_ADDR bfd_lookup_symbol (bfd *, char *, flagword);
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/*
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LOCAL FUNCTION
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bfd_lookup_symbol -- lookup the value for a specific symbol
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SYNOPSIS
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CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname, flagword sect_flags)
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DESCRIPTION
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An expensive way to lookup the value of a single symbol for
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bfd's that are only temporary anyway. This is used by the
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shared library support to find the address of the debugger
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interface structures in the shared library.
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If SECT_FLAGS is non-zero, only match symbols in sections whose
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flags include all those in SECT_FLAGS.
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Note that 0 is specifically allowed as an error return (no
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such symbol).
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*/
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static CORE_ADDR
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bfd_lookup_symbol (bfd *abfd, char *symname, flagword sect_flags)
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{
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long storage_needed;
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asymbol *sym;
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asymbol **symbol_table;
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unsigned int number_of_symbols;
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unsigned int i;
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struct cleanup *back_to;
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CORE_ADDR symaddr = 0;
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storage_needed = bfd_get_symtab_upper_bound (abfd);
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if (storage_needed > 0)
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{
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symbol_table = (asymbol **) xmalloc (storage_needed);
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back_to = make_cleanup (xfree, symbol_table);
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number_of_symbols = bfd_canonicalize_symtab (abfd, symbol_table);
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for (i = 0; i < number_of_symbols; i++)
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{
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sym = *symbol_table++;
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if (STREQ (sym->name, symname)
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&& (sym->section->flags & sect_flags) == sect_flags)
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{
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/* Bfd symbols are section relative. */
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symaddr = sym->value + sym->section->vma;
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break;
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}
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}
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do_cleanups (back_to);
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}
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if (symaddr)
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return symaddr;
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/* On FreeBSD, the dynamic linker is stripped by default. So we'll
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have to check the dynamic string table too. */
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storage_needed = bfd_get_dynamic_symtab_upper_bound (abfd);
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if (storage_needed > 0)
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{
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symbol_table = (asymbol **) xmalloc (storage_needed);
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back_to = make_cleanup (xfree, symbol_table);
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number_of_symbols = bfd_canonicalize_dynamic_symtab (abfd, symbol_table);
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for (i = 0; i < number_of_symbols; i++)
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{
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sym = *symbol_table++;
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if (STREQ (sym->name, symname)
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&& (sym->section->flags & sect_flags) == sect_flags)
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{
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/* Bfd symbols are section relative. */
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symaddr = sym->value + sym->section->vma;
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break;
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}
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}
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do_cleanups (back_to);
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}
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return symaddr;
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}
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#ifdef HANDLE_SVR4_EXEC_EMULATORS
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/*
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Solaris BCP (the part of Solaris which allows it to run SunOS4
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a.out files) throws in another wrinkle. Solaris does not fill
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in the usual a.out link map structures when running BCP programs,
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the only way to get at them is via groping around in the dynamic
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linker.
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The dynamic linker and it's structures are located in the shared
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C library, which gets run as the executable's "interpreter" by
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the kernel.
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Note that we can assume nothing about the process state at the time
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we need to find these structures. We may be stopped on the first
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instruction of the interpreter (C shared library), the first
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instruction of the executable itself, or somewhere else entirely
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(if we attached to the process for example).
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*/
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static char *debug_base_symbols[] =
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{
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"r_debug", /* Solaris 2.3 */
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"_r_debug", /* Solaris 2.1, 2.2 */
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NULL
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};
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static int look_for_base (int, CORE_ADDR);
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/*
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LOCAL FUNCTION
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look_for_base -- examine file for each mapped address segment
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SYNOPSYS
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static int look_for_base (int fd, CORE_ADDR baseaddr)
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DESCRIPTION
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This function is passed to proc_iterate_over_mappings, which
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causes it to get called once for each mapped address space, with
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an open file descriptor for the file mapped to that space, and the
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base address of that mapped space.
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Our job is to find the debug base symbol in the file that this
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fd is open on, if it exists, and if so, initialize the dynamic
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linker structure base address debug_base.
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Note that this is a computationally expensive proposition, since
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we basically have to open a bfd on every call, so we specifically
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avoid opening the exec file.
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*/
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static int
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look_for_base (int fd, CORE_ADDR baseaddr)
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{
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bfd *interp_bfd;
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CORE_ADDR address = 0;
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char **symbolp;
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/* If the fd is -1, then there is no file that corresponds to this
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mapped memory segment, so skip it. Also, if the fd corresponds
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to the exec file, skip it as well. */
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if (fd == -1
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|| (exec_bfd != NULL
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&& fdmatch (fileno ((FILE *) (exec_bfd->iostream)), fd)))
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{
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return (0);
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}
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/* Try to open whatever random file this fd corresponds to. Note that
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we have no way currently to find the filename. Don't gripe about
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any problems we might have, just fail. */
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if ((interp_bfd = bfd_fdopenr ("unnamed", gnutarget, fd)) == NULL)
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{
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return (0);
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}
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if (!bfd_check_format (interp_bfd, bfd_object))
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{
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/* FIXME-leak: on failure, might not free all memory associated with
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interp_bfd. */
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bfd_close (interp_bfd);
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return (0);
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}
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/* Now try to find our debug base symbol in this file, which we at
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least know to be a valid ELF executable or shared library. */
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for (symbolp = debug_base_symbols; *symbolp != NULL; symbolp++)
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{
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address = bfd_lookup_symbol (interp_bfd, *symbolp, 0);
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if (address != 0)
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{
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break;
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}
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}
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if (address == 0)
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{
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/* FIXME-leak: on failure, might not free all memory associated with
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interp_bfd. */
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bfd_close (interp_bfd);
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return (0);
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}
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/* Eureka! We found the symbol. But now we may need to relocate it
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by the base address. If the symbol's value is less than the base
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address of the shared library, then it hasn't yet been relocated
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by the dynamic linker, and we have to do it ourself. FIXME: Note
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that we make the assumption that the first segment that corresponds
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to the shared library has the base address to which the library
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was relocated. */
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if (address < baseaddr)
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{
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address += baseaddr;
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}
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debug_base = address;
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/* FIXME-leak: on failure, might not free all memory associated with
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interp_bfd. */
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bfd_close (interp_bfd);
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return (1);
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}
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#endif /* HANDLE_SVR4_EXEC_EMULATORS */
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/*
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LOCAL FUNCTION
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elf_locate_base -- locate the base address of dynamic linker structs
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for SVR4 elf targets.
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SYNOPSIS
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CORE_ADDR elf_locate_base (void)
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DESCRIPTION
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For SVR4 elf targets the address of the dynamic linker's runtime
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structure is contained within the dynamic info section in the
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executable file. The dynamic section is also mapped into the
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inferior address space. Because the runtime loader fills in the
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real address before starting the inferior, we have to read in the
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dynamic info section from the inferior address space.
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If there are any errors while trying to find the address, we
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silently return 0, otherwise the found address is returned.
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*/
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static CORE_ADDR
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elf_locate_base (void)
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{
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sec_ptr dyninfo_sect;
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int dyninfo_sect_size;
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CORE_ADDR dyninfo_addr;
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char *buf;
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char *bufend;
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int arch_size;
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/* Find the start address of the .dynamic section. */
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dyninfo_sect = bfd_get_section_by_name (exec_bfd, ".dynamic");
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if (dyninfo_sect == NULL)
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return 0;
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dyninfo_addr = bfd_section_vma (exec_bfd, dyninfo_sect);
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/* Read in .dynamic section, silently ignore errors. */
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dyninfo_sect_size = bfd_section_size (exec_bfd, dyninfo_sect);
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buf = alloca (dyninfo_sect_size);
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if (target_read_memory (dyninfo_addr, buf, dyninfo_sect_size))
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return 0;
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/* Find the DT_DEBUG entry in the the .dynamic section.
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For mips elf we look for DT_MIPS_RLD_MAP, mips elf apparently has
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no DT_DEBUG entries. */
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arch_size = bfd_get_arch_size (exec_bfd);
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if (arch_size == -1) /* failure */
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return 0;
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if (arch_size == 32)
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{ /* 32-bit elf */
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for (bufend = buf + dyninfo_sect_size;
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buf < bufend;
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buf += sizeof (Elf32_External_Dyn))
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{
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Elf32_External_Dyn *x_dynp = (Elf32_External_Dyn *) buf;
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long dyn_tag;
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CORE_ADDR dyn_ptr;
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dyn_tag = bfd_h_get_32 (exec_bfd, (bfd_byte *) x_dynp->d_tag);
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if (dyn_tag == DT_NULL)
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break;
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else if (dyn_tag == DT_DEBUG)
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{
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dyn_ptr = bfd_h_get_32 (exec_bfd,
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(bfd_byte *) x_dynp->d_un.d_ptr);
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return dyn_ptr;
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}
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else if (dyn_tag == DT_MIPS_RLD_MAP)
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{
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char *pbuf;
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int pbuf_size = TARGET_PTR_BIT / HOST_CHAR_BIT;
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pbuf = alloca (pbuf_size);
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/* DT_MIPS_RLD_MAP contains a pointer to the address
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of the dynamic link structure. */
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dyn_ptr = bfd_h_get_32 (exec_bfd,
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(bfd_byte *) x_dynp->d_un.d_ptr);
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if (target_read_memory (dyn_ptr, pbuf, pbuf_size))
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return 0;
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return extract_unsigned_integer (pbuf, pbuf_size);
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}
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}
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}
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else /* 64-bit elf */
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{
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for (bufend = buf + dyninfo_sect_size;
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buf < bufend;
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buf += sizeof (Elf64_External_Dyn))
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{
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Elf64_External_Dyn *x_dynp = (Elf64_External_Dyn *) buf;
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long dyn_tag;
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CORE_ADDR dyn_ptr;
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dyn_tag = bfd_h_get_64 (exec_bfd, (bfd_byte *) x_dynp->d_tag);
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if (dyn_tag == DT_NULL)
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break;
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else if (dyn_tag == DT_DEBUG)
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{
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dyn_ptr = bfd_h_get_64 (exec_bfd,
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(bfd_byte *) x_dynp->d_un.d_ptr);
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return dyn_ptr;
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}
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else if (dyn_tag == DT_MIPS_RLD_MAP)
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{
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char *pbuf;
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int pbuf_size = TARGET_PTR_BIT / HOST_CHAR_BIT;
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pbuf = alloca (pbuf_size);
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/* DT_MIPS_RLD_MAP contains a pointer to the address
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of the dynamic link structure. */
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dyn_ptr = bfd_h_get_64 (exec_bfd,
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(bfd_byte *) x_dynp->d_un.d_ptr);
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if (target_read_memory (dyn_ptr, pbuf, pbuf_size))
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return 0;
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return extract_unsigned_integer (pbuf, pbuf_size);
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}
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}
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}
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/* DT_DEBUG entry not found. */
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return 0;
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|
}
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
locate_base -- locate the base address of dynamic linker structs
|
|
|
|
SYNOPSIS
|
|
|
|
CORE_ADDR locate_base (void)
|
|
|
|
DESCRIPTION
|
|
|
|
For both the SunOS and SVR4 shared library implementations, if the
|
|
inferior executable has been linked dynamically, there is a single
|
|
address somewhere in the inferior's data space which is the key to
|
|
locating all of the dynamic linker's runtime structures. This
|
|
address is the value of the debug base symbol. The job of this
|
|
function is to find and return that address, or to return 0 if there
|
|
is no such address (the executable is statically linked for example).
|
|
|
|
For SunOS, the job is almost trivial, since the dynamic linker and
|
|
all of it's structures are statically linked to the executable at
|
|
link time. Thus the symbol for the address we are looking for has
|
|
already been added to the minimal symbol table for the executable's
|
|
objfile at the time the symbol file's symbols were read, and all we
|
|
have to do is look it up there. Note that we explicitly do NOT want
|
|
to find the copies in the shared library.
|
|
|
|
The SVR4 version is a bit more complicated because the address
|
|
is contained somewhere in the dynamic info section. We have to go
|
|
to a lot more work to discover the address of the debug base symbol.
|
|
Because of this complexity, we cache the value we find and return that
|
|
value on subsequent invocations. Note there is no copy in the
|
|
executable symbol tables.
|
|
|
|
*/
|
|
|
|
static CORE_ADDR
|
|
locate_base (void)
|
|
{
|
|
/* Check to see if we have a currently valid address, and if so, avoid
|
|
doing all this work again and just return the cached address. If
|
|
we have no cached address, try to locate it in the dynamic info
|
|
section for ELF executables. There's no point in doing any of this
|
|
though if we don't have some link map offsets to work with. */
|
|
|
|
if (debug_base == 0 && svr4_have_link_map_offsets ())
|
|
{
|
|
if (exec_bfd != NULL
|
|
&& bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
|
|
debug_base = elf_locate_base ();
|
|
#ifdef HANDLE_SVR4_EXEC_EMULATORS
|
|
/* Try it the hard way for emulated executables. */
|
|
else if (!ptid_equal (inferior_ptid, null_ptid) && target_has_execution)
|
|
proc_iterate_over_mappings (look_for_base);
|
|
#endif
|
|
}
|
|
return (debug_base);
|
|
}
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
first_link_map_member -- locate first member in dynamic linker's map
|
|
|
|
SYNOPSIS
|
|
|
|
static CORE_ADDR first_link_map_member (void)
|
|
|
|
DESCRIPTION
|
|
|
|
Find the first element in the inferior's dynamic link map, and
|
|
return its address in the inferior. This function doesn't copy the
|
|
link map entry itself into our address space; current_sos actually
|
|
does the reading. */
|
|
|
|
static CORE_ADDR
|
|
first_link_map_member (void)
|
|
{
|
|
CORE_ADDR lm = 0;
|
|
struct link_map_offsets *lmo = SVR4_FETCH_LINK_MAP_OFFSETS ();
|
|
char *r_map_buf = xmalloc (lmo->r_map_size);
|
|
struct cleanup *cleanups = make_cleanup (xfree, r_map_buf);
|
|
|
|
read_memory (debug_base + lmo->r_map_offset, r_map_buf, lmo->r_map_size);
|
|
|
|
/* Assume that the address is unsigned. */
|
|
lm = extract_unsigned_integer (r_map_buf, lmo->r_map_size);
|
|
|
|
/* FIXME: Perhaps we should validate the info somehow, perhaps by
|
|
checking r_version for a known version number, or r_state for
|
|
RT_CONSISTENT. */
|
|
|
|
do_cleanups (cleanups);
|
|
|
|
return (lm);
|
|
}
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
open_symbol_file_object
|
|
|
|
SYNOPSIS
|
|
|
|
void open_symbol_file_object (void *from_tty)
|
|
|
|
DESCRIPTION
|
|
|
|
If no open symbol file, attempt to locate and open the main symbol
|
|
file. On SVR4 systems, this is the first link map entry. If its
|
|
name is here, we can open it. Useful when attaching to a process
|
|
without first loading its symbol file.
|
|
|
|
If FROM_TTYP dereferences to a non-zero integer, allow messages to
|
|
be printed. This parameter is a pointer rather than an int because
|
|
open_symbol_file_object() is called via catch_errors() and
|
|
catch_errors() requires a pointer argument. */
|
|
|
|
static int
|
|
open_symbol_file_object (void *from_ttyp)
|
|
{
|
|
CORE_ADDR lm, l_name;
|
|
char *filename;
|
|
int errcode;
|
|
int from_tty = *(int *)from_ttyp;
|
|
struct link_map_offsets *lmo = SVR4_FETCH_LINK_MAP_OFFSETS ();
|
|
char *l_name_buf = xmalloc (lmo->l_name_size);
|
|
struct cleanup *cleanups = make_cleanup (xfree, l_name_buf);
|
|
|
|
if (symfile_objfile)
|
|
if (!query ("Attempt to reload symbols from process? "))
|
|
return 0;
|
|
|
|
if ((debug_base = locate_base ()) == 0)
|
|
return 0; /* failed somehow... */
|
|
|
|
/* First link map member should be the executable. */
|
|
if ((lm = first_link_map_member ()) == 0)
|
|
return 0; /* failed somehow... */
|
|
|
|
/* Read address of name from target memory to GDB. */
|
|
read_memory (lm + lmo->l_name_offset, l_name_buf, lmo->l_name_size);
|
|
|
|
/* Convert the address to host format. Assume that the address is
|
|
unsigned. */
|
|
l_name = extract_unsigned_integer (l_name_buf, lmo->l_name_size);
|
|
|
|
/* Free l_name_buf. */
|
|
do_cleanups (cleanups);
|
|
|
|
if (l_name == 0)
|
|
return 0; /* No filename. */
|
|
|
|
/* Now fetch the filename from target memory. */
|
|
target_read_string (l_name, &filename, SO_NAME_MAX_PATH_SIZE - 1, &errcode);
|
|
|
|
if (errcode)
|
|
{
|
|
warning ("failed to read exec filename from attached file: %s",
|
|
safe_strerror (errcode));
|
|
return 0;
|
|
}
|
|
|
|
make_cleanup (xfree, filename);
|
|
/* Have a pathname: read the symbol file. */
|
|
symbol_file_add_main (filename, from_tty);
|
|
|
|
return 1;
|
|
}
|
|
|
|
/* LOCAL FUNCTION
|
|
|
|
current_sos -- build a list of currently loaded shared objects
|
|
|
|
SYNOPSIS
|
|
|
|
struct so_list *current_sos ()
|
|
|
|
DESCRIPTION
|
|
|
|
Build a list of `struct so_list' objects describing the shared
|
|
objects currently loaded in the inferior. This list does not
|
|
include an entry for the main executable file.
|
|
|
|
Note that we only gather information directly available from the
|
|
inferior --- we don't examine any of the shared library files
|
|
themselves. The declaration of `struct so_list' says which fields
|
|
we provide values for. */
|
|
|
|
static struct so_list *
|
|
svr4_current_sos (void)
|
|
{
|
|
CORE_ADDR lm;
|
|
struct so_list *head = 0;
|
|
struct so_list **link_ptr = &head;
|
|
|
|
/* Make sure we've looked up the inferior's dynamic linker's base
|
|
structure. */
|
|
if (! debug_base)
|
|
{
|
|
debug_base = locate_base ();
|
|
|
|
/* If we can't find the dynamic linker's base structure, this
|
|
must not be a dynamically linked executable. Hmm. */
|
|
if (! debug_base)
|
|
return 0;
|
|
}
|
|
|
|
/* Walk the inferior's link map list, and build our list of
|
|
`struct so_list' nodes. */
|
|
lm = first_link_map_member ();
|
|
while (lm)
|
|
{
|
|
struct link_map_offsets *lmo = SVR4_FETCH_LINK_MAP_OFFSETS ();
|
|
struct so_list *new
|
|
= (struct so_list *) xmalloc (sizeof (struct so_list));
|
|
struct cleanup *old_chain = make_cleanup (xfree, new);
|
|
|
|
memset (new, 0, sizeof (*new));
|
|
|
|
new->lm_info = xmalloc (sizeof (struct lm_info));
|
|
make_cleanup (xfree, new->lm_info);
|
|
|
|
new->lm_info->lm = xmalloc (lmo->link_map_size);
|
|
make_cleanup (xfree, new->lm_info->lm);
|
|
memset (new->lm_info->lm, 0, lmo->link_map_size);
|
|
|
|
read_memory (lm, new->lm_info->lm, lmo->link_map_size);
|
|
|
|
lm = LM_NEXT (new);
|
|
|
|
/* For SVR4 versions, the first entry in the link map is for the
|
|
inferior executable, so we must ignore it. For some versions of
|
|
SVR4, it has no name. For others (Solaris 2.3 for example), it
|
|
does have a name, so we can no longer use a missing name to
|
|
decide when to ignore it. */
|
|
if (IGNORE_FIRST_LINK_MAP_ENTRY (new))
|
|
free_so (new);
|
|
else
|
|
{
|
|
int errcode;
|
|
char *buffer;
|
|
|
|
/* Extract this shared object's name. */
|
|
target_read_string (LM_NAME (new), &buffer,
|
|
SO_NAME_MAX_PATH_SIZE - 1, &errcode);
|
|
if (errcode != 0)
|
|
{
|
|
warning ("current_sos: Can't read pathname for load map: %s\n",
|
|
safe_strerror (errcode));
|
|
}
|
|
else
|
|
{
|
|
strncpy (new->so_name, buffer, SO_NAME_MAX_PATH_SIZE - 1);
|
|
new->so_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0';
|
|
xfree (buffer);
|
|
strcpy (new->so_original_name, new->so_name);
|
|
}
|
|
|
|
/* If this entry has no name, or its name matches the name
|
|
for the main executable, don't include it in the list. */
|
|
if (! new->so_name[0]
|
|
|| match_main (new->so_name))
|
|
free_so (new);
|
|
else
|
|
{
|
|
new->next = 0;
|
|
*link_ptr = new;
|
|
link_ptr = &new->next;
|
|
}
|
|
}
|
|
|
|
discard_cleanups (old_chain);
|
|
}
|
|
|
|
return head;
|
|
}
|
|
|
|
/* Get the address of the link_map for a given OBJFILE. Loop through
|
|
the link maps, and return the address of the one corresponding to
|
|
the given objfile. Note that this function takes into account that
|
|
objfile can be the main executable, not just a shared library. The
|
|
main executable has always an empty name field in the linkmap. */
|
|
|
|
CORE_ADDR
|
|
svr4_fetch_objfile_link_map (struct objfile *objfile)
|
|
{
|
|
CORE_ADDR lm;
|
|
|
|
if ((debug_base = locate_base ()) == 0)
|
|
return 0; /* failed somehow... */
|
|
|
|
/* Position ourselves on the first link map. */
|
|
lm = first_link_map_member ();
|
|
while (lm)
|
|
{
|
|
/* Get info on the layout of the r_debug and link_map structures. */
|
|
struct link_map_offsets *lmo = SVR4_FETCH_LINK_MAP_OFFSETS ();
|
|
int errcode;
|
|
char *buffer;
|
|
struct lm_info objfile_lm_info;
|
|
struct cleanup *old_chain;
|
|
CORE_ADDR name_address;
|
|
char *l_name_buf = xmalloc (lmo->l_name_size);
|
|
old_chain = make_cleanup (xfree, l_name_buf);
|
|
|
|
/* Set up the buffer to contain the portion of the link_map
|
|
structure that gdb cares about. Note that this is not the
|
|
whole link_map structure. */
|
|
objfile_lm_info.lm = xmalloc (lmo->link_map_size);
|
|
make_cleanup (xfree, objfile_lm_info.lm);
|
|
memset (objfile_lm_info.lm, 0, lmo->link_map_size);
|
|
|
|
/* Read the link map into our internal structure. */
|
|
read_memory (lm, objfile_lm_info.lm, lmo->link_map_size);
|
|
|
|
/* Read address of name from target memory to GDB. */
|
|
read_memory (lm + lmo->l_name_offset, l_name_buf, lmo->l_name_size);
|
|
|
|
/* Extract this object's name. Assume that the address is
|
|
unsigned. */
|
|
name_address = extract_unsigned_integer (l_name_buf, lmo->l_name_size);
|
|
target_read_string (name_address, &buffer,
|
|
SO_NAME_MAX_PATH_SIZE - 1, &errcode);
|
|
make_cleanup (xfree, buffer);
|
|
if (errcode != 0)
|
|
{
|
|
warning ("svr4_fetch_objfile_link_map: Can't read pathname for load map: %s\n",
|
|
safe_strerror (errcode));
|
|
}
|
|
else
|
|
{
|
|
/* Is this the linkmap for the file we want? */
|
|
/* If the file is not a shared library and has no name,
|
|
we are sure it is the main executable, so we return that. */
|
|
if ((buffer && strcmp (buffer, objfile->name) == 0)
|
|
|| (!(objfile->flags & OBJF_SHARED) && (strcmp (buffer, "") == 0)))
|
|
{
|
|
do_cleanups (old_chain);
|
|
return lm;
|
|
}
|
|
}
|
|
/* Not the file we wanted, continue checking. Assume that the
|
|
address is unsigned. */
|
|
lm = extract_unsigned_integer (objfile_lm_info.lm + lmo->l_next_offset,
|
|
lmo->l_next_size);
|
|
do_cleanups (old_chain);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* On some systems, the only way to recognize the link map entry for
|
|
the main executable file is by looking at its name. Return
|
|
non-zero iff SONAME matches one of the known main executable names. */
|
|
|
|
static int
|
|
match_main (char *soname)
|
|
{
|
|
char **mainp;
|
|
|
|
for (mainp = main_name_list; *mainp != NULL; mainp++)
|
|
{
|
|
if (strcmp (soname, *mainp) == 0)
|
|
return (1);
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
/* Return 1 if PC lies in the dynamic symbol resolution code of the
|
|
SVR4 run time loader. */
|
|
static CORE_ADDR interp_text_sect_low;
|
|
static CORE_ADDR interp_text_sect_high;
|
|
static CORE_ADDR interp_plt_sect_low;
|
|
static CORE_ADDR interp_plt_sect_high;
|
|
|
|
static int
|
|
svr4_in_dynsym_resolve_code (CORE_ADDR pc)
|
|
{
|
|
return ((pc >= interp_text_sect_low && pc < interp_text_sect_high)
|
|
|| (pc >= interp_plt_sect_low && pc < interp_plt_sect_high)
|
|
|| in_plt_section (pc, NULL));
|
|
}
|
|
|
|
/* Given an executable's ABFD and target, compute the entry-point
|
|
address. */
|
|
|
|
static CORE_ADDR
|
|
exec_entry_point (struct bfd *abfd, struct target_ops *targ)
|
|
{
|
|
/* KevinB wrote ... for most targets, the address returned by
|
|
bfd_get_start_address() is the entry point for the start
|
|
function. But, for some targets, bfd_get_start_address() returns
|
|
the address of a function descriptor from which the entry point
|
|
address may be extracted. This address is extracted by
|
|
gdbarch_convert_from_func_ptr_addr(). The method
|
|
gdbarch_convert_from_func_ptr_addr() is the merely the identify
|
|
function for targets which don't use function descriptors. */
|
|
return gdbarch_convert_from_func_ptr_addr (current_gdbarch,
|
|
bfd_get_start_address (abfd),
|
|
targ);
|
|
}
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
enable_break -- arrange for dynamic linker to hit breakpoint
|
|
|
|
SYNOPSIS
|
|
|
|
int enable_break (void)
|
|
|
|
DESCRIPTION
|
|
|
|
Both the SunOS and the SVR4 dynamic linkers have, as part of their
|
|
debugger interface, support for arranging for the inferior to hit
|
|
a breakpoint after mapping in the shared libraries. This function
|
|
enables that breakpoint.
|
|
|
|
For SunOS, there is a special flag location (in_debugger) which we
|
|
set to 1. When the dynamic linker sees this flag set, it will set
|
|
a breakpoint at a location known only to itself, after saving the
|
|
original contents of that place and the breakpoint address itself,
|
|
in it's own internal structures. When we resume the inferior, it
|
|
will eventually take a SIGTRAP when it runs into the breakpoint.
|
|
We handle this (in a different place) by restoring the contents of
|
|
the breakpointed location (which is only known after it stops),
|
|
chasing around to locate the shared libraries that have been
|
|
loaded, then resuming.
|
|
|
|
For SVR4, the debugger interface structure contains a member (r_brk)
|
|
which is statically initialized at the time the shared library is
|
|
built, to the offset of a function (_r_debug_state) which is guaran-
|
|
teed to be called once before mapping in a library, and again when
|
|
the mapping is complete. At the time we are examining this member,
|
|
it contains only the unrelocated offset of the function, so we have
|
|
to do our own relocation. Later, when the dynamic linker actually
|
|
runs, it relocates r_brk to be the actual address of _r_debug_state().
|
|
|
|
The debugger interface structure also contains an enumeration which
|
|
is set to either RT_ADD or RT_DELETE prior to changing the mapping,
|
|
depending upon whether or not the library is being mapped or unmapped,
|
|
and then set to RT_CONSISTENT after the library is mapped/unmapped.
|
|
*/
|
|
|
|
static int
|
|
enable_break (void)
|
|
{
|
|
int success = 0;
|
|
|
|
#ifdef BKPT_AT_SYMBOL
|
|
|
|
struct minimal_symbol *msymbol;
|
|
char **bkpt_namep;
|
|
asection *interp_sect;
|
|
|
|
/* First, remove all the solib event breakpoints. Their addresses
|
|
may have changed since the last time we ran the program. */
|
|
remove_solib_event_breakpoints ();
|
|
|
|
interp_text_sect_low = interp_text_sect_high = 0;
|
|
interp_plt_sect_low = interp_plt_sect_high = 0;
|
|
|
|
/* Find the .interp section; if not found, warn the user and drop
|
|
into the old breakpoint at symbol code. */
|
|
interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
|
|
if (interp_sect)
|
|
{
|
|
unsigned int interp_sect_size;
|
|
char *buf;
|
|
CORE_ADDR load_addr = 0;
|
|
int load_addr_found = 0;
|
|
struct so_list *inferior_sos;
|
|
bfd *tmp_bfd = NULL;
|
|
struct target_ops *tmp_bfd_target;
|
|
int tmp_fd = -1;
|
|
char *tmp_pathname = NULL;
|
|
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_fd = solib_open (buf, &tmp_pathname);
|
|
if (tmp_fd >= 0)
|
|
tmp_bfd = bfd_fdopenr (tmp_pathname, gnutarget, tmp_fd);
|
|
|
|
if (tmp_bfd == NULL)
|
|
goto bkpt_at_symbol;
|
|
|
|
/* 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);
|
|
goto bkpt_at_symbol;
|
|
}
|
|
|
|
/* Now convert the TMP_BFD into a target. That way target, as
|
|
well as BFD operations can be used. Note that closing the
|
|
target will also close the underlying bfd. */
|
|
tmp_bfd_target = target_bfd_reopen (tmp_bfd);
|
|
|
|
/* If the entry in _DYNAMIC for the dynamic linker has already
|
|
been filled in, we can read its base address from there. */
|
|
inferior_sos = svr4_current_sos ();
|
|
if (inferior_sos)
|
|
{
|
|
/* Connected to a running target. Update our shared library table. */
|
|
solib_add (NULL, 0, NULL, auto_solib_add);
|
|
}
|
|
while (inferior_sos)
|
|
{
|
|
if (strcmp (buf, inferior_sos->so_original_name) == 0)
|
|
{
|
|
load_addr_found = 1;
|
|
load_addr = LM_ADDR (inferior_sos);
|
|
break;
|
|
}
|
|
inferior_sos = inferior_sos->next;
|
|
}
|
|
|
|
/* Otherwise we find the dynamic linker's base address by examining
|
|
the current pc (which should point at the entry point for the
|
|
dynamic linker) and subtracting the offset of the entry point. */
|
|
if (!load_addr_found)
|
|
load_addr = (read_pc ()
|
|
- exec_entry_point (tmp_bfd, tmp_bfd_target));
|
|
|
|
/* Record the relocated start and end address of the dynamic linker
|
|
text and plt section for svr4_in_dynsym_resolve_code. */
|
|
interp_sect = bfd_get_section_by_name (tmp_bfd, ".text");
|
|
if (interp_sect)
|
|
{
|
|
interp_text_sect_low =
|
|
bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
|
|
interp_text_sect_high =
|
|
interp_text_sect_low + bfd_section_size (tmp_bfd, interp_sect);
|
|
}
|
|
interp_sect = bfd_get_section_by_name (tmp_bfd, ".plt");
|
|
if (interp_sect)
|
|
{
|
|
interp_plt_sect_low =
|
|
bfd_section_vma (tmp_bfd, interp_sect) + load_addr;
|
|
interp_plt_sect_high =
|
|
interp_plt_sect_low + bfd_section_size (tmp_bfd, interp_sect);
|
|
}
|
|
|
|
/* Now try to set a breakpoint in the dynamic linker. */
|
|
for (bkpt_namep = solib_break_names; *bkpt_namep != NULL; bkpt_namep++)
|
|
{
|
|
/* On ABI's that use function descriptors, there are usually
|
|
two linker symbols associated with each C function: one
|
|
pointing at the actual entry point of the machine code,
|
|
and one pointing at the function's descriptor. The
|
|
latter symbol has the same name as the C function.
|
|
|
|
What we're looking for here is the machine code entry
|
|
point, so we are only interested in symbols in code
|
|
sections. */
|
|
sym_addr = bfd_lookup_symbol (tmp_bfd, *bkpt_namep, SEC_CODE);
|
|
if (sym_addr != 0)
|
|
break;
|
|
}
|
|
|
|
/* We're done with both the temporary bfd and target. Remember,
|
|
closing the target closes the underlying bfd. */
|
|
target_close (tmp_bfd_target, 0);
|
|
|
|
if (sym_addr != 0)
|
|
{
|
|
create_solib_event_breakpoint (load_addr + sym_addr);
|
|
return 1;
|
|
}
|
|
|
|
/* For whatever reason we couldn't set a breakpoint in the dynamic
|
|
linker. Warn and drop into the old code. */
|
|
bkpt_at_symbol:
|
|
warning ("Unable to find dynamic linker breakpoint function.\nGDB will be unable to debug shared library initializers\nand track explicitly loaded dynamic code.");
|
|
}
|
|
|
|
/* Scan through the list of symbols, trying to look up the symbol and
|
|
set a breakpoint there. Terminate loop when we/if we succeed. */
|
|
|
|
breakpoint_addr = 0;
|
|
for (bkpt_namep = bkpt_names; *bkpt_namep != NULL; bkpt_namep++)
|
|
{
|
|
msymbol = lookup_minimal_symbol (*bkpt_namep, NULL, symfile_objfile);
|
|
if ((msymbol != NULL) && (SYMBOL_VALUE_ADDRESS (msymbol) != 0))
|
|
{
|
|
create_solib_event_breakpoint (SYMBOL_VALUE_ADDRESS (msymbol));
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
/* Nothing good happened. */
|
|
success = 0;
|
|
|
|
#endif /* BKPT_AT_SYMBOL */
|
|
|
|
return (success);
|
|
}
|
|
|
|
/*
|
|
|
|
LOCAL FUNCTION
|
|
|
|
special_symbol_handling -- additional shared library symbol handling
|
|
|
|
SYNOPSIS
|
|
|
|
void special_symbol_handling ()
|
|
|
|
DESCRIPTION
|
|
|
|
Once the symbols from a shared object have been loaded in the usual
|
|
way, we are called to do any system specific symbol handling that
|
|
is needed.
|
|
|
|
For SunOS4, this consisted of grunging around in the dynamic
|
|
linkers structures to find symbol definitions for "common" symbols
|
|
and adding them to the minimal symbol table for the runtime common
|
|
objfile.
|
|
|
|
However, for SVR4, there's nothing to do.
|
|
|
|
*/
|
|
|
|
static void
|
|
svr4_special_symbol_handling (void)
|
|
{
|
|
}
|
|
|
|
/* Relocate the main executable. This function should be called upon
|
|
stopping the inferior process at the entry point to the program.
|
|
The entry point from BFD is compared to the PC and if they are
|
|
different, the main executable is relocated by the proper amount.
|
|
|
|
As written it will only attempt to relocate executables which
|
|
lack interpreter sections. It seems likely that only dynamic
|
|
linker executables will get relocated, though it should work
|
|
properly for a position-independent static executable as well. */
|
|
|
|
static void
|
|
svr4_relocate_main_executable (void)
|
|
{
|
|
asection *interp_sect;
|
|
CORE_ADDR pc = read_pc ();
|
|
|
|
/* Decide if the objfile needs to be relocated. As indicated above,
|
|
we will only be here when execution is stopped at the beginning
|
|
of the program. Relocation is necessary if the address at which
|
|
we are presently stopped differs from the start address stored in
|
|
the executable AND there's no interpreter section. The condition
|
|
regarding the interpreter section is very important because if
|
|
there *is* an interpreter section, execution will begin there
|
|
instead. When there is an interpreter section, the start address
|
|
is (presumably) used by the interpreter at some point to start
|
|
execution of the program.
|
|
|
|
If there is an interpreter, it is normal for it to be set to an
|
|
arbitrary address at the outset. The job of finding it is
|
|
handled in enable_break().
|
|
|
|
So, to summarize, relocations are necessary when there is no
|
|
interpreter section and the start address obtained from the
|
|
executable is different from the address at which GDB is
|
|
currently stopped.
|
|
|
|
[ The astute reader will note that we also test to make sure that
|
|
the executable in question has the DYNAMIC flag set. It is my
|
|
opinion that this test is unnecessary (undesirable even). It
|
|
was added to avoid inadvertent relocation of an executable
|
|
whose e_type member in the ELF header is not ET_DYN. There may
|
|
be a time in the future when it is desirable to do relocations
|
|
on other types of files as well in which case this condition
|
|
should either be removed or modified to accomodate the new file
|
|
type. (E.g, an ET_EXEC executable which has been built to be
|
|
position-independent could safely be relocated by the OS if
|
|
desired. It is true that this violates the ABI, but the ABI
|
|
has been known to be bent from time to time.) - Kevin, Nov 2000. ]
|
|
*/
|
|
|
|
interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
|
|
if (interp_sect == NULL
|
|
&& (bfd_get_file_flags (exec_bfd) & DYNAMIC) != 0
|
|
&& (exec_entry_point (exec_bfd, &exec_ops) != pc))
|
|
{
|
|
struct cleanup *old_chain;
|
|
struct section_offsets *new_offsets;
|
|
int i, changed;
|
|
CORE_ADDR displacement;
|
|
|
|
/* It is necessary to relocate the objfile. The amount to
|
|
relocate by is simply the address at which we are stopped
|
|
minus the starting address from the executable.
|
|
|
|
We relocate all of the sections by the same amount. This
|
|
behavior is mandated by recent editions of the System V ABI.
|
|
According to the System V Application Binary Interface,
|
|
Edition 4.1, page 5-5:
|
|
|
|
... Though the system chooses virtual addresses for
|
|
individual processes, it maintains the segments' relative
|
|
positions. Because position-independent code uses relative
|
|
addressesing between segments, the difference between
|
|
virtual addresses in memory must match the difference
|
|
between virtual addresses in the file. The difference
|
|
between the virtual address of any segment in memory and
|
|
the corresponding virtual address in the file is thus a
|
|
single constant value for any one executable or shared
|
|
object in a given process. This difference is the base
|
|
address. One use of the base address is to relocate the
|
|
memory image of the program during dynamic linking.
|
|
|
|
The same language also appears in Edition 4.0 of the System V
|
|
ABI and is left unspecified in some of the earlier editions. */
|
|
|
|
displacement = pc - exec_entry_point (exec_bfd, &exec_ops);
|
|
changed = 0;
|
|
|
|
new_offsets = xcalloc (symfile_objfile->num_sections,
|
|
sizeof (struct section_offsets));
|
|
old_chain = make_cleanup (xfree, new_offsets);
|
|
|
|
for (i = 0; i < symfile_objfile->num_sections; i++)
|
|
{
|
|
if (displacement != ANOFFSET (symfile_objfile->section_offsets, i))
|
|
changed = 1;
|
|
new_offsets->offsets[i] = displacement;
|
|
}
|
|
|
|
if (changed)
|
|
objfile_relocate (symfile_objfile, new_offsets);
|
|
|
|
do_cleanups (old_chain);
|
|
}
|
|
}
|
|
|
|
/*
|
|
|
|
GLOBAL FUNCTION
|
|
|
|
svr4_solib_create_inferior_hook -- shared library startup support
|
|
|
|
SYNOPSIS
|
|
|
|
void svr4_solib_create_inferior_hook()
|
|
|
|
DESCRIPTION
|
|
|
|
When gdb starts up the inferior, it nurses it along (through the
|
|
shell) until it is ready to execute it's first instruction. At this
|
|
point, this function gets called via expansion of the macro
|
|
SOLIB_CREATE_INFERIOR_HOOK.
|
|
|
|
For SunOS executables, this first instruction is typically the
|
|
one at "_start", or a similar text label, regardless of whether
|
|
the executable is statically or dynamically linked. The runtime
|
|
startup code takes care of dynamically linking in any shared
|
|
libraries, once gdb allows the inferior to continue.
|
|
|
|
For SVR4 executables, this first instruction is either the first
|
|
instruction in the dynamic linker (for dynamically linked
|
|
executables) or the instruction at "start" for statically linked
|
|
executables. For dynamically linked executables, the system
|
|
first exec's /lib/libc.so.N, which contains the dynamic linker,
|
|
and starts it running. The dynamic linker maps in any needed
|
|
shared libraries, maps in the actual user executable, and then
|
|
jumps to "start" in the user executable.
|
|
|
|
For both SunOS shared libraries, and SVR4 shared libraries, we
|
|
can arrange to cooperate with the dynamic linker to discover the
|
|
names of shared libraries that are dynamically linked, and the
|
|
base addresses to which they are linked.
|
|
|
|
This function is responsible for discovering those names and
|
|
addresses, and saving sufficient information about them to allow
|
|
their symbols to be read at a later time.
|
|
|
|
FIXME
|
|
|
|
Between enable_break() and disable_break(), this code does not
|
|
properly handle hitting breakpoints which the user might have
|
|
set in the startup code or in the dynamic linker itself. Proper
|
|
handling will probably have to wait until the implementation is
|
|
changed to use the "breakpoint handler function" method.
|
|
|
|
Also, what if child has exit()ed? Must exit loop somehow.
|
|
*/
|
|
|
|
static void
|
|
svr4_solib_create_inferior_hook (void)
|
|
{
|
|
/* Relocate the main executable if necessary. */
|
|
svr4_relocate_main_executable ();
|
|
|
|
if (!svr4_have_link_map_offsets ())
|
|
{
|
|
warning ("no shared library support for this OS / ABI");
|
|
return;
|
|
|
|
}
|
|
|
|
if (!enable_break ())
|
|
{
|
|
warning ("shared library handler failed to enable breakpoint");
|
|
return;
|
|
}
|
|
|
|
#if defined(_SCO_DS)
|
|
/* SCO needs the loop below, other systems should be using the
|
|
special shared library breakpoints and the shared library breakpoint
|
|
service routine.
|
|
|
|
Now run the target. It will eventually hit the breakpoint, at
|
|
which point all of the libraries will have been mapped in and we
|
|
can go groveling around in the dynamic linker structures to find
|
|
out what we need to know about them. */
|
|
|
|
clear_proceed_status ();
|
|
stop_soon = STOP_QUIETLY;
|
|
stop_signal = TARGET_SIGNAL_0;
|
|
do
|
|
{
|
|
target_resume (pid_to_ptid (-1), 0, stop_signal);
|
|
wait_for_inferior ();
|
|
}
|
|
while (stop_signal != TARGET_SIGNAL_TRAP);
|
|
stop_soon = NO_STOP_QUIETLY;
|
|
#endif /* defined(_SCO_DS) */
|
|
}
|
|
|
|
static void
|
|
svr4_clear_solib (void)
|
|
{
|
|
debug_base = 0;
|
|
}
|
|
|
|
static void
|
|
svr4_free_so (struct so_list *so)
|
|
{
|
|
xfree (so->lm_info->lm);
|
|
xfree (so->lm_info);
|
|
}
|
|
|
|
|
|
/* Clear any bits of ADDR that wouldn't fit in a target-format
|
|
data pointer. "Data pointer" here refers to whatever sort of
|
|
address the dynamic linker uses to manage its sections. At the
|
|
moment, we don't support shared libraries on any processors where
|
|
code and data pointers are different sizes.
|
|
|
|
This isn't really the right solution. What we really need here is
|
|
a way to do arithmetic on CORE_ADDR values that respects the
|
|
natural pointer/address correspondence. (For example, on the MIPS,
|
|
converting a 32-bit pointer to a 64-bit CORE_ADDR requires you to
|
|
sign-extend the value. There, simply truncating the bits above
|
|
TARGET_PTR_BIT, as we do below, is no good.) This should probably
|
|
be a new gdbarch method or something. */
|
|
static CORE_ADDR
|
|
svr4_truncate_ptr (CORE_ADDR addr)
|
|
{
|
|
if (TARGET_PTR_BIT == sizeof (CORE_ADDR) * 8)
|
|
/* We don't need to truncate anything, and the bit twiddling below
|
|
will fail due to overflow problems. */
|
|
return addr;
|
|
else
|
|
return addr & (((CORE_ADDR) 1 << TARGET_PTR_BIT) - 1);
|
|
}
|
|
|
|
|
|
static void
|
|
svr4_relocate_section_addresses (struct so_list *so,
|
|
struct section_table *sec)
|
|
{
|
|
sec->addr = svr4_truncate_ptr (sec->addr + LM_ADDR (so));
|
|
sec->endaddr = svr4_truncate_ptr (sec->endaddr + LM_ADDR (so));
|
|
}
|
|
|
|
|
|
/* Fetch a link_map_offsets structure for native targets using struct
|
|
definitions from link.h. See solib-legacy.c for the function
|
|
which does the actual work.
|
|
|
|
Note: For non-native targets (i.e. cross-debugging situations),
|
|
a target specific fetch_link_map_offsets() function should be
|
|
defined and registered via set_solib_svr4_fetch_link_map_offsets(). */
|
|
|
|
static struct link_map_offsets *
|
|
legacy_fetch_link_map_offsets (void)
|
|
{
|
|
if (legacy_svr4_fetch_link_map_offsets_hook)
|
|
return legacy_svr4_fetch_link_map_offsets_hook ();
|
|
else
|
|
{
|
|
internal_error (__FILE__, __LINE__,
|
|
"legacy_fetch_link_map_offsets called without legacy "
|
|
"link_map support enabled.");
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* Fetch a link_map_offsets structure using the method registered in the
|
|
architecture vector. */
|
|
|
|
static struct link_map_offsets *
|
|
svr4_fetch_link_map_offsets (void)
|
|
{
|
|
struct link_map_offsets *(*flmo)(void) =
|
|
gdbarch_data (current_gdbarch, fetch_link_map_offsets_gdbarch_data);
|
|
|
|
if (flmo == NULL)
|
|
{
|
|
internal_error (__FILE__, __LINE__,
|
|
"svr4_fetch_link_map_offsets: fetch_link_map_offsets "
|
|
"method not defined for this architecture.");
|
|
return 0;
|
|
}
|
|
else
|
|
return (flmo ());
|
|
}
|
|
|
|
/* Return 1 if a link map offset fetcher has been defined, 0 otherwise. */
|
|
static int
|
|
svr4_have_link_map_offsets (void)
|
|
{
|
|
struct link_map_offsets *(*flmo)(void) =
|
|
gdbarch_data (current_gdbarch, fetch_link_map_offsets_gdbarch_data);
|
|
if (flmo == NULL
|
|
|| (flmo == legacy_fetch_link_map_offsets
|
|
&& legacy_svr4_fetch_link_map_offsets_hook == NULL))
|
|
return 0;
|
|
else
|
|
return 1;
|
|
}
|
|
|
|
/* set_solib_svr4_fetch_link_map_offsets() is intended to be called by
|
|
a <arch>_gdbarch_init() function. It is used to establish an
|
|
architecture specific link_map_offsets fetcher for the architecture
|
|
being defined. */
|
|
|
|
void
|
|
set_solib_svr4_fetch_link_map_offsets (struct gdbarch *gdbarch,
|
|
struct link_map_offsets *(*flmo) (void))
|
|
{
|
|
set_gdbarch_data (gdbarch, fetch_link_map_offsets_gdbarch_data, flmo);
|
|
}
|
|
|
|
/* Initialize the architecture-specific link_map_offsets fetcher.
|
|
This is called after <arch>_gdbarch_init() has set up its `struct
|
|
gdbarch' for the new architecture, and is only called if the
|
|
link_map_offsets fetcher isn't already initialized (which is
|
|
usually done by calling set_solib_svr4_fetch_link_map_offsets()
|
|
above in <arch>_gdbarch_init()). Therefore we attempt to provide a
|
|
reasonable alternative (for native targets anyway) if the
|
|
<arch>_gdbarch_init() fails to call
|
|
set_solib_svr4_fetch_link_map_offsets(). */
|
|
|
|
static void *
|
|
init_fetch_link_map_offsets (struct gdbarch *gdbarch)
|
|
{
|
|
return legacy_fetch_link_map_offsets;
|
|
}
|
|
|
|
static struct target_so_ops svr4_so_ops;
|
|
|
|
extern initialize_file_ftype _initialize_svr4_solib; /* -Wmissing-prototypes */
|
|
|
|
void
|
|
_initialize_svr4_solib (void)
|
|
{
|
|
fetch_link_map_offsets_gdbarch_data =
|
|
register_gdbarch_data (init_fetch_link_map_offsets);
|
|
|
|
svr4_so_ops.relocate_section_addresses = svr4_relocate_section_addresses;
|
|
svr4_so_ops.free_so = svr4_free_so;
|
|
svr4_so_ops.clear_solib = svr4_clear_solib;
|
|
svr4_so_ops.solib_create_inferior_hook = svr4_solib_create_inferior_hook;
|
|
svr4_so_ops.special_symbol_handling = svr4_special_symbol_handling;
|
|
svr4_so_ops.current_sos = svr4_current_sos;
|
|
svr4_so_ops.open_symbol_file_object = open_symbol_file_object;
|
|
svr4_so_ops.in_dynsym_resolve_code = svr4_in_dynsym_resolve_code;
|
|
|
|
/* FIXME: Don't do this here. *_gdbarch_init() should set so_ops. */
|
|
current_target_so_ops = &svr4_so_ops;
|
|
}
|