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
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
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., 51 Franklin Street, Fifth Floor,
- Boston, MA 02110-1301, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "bfd-target.h"
#include "elf-bfd.h"
#include "exec.h"
+#include "auxv.h"
static struct link_map_offsets *svr4_fetch_link_map_offsets (void);
static int svr4_have_link_map_offsets (void);
-/* This hook is set to a function that provides native link map
- offsets if the code in solib-legacy.c is linked in. */
-struct link_map_offsets *(*legacy_svr4_fetch_link_map_offsets_hook) (void);
-
/* Link map info to include in an allocated so_list entry */
struct lm_info
"rtld_db_dlactivity",
"_rtld_debug_state",
- /* On the 64-bit PowerPC, the linker symbol with the same name as
- the C function points to a function descriptor, not to the entry
- point. The linker symbol whose name is the C function name
- prefixed with a '.' points to the function's entry point. So
- when we look through this table, we ignore symbols that point
- into the data section (thus skipping the descriptor's symbol),
- and eventually try this one, giving us the real entry point
- address. */
- "._dl_debug_state",
-
NULL
};
don't adjust the base offset in the latter case, although
odds are that, if things really changed, debugging won't
quite work. */
- if ((l_addr & align) == 0 && ((dynaddr - l_dynaddr) & align) == 0)
+ if ((l_addr & align) == ((l_dynaddr - dynaddr) & align))
{
l_addr = l_dynaddr - dynaddr;
static int match_main (char *);
-static CORE_ADDR bfd_lookup_symbol (bfd *, char *, flagword);
+static CORE_ADDR bfd_lookup_symbol (bfd *, char *);
/*
SYNOPSIS
- CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname, flagword sect_flags)
+ CORE_ADDR bfd_lookup_symbol (bfd *abfd, char *symname)
DESCRIPTION
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.
+ notification routine in the shared library.
- If SECT_FLAGS is non-zero, only match symbols in sections whose
- flags include all those in SECT_FLAGS.
+ The returned symbol may be in a code or data section; functions
+ will normally be in a code section, but may be in a data section
+ if this architecture uses function descriptors.
Note that 0 is specifically allowed as an error return (no
such symbol).
*/
static CORE_ADDR
-bfd_lookup_symbol (bfd *abfd, char *symname, flagword sect_flags)
+bfd_lookup_symbol (bfd *abfd, char *symname)
{
long storage_needed;
asymbol *sym;
{
sym = *symbol_table++;
if (strcmp (sym->name, symname) == 0
- && (sym->section->flags & sect_flags) == sect_flags)
+ && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0)
{
- /* Bfd symbols are section relative. */
+ /* BFD symbols are section relative. */
symaddr = sym->value + sym->section->vma;
break;
}
sym = *symbol_table++;
if (strcmp (sym->name, symname) == 0
- && (sym->section->flags & sect_flags) == sect_flags)
+ && (sym->section->flags & (SEC_CODE | SEC_DATA)) != 0)
{
- /* Bfd symbols are section relative. */
+ /* BFD symbols are section relative. */
symaddr = sym->value + sym->section->vma;
break;
}
return symaddr;
}
+/* Scan for DYNTAG in .dynamic section of ABFD. If DYNTAG is found 1 is
+ returned and the corresponding PTR is set. */
+
+static int
+scan_dyntag (int dyntag, bfd *abfd, CORE_ADDR *ptr)
+{
+ int arch_size, step, sect_size;
+ long dyn_tag;
+ CORE_ADDR dyn_ptr, dyn_addr;
+ gdb_byte *bufend, *bufstart, *buf;
+ Elf32_External_Dyn *x_dynp_32;
+ Elf64_External_Dyn *x_dynp_64;
+ struct bfd_section *sect;
+
+ if (abfd == NULL)
+ return 0;
+ arch_size = bfd_get_arch_size (abfd);
+ if (arch_size == -1)
+ return 0;
+
+ /* Find the start address of the .dynamic section. */
+ sect = bfd_get_section_by_name (abfd, ".dynamic");
+ if (sect == NULL)
+ return 0;
+ dyn_addr = bfd_section_vma (abfd, sect);
+
+ /* Read in .dynamic from the BFD. We will get the actual value
+ from memory later. */
+ sect_size = bfd_section_size (abfd, sect);
+ buf = bufstart = alloca (sect_size);
+ if (!bfd_get_section_contents (abfd, sect,
+ buf, 0, sect_size))
+ return 0;
+
+ /* Iterate over BUF and scan for DYNTAG. If found, set PTR and return. */
+ step = (arch_size == 32) ? sizeof (Elf32_External_Dyn)
+ : sizeof (Elf64_External_Dyn);
+ for (bufend = buf + sect_size;
+ buf < bufend;
+ buf += step)
+ {
+ if (arch_size == 32)
+ {
+ x_dynp_32 = (Elf32_External_Dyn *) buf;
+ dyn_tag = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_tag);
+ dyn_ptr = bfd_h_get_32 (abfd, (bfd_byte *) x_dynp_32->d_un.d_ptr);
+ }
+ else
+ {
+ x_dynp_64 = (Elf64_External_Dyn *) buf;
+ dyn_tag = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_tag);
+ dyn_ptr = bfd_h_get_64 (abfd, (bfd_byte *) x_dynp_64->d_un.d_ptr);
+ }
+ if (dyn_tag == DT_NULL)
+ return 0;
+ if (dyn_tag == dyntag)
+ {
+ /* If requested, try to read the runtime value of this .dynamic
+ entry. */
+ if (ptr)
+ {
+ gdb_byte ptr_buf[8];
+ CORE_ADDR ptr_addr;
+
+ ptr_addr = dyn_addr + (buf - bufstart) + arch_size / 8;
+ if (target_read_memory (ptr_addr, ptr_buf, arch_size / 8) == 0)
+ dyn_ptr = extract_typed_address (ptr_buf,
+ builtin_type_void_data_ptr);
+ *ptr = dyn_ptr;
+ }
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+
/*
LOCAL FUNCTION
static CORE_ADDR
elf_locate_base (void)
{
- struct bfd_section *dyninfo_sect;
- int dyninfo_sect_size;
- CORE_ADDR dyninfo_addr;
- gdb_byte *buf;
- gdb_byte *bufend;
- int arch_size;
+ struct minimal_symbol *msymbol;
+ CORE_ADDR dyn_ptr;
- /* Find the start address of the .dynamic section. */
- dyninfo_sect = bfd_get_section_by_name (exec_bfd, ".dynamic");
- if (dyninfo_sect == NULL)
+ /* Look for DT_MIPS_RLD_MAP first. MIPS executables use this
+ instead of DT_DEBUG, although they sometimes contain an unused
+ DT_DEBUG. */
+ if (scan_dyntag (DT_MIPS_RLD_MAP, exec_bfd, &dyn_ptr))
{
- /* This may be a static executable. Look for the symbol
- conventionally named _r_debug, as a last resort. */
- struct minimal_symbol *msymbol;
-
- msymbol = lookup_minimal_symbol ("_r_debug", NULL, symfile_objfile);
- if (msymbol != NULL)
- return SYMBOL_VALUE_ADDRESS (msymbol);
- else
+ gdb_byte *pbuf;
+ int pbuf_size = TYPE_LENGTH (builtin_type_void_data_ptr);
+ pbuf = alloca (pbuf_size);
+ /* DT_MIPS_RLD_MAP contains a pointer to the address
+ of the dynamic link structure. */
+ if (target_read_memory (dyn_ptr, pbuf, pbuf_size))
return 0;
+ return extract_typed_address (pbuf, builtin_type_void_data_ptr);
}
- dyninfo_addr = bfd_section_vma (exec_bfd, dyninfo_sect);
+ /* Find DT_DEBUG. */
+ if (scan_dyntag (DT_DEBUG, exec_bfd, &dyn_ptr))
+ return dyn_ptr;
- /* Read in .dynamic section, silently ignore errors. */
- 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;
-
- /* Find the DT_DEBUG entry in the the .dynamic section.
- For mips elf we look for DT_MIPS_RLD_MAP, mips elf apparently has
- no DT_DEBUG entries. */
-
- arch_size = bfd_get_arch_size (exec_bfd);
- if (arch_size == -1) /* failure */
- return 0;
-
- if (arch_size == 32)
- { /* 32-bit elf */
- for (bufend = buf + dyninfo_sect_size;
- buf < bufend;
- buf += sizeof (Elf32_External_Dyn))
- {
- Elf32_External_Dyn *x_dynp = (Elf32_External_Dyn *) buf;
- long dyn_tag;
- CORE_ADDR dyn_ptr;
-
- dyn_tag = bfd_h_get_32 (exec_bfd, (bfd_byte *) x_dynp->d_tag);
- if (dyn_tag == DT_NULL)
- break;
- else if (dyn_tag == DT_DEBUG)
- {
- dyn_ptr = bfd_h_get_32 (exec_bfd,
- (bfd_byte *) x_dynp->d_un.d_ptr);
- return dyn_ptr;
- }
- else if (dyn_tag == DT_MIPS_RLD_MAP)
- {
- gdb_byte *pbuf;
- int pbuf_size = TYPE_LENGTH (builtin_type_void_data_ptr);
-
- pbuf = alloca (pbuf_size);
- /* DT_MIPS_RLD_MAP contains a pointer to the address
- of the dynamic link structure. */
- dyn_ptr = bfd_h_get_32 (exec_bfd,
- (bfd_byte *) x_dynp->d_un.d_ptr);
- if (target_read_memory (dyn_ptr, pbuf, pbuf_size))
- return 0;
- return extract_typed_address (pbuf, builtin_type_void_data_ptr);
- }
- }
- }
- else /* 64-bit elf */
- {
- for (bufend = buf + dyninfo_sect_size;
- buf < bufend;
- buf += sizeof (Elf64_External_Dyn))
- {
- Elf64_External_Dyn *x_dynp = (Elf64_External_Dyn *) buf;
- long dyn_tag;
- CORE_ADDR dyn_ptr;
-
- dyn_tag = bfd_h_get_64 (exec_bfd, (bfd_byte *) x_dynp->d_tag);
- if (dyn_tag == DT_NULL)
- break;
- else if (dyn_tag == DT_DEBUG)
- {
- dyn_ptr = bfd_h_get_64 (exec_bfd,
- (bfd_byte *) x_dynp->d_un.d_ptr);
- return dyn_ptr;
- }
- else if (dyn_tag == DT_MIPS_RLD_MAP)
- {
- gdb_byte *pbuf;
- int pbuf_size = TYPE_LENGTH (builtin_type_void_data_ptr);
-
- pbuf = alloca (pbuf_size);
- /* DT_MIPS_RLD_MAP contains a pointer to the address
- of the dynamic link structure. */
- dyn_ptr = bfd_h_get_64 (exec_bfd,
- (bfd_byte *) x_dynp->d_un.d_ptr);
- if (target_read_memory (dyn_ptr, pbuf, pbuf_size))
- return 0;
- return extract_typed_address (pbuf, builtin_type_void_data_ptr);
- }
- }
- }
+ /* This may be a static executable. Look for the symbol
+ conventionally named _r_debug, as a last resort. */
+ msymbol = lookup_minimal_symbol ("_r_debug", NULL, symfile_objfile);
+ if (msymbol != NULL)
+ return SYMBOL_VALUE_ADDRESS (msymbol);
/* DT_DEBUG entry not found. */
return 0;
/* Now fetch the filename from target memory. */
target_read_string (l_name, &filename, SO_NAME_MAX_PATH_SIZE - 1, &errcode);
+ make_cleanup (xfree, filename);
if (errcode)
{
return 0;
}
- make_cleanup (xfree, filename);
/* Have a pathname: read the symbol file. */
symbol_file_add_main (filename, from_tty);
{
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);
}
+ xfree (buffer);
/* If this entry has no name, or its name matches the name
for the main executable, don't include it in the list. */
/* 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)))
+
+ if (buffer
+ && ((strcmp (buffer, objfile->name) == 0)
+ || (!(objfile->flags & OBJF_SHARED)
+ && (strcmp (buffer, "") == 0))))
{
do_cleanups (old_chain);
return lm;
static CORE_ADDR interp_plt_sect_low;
static CORE_ADDR interp_plt_sect_high;
-static int
+int
svr4_in_dynsym_resolve_code (CORE_ADDR pc)
{
return ((pc >= interp_text_sect_low && pc < interp_text_sect_high)
char *buf;
CORE_ADDR load_addr = 0;
int load_addr_found = 0;
+ int loader_found_in_list = 0;
struct so_list *so;
bfd *tmp_bfd = NULL;
struct target_ops *tmp_bfd_target;
be trivial on GNU/Linux). Therefore, we have to try an alternate
mechanism to find the dynamic linker's base address. */
- /* TODO drow/2006-09-12: This is somewhat fragile, because it
- relies on read_pc. On both Solaris and GNU/Linux we can use
- the AT_BASE auxilliary entry, which GDB now knows how to
- access, to find the base address. */
-
tmp_fd = solib_open (buf, &tmp_pathname);
if (tmp_fd >= 0)
tmp_bfd = bfd_fopen (tmp_pathname, gnutarget, FOPEN_RB, tmp_fd);
/* On a running target, we can get the dynamic linker's base
address from the shared library table. */
- solib_add (NULL, 0, NULL, auto_solib_add);
+ solib_add (NULL, 0, ¤t_target, auto_solib_add);
so = master_so_list ();
while (so)
{
if (strcmp (buf, so->so_original_name) == 0)
{
load_addr_found = 1;
+ loader_found_in_list = 1;
load_addr = LM_ADDR_CHECK (so, tmp_bfd);
break;
}
so = so->next;
}
+ /* If we were not able to find the base address of the loader
+ from our so_list, then try using the AT_BASE auxilliary entry. */
+ if (!load_addr_found)
+ if (target_auxv_search (¤t_target, AT_BASE, &load_addr) > 0)
+ load_addr_found = 1;
+
/* 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. */
+ dynamic linker) and subtracting the offset of the entry point.
+
+ This is more fragile than the previous approaches, but is a good
+ fallback method because it has actually been working well in
+ most cases. */
if (!load_addr_found)
+ load_addr = (read_pc ()
+ - exec_entry_point (tmp_bfd, tmp_bfd_target));
+
+ if (!loader_found_in_list)
{
- load_addr = (read_pc ()
- - exec_entry_point (tmp_bfd, tmp_bfd_target));
debug_loader_name = xstrdup (buf);
debug_loader_offset_p = 1;
debug_loader_offset = load_addr;
- solib_add (NULL, 0, NULL, auto_solib_add);
+ solib_add (NULL, 0, ¤t_target, auto_solib_add);
}
/* Record the relocated start and end address of the dynamic linker
/* 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);
+ sym_addr = bfd_lookup_symbol (tmp_bfd, *bkpt_namep);
if (sym_addr != 0)
break;
}
+ if (sym_addr != 0)
+ /* Convert 'sym_addr' from a function pointer to an address.
+ Because we pass tmp_bfd_target instead of the current
+ target, this will always produce an unrelocated value. */
+ sym_addr = gdbarch_convert_from_func_ptr_addr (current_gdbarch,
+ sym_addr,
+ tmp_bfd_target);
+
/* We're done with both the temporary bfd and target. Remember,
closing the target closes the underlying bfd. */
target_close (tmp_bfd_target, 0);
/* For whatever reason we couldn't set a breakpoint in the dynamic
linker. Warn and drop into the old code. */
bkpt_at_symbol:
+ xfree (tmp_pathname);
warning (_("Unable to find dynamic linker breakpoint function.\n"
"GDB will be unable to debug shared library initializers\n"
"and track explicitly loaded dynamic code."));
svr4_relocate_main_executable ();
if (!svr4_have_link_map_offsets ())
- {
- warning (_("no shared library support for this OS / ABI"));
- return;
-
- }
+ return;
if (!enable_break ())
return;
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
+ gdbarch_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)
+ if (gdbarch_ptr_bit (current_gdbarch) == 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);
+ return addr & (((CORE_ADDR) 1 << gdbarch_ptr_bit (current_gdbarch)) - 1);
}
struct solib_svr4_ops *ops;
ops = OBSTACK_ZALLOC (obstack, struct solib_svr4_ops);
- ops->fetch_link_map_offsets = legacy_svr4_fetch_link_map_offsets_hook;
+ ops->fetch_link_map_offsets = NULL;
return ops;
}
/* Set the architecture-specific `struct link_map_offsets' fetcher for
- GDBARCH to FLMO. */
+ GDBARCH to FLMO. Also, install SVR4 solib_ops into GDBARCH. */
void
set_solib_svr4_fetch_link_map_offsets (struct gdbarch *gdbarch,
struct solib_svr4_ops *ops = gdbarch_data (gdbarch, solib_svr4_data);
ops->fetch_link_map_offsets = flmo;
+
+ set_solib_ops (gdbarch, &svr4_so_ops);
}
/* Fetch a link_map_offsets structure using the architecture-specific
}
\f
-static struct target_so_ops svr4_so_ops;
+struct target_so_ops svr4_so_ops;
+
+/* Lookup global symbol for ELF DSOs linked with -Bsymbolic. Those DSOs have a
+ different rule for symbol lookup. The lookup begins here in the DSO, not in
+ the main executable. */
+
+static struct symbol *
+elf_lookup_lib_symbol (const struct objfile *objfile,
+ const char *name,
+ const char *linkage_name,
+ const domain_enum domain, struct symtab **symtab)
+{
+ if (objfile->obfd == NULL
+ || scan_dyntag (DT_SYMBOLIC, objfile->obfd, NULL) != 1)
+ return NULL;
+
+ return lookup_global_symbol_from_objfile
+ (objfile, name, linkage_name, domain, symtab);
+}
extern initialize_file_ftype _initialize_svr4_solib; /* -Wmissing-prototypes */
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;
+ svr4_so_ops.lookup_lib_global_symbol = elf_lookup_lib_symbol;
}
projects / deliverable / binutils-gdb.git / blobdiff