static int
enable_break (void)
{
int success = 0;
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;
bfd *tmp_bfd;
CORE_ADDR sym_addr = 0;
/* Read the contents of the .interp section into a local buffer;
the contents specify the dynamic linker this program uses. */
interp_sect_size = bfd_section_size (exec_bfd, interp_sect);
buf = alloca (interp_sect_size);
bfd_get_section_contents (exec_bfd, interp_sect,
buf, 0, interp_sect_size);
/* Now we need to figure out where the dynamic linker was
loaded so that we can load its symbols and place a breakpoint
in the dynamic linker itself.
This address is stored on the stack. However, I've been unable
to find any magic formula to find it for Solaris (appears to
be trivial on GNU/Linux). Therefore, we have to try an alternate
mechanism to find the dynamic linker's base address. */
tmp_bfd = bfd_openr (buf, gnutarget);
if (tmp_bfd == NULL)
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;
}
/* We find the dynamic linker's base address by examining the
current pc (which point at the entry point for the dynamic
linker) and subtracting the offset of the entry point. */
load_addr = read_pc () - tmp_bfd->start_address;
/* Record the relocated start and end address of the dynamic linker
text and plt section for aix5_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++)
{
sym_addr = bfd_lookup_symbol (tmp_bfd, *bkpt_namep);
if (sym_addr != 0)
break;
}
/* We're done with the temporary bfd. */
bfd_close (tmp_bfd);
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."));
}
/* Nothing good happened. */
success = 0;
return (success);
}
static int
enable_break2 (void)
{
enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
int success = 0;
char **bkpt_namep;
asection *interp_sect;
if (enable_break2_done)
return 1;
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;
gdb_byte *buf;
bfd *tmp_bfd = NULL;
int status;
CORE_ADDR addr, interp_loadmap_addr;
gdb_byte addr_buf[FRV_PTR_SIZE];
struct int_elf32_fdpic_loadmap *ldm;
volatile struct gdb_exception ex;
/* 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. */
TRY_CATCH (ex, RETURN_MASK_ALL)
{
tmp_bfd = solib_bfd_open (buf);
}
if (tmp_bfd == NULL)
{
enable_break_failure_warning ();
return 0;
}
status = frv_fdpic_loadmap_addresses (target_gdbarch,
&interp_loadmap_addr, 0);
if (status < 0)
{
warning (_("Unable to determine dynamic linker loadmap address."));
enable_break_failure_warning ();
bfd_close (tmp_bfd);
return 0;
}
if (solib_frv_debug)
fprintf_unfiltered (gdb_stdlog,
"enable_break: interp_loadmap_addr = %s\n",
hex_string_custom (interp_loadmap_addr, 8));
ldm = fetch_loadmap (interp_loadmap_addr);
if (ldm == NULL)
{
warning (_("Unable to load dynamic linker loadmap at address %s."),
hex_string_custom (interp_loadmap_addr, 8));
enable_break_failure_warning ();
bfd_close (tmp_bfd);
return 0;
}
/* 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);
interp_text_sect_low
+= displacement_from_map (ldm, interp_text_sect_low);
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);
interp_plt_sect_low
+= displacement_from_map (ldm, interp_plt_sect_low);
interp_plt_sect_high =
interp_plt_sect_low + bfd_section_size (tmp_bfd, interp_sect);
}
addr = bfd_lookup_symbol (tmp_bfd, "_dl_debug_addr");
if (addr == 0)
{
warning (_("Could not find symbol _dl_debug_addr in dynamic linker"));
enable_break_failure_warning ();
bfd_close (tmp_bfd);
return 0;
}
if (solib_frv_debug)
fprintf_unfiltered (gdb_stdlog,
"enable_break: _dl_debug_addr (prior to relocation) = %s\n",
hex_string_custom (addr, 8));
addr += displacement_from_map (ldm, addr);
if (solib_frv_debug)
fprintf_unfiltered (gdb_stdlog,
"enable_break: _dl_debug_addr (after relocation) = %s\n",
hex_string_custom (addr, 8));
/* Fetch the address of the r_debug struct. */
if (target_read_memory (addr, addr_buf, sizeof addr_buf) != 0)
{
warning (_("Unable to fetch contents of _dl_debug_addr (at address %s) from dynamic linker"),
hex_string_custom (addr, 8));
}
addr = extract_unsigned_integer (addr_buf, sizeof addr_buf, byte_order);
if (solib_frv_debug)
fprintf_unfiltered (gdb_stdlog,
"enable_break: _dl_debug_addr[0..3] = %s\n",
hex_string_custom (addr, 8));
/* If it's zero, then the ldso hasn't initialized yet, and so
there are no shared libs yet loaded. */
if (addr == 0)
{
if (solib_frv_debug)
fprintf_unfiltered (gdb_stdlog,
"enable_break: ldso not yet initialized\n");
/* Do not warn, but mark to run again. */
return 0;
}
/* Fetch the r_brk field. It's 8 bytes from the start of
_dl_debug_addr. */
if (target_read_memory (addr + 8, addr_buf, sizeof addr_buf) != 0)
{
warning (_("Unable to fetch _dl_debug_addr->r_brk (at address %s) from dynamic linker"),
hex_string_custom (addr + 8, 8));
enable_break_failure_warning ();
bfd_close (tmp_bfd);
return 0;
}
addr = extract_unsigned_integer (addr_buf, sizeof addr_buf, byte_order);
/* Now fetch the function entry point. */
if (target_read_memory (addr, addr_buf, sizeof addr_buf) != 0)
{
warning (_("Unable to fetch _dl_debug_addr->.r_brk entry point (at address %s) from dynamic linker"),
hex_string_custom (addr, 8));
enable_break_failure_warning ();
bfd_close (tmp_bfd);
return 0;
}
addr = extract_unsigned_integer (addr_buf, sizeof addr_buf, byte_order);
/* We're done with the temporary bfd. */
bfd_close (tmp_bfd);
/* We're also done with the loadmap. */
xfree (ldm);
/* Remove all the solib event breakpoints. Their addresses
may have changed since the last time we ran the program. */
remove_solib_event_breakpoints ();
/* Now (finally!) create the solib breakpoint. */
create_solib_event_breakpoint (target_gdbarch, addr);
enable_break2_done = 1;
return 1;
}
