#include "elf-bfd.h"
#include "exec.h"
#include "auxv.h"
+#include "exceptions.h"
static struct link_map_offsets *svr4_fetch_link_map_offsets (void);
static int svr4_have_link_map_offsets (void);
address changes, we may need a different offset, we want to
warn about the difference and compute it only once. */
CORE_ADDR l_addr;
+
+ /* The target location of lm. */
+ CORE_ADDR lm_addr;
};
/* On SVR4 systems, a list of symbols in the dynamic linker where
NULL
};
-#define BKPT_AT_SYMBOL 1
-
-#if defined (BKPT_AT_SYMBOL)
static char *bkpt_names[] =
{
-#ifdef SOLIB_BKPT_NAME
- SOLIB_BKPT_NAME, /* Prefer configured name if it exists. */
-#endif
"_start",
"__start",
"main",
NULL
};
-#endif
static char *main_name_list[] =
{
/* Name of the dynamic linker, valid if debug_loader_offset_p. */
static char *debug_loader_name;
+/* Load map address for the main executable. */
+static CORE_ADDR main_lm_addr;
+
/* Local function prototypes */
static int match_main (char *);
return symaddr;
}
+
+/* Read program header TYPE from inferior memory. The header is found
+ by scanning the OS auxillary vector.
+
+ Return a pointer to allocated memory holding the program header contents,
+ or NULL on failure. If sucessful, and unless P_SECT_SIZE is NULL, the
+ size of those contents is returned to P_SECT_SIZE. Likewise, the target
+ architecture size (32-bit or 64-bit) is returned to P_ARCH_SIZE. */
+
+static gdb_byte *
+read_program_header (int type, int *p_sect_size, int *p_arch_size)
+{
+ CORE_ADDR at_phdr, at_phent, at_phnum;
+ int arch_size, sect_size;
+ CORE_ADDR sect_addr;
+ gdb_byte *buf;
+
+ /* Get required auxv elements from target. */
+ if (target_auxv_search (¤t_target, AT_PHDR, &at_phdr) <= 0)
+ return 0;
+ if (target_auxv_search (¤t_target, AT_PHENT, &at_phent) <= 0)
+ return 0;
+ if (target_auxv_search (¤t_target, AT_PHNUM, &at_phnum) <= 0)
+ return 0;
+ if (!at_phdr || !at_phnum)
+ return 0;
+
+ /* Determine ELF architecture type. */
+ if (at_phent == sizeof (Elf32_External_Phdr))
+ arch_size = 32;
+ else if (at_phent == sizeof (Elf64_External_Phdr))
+ arch_size = 64;
+ else
+ return 0;
+
+ /* Find .dynamic section via the PT_DYNAMIC PHDR. */
+ if (arch_size == 32)
+ {
+ Elf32_External_Phdr phdr;
+ int i;
+
+ /* Search for requested PHDR. */
+ for (i = 0; i < at_phnum; i++)
+ {
+ if (target_read_memory (at_phdr + i * sizeof (phdr),
+ (gdb_byte *)&phdr, sizeof (phdr)))
+ return 0;
+
+ if (extract_unsigned_integer ((gdb_byte *)phdr.p_type, 4) == type)
+ break;
+ }
+
+ if (i == at_phnum)
+ return 0;
+
+ /* Retrieve address and size. */
+ sect_addr = extract_unsigned_integer ((gdb_byte *)phdr.p_vaddr, 4);
+ sect_size = extract_unsigned_integer ((gdb_byte *)phdr.p_memsz, 4);
+ }
+ else
+ {
+ Elf64_External_Phdr phdr;
+ int i;
+
+ /* Search for requested PHDR. */
+ for (i = 0; i < at_phnum; i++)
+ {
+ if (target_read_memory (at_phdr + i * sizeof (phdr),
+ (gdb_byte *)&phdr, sizeof (phdr)))
+ return 0;
+
+ if (extract_unsigned_integer ((gdb_byte *)phdr.p_type, 4) == type)
+ break;
+ }
+
+ if (i == at_phnum)
+ return 0;
+
+ /* Retrieve address and size. */
+ sect_addr = extract_unsigned_integer ((gdb_byte *)phdr.p_vaddr, 8);
+ sect_size = extract_unsigned_integer ((gdb_byte *)phdr.p_memsz, 8);
+ }
+
+ /* Read in requested program header. */
+ buf = xmalloc (sect_size);
+ if (target_read_memory (sect_addr, buf, sect_size))
+ {
+ xfree (buf);
+ return NULL;
+ }
+
+ if (p_arch_size)
+ *p_arch_size = arch_size;
+ if (p_sect_size)
+ *p_sect_size = sect_size;
+
+ return buf;
+}
+
+
+/* Return program interpreter string. */
+static gdb_byte *
+find_program_interpreter (void)
+{
+ gdb_byte *buf = NULL;
+
+ /* If we have an exec_bfd, use its section table. */
+ if (exec_bfd
+ && bfd_get_flavour (exec_bfd) == bfd_target_elf_flavour)
+ {
+ struct bfd_section *interp_sect;
+
+ interp_sect = bfd_get_section_by_name (exec_bfd, ".interp");
+ if (interp_sect != NULL)
+ {
+ CORE_ADDR sect_addr = bfd_section_vma (exec_bfd, interp_sect);
+ int sect_size = bfd_section_size (exec_bfd, interp_sect);
+
+ buf = xmalloc (sect_size);
+ bfd_get_section_contents (exec_bfd, interp_sect, buf, 0, sect_size);
+ }
+ }
+
+ /* If we didn't find it, use the target auxillary vector. */
+ if (!buf)
+ buf = read_program_header (PT_INTERP, NULL, NULL);
+
+ return buf;
+}
+
+
/* Scan for DYNTAG in .dynamic section of ABFD. If DYNTAG is found 1 is
returned and the corresponding PTR is set. */
return 0;
}
+/* Scan for DYNTAG in .dynamic section of the target's main executable,
+ found by consulting the OS auxillary vector. If DYNTAG is found 1 is
+ returned and the corresponding PTR is set. */
+
+static int
+scan_dyntag_auxv (int dyntag, CORE_ADDR *ptr)
+{
+ int sect_size, arch_size, step;
+ long dyn_tag;
+ CORE_ADDR dyn_ptr;
+ gdb_byte *bufend, *bufstart, *buf;
+
+ /* Read in .dynamic section. */
+ buf = bufstart = read_program_header (PT_DYNAMIC, §_size, &arch_size);
+ if (!buf)
+ 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)
+ {
+ Elf32_External_Dyn *dynp = (Elf32_External_Dyn *) buf;
+ dyn_tag = extract_unsigned_integer ((gdb_byte *) dynp->d_tag, 4);
+ dyn_ptr = extract_unsigned_integer ((gdb_byte *) dynp->d_un.d_ptr, 4);
+ }
+ else
+ {
+ Elf64_External_Dyn *dynp = (Elf64_External_Dyn *) buf;
+ dyn_tag = extract_unsigned_integer ((gdb_byte *) dynp->d_tag, 8);
+ dyn_ptr = extract_unsigned_integer ((gdb_byte *) dynp->d_un.d_ptr, 8);
+ }
+ if (dyn_tag == DT_NULL)
+ break;
+
+ if (dyn_tag == dyntag)
+ {
+ if (ptr)
+ *ptr = dyn_ptr;
+
+ xfree (bufstart);
+ return 1;
+ }
+ }
+
+ xfree (bufstart);
+ return 0;
+}
+
/*
/* 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))
+ if (scan_dyntag (DT_MIPS_RLD_MAP, exec_bfd, &dyn_ptr)
+ || scan_dyntag_auxv (DT_MIPS_RLD_MAP, &dyn_ptr))
{
gdb_byte *pbuf;
int pbuf_size = TYPE_LENGTH (builtin_type_void_data_ptr);
}
/* Find DT_DEBUG. */
- if (scan_dyntag (DT_DEBUG, exec_bfd, &dyn_ptr))
+ if (scan_dyntag (DT_DEBUG, exec_bfd, &dyn_ptr)
+ || scan_dyntag_auxv (DT_DEBUG, &dyn_ptr))
return dyn_ptr;
/* This may be a static executable. Look for the symbol
/* Nothing will ever check the cached copy of the link
map if we set l_addr. */
new->lm_info->l_addr = debug_loader_offset;
+ new->lm_info->lm_addr = 0;
new->lm_info->lm = NULL;
strncpy (new->so_name, debug_loader_name, SO_NAME_MAX_PATH_SIZE - 1);
make_cleanup (xfree, new->lm_info);
new->lm_info->l_addr = (CORE_ADDR)-1;
+ new->lm_info->lm_addr = lm;
new->lm_info->lm = xzalloc (lmo->link_map_size);
make_cleanup (xfree, new->lm_info->lm);
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) && ldsomap == 0)
- free_so (new);
+ {
+ main_lm_addr = new->lm_info->lm_addr;
+ free_so (new);
+ }
else
{
int errcode;
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. */
+/* Get the address of the link_map for a given OBJFILE. */
CORE_ADDR
svr4_fetch_objfile_link_map (struct objfile *objfile)
{
- CORE_ADDR lm;
+ struct so_list *so;
- if (locate_base () == 0)
- return 0; /* failed somehow... */
+ /* Cause svr4_current_sos() to be run if it hasn't been already. */
+ if (main_lm_addr == 0)
+ solib_add (NULL, 0, ¤t_target, auto_solib_add);
- /* Position ourselves on the first link map. */
- lm = solib_svr4_r_map ();
- 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;
- int l_name_size = TYPE_LENGTH (builtin_type_void_data_ptr);
- gdb_byte *l_name_buf = xmalloc (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 = xzalloc (lmo->link_map_size);
- make_cleanup (xfree, objfile_lm_info.lm);
-
- /* 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, l_name_size);
-
- /* Extract this object's name. */
- name_address = extract_typed_address (l_name_buf,
- builtin_type_void_data_ptr);
- target_read_string (name_address, &buffer,
- SO_NAME_MAX_PATH_SIZE - 1, &errcode);
- make_cleanup (xfree, buffer);
- if (errcode != 0)
- warning (_("Can't read pathname for load map: %s."),
- 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. */
- lm = extract_typed_address (objfile_lm_info.lm + lmo->l_next_offset,
- builtin_type_void_data_ptr);
- do_cleanups (old_chain);
- }
+ /* svr4_current_sos() will set main_lm_addr for the main executable. */
+ if (objfile == symfile_objfile)
+ return main_lm_addr;
+
+ /* The other link map addresses may be found by examining the list
+ of shared libraries. */
+ for (so = master_so_list (); so; so = so->next)
+ if (so->objfile == objfile)
+ return so->lm_info->lm_addr;
+
+ /* Not found! */
return 0;
}
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,
+ return gdbarch_convert_from_func_ptr_addr (target_gdbarch,
bfd_get_start_address (abfd),
targ);
}
static int
enable_break (void)
{
-#ifdef BKPT_AT_SYMBOL
-
struct minimal_symbol *msymbol;
char **bkpt_namep;
asection *interp_sect;
+ gdb_byte *interp_name;
CORE_ADDR sym_addr;
/* First, remove all the solib event breakpoints. Their addresses
struct obj_section *os;
sym_addr = gdbarch_addr_bits_remove
- (current_gdbarch, gdbarch_convert_from_func_ptr_addr (current_gdbarch,
+ (target_gdbarch, gdbarch_convert_from_func_ptr_addr (target_gdbarch,
sym_addr,
¤t_target));
}
}
- /* Find the .interp section; if not found, warn the user and drop
+ /* Find the program interpreter; 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)
+ interp_name = find_program_interpreter ();
+ if (interp_name)
{
- unsigned int interp_sect_size;
- 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;
- int tmp_fd = -1;
- char *tmp_pathname = NULL;
+ 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. */
sym_addr = 0;
- 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
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_fopen (tmp_pathname, gnutarget, FOPEN_RB, tmp_fd);
-
+ TRY_CATCH (ex, RETURN_MASK_ALL)
+ {
+ tmp_bfd = solib_bfd_open (interp_name);
+ }
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. */
so = master_so_list ();
while (so)
{
- if (svr4_same_1 (buf, so->so_original_name))
+ if (svr4_same_1 (interp_name, so->so_original_name))
{
load_addr_found = 1;
loader_found_in_list = 1;
if (!loader_found_in_list)
{
- debug_loader_name = xstrdup (buf);
+ debug_loader_name = xstrdup (interp_name);
debug_loader_offset_p = 1;
debug_loader_offset = load_addr;
solib_add (NULL, 0, ¤t_target, auto_solib_add);
/* 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 = gdbarch_convert_from_func_ptr_addr (target_gdbarch,
sym_addr,
tmp_bfd_target);
if (sym_addr != 0)
{
create_solib_event_breakpoint (load_addr + sym_addr);
+ xfree (interp_name);
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:
- xfree (tmp_pathname);
+ xfree (interp_name);
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."));
return 1;
}
}
-#endif /* BKPT_AT_SYMBOL */
-
return 0;
}
debug_loader_offset = 0;
xfree (debug_loader_name);
debug_loader_name = NULL;
+ main_lm_addr = 0;
}
static void
static CORE_ADDR
svr4_truncate_ptr (CORE_ADDR addr)
{
- if (gdbarch_ptr_bit (current_gdbarch) == sizeof (CORE_ADDR) * 8)
+ if (gdbarch_ptr_bit (target_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 << gdbarch_ptr_bit (current_gdbarch)) - 1);
+ return addr & (((CORE_ADDR) 1 << gdbarch_ptr_bit (target_gdbarch)) - 1);
}
static struct link_map_offsets *
svr4_fetch_link_map_offsets (void)
{
- struct solib_svr4_ops *ops = gdbarch_data (current_gdbarch, solib_svr4_data);
+ struct solib_svr4_ops *ops = gdbarch_data (target_gdbarch, solib_svr4_data);
gdb_assert (ops->fetch_link_map_offsets);
return ops->fetch_link_map_offsets ();
static int
svr4_have_link_map_offsets (void)
{
- struct solib_svr4_ops *ops = gdbarch_data (current_gdbarch, solib_svr4_data);
+ struct solib_svr4_ops *ops = gdbarch_data (target_gdbarch, solib_svr4_data);
return (ops->fetch_link_map_offsets != NULL);
}
\f
elf_lookup_lib_symbol (const struct objfile *objfile,
const char *name,
const char *linkage_name,
- const domain_enum domain, struct symtab **symtab)
+ const domain_enum domain)
{
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);
+ (objfile, name, linkage_name, domain);
}
extern initialize_file_ftype _initialize_svr4_solib; /* -Wmissing-prototypes */
projects / deliverable / binutils-gdb.git / blobdiff