#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);
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[] =
{
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
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;
}
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
projects / deliverable / binutils-gdb.git / blobdiff