pointer_address = SYMBOL_VALUE_ADDRESS (msym);
- data_address = read_memory_typed_address (pointer_address, ptr_type);
+ /* The location of the _dl_auxv symbol may no longer be correct if
+ ld.so runs at a different address than the one present in the file.
+ This is very common case - for unprelinked ld.so or with a PIE executable.
+ PIE executable forces random address even for libraries already being
+ prelinked to some address. PIE executables themselves are never prelinked
+ even on prelinked systems. Prelinking of a PIE executable would block
+ their purpose of randomizing load of everything including the executable.
+
+ If the memory read fails, return -1 to fallback on another mechanism for
+ retrieving the AUXV.
+
+ In most cases of a PIE running under valgrind there is no way to find
+ out the base addresses of any of ld.so, executable or AUXV as everything
+ is randomized and /proc information is not relevant for the virtual
+ executable running under valgrind. We think that we might need a valgrind
+ extension to make it work. This is PR 11440. */
+
+ if (target_read_memory (pointer_address, ptr_buf, ptr_size) != 0)
+ return -1;
+
+ data_address = extract_typed_address (ptr_buf, ptr_type);
/* Possibly still not initialized such as during an inferior startup. */
if (data_address == 0)
gdb_assert (readbuf || writebuf);
/* ld_so_xfer_auxv is the only function safe for virtual executables being
- executed by valgrind's memcheck. As using ld_so_xfer_auxv is problematic
- during inferior startup GDB does call it only for attached processes. */
+ executed by valgrind's memcheck. Using ld_so_xfer_auxv during inferior
+ startup is problematic, because ld.so symbol tables have not yet been
+ relocated. So GDB uses this function only when attaching to a process.
+ */
if (current_inferior ()->attach_flag != 0)
{
gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp)
{
struct target_ops *t;
+
for (t = ops; t != NULL; t = t->beneath)
if (t->to_auxv_parse != NULL)
return t->to_auxv_parse (t, readptr, endptr, typep, valp);
case str:
{
struct value_print_options opts;
+
get_user_print_options (&opts);
if (opts.addressprint)
fprintf_filtered (file, "%s", paddress (target_gdbarch, val));
else
{
int ents = fprint_target_auxv (gdb_stdout, ¤t_target);
+
if (ents < 0)
error (_("No auxiliary vector found, or failed reading it."));
else if (ents == 0)