/* Auxiliary vector support for GDB, the GNU debugger.
- Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+ Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010
+ Free Software Foundation, Inc.
This file is part of GDB.
#include "inferior.h"
#include "valprint.h"
#include "gdb_assert.h"
+#include "gdbcore.h"
#include "auxv.h"
#include "elf/common.h"
#include <fcntl.h>
-/* This function is called like a to_xfer_partial hook,
- but must be called with TARGET_OBJECT_AUXV.
- It handles access via /proc/PID/auxv, which is the common method.
- This function is appropriate for doing:
- #define NATIVE_XFER_AUXV procfs_xfer_auxv
- for a native target that uses inftarg.c's child_xfer_partial hook. */
+/* This function handles access via /proc/PID/auxv, which is a common method
+ for native targets. */
-LONGEST
-procfs_xfer_auxv (struct target_ops *ops,
- int /* enum target_object */ object,
- const char *annex,
- gdb_byte *readbuf,
+static LONGEST
+procfs_xfer_auxv (gdb_byte *readbuf,
const gdb_byte *writebuf,
ULONGEST offset,
LONGEST len)
int fd;
LONGEST n;
- gdb_assert (object == TARGET_OBJECT_AUXV);
- gdb_assert (readbuf || writebuf);
-
pathname = xstrprintf ("/proc/%d/auxv", PIDGET (inferior_ptid));
fd = open (pathname, writebuf != NULL ? O_WRONLY : O_RDONLY);
xfree (pathname);
return n;
}
+/* This function handles access via ld.so's symbol `_dl_auxv'. */
+
+static LONGEST
+ld_so_xfer_auxv (gdb_byte *readbuf,
+ const gdb_byte *writebuf,
+ ULONGEST offset,
+ LONGEST len)
+{
+ struct minimal_symbol *msym;
+ CORE_ADDR data_address, pointer_address;
+ struct type *ptr_type = builtin_type (target_gdbarch)->builtin_data_ptr;
+ size_t ptr_size = TYPE_LENGTH (ptr_type);
+ size_t auxv_pair_size = 2 * ptr_size;
+ gdb_byte *ptr_buf = alloca (ptr_size);
+ LONGEST retval;
+ size_t block;
+
+ msym = lookup_minimal_symbol ("_dl_auxv", NULL, NULL);
+ if (msym == NULL)
+ return -1;
+
+ if (MSYMBOL_SIZE (msym) != ptr_size)
+ return -1;
+
+ /* POINTER_ADDRESS is a location where the `_dl_auxv' variable resides.
+ DATA_ADDRESS is the inferior value present in `_dl_auxv', therefore the
+ real inferior AUXV address. */
+
+ pointer_address = SYMBOL_VALUE_ADDRESS (msym);
+
+ /* 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)
+ return -1;
+
+ data_address += offset;
+
+ if (writebuf != NULL)
+ {
+ if (target_write_memory (data_address, writebuf, len) == 0)
+ return len;
+ else
+ return -1;
+ }
+
+ /* Stop if trying to read past the existing AUXV block. The final AT_NULL
+ was already returned before. */
+
+ if (offset >= auxv_pair_size)
+ {
+ if (target_read_memory (data_address - auxv_pair_size, ptr_buf,
+ ptr_size) != 0)
+ return -1;
+
+ if (extract_typed_address (ptr_buf, ptr_type) == AT_NULL)
+ return 0;
+ }
+
+ retval = 0;
+ block = 0x400;
+ gdb_assert (block % auxv_pair_size == 0);
+
+ while (len > 0)
+ {
+ if (block > len)
+ block = len;
+
+ /* Reading sizes smaller than AUXV_PAIR_SIZE is not supported. Tails
+ unaligned to AUXV_PAIR_SIZE will not be read during a call (they
+ should be completed during next read with new/extended buffer). */
+
+ block &= -auxv_pair_size;
+ if (block == 0)
+ return retval;
+
+ if (target_read_memory (data_address, readbuf, block) != 0)
+ {
+ if (block <= auxv_pair_size)
+ return retval;
+
+ block = auxv_pair_size;
+ continue;
+ }
+
+ data_address += block;
+ len -= block;
+
+ /* Check terminal AT_NULL. This function is being called indefinitely
+ being extended its READBUF until it returns EOF (0). */
+
+ while (block >= auxv_pair_size)
+ {
+ retval += auxv_pair_size;
+
+ if (extract_typed_address (readbuf, ptr_type) == AT_NULL)
+ return retval;
+
+ readbuf += auxv_pair_size;
+ block -= auxv_pair_size;
+ }
+ }
+
+ return retval;
+}
+
+/* This function is called like a to_xfer_partial hook, but must be
+ called with TARGET_OBJECT_AUXV. It handles access to AUXV. */
+
+LONGEST
+memory_xfer_auxv (struct target_ops *ops,
+ enum target_object object,
+ const char *annex,
+ gdb_byte *readbuf,
+ const gdb_byte *writebuf,
+ ULONGEST offset,
+ LONGEST len)
+{
+ gdb_assert (object == TARGET_OBJECT_AUXV);
+ gdb_assert (readbuf || writebuf);
+
+ /* ld_so_xfer_auxv is the only function safe for virtual executables being
+ 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)
+ {
+ LONGEST retval;
+
+ retval = ld_so_xfer_auxv (readbuf, writebuf, offset, len);
+ if (retval != -1)
+ return retval;
+ }
+
+ return procfs_xfer_auxv (readbuf, writebuf, offset, len);
+}
+
/* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
Return 0 if *READPTR is already at the end of the buffer.
Return -1 if there is insufficient buffer for a whole entry.
Return 1 if an entry was read into *TYPEP and *VALP. */
-int
+static int
default_auxv_parse (struct target_ops *ops, gdb_byte **readptr,
gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp)
{
const int sizeof_auxv_field = gdbarch_ptr_bit (target_gdbarch)
/ TARGET_CHAR_BIT;
+ const enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch);
gdb_byte *ptr = *readptr;
if (endptr == ptr)
if (endptr - ptr < sizeof_auxv_field * 2)
return -1;
- *typep = extract_unsigned_integer (ptr, sizeof_auxv_field);
+ *typep = extract_unsigned_integer (ptr, sizeof_auxv_field, byte_order);
ptr += sizeof_auxv_field;
- *valp = extract_unsigned_integer (ptr, sizeof_auxv_field);
+ *valp = extract_unsigned_integer (ptr, sizeof_auxv_field, byte_order);
ptr += sizeof_auxv_field;
*readptr = ptr;
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);
gdb_byte *data;
LONGEST n = target_read_alloc (ops, TARGET_OBJECT_AUXV, NULL, &data);
gdb_byte *ptr = data;
- int ents = 0;
if (n <= 0)
return n;
TAG (AT_UCACHEBSIZE, _("Unified cache block size"), dec);
TAG (AT_IGNOREPPC, _("Entry should be ignored"), dec);
TAG (AT_BASE_PLATFORM, _("String identifying base platform"), str);
+ TAG (AT_RANDOM, _("Address of 16 random bytes"), hex);
TAG (AT_EXECFN, _("File name of executable"), str);
TAG (AT_SECURE, _("Boolean, was exec setuid-like?"), dec);
TAG (AT_SYSINFO, _("Special system info/entry points"), hex);
fprintf_filtered (file, "%s\n", plongest (val));
break;
case hex:
- fprintf_filtered (file, "0x%s\n", paddr_nz (val));
+ fprintf_filtered (file, "%s\n", paddress (target_gdbarch, val));
break;
case str:
{
struct value_print_options opts;
+
get_user_print_options (&opts);
if (opts.addressprint)
- fprintf_filtered (file, "0x%s", paddr_nz (val));
- val_print_string (val, -1, 1, file, &opts);
+ fprintf_filtered (file, "%s", paddress (target_gdbarch, val));
+ val_print_string (builtin_type (target_gdbarch)->builtin_char,
+ val, -1, file, &opts);
fprintf_filtered (file, "\n");
}
break;
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)
projects / binutils-gdb.git / blobdiff