/* Auxiliary vector support for GDB, the GNU debugger.
- Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
+ Copyright (C) 2004-2015 Free Software Foundation, Inc.
This file is part of GDB.
#include "command.h"
#include "inferior.h"
#include "valprint.h"
-#include "gdb_assert.h"
+#include "gdbcore.h"
+#include "observer.h"
+#include "filestuff.h"
+#include "objfiles.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. */
+/* Implement the to_xfer_partial target_ops method. 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 enum target_xfer_status
+procfs_xfer_auxv (gdb_byte *readbuf,
const gdb_byte *writebuf,
ULONGEST offset,
- LONGEST len)
+ ULONGEST len,
+ ULONGEST *xfered_len)
{
char *pathname;
int fd;
- LONGEST n;
-
- gdb_assert (object == TARGET_OBJECT_AUXV);
- gdb_assert (readbuf || writebuf);
+ ssize_t l;
- pathname = xstrprintf ("/proc/%d/auxv", PIDGET (inferior_ptid));
- fd = open (pathname, writebuf != NULL ? O_WRONLY : O_RDONLY);
+ pathname = xstrprintf ("/proc/%d/auxv", ptid_get_pid (inferior_ptid));
+ fd = gdb_open_cloexec (pathname, writebuf != NULL ? O_WRONLY : O_RDONLY, 0);
xfree (pathname);
if (fd < 0)
- return -1;
+ return TARGET_XFER_E_IO;
if (offset != (ULONGEST) 0
&& lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
- n = -1;
+ l = -1;
else if (readbuf != NULL)
- n = read (fd, readbuf, len);
+ l = read (fd, readbuf, (size_t) len);
else
- n = write (fd, writebuf, len);
+ l = write (fd, writebuf, (size_t) len);
(void) close (fd);
- return n;
+ if (l < 0)
+ return TARGET_XFER_E_IO;
+ else if (l == 0)
+ return TARGET_XFER_EOF;
+ else
+ {
+ *xfered_len = (ULONGEST) l;
+ return TARGET_XFER_OK;
+ }
+}
+
+/* This function handles access via ld.so's symbol `_dl_auxv'. */
+
+static enum target_xfer_status
+ld_so_xfer_auxv (gdb_byte *readbuf,
+ const gdb_byte *writebuf,
+ ULONGEST offset,
+ ULONGEST len, ULONGEST *xfered_len)
+{
+ struct bound_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.minsym == NULL)
+ return TARGET_XFER_E_IO;
+
+ if (MSYMBOL_SIZE (msym.minsym) != ptr_size)
+ return TARGET_XFER_E_IO;
+
+ /* 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 = BMSYMBOL_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 TARGET_XFER_E_IO;
+
+ data_address = extract_typed_address (ptr_buf, ptr_type);
+
+ /* Possibly still not initialized such as during an inferior
+ startup. */
+ if (data_address == 0)
+ return TARGET_XFER_E_IO;
+
+ data_address += offset;
+
+ if (writebuf != NULL)
+ {
+ if (target_write_memory (data_address, writebuf, len) == 0)
+ {
+ *xfered_len = (ULONGEST) len;
+ return TARGET_XFER_OK;
+ }
+ else
+ return TARGET_XFER_E_IO;
+ }
+
+ /* 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 TARGET_XFER_E_IO;
+
+ if (extract_typed_address (ptr_buf, ptr_type) == AT_NULL)
+ return TARGET_XFER_EOF;
+ }
+
+ 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)
+ break;
+
+ if (target_read_memory (data_address, readbuf, block) != 0)
+ {
+ if (block <= auxv_pair_size)
+ break;
+
+ 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)
+ {
+ *xfered_len = (ULONGEST) retval;
+ return TARGET_XFER_OK;
+ }
+
+ readbuf += auxv_pair_size;
+ block -= auxv_pair_size;
+ }
+ }
+
+ *xfered_len = (ULONGEST) retval;
+ return TARGET_XFER_OK;
+}
+
+/* Implement the to_xfer_partial target_ops method for
+ TARGET_OBJECT_AUXV. It handles access to AUXV. */
+
+enum target_xfer_status
+memory_xfer_auxv (struct target_ops *ops,
+ enum target_object object,
+ const char *annex,
+ gdb_byte *readbuf,
+ const gdb_byte *writebuf,
+ ULONGEST offset,
+ ULONGEST len, ULONGEST *xfered_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)
+ {
+ enum target_xfer_status ret;
+
+ ret = ld_so_xfer_auxv (readbuf, writebuf, offset, len, xfered_len);
+ if (ret != TARGET_XFER_E_IO)
+ return ret;
+ }
+
+ return procfs_xfer_auxv (readbuf, writebuf, offset, len, xfered_len);
}
/* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
Return -1 if there is insufficient buffer for a whole entry.
Return 1 if an entry was read into *TYPEP and *VALP. */
int
-target_auxv_parse (struct target_ops *ops, gdb_byte **readptr,
+default_auxv_parse (struct target_ops *ops, gdb_byte **readptr,
gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp)
{
- const int sizeof_auxv_field = TYPE_LENGTH (builtin_type_void_data_ptr);
+ 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;
return 1;
}
+/* 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
+target_auxv_parse (struct target_ops *ops, gdb_byte **readptr,
+ gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp)
+{
+ struct gdbarch *gdbarch = target_gdbarch();
+
+ if (gdbarch_auxv_parse_p (gdbarch))
+ return gdbarch_auxv_parse (gdbarch, readptr, endptr, typep, valp);
+
+ return current_target.to_auxv_parse (¤t_target, readptr, endptr,
+ typep, valp);
+}
+
+
+/* Per-inferior data key for auxv. */
+static const struct inferior_data *auxv_inferior_data;
+
+/* Auxiliary Vector information structure. This is used by GDB
+ for caching purposes for each inferior. This helps reduce the
+ overhead of transfering data from a remote target to the local host. */
+struct auxv_info
+{
+ LONGEST length;
+ gdb_byte *data;
+};
+
+/* Handles the cleanup of the auxv cache for inferior INF. ARG is ignored.
+ Frees whatever allocated space there is to be freed and sets INF's auxv cache
+ data pointer to NULL.
+
+ This function is called when the following events occur: inferior_appeared,
+ inferior_exit and executable_changed. */
+
+static void
+auxv_inferior_data_cleanup (struct inferior *inf, void *arg)
+{
+ struct auxv_info *info;
+
+ info = inferior_data (inf, auxv_inferior_data);
+ if (info != NULL)
+ {
+ xfree (info->data);
+ xfree (info);
+ set_inferior_data (inf, auxv_inferior_data, NULL);
+ }
+}
+
+/* Invalidate INF's auxv cache. */
+
+static void
+invalidate_auxv_cache_inf (struct inferior *inf)
+{
+ auxv_inferior_data_cleanup (inf, NULL);
+}
+
+/* Invalidate current inferior's auxv cache. */
+
+static void
+invalidate_auxv_cache (void)
+{
+ invalidate_auxv_cache_inf (current_inferior ());
+}
+
+/* Fetch the auxv object from inferior INF. If auxv is cached already,
+ return a pointer to the cache. If not, fetch the auxv object from the
+ target and cache it. This function always returns a valid INFO pointer. */
+
+static struct auxv_info *
+get_auxv_inferior_data (struct target_ops *ops)
+{
+ struct auxv_info *info;
+ struct inferior *inf = current_inferior ();
+
+ info = inferior_data (inf, auxv_inferior_data);
+ if (info == NULL)
+ {
+ info = XCNEW (struct auxv_info);
+ info->length = target_read_alloc (ops, TARGET_OBJECT_AUXV,
+ NULL, &info->data);
+ set_inferior_data (inf, auxv_inferior_data, info);
+ }
+
+ return info;
+}
+
/* Extract the auxiliary vector entry with a_type matching MATCH.
Return zero if no such entry was found, or -1 if there was
an error getting the information. On success, return 1 after
{
CORE_ADDR type, val;
gdb_byte *data;
- LONGEST n = target_read_alloc (ops, TARGET_OBJECT_AUXV, NULL, &data);
- gdb_byte *ptr = data;
- int ents = 0;
+ gdb_byte *ptr;
+ struct auxv_info *info;
+
+ info = get_auxv_inferior_data (ops);
+
+ data = info->data;
+ ptr = data;
- if (n <= 0)
- return n;
+ if (info->length <= 0)
+ return info->length;
while (1)
- switch (target_auxv_parse (ops, &ptr, data + n, &type, &val))
+ switch (target_auxv_parse (ops, &ptr, data + info->length, &type, &val))
{
case 1: /* Here's an entry, check it. */
if (type == match)
{
- xfree (data);
*valp = val;
return 1;
}
break;
case 0: /* End of the vector. */
- xfree (data);
return 0;
default: /* Bogosity. */
- xfree (data);
return -1;
}
}
-/* Print the contents of the target's AUXV on the specified file. */
+/* Print the contents of the target's AUXV on the specified file. */
int
fprint_target_auxv (struct ui_file *file, struct target_ops *ops)
{
CORE_ADDR type, val;
gdb_byte *data;
- LONGEST len = target_read_alloc (ops, TARGET_OBJECT_AUXV, NULL,
- &data);
- gdb_byte *ptr = data;
+ gdb_byte *ptr;
+ struct auxv_info *info;
int ents = 0;
- if (len <= 0)
- return len;
+ info = get_auxv_inferior_data (ops);
- while (target_auxv_parse (ops, &ptr, data + len, &type, &val) > 0)
+ data = info->data;
+ ptr = data;
+ if (info->length <= 0)
+ return info->length;
+
+ while (target_auxv_parse (ops, &ptr, data + info->length, &type, &val) > 0)
{
- extern int addressprint;
const char *name = "???";
const char *description = "";
enum { dec, hex, str } flavor = hex;
TAG (AT_ICACHEBSIZE, _("Instruction cache block size"), dec);
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_HWCAP2, _("Extension of AT_HWCAP"), 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);
TAG (AT_SYSINFO_EHDR, _("System-supplied DSO's ELF header"), hex);
- TAG (AT_SECURE, _("Boolean, was exec setuid-like?"), dec);
+ TAG (AT_L1I_CACHESHAPE, _("L1 Instruction cache information"), hex);
+ TAG (AT_L1D_CACHESHAPE, _("L1 Data cache information"), hex);
+ TAG (AT_L2_CACHESHAPE, _("L2 cache information"), hex);
+ TAG (AT_L3_CACHESHAPE, _("L3 cache information"), hex);
TAG (AT_SUN_UID, _("Effective user ID"), dec);
TAG (AT_SUN_RUID, _("Real user ID"), dec);
TAG (AT_SUN_GID, _("Effective group ID"), dec);
_("Canonicalized file name given to execve"), str);
TAG (AT_SUN_MMU, _("String for name of MMU module"), str);
TAG (AT_SUN_LDDATA, _("Dynamic linker's data segment address"), hex);
+ TAG (AT_SUN_AUXFLAGS,
+ _("AF_SUN_ flags passed from the kernel"), hex);
}
fprintf_filtered (file, "%-4s %-20s %-30s ",
- paddr_d (type), name, description);
+ plongest (type), name, description);
switch (flavor)
{
case dec:
- fprintf_filtered (file, "%s\n", paddr_d (val));
+ 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:
- if (addressprint)
- fprintf_filtered (file, "0x%s", paddr_nz (val));
- val_print_string (val, -1, 1, file);
- fprintf_filtered (file, "\n");
+ {
+ struct value_print_options opts;
+
+ get_user_print_options (&opts);
+ if (opts.addressprint)
+ fprintf_filtered (file, "%s ", paddress (target_gdbarch (), val));
+ val_print_string (builtin_type (target_gdbarch ())->builtin_char,
+ NULL, val, -1, file, &opts);
+ fprintf_filtered (file, "\n");
+ }
break;
}
++ents;
+ if (type == AT_NULL)
+ break;
}
- xfree (data);
-
return ents;
}
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)
add_info ("auxv", info_auxv_command,
_("Display the inferior's auxiliary vector.\n\
This is information provided by the operating system at program startup."));
+
+ /* Set an auxv cache per-inferior. */
+ auxv_inferior_data
+ = register_inferior_data_with_cleanup (NULL, auxv_inferior_data_cleanup);
+
+ /* Observers used to invalidate the auxv cache when needed. */
+ observer_attach_inferior_exit (invalidate_auxv_cache_inf);
+ observer_attach_inferior_appeared (invalidate_auxv_cache_inf);
+ observer_attach_executable_changed (invalidate_auxv_cache);
}
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