[deliverable/binutils-gdb.git] / gdb / auxv.c

/* Auxiliary vector support for GDB, the GNU debugger.

   Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.  */

#include "defs.h"
#include "target.h"
#include "gdbtypes.h"
#include "command.h"
#include "inferior.h"
#include "valprint.h"
#include "gdb_assert.h"

#include "auxv.h"
#include "elf/common.h"

#include <unistd.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.  */

LONGEST
procfs_xfer_auxv (struct target_ops *ops,
		  int /* enum target_object */ object,
		  const char *annex,
		  gdb_byte *readbuf,
		  const gdb_byte *writebuf,
		  ULONGEST offset,
		  LONGEST len)
{
  char *pathname;
  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);
  if (fd < 0)
    return -1;

  if (offset != (ULONGEST) 0
      && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
    n = -1;
  else if (readbuf != NULL)
    n = read (fd, readbuf, len);
  else
    n = write (fd, writebuf, len);

  (void) close (fd);

  return n;
}

/* 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)
{
  const int sizeof_auxv_field = TYPE_LENGTH (builtin_type_void_data_ptr);
  gdb_byte *ptr = *readptr;

  if (endptr == ptr)
    return 0;

  if (endptr - ptr < sizeof_auxv_field * 2)
    return -1;

  *typep = extract_unsigned_integer (ptr, sizeof_auxv_field);
  ptr += sizeof_auxv_field;
  *valp = extract_unsigned_integer (ptr, sizeof_auxv_field);
  ptr += sizeof_auxv_field;

  *readptr = ptr;
  return 1;
}

/* 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
   storing the entry's value field in *VALP.  */
int
target_auxv_search (struct target_ops *ops, CORE_ADDR match, CORE_ADDR *valp)
{
  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;

  if (n <= 0)
    return n;

  while (1)
    switch (target_auxv_parse (ops, &ptr, data + n, &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;
      }

  /*NOTREACHED*/
}


/* 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;
  int ents = 0;

  if (len <= 0)
    return len;

  while (target_auxv_parse (ops, &ptr, data + len, &type, &val) > 0)
    {
      extern int addressprint;
      const char *name = "???";
      const char *description = "";
      enum { dec, hex, str } flavor = hex;

      switch (type)
	{
#define TAG(tag, text, kind) \
	case tag: name = #tag; description = text; flavor = kind; break
	  TAG (AT_NULL, _("End of vector"), hex);
	  TAG (AT_IGNORE, _("Entry should be ignored"), hex);
	  TAG (AT_EXECFD, _("File descriptor of program"), dec);
	  TAG (AT_PHDR, _("Program headers for program"), hex);
	  TAG (AT_PHENT, _("Size of program header entry"), dec);
	  TAG (AT_PHNUM, _("Number of program headers"), dec);
	  TAG (AT_PAGESZ, _("System page size"), dec);
	  TAG (AT_BASE, _("Base address of interpreter"), hex);
	  TAG (AT_FLAGS, _("Flags"), hex);
	  TAG (AT_ENTRY, _("Entry point of program"), hex);
	  TAG (AT_NOTELF, _("Program is not ELF"), dec);
	  TAG (AT_UID, _("Real user ID"), dec);
	  TAG (AT_EUID, _("Effective user ID"), dec);
	  TAG (AT_GID, _("Real group ID"), dec);
	  TAG (AT_EGID, _("Effective group ID"), dec);
	  TAG (AT_CLKTCK, _("Frequency of times()"), dec);
	  TAG (AT_PLATFORM, _("String identifying platform"), str);
	  TAG (AT_HWCAP, _("Machine-dependent CPU capability hints"), hex);
	  TAG (AT_FPUCW, _("Used FPU control word"), dec);
	  TAG (AT_DCACHEBSIZE, _("Data cache block size"), dec);
	  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_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_SUN_UID, _("Effective user ID"), dec);
	  TAG (AT_SUN_RUID, _("Real user ID"), dec);
	  TAG (AT_SUN_GID, _("Effective group ID"), dec);
	  TAG (AT_SUN_RGID, _("Real group ID"), dec);
	  TAG (AT_SUN_LDELF, _("Dynamic linker's ELF header"), hex);
	  TAG (AT_SUN_LDSHDR, _("Dynamic linker's section headers"), hex);
	  TAG (AT_SUN_LDNAME, _("String giving name of dynamic linker"), str);
	  TAG (AT_SUN_LPAGESZ, _("Large pagesize"), dec);
	  TAG (AT_SUN_PLATFORM, _("Platform name string"), str);
	  TAG (AT_SUN_HWCAP, _("Machine-dependent CPU capability hints"), hex);
	  TAG (AT_SUN_IFLUSH, _("Should flush icache?"), dec);
	  TAG (AT_SUN_CPU, _("CPU name string"), str);
	  TAG (AT_SUN_EMUL_ENTRY, _("COFF entry point address"), hex);
	  TAG (AT_SUN_EMUL_EXECFD, _("COFF executable file descriptor"), dec);
	  TAG (AT_SUN_EXECNAME,
	       _("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);
	}

      fprintf_filtered (file, "%-4s %-20s %-30s ",
			paddr_d (type), name, description);
      switch (flavor)
	{
	case dec:
	  fprintf_filtered (file, "%s\n", paddr_d (val));
	  break;
	case hex:
	  fprintf_filtered (file, "0x%s\n", paddr_nz (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");
	  break;
	}
      ++ents;
    }

  xfree (data);

  return ents;
}

static void
info_auxv_command (char *cmd, int from_tty)
{
  if (! target_has_stack)
    error (_("The program has no auxiliary information now."));
  else
    {
      int ents = fprint_target_auxv (gdb_stdout, &current_target);
      if (ents < 0)
	error (_("No auxiliary vector found, or failed reading it."));
      else if (ents == 0)
	error (_("Auxiliary vector is empty."));
    }
}


extern initialize_file_ftype _initialize_auxv; /* -Wmissing-prototypes; */

void
_initialize_auxv (void)
{
  add_info ("auxv", info_auxv_command,
	    _("Display the inferior's auxiliary vector.\n\
This is information provided by the operating system at program startup."));
}
Commit	Line	Data
14ed0a8b RM	1	/* Auxiliary vector support for GDB, the GNU debugger.
14ed0a8b RM	2
6aba47ca	3	Copyright (C) 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
14ed0a8b RM	4
	5	This file is part of GDB.
	6
	7	This program is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 2 of the License, or
	10	(at your option) any later version.
	11
	12	This program is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with this program; if not, write to the Free Software
197e01b6 EZ	19	Foundation, Inc., 51 Franklin Street, Fifth Floor,
197e01b6 EZ	20	Boston, MA 02110-1301, USA. */
14ed0a8b RM	21
	22	#include "defs.h"
	23	#include "target.h"
	24	#include "gdbtypes.h"
	25	#include "command.h"
	26	#include "inferior.h"
	27	#include "valprint.h"
	28	#include "gdb_assert.h"
	29
	30	#include "auxv.h"
	31	#include "elf/common.h"
	32
	33	#include <unistd.h>
	34	#include <fcntl.h>
	35
	36
	37	/* This function is called like a to_xfer_partial hook,
	38	but must be called with TARGET_OBJECT_AUXV.
	39	It handles access via /proc/PID/auxv, which is the common method.
	40	This function is appropriate for doing:
	41	#define NATIVE_XFER_AUXV procfs_xfer_auxv
	42	for a native target that uses inftarg.c's child_xfer_partial hook. */
	43
	44	LONGEST
	45	procfs_xfer_auxv (struct target_ops *ops,
	46	int /* enum target_object */ object,
	47	const char *annex,
36aa5e41 AC	48	gdb_byte *readbuf,
36aa5e41 AC	49	const gdb_byte *writebuf,
14ed0a8b RM	50	ULONGEST offset,
	51	LONGEST len)
	52	{
	53	char *pathname;
	54	int fd;
	55	LONGEST n;
	56
	57	gdb_assert (object == TARGET_OBJECT_AUXV);
	58	gdb_assert (readbuf \|\| writebuf);
	59
	60	pathname = xstrprintf ("/proc/%d/auxv", PIDGET (inferior_ptid));
	61	fd = open (pathname, writebuf != NULL ? O_WRONLY : O_RDONLY);
	62	xfree (pathname);
	63	if (fd < 0)
	64	return -1;
	65
	66	if (offset != (ULONGEST) 0
	67	&& lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
	68	n = -1;
	69	else if (readbuf != NULL)
	70	n = read (fd, readbuf, len);
	71	else
	72	n = write (fd, writebuf, len);
	73
	74	(void) close (fd);
	75
	76	return n;
	77	}
	78
14ed0a8b RM	79	/* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
	80	Return 0 if *READPTR is already at the end of the buffer.
	81	Return -1 if there is insufficient buffer for a whole entry.
	82	Return 1 if an entry was read into TYPEP and VALP. */
	83	int
36aa5e41 AC	84	target_auxv_parse (struct target_ops ops, gdb_byte *readptr,
36aa5e41 AC	85	gdb_byte endptr, CORE_ADDR typep, CORE_ADDR *valp)
14ed0a8b RM	86	{
14ed0a8b RM	87	const int sizeof_auxv_field = TYPE_LENGTH (builtin_type_void_data_ptr);
36aa5e41	88	gdb_byte ptr = readptr;
14ed0a8b RM	89
	90	if (endptr == ptr)
	91	return 0;
	92
	93	if (endptr - ptr < sizeof_auxv_field * 2)
	94	return -1;
	95
	96	*typep = extract_unsigned_integer (ptr, sizeof_auxv_field);
	97	ptr += sizeof_auxv_field;
	98	*valp = extract_unsigned_integer (ptr, sizeof_auxv_field);
	99	ptr += sizeof_auxv_field;
	100
	101	*readptr = ptr;
	102	return 1;
	103	}
	104
	105	/* Extract the auxiliary vector entry with a_type matching MATCH.
	106	Return zero if no such entry was found, or -1 if there was
	107	an error getting the information. On success, return 1 after
	108	storing the entry's value field in VALP. /
	109	int
	110	target_auxv_search (struct target_ops ops, CORE_ADDR match, CORE_ADDR valp)
	111	{
	112	CORE_ADDR type, val;
36aa5e41	113	gdb_byte *data;
13547ab6	114	LONGEST n = target_read_alloc (ops, TARGET_OBJECT_AUXV, NULL, &data);
36aa5e41	115	gdb_byte *ptr = data;
14ed0a8b RM	116	int ents = 0;
	117
	118	if (n <= 0)
	119	return n;
	120
	121	while (1)
	122	switch (target_auxv_parse (ops, &ptr, data + n, &type, &val))
	123	{
	124	case 1: /* Here's an entry, check it. */
	125	if (type == match)
	126	{
	127	xfree (data);
	128	*valp = val;
	129	return 1;
	130	}
	131	break;
	132	case 0: /* End of the vector. */
	133	xfree (data);
	134	return 0;
	135	default: /* Bogosity. */
	136	xfree (data);
	137	return -1;
	138	}
	139
	140	/NOTREACHED/
	141	}
	142
	143
	144	/* Print the contents of the target's AUXV on the specified file. */
	145	int
	146	fprint_target_auxv (struct ui_file file, struct target_ops ops)
	147	{
	148	CORE_ADDR type, val;
36aa5e41	149	gdb_byte *data;
13547ab6 DJ	150	LONGEST len = target_read_alloc (ops, TARGET_OBJECT_AUXV, NULL,
13547ab6 DJ	151	&data);
36aa5e41	152	gdb_byte *ptr = data;
14ed0a8b RM	153	int ents = 0;
	154
	155	if (len <= 0)
	156	return len;
	157
	158	while (target_auxv_parse (ops, &ptr, data + len, &type, &val) > 0)
	159	{
	160	extern int addressprint;
	161	const char *name = "???";
	162	const char *description = "";
	163	enum { dec, hex, str } flavor = hex;
	164
	165	switch (type)
	166	{
	167	#define TAG(tag, text, kind) \
	168	case tag: name = #tag; description = text; flavor = kind; break
edefbb7c AC	169	TAG (AT_NULL, _("End of vector"), hex);
	170	TAG (AT_IGNORE, _("Entry should be ignored"), hex);
	171	TAG (AT_EXECFD, _("File descriptor of program"), dec);
	172	TAG (AT_PHDR, _("Program headers for program"), hex);
	173	TAG (AT_PHENT, _("Size of program header entry"), dec);
	174	TAG (AT_PHNUM, _("Number of program headers"), dec);
	175	TAG (AT_PAGESZ, _("System page size"), dec);
	176	TAG (AT_BASE, _("Base address of interpreter"), hex);
	177	TAG (AT_FLAGS, _("Flags"), hex);
	178	TAG (AT_ENTRY, _("Entry point of program"), hex);
	179	TAG (AT_NOTELF, _("Program is not ELF"), dec);
	180	TAG (AT_UID, _("Real user ID"), dec);
	181	TAG (AT_EUID, _("Effective user ID"), dec);
	182	TAG (AT_GID, _("Real group ID"), dec);
	183	TAG (AT_EGID, _("Effective group ID"), dec);
	184	TAG (AT_CLKTCK, _("Frequency of times()"), dec);
	185	TAG (AT_PLATFORM, _("String identifying platform"), str);
	186	TAG (AT_HWCAP, _("Machine-dependent CPU capability hints"), hex);
	187	TAG (AT_FPUCW, _("Used FPU control word"), dec);
	188	TAG (AT_DCACHEBSIZE, _("Data cache block size"), dec);
	189	TAG (AT_ICACHEBSIZE, _("Instruction cache block size"), dec);
	190	TAG (AT_UCACHEBSIZE, _("Unified cache block size"), dec);
	191	TAG (AT_IGNOREPPC, _("Entry should be ignored"), dec);
	192	TAG (AT_SYSINFO, _("Special system info/entry points"), hex);
	193	TAG (AT_SYSINFO_EHDR, _("System-supplied DSO's ELF header"), hex);
	194	TAG (AT_SECURE, _("Boolean, was exec setuid-like?"), dec);
	195	TAG (AT_SUN_UID, _("Effective user ID"), dec);
	196	TAG (AT_SUN_RUID, _("Real user ID"), dec);
	197	TAG (AT_SUN_GID, _("Effective group ID"), dec);
	198	TAG (AT_SUN_RGID, _("Real group ID"), dec);
	199	TAG (AT_SUN_LDELF, _("Dynamic linker's ELF header"), hex);
	200	TAG (AT_SUN_LDSHDR, _("Dynamic linker's section headers"), hex);
	201	TAG (AT_SUN_LDNAME, _("String giving name of dynamic linker"), str);
	202	TAG (AT_SUN_LPAGESZ, _("Large pagesize"), dec);
	203	TAG (AT_SUN_PLATFORM, _("Platform name string"), str);
	204	TAG (AT_SUN_HWCAP, _("Machine-dependent CPU capability hints"), hex);
	205	TAG (AT_SUN_IFLUSH, _("Should flush icache?"), dec);
	206	TAG (AT_SUN_CPU, _("CPU name string"), str);
	207	TAG (AT_SUN_EMUL_ENTRY, _("COFF entry point address"), hex);
	208	TAG (AT_SUN_EMUL_EXECFD, _("COFF executable file descriptor"), dec);
14ed0a8b	209	TAG (AT_SUN_EXECNAME,
edefbb7c AC	210	_("Canonicalized file name given to execve"), str);
	211	TAG (AT_SUN_MMU, _("String for name of MMU module"), str);
	212	TAG (AT_SUN_LDDATA, _("Dynamic linker's data segment address"), hex);
14ed0a8b RM	213	}
	214
	215	fprintf_filtered (file, "%-4s %-20s %-30s ",
	216	paddr_d (type), name, description);
	217	switch (flavor)
	218	{
	219	case dec:
	220	fprintf_filtered (file, "%s\n", paddr_d (val));
	221	break;
	222	case hex:
	223	fprintf_filtered (file, "0x%s\n", paddr_nz (val));
	224	break;
	225	case str:
	226	if (addressprint)
	227	fprintf_filtered (file, "0x%s", paddr_nz (val));
	228	val_print_string (val, -1, 1, file);
	229	fprintf_filtered (file, "\n");
	230	break;
	231	}
	232	++ents;
	233	}
	234
	235	xfree (data);
	236
	237	return ents;
	238	}
	239
	240	static void
	241	info_auxv_command (char *cmd, int from_tty)
	242	{
14ed0a8b	243	if (! target_has_stack)
edefbb7c	244	error (_("The program has no auxiliary information now."));
14ed0a8b RM	245	else
	246	{
	247	int ents = fprint_target_auxv (gdb_stdout, &current_target);
	248	if (ents < 0)
edefbb7c	249	error (_("No auxiliary vector found, or failed reading it."));
14ed0a8b	250	else if (ents == 0)
edefbb7c	251	error (_("Auxiliary vector is empty."));
14ed0a8b RM	252	}
	253	}
	254
	255
	256	extern initialize_file_ftype _initialize_auxv; /* -Wmissing-prototypes; */
	257
	258	void
	259	_initialize_auxv (void)
	260	{
	261	add_info ("auxv", info_auxv_command,
edefbb7c AC	262	_("Display the inferior's auxiliary vector.\n\
edefbb7c AC	263	This is information provided by the operating system at program startup."));
14ed0a8b	264	}