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

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

   Copyright 2004 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., 59 Temple Place - Suite 330,
   Boston, MA 02111-1307, 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,
		  void *readbuf,
		  const void *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 all the auxv data into a contiguous xmalloc'd buffer,
   stored in *DATA.  Return the size in bytes of this data.
   If zero, there is no data and *DATA is null.
   if < 0, there was an error and *DATA is null.  */
LONGEST
target_auxv_read (struct target_ops *ops, char **data)
{
  size_t auxv_alloc = 512, auxv_pos = 0;
  char *auxv = xmalloc (auxv_alloc);
  int n;

  while (1)
    {
      n = target_read_partial (ops, TARGET_OBJECT_AUXV,
			       NULL, &auxv[auxv_pos], 0,
			       auxv_alloc - auxv_pos);
      if (n <= 0)
	break;
      auxv_pos += n;
      if (auxv_pos < auxv_alloc) /* Read all there was.  */
	break;
      gdb_assert (auxv_pos == auxv_alloc);
      auxv_alloc *= 2;
      auxv = xrealloc (auxv, auxv_alloc);
    }

  if (auxv_pos == 0)
    {
      xfree (auxv);
      *data = NULL;
      return n;
    }

  *data = auxv;
  return auxv_pos;
}

/* 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, char **readptr, char *endptr,
		   CORE_ADDR *typep, CORE_ADDR *valp)
{
  const int sizeof_auxv_field = TYPE_LENGTH (builtin_type_void_data_ptr);
  char *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;
  char *data;
  int n = target_auxv_read (ops, &data);
  char *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;
  char *data;
  int len = target_auxv_read (ops, &data);
  char *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 auxilary vector found, or failed reading it.");
      else if (ents == 0)
	error ("Auxilary 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.
	2
	3	Copyright 2004 Free Software Foundation, Inc.
	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
	19	Foundation, Inc., 59 Temple Place - Suite 330,
	20	Boston, MA 02111-1307, USA. */
	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,
	48	void *readbuf,
	49	const void *writebuf,
	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
79	/* Read all the auxv data into a contiguous xmalloc'd buffer,
80	stored in *DATA. Return the size in bytes of this data.
81	If zero, there is no data and *DATA is null.
82	if < 0, there was an error and DATA is null. /
83	LONGEST
84	target_auxv_read (struct target_ops ops, char *data)
85	{
86	size_t auxv_alloc = 512, auxv_pos = 0;
87	char *auxv = xmalloc (auxv_alloc);
88	int n;
89
90	while (1)
91	{
92	n = target_read_partial (ops, TARGET_OBJECT_AUXV,
93	NULL, &auxv[auxv_pos], 0,
94	auxv_alloc - auxv_pos);
95	if (n <= 0)
96	break;
97	auxv_pos += n;
98	if (auxv_pos < auxv_alloc) /* Read all there was. */
99	break;
100	gdb_assert (auxv_pos == auxv_alloc);
101	auxv_alloc *= 2;
102	auxv = xrealloc (auxv, auxv_alloc);
103	}
104
105	if (auxv_pos == 0)
106	{
107	xfree (auxv);
108	*data = NULL;
109	return n;
110	}
111
112	*data = auxv;
113	return auxv_pos;
114	}
115
116	/* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
117	Return 0 if *READPTR is already at the end of the buffer.
118	Return -1 if there is insufficient buffer for a whole entry.
119	Return 1 if an entry was read into TYPEP and VALP. */
120	int
121	target_auxv_parse (struct target_ops ops, char readptr, char endptr,
122	CORE_ADDR typep, CORE_ADDR valp)
123	{
124	const int sizeof_auxv_field = TYPE_LENGTH (builtin_type_void_data_ptr);
125	char ptr = readptr;
126
127	if (endptr == ptr)
128	return 0;
129
130	if (endptr - ptr < sizeof_auxv_field * 2)
131	return -1;
132
133	*typep = extract_unsigned_integer (ptr, sizeof_auxv_field);
134	ptr += sizeof_auxv_field;
135	*valp = extract_unsigned_integer (ptr, sizeof_auxv_field);
136	ptr += sizeof_auxv_field;
137
138	*readptr = ptr;
139	return 1;
140	}
141
142	/* Extract the auxiliary vector entry with a_type matching MATCH.
143	Return zero if no such entry was found, or -1 if there was
144	an error getting the information. On success, return 1 after
145	storing the entry's value field in VALP. /
146	int
147	target_auxv_search (struct target_ops ops, CORE_ADDR match, CORE_ADDR valp)
148	{
149	CORE_ADDR type, val;
150	char *data;
151	int n = target_auxv_read (ops, &data);
152	char *ptr = data;
153	int ents = 0;
154
155	if (n <= 0)
156	return n;
157
158	while (1)
159	switch (target_auxv_parse (ops, &ptr, data + n, &type, &val))
160	{
161	case 1: /* Here's an entry, check it. */
162	if (type == match)
163	{
164	xfree (data);
165	*valp = val;
166	return 1;
167	}
168	break;
169	case 0: /* End of the vector. */
170	xfree (data);
171	return 0;
172	default: /* Bogosity. */
173	xfree (data);
174	return -1;
175	}
176
177	/NOTREACHED/
178	}
179
180
181	/* Print the contents of the target's AUXV on the specified file. */
182	int
183	fprint_target_auxv (struct ui_file file, struct target_ops ops)
184	{
185	CORE_ADDR type, val;
186	char *data;
187	int len = target_auxv_read (ops, &data);
188	char *ptr = data;
189	int ents = 0;
190
191	if (len <= 0)
192	return len;
193
194	while (target_auxv_parse (ops, &ptr, data + len, &type, &val) > 0)
195	{
196	extern int addressprint;
197	const char *name = "???";
198	const char *description = "";
199	enum { dec, hex, str } flavor = hex;
200
201	switch (type)
202	{
203	#define TAG(tag, text, kind) \
204	case tag: name = #tag; description = text; flavor = kind; break
205	TAG (AT_NULL, "End of vector", hex);
206	TAG (AT_IGNORE, "Entry should be ignored", hex);
207	TAG (AT_EXECFD, "File descriptor of program", dec);
208	TAG (AT_PHDR, "Program headers for program", hex);
209	TAG (AT_PHENT, "Size of program header entry", dec);
210	TAG (AT_PHNUM, "Number of program headers", dec);
211	TAG (AT_PAGESZ, "System page size", dec);
212	TAG (AT_BASE, "Base address of interpreter", hex);
213	TAG (AT_FLAGS, "Flags", hex);
214	TAG (AT_ENTRY, "Entry point of program", hex);
215	TAG (AT_NOTELF, "Program is not ELF", dec);
216	TAG (AT_UID, "Real user ID", dec);
217	TAG (AT_EUID, "Effective user ID", dec);
218	TAG (AT_GID, "Real group ID", dec);
219	TAG (AT_EGID, "Effective group ID", dec);
220	TAG (AT_CLKTCK, "Frequency of times()", dec);
221	TAG (AT_PLATFORM, "String identifying platform", str);
222	TAG (AT_HWCAP, "Machine-dependent CPU capability hints", hex);
223	TAG (AT_FPUCW, "Used FPU control word", dec);
224	TAG (AT_DCACHEBSIZE, "Data cache block size", dec);
225	TAG (AT_ICACHEBSIZE, "Instruction cache block size", dec);
226	TAG (AT_UCACHEBSIZE, "Unified cache block size", dec);
227	TAG (AT_IGNOREPPC, "Entry should be ignored", dec);
228	TAG (AT_SYSINFO, "Special system info/entry points", hex);
229	TAG (AT_SYSINFO_EHDR, "System-supplied DSO's ELF header", hex);
230	TAG (AT_SECURE, "Boolean, was exec setuid-like?", dec);
231	TAG (AT_SUN_UID, "Effective user ID", dec);
232	TAG (AT_SUN_RUID, "Real user ID", dec);
233	TAG (AT_SUN_GID, "Effective group ID", dec);
234	TAG (AT_SUN_RGID, "Real group ID", dec);
235	TAG (AT_SUN_LDELF, "Dynamic linker's ELF header", hex);
236	TAG (AT_SUN_LDSHDR, "Dynamic linker's section headers", hex);
237	TAG (AT_SUN_LDNAME, "String giving name of dynamic linker", str);
238	TAG (AT_SUN_LPAGESZ, "Large pagesize", dec);
239	TAG (AT_SUN_PLATFORM, "Platform name string", str);
240	TAG (AT_SUN_HWCAP, "Machine-dependent CPU capability hints", hex);
241	TAG (AT_SUN_IFLUSH, "Should flush icache?", dec);
242	TAG (AT_SUN_CPU, "CPU name string", str);
243	TAG (AT_SUN_EMUL_ENTRY, "COFF entry point address", hex);
244	TAG (AT_SUN_EMUL_EXECFD, "COFF executable file descriptor", dec);
245	TAG (AT_SUN_EXECNAME,
246	"Canonicalized file name given to execve", str);
247	TAG (AT_SUN_MMU, "String for name of MMU module", str);
248	TAG (AT_SUN_LDDATA, "Dynamic linker's data segment address", hex);
249	}
250
251	fprintf_filtered (file, "%-4s %-20s %-30s ",
252	paddr_d (type), name, description);
253	switch (flavor)
254	{
255	case dec:
256	fprintf_filtered (file, "%s\n", paddr_d (val));
257	break;
258	case hex:
259	fprintf_filtered (file, "0x%s\n", paddr_nz (val));
260	break;
261	case str:
262	if (addressprint)
263	fprintf_filtered (file, "0x%s", paddr_nz (val));
264	val_print_string (val, -1, 1, file);
265	fprintf_filtered (file, "\n");
266	break;
267	}
268	++ents;
269	}
270
271	xfree (data);
272
273	return ents;
274	}
275
276	static void
277	info_auxv_command (char *cmd, int from_tty)
278	{
279
280	if (! target_has_stack)
281	error ("The program has no auxiliary information now.");
282	else
283	{
284	int ents = fprint_target_auxv (gdb_stdout, &current_target);
285	if (ents < 0)
286	error ("No auxilary vector found, or failed reading it.");
287	else if (ents == 0)
288	error ("Auxilary vector is empty.");
289	}
290	}
291
292
293	extern initialize_file_ftype _initialize_auxv; /* -Wmissing-prototypes; */
294
295	void
296	_initialize_auxv (void)
297	{
298	add_info ("auxv", info_auxv_command,
299	"Display the inferior's auxiliary vector.\n\
300	This is information provided by the operating system at program startup.");
301	}