[thirdparty/glibc.git] / elf / pldd.c

/* List dynamic shared objects linked into given process.
   Copyright (C) 2011-2015 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.  */

#include <alloca.h>
#include <argp.h>
#include <assert.h>
#include <dirent.h>
#include <elf.h>
#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <libintl.h>
#include <link.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/ptrace.h>
#include <sys/stat.h>
#include <sys/wait.h>

#include <ldsodefs.h>
#include <version.h>

/* Global variables.  */
extern char *program_invocation_short_name;
#define PACKAGE _libc_intl_domainname

/* External functions.  */
#include <programs/xmalloc.h>

/* Name and version of program.  */
static void print_version (FILE *stream, struct argp_state *state);
void (*argp_program_version_hook) (FILE *, struct argp_state *) = print_version;

/* Function to print some extra text in the help message.  */
static char *more_help (int key, const char *text, void *input);

/* Definitions of arguments for argp functions.  */
static const struct argp_option options[] =
{
  { NULL, 0, NULL, 0, NULL }
};

/* Short description of program.  */
static const char doc[] = N_("\
List dynamic shared objects loaded into process.");

/* Strings for arguments in help texts.  */
static const char args_doc[] = N_("PID");

/* Prototype for option handler.  */
static error_t parse_opt (int key, char *arg, struct argp_state *state);

/* Data structure to communicate with argp functions.  */
static struct argp argp =
{
  options, parse_opt, args_doc, doc, NULL, more_help, NULL
};

// File descriptor of /proc/*/mem file.
static int memfd;

/* Name of the executable  */
static char *exe;

/* Local functions.  */
static int get_process_info (int dfd, long int pid);
static void wait_for_ptrace_stop (long int pid);


int
main (int argc, char *argv[])
{
  /* Parse and process arguments.  */
  int remaining;
  argp_parse (&argp, argc, argv, 0, &remaining, NULL);

  if (remaining != argc - 1)
    {
      fprintf (stderr,
	       gettext ("Exactly one parameter with process ID required.\n"));
      argp_help (&argp, stderr, ARGP_HELP_SEE, program_invocation_short_name);
      return 1;
    }

  assert (sizeof (pid_t) == sizeof (int)
	  || sizeof (pid_t) == sizeof (long int));
  char *endp;
  errno = 0;
  long int pid = strtol (argv[remaining], &endp, 10);
  if (pid < 0 || (pid == ULONG_MAX && errno == ERANGE) || *endp != '\0'
      || (sizeof (pid_t) < sizeof (pid) && pid > INT_MAX))
    error (EXIT_FAILURE, 0, gettext ("invalid process ID '%s'"),
	   argv[remaining]);

  /* Determine the program name.  */
  char buf[7 + 3 * sizeof (pid)];
  snprintf (buf, sizeof (buf), "/proc/%lu", pid);
  int dfd = open (buf, O_RDONLY | O_DIRECTORY);
  if (dfd == -1)
    error (EXIT_FAILURE, errno, gettext ("cannot open %s"), buf);

  size_t exesize = 1024;
#ifdef PATH_MAX
  exesize = PATH_MAX;
#endif
  exe = alloca (exesize);
  ssize_t nexe;
  while ((nexe = readlinkat (dfd, "exe", exe, exesize)) == exesize)
    extend_alloca (exe, exesize, 2 * exesize);
  if (nexe == -1)
    exe = (char *) "<program name undetermined>";
  else
    exe[nexe] = '\0';

  /* Stop all threads since otherwise the list of loaded modules might
     change while we are reading it.  */
  struct thread_list
  {
    pid_t tid;
    struct thread_list *next;
  } *thread_list = NULL;

  int taskfd = openat (dfd, "task", O_RDONLY | O_DIRECTORY | O_CLOEXEC);
  if (taskfd == 1)
    error (EXIT_FAILURE, errno, gettext ("cannot open %s/task"), buf);
  DIR *dir = fdopendir (taskfd);
  if (dir == NULL)
    error (EXIT_FAILURE, errno, gettext ("cannot prepare reading %s/task"),
	   buf);

  struct dirent64 *d;
  while ((d = readdir64 (dir)) != NULL)
    {
      if (! isdigit (d->d_name[0]))
	continue;

      errno = 0;
      long int tid = strtol (d->d_name, &endp, 10);
      if (tid < 0 || (tid == ULONG_MAX && errno == ERANGE) || *endp != '\0'
	  || (sizeof (pid_t) < sizeof (pid) && tid > INT_MAX))
	error (EXIT_FAILURE, 0, gettext ("invalid thread ID '%s'"),
	       d->d_name);

      if (ptrace (PTRACE_ATTACH, tid, NULL, NULL) != 0)
	{
	  /* There might be a race between reading the directory and
	     threads terminating.  Ignore errors attaching to unknown
	     threads unless this is the main thread.  */
	  if (errno == ESRCH && tid != pid)
	    continue;

	  error (EXIT_FAILURE, errno, gettext ("cannot attach to process %lu"),
		 tid);
	}

      wait_for_ptrace_stop (tid);

      struct thread_list *newp = alloca (sizeof (*newp));
      newp->tid = tid;
      newp->next = thread_list;
      thread_list = newp;
    }

  closedir (dir);

  int status = get_process_info (dfd, pid);

  assert (thread_list != NULL);
  do
    {
      ptrace (PTRACE_DETACH, thread_list->tid, NULL, NULL);
      thread_list = thread_list->next;
    }
  while (thread_list != NULL);

  close (dfd);

  return status;
}


/* Wait for PID to enter ptrace-stop state after being attached.  */
static void
wait_for_ptrace_stop (long int pid)
{
  int status;

  /* While waiting for SIGSTOP being delivered to the tracee we have to
     reinject any other pending signal.  Ignore all other errors.  */
  while (waitpid (pid, &status, __WALL) == pid && WIFSTOPPED (status))
    {
      /* The STOP signal should not be delivered to the tracee.  */
      if (WSTOPSIG (status) == SIGSTOP)
	return;
      if (ptrace (PTRACE_CONT, pid, NULL,
		  (void *) (uintptr_t) WSTOPSIG (status)))
	/* The only possible error is that the process died.  */
	return;
    }
}


/* Handle program arguments.  */
static error_t
parse_opt (int key, char *arg, struct argp_state *state)
{
  switch (key)
    {
    default:
      return ARGP_ERR_UNKNOWN;
    }
  return 0;
}


/* Print bug-reporting information in the help message.  */
static char *
more_help (int key, const char *text, void *input)
{
  char *tp = NULL;
  switch (key)
    {
    case ARGP_KEY_HELP_EXTRA:
      /* We print some extra information.  */
      if (asprintf (&tp, gettext ("\
For bug reporting instructions, please see:\n\
%s.\n"), REPORT_BUGS_TO) < 0)
	return NULL;
      return tp;
    default:
      break;
    }
  return (char *) text;
}

/* Print the version information.  */
static void
print_version (FILE *stream, struct argp_state *state)
{
  fprintf (stream, "pldd %s%s\n", PKGVERSION, VERSION);
  fprintf (stream, gettext ("\
Copyright (C) %s Free Software Foundation, Inc.\n\
This is free software; see the source for copying conditions.  There is NO\n\
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
"), "2014");
  fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper");
}


#define CLASS 32
#include "pldd-xx.c"
#define CLASS 64
#include "pldd-xx.c"


static int
get_process_info (int dfd, long int pid)
{
  memfd = openat (dfd, "mem", O_RDONLY);
  if (memfd == -1)
    goto no_info;

  int fd = openat (dfd, "exe", O_RDONLY);
  if (fd == -1)
    {
    no_info:
      error (0, errno, gettext ("cannot get information about process %lu"),
	     pid);
      return EXIT_FAILURE;
    }

  char e_ident[EI_NIDENT];
  if (read (fd, e_ident, EI_NIDENT) != EI_NIDENT)
    goto no_info;

  close (fd);

  if (memcmp (e_ident, ELFMAG, SELFMAG) != 0)
    {
      error (0, 0, gettext ("process %lu is no ELF program"), pid);
      return EXIT_FAILURE;
    }

  fd = openat (dfd, "auxv", O_RDONLY);
  if (fd == -1)
    goto no_info;

  size_t auxv_size = 0;
  void *auxv = NULL;
  while (1)
    {
      auxv_size += 512;
      auxv = xrealloc (auxv, auxv_size);

      ssize_t n = pread (fd, auxv, auxv_size, 0);
      if (n < 0)
	goto no_info;
      if (n < auxv_size)
	{
	  auxv_size = n;
	  break;
	}
    }

  close (fd);

  int retval;
  if (e_ident[EI_CLASS] == ELFCLASS32)
    retval = find_maps32 (pid, auxv, auxv_size);
  else
    retval = find_maps64 (pid, auxv, auxv_size);

  free (auxv);
  close (memfd);

  return retval;
}
Commit	Line	Data
11988f8f	1	/* List dynamic shared objects linked into given process.
b168057a	2	Copyright (C) 2011-2015 Free Software Foundation, Inc.
11988f8f UD	3	This file is part of the GNU C Library.
	4	Contributed by Ulrich Drepper <drepper@gmail.com>, 2011.
	5
	6	The GNU C Library is free software; you can redistribute it and/or
	7	modify it under the terms of the GNU Lesser General Public
	8	License as published by the Free Software Foundation; either
	9	version 2.1 of the License, or (at your option) any later version.
	10
	11	The GNU C Library is distributed in the hope that it will be useful,
	12	but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	Lesser General Public License for more details.
	15
	16	You should have received a copy of the GNU Lesser General Public
59ba27a6 PE	17	License along with the GNU C Library; if not, see
59ba27a6 PE	18	<http://www.gnu.org/licenses/>. */
11988f8f UD	19
	20	#include <alloca.h>
	21	#include <argp.h>
27724598 UD	22	#include <assert.h>
27724598 UD	23	#include <dirent.h>
11988f8f UD	24	#include <elf.h>
	25	#include <errno.h>
	26	#include <error.h>
	27	#include <fcntl.h>
	28	#include <libintl.h>
	29	#include <link.h>
	30	#include <stddef.h>
	31	#include <stdio.h>
	32	#include <stdlib.h>
	33	#include <string.h>
	34	#include <unistd.h>
	35	#include <sys/ptrace.h>
	36	#include <sys/stat.h>
b04acb26	37	#include <sys/wait.h>
11988f8f UD	38
	39	#include <ldsodefs.h>
	40	#include <version.h>
	41
	42	/* Global variables. */
	43	extern char *program_invocation_short_name;
	44	#define PACKAGE _libc_intl_domainname
	45
	46	/* External functions. */
6ff444c4	47	#include <programs/xmalloc.h>
11988f8f UD	48
	49	/* Name and version of program. */
	50	static void print_version (FILE stream, struct argp_state state);
	51	void (argp_program_version_hook) (FILE , struct argp_state *) = print_version;
	52
8b748aed JM	53	/* Function to print some extra text in the help message. */
8b748aed JM	54	static char more_help (int key, const char text, void *input);
11988f8f UD	55
	56	/* Definitions of arguments for argp functions. */
	57	static const struct argp_option options[] =
	58	{
	59	{ NULL, 0, NULL, 0, NULL }
	60	};
	61
	62	/* Short description of program. */
	63	static const char doc[] = N_("\
	64	List dynamic shared objects loaded into process.");
	65
	66	/* Strings for arguments in help texts. */
	67	static const char args_doc[] = N_("PID");
	68
	69	/* Prototype for option handler. */
	70	static error_t parse_opt (int key, char arg, struct argp_state state);
	71
	72	/* Data structure to communicate with argp functions. */
	73	static struct argp argp =
	74	{
8b748aed	75	options, parse_opt, args_doc, doc, NULL, more_help, NULL
11988f8f UD	76	};
	77
	78	// File descriptor of /proc/*/mem file.
	79	static int memfd;
	80
	81	/* Name of the executable */
	82	static char *exe;
	83
	84	/* Local functions. */
27724598	85	static int get_process_info (int dfd, long int pid);
b04acb26	86	static void wait_for_ptrace_stop (long int pid);
11988f8f UD	87
	88
	89	int
	90	main (int argc, char *argv[])
	91	{
	92	/* Parse and process arguments. */
	93	int remaining;
	94	argp_parse (&argp, argc, argv, 0, &remaining, NULL);
	95
	96	if (remaining != argc - 1)
	97	{
	98	fprintf (stderr,
	99	gettext ("Exactly one parameter with process ID required.\n"));
	100	argp_help (&argp, stderr, ARGP_HELP_SEE, program_invocation_short_name);
	101	return 1;
	102	}
	103
27724598 UD	104	assert (sizeof (pid_t) == sizeof (int)
27724598 UD	105	\|\| sizeof (pid_t) == sizeof (long int));
11988f8f UD	106	char *endp;
11988f8f UD	107	errno = 0;
27724598 UD	108	long int pid = strtol (argv[remaining], &endp, 10);
	109	if (pid < 0 \|\| (pid == ULONG_MAX && errno == ERANGE) \|\| *endp != '\0'
	110	\|\| (sizeof (pid_t) < sizeof (pid) && pid > INT_MAX))
11988f8f UD	111	error (EXIT_FAILURE, 0, gettext ("invalid process ID '%s'"),
	112	argv[remaining]);
	113
	114	/* Determine the program name. */
27724598 UD	115	char buf[7 + 3 * sizeof (pid)];
	116	snprintf (buf, sizeof (buf), "/proc/%lu", pid);
	117	int dfd = open (buf, O_RDONLY \| O_DIRECTORY);
	118	if (dfd == -1)
	119	error (EXIT_FAILURE, errno, gettext ("cannot open %s"), buf);
	120
11988f8f	121	size_t exesize = 1024;
27724598 UD	122	#ifdef PATH_MAX
	123	exesize = PATH_MAX;
	124	#endif
11988f8f UD	125	exe = alloca (exesize);
11988f8f UD	126	ssize_t nexe;
27724598	127	while ((nexe = readlinkat (dfd, "exe", exe, exesize)) == exesize)
11988f8f UD	128	extend_alloca (exe, exesize, 2 * exesize);
	129	if (nexe == -1)
	130	exe = (char *) "<program name undetermined>";
	131	else
	132	exe[nexe] = '\0';
	133
27724598 UD	134	/* Stop all threads since otherwise the list of loaded modules might
	135	change while we are reading it. */
	136	struct thread_list
	137	{
	138	pid_t tid;
	139	struct thread_list *next;
	140	} *thread_list = NULL;
	141
	142	int taskfd = openat (dfd, "task", O_RDONLY \| O_DIRECTORY \| O_CLOEXEC);
	143	if (taskfd == 1)
	144	error (EXIT_FAILURE, errno, gettext ("cannot open %s/task"), buf);
	145	DIR *dir = fdopendir (taskfd);
	146	if (dir == NULL)
	147	error (EXIT_FAILURE, errno, gettext ("cannot prepare reading %s/task"),
	148	buf);
	149
	150	struct dirent64 *d;
	151	while ((d = readdir64 (dir)) != NULL)
	152	{
	153	if (! isdigit (d->d_name[0]))
	154	continue;
	155
	156	errno = 0;
	157	long int tid = strtol (d->d_name, &endp, 10);
	158	if (tid < 0 \|\| (tid == ULONG_MAX && errno == ERANGE) \|\| *endp != '\0'
	159	\|\| (sizeof (pid_t) < sizeof (pid) && tid > INT_MAX))
	160	error (EXIT_FAILURE, 0, gettext ("invalid thread ID '%s'"),
	161	d->d_name);
	162
	163	if (ptrace (PTRACE_ATTACH, tid, NULL, NULL) != 0)
	164	{
	165	/* There might be a race between reading the directory and
	166	threads terminating. Ignore errors attaching to unknown
	167	threads unless this is the main thread. */
	168	if (errno == ESRCH && tid != pid)
	169	continue;
	170
	171	error (EXIT_FAILURE, errno, gettext ("cannot attach to process %lu"),
	172	tid);
	173	}
	174
b04acb26 AS	175	wait_for_ptrace_stop (tid);
b04acb26 AS	176
27724598 UD	177	struct thread_list newp = alloca (sizeof (newp));
	178	newp->tid = tid;
	179	newp->next = thread_list;
	180	thread_list = newp;
	181	}
	182
	183	closedir (dir);
11988f8f	184
27724598 UD	185	int status = get_process_info (dfd, pid);
	186
	187	assert (thread_list != NULL);
	188	do
	189	{
	190	ptrace (PTRACE_DETACH, thread_list->tid, NULL, NULL);
	191	thread_list = thread_list->next;
	192	}
	193	while (thread_list != NULL);
11988f8f	194
27724598	195	close (dfd);
11988f8f UD	196
	197	return status;
	198	}
	199
	200
b04acb26 AS	201	/* Wait for PID to enter ptrace-stop state after being attached. */
	202	static void
	203	wait_for_ptrace_stop (long int pid)
	204	{
	205	int status;
	206
	207	/* While waiting for SIGSTOP being delivered to the tracee we have to
	208	reinject any other pending signal. Ignore all other errors. */
	209	while (waitpid (pid, &status, __WALL) == pid && WIFSTOPPED (status))
	210	{
	211	/* The STOP signal should not be delivered to the tracee. */
	212	if (WSTOPSIG (status) == SIGSTOP)
	213	return;
	214	if (ptrace (PTRACE_CONT, pid, NULL,
	215	(void *) (uintptr_t) WSTOPSIG (status)))
	216	/* The only possible error is that the process died. */
	217	return;
	218	}
	219	}
	220
	221
11988f8f UD	222	/* Handle program arguments. */
	223	static error_t
	224	parse_opt (int key, char arg, struct argp_state state)
	225	{
	226	switch (key)
	227	{
	228	default:
	229	return ARGP_ERR_UNKNOWN;
	230	}
	231	return 0;
	232	}
	233
	234
8b748aed JM	235	/* Print bug-reporting information in the help message. */
	236	static char *
	237	more_help (int key, const char text, void input)
	238	{
	239	char *tp = NULL;
	240	switch (key)
	241	{
	242	case ARGP_KEY_HELP_EXTRA:
	243	/* We print some extra information. */
	244	if (asprintf (&tp, gettext ("\
	245	For bug reporting instructions, please see:\n\
	246	%s.\n"), REPORT_BUGS_TO) < 0)
	247	return NULL;
	248	return tp;
	249	default:
	250	break;
	251	}
	252	return (char *) text;
	253	}
	254
11988f8f UD	255	/* Print the version information. */
	256	static void
	257	print_version (FILE stream, struct argp_state state)
	258	{
8b748aed	259	fprintf (stream, "pldd %s%s\n", PKGVERSION, VERSION);
11988f8f UD	260	fprintf (stream, gettext ("\
	261	Copyright (C) %s Free Software Foundation, Inc.\n\
	262	This is free software; see the source for copying conditions. There is NO\n\
	263	warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\
88726d48	264	"), "2014");
11988f8f UD	265	fprintf (stream, gettext ("Written by %s.\n"), "Ulrich Drepper");
	266	}
	267
	268
	269	#define CLASS 32
	270	#include "pldd-xx.c"
	271	#define CLASS 64
	272	#include "pldd-xx.c"
	273
	274
	275	static int
27724598	276	get_process_info (int dfd, long int pid)
11988f8f	277	{
27724598	278	memfd = openat (dfd, "mem", O_RDONLY);
11988f8f UD	279	if (memfd == -1)
	280	goto no_info;
	281
27724598	282	int fd = openat (dfd, "exe", O_RDONLY);
11988f8f UD	283	if (fd == -1)
	284	{
	285	no_info:
	286	error (0, errno, gettext ("cannot get information about process %lu"),
27724598	287	pid);
11988f8f UD	288	return EXIT_FAILURE;
	289	}
	290
6585cb60 UD	291	char e_ident[EI_NIDENT];
6585cb60 UD	292	if (read (fd, e_ident, EI_NIDENT) != EI_NIDENT)
11988f8f UD	293	goto no_info;
	294
	295	close (fd);
	296
6585cb60	297	if (memcmp (e_ident, ELFMAG, SELFMAG) != 0)
11988f8f	298	{
27724598	299	error (0, 0, gettext ("process %lu is no ELF program"), pid);
11988f8f UD	300	return EXIT_FAILURE;
	301	}
	302
27724598	303	fd = openat (dfd, "auxv", O_RDONLY);
11988f8f UD	304	if (fd == -1)
	305	goto no_info;
	306
	307	size_t auxv_size = 0;
	308	void *auxv = NULL;
	309	while (1)
	310	{
	311	auxv_size += 512;
	312	auxv = xrealloc (auxv, auxv_size);
	313
c5305d88	314	ssize_t n = pread (fd, auxv, auxv_size, 0);
11988f8f UD	315	if (n < 0)
	316	goto no_info;
	317	if (n < auxv_size)
	318	{
	319	auxv_size = n;
	320	break;
	321	}
	322	}
	323
	324	close (fd);
	325
27724598	326	int retval;
6585cb60 UD	327	if (e_ident[EI_CLASS] == ELFCLASS32)
6585cb60 UD	328	retval = find_maps32 (pid, auxv, auxv_size);
11988f8f	329	else
6585cb60	330	retval = find_maps64 (pid, auxv, auxv_size);
27724598 UD	331
	332	free (auxv);
	333	close (memfd);
	334
	335	return retval;
11988f8f	336	}