xref: /titanic_51/usr/src/tools/scripts/find_elf.pl (revision ed22c7109fc5dd9e1b7a5d0333bdc7ad2718e2ab)
1#!/usr/bin/perl -w
2#
3# CDDL HEADER START
4#
5# The contents of this file are subject to the terms of the
6# Common Development and Distribution License (the "License").
7# You may not use this file except in compliance with the License.
8#
9# You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10# or http://www.opensolaris.org/os/licensing.
11# See the License for the specific language governing permissions
12# and limitations under the License.
13#
14# When distributing Covered Code, include this CDDL HEADER in each
15# file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16# If applicable, add the following below this CDDL HEADER, with the
17# fields enclosed by brackets "[]" replaced with your own identifying
18# information: Portions Copyright [yyyy] [name of copyright owner]
19#
20# CDDL HEADER END
21#
22
23#
24# Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
25#
26
27#
28# Find ELF executables and sharable objects
29#
30# This script descends a directory hierarchy and reports the ELF
31# objects found, one object per line of output.
32#
33#	find_elf [-frs] path
34#
35# Where path is a file or directory.
36#
37# Each line of output is of the form:
38#
39#	ELFCLASS  ELFTYPE VERDEF|NOVERDEF relpath
40#
41# where relpath is the path relative to the directory from which the
42# search started.
43
44use strict;
45
46use vars  qw($Prog %Output @SaveArgv);
47use vars  qw(%opt $HaveElfedit);
48
49# Hashes used to detect aliases --- symlinks that reference a common file
50#
51#	id_hash - Maps the unique st_dev/st_ino pair to the real file
52#	alias_hash - Maps symlinks to the real file they reference
53#
54use vars  qw(%id_hash %alias_hash);
55
56use POSIX qw(getenv);
57use Getopt::Std;
58use File::Basename;
59use IO::Dir;
60
61
62## GetObjectInfo(path)
63#
64# Return a 3 element output array describing the object
65# given by path. The elements of the array contain:
66#
67#	Index   Meaning
68#	-----------------------------------------------
69#	0	ELFCLASS of object (0 if not an ELF object)
70#	1	Type of object (NONE if not an ELF object)
71#	2	VERDEF if object defines versions, NOVERDEF otherwise
72#
73sub GetObjectInfo {
74	my $path = $_[0];
75
76	# If elfedit is available, we use it to obtain the desired information
77	# by executing three commands in order, to produce a 0, 2, or 3
78	# element output array.
79	#
80	#	Command                 Meaning
81	#	-----------------------------------------------
82	#	ehdr:ei_class		ELFCLASS of object
83	#	ehdr:ei_e_type		Type of object
84	#	dyn:tag verdef		Address of verdef items
85	#
86	# We discard stderr, and simply examine the resulting array to
87	# determine the situation:
88	#
89	#	# Array Elements	Meaning
90	#	-----------------------------------------------
91	#	  0			File is not ELF object
92	#	  2			Object with no versions (no VERDEF)
93	#	  3			Object that has versions
94	if ($HaveElfedit) {
95		my $ecmd = "elfedit -r -o simple -e ehdr:ei_class " .
96		    "-e ehdr:e_type -e 'dyn:tag verdef'";
97		my @Elf = split(/\n/, `$ecmd $path 2>/dev/null`);
98
99		my $ElfCnt = scalar @Elf;
100
101		# Return ET_NONE array if not an ELF object
102		return (0, 'NONE', 'NOVERDEF') if ($ElfCnt == 0);
103
104		# Otherwise, convert the result to standard form
105		$Elf[0] =~ s/^ELFCLASS//;
106		$Elf[1] =~ s/^ET_//;
107		$Elf[2] = ($ElfCnt == 3) ? 'VERDEF' : 'NOVERDEF';
108		return @Elf;
109	}
110
111	# For older platforms, we use elfdump to get the desired information.
112	my @Elf = split(/\n/, `elfdump -ed $path 2>&1`);
113	my $Header = 'None';
114	my $Verdef = 'NOVERDEF';
115	my ($Class, $Type);
116
117	foreach my $Line (@Elf) {
118		# If we have an invalid file type (which we can tell from the
119		# first line), or we're processing an archive, bail.
120		if ($Header eq 'None') {
121			if (($Line =~ /invalid file/) ||
122			    ($Line =~ /$path(.*):/)) {
123				return (0, 'NONE', 'NOVERDEF');
124			}
125		}
126
127		if ($Line =~ /^ELF Header/) {
128			$Header = 'Ehdr';
129			next;
130		}
131
132		if ($Line =~ /^Dynamic Section/) {
133			$Header = 'Dyn';
134			next;
135		}
136
137		if ($Header eq 'Ehdr') {
138			if ($Line =~ /e_type:\s*ET_([^\s]+)/) {
139				$Type = $1;
140				next;
141			}
142			if ($Line =~ /ei_class:\s+ELFCLASS(\d+)/) {
143				$Class = $1;
144				next;
145			}
146			next;
147		}
148
149		if (($Header eq 'Dyn') &&
150		    ($Line =~ /^\s*\[\d+\]\s+VERDEF\s+/)) {
151			$Verdef = 'VERDEF';
152			next;
153		}
154	}
155	return ($Class, $Type, $Verdef);
156}
157
158
159## ProcFile(FullPath, RelPath, AliasedPath, IsSymLink, dev, ino)
160#
161# Determine whether this a ELF dynamic object and if so, add a line
162# of output for it to @Output describing it.
163#
164# entry:
165#	FullPath - Fully qualified path
166#	RelPath - Path relative to starting root directory
167#	AliasedPath - True if RelPath contains a symlink directory component.
168#		Such a path represents an alias to the same file found
169#		completely via actual directories.
170#	IsSymLink - True if basename (final component) of path is a symlink.
171#
172sub ProcFile {
173	my($FullPath, $RelPath, $AliasedPath, $IsSymLink, $dev, $ino) = @_;
174	my(@Elf, @Pvs, @Pvs_don, @Vers, %TopVer);
175	my($Aud, $Max, $Priv, $Pub, $ElfCnt, $Val, $Ttl, $NotPlugin);
176
177	my $uniqid = sprintf("%llx-%llx", $dev, $ino);
178
179	# Remove ./ from front of relative path
180	$RelPath =~ s/^\.\///;
181
182	my $name = $opt{r} ? $RelPath : $FullPath;
183
184	# If this is a symlink, or the path contains a symlink, put it in
185	# the alias hash for later analysis. We do this before testing to
186	# see if it is an ELF file, because that's a relatively expensive
187	# test. The tradeoff is that the alias hash will contain some files
188	# we don't care about. That is a small cost.
189	if (($IsSymLink || $AliasedPath) && !$opt{a}) {
190		$alias_hash{$name} = $uniqid;
191		return;
192	}
193
194	# Obtain the ELF information for this object.
195	@Elf = GetObjectInfo($FullPath);
196
197        # Return quietly if:
198	#	- Not an executable or sharable object
199	#	- An executable, but the -s option was used.
200	if ((($Elf[1] ne 'EXEC') && ($Elf[1] ne 'DYN')) ||
201	    (($Elf[1] eq 'EXEC') && $opt{s})) {
202		return;
203	}
204
205	$Output{$name} = sprintf("OBJECT %2s %-4s %-8s %s\n",
206	    $Elf[0], $Elf[1], $Elf[2], $name);
207
208	# Remember it for later alias analysis
209	$id_hash{$uniqid} = $name;
210}
211
212
213## ProcDir(FullPath, RelPath, AliasedPath, SelfSymlink)
214#
215# Recursively search directory for dynamic ELF objects, calling
216# ProcFile() on each one.
217#
218# entry:
219#	FullPath - Fully qualified path
220#	RelPath - Path relative to starting root directory
221#	AliasedPath - True if RelPath contains a symlink directory component.
222#		Such a path represents an alias to the same file found
223#		completely via actual directories.
224#	SelfSymlink - True (1) if the last segment in the path is a symlink
225#		that points at the same directory (i.e. 32->.). If SelfSymlink
226#		is True, ProcDir() examines the given directory for objects,
227#		but does not recurse past it. This captures the aliases for
228#		those objects, while avoiding entering a recursive loop,
229#		or generating nonsensical paths (i.e., 32/amd64/...).
230#
231sub ProcDir {
232	my($FullDir, $RelDir, $AliasedPath, $SelfSymlink) = @_;
233	my($NewFull, $NewRel, $Entry);
234
235	# Open the directory and read each entry, omit files starting with "."
236	my $Dir = IO::Dir->new($FullDir);
237	if (defined($Dir)) {
238		foreach $Entry ($Dir->read()) {
239
240			# In fast mode, we skip any file name that starts
241			# with a dot, which by side effect also skips the
242			# '.' and '..' entries. In regular mode, we must
243			# explicitly filter out those entries.
244			if ($opt{f}) {
245				next if ($Entry =~ /^\./);
246			} else {
247				next if ($Entry =~ /^\.\.?$/);
248			}
249
250			$NewFull = join('/', $FullDir, $Entry);
251
252			# We need to follow symlinks in order to capture
253			# all possible aliases for each object. However,
254			# symlinks that point back at the same directory
255			# (e.g. 32->.) must be flagged via the SelfSymlink
256			# argument to our recursive self in order to avoid
257			# taking it more than one level down.
258			my $RecurseAliasedPath = $AliasedPath;
259			my $RecurseSelfSymlink = 0;
260			my $IsSymLink = -l $NewFull;
261			if ($IsSymLink) {
262				my $trans = readlink($NewFull);
263
264				$trans =~ s/\/*$//;
265				$RecurseSelfSymlink = 1 if $trans eq '.';
266				$RecurseAliasedPath = 1;
267			}
268
269			if (!stat($NewFull)) {
270				next;
271			}
272			$NewRel = join('/', $RelDir, $Entry);
273
274			# Descend into and process any directories.
275			if (-d _) {
276				# If we have recursed here via a $SelfSymlink,
277				# then do not persue directories. We only
278				# want to find objects in the same directory
279				# via that link.
280				next if $SelfSymlink;
281
282				ProcDir($NewFull, $NewRel, $RecurseAliasedPath,
283				    $RecurseSelfSymlink);
284				next;
285			}
286
287			# In fast mode, we skip objects unless they end with
288			# a .so extension, or are executable. We touch
289			# considerably fewer files this way.
290			if ($opt{f} && !($Entry =~ /\.so$/) &&
291			    !($Entry =~ /\.so\./) &&
292			    ($opt{s} || (! -x _))) {
293			    next;
294			}
295
296			# Process any standard files.
297			if (-f _) {
298				my ($dev, $ino) = stat(_);
299				ProcFile($NewFull, $NewRel, $AliasedPath,
300				    $IsSymLink, $dev, $ino);
301				next;
302			}
303
304		}
305		$Dir->close();
306	}
307}
308
309
310# -----------------------------------------------------------------------------
311
312# Establish a program name for any error diagnostics.
313chomp($Prog = `basename $0`);
314
315# The onbld_elfmod package is maintained in the same directory as this
316# script, and is installed in ../lib/perl. Use the local one if present,
317# and the installed one otherwise.
318my $moddir = dirname($0);
319$moddir = "$moddir/../lib/perl" if ! -f "$moddir/onbld_elfmod.pm";
320require "$moddir/onbld_elfmod.pm";
321
322# Check that we have arguments.
323@SaveArgv = @ARGV;
324if ((getopts('afrs', \%opt) == 0) || (scalar(@ARGV) != 1)) {
325	print "usage: $Prog [-frs] file | dir\n";
326	print "\t[-a]\texpand symlink aliases\n";
327	print "\t[-f]\tuse file name at mode to speed search\n";
328	print "\t[-r]\treport relative paths\n";
329	print "\t[-s]\tonly remote sharable (ET_DYN) objects\n";
330	exit 1;
331}
332
333%Output = ();
334%id_hash = ();
335%alias_hash = ();
336$HaveElfedit = -x '/usr/bin/elfedit';
337
338my $Arg = $ARGV[0];
339my $Error = 0;
340
341ARG: {
342	# Process simple files.
343	if (-f $Arg) {
344		my($RelPath) = $Arg;
345
346		if ($opt{r}) {
347			my $Prefix = $Arg;
348
349			$Prefix =~ s/(^.*)\/.*$/$1/;
350			$Prefix = '.' if ($Prefix eq $Arg);
351			print "PREFIX $Prefix\n";
352		}
353		$RelPath =~ s/^.*\//.\//;
354		my ($dev, $ino) = stat(_);
355		my $IsSymLink = -l $Arg;
356		ProcFile($Arg, $RelPath, 0, $IsSymLink, $dev, $ino);
357		next;
358	}
359
360	# Process directories.
361	if (-d $Arg) {
362		$Arg =~ s/\/$//;
363		print "PREFIX $Arg\n" if $opt{r};
364		ProcDir($Arg, ".", 0, 0);
365		next;
366	}
367
368	print STDERR "$Prog: not a file or directory: $Arg\n";
369	$Error = 1;
370}
371
372# Build a hash, using the primary file name as the key, that has the
373# strings for any aliases to that file.
374my %alias_text = ();
375foreach my $Alias (sort keys %alias_hash) {
376	my $id = $alias_hash{$Alias};
377	if (defined($id_hash{$id})) {
378		my $obj = $id_hash{$id};
379		my $str = "ALIAS                   $id_hash{$id}\t$Alias\n";
380
381		if (defined($alias_text{$obj})) {
382			$alias_text{$obj} .= $str;
383		} else {
384			$alias_text{$obj} = $str;
385		}
386	}
387}
388
389# Output the main files sorted by name. Place the alias lines immediately
390# following each main file.
391foreach my $Path (sort keys %Output) {
392	print $Output{$Path};
393	print $alias_text{$Path} if defined($alias_text{$Path});
394}
395
396exit $Error;
397