xref: /titanic_41/usr/src/tools/scripts/find_elf.pl (revision 450396635f70344c58b6b1e4db38cf17ff34445c)
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 2009 Sun Microsystems, Inc.  All rights reserved.
25# Use is subject to license terms.
26#
27
28#
29# Find ELF executables and sharable objects
30#
31# This script descends a directory hierarchy and reports the ELF
32# objects found, one object per line of output.
33#
34#	find_elf [-frs] path
35#
36# Where path is a file or directory.
37#
38# Each line of output is of the form:
39#
40#	ELFCLASS  ELFTYPE VERDEF|NOVERDEF relpath
41#
42# where relpath is the path relative to the directory from which the
43# search started.
44
45use strict;
46
47use vars  qw($Prog %Output @SaveArgv);
48use vars  qw(%opt $HaveElfedit);
49
50# Hashes used to detect aliases --- symlinks that reference a common file
51#
52#	id_hash - Maps the unique st_dev/st_ino pair to the real file
53#	alias_hash - Maps symlinks to the real file they reference
54#
55use vars  qw(%id_hash %alias_hash);
56
57use POSIX qw(getenv);
58use Getopt::Std;
59use File::Basename;
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) {
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	if (opendir(DIR, $FullDir)) {
237		foreach $Entry (readdir(DIR)) {
238
239			if ($Entry =~ /^\./) {
240				next;
241			}
242			$NewFull = join('/', $FullDir, $Entry);
243
244			# We need to follow symlinks in order to capture
245			# all possible aliases for each object. However,
246			# symlinks that point back at the same directory
247			# (e.g. 32->.) must be flagged via the SelfSymlink
248			# argument to our recursive self in order to avoid
249			# taking it more than one level down.
250			my $RecurseAliasedPath = $AliasedPath;
251			my $RecurseSelfSymlink = 0;
252			my $IsSymLink = -l $NewFull;
253			if ($IsSymLink) {
254				my $trans = readlink($NewFull);
255
256				$trans =~ s/\/*$//;
257				$RecurseSelfSymlink = 1 if $trans eq '.';
258				$RecurseAliasedPath = 1;
259			}
260
261			if (!stat($NewFull)) {
262				next;
263			}
264			$NewRel = join('/', $RelDir, $Entry);
265
266			# Descend into and process any directories.
267			if (-d _) {
268				# If we have recursed here via a $SelfSymlink,
269				# then do not persue directories. We only
270				# want to find objects in the same directory
271				# via that link.
272				next if $SelfSymlink;
273
274				ProcDir($NewFull, $NewRel, $RecurseAliasedPath,
275				    $RecurseSelfSymlink);
276				next;
277			}
278
279			# In fast mode, we skip objects unless they end with
280			# a .so extension, or are executable. We touch
281			# considerably fewer files this way.
282			if ($opt{f} && !($Entry =~ /\.so$/) &&
283			    !($Entry =~ /\.so\./) &&
284			    ($opt{s} || (! -x _))) {
285			    next;
286			}
287
288			# Process any standard files.
289			if (-f _) {
290				my ($dev, $ino) = stat(_);
291				ProcFile($NewFull, $NewRel, $AliasedPath,
292				    $IsSymLink, $dev, $ino);
293				next;
294			}
295
296		}
297		closedir(DIR);
298	}
299}
300
301
302# -----------------------------------------------------------------------------
303
304# Establish a program name for any error diagnostics.
305chomp($Prog = `basename $0`);
306
307# The onbld_elfmod package is maintained in the same directory as this
308# script, and is installed in ../lib/perl. Use the local one if present,
309# and the installed one otherwise.
310my $moddir = dirname($0);
311$moddir = "$moddir/../lib/perl" if ! -f "$moddir/onbld_elfmod.pm";
312require "$moddir/onbld_elfmod.pm";
313
314# Check that we have arguments.
315@SaveArgv = @ARGV;
316if ((getopts('frs', \%opt) == 0) || (scalar(@ARGV) != 1)) {
317	print "usage: $Prog [-frs] file | dir\n";
318	print "\t[-f]\tuse file name at mode to speed search\n";
319	print "\t[-r]\treport relative paths\n";
320	print "\t[-s]\tonly remote sharable (ET_DYN) objects\n";
321	exit 1;
322}
323
324%Output = ();
325%id_hash = ();
326%alias_hash = ();
327$HaveElfedit = -x '/usr/bin/elfedit';
328
329my $Arg = $ARGV[0];
330my $Error = 0;
331
332ARG: {
333	# Process simple files.
334	if (-f $Arg) {
335		my($RelPath) = $Arg;
336
337		if ($opt{r}) {
338			my $Prefix = $Arg;
339
340			$Prefix =~ s/(^.*)\/.*$/$1/;
341			$Prefix = '.' if ($Prefix eq $Arg);
342			print "PREFIX $Prefix\n";
343		}
344		$RelPath =~ s/^.*\//.\//;
345		my ($dev, $ino) = stat(_);
346		my $IsSymLink = -l $Arg;
347		ProcFile($Arg, $RelPath, 0, $IsSymLink, $dev, $ino);
348		next;
349	}
350
351	# Process directories.
352	if (-d $Arg) {
353		$Arg =~ s/\/$//;
354		print "PREFIX $Arg\n" if $opt{r};
355		ProcDir($Arg, ".", 0, 0);
356		next;
357	}
358
359	print "$Arg is not a file or directory\n";
360	$Error = 1;
361}
362
363# Build a hash, using the primary file name as the key, that has the
364# strings for any aliases to that file.
365my %alias_text = ();
366foreach my $Alias (sort keys %alias_hash) {
367	my $id = $alias_hash{$Alias};
368	if (defined($id_hash{$id})) {
369		my $obj = $id_hash{$id};
370		my $str = "ALIAS                   $id_hash{$id}\t$Alias\n";
371
372		if (defined($alias_text{$obj})) {
373			$alias_text{$obj} .= $str;
374		} else {
375			$alias_text{$obj} = $str;
376		}
377	}
378}
379
380# Output the main files sorted by name. Place the alias lines immediately
381# following each main file.
382foreach my $Path (sort keys %Output) {
383	print $Output{$Path};
384	print $alias_text{$Path} if defined($alias_text{$Path});
385}
386
387exit $Error;
388