| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <f5c1e7b14a27132821c08f0459ba9aea3ed69028.1631957565.git.mchehab+huawei@kernel.org>
Date: Sat, 18 Sep 2021 11:52:17 +0200
From: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
To: Linux Doc Mailing List <linux-doc@...r.kernel.org>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>,
"Jonathan Corbet" <corbet@....net>, linux-kernel@...r.kernel.org
Subject: [PATCH v3 7/7] scripts: get_abi.pl: add a graph to speedup the undefined algorithm
Searching for symlinks is an expensive operation with the current
logic, as it is at the order of O(n^3). In practice, running the
check spends 2-3 minutes to check all symbols.
Fix it by storing the directory tree into a graph, and using
a Breadth First Search (BFS) to find the links for each sysfs node.
With such improvement, it can now report issues with ~11 seconds
on my machine.
It comes with a price, though: there are more symbols reported
as undefined after this change. I suspect it is due to some
sysfs circular loops that are dropped by BFS. Despite such
increase, it seems that the reports are now more coherent.
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@...nel.org>
---
scripts/get_abi.pl | 188 ++++++++++++++++++++++++++++++---------------
1 file changed, 127 insertions(+), 61 deletions(-)
diff --git a/scripts/get_abi.pl b/scripts/get_abi.pl
index aa0a751563ba..c52a1cf0f49d 100755
--- a/scripts/get_abi.pl
+++ b/scripts/get_abi.pl
@@ -546,6 +546,73 @@ sub dont_parse_special_attributes {
my %leaf;
my %aliases;
my @files;
+my %root;
+
+sub graph_add_file {
+ my $file = shift;
+ my $type = shift;
+
+ my $dir = $file;
+ $dir =~ s,^(.*/).*,$1,;
+ $file =~ s,.*/,,;
+
+ my $name;
+ my $file_ref = \%root;
+ foreach my $edge(split "/", $dir) {
+ $name .= "$edge/";
+ if (!defined ${$file_ref}{$edge}) {
+ ${$file_ref}{$edge} = { };
+ }
+ $file_ref = \%{$$file_ref{$edge}};
+ ${$file_ref}{"__name"} = [ $name ];
+ }
+ $name .= "$file";
+ ${$file_ref}{$file} = {
+ "__name" => [ $name ]
+ };
+
+ return \%{$$file_ref{$file}};
+}
+
+sub graph_add_link {
+ my $file = shift;
+ my $link = shift;
+
+ # Traverse graph to find the reference
+ my $file_ref = \%root;
+ foreach my $edge(split "/", $file) {
+ $file_ref = \%{$$file_ref{$edge}} || die "Missing node!";
+ }
+
+ # do a BFS
+
+ my @queue;
+ my %seen;
+ my $base_name;
+ my $st;
+
+ push @queue, $file_ref;
+ $seen{$start}++;
+
+ while (@queue) {
+ my $v = shift @queue;
+ my @child = keys(%{$v});
+
+ foreach my $c(@child) {
+ next if $seen{$$v{$c}};
+ next if ($c eq "__name");
+
+ # Add new name
+ my $name = @{$$v{$c}{"__name"}}[0];
+ if ($name =~ s#^$file/#$link/#) {
+ push @{$$v{$c}{"__name"}}, $name;
+ }
+ # Add child to the queue and mark as seen
+ push @queue, $$v{$c};
+ $seen{$c}++;
+ }
+ }
+}
my $escape_symbols = qr { ([\x01-\x08\x0e-\x1f\x21-\x29\x2b-\x2d\x3a-\x40\x7b-\xfe]) }x;
sub parse_existing_sysfs {
@@ -568,19 +635,50 @@ sub parse_existing_sysfs {
return if (defined($data{$file}));
return if (defined($data{$abs_file}));
- push @files, $abs_file;
+ push @files, graph_add_file($abs_file, "file");
+}
+
+sub get_leave($)
+{
+ my $what = shift;
+ my $leave;
+
+ my $l = $what;
+ my $stop = 1;
+
+ $leave = $l;
+ $leave =~ s,/$,,;
+ $leave =~ s,.*/,,;
+ $leave =~ s/[\(\)]//g;
+
+ # $leave is used to improve search performance at
+ # check_undefined_symbols, as the algorithm there can seek
+ # for a small number of "what". It also allows giving a
+ # hint about a leave with the same name somewhere else.
+ # However, there are a few occurences where the leave is
+ # either a wildcard or a number. Just group such cases
+ # altogether.
+ if ($leave =~ m/^\.\*/ || $leave eq "" || $leave =~ /^\d+$/) {
+ $leave = "others";
+ }
+
+ return $leave;
}
sub check_undefined_symbols {
- foreach my $file (sort @files) {
+ foreach my $file_ref (sort @files) {
+ my @names = @{$$file_ref{"__name"}};
+ my $file = $names[0];
my $defined = 0;
my $exact = 0;
- my $whats = "";
my $found_string;
- my $leave = $file;
- $leave =~ s,.*/,,;
+ my $leave = get_leave($file);
+ if (!defined($leaf{$leave})) {
+ $leave = "others";
+ }
+ my $what = $leaf{$leave};
my $path = $file;
$path =~ s,(.*/).*,$1,;
@@ -590,41 +688,12 @@ sub check_undefined_symbols {
$found_string = 1;
}
- if ($leave =~ /^\d+$/ || !defined($leaf{$leave})) {
- $leave = "others";
- }
-
- print "--> $file\n" if ($found_string && $hint);
- my $what = $leaf{$leave};
- $whats .= " $what" if (!($whats =~ m/$what/));
-
- foreach my $w (split / /, $what) {
- if ($file =~ m#^$w$#) {
- $exact = 1;
- last;
- }
- }
- # Check for aliases
- #
- # TODO: this algorithm is O(w * n²). It can be
- # improved in the future in order to handle it
- # faster, by changing parse_existing_sysfs to
- # store the sysfs inside a tree, at the expense
- # on making the code less readable and/or using some
- # additional perl library.
- foreach my $a (keys %aliases) {
- my $new = $aliases{$a};
- my $len = length($new);
-
- if (substr($file, 0, $len) eq $new) {
- my $newf = $a . substr($file, $len);
-
- print " $newf\n" if ($found_string && $hint);
- foreach my $w (split / /, $what) {
- if ($newf =~ m#^$w$#) {
- $exact = 1;
- last;
- }
+ foreach my $a (@names) {
+ print "--> $a\n" if ($found_string && $hint);
+ foreach my $w (split /\xac/, $what) {
+ if ($a =~ m#^$w$#) {
+ $exact = 1;
+ last;
}
}
}
@@ -641,8 +710,13 @@ sub check_undefined_symbols {
# is not easily parseable.
next if ($file =~ m#/parameters/#);
- if ($hint && $defined && $leave ne "others") {
- print "$leave at $path might be one of:$whats\n" if (!$search_string || $found_string);
+ if ($hint && $defined && (!$search_string || $found_string)) {
+ $what =~ s/\xac/\n\t/g;
+ if ($leave ne "others") {
+ print " more likely regexes:\n\t$what\n";
+ } else {
+ print " tested regexes:\n\t$what\n";
+ }
next;
}
print "$file not found.\n" if (!$search_string || $found_string);
@@ -656,8 +730,10 @@ sub undefined_symbols {
no_chdir => 1
}, $sysfs_prefix);
+ $leaf{"others"} = "";
+
foreach my $w (sort keys %data) {
- foreach my $what (split /\xac /,$w) {
+ foreach my $what (split /\xac/,$w) {
next if (!($what =~ m/^$sysfs_prefix/));
# Convert what into regular expressions
@@ -700,19 +776,7 @@ sub undefined_symbols {
# (this happens on a few IIO definitions)
$what =~ s,\s*\=.*$,,;
- my $leave = $what;
- $leave =~ s,.*/,,;
-
- # $leave is used to improve search performance at
- # check_undefined_symbols, as the algorithm there can seek
- # for a small number of "what". It also allows giving a
- # hint about a leave with the same name somewhere else.
- # However, there are a few occurences where the leave is
- # either a wildcard or a number. Just group such cases
- # altogether.
- if ($leave =~ m/^\.\*/ || $leave eq "" || $leave =~ /^\d+$/) {
- $leave = "others" ;
- }
+ my $leave = get_leave($what);
# Escape all other symbols
$what =~ s/$escape_symbols/\\$1/g;
@@ -722,17 +786,14 @@ sub undefined_symbols {
$what =~ s/\xff/\\d+/g;
-
# Special case: IIO ABI which a parenthesis.
$what =~ s/sqrt(.*)/sqrt\(.*\)/;
- $leave =~ s/[\(\)]//g;
-
my $added = 0;
foreach my $l (split /\|/, $leave) {
if (defined($leaf{$l})) {
- next if ($leaf{$l} =~ m/$what/);
- $leaf{$l} .= " " . $what;
+ next if ($leaf{$l} =~ m/\b$what\b/);
+ $leaf{$l} .= "\xac" . $what;
$added = 1;
} else {
$leaf{$l} = $what;
@@ -745,6 +806,11 @@ sub undefined_symbols {
}
}
+ # Take links into account
+ foreach my $link (keys %aliases) {
+ my $abs_file = $aliases{$link};
+ graph_add_link($abs_file, $link);
+ }
check_undefined_symbols;
}
--
2.31.1
Powered by blists - more mailing lists