Revision eb35bdd7bca29a13c8ecd44e6fd747a84ce675db authored by Will Deacon on 11 September 2014, 13:38:16 UTC, committed by Will Deacon on 11 September 2014, 17:34:58 UTC
Nathan reports that we leak TLS information from the parent context during an exec, as we don't clear the TLS registers when flushing the thread state. This patch updates the flushing code so that we: (1) Unconditionally zero the tpidr_el0 register (since this is fully context switched for native tasks and zeroed for compat tasks) (2) Zero the tp_value state in thread_info before clearing the tpidrr0_el0 register for compat tasks (since this is only writable by the set_tls compat syscall and therefore not fully switched). A missing compiler barrier is also added to the compat set_tls syscall. Cc: <stable@vger.kernel.org> Acked-by: Nathan Lynch <Nathan_Lynch@mentor.com> Reported-by: Nathan Lynch <Nathan_Lynch@mentor.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
1 parent 3d8afe3
headerdep.pl
#! /usr/bin/perl
#
# Detect cycles in the header file dependency graph
# Vegard Nossum <vegardno@ifi.uio.no>
#
use strict;
use warnings;
use Getopt::Long;
my $opt_all;
my @opt_include;
my $opt_graph;
&Getopt::Long::Configure(qw(bundling pass_through));
&GetOptions(
help => \&help,
version => \&version,
all => \$opt_all,
"I=s" => \@opt_include,
graph => \$opt_graph,
);
push @opt_include, 'include';
my %deps = ();
my %linenos = ();
my @headers = grep { strip($_) } @ARGV;
parse_all(@headers);
if($opt_graph) {
graph();
} else {
detect_cycles(@headers);
}
sub help {
print "Usage: $0 [options] file...\n";
print "\n";
print "Options:\n";
print " --all\n";
print " --graph\n";
print "\n";
print " -I includedir\n";
print "\n";
print "To make nice graphs, try:\n";
print " $0 --graph include/linux/kernel.h | dot -Tpng -o graph.png\n";
exit;
}
sub version {
print "headerdep version 2\n";
exit;
}
# Get a file name that is relative to our include paths
sub strip {
my $filename = shift;
for my $i (@opt_include) {
my $stripped = $filename;
$stripped =~ s/^$i\///;
return $stripped if $stripped ne $filename;
}
return $filename;
}
# Search for the file name in the list of include paths
sub search {
my $filename = shift;
return $filename if -f $filename;
for my $i (@opt_include) {
my $path = "$i/$filename";
return $path if -f $path;
}
return;
}
sub parse_all {
# Parse all the headers.
my @queue = @_;
while(@queue) {
my $header = pop @queue;
next if exists $deps{$header};
$deps{$header} = [] unless exists $deps{$header};
my $path = search($header);
next unless $path;
open(my $file, '<', $path) or die($!);
chomp(my @lines = <$file>);
close($file);
for my $i (0 .. $#lines) {
my $line = $lines[$i];
if(my($dep) = ($line =~ m/^#\s*include\s*<(.*?)>/)) {
push @queue, $dep;
push @{$deps{$header}}, [$i + 1, $dep];
}
}
}
}
sub print_cycle {
# $cycle[n] includes $cycle[n + 1];
# $cycle[-1] will be the culprit
my $cycle = shift;
# Adjust the line numbers
for my $i (0 .. $#$cycle - 1) {
$cycle->[$i]->[0] = $cycle->[$i + 1]->[0];
}
$cycle->[-1]->[0] = 0;
my $first = shift @$cycle;
my $last = pop @$cycle;
my $msg = "In file included";
printf "%s from %s,\n", $msg, $last->[1] if defined $last;
for my $header (reverse @$cycle) {
printf "%s from %s:%d%s\n",
" " x length $msg,
$header->[1], $header->[0],
$header->[1] eq $last->[1] ? ' <-- here' : '';
}
printf "%s:%d: warning: recursive header inclusion\n",
$first->[1], $first->[0];
}
# Find and print the smallest cycle starting in the specified node.
sub detect_cycles {
my @queue = map { [[0, $_]] } @_;
while(@queue) {
my $top = pop @queue;
my $name = $top->[-1]->[1];
for my $dep (@{$deps{$name}}) {
my $chain = [@$top, [$dep->[0], $dep->[1]]];
# If the dep already exists in the chain, we have a
# cycle...
if(grep { $_->[1] eq $dep->[1] } @$top) {
print_cycle($chain);
next if $opt_all;
return;
}
push @queue, $chain;
}
}
}
sub mangle {
$_ = shift;
s/\//__/g;
s/\./_/g;
s/-/_/g;
$_;
}
# Output dependency graph in GraphViz language.
sub graph {
print "digraph {\n";
print "\t/* vertices */\n";
for my $header (keys %deps) {
printf "\t%s [label=\"%s\"];\n",
mangle($header), $header;
}
print "\n";
print "\t/* edges */\n";
for my $header (keys %deps) {
for my $dep (@{$deps{$header}}) {
printf "\t%s -> %s;\n",
mangle($header), mangle($dep->[1]);
}
}
print "}\n";
}
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