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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271#!/usr/bin/env perl# SPDX-License-Identifier: GPL-2.0## Generates a linker script that specifies the correct initcall order.## Copyright (C) 2019 Google LLC
use strict;use warnings;use IO::Handle;use IO::Select;use POSIX ":sys_wait_h";
my $nm = $ENV{'NM'} || die "$0: ERROR: NM not set?";my $objtree = $ENV{'objtree'} || '.';
## currently active child processesmy $jobs = {}; # child process pid -> file handle## results from child processesmy $results = {}; # object index -> [ { level, secname }, ... ]
## reads _NPROCESSORS_ONLN to determine the maximum number of processes to## startsub get_online_processors { open(my $fh, "getconf _NPROCESSORS_ONLN 2>/dev/null |") or die "$0: ERROR: failed to execute getconf: $!"; my $procs = <$fh>; close($fh);
if (!($procs =~ /^\d+$/)) { return 1; }
return int($procs);}
## writes results to the parent process## format: <file index> <initcall level> <base initcall section name>sub write_results { my ($index, $initcalls) = @_;
# sort by the counter value to ensure the order of initcalls within # each object file is correct foreach my $counter (sort { $a <=> $b } keys(%{$initcalls})) { my $level = $initcalls->{$counter}->{'level'};
# section name for the initcall function my $secname = $initcalls->{$counter}->{'module'} . '__' . $counter . '_' . $initcalls->{$counter}->{'line'} . '_' . $initcalls->{$counter}->{'function'};
print "$index $level $secname\n"; }}
## reads a result line from a child process and adds it to the $results arraysub read_results{ my ($fh) = @_;
# each child prints out a full line w/ autoflush and exits after the # last line, so even if buffered I/O blocks here, it shouldn't block # very long my $data = <$fh>;
if (!defined($data)) { return 0; }
chomp($data);
my ($index, $level, $secname) = $data =~ /^(\d+)\ ([^\ ]+)\ (.*)$/;
if (!defined($index) || !defined($level) || !defined($secname)) { die "$0: ERROR: child process returned invalid data: $data\n"; }
$index = int($index);
if (!exists($results->{$index})) { $results->{$index} = []; }
push (@{$results->{$index}}, { 'level' => $level, 'secname' => $secname });
return 1;}
## finds initcalls from an object file or all object files in an archive, and## writes results back to the parent processsub find_initcalls { my ($index, $file) = @_;
die "$0: ERROR: file $file doesn't exist?" if (! -f $file);
open(my $fh, "\"$nm\" --defined-only \"$file\" 2>/dev/null |") or die "$0: ERROR: failed to execute \"$nm\": $!";
my $initcalls = {};
while (<$fh>) { chomp;
# check for the start of a new object file (if processing an # archive) my ($path)= $_ =~ /^(.+)\:$/;
if (defined($path)) { write_results($index, $initcalls); $initcalls = {}; next; }
# look for an initcall my ($module, $counter, $line, $symbol) = $_ =~ /[a-z]\s+__initcall__(\S*)__(\d+)_(\d+)_(.*)$/;
if (!defined($module)) { $module = '' }
if (!defined($counter) || !defined($line) || !defined($symbol)) { next; }
# parse initcall level my ($function, $level) = $symbol =~ /^(.*)((early|rootfs|con|[0-9])s?)$/;
die "$0: ERROR: invalid initcall name $symbol in $file($path)" if (!defined($function) || !defined($level));
$initcalls->{$counter} = { 'module' => $module, 'line' => $line, 'function' => $function, 'level' => $level, }; }
close($fh); write_results($index, $initcalls);}
## waits for any child process to complete, reads the results, and adds them to## the $results array for later processingsub wait_for_results { my ($select) = @_;
my $pid = 0; do { # unblock children that may have a full write buffer foreach my $fh ($select->can_read(0)) { read_results($fh); }
# check for children that have exited, read the remaining data # from them, and clean up $pid = waitpid(-1, WNOHANG); if ($pid > 0) { if (!exists($jobs->{$pid})) { next; }
my $fh = $jobs->{$pid}; $select->remove($fh);
while (read_results($fh)) { # until eof }
close($fh); delete($jobs->{$pid}); } } while ($pid > 0);}
## forks a child to process each file passed in the command line and collects## the resultssub process_files { my $index = 0; my $njobs = $ENV{'PARALLELISM'} || get_online_processors(); my $select = IO::Select->new();
while (my $file = shift(@ARGV)) { # fork a child process and read it's stdout my $pid = open(my $fh, '-|');
if (!defined($pid)) { die "$0: ERROR: failed to fork: $!"; } elsif ($pid) { # save the child process pid and the file handle $select->add($fh); $jobs->{$pid} = $fh; } else { # in the child process STDOUT->autoflush(1); find_initcalls($index, "$objtree/$file"); exit; }
$index++;
# limit the number of children to $njobs if (scalar(keys(%{$jobs})) >= $njobs) { wait_for_results($select); } }
# wait for the remaining children to complete while (scalar(keys(%{$jobs})) > 0) { wait_for_results($select); }}
sub generate_initcall_lds() { process_files();
my $sections = {}; # level -> [ secname, ...]
# sort results to retain link order and split to sections per # initcall level foreach my $index (sort { $a <=> $b } keys(%{$results})) { foreach my $result (@{$results->{$index}}) { my $level = $result->{'level'};
if (!exists($sections->{$level})) { $sections->{$level} = []; }
push(@{$sections->{$level}}, $result->{'secname'}); } }
die "$0: ERROR: no initcalls?" if (!keys(%{$sections}));
# print out a linker script that defines the order of initcalls for # each level print "SECTIONS {\n";
foreach my $level (sort(keys(%{$sections}))) { my $section;
if ($level eq 'con') { $section = '.con_initcall.init'; } else { $section = ".initcall${level}.init"; }
print "\t${section} : {\n";
foreach my $secname (@{$sections->{$level}}) { print "\t\t*(${section}..${secname}) ;\n"; }
print "\t}\n"; }
print "}\n";}
generate_initcall_lds();