forked from luck/tmp_suning_uos_patched
89034bc2c7
Conflicts: kernel/trace/trace_events_filter.c We use the tracing/core version. Signed-off-by: Ingo Molnar <mingo@elte.hu>
514 lines
14 KiB
Perl
Executable File
514 lines
14 KiB
Perl
Executable File
#!/usr/bin/perl -w
|
|
# (c) 2008, Steven Rostedt <srostedt@redhat.com>
|
|
# Licensed under the terms of the GNU GPL License version 2
|
|
#
|
|
# recordmcount.pl - makes a section called __mcount_loc that holds
|
|
# all the offsets to the calls to mcount.
|
|
#
|
|
#
|
|
# What we want to end up with is a section in vmlinux called
|
|
# __mcount_loc that contains a list of pointers to all the
|
|
# call sites in the kernel that call mcount. Later on boot up, the kernel
|
|
# will read this list, save the locations and turn them into nops.
|
|
# When tracing or profiling is later enabled, these locations will then
|
|
# be converted back to pointers to some function.
|
|
#
|
|
# This is no easy feat. This script is called just after the original
|
|
# object is compiled and before it is linked.
|
|
#
|
|
# The references to the call sites are offsets from the section of text
|
|
# that the call site is in. Hence, all functions in a section that
|
|
# has a call site to mcount, will have the offset from the beginning of
|
|
# the section and not the beginning of the function.
|
|
#
|
|
# The trick is to find a way to record the beginning of the section.
|
|
# The way we do this is to look at the first function in the section
|
|
# which will also be the location of that section after final link.
|
|
# e.g.
|
|
#
|
|
# .section ".sched.text", "ax"
|
|
# .globl my_func
|
|
# my_func:
|
|
# [...]
|
|
# call mcount (offset: 0x5)
|
|
# [...]
|
|
# ret
|
|
# other_func:
|
|
# [...]
|
|
# call mcount (offset: 0x1b)
|
|
# [...]
|
|
#
|
|
# Both relocation offsets for the mcounts in the above example will be
|
|
# offset from .sched.text. If we make another file called tmp.s with:
|
|
#
|
|
# .section __mcount_loc
|
|
# .quad my_func + 0x5
|
|
# .quad my_func + 0x1b
|
|
#
|
|
# We can then compile this tmp.s into tmp.o, and link it to the original
|
|
# object.
|
|
#
|
|
# But this gets hard if my_func is not globl (a static function).
|
|
# In such a case we have:
|
|
#
|
|
# .section ".sched.text", "ax"
|
|
# my_func:
|
|
# [...]
|
|
# call mcount (offset: 0x5)
|
|
# [...]
|
|
# ret
|
|
# other_func:
|
|
# [...]
|
|
# call mcount (offset: 0x1b)
|
|
# [...]
|
|
#
|
|
# If we make the tmp.s the same as above, when we link together with
|
|
# the original object, we will end up with two symbols for my_func:
|
|
# one local, one global. After final compile, we will end up with
|
|
# an undefined reference to my_func.
|
|
#
|
|
# Since local objects can reference local variables, we need to find
|
|
# a way to make tmp.o reference the local objects of the original object
|
|
# file after it is linked together. To do this, we convert the my_func
|
|
# into a global symbol before linking tmp.o. Then after we link tmp.o
|
|
# we will only have a single symbol for my_func that is global.
|
|
# We can convert my_func back into a local symbol and we are done.
|
|
#
|
|
# Here are the steps we take:
|
|
#
|
|
# 1) Record all the local symbols by using 'nm'
|
|
# 2) Use objdump to find all the call site offsets and sections for
|
|
# mcount.
|
|
# 3) Compile the list into its own object.
|
|
# 4) Do we have to deal with local functions? If not, go to step 8.
|
|
# 5) Make an object that converts these local functions to global symbols
|
|
# with objcopy.
|
|
# 6) Link together this new object with the list object.
|
|
# 7) Convert the local functions back to local symbols and rename
|
|
# the result as the original object.
|
|
# End.
|
|
# 8) Link the object with the list object.
|
|
# 9) Move the result back to the original object.
|
|
# End.
|
|
#
|
|
|
|
use strict;
|
|
|
|
my $P = $0;
|
|
$P =~ s@.*/@@g;
|
|
|
|
my $V = '0.1';
|
|
|
|
if ($#ARGV < 7) {
|
|
print "usage: $P arch bits objdump objcopy cc ld nm rm mv is_module inputfile\n";
|
|
print "version: $V\n";
|
|
exit(1);
|
|
}
|
|
|
|
my ($arch, $bits, $objdump, $objcopy, $cc,
|
|
$ld, $nm, $rm, $mv, $is_module, $inputfile) = @ARGV;
|
|
|
|
# This file refers to mcount and shouldn't be ftraced, so lets' ignore it
|
|
if ($inputfile eq "kernel/trace/ftrace.o") {
|
|
exit(0);
|
|
}
|
|
|
|
# Acceptable sections to record.
|
|
my %text_sections = (
|
|
".text" => 1,
|
|
".sched.text" => 1,
|
|
".spinlock.text" => 1,
|
|
".irqentry.text" => 1,
|
|
);
|
|
|
|
$objdump = "objdump" if ((length $objdump) == 0);
|
|
$objcopy = "objcopy" if ((length $objcopy) == 0);
|
|
$cc = "gcc" if ((length $cc) == 0);
|
|
$ld = "ld" if ((length $ld) == 0);
|
|
$nm = "nm" if ((length $nm) == 0);
|
|
$rm = "rm" if ((length $rm) == 0);
|
|
$mv = "mv" if ((length $mv) == 0);
|
|
|
|
#print STDERR "running: $P '$arch' '$objdump' '$objcopy' '$cc' '$ld' " .
|
|
# "'$nm' '$rm' '$mv' '$inputfile'\n";
|
|
|
|
my %locals; # List of local (static) functions
|
|
my %weak; # List of weak functions
|
|
my %convert; # List of local functions used that needs conversion
|
|
|
|
my $type;
|
|
my $nm_regex; # Find the local functions (return function)
|
|
my $section_regex; # Find the start of a section
|
|
my $function_regex; # Find the name of a function
|
|
# (return offset and func name)
|
|
my $mcount_regex; # Find the call site to mcount (return offset)
|
|
my $alignment; # The .align value to use for $mcount_section
|
|
my $section_type; # Section header plus possible alignment command
|
|
|
|
if ($arch eq "x86") {
|
|
if ($bits == 64) {
|
|
$arch = "x86_64";
|
|
} else {
|
|
$arch = "i386";
|
|
}
|
|
}
|
|
|
|
#
|
|
# We base the defaults off of i386, the other archs may
|
|
# feel free to change them in the below if statements.
|
|
#
|
|
$nm_regex = "^[0-9a-fA-F]+\\s+t\\s+(\\S+)";
|
|
$section_regex = "Disassembly of section\\s+(\\S+):";
|
|
$function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
|
|
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount\$";
|
|
$section_type = '@progbits';
|
|
$type = ".long";
|
|
|
|
if ($arch eq "x86_64") {
|
|
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount([+-]0x[0-9a-zA-Z]+)?\$";
|
|
$type = ".quad";
|
|
$alignment = 8;
|
|
|
|
# force flags for this arch
|
|
$ld .= " -m elf_x86_64";
|
|
$objdump .= " -M x86-64";
|
|
$objcopy .= " -O elf64-x86-64";
|
|
$cc .= " -m64";
|
|
|
|
} elsif ($arch eq "i386") {
|
|
$alignment = 4;
|
|
|
|
# force flags for this arch
|
|
$ld .= " -m elf_i386";
|
|
$objdump .= " -M i386";
|
|
$objcopy .= " -O elf32-i386";
|
|
$cc .= " -m32";
|
|
|
|
} elsif ($arch eq "s390" && $bits == 32) {
|
|
$mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_390_32\\s+_mcount\$";
|
|
$alignment = 4;
|
|
$ld .= " -m elf_s390";
|
|
$cc .= " -m31";
|
|
|
|
} elsif ($arch eq "s390" && $bits == 64) {
|
|
$mcount_regex = "^\\s*([0-9a-fA-F]+):\\s*R_390_(PC|PLT)32DBL\\s+_mcount\\+0x2\$";
|
|
$alignment = 8;
|
|
$type = ".quad";
|
|
$ld .= " -m elf64_s390";
|
|
$cc .= " -m64";
|
|
|
|
} elsif ($arch eq "sh") {
|
|
$alignment = 2;
|
|
|
|
# force flags for this arch
|
|
$ld .= " -m shlelf_linux";
|
|
$objcopy .= " -O elf32-sh-linux";
|
|
$cc .= " -m32";
|
|
|
|
} elsif ($arch eq "powerpc") {
|
|
$nm_regex = "^[0-9a-fA-F]+\\s+t\\s+(\\.?\\S+)";
|
|
$function_regex = "^([0-9a-fA-F]+)\\s+<(\\.?.*?)>:";
|
|
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s\\.?_mcount\$";
|
|
|
|
if ($bits == 64) {
|
|
$type = ".quad";
|
|
}
|
|
|
|
} elsif ($arch eq "arm") {
|
|
$alignment = 2;
|
|
$section_type = '%progbits';
|
|
|
|
} elsif ($arch eq "ia64") {
|
|
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$";
|
|
$type = "data8";
|
|
|
|
if ($is_module eq "0") {
|
|
$cc .= " -mconstant-gp";
|
|
}
|
|
} elsif ($arch eq "sparc64") {
|
|
# In the objdump output there are giblets like:
|
|
# 0000000000000000 <igmp_net_exit-0x18>:
|
|
# As there's some data blobs that get emitted into the
|
|
# text section before the first instructions and the first
|
|
# real symbols. We don't want to match that, so to combat
|
|
# this we use '\w' so we'll match just plain symbol names,
|
|
# and not those that also include hex offsets inside of the
|
|
# '<>' brackets. Actually the generic function_regex setting
|
|
# could safely use this too.
|
|
$function_regex = "^([0-9a-fA-F]+)\\s+<(\\w*?)>:";
|
|
|
|
# Sparc64 calls '_mcount' instead of plain 'mcount'.
|
|
$mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\s_mcount\$";
|
|
|
|
$alignment = 8;
|
|
$type = ".xword";
|
|
$ld .= " -m elf64_sparc";
|
|
$cc .= " -m64";
|
|
$objcopy .= " -O elf64-sparc";
|
|
} else {
|
|
die "Arch $arch is not supported with CONFIG_FTRACE_MCOUNT_RECORD";
|
|
}
|
|
|
|
my $text_found = 0;
|
|
my $read_function = 0;
|
|
my $opened = 0;
|
|
my $mcount_section = "__mcount_loc";
|
|
|
|
my $dirname;
|
|
my $filename;
|
|
my $prefix;
|
|
my $ext;
|
|
|
|
if ($inputfile =~ m,^(.*)/([^/]*)$,) {
|
|
$dirname = $1;
|
|
$filename = $2;
|
|
} else {
|
|
$dirname = ".";
|
|
$filename = $inputfile;
|
|
}
|
|
|
|
if ($filename =~ m,^(.*)(\.\S),) {
|
|
$prefix = $1;
|
|
$ext = $2;
|
|
} else {
|
|
$prefix = $filename;
|
|
$ext = "";
|
|
}
|
|
|
|
my $mcount_s = $dirname . "/.tmp_mc_" . $prefix . ".s";
|
|
my $mcount_o = $dirname . "/.tmp_mc_" . $prefix . ".o";
|
|
|
|
#
|
|
# --globalize-symbols came out in 2.17, we must test the version
|
|
# of objcopy, and if it is less than 2.17, then we can not
|
|
# record local functions.
|
|
my $use_locals = 01;
|
|
my $local_warn_once = 0;
|
|
my $found_version = 0;
|
|
|
|
open (IN, "$objcopy --version |") || die "error running $objcopy";
|
|
while (<IN>) {
|
|
if (/objcopy.*\s(\d+)\.(\d+)/) {
|
|
my $major = $1;
|
|
my $minor = $2;
|
|
|
|
$found_version = 1;
|
|
if ($major < 2 ||
|
|
($major == 2 && $minor < 17)) {
|
|
$use_locals = 0;
|
|
}
|
|
last;
|
|
}
|
|
}
|
|
close (IN);
|
|
|
|
if (!$found_version) {
|
|
print STDERR "WARNING: could not find objcopy version.\n" .
|
|
"\tDisabling local function references.\n";
|
|
}
|
|
|
|
#
|
|
# Step 1: find all the local (static functions) and weak symbols.
|
|
# 't' is local, 'w/W' is weak (we never use a weak function)
|
|
#
|
|
open (IN, "$nm $inputfile|") || die "error running $nm";
|
|
while (<IN>) {
|
|
if (/$nm_regex/) {
|
|
$locals{$1} = 1;
|
|
} elsif (/^[0-9a-fA-F]+\s+([wW])\s+(\S+)/) {
|
|
$weak{$2} = $1;
|
|
}
|
|
}
|
|
close(IN);
|
|
|
|
my @offsets; # Array of offsets of mcount callers
|
|
my $ref_func; # reference function to use for offsets
|
|
my $offset = 0; # offset of ref_func to section beginning
|
|
|
|
##
|
|
# update_funcs - print out the current mcount callers
|
|
#
|
|
# Go through the list of offsets to callers and write them to
|
|
# the output file in a format that can be read by an assembler.
|
|
#
|
|
sub update_funcs
|
|
{
|
|
return if ($#offsets < 0);
|
|
|
|
defined($ref_func) || die "No function to reference";
|
|
|
|
# A section only had a weak function, to represent it.
|
|
# Unfortunately, a weak function may be overwritten by another
|
|
# function of the same name, making all these offsets incorrect.
|
|
# To be safe, we simply print a warning and bail.
|
|
if (defined $weak{$ref_func}) {
|
|
print STDERR
|
|
"$inputfile: WARNING: referencing weak function" .
|
|
" $ref_func for mcount\n";
|
|
return;
|
|
}
|
|
|
|
# is this function static? If so, note this fact.
|
|
if (defined $locals{$ref_func}) {
|
|
|
|
# only use locals if objcopy supports globalize-symbols
|
|
if (!$use_locals) {
|
|
return;
|
|
}
|
|
$convert{$ref_func} = 1;
|
|
}
|
|
|
|
# Loop through all the mcount caller offsets and print a reference
|
|
# to the caller based from the ref_func.
|
|
for (my $i=0; $i <= $#offsets; $i++) {
|
|
if (!$opened) {
|
|
open(FILE, ">$mcount_s") || die "can't create $mcount_s\n";
|
|
$opened = 1;
|
|
print FILE "\t.section $mcount_section,\"a\",$section_type\n";
|
|
print FILE "\t.align $alignment\n" if (defined($alignment));
|
|
}
|
|
printf FILE "\t%s %s + %d\n", $type, $ref_func, $offsets[$i] - $offset;
|
|
}
|
|
}
|
|
|
|
#
|
|
# Step 2: find the sections and mcount call sites
|
|
#
|
|
open(IN, "$objdump -hdr $inputfile|") || die "error running $objdump";
|
|
|
|
my $text;
|
|
|
|
my $read_headers = 1;
|
|
|
|
while (<IN>) {
|
|
# is it a section?
|
|
if (/$section_regex/) {
|
|
$read_headers = 0;
|
|
|
|
# Only record text sections that we know are safe
|
|
if (defined($text_sections{$1})) {
|
|
$read_function = 1;
|
|
} else {
|
|
$read_function = 0;
|
|
}
|
|
# print out any recorded offsets
|
|
update_funcs() if (defined($ref_func));
|
|
|
|
# reset all markers and arrays
|
|
$text_found = 0;
|
|
undef($ref_func);
|
|
undef(@offsets);
|
|
|
|
# section found, now is this a start of a function?
|
|
} elsif ($read_function && /$function_regex/) {
|
|
$text_found = 1;
|
|
$text = $2;
|
|
|
|
# if this is either a local function or a weak function
|
|
# keep looking for functions that are global that
|
|
# we can use safely.
|
|
if (!defined($locals{$text}) && !defined($weak{$text})) {
|
|
$ref_func = $text;
|
|
$read_function = 0;
|
|
$offset = hex $1;
|
|
} else {
|
|
# if we already have a function, and this is weak, skip it
|
|
if (!defined($ref_func) && !defined($weak{$text}) &&
|
|
# PPC64 can have symbols that start with .L and
|
|
# gcc considers these special. Don't use them!
|
|
$text !~ /^\.L/) {
|
|
$ref_func = $text;
|
|
$offset = hex $1;
|
|
}
|
|
}
|
|
} elsif ($read_headers && /$mcount_section/) {
|
|
#
|
|
# Somehow the make process can execute this script on an
|
|
# object twice. If it does, we would duplicate the mcount
|
|
# section and it will cause the function tracer self test
|
|
# to fail. Check if the mcount section exists, and if it does,
|
|
# warn and exit.
|
|
#
|
|
print STDERR "ERROR: $mcount_section already in $inputfile\n" .
|
|
"\tThis may be an indication that your build is corrupted.\n" .
|
|
"\tDelete $inputfile and try again. If the same object file\n" .
|
|
"\tstill causes an issue, then disable CONFIG_DYNAMIC_FTRACE.\n";
|
|
exit(-1);
|
|
}
|
|
|
|
# is this a call site to mcount? If so, record it to print later
|
|
if ($text_found && /$mcount_regex/) {
|
|
$offsets[$#offsets + 1] = hex $1;
|
|
}
|
|
}
|
|
|
|
# dump out anymore offsets that may have been found
|
|
update_funcs() if (defined($ref_func));
|
|
|
|
# If we did not find any mcount callers, we are done (do nothing).
|
|
if (!$opened) {
|
|
exit(0);
|
|
}
|
|
|
|
close(FILE);
|
|
|
|
#
|
|
# Step 3: Compile the file that holds the list of call sites to mcount.
|
|
#
|
|
`$cc -o $mcount_o -c $mcount_s`;
|
|
|
|
my @converts = keys %convert;
|
|
|
|
#
|
|
# Step 4: Do we have sections that started with local functions?
|
|
#
|
|
if ($#converts >= 0) {
|
|
my $globallist = "";
|
|
my $locallist = "";
|
|
|
|
foreach my $con (@converts) {
|
|
$globallist .= " --globalize-symbol $con";
|
|
$locallist .= " --localize-symbol $con";
|
|
}
|
|
|
|
my $globalobj = $dirname . "/.tmp_gl_" . $filename;
|
|
my $globalmix = $dirname . "/.tmp_mx_" . $filename;
|
|
|
|
#
|
|
# Step 5: set up each local function as a global
|
|
#
|
|
`$objcopy $globallist $inputfile $globalobj`;
|
|
|
|
#
|
|
# Step 6: Link the global version to our list.
|
|
#
|
|
`$ld -r $globalobj $mcount_o -o $globalmix`;
|
|
|
|
#
|
|
# Step 7: Convert the local functions back into local symbols
|
|
#
|
|
`$objcopy $locallist $globalmix $inputfile`;
|
|
|
|
# Remove the temp files
|
|
`$rm $globalobj $globalmix`;
|
|
|
|
} else {
|
|
|
|
my $mix = $dirname . "/.tmp_mx_" . $filename;
|
|
|
|
#
|
|
# Step 8: Link the object with our list of call sites object.
|
|
#
|
|
`$ld -r $inputfile $mcount_o -o $mix`;
|
|
|
|
#
|
|
# Step 9: Move the result back to the original object.
|
|
#
|
|
`$mv $mix $inputfile`;
|
|
}
|
|
|
|
# Clean up the temp files
|
|
`$rm $mcount_o $mcount_s`;
|
|
|
|
exit(0);
|