X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=scripts%2Frecordmcount.pl;h=090d300d7394d1d890057633826ff5f6b5f03eaa;hb=2ceb532b04b7a3b8f534d11a6e839f8b8bff94c1;hp=e4922a6c963b8907189a8e0981c149a91fb669f5;hpb=3989cce82b272bd6312555fcc47c11715c157102;p=safe%2Fjmp%2Flinux-2.6 diff --git a/scripts/recordmcount.pl b/scripts/recordmcount.pl index e4922a6..090d300 100755 --- a/scripts/recordmcount.pl +++ b/scripts/recordmcount.pl @@ -26,7 +26,7 @@ # which will also be the location of that section after final link. # e.g. # -# .section ".text.sched" +# .section ".sched.text", "ax" # .globl my_func # my_func: # [...] @@ -39,7 +39,7 @@ # [...] # # Both relocation offsets for the mcounts in the above example will be -# offset from .text.sched. If we make another file called tmp.s with: +# offset from .sched.text. If we make another file called tmp.s with: # # .section __mcount_loc # .quad my_func + 0x5 @@ -51,13 +51,12 @@ # But this gets hard if my_func is not globl (a static function). # In such a case we have: # -# .section ".text.sched" +# .section ".sched.text", "ax" # my_func: # [...] # call mcount (offset: 0x5) # [...] # ret -# .globl my_func # other_func: # [...] # call mcount (offset: 0x1b) @@ -100,27 +99,27 @@ $P =~ s@.*/@@g; my $V = '0.1'; -if ($#ARGV < 6) { - print "usage: $P arch objdump objcopy cc ld nm rm mv inputfile\n"; +if ($#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, $objdump, $objcopy, $cc, $ld, $nm, $rm, $mv, $inputfile) = @ARGV; +my ($arch, $bits, $objdump, $objcopy, $cc, + $ld, $nm, $rm, $mv, $is_module, $inputfile) = @ARGV; -if ($arch eq "i386") { - $ld = "ld -m elf_i386"; - $objdump = "objdump -M i386"; - $objcopy = "objcopy -O elf32-i386"; - $cc = "gcc -m32"; +# This file refers to mcount and shouldn't be ftraced, so lets' ignore it +if ($inputfile eq "kernel/trace/ftrace.o") { + exit(0); } -if ($arch eq "x86_64") { - $ld = "ld -m elf_x86_64"; - $objdump = "objdump -M x86-64"; - $objcopy = "objcopy -O elf64-x86-64"; - $cc = "gcc -m64"; -} +# 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); @@ -133,24 +132,119 @@ $mv = "mv" if ((length $mv) == 0); #print STDERR "running: $P '$arch' '$objdump' '$objcopy' '$cc' '$ld' " . # "'$nm' '$rm' '$mv' '$inputfile'\n"; -my %locals; -my %convert; +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 func name) +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") { - $section_regex = "Disassembly of section"; - $function_regex = "<(.*?)>:"; $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") { - $section_regex = "Disassembly of section"; - $function_regex = "<(.*?)>:"; - $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount\$"; - $type = ".long"; + $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 : + # 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 $arch is not supported with CONFIG_FTRACE_MCOUNT_RECORD"; } @@ -158,7 +252,6 @@ if ($arch eq "x86_64") { my $text_found = 0; my $read_function = 0; my $opened = 0; -my $text = ""; my $mcount_section = "__mcount_loc"; my $dirname; @@ -186,46 +279,172 @@ my $mcount_s = $dirname . "/.tmp_mc_" . $prefix . ".s"; my $mcount_o = $dirname . "/.tmp_mc_" . $prefix . ".o"; # -# Step 1: find all the local symbols (static functions). +# --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 () { + 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 $nm"; while () { - if (/^[0-9a-fA-F]+\s+t\s+(\S+)/) { + if (/$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 -dr $inputfile|") || die "error running $objdump"; +open(IN, "$objdump -hdr $inputfile|") || die "error running $objdump"; + +my $text; + +my $read_headers = 1; while () { # is it a section? if (/$section_regex/) { - $read_function = 1; + $read_headers = 0; + + # Only record text sections that we know are safe + if (defined($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/) { - $read_function = 0; $text_found = 1; - $text = $1; - # is this function static? If so, note this fact. - if (defined $locals{$text}) { - $convert{$text} = 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 $1; + } } - # is this a call site to mcount? If so, print the offset from the section - } elsif ($text_found && /$mcount_regex/) { - if (!$opened) { - open(FILE, ">$mcount_s") || die "can't create $mcount_s\n"; - $opened = 1; - print FILE "\t.section $mcount_section,\"a\",\@progbits\n"; - } - print FILE "\t$type $text + 0x$1\n"; + } elsif ($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);