# 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:
# [...]
# [...]
#
# 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
# 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)
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, $inputfile) = @ARGV;
+
+# This file refers to mcount and shouldn't be ftraced, so lets' ignore it
+if ($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);
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") {
- $section_regex = "Disassembly of section";
- $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
$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";
$cc .= " -m64";
} elsif ($arch eq "i386") {
- $section_regex = "Disassembly of section";
- $function_regex = "^([0-9a-fA-F]+)\\s+<(.*?)>:";
- $mcount_regex = "^\\s*([0-9a-fA-F]+):.*\\smcount\$";
- $type = ".long";
+ $alignment = 4;
# force flags for this arch
$ld .= " -m elf_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 $arch is not supported with CONFIG_FTRACE_MCOUNT_RECORD";
}
"\tDisabling local function references.\n";
}
-
#
# Step 1: find all the local (static functions) and weak symbols.
# 't' is local, 'w/W' is weak (we never use a weak function)
#
open (IN, "$nm $inputfile|") || die "error running $nm";
while (<IN>) {
- if (/^[0-9a-fA-F]+\s+t\s+(\S+)/) {
+ if (/$nm_regex/) {
$locals{$1} = 1;
} elsif (/^[0-9a-fA-F]+\s+([wW])\s+(\S+)/) {
$weak{$2} = $1;
# only use locals if objcopy supports globalize-symbols
if (!$use_locals) {
- print STDERR
- "$inputfile: WARNING: referencing local function " .
- "$ref_func for mcount\n" .
- "\tConsider upgrading objcopy to support the globalize-" .
- "symbols option.\n"
- if (!$local_warn_once++);
return;
}
$convert{$ref_func} = 1;
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.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 $read_headers = 1;
+
while (<IN>) {
# is it a section?
if (/$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 {
+ $read_function = 0;
+ }
# print out any recorded offsets
- update_funcs() if ($text_found);
+ update_funcs() if (defined($ref_func));
# reset all markers and arrays
$text_found = 0;
# section found, now is this a start of a function?
} elsif ($read_function && /$function_regex/) {
$text_found = 1;
- $offset = hex $1;
$text = $2;
# if this is either a local function or a weak function
if (!defined($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})) {
+ 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 $inputfile and try again. If the same object file\n" .
+ "\tstill causes an issue, then disable CONFIG_DYNAMIC_FTRACE.\n";
+ exit(-1);
}
# is this a call site to mcount? If so, record it to print later
}
# dump out anymore offsets that may have been found
-update_funcs() if ($text_found);
+update_funcs() if (defined($ref_func));
# If we did not find any mcount callers, we are done (do nothing).
if (!$opened) {
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