#!/usr/bin/gawk -f
# SPDX-License-Identifier: GPL-2.0
# generate_builtin_ranges.awk: Generate address range data for builtin modules
# Written by Kris Van Hees <[email protected]>
#
# Usage: generate_builtin_ranges.awk modules.builtin vmlinux.map \
# vmlinux.o.map > modules.builtin.ranges
#
# Return the module name(s) (if any) associated with the given object.
#
# If we have seen this object before, return information from the cache.
# Otherwise, retrieve it from the corresponding .cmd file.
#
function get_module_info(fn, mod, obj, s) {
if (fn in omod)
return omod[fn];
if (match(fn, /\/[^/]+$/) == 0)
return "";
obj = fn;
mod = "";
fn = substr(fn, 1, RSTART) "." substr(fn, RSTART + 1) ".cmd";
if (getline s <fn == 1) {
if (match(s, /DKBUILD_MODFILE=['"]+[^'"]+/) > 0) {
mod = substr(s, RSTART + 16, RLENGTH - 16);
gsub(/['"]/, "", mod);
} else if (match(s, /RUST_MODFILE=[^ ]+/) > 0)
mod = substr(s, RSTART + 13, RLENGTH - 13);
}
close(fn);
# A single module (common case) also reflects objects that are not part
# of a module. Some of those objects have names that are also a module
# name (e.g. core). We check the associated module file name, and if
# they do not match, the object is not part of a module.
if (mod !~ / /) {
if (!(mod in mods))
mod = "";
}
gsub(/([^/ ]*\/)+/, "", mod);
gsub(/-/, "_", mod);
# At this point, mod is a single (valid) module name, or a list of
# module names (that do not need validation).
omod[obj] = mod;
return mod;
}
# Update the ranges entry for the given module 'mod' in section 'osect'.
#
# We use a modified absolute start address (soff + base) as index because we
# may need to insert an anchor record later that must be at the start of the
# section data, and the first module may very well start at the same address.
# So, we use (addr << 1) + 1 to allow a possible anchor record to be placed at
# (addr << 1). This is safe because the index is only used to sort the entries
# before writing them out.
#
function update_entry(osect, mod, soff, eoff, sect, idx) {
sect = sect_in[osect];
idx = sprintf("%016x", (soff + sect_base[osect]) * 2 + 1);
entries[idx] = sprintf("%s %08x-%08x %s", sect, soff, eoff, mod);
count[sect]++;
}
# (1) Build a lookup map of built-in module names.
#
# The first file argument is used as input (modules.builtin).
#
# Lines will be like:
# kernel/crypto/lzo-rle.ko
# and we record the object name "crypto/lzo-rle".
#
ARGIND == 1 {
sub(/kernel\//, ""); # strip off "kernel/" prefix
sub(/\.ko$/, ""); # strip off .ko suffix
mods[$1] = 1;
next;
}
# (2) Collect address information for each section.
#
# The second file argument is used as input (vmlinux.map).
#
# We collect the base address of the section in order to convert all addresses
# in the section into offset values.
#
# We collect the address of the anchor (or first symbol in the section if there
# is no explicit anchor) to allow users of the range data to calculate address
# ranges based on the actual load address of the section in the running kernel.
#
# We collect the start address of any sub-section (section included in the top
# level section being processed). This is needed when the final linking was
# done using vmlinux.a because then the list of objects contained in each
# section is to be obtained from vmlinux.o.map. The offset of the sub-section
# is recorded here, to be used as an addend when processing vmlinux.o.map
# later.
#
# Both GNU ld and LLVM lld linker map format are supported by converting LLVM
# lld linker map records into equivalent GNU ld linker map records.
#
# The first record of the vmlinux.map file provides enough information to know
# which format we are dealing with.
#
ARGIND == 2 && FNR == 1 && NF == 7 && $1 == "VMA" && $7 == "Symbol" {
map_is_lld = 1;
if (dbg)
printf "NOTE: %s uses LLVM lld linker map format\n", FILENAME >"/dev/stderr";
next;
}
# (LLD) Convert a section record fronm lld format to ld format.
#
# lld: ffffffff82c00000 2c00000 2493c0 8192 .data
# ->
# ld: .data 0xffffffff82c00000 0x2493c0 load address 0x0000000002c00000
#
ARGIND == 2 && map_is_lld && NF == 5 && /[0-9] [^ ]+$/ {
$0 = $5 " 0x"$1 " 0x"$3 " load address 0x"$2;
}
# (LLD) Convert an anchor record from lld format to ld format.
#
# lld: ffffffff81000000 1000000 0 1 _text = .
# ->
# ld: 0xffffffff81000000 _text = .
#
ARGIND == 2 && map_is_lld && !anchor && NF == 7 && raw_addr == "0x"$1 && $6 == "=" && $7 == "." {
$0 = " 0x"$1 " " $5 " = .";
}
# (LLD) Convert an object record from lld format to ld format.
#
# lld: 11480 11480 1f07 16 vmlinux.a(arch/x86/events/amd/uncore.o):(.text)
# ->
# ld: .text 0x0000000000011480 0x1f07 arch/x86/events/amd/uncore.o
#
ARGIND == 2 && map_is_lld && NF == 5 && $5 ~ /:\(/ {
gsub(/\)/, "");
sub(/ vmlinux\.a\(/, " ");
sub(/:\(/, " ");
$0 = " "$6 " 0x"$1 " 0x"$3 " " $5;
}
# (LLD) Convert a symbol record from lld format to ld format.
#
# We only care about these while processing a section for which no anchor has
# been determined yet.
#
# lld: ffffffff82a859a4 2a859a4 0 1 btf_ksym_iter_id
# ->
# ld: 0xffffffff82a859a4 btf_ksym_iter_id
#
ARGIND == 2 && map_is_lld && sect && !anchor && NF == 5 && $5 ~ /^[_A-Za-z][_A-Za-z0-9]*$/ {
$0 = " 0x"$1 " " $5;
}
# (LLD) We do not need any other ldd linker map records.
#
ARGIND == 2 && map_is_lld && /^[0-9a-f]{16} / {
next;
}
# (LD) Section records with just the section name at the start of the line
# need to have the next line pulled in to determine whether it is a
# loadable section. If it is, the next line will contains a hex value
# as first and second items.
#
ARGIND == 2 && !map_is_lld && NF == 1 && /^[^ ]/ {
s = $0;
getline;
if ($1 !~ /^0x/ || $2 !~ /^0x/)
next;
$0 = s " " $0;
}
# (LD) Object records with just the section name denote records with a long
# section name for which the remainder of the record can be found on the
# next line.
#
# (This is also needed for vmlinux.o.map, when used.)
#
ARGIND >= 2 && !map_is_lld && NF == 1 && /^ [^ \*]/ {
s = $0;
getline;
$0 = s " " $0;
}
# Beginning a new section - done with the previous one (if any).
#
ARGIND == 2 && /^[^ ]/ {
sect = 0;
}
# Process a loadable section (we only care about .-sections).
#
# Record the section name and its base address.
# We also record the raw (non-stripped) address of the section because it can
# be used to identify an anchor record.
#
# Note:
# Since some AWK implementations cannot handle large integers, we strip off the
# first 4 hex digits from the address. This is safe because the kernel space
# is not large enough for addresses to extend into those digits. The portion
# to strip off is stored in addr_prefix as a regexp, so further clauses can
# perform a simple substitution to do the address stripping.
#
ARGIND == 2 && /^\./ {
# Explicitly ignore a few sections that are not relevant here.
if ($1 ~ /^\.orc_/ || $1 ~ /_sites$/ || $1 ~ /\.percpu/)
next;
# Sections with a 0-address can be ignored as well.
if ($2 ~ /^0x0+$/)
next;
raw_addr = $2;
addr_prefix = "^" substr($2, 1, 6);
base = $2;
sub(addr_prefix, "0x", base);
base = strtonum(base);
sect = $1;
anchor = 0;
sect_base[sect] = base;
sect_size[sect] = strtonum($3);
if (dbg)
printf "[%s] BASE %016x\n", sect, base >"/dev/stderr";
next;
}
# If we are not in a section we care about, we ignore the record.
#
ARGIND == 2 && !sect {
next;
}
# Record the first anchor symbol for the current section.
#
# An anchor record for the section bears the same raw address as the section
# record.
#
ARGIND == 2 && !anchor && NF == 4 && raw_addr == $1 && $3 == "=" && $4 == "." {
anchor = sprintf("%s %08x-%08x = %s", sect, 0, 0, $2);
sect_anchor[sect] = anchor;
if (dbg)
printf "[%s] ANCHOR %016x = %s (.)\n", sect, 0, $2 >"/dev/stderr";
next;
}
# If no anchor record was found for the current section, use the first symbol
# in the section as anchor.
#
ARGIND == 2 && !anchor && NF == 2 && $1 ~ /^0x/ && $2 !~ /^0x/ {
addr = $1;
sub(addr_prefix, "0x", addr);
addr = strtonum(addr) - base;
anchor = sprintf("%s %08x-%08x = %s", sect, addr, addr, $2);
sect_anchor[sect] = anchor;
if (dbg)
printf "[%s] ANCHOR %016x = %s\n", sect, addr, $2 >"/dev/stderr";
next;
}
# The first occurrence of a section name in an object record establishes the
# addend (often 0) for that section. This information is needed to handle
# sections that get combined in the final linking of vmlinux (e.g. .head.text
# getting included at the start of .text).
#
# If the section does not have a base yet, use the base of the encapsulating
# section.
#
ARGIND == 2 && sect && NF == 4 && /^ [^ \*]/ && !($1 in sect_addend) {
if (!($1 in sect_base)) {
sect_base[$1] = base;
if (dbg)
printf "[%s] BASE %016x\n", $1, base >"/dev/stderr";
}
addr = $2;
sub(addr_prefix, "0x", addr);
addr = strtonum(addr);
sect_addend[$1] = addr - sect_base[$1];
sect_in[$1] = sect;
if (dbg)
printf "[%s] ADDEND %016x - %016x = %016x\n", $1, addr, base, sect_addend[$1] >"/dev/stderr";
# If the object is vmlinux.o then we will need vmlinux.o.map to get the
# actual offsets of objects.
if ($4 == "vmlinux.o")
need_o_map = 1;
}
# (3) Collect offset ranges (relative to the section base address) for built-in
# modules.
#
# If the final link was done using the actual objects, vmlinux.map contains all
# the information we need (see section (3a)).
# If linking was done using vmlinux.a as intermediary, we will need to process
# vmlinux.o.map (see section (3b)).
# (3a) Determine offset range info using vmlinux.map.
#
# Since we are already processing vmlinux.map, the top level section that is
# being processed is already known. If we do not have a base address for it,
# we do not need to process records for it.
#
# Given the object name, we determine the module(s) (if any) that the current
# object is associated with.
#
# If we were already processing objects for a (list of) module(s):
# - If the current object belongs to the same module(s), update the range data
# to include the current object.
# - Otherwise, ensure that the end offset of the range is valid.
#
# If the current object does not belong to a built-in module, ignore it.
#
# If it does, we add a new built-in module offset range record.
#
ARGIND == 2 && !need_o_map && /^ [^ ]/ && NF == 4 && $3 != "0x0" {
if (!(sect in sect_base))
next;
# Turn the address into an offset from the section base.
soff = $2;
sub(addr_prefix, "0x", soff);
soff = strtonum(soff) - sect_base[sect];
eoff = soff + strtonum($3);
# Determine which (if any) built-in modules the object belongs to.
mod = get_module_info($4);
# If we are processing a built-in module:
# - If the current object is within the same module, we update its
# entry by extending the range and move on
# - Otherwise:
# + If we are still processing within the same main section, we
# validate the end offset against the start offset of the
# current object (e.g. .rodata.str1.[18] objects are often
# listed with an incorrect size in the linker map)
# + Otherwise, we validate the end offset against the section
# size
if (mod_name) {
if (mod == mod_name) {
mod_eoff = eoff;
update_entry(mod_sect, mod_name, mod_soff, eoff);
next;
} else if (sect == sect_in[mod_sect]) {
if (mod_eoff > soff)
update_entry(mod_sect, mod_name, mod_soff, soff);
} else {
v = sect_size[sect_in[mod_sect]];
if (mod_eoff > v)
update_entry(mod_sect, mod_name, mod_soff, v);
}
}
mod_name = mod;
# If we encountered an object that is not part of a built-in module, we
# do not need to record any data.
if (!mod)
next;
# At this point, we encountered the start of a new built-in module.
mod_name = mod;
mod_soff = soff;
mod_eoff = eoff;
mod_sect = $1;
update_entry($1, mod, soff, mod_eoff);
next;
}
# If we do not need to parse the vmlinux.o.map file, we are done.
#
ARGIND == 3 && !need_o_map {
if (dbg)
printf "Note: %s is not needed.\n", FILENAME >"/dev/stderr";
exit;
}
# (3) Collect offset ranges (relative to the section base address) for built-in
# modules.
#
# (LLD) Convert an object record from lld format to ld format.
#
ARGIND == 3 && map_is_lld && NF == 5 && $5 ~ /:\(/ {
gsub(/\)/, "");
sub(/:\(/, " ");
sect = $6;
if (!(sect in sect_addend))
next;
sub(/ vmlinux\.a\(/, " ");
$0 = " "sect " 0x"$1 " 0x"$3 " " $5;
}
# (3b) Determine offset range info using vmlinux.o.map.
#
# If we do not know an addend for the object's section, we are interested in
# anything within that section.
#
# Determine the top-level section that the object's section was included in
# during the final link. This is the section name offset range data will be
# associated with for this object.
#
# The remainder of the processing of the current object record follows the
# procedure outlined in (3a).
#
ARGIND == 3 && /^ [^ ]/ && NF == 4 && $3 != "0x0" {
osect = $1;
if (!(osect in sect_addend))
next;
# We need to work with the main section.
sect = sect_in[osect];
# Turn the address into an offset from the section base.
soff = $2;
sub(addr_prefix, "0x", soff);
soff = strtonum(soff) + sect_addend[osect];
eoff = soff + strtonum($3);
# Determine which (if any) built-in modules the object belongs to.
mod = get_module_info($4);
# If we are processing a built-in module:
# - If the current object is within the same module, we update its
# entry by extending the range and move on
# - Otherwise:
# + If we are still processing within the same main section, we
# validate the end offset against the start offset of the
# current object (e.g. .rodata.str1.[18] objects are often
# listed with an incorrect size in the linker map)
# + Otherwise, we validate the end offset against the section
# size
if (mod_name) {
if (mod == mod_name) {
mod_eoff = eoff;
update_entry(mod_sect, mod_name, mod_soff, eoff);
next;
} else if (sect == sect_in[mod_sect]) {
if (mod_eoff > soff)
update_entry(mod_sect, mod_name, mod_soff, soff);
} else {
v = sect_size[sect_in[mod_sect]];
if (mod_eoff > v)
update_entry(mod_sect, mod_name, mod_soff, v);
}
}
mod_name = mod;
# If we encountered an object that is not part of a built-in module, we
# do not need to record any data.
if (!mod)
next;
# At this point, we encountered the start of a new built-in module.
mod_name = mod;
mod_soff = soff;
mod_eoff = eoff;
mod_sect = osect;
update_entry(osect, mod, soff, mod_eoff);
next;
}
# (4) Generate the output.
#
# Anchor records are added for each section that contains offset range data
# records. They are added at an adjusted section base address (base << 1) to
# ensure they come first in the second records (see update_entry() above for
# more information).
#
# All entries are sorted by (adjusted) address to ensure that the output can be
# parsed in strict ascending address order.
#
END {
for (sect in count) {
if (sect in sect_anchor) {
idx = sprintf("%016x", sect_base[sect] * 2);
entries[idx] = sect_anchor[sect];
}
}
n = asorti(entries, indices);
for (i = 1; i <= n; i++)
print entries[indices[i]];
}
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