1#!/usr/bin/gawk -f
2# SPDX-License-Identifier: GPL-2.0
3# generate_builtin_ranges.awk: Generate address range data for builtin modules
4# Written by Kris Van Hees <kris.van.hees@oracle.com>
5#
6# Usage: generate_builtin_ranges.awk modules.builtin vmlinux.map \
7#		vmlinux.o.map > modules.builtin.ranges
8#
9
10# Return the module name(s) (if any) associated with the given object.
11#
12# If we have seen this object before, return information from the cache.
13# Otherwise, retrieve it from the corresponding .cmd file.
14#
15function get_module_info(fn, mod, obj, s) {
16	if (fn in omod)
17		return omod[fn];
18
19	if (match(fn, /\/[^/]+$/) == 0)
20		return "";
21
22	obj = fn;
23	mod = "";
24	fn = substr(fn, 1, RSTART) "." substr(fn, RSTART + 1) ".cmd";
25	if (getline s <fn == 1) {
26		if (match(s, /DKBUILD_MODFILE=['"]+[^'"]+/) > 0) {
27			mod = substr(s, RSTART + 16, RLENGTH - 16);
28			gsub(/['"]/, "", mod);
29		} else if (match(s, /RUST_MODFILE=[^ ]+/) > 0)
30			mod = substr(s, RSTART + 13, RLENGTH - 13);
31	}
32	close(fn);
33
34	# A single module (common case) also reflects objects that are not part
35	# of a module.  Some of those objects have names that are also a module
36	# name (e.g. core).  We check the associated module file name, and if
37	# they do not match, the object is not part of a module.
38	if (mod !~ / /) {
39		if (!(mod in mods))
40			mod = "";
41	}
42
43	gsub(/([^/ ]*\/)+/, "", mod);
44	gsub(/-/, "_", mod);
45
46	# At this point, mod is a single (valid) module name, or a list of
47	# module names (that do not need validation).
48	omod[obj] = mod;
49
50	return mod;
51}
52
53# Update the ranges entry for the given module 'mod' in section 'osect'.
54#
55# We use a modified absolute start address (soff + base) as index because we
56# may need to insert an anchor record later that must be at the start of the
57# section data, and the first module may very well start at the same address.
58# So, we use (addr << 1) + 1 to allow a possible anchor record to be placed at
59# (addr << 1).  This is safe because the index is only used to sort the entries
60# before writing them out.
61#
62function update_entry(osect, mod, soff, eoff, sect, idx) {
63	sect = sect_in[osect];
64	idx = sprintf("%016x", (soff + sect_base[osect]) * 2 + 1);
65	entries[idx] = sprintf("%s %08x-%08x %s", sect, soff, eoff, mod);
66	count[sect]++;
67}
68
69# (1) Build a lookup map of built-in module names.
70#
71# The first file argument is used as input (modules.builtin).
72#
73# Lines will be like:
74#	kernel/crypto/lzo-rle.ko
75# and we record the object name "crypto/lzo-rle".
76#
77ARGIND == 1 {
78	sub(/kernel\//, "");			# strip off "kernel/" prefix
79	sub(/\.ko$/, "");			# strip off .ko suffix
80
81	mods[$1] = 1;
82	next;
83}
84
85# (2) Collect address information for each section.
86#
87# The second file argument is used as input (vmlinux.map).
88#
89# We collect the base address of the section in order to convert all addresses
90# in the section into offset values.
91#
92# We collect the address of the anchor (or first symbol in the section if there
93# is no explicit anchor) to allow users of the range data to calculate address
94# ranges based on the actual load address of the section in the running kernel.
95#
96# We collect the start address of any sub-section (section included in the top
97# level section being processed).  This is needed when the final linking was
98# done using vmlinux.a because then the list of objects contained in each
99# section is to be obtained from vmlinux.o.map.  The offset of the sub-section
100# is recorded here, to be used as an addend when processing vmlinux.o.map
101# later.
102#
103
104# Both GNU ld and LLVM lld linker map format are supported by converting LLVM
105# lld linker map records into equivalent GNU ld linker map records.
106#
107# The first record of the vmlinux.map file provides enough information to know
108# which format we are dealing with.
109#
110ARGIND == 2 && FNR == 1 && NF == 7 && $1 == "VMA" && $7 == "Symbol" {
111	map_is_lld = 1;
112	if (dbg)
113		printf "NOTE: %s uses LLVM lld linker map format\n", FILENAME >"/dev/stderr";
114	next;
115}
116
117# (LLD) Convert a section record fronm lld format to ld format.
118#
119# lld: ffffffff82c00000          2c00000   2493c0  8192 .data
120#  ->
121# ld:  .data           0xffffffff82c00000   0x2493c0 load address 0x0000000002c00000
122#
123ARGIND == 2 && map_is_lld && NF == 5 && /[0-9] [^ ]+$/ {
124	$0 = $5 " 0x"$1 " 0x"$3 " load address 0x"$2;
125}
126
127# (LLD) Convert an anchor record from lld format to ld format.
128#
129# lld: ffffffff81000000          1000000        0     1         _text = .
130#  ->
131# ld:                  0xffffffff81000000                _text = .
132#
133ARGIND == 2 && map_is_lld && !anchor && NF == 7 && raw_addr == "0x"$1 && $6 == "=" && $7 == "." {
134	$0 = "  0x"$1 " " $5 " = .";
135}
136
137# (LLD) Convert an object record from lld format to ld format.
138#
139# lld:            11480            11480     1f07    16         vmlinux.a(arch/x86/events/amd/uncore.o):(.text)
140#  ->
141# ld:   .text          0x0000000000011480     0x1f07 arch/x86/events/amd/uncore.o
142#
143ARGIND == 2 && map_is_lld && NF == 5 && $5 ~ /:\(/ {
144	gsub(/\)/, "");
145	sub(/ vmlinux\.a\(/, " ");
146	sub(/:\(/, " ");
147	$0 = " "$6 " 0x"$1 " 0x"$3 " " $5;
148}
149
150# (LLD) Convert a symbol record from lld format to ld format.
151#
152# We only care about these while processing a section for which no anchor has
153# been determined yet.
154#
155# lld: ffffffff82a859a4          2a859a4        0     1                 btf_ksym_iter_id
156#  ->
157# ld:                  0xffffffff82a859a4                btf_ksym_iter_id
158#
159ARGIND == 2 && map_is_lld && sect && !anchor && NF == 5 && $5 ~ /^[_A-Za-z][_A-Za-z0-9]*$/ {
160	$0 = "  0x"$1 " " $5;
161}
162
163# (LLD) We do not need any other ldd linker map records.
164#
165ARGIND == 2 && map_is_lld && /^[0-9a-f]{16} / {
166	next;
167}
168
169# (LD) Section records with just the section name at the start of the line
170#      need to have the next line pulled in to determine whether it is a
171#      loadable section.  If it is, the next line will contains a hex value
172#      as first and second items.
173#
174ARGIND == 2 && !map_is_lld && NF == 1 && /^[^ ]/ {
175	s = $0;
176	getline;
177	if ($1 !~ /^0x/ || $2 !~ /^0x/)
178		next;
179
180	$0 = s " " $0;
181}
182
183# (LD) Object records with just the section name denote records with a long
184#      section name for which the remainder of the record can be found on the
185#      next line.
186#
187# (This is also needed for vmlinux.o.map, when used.)
188#
189ARGIND >= 2 && !map_is_lld && NF == 1 && /^ [^ \*]/ {
190	s = $0;
191	getline;
192	$0 = s " " $0;
193}
194
195# Beginning a new section - done with the previous one (if any).
196#
197ARGIND == 2 && /^[^ ]/ {
198	sect = 0;
199}
200
201# Process a loadable section (we only care about .-sections).
202#
203# Record the section name and its base address.
204# We also record the raw (non-stripped) address of the section because it can
205# be used to identify an anchor record.
206#
207# Note:
208# Since some AWK implementations cannot handle large integers, we strip off the
209# first 4 hex digits from the address.  This is safe because the kernel space
210# is not large enough for addresses to extend into those digits.  The portion
211# to strip off is stored in addr_prefix as a regexp, so further clauses can
212# perform a simple substitution to do the address stripping.
213#
214ARGIND == 2 && /^\./ {
215	# Explicitly ignore a few sections that are not relevant here.
216	if ($1 ~ /^\.orc_/ || $1 ~ /_sites$/ || $1 ~ /\.percpu/)
217		next;
218
219	# Sections with a 0-address can be ignored as well.
220	if ($2 ~ /^0x0+$/)
221		next;
222
223	raw_addr = $2;
224	addr_prefix = "^" substr($2, 1, 6);
225	base = $2;
226	sub(addr_prefix, "0x", base);
227	base = strtonum(base);
228	sect = $1;
229	anchor = 0;
230	sect_base[sect] = base;
231	sect_size[sect] = strtonum($3);
232
233	if (dbg)
234		printf "[%s] BASE   %016x\n", sect, base >"/dev/stderr";
235
236	next;
237}
238
239# If we are not in a section we care about, we ignore the record.
240#
241ARGIND == 2 && !sect {
242	next;
243}
244
245# Record the first anchor symbol for the current section.
246#
247# An anchor record for the section bears the same raw address as the section
248# record.
249#
250ARGIND == 2 && !anchor && NF == 4 && raw_addr == $1 && $3 == "=" && $4 == "." {
251	anchor = sprintf("%s %08x-%08x = %s", sect, 0, 0, $2);
252	sect_anchor[sect] = anchor;
253
254	if (dbg)
255		printf "[%s] ANCHOR %016x = %s (.)\n", sect, 0, $2 >"/dev/stderr";
256
257	next;
258}
259
260# If no anchor record was found for the current section, use the first symbol
261# in the section as anchor.
262#
263ARGIND == 2 && !anchor && NF == 2 && $1 ~ /^0x/ && $2 !~ /^0x/ {
264	addr = $1;
265	sub(addr_prefix, "0x", addr);
266	addr = strtonum(addr) - base;
267	anchor = sprintf("%s %08x-%08x = %s", sect, addr, addr, $2);
268	sect_anchor[sect] = anchor;
269
270	if (dbg)
271		printf "[%s] ANCHOR %016x = %s\n", sect, addr, $2 >"/dev/stderr";
272
273	next;
274}
275
276# The first occurrence of a section name in an object record establishes the
277# addend (often 0) for that section.  This information is needed to handle
278# sections that get combined in the final linking of vmlinux (e.g. .head.text
279# getting included at the start of .text).
280#
281# If the section does not have a base yet, use the base of the encapsulating
282# section.
283#
284ARGIND == 2 && sect && NF == 4 && /^ [^ \*]/ && !($1 in sect_addend) {
285	if (!($1 in sect_base)) {
286		sect_base[$1] = base;
287
288		if (dbg)
289			printf "[%s] BASE   %016x\n", $1, base >"/dev/stderr";
290	}
291
292	addr = $2;
293	sub(addr_prefix, "0x", addr);
294	addr = strtonum(addr);
295	sect_addend[$1] = addr - sect_base[$1];
296	sect_in[$1] = sect;
297
298	if (dbg)
299		printf "[%s] ADDEND %016x - %016x = %016x\n",  $1, addr, base, sect_addend[$1] >"/dev/stderr";
300
301	# If the object is vmlinux.o then we will need vmlinux.o.map to get the
302	# actual offsets of objects.
303	if ($4 == "vmlinux.o")
304		need_o_map = 1;
305}
306
307# (3) Collect offset ranges (relative to the section base address) for built-in
308# modules.
309#
310# If the final link was done using the actual objects, vmlinux.map contains all
311# the information we need (see section (3a)).
312# If linking was done using vmlinux.a as intermediary, we will need to process
313# vmlinux.o.map (see section (3b)).
314
315# (3a) Determine offset range info using vmlinux.map.
316#
317# Since we are already processing vmlinux.map, the top level section that is
318# being processed is already known.  If we do not have a base address for it,
319# we do not need to process records for it.
320#
321# Given the object name, we determine the module(s) (if any) that the current
322# object is associated with.
323#
324# If we were already processing objects for a (list of) module(s):
325#  - If the current object belongs to the same module(s), update the range data
326#    to include the current object.
327#  - Otherwise, ensure that the end offset of the range is valid.
328#
329# If the current object does not belong to a built-in module, ignore it.
330#
331# If it does, we add a new built-in module offset range record.
332#
333ARGIND == 2 && !need_o_map && /^ [^ ]/ && NF == 4 && $3 != "0x0" {
334	if (!(sect in sect_base))
335		next;
336
337	# Turn the address into an offset from the section base.
338	soff = $2;
339	sub(addr_prefix, "0x", soff);
340	soff = strtonum(soff) - sect_base[sect];
341	eoff = soff + strtonum($3);
342
343	# Determine which (if any) built-in modules the object belongs to.
344	mod = get_module_info($4);
345
346	# If we are processing a built-in module:
347	#   - If the current object is within the same module, we update its
348	#     entry by extending the range and move on
349	#   - Otherwise:
350	#       + If we are still processing within the same main section, we
351	#         validate the end offset against the start offset of the
352	#         current object (e.g. .rodata.str1.[18] objects are often
353	#         listed with an incorrect size in the linker map)
354	#       + Otherwise, we validate the end offset against the section
355	#         size
356	if (mod_name) {
357		if (mod == mod_name) {
358			mod_eoff = eoff;
359			update_entry(mod_sect, mod_name, mod_soff, eoff);
360
361			next;
362		} else if (sect == sect_in[mod_sect]) {
363			if (mod_eoff > soff)
364				update_entry(mod_sect, mod_name, mod_soff, soff);
365		} else {
366			v = sect_size[sect_in[mod_sect]];
367			if (mod_eoff > v)
368				update_entry(mod_sect, mod_name, mod_soff, v);
369		}
370	}
371
372	mod_name = mod;
373
374	# If we encountered an object that is not part of a built-in module, we
375	# do not need to record any data.
376	if (!mod)
377		next;
378
379	# At this point, we encountered the start of a new built-in module.
380	mod_name = mod;
381	mod_soff = soff;
382	mod_eoff = eoff;
383	mod_sect = $1;
384	update_entry($1, mod, soff, mod_eoff);
385
386	next;
387}
388
389# If we do not need to parse the vmlinux.o.map file, we are done.
390#
391ARGIND == 3 && !need_o_map {
392	if (dbg)
393		printf "Note: %s is not needed.\n", FILENAME >"/dev/stderr";
394	exit;
395}
396
397# (3) Collect offset ranges (relative to the section base address) for built-in
398# modules.
399#
400
401# (LLD) Convert an object record from lld format to ld format.
402#
403ARGIND == 3 && map_is_lld && NF == 5 && $5 ~ /:\(/ {
404	gsub(/\)/, "");
405	sub(/:\(/, " ");
406
407	sect = $6;
408	if (!(sect in sect_addend))
409		next;
410
411	sub(/ vmlinux\.a\(/, " ");
412	$0 = " "sect " 0x"$1 " 0x"$3 " " $5;
413}
414
415# (3b) Determine offset range info using vmlinux.o.map.
416#
417# If we do not know an addend for the object's section, we are interested in
418# anything within that section.
419#
420# Determine the top-level section that the object's section was included in
421# during the final link.  This is the section name offset range data will be
422# associated with for this object.
423#
424# The remainder of the processing of the current object record follows the
425# procedure outlined in (3a).
426#
427ARGIND == 3 && /^ [^ ]/ && NF == 4 && $3 != "0x0" {
428	osect = $1;
429	if (!(osect in sect_addend))
430		next;
431
432	# We need to work with the main section.
433	sect = sect_in[osect];
434
435	# Turn the address into an offset from the section base.
436	soff = $2;
437	sub(addr_prefix, "0x", soff);
438	soff = strtonum(soff) + sect_addend[osect];
439	eoff = soff + strtonum($3);
440
441	# Determine which (if any) built-in modules the object belongs to.
442	mod = get_module_info($4);
443
444	# If we are processing a built-in module:
445	#   - If the current object is within the same module, we update its
446	#     entry by extending the range and move on
447	#   - Otherwise:
448	#       + If we are still processing within the same main section, we
449	#         validate the end offset against the start offset of the
450	#         current object (e.g. .rodata.str1.[18] objects are often
451	#         listed with an incorrect size in the linker map)
452	#       + Otherwise, we validate the end offset against the section
453	#         size
454	if (mod_name) {
455		if (mod == mod_name) {
456			mod_eoff = eoff;
457			update_entry(mod_sect, mod_name, mod_soff, eoff);
458
459			next;
460		} else if (sect == sect_in[mod_sect]) {
461			if (mod_eoff > soff)
462				update_entry(mod_sect, mod_name, mod_soff, soff);
463		} else {
464			v = sect_size[sect_in[mod_sect]];
465			if (mod_eoff > v)
466				update_entry(mod_sect, mod_name, mod_soff, v);
467		}
468	}
469
470	mod_name = mod;
471
472	# If we encountered an object that is not part of a built-in module, we
473	# do not need to record any data.
474	if (!mod)
475		next;
476
477	# At this point, we encountered the start of a new built-in module.
478	mod_name = mod;
479	mod_soff = soff;
480	mod_eoff = eoff;
481	mod_sect = osect;
482	update_entry(osect, mod, soff, mod_eoff);
483
484	next;
485}
486
487# (4) Generate the output.
488#
489# Anchor records are added for each section that contains offset range data
490# records.  They are added at an adjusted section base address (base << 1) to
491# ensure they come first in the second records (see update_entry() above for
492# more information).
493#
494# All entries are sorted by (adjusted) address to ensure that the output can be
495# parsed in strict ascending address order.
496#
497END {
498	for (sect in count) {
499		if (sect in sect_anchor) {
500			idx = sprintf("%016x", sect_base[sect] * 2);
501			entries[idx] = sect_anchor[sect];
502		}
503	}
504
505	n = asorti(entries, indices);
506	for (i = 1; i <= n; i++)
507		print entries[indices[i]];
508}
509