Merge tag 'objtool-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool updates from Ingo Molnar: - KLP support updates and fixes (Song Liu) - KLP-build script updates and fixes (Joe Lawrence) - Support Clang RAX DRAP sequence, to address clang false positive (Josh Poimboeuf) - Reorder ORC register numbering to match regular x86 register numbering (Josh Poimboeuf) - Misc cleanups (Wentong Tian, Song Liu) * tag 'objtool-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: objtool/x86: Reorder ORC register numbering objtool: Support Clang RAX DRAP sequence livepatch/klp-build: report patch validation fuzz livepatch/klp-build: add terminal color output livepatch/klp-build: provide friendlier error messages livepatch/klp-build: improve short-circuit validation livepatch/klp-build: fix shellcheck complaints livepatch/klp-build: add Makefile with check target livepatch/klp-build: add grep-override function livepatch/klp-build: switch to GNU patch and recountdiff livepatch/klp-build: support patches that add/remove files objtool/klp: Correlate locals to globals objtool/klp: Match symbols based on demangled_name for global variables objtool/klp: Remove .llvm suffix in demangle_name() objtool/klp: Also demangle global objects objtool/klp: Use sym->demangled_name for symbol_name hash objtool/klp: Remove trailing '_' in demangle_name() objtool/klp: Remove redundant strcmp() in correlate_symbols() objtool: Use section/symbol type helpers
2026-04-18 06:44:00 -04:00 · 2026-04-14 13:00:04 -07:00
parent 7393febcb1 1735858caa
commit 4b2bdc2221
12 changed files with 337 additions and 126 deletions
--- a/arch/x86/include/asm/orc_types.h
+++ b/arch/x86/include/asm/orc_types.h
@@ -28,15 +28,16 @@
 * and GCC realigned stacks.
 */
 #define ORC_REG_UNDEFINED		0
-#define ORC_REG_PREV_SP			1
+#define ORC_REG_AX			1
 #define ORC_REG_DX			2
-#define ORC_REG_DI			3
+#define ORC_REG_SP			3
 #define ORC_REG_BP			4
-#define ORC_REG_SP			5
+#define ORC_REG_DI			5
 #define ORC_REG_R10			6
 #define ORC_REG_R13			7
-#define ORC_REG_BP_INDIRECT		8
+#define ORC_REG_PREV_SP			8
 #define ORC_REG_SP_INDIRECT		9
+#define ORC_REG_BP_INDIRECT		10
 #define ORC_REG_MAX			15

 #define ORC_TYPE_UNDEFINED		0
--- a/arch/x86/kernel/unwind_orc.c
+++ b/arch/x86/kernel/unwind_orc.c
@@ -546,17 +546,23 @@ bool unwind_next_frame(struct unwind_state *state)
 		indirect = true;
 		break;

-	case ORC_REG_R10:
-		if (!get_reg(state, offsetof(struct pt_regs, r10), &sp)) {
-			orc_warn_current("missing R10 value at %pB\n",
+	/*
+	 * Any of the below registers may temporarily hold the stack pointer,
+	 * typically during a DRAP stack realignment sequence or some other
+	 * stack swizzle.
+	 */
+
+	case ORC_REG_AX:
+		if (!get_reg(state, offsetof(struct pt_regs, ax), &sp)) {
+			orc_warn_current("missing AX value at %pB\n",
 					 (void *)state->ip);
 			goto err;
 		}
 		break;

-	case ORC_REG_R13:
-		if (!get_reg(state, offsetof(struct pt_regs, r13), &sp)) {
-			orc_warn_current("missing R13 value at %pB\n",
+	case ORC_REG_DX:
+		if (!get_reg(state, offsetof(struct pt_regs, dx), &sp)) {
+			orc_warn_current("missing DX value at %pB\n",
 					 (void *)state->ip);
 			goto err;
 		}
@@ -570,9 +576,17 @@ bool unwind_next_frame(struct unwind_state *state)
 		}
 		break;

-	case ORC_REG_DX:
-		if (!get_reg(state, offsetof(struct pt_regs, dx), &sp)) {
-			orc_warn_current("missing DX value at %pB\n",
+	case ORC_REG_R10:
+		if (!get_reg(state, offsetof(struct pt_regs, r10), &sp)) {
+			orc_warn_current("missing R10 value at %pB\n",
+					 (void *)state->ip);
+			goto err;
+		}
+		break;
+
+	case ORC_REG_R13:
+		if (!get_reg(state, offsetof(struct pt_regs, r13), &sp)) {
+			orc_warn_current("missing R13 value at %pB\n",
 					 (void *)state->ip);
 			goto err;
 		}
--- a/scripts/livepatch/Makefile
+++ b/scripts/livepatch/Makefile
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0
+# Standalone Makefile for developer tooling (not part of kbuild).
+
+SHELLCHECK := $(shell which shellcheck 2> /dev/null)
+
+SRCS := \
+  klp-build
+
+.DEFAULT_GOAL := help
+.PHONY: help
+help:
+	@echo "  check      - Run shellcheck on $(SRCS)"
+	@echo "  help       - Show this help message"
+
+.PHONY: check
+check:
+ifndef SHELLCHECK
+	$(error shellcheck is not installed. Please install it to run checks)
+endif
+	@$(SHELLCHECK) $(SHELLCHECK_OPTIONS) $(SRCS)
--- a/scripts/livepatch/klp-build
+++ b/scripts/livepatch/klp-build
@@ -52,20 +52,37 @@ PATCH_TMP_DIR="$TMP_DIR/tmp"

 KLP_DIFF_LOG="$DIFF_DIR/diff.log"

+# Terminal output colors
+read -r COLOR_RESET COLOR_BOLD COLOR_ERROR COLOR_WARN <<< ""
+if [[ -t 1 && -t 2 ]]; then
+	COLOR_RESET="\033[0m"
+	COLOR_BOLD="\033[1m"
+	COLOR_ERROR="\033[0;31m"
+	COLOR_WARN="\033[0;33m"
+fi
+
 grep0() {
+	# shellcheck disable=SC2317
 	command grep "$@" || true
 }

+# Because pipefail is enabled, the grep0 helper should be used instead of
+# grep, otherwise a failed match can propagate to an error.
+grep() {
+	echo "error: $SCRIPT: use grep0 or 'command grep' instead of bare grep" >&2
+	exit 1
+}
+
 status() {
-	echo "$*"
+	echo -e "${COLOR_BOLD}$*${COLOR_RESET}"
 }

 warn() {
-	echo "error: $SCRIPT: $*" >&2
+	echo -e "${COLOR_WARN}warning${COLOR_RESET}: $SCRIPT: $*" >&2
 }

 die() {
-	warn "$@"
+	echo -e "${COLOR_ERROR}error${COLOR_RESET}: $SCRIPT: $*" >&2
 	exit 1
 }

@@ -95,14 +112,14 @@ restore_files() {

 cleanup() {
 	set +o nounset
-	revert_patches "--recount"
+	revert_patches
 	restore_files
 	[[ "$KEEP_TMP" -eq 0 ]] && rm -rf "$TMP_DIR"
 	return 0
 }

 trap_err() {
-	warn "line ${BASH_LINENO[0]}: '$BASH_COMMAND'"
+	die "line ${BASH_LINENO[0]}: '$BASH_COMMAND'"
 }

 trap cleanup  EXIT INT TERM HUP
@@ -212,7 +229,7 @@ process_args() {
 		esac
 	done

-	if [[ $# -eq 0 ]]; then
+	if [[ $# -eq 0 ]] && (( SHORT_CIRCUIT <= 2 )); then
 		usage
 		exit 1
 	fi
@@ -282,7 +299,7 @@ set_module_name() {
 }

 # Hardcode the value printed by the localversion script to prevent patch
-# application from appending it with '+' due to a dirty git working tree.
+# application from appending it with '+' due to a dirty working tree.
 set_kernelversion() {
 	local file="$SRC/scripts/setlocalversion"
 	local kernelrelease
@@ -295,28 +312,31 @@ set_kernelversion() {
 	sed -i "2i echo $kernelrelease; exit 0" scripts/setlocalversion
 }

-get_patch_files() {
+get_patch_input_files() {
 	local patch="$1"

-	grep0 -E '^(--- |\+\+\+ )' "$patch"			\
+	grep0 -E '^--- ' "$patch"				\
+		| grep0 -v -e '/dev/null' -e '1969-12-31' -e '1970-01-01' \
 		| gawk '{print $2}'				\
 		| sed 's|^[^/]*/||'				\
 		| sort -u
 }

-# Make sure git re-stats the changed files
-git_refresh() {
+get_patch_output_files() {
 	local patch="$1"
-	local files=()

-	[[ ! -e "$SRC/.git" ]] && return
+	grep0 -E '^\+\+\+ ' "$patch"				\
+		| grep0 -v -e '/dev/null' -e '1969-12-31' -e '1970-01-01' \
+		| gawk '{print $2}'				\
+		| sed 's|^[^/]*/||'				\
+		| sort -u
+}

-	get_patch_files "$patch" | mapfile -t files
+get_patch_files() {
+	local patch="$1"

-	(
-		cd "$SRC"
-		git update-index -q --refresh -- "${files[@]}"
-	)
+	{ get_patch_input_files "$patch"; get_patch_output_files "$patch"; } \
+		| sort -u
 }

 check_unsupported_patches() {
@@ -330,7 +350,7 @@ check_unsupported_patches() {
 		for file in "${files[@]}"; do
 			case "$file" in
 				lib/*|*.S)
-					die "unsupported patch to $file"
+					die "${patch}: unsupported patch to $file"
 					;;
 			esac
 		done
@@ -341,34 +361,30 @@ apply_patch() {
 	local patch="$1"
 	shift
 	local extra_args=("$@")
+	local drift_regex="with fuzz|offset [0-9]+ line"
+	local output
+	local status

 	[[ ! -f "$patch" ]] && die "$patch doesn't exist"
+	status=0
+	output=$(patch -d "$SRC" -p1 --dry-run --no-backup-if-mismatch -r /dev/null "${extra_args[@]}" < "$patch" 2>&1) || status=$?
+	if [[ "$status" -ne 0 ]]; then
+		echo "$output" >&2
+		die "$patch did not apply"
+	elif [[ "$output" =~ $drift_regex ]]; then
+		echo "$output" >&2
+		warn "${patch} applied with fuzz"
+	fi

-	(
-		cd "$SRC"
-
-		# The sed strips the version signature from 'git format-patch',
-		# otherwise 'git apply --recount' warns.
-		sed -n '/^-- /q;p' "$patch" |
-			git apply "${extra_args[@]}"
-	)
-
+	patch -d "$SRC" -p1 --no-backup-if-mismatch -r /dev/null "${extra_args[@]}" --silent < "$patch"
 	APPLIED_PATCHES+=("$patch")
 }

 revert_patch() {
 	local patch="$1"
-	shift
-	local extra_args=("$@")
 	local tmp=()

-	(
-		cd "$SRC"
-
-		sed -n '/^-- /q;p' "$patch" |
-			git apply --reverse "${extra_args[@]}"
-	)
-	git_refresh "$patch"
+	patch -d "$SRC" -p1 -R --silent --no-backup-if-mismatch -r /dev/null < "$patch"

 	for p in "${APPLIED_PATCHES[@]}"; do
 		[[ "$p" == "$patch" ]] && continue
@@ -379,19 +395,19 @@ revert_patch() {
 }

 apply_patches() {
+	local extra_args=("$@")
 	local patch

 	for patch in "${PATCHES[@]}"; do
-		apply_patch "$patch"
+		apply_patch "$patch" "${extra_args[@]}"
 	done
 }

 revert_patches() {
-	local extra_args=("$@")
 	local patches=("${APPLIED_PATCHES[@]}")

 	for (( i=${#patches[@]}-1 ; i>=0 ; i-- )) ; do
-		revert_patch "${patches[$i]}" "${extra_args[@]}"
+		revert_patch "${patches[$i]}"
 	done

 	APPLIED_PATCHES=()
@@ -415,6 +431,7 @@ do_init() {
 	APPLIED_PATCHES=()

 	[[ -x "$FIX_PATCH_LINES" ]] || die "can't find fix-patch-lines"
+	command -v recountdiff &>/dev/null || die "recountdiff not found (install patchutils)"

 	validate_config
 	set_module_name
@@ -425,25 +442,27 @@ do_init() {
 refresh_patch() {
 	local patch="$1"
 	local tmpdir="$PATCH_TMP_DIR"
-	local files=()
+	local input_files=()
+	local output_files=()

 	rm -rf "$tmpdir"
 	mkdir -p "$tmpdir/a"
 	mkdir -p "$tmpdir/b"

 	# Get all source files affected by the patch
-	get_patch_files "$patch" | mapfile -t files
+	get_patch_input_files "$patch" | mapfile -t input_files
+	get_patch_output_files "$patch" | mapfile -t output_files

 	# Copy orig source files to 'a'
-	( cd "$SRC" && echo "${files[@]}" | xargs cp --parents --target-directory="$tmpdir/a" )
+	( cd "$SRC" && echo "${input_files[@]}" | xargs cp --parents --target-directory="$tmpdir/a" )

 	# Copy patched source files to 'b'
-	apply_patch "$patch" --recount
-	( cd "$SRC" && echo "${files[@]}" | xargs cp --parents --target-directory="$tmpdir/b" )
-	revert_patch "$patch" --recount
+	apply_patch "$patch" "--silent"
+	( cd "$SRC" && echo "${output_files[@]}" | xargs cp --parents --target-directory="$tmpdir/b" )
+	revert_patch "$patch"

 	# Diff 'a' and 'b' to make a clean patch
-	( cd "$tmpdir" && git diff --no-index --no-prefix a b > "$patch" ) || true
+	( cd "$tmpdir" && diff -Nupr a b > "$patch" ) || true
 }

 # Copy the patches to a temporary directory, fix their lines so as not to
@@ -466,8 +485,7 @@ fix_patches() {

 		cp -f "$old_patch" "$tmp_patch"
 		refresh_patch "$tmp_patch"
-		"$FIX_PATCH_LINES" "$tmp_patch" > "$new_patch"
-		refresh_patch "$new_patch"
+		"$FIX_PATCH_LINES" "$tmp_patch" | recountdiff > "$new_patch"

 		PATCHES[i]="$new_patch"

@@ -491,6 +509,7 @@ clean_kernel() {
 }

 build_kernel() {
+	local build="$1"
 	local log="$TMP_DIR/build.log"
 	local objtool_args=()
 	local cmd=()
@@ -528,7 +547,7 @@ build_kernel() {
 		"${cmd[@]}"							\
 			1> >(tee -a "$log")					\
 			2> >(tee -a "$log" | grep0 -v "modpost.*undefined!" >&2)
-	)
+	) || die "$build kernel build failed"
 }

 find_objects() {
@@ -555,7 +574,6 @@ copy_orig_objects() {
 	for _file in "${files[@]}"; do
 		local rel_file="${_file/.ko/.o}"
 		local file="$OBJ/$rel_file"
-		local file_dir="$(dirname "$file")"
 		local orig_file="$ORIG_DIR/$rel_file"
 		local orig_dir="$(dirname "$orig_file")"

@@ -796,12 +814,15 @@ build_patch_module() {
 process_args "$@"
 do_init

-if (( SHORT_CIRCUIT <= 1 )); then
+if (( SHORT_CIRCUIT <= 2 )); then
 	status "Validating patch(es)"
 	validate_patches
+fi
+
+if (( SHORT_CIRCUIT <= 1 )); then
 	status "Building original kernel"
 	clean_kernel
-	build_kernel
+	build_kernel "original"
 	status "Copying original object files"
 	copy_orig_objects
 fi
@@ -809,9 +830,9 @@ fi
 if (( SHORT_CIRCUIT <= 2 )); then
 	status "Fixing patch(es)"
 	fix_patches
-	apply_patches
+	apply_patches "--silent"
 	status "Building patched kernel"
-	build_kernel
+	build_kernel "patched"
 	revert_patches
 	status "Copying patched object files"
 	copy_patched_objects
--- a/tools/arch/x86/include/asm/orc_types.h
+++ b/tools/arch/x86/include/asm/orc_types.h
@@ -28,15 +28,16 @@
 * and GCC realigned stacks.
 */
 #define ORC_REG_UNDEFINED		0
-#define ORC_REG_PREV_SP			1
+#define ORC_REG_AX			1
 #define ORC_REG_DX			2
-#define ORC_REG_DI			3
+#define ORC_REG_SP			3
 #define ORC_REG_BP			4
-#define ORC_REG_SP			5
+#define ORC_REG_DI			5
 #define ORC_REG_R10			6
 #define ORC_REG_R13			7
-#define ORC_REG_BP_INDIRECT		8
+#define ORC_REG_PREV_SP			8
 #define ORC_REG_SP_INDIRECT		9
+#define ORC_REG_BP_INDIRECT		10
 #define ORC_REG_MAX			15

 #define ORC_TYPE_UNDEFINED		0
--- a/tools/objtool/arch/x86/decode.c
+++ b/tools/objtool/arch/x86/decode.c
@@ -875,14 +875,20 @@ int arch_decode_hint_reg(u8 sp_reg, int *base)
 	case ORC_REG_UNDEFINED:
 		*base = CFI_UNDEFINED;
 		break;
+	case ORC_REG_AX:
+		*base = CFI_AX;
+		break;
+	case ORC_REG_DX:
+		*base = CFI_DX;
+		break;
 	case ORC_REG_SP:
 		*base = CFI_SP;
 		break;
 	case ORC_REG_BP:
 		*base = CFI_BP;
 		break;
-	case ORC_REG_SP_INDIRECT:
-		*base = CFI_SP_INDIRECT;
+	case ORC_REG_DI:
+		*base = CFI_DI;
 		break;
 	case ORC_REG_R10:
 		*base = CFI_R10;
@@ -890,11 +896,11 @@ int arch_decode_hint_reg(u8 sp_reg, int *base)
 	case ORC_REG_R13:
 		*base = CFI_R13;
 		break;
-	case ORC_REG_DI:
-		*base = CFI_DI;
+	case ORC_REG_SP_INDIRECT:
+		*base = CFI_SP_INDIRECT;
 		break;
-	case ORC_REG_DX:
-		*base = CFI_DX;
+	case ORC_REG_BP_INDIRECT:
+		*base = CFI_BP_INDIRECT;
 		break;
 	default:
 		return -1;
--- a/tools/objtool/arch/x86/orc.c
+++ b/tools/objtool/arch/x86/orc.c
@@ -46,17 +46,20 @@ int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruct
 	orc->signal = cfi->signal;

 	switch (cfi->cfa.base) {
+	case CFI_AX:
+		orc->sp_reg = ORC_REG_AX;
+		break;
+	case CFI_DX:
+		orc->sp_reg = ORC_REG_DX;
+		break;
 	case CFI_SP:
 		orc->sp_reg = ORC_REG_SP;
 		break;
-	case CFI_SP_INDIRECT:
-		orc->sp_reg = ORC_REG_SP_INDIRECT;
-		break;
 	case CFI_BP:
 		orc->sp_reg = ORC_REG_BP;
 		break;
-	case CFI_BP_INDIRECT:
-		orc->sp_reg = ORC_REG_BP_INDIRECT;
+	case CFI_DI:
+		orc->sp_reg = ORC_REG_DI;
 		break;
 	case CFI_R10:
 		orc->sp_reg = ORC_REG_R10;
@@ -64,11 +67,11 @@ int init_orc_entry(struct orc_entry *orc, struct cfi_state *cfi, struct instruct
 	case CFI_R13:
 		orc->sp_reg = ORC_REG_R13;
 		break;
-	case CFI_DI:
-		orc->sp_reg = ORC_REG_DI;
+	case CFI_SP_INDIRECT:
+		orc->sp_reg = ORC_REG_SP_INDIRECT;
 		break;
-	case CFI_DX:
-		orc->sp_reg = ORC_REG_DX;
+	case CFI_BP_INDIRECT:
+		orc->sp_reg = ORC_REG_BP_INDIRECT;
 		break;
 	default:
 		ERROR_INSN(insn, "unknown CFA base reg %d", cfi->cfa.base);
@@ -122,22 +125,24 @@ static const char *reg_name(unsigned int reg)
 	switch (reg) {
 	case ORC_REG_PREV_SP:
 		return "prevsp";
+	case ORC_REG_AX:
+		return "ax";
 	case ORC_REG_DX:
 		return "dx";
-	case ORC_REG_DI:
-		return "di";
 	case ORC_REG_BP:
 		return "bp";
 	case ORC_REG_SP:
 		return "sp";
+	case ORC_REG_DI:
+		return "di";
 	case ORC_REG_R10:
 		return "r10";
 	case ORC_REG_R13:
 		return "r13";
-	case ORC_REG_BP_INDIRECT:
-		return "bp(ind)";
 	case ORC_REG_SP_INDIRECT:
 		return "sp(ind)";
+	case ORC_REG_BP_INDIRECT:
+		return "bp(ind)";
 	default:
 		return "?";
 	}
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -4306,8 +4306,8 @@ static int validate_retpoline(struct objtool_file *file)
 	list_for_each_entry(insn, &file->retpoline_call_list, call_node) {
 		struct symbol *sym = insn->sym;

-		if (sym && (sym->type == STT_NOTYPE ||
-			    sym->type == STT_FUNC) && !sym->nocfi) {
+		if (sym && (is_notype_sym(sym) ||
+			    is_func_sym(sym)) && !sym->nocfi) {
 			struct instruction *prev =
 				prev_insn_same_sym(file, insn);

--- a/tools/objtool/disas.c
+++ b/tools/objtool/disas.c
@@ -264,7 +264,7 @@ static void disas_print_addr_reloc(bfd_vma addr, struct disassemble_info *dinfo)
 	 * If the relocation symbol is a section name (for example ".bss")
 	 * then we try to further resolve the name.
 	 */
-	if (reloc->sym->type == STT_SECTION) {
+	if (is_sec_sym(reloc->sym)) {
 		str = offstr(reloc->sym->sec, reloc->sym->offset + offset);
 		DINFO_FPRINTF(dinfo, bfd_vma_fmt, addr, str);
 		free(str);
@@ -580,7 +580,7 @@ static size_t disas_insn_common(struct disas_context *dctx,
 	 */
 	dinfo->buffer = insn->sec->data->d_buf;
 	dinfo->buffer_vma = 0;
-	dinfo->buffer_length = insn->sec->sh.sh_size;
+	dinfo->buffer_length = sec_size(insn->sec);

 	return disasm(insn->offset, &dctx->info);
 }
@@ -1231,7 +1231,7 @@ void disas_funcs(struct disas_context *dctx)

 	for_each_sec(dctx->file->elf, sec) {

-		if (!(sec->sh.sh_flags & SHF_EXECINSTR))
+		if (!is_text_sec(sec))
 			continue;

 		sec_for_each_sym(sec, sym) {
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -25,11 +25,18 @@
 #include <objtool/elf.h>
 #include <objtool/warn.h>

+static ssize_t demangled_name_len(const char *name);
+
 static inline u32 str_hash(const char *str)
 {
 	return jhash(str, strlen(str), 0);
 }

+static inline u32 str_hash_demangled(const char *str)
+{
+	return jhash(str, demangled_name_len(str), 0);
+}
+
 #define __elf_table(name)	(elf->name##_hash)
 #define __elf_bits(name)	(elf->name##_bits)

@@ -293,7 +300,7 @@ static struct symbol *find_local_symbol_by_file_and_name(const struct elf *elf,
 {
 	struct symbol *sym;

-	elf_hash_for_each_possible(symbol_name, sym, name_hash, str_hash(name)) {
+	elf_hash_for_each_possible(symbol_name, sym, name_hash, str_hash_demangled(name)) {
 		if (sym->bind == STB_LOCAL && sym->file == file &&
 		    !strcmp(sym->name, name)) {
 			return sym;
@@ -307,7 +314,7 @@ struct symbol *find_global_symbol_by_name(const struct elf *elf, const char *nam
 {
 	struct symbol *sym;

-	elf_hash_for_each_possible(symbol_name, sym, name_hash, str_hash(name)) {
+	elf_hash_for_each_possible(symbol_name, sym, name_hash, str_hash_demangled(name)) {
 		if (!strcmp(sym->name, name) && !is_local_sym(sym))
 			return sym;
 	}
@@ -315,6 +322,19 @@ struct symbol *find_global_symbol_by_name(const struct elf *elf, const char *nam
 	return NULL;
 }

+void iterate_global_symbol_by_demangled_name(const struct elf *elf,
+					     const char *demangled_name,
+					     void (*process)(struct symbol *sym, void *data),
+					     void *data)
+{
+	struct symbol *sym;
+
+	elf_hash_for_each_possible(symbol_name, sym, name_hash, str_hash(demangled_name)) {
+		if (!strcmp(sym->demangled_name, demangled_name) && !is_local_sym(sym))
+			process(sym, data);
+	}
+}
+
 struct reloc *find_reloc_by_dest_range(const struct elf *elf, struct section *sec,
 				     unsigned long offset, unsigned int len)
 {
@@ -440,34 +460,67 @@ static int read_sections(struct elf *elf)
 	return 0;
 }

+/*
+ * Returns desired length of the demangled name.
+ * If name doesn't need demangling, return strlen(name).
+ */
+static ssize_t demangled_name_len(const char *name)
+{
+	ssize_t idx;
+	const char *p;
+
+	p = strstr(name, ".llvm.");
+	if (p)
+		return p - name;
+
+	if (!strstarts(name, "__UNIQUE_ID_") && !strchr(name, '.'))
+		return strlen(name);
+
+	for (idx = strlen(name) - 1; idx >= 0; idx--) {
+		char c = name[idx];
+
+		if (!isdigit(c) && c != '.' && c != '_')
+			break;
+	}
+	if (idx <= 0)
+		return strlen(name);
+	return idx + 1;
+}
+
+/*
+ * Remove number suffix of a symbol.
+ *
+ * Specifically, remove trailing numbers for "__UNIQUE_ID_" symbols and
+ * symbols with '.'.
+ *
+ * With CONFIG_LTO_CLANG_THIN, it is possible to have nested __UNIQUE_ID_,
+ * such as
+ *
+ *   __UNIQUE_ID_addressable___UNIQUE_ID_pci_invalid_bar_694_695
+ *
+ * to remove both trailing numbers, also remove trailing '_'.
+ *
+ * For symbols with llvm suffix, i.e., foo.llvm.<hash>, remove the
+ * .llvm.<hash> part.
+ */
 static const char *demangle_name(struct symbol *sym)
 {
 	char *str;
-
-	if (!is_local_sym(sym))
-		return sym->name;
+	ssize_t len;

 	if (!is_func_sym(sym) && !is_object_sym(sym))
 		return sym->name;

-	if (!strstarts(sym->name, "__UNIQUE_ID_") && !strchr(sym->name, '.'))
+	len = demangled_name_len(sym->name);
+	if (len == strlen(sym->name))
 		return sym->name;

-	str = strdup(sym->name);
+	str = strndup(sym->name, len);
 	if (!str) {
 		ERROR_GLIBC("strdup");
 		return NULL;
 	}

-	for (int i = strlen(str) - 1; i >= 0; i--) {
-		char c = str[i];
-
-		if (!isdigit(c) && c != '.') {
-			str[i + 1] = '\0';
-			break;
-		}
-	}
-
 	return str;
 }

@@ -503,9 +556,13 @@ static int elf_add_symbol(struct elf *elf, struct symbol *sym)
 		entry = &sym->sec->symbol_list;
 	list_add(&sym->list, entry);

+	sym->demangled_name = demangle_name(sym);
+	if (!sym->demangled_name)
+		return -1;
+
 	list_add_tail(&sym->global_list, &elf->symbols);
 	elf_hash_add(symbol, &sym->hash, sym->idx);
-	elf_hash_add(symbol_name, &sym->name_hash, str_hash(sym->name));
+	elf_hash_add(symbol_name, &sym->name_hash, str_hash(sym->demangled_name));

 	if (is_func_sym(sym) &&
 	    (strstarts(sym->name, "__pfx_") ||
@@ -529,10 +586,6 @@ static int elf_add_symbol(struct elf *elf, struct symbol *sym)

 	sym->pfunc = sym->cfunc = sym;

-	sym->demangled_name = demangle_name(sym);
-	if (!sym->demangled_name)
-		return -1;
-
 	return 0;
 }

@@ -613,7 +666,7 @@ static int read_symbols(struct elf *elf)
 		if (elf_add_symbol(elf, sym))
 			return -1;

-		if (sym->type == STT_FILE)
+		if (is_file_sym(sym))
 			file = sym;
 		else if (sym->bind == STB_LOCAL)
 			sym->file = file;
@@ -1318,7 +1371,7 @@ unsigned int elf_add_string(struct elf *elf, struct section *strtab, const char
 		return -1;
 	}

-	offset = ALIGN(strtab->sh.sh_size, strtab->sh.sh_addralign);
+	offset = ALIGN(sec_size(strtab), strtab->sh.sh_addralign);

 	if (!elf_add_data(elf, strtab, str, strlen(str) + 1))
 		return -1;
@@ -1360,7 +1413,7 @@ void *elf_add_data(struct elf *elf, struct section *sec, const void *data, size_
 	sec->data->d_size = size;
 	sec->data->d_align = sec->sh.sh_addralign;

-	offset = ALIGN(sec->sh.sh_size, sec->sh.sh_addralign);
+	offset = ALIGN(sec_size(sec), sec->sh.sh_addralign);
 	sec->sh.sh_size = offset + size;

 	mark_sec_changed(elf, sec, true);
--- a/tools/objtool/include/objtool/elf.h
+++ b/tools/objtool/include/objtool/elf.h
@@ -186,6 +186,9 @@ struct symbol *find_func_by_offset(struct section *sec, unsigned long offset);
 struct symbol *find_symbol_by_offset(struct section *sec, unsigned long offset);
 struct symbol *find_symbol_by_name(const struct elf *elf, const char *name);
 struct symbol *find_global_symbol_by_name(const struct elf *elf, const char *name);
+void iterate_global_symbol_by_demangled_name(const struct elf *elf, const char *demangled_name,
+					     void (*process)(struct symbol *sym, void *data),
+					     void *data);
 struct symbol *find_symbol_containing(const struct section *sec, unsigned long offset);
 int find_symbol_hole_containing(const struct section *sec, unsigned long offset);
 struct reloc *find_reloc_by_dest(const struct elf *elf, struct section *sec, unsigned long offset);
--- a/tools/objtool/klp-diff.c
+++ b/tools/objtool/klp-diff.c
@@ -272,7 +272,7 @@ static bool is_uncorrelated_static_local(struct symbol *sym)
 */
 static bool is_clang_tmp_label(struct symbol *sym)
 {
-	return sym->type == STT_NOTYPE &&
+	return is_notype_sym(sym) &&
 	       is_text_sec(sym->sec) &&
 	       strstarts(sym->name, ".Ltmp") &&
 	       isdigit(sym->name[5]);
@@ -356,6 +356,46 @@ static bool dont_correlate(struct symbol *sym)
 	       strstarts(sym->name, "__initcall__");
 }

+struct process_demangled_name_data {
+	struct symbol *ret;
+	int count;
+};
+
+static void process_demangled_name(struct symbol *sym, void *d)
+{
+	struct process_demangled_name_data *data = d;
+
+	if (sym->twin)
+		return;
+
+	data->count++;
+	data->ret = sym;
+}
+
+/*
+ * When there is no full name match, try match demangled_name. This would
+ * match original foo.llvm.123 to patched foo.llvm.456.
+ *
+ * Note that, in very rare cases, it is possible to have multiple
+ * foo.llvm.<hash> in the same kernel. When this happens, report error and
+ * fail the diff.
+ */
+static int find_global_symbol_by_demangled_name(struct elf *elf, struct symbol *sym,
+						struct symbol **out_sym)
+{
+	struct process_demangled_name_data data = {};
+
+	iterate_global_symbol_by_demangled_name(elf, sym->demangled_name,
+						process_demangled_name,
+						&data);
+	if (data.count > 1) {
+		ERROR("Multiple (%d) correlation candidates for %s", data.count, sym->name);
+		return -1;
+	}
+	*out_sym = data.ret;
+	return 0;
+}
+
 /*
 * For each symbol in the original kernel, find its corresponding "twin" in the
 * patched kernel.
@@ -454,13 +494,60 @@ static int correlate_symbols(struct elfs *e)
 			continue;

 		sym2 = find_global_symbol_by_name(e->patched, sym1->name);
-
-		if (sym2 && !sym2->twin && !strcmp(sym1->name, sym2->name)) {
+		if (sym2 && !sym2->twin) {
 			sym1->twin = sym2;
 			sym2->twin = sym1;
 		}
 	}

+	/*
+	 * Correlate globals with demangled_name.
+	 * A separate loop is needed because we want to finish all the
+	 * full name correlations first.
+	 */
+	for_each_sym(e->orig, sym1) {
+		if (sym1->bind == STB_LOCAL || sym1->twin)
+			continue;
+
+		if (find_global_symbol_by_demangled_name(e->patched, sym1, &sym2))
+			return -1;
+
+		if (sym2 && !sym2->twin) {
+			sym1->twin = sym2;
+			sym2->twin = sym1;
+		}
+	}
+
+	/* Correlate original locals with patched globals */
+	for_each_sym(e->orig, sym1) {
+		if (sym1->twin || dont_correlate(sym1) || !is_local_sym(sym1))
+			continue;
+
+		sym2 = find_global_symbol_by_name(e->patched, sym1->name);
+		if (!sym2 && find_global_symbol_by_demangled_name(e->patched, sym1, &sym2))
+			return -1;
+
+		if (sym2 && !sym2->twin) {
+			sym1->twin = sym2;
+			sym2->twin = sym1;
+		}
+	}
+
+	/* Correlate original globals with patched locals */
+	for_each_sym(e->patched, sym2) {
+		if (sym2->twin || dont_correlate(sym2) || !is_local_sym(sym2))
+			continue;
+
+		sym1 = find_global_symbol_by_name(e->orig, sym2->name);
+		if (!sym1 && find_global_symbol_by_demangled_name(e->orig, sym2, &sym1))
+			return -1;
+
+		if (sym1 && !sym1->twin) {
+			sym2->twin = sym1;
+			sym1->twin = sym2;
+		}
+	}
+
 	for_each_sym(e->orig, sym1) {
 		if (sym1->twin || dont_correlate(sym1))
 			continue;
@@ -481,7 +568,7 @@ static unsigned long find_sympos(struct elf *elf, struct symbol *sym)
 	if (sym->bind != STB_LOCAL)
 		return 0;

-	if (vmlinux && sym->type == STT_FUNC) {
+	if (vmlinux && is_func_sym(sym)) {
 		/*
 		 * HACK: Unfortunately, symbol ordering can differ between
 		 * vmlinux.o and vmlinux due to the linker script emitting
@@ -1047,8 +1134,8 @@ static int clone_reloc_klp(struct elfs *e, struct reloc *patched_reloc,
 		   sec->name, offset, patched_sym->name,				\
 		   addend >= 0 ? "+" : "-", labs(addend),				\
 		   sym_type(patched_sym),						\
-		   patched_sym->type == STT_SECTION ? "" : " ",				\
-		   patched_sym->type == STT_SECTION ? "" : sym_bind(patched_sym),	\
+		   is_sec_sym(patched_sym) ? "" : " ",					\
+		   is_sec_sym(patched_sym) ? "" : sym_bind(patched_sym),		\
 		   is_undef_sym(patched_sym) ? " UNDEF" : "",				\
 		   export ? " EXPORTED" : "",						\
 		   klp ? " KLP" : "")