symbols: explicitly specify source file name for symtab

If there are any local symbols in an object file, GNU ld will create an
STT_FILE symbol derived from the object file name if there is none in the
incoming symbol table. The object file name, however, varies between
linking passes. As a result, symbol name compression can yield different
results if any of those local symbols need retaining (Arm [and RISC-V]
mapping symbols are omitted, for example). If that difference in
compression would yield a difference in the sizes of symbol_names[] or
symbols_token_table[], the compare-symbol-tables sanity check will fail.

Fixes: d37d63d4b5 ("symbols: prefix static symbols with their source file names")
Reported-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
master commit: c5d554edff
master date: 2026-05-13 10:00:52 +0200

xen/arch/x86/Makefile

@@ -216,6 +216,7 @@ endif
 		> $(dot-target).0r.S
 	$(NM) -pa --format=sysv $(dot-target).$(VIRT_BASE).0 \
 		| $(objtree)/tools/symbols $(all_symbols) --sysv --sort \
+                  --source-name=$(@F).S \
 		> $(dot-target).0s.S
 	$(MAKE) $(build)=$(@D) .$(@F).0r.o .$(@F).0s.o
 	$(foreach base, $(VIRT_BASE) $(ALT_BASE), \
@@ -226,6 +227,7 @@ endif
 		> $(dot-target).1r.S
 	$(NM) -pa --format=sysv $(dot-target).$(VIRT_BASE).1 \
 		| $(objtree)/tools/symbols $(all_symbols) --sysv --sort \
+                  --source-name=$(@F).S \
 		> $(dot-target).1s.S
 	$(MAKE) $(build)=$(@D) .$(@F).1r.o .$(@F).1s.o
 	$(LD) $(call EFI_LDFLAGS,$(VIRT_BASE)) -T $(obj)/efi.lds $< \

xen/tools/symbols.c

@@ -63,6 +63,7 @@ int token_profit[0x10000];
 unsigned char best_table[256][2];
 unsigned char best_table_len[256];
 
+static const char *srcname = "xen-syms.S";
 
 static void usage(void)
 {
@@ -320,6 +321,7 @@ static void write_src(void)
 	printf("#define ALGN .align 4\n");
 	printf("#endif\n");
 
+	printf("\t.file \"%s\"\n", srcname);
 	printf("\t.section .rodata, \"a\"\n");
 
 	printf("#ifndef SYMBOLS_ORIGIN\n");
@@ -612,6 +614,8 @@ int main(int argc, char **argv)
 				unsorted = true;
 			else if (strcmp(argv[i], "--sort-by-name") == 0)
 				sort_by_name = 1;
+			else if (strncmp(argv[i], "--source-name=", 14) == 0)
+				srcname = argv[i] + 14;
 			else if (strcmp(argv[i], "--warn-dup") == 0)
 				warn_dup = true;
 			else if (strcmp(argv[i], "--error-dup") == 0)