symbols: Generate an xen-sym.map

You could construct _most_ of the names of the functions
by doing 'nm --defined' but unfortunatly you do not get the
<file> prefix that is added on in Xen . For example:

$ cat xen-syms.symbols |grep do_domain_pause
0xffff82d080104920 t domain.c#do_domain_pause
$ nm --defined xen-syms|grep do_domain_pause
ffff82d080104920 t do_domain_pause

This is normally not an issue, but if one is doing livepatching and
wants during build-time verify that the symbols the livepatch payloads
will patch do correspond to the one the hypervisor has built - this helps a lot.

Note that during runtime one can do:
[root@localhost xen]# cat /proc/xen/xensyms |grep do_domain_pause
ffff82d080104920 t domain.c#do_domain_pause

But one may not want to build and verify a livepatch on the same host.

Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

.gitignore

@@ -273,6 +273,7 @@ tools/flask/policy/policy.conf
 tools/flask/policy/xenpolicy-*
 xen/xen
 xen/xen-syms
+xen/xen-syms.map
 xen/xen.*
 unmodified_drivers/linux-2.6/.tmp_versions
 unmodified_drivers/linux-2.6/*.cmd

xen/Makefile

@@ -62,10 +62,12 @@ _install: $(TARGET)$(CONFIG_XEN_INSTALL_SUFFIX)
 	ln -f -s $(T)-$(XEN_FULLVERSION)$(Z) $(D)$(BOOT_DIR)/$(T)$(Z)
 	[ -d "$(D)$(DEBUG_DIR)" ] || $(INSTALL_DIR) $(D)$(DEBUG_DIR)
 	$(INSTALL_DATA) $(TARGET)-syms $(D)$(DEBUG_DIR)/$(T)-syms-$(XEN_FULLVERSION)
+	$(INSTALL_DATA) $(TARGET)-syms.map $(D)$(DEBUG_DIR)/$(T)-syms-$(XEN_FULLVERSION).map
 	$(INSTALL_DATA) $(KCONFIG_CONFIG) $(D)$(BOOT_DIR)/$(T)-$(XEN_FULLVERSION).config
 	if [ -r $(TARGET).efi -a -n '$(EFI_DIR)' ]; then \
 		[ -d $(D)$(EFI_DIR) ] || $(INSTALL_DIR) $(D)$(EFI_DIR); \
 		$(INSTALL_DATA) $(TARGET).efi $(D)$(EFI_DIR)/$(T)-$(XEN_FULLVERSION).efi; \
+		$(INSTALL_DATA) $(TARGET)-efi.map $(D)$(DEBUG_DIR)/$(T)-$(XEN_FULLVERSION).efi.map \
 		ln -sf $(T)-$(XEN_FULLVERSION).efi $(D)$(EFI_DIR)/$(T)-$(XEN_VERSION).$(XEN_SUBVERSION).efi; \
 		ln -sf $(T)-$(XEN_FULLVERSION).efi $(D)$(EFI_DIR)/$(T)-$(XEN_VERSION).efi; \
 		ln -sf $(T)-$(XEN_FULLVERSION).efi $(D)$(EFI_DIR)/$(T).efi; \
@@ -91,8 +93,10 @@ _uninstall:
 	rm -f $(D)$(BOOT_DIR)/$(T)-$(XEN_VERSION)$(Z)
 	rm -f $(D)$(BOOT_DIR)/$(T)$(Z)
 	rm -f $(D)$(DEBUG_DIR)/$(T)-syms-$(XEN_FULLVERSION)
+	rm -f $(D)$(DEBUG_DIR)/$(T)-syms-$(XEN_FULLVERSION).map
 	rm -f $(D)$(EFI_DIR)/$(T)-$(XEN_FULLVERSION).efi
 	rm -f $(D)$(EFI_DIR)/$(T)-$(XEN_VERSION).$(XEN_SUBVERSION).efi
+	rm -f $(D)$(DEBUG_DIR)/$(T)-$(XEN_FULLVERSION).efi.map
 	rm -f $(D)$(EFI_DIR)/$(T)-$(XEN_VERSION).efi
 	rm -f $(D)$(EFI_DIR)/$(T).efi
 	rm -f $(D)$(EFI_MOUNTPOINT)/efi/$(EFI_VENDOR)/$(T)-$(XEN_FULLVERSION).efi
@@ -112,7 +116,7 @@ _clean: delete-unfresh-files
 	$(MAKE) -f $(BASEDIR)/Rules.mk -C arch/$(TARGET_ARCH) clean
 	$(MAKE) -f $(BASEDIR)/tools/kconfig/Makefile.kconfig ARCH=$(ARCH) SRCARCH=$(SRCARCH) clean
 	find . \( -name "*.o" -o -name ".*.d" \) -exec rm -f {} \;
-	rm -f include/asm $(TARGET) $(TARGET).gz $(TARGET).efi $(TARGET)-syms *~ core
+	rm -f include/asm $(TARGET) $(TARGET).gz $(TARGET).efi $(TARGET).efi.map $(TARGET)-syms $(TARGET)-syms.map *~ core
 	rm -f include/asm-*/asm-offsets.h
 	rm -f .banner
 

xen/arch/arm/Makefile

@@ -102,6 +102,9 @@ $(TARGET)-syms: prelink.o xen.lds $(BASEDIR)/common/symbols-dummy.o
 	$(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).1.o
 	$(LD) $(LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
 	    $(@D)/.$(@F).1.o -o $@
+	$(NM) -pa --format=sysv $(@D)/$(@F) \
+		| $(BASEDIR)/tools/symbols --xensyms --sysv --sort \
+		>$(@D)/$(@F).map
 	rm -f $(@D)/.$(@F).[0-9]*
 
 asm-offsets.s: $(TARGET_SUBARCH)/asm-offsets.c

xen/arch/x86/Makefile

@@ -139,6 +139,9 @@ $(TARGET)-syms: prelink.o xen.lds $(BASEDIR)/common/symbols-dummy.o
 	$(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).1.o
 	$(LD) $(LDFLAGS) -T xen.lds -N prelink.o $(build_id_linker) \
 	    $(@D)/.$(@F).1.o -o $@
+	$(NM) -pa --format=sysv $(@D)/$(@F) \
+		| $(BASEDIR)/tools/symbols --xensyms --sysv --sort \
+		>$(@D)/$(@F).map
 	rm -f $(@D)/.$(@F).[0-9]*
 
 note.o: $(TARGET)-syms
@@ -189,7 +192,9 @@ $(TARGET).efi: prelink-efi.o $(note_file) efi.lds efi/relocs-dummy.o $(BASEDIR)/
 	$(guard) $(MAKE) -f $(BASEDIR)/Rules.mk $(@D)/.$(@F).1r.o $(@D)/.$(@F).1s.o
 	$(guard) $(LD) $(call EFI_LDFLAGS,$(VIRT_BASE)) -T efi.lds -N $< \
 	                $(@D)/.$(@F).1r.o $(@D)/.$(@F).1s.o $(note_file) -o $@
-	if $(guard) false; then rm -f $@; echo 'EFI support disabled'; fi
+	if $(guard) false; then rm -f $@; echo 'EFI support disabled'; \
+	else $(NM) -pa --format=sysv $(@D)/$(@F) \
+		| $(BASEDIR)/tools/symbols --xensyms --sysv --sort >$(@D)/$(@F).map; fi
 	rm -f $(@D)/.$(@F).[0-9]*
 
 efi/boot.init.o efi/runtime.o efi/compat.o efi/buildid.o: $(BASEDIR)/arch/x86/efi/built_in.o

xen/tools/symbols.c

@@ -52,6 +52,7 @@ static unsigned int table_size, table_cnt;
 static unsigned long long _stext, _etext, _sinittext, _einittext, _sextratext, _eextratext;
 static int all_symbols = 0;
 static int sort_by_name = 0;
+static int map_only = 0;
 static char symbol_prefix_char = '\0';
 static enum { fmt_bsd, fmt_sysv } input_format;
 static int compare_name(const void *p1, const void *p2);
@@ -181,7 +182,7 @@ static int read_symbol(FILE *in, struct sym_entry *s)
 		*sym++ = '#';
 	}
 	strcpy(sym, str);
-	if (sort_by_name) {
+	if (sort_by_name || map_only) {
 		s->orig_symbol = strdup(SYMBOL_NAME(s));
 		s->type = stype; /* As s->sym[0] ends mangled. */
 	}
@@ -307,6 +308,13 @@ static void write_src(void)
 	unsigned int *markers;
 	char buf[KSYM_NAME_LEN+1];
 
+	if (map_only) {
+		for (i = 0; i < table_cnt; i++)
+			printf("%#llx %c %s\n", table[i].addr, table[i].type,
+						table[i].orig_symbol);
+
+		return;
+	}
 	printf("#include <xen/config.h>\n");
 	printf("#include <asm/types.h>\n");
 	printf("#if BITS_PER_LONG == 64 && !defined(SYMBOLS_ORIGIN)\n");
@@ -609,6 +617,8 @@ int main(int argc, char **argv)
 				sort_by_name = 1;
 			else if (strcmp(argv[i], "--warn-dup") == 0)
 				warn_dup = true;
+			else if (strcmp(argv[i], "--xensyms") == 0)
+				map_only = true;
 			else
 				usage();
 		}