[RFC PATCH v6 05/12] modpost: Integrate klp-convert
From: Joe Lawrence
Date: Wed Feb 16 2022 - 11:41:05 EST
From: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Create cmd_klp_convert and hook it into scripts/Makefile.modpost.
cmd_klp_convert invokes klp-convert with the right arguments for the
conversion of unresolved symbols inside a livepatch.
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>
Signed-off-by: Miroslav Benes <mbenes@xxxxxxx>
Signed-off-by: Joao Moreira <jmoreira@xxxxxxx>
Signed-off-by: Joe Lawrence <joe.lawrence@xxxxxxxxxx>
---
.gitignore | 1 +
Makefile | 18 ++----------------
scripts/Makefile.modfinal | 38 +++++++++++++++++++++++++++++++++++++-
scripts/Makefile.modpost | 5 +++++
scripts/mod/modpost.c | 28 ++++++++++++++++++++++++++--
scripts/mod/modpost.h | 1 +
6 files changed, 72 insertions(+), 19 deletions(-)
diff --git a/.gitignore b/.gitignore
index 50638a15a527..eb0179d00260 100644
--- a/.gitignore
+++ b/.gitignore
@@ -48,6 +48,7 @@
*.xz
*.zst
Module.symvers
+modules.livepatch
modules.order
#
diff --git a/Makefile b/Makefile
index 64ec4bc8172c..31d5b6f608d9 100644
--- a/Makefile
+++ b/Makefile
@@ -1089,6 +1089,7 @@ PHONY += prepare0
export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/)
export MODORDER := $(extmod_prefix)modules.order
export MODULES_NSDEPS := $(extmod_prefix)modules.nsdeps
+export MODULES_LIVEPATCH := $(extmod-prefix)modules.livepatch
ifeq ($(KBUILD_EXTMOD),)
core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/
@@ -1485,7 +1486,7 @@ endif # CONFIG_MODULES
# Directories & files removed with 'make clean'
CLEAN_FILES += include/ksym vmlinux.symvers modules-only.symvers \
modules.builtin modules.builtin.modinfo modules.nsdeps \
- compile_commands.json .thinlto-cache
+ compile_commands.json .thinlto-cache modules.livepatch
# Directories & files removed with 'make mrproper'
MRPROPER_FILES += include/config include/generated \
@@ -1747,22 +1748,7 @@ PHONY += modules modules_install
ifdef CONFIG_MODULES
-quiet_cmd_klp_map = KLP symbols.klp
-
-define cmd_klp_map
- $(shell echo "klp-convert-symbol-data.0.1" > $(objtree)/symbols.klp) \
- $(shell echo "*vmlinux" >> $(objtree)/symbols.klp) \
- $(shell nm -f posix $(objtree)/vmlinux | cut -d\ -f1 >> $(objtree)/symbols.klp) \
- $(foreach ko, $(sort $(shell cat modules.order)), \
- $(eval mod = $(patsubst %.ko,%.mod,$(ko))) \
- $(eval obj = $(patsubst %.ko,%.o,$(ko))) \
- $(if $(shell grep -o LIVEPATCH $(mod)),, \
- $(shell echo "*$(shell basename -s .ko $(ko))" >> $(objtree)/symbols.klp) \
- $(shell nm -f posix $(obj) | cut -d\ -f1 >> $(objtree)/symbols.klp)))
-endef
-
modules: modules_check
- $(if $(CONFIG_LIVEPATCH), $(call cmd,klp_map))
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
PHONY += modules_check
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 7f39599e9fae..cb31262436ba 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -14,6 +14,8 @@ include $(srctree)/scripts/Makefile.lib
# find all modules listed in modules.order
modules := $(sort $(shell cat $(MODORDER)))
+modules-klp := $(sort $(shell cat $(MODULES_LIVEPATCH)))
+modules-no-klp := $(filter-out $(modules-klp), $(modules))
__modfinal: $(modules)
@:
@@ -56,7 +58,7 @@ if_changed_except = $(if $(call newer_prereqs_except,$(2))$(cmd-check), \
# Re-generate module BTFs if either module's .ko or vmlinux changed
-$(modules): %.ko: %$(mod-prelink-ext).o %.mod.o scripts/module.lds $(if $(KBUILD_BUILTIN),vmlinux) FORCE
+$(modules-no-klp): %.ko: %$(mod-prelink-ext).o %.mod.o scripts/module.lds $(if $(KBUILD_BUILTIN),vmlinux) FORCE
+$(call if_changed_except,ld_ko_o,vmlinux)
ifdef CONFIG_DEBUG_INFO_BTF_MODULES
+$(if $(newer-prereqs),$(call cmd,btf_ko))
@@ -64,6 +66,40 @@ endif
targets += $(modules) $(modules:.ko=.mod.o)
+# Live Patch
+# ---------------------------------------------------------------------------
+
+%.tmp.ko: %.o %.mod.o symbols.klp FORCE
+ +$(call if_changed,ld_ko_o)
+
+quiet_cmd_klp_convert = KLP $@
+ cmd_klp_convert = scripts/livepatch/klp-convert symbols.klp $< $@
+
+$(modules-klp): %.ko: %.tmp.ko FORCE
+ $(call if_changed,klp_convert)
+
+targets += $(modules-klp:.ko=.tmp.ko)
+
+ifeq ($(KBUILD_EXTMOD),)
+# Read out modules.{order,livepatch} instead of expanding $(modules-no-klp).
+# Otherwise, allmodconfig would fail with "Argument list too long".
+filechk_klp_map = \
+ echo "klp-convert-symbol-data.0.1"; \
+ echo "*vmlinux"; \
+ $(NM) -f posix vmlinux | cut -d\ -f1; \
+ sort $(MODORDER) $(MODULES_LIVEPATCH) | \
+ uniq -u | \
+ sed 's/\.ko$$//' | \
+ while read o; \
+ do \
+ echo "*$$(basename $$o)"; \
+ $(NM) -f posix $$o.o | cut -d\ -f1; \
+ done
+
+symbols.klp: FORCE
+ $(call filechk,klp_map)
+endif
+
# Add FORCE to the prequisites of a target to force it to be always rebuilt.
# ---------------------------------------------------------------------------
diff --git a/scripts/Makefile.modpost b/scripts/Makefile.modpost
index 48585c4d04ad..c5df629de7b2 100644
--- a/scripts/Makefile.modpost
+++ b/scripts/Makefile.modpost
@@ -48,6 +48,7 @@ MODPOST = scripts/mod/modpost \
$(if $(CONFIG_MODVERSIONS),-m) \
$(if $(CONFIG_MODULE_SRCVERSION_ALL),-a) \
$(if $(CONFIG_SECTION_MISMATCH_WARN_ONLY),,-E) \
+ $(if $(CONFIG_LIVEPATCH),-l $(MODULES_LIVEPATCH)) \
-o $@
ifdef MODPOST_VMLINUX
@@ -136,6 +137,10 @@ $(output-symdump): $(MODORDER) $(input-symdump) $(modules:.ko=$(mod-prelink-ext)
targets += $(output-symdump)
__modpost: $(output-symdump)
+ifndef CONFIG_LIVEPATCH
+ $(Q)rm -f $(MODULES_LIVEPATCH)
+ $(Q)touch $(MODULES_LIVEPATCH)
+endif
ifneq ($(KBUILD_MODPOST_NOFINAL),1)
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modfinal
endif
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 6bfa33217914..1034b673c95c 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2051,6 +2051,10 @@ static void read_symbols(const char *modname)
handle_moddevtable(mod, &info, sym, symname);
}
+ /* Livepatch modules have unresolved symbols resolved by klp-convert */
+ if (get_modinfo(&info, "livepatch"))
+ mod->livepatch = 1;
+
for (sym = info.symtab_start; sym < info.symtab_stop; sym++) {
symname = remove_dot(info.strtab + sym->st_name);
@@ -2170,7 +2174,7 @@ static void check_exports(struct module *mod)
const char *basename;
exp = find_symbol(s->name);
if (!exp || exp->module == mod) {
- if (!s->weak && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
+ if (!s->weak && !mod->livepatch && nr_unresolved++ < MAX_UNRESOLVED_REPORTS)
modpost_log(warn_unresolved ? LOG_WARN : LOG_ERROR,
"\"%s\" [%s.ko] undefined!\n",
s->name, mod->name);
@@ -2502,6 +2506,20 @@ static void write_namespace_deps_files(const char *fname)
free(ns_deps_buf.p);
}
+static void write_livepatch_modules(const char *fname)
+{
+ struct buffer buf = { };
+ struct module *mod;
+
+ for (mod = modules; mod; mod = mod->next) {
+ if (mod->livepatch)
+ buf_printf(&buf, "%s.ko\n", mod->name);
+ }
+
+ write_if_changed(&buf, fname);
+ free(buf.p);
+}
+
struct dump_list {
struct dump_list *next;
const char *file;
@@ -2513,12 +2531,13 @@ int main(int argc, char **argv)
struct buffer buf = { };
char *missing_namespace_deps = NULL;
char *dump_write = NULL, *files_source = NULL;
+ char *livepatch_modules = NULL;
int opt;
int n;
struct dump_list *dump_read_start = NULL;
struct dump_list **dump_read_iter = &dump_read_start;
- while ((opt = getopt(argc, argv, "ei:mnT:o:awENd:")) != -1) {
+ while ((opt = getopt(argc, argv, "ei:l:mnT:o:awENd:")) != -1) {
switch (opt) {
case 'e':
external_module = 1;
@@ -2529,6 +2548,9 @@ int main(int argc, char **argv)
(*dump_read_iter)->file = optarg;
dump_read_iter = &(*dump_read_iter)->next;
break;
+ case 'l':
+ livepatch_modules = optarg;
+ break;
case 'm':
modversions = 1;
break;
@@ -2605,6 +2627,8 @@ int main(int argc, char **argv)
if (dump_write)
write_dump(dump_write);
+ if (livepatch_modules)
+ write_livepatch_modules(livepatch_modules);
if (sec_mismatch_count && !sec_mismatch_warn_only)
error("Section mismatches detected.\n"
"Set CONFIG_SECTION_MISMATCH_WARN_ONLY=y to allow them.\n");
diff --git a/scripts/mod/modpost.h b/scripts/mod/modpost.h
index 0c47ff95c0e2..8c7e7e546158 100644
--- a/scripts/mod/modpost.h
+++ b/scripts/mod/modpost.h
@@ -123,6 +123,7 @@ struct module {
int seen;
int has_init;
int has_cleanup;
+ int livepatch;
struct buffer dev_table_buf;
char srcversion[25];
// Missing namespace dependencies
--
2.26.3