objtool: Make static call annotation optional

As part of making objtool more modular, put the existing static call
code behind a new '--static-call' option.

Signed-off-by: Josh Poimboeuf <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Miroslav Benes <[email protected]>
Link: https://lkml.kernel.org/r/d59ac57ef3d6d8380cdce20322314c9e2e556750.1650300597.git.jpoimboe@redhat.com

Author: jpoimboe

scripts/Makefile.build

@@ -233,6 +233,7 @@ objtool_args =								\
 	$(if $(CONFIG_RETPOLINE), --retpoline)				\
 	$(if $(CONFIG_SLS), --sls)					\
 	$(if $(CONFIG_STACK_VALIDATION), --stackval)			\
+	$(if $(CONFIG_HAVE_STATIC_CALL_INLINE), --static-call)		\
 	$(if $(CONFIG_X86_SMAP), --uaccess)				\
 	$(if $(part-of-module), --module)				\
 	$(if $(CONFIG_GCOV_KERNEL), --no-unreachable)

scripts/link-vmlinux.sh

@@ -141,11 +141,14 @@ objtool_link()
 			objtoolopt="${objtoolopt} --stackval"
 		fi
 
+		if is_enabled CONFIG_HAVE_STATIC_CALL_INLINE; then
+			objtoolopt="${objtoolopt} --static-call"
+		fi
+
 		if is_enabled CONFIG_X86_SMAP; then
 			objtoolopt="${objtoolopt} --uaccess"
 		fi
 
-
 		objtoolopt="${objtoolopt} --lto"
 	fi
 

tools/objtool/builtin-check.c

@@ -40,6 +40,7 @@ const struct option check_options[] = {
 	OPT_BOOLEAN('r', "retpoline", &opts.retpoline, "validate and annotate retpoline usage"),
 	OPT_BOOLEAN('l', "sls", &opts.sls, "validate straight-line-speculation mitigations"),
 	OPT_BOOLEAN('s', "stackval", &opts.stackval, "validate frame pointer rules"),
+	OPT_BOOLEAN('t', "static-call", &opts.static_call, "annotate static calls"),
 	OPT_BOOLEAN('u', "uaccess", &opts.uaccess, "validate uaccess rules for SMAP"),
 	OPT_CALLBACK_OPTARG(0, "dump", NULL, NULL, "orc", "dump metadata", parse_dump),
 
@@ -93,6 +94,7 @@ static bool opts_valid(void)
 	    opts.retpoline	||
 	    opts.sls		||
 	    opts.stackval	||
+	    opts.static_call	||
 	    opts.uaccess) {
 		if (opts.dump_orc) {
 			fprintf(stderr, "--dump can't be combined with other options\n");

tools/objtool/check.c

@@ -3969,10 +3969,12 @@ int check(struct objtool_file *file)
 		warnings += ret;
 	}
 
-	ret = create_static_call_sections(file);
-	if (ret < 0)
-		goto out;
-	warnings += ret;
+	if (opts.static_call) {
+		ret = create_static_call_sections(file);
+		if (ret < 0)
+			goto out;
+		warnings += ret;
+	}
 
 	if (opts.retpoline) {
 		ret = create_retpoline_sites_sections(file);

tools/objtool/include/objtool/builtin.h

@@ -19,6 +19,7 @@ struct opts {
 	bool retpoline;
 	bool sls;
 	bool stackval;
+	bool static_call;
 	bool uaccess;
 
 	/* options: */