objtool: Remove --lto and --vmlinux in favor of --link

The '--lto' option is a confusing way of telling objtool to do stack
validation despite it being a linked object.  It's no longer needed now
that an explicit '--stackval' option exists.  The '--vmlinux' option is
also redundant.

Remove both options in favor of a straightforward '--link' option which
identifies a linked object.

Also, implicitly set '--link' with a warning if the user forgets to do
so and we can tell that it's a linked object.  This makes it easier for
manual vmlinux runs.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Link: https://lkml.kernel.org/r/dcd3ceffd15a54822c6183e5766d21ad06082b45.1650300597.git.jpoimboe@redhat.com

1 files changed, 14 insertions, 26 deletions

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 30b24dce48b5..2063f9fea1a2 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -263,7 +263,8 @@ static void init_cfi_state(struct cfi_state *cfi)
 	cfi->drap_offset = -1;
 }
 
-static void init_insn_state(struct insn_state *state, struct section *sec)
+static void init_insn_state(struct objtool_file *file, struct insn_state *state,
+			    struct section *sec)
 {
 	memset(state, 0, sizeof(*state));
 	init_cfi_state(&state->cfi);
@@ -273,7 +274,7 @@ static void init_insn_state(struct insn_state *state, struct section *sec)
 	 * not correctly determine insn->call_dest->sec (external symbols do
 	 * not have a section).
 	 */
-	if (opts.vmlinux && opts.noinstr && sec)
+	if (opts.link && opts.noinstr && sec)
 		state->noinstr = sec->noinstr;
 }
 
@@ -3405,7 +3406,7 @@ static int validate_unwind_hints(struct objtool_file *file, struct section *sec)
 	if (!file->hints)
 		return 0;
 
-	init_insn_state(&state, sec);
+	init_insn_state(file, &state, sec);
 
 	if (sec) {
 		insn = find_insn(file, sec, 0);
@@ -3491,14 +3492,14 @@ static bool ignore_unreachable_insn(struct objtool_file *file, struct instructio
 		return true;
 
 	/*
-	 * Whole archive runs might encounder dead code from weak symbols.
+	 * Whole archive runs might encounter dead code from weak symbols.
 	 * This is where the linker will have dropped the weak symbol in
 	 * favour of a regular symbol, but leaves the code in place.
 	 *
 	 * In this case we'll find a piece of code (whole function) that is not
 	 * covered by a !section symbol. Ignore them.
 	 */
-	if (!insn->func && opts.lto) {
+	if (opts.link && !insn->func) {
 		int size = find_symbol_hole_containing(insn->sec, insn->offset);
 		unsigned long end = insn->offset + size;
 
@@ -3620,7 +3621,7 @@ static int validate_section(struct objtool_file *file, struct section *sec)
 		if (func->type != STT_FUNC)
 			continue;
 
-		init_insn_state(&state, sec);
+		init_insn_state(file, &state, sec);
 		set_func_state(&state.cfi);
 
 		warnings += validate_symbol(file, sec, func, &state);
@@ -3629,7 +3630,7 @@ static int validate_section(struct objtool_file *file, struct section *sec)
 	return warnings;
 }
 
-static int validate_vmlinux_functions(struct objtool_file *file)
+static int validate_noinstr_sections(struct objtool_file *file)
 {
 	struct section *sec;
 	int warnings = 0;
@@ -3890,16 +3891,6 @@ int check(struct objtool_file *file)
 {
 	int ret, warnings = 0;
 
-	if (opts.lto && !(opts.vmlinux || opts.module)) {
-		fprintf(stderr, "--lto requires: --vmlinux or --module\n");
-		return 1;
-	}
-
-	if (opts.ibt && !opts.lto) {
-		fprintf(stderr, "--ibt requires: --lto\n");
-		return 1;
-	}
-
 	arch_initial_func_cfi_state(&initial_func_cfi);
 	init_cfi_state(&init_cfi);
 	init_cfi_state(&func_cfi);
@@ -3920,15 +3911,6 @@ int check(struct objtool_file *file)
 	if (list_empty(&file->insn_list))
 		goto out;
 
-	if (opts.vmlinux && !opts.lto) {
-		ret = validate_vmlinux_functions(file);
-		if (ret < 0)
-			goto out;
-
-		warnings += ret;
-		goto out;
-	}
-
 	if (opts.retpoline) {
 		ret = validate_retpoline(file);
 		if (ret < 0)
@@ -3953,6 +3935,12 @@ int check(struct objtool_file *file)
 				goto out;
 			warnings += ret;
 		}
+
+	} else if (opts.noinstr) {
+		ret = validate_noinstr_sections(file);
+		if (ret < 0)
+			goto out;
+		warnings += ret;
 	}
 
 	if (opts.ibt) {