objtool: Clean instruction state before each function validation

When a function fails its validation, it might leave a stale state
that will be used for the validation of other functions. That would
cause false warnings on potentially valid functions.

Reset the instruction state before the validation of each individual
function.
Signed-off-by: Julien Thierry <jthierry@redhat.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

tools/objtool/check.c

@@ -2411,13 +2411,6 @@ static int validate_section(struct objtool_file *file, struct section *sec)
 	struct insn_state state;
 	int ret, warnings = 0;
 
-	clear_insn_state(&state);
-
-	state.cfa = initial_func_cfi.cfa;
-	memcpy(&state.regs, &initial_func_cfi.regs,
-	       CFI_NUM_REGS * sizeof(struct cfi_reg));
-	state.stack_size = initial_func_cfi.cfa.offset;
-
 	list_for_each_entry(func, &sec->symbol_list, list) {
 		if (func->type != STT_FUNC)
 			continue;
@@ -2435,6 +2428,12 @@ static int validate_section(struct objtool_file *file, struct section *sec)
 		if (!insn || insn->ignore || insn->visited)
 			continue;
 
+		clear_insn_state(&state);
+		state.cfa = initial_func_cfi.cfa;
+		memcpy(&state.regs, &initial_func_cfi.regs,
+		       CFI_NUM_REGS * sizeof(struct cfi_reg));
+		state.stack_size = initial_func_cfi.cfa.offset;
+
 		state.uaccess = func->uaccess_safe;
 
 		ret = validate_branch(file, func, insn, state);