objtool: Also consider .entry.text as noinstr

Consider all of .entry.text as noinstr. This gets us coverage across
the PTI boundary. While we could add everything .noinstr.text into
.entry.text that would bloat the amount of code in the user mapping.

Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Miroslav Benes <[email protected]>
Reviewed-by: Alexandre Chartre <[email protected]>
Acked-by: Josh Poimboeuf <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

Author: KAGA-KOKO

tools/objtool/check.c

@@ -266,7 +266,8 @@ static int decode_instructions(struct objtool_file *file)
 		    strncmp(sec->name, ".discard.", 9))
 			sec->text = true;
 
-		if (!strcmp(sec->name, ".noinstr.text"))
+		if (!strcmp(sec->name, ".noinstr.text") ||
+		    !strcmp(sec->name, ".entry.text"))
 			sec->noinstr = true;
 
 		for (offset = 0; offset < sec->len; offset += insn->len) {
@@ -2071,7 +2072,7 @@ static inline const char *call_dest_name(struct instruction *insn)
 static int validate_call(struct instruction *insn, struct insn_state *state)
 {
 	if (state->noinstr && state->instr <= 0 &&
-	    (!insn->call_dest || insn->call_dest->sec != insn->sec)) {
+	    (!insn->call_dest || !insn->call_dest->sec->noinstr)) {
 		WARN_FUNC("call to %s() leaves .noinstr.text section",
 				insn->sec, insn->offset, call_dest_name(insn));
 		return 1;
@@ -2558,11 +2559,16 @@ static int validate_vmlinux_functions(struct objtool_file *file)
 	int warnings = 0;
 
 	sec = find_section_by_name(file->elf, ".noinstr.text");
-	if (!sec)
-		return 0;
+	if (sec) {
+		warnings += validate_section(file, sec);
+		warnings += validate_unwind_hints(file, sec);
+	}
 
-	warnings += validate_section(file, sec);
-	warnings += validate_unwind_hints(file, sec);
+	sec = find_section_by_name(file->elf, ".entry.text");
+	if (sec) {
+		warnings += validate_section(file, sec);
+		warnings += validate_unwind_hints(file, sec);
+	}
 
 	return warnings;
 }