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 <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20200416115119.525037514@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 0d9f9cfc27be5f8159150b5fd46be74945ccbe9b..f2a84271e8073930ba098f1e54419efb6ead5f6f 100644 (file)
--- a/tools/objtool/check.c
+++ b/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;
 }