objtool: Fix function fallthrough detection for vmlinux

Objtool's function fallthrough detection only works on C objects.
The distinction between C and assembly objects no longer makes sense
with objtool running on vmlinux.o.

Now that copy_user_64.S has been fixed up, and an objtool sibling call
detection bug has been fixed, the asm code is in "compliance" and this
hack is no longer needed.  Remove it.

Fixes: ed53a0d97192 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/b434cff98eca3a60dcc64c620d7d5d405a0f441c.1649718562.git.jpoimboe@redhat.com

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 0f5d3de..5f10653 100644 (file)
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -3310,7 +3310,7 @@ static int validate_branch(struct objtool_file *file, struct symbol *func,
        while (1) {
                next_insn = next_insn_to_validate(file, insn);
 
-               if (file->c_file && func && insn->func && func != insn->func->pfunc) {
+               if (func && insn->func && func != insn->func->pfunc) {
                        WARN("%s() falls through to next function %s()",
                             func->name, insn->func->name);
                        return 1;

diff --git a/tools/objtool/include/objtool/objtool.h b/tools/objtool/include/objtool/objtool.h
index 7a5c13a..a6e72d9 100644 (file)
--- a/tools/objtool/include/objtool/objtool.h
+++ b/tools/objtool/include/objtool/objtool.h
@@ -27,7 +27,7 @@ struct objtool_file {
        struct list_head static_call_list;
        struct list_head mcount_loc_list;
        struct list_head endbr_list;
-       bool ignore_unreachables, c_file, hints, rodata;
+       bool ignore_unreachables, hints, rodata;
 
        unsigned int nr_endbr;
        unsigned int nr_endbr_int;

diff --git a/tools/objtool/objtool.c b/tools/objtool/objtool.c
index b09946f..843ff3c 100644 (file)
--- a/tools/objtool/objtool.c
+++ b/tools/objtool/objtool.c
@@ -129,7 +129,6 @@ struct objtool_file *objtool_open_read(const char *_objname)
        INIT_LIST_HEAD(&file.static_call_list);
        INIT_LIST_HEAD(&file.mcount_loc_list);
        INIT_LIST_HEAD(&file.endbr_list);
-       file.c_file = !vmlinux && find_section_by_name(file.elf, ".comment");
        file.ignore_unreachables = no_unreachable;
        file.hints = false;