objtool: print out the symbol type when complaining about it
authorLinus Torvalds <torvalds@linux-foundation.org>
Sun, 3 Oct 2021 20:45:48 +0000 (13:45 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sun, 3 Oct 2021 20:45:48 +0000 (13:45 -0700)
The objtool warning that the kvm instruction emulation code triggered
wasn't very useful:

    arch/x86/kvm/emulate.o: warning: objtool: __ex_table+0x4: don't know how to handle reloc symbol type: kvm_fastop_exception

in that it helpfully tells you which symbol name it had trouble figuring
out the relocation for, but it doesn't actually say what the unknown
symbol type was that triggered it all.

In this case it was because of missing type information (type 0, aka
STT_NOTYPE), but on the whole it really should just have printed that
out as part of the message.

Because if this warning triggers, that's very much the first thing you
want to know - why did reloc2sec_off() return failure for that symbol?

So rather than just saying you can't handle some type of symbol without
saying what the type _was_, just print out the type number too.

Fixes: 24ff65257375 ("objtool: Teach get_alt_entry() about more relocation types")
Link: https://lore.kernel.org/lkml/CAHk-=wiZwq-0LknKhXN4M+T8jbxn_2i9mcKpO+OaBSSq_Eh7tg@mail.gmail.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
tools/objtool/special.c

index f58ecc5..f1428e3 100644 (file)
@@ -110,8 +110,10 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
                return -1;
        }
        if (!reloc2sec_off(orig_reloc, &alt->orig_sec, &alt->orig_off)) {
-               WARN_FUNC("don't know how to handle reloc symbol type: %s",
-                          sec, offset + entry->orig, orig_reloc->sym->name);
+               WARN_FUNC("don't know how to handle reloc symbol type %d: %s",
+                          sec, offset + entry->orig,
+                          orig_reloc->sym->type,
+                          orig_reloc->sym->name);
                return -1;
        }
 
@@ -132,8 +134,10 @@ static int get_alt_entry(struct elf *elf, struct special_entry *entry,
                        return 1;
 
                if (!reloc2sec_off(new_reloc, &alt->new_sec, &alt->new_off)) {
-                       WARN_FUNC("don't know how to handle reloc symbol type: %s",
-                                 sec, offset + entry->new, new_reloc->sym->name);
+                       WARN_FUNC("don't know how to handle reloc symbol type %d: %s",
+                                 sec, offset + entry->new,
+                                 new_reloc->sym->type,
+                                 new_reloc->sym->name);
                        return -1;
                }