On Wed, Mar 01, 2017 at 04:21:36PM +0100, Arnd Bergmann wrote:
> On Wed, Mar 1, 2017 at 3:31 PM, Josh Poimboeuf <jpoim...@redhat.com> wrote:
> > On Wed, Mar 01, 2017 at 10:34:42AM +0100, Arnd Bergmann wrote:
> >> On Tue, Oct 11, 2016 at 10:38 PM, Arnd Bergmann <a...@arndb.de> wrote:
> >> > On Tuesday, October 11, 2016 10:51:46 AM CEST Josh Poimboeuf wrote:
> >> >>
> >> >> 3) 0xFC244C03-config:
> >> >> drivers/scsi/fnic/fnic_main.o: warning: objtool: fnic_log_q_error()
> >> >> falls through to next function fnic_handle_link_event()
> >> >> drivers/scsi/snic/snic_res.o: warning: objtool: .text: unexpected end
> >> >> of section
> >> >>
> >> >> These look like another bad gcc bug which is truncating functions:
> >> >
> >> > Same bug for both of them?
> >>
> >> I ran into this one again today, after updating to the latest gcc-7.0.1:
> >>
> >> drivers/infiniband/sw/rxe/rxe_resp.o: warning: objtool:
> >> rxe_responder()+0xfe: sibling call from callable instruction with
> >> changed frame pointer
> >>
> >> Josh, did you get around to updating objtool the last time I reported it,
> >> or
> >> is it still the same problem? If this is a new variation, I can provide
> >> more
> >> details about the failure, otherwise I'll just ignore it for now.
> >
> > This one should have been fixed with:
> >
> > 3732710ff6f2 ("objtool: Improve rare switch jump table pattern detection")
>
> It was on the current linux-next, so that commit should certainly be included.
>
> > Can you attach the object file?
Here's the preliminary fix for this one (still needs more testing):
diff --git a/tools/objtool/builtin-check.c b/tools/objtool/builtin-check.c
index bd12eb1..7b718bb 100644
--- a/tools/objtool/builtin-check.c
+++ b/tools/objtool/builtin-check.c
@@ -806,11 +806,20 @@ static struct rela *find_switch_table(struct objtool_file
*file,
insn->jump_dest->offset > orig_insn->offset))
break;
+ /* look for a rela which references .rodata */
text_rela = find_rela_by_dest_range(insn->sec, insn->offset,
insn->len);
- if (text_rela && text_rela->sym == file->rodata->sym)
- return find_rela_by_dest(file->rodata,
- text_rela->addend);
+ if (!text_rela || text_rela->sym != file->rodata->sym)
+ continue;
+
+ /*
+ * Make sure the .rodata address isn't associated with a
+ * symbol. gcc jump tables are anonymous data.
+ */
+ if (find_symbol_containing(file->rodata, text_rela->addend))
+ continue;
+
+ return find_rela_by_dest(file->rodata, text_rela->addend);
}
return NULL;
diff --git a/tools/objtool/elf.c b/tools/objtool/elf.c
index 0d7983a..d897702 100644
--- a/tools/objtool/elf.c
+++ b/tools/objtool/elf.c
@@ -85,6 +85,18 @@ struct symbol *find_symbol_by_offset(struct section *sec,
unsigned long offset)
return NULL;
}
+struct symbol *find_symbol_containing(struct section *sec, unsigned long
offset)
+{
+ struct symbol *sym;
+
+ list_for_each_entry(sym, &sec->symbol_list, list)
+ if (sym->type != STT_SECTION &&
+ offset >= sym->offset && offset < sym->offset + sym->len)
+ return sym;
+
+ return NULL;
+}
+
struct rela *find_rela_by_dest_range(struct section *sec, unsigned long offset,
unsigned int len)
{
diff --git a/tools/objtool/elf.h b/tools/objtool/elf.h
index aa1ff65..731973e 100644
--- a/tools/objtool/elf.h
+++ b/tools/objtool/elf.h
@@ -79,6 +79,7 @@ struct elf {
struct elf *elf_open(const char *name);
struct section *find_section_by_name(struct elf *elf, const char *name);
struct symbol *find_symbol_by_offset(struct section *sec, unsigned long
offset);
+struct symbol *find_symbol_containing(struct section *sec, unsigned long
offset);
struct rela *find_rela_by_dest(struct section *sec, unsigned long offset);
struct rela *find_rela_by_dest_range(struct section *sec, unsigned long offset,
unsigned int len);
