Messages in this thread | | | Date | Wed, 25 Mar 2020 09:42:11 -0500 | From | Josh Poimboeuf <> | Subject | Re: [PATCH v3 26/26] objtool: Add STT_NOTYPE noinstr validation |
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On Tue, Mar 24, 2020 at 11:34:55PM +0100, Peter Zijlstra wrote: > On Tue, Mar 24, 2020 at 05:16:16PM -0500, Josh Poimboeuf wrote: > > On Tue, Mar 24, 2020 at 04:31:39PM +0100, Peter Zijlstra wrote: > > > > + if (state.noinstr) { > > > + /* > > > + * In vmlinux mode we will not run validate_unwind_hints() by > > > + * default which means we'll not otherwise visit STT_NOTYPE > > > + * symbols. > > > + * > > > + * In case of --duplicate mode, insn->visited will avoid actual > > > + * duplicate work being done. > > > + */ > > > + list_for_each_entry(func, &sec->symbol_list, list) { > > > + if (func->type != STT_NOTYPE) > > > + continue; > > > + > > > + warnings += validate_symbol(file, sec, func, &state); > > > + } > > > + } > > > + > > > > I guess this is ok, but is there a valid reason why we don't just call > > validate_unwind_hints()? > > > > It's also slightly concerning that validate_reachable_instructions() > > isn't called, I'm not 100% convinced all the code will get checked. > > This will only end up running on .noinstr.text, while > validate_unwind_hints() will run on *everything*. That is, we're > purposely not checking everything. > > It very much relies on the !vmlinux mode to do the unreachable things.
Sure, but couldn't validate_unwind_hints() and validate_reachable_instructions() be changed to *only* run on .noinstr.text, for the vmlinux case? That might help converge the vmlinux and !vmlinux paths.
-- Josh
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