Subject: Re: [PATCH v17 0/9] Compile-time stack metadata validation

From: Ingo Molnar <[email-masked]>
Date: Thu, 25 Feb 2016 09:02:04 +0100

* Josh Poimboeuf <[email-masked]> wrote:

> This is v17 of the compile-time stack metadata validation patch set.
> 
> It's based on tip:x86/debug.  However, note that when run against that
> branch it will give a lot of warnings:
> 
>   objtool: arch/x86/ia32/sys_ia32.o: __ex_table size not a multiple of 12
>   objtool: arch/x86/ia32/ia32_signal.o: __ex_table size not a multiple of 12
>   objtool: arch/x86/entry/common.o: __ex_table size not a multiple of 12
>   ...
> 
> These warnings means that objtool is expecting the new exception table
> format which was introduced with:
> 
>   548acf19234d ("x86/mm: Expand the exception table logic to allow new handling options")
> 
> So that commit is needed for those warnings to go away.

Ok. I have created a new topic branch for the objtool commits: tip:core/objtool, 
and merged tip:ras/core into it (which hosts 548acf19234d).

So please use tip:core/objtool as a base from now on.

Two more minor observations:

Please re-order the patches slightly so that the annotations are added first, and 
objtool is added and Kconfig-enabled in the final patches.

>   x86/objtool: Compile-time stack metadata validation
>   x86/objtool: Add CONFIG_STACK_VALIDATION option
>   x86/objtool: Enable objtool on x86_64
>   x86/objtool: Add STACK_FRAME_NON_STANDARD macro
>   x86/objtool: Add directory and file whitelists

btw., please use the more generic 'objtool: ' prefix, the concept is not 
fundamentally x86 specific - especially once dwarf debuginfo is interpreted it 
will be useful beyond x86 as well I suspect.

>   x86/xen: Add xen_cpuid() to objtool whitelist
>   bpf: Add __bpf_prog_run() to objtool whitelist
>   sched: Add __schedule() to objtool whitelist
>   x86/kprobes: Add kretprobe_trampoline() to objtool whitelist

Thanks,

	Ingo