Re: Edited seccomp.2 man page for review [v2]

From: Kees Cook
Date: Mon Jan 05 2015 - 15:25:48 EST


On Tue, Dec 30, 2014 at 11:45 AM, Michael Kerrisk (man-pages)
<mtk.manpages@xxxxxxxxx> wrote:
>>> The program counter will be as though the system call happened
>>> (i.e., it will not point to the system call instruction).
>>> The return value register will contain an architecture\-dependent value;
>>> if resuming execution, set it to something sensible.
>>> .\" FIXME Regarding the preceding line, can you give an example(s)
>>> .\" of "something sensible"? (Depending on the answer, maybe it
>>> .\" might be useful to add some text on this point.)
>>
>> This means sensible in the context of the syscall made, or the desired
>> behavior. For example, setting the return value to ELOOP for something
>> like a "bind" syscall isn't very sensible.
>
> Okay -- I did s/sensible/appropriate for the system call/

Yes, perfect. That captures it nicely.

>>> .\"
>>> .\" FIXME Please check:
>>> .\" In an attempt to make the text clearer, I changed
>>> .\" "replacing it with" to "setting the return value register to"
>>> .\" Okay?
>>> (The architecture dependency is because setting the return value register to
>>> .BR ENOSYS
>>> could overwrite some useful information.)
>>
>> Well, the arch dependency is really because _how_ to change the
>> register, and the register itself, is different between architectures.
>> (i.e. which ptrace call is needed, and which register is being
>> changed.) The overwriting of useful information is certainly true too,
>> though.
>
> So, revert to the previous wording? Or do you have a suggested
> better wording?

I think the previous wording is better. I'm struggling to produce
language that makes more sense here.

> Thanks. We're getting close now.

Excellent! :)

-Kees

--
Kees Cook
Chrome OS Security
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/