linux-kernel - Re: [PATCH 0/2] sys_write() should write all valid data

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 14 May 2009 20:48:18 +0200
From:	Vitaly Mayatskikh <v.mayatskih@...il.com>
To:	Josef Bacik <josef@...hat.com>
Cc:	Vitaly Mayatskikh <v.mayatskih@...il.com>, sandeen@...hat.com,
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 0/2] sys_write() should write all valid data

At Thu, 14 May 2009 14:02:34 -0400, Josef Bacik wrote:

> Ok all in all I don't think this is a good way to handle this problem.
> Hopefully somebody smarter than I will speak up, but what you are trying to do
> here is have your cake and eat it too.  You want to get the size of what we were
> able to fault in and return that, which should be a size_t,

btw, fault_in_pages_readable() has argument `size' of type int...

> but you also want to
> throw back an error if something happened, which needs a signed value.  I think
> the best way to handle this would be to make check_readable_bytes return size_t,
> and then if you get an EFAULT back, have it return 0.  Then the caller can say
> "hey I couldn't fault anything in, let me make what I want to fault in smaller",
> and then if that fault returns 0 we can exit.

Won't it be suboptimal to trap in the same place twice?

> I hope thats helpful/correct :).

-- 
wbr, Vitaly
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/