Re: [PATCH 2/2] Perform check in iov_iter_fault_in_readable() by check_readable_bytes()

From: Vitaly Mayatskikh
Date: Fri May 15 2009 - 07:57:10 EST


At Fri, 15 May 2009 11:38:38 +0200, Andi Kleen wrote:

> Is that really something that users rely on? It looks like a seriously
> broken user program. Which one is that? (just that I can avoid it :)

IIRC, it was first noticed in some sanity test from ltp suite ;)

I'm readiny POSIX spec for write() once again:

http://www.opengroup.org/onlinepubs/9699919799/functions/write.html

"The write() function shall attempt to write nbyte bytes from the
buffer pointed to by buf to the file associated with the open file
descriptor, fildes."

Well, "shall attempt"... It's not clear to me, is it enough just to
validate user's buffer and gave up with error, like we do now?

--
wbr, Vitaly
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