From: Ralf Baechle <ralf@uni-koblenz.de>
To: Petr Vandrovec <VANDROVE@vc.cvut.cz>
Cc: "Khachaturov, Vassilii" <Vassilii.Khachaturov@comverse.com>,
linux-kernel@vger.kernel.org
Subject: Re: uid_t and gid_t vs. __kernel_uid_t and __kernel_gid_t
Date: Wed, 16 May 2001 01:33:55 -0300 [thread overview]
Message-ID: <20010516013355.A1299@bacchus.dhis.org> (raw)
In-Reply-To: <2E927786773@vcnet.vc.cvut.cz>
In-Reply-To: <2E927786773@vcnet.vc.cvut.cz>; from VANDROVE@vc.cvut.cz on Mon, May 14, 2001 at 09:14:26PM +0000
On Mon, May 14, 2001 at 09:14:26PM +0000, Petr Vandrovec wrote:
> > I had to communicate uid/gid from an application down
> > to a driver, and discovered that uid and gid in user
> > space are different from those in kernel space.
>
> ncpfs uses 'unsigned long' in its ncp_mount_data_v4, as MIPS uses
> 'long' type for uid/gid. Unfortunately it still needs conversions
> on some archs, so maybe using u_int64_t is just best solution
> (AFAIK as MIPS unsigned long is 64bit, you have to use u_int64_t
> if you want same type accross architectures).
Only for the 64 bit ABI and kernel on MIPS have a long data type of 64 bits.
General rule for Linux sizeof(pointer) = sizeof(long).
> Kernel part then just checks wheter uid == (__kernel_uid_t)uid and
> gives up if they differ.
Otherwise funny ones line (u16) 65536 == 0 -> root access could happen ...
Ralf
next prev parent reply other threads:[~2001-05-17 19:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-05-14 21:14 Petr Vandrovec
2001-05-16 4:33 ` Ralf Baechle [this message]
-- strict thread matches above, loose matches on Subject: below --
2001-05-14 19:37 Khachaturov, Vassilii
2001-05-14 19:49 ` Chris Wing
2001-05-14 19:27 Chris Wing
2001-05-14 19:00 Khachaturov, Vassilii
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