Date: Tue, 4 Nov 2014 06:22:56 -0800 From: Alfred Perlstein <bright@mu.org> To: Konstantin Belousov <kostikbel@gmail.com> Cc: "svn-src-head@freebsd.org" <svn-src-head@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, Alfred Perlstein <alfred@freebsd.org>, "src-committers@freebsd.org" <src-committers@freebsd.org>, Mateusz Guzik <mjg@FreeBSD.org> Subject: Re: svn commit: r274017 - head/sys/kern Message-ID: <88CC9FA2-D677-484A-8D6B-9DA66D8479AE@mu.org> In-Reply-To: <20141104092558.GP53947@kib.kiev.ua> References: <201411030746.sA37kpPu037113@svn.freebsd.org> <5457F771.3010509@freebsd.org> <20141104092558.GP53947@kib.kiev.ua>
next in thread | previous in thread | raw e-mail | index | archive | help
> On Nov 4, 2014, at 1:25 AM, Konstantin Belousov <kostikbel@gmail.com> wrot= e: >=20 >> On Mon, Nov 03, 2014 at 01:45:21PM -0800, Alfred Perlstein wrote: >> Isn't there a problem where the stack can be swapped out? >>=20 >> I seem to recall a problem where a swapped out process was causing=20 >> problems due to a buffer passed being stack allocated and that process=20= >> being swapped out... >>=20 >> If this is not the case then please disregard. >=20 > Sure, stack can be swapped out, but buffer passing is usually not a proble= m. > At least, I am not aware of cases. >=20 > In fact, many compat layers do exactly this, allocate the native-ABI > structure on the stack, copyin the foreighn-ABI structure in pieces > into the native-ABI one, and pass native to kern_foo() implementations. >=20 > So I think you worries are not realized. >=20 Ok then as long as system will not pass this buffer as Dma target down to dr= iver we are ok. =20=
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?88CC9FA2-D677-484A-8D6B-9DA66D8479AE>