Date: Wed, 17 Aug 2005 10:04:37 -0700 From: Nate Lawson <nate@root.org> To: Poul-Henning Kamp <phk@FreeBSD.org> Cc: cvs-src@FreeBSD.org, src-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/sys/fs/devfs devfs_vnops.c src/sys/kern kern_conf.c src/sys/sys conf.h Message-ID: <43036E25.6010508@root.org> In-Reply-To: <20050817082000.0B70016A437@hub.freebsd.org> References: <20050817082000.0B70016A437@hub.freebsd.org>
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Poul-Henning Kamp wrote:
> phk 2005-08-17 08:19:53 UTC
>
> FreeBSD src repository
>
> Modified files:
> sys/fs/devfs devfs_vnops.c
> sys/kern kern_conf.c
> sys/sys conf.h
> Log:
> Handle device drivers with D_NEEDGIANT in a way which does not
> penalize the 'good' drivers: Allocate a shadow cdevsw and populate
> it with wrapper functions which grab Giant
>
> Revision Changes Path
> 1.120 +0 -24 src/sys/fs/devfs/devfs_vnops.c
> 1.190 +155 -9 src/sys/kern/kern_conf.c
> 1.226 +1 -0 src/sys/sys/conf.h
>
>
> static void
> prep_cdevsw(struct cdevsw *devsw)
> {
> + struct cdevsw *dsw2;
>
> + if (devsw->d_flags & D_NEEDGIANT)
> + dsw2 = malloc(sizeof *dsw2, M_DEVT, M_WAITOK);
> + else
> + dsw2 = NULL;
> dev_lock();
>
> if (devsw->d_version != D_VERSION_01) {
Is it guaranteed that prep_cdevsw() won't be called twice without a call
to fini_cdevsw()? Otherwise, the shadow cdevsw could leak when its
pointer is set to NULL. I'm not familiar with this code, just asking.
--
Nate
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