linux-kernel - RE: [PATCH 1/3]: Staging: hv: Use native page allocation/free functions

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:	Fri, 11 Feb 2011 21:27:14 +0000
From:	Hank Janssen <hjanssen@...rosoft.com>
To:	KY Srinivasan <kys@...rosoft.com>, Greg KH <gregkh@...e.de>
CC:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"devel@...uxdriverproject.org" <devel@...uxdriverproject.org>,
	"virtualization@...ts.osdl.org" <virtualization@...ts.osdl.org>
Subject: RE: [PATCH 1/3]: Staging: hv: Use native page allocation/free
 functions



> -----Original Message-----
> And then KY Srinivasan spoke on Friday, February 11, 2011 12:56 PM
> > From: Greg KH [mailto:gregkh@...e.de]
> > Sent: Friday, February 11, 2011 1:30 PM
> > > -	virtaddr = osd_virtual_alloc_exec(PAGE_SIZE);
> > > +#ifdef __x86_64__
> > > +	virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL,
> PAGE_KERNEL_EXEC);
> > #else
> > > +	virtaddr =  __vmalloc(PAGE_SIZE, GFP_KERNEL,
> > > +			__pgprot(__PAGE_KERNEL & (~_PAGE_NX))); #endif
> >
> > I'm not saying this patch is wrong at all, but I still don't
> > understand why this is different depending on the architecture of the
> > machine.  Why is this necessary, it should be ok to do the same type
> > of allocation no matter what the processor is, right?
> 
> You are right Greg; I don't think there is a need to specify different page
> protection bits based on the architecture - PAGE_KERNEL_EXEC should be
> enough.
> However, this is the code that is currently in the tree - refer to osd.c.
> If it is ok with you, I could submit an additional patch to clean this up.
> 

I seem to recall that we did it for very old versions of Linux (pre 2.6.18)
But I cannot for the life of me remember why.

Hank.

--
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/