From: David Laight <David.Laight@ACULAB.COM>
To: 'Geert Uytterhoeven' <geert@linux-m68k.org>
Cc: Kees Cook <keescook@chromium.org>,
linux-m68k <linux-m68k@lists.linux-m68k.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
"linux-hardening@vger.kernel.org"
<linux-hardening@vger.kernel.org>
Subject: RE: [PATCH] m68k: Implement "current_stack_pointer"
Date: Thu, 24 Feb 2022 09:54:04 +0000 [thread overview]
Message-ID: <95b9c3e8227a4892b26cc0384d1782c2@AcuMS.aculab.com> (raw)
In-Reply-To: <CAMuHMdWtQ+B-01ZOwZNvgQ7pndNsP3V90_jHdR=RS4K7O3Vk9g@mail.gmail.com>
From: Geert Uytterhoeven <geert@linux-m68k.org>
> Sent: 24 February 2022 09:17
>
> On Thu, Feb 24, 2022 at 10:12 AM David Laight <David.Laight@aculab.com> wrote:
> > From: Geert Uytterhoeven
> > > Sent: 24 February 2022 08:59
> > ...
> > > > +register unsigned long current_stack_pointer __asm__("sp");
> > >
> > > I don't know what HARDENED_USERCOPY does, so I don't know if you need
> > > "usp" (see rdusp()) or "sp"?
> >
> > HARDENED_USERCOPY significantly slows down some systems calls
> > (especially things like sendmsg()) by trying to run-time verify
> > that the kernel buffer doesn't overrun a stack frame or kmalloc()ed
>
> Kernel stack frame of user stack frame?
Kernel, the kernel doesn't care if the user stack gets trashed.
David
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Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2022-02-24 9:54 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-24 6:04 [PATCH] m68k: Implement "current_stack_pointer" Kees Cook
2022-02-24 8:59 ` Geert Uytterhoeven
2022-02-24 9:12 ` David Laight
2022-02-24 9:16 ` Geert Uytterhoeven
2022-02-24 9:54 ` David Laight [this message]
2022-02-24 9:56 ` Geert Uytterhoeven
2022-02-25 17:37 ` Kees Cook
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