linux-kernel - Re: [PATCH 2/3] x86-64: Clean up vsyscall emulation and remove fixed-address ret

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:	Mon, 6 Jun 2011 13:45:52 -0400
From:	Andrew Lutomirski <luto@....edu>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	x86@...nel.org, pageexec@...email.hu,
	Mikael Pettersson <mikpe@...uu.se>,
	"H. Peter Anvin" <hpa@...or.com>, linux-kernel@...r.kernel.org,
	Linus Torvalds <torvalds@...ux-foundation.org>
Subject: Re: [PATCH 2/3] x86-64: Clean up vsyscall emulation and remove
 fixed-address ret

On Mon, Jun 6, 2011 at 1:41 PM, Ingo Molnar <mingo@...e.hu> wrote:
>
> * Andy Lutomirski <luto@....EDU> wrote:
>
>> Remove the fixed-address ret in the vsyscall emulation stubs.  As a
>> result, int 0xcc no longer works if executed from user address space
>> (which is OK -- nothing sensible should do that).
>>
>> Removing support for int 0xcc in user address space cleans up the
>> code considerably.
>>
>> Signed-off-by: Andy Lutomirski <luto@....edu>
>> ---
>>  arch/x86/include/asm/vsyscall.h   |   10 ++++-
>>  arch/x86/kernel/vsyscall_64.c     |   78 +++++++++++--------------------------
>>  arch/x86/kernel/vsyscall_emu_64.S |   17 +--------
>>  3 files changed, 32 insertions(+), 73 deletions(-)
>
> Ok, this makes the whole series a lot more palatable!
>
> Can i propagate the rename suggested by hpa into patch #3:
>
>  CONFIG_COMPAT_VSYSCALL => CONFIG_LEGACY_VSYSCALL

Certainly!  CONFIG_LEGACY_VTIME might be even better, but I'm fine
with any renaming you'd like to do.

--Andy

>
> ? 'legacy' is probably the best name for this and it thus won't be
> confused with the 32-bit compat facilities we have.
>
> Thanks,
>
>        Ingo
>
--
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/