[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date: Fri, 13 Oct 2017 20:03:59 +0300
From: Alexander Popov <alex.popov@...ux.com>
To: Ingo Molnar <mingo@...nel.org>
Cc: kernel-hardening@...ts.openwall.com, keescook@...omium.org,
pageexec@...email.hu, spender@...ecurity.net, tycho@...ker.com,
Laura Abbott <labbott@...hat.com>, Mark Rutland <mark.rutland@....com>,
Ard Biesheuvel <ard.biesheuvel@...aro.org>,
Andy Lutomirski <luto@...capital.net>, x86@...nel.org,
Linus Torvalds <torvalds@...ux-foundation.org>,
Andy Lutomirski <luto@...nel.org>, Borislav Petkov <bp@...en8.de>,
Thomas Gleixner <tglx@...utronix.de>, "H. Peter Anvin" <hpa@...or.com>,
Peter Zijlstra <a.p.zijlstra@...llo.nl>
Subject: Re: [PATCH RFC v4 1/3] gcc-plugins: Add STACKLEAK erasing the kernel
stack at the end of syscalls
Hello Ingo,
On 05.10.2017 10:27, Ingo Molnar wrote:
> - The GCC plugin adds instrumentation in form of extra 'track_stack()' and
> 'check_alloca()' calls. Could you please provide a frequency analysis of the
> impact of this: x86-64 defconfig vmlinux size before/after the patch, and the
> number of instrumentation function calls inserted, compared to the number of
> functions?
Size of vmlinux (x86_64_defconfig):
file size:
- STACKLEAK disabled: 35014784 bytes
- STACKLEAK enabled: 35044952 bytes (+0.086%)
.text section size (calculated by size utility):
- STACKLEAK disabled: 10752983
- STACKLEAK enabled: 11062221 (+2.876%)
The readelf utility shows 45602 functions in vmlinux.
The STACKLEAK gcc plugin inserted 36 check_alloca() calls and 1265 track_stack()
calls (42274 calls are inserted during GIMPLE pass and 41009 calls are deleted
during RTL pass). So 2.853% of functions are instrumented.
I will add this information to the cover letter of the 5'th version, which I'm
currently preparing.
Best regards,
Alexander
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
