Skip site navigation (1)Skip section navigation (2)
Date:      Thu, 4 Jan 2018 19:23:56 +0100
From:      "Klaus P. Ohrhallinger" <k@7he.at>
To:        freebsd-current@freebsd.org
Subject:   Re: Intel CPU design flaw - FreeBSD affected? // disabling LDTSC
Message-ID:  <18376c97-3c0d-49c8-9483-96b95a84f3f1@7he.at>
In-Reply-To: <9dda0496-be16-35c6-6c45-63d03b218ccb@protected-networks.net>
References:  <9dda0496-be16-35c6-6c45-63d03b218ccb@protected-networks.net>

next in thread | previous in thread | raw e-mail | index | archive | help
This is a multi-part message in MIME format.
--------------80572298F8A81184E6F60AC9
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit

Hello,

I disabled the ldtsc and ldtscp instructions for usermode on one of my
production servers:

% ./spectre
Reading 40 bytes:
Bus error (core dumped)

All PoC code I have seen today relies on those instructions.
Is there any other way to measure the memory/cache access times ?

On 10.4-RELEASE I had to rebuild world and some ports, but now
everything seems to be working fine.
Patches attached.

Regards, Klaus

--------------80572298F8A81184E6F60AC9
Content-Type: text/plain; charset=UTF-8;
 name="rdtsc-sys-02.diff"
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
 filename="rdtsc-sys-02.diff"

ZGlmZiAtYXVwciBzcmMub3JpZy9zeXMvYW1kNjQvYW1kNjQvaW5pdGNwdS5jIHNyYy9zeXMv
YW1kNjQvYW1kNjQvaW5pdGNwdS5jCi0tLSBzcmMub3JpZy9zeXMvYW1kNjQvYW1kNjQvaW5p
dGNwdS5jCTIwMTctMDktMjkgMDI6MjA6MDUuMDAwMDAwMDAwICswMjAwCisrKyBzcmMvc3lz
L2FtZDY0L2FtZDY0L2luaXRjcHUuYwkyMDE4LTAxLTA0IDE1OjE5OjMyLjc0MTcyOTAwMCAr
MDEwMApAQCAtMjEwLDYgKzIxMCw3IEBAIGluaXRpYWxpemVjcHUodm9pZCkKIAl9CiAJaWYg
KGNwdV9zdGRleHRfZmVhdHVyZSAmIENQVUlEX1NUREVYVF9GU0dTQkFTRSkKIAkJY3I0IHw9
IENSNF9GU0dTQkFTRTsKKwljcjQgfD0gQ1I0X1RTRDsKIAogCS8qCiAJICogUG9zdHBvbmUg
ZW5hYmxpbmcgdGhlIFNNRVAgb24gdGhlIGJvb3QgQ1BVIHVudGlsIHRoZSBwYWdlCmRpZmYg
LWF1cHIgc3JjLm9yaWcvc3lzL3g4Ni94ODYvdHNjLmMgc3JjL3N5cy94ODYveDg2L3RzYy5j
Ci0tLSBzcmMub3JpZy9zeXMveDg2L3g4Ni90c2MuYwkyMDE3LTA5LTI5IDAyOjIwOjA2LjAw
MDAwMDAwMCArMDIwMAorKysgc3JjL3N5cy94ODYveDg2L3RzYy5jCTIwMTgtMDEtMDQgMTU6
MTk6MzIuNzU2MTIzMDAwICswMTAwCkBAIC02NTgsNiArNjU4LDcgQEAgdHNjX2ZyZXFfY2hh
bmdlZCh2b2lkICphcmcsIGNvbnN0IHN0cnVjdAogc3RhdGljIGludAogc3lzY3RsX21hY2hk
ZXBfdHNjX2ZyZXEoU1lTQ1RMX0hBTkRMRVJfQVJHUykKIHsKKyNpZiAwCiAJaW50IGVycm9y
OwogCXVpbnQ2NF90IGZyZXE7CiAKQEAgLTY3MSw2ICs2NzIsOSBAQCBzeXNjdGxfbWFjaGRl
cF90c2NfZnJlcShTWVNDVExfSEFORExFUl9BCiAJCSAgICBmcmVxID4+IChpbnQpKGludHB0
cl90KXRzY190aW1lY291bnRlci50Y19wcml2KTsKIAl9CiAJcmV0dXJuIChlcnJvcik7Cisj
ZWxzZQorCXJldHVybiAoRU9QTk9UU1VQUCk7CisjZW5kaWYKIH0KIAogU1lTQ1RMX1BST0Mo
X21hY2hkZXAsIE9JRF9BVVRPLCB0c2NfZnJlcSwgQ1RMVFlQRV9VNjQgfCBDVExGTEFHX1JX
LAo=
--------------80572298F8A81184E6F60AC9
Content-Type: text/plain; charset=UTF-8;
 name="rdtsc-libc-02.diff"
Content-Transfer-Encoding: base64
Content-Disposition: attachment;
 filename="rdtsc-libc-02.diff"
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--------------80572298F8A81184E6F60AC9--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?18376c97-3c0d-49c8-9483-96b95a84f3f1>