Gentoo Archives: gentoo-user

From: tuxic@××××××.de
To: gentoo-user@l.g.o
Subject: Re: [gentoo-user] x86.c:(.text+0xb2): undefined reference to `l1tf_vmx_mitigation' with linux kernel 4.18.1
Date: Fri, 17 Aug 2018 05:10:53
Message-Id: 20180817051032.u75dwomjje5uerg3@solfire
In Reply to: Re: [gentoo-user] x86.c:(.text+0xb2): undefined reference to `l1tf_vmx_mitigation' with linux kernel 4.18.1 by Adam Carter
1 On 08/17 02:53, Adam Carter wrote:
2 > On Fri, Aug 17, 2018 at 1:15 PM, <tuxic@××××××.de> wrote:
3 >
4 > > Hi,
5 > >
6 > > CPU bugs seem to be more and more common:
7 > > https://www.heise.de/security/meldung/Linux-Kernel-und-
8 > > Distributionen-schuetzen-vor-Prozessorluecke-Foreshadow-L1TF-4137264.html
9 > > https://www.heise.de/security/meldung/Spectre-NG-Foreshadow-
10 > > gefaehrdet-Intel-Prozessoren-4137209.html
11 > > (sorry, I only know of this german spoken references...)
12 > >
13 > > With Linux kernel 4.18.1 Linus has introduced a fix (aka workaround)
14 > > of the Foreshadow bug.
15 > >
16 >
17 > 4.18, 4.17, 4.14, 4.9, and 4.4 have all had the fixes applied.
18 >
19 > >
20 > > Unfortunately compiling that kernel (as downloaded from
21 > > https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/ )
22 > >
23 > > gives me this bug:
24 > >
25 >
26 > gentoo-sources with gcc 7.3 builds fine for me.
27 >
28 > Intel: grep . /sys/devices/system/cpu/vulnerabilities/*
29 > /sys/devices/system/cpu/vulnerabilities/l1tf:Mitigation: PTE Inversion
30 > /sys/devices/system/cpu/vulnerabilities/meltdown:Mitigation: PTI
31 > /sys/devices/system/cpu/vulnerabilities/spec_store_bypass:Mitigation:
32 > Speculative Store Bypass disabled via prctl and seccomp
33 > /sys/devices/system/cpu/vulnerabilities/spectre_v1:Mitigation: __user
34 > pointer sanitization
35 > /sys/devices/system/cpu/vulnerabilities/spectre_v2:Mitigation: Full generic
36 > retpoline, IBPB, IBRS_FW
37 >
38 > AMD: grep . /sys/devices/system/cpu/vulnerabilities/*
39 > /sys/devices/system/cpu/vulnerabilities/l1tf:Not affected
40 > /sys/devices/system/cpu/vulnerabilities/meltdown:Not affected
41 > /sys/devices/system/cpu/vulnerabilities/spec_store_bypass:Mitigation:
42 > Speculative Store Bypass disabled via prctl and seccomp
43 > /sys/devices/system/cpu/vulnerabilities/spectre_v1:Mitigation: __user
44 > pointer sanitization
45 > /sys/devices/system/cpu/vulnerabilities/spectre_v2:Mitigation: Full AMD
46 > retpoline, IBPB
47
48 Hi,
49
50 I am happy, that other sources do work for you Adam.
51
52 Interesting would be, why the original sources does not compile for
53 me.
54 Any idea?

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