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authorLinus Torvalds <torvalds@linux-foundation.org>2019-05-06 23:01:16 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2019-05-06 23:01:16 +0300
commit0a499fc5c37e6db096969a83534fd98a2bf2b36c (patch)
tree682875f57706b1e28bfe579372a465bd778ce3dc /Documentation/admin-guide
parente50c5d2e725eb7192a62868d4a9987907741ff62 (diff)
parent0336e04a6520bdaefdb0769d2a70084fa52e81ed (diff)
downloadlinux-0a499fc5c37e6db096969a83534fd98a2bf2b36c.tar.xz
Merge branch 'core-speculation-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull speculation mitigation update from Ingo Molnar: "This adds the "mitigations=" bootline option, which offers a cross-arch set of options that will work on x86, PowerPC and s390 that will map to the arch specific option internally" * 'core-speculation-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: s390/speculation: Support 'mitigations=' cmdline option powerpc/speculation: Support 'mitigations=' cmdline option x86/speculation: Support 'mitigations=' cmdline option cpu/speculation: Add 'mitigations=' cmdline option
Diffstat (limited to 'Documentation/admin-guide')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt32
1 files changed, 32 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index d377a2166b79..b7e23e9d1770 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2544,6 +2544,38 @@
in the "bleeding edge" mini2440 support kernel at
http://repo.or.cz/w/linux-2.6/mini2440.git
+ mitigations=
+ [X86,PPC,S390] Control optional mitigations for CPU
+ vulnerabilities. This is a set of curated,
+ arch-independent options, each of which is an
+ aggregation of existing arch-specific options.
+
+ off
+ Disable all optional CPU mitigations. This
+ improves system performance, but it may also
+ expose users to several CPU vulnerabilities.
+ Equivalent to: nopti [X86,PPC]
+ nospectre_v1 [PPC]
+ nobp=0 [S390]
+ nospectre_v2 [X86,PPC,S390]
+ spectre_v2_user=off [X86]
+ spec_store_bypass_disable=off [X86,PPC]
+ l1tf=off [X86]
+
+ auto (default)
+ Mitigate all CPU vulnerabilities, but leave SMT
+ enabled, even if it's vulnerable. This is for
+ users who don't want to be surprised by SMT
+ getting disabled across kernel upgrades, or who
+ have other ways of avoiding SMT-based attacks.
+ Equivalent to: (default behavior)
+
+ auto,nosmt
+ Mitigate all CPU vulnerabilities, disabling SMT
+ if needed. This is for users who always want to
+ be fully mitigated, even if it means losing SMT.
+ Equivalent to: l1tf=flush,nosmt [X86]
+
mminit_loglevel=
[KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this
parameter allows control of the logging verbosity for