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author | Otavio Salvador <otavio@ossystems.com.br> | 2019-07-15 11:15:02 -0300 |
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committer | GitHub <noreply@github.com> | 2019-07-15 11:15:02 -0300 |
commit | 6b774eec1f9d3064e9b33634dfa99d5666d0a73a (patch) | |
tree | 64fa879c312d6a52f90e6dbf3f7be2d66de3ddd4 /Documentation/admin-guide/kernel-parameters.txt | |
parent | 774f42075a4800fe4106dffca804e3207bc3c2e7 (diff) | |
parent | 286d8c46ed06d5fc1b8c212356a11a19b2c94bc4 (diff) |
Merge pull request #50 from MaxKrummenacher/4.14-2.0.x-imx
4.14 2.0.x imx
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
-rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 62 |
1 files changed, 61 insertions, 1 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 94fa46d2d805..9240b2caa0b1 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1971,7 +1971,7 @@ Default is 'flush'. - For details see: Documentation/admin-guide/l1tf.rst + For details see: Documentation/admin-guide/hw-vuln/l1tf.rst l2cr= [PPC] @@ -2214,6 +2214,32 @@ Format: <first>,<last> Specifies range of consoles to be captured by the MDA. + mds= [X86,INTEL] + Control mitigation for the Micro-architectural Data + Sampling (MDS) vulnerability. + + Certain CPUs are vulnerable to an exploit against CPU + internal buffers which can forward information to a + disclosure gadget under certain conditions. + + In vulnerable processors, the speculatively + forwarded data can be used in a cache side channel + attack, to access data to which the attacker does + not have direct access. + + This parameter controls the MDS mitigation. The + options are: + + full - Enable MDS mitigation on vulnerable CPUs + full,nosmt - Enable MDS mitigation and disable + SMT on vulnerable CPUs + off - Unconditionally disable MDS mitigation + + Not specifying this option is equivalent to + mds=full. + + For details see: Documentation/admin-guide/hw-vuln/mds.rst + mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory Amount of memory to be used when the kernel is not able to see the whole system memory or for test. @@ -2362,6 +2388,40 @@ 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] + mds=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] + mds=full,nosmt [X86] + mminit_loglevel= [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this parameter allows control of the logging verbosity for |