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| author | Pawan Gupta <pawan.kumar.gupta@linux.intel.com> | 2019-10-23 13:32:55 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-11-16 12:29:46 +0300 |
| commit | ba54aadc5c641dfe4e387edc977e07cd175ed59b (patch) | |
| tree | 735ad9f6db26114a6abf031c66bf6d72f1fbe1f4 /Documentation/kernel-parameters.txt | |
| parent | 562afad430aaf280d224c65589d8db4e29ca8ace (diff) | |
| download | linux-ba54aadc5c641dfe4e387edc977e07cd175ed59b.tar.xz | |
x86/speculation/taa: Add documentation for TSX Async Abort
commit a7a248c593e4fd7a67c50b5f5318fe42a0db335e upstream.
Add the documenation for TSX Async Abort. Include the description of
the issue, how to check the mitigation state, control the mitigation,
guidance for system administrators.
[ bp: Add proper SPDX tags, touch ups by Josh and me. ]
Co-developed-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Antonio Gomez Iglesias <antonio.gomez.iglesias@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mark Gross <mgross@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
[bwh: Backported to 4.9: adjust filenames, context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index fbaf96a142ed..40bddc59226b 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2490,6 +2490,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. spec_store_bypass_disable=off [X86] l1tf=off [X86] mds=off [X86] + tsx_async_abort=off [X86] auto (default) Mitigate all CPU vulnerabilities, but leave SMT @@ -2505,6 +2506,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. be fully mitigated, even if it means losing SMT. Equivalent to: l1tf=flush,nosmt [X86] mds=full,nosmt [X86] + tsx_async_abort=full,nosmt [X86] mminit_loglevel= [KNL] When CONFIG_DEBUG_MEMORY_INIT is set, this @@ -4545,6 +4547,42 @@ bytes respectively. Such letter suffixes can also be entirely omitted. See Documentation/hw-vuln/tsx_async_abort.rst for more details. + tsx_async_abort= [X86,INTEL] Control mitigation for the TSX Async + Abort (TAA) vulnerability. + + Similar to Micro-architectural Data Sampling (MDS) + certain CPUs that support Transactional + Synchronization Extensions (TSX) 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 TAA mitigation. The + options are: + + full - Enable TAA mitigation on vulnerable CPUs + if TSX is enabled. + + full,nosmt - Enable TAA mitigation and disable SMT on + vulnerable CPUs. If TSX is disabled, SMT + is not disabled because CPU is not + vulnerable to cross-thread TAA attacks. + off - Unconditionally disable TAA mitigation + + Not specifying this option is equivalent to + tsx_async_abort=full. On CPUs which are MDS affected + and deploy MDS mitigation, TAA mitigation is not + required and doesn't provide any additional + mitigation. + + For details see: + Documentation/hw-vuln/tsx_async_abort.rst + turbografx.map[2|3]= [HW,JOY] TurboGraFX parallel port interface Format: |