diff options
| author | Kim Phillips <kim.phillips@amd.com> | 2022-06-14 23:15:51 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-07-23 12:54:02 +0200 |
| commit | b4e05ea71edaf52f2ecef675407a82160176ac54 (patch) | |
| tree | 4bdc8369fa1fb03b83ac0e41a2de7ab30be6dab7 /Documentation/admin-guide | |
| parent | 89eba42632fcfff30e84f66a5a7ca63882ac64ea (diff) | |
x86/bugs: Enable STIBP for JMP2RET
commit e8ec1b6e08a2102d8755ccb06fa26d540f26a2fa upstream.
For untrained return thunks to be fully effective, STIBP must be enabled
or SMT disabled.
Co-developed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Kim Phillips <kim.phillips@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 961843aa8403..998420529fbc 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4972,11 +4972,17 @@ Speculative Code Execution with Return Instructions) vulnerability. - off - unconditionally disable - auto - automatically select a migitation - unret - force enable untrained return thunks, - only effective on AMD Zen {1,2} - based systems. + off - no mitigation + auto - automatically select a migitation + auto,nosmt - automatically select a mitigation, + disabling SMT if necessary for + the full mitigation (only on Zen1 + and older without STIBP). + unret - force enable untrained return thunks, + only effective on AMD f15h-f17h + based systems. + unret,nosmt - like unret, will disable SMT when STIBP + is not available. Selecting 'auto' will choose a mitigation method at run time according to the CPU. |