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| author | Michael Ellerman <mpe@ellerman.id.au> | 2018-07-10 12:08:36 +1000 |
|---|---|---|
| committer | Jonathan Corbet <corbet@lwn.net> | 2018-07-10 15:13:20 -0600 |
| commit | 6b4c1360e8adc2cbecf400b97c1ffcf9c5aad31e (patch) | |
| tree | 481fc6e253292da3cc943bac75800fe2f7f1adcc /Documentation/admin-guide | |
| parent | 9ac8c3bd50018c80ad413bff00f054496998cc0d (diff) | |
| download | linux-6b4c1360e8adc2cbecf400b97c1ffcf9c5aad31e.tar.bz2 | |
Documentation: Add powerpc options for spec_store_bypass_disable
Document the support for spec_store_bypass_disable that was added for
powerpc in commit a048a07d7f45 ("powerpc/64s: Add support for a store
forwarding barrier at kernel entry/exit").
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to 'Documentation/admin-guide')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 533ff5c68970..4bb60048f583 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -4060,6 +4060,8 @@ This parameter controls whether the Speculative Store Bypass optimization is used. + On x86 the options are: + on - Unconditionally disable Speculative Store Bypass off - Unconditionally enable Speculative Store Bypass auto - Kernel detects whether the CPU model contains an @@ -4075,12 +4077,20 @@ seccomp - Same as "prctl" above, but all seccomp threads will disable SSB unless they explicitly opt out. - Not specifying this option is equivalent to - spec_store_bypass_disable=auto. - Default mitigations: X86: If CONFIG_SECCOMP=y "seccomp", otherwise "prctl" + On powerpc the options are: + + on,auto - On Power8 and Power9 insert a store-forwarding + barrier on kernel entry and exit. On Power7 + perform a software flush on kernel entry and + exit. + off - No action. + + Not specifying this option is equivalent to + spec_store_bypass_disable=auto. + spia_io_base= [HW,MTD] spia_fio_base= spia_pedr= |