powerpc: Add ppc_strict_facility_enable boot option
Add a boot option that strictly manages the MSR unavailable bits.
This catches kernel uses of FP/Altivec/SPE that would otherwise
corrupt user state.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 742f69d..8978c26 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2978,6 +2978,12 @@
may be specified.
Format: <port>,<port>....
+ ppc_strict_facility_enable
+ [PPC] This option catches any kernel floating point,
+ Altivec, VSX and SPE outside of regions specifically
+ allowed (eg kernel_enable_fpu()/kernel_disable_fpu()).
+ There is some performance impact when enabling this.
+
print-fatal-signals=
[KNL] debug: print fatal signals