Re: [PATCH] powerpc/security: Use a mutex for interrupt exit code patching

2021-11-02 Thread Michael Ellerman
On Wed, 27 Oct 2021 17:24:10 +1000, Russell Currey wrote: > The mitigation-patching.sh script in the powerpc selftests toggles > all mitigations on and off simultaneously, revealing that rfi_flush > and stf_barrier cannot safely operate at the same time due to races > in updating the static key. >

Re: [PATCH] powerpc/security: Use a mutex for interrupt exit code patching

2021-10-27 Thread Nicholas Piggin
Excerpts from Russell Currey's message of October 27, 2021 5:24 pm: > The mitigation-patching.sh script in the powerpc selftests toggles > all mitigations on and off simultaneously, revealing that rfi_flush > and stf_barrier cannot safely operate at the same time due to races > in updating the stat

[PATCH] powerpc/security: Use a mutex for interrupt exit code patching

2021-10-27 Thread Russell Currey
The mitigation-patching.sh script in the powerpc selftests toggles all mitigations on and off simultaneously, revealing that rfi_flush and stf_barrier cannot safely operate at the same time due to races in updating the static key. On some systems, the static key code throws a warning and the kerne