diff options
author | Marc Zyngier <marc.zyngier@arm.com> | 2018-07-20 10:53:07 +0100 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-22 14:28:51 +0200 |
commit | e7d02797288f12ca257cdab49d19ccf9b3d2cb12 (patch) | |
tree | 4976686f0cb4f45dda624031a9d12e2b647413af /arch/arm64/kernel | |
parent | c5c89bb4deb8e1f0eed0968f37dfa936f6b5e4c1 (diff) |
arm64: ssbd: Introduce thread flag to control userspace mitigation
commit 9dd9614f5476687abbff8d4b12cd08ae70d7c2ad upstream.
In order to allow userspace to be mitigated on demand, let's
introduce a new thread flag that prevents the mitigation from
being turned off when exiting to userspace, and doesn't turn
it on on entry into the kernel (with the assumption that the
mitigation is always enabled in the kernel itself).
This will be used by a prctl interface introduced in a later
patch.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64/kernel')
-rw-r--r-- | arch/arm64/kernel/entry.S | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S index 5a585976d14c..c1ffa95c0ad2 100644 --- a/arch/arm64/kernel/entry.S +++ b/arch/arm64/kernel/entry.S @@ -147,6 +147,8 @@ alternative_cb arm64_enable_wa2_handling alternative_cb_end ldr_this_cpu \tmp2, arm64_ssbd_callback_required, \tmp1 cbz \tmp2, \targ + ldr \tmp2, [tsk, #TSK_TI_FLAGS] + tbnz \tmp2, #TIF_SSBD, \targ mov w0, #ARM_SMCCC_ARCH_WORKAROUND_2 mov w1, #\state alternative_cb arm64_update_smccc_conduit |