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| author | Will Deacon <will.deacon@arm.com> | 2018-08-07 13:47:06 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2018-09-14 17:46:19 +0100 |
| commit | 8f04e8e6e29c93421a95b61cad62e3918425eac7 (patch) | |
| tree | d933a8bd5c9e9a3094019c9bc51d5b5178eb768e /arch/arm64/kernel/process.c | |
| parent | 0bf0f444b2c49241b2b39aa3cf210d7c95ef6c34 (diff) | |
| download | linux-stable-8f04e8e6e29c93421a95b61cad62e3918425eac7.tar.gz linux-stable-8f04e8e6e29c93421a95b61cad62e3918425eac7.tar.bz2 linux-stable-8f04e8e6e29c93421a95b61cad62e3918425eac7.zip | |
arm64: ssbd: Add support for PSTATE.SSBS rather than trapping to EL3
On CPUs with support for PSTATE.SSBS, the kernel can toggle the SSBD
state without needing to call into firmware.
This patch hooks into the existing SSBD infrastructure so that SSBS is
used on CPUs that support it, but it's all made horribly complicated by
the very real possibility of big/little systems that don't uniformly
provide the new capability.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kernel/process.c')
| -rw-r--r-- | arch/arm64/kernel/process.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 7f1628effe6d..ce99c58cd1f1 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -358,6 +358,10 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, if (IS_ENABLED(CONFIG_ARM64_UAO) && cpus_have_const_cap(ARM64_HAS_UAO)) childregs->pstate |= PSR_UAO_BIT; + + if (arm64_get_ssbd_state() == ARM64_SSBD_FORCE_DISABLE) + childregs->pstate |= PSR_SSBS_BIT; + p->thread.cpu_context.x19 = stack_start; p->thread.cpu_context.x20 = stk_sz; } |