From d82158fa6df4237c9859b27d719c53b4fe09e69e Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Fri, 30 Jul 2021 12:24:37 +0100 Subject: [PATCH] arm64: Implement task_cpu_possible_mask() Provide an implementation of task_cpu_possible_mask() so that we can prevent 64-bit-only cores being added to the 'cpus_mask' for compat tasks on systems with mismatched 32-bit support at EL0, Signed-off-by: Will Deacon Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Catalin Marinas Link: https://lore.kernel.org/r/20210730112443.23245-11-will@kernel.org --- arch/arm64/include/asm/mmu_context.h | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/arm64/include/asm/mmu_context.h b/arch/arm64/include/asm/mmu_context.h index eeb210997149a..f4ba93d4ffebe 100644 --- a/arch/arm64/include/asm/mmu_context.h +++ b/arch/arm64/include/asm/mmu_context.h @@ -231,6 +231,19 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next, update_saved_ttbr0(tsk, next); } +static inline const struct cpumask * +task_cpu_possible_mask(struct task_struct *p) +{ + if (!static_branch_unlikely(&arm64_mismatched_32bit_el0)) + return cpu_possible_mask; + + if (!is_compat_thread(task_thread_info(p))) + return cpu_possible_mask; + + return system_32bit_el0_cpumask(); +} +#define task_cpu_possible_mask task_cpu_possible_mask + void verify_cpu_asid_bits(void); void post_ttbr_update_workaround(void); -- 2.39.5