When exec'ing a 32-bit task on a system with mismatched support for 32-bit EL0, try to ensure that it starts life on a CPU that can actually run it.
Signed-off-by: Will Deacon <[email protected]> --- arch/arm64/kernel/process.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index 1540ab0fbf23..17b94007fed4 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -625,6 +625,16 @@ unsigned long arch_align_stack(unsigned long sp) return sp & ~0xf; } +static void adjust_compat_task_affinity(struct task_struct *p) +{ + const struct cpumask *mask = system_32bit_el0_cpumask(); + + if (restrict_cpus_allowed_ptr(p, mask)) + set_cpus_allowed_ptr(p, mask); + + set_tsk_thread_flag(current, TIF_NOTIFY_RESUME); +} + /* * Called from setup_new_exec() after (COMPAT_)SET_PERSONALITY. */ @@ -635,7 +645,7 @@ void arch_setup_new_exec(void) if (is_compat_task()) { mmflags = MMCF_AARCH32; if (static_branch_unlikely(&arm64_mismatched_32bit_el0)) - set_tsk_thread_flag(current, TIF_NOTIFY_RESUME); + adjust_compat_task_affinity(current); } current->mm->context.flags = mmflags; -- 2.29.2.299.gdc1121823c-goog
