diff options
Diffstat (limited to 'arch/arm64/kernel/process.c')
| -rw-r--r-- | arch/arm64/kernel/process.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c index c15ec41e9f84..b2adcce7bc18 100644 --- a/arch/arm64/kernel/process.c +++ b/arch/arm64/kernel/process.c @@ -49,6 +49,7 @@ #include <linux/notifier.h> #include <trace/events/power.h> #include <linux/percpu.h> +#include <linux/thread_info.h> #include <asm/alternative.h> #include <asm/compat.h> @@ -273,11 +274,27 @@ void release_thread(struct task_struct *dead_task) { } +void arch_release_task_struct(struct task_struct *tsk) +{ + fpsimd_release_task(tsk); +} + +/* + * src and dst may temporarily have aliased sve_state after task_struct + * is copied. We cannot fix this properly here, because src may have + * live SVE state and dst's thread_info may not exist yet, so tweaking + * either src's or dst's TIF_SVE is not safe. + * + * The unaliasing is done in copy_thread() instead. This works because + * dst is not schedulable or traceable until both of these functions + * have been called. + */ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) { if (current->mm) fpsimd_preserve_current_state(); *dst = *src; + return 0; } @@ -290,6 +307,13 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start, memset(&p->thread.cpu_context, 0, sizeof(struct cpu_context)); + /* + * Unalias p->thread.sve_state (if any) from the parent task + * and disable discard SVE state for p: + */ + clear_tsk_thread_flag(p, TIF_SVE); + p->thread.sve_state = NULL; + if (likely(!(p->flags & PF_KTHREAD))) { *childregs = *current_pt_regs(); childregs->regs[0] = 0; |