diff --git a/include/linux/sync_core.h b/include/linux/sync_core.h index 013da4b8b3272c6aff56a84cc40ce8d8a5d17041..67bb9794b87585c5d4584205879fbcb469fa0469 100644 --- a/include/linux/sync_core.h +++ b/include/linux/sync_core.h @@ -17,5 +17,19 @@ static inline void sync_core_before_usermode(void) } #endif -#endif /* _LINUX_SYNC_CORE_H */ +#ifdef CONFIG_ARCH_HAS_PREPARE_SYNC_CORE_CMD +#include <asm/sync_core.h> +#else +/* + * This is a dummy prepare_sync_core_cmd() implementation that can be used on + * all architectures which provide unconditional core serializing instructions + * in switch_mm(). + * If your architecture doesn't provide such core serializing instructions in + * switch_mm(), you may need to write your own functions. + */ +static inline void prepare_sync_core_cmd(struct mm_struct *mm) +{ +} +#endif +#endif /* _LINUX_SYNC_CORE_H */ diff --git a/init/Kconfig b/init/Kconfig index 8df18f3a974846b48e41b2a8dcbc2f2f2f90128e..c3994b92333ded7989a672cf0e594896debfad67 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -1970,6 +1970,9 @@ source "kernel/Kconfig.locks" config ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE bool +config ARCH_HAS_PREPARE_SYNC_CORE_CMD + bool + config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE bool diff --git a/kernel/sched/membarrier.c b/kernel/sched/membarrier.c index f3d91628d6b8ab5f98ace3b211ac2d2cd74e30f2..6d1f31b3a967b3d3fd8ac0ee6a316ea9f4ae3b56 100644 --- a/kernel/sched/membarrier.c +++ b/kernel/sched/membarrier.c @@ -320,6 +320,7 @@ static int membarrier_private_expedited(int flags, int cpu_id) MEMBARRIER_STATE_PRIVATE_EXPEDITED_SYNC_CORE_READY)) return -EPERM; ipi_func = ipi_sync_core; + prepare_sync_core_cmd(mm); } else if (flags == MEMBARRIER_FLAG_RSEQ) { if (!IS_ENABLED(CONFIG_RSEQ)) return -EINVAL;