diff options
| -rw-r--r-- | arch/Kconfig | 7 | ||||
| -rw-r--r-- | fs/exec.c | 15 |
2 files changed, 21 insertions, 1 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 77b3e21c4844..95567f683275 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -339,6 +339,13 @@ config HAVE_RCU_TABLE_FREE config HAVE_RCU_TABLE_INVALIDATE bool +config ARCH_WANT_IRQS_OFF_ACTIVATE_MM + bool + help + Temporary select until all architectures can be converted to have + irqs disabled over activate_mm. Architectures that do IPI based TLB + shootdowns should enable this. + config ARCH_HAVE_NMI_SAFE_CMPXCHG bool diff --git a/fs/exec.c b/fs/exec.c index 92fd21f0b0ff..e8d1e6705977 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1024,10 +1024,23 @@ static int exec_mmap(struct mm_struct *mm) } } task_lock(tsk); + + local_irq_disable(); active_mm = tsk->active_mm; - tsk->mm = mm; tsk->active_mm = mm; + tsk->mm = mm; + /* + * This prevents preemption while active_mm is being loaded and + * it and mm are being updated, which could cause problems for + * lazy tlb mm refcounting when these are updated by context + * switches. Not all architectures can handle irqs off over + * activate_mm yet. + */ + if (!IS_ENABLED(CONFIG_ARCH_WANT_IRQS_OFF_ACTIVATE_MM)) + local_irq_enable(); activate_mm(active_mm, mm); + if (IS_ENABLED(CONFIG_ARCH_WANT_IRQS_OFF_ACTIVATE_MM)) + local_irq_enable(); tsk->mm->vmacache_seqnum = 0; vmacache_flush(tsk); task_unlock(tsk); |