diff options
| -rw-r--r-- | arch/powerpc/platforms/book3s/vas-api.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/arch/powerpc/platforms/book3s/vas-api.c b/arch/powerpc/platforms/book3s/vas-api.c index 82f32781c5d2..f9a1615b74da 100644 --- a/arch/powerpc/platforms/book3s/vas-api.c +++ b/arch/powerpc/platforms/book3s/vas-api.c @@ -497,10 +497,29 @@ static int coproc_mmap(struct file *fp, struct vm_area_struct *vma) return -EACCES; } + /* + * The initial mmap is done after the window is opened + * with ioctl. But before mmap(), this window can be closed in + * the hypervisor due to lost credit (core removal on pseries). + * So if the window is not active, return mmap() failure with + * -EACCES and expects the user space reissue mmap() when it + * is active again or open new window when the credit is available. + * mmap_mutex protects the paste address mmap() with DLPAR + * close/open event and allows mmap() only when the window is + * active. + */ + mutex_lock(&txwin->task_ref.mmap_mutex); + if (txwin->status != VAS_WIN_ACTIVE) { + pr_err("%s(): Window is not active\n", __func__); + rc = -EACCES; + goto out; + } + paste_addr = cp_inst->coproc->vops->paste_addr(txwin); if (!paste_addr) { pr_err("%s(): Window paste address failed\n", __func__); - return -EINVAL; + rc = -EINVAL; + goto out; } pfn = paste_addr >> PAGE_SHIFT; @@ -520,6 +539,8 @@ static int coproc_mmap(struct file *fp, struct vm_area_struct *vma) txwin->task_ref.vma = vma; vma->vm_ops = &vas_vm_ops; +out: + mutex_unlock(&txwin->task_ref.mmap_mutex); return rc; } |