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-rw-r--r--arch/powerpc/platforms/book3s/vas-api.c36
1 files changed, 36 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/book3s/vas-api.c b/arch/powerpc/platforms/book3s/vas-api.c
index f381b177ea06..0b6365d85d11 100644
--- a/arch/powerpc/platforms/book3s/vas-api.c
+++ b/arch/powerpc/platforms/book3s/vas-api.c
@@ -464,7 +464,43 @@ static vm_fault_t vas_mmap_fault(struct vm_fault *vmf)
return VM_FAULT_SIGBUS;
}
+/*
+ * During mmap() paste address, mapping VMA is saved in VAS window
+ * struct which is used to unmap during migration if the window is
+ * still open. But the user space can remove this mapping with
+ * munmap() before closing the window and the VMA address will
+ * be invalid. Set VAS window VMA to NULL in this function which
+ * is called before VMA free.
+ */
+static void vas_mmap_close(struct vm_area_struct *vma)
+{
+ struct file *fp = vma->vm_file;
+ struct coproc_instance *cp_inst = fp->private_data;
+ struct vas_window *txwin;
+
+ /* Should not happen */
+ if (!cp_inst || !cp_inst->txwin) {
+ pr_err("No attached VAS window for the paste address mmap\n");
+ return;
+ }
+
+ txwin = cp_inst->txwin;
+ /*
+ * task_ref.vma is set in coproc_mmap() during mmap paste
+ * address. So it has to be the same VMA that is getting freed.
+ */
+ if (WARN_ON(txwin->task_ref.vma != vma)) {
+ pr_err("Invalid paste address mmaping\n");
+ return;
+ }
+
+ mutex_lock(&txwin->task_ref.mmap_mutex);
+ txwin->task_ref.vma = NULL;
+ mutex_unlock(&txwin->task_ref.mmap_mutex);
+}
+
static const struct vm_operations_struct vas_vm_ops = {
+ .close = vas_mmap_close,
.fault = vas_mmap_fault,
};