1 files changed, 75 insertions, 38 deletions

diff --git a/arch/powerpc/platforms/book3s/vas-api.c b/arch/powerpc/platforms/book3s/vas-api.c
index 40f5ae5e1238..49b15e7a8265 100644
--- a/arch/powerpc/platforms/book3s/vas-api.c
+++ b/arch/powerpc/platforms/book3s/vas-api.c
@@ -4,6 +4,8 @@
  * Copyright (C) 2019 Haren Myneni, IBM Corp
  */
 
+#define pr_fmt(fmt)	"vas-api: " fmt
+
 #include <linux/kernel.h>
 #include <linux/device.h>
 #include <linux/cdev.h>
@@ -53,7 +55,7 @@ struct coproc_instance {
 	struct vas_window *txwin;
 };
 
-static char *coproc_devnode(struct device *dev, umode_t *mode)
+static char *coproc_devnode(const struct device *dev, umode_t *mode)
 {
 	return kasprintf(GFP_KERNEL, "crypto/%s", dev_name(dev));
 }
@@ -78,7 +80,7 @@ int get_vas_user_win_ref(struct vas_user_win_ref *task_ref)
 	task_ref->mm = get_task_mm(current);
 	if (!task_ref->mm) {
 		put_pid(task_ref->pid);
-		pr_err("VAS: pid(%d): mm_struct is not found\n",
+		pr_err("pid(%d): mm_struct is not found\n",
 				current->pid);
 		return -EPERM;
 	}
@@ -235,8 +237,7 @@ void vas_update_csb(struct coprocessor_request_block *crb,
 	rc = kill_pid_info(SIGSEGV, &info, pid);
 	rcu_read_unlock();
 
-	pr_devel("%s(): pid %d kill_proc_info() rc %d\n", __func__,
-			pid_vnr(pid), rc);
+	pr_devel("pid %d kill_proc_info() rc %d\n", pid_vnr(pid), rc);
 }
 
 void vas_dump_crb(struct coprocessor_request_block *crb)
@@ -294,7 +295,7 @@ static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
 
 	rc = copy_from_user(&uattr, uptr, sizeof(uattr));
 	if (rc) {
-		pr_err("%s(): copy_from_user() returns %d\n", __func__, rc);
+		pr_err("copy_from_user() returns %d\n", rc);
 		return -EFAULT;
 	}
 
@@ -311,7 +312,7 @@ static int coproc_ioc_tx_win_open(struct file *fp, unsigned long arg)
 	txwin = cp_inst->coproc->vops->open_win(uattr.vas_id, uattr.flags,
 						cp_inst->coproc->cop_type);
 	if (IS_ERR(txwin)) {
-		pr_err("%s() VAS window open failed, %ld\n", __func__,
+		pr_err_ratelimited("VAS window open failed rc=%ld\n",
 				PTR_ERR(txwin));
 		return PTR_ERR(txwin);
 	}
@@ -405,8 +406,7 @@ static vm_fault_t vas_mmap_fault(struct vm_fault *vmf)
 	 * window is not opened. Shouldn't expect this error.
 	 */
 	if (!cp_inst || !cp_inst->txwin) {
-		pr_err("%s(): Unexpected fault on paste address with TX window closed\n",
-				__func__);
+		pr_err("Unexpected fault on paste address with TX window closed\n");
 		return VM_FAULT_SIGBUS;
 	}
 
@@ -414,35 +414,33 @@ static vm_fault_t vas_mmap_fault(struct vm_fault *vmf)
 	/*
 	 * When the LPAR lost credits due to core removal or during
 	 * migration, invalidate the existing mapping for the current
-	 * paste addresses and set windows in-active (zap_page_range in
+	 * paste addresses and set windows in-active (zap_vma_pages in
 	 * reconfig_close_windows()).
 	 * New mapping will be done later after migration or new credits
 	 * available. So continue to receive faults if the user space
 	 * issue NX request.
 	 */
 	if (txwin->task_ref.vma != vmf->vma) {
-		pr_err("%s(): No previous mapping with paste address\n",
-			__func__);
+		pr_err("No previous mapping with paste address\n");
 		return VM_FAULT_SIGBUS;
 	}
 
-	mutex_lock(&txwin->task_ref.mmap_mutex);
 	/*
 	 * The window may be inactive due to lost credit (Ex: core
 	 * removal with DLPAR). If the window is active again when
 	 * the credit is available, map the new paste address at the
 	 * window virtual address.
 	 */
-	if (txwin->status == VAS_WIN_ACTIVE) {
-		paste_addr = cp_inst->coproc->vops->paste_addr(txwin);
-		if (paste_addr) {
-			fault = vmf_insert_pfn(vma, vma->vm_start,
-					(paste_addr >> PAGE_SHIFT));
-			mutex_unlock(&txwin->task_ref.mmap_mutex);
-			return fault;
+	scoped_guard(mutex, &txwin->task_ref.mmap_mutex) {
+		if (txwin->status == VAS_WIN_ACTIVE) {
+			paste_addr = cp_inst->coproc->vops->paste_addr(txwin);
+			if (paste_addr) {
+				fault = vmf_insert_pfn(vma, vma->vm_start,
+						(paste_addr >> PAGE_SHIFT));
+				return fault;
+			}
 		}
 	}
-	mutex_unlock(&txwin->task_ref.mmap_mutex);
 
 	/*
 	 * Received this fault due to closing the actual window.
@@ -465,7 +463,42 @@ 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;
+	}
+
+	scoped_guard(mutex, &txwin->task_ref.mmap_mutex)
+		txwin->task_ref.vma = NULL;
+}
+
 static const struct vm_operations_struct vas_vm_ops = {
+	.close = vas_mmap_close,
 	.fault = vas_mmap_fault,
 };
 
@@ -481,19 +514,28 @@ static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
 	txwin = cp_inst->txwin;
 
 	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
-		pr_debug("%s(): size 0x%zx, PAGE_SIZE 0x%zx\n", __func__,
+		pr_debug("size 0x%zx, PAGE_SIZE 0x%zx\n",
 				(vma->vm_end - vma->vm_start), PAGE_SIZE);
 		return -EINVAL;
 	}
 
+	/*
+	 * Map complete page to the paste address. So the user
+	 * space should pass 0ULL to the offset parameter.
+	 */
+	if (vma->vm_pgoff) {
+		pr_debug("Page offset unsupported to map paste address\n");
+		return -EINVAL;
+	}
+
 	/* Ensure instance has an open send window */
 	if (!txwin) {
-		pr_err("%s(): No send window open?\n", __func__);
+		pr_err("No send window open?\n");
 		return -EINVAL;
 	}
 
 	if (!cp_inst->coproc->vops || !cp_inst->coproc->vops->paste_addr) {
-		pr_err("%s(): VAS API is not registered\n", __func__);
+		pr_err("VAS API is not registered\n");
 		return -EACCES;
 	}
 
@@ -508,24 +550,22 @@ static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
 	 * close/open event and allows mmap() only when the window is
 	 * active.
 	 */
-	mutex_lock(&txwin->task_ref.mmap_mutex);
+	guard(mutex)(&txwin->task_ref.mmap_mutex);
 	if (txwin->status != VAS_WIN_ACTIVE) {
-		pr_err("%s(): Window is not active\n", __func__);
-		rc = -EACCES;
-		goto out;
+		pr_err("Window is not active\n");
+		return -EACCES;
 	}
 
 	paste_addr = cp_inst->coproc->vops->paste_addr(txwin);
 	if (!paste_addr) {
-		pr_err("%s(): Window paste address failed\n", __func__);
-		rc = -EINVAL;
-		goto out;
+		pr_err("Window paste address failed\n");
+		return -EINVAL;
 	}
 
 	pfn = paste_addr >> PAGE_SHIFT;
 
 	/* flags, page_prot from cxl_mmap(), except we want cachable */
-	vma->vm_flags |= VM_IO | VM_PFNMAP;
+	vm_flags_set(vma, VM_IO | VM_PFNMAP);
 	vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
 
 	prot = __pgprot(pgprot_val(vma->vm_page_prot) | _PAGE_DIRTY);
@@ -533,14 +573,12 @@ static int coproc_mmap(struct file *fp, struct vm_area_struct *vma)
 	rc = remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
 			vma->vm_end - vma->vm_start, prot);
 
-	pr_devel("%s(): paste addr %llx at %lx, rc %d\n", __func__,
-			paste_addr, vma->vm_start, rc);
+	pr_devel("paste addr %llx at %lx, rc %d\n", paste_addr,
+			vma->vm_start, rc);
 
 	txwin->task_ref.vma = vma;
 	vma->vm_ops = &vas_vm_ops;
 
-out:
-	mutex_unlock(&txwin->task_ref.mmap_mutex);
 	return rc;
 }
 
@@ -581,7 +619,7 @@ int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
 	pr_devel("%s device allocated, dev [%i,%i]\n", name,
 			MAJOR(coproc_device.devt), MINOR(coproc_device.devt));
 
-	coproc_device.class = class_create(mod, name);
+	coproc_device.class = class_create(name);
 	if (IS_ERR(coproc_device.class)) {
 		rc = PTR_ERR(coproc_device.class);
 		pr_err("Unable to create %s class %d\n", name, rc);
@@ -609,8 +647,7 @@ int vas_register_coproc_api(struct module *mod, enum vas_cop_type cop_type,
 		goto err;
 	}
 
-	pr_devel("%s: Added dev [%d,%d]\n", __func__, MAJOR(devno),
-			MINOR(devno));
+	pr_devel("Added dev [%d,%d]\n", MAJOR(devno), MINOR(devno));
 
 	return 0;