misc: mic: fix incorrect use of error codes in SCIF DMA driver

The error code passed to ERR_PTR() always should be negated.  Also, the
return value of scif_add_mmu_notifier() was never checked.

Signed-off-by: Eric Biggers <ebiggers3@gmail.com>
Reviewed-by: Sudeep Dutt <sudeep.dutt@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/mic/scif/scif_dma.c b/drivers/misc/mic/scif/scif_dma.c
index 8804bccf04b610693d89fd71ed09e7fb8d701424..cd01a0efda6b9a4f8710ab3ad94a24f060a9fba1 100644 (file)
--- a/drivers/misc/mic/scif/scif_dma.c
+++ b/drivers/misc/mic/scif/scif_dma.c
@@ -271,13 +271,10 @@ static struct scif_mmu_notif *
 scif_find_mmu_notifier(struct mm_struct *mm, struct scif_endpt_rma_info *rma)
 {
        struct scif_mmu_notif *mmn;
-       struct list_head *item;
 
-       list_for_each(item, &rma->mmn_list) {
-               mmn = list_entry(item, struct scif_mmu_notif, list);
+       list_for_each_entry(mmn, &rma->mmn_list, list)
                if (mmn->mm == mm)
                        return mmn;
-       }
        return NULL;
 }
 
@@ -288,13 +285,12 @@ scif_add_mmu_notifier(struct mm_struct *mm, struct scif_endpt *ep)
                 = kzalloc(sizeof(*mmn), GFP_KERNEL);
 
        if (!mmn)
-               return ERR_PTR(ENOMEM);
+               return ERR_PTR(-ENOMEM);
 
        scif_init_mmu_notifier(mmn, current->mm, ep);
-       if (mmu_notifier_register(&mmn->ep_mmu_notifier,
-                                 current->mm)) {
+       if (mmu_notifier_register(&mmn->ep_mmu_notifier, current->mm)) {
                kfree(mmn);
-               return ERR_PTR(EBUSY);
+               return ERR_PTR(-EBUSY);
        }
        list_add(&mmn->list, &ep->rma_info.mmn_list);
        return mmn;
@@ -1725,7 +1721,7 @@ static int scif_rma_copy(scif_epd_t epd, off_t loffset, unsigned long addr,
                mutex_lock(&ep->rma_info.mmn_lock);
                mmn = scif_find_mmu_notifier(current->mm, &ep->rma_info);
                if (!mmn)
-                       scif_add_mmu_notifier(current->mm, ep);
+                       mmn = scif_add_mmu_notifier(current->mm, ep);
                mutex_unlock(&ep->rma_info.mmn_lock);
                if (IS_ERR(mmn)) {
                        scif_put_peer_dev(spdev);