gru: handle failures to mmu_notifier_register

Under some conditions, mmu_notifier_register() will fail to register a
mmu_notifier.  Fix the GRU driver to correctly handle these failures.

Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c
index 9470303a9cb9..ada7df7e0968 100644
--- a/drivers/misc/sgi-gru/grufault.c
+++ b/drivers/misc/sgi-gru/grufault.c
@@ -96,7 +96,7 @@ static struct gru_thread_state *gru_alloc_locked_gts(unsigned long vaddr)
         vma = gru_find_vma(vaddr);
         if (vma)
                 gts = gru_alloc_thread_state(vma, TSID(vaddr, vma));
-        if (gts) {
+        if (!IS_ERR(gts)) {
                 mutex_lock(&gts->ts_ctxlock);
                 downgrade_write(&mm->mmap_sem);
         } else {
@@ -747,8 +747,8 @@ int gru_set_context_option(unsigned long arg)
         gru_dbg(grudev, "op %d, gseg 0x%lx, value1 0x%lx\n", req.op, req.gseg, req.val1);
 
         gts = gru_alloc_locked_gts(req.gseg);
-        if (!gts)
-                return -EINVAL;
+        if (IS_ERR(gts))
+                return PTR_ERR(gts);
 
         switch (req.op) {
         case sco_blade_chiplet: