drivers/misc/sgi-gru: fix dereference of ERR_PTR

gru_alloc_gts() can fail and it can return ERR_PTR(errvalue). We should
not dereference it if it has returned error. And incase it has returned
error then wait for some time and try again.

Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org>
Acked-by: Dimitri Sivanich <sivanich@sgi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/misc/sgi-gru/grukservices.c b/drivers/misc/sgi-gru/grukservices.c
index 490b79a27c88..7812e34a1112 100644
--- a/drivers/misc/sgi-gru/grukservices.c
+++ b/drivers/misc/sgi-gru/grukservices.c
@@ -160,7 +160,12 @@ static void gru_load_kernel_context(struct gru_blade_state *bs, int blade_id)
         down_write(&bs->bs_kgts_sema);
 
         if (!bs->bs_kgts) {
-                bs->bs_kgts = gru_alloc_gts(NULL, 0, 0, 0, 0, 0);
+                do {
+                        bs->bs_kgts = gru_alloc_gts(NULL, 0, 0, 0, 0, 0);
+                        if (!IS_ERR(bs->bs_kgts))
+                                break;
+                        msleep(1);
+                } while (true);
                 bs->bs_kgts->ts_user_blade_id = blade_id;
         }
         kgts = bs->bs_kgts;