Merge remote-tracking branch 'airlied/drm-next' into drm-misc-next

Picking up drm-next @ 4.12-rc1 in order to apply Michal Hocko's vmalloc patch set

Signed-off-by: Sean Paul <seanpaul@chromium.org>

1 files changed, 12 insertions, 3 deletions

diff --git a/drivers/misc/cxl/file.c b/drivers/misc/cxl/file.c
index e7139c76f961..17b433f1ce23 100644
--- a/drivers/misc/cxl/file.c
+++ b/drivers/misc/cxl/file.c
@@ -18,6 +18,7 @@
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/slab.h>
+#include <linux/sched/mm.h>
 #include <asm/cputable.h>
 #include <asm/current.h>
 #include <asm/copro.h>
@@ -216,8 +217,16 @@ static long afu_ioctl_start_work(struct cxl_context *ctx,
 	 * process is still accessible.
 	 */
 	ctx->pid = get_task_pid(current, PIDTYPE_PID);
-	ctx->glpid = get_task_pid(current->group_leader, PIDTYPE_PID);
 
+	/* acquire a reference to the task's mm */
+	ctx->mm = get_task_mm(current);
+
+	/* ensure this mm_struct can't be freed */
+	cxl_context_mm_count_get(ctx);
+
+	/* decrement the use count */
+	if (ctx->mm)
+		mmput(ctx->mm);
 
 	trace_cxl_attach(ctx, work.work_element_descriptor, work.num_interrupts, amr);
 
@@ -225,9 +234,9 @@ static long afu_ioctl_start_work(struct cxl_context *ctx,
 							amr))) {
 		afu_release_irqs(ctx, ctx);
 		cxl_adapter_context_put(ctx->afu->adapter);
-		put_pid(ctx->glpid);
 		put_pid(ctx->pid);
-		ctx->glpid = ctx->pid = NULL;
+		ctx->pid = NULL;
+		cxl_context_mm_count_put(ctx);
 		goto out;
 	}