drm/i915/selftests: fix error handling in __live_lrc_indirect_ctx_bb()

If intel_context_create() fails then it leads to an error pointer
dereference.  I shuffled things around to make error handling easier.

Fixes: 1dd47b54baea ("drm/i915: Add live selftests for indirect ctx batchbuffers")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Andi Shyti <andi.shyti@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200429132425.GE815283@mwanda

diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index d3fa91a..c4bfad5 100644 (file)
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -5795,26 +5795,29 @@ static int indirect_ctx_bb_check(struct intel_context *ce)
 static int __live_lrc_indirect_ctx_bb(struct intel_engine_cs *engine)
 {
        struct intel_context *a, *b;
-       int err = 0;
+       int err;
 
        a = intel_context_create(engine);
-       b = intel_context_create(engine);
-
+       if (IS_ERR(a))
+               return PTR_ERR(a);
        err = intel_context_pin(a);
        if (err)
-               return err;
+               goto put_a;
 
-       err = intel_context_pin(b);
-       if (err) {
-               intel_context_put(a);
-               return err;
+       b = intel_context_create(engine);
+       if (IS_ERR(b)) {
+               err = PTR_ERR(b);
+               goto unpin_a;
        }
+       err = intel_context_pin(b);
+       if (err)
+               goto put_b;
 
        /* We use the already reserved extra page in context state */
        if (!a->wa_bb_page) {
                GEM_BUG_ON(b->wa_bb_page);
                GEM_BUG_ON(INTEL_GEN(engine->i915) == 12);
-               goto out;
+               goto unpin_b;
        }
 
        /*
@@ -5829,14 +5832,17 @@ static int __live_lrc_indirect_ctx_bb(struct intel_engine_cs *engine)
 
        err = indirect_ctx_bb_check(a);
        if (err)
-               goto out;
+               goto unpin_b;
 
        err = indirect_ctx_bb_check(b);
-out:
+
+unpin_b:
        intel_context_unpin(b);
+put_b:
        intel_context_put(b);
-
+unpin_a:
        intel_context_unpin(a);
+put_a:
        intel_context_put(a);
 
        return err;