[PATCH] drm/i915/gvt: fix uninitialized return in intel_gvt_update_reg_whitelist()

From: Dan Carpenter
Date: Tue Jan 26 2021 - 01:25:13 EST


Smatch found an uninitialized variable bug in this code:

drivers/gpu/drm/i915/gvt/cmd_parser.c:3191 intel_gvt_update_reg_whitelist()
error: uninitialized symbol 'ret'.

The first thing that Smatch complains about is that "ret" isn't set if
we don't enter the "for_each_engine(engine, &dev_priv->gt, id) {" loop.
Presumably we always have at least one engine so that's a false
positive.

But it's definitely a bug to not set "ret" if i915_gem_object_pin_map()
fails.

Let's fix the bug and silence the false positive.

Fixes: 493f30cd086e ("drm/i915/gvt: parse init context to update cmd accessible reg whitelist")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
drivers/gpu/drm/i915/gvt/cmd_parser.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gvt/cmd_parser.c b/drivers/gpu/drm/i915/gvt/cmd_parser.c
index 7fb91de06557..d54ea0e4681d 100644
--- a/drivers/gpu/drm/i915/gvt/cmd_parser.c
+++ b/drivers/gpu/drm/i915/gvt/cmd_parser.c
@@ -3103,7 +3103,7 @@ void intel_gvt_update_reg_whitelist(struct intel_vgpu *vgpu)
struct intel_vgpu_submission *s = &vgpu->submission;
struct i915_request *requests[I915_NUM_ENGINES] = {};
bool is_ctx_pinned[I915_NUM_ENGINES] = {};
- int ret;
+ int ret = 0;

if (gvt->is_reg_whitelist_updated)
return;
@@ -3157,6 +3157,7 @@ void intel_gvt_update_reg_whitelist(struct intel_vgpu *vgpu)
if (IS_ERR(vaddr)) {
gvt_err("failed to pin init ctx obj, ring=%d, err=%lx\n",
id, PTR_ERR(vaddr));
+ ret = PTR_ERR(vaddr);
goto out;
}

--
2.29.2