[PATCH] drm/i915/gvt/scheduler: fix potential NULL pointer dereference
From: Gustavo A. R. Silva
Date: Mon Mar 19 2018 - 15:31:09 EST
_workload_ is being dereferenced before it is null checked, hence
there is a potential null pointer dereference.
Fix this by moving the pointer dereference after _workload_ has
been null checked.
Addresses-Coverity-ID: 1430136 ("Dereference before null check")
Fixes: fa3dd623e559 ("drm/i915/gvt: keep oa config in shadow ctx")
Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gvt/scheduler.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/gvt/scheduler.c b/drivers/gpu/drm/i915/gvt/scheduler.c
index 0681264..be1a297 100644
--- a/drivers/gpu/drm/i915/gvt/scheduler.c
+++ b/drivers/gpu/drm/i915/gvt/scheduler.c
@@ -60,9 +60,9 @@ static void set_context_pdp_root_pointer(
static void sr_oa_regs(struct intel_vgpu_workload *workload,
u32 *reg_state, bool save)
{
- struct drm_i915_private *dev_priv = workload->vgpu->gvt->dev_priv;
- u32 ctx_oactxctrl = dev_priv->perf.oa.ctx_oactxctrl_offset;
- u32 ctx_flexeu0 = dev_priv->perf.oa.ctx_flexeu0_offset;
+ struct drm_i915_private *dev_priv;
+ u32 ctx_oactxctrl;
+ u32 ctx_flexeu0;
int i = 0;
u32 flex_mmio[] = {
i915_mmio_reg_offset(EU_PERF_CNTL0),
@@ -77,6 +77,10 @@ static void sr_oa_regs(struct intel_vgpu_workload *workload,
if (!workload || !reg_state || workload->ring_id != RCS)
return;
+ dev_priv = workload->vgpu->gvt->dev_priv;
+ ctx_oactxctrl = dev_priv->perf.oa.ctx_oactxctrl_offset;
+ ctx_flexeu0 = dev_priv->perf.oa.ctx_flexeu0_offset;
+
if (save) {
workload->oactxctrl = reg_state[ctx_oactxctrl + 1];
--
2.7.4