From 54ddf3a6af537cbfe038f9a2754f26de80c5818b Mon Sep 17 00:00:00 2001 From: Grazvydas Ignotas Date: Sun, 25 Sep 2016 23:34:46 +0300 Subject: [PATCH] drm/amdgpu: don't leave dangling pointers around Right now it's possible to trigger fence_drv.fences[] dereference after the array has been freed. While the real problem is elsewhere, this still results in confusing errors that depend on how the freed memory was reused (I've seen "kernel tried to execute NX-protected page"), it's better to clear them and get NULL dereference so that it's obvious what's going wrong. Signed-off-by: Grazvydas Ignotas Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c | 2 ++ drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 1 + 2 files changed, 3 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c index 17e13621fae9..e203e5561107 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c @@ -60,6 +60,7 @@ static int amdgpu_ctx_init(struct amdgpu_device *adev, struct amdgpu_ctx *ctx) amd_sched_entity_fini(&adev->rings[j]->sched, &ctx->rings[j].entity); kfree(ctx->fences); + ctx->fences = NULL; return r; } return 0; @@ -77,6 +78,7 @@ static void amdgpu_ctx_fini(struct amdgpu_ctx *ctx) for (j = 0; j < amdgpu_sched_jobs; ++j) fence_put(ctx->rings[i].fences[j]); kfree(ctx->fences); + ctx->fences = NULL; for (i = 0; i < adev->num_rings; i++) amd_sched_entity_fini(&adev->rings[i]->sched, diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c index 0b109aebfec6..3a2e42f4b897 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c @@ -454,6 +454,7 @@ void amdgpu_fence_driver_fini(struct amdgpu_device *adev) for (j = 0; j <= ring->fence_drv.num_fences_mask; ++j) fence_put(ring->fence_drv.fences[j]); kfree(ring->fence_drv.fences); + ring->fence_drv.fences = NULL; ring->fence_drv.initialized = false; } } -- 2.39.5