From 88b333b0ed790f9433ff542b163bf972953b74d3 Mon Sep 17 00:00:00 2001 From: Jordan Crouse Date: Tue, 20 Dec 2016 08:54:29 -0700 Subject: [PATCH 1/3] drm/msm: Ensure that the hardware write pointer is valid Currently the value written to CP_RB_WPTR is calculated on the fly as (rb->next - rb->start). But as the code is designed rb->next is wrapped before writing the commands so if a series of commands happened to fit perfectly in the ringbuffer, rb->next would end up being equal to rb->size / 4 and thus result in an out of bounds address to CP_RB_WPTR. The easiest way to fix this is to mask WPTR when writing it to the hardware; it makes the hardware happy and the rest of the ringbuffer math appears to work and there isn't any point in upsetting anything. Signed-off-by: Jordan Crouse [squash in is_power_of_2() check] Signed-off-by: Rob Clark --- drivers/gpu/drm/msm/adreno/adreno_gpu.c | 9 ++++++++- drivers/gpu/drm/msm/msm_ringbuffer.c | 3 ++- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c index a18126150e11..14ff87686a36 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c @@ -213,7 +213,14 @@ void adreno_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit, void adreno_flush(struct msm_gpu *gpu) { struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu); - uint32_t wptr = get_wptr(gpu->rb); + uint32_t wptr; + + /* + * Mask wptr value that we calculate to fit in the HW range. This is + * to account for the possibility that the last command fit exactly into + * the ringbuffer and rb->next hasn't wrapped to zero yet + */ + wptr = get_wptr(gpu->rb) & ((gpu->rb->size / 4) - 1); /* ensure writes to ringbuffer have hit system memory: */ mb(); diff --git a/drivers/gpu/drm/msm/msm_ringbuffer.c b/drivers/gpu/drm/msm/msm_ringbuffer.c index f326cf6a32e6..67b34e069abf 100644 --- a/drivers/gpu/drm/msm/msm_ringbuffer.c +++ b/drivers/gpu/drm/msm/msm_ringbuffer.c @@ -23,7 +23,8 @@ struct msm_ringbuffer *msm_ringbuffer_new(struct msm_gpu *gpu, int size) struct msm_ringbuffer *ring; int ret; - size = ALIGN(size, 4); /* size should be dword aligned */ + if (WARN_ON(!is_power_of_2(size))) + return ERR_PTR(-EINVAL); ring = kzalloc(sizeof(*ring), GFP_KERNEL); if (!ring) { From 6490abc4bc35fa4f3bdb9c7e49096943c50e29ea Mon Sep 17 00:00:00 2001 From: Jordan Crouse Date: Tue, 20 Dec 2016 08:54:30 -0700 Subject: [PATCH 2/3] drm/msm: Put back the vaddr in submit_reloc() The error cases in submit_reloc() need to put back the virtual address of the bo before failling. Add a single failure path for the function. Signed-off-by: Jordan Crouse Signed-off-by: Rob Clark --- drivers/gpu/drm/msm/msm_gem_submit.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c index 166e84e4f0d4..b6411ea6ed17 100644 --- a/drivers/gpu/drm/msm/msm_gem_submit.c +++ b/drivers/gpu/drm/msm/msm_gem_submit.c @@ -290,7 +290,7 @@ static int submit_reloc(struct msm_gem_submit *submit, struct msm_gem_object *ob { uint32_t i, last_offset = 0; uint32_t *ptr; - int ret; + int ret = 0; if (offset % 4) { DRM_ERROR("non-aligned cmdstream buffer: %u\n", offset); @@ -318,12 +318,13 @@ static int submit_reloc(struct msm_gem_submit *submit, struct msm_gem_object *ob ret = copy_from_user(&submit_reloc, userptr, sizeof(submit_reloc)); if (ret) - return -EFAULT; + goto out; if (submit_reloc.submit_offset % 4) { DRM_ERROR("non-aligned reloc offset: %u\n", submit_reloc.submit_offset); - return -EINVAL; + ret = -EINVAL; + goto out; } /* offset in dwords: */ @@ -332,12 +333,13 @@ static int submit_reloc(struct msm_gem_submit *submit, struct msm_gem_object *ob if ((off >= (obj->base.size / 4)) || (off < last_offset)) { DRM_ERROR("invalid offset %u at reloc %u\n", off, i); - return -EINVAL; + ret = -EINVAL; + goto out; } ret = submit_bo(submit, submit_reloc.reloc_idx, NULL, &iova, &valid); if (ret) - return ret; + goto out; if (valid) continue; @@ -354,9 +356,10 @@ static int submit_reloc(struct msm_gem_submit *submit, struct msm_gem_object *ob last_offset = off; } +out: msm_gem_put_vaddr_locked(&obj->base); - return 0; + return ret; } static void submit_cleanup(struct msm_gem_submit *submit) From a6cb3b864b21b7345f824a4faa12b723c8aaf099 Mon Sep 17 00:00:00 2001 From: Jordan Crouse Date: Tue, 20 Dec 2016 08:54:31 -0700 Subject: [PATCH 3/3] drm/msm: Verify that MSM_SUBMIT_BO_FLAGS are set For every submission buffer object one of MSM_SUBMIT_BO_WRITE and MSM_SUBMIT_BO_READ must be set (and nothing else). If we allowed zero then the buffer object would never get queued to be unreferenced. Signed-off-by: Jordan Crouse Signed-off-by: Rob Clark --- drivers/gpu/drm/msm/msm_gem_submit.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c index b6411ea6ed17..489676568a10 100644 --- a/drivers/gpu/drm/msm/msm_gem_submit.c +++ b/drivers/gpu/drm/msm/msm_gem_submit.c @@ -106,7 +106,8 @@ static int submit_lookup_objects(struct msm_gem_submit *submit, pagefault_disable(); } - if (submit_bo.flags & ~MSM_SUBMIT_BO_FLAGS) { + if ((submit_bo.flags & ~MSM_SUBMIT_BO_FLAGS) || + !(submit_bo.flags & MSM_SUBMIT_BO_FLAGS)) { DRM_ERROR("invalid flags: %x\n", submit_bo.flags); ret = -EINVAL; goto out_unlock;