From 774449ebcb18bae146e2b6f6d012b46e64a095b9 Mon Sep 17 00:00:00 2001 From: Rob Clark Date: Fri, 15 May 2015 09:19:36 -0400 Subject: [PATCH] drm/msm: fix locking inconsistencies in gpu->destroy() In error paths, this was being called without struct_mutex held. Leading to panics like: msm 1a00000.qcom,mdss_mdp: No memory protection without IOMMU Kernel panic - not syncing: BUG! CPU: 0 PID: 1409 Comm: cat Not tainted 4.0.0-dirty #4 Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) Call trace: [] dump_backtrace+0x0/0x118 [] show_stack+0x10/0x20 [] dump_stack+0x84/0xc4 [] panic+0xd0/0x210 [] drm_gem_object_free+0x5c/0x60 [] adreno_gpu_cleanup+0x60/0x80 [] a3xx_destroy+0x20/0x70 [] a3xx_gpu_init+0x84/0x108 [] adreno_load_gpu+0x58/0x190 [] msm_open+0x74/0x88 [] drm_open+0x168/0x400 [] drm_stub_open+0xa8/0x118 [] chrdev_open+0x94/0x198 [] do_dentry_open+0x208/0x310 [] vfs_open+0x44/0x50 [] do_last.isra.14+0x2c4/0xc10 [] path_openat+0x80/0x5e8 [] do_filp_open+0x2c/0x98 [] do_sys_open+0x13c/0x228 [] SyS_openat+0xc/0x18 CPU1: stopping But there isn't any particularly good reason to hold struct_mutex for teardown, so just standardize on calling it without the mutex held and use the _unlocked() versions for GEM obj unref'ing Signed-off-by: Rob Clark --- drivers/gpu/drm/msm/adreno/adreno_gpu.c | 2 +- drivers/gpu/drm/msm/msm_drv.c | 2 +- drivers/gpu/drm/msm/msm_ringbuffer.c | 2 +- 3 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c index 94a5bee69fe7..bbdcab0a56c1 100644 --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c @@ -384,7 +384,7 @@ void adreno_gpu_cleanup(struct adreno_gpu *gpu) if (gpu->memptrs_bo) { if (gpu->memptrs_iova) msm_gem_put_iova(gpu->memptrs_bo, gpu->base.id); - drm_gem_object_unreference(gpu->memptrs_bo); + drm_gem_object_unreference_unlocked(gpu->memptrs_bo); } release_firmware(gpu->pm4); release_firmware(gpu->pfp); diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c index cc6485ef2949..c80a6bee2b18 100644 --- a/drivers/gpu/drm/msm/msm_drv.c +++ b/drivers/gpu/drm/msm/msm_drv.c @@ -145,8 +145,8 @@ static int msm_unload(struct drm_device *dev) if (gpu) { mutex_lock(&dev->struct_mutex); gpu->funcs->pm_suspend(gpu); - gpu->funcs->destroy(gpu); mutex_unlock(&dev->struct_mutex); + gpu->funcs->destroy(gpu); } if (priv->vram.paddr) { diff --git a/drivers/gpu/drm/msm/msm_ringbuffer.c b/drivers/gpu/drm/msm/msm_ringbuffer.c index 8171537dd7d1..1f14b908b221 100644 --- a/drivers/gpu/drm/msm/msm_ringbuffer.c +++ b/drivers/gpu/drm/msm/msm_ringbuffer.c @@ -56,6 +56,6 @@ fail: void msm_ringbuffer_destroy(struct msm_ringbuffer *ring) { if (ring->bo) - drm_gem_object_unreference(ring->bo); + drm_gem_object_unreference_unlocked(ring->bo); kfree(ring); } -- 2.34.1