[PATCH v2] drm/etnaviv: fix ref count leak via pm_runtime_get_sync

From: Navid Emamdoost
Date: Mon Jun 15 2020 - 02:12:38 EST


in etnaviv_gpu_submit, etnaviv_gpu_recover_hang, etnaviv_gpu_debugfs,
and etnaviv_gpu_init the call to pm_runtime_get_sync increments the
counter even in case of failure, leading to incorrect ref count.
In case of failure, decrement the ref count before returning.

Signed-off-by: Navid Emamdoost <navid.emamdoost@xxxxxxxxx>
---
Changes in v2:
- replace pm_runtime_put with pm_runtime_put_noidle
---
drivers/gpu/drm/etnaviv/etnaviv_gpu.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
index a31eeff2b297..7c9f3f9ba123 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gpu.c
@@ -722,7 +722,7 @@ int etnaviv_gpu_init(struct etnaviv_gpu *gpu)
ret = pm_runtime_get_sync(gpu->dev);
if (ret < 0) {
dev_err(gpu->dev, "Failed to enable GPU power domain\n");
- return ret;
+ goto pm_put;
}

etnaviv_hw_identify(gpu);
@@ -819,6 +819,7 @@ int etnaviv_gpu_init(struct etnaviv_gpu *gpu)

fail:
pm_runtime_mark_last_busy(gpu->dev);
+pm_put:
pm_runtime_put_autosuspend(gpu->dev);

return ret;
@@ -859,7 +860,7 @@ int etnaviv_gpu_debugfs(struct etnaviv_gpu *gpu, struct seq_file *m)

ret = pm_runtime_get_sync(gpu->dev);
if (ret < 0)
- return ret;
+ goto pm_put;

dma_lo = gpu_read(gpu, VIVS_FE_DMA_LOW);
dma_hi = gpu_read(gpu, VIVS_FE_DMA_HIGH);
@@ -1003,6 +1004,7 @@ int etnaviv_gpu_debugfs(struct etnaviv_gpu *gpu, struct seq_file *m)
ret = 0;

pm_runtime_mark_last_busy(gpu->dev);
+pm_put:
pm_runtime_put_autosuspend(gpu->dev);

return ret;
@@ -1016,7 +1018,7 @@ void etnaviv_gpu_recover_hang(struct etnaviv_gpu *gpu)
dev_err(gpu->dev, "recover hung GPU!\n");

if (pm_runtime_get_sync(gpu->dev) < 0)
- return;
+ goto pm_put;

mutex_lock(&gpu->lock);

@@ -1035,6 +1037,7 @@ void etnaviv_gpu_recover_hang(struct etnaviv_gpu *gpu)

mutex_unlock(&gpu->lock);
pm_runtime_mark_last_busy(gpu->dev);
+pm_put:
pm_runtime_put_autosuspend(gpu->dev);
}

@@ -1308,8 +1311,10 @@ struct dma_fence *etnaviv_gpu_submit(struct etnaviv_gem_submit *submit)

if (!submit->runtime_resumed) {
ret = pm_runtime_get_sync(gpu->dev);
- if (ret < 0)
+ if (ret < 0) {
+ pm_runtime_put_noidle(gpu->dev);
return NULL;
+ }
submit->runtime_resumed = true;
}

@@ -1326,6 +1331,7 @@ struct dma_fence *etnaviv_gpu_submit(struct etnaviv_gem_submit *submit)
ret = event_alloc(gpu, nr_events, event);
if (ret) {
DRM_ERROR("no free events\n");
+ pm_runtime_put_noidle(gpu->dev);
return NULL;
}

--
2.17.1