For core ops we are having only write protect but
there is no read protect, because of this in mult
-threading and concurrency, one CPU core is readi
-ing without waiting which is causing the NULL
pointer dereferece crash.
one such scenario is as show below, where in one
core core->ops becoming NULL and in another core
calling core->ops->session_init().
CPU: 7(core):
Call trace:
hfi_session_init+0x180/0x1dc [venus_core]
vdec_queue_setup+0x9c/0x364 [venus_dec]
vb2_core_reqbufs+0x1e4/0x368 [videobuf2_common]
vb2_reqbufs+0x4c/0x64 [videobuf2_v4l2]
v4l2_m2m_reqbufs+0x50/0x84 [v4l2_mem2mem]
v4l2_m2m_ioctl_reqbufs+0x2c/0x38 [v4l2_mem2mem]
v4l_reqbufs+0x4c/0x5c
__video_do_ioctl+0x2b0/0x39c
CPU: 0(core):
Call trace:
venus_shutdown+0x98/0xfc [venus_core]
venus_sys_error_handler+0x64/0x148 [venus_core]
process_one_work+0x210/0x3d0
worker_thread+0x248/0x3f4
kthread+0x11c/0x12c
Signed-off-by: Mansur Alisha Shaik <mansur@xxxxxxxxxxxxxx>
---
drivers/media/platform/qcom/venus/core.c | 2 +-
drivers/media/platform/qcom/venus/hfi.c | 5 ++++-
2 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/media/platform/qcom/venus/core.c b/drivers/media/platform/qcom/venus/core.c
index 203c653..fe99c83 100644
--- a/drivers/media/platform/qcom/venus/core.c
+++ b/drivers/media/platform/qcom/venus/core.c
@@ -64,8 +64,8 @@ static void venus_sys_error_handler(struct work_struct *work)
pm_runtime_get_sync(core->dev);
hfi_core_deinit(core, true);
- hfi_destroy(core);
mutex_lock(&core->lock);
+ hfi_destroy(core);
venus_shutdown(core);
pm_runtime_put_sync(core->dev);
diff --git a/drivers/media/platform/qcom/venus/hfi.c b/drivers/media/platform/qcom/venus/hfi.c
index a211eb9..2eeb31f 100644
--- a/drivers/media/platform/qcom/venus/hfi.c
+++ b/drivers/media/platform/qcom/venus/hfi.c
@@ -195,7 +195,7 @@ EXPORT_SYMBOL_GPL(hfi_session_create);
int hfi_session_init(struct venus_inst *inst, u32 pixfmt)
{
struct venus_core *core = inst->core;
- const struct hfi_ops *ops = core->ops;
+ const struct hfi_ops *ops;
int ret;
if (inst->state != INST_UNINIT)
@@ -204,10 +204,13 @@ int hfi_session_init(struct venus_inst *inst, u32 pixfmt)
inst->hfi_codec = to_codec_type(pixfmt);
reinit_completion(&inst->done);
+ mutex_lock(&core->lock);
+ ops = core->ops;
ret = ops->session_init(inst, inst->session_type, inst->hfi_codec);
if (ret)
return ret;
+ mutex_unlock(&core->lock);
ret = wait_session_msg(inst);
if (ret)
return ret;
--
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of Code Aurora Forum, hosted by The Linux Foundation
