Hi Mansur, On 8/10/20 12:50 PM, Stanimir Varbanov wrote: > Hi Mansur, > > Thanks for the patches! > > On 8/7/20 9:24 AM, Mansur Alisha Shaik wrote: >> For core ops we are having only write protect but there >> is no read protect, because of this in multthreading >> and concurrency, one CPU core is reading without wait >> 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: core-7: >> 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: core-0: >> 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(-) See below comment, otherwise: Acked-by: Stanimir Varbanov <stanimir.varbanov@xxxxxxxxxx> >> >> 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); > > As my recovery fixes [1] touches this part also, could you please apply > them on top of yours and re-test? I'll drop above chunk from the patch because it is already taken into account in my recovery fixes series and queue up the patch for v5.10. > > Otherwise this patch looks good to me. > > [1] https://www.spinics.net/lists/linux-arm-msm/msg70092.html > >> 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; >> > -- regards, Stan
