On 05/09/2023 09:13, wangweidong.a@xxxxxxxxxx wrote: > Thank you very much for your reply. > > On 05/09/2023 15:05, krzysztof.kozlowski@xxxxxxxxxx wrote: >> On 05/09/2023 04:46, wangweidong.a@xxxxxxxxxx wrote: > >>>> Even though it does not look like from the diff, the property is not >>>> actually used by the driver, because once set, it is read only in loops >>>> depending on ddt_num (prof_hdr->ddt_num, cfg_hdr->ddt_num). The >>>> variable ddt_num is never set and is always 0, so the loops do not have >>>> any iteration. Dropping sound-channel and ddt_num-related loops allows >>>> to drop empty functions which in turn drop quite a lot of code. This >>>> entire code was not possible to execute. >>> >>> The ddt_num variable is not always 0, this variable is defined >>> in the configuration file. The "prof_hdr" variable is assigned by >>> the "cfg_hdr" variable. The "cfg_hdr" variable is assigned by "aw_cfg" >>> aw_cfg is the data obtained through request_firmware.The specific >>> process is as follows: >>> >>> request_firmware ---> cont->data ---> aw_cfg->data --> cfg_hdr --> prof_hdr > >> Hm. So you load user-space provided file and assign it directly, without >> any validation (aw88395_dev_load_acf_check() checks only for magic), to >> a kernel structure. Sounds bullet-proof. Why using known kernel >> interfaces, better to implement some conf-file-parsing. > > Could you please tell me what known kernel interfaces > can be used to parse files? With exception of Audio topology and FDT, I do not think we parse user-provided files in Linux kernel. Best regards, Krzysztof
