Ok, firstly we need to discuss the list usage, for list head we need do initialization, but for list node we don't need initialization at all. And for misc_list head, we use LIST_HEAD to define and initialize it. So I don't know why we put INIT_LIST_HEAD(&misc->list) in function misc_register, any bugs when without it?
-----Original Message----- From: arndbergm...@gmail.com [mailto:arndbergm...@gmail.com] On Behalf Of Arnd Bergmann Sent: Monday, June 26, 2017 10:10 PM To: Zhongping Tan (谭中平) Cc: Orson Zhai (翟京); Greg Kroah-Hartman; Linux Kernel Mailing List Subject: Re: 答复: [RFC PATCH] char: misc: Init misc->list in a safe way On Mon, Jun 26, 2017 at 4:00 PM, Zhongping Tan (谭中平) <zhongping....@spreadtrum.com> wrote: > hi Arnd: > Another way to describe this question, misc_register shouldn't modify > the member of the miscdevice especially when return error. Let the caller to > ensure the list have been initialized, or when return error, please don't > initialize the list. Why not? The caller should only initialize a couple of fields in the structure (name, minor, fops, ...) not never even look at the list entry, which is really internal to the misc_register()/misc_unregister(). Arnd
