Date: Sun, 19 Mar 2023 10:34:21 -0500 From: Kyle Evans <kevans@freebsd.org> To: Yuri <yuri@aetern.org> Cc: =?UTF-8?B?R29yYW4gTWVracSH?= <meka@tilda.center>, freebsd-current@freebsd.org Subject: Re: Infinite loop with d_write_t Message-ID: <CACNAnaET0DKngOqrE_%2B2B8g8MRhzjmf8Ci3RKzNo0CHwtcsKNw@mail.gmail.com> In-Reply-To: <e418c6f4-ab10-020e-0b94-2f47d3182fb2@aetern.org> References: <20230319111404.a6ac2w44u4trtedy@tilda.center> <e418c6f4-ab10-020e-0b94-2f47d3182fb2@aetern.org>
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On Sun, Mar 19, 2023 at 6:33 AM Yuri <yuri@aetern.org> wrote: > > Goran Mekić wrote: > > Hello, > > > > I'm trying to assemble a minimal kernel module and user space program as > > a skeleton, and no matter what I do I get infinite loop. The code for > > kernel is https://github.com/mekanix/freebsd-project/blob/master/kernel/main.c. > > The way to test: > > # make > > # sudo kldload ./hello.ko > > # echo "something" >/dev/hello > > Write done. > > Write done. > > ... > > > > What am I doing wrong and where does that infinite loop comes from? > > Why are you using copyin() and not uiomove() in d_write entry? > > There's an example that looks like you are trying to do: > > https://docs.freebsd.org/en/books/arch-handbook/driverbasics/#driverbasics-char > This... d_write/d_read need the uio accounting updated to reflect how much data was written/read, it doesn't want to assume you were able to do everything in a single call. Thanks, Kyle Evanshelp
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