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Date:   Fri, 13 Mar 2020 08:22:54 +0100
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Bruno Meneguele <bmeneg@redhat.com>
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        pmladek@suse.com, sergey.senozhatsky@gmail.com, rostedt@goodmis.org
Subject: Re: [PATCH] kernel/printk: add kmsg SEEK_CUR handling
Message-ID: <20200313072254.GA1960396@kroah.com>
References: <20200313003533.2203429-1-bmeneg@redhat.com>
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On Thu, Mar 12, 2020 at 09:35:33PM -0300, Bruno Meneguele wrote:
> Userspace libraries, e.g. glibc's dprintf(), expect the default return value
> for invalid seek situations: -ESPIPE, but when the IO was over /dev/kmsg the
> current state of kernel code was returning the generic case of an -EINVAL.
> Hence, userspace programs were not behaving as expected or documented.
> 
> With this patch we add SEEK_CUR case returning the expected value and also a
> simple mention of it in kernel's documentation for those relying on that for
> guidance.
> 
> Signed-off-by: Bruno Meneguele <bmeneg@redhat.com>
> ---
>  Documentation/ABI/testing/dev-kmsg | 2 ++
>  kernel/printk/printk.c             | 4 ++++
>  2 files changed, 6 insertions(+)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>