Re: [PATCH] printk: fix buffer overflow potential for print_text()

[John Ogness <john.ogness@linutronix.de>]

On 2021-01-19, Sergey Senozhatsky <sergey.senozhatsky@gmail.com> wrote:
> John, how did you spot these problems?

I am preparing my series to remove the logbuf_lock, which also refactors
and consolidates code from syslog_print_all() and
kmsg_dump_get_buffer(). While testing/verifying my series, I noticed the
these oddities in the semantics and decided I should research where they
came from and if they were actually necessary.

I wouldn't say the oddities are necessary (in fact, they are quite
annoying), but we have decided to keep them in out of fear of breaking
out-of-tree modules and/or interesting userspace code.

One positive effect of the rework is that we are finding these oddities
and documenting them. I think you and Petr are going down a similar path
with the console registration stuff now.

John