Re: [RFC PATCH] cmdline: Hide "debug" from /proc/cmdline

From: Borislav Petkov
Date: Wed Apr 02 2014 - 15:09:23 EST


On Wed, Apr 02, 2014 at 02:42:19PM -0400, Steven Rostedt wrote:
> It has come to our attention that a system running a specific user
> space init program will not boot if you add "debug" to the kernel
> command line. What happens is that the user space tool parses the
> kernel command line, and if it sees "debug" it will spit out so much
> information that the system fails to boot. This basically renders the
> "debug" option for the kernel useless.
>
> This bug has been reported to the developers of said tool
> here:
>
> https://bugs.freedesktop.org/show_bug.cgi?id=76935
>
> The response is:
>
> "Generic terms are generic, not the first user owns them."
>
> That is, the "debug" statement on the *kernel* command line is not
> owned by the kernel just because it was the first user of it, and
> they refuse to fix their bug.
>
> Well, my response is, we OWN the kernel command line, and as such, we
> can keep the users from seeing stuff on it if we so choose. And with
> that, I propose this patch, which hides "debug" from /proc/cmdline,
> such that we don't have to worry about tools parsing for it and causing
> hardship for those trying to debug the kernel.
>
> Reported-by: Borislav Petkov <bp@xxxxxxxxx>
> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

Well, maybe the minor nit that it leaves two spaces in /proc/cmdline now:

"root=/dev/sda1 ignore_loglevel log_buf_len=10M earlyprintk=ttyS0,115200 console=ttyS0,115200 console=tty0"

Also, you need to add

Suggested-by: PeterZ.

Other than that:

Vehemently-and-totally-acked-by: Borislav Petkov <bp@xxxxxxx>

It is about time this idiotic shit stopped.

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
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