Re: [PATCH v2] init: Print out unknown kernel parameters

From: Borislav Petkov
Date: Mon May 17 2021 - 04:23:58 EST

On Tue, May 11, 2021 at 04:10:09PM -0500, Andrew Halaney wrote:
> It is easy to foobar setting a kernel parameter on the command line
> without realizing it, there's not much output that you can use to
> assess what the kernel did with that parameter by default.
> Make it a little more explicit which parameters on the command line
> _looked_ like a valid parameter for the kernel, but did not match
> anything and ultimately got tossed to init. This is very similar to the
> unknown parameter message received when loading a module.
> This assumes the parameters are processed in a normal fashion, some
> parameters (dyndbg= for example) don't register their
> parameter with the rest of the kernel's parameters, and therefore
> always show up in this list (and are also given to init - like the
> rest of this list).
> Another example is BOOT_IMAGE= is highlighted as an offender, which it
> technically is, but is passed by LILO and GRUB so most systems will see
> that complaint.
> An example output where "foobared" and "unrecognized" are intentionally
> invalid parameters:
> Kernel command line: BOOT_IMAGE=/boot/vmlinuz-5.12-dirty debug log_buf_len=4M foobared unrecognized=foo
> Unknown command line parameters: foobared BOOT_IMAGE=/boot/vmlinuz-5.12-dirty unrecognized=foo
> Suggested-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Suggested-by: Borislav Petkov <bp@xxxxxxx>
> Signed-off-by: Andrew Halaney <ahalaney@xxxxxxxxxx>
> ---
> It's my first time sending a v2 via email, please let me know if I've
> messed that up in anyway. I decided it wasn't worth the effort to do
> "autocorrect" functionality Borislav was pondering about, feel free to
> disagree on that if you have a strong opinion.

Oh well, I guess let's first see how this works in practice.

Looks ok to me:

Acked-by: Borislav Petkov <bp@xxxxxxx>



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