Re: [PATCH] of: print warning when cmdline overflows from bootargs

[enlin.mu]

On 2025/11/6 16:55, Krzysztof Kozlowski wrote:
> On Wed, Nov 05, 2025 at 04:27:17PM +0800, Enlin Mu wrote:
> > From: Enlin Mu <enlin.mu@xxxxxxxxx>
> >
> > add debug info. sometimes cmdline in dts is too long,
>
> I don't see debug info here.
>
> Please use full sentences, starting with capital letter and ending with
> full stop.
>
> Please wrap commit message according to Linux coding style / submission
> process (neither too early nor over the limit):
> https://elixir.bootlin.com/linux/v6.4-rc1/source/Documentation/process/submitting-patches.rst#L597
>
>
> > developers are not aware of the length limit of the
> > cmdline, resulting in some misjudgments.
> >
> > Signed-off-by: Enlin Mu <enlin.mu@xxxxxxxxx>
> > ---
> >   drivers/of/fdt.c | 2 ++
> >   1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
> > index 0edd639898a6..077799b2f565 100644
> > --- a/drivers/of/fdt.c
> > +++ b/drivers/of/fdt.c
> > @@ -1085,6 +1085,8 @@ int __init early_init_dt_scan_chosen(char *cmdline)
> >   	p = of_get_flat_dt_prop(node, "bootargs", &l);
> >   	if (p != NULL && l > 0)
> >   		strscpy(cmdline, p, min(l, COMMAND_LINE_SIZE));
> > +	if (l > COMMAND_LINE_SIZE)
> > +		pr_warn("cmdline overflows from bootargs\n");
>
> Why only OF early should have this warning and cmdline passed via ATAGS
> or in ACPI system should not?
I have a Raspberry Pi 5, so I can test my patch. But for chips with 
other architectures, I don't have the equipment and I am not very
familiar with them. If you are familiar with other architectures,
I hope you can help impore the patch or independently complete this
idea.

Thanks.
> Best regards,
> Krzysztof