Re: Regression for PXE boot from patch "Remove the 'bugger off' message" in stable 6.6.18

[Greg KH <gregkh@linuxfoundation.org>]

On Tue, Mar 04, 2025 at 03:49:35PM +0100, Ulrich Gemkow wrote:
> Hello,
> 
> starting with stable kernel 6.6.18 we have problems with PXE booting.
> A bisect shows that the following patch is guilty:
> 
>   From 768171d7ebbce005210e1cf8456f043304805c15 Mon Sep 17 00:00:00 2001
>   From: Ard Biesheuvel <ardb@kernel.org>
>   Date: Tue, 12 Sep 2023 09:00:55 +0000
>   Subject: x86/boot: Remove the 'bugger off' message
> 
>   Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
>   Signed-off-by: Ingo Molnar <mingo@kernel.org>
>   Acked-by: H. Peter Anvin (Intel) <hpa@zytor.com>
>   Link: https://lore.kernel.org/r/20230912090051.4014114-21-ardb@google.com
> 
> With this patch applied PXE starts, requests the kernel and the initrd.
> Without showing anything on the console, the boot process stops.
> It seems, that the kernel crashes very early.
> 
> With stable kernel 6.6.17 PXE boot works without problems.
> 
> Reverting this single patch (which is part of a larger set of
> patches) solved the problem for us, PXE boot is working again.
> 
> We use the packages syslinux-efi and syslinux-common from Debian 12.
> The used boot files are /efi64/syslinux.efi and /ldlinux.e64.
> 
> Our config-File (for 6.6.80) is attached.
> 
> Regarding the patch description, we really do not boot with a floppy :-)
> 
> Any help would be greatly appreciated, I have a bit of a bad feeling
> about simply reverting a patch at such a deep level in the kernel.

Does newer kernels than 6.7.y work properly?  What about the latest
6.12.y release?

thanks,

greg k-h