bug - bootflow: grub efi crashes when bootflow selected explicitly

[Simon Glass]

Hi Shantur,

On Wed, 15 Nov 2023 at 15:13, Shantur Rathore <i at shantur.com> wrote:
>
> Hi Simon,
>
> I have figured out the cause of the crash.
> It happens here -
> https://github.com/u-boot/u-boot/blob/master/boot/bootflow.c#L470
> while doing - free(bflow->buf)
>
> As I understand it,
> - Just before starting kernel EFI binary calls usb-uclass->usb_stop()
> - This starts removing all devices in my case ( 6x usb_hub, 2x
> partition, 1x blk, 2x bootdev, 1x usb_maas_storage)
> - While removing bootdev, it ends up calling bootdev-uclass ->
> bootdev_pre_unbind -> bootdev_clear_bootflows which calls
> bootflow->bootflow_remove and bootflow_free
>
> I don't know why this buf cannot be freed, is it because the EFI
> binary in the buffer is still being used ( efi/boot/bootaa64.efi ) ?
> But commenting this line out fixes the crash and linux boots happily.
>
> Fixing this properly is above my pay grade as of now.

Great, thank you! I will send a patch.

Regards,
Simon

>
> Kind regards,
> Shantur
>
> On Wed, Nov 15, 2023 at 3:58 PM Simon Glass <sjg at chromium.org> wrote:
> >
> > Hi Shantur,
> >
> > On Wed, 15 Nov 2023 at 08:23, Shantur Rathore <i at shantur.com> wrote:
> > >
> > > Hi Simon,
> > >
> > > >
> > > > Is this the blue port on top of the USB-C connector?
> > > >
> > > Yes, that's correct.
> > > For my drive I needed -
> > > https://patchwork.ozlabs.org/project/uboot/patch/20231110141311.512334-1-i@shantur.com/
> > >
> > > >
> > > > Which version of Armbian / download link?
> > > >
> > > https://redirect.armbian.com/rockpro64/Bookworm_current
> > >
> > > > Yes it is scanning first, before reading the efi app, etc.
> > > >
> > > > I have the same hardware so may be able to dig into this.
> > >
> > > Sorry, I meant to ask if anything specific to USB.
> > > I see it loads efi from the network or disk and calls bootefi with the
> > > loaded address.
> > > I don't know deep boot / efi stuff, just trying to compare how it's
> > > loading efi differently than fatload in this case.
> >
> > There is nothing special about USB in boootstd, so far as I know.
> >
> > But until we figure out this bug, it is hard to be sure.
> >
> > Regards,
> > Simon