On Wed, Jul 24, 2019 at 08:25:04PM +0530, Amol Surati wrote: > On Wed, Jul 24, 2019 at 06:57:30PM +1000, David Gibson wrote: > > On Wed, Jul 24, 2019 at 09:11:54AM +0200, Cédric Le Goater wrote: > > > On 24/07/2019 05:23, David Gibson wrote: > > > > On Tue, Jul 23, 2019 at 11:01:38AM +0200, Cédric Le Goater wrote: > > > >> Devices such as the BT or serial devices require a valid > > > >> "interrupt-parent" phandle in the device tree and it is currently > > > >> empty (0x0). It was not a problem until now but since OpenFirmare > > > >> started using a recent libdft (>= 1.4.7), petitboot fails to boot the > > > >> system image with error : > > > >> > > > >> dtc_resize: fdt_open_into returned FDT_ERR_BADMAGIC > > > >> > > > >> Provide a phandle for the LPC bus. > > > >> > > > >> Suggested-by: Greg Kurz <gr...@kaod.org> > > > >> Signed-off-by: Cédric Le Goater <c...@kaod.org> > > > > > > > > I've applied this, since it looks to be correct. > > > > > > > > But.. can you connect the dots for me in how this being missing > > > > results in a BADMAGIC error?? > > > > > > Some binary called by petitboot segfaults when trying to kexec an image > > > on > > > a system with a bogus DT (generated by QEMU). I don't know exactly which > > > one > > > as I only see the error message above and the segv message in dmesg > > > > Ok, I'm still not seeing how that gets you to a BADMAGIC error. > > If I may interject, as this patch is related to the qemu bug: > https://bugs.launchpad.net/qemu/+bug/1826827. > > The error is printed by dtc_resize in kexec.c from kexec-lite > (antonblanchard/kexec-lite). > > There are two places where dtc_resize is called - > (1) initialize_fdt, when kexec is passed a dtb file. > (2) fdt_from_fs, when kexec must make dtc read /proc/device-tree to form > a dtb. > > If initialize_fdt is called with a file which is an invalid dtb, the > dtc_resize prints the FDT_ERR_BADMAGIC error. > > Bug# 1826827 shows that dtc is one application that does > crash, although through the firing of an assertion, in the absence of > the mentioned properties. (fix to avoid the crash already checked into > dtc upstream, commit 8f69567622; to be released with dtc-v1.5.1). > > Assuming that the crashing app (it is not known here what it is) is > supposed to create a dtb for kexec, and its crash leaves behind an > incomplete/invalid dtb file, the initialize_fdt might receive an invalid > dtb.
Ok, thanks. That's what I was after.
>
>
> Another possibility for that error exists within the fdt_from_fs function,
> but that needs a version of kexec-lite at least 5 years old, which is
> unlikely to be used here I guess.
>
>
>
> If this patch fixes both the crash and the error "dtc_resize: ....",
> it is likely that dtc (or anything else which depends on libfdt) was the
> cause of the crash, with dtc/libfdt version being < g8f69567622.
>
>
> Thanks,
> -amol
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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