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Piotr Kubaj
081f751823
When the OpenFirmware loader flattens the firmware device tree into the
FDT it hands to the kernel (usefdt=1, i.e. on every real-mode OF system
such as pSeries LPARs and QEMU pseries guests), add_node_to_fdt() clamps
every property value to 1024 bytes. Any larger property reaches the
kernel truncated.
On QEMU pseries the PCI host bridge's "interrupt-map" is 3584 bytes
(32 slots x 4 pins x 7 cells), so only the entries for slots 0-8 survive
and the entry for slot 9 is cut in the middle. A PCI device in slot 9
or above therefore gets no INTx routing (irq 0), and with INVARIANTS the
partial trailing entry trips the "ofw_bus_search_intrmap: truncated map"
assertion in ofw_bus_search_intrmap() during PCI attach, panicking the
kernel as soon as such a device is present. "ibm,drc-indexes",
"ibm,drc-names" and "ibm,drc-power-domains" are cut the same way.
Drop the clamp. fdt_setprop() already reports a property that does not
fit into the FDT buffer, so no separate limit is needed.
Fixes: 5ecf8e3852 ("Clean up some FDT-related code in the PowerPC bootloader, improving error checking and robustness. Prevents errors and crashes in FDT commands on PowerMac G5 systems.")
Differential Revision: https://reviews.freebsd.org/D60086