[PATCH kvmtool 2/4] arm/fdt.c: Warn if MMIO device doesn't provide a node generator

[Alexandru Elisei <alexandru.elisei@xxxxxxx>]

Print a more helpful warning when a MMIO device hasn't set a function to
generate an FDT instead of causing a segmentation fault by dereferencing a
NULL pointer.

Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
---
 arm/fdt.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/arm/fdt.c b/arm/fdt.c
index 02091e9e0bee..06287a13e395 100644
--- a/arm/fdt.c
+++ b/arm/fdt.c
@@ -171,7 +171,12 @@ static int setup_fdt(struct kvm *kvm)
 	dev_hdr = device__first_dev(DEVICE_BUS_MMIO);
 	while (dev_hdr) {
 		generate_mmio_fdt_nodes = dev_hdr->data;
-		generate_mmio_fdt_nodes(fdt, dev_hdr, generate_irq_prop);
+		if (generate_mmio_fdt_nodes) {
+			generate_mmio_fdt_nodes(fdt, dev_hdr, generate_irq_prop);
+		} else {
+			pr_warning("Missing FDT node generator for MMIO device %d",
+				   dev_hdr->dev_num);
+		}
 		dev_hdr = device__next_dev(dev_hdr);
 	}
 
-- 
2.32.0