ARM: DT: don't try to access physical address zero

Message ID alpine.LFD.2.00.1106082355260.2142@xanadu.home
State New
Headers show

Commit Message

Nicolas Pitre June 9, 2011, 3:58 a.m.
If the DT physical address is zero, this is equivalent to no DT.
Especially when the actual RAM physical address is not located at zero,
the result of phys_to_virt() would point to la-la-land and crash the
kernel, which crash is completely silent this early during boot.

Signed-off-by: Nicolas Pitre <nicolas.pitre@linaro.org>
Acked-by: Grant Likely <grant.likely@secretlab.ca>

PATCH FOLLOWS
KernelVersion: v3.0-rc1

Patch

diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c
index a701e42..0cdd7b4 100644
--- a/arch/arm/kernel/devtree.c
+++ b/arch/arm/kernel/devtree.c
@@ -76,6 +76,9 @@  struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
 	unsigned long dt_root;
 	const char *model;
 
+	if (!dt_phys)
+		return NULL;
+
 	devtree = phys_to_virt(dt_phys);
 
 	/* check device tree validity */