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authorJames Hogan <james.hogan@imgtec.com>2013-02-20 13:59:13 +0000
committerJames Hogan <james.hogan@imgtec.com>2013-03-02 20:11:17 +0000
commit2270e6d30bb6601ffd42e9d972442df0499ad547 (patch)
treec72e32a15d041cfe38560dca277f335da3f6e7cf
parentd7900504480ea9d49a6b5f8811f2678ad08d3255 (diff)
downloadlinux-stericsson-2270e6d30bb6601ffd42e9d972442df0499ad547.tar.gz
metag: copy devicetree to non-init memory
Make a copy of the device tree blob in non-init memory. It is required when using built-in device tree files that the platform code copies the blob to non-init memory prior to calling unflatten_device_tree(), otherwise the strings that the device tree refer to will get poisoned and potentially reused, breaking later reading of the device tree post-init (such as compatible matching in modules, debugfs, and the procfs interface). Signed-off-by: James Hogan <james.hogan@imgtec.com> Reviewed-by: Vineet Gupta <vgupta@synopsys.com>
-rw-r--r--arch/metag/include/asm/prom.h1
-rw-r--r--arch/metag/kernel/devtree.c17
-rw-r--r--arch/metag/kernel/setup.c2
3 files changed, 20 insertions, 0 deletions
diff --git a/arch/metag/include/asm/prom.h b/arch/metag/include/asm/prom.h
index d881396c392c..ccac97e865d0 100644
--- a/arch/metag/include/asm/prom.h
+++ b/arch/metag/include/asm/prom.h
@@ -18,6 +18,7 @@
#define HAVE_ARCH_DEVTREE_FIXUPS
extern struct machine_desc *setup_machine_fdt(void *dt);
+extern void copy_fdt(void);
extern void metag_dt_memblock_reserve(void);
#endif /* __ASM_METAG_PROM_H */
diff --git a/arch/metag/kernel/devtree.c b/arch/metag/kernel/devtree.c
index 5b6b1d855492..7cd02529636e 100644
--- a/arch/metag/kernel/devtree.c
+++ b/arch/metag/kernel/devtree.c
@@ -95,3 +95,20 @@ struct machine_desc * __init setup_machine_fdt(void *dt)
return mdesc_best;
}
+
+/**
+ * copy_fdt - Copy device tree into non-init memory.
+ *
+ * We must copy the flattened device tree blob into non-init memory because the
+ * unflattened device tree will reference the strings in it directly.
+ */
+void __init copy_fdt(void)
+{
+ void *alloc = early_init_dt_alloc_memory_arch(
+ be32_to_cpu(initial_boot_params->totalsize), 0x40);
+ if (alloc) {
+ memcpy(alloc, initial_boot_params,
+ be32_to_cpu(initial_boot_params->totalsize));
+ initial_boot_params = alloc;
+ }
+}
diff --git a/arch/metag/kernel/setup.c b/arch/metag/kernel/setup.c
index dd6c5ad73917..879246170aec 100644
--- a/arch/metag/kernel/setup.c
+++ b/arch/metag/kernel/setup.c
@@ -406,6 +406,8 @@ void __init setup_arch(char **cmdline_p)
cpu_2_hwthread_id[smp_processor_id()] = hard_processor_id();
hwthread_id_2_cpu[hard_processor_id()] = smp_processor_id();
+ /* Copy device tree blob into non-init memory before unflattening */
+ copy_fdt();
unflatten_device_tree();
#ifdef CONFIG_SMP