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>
This commit is contained in:
James Hogan 2013-02-20 13:59:13 +00:00
parent d790050448
commit 2270e6d30b
3 changed files with 20 additions and 0 deletions

View File

@ -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 */

View File

@ -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;
}
}

View File

@ -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