This patch makes unflatten_device_tree() safe to call from any arch setup code with the following changes: - Make sure initial_boot_params actually points to a device tree blob before unflattening - Make sure the initial_boot_params->magic field is correct - If CONFIG_OF_FLATTREE is not set, then make unflatten_device_tree() an empty #define.
This patch also adds some additional debug output to the top of unflatten_device_tree(). Signed-off-by: Grant Likely <[email protected]> --- drivers/of/fdt.c | 15 +++++++++++++++ include/linux/of_fdt.h | 2 ++ 2 files changed, 17 insertions(+), 0 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 406757a..5ce7bd5 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -553,6 +553,21 @@ void __init unflatten_device_tree(void) pr_debug(" -> unflatten_device_tree()\n"); + if (!initial_boot_params) { + pr_debug("No device tree pointer\n"); + return; + } + + pr_debug("Unflattening device tree:\n"); + pr_debug("magic: %08x\n", be32_to_cpu(initial_boot_params->magic)); + pr_debug("size: %08x\n", be32_to_cpu(initial_boot_params->totalsize)); + pr_debug("version: %08x\n", be32_to_cpu(initial_boot_params->version)); + + if (be32_to_cpu(initial_boot_params->magic) != OF_DT_HEADER) { + pr_err("Invalid device tree blob header\n"); + return; + } + /* First pass, scan for size */ start = ((unsigned long)initial_boot_params) + be32_to_cpu(initial_boot_params->off_dt_struct); diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h index f0fdd1f..9d7fd6d 100644 --- a/include/linux/of_fdt.h +++ b/include/linux/of_fdt.h @@ -99,6 +99,8 @@ extern int early_init_dt_scan_root(unsigned long node, const char *uname, /* Other Prototypes */ extern void unflatten_device_tree(void); extern void early_init_devtree(void *); +#else /* CONFIG_OF_FLATTREE */ +#define unflatten_device_tree() do {} while(0) #endif /* CONFIG_OF_FLATTREE */ #endif /* __ASSEMBLY__ */ _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
