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authorGrant Likely <grant.likely@secretlab.ca>2010-04-13 16:12:26 -0700
committerGrant Likely <grant.likely@secretlab.ca>2010-04-28 18:20:29 -0600
commit8bfe9b5c3a684fe39eb58a65e466c103d1c32c9a (patch)
treeeb7709a314b7ec5ba3eef1dcd60018f41d512a45
parentcf32eb89cb4e674f88e4af5025839d85d02485c6 (diff)
downloadlinux-8bfe9b5c3a684fe39eb58a65e466c103d1c32c9a.tar.bz2
of/flattree: Make unflatten_device_tree() safe to call from any arch
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 static inline function. This patch also adds some additional debug output to the top of unflatten_device_tree(). Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
-rw-r--r--drivers/of/fdt.c15
-rw-r--r--include/linux/of_fdt.h2
2 files changed, 17 insertions, 0 deletions
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index dee4fb56b094..b6987bba8556 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -556,6 +556,21 @@ 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 f0fdd1f43688..71e1a916d3fa 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 */
+static inline void unflatten_device_tree(void) {}
#endif /* CONFIG_OF_FLATTREE */
#endif /* __ASSEMBLY__ */