[PATCH 2/3] of/flattree: Make unflatten_device_tree() safe to call from any arch

[Grant Likely]

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 <grant....@secretlab.ca>
---

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..54399f1 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 define unflatten_device_tree(void) {}
#endif /* CONFIG_OF_FLATTREE */

#endif /* __ASSEMBLY__ */

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[Stephen Rothwell]

Hi Grant,

On Thu, 11 Mar 2010 10:32:03 -0700 Grant Likely <grant....@secretlab.ca> wrote:
>
> - If CONFIG_OF_FLATTREE is not set, then make unflatten_device_tree()
> an empty #define.

"an empty static inline funtion."

> diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
> index f0fdd1f..54399f1 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 define unflatten_device_tree(void) {}

^^^^^^
You need to remove that.

--
Cheers,
Stephen Rothwell s...@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

[Grant Likely]

On Thu, Mar 11, 2010 at 4:48 PM, Stephen Rothwell <s...@canb.auug.org.au> wrote:
> Hi Grant,
>
> On Thu, 11 Mar 2010 10:32:03 -0700 Grant Likely <grant....@secretlab.ca> wrote:
>>
>> - If CONFIG_OF_FLATTREE is not set, then make unflatten_device_tree()
>>   an empty #define.
>
> "an empty static inline funtion."
>
>> diff --git a/include/linux/of_fdt.h b/include/linux/of_fdt.h
>> index f0fdd1f..54399f1 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 define unflatten_device_tree(void) {}
>                      ^^^^^^
> You need to remove that.

Fixed. Thanks.

g.