unflatten_dt_node() is called recursively to unflatten FDT nodes with the assumption that FDT blob has only one root node, which isn't true when the FDT blob represents device sub-tree. This improves the function to supporting device sub-tree that have multiple nodes in the first level: * Rename original unflatten_dt_node() to __unflatten_dt_node(). * Wrapper unflatten_dt_node() calls __unflatten_dt_node() with adjusted current node depth to 1 to avoid underflow. Signed-off-by: Gavin Shan <gwshan@xxxxxxxxxxxxxxxxxx> --- drivers/of/fdt.c | 53 ++++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 40 insertions(+), 13 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 0749656..a18a2ce 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -161,7 +161,7 @@ static void *unflatten_dt_alloc(void **mem, unsigned long size, } /** - * unflatten_dt_node - Alloc and populate a device_node from the flat tree + * __unflatten_dt_node - Alloc and populate a device_node from the flat tree * @blob: The parent device tree blob * @mem: Memory chunk to use for allocating device nodes and properties * @poffset: pointer to node in flat tree @@ -171,20 +171,20 @@ static void *unflatten_dt_alloc(void **mem, unsigned long size, * @dryrun: If true, do not allocate device nodes but still calculate needed * memory size */ -static void * unflatten_dt_node(const void *blob, +static void *__unflatten_dt_node(const void *blob, void *mem, int *poffset, struct device_node *dad, struct device_node **nodepp, unsigned long fpsize, - bool dryrun) + bool dryrun, + int *depth) { const __be32 *p; struct device_node *np; struct property *pp, **prev_pp = NULL; const char *pathp; unsigned int l, allocl; - static int depth = 0; int old_depth; int offset; int has_name = 0; @@ -337,13 +337,25 @@ static void * unflatten_dt_node(const void *blob, np->type = "<NULL>"; } - old_depth = depth; - *poffset = fdt_next_node(blob, *poffset, &depth); - if (depth < 0) - depth = 0; - while (*poffset > 0 && depth > old_depth) - mem = unflatten_dt_node(blob, mem, poffset, np, NULL, - fpsize, dryrun); + /* Multiple nodes might be in the first depth level if + * the device tree is sub-tree. All nodes in current + * or deeper depth are unflattened after it returns. + */ + old_depth = *depth; + *poffset = fdt_next_node(blob, *poffset, depth); + while (*poffset > 0) { + if (*depth < old_depth) + break; + + if (*depth == old_depth) + mem = __unflatten_dt_node(blob, mem, poffset, + dad, NULL, fpsize, + dryrun, depth); + else if (*depth > old_depth) + mem = __unflatten_dt_node(blob, mem, poffset, + np, NULL, fpsize, + dryrun, depth); + } if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND) pr_err("unflatten: error %d processing FDT\n", *poffset); @@ -369,6 +381,20 @@ static void * unflatten_dt_node(const void *blob, return mem; } +static void *unflatten_dt_node(const void *blob, + void *mem, + int *poffset, + struct device_node *dad, + struct device_node **nodepp, + bool dryrun) +{ + int depth = 1; + + return __unflatten_dt_node(blob, mem, poffset, + dad, nodepp, 0, + dryrun, &depth); +} + /** * __unflatten_device_tree - create tree of device_nodes from flat blob * @@ -408,7 +434,8 @@ static void __unflatten_device_tree(const void *blob, /* First pass, scan for size */ start = 0; - size = (unsigned long)unflatten_dt_node(blob, NULL, &start, NULL, NULL, 0, true); + size = (unsigned long)unflatten_dt_node(blob, NULL, &start, + NULL, NULL, true); size = ALIGN(size, 4); pr_debug(" size is %lx, allocating...\n", size); @@ -423,7 +450,7 @@ static void __unflatten_device_tree(const void *blob, /* Second pass, do actual unflattening */ start = 0; - unflatten_dt_node(blob, mem, &start, NULL, mynodes, 0, false); + unflatten_dt_node(blob, mem, &start, NULL, mynodes, false); if (be32_to_cpup(mem + size) != 0xdeadbeef) pr_warning("End of tree marker overwritten: %08x\n", be32_to_cpup(mem + size)); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html