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. The
patch improves the function to supporting device sub-tree that
have multiple root nodes:
* 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>
---
v5:
* Split from PATCH[v4 19/21]
* Fixed "line over 80 characters" from checkpatch.pl
---
drivers/of/fdt.c | 56 ++++++++++++++++++++++++++++++++++++++------------------
1 file changed, 38 insertions(+), 18 deletions(-)
diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index cde35c5d01..b87c157 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -28,6 +28,8 @@
#include <asm/setup.h> /* for COMMAND_LINE_SIZE */
#include <asm/page.h>
+static int cur_node_depth;
+
/*
* of_fdt_limit_memory - limit the number of regions in the /memory node
* @limit: maximum entries
@@ -161,27 +163,26 @@ 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
* @p: pointer to node in flat tree
* @dad: Parent struct device_node
* @fpsize: Size of the node path up at the current depth.
*/
-static void * unflatten_dt_node(void *blob,
- void *mem,
- int *poffset,
- struct device_node *dad,
- struct device_node **nodepp,
- unsigned long fpsize,
- bool dryrun)
+static void *__unflatten_dt_node(void *blob,
+ void *mem,
+ int *poffset,
+ struct device_node *dad,
+ struct device_node **nodepp,
+ unsigned long fpsize,
+ bool dryrun)
{
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;
@@ -334,13 +335,19 @@ static void * unflatten_dt_node(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);
+ old_depth = cur_node_depth;
+ *poffset = fdt_next_node(blob, *poffset, &cur_node_depth);
+ while (*poffset > 0) {
+ if (cur_node_depth < old_depth)
+ break;
+
+ if (cur_node_depth == old_depth)
+ mem = __unflatten_dt_node(blob, mem, poffset,
+ dad, NULL, fpsize, dryrun);
+ else if (cur_node_depth > old_depth)
+ mem = __unflatten_dt_node(blob, mem, poffset,
+ np, NULL, fpsize, dryrun);
+ }
if (*poffset < 0 && *poffset != -FDT_ERR_NOTFOUND)
pr_err("unflatten: error %d processing FDT\n", *poffset);
@@ -366,6 +373,18 @@ static void * unflatten_dt_node(void *blob,
return mem;
}
+static void *unflatten_dt_node(void *blob,
+ void *mem,
+ int *poffset,
+ struct device_node *dad,
+ struct device_node **nodepp,
+ bool dryrun)
+{
+ cur_node_depth = 1;
+ return __unflatten_dt_node(blob, mem, poffset,
+ dad, nodepp, 0, dryrun);
+}
+
/**
* __unflatten_device_tree - create tree of device_nodes from flat blob
*
@@ -405,7 +424,8 @@ static void __unflatten_device_tree(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);
@@ -420,7 +440,7 @@ static void __unflatten_device_tree(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
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