libfdt: Several cleanups to parameter checking
This patch makes a couple of small cleanups to parameter checking of
libfdt functions.
- In several functions which take a node offset, we use an
idiom involving fdt_next_tag() first to check that we have indeed been
given a node offset. This patch adds a helper function
_fdt_check_node_offset() to encapsulate this usage of fdt_next_tag().
- In fdt_rw.c in several places we have the expanded version
of the RW_CHECK_HEADER() macro for no particular reason. This patch
replaces those instances with an invocation of the macro; that's what
it's for.
- In fdt_sw.c we rename the check_header_sw() function to
sw_check_header() to match the analgous function in fdt_rw.c, and we
provide an SW_CHECK_HEADER() wrapper macro as RW_CHECK_HEADER()
functions in fdt_rw.c
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/libfdt/fdt.c b/libfdt/fdt.c
index cfa1989..cb08ba0 100644
--- a/libfdt/fdt.c
+++ b/libfdt/fdt.c
@@ -133,16 +133,23 @@
return tag;
}
+int _fdt_check_node_offset(const void *fdt, int offset)
+{
+ if ((offset < 0) || (offset % FDT_TAGSIZE)
+ || (fdt_next_tag(fdt, offset, &offset) != FDT_BEGIN_NODE))
+ return -FDT_ERR_BADOFFSET;
+
+ return offset;
+}
+
int fdt_next_node(const void *fdt, int offset, int *depth)
{
int nextoffset = 0;
uint32_t tag;
- if (offset >= 0) {
- tag = fdt_next_tag(fdt, offset, &nextoffset);
- if (tag != FDT_BEGIN_NODE)
- return -FDT_ERR_BADOFFSET;
- }
+ if (offset >= 0)
+ if ((nextoffset = _fdt_check_node_offset(fdt, offset)) < 0)
+ return nextoffset;
do {
offset = nextoffset;