Fix an overflow case in fdt_offset_ptr() detected by GCC 4.3.

Using Gcc 4.3 detected this problem:

    ../dtc/libfdt/fdt.c: In function 'fdt_next_tag':
    ../dtc/libfdt/fdt.c:82: error: assuming signed overflow does not
    occur when assuming that (X + c) < X is always false

To fix the problem, treat the offset as an unsigned int.

The problem report and proposed fix were provided
by Steve Papacharalambous <stevep@freescale.com>.

Signed-off-by: Jon Loeliger <jdl@freescale.com>

diff --git a/include/libfdt.h b/include/libfdt.h
index 94c35e330c8d7a62a760b9d8774f08d3df1c2db0..5492a535207816765730f366bbec52e600969e40 100644 (file)
--- a/include/libfdt.h
+++ b/include/libfdt.h
@@ -122,7 +122,7 @@
 /* Low-level functions (you probably don't need these)                */
 /**********************************************************************/
 
-const void *fdt_offset_ptr(const void *fdt, int offset, int checklen);
+const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen);
 static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
 {
        return (void *)(uintptr_t)fdt_offset_ptr(fdt, offset, checklen);

diff --git a/libfdt/fdt.c b/libfdt/fdt.c
index 732103b07bd368790ba28ecfe1ea551345aa80a8..a59a518b0e2e1684d976c7e36e37063e8bce2579 100644 (file)
--- a/libfdt/fdt.c
+++ b/libfdt/fdt.c
@@ -78,7 +78,7 @@ int fdt_check_header(const void *fdt)
        return 0;
 }
 
-const void *fdt_offset_ptr(const void *fdt, int offset, int len)
+const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
 {
        const char *p;