With -Wsign-compare, compilers warn about mismatching signedness in
comparisons in fdt_offset_ptr().
This mostly stems from "offset" being passed in as a signed integer,
even though the function would not really tolerate negative values.
Short of changing the prototype, check that offset is not negative, and
use an unsigned type internally.
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
---
libfdt/fdt.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/libfdt/fdt.c b/libfdt/fdt.c
index 37b7b93..04e1e06 100644
--- a/libfdt/fdt.c
+++ b/libfdt/fdt.c
@@ -134,16 +134,20 @@ int fdt_check_header(const void *fdt)
const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
{
- unsigned absoffset = offset + fdt_off_dt_struct(fdt);
+ unsigned int uoffset = offset;
+ unsigned int absoffset = offset + fdt_off_dt_struct(fdt);
+
+ if (offset < 0)
+ return NULL;
if (!can_assume(VALID_INPUT))
- if ((absoffset < offset)
+ if ((absoffset < uoffset)
|| ((absoffset + len) < absoffset)
|| (absoffset + len) > fdt_totalsize(fdt))
return NULL;
if (can_assume(LATEST) || fdt_version(fdt) >= 0x11)
- if (((offset + len) < offset)
+ if (((uoffset + len) < uoffset)
|| ((offset + len) > fdt_size_dt_struct(fdt)))
return NULL;
--
2.17.5
