Let m = user estimate of the (max) src string length, low = smaller
address of (src, dst), hi = larger address (src, dst).
if (low + (m - 1) >= hi), we have a *potential* overlapping copy which
is not allowed. Before we declare overlap - and return an error -
retry the check with m = actual src string length.
The resulting "test string" failure affected aarch64 (only) because of
differences in test code stack variable placement / alignment.
Change-Id: I2931d1ce2c61af3d3880075b033d2a4c4e421f09
Signed-off-by: Dave Barach <dave@barachs.net>
low = (uword) (src < dest ? src : dest);
hi = (uword) (src < dest ? dest : src);
low = (uword) (src < dest ? src : dest);
hi = (uword) (src < dest ? dest : src);
+ /*
+ * This check may fail innocently if src + dmax >= dst, but
+ * src + strlen(src) < dst. If it fails, check more carefully before
+ * blowing the whistle.
+ */
if (PREDICT_FALSE (low + (m - 1) >= hi))
{
if (PREDICT_FALSE (low + (m - 1) >= hi))
{
- clib_c11_violation ("src/dest overlap");
- return EINVAL;
+ m = clib_strnlen (src, m);
+
+ if (low + (m - 1) >= hi)
+ {
+ clib_c11_violation ("src/dest overlap");
+ return EINVAL;
+ }
}
clib_memcpy_fast (dest, src, m);
}
clib_memcpy_fast (dest, src, m);