cppcheck static analysis flags that shifting the signed 32-bit literal `1` by `ilog2(dict_size)` can lead to undefined behavior if the shift amount reaches or exceeds 31.
This patch casts the literal to `1ULL` to ensure the shift operates safely on an unsigned 64-bit integer, preventing potential overflows on different architectures. Signed-off-by: Nithurshen <[email protected]> --- lib/compressor_libzstd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/compressor_libzstd.c b/lib/compressor_libzstd.c index c475077..f47635e 100644 --- a/lib/compressor_libzstd.c +++ b/lib/compressor_libzstd.c @@ -123,10 +123,10 @@ static int erofs_compressor_libzstd_setdictsize(struct erofs_compress *c, } else { dict_size = min_t(u32, Z_EROFS_ZSTD_MAX_DICT_SIZE, pclustersize_max << 3); - dict_size = 1 << ilog2(dict_size); + dict_size = 1ULL << ilog2(dict_size); } } - if (dict_size != 1 << ilog2(dict_size) || + if (dict_size != 1ULL << ilog2(dict_size) || dict_size > Z_EROFS_ZSTD_MAX_DICT_SIZE) { erofs_err("invalid dictionary size %u", dict_size); return -EINVAL; -- 2.51.0
