This is an effort to eliminate the uninitialized_var() macro[1]. The use of this macro is the wrong solution because it forces off ANY analysis by the compiler for a given variable. It even masks "unused variable" warnings.
Quoted from Linus[2]: "It's a horrible thing to use, in that it adds extra cruft to the source code, and then shuts up a compiler warning (even the _reliable_ warnings from gcc)." The gcc option "-Wmaybe-uninitialized" has been disabled and this change will not produce any warnnings even with "make W=1". [1] https://github.com/KSPP/linux/issues/81 [2] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yvju65tplgn_ybynv0ve...@mail.gmail.com/ Cc: Kees Cook <keesc...@chromium.org> Cc: Ming Lei <ming....@redhat.com> Signed-off-by: Jason Yan <yanai...@huawei.com> --- block/blk-merge.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index f0b0bae075a0..006402edef6b 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -473,7 +473,7 @@ static int __blk_bios_map_sg(struct request_queue *q, struct bio *bio, struct scatterlist *sglist, struct scatterlist **sg) { - struct bio_vec uninitialized_var(bvec), bvprv = { NULL }; + struct bio_vec bvec, bvprv = { NULL }; struct bvec_iter iter; int nsegs = 0; bool new_bio = false; -- 2.25.4
