From b94bd57a803fd1a9934a97e2f6a6bd059c54d9ba Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 3 Jun 2020 13:09:38 -0700 Subject: [PATCH] erofs: Remove uninitialized_var() usage Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe # IB Acked-by: Kalle Valo # wireless drivers Reviewed-by: Chao Yu # erofs Change-Id: If77dad2c11421fce9d2fad6d034e7f36d405e11c Signed-off-by: Kees Cook --- fs/erofs/data.c | 4 ++-- fs/erofs/zdata.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/erofs/data.c b/fs/erofs/data.c index 21bd456df249..b22a08ac53a2 100644 --- a/fs/erofs/data.c +++ b/fs/erofs/data.c @@ -265,7 +265,7 @@ submit_bio_out: */ static int erofs_raw_access_readpage(struct file *file, struct page *page) { - erofs_off_t uninitialized_var(last_block); + erofs_off_t last_block; struct bio *bio; trace_erofs_readpage(page, true); @@ -285,7 +285,7 @@ static int erofs_raw_access_readpages(struct file *filp, struct list_head *pages, unsigned int nr_pages) { - erofs_off_t uninitialized_var(last_block); + erofs_off_t last_block; struct bio *bio = NULL; gfp_t gfp = readahead_gfp_mask(mapping); struct page *page = list_last_entry(pages, struct page, lru); diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c index 84b1b79ae047..b78c8580ac05 100644 --- a/fs/erofs/zdata.c +++ b/fs/erofs/zdata.c @@ -1162,7 +1162,7 @@ static void z_erofs_submit_queue(struct super_block *sb, struct z_erofs_decompressqueue *q[NR_JOBQUEUES]; void *bi_private; /* since bio will be NULL, no need to initialize last_index */ - pgoff_t uninitialized_var(last_index); + pgoff_t last_index; unsigned int nr_bios = 0; struct bio *bio = NULL;