From: Gao Xiang <hsiangkao@redhat.com>
To: linux-erofs@lists.ozlabs.org, Chao Yu <chao@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org
Subject: [PATCH] erofs: suppress false positive last_block warning
Date: Thu, 28 May 2020 04:48:44 -0400 [thread overview]
Message-ID: <20200528084844.23359-1-hsiangkao@redhat.com> (raw)
As Andrew mentioned, some rare specific gcc versions could report
last_block uninitialized warning. Actually last_block doesn't need
to be uninitialized first from its implementation due to bio == NULL
condition. After a bio is allocated, last_block will be assigned
then.
The detailed analysis is in this thread [1]. So let's silence those
confusing gccs simply.
[1] https://lore.kernel.org/r/20200421072839.GA13867@hsiangkao-HP-ZHAN-66-Pro-G1
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
---
fs/erofs/data.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index fc3a8d8064f8..2812645b361e 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -265,7 +265,7 @@ static inline struct bio *erofs_read_raw_page(struct bio *bio,
*/
static int erofs_raw_access_readpage(struct file *file, struct page *page)
{
- erofs_off_t last_block;
+ erofs_off_t uninitialized_var(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 last_block;
+ erofs_off_t uninitialized_var(last_block);
struct bio *bio = NULL;
gfp_t gfp = readahead_gfp_mask(mapping);
struct page *page = list_last_entry(pages, struct page, lru);
--
2.18.1
next reply other threads:[~2020-05-28 8:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-28 8:48 Gao Xiang [this message]
2020-05-28 9:25 ` [PATCH] erofs: suppress false positive last_block warning Chao Yu
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