From: Arnd Bergmann <arnd@arndb.de>
To: "Theodore Ts'o" <tytso@mit.edu>,
Andreas Dilger <adilger.kernel@dilger.ca>
Cc: clang-built-linux@googlegroups.com,
Nick Desaulniers <ndesaulniers@google.com>,
Nathan Chancellor <natechancellor@gmail.com>,
Arnd Bergmann <arnd@arndb.de>, Eric Whitney <enwlinux@gmail.com>,
Sean Fu <fxinrong@gmail.com>, Jan Kara <jack@suse.cz>,
Eric Biggers <ebiggers@google.com>,
linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] ext4: use BUG() instead of BUG_ON(1)
Date: Mon, 25 Mar 2019 14:00:25 +0100 [thread overview]
Message-ID: <20190325130040.1437445-1-arnd@arndb.de> (raw)
BUG_ON(1) leads to bogus warnings from clang when
CONFIG_PROFILE_ANNOTATED_BRANCHES is set:
fs/ext4/inode.c:544:4: error: variable 'retval' is used uninitialized whenever 'if' condition is false
[-Werror,-Wsometimes-uninitialized]
BUG_ON(1);
^~~~~~~~~
include/asm-generic/bug.h:61:36: note: expanded from macro 'BUG_ON'
^~~~~~~~~~~~~~~~~~~
include/linux/compiler.h:48:23: note: expanded from macro 'unlikely'
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/ext4/inode.c:591:6: note: uninitialized use occurs here
if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
^~~~~~
fs/ext4/inode.c:544:4: note: remove the 'if' if its condition is always true
BUG_ON(1);
^
include/asm-generic/bug.h:61:32: note: expanded from macro 'BUG_ON'
^
fs/ext4/inode.c:502:12: note: initialize the variable 'retval' to silence this warning
Change it to BUG() so clang can see that this code path can never
continue.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
fs/ext4/extents_status.c | 4 ++--
fs/ext4/inode.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 2b439afafe13..023a3eb3afa3 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -711,7 +711,7 @@ static void ext4_es_insert_extent_ind_check(struct inode *inode,
* We don't need to check unwritten extent because
* indirect-based file doesn't have it.
*/
- BUG_ON(1);
+ BUG();
}
} else if (retval == 0) {
if (ext4_es_is_written(es)) {
@@ -780,7 +780,7 @@ static int __es_insert_extent(struct inode *inode, struct extent_status *newes)
}
p = &(*p)->rb_right;
} else {
- BUG_ON(1);
+ BUG();
return -EINVAL;
}
}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b32a57bc5d5d..190f0478582a 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -541,7 +541,7 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode,
map->m_len = retval;
retval = 0;
} else {
- BUG_ON(1);
+ BUG();
}
#ifdef ES_AGGRESSIVE_TEST
ext4_map_blocks_es_recheck(handle, inode, map,
@@ -1876,7 +1876,7 @@ static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
else if (ext4_es_is_unwritten(&es))
map->m_flags |= EXT4_MAP_UNWRITTEN;
else
- BUG_ON(1);
+ BUG();
#ifdef ES_AGGRESSIVE_TEST
ext4_map_blocks_es_recheck(NULL, inode, map, &orig_map, 0);
--
2.20.0
next reply other threads:[~2019-03-25 13:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-25 13:00 Arnd Bergmann [this message]
2019-03-25 17:29 ` Nick Desaulniers
2019-03-25 17:30 ` Jan Kara
2019-03-25 18:14 ` Darrick J. Wong
2019-03-25 19:59 ` Andreas Dilger
2019-04-07 16:29 ` Theodore Ts'o
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