| Message ID | 3125077.SmBO9VTSER@wuerfel |
|---|---|
| State | New |
| Headers | show |
On Sat, Jan 02, 2016 at 08:50:11PM +0100, Arnd Bergmann wrote: > gcc correctly warns that the ctx variable in ext4_set_encrypted_filename > has gone out of scope in ext4_set_encrypted_filename if we enter the > retry path and a 'goto' into the previous code block can not guarantee > to get the contents back: > > fs/ext4/namei.c: In function 'ext4_set_encrypted_filename': > fs/ext4/namei.c:4035:10: warning: 'ctx' may be used uninitialized in this function [-Wmaybe-uninitialized] > retval = ext4_xattr_set_handle(handle, inode, Sorry, this was a known bug that I fixed about a week ago, but I hadn't pushed out an update to the ext4 dev branch because I hadn't had a chance to finish testing the project quota changes. I've just pushed out an update. - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index c03f310200d6..fd2bd090bdfa 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -4113,7 +4113,7 @@ out: } if (handle) ext4_journal_stop(handle); - if (do_retry) { + if (do_retry /* FIXME: ctx is invalid */ && 0) { do_retry = 0; goto retry; }
gcc correctly warns that the ctx variable in ext4_set_encrypted_filename has gone out of scope in ext4_set_encrypted_filename if we enter the retry path and a 'goto' into the previous code block can not guarantee to get the contents back: fs/ext4/namei.c: In function 'ext4_set_encrypted_filename': fs/ext4/namei.c:4035:10: warning: 'ctx' may be used uninitialized in this function [-Wmaybe-uninitialized] retval = ext4_xattr_set_handle(handle, inode, I tried moving the variable declaration to the start of the function, but that does not shut up the warning, as it's apparently too hard for the compiler to follow the control flow and determine that it's correct (or for me reading the code, for that matter). This adds a hack to avoid the undefined behavior at the cost of losing the chance to retry on a spurious -ENOSPC error. We probably need a better solution. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 374431bae296 ("ext4 crypto: add ioctls to allow backup of encryption metadata") --- The warning appeared with next-20121231, which is the latest next release, nevermind if it has already been fixed in the meantime. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/