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Miller" , Luc Van Oostenryck , "Paul E. McKenney" , Alexander Potapenko , Arnd Bergmann , Bart Van Assche , Bill Wendling , Dmitry Vyukov , Eric Dumazet , Frederic Weisbecker , Greg Kroah-Hartman , Herbert Xu , Ian Rogers , Jann Horn , Joel Fernandes , Jonathan Corbet , Josh Triplett , Justin Stitt , Kees Cook , Kentaro Takeda , Lukas Bulwahn , Mark Rutland , Mathieu Desnoyers , Miguel Ojeda , Neeraj Upadhyay , Nick Desaulniers , Steven Rostedt , Tetsuo Handa , Thomas Gleixner , Thomas Graf , Uladzislau Rezki , Waiman Long , kasan-dev@googlegroups.com, linux-crypto@vger.kernel.org, linux-doc@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-security-module@vger.kernel.org, linux-sparse@vger.kernel.org, llvm@lists.linux.dev, rcu@vger.kernel.org Subject: Re: [PATCH v3 00/35] Compiler-Based Capability- and Locking-Analysis Message-ID: References: <20250918140451.1289454-1-elver@google.com> <20250918141511.GA30263@lst.de> <20250918174555.GA3366400@ax162> <20250919140803.GA23745@lst.de> <20250919140954.GA24160@lst.de> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250919140954.GA24160@lst.de> User-Agent: Mutt/2.2.13 (2024-03-09) On Fri, Sep 19, 2025 at 04:09PM +0200, Christoph Hellwig wrote: > On Fri, Sep 19, 2025 at 04:08:03PM +0200, Christoph Hellwig wrote: > > I started to play around with that. For the nvme code adding the > > annotations was very simply, and I also started adding trivial > > __guarded_by which instantly found issues. > > > > For XFS it was a lot more work and I still see tons of compiler > > warnings, which I'm not entirely sure how to address. Right now I > > see three major classes: > > And in case anyone cares, here are my patches for that: > > https://git.infradead.org/?p=users/hch/misc.git;a=shortlog;h=refs/heads/cap-analysis > > git://git.infradead.org/users/hch/misc.git cap-analysis I gave this a try, and with the below patch and the Clang fix [1], fs/xfs compiles cleanly. I think the fundamental limitation are the conditional locking wrappers. I suspect it's possible to do better than disabling the analysis here, by overapproximating the lock set taken (like you did elsewhere), so that at least the callers are checked, but when I tried it showed lots of callers need annotating as well, so I gave up at that point. Still, it might be better than no checking at all. [1] https://github.com/llvm/llvm-project/pull/159921 Thanks, -- Marco diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c index 9c39251961a3..f371a08e5d44 100644 --- a/fs/xfs/xfs_inode.c +++ b/fs/xfs/xfs_inode.c @@ -140,6 +140,7 @@ void xfs_ilock( xfs_inode_t *ip, uint lock_flags) + __capability_unsafe(/* conditional locking */) { trace_xfs_ilock(ip, lock_flags, _RET_IP_); @@ -183,6 +184,7 @@ int xfs_ilock_nowait( xfs_inode_t *ip, uint lock_flags) + __capability_unsafe(/* conditional locking */) { trace_xfs_ilock_nowait(ip, lock_flags, _RET_IP_); @@ -243,6 +245,7 @@ void xfs_iunlock( xfs_inode_t *ip, uint lock_flags) + __capability_unsafe(/* conditional locking */) { xfs_lock_flags_assert(lock_flags); @@ -272,6 +275,7 @@ void xfs_ilock_demote( xfs_inode_t *ip, uint lock_flags) + __capability_unsafe(/* conditional locking */) { ASSERT(lock_flags & (XFS_IOLOCK_EXCL|XFS_MMAPLOCK_EXCL|XFS_ILOCK_EXCL)); ASSERT((lock_flags & diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index d9ac9521c203..9c4ec3aa8bf9 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -472,6 +472,7 @@ xfs_log_reserve( static void xlog_state_shutdown_callbacks( struct xlog *log) + __must_hold(&log->l_icloglock) { struct xlog_in_core *iclog; LIST_HEAD(cb_list);