On Fri, 19 Sept 2025 at 16:08, Christoph Hellwig <h...@lst.de> wrote: > > On Thu, Sep 18, 2025 at 10:45:55AM -0700, Nathan Chancellor wrote: > > On Thu, Sep 18, 2025 at 04:15:11PM +0200, Christoph Hellwig wrote: > > > On Thu, Sep 18, 2025 at 03:59:11PM +0200, Marco Elver wrote: > > > > A Clang version that supports `-Wthread-safety-pointer` and the new > > > > alias-analysis of capability pointers is required (from this version > > > > onwards): > > > > > > > > > > > > https://github.com/llvm/llvm-project/commit/b4c98fcbe1504841203e610c351a3227f36c92a4 > > > > [3] > > > > > > There's no chance to make say x86 pre-built binaries for that available? > > > > I can use my existing kernel.org LLVM [1] build infrastructure to > > generate prebuilt x86 binaries. Just give me a bit to build and upload > > them. You may not be the only developer or maintainer who may want to > > play with this. > > That did work, thanks. > > 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: > > 1) locks held over loop iterations like: > > fs/xfs/xfs_extent_busy.c:573:26: warning: expecting spinlock > 'xfs_group_hold(busyp->group)..xg_busy_extents->eb_lock' to be held at start > of each loop [-Wthread-safety-analysis] > 573 | struct xfs_group *xg = > xfs_group_hold(busyp->group); > | ^ > fs/xfs/xfs_extent_busy.c:577:3: note: spinlock acquired here > 577 | spin_lock(&eb->eb_lock); > | ^ > > This is perfectly find code and needs some annotations, but I can't find > any good example.
This is an interesting one, and might be a bug in the alias analysis I recently implemented in Clang. I'll try to figure out a fix.
