From d4e3b928ab487a8aecd1f6a140b40ac365116cfb Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Fri, 17 Nov 2023 19:13:27 -0500 Subject: closures: CLOSURE_CALLBACK() to fix type punning Control flow integrity is now checking that type signatures match on indirect function calls. That breaks closures, which embed a work_struct in a closure in such a way that a closure_fn may also be used as a workqueue fn by the underlying closure code. So we have to change closure fns to take a work_struct as their argument - but that results in a loss of clarity, as closure fns have different semantics from normal workqueue functions (they run owning a ref on the closure, which must be released with continue_at() or closure_return()). Thus, this patc introduces CLOSURE_CALLBACK() and closure_type() macros as suggested by Kees, to smooth things over a bit. Suggested-by: Kees Cook Cc: Coly Li Signed-off-by: Kent Overstreet --- fs/bcachefs/io_write.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'fs/bcachefs/io_write.c') diff --git a/fs/bcachefs/io_write.c b/fs/bcachefs/io_write.c index d704a8f829c8..8ede46b1e354 100644 --- a/fs/bcachefs/io_write.c +++ b/fs/bcachefs/io_write.c @@ -580,9 +580,9 @@ static inline void wp_update_state(struct write_point *wp, bool running) __wp_update_state(wp, state); } -static void bch2_write_index(struct closure *cl) +static CLOSURE_CALLBACK(bch2_write_index) { - struct bch_write_op *op = container_of(cl, struct bch_write_op, cl); + closure_type(op, struct bch_write_op, cl); struct write_point *wp = op->wp; struct workqueue_struct *wq = index_update_wq(op); unsigned long flags; @@ -1208,9 +1208,9 @@ static void __bch2_nocow_write_done(struct bch_write_op *op) bch2_nocow_write_convert_unwritten(op); } -static void bch2_nocow_write_done(struct closure *cl) +static CLOSURE_CALLBACK(bch2_nocow_write_done) { - struct bch_write_op *op = container_of(cl, struct bch_write_op, cl); + closure_type(op, struct bch_write_op, cl); __bch2_nocow_write_done(op); bch2_write_done(cl); @@ -1363,7 +1363,7 @@ err: op->insert_keys.top = op->insert_keys.keys; } else if (op->flags & BCH_WRITE_SYNC) { closure_sync(&op->cl); - bch2_nocow_write_done(&op->cl); + bch2_nocow_write_done(&op->cl.work); } else { /* * XXX @@ -1566,9 +1566,9 @@ err: * If op->discard is true, instead of inserting the data it invalidates the * region of the cache represented by op->bio and op->inode. */ -void bch2_write(struct closure *cl) +CLOSURE_CALLBACK(bch2_write) { - struct bch_write_op *op = container_of(cl, struct bch_write_op, cl); + closure_type(op, struct bch_write_op, cl); struct bio *bio = &op->wbio.bio; struct bch_fs *c = op->c; unsigned data_len; -- cgit v1.2.3