diff options
| author | Kent Overstreet <kent.overstreet@linux.dev> | 2023-11-17 19:13:27 -0500 |
|---|---|---|
| committer | Kent Overstreet <kent.overstreet@linux.dev> | 2023-11-24 00:29:58 -0500 |
| commit | d4e3b928ab487a8aecd1f6a140b40ac365116cfb (patch) | |
| tree | 3beb53d9f7492d60014d84af51ad7e3c56ade753 /include | |
| parent | 98b1cc82c4affc16f5598d4fa14b1858671b2263 (diff) | |
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 <keescook@chromium.org>
Cc: Coly Li <colyli@suse.de>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/closure.h | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/include/linux/closure.h b/include/linux/closure.h index de7bb47d8a46..c554c6a08768 100644 --- a/include/linux/closure.h +++ b/include/linux/closure.h @@ -104,7 +104,7 @@ struct closure; struct closure_syncer; -typedef void (closure_fn) (struct closure *); +typedef void (closure_fn) (struct work_struct *); extern struct dentry *bcache_debug; struct closure_waitlist { @@ -254,7 +254,7 @@ static inline void closure_queue(struct closure *cl) INIT_WORK(&cl->work, cl->work.func); BUG_ON(!queue_work(wq, &cl->work)); } else - cl->fn(cl); + cl->fn(&cl->work); } /** @@ -309,6 +309,11 @@ static inline void closure_wake_up(struct closure_waitlist *list) __closure_wake_up(list); } +#define CLOSURE_CALLBACK(name) void name(struct work_struct *ws) +#define closure_type(name, type, member) \ + struct closure *cl = container_of(ws, struct closure, work); \ + type *name = container_of(cl, type, member) + /** * continue_at - jump to another function with barrier * |