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 /lib/closure.c | |
| 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 'lib/closure.c')
| -rw-r--r-- | lib/closure.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/lib/closure.c b/lib/closure.c index f86c9eeafb35..c16540552d61 100644 --- a/lib/closure.c +++ b/lib/closure.c @@ -36,7 +36,7 @@ static inline void closure_put_after_sub(struct closure *cl, int flags) closure_debug_destroy(cl); if (destructor) - destructor(cl); + destructor(&cl->work); if (parent) closure_put(parent); @@ -108,8 +108,9 @@ struct closure_syncer { int done; }; -static void closure_sync_fn(struct closure *cl) +static CLOSURE_CALLBACK(closure_sync_fn) { + struct closure *cl = container_of(ws, struct closure, work); struct closure_syncer *s = cl->s; struct task_struct *p; |