summaryrefslogtreecommitdiff
path: root/lib
diff options
context:
space:
mode:
authorKent Overstreet <kent.overstreet@linux.dev>2023-11-17 19:13:27 -0500
committerKent Overstreet <kent.overstreet@linux.dev>2023-11-24 00:29:58 -0500
commitd4e3b928ab487a8aecd1f6a140b40ac365116cfb (patch)
tree3beb53d9f7492d60014d84af51ad7e3c56ade753 /lib
parent98b1cc82c4affc16f5598d4fa14b1858671b2263 (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')
-rw-r--r--lib/closure.c5
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;