iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

bpf: replace bpf_timer_set_callback with a generic helper

Browse Source 
In the same way we have a generic __bpf_async_init(), we also need
to share code between timer and workqueue for the set_callback call.

We just add an unused flags parameter, as it will be used for workqueues.

Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Link: https://lore.kernel.org/r/20240420-bpf_wq-v2-3-6c986a5a741f@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Benjamin Tissoires 2024-04-20 11:09:03 +02:00 committed by Alexei Starovoitov
parent 56b4a177ae
commit 073f11b026
1 changed files with 18 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
kernel/bpf/helpers.c
View File

@ -1262,22 +1262,23 @@ static const struct bpf_func_proto bpf_timer_init_proto = {
.arg3_type = ARG_ANYTHING,
};
BPF_CALL_3(bpf_timer_set_callback, struct bpf_async_kern *, timer, void *, callback_fn,
struct bpf_prog_aux *, aux)
static int __bpf_async_set_callback(struct bpf_async_kern *async, void *callback_fn,
struct bpf_prog_aux *aux, unsigned int flags,
enum bpf_async_type type)
{
struct bpf_prog *prev, *prog = aux->prog;
struct bpf_hrtimer *t;
struct bpf_async_cb *cb;
int ret = 0;
if (in_nmi())
return -EOPNOTSUPP;
__bpf_spin_lock_irqsave(&timer->lock);
t = timer->timer;
if (!t) {
__bpf_spin_lock_irqsave(&async->lock);
cb = async->cb;
if (!cb) {
ret = -EINVAL;
goto out;
}
if (!atomic64_read(&t->cb.map->usercnt)) {
if (!atomic64_read(&cb->map->usercnt)) {
/* maps with timers must be either held by user space
* or pinned in bpffs. Otherwise timer might still be
* running even when bpf prog is detached and user space
@ -1286,7 +1287,7 @@ BPF_CALL_3(bpf_timer_set_callback, struct bpf_async_kern *, timer, void *, callb
ret = -EPERM;
goto out;
}
prev = t->cb.prog;
prev = cb->prog;
if (prev != prog) {
/* Bump prog refcnt once. Every bpf_timer_set_callback()
* can pick different callback_fn-s within the same prog.
@ -1299,14 +1300,20 @@ BPF_CALL_3(bpf_timer_set_callback, struct bpf_async_kern *, timer, void *, callb
if (prev)
/* Drop prev prog refcnt when swapping with new prog */
bpf_prog_put(prev);
t->cb.prog = prog;
cb->prog = prog;
}
rcu_assign_pointer(t->cb.callback_fn, callback_fn);
rcu_assign_pointer(cb->callback_fn, callback_fn);
out:
__bpf_spin_unlock_irqrestore(&timer->lock);
__bpf_spin_unlock_irqrestore(&async->lock);
return ret;
}
BPF_CALL_3(bpf_timer_set_callback, struct bpf_async_kern *, timer, void *, callback_fn,
struct bpf_prog_aux *, aux)
{
return __bpf_async_set_callback(timer, callback_fn, aux, 0, BPF_ASYNC_TYPE_TIMER);
}
static const struct bpf_func_proto bpf_timer_set_callback_proto = {
.func = bpf_timer_set_callback,
.gpl_only = true,