| Message ID | 20220211175700.2427105-1-yhs@fb.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | BPF |
| Headers | show |
| Series | bpf: fix a bpf_timer initialization issue | expand |
On 2/11/22 9:57 AM, Yonghong Song wrote: > Currently the following code in check_and_init_map_value() > *(struct bpf_timer *)(dst + map->timer_off) = > (struct bpf_timer){}; > can help generate bpf_timer definition in vmlinuxBTF. > But the code above may not zero the whole structure > due to anonymour members and that code will be replaced > by memset in the subsequent patch and > bpf_timer definition will disappear from vmlinuxBTF. > Let us emit the type explicitly so bpf program can continue > to use it from vmlinux.h. > > Signed-off-by: Yonghong Song <yhs@fb.com> > --- > kernel/bpf/helpers.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c > index 01cfdf40c838..66f9ed5093b2 100644 > --- a/kernel/bpf/helpers.c > +++ b/kernel/bpf/helpers.c > @@ -16,6 +16,7 @@ > #include <linux/pid_namespace.h> > #include <linux/proc_ns.h> > #include <linux/security.h> > +#include <linux/btf.h> To avoid conflict with bpf-next can you move this #include a bit up? I suspect having it right after linux/bpf.h will make this patch applicable to both bpf and bpf-next. Which means there will be no conflicts when bpf merges with bpf-next.
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 01cfdf40c838..66f9ed5093b2 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -16,6 +16,7 @@ #include <linux/pid_namespace.h> #include <linux/proc_ns.h> #include <linux/security.h> +#include <linux/btf.h> #include "../../lib/kstrtox.h" @@ -1075,6 +1076,7 @@ static enum hrtimer_restart bpf_timer_cb(struct hrtimer *hrtimer) void *key; u32 idx; + BTF_TYPE_EMIT(struct bpf_timer); callback_fn = rcu_dereference_check(t->callback_fn, rcu_read_lock_bh_held()); if (!callback_fn) goto out;
Currently the following code in check_and_init_map_value() *(struct bpf_timer *)(dst + map->timer_off) = (struct bpf_timer){}; can help generate bpf_timer definition in vmlinuxBTF. But the code above may not zero the whole structure due to anonymour members and that code will be replaced by memset in the subsequent patch and bpf_timer definition will disappear from vmlinuxBTF. Let us emit the type explicitly so bpf program can continue to use it from vmlinux.h. Signed-off-by: Yonghong Song <yhs@fb.com> --- kernel/bpf/helpers.c | 2 ++ 1 file changed, 2 insertions(+)