In order to get rid of propagating tail call counter by rax and stack,
it's to store tail call counter at task_struct.
Then, at the prologue of bpf prog, it has to initialise the tail call
counter at task_struct. And when tail call happens, it has to compare
and increment the tail call counter at task_struct.
Signed-off-by: Leon Hwang <hffilwlqm@xxxxxxxxx>
---
include/linux/sched.h | 2 ++
1 file changed, 2 insertions(+)
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 3c2abbc587b49..d0696fcabf14f 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1501,6 +1501,8 @@ struct task_struct {
struct bpf_local_storage __rcu *bpf_storage;
/* Used for BPF run context */
struct bpf_run_ctx *bpf_ctx;
+ /* Used for BPF run time */
+ u32 bpf_tail_call_cnt;
#endif
#ifdef CONFIG_GCC_PLUGIN_STACKLEAK
--
2.44.0
