[PATCH bpf-next 05/17] bpf: Factor fsession link to use struct bpf_tramp_node
From: Jiri Olsa <jolsa@kernel.org>
Date: 2026-02-20 10:08:08
Also in:
bpf
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Now that we split trampoline attachment object (bpf_tramp_node) from the link object (bpf_tramp_link) we can use bpf_tramp_node as fsession's fexit attachment object and get rid of the bpf_fsession_link object. Signed-off-by: Jiri Olsa <jolsa@kernel.org> --- include/linux/bpf.h | 6 +----- kernel/bpf/syscall.c | 21 ++++++--------------- kernel/bpf/trampoline.c | 14 +++++++------- 3 files changed, 14 insertions(+), 27 deletions(-)
diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 9c7f5ab3c7ce..d79951c0ab79 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h@@ -1883,15 +1883,11 @@ struct bpf_shim_tramp_link { struct bpf_tracing_link { struct bpf_tramp_link link; + struct bpf_tramp_node fexit; struct bpf_trampoline *trampoline; struct bpf_prog *tgt_prog; }; -struct bpf_fsession_link { - struct bpf_tracing_link link; - struct bpf_tramp_link fexit; -}; - struct bpf_raw_tp_link { struct bpf_link link; struct bpf_raw_event_map *btp;
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index e9d482c59977..95a4bfbeab62 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c@@ -3637,21 +3637,7 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog, key = bpf_trampoline_compute_key(tgt_prog, NULL, btf_id); } - if (prog->expected_attach_type == BPF_TRACE_FSESSION) { - struct bpf_fsession_link *fslink; - - fslink = kzalloc(sizeof(*fslink), GFP_USER); - if (fslink) { - bpf_tramp_link_init(&fslink->fexit, BPF_LINK_TYPE_TRACING, - &bpf_tracing_link_lops, prog, attach_type, - bpf_cookie); - link = &fslink->link; - } else { - link = NULL; - } - } else { - link = kzalloc(sizeof(*link), GFP_USER); - } + link = kzalloc(sizeof(*link), GFP_USER); if (!link) { err = -ENOMEM; goto out_put_prog;
@@ -3659,6 +3645,11 @@ static int bpf_tracing_prog_attach(struct bpf_prog *prog, bpf_tramp_link_init(&link->link, BPF_LINK_TYPE_TRACING, &bpf_tracing_link_lops, prog, attach_type, bpf_cookie); + if (prog->expected_attach_type == BPF_TRACE_FSESSION) { + link->fexit.link = &link->link.link; + link->fexit.cookie = bpf_cookie; + } + mutex_lock(&prog->aux->dst_mutex); /* There are a few possible cases here:
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index f4acf3771600..14fa7012738a 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c@@ -827,7 +827,7 @@ static int __bpf_trampoline_link_prog(struct bpf_tramp_node *node, struct bpf_trampoline_ops *ops, void *data) { - struct bpf_fsession_link *fslink = NULL; + struct bpf_tracing_link *tr_link = NULL; enum bpf_tramp_prog_type kind; struct bpf_tramp_node *node_existing; struct hlist_head *prog_list;
@@ -877,8 +877,8 @@ static int __bpf_trampoline_link_prog(struct bpf_tramp_node *node, hlist_add_head(&node->tramp_hlist, prog_list); if (kind == BPF_TRAMP_FSESSION) { tr->progs_cnt[BPF_TRAMP_FENTRY]++; - fslink = container_of(node, struct bpf_fsession_link, link.link.node); - hlist_add_head(&fslink->fexit.node.tramp_hlist, &tr->progs_hlist[BPF_TRAMP_FEXIT]); + tr_link = container_of(node, struct bpf_tracing_link, link.node); + hlist_add_head(&tr_link->fexit.tramp_hlist, &tr->progs_hlist[BPF_TRAMP_FEXIT]); tr->progs_cnt[BPF_TRAMP_FEXIT]++; } else { tr->progs_cnt[kind]++;
@@ -888,7 +888,7 @@ static int __bpf_trampoline_link_prog(struct bpf_tramp_node *node, hlist_del_init(&node->tramp_hlist); if (kind == BPF_TRAMP_FSESSION) { tr->progs_cnt[BPF_TRAMP_FENTRY]--; - hlist_del_init(&fslink->fexit.node.tramp_hlist); + hlist_del_init(&tr_link->fexit.tramp_hlist); tr->progs_cnt[BPF_TRAMP_FEXIT]--; } else { tr->progs_cnt[kind]--;
@@ -929,10 +929,10 @@ static int __bpf_trampoline_unlink_prog(struct bpf_tramp_node *node, tgt_prog->aux->is_extended = false; return err; } else if (kind == BPF_TRAMP_FSESSION) { - struct bpf_fsession_link *fslink = - container_of(node, struct bpf_fsession_link, link.link.node); + struct bpf_tracing_link *tr_link = + container_of(node, struct bpf_tracing_link, link.node); - hlist_del_init(&fslink->fexit.node.tramp_hlist); + hlist_del_init(&tr_link->fexit.tramp_hlist); tr->progs_cnt[BPF_TRAMP_FEXIT]--; kind = BPF_TRAMP_FENTRY; }
--
2.52.0