[PATCH bpf-next 2/9] bpf: Append _recur naming to the bpf_task_storage helper proto

Martin KaFai Lau
2022-10-25T18:46:15Z

This patch adds the "_recur" naming to the bpf_task_storage_{get,delete}
proto. In a latter patch, they will only be used by the tracing
programs that requires a deadlock detection because a tracing
prog may use bpf_task_storage_{get,delete} recursively and cause a
deadlock.

Another following patch will add a different helper proto for the non
tracing programs because they do not need the deadlock prevention.
This patch does this rename to prepare for this future proto
additions.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
---
include/linux/bpf.h | 4 ++--
kernel/bpf/bpf_task_storage.c | 12 ++++++------
kernel/trace/bpf_trace.c | 4 ++--
3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 1279e699dc98..b04fe3f4342e 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2519,8 +2519,8 @@ extern const struct bpf_func_proto bpf_this_cpu_ptr_proto;
extern const struct bpf_func_proto bpf_ktime_get_coarse_ns_proto;
extern const struct bpf_func_proto bpf_sock_from_file_proto;
extern const struct bpf_func_proto bpf_get_socket_ptr_cookie_proto;
-extern const struct bpf_func_proto bpf_task_storage_get_proto;
-extern const struct bpf_func_proto bpf_task_storage_delete_proto;
+extern const struct bpf_func_proto bpf_task_storage_get_recur_proto;
+extern const struct bpf_func_proto bpf_task_storage_delete_recur_proto;
extern const struct bpf_func_proto bpf_for_each_map_elem_proto;
extern const struct bpf_func_proto bpf_btf_find_by_name_kind_proto;
extern const struct bpf_func_proto bpf_sk_setsockopt_proto;
diff --git a/kernel/bpf/bpf_task_storage.c b/kernel/bpf/bpf_task_storage.c
index 6f290623347e..bce50ae03f42 100644
--- a/kernel/bpf/bpf_task_storage.c
+++ b/kernel/bpf/bpf_task_storage.c
@@ -228,7 +228,7 @@ static int bpf_pid_task_storage_delete_elem(struct bpf_map *map, void *key)
}

/* *gfp_flags* is a hidden argument provided by the verifier */
-BPF_CALL_5(bpf_task_storage_get, struct bpf_map *, map, struct task_struct *,
+BPF_CALL_5(bpf_task_storage_get_recur, struct bpf_map *, map, struct task_struct *,
task, void *, value, u64, flags, gfp_t, gfp_flags)
{
struct bpf_local_storage_data *sdata;
@@ -260,7 +260,7 @@ BPF_CALL_5(bpf_task_storage_get, struct bpf_map *, map, struct task_struct *,
(unsigned long)sdata->data;
}

-BPF_CALL_2(bpf_task_storage_delete, struct bpf_map *, map, struct task_struct *,
+BPF_CALL_2(bpf_task_storage_delete_recur, struct bpf_map *, map, struct task_struct *,
task)
{
int ret;
@@ -322,8 +322,8 @@ const struct bpf_map_ops task_storage_map_ops = {
.map_owner_storage_ptr = task_storage_ptr,
};

-const struct bpf_func_proto bpf_task_storage_get_proto = {
- .func = bpf_task_storage_get,
+const struct bpf_func_proto bpf_task_storage_get_recur_proto = {
+ .func = bpf_task_storage_get_recur,
.gpl_only = false,
.ret_type = RET_PTR_TO_MAP_VALUE_OR_NULL,
.arg1_type = ARG_CONST_MAP_PTR,
@@ -333,8 +333,8 @@ const struct bpf_func_proto bpf_task_storage_get_proto = {
.arg4_type = ARG_ANYTHING,
};

-const struct bpf_func_proto bpf_task_storage_delete_proto = {
- .func = bpf_task_storage_delete,
+const struct bpf_func_proto bpf_task_storage_delete_recur_proto = {
+ .func = bpf_task_storage_delete_recur,
.gpl_only = false,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 49fb9ec8366d..591caf0eb973 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -1488,9 +1488,9 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
case BPF_FUNC_this_cpu_ptr:
return &bpf_this_cpu_ptr_proto;
case BPF_FUNC_task_storage_get:
- return &bpf_task_storage_get_proto;
+ return &bpf_task_storage_get_recur_proto;
case BPF_FUNC_task_storage_delete:
- return &bpf_task_storage_delete_proto;
+ return &bpf_task_storage_delete_recur_proto;
case BPF_FUNC_for_each_map_elem:
return &bpf_for_each_map_elem_proto;
case BPF_FUNC_snprintf:
--
2.30.2