From b9a5a07aeaa2a903fb1306eb422880b2fa5f937f Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Wed, 23 Oct 2024 16:47:50 -0700 Subject: bpf: Add "bool swap_uptrs" arg to bpf_local_storage_update() and bpf_selem_alloc() In a later patch, the task local storage will only accept uptr from the syscall update_elem and will not accept uptr from the bpf prog. The reason is the bpf prog does not have a way to provide a valid user space address. bpf_local_storage_update() and bpf_selem_alloc() are used by both bpf prog bpf_task_storage_get(BPF_LOCAL_STORAGE_GET_F_CREATE) and bpf syscall update_elem. "bool swap_uptrs" arg is added to bpf_local_storage_update() and bpf_selem_alloc() to tell if it is called by the bpf prog or by the bpf syscall. When swap_uptrs==true, it is called by the syscall. The arg is named (swap_)uptrs because the later patch will swap the uptrs between the newly allocated selem and the user space provided map_value. It will make error handling easier in case map->ops->map_update_elem() fails and the caller can decide if it needs to unpin the uptr in the user space provided map_value or the bpf_local_storage_update() has already taken the uptr ownership and will take care of unpinning it also. Only swap_uptrs==false is passed now. The logic to handle the true case will be added in a later patch. Signed-off-by: Martin KaFai Lau Link: https://lore.kernel.org/r/20241023234759.860539-4-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov --- net/core/bpf_sk_storage.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'net') diff --git a/net/core/bpf_sk_storage.c b/net/core/bpf_sk_storage.c index bc01b3aa6b0f..2f4ed83a75ae 100644 --- a/net/core/bpf_sk_storage.c +++ b/net/core/bpf_sk_storage.c @@ -106,7 +106,7 @@ static long bpf_fd_sk_storage_update_elem(struct bpf_map *map, void *key, if (sock) { sdata = bpf_local_storage_update( sock->sk, (struct bpf_local_storage_map *)map, value, - map_flags, GFP_ATOMIC); + map_flags, false, GFP_ATOMIC); sockfd_put(sock); return PTR_ERR_OR_ZERO(sdata); } @@ -137,7 +137,7 @@ bpf_sk_storage_clone_elem(struct sock *newsk, { struct bpf_local_storage_elem *copy_selem; - copy_selem = bpf_selem_alloc(smap, newsk, NULL, true, GFP_ATOMIC); + copy_selem = bpf_selem_alloc(smap, newsk, NULL, true, false, GFP_ATOMIC); if (!copy_selem) return NULL; @@ -243,7 +243,7 @@ BPF_CALL_5(bpf_sk_storage_get, struct bpf_map *, map, struct sock *, sk, refcount_inc_not_zero(&sk->sk_refcnt)) { sdata = bpf_local_storage_update( sk, (struct bpf_local_storage_map *)map, value, - BPF_NOEXIST, gfp_flags); + BPF_NOEXIST, false, gfp_flags); /* sk must be a fullsock (guaranteed by verifier), * so sock_gen_put() is unnecessary. */ -- cgit v1.2.3