From 68bbc370d1c59e8c8877cfd79f17a83cc6d451e9 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Fri, 22 Nov 2019 21:07:55 +0100 Subject: [PATCH] BACKPORT: bpf: Move bpf_free_used_maps into sleepable section We later on are going to need a sleepable context as opposed to plain RCU callback in order to untrack programs we need to poke at runtime and tracking as well as image update is performed under mutex. Change-Id: I36a54ad87d45ecb97b92e679cbe08663a40fea7f Signed-off-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/09823b1d5262876e9b83a8e75df04cf0467357a4.1574452833.git.daniel@iogearbox.net --- include/linux/bpf.h | 4 ++++ kernel/bpf/core.c | 23 +++++++++++++++++++++++ kernel/bpf/syscall.c | 20 -------------------- 3 files changed, 27 insertions(+), 20 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 78edd1ac99e4..b7353f907f5e 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1041,6 +1041,10 @@ static inline int bpf_prog_test_run_flow_dissector(struct bpf_prog *prog, return -ENOTSUPP; } +static inline void bpf_map_put(struct bpf_map *map) +{ +} + static inline bool unprivileged_ebpf_enabled(void) { return false; diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 1e35d00e8331..01262974b196 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2061,12 +2061,35 @@ int bpf_prog_array_copy_info(struct bpf_prog_array *array, : 0; } +static void bpf_free_cgroup_storage(struct bpf_prog_aux *aux) +{ + enum bpf_cgroup_storage_type stype; + + for_each_cgroup_storage_type(stype) { + if (!aux->cgroup_storage[stype]) + continue; + bpf_cgroup_storage_release(aux->prog, + aux->cgroup_storage[stype]); + } +} + +static void bpf_free_used_maps(struct bpf_prog_aux *aux) +{ + int i; + + bpf_free_cgroup_storage(aux); + for (i = 0; i < aux->used_map_cnt; i++) + bpf_map_put(aux->used_maps[i]); + kfree(aux->used_maps); +} + static void bpf_prog_free_deferred(struct work_struct *work) { struct bpf_prog_aux *aux; int i; aux = container_of(work, struct bpf_prog_aux, work); + bpf_free_used_maps(aux); if (bpf_prog_is_dev_bound(aux)) bpf_prog_offload_destroy(aux->prog); #ifdef CONFIG_PERF_EVENTS diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 5f9c773c2192..dd1b498dcbe4 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -1305,25 +1305,6 @@ static int find_prog_type(enum bpf_prog_type type, struct bpf_prog *prog) return 0; } -/* drop refcnt on maps used by eBPF program and free auxilary data */ -static void free_used_maps(struct bpf_prog_aux *aux) -{ - enum bpf_cgroup_storage_type stype; - int i; - - for_each_cgroup_storage_type(stype) { - if (!aux->cgroup_storage[stype]) - continue; - bpf_cgroup_storage_release(aux->prog, - aux->cgroup_storage[stype]); - } - - for (i = 0; i < aux->used_map_cnt; i++) - bpf_map_put(aux->used_maps[i]); - - kfree(aux->used_maps); -} - int __bpf_prog_charge(struct user_struct *user, u32 pages) { unsigned long memlock_limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT; @@ -1418,7 +1399,6 @@ static void __bpf_prog_put_rcu(struct rcu_head *rcu) kvfree(aux->func_info); kfree(aux->func_info_aux); - free_used_maps(aux); bpf_prog_uncharge_memlock(aux->prog); security_bpf_prog_free(aux); bpf_prog_free(aux->prog);