From patchwork Mon Sep 14 18:36:11 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 1363864 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Original-To: incoming-bpf@patchwork.ozlabs.org Delivered-To: patchwork-incoming-bpf@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.a=rsa-sha256 header.s=20161025 header.b=qyHU4B85; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4Bqw7P4ZdGz9sTp for ; Tue, 15 Sep 2020 04:36:49 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725984AbgINSgd (ORCPT ); Mon, 14 Sep 2020 14:36:33 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48002 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726004AbgINSgU (ORCPT ); Mon, 14 Sep 2020 14:36:20 -0400 Received: from mail-qt1-x849.google.com (mail-qt1-x849.google.com [IPv6:2607:f8b0:4864:20::849]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A35AC06178A for ; Mon, 14 Sep 2020 11:36:19 -0700 (PDT) Received: by mail-qt1-x849.google.com with SMTP id a26so501774qtb.16 for ; Mon, 14 Sep 2020 11:36:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=sender:date:in-reply-to:message-id:mime-version:references:subject :from:to:cc; bh=5htW8/NrtaQSQKGByFCDzoFMBOFZd2oqLmR2u1zJJd8=; b=qyHU4B85d72PPdFlwdIQDmWdWFEsH1aIADE0LADTh4281PQo2ENo+eIT3PPqe9hAEh ECEtN96ZcdZu4udBNLl9slUQa8ITUl6BfzFjyJDgz4TCn/3zgdjPIu4lc8xuCoJTnZk1 uY1taAfqlnssYmfFlSfNg/lF00kDf/SBr3FO3fQdVpy1nlz7ciROCJtZ3FzI7YtdWzPY dK7laerZ2fZgkgx7QgJScNMt9Ofx7sgq9/WHnsNM77+Bxs+WsKR7uOVzT+bSi1AsMRsJ 6oGaI+3NmO0fis83GXC6u62flszLYHYJwH/pozgjQX16yAN/S2jlCSXwRR+jwSKSZnfa x7DQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=5htW8/NrtaQSQKGByFCDzoFMBOFZd2oqLmR2u1zJJd8=; b=nIiYqMVaWvOAKfJAFaGM5BM8Oac2CP0UeJTyQFXxw5gbpkUdXPylHuDAZClixPNpg5 YS5IWVFqlMXo8vBAVfQ1vCx4JGuuedOVMp+j5M5PKFcIVg896970q896Gg6skuGRDdTD 26DF/AEYX0Np7yLuuw4dBADG0/dHvc548FGDRLop8FrUxkTWeUXI+oX4jhO/Vq+AaYW7 bfVp+sEZaIpvBIqM4et9JCyIcr6nh0CQmgzT0eWHLopPqYRh4k/3z1JXdWlSu0g66ACU y2bK6ZWdQbR1HCV0h/5s3TxpJ4K1U6xXPt2d5EEJo96iP/tiPQQNTMqgOIQ+nAduqyM8 LEHw== X-Gm-Message-State: AOAM5303b81lqRrgpRRSLf1RJGAvohruPtYY7KM+EVv/ex8EEG6LO1Z/ 2B85WP1BlxBvQqBCHmZ1aOpO/Wk= X-Google-Smtp-Source: ABdhPJxn3ZrTkWq9taGffUyH3o19cKJSE2BXKStTUJawlJ0gITXI8eCvs3Vkb8VbY75HjC9n/FYVk9k= X-Received: from sdf2.svl.corp.google.com ([2620:15c:2c4:1:7220:84ff:fe09:7732]) (user=sdf job=sendgmr) by 2002:a0c:f44e:: with SMTP id h14mr14424238qvm.4.1600108578695; Mon, 14 Sep 2020 11:36:18 -0700 (PDT) Date: Mon, 14 Sep 2020 11:36:11 -0700 In-Reply-To: <20200914183615.2038347-1-sdf@google.com> Message-Id: <20200914183615.2038347-2-sdf@google.com> Mime-Version: 1.0 References: <20200914183615.2038347-1-sdf@google.com> X-Mailer: git-send-email 2.28.0.618.gf4bc123cb7-goog Subject: [PATCH bpf-next v5 1/5] bpf: Mutex protect used_maps array and count From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net, Andrii Nakryiko , YiFei Zhu , Stanislav Fomichev Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: YiFei Zhu To support modifying the used_maps array, we use a mutex to protect the use of the counter and the array. The mutex is initialized right after the prog aux is allocated, and destroyed right before prog aux is freed. This way we guarantee it's initialized for both cBPF and eBPF. Acked-by: Andrii Nakryiko Cc: YiFei Zhu Signed-off-by: YiFei Zhu Signed-off-by: Stanislav Fomichev --- .../net/ethernet/netronome/nfp/bpf/offload.c | 18 ++++++++++++------ include/linux/bpf.h | 1 + kernel/bpf/core.c | 15 +++++++++++---- kernel/bpf/syscall.c | 16 ++++++++++++---- net/core/dev.c | 11 ++++++++--- 5 files changed, 44 insertions(+), 17 deletions(-) diff --git a/drivers/net/ethernet/netronome/nfp/bpf/offload.c b/drivers/net/ethernet/netronome/nfp/bpf/offload.c index ac02369174a9..53851853562c 100644 --- a/drivers/net/ethernet/netronome/nfp/bpf/offload.c +++ b/drivers/net/ethernet/netronome/nfp/bpf/offload.c @@ -111,7 +111,9 @@ static int nfp_map_ptrs_record(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog, struct bpf_prog *prog) { - int i, cnt, err; + int i, cnt, err = 0; + + mutex_lock(&prog->aux->used_maps_mutex); /* Quickly count the maps we will have to remember */ cnt = 0; @@ -119,13 +121,15 @@ nfp_map_ptrs_record(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog, if (bpf_map_offload_neutral(prog->aux->used_maps[i])) cnt++; if (!cnt) - return 0; + goto out; nfp_prog->map_records = kmalloc_array(cnt, sizeof(nfp_prog->map_records[0]), GFP_KERNEL); - if (!nfp_prog->map_records) - return -ENOMEM; + if (!nfp_prog->map_records) { + err = -ENOMEM; + goto out; + } for (i = 0; i < prog->aux->used_map_cnt; i++) if (bpf_map_offload_neutral(prog->aux->used_maps[i])) { @@ -133,12 +137,14 @@ nfp_map_ptrs_record(struct nfp_app_bpf *bpf, struct nfp_prog *nfp_prog, prog->aux->used_maps[i]); if (err) { nfp_map_ptrs_forget(bpf, nfp_prog); - return err; + goto out; } } WARN_ON(cnt != nfp_prog->map_records_cnt); - return 0; +out: + mutex_unlock(&prog->aux->used_maps_mutex); + return err; } static int diff --git a/include/linux/bpf.h b/include/linux/bpf.h index c6d9f2c444f4..5dcce0364634 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -751,6 +751,7 @@ struct bpf_prog_aux { struct bpf_ksym ksym; const struct bpf_prog_ops *ops; struct bpf_map **used_maps; + struct mutex used_maps_mutex; /* mutex for used_maps and used_map_cnt */ struct bpf_prog *prog; struct user_struct *user; u64 load_time; /* ns since boottime */ diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index ed0b3578867c..2a20c2833996 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -98,6 +98,7 @@ struct bpf_prog *bpf_prog_alloc_no_stats(unsigned int size, gfp_t gfp_extra_flag fp->jit_requested = ebpf_jit_enabled(); INIT_LIST_HEAD_RCU(&fp->aux->ksym.lnode); + mutex_init(&fp->aux->used_maps_mutex); return fp; } @@ -253,6 +254,7 @@ struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, void __bpf_prog_free(struct bpf_prog *fp) { if (fp->aux) { + mutex_destroy(&fp->aux->used_maps_mutex); free_percpu(fp->aux->stats); kfree(fp->aux->poke_tab); kfree(fp->aux); @@ -1747,8 +1749,9 @@ bool bpf_prog_array_compatible(struct bpf_array *array, static int bpf_check_tail_call(const struct bpf_prog *fp) { struct bpf_prog_aux *aux = fp->aux; - int i; + int i, ret = 0; + mutex_lock(&aux->used_maps_mutex); for (i = 0; i < aux->used_map_cnt; i++) { struct bpf_map *map = aux->used_maps[i]; struct bpf_array *array; @@ -1757,11 +1760,15 @@ static int bpf_check_tail_call(const struct bpf_prog *fp) continue; array = container_of(map, struct bpf_array, map); - if (!bpf_prog_array_compatible(array, fp)) - return -EINVAL; + if (!bpf_prog_array_compatible(array, fp)) { + ret = -EINVAL; + goto out; + } } - return 0; +out: + mutex_unlock(&aux->used_maps_mutex); + return ret; } static void bpf_prog_select_func(struct bpf_prog *fp) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 4108ef3b828b..a67b8c6746be 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -3162,21 +3162,25 @@ static const struct bpf_map *bpf_map_from_imm(const struct bpf_prog *prog, const struct bpf_map *map; int i; + mutex_lock(&prog->aux->used_maps_mutex); for (i = 0, *off = 0; i < prog->aux->used_map_cnt; i++) { map = prog->aux->used_maps[i]; if (map == (void *)addr) { *type = BPF_PSEUDO_MAP_FD; - return map; + goto out; } if (!map->ops->map_direct_value_meta) continue; if (!map->ops->map_direct_value_meta(map, addr, off)) { *type = BPF_PSEUDO_MAP_VALUE; - return map; + goto out; } } + map = NULL; - return NULL; +out: + mutex_unlock(&prog->aux->used_maps_mutex); + return map; } static struct bpf_insn *bpf_insn_prepare_dump(const struct bpf_prog *prog, @@ -3294,6 +3298,7 @@ static int bpf_prog_get_info_by_fd(struct file *file, memcpy(info.tag, prog->tag, sizeof(prog->tag)); memcpy(info.name, prog->aux->name, sizeof(prog->aux->name)); + mutex_lock(&prog->aux->used_maps_mutex); ulen = info.nr_map_ids; info.nr_map_ids = prog->aux->used_map_cnt; ulen = min_t(u32, info.nr_map_ids, ulen); @@ -3303,9 +3308,12 @@ static int bpf_prog_get_info_by_fd(struct file *file, for (i = 0; i < ulen; i++) if (put_user(prog->aux->used_maps[i]->id, - &user_map_ids[i])) + &user_map_ids[i])) { + mutex_unlock(&prog->aux->used_maps_mutex); return -EFAULT; + } } + mutex_unlock(&prog->aux->used_maps_mutex); err = set_info_rec_size(&info); if (err) diff --git a/net/core/dev.c b/net/core/dev.c index d42c9ea0c3c0..75d7f91337d9 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5441,15 +5441,20 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp) if (new) { u32 i; + mutex_lock(&new->aux->used_maps_mutex); + /* generic XDP does not work with DEVMAPs that can * have a bpf_prog installed on an entry */ for (i = 0; i < new->aux->used_map_cnt; i++) { - if (dev_map_can_have_prog(new->aux->used_maps[i])) - return -EINVAL; - if (cpu_map_prog_allowed(new->aux->used_maps[i])) + if (dev_map_can_have_prog(new->aux->used_maps[i]) || + cpu_map_prog_allowed(new->aux->used_maps[i])) { + mutex_unlock(&new->aux->used_maps_mutex); return -EINVAL; + } } + + mutex_unlock(&new->aux->used_maps_mutex); } switch (xdp->command) {