From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86833C43219 for ; Wed, 6 Apr 2022 00:10:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1453353AbiDEXrK (ORCPT ); Tue, 5 Apr 2022 19:47:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38024 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1577621AbiDEXMg (ORCPT ); Tue, 5 Apr 2022 19:12:36 -0400 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3795CF7F5B for ; Tue, 5 Apr 2022 14:44:14 -0700 (PDT) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-2eb7d137101so4616297b3.12 for ; Tue, 05 Apr 2022 14:44:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=Ef67EnXWWhCb2BYe2KO6rF+1VUv5TW07S9SVbOQXy7g=; b=J4G2I65mvrsZaQKVgzq5ohqRykvDGgexG0oPDdKoMCyKS/pmHFCAEIh+feMIt2zVun q5Er3hHnAFr+auynneQu9NNH0t9VkXlJed8Zj+dQr0KwaSSlfkmvqPdwDE9VRH4fFcTa hlGTksX8Hh0mBP1uL6Lux888X4zeMeNLnqXn27Cuc9A9NBjtvD0TsMq4Gupzoqf/mVXN DcTiWOz9T7rZuU6imAuTl+RSx5UUVR6QZCPXwifjuI0SdTgwX4q6bwp+Lh0UPMJVYUAp mmBHA0VN3DyjRl5Or2BM84uKQBgmCBNoHEnYprpQjJjrla1F1tcSR/AoYokgWDySeteT nuYg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=Ef67EnXWWhCb2BYe2KO6rF+1VUv5TW07S9SVbOQXy7g=; b=M5Jgu5pySVR+idT+0bTCx+ySVHs2OJI9pnphUATrjaTG2hMc7YEVbA4HyzVOdhscmb RkdKXyoO43AbI4D12/ZVuhbQZYMoZHeZDSDjOZOrelsU+cRME2fZxI3evRvdQuxaY9eF G5LD5LO1vfHLJhckaa58+mIuchIwrgLZjuETlMMWZdpfR8qP1zuuJgEXhhHGZIhxDROC NTHyWV2js8JRaeMMaF/Nv7f0QXa8dOAmkHRPKdQYyhfDDd4pTEZVHKJdOLaJwhn1vCXy FWRxT+hQonS7baZ4N3rzRqauACGE/MwhlhaTfrBj8973l+a1OglrPEg5xgnKKw4vNnfO WQKw== X-Gm-Message-State: AOAM533UKkAgR7L7TUXvqldnE0HlebnIJ8oW0+GTFaCS9tWqyXR4MS4k QzW6KUG9pJjbto1c0IQaBHeYcBo= X-Google-Smtp-Source: ABdhPJwA90IuQhTY9kpiqRpGPw00uHt1oblCwF8RTdKKkahmlNwx3J5b0/oWh+H8r/eEhmUn2lQmmXg= X-Received: from sdf2.svl.corp.google.com ([2620:15c:2c4:201:73b5:ffab:2024:2901]) (user=sdf job=sendgmr) by 2002:a81:6689:0:b0:2eb:6dc1:6a58 with SMTP id a131-20020a816689000000b002eb6dc16a58mr4592992ywc.47.1649195027666; Tue, 05 Apr 2022 14:43:47 -0700 (PDT) Date: Tue, 5 Apr 2022 14:43:36 -0700 In-Reply-To: <20220405214342.1968262-1-sdf@google.com> Message-Id: <20220405214342.1968262-2-sdf@google.com> Mime-Version: 1.0 References: <20220405214342.1968262-1-sdf@google.com> X-Mailer: git-send-email 2.35.1.1094.g7c7d902a7c-goog Subject: [PATCH bpf-next v2 1/7] bpf: add bpf_func_t and trampoline helpers From: Stanislav Fomichev To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, Stanislav Fomichev Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org I'll be adding lsm cgroup specific helpers that grab trampoline mutex. No functional changes. Signed-off-by: Stanislav Fomichev --- include/linux/bpf.h | 11 ++++--- kernel/bpf/trampoline.c | 63 +++++++++++++++++++++++------------------ 2 files changed, 40 insertions(+), 34 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index bdb5298735ce..487aba40ce52 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -52,6 +52,8 @@ typedef u64 (*bpf_callback_t)(u64, u64, u64, u64, u64); typedef int (*bpf_iter_init_seq_priv_t)(void *private_data, struct bpf_iter_aux_info *aux); typedef void (*bpf_iter_fini_seq_priv_t)(void *private_data); +typedef unsigned int (*bpf_func_t)(const void *, + const struct bpf_insn *); struct bpf_iter_seq_info { const struct seq_operations *seq_ops; bpf_iter_init_seq_priv_t init_seq_private; @@ -798,8 +800,7 @@ struct bpf_dispatcher { static __always_inline __nocfi unsigned int bpf_dispatcher_nop_func( const void *ctx, const struct bpf_insn *insnsi, - unsigned int (*bpf_func)(const void *, - const struct bpf_insn *)) + bpf_func_t bpf_func) { return bpf_func(ctx, insnsi); } @@ -827,8 +828,7 @@ int arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs); noinline __nocfi unsigned int bpf_dispatcher_##name##_func( \ const void *ctx, \ const struct bpf_insn *insnsi, \ - unsigned int (*bpf_func)(const void *, \ - const struct bpf_insn *)) \ + bpf_func_t bpf_func) \ { \ return bpf_func(ctx, insnsi); \ } \ @@ -839,8 +839,7 @@ int arch_prepare_bpf_dispatcher(void *image, s64 *funcs, int num_funcs); unsigned int bpf_dispatcher_##name##_func( \ const void *ctx, \ const struct bpf_insn *insnsi, \ - unsigned int (*bpf_func)(const void *, \ - const struct bpf_insn *)); \ + bpf_func_t bpf_func); \ extern struct bpf_dispatcher bpf_dispatcher_##name; #define BPF_DISPATCHER_FUNC(name) bpf_dispatcher_##name##_func #define BPF_DISPATCHER_PTR(name) (&bpf_dispatcher_##name) diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index ada97751ae1b..0c4fd194e801 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -407,42 +407,34 @@ static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(struct bpf_prog *prog) } } -int bpf_trampoline_link_prog(struct bpf_prog *prog, struct bpf_trampoline *tr) +static int __bpf_trampoline_link_prog(struct bpf_prog *prog, + struct bpf_trampoline *tr) { enum bpf_tramp_prog_type kind; int err = 0; int cnt; kind = bpf_attach_type_to_tramp(prog); - mutex_lock(&tr->mutex); - if (tr->extension_prog) { + if (tr->extension_prog) /* cannot attach fentry/fexit if extension prog is attached. * cannot overwrite extension prog either. */ - err = -EBUSY; - goto out; - } + return -EBUSY; + cnt = tr->progs_cnt[BPF_TRAMP_FENTRY] + tr->progs_cnt[BPF_TRAMP_FEXIT]; if (kind == BPF_TRAMP_REPLACE) { /* Cannot attach extension if fentry/fexit are in use. */ - if (cnt) { - err = -EBUSY; - goto out; - } + if (cnt) + return -EBUSY; tr->extension_prog = prog; - err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL, - prog->bpf_func); - goto out; - } - if (cnt >= BPF_MAX_TRAMP_PROGS) { - err = -E2BIG; - goto out; + return bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL, + prog->bpf_func); } - if (!hlist_unhashed(&prog->aux->tramp_hlist)) { + if (cnt >= BPF_MAX_TRAMP_PROGS) + return -E2BIG; + if (!hlist_unhashed(&prog->aux->tramp_hlist)) /* prog already linked */ - err = -EBUSY; - goto out; - } + return -EBUSY; hlist_add_head(&prog->aux->tramp_hlist, &tr->progs_hlist[kind]); tr->progs_cnt[kind]++; err = bpf_trampoline_update(tr); @@ -450,30 +442,45 @@ int bpf_trampoline_link_prog(struct bpf_prog *prog, struct bpf_trampoline *tr) hlist_del_init(&prog->aux->tramp_hlist); tr->progs_cnt[kind]--; } -out: + return err; +} + +int bpf_trampoline_link_prog(struct bpf_prog *prog, struct bpf_trampoline *tr) +{ + int err; + + mutex_lock(&tr->mutex); + err = __bpf_trampoline_link_prog(prog, tr); mutex_unlock(&tr->mutex); return err; } -/* bpf_trampoline_unlink_prog() should never fail. */ -int bpf_trampoline_unlink_prog(struct bpf_prog *prog, struct bpf_trampoline *tr) +static int __bpf_trampoline_unlink_prog(struct bpf_prog *prog, + struct bpf_trampoline *tr) { enum bpf_tramp_prog_type kind; int err; kind = bpf_attach_type_to_tramp(prog); - mutex_lock(&tr->mutex); if (kind == BPF_TRAMP_REPLACE) { WARN_ON_ONCE(!tr->extension_prog); err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, tr->extension_prog->bpf_func, NULL); tr->extension_prog = NULL; - goto out; + return err; } hlist_del_init(&prog->aux->tramp_hlist); tr->progs_cnt[kind]--; - err = bpf_trampoline_update(tr); -out: + return bpf_trampoline_update(tr); +} + +/* bpf_trampoline_unlink_prog() should never fail. */ +int bpf_trampoline_unlink_prog(struct bpf_prog *prog, struct bpf_trampoline *tr) +{ + int err; + + mutex_lock(&tr->mutex); + err = __bpf_trampoline_unlink_prog(prog, tr); mutex_unlock(&tr->mutex); return err; } -- 2.35.1.1094.g7c7d902a7c-goog