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 232CFC433FE for ; Fri, 29 Apr 2022 21:15:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235829AbiD2VTG (ORCPT ); Fri, 29 Apr 2022 17:19:06 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36820 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236056AbiD2VTF (ORCPT ); Fri, 29 Apr 2022 17:19:05 -0400 Received: from mail-yw1-x114a.google.com (mail-yw1-x114a.google.com [IPv6:2607:f8b0:4864:20::114a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E50D73079 for ; Fri, 29 Apr 2022 14:15:45 -0700 (PDT) Received: by mail-yw1-x114a.google.com with SMTP id 00721157ae682-2f8d487f575so13005387b3.5 for ; Fri, 29 Apr 2022 14:15:45 -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=W6GhaZPDt9FfKll/xX0f68VRTyPyrFbbhuycjdtUJ/A=; b=dt47BF0abMA7Ee/Qdh/4+alqMRPgFLbHisnNJk5fQV45V64HcYHX2NvkeRR07MHu76 lbxkI3KvHB5P1AU8WalnwPsO2kfe4qXAF3iQbVIqFQ4DvvPD7D/K1S17/9Sk3U98HbQy X2mPnxcf18szSkTZWfTzqLb45dl9FK2DNHKPnNcM6VEpCqMQTlPv2Cmx0sruXV15bYRf n2lMduE7lPqg8Wjyt9iVu2fd3s/AVmvu8TlJxChl4ObfhEpPQxEpurv6NIJdqpKpDr49 hEbvoqBBj7ACdixv/05scQsBihd3ce24YwubFhP5gdFJVlEYwHcoz+mGze6rvEAk2Fur Vhaw== 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=W6GhaZPDt9FfKll/xX0f68VRTyPyrFbbhuycjdtUJ/A=; b=JBjpDcCu3Tcjo6VjTQIubrVXc+NbynE2qtERfAVmrU91fgKVB1jbWg5HrgHAOHJ1+h GbQIb6wwfM9TPV05QclJLYECYosjxMqnYMKNBLr6C3LPtbmy77g6xRWeQdfISIZHx/dx cSHXUDrwpuiVzKbL0ypjMPHy2W8WWitYVBRW84sNQrXLfM/4EGLATmBki0k9FXLz4eEG UYyZrv1hiRtblp1GSOPvJK7noOBNZuKeEen365bEyQue9iUdMc7BU3XR7LD/FjrYbC3t D+EZVI/Mjg5WJyc7ANHw/IjPQWp3LJVpSwvwSWY59izUrWiTCpGX8jCqGpBzNsqNnGbj Yj4Q== X-Gm-Message-State: AOAM533zZbK8B+1l7qUQ2iLEsSm2PNnr7Q04HP+1gn1yI2rRjKpZf51h +JzXmFAJS6nvZCpuqpCS7OR6iqc= X-Google-Smtp-Source: ABdhPJzmCPfSQFVoB9REyFMBDmjLu4YG17saT2zp0Q5p99Fma1TQbNDJ5/YEEsqJkSXmTwJNf5eH5Jo= X-Received: from sdf2.svl.corp.google.com ([2620:15c:2c4:201:b0cc:7605:1029:2d96]) (user=sdf job=sendgmr) by 2002:a81:6a46:0:b0:2f4:dc3f:e8f8 with SMTP id f67-20020a816a46000000b002f4dc3fe8f8mr1383160ywc.292.1651266944897; Fri, 29 Apr 2022 14:15:44 -0700 (PDT) Date: Fri, 29 Apr 2022 14:15:31 -0700 In-Reply-To: <20220429211540.715151-1-sdf@google.com> Message-Id: <20220429211540.715151-2-sdf@google.com> Mime-Version: 1.0 References: <20220429211540.715151-1-sdf@google.com> X-Mailer: git-send-email 2.36.0.464.gb9c8b46e94-goog Subject: [PATCH bpf-next v6 01/10] 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 be94833d390a..0a8927103018 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -53,6 +53,8 @@ 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; @@ -847,8 +849,7 @@ 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); } @@ -876,8 +877,7 @@ 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); \ } \ @@ -888,8 +888,7 @@ 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; } -- 2.36.0.464.gb9c8b46e94-goog