From patchwork Fri Jun 10 16:57:54 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stanislav Fomichev X-Patchwork-Id: 12877806 X-Patchwork-Delegate: bpf@iogearbox.net 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 CD633CCA47B for ; Fri, 10 Jun 2022 16:58:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349872AbiFJQ6M (ORCPT ); Fri, 10 Jun 2022 12:58:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60156 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349886AbiFJQ6K (ORCPT ); Fri, 10 Jun 2022 12:58:10 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3CD4631909 for ; Fri, 10 Jun 2022 09:58:08 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id j2-20020a2597c2000000b0064b3e54191aso23220934ybo.20 for ; Fri, 10 Jun 2022 09:58:08 -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=+Act5KFf04cq4PKBPIkiL9PndkyGSjHXudEO9oDVyp8=; b=I8fWVZMoNGNOE/JIXn835qEhaPI78vbK1Om5QONSJFQkn2yY4kd87HJkSi2yRK7LT7 1cWE4482pc2tgHhPU8ZqBaM30qAsyqNNlRsncVYCTOCOlId+/lNaKYd1mCJg0k65kDj4 O6HXAjVah0YL6zVvkTQ+dorf/jp+RZp46BUigdhrcBClDJFf8JQxZejui9aNbIteoyo1 pK15lpzf+ZJLT86apGi8yDf481OCffhnuWBMJxio6tSOc16o2F4bjuiutak1nGudYSYI wFzGhij8f15ZwsUGTc0BAFLzJiTED0jYPl35zOf12M1qNrKKBxFghIi1Ybg+7dkD05IH 5r/A== 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=+Act5KFf04cq4PKBPIkiL9PndkyGSjHXudEO9oDVyp8=; b=uYcpiaCX7x7B2+RSHxkxL6QyrcD9wwqQoaAJDa6sRPv2HJw9VzEdqzSFUnTcooxdXT XGzB1THfdmiDrM3ItOKlfgMmKuAPAKMJOu/m+nkJJOLHbxRgj7C+wOLtJlG19eGdZfNv fY1wyNS6DeO7q0+48iznO3ESXAaVsqxsfWhhn8Km25+CwAmIMDPd6KWq+CF84dB3+sp3 wt4iwjjtpExTn7VbvJGGtPf4JtFCFszrmMK5cZ4LD33SvFUwlq0CBaWCK7204zFf6KRn My3/Mq2T+8BGj95HL4A490t/WRpFy8M9UK8n5/SB5lMCm74rbTect3UnlIDxZf33LIwk YJyA== X-Gm-Message-State: AOAM533cTcvcH6vDsmwdRbM7zzZfnwDLhXIpkQknQjDesI8RKJ+3lfFl 3meNRiUaC7U/KAy3yaAWMaiN5IAAgUVTvU6C5uxXojnkNL1KjA9dTZL3XMAV8VWTIo8dBxBMS4U ugLtc3UNwG13lANx7ePRW7H0EgAOh/lHl7XdphMkQLLxOxKqe0EXgrg== X-Google-Smtp-Source: ABdhPJyo+KRRGhQLMHgYiuT84DB/ppKEzPvIbVooxu6oMq/2/hsNfhWA2tBrNa4EBRsUeGSTfnkJN2k= X-Received: from sdf.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:5935]) (user=sdf job=sendgmr) by 2002:a25:3445:0:b0:664:3b67:144a with SMTP id b66-20020a253445000000b006643b67144amr7665405yba.526.1654880287404; Fri, 10 Jun 2022 09:58:07 -0700 (PDT) Date: Fri, 10 Jun 2022 09:57:54 -0700 In-Reply-To: <20220610165803.2860154-1-sdf@google.com> Message-Id: <20220610165803.2860154-2-sdf@google.com> Mime-Version: 1.0 References: <20220610165803.2860154-1-sdf@google.com> X-Mailer: git-send-email 2.36.1.476.g0c4daa206d-goog Subject: [PATCH bpf-next v9 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 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net I'll be adding lsm cgroup specific helpers that grab trampoline mutex. No functional changes. Signed-off-by: Stanislav Fomichev Reviewed-by: Martin KaFai Lau --- include/linux/bpf.h | 11 ++++--- kernel/bpf/trampoline.c | 63 +++++++++++++++++++++-------------------- 2 files changed, 38 insertions(+), 36 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 8e6092d0ea95..b0af68b6297b 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; @@ -863,8 +865,7 @@ 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); } @@ -893,8 +894,7 @@ 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); \ } \ @@ -905,8 +905,7 @@ 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 93c7675f0c9e..5466e15be61f 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -410,7 +410,7 @@ static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(struct bpf_prog *prog) } } -int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) +static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) { enum bpf_tramp_prog_type kind; struct bpf_tramp_link *link_exiting; @@ -418,44 +418,33 @@ int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline int cnt = 0, i; kind = bpf_attach_type_to_tramp(link->link.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; for (i = 0; i < BPF_TRAMP_MAX; i++) cnt += tr->progs_cnt[i]; 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 = link->link.prog; - err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL, - link->link.prog->bpf_func); - goto out; - } - if (cnt >= BPF_MAX_TRAMP_LINKS) { - err = -E2BIG; - goto out; + return bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL, + link->link.prog->bpf_func); } - if (!hlist_unhashed(&link->tramp_hlist)) { + if (cnt >= BPF_MAX_TRAMP_LINKS) + return -E2BIG; + if (!hlist_unhashed(&link->tramp_hlist)) /* prog already linked */ - err = -EBUSY; - goto out; - } + return -EBUSY; hlist_for_each_entry(link_exiting, &tr->progs_hlist[kind], tramp_hlist) { if (link_exiting->link.prog != link->link.prog) continue; /* prog already linked */ - err = -EBUSY; - goto out; + return -EBUSY; } hlist_add_head(&link->tramp_hlist, &tr->progs_hlist[kind]); @@ -465,30 +454,44 @@ int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline hlist_del_init(&link->tramp_hlist); tr->progs_cnt[kind]--; } -out: + return err; +} + +int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) +{ + int err; + + mutex_lock(&tr->mutex); + err = __bpf_trampoline_link_prog(link, tr); mutex_unlock(&tr->mutex); return err; } -/* bpf_trampoline_unlink_prog() should never fail. */ -int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) +static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr) { enum bpf_tramp_prog_type kind; int err; kind = bpf_attach_type_to_tramp(link->link.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(&link->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_tramp_link *link, struct bpf_trampoline *tr) +{ + int err; + + mutex_lock(&tr->mutex); + err = __bpf_trampoline_unlink_prog(link, tr); mutex_unlock(&tr->mutex); return err; }