From patchwork Sat Feb 8 15:42:07 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 1235318 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=none (no SPF record) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=bpf-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 48FGf563mZz9sRQ for ; Sun, 9 Feb 2020 02:43:09 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727582AbgBHPnJ convert rfc822-to-8bit (ORCPT ); Sat, 8 Feb 2020 10:43:09 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:34550 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727557AbgBHPnJ (ORCPT ); Sat, 8 Feb 2020 10:43:09 -0500 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-2-_G4WUAj2MtSddpsluOlogQ-1; Sat, 08 Feb 2020 10:43:04 -0500 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 551C58014CE; Sat, 8 Feb 2020 15:43:02 +0000 (UTC) Received: from krava.redhat.com (ovpn-204-79.brq.redhat.com [10.40.204.79]) by smtp.corp.redhat.com (Postfix) with ESMTP id 60BD65C28F; Sat, 8 Feb 2020 15:42:59 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Andrii Nakryiko , Yonghong Song , Song Liu , Martin KaFai Lau , Jakub Kicinski , David Miller , =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , John Fastabend , Jesper Dangaard Brouer Subject: [PATCH 12/14] bpf: Add trampolines to kallsyms Date: Sat, 8 Feb 2020 16:42:07 +0100 Message-Id: <20200208154209.1797988-13-jolsa@kernel.org> In-Reply-To: <20200208154209.1797988-1-jolsa@kernel.org> References: <20200208154209.1797988-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-MC-Unique: _G4WUAj2MtSddpsluOlogQ-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Adding trampolines to kallsyms. It's displayed as bpf_trampoline_ [bpf] where ID is the BTF id of the trampoline function. Signed-off-by: Jiri Olsa --- include/linux/bpf.h | 2 ++ kernel/bpf/trampoline.c | 23 +++++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 7a4626c8e747..b91bac10d3ea 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -502,6 +502,7 @@ struct bpf_trampoline { /* Executable image of trampoline */ void *image; u64 selector; + struct bpf_ksym ksym; }; #define BPF_DISPATCHER_MAX 48 /* Fits in 2048B */ @@ -573,6 +574,7 @@ struct bpf_image { #define BPF_IMAGE_SIZE (PAGE_SIZE - sizeof(struct bpf_image)) bool is_bpf_image_address(unsigned long address); void *bpf_image_alloc(void); +void bpf_image_ksym_add(void *data, struct bpf_ksym *ksym); /* Called only from code, so there's no need for stubs. */ void bpf_ksym_add(struct bpf_ksym *ksym); void bpf_ksym_del(struct bpf_ksym *ksym); diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index 6b264a92064b..1ee29907cbe5 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -96,6 +96,15 @@ bool is_bpf_image_address(unsigned long addr) return ret; } +void bpf_image_ksym_add(void *data, struct bpf_ksym *ksym) +{ + struct bpf_image *image = container_of(data, struct bpf_image, data); + + ksym->start = (unsigned long) image; + ksym->end = ksym->start + PAGE_SIZE; + bpf_ksym_add(ksym); +} + struct bpf_trampoline *bpf_trampoline_lookup(u64 key) { struct bpf_trampoline *tr; @@ -131,6 +140,7 @@ struct bpf_trampoline *bpf_trampoline_lookup(u64 key) for (i = 0; i < BPF_TRAMP_MAX; i++) INIT_HLIST_HEAD(&tr->progs_hlist[i]); tr->image = image; + INIT_LIST_HEAD_RCU(&tr->ksym.lnode); out: mutex_unlock(&trampoline_mutex); return tr; @@ -267,6 +277,15 @@ static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(enum bpf_attach_type t) } } +static void bpf_trampoline_kallsyms_add(struct bpf_trampoline *tr) +{ + struct bpf_ksym *ksym = &tr->ksym; + + snprintf(ksym->name, KSYM_NAME_LEN, "bpf_trampoline_%llu", + tr->key & ((u64) (1LU << 32) - 1)); + bpf_image_ksym_add(tr->image, &tr->ksym); +} + int bpf_trampoline_link_prog(struct bpf_prog *prog) { enum bpf_tramp_prog_type kind; @@ -311,6 +330,8 @@ int bpf_trampoline_link_prog(struct bpf_prog *prog) if (err) { hlist_del(&prog->aux->tramp_hlist); tr->progs_cnt[kind]--; + } else if (cnt == 0) { + bpf_trampoline_kallsyms_add(tr); } out: mutex_unlock(&tr->mutex); @@ -336,6 +357,8 @@ int bpf_trampoline_unlink_prog(struct bpf_prog *prog) } hlist_del(&prog->aux->tramp_hlist); tr->progs_cnt[kind]--; + if (!(tr->progs_cnt[BPF_TRAMP_FENTRY] + tr->progs_cnt[BPF_TRAMP_FEXIT])) + bpf_ksym_del(&tr->ksym); err = bpf_trampoline_update(prog->aux->trampoline); out: mutex_unlock(&tr->mutex);