From patchwork Mon May 16 23:05:06 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eugene Syromiatnikov X-Patchwork-Id: 12851648 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 48AC7C433EF for ; Mon, 16 May 2022 23:05:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S242921AbiEPXFg (ORCPT ); Mon, 16 May 2022 19:05:36 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45338 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1350081AbiEPXF2 (ORCPT ); Mon, 16 May 2022 19:05:28 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 8F27846671 for ; Mon, 16 May 2022 16:05:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1652742318; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type; bh=shvwfut6i8VPs3cAVyDak3cwO9KQU+d8ysvDzTvpaAA=; b=dyVSgAOPWz26+KaTQYjTAGmq9igYuom29AG78D1tYYwWMKqL7wTxk67x3HDelIo1c4YL4P JfZnUsufLy1OiavcGuwnfHmZQvHLGtxKotzQhACYZEwiMdE7bE1QLomY9RG4Hl3UP1CNqL WT3wjpQJtQHQwvHEYJvfyvKuC6TgXd4= Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-664-3WHrexlZPXOqCxQ8_rX5Ng-1; Mon, 16 May 2022 19:05:14 -0400 X-MC-Unique: 3WHrexlZPXOqCxQ8_rX5Ng-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7E3971D96CA2; Mon, 16 May 2022 23:05:13 +0000 (UTC) Received: from asgard.redhat.com (unknown [10.36.110.3]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 6D5F11551CF2; Mon, 16 May 2022 23:05:09 +0000 (UTC) Date: Tue, 17 May 2022 01:05:06 +0200 From: Eugene Syromiatnikov To: Jiri Olsa , Masami Hiramatsu , Steven Rostedt , Ingo Molnar , Alexei Starovoitov , Daniel Borkmann Cc: Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kernel@vger.kernel.org, Shuah Khan , linux-kselftest@vger.kernel.org Subject: [PATCH bpf v2 2/4] bpf_trace: support 32-bit kernels in bpf_kprobe_multi_link_attach Message-ID: <20220516230506.GA25374@asgard.redhat.com> MIME-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.5.23 (2014-03-12) X-Scanned-By: MIMEDefang 2.85 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org It seems that there is no reason not to support 32-bit architectures; doing so requires a bit of rework with respect to cookies handling, however, as the current code implicitly assumes that sizeof(long) == sizeof(u64). Signed-off-by: Eugene Syromiatnikov --- kernel/trace/bpf_trace.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index f1d4e68..bf5bcfb 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2406,16 +2406,12 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr struct bpf_link_primer link_primer; void __user *ucookies; unsigned long *addrs; - u32 flags, cnt, size; + u32 flags, cnt, size, cookies_size; void __user *uaddrs; u64 *cookies = NULL; void __user *usyms; int err; - /* no support for 32bit archs yet */ - if (sizeof(u64) != sizeof(void *)) - return -EOPNOTSUPP; - if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) return -EINVAL; @@ -2425,6 +2421,7 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr uaddrs = u64_to_user_ptr(attr->link_create.kprobe_multi.addrs); usyms = u64_to_user_ptr(attr->link_create.kprobe_multi.syms); + ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); if (!!uaddrs == !!usyms) return -EINVAL; @@ -2432,8 +2429,11 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr if (!cnt) return -EINVAL; - if (check_mul_overflow(cnt, (u32)sizeof(*addrs), &size)) + if (check_mul_overflow(cnt, (u32)sizeof(*addrs), &size) || + (ucookies && + check_mul_overflow(cnt, (u32)sizeof(*cookies), &cookies_size))) { return -EOVERFLOW; + } size = cnt * sizeof(*addrs); addrs = kvmalloc(size, GFP_KERNEL); if (!addrs) @@ -2450,14 +2450,14 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr goto error; } - ucookies = u64_to_user_ptr(attr->link_create.kprobe_multi.cookies); if (ucookies) { - cookies = kvmalloc(size, GFP_KERNEL); + cookies_size = cnt * sizeof(*cookies); + cookies = kvmalloc(cookies_size, GFP_KERNEL); if (!cookies) { err = -ENOMEM; goto error; } - if (copy_from_user(cookies, ucookies, size)) { + if (copy_from_user(cookies, ucookies, cookies_size)) { err = -EFAULT; goto error; }