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 X-Spam-Level: X-Spam-Status: No, score=-12.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2760FC4332D for ; Tue, 12 Jan 2021 15:37:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E48B223132 for ; Tue, 12 Jan 2021 15:37:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391778AbhALPgt (ORCPT ); Tue, 12 Jan 2021 10:36:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391149AbhALPgr (ORCPT ); Tue, 12 Jan 2021 10:36:47 -0500 Received: from mail-ej1-x62b.google.com (mail-ej1-x62b.google.com [IPv6:2a00:1450:4864:20::62b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2BDE8C061786; Tue, 12 Jan 2021 07:36:07 -0800 (PST) Received: by mail-ej1-x62b.google.com with SMTP id g20so4154788ejb.1; Tue, 12 Jan 2021 07:36:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=3H58F2EgPUmA9bBKPktDhyUlZCxmuNrKvZMlcefSEDw=; b=ukQC+u6UU6t7vIYYTsdaKblvTwE2VZ68ooJSzYA3HhooqQ2y9Wug/aYJRae3XvdFWQ MdUl9O3DpIUtquLNVEURj8/Uin0KvUjSfBaKa9/c8MNAuoPUudPwapeVfERWj50je7IT ztD+8fOsVUuQ3BSMSInF+/Q3IWWQa1g4OnHRLqE1/LiojhuYXIrpWic02h6zPf8HKfDZ EOA9SYtNayXd+hc7QnG09kvp4PACyHsXXSEz/1MCDUFhrpL+ieza5dvav1r8dCkuN+e+ Abdn//3VwCsspRWEXnZTTuxLPzGzk85bB2EPvJUBD7tydn+MsFiNRXt1RnRVqkYpFRqg E6Wg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=3H58F2EgPUmA9bBKPktDhyUlZCxmuNrKvZMlcefSEDw=; b=PsAym8jOAy2cZC5uprS9mpAv+8NYX4gRMLhJ7AcfjIrJfWrP/DwUPb4dwj1ET3OrLz 4M86FhOmtYq+g2kD4l+xwuovQZOw0novsO4Q3UDjT5K8AlRRUGTAItrtrE0Q1CLuYDt7 yjbvxif/y49sPT+2WrW7JgWU4taYf/np3mCM70DC1akul95FARwxjBafjI8j/oy2OI42 cqM+I19rj4Dx0p+H7DYoxV/qN33iB2HhM+DpXgh5s1d+RNavPLYeqYDWqSP4MC6QS1KR VdfsyyT90RTWKomPtkZu3y8afsRfpo0Gi9VXOjpYLn75biNXDIh9P1JCCMOaWNJo2GlU IbQQ== X-Gm-Message-State: AOAM531opSG0EJyiVOA9hbCRgK5BQgw/IWsVxq2dEsy9J+3dHy77lUMR N7RUDl9QHNztjjZSgSm5ncDpSW3l7Ji+LGCsBuU= X-Google-Smtp-Source: ABdhPJyBthTeKmOHV1bPwZzzrSsODrn8asKpgzmW7chz9v9JOHxcYnX2KugHRntNpQOYwB2em9V1TVZ00aOdGtDGhZA= X-Received: by 2002:a17:906:2ccb:: with SMTP id r11mr3715902ejr.39.1610465765748; Tue, 12 Jan 2021 07:36:05 -0800 (PST) MIME-Version: 1.0 References: <20210112091545.10535-1-gilad.reti@gmail.com> In-Reply-To: From: Gilad Reti Date: Tue, 12 Jan 2021 17:35:29 +0200 Message-ID: Subject: Re: [PATCH 2/2] selftests/bpf: add verifier test for PTR_TO_MEM spill To: KP Singh Cc: bpf , Shuah Khan , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , linux-kselftest@vger.kernel.org, Networking , open list Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 12, 2021 at 4:56 PM KP Singh wrote: > > On Tue, Jan 12, 2021 at 10:16 AM Gilad Reti wrote: > > > > Add test to check that the verifier is able to recognize spilling of > > PTR_TO_MEM registers. > > > > It would be nice to have some explanation of what the test does to > recognize the spilling of the PTR_TO_MEM registers in the commit > log as well. > > Would it be possible to augment an existing test_progs > program like tools/testing/selftests/bpf/progs/test_ringbuf.c to test > this functionality? > It may be possible, but from what I understood from Daniel's comment here https://lore.kernel.org/bpf/17629073-4fab-a922-ecc3-25b019960f44@iogearbox.net/ the test should be a part of the verifier tests (which is reasonable to me since it is a verifier bugfix) > > > > The patch was partially contibuted by CyberArk Software, Inc. > > > > Signed-off-by: Gilad Reti > > --- > > tools/testing/selftests/bpf/test_verifier.c | 12 +++++++- > > .../selftests/bpf/verifier/spill_fill.c | 30 +++++++++++++++++++ > > 2 files changed, 41 insertions(+), 1 deletion(-) > > > > diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c > > index 777a81404fdb..f8569f04064b 100644 > > --- a/tools/testing/selftests/bpf/test_verifier.c > > +++ b/tools/testing/selftests/bpf/test_verifier.c > > @@ -50,7 +50,7 @@ > > #define MAX_INSNS BPF_MAXINSNS > > #define MAX_TEST_INSNS 1000000 > > #define MAX_FIXUPS 8 > > -#define MAX_NR_MAPS 20 > > +#define MAX_NR_MAPS 21 > > #define MAX_TEST_RUNS 8 > > #define POINTER_VALUE 0xcafe4all > > #define TEST_DATA_LEN 64 > > @@ -87,6 +87,7 @@ struct bpf_test { > > int fixup_sk_storage_map[MAX_FIXUPS]; > > int fixup_map_event_output[MAX_FIXUPS]; > > int fixup_map_reuseport_array[MAX_FIXUPS]; > > + int fixup_map_ringbuf[MAX_FIXUPS]; > > const char *errstr; > > const char *errstr_unpriv; > > uint32_t insn_processed; > > @@ -640,6 +641,7 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type, > > int *fixup_sk_storage_map = test->fixup_sk_storage_map; > > int *fixup_map_event_output = test->fixup_map_event_output; > > int *fixup_map_reuseport_array = test->fixup_map_reuseport_array; > > + int *fixup_map_ringbuf = test->fixup_map_ringbuf; > > > > if (test->fill_helper) { > > test->fill_insns = calloc(MAX_TEST_INSNS, sizeof(struct bpf_insn)); > > @@ -817,6 +819,14 @@ static void do_test_fixup(struct bpf_test *test, enum bpf_prog_type prog_type, > > fixup_map_reuseport_array++; > > } while (*fixup_map_reuseport_array); > > } > > + if (*fixup_map_ringbuf) { > > + map_fds[20] = create_map(BPF_MAP_TYPE_RINGBUF, 0, > > + 0, 4096); > > + do { > > + prog[*fixup_map_ringbuf].imm = map_fds[20]; > > + fixup_map_ringbuf++; > > + } while (*fixup_map_ringbuf); > > + } > > } > > > > struct libcap { > > diff --git a/tools/testing/selftests/bpf/verifier/spill_fill.c b/tools/testing/selftests/bpf/verifier/spill_fill.c > > index 45d43bf82f26..1833b6c730dd 100644 > > --- a/tools/testing/selftests/bpf/verifier/spill_fill.c > > +++ b/tools/testing/selftests/bpf/verifier/spill_fill.c > > @@ -28,6 +28,36 @@ > > .result = ACCEPT, > > .result_unpriv = ACCEPT, > > }, > > +{ > > + "check valid spill/fill, ptr to mem", > > + .insns = { > > + /* reserve 8 byte ringbuf memory */ > > + BPF_ST_MEM(BPF_DW, BPF_REG_10, -8, 0), > > + BPF_LD_MAP_FD(BPF_REG_1, 0), > > + BPF_MOV64_IMM(BPF_REG_2, 8), > > + BPF_MOV64_IMM(BPF_REG_3, 0), > > + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_reserve), > > + /* store a pointer to the reserved memory in R6 */ > > + BPF_MOV64_REG(BPF_REG_6, BPF_REG_0), > > + /* check whether the reservation was successful */ > > + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 0, 6), > > + /* spill R6(mem) into the stack */ > > + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -8), > > + /* fill it back in R7 */ > > + BPF_LDX_MEM(BPF_DW, BPF_REG_7, BPF_REG_10, -8), > > + /* should be able to access *(R7) = 0 */ > > + BPF_ST_MEM(BPF_DW, BPF_REG_7, 0, 0), > > + /* submit the reserved rungbuf memory */ > > + BPF_MOV64_REG(BPF_REG_1, BPF_REG_7), > > + BPF_MOV64_IMM(BPF_REG_2, 0), > > + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_ringbuf_submit), > > + BPF_MOV64_IMM(BPF_REG_0, 0), > > + BPF_EXIT_INSN(), > > + }, > > + .fixup_map_ringbuf = { 1 }, > > + .result = ACCEPT, > > + .result_unpriv = ACCEPT, > > +}, > > { > > "check corrupted spill/fill", > > .insns = { > > -- > > 2.27.0 > >