From patchwork Tue Feb 14 23:50:51 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexei Starovoitov X-Patchwork-Id: 13141043 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 2C5DCC64ED6 for ; Tue, 14 Feb 2023 23:51:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229739AbjBNXvG (ORCPT ); Tue, 14 Feb 2023 18:51:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37312 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230411AbjBNXu5 (ORCPT ); Tue, 14 Feb 2023 18:50:57 -0500 Received: from mail-pl1-x62d.google.com (mail-pl1-x62d.google.com [IPv6:2607:f8b0:4864:20::62d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 46DDF28D3E; Tue, 14 Feb 2023 15:50:56 -0800 (PST) Received: by mail-pl1-x62d.google.com with SMTP id k13so18714254plg.0; Tue, 14 Feb 2023 15:50:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=6qa9d0wjdZSzWDoohRD0RmplfddG8vBXNpncs00Cr04=; b=SSxDj+KYdwBbryAwpgvo3l9UngPoJA0w2EiDdxuvABtsldg5bjsPVWyKfI3hAR+hXN 89ff6npUjQdzSSRukhbPkmQFgbApMstApL1e/SjCzjXJ6d37JkQjXSm6fSJmKQKLTiVg 4WAB3KbgYCfFY5Tiy+AOAXfs8gj9FSdPevVuOQ034zRbHL1RJLKTWQXqJPDQ6RZRLY8V 73xVoaoQ2qf9jneoYwucmYRAMB3aDhTEV2Hw4qlgyNWhSrjIpberOPw/g5Pd8xCWLl6e POKZEavlwkin/X5xPs5J7uNOLe3cTn2LunFCCKqypM2MRnWeeS1fnfwMBxZULBbIPmWD pXSw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=6qa9d0wjdZSzWDoohRD0RmplfddG8vBXNpncs00Cr04=; b=NPMsAVpxptU+C3Z1DYO1Dt+gtXy6VcdCb+SkcwxXL1WwJD8smRtFM9zLwUtSi8jc2X 9yDaqfSwUvJb4rIMSCkopkN813ilhFQdfux0RwVA2MQ+5eF2SUw/TKNitSufLzyXCiqN dlE0FKv+m3zgupsT3j8Bg2FqwrhJ8/XvmiCVgV4dNlGgbVunV46Dic6KFXa0vBmpDI8+ lCKzd69yGPIZEuYPW+yPkun3bbqKSJZZb6AWbQCe4NzhPkxSwI82ADSePE3JKiSEkGSR CPBBkfhDFI52ehY6ldxYmEPZ3+n8iAEsUbqOQJZoavMKzsjPfk76xZ4aRJwhvX2HYGCn YW7A== X-Gm-Message-State: AO0yUKUCz6nfb6mNG9HTX6x5k6XzGeqvOYbRo8+juYoBNIonLA1YQh+S jgOCIjktRDFRQnTQPnK9YFw= X-Google-Smtp-Source: AK7set8d/EqhdvJoFoynH7bAAXhCIVO2YlPCyDY64PxYjOPOWwZtGFItpnQx3AhT+m8yzyo+a+abxA== X-Received: by 2002:a17:90b:4b41:b0:233:ebd4:301c with SMTP id mi1-20020a17090b4b4100b00233ebd4301cmr754343pjb.1.1676418655478; Tue, 14 Feb 2023 15:50:55 -0800 (PST) Received: from localhost.localdomain ([2620:10d:c090:400::5:d0de]) by smtp.gmail.com with ESMTPSA id kn14-20020a17090b480e00b00233d6547000sm87198pjb.54.2023.02.14.15.50.53 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Tue, 14 Feb 2023 15:50:55 -0800 (PST) From: Alexei Starovoitov To: davem@davemloft.net Cc: daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org, memxor@gmail.com, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com Subject: [PATCH bpf-next] selftests/bpf: Fix map_kptr test. Date: Tue, 14 Feb 2023 15:50:51 -0800 Message-Id: <20230214235051.22938-1-alexei.starovoitov@gmail.com> X-Mailer: git-send-email 2.37.1 (Apple Git-137.1) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net From: Alexei Starovoitov The compiler is optimizing out majority of unref_ptr read/writes, so the test wasn't testing much. For example, one could delete '__kptr' tag from 'struct prog_test_ref_kfunc __kptr *unref_ptr;' and the test would still "pass". Convert it to volatile stores. Confirmed by comparing bpf asm before/after. Fixes: 2cbc469a6fc3 ("selftests/bpf: Add C tests for kptr") Signed-off-by: Alexei Starovoitov Acked-by: Stanislav Fomichev Acked-by: Kumar Kartikeya Dwivedi --- tools/testing/selftests/bpf/progs/map_kptr.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/map_kptr.c b/tools/testing/selftests/bpf/progs/map_kptr.c index eb8217803493..228ec45365a8 100644 --- a/tools/testing/selftests/bpf/progs/map_kptr.c +++ b/tools/testing/selftests/bpf/progs/map_kptr.c @@ -62,21 +62,23 @@ extern struct prog_test_ref_kfunc * bpf_kfunc_call_test_kptr_get(struct prog_test_ref_kfunc **p, int a, int b) __ksym; extern void bpf_kfunc_call_test_release(struct prog_test_ref_kfunc *p) __ksym; +#define WRITE_ONCE(x, val) ((*(volatile typeof(x) *) &(x)) = (val)) + static void test_kptr_unref(struct map_value *v) { struct prog_test_ref_kfunc *p; p = v->unref_ptr; /* store untrusted_ptr_or_null_ */ - v->unref_ptr = p; + WRITE_ONCE(v->unref_ptr, p); if (!p) return; if (p->a + p->b > 100) return; /* store untrusted_ptr_ */ - v->unref_ptr = p; + WRITE_ONCE(v->unref_ptr, p); /* store NULL */ - v->unref_ptr = NULL; + WRITE_ONCE(v->unref_ptr, NULL); } static void test_kptr_ref(struct map_value *v) @@ -85,7 +87,7 @@ static void test_kptr_ref(struct map_value *v) p = v->ref_ptr; /* store ptr_or_null_ */ - v->unref_ptr = p; + WRITE_ONCE(v->unref_ptr, p); if (!p) return; if (p->a + p->b > 100) @@ -99,7 +101,7 @@ static void test_kptr_ref(struct map_value *v) return; } /* store ptr_ */ - v->unref_ptr = p; + WRITE_ONCE(v->unref_ptr, p); bpf_kfunc_call_test_release(p); p = bpf_kfunc_call_test_acquire(&(unsigned long){0});