From patchwork Tue Sep 14 09:18:41 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johan Almbladh X-Patchwork-Id: 12492579 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 X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 0E897C433F5 for ; Tue, 14 Sep 2021 09:19:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC0FC61056 for ; Tue, 14 Sep 2021 09:19:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231809AbhINJUy (ORCPT ); Tue, 14 Sep 2021 05:20:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231361AbhINJUi (ORCPT ); Tue, 14 Sep 2021 05:20:38 -0400 Received: from mail-ed1-x535.google.com (mail-ed1-x535.google.com [IPv6:2a00:1450:4864:20::535]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8D2A5C0613CF for ; Tue, 14 Sep 2021 02:19:19 -0700 (PDT) Received: by mail-ed1-x535.google.com with SMTP id q3so18807841edt.5 for ; Tue, 14 Sep 2021 02:19:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=anyfinetworks-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=/cnrIrM7g/uJKhfp+dzP29PUmgqyu/MxCbDo7R/V/lo=; b=zILMdvWaZpQbmnu84QnqgwxlGq3MvEn+WV9+Nuk6a3bURVSOhkXaLm7pDYVJhdSVFU EGskyxUO6xSjCYjk9n92yhP4hfOmNhNipUwLSVF46EUMcNDCEUWfMcUBFFMYDKu5TOxn PcpKAXDLrDPnAo08cyie7bEyV69dIK5euGbrHpGsoaVUiIF0i+/S6cs8bWG7zvLOs4rK IdJAao0Zzv2E55SeHcFiZZP4BlpYaXncTJKCvF99TVcMTKkHv3IR3eenUnZRygyh/Qn9 RHpnzCO0VtfFi7FOMyv/GlSVJQwNfR4ExYLL4/6vjUvTeLT5seZVBHdNQD9kaRZtwfzV mSqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=/cnrIrM7g/uJKhfp+dzP29PUmgqyu/MxCbDo7R/V/lo=; b=sdcXcL9u0DhAqyYNDXgMNJ5pRJeq0AfY2ijkzDWpzDSMaIJvNr7+U78AqyOF7R4onx 6ErdJSIBR+V48qARWmUcY6/Kr8XSNyhlegP36jIWJPPu6ISmkSPGXmVohuQMl+ib0uyJ t1seHqDBu8RoomYR9UE8kUrTKXwS4SZOLHoUrBbFA9MKEU44wgFNiaTAdcEkjKC5qLbz qokUZnhAh35wfowWFtwZH7kcNqTxFMJVYKS/hA68kteVd0NYRxk7KrwCo/2AF2IpIBrQ BGoyhH5EySNTTk4Oa22Z6ZjuPNXORRXnHSDtB7UC5cLB5s09+tYSJCR5KbbTjjpAEIR2 iHpQ== X-Gm-Message-State: AOAM531kuYAMPGt+CdnxQ5z0kncC4clFdG9sO/1sXXldEMILdEMS8nfi 5C/+VaG2w5PQUXGVXW29he2xgg== X-Google-Smtp-Source: ABdhPJxbQJTk1TFZplzKCCUuWHgLiQ4RJ942jUDc6Lf6Yuiex98Who8KPgEfOD3ixlylqpruSUiYBQ== X-Received: by 2002:a05:6402:646:: with SMTP id u6mr17838621edx.127.1631611158184; Tue, 14 Sep 2021 02:19:18 -0700 (PDT) Received: from anpc2.lan (static-213-115-136-2.sme.telenor.se. [213.115.136.2]) by smtp.gmail.com with ESMTPSA id h10sm4615915ede.28.2021.09.14.02.19.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 14 Sep 2021 02:19:17 -0700 (PDT) From: Johan Almbladh To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org Cc: kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, iii@linux.ibm.com, paul@cilium.io, yangtiezhu@loongson.cn, netdev@vger.kernel.org, bpf@vger.kernel.org, Johan Almbladh Subject: [PATCH bpf v4 13/14] bpf/tests: Fix error in tail call limit tests Date: Tue, 14 Sep 2021 11:18:41 +0200 Message-Id: <20210914091842.4186267-14-johan.almbladh@anyfinetworks.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210914091842.4186267-1-johan.almbladh@anyfinetworks.com> References: <20210914091842.4186267-1-johan.almbladh@anyfinetworks.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net This patch fixes an error in the tail call limit test that caused the test to fail on for x86-64 JIT. Previously, the register R0 was used to report the total number of tail calls made. However, after a tail call fall-through, the value of the R0 register is undefined. Now, all tail call error path tests instead use context state to store the count. Fixes: 874be05f525e ("bpf, tests: Add tail call test suite") Reported-by: Paul Chaignon Reported-by: Tiezhu Yang Signed-off-by: Johan Almbladh Tested-by: Tiezhu Yang --- lib/test_bpf.c | 37 +++++++++++++++++++++++++++---------- 1 file changed, 27 insertions(+), 10 deletions(-) diff --git a/lib/test_bpf.c b/lib/test_bpf.c index 7475abfd2186..ddb9a8089d2e 100644 --- a/lib/test_bpf.c +++ b/lib/test_bpf.c @@ -12179,10 +12179,15 @@ static __init int test_bpf(void) struct tail_call_test { const char *descr; struct bpf_insn insns[MAX_INSNS]; + int flags; int result; int stack_depth; }; +/* Flags that can be passed to tail call test cases */ +#define FLAG_NEED_STATE BIT(0) +#define FLAG_RESULT_IN_STATE BIT(1) + /* * Magic marker used in test snippets for tail calls below. * BPF_LD/MOV to R2 and R2 with this immediate value is replaced @@ -12252,32 +12257,38 @@ static struct tail_call_test tail_call_tests[] = { { "Tail call error path, max count reached", .insns = { - BPF_ALU64_IMM(BPF_ADD, R1, 1), - BPF_ALU64_REG(BPF_MOV, R0, R1), + BPF_LDX_MEM(BPF_W, R2, R1, 0), + BPF_ALU64_IMM(BPF_ADD, R2, 1), + BPF_STX_MEM(BPF_W, R1, R2, 0), TAIL_CALL(0), BPF_EXIT_INSN(), }, - .result = MAX_TAIL_CALL_CNT + 1, + .flags = FLAG_NEED_STATE | FLAG_RESULT_IN_STATE, + .result = (MAX_TAIL_CALL_CNT + 1 + 1) * MAX_TESTRUNS, }, { "Tail call error path, NULL target", .insns = { - BPF_ALU64_IMM(BPF_MOV, R0, -1), + BPF_LDX_MEM(BPF_W, R2, R1, 0), + BPF_ALU64_IMM(BPF_ADD, R2, 1), + BPF_STX_MEM(BPF_W, R1, R2, 0), TAIL_CALL(TAIL_CALL_NULL), - BPF_ALU64_IMM(BPF_MOV, R0, 1), BPF_EXIT_INSN(), }, - .result = 1, + .flags = FLAG_NEED_STATE | FLAG_RESULT_IN_STATE, + .result = MAX_TESTRUNS, }, { "Tail call error path, index out of range", .insns = { - BPF_ALU64_IMM(BPF_MOV, R0, -1), + BPF_LDX_MEM(BPF_W, R2, R1, 0), + BPF_ALU64_IMM(BPF_ADD, R2, 1), + BPF_STX_MEM(BPF_W, R1, R2, 0), TAIL_CALL(TAIL_CALL_INVALID), - BPF_ALU64_IMM(BPF_MOV, R0, 1), BPF_EXIT_INSN(), }, - .result = 1, + .flags = FLAG_NEED_STATE | FLAG_RESULT_IN_STATE, + .result = MAX_TESTRUNS, }, }; @@ -12383,6 +12394,8 @@ static __init int test_tail_calls(struct bpf_array *progs) for (i = 0; i < ARRAY_SIZE(tail_call_tests); i++) { struct tail_call_test *test = &tail_call_tests[i]; struct bpf_prog *fp = progs->ptrs[i]; + int *data = NULL; + int state = 0; u64 duration; int ret; @@ -12399,7 +12412,11 @@ static __init int test_tail_calls(struct bpf_array *progs) if (fp->jited) jit_cnt++; - ret = __run_one(fp, NULL, MAX_TESTRUNS, &duration); + if (test->flags & FLAG_NEED_STATE) + data = &state; + ret = __run_one(fp, data, MAX_TESTRUNS, &duration); + if (test->flags & FLAG_RESULT_IN_STATE) + ret = state; if (ret == test->result) { pr_cont("%lld PASS", duration); pass_cnt++;