From patchwork Mon Jun 20 23:53:43 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduard Zingerman X-Patchwork-Id: 12888616 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 B4868C43334 for ; Mon, 20 Jun 2022 23:54:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245097AbiFTXyu (ORCPT ); Mon, 20 Jun 2022 19:54:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244396AbiFTXyt (ORCPT ); Mon, 20 Jun 2022 19:54:49 -0400 Received: from mail-ed1-x52f.google.com (mail-ed1-x52f.google.com [IPv6:2a00:1450:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 087F813D39 for ; Mon, 20 Jun 2022 16:54:48 -0700 (PDT) Received: by mail-ed1-x52f.google.com with SMTP id es26so15433952edb.4 for ; Mon, 20 Jun 2022 16:54:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=gUNlDq4gqclg6ilFHgssD0hNdQf9GAvVjVxet0bXss8=; b=XZ/5JqP6kIBTJ94NXEDP5ZmStL0L0jqpUUcBbFlj5q8zpDrnSNk2BsYBHMfGCHM0pU Z0EN3ntEDaalJMkZRL8g3RgmrshBZKiAwOZC7Ly/j9qnlpq1DwQvNSUDyIcYWgxTGueO BXEaPx5gGs1jftbVGHzoZ8iCfsFKsGNVoVWVtaGdZuejnghubhKXwgj7dV99kHiQp4Pj la5HnsskKi0LNx6rAc11RddFCyPLfB/bRijWvT/gk1likw/2xfxPlPGKs/bLOBsfwECu UARComszD79sEIfA9u4zhte7+cpPMgwKhMVBqUxHkYAmuQXLO+sc73OR+vVR4LTwU8cI FI0A== 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=gUNlDq4gqclg6ilFHgssD0hNdQf9GAvVjVxet0bXss8=; b=KP9leRv6suD/8R/oVZOSg60XTgctIY/K7M02JuEjoIrAPQjjPgkqNRbvz6Rih+nl7B MVni7Hfwc+lOAfq9Ez4dOJLtI7Av6t4iDaE5IK+/7XdVIQOI6DFS1yODoQTHxdCFqPWV P64uR/WB8iTQX+Z53pP6xQaRRq71NbmtzkmD0UehmblZYLI0ADXwNjyrYpigeQ9kCwSw Fzg6MecHeia00NWiRkbnqkgxwPF0k1+eK2LXwHf7c8VIGbRJBMjdq5BZoAep9C5jJj65 UIFqGPbwKUe7q4VSQbxA8xSW6sIYoN70xSgEo4ybJd9pVqO3qoJ0omU9BJRKI9N9Sf7g 5oKQ== X-Gm-Message-State: AJIora9grUD68wyPE2zd1G5jMnIH8XRfrWr5i3AhyoRShRTOH1zO5Tyo Bb20wMkTYEw1xk87iLiyZCme/25dJlalvEFD X-Google-Smtp-Source: AGRyM1uMqV+5AwuLa4GM7uKyhG7i1LhXtkvtbOwcn87z+Ad2gc85vgwG2CL3azGW+53Xmn3DEaf11w== X-Received: by 2002:a05:6402:3988:b0:434:e2a8:8459 with SMTP id fk8-20020a056402398800b00434e2a88459mr32208561edb.253.1655769286256; Mon, 20 Jun 2022 16:54:46 -0700 (PDT) Received: from localhost.localdomain (boundsly.muster.volia.net. [93.72.16.93]) by smtp.gmail.com with ESMTPSA id e21-20020a056402105500b004356d08bbbasm7078560edu.40.2022.06.20.16.54.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 20 Jun 2022 16:54:43 -0700 (PDT) From: Eduard Zingerman To: bpf@vger.kernel.org, ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net, kernel-team@fb.com, song@kernel.org, joannelkoong@gmail.com Cc: eddyz87@gmail.com Subject: [PATCH bpf-next v8 4/5] selftests/bpf: BPF test_verifier selftests for bpf_loop inlining Date: Tue, 21 Jun 2022 02:53:43 +0300 Message-Id: <20220620235344.569325-5-eddyz87@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220620235344.569325-1-eddyz87@gmail.com> References: <20220620235344.569325-1-eddyz87@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net A number of test cases for BPF selftests test_verifier to check how bpf_loop inline transformation rewrites the BPF program. The following cases are covered: - happy path - no-rewrite when flags is non-zero - no-rewrite when callback is non-constant - subprogno in insn_aux is updated correctly when dead sub-programs are removed - check that correct stack offsets are assigned for spilling of R6-R8 registers Signed-off-by: Eduard Zingerman Acked-by: Song Liu --- .../selftests/bpf/verifier/bpf_loop_inline.c | 252 ++++++++++++++++++ 1 file changed, 252 insertions(+) create mode 100644 tools/testing/selftests/bpf/verifier/bpf_loop_inline.c diff --git a/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c b/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c new file mode 100644 index 000000000000..232da07c93b5 --- /dev/null +++ b/tools/testing/selftests/bpf/verifier/bpf_loop_inline.c @@ -0,0 +1,252 @@ +#define BTF_TYPES \ + .btf_strings = "\0int\0i\0ctx\0callback\0main\0", \ + .btf_types = { \ + /* 1: int */ BTF_TYPE_INT_ENC(1, BTF_INT_SIGNED, 0, 32, 4), \ + /* 2: int* */ BTF_PTR_ENC(1), \ + /* 3: void* */ BTF_PTR_ENC(0), \ + /* 4: int __(void*) */ BTF_FUNC_PROTO_ENC(1, 1), \ + BTF_FUNC_PROTO_ARG_ENC(7, 3), \ + /* 5: int __(int, int*) */ BTF_FUNC_PROTO_ENC(1, 2), \ + BTF_FUNC_PROTO_ARG_ENC(5, 1), \ + BTF_FUNC_PROTO_ARG_ENC(7, 2), \ + /* 6: main */ BTF_FUNC_ENC(20, 4), \ + /* 7: callback */ BTF_FUNC_ENC(11, 5), \ + BTF_END_RAW \ + } + +#define MAIN_TYPE 6 +#define CALLBACK_TYPE 7 + +/* can't use BPF_CALL_REL, jit_subprogs adjusts IMM & OFF + * fields for pseudo calls + */ +#define PSEUDO_CALL_INSN() \ + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, BPF_PSEUDO_CALL, \ + INSN_OFF_MASK, INSN_IMM_MASK) + +/* can't use BPF_FUNC_loop constant, + * do_mix_fixups adjusts the IMM field + */ +#define HELPER_CALL_INSN() \ + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, INSN_OFF_MASK, INSN_IMM_MASK) + +{ + "inline simple bpf_loop call", + .insns = { + /* main */ + /* force verifier state branching to verify logic on first and + * subsequent bpf_loop insn processing steps + */ + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_jiffies64), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 777, 2), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1), + BPF_JMP_IMM(BPF_JA, 0, 0, 1), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 2), + + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 6), + BPF_RAW_INSN(0, 0, 0, 0, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* callback */ + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .expected_insns = { PSEUDO_CALL_INSN() }, + .unexpected_insns = { HELPER_CALL_INSN() }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .result = ACCEPT, + .runs = 0, + .func_info = { { 0, MAIN_TYPE }, { 12, CALLBACK_TYPE } }, + .func_info_cnt = 2, + BTF_TYPES +}, +{ + "don't inline bpf_loop call, flags non-zero", + .insns = { + /* main */ + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_jiffies64), + BPF_ALU64_REG(BPF_MOV, BPF_REG_6, BPF_REG_0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_jiffies64), + BPF_ALU64_REG(BPF_MOV, BPF_REG_7, BPF_REG_0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_6, 0, 9), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0), + BPF_JMP_IMM(BPF_JNE, BPF_REG_7, 0, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1), + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 7), + BPF_RAW_INSN(0, 0, 0, 0, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0), + BPF_EXIT_INSN(), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 1), + BPF_JMP_IMM(BPF_JA, 0, 0, -10), + /* callback */ + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .expected_insns = { HELPER_CALL_INSN() }, + .unexpected_insns = { PSEUDO_CALL_INSN() }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .result = ACCEPT, + .runs = 0, + .func_info = { { 0, MAIN_TYPE }, { 16, CALLBACK_TYPE } }, + .func_info_cnt = 2, + BTF_TYPES +}, +{ + "don't inline bpf_loop call, callback non-constant", + .insns = { + /* main */ + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_jiffies64), + BPF_JMP_IMM(BPF_JEQ, BPF_REG_0, 777, 4), /* pick a random callback */ + + BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1), + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 10), + BPF_RAW_INSN(0, 0, 0, 0, 0), + BPF_JMP_IMM(BPF_JA, 0, 0, 3), + + BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1), + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 8), + BPF_RAW_INSN(0, 0, 0, 0, 0), + + BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* callback */ + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1), + BPF_EXIT_INSN(), + /* callback #2 */ + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .expected_insns = { HELPER_CALL_INSN() }, + .unexpected_insns = { PSEUDO_CALL_INSN() }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .result = ACCEPT, + .runs = 0, + .func_info = { + { 0, MAIN_TYPE }, + { 14, CALLBACK_TYPE }, + { 16, CALLBACK_TYPE } + }, + .func_info_cnt = 3, + BTF_TYPES +}, +{ + "bpf_loop_inline and a dead func", + .insns = { + /* main */ + + /* A reference to callback #1 to make verifier count it as a func. + * This reference is overwritten below and callback #1 is dead. + */ + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 9), + BPF_RAW_INSN(0, 0, 0, 0, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1), + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 8), + BPF_RAW_INSN(0, 0, 0, 0, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* callback */ + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1), + BPF_EXIT_INSN(), + /* callback #2 */ + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .expected_insns = { PSEUDO_CALL_INSN() }, + .unexpected_insns = { HELPER_CALL_INSN() }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .result = ACCEPT, + .runs = 0, + .func_info = { + { 0, MAIN_TYPE }, + { 10, CALLBACK_TYPE }, + { 12, CALLBACK_TYPE } + }, + .func_info_cnt = 3, + BTF_TYPES +}, +{ + "bpf_loop_inline stack locations for loop vars", + .insns = { + /* main */ + BPF_ST_MEM(BPF_W, BPF_REG_10, -12, 0x77), + /* bpf_loop call #1 */ + BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 1), + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 22), + BPF_RAW_INSN(0, 0, 0, 0, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop), + /* bpf_loop call #2 */ + BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 2), + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 16), + BPF_RAW_INSN(0, 0, 0, 0, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop), + /* call func and exit */ + BPF_CALL_REL(2), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* func */ + BPF_ST_MEM(BPF_DW, BPF_REG_10, -32, 0x55), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_1, 2), + BPF_RAW_INSN(BPF_LD | BPF_IMM | BPF_DW, BPF_REG_2, BPF_PSEUDO_FUNC, 0, 6), + BPF_RAW_INSN(0, 0, 0, 0, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_3, 0), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_4, 0), + BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_loop), + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 0), + BPF_EXIT_INSN(), + /* callback */ + BPF_ALU64_IMM(BPF_MOV, BPF_REG_0, 1), + BPF_EXIT_INSN(), + }, + .expected_insns = { + BPF_ST_MEM(BPF_W, BPF_REG_10, -12, 0x77), + SKIP_INSNS(), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -40), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_7, -32), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_8, -24), + SKIP_INSNS(), + /* offsets are the same as in the first call */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -40), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_7, -32), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_8, -24), + SKIP_INSNS(), + BPF_ST_MEM(BPF_DW, BPF_REG_10, -32, 0x55), + SKIP_INSNS(), + /* offsets differ from main because of different offset + * in BPF_ST_MEM instruction + */ + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_6, -56), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_7, -48), + BPF_STX_MEM(BPF_DW, BPF_REG_10, BPF_REG_8, -40), + }, + .unexpected_insns = { HELPER_CALL_INSN() }, + .prog_type = BPF_PROG_TYPE_TRACEPOINT, + .result = ACCEPT, + .func_info = { + { 0, MAIN_TYPE }, + { 16, MAIN_TYPE }, + { 25, CALLBACK_TYPE }, + }, + .func_info_cnt = 3, + BTF_TYPES +}, + +#undef HELPER_CALL_INSN +#undef PSEUDO_CALL_INSN +#undef CALLBACK_TYPE +#undef MAIN_TYPE +#undef BTF_TYPES