From patchwork Thu Aug 29 21:08:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin KaFai Lau X-Patchwork-Id: 13783878 X-Patchwork-Delegate: bpf@iogearbox.net Received: from out-180.mta1.migadu.com (out-180.mta1.migadu.com [95.215.58.180]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DB6BE18C004 for ; Thu, 29 Aug 2024 21:09:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.180 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724965781; cv=none; b=QBlA/lkYK7Qm5e+fAn5O3/WZ6itZl8j2BJyUe98edeBKWcodmuOWwm8KTd01xnwnkXkgyYOsacmQsBwHWnOajMpkcYIvu7wvavZFMQE4836JiBxNAHUEH9iLBaXM5jWD01vcplwL5Yu7T5pYE2s7xRJ8XkYlOeT29QU4dTEmNv0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724965781; c=relaxed/simple; bh=b5Fwe61DFmJ8tmrcnmSF8rJjSIL1m4OZD7BoGZFBwVc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=EYUfw7to2tVZnR6KmqsfkVl5ktOdnDan6iKj/npZuUgjjo2RNVpa/OajiFzXNnaKly9roM2TzZT4Z5KrFAhYRLIxvwotK2/Giq8aROQMuaI/dXBGlp2zr4/zdxLbUhofBIOW0VYh15AL83/5fQ7MKgeu+EmSSbAqwZmpY67F26E= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=EL5qWfE+; arc=none smtp.client-ip=95.215.58.180 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="EL5qWfE+" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1724965778; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=YDxOXoz1D1BErybxpiUhhKu2WtIM5oqXzOaZ4JKezYg=; b=EL5qWfE+QsxVtqCxh/KoGkUmpHP/mpA5cdHQYdcCKqFzhtLp8RouYYniTc2mzJCwer8Ar6 Uo/ldK7x27uJ3H+8ApxcIwcZ5+k0z5sUufuIwSZ5Qa6qFRthPR7isl/yyCe0SNvnj0vHGr FOUamh0X5nJ23bOUkEBJjYw9aGgrKBE= From: Martin KaFai Lau To: bpf@vger.kernel.org Cc: Alexei Starovoitov , Andrii Nakryiko , Daniel Borkmann , Eduard Zingerman , Yonghong Song , Amery Hung , kernel-team@meta.com Subject: [PATCH v5 bpf-next 9/9] selftests/bpf: Test epilogue patching when the main prog has multiple BPF_EXIT Date: Thu, 29 Aug 2024 14:08:31 -0700 Message-ID: <20240829210833.388152-10-martin.lau@linux.dev> In-Reply-To: <20240829210833.388152-1-martin.lau@linux.dev> References: <20240829210833.388152-1-martin.lau@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-Patchwork-Delegate: bpf@iogearbox.net From: Martin KaFai Lau This patch tests the epilogue patching when the main prog has multiple BPF_EXIT. The verifier should have patched the 2nd (and later) BPF_EXIT with a BPF_JA that goes back to the earlier patched epilogue instructions. Acked-by: Eduard Zingerman Signed-off-by: Martin KaFai Lau --- .../selftests/bpf/prog_tests/pro_epilogue.c | 2 + .../selftests/bpf/progs/epilogue_exit.c | 82 +++++++++++++++++++ 2 files changed, 84 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/epilogue_exit.c diff --git a/tools/testing/selftests/bpf/prog_tests/pro_epilogue.c b/tools/testing/selftests/bpf/prog_tests/pro_epilogue.c index f974ae9ac610..509883e6823a 100644 --- a/tools/testing/selftests/bpf/prog_tests/pro_epilogue.c +++ b/tools/testing/selftests/bpf/prog_tests/pro_epilogue.c @@ -5,6 +5,7 @@ #include "pro_epilogue.skel.h" #include "epilogue_tailcall.skel.h" #include "pro_epilogue_goto_start.skel.h" +#include "epilogue_exit.skel.h" struct st_ops_args { __u64 a; @@ -53,6 +54,7 @@ void test_pro_epilogue(void) { RUN_TESTS(pro_epilogue); RUN_TESTS(pro_epilogue_goto_start); + RUN_TESTS(epilogue_exit); if (test__start_subtest("tailcall")) test_tailcall(); } diff --git a/tools/testing/selftests/bpf/progs/epilogue_exit.c b/tools/testing/selftests/bpf/progs/epilogue_exit.c new file mode 100644 index 000000000000..33d3a57bee90 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/epilogue_exit.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ + +#include +#include +#include "bpf_misc.h" +#include "../bpf_testmod/bpf_testmod.h" +#include "../bpf_testmod/bpf_testmod_kfunc.h" + +char _license[] SEC("license") = "GPL"; + +__success +/* save __u64 *ctx to stack */ +__xlated("0: *(u64 *)(r10 -8) = r1") +/* main prog */ +__xlated("1: r1 = *(u64 *)(r1 +0)") +__xlated("2: r2 = *(u64 *)(r1 +0)") +__xlated("3: r3 = 0") +__xlated("4: r4 = 1") +__xlated("5: if r2 == 0x0 goto pc+10") +__xlated("6: r0 = 0") +__xlated("7: *(u64 *)(r1 +0) = r3") +/* epilogue */ +__xlated("8: r1 = *(u64 *)(r10 -8)") +__xlated("9: r1 = *(u64 *)(r1 +0)") +__xlated("10: r6 = *(u64 *)(r1 +0)") +__xlated("11: r6 += 10000") +__xlated("12: *(u64 *)(r1 +0) = r6") +__xlated("13: r0 = r6") +__xlated("14: r0 *= 2") +__xlated("15: exit") +/* 2nd part of the main prog after the first exit */ +__xlated("16: *(u64 *)(r1 +0) = r4") +__xlated("17: r0 = 1") +/* Clear the r1 to ensure it does not have + * off-by-1 error and ensure it jumps back to the + * beginning of epilogue which initializes + * the r1 with the ctx ptr. + */ +__xlated("18: r1 = 0") +__xlated("19: gotol pc-12") +SEC("struct_ops/test_epilogue_exit") +__naked int test_epilogue_exit(void) +{ + asm volatile ( + "r1 = *(u64 *)(r1 +0);" + "r2 = *(u64 *)(r1 +0);" + "r3 = 0;" + "r4 = 1;" + "if r2 == 0 goto +3;" + "r0 = 0;" + "*(u64 *)(r1 + 0) = r3;" + "exit;" + "*(u64 *)(r1 + 0) = r4;" + "r0 = 1;" + "r1 = 0;" + "exit;" + ::: __clobber_all); +} + +SEC(".struct_ops.link") +struct bpf_testmod_st_ops epilogue_exit = { + .test_epilogue = (void *)test_epilogue_exit, +}; + +SEC("syscall") +__retval(20000) +int syscall_epilogue_exit0(void *ctx) +{ + struct st_ops_args args = { .a = 1 }; + + return bpf_kfunc_st_ops_test_epilogue(&args); +} + +SEC("syscall") +__retval(20002) +int syscall_epilogue_exit1(void *ctx) +{ + struct st_ops_args args = {}; + + return bpf_kfunc_st_ops_test_epilogue(&args); +}