From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 47F223559CD; Mon, 12 Jan 2026 12:12:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768219942; cv=none; b=K9FOxbH2tA8ds0jH2wFBcf/ZojcDtfIFG9BJMsN1uxAFBh+oslAQVqVGkNDb25RzPJoShBqtk2xOFwIx3mWPrmu5ZNz8ROAxfsmaVbN+SF+ixNxvPwr4RXtFNEqMcdCZe+z9/uj4+H6adw1oZS5KS8E+qFl5zRBQ4igLQgsAKJ0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768219942; c=relaxed/simple; bh=KYN08OfhJKdVOxdem4pFSBq1PJAMgzGcdLnB3YeasnE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AdzOxjOKc6lDlzeuqU3FlWsbo0JShzHn9kPkihoqbMBftxDOr3EI74XhT2fNvcWtE1sPrnzCujH97sFgsJ5iUxnqFypsZP1HbdmPomeZtOwjx4GVsVNPDB6UGq3cwHxynTpwdkACfadJdZtmpN2uQLI6fUwN5tfcqQ47nFaWQhY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=P2XBidzz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="P2XBidzz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 61294C16AAE; Mon, 12 Jan 2026 12:12:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768219941; bh=KYN08OfhJKdVOxdem4pFSBq1PJAMgzGcdLnB3YeasnE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=P2XBidzzhTmyO2SwYfh5ARhZLgNvJNHbUPixPtPUCNfnsLWXoVheNL+Urc8k0LyVg 9fEgCwyfa1amaJZZ4qrYkLTdwayQ/M9A4CyrCU2arz2pjo8nhxAhmX4PjfvW65XZwW NehGLc77SnciQyAzAQ0MdsdMn6JQBzTwOI4U3Bu09gX+DLs2BVVuqCZePoCjaCzfpL ARkvlSfzN9z5YiY5JBCzBEbafXjZlZ+LyzdbYUpcpntBJRWZPs8iSJsAtJnttDzd0c ZIMoMnObhYpUD7JjxNCT/Ovckdk4vRdjEQiZ7eaopPG4QRWssbQOP3s3KuMcfskj/K Pr9Od2SJJOzow== From: Jiri Olsa To: Masami Hiramatsu , Steven Rostedt , Will Deacon Cc: Song Liu , Peter Zijlstra , bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, x86@kernel.org, Yonghong Song , Song Liu , Andrii Nakryiko , Mark Rutland , Mahe Tardy Subject: [PATCHv3 bpf-next 2/2] selftests/bpf: Add test for bpf_override_return helper Date: Mon, 12 Jan 2026 13:11:57 +0100 Message-ID: <20260112121157.854473-2-jolsa@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260112121157.854473-1-jolsa@kernel.org> References: <20260112121157.854473-1-jolsa@kernel.org> Precedence: bulk X-Mailing-List: linux-trace-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit We do not actually test the bpf_override_return helper functionality itself at the moment, only the bpf program being able to attach it. Adding test that override prctl syscall return value on top of kprobe and kprobe.multi. Acked-by: Song Liu Signed-off-by: Jiri Olsa --- .../bpf/prog_tests/kprobe_multi_test.c | 44 +++++++++++++++++++ .../bpf/progs/kprobe_multi_override.c | 15 +++++++ tools/testing/selftests/bpf/trace_helpers.h | 12 +++++ 3 files changed, 71 insertions(+) diff --git a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c index 6cfaa978bc9a..9caef222e528 100644 --- a/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c +++ b/tools/testing/selftests/bpf/prog_tests/kprobe_multi_test.c @@ -1,4 +1,6 @@ // SPDX-License-Identifier: GPL-2.0 +#include +#include #include #include "kprobe_multi.skel.h" #include "trace_helpers.h" @@ -540,6 +542,46 @@ static void test_attach_override(void) kprobe_multi_override__destroy(skel); } +static void test_override(void) +{ + struct kprobe_multi_override *skel = NULL; + int err; + + skel = kprobe_multi_override__open_and_load(); + if (!ASSERT_OK_PTR(skel, "kprobe_multi_empty__open_and_load")) + goto cleanup; + + skel->bss->pid = getpid(); + + /* no override */ + err = prctl(0xffff, 0); + ASSERT_EQ(err, -1, "err"); + + /* kprobe.multi override */ + skel->links.test_override = bpf_program__attach_kprobe_multi_opts(skel->progs.test_override, + SYS_PREFIX "sys_prctl", NULL); + if (!ASSERT_OK_PTR(skel->links.test_override, "bpf_program__attach_kprobe_multi_opts")) + goto cleanup; + + err = prctl(0xffff, 0); + ASSERT_EQ(err, 123, "err"); + + bpf_link__destroy(skel->links.test_override); + skel->links.test_override = NULL; + + /* kprobe override */ + skel->links.test_kprobe_override = bpf_program__attach_kprobe(skel->progs.test_kprobe_override, + false, SYS_PREFIX "sys_prctl"); + if (!ASSERT_OK_PTR(skel->links.test_kprobe_override, "bpf_program__attach_kprobe")) + goto cleanup; + + err = prctl(0xffff, 0); + ASSERT_EQ(err, 123, "err"); + +cleanup: + kprobe_multi_override__destroy(skel); +} + #ifdef __x86_64__ static void test_attach_write_ctx(void) { @@ -597,6 +639,8 @@ void test_kprobe_multi_test(void) test_attach_api_fails(); if (test__start_subtest("attach_override")) test_attach_override(); + if (test__start_subtest("override")) + test_override(); if (test__start_subtest("session")) test_session_skel_api(); if (test__start_subtest("session_cookie")) diff --git a/tools/testing/selftests/bpf/progs/kprobe_multi_override.c b/tools/testing/selftests/bpf/progs/kprobe_multi_override.c index 28f8487c9059..14f39fa6d515 100644 --- a/tools/testing/selftests/bpf/progs/kprobe_multi_override.c +++ b/tools/testing/selftests/bpf/progs/kprobe_multi_override.c @@ -5,9 +5,24 @@ char _license[] SEC("license") = "GPL"; +int pid = 0; + SEC("kprobe.multi") int test_override(struct pt_regs *ctx) { + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + + bpf_override_return(ctx, 123); + return 0; +} + +SEC("kprobe") +int test_kprobe_override(struct pt_regs *ctx) +{ + if (bpf_get_current_pid_tgid() >> 32 != pid) + return 0; + bpf_override_return(ctx, 123); return 0; } diff --git a/tools/testing/selftests/bpf/trace_helpers.h b/tools/testing/selftests/bpf/trace_helpers.h index 9437bdd4afa5..a5576b2dfc26 100644 --- a/tools/testing/selftests/bpf/trace_helpers.h +++ b/tools/testing/selftests/bpf/trace_helpers.h @@ -4,6 +4,18 @@ #include +#ifdef __x86_64__ +#define SYS_PREFIX "__x64_" +#elif defined(__s390x__) +#define SYS_PREFIX "__s390x_" +#elif defined(__aarch64__) +#define SYS_PREFIX "__arm64_" +#elif defined(__riscv) +#define SYS_PREFIX "__riscv_" +#else +#define SYS_PREFIX "" +#endif + #define __ALIGN_MASK(x, mask) (((x)+(mask))&~(mask)) #define ALIGN(x, a) __ALIGN_MASK(x, (typeof(x))(a)-1) -- 2.52.0