From patchwork Fri Mar 5 13:40:50 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 394162 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=-14.0 required=3.0 tests=BAYES_00, INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 AC1F7C433E6 for ; Fri, 5 Mar 2021 13:42:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7EDEF65005 for ; Fri, 5 Mar 2021 13:42:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230493AbhCENlf convert rfc822-to-8bit (ORCPT ); Fri, 5 Mar 2021 08:41:35 -0500 Received: from us-smtp-delivery-44.mimecast.com ([207.211.30.44]:40424 "EHLO us-smtp-delivery-44.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229750AbhCENlF (ORCPT ); Fri, 5 Mar 2021 08:41:05 -0500 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-195-DqrQ0yZ5PqOvooL5r5B_Mg-1; Fri, 05 Mar 2021 08:41:00 -0500 X-MC-Unique: DqrQ0yZ5PqOvooL5r5B_Mg-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4463D1842144; Fri, 5 Mar 2021 13:40:58 +0000 (UTC) Received: from krava.redhat.com (unknown [10.40.196.10]) by smtp.corp.redhat.com (Postfix) with ESMTP id A254718AD6; Fri, 5 Mar 2021 13:40:51 +0000 (UTC) From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: Michael Ellerman , "Naveen N . Rao" , netdev@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rg?= =?utf-8?q?ensen?= , Yauheni Kaliuta Subject: [PATCHv2 bpf-next] selftests/bpf: Fix test_attach_probe for powerpc uprobes Date: Fri, 5 Mar 2021 14:40:50 +0100 Message-Id: <20210305134050.139840-1-jolsa@kernel.org> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=jolsa@kernel.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org When testing uprobes we the test gets GEP (Global Entry Point) address from kallsyms, but then the function is called locally so the uprobe is not triggered. Fixing this by adjusting the address to LEP (Local Entry Point) for powerpc arch plus instruction check stolen from ppc_function_entry function pointed out and explained by Michael and Naveen. Cc: Michael Ellerman Cc: Naveen N. Rao Signed-off-by: Jiri Olsa Acked-by: Naveen N. Rao --- .../selftests/bpf/prog_tests/attach_probe.c | 40 ++++++++++++++++++- 1 file changed, 39 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/prog_tests/attach_probe.c b/tools/testing/selftests/bpf/prog_tests/attach_probe.c index a0ee87c8e1ea..9dc4e3dfbcf3 100644 --- a/tools/testing/selftests/bpf/prog_tests/attach_probe.c +++ b/tools/testing/selftests/bpf/prog_tests/attach_probe.c @@ -2,6 +2,44 @@ #include #include "test_attach_probe.skel.h" +#if defined(__powerpc64__) && defined(_CALL_ELF) && _CALL_ELF == 2 + +#define OP_RT_RA_MASK 0xffff0000UL +#define LIS_R2 0x3c400000UL +#define ADDIS_R2_R12 0x3c4c0000UL +#define ADDI_R2_R2 0x38420000UL + +static ssize_t get_offset(ssize_t addr, ssize_t base) +{ + u32 *insn = (u32 *) addr; + + /* + * A PPC64 ABIv2 function may have a local and a global entry + * point. We need to use the local entry point when patching + * functions, so identify and step over the global entry point + * sequence. + * + * The global entry point sequence is always of the form: + * + * addis r2,r12,XXXX + * addi r2,r2,XXXX + * + * A linker optimisation may convert the addis to lis: + * + * lis r2,XXXX + * addi r2,r2,XXXX + */ + if ((((*insn & OP_RT_RA_MASK) == ADDIS_R2_R12) || + ((*insn & OP_RT_RA_MASK) == LIS_R2)) && + ((*(insn + 1) & OP_RT_RA_MASK) == ADDI_R2_R2)) + return (ssize_t)(insn + 2) - base; + else + return addr - base; +} +#else +#define get_offset(addr, base) (addr - base) +#endif + ssize_t get_base_addr() { size_t start, offset; char buf[256]; @@ -36,7 +74,7 @@ void test_attach_probe(void) if (CHECK(base_addr < 0, "get_base_addr", "failed to find base addr: %zd", base_addr)) return; - uprobe_offset = (size_t)&get_base_addr - base_addr; + uprobe_offset = get_offset((size_t)&get_base_addr, base_addr); skel = test_attach_probe__open_and_load(); if (CHECK(!skel, "skel_open", "failed to open skeleton\n"))