From nobody Sat Apr 11 18:34:14 2026 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 CFB17C19F2D for ; Tue, 9 Aug 2022 04:06:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233912AbiHIEGZ (ORCPT ); Tue, 9 Aug 2022 00:06:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58324 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233643AbiHIEGU (ORCPT ); Tue, 9 Aug 2022 00:06:20 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id F3CAAB7E6 for ; Mon, 8 Aug 2022 21:06:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1660017979; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=v7Wypa4oOYW4jZXZehboAwCarfEU3fnRZX5wpPKbgRs=; b=dDJY3TX7PK3vxV16FZRT6T2aRYQMH/XQcJJqm23cvlitdBA2VlGS+GP9L6dsR4O+df+miE 3McsxOcyekfnywoG7Z95/m1WZh2NcovT23DDhQv71hD3L6AKQfGhZ7ruk0HY0nSC3XgRlA 0kFh9pyxoD/I3nExOFSoY+tJpH5ckUA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-170-JGUT5zIuPAWUE7gJa_yylg-1; Tue, 09 Aug 2022 00:06:16 -0400 X-MC-Unique: JGUT5zIuPAWUE7gJa_yylg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 892AF85A58A; Tue, 9 Aug 2022 04:06:15 +0000 (UTC) Received: from gshan.redhat.com (vpn2-54-20.bne.redhat.com [10.64.54.20]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E4B932166B26; Tue, 9 Aug 2022 04:06:10 +0000 (UTC) From: Gavin Shan To: kvmarm@lists.cs.columbia.edu Cc: kvm@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, pbonzini@redhat.com, maz@kernel.org, oliver.upton@linux.dev, andrew.jones@linux.dev, seanjc@google.com, mathieu.desnoyers@efficios.com, fweimer@redhat.com, yihyu@redhat.com, shan.gavin@gmail.com Subject: [PATCH 1/2] KVM: selftests: Make rseq compatible with glibc-2.35 Date: Tue, 9 Aug 2022 14:06:26 +0800 Message-Id: <20220809060627.115847-2-gshan@redhat.com> In-Reply-To: <20220809060627.115847-1-gshan@redhat.com> References: <20220809060627.115847-1-gshan@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The rseq information is registered by TLS, starting from glibc-2.35. In this case, the test always fails due to syscall(__NR_rseq). For example, on RHEL9.1 where upstream glibc-2.35 features are enabled on downstream glibc-2.34, the test fails like below. # ./rseq_test =3D=3D=3D=3D Test Assertion Failure =3D=3D=3D=3D rseq_test.c:60: !r pid=3D112043 tid=3D112043 errno=3D22 - Invalid argument 1 0x0000000000401973: main at rseq_test.c:226 2 0x0000ffff84b6c79b: ?? ??:0 3 0x0000ffff84b6c86b: ?? ??:0 4 0x0000000000401b6f: _start at ??:? rseq failed, errno =3D 22 (Invalid argument) # rpm -aq | grep glibc-2 glibc-2.34-39.el9.aarch64 Fix the issue by using the registered rseq information from TLS if it exists. Otherwise, we're going to register our own rseq information as before. Reported-by: Yihuang Yu Suggested-by: Florian Weimer Suggested-by: Mathieu Desnoyers Signed-off-by: Gavin Shan --- tools/testing/selftests/kvm/rseq_test.c | 30 +++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/kvm/rseq_test.c b/tools/testing/selfte= sts/kvm/rseq_test.c index a54d4d05a058..acb1bf1f06b3 100644 --- a/tools/testing/selftests/kvm/rseq_test.c +++ b/tools/testing/selftests/kvm/rseq_test.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -36,6 +37,8 @@ static __thread volatile struct rseq __rseq =3D { */ #define NR_TASK_MIGRATIONS 100000 =20 +static bool __rseq_ownership; +static volatile struct rseq *__rseq_info; static pthread_t migration_thread; static cpu_set_t possible_mask; static int min_cpu, max_cpu; @@ -49,11 +52,33 @@ static void guest_code(void) GUEST_SYNC(0); } =20 +static void sys_rseq_ownership(void) +{ + long *offset; + unsigned int *size, *flags; + + offset =3D dlsym(RTLD_NEXT, "__rseq_offset"); + size =3D dlsym(RTLD_NEXT, "__rseq_size"); + flags =3D dlsym(RTLD_NEXT, "__rseq_flags"); + + if (offset && size && *size && flags) { + __rseq_ownership =3D false; + __rseq_info =3D (struct rseq *)((uintptr_t)__builtin_thread_pointer() + + *offset); + } else { + __rseq_ownership =3D true; + __rseq_info =3D &__rseq; + } +} + static void sys_rseq(int flags) { int r; =20 - r =3D syscall(__NR_rseq, &__rseq, sizeof(__rseq), flags, RSEQ_SIG); + if (!__rseq_ownership) + return; + + r =3D syscall(__NR_rseq, __rseq_info, sizeof(*__rseq_info), flags, RSEQ_S= IG); TEST_ASSERT(!r, "rseq failed, errno =3D %d (%s)", errno, strerror(errno)); } =20 @@ -218,6 +243,7 @@ int main(int argc, char *argv[]) =20 calc_min_max_cpu(); =20 + sys_rseq_ownership(); sys_rseq(0); =20 /* @@ -256,7 +282,7 @@ int main(int argc, char *argv[]) */ smp_rmb(); cpu =3D sched_getcpu(); - rseq_cpu =3D READ_ONCE(__rseq.cpu_id); + rseq_cpu =3D READ_ONCE(__rseq_info->cpu_id); smp_rmb(); } while (snapshot !=3D atomic_read(&seq_cnt)); =20 --=20 2.23.0