From mboxrd@z Thu Jan 1 00:00:00 1970 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 86A8EC25B08 for ; Wed, 10 Aug 2022 12:22:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232238AbiHJMWk (ORCPT ); Wed, 10 Aug 2022 08:22:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49662 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229501AbiHJMWj (ORCPT ); Wed, 10 Aug 2022 08:22:39 -0400 Received: from mail.efficios.com (mail.efficios.com [167.114.26.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 332327333F; Wed, 10 Aug 2022 05:22:38 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id 8CD7643EA2C; Wed, 10 Aug 2022 08:22:37 -0400 (EDT) Received: from mail.efficios.com ([127.0.0.1]) by localhost (mail03.efficios.com [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id macRiZ503hEg; Wed, 10 Aug 2022 08:22:37 -0400 (EDT) Received: from localhost (localhost [127.0.0.1]) by mail.efficios.com (Postfix) with ESMTP id 1862A43EC11; Wed, 10 Aug 2022 08:22:37 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com 1862A43EC11 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=default; t=1660134157; bh=sfAauo/mWpg8zOIkCNkUX/HMbO4wG21Si6g++dnvoyE=; h=Date:From:To:Message-ID:MIME-Version; b=nZdbRT4AvSFpu8TzhuYZxIHHOAeTCCeHwddyfuBKZ1bmiJDKmNy9as3q6La1j3OfM YVPperUtSSs4kRCThx1MGYQbi/kzkwT94oHNkCqB0UvliKkhsoFQ2yLqAEzV1AmZqm vfw+Qp3Mo9VVmQCpvm/rJ3Zp99aKBrJ7dufoCiOMGld4ZRXr7kcskGL3n63moV63rL jC+XE6JA5OhDAudAGBr+NBVb592c+ZPm9JAQaZOHnhDBpKKTp1gnuo2G80FAWedMLT AsLVLBUrYatb4KKixttIkRUlnfot42FgWXu1HfsICe4e8aksGtRArF7e0KsLEHZShn jxrtT1VdGkoIw== X-Virus-Scanned: amavisd-new at efficios.com Received: from mail.efficios.com ([127.0.0.1]) by localhost (mail03.efficios.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id pk8I3S8vxJQb; Wed, 10 Aug 2022 08:22:37 -0400 (EDT) Received: from mail03.efficios.com (mail03.efficios.com [167.114.26.124]) by mail.efficios.com (Postfix) with ESMTP id 03E2C43E9B8; Wed, 10 Aug 2022 08:22:37 -0400 (EDT) Date: Wed, 10 Aug 2022 08:22:36 -0400 (EDT) From: Mathieu Desnoyers To: Gavin Shan Cc: kvmarm , KVM list , linux-kernel , linux-kselftest , Florian Weimer , shan gavin , maz , andrew jones , Paolo Bonzini , yihyu , Sean Christopherson , oliver upton Message-ID: <876568572.367.1660134156963.JavaMail.zimbra@efficios.com> In-Reply-To: <20220810104114.6838-2-gshan@redhat.com> References: <20220810104114.6838-1-gshan@redhat.com> <20220810104114.6838-2-gshan@redhat.com> Subject: Re: [PATCH v2 1/2] KVM: selftests: Make rseq compatible with glibc-2.35 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [167.114.26.124] X-Mailer: Zimbra 8.8.15_GA_4372 (ZimbraWebClient - FF103 (Linux)/8.8.15_GA_4372) Thread-Topic: selftests: Make rseq compatible with glibc-2.35 Thread-Index: Hk36Kh5rkKAuYYVYbwiYIwpCd68vFA== Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org ----- On Aug 10, 2022, at 6:41 AM, Gavin Shan gshan@redhat.com wrote: > 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 > ==== Test Assertion Failure ==== > rseq_test.c:60: !r > pid=112043 tid=112043 errno=22 - Invalid argument > 1 0x0000000000401973: main at rseq_test.c:226 > 2 0x0000ffff84b6c79b: ?? ??:0 > 3 0x0000ffff84b6c86b: ?? ??:0 > 4 0x0000000000401b6f: _start at ??:? > rseq failed, errno = 22 (Invalid argument) > # rpm -aq | grep glibc-2 > glibc-2.34-39.el9.aarch64 > > Fix the issue by using "../rseq/rseq.c" to fetch the rseq information, > registred by 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 > Suggested-by: Paolo Bonzini > Signed-off-by: Gavin Shan > --- > tools/testing/selftests/kvm/Makefile | 5 +++-- > tools/testing/selftests/kvm/rseq_test.c | 28 +++++++------------------ > 2 files changed, 11 insertions(+), 22 deletions(-) > > diff --git a/tools/testing/selftests/kvm/Makefile > b/tools/testing/selftests/kvm/Makefile > index c7f47429d6cd..89c9a8c52c5f 100644 > --- a/tools/testing/selftests/kvm/Makefile > +++ b/tools/testing/selftests/kvm/Makefile > @@ -197,7 +197,8 @@ endif > CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \ > -fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) \ > -I$(LINUX_TOOL_ARCH_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude \ > - -I$( + -I$( + $(KHDR_INCLUDES) > > no-pie-option := $(call try-run, echo 'int main() { return 0; }' | \ > $(CC) -Werror -no-pie -x c - -o "$$TMP", -no-pie) > @@ -206,7 +207,7 @@ no-pie-option := $(call try-run, echo 'int main() { return > 0; }' | \ > pgste-option = $(call try-run, echo 'int main() { return 0; }' | \ > $(CC) -Werror -Wl$(comma)--s390-pgste -x c - -o "$$TMP",-Wl$(comma)--s390-pgste) > > - > +LDLIBS += -ldl > LDFLAGS += -pthread $(no-pie-option) $(pgste-option) > > # After inclusion, $(OUTPUT) is defined and > diff --git a/tools/testing/selftests/kvm/rseq_test.c > b/tools/testing/selftests/kvm/rseq_test.c > index a54d4d05a058..2cd5fe49ac8b 100644 > --- a/tools/testing/selftests/kvm/rseq_test.c > +++ b/tools/testing/selftests/kvm/rseq_test.c > @@ -20,15 +20,7 @@ > #include "processor.h" > #include "test_util.h" > > -static __thread volatile struct rseq __rseq = { > - .cpu_id = RSEQ_CPU_ID_UNINITIALIZED, > -}; > - > -/* > - * Use an arbitrary, bogus signature for configuring rseq, this test does not > - * actually enter an rseq critical section. > - */ > -#define RSEQ_SIG 0xdeadbeef > +#include "../rseq/rseq.c" > > /* > * Any bug related to task migration is likely to be timing-dependent; perform > @@ -37,6 +29,7 @@ static __thread volatile struct rseq __rseq = { > #define NR_TASK_MIGRATIONS 100000 > > static pthread_t migration_thread; > +static struct rseq_abi *__rseq; What is this ? > static cpu_set_t possible_mask; > static int min_cpu, max_cpu; > static bool done; > @@ -49,14 +42,6 @@ static void guest_code(void) > GUEST_SYNC(0); > } > > -static void sys_rseq(int flags) > -{ > - int r; > - > - r = syscall(__NR_rseq, &__rseq, sizeof(__rseq), flags, RSEQ_SIG); > - TEST_ASSERT(!r, "rseq failed, errno = %d (%s)", errno, strerror(errno)); > -} > - > static int next_cpu(int cpu) > { > /* > @@ -218,7 +203,10 @@ int main(int argc, char *argv[]) > > calc_min_max_cpu(); > > - sys_rseq(0); > + r = rseq_register_current_thread(); > + TEST_ASSERT(!r, "rseq_register_current_thread failed, errno = %d (%s)", > + errno, strerror(errno)); > + __rseq = rseq_get_abi(); > > /* > * Create and run a dummy VM that immediately exits to userspace via > @@ -256,7 +244,7 @@ int main(int argc, char *argv[]) > */ > smp_rmb(); > cpu = sched_getcpu(); > - rseq_cpu = READ_ONCE(__rseq.cpu_id); > + rseq_cpu = READ_ONCE(__rseq->cpu_id); #include and use rseq_current_cpu_raw(). Thanks, Mathieu > smp_rmb(); > } while (snapshot != atomic_read(&seq_cnt)); > > @@ -278,7 +266,7 @@ int main(int argc, char *argv[]) > > kvm_vm_free(vm); > > - sys_rseq(RSEQ_FLAG_UNREGISTER); > + rseq_unregister_current_thread(); > > return 0; > } > -- > 2.23.0 -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com