From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vmicros1.altlinux.org (vmicros1.altlinux.org [194.107.17.57]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 72033213E62; Tue, 4 Feb 2025 15:14:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=194.107.17.57 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738682071; cv=none; b=goGwlnDEz/5HX9ImSxhvToq9d7CeW6t6VARTXmAYx6JFL2fjiBTtaFkfGsCUtbz/RTEerlF7f+bEd4kMnQ30LvH4Kd+gjJxG2Mi4afZ6HpB3jG/L0ggrEZoTjuZ9xyH+Tqm1mJQXSbnJYfzgxBI+HbgVYcmBzONEdW39GEQTciw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738682071; c=relaxed/simple; bh=0VF9NjSm+wa57QWPS0q6hwOKkX1Utbbo0dCdpkggj6Y=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition:In-Reply-To; b=Zbz4X+xkYwWv3ddYB5/wo8fuskUHe96pdA7kVpFtDsSODSr+qfqTqk5NxyZTubKUe/FHFC8+Zk/RWrhKoyMGAwcFZ36O2ppPCVyzvAS9t1O7UA95JNWE8e17Ict6YrfSoaC1Wa4SVp4NtYLNu/VZ0FbbXocyEPrvCVafS/l5G+A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strace.io; spf=pass smtp.mailfrom=altlinux.org; arc=none smtp.client-ip=194.107.17.57 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=strace.io Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=altlinux.org Received: from mua.local.altlinux.org (mua.local.altlinux.org [192.168.1.14]) by vmicros1.altlinux.org (Postfix) with ESMTP id EA38B72C8CC; Tue, 4 Feb 2025 18:14:20 +0300 (MSK) Received: by mua.local.altlinux.org (Postfix, from userid 508) id DC6C57CCB3A; Tue, 4 Feb 2025 17:14:20 +0200 (IST) Date: Tue, 4 Feb 2025 17:14:20 +0200 From: "Dmitry V. Levin" To: Alexander Gordeev Cc: Andrew Morton , Oleg Nesterov , Shuah Khan , Alexey Gladkov , Eugene Syromyatnikov , Mike Frysinger , Renzo Davoli , Davide Berardi , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , Sven Schnelle , strace-devel@lists.strace.io, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 0/7] ptrace: introduce PTRACE_SET_SYSCALL_INFO API Message-ID: <20250204151420.GA30282@strace.io> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250203103542.GA16165@strace.io> On Mon, Feb 03, 2025 at 12:35:42PM +0200, Dmitry V. Levin wrote: > On Mon, Feb 03, 2025 at 10:29:37AM +0100, Alexander Gordeev wrote: > > On Mon, Feb 03, 2025 at 08:58:49AM +0200, Dmitry V. Levin wrote: > > > > Hi Dmitry, > > > > > PTRACE_SET_SYSCALL_INFO is a generic ptrace API that complements > > > PTRACE_GET_SYSCALL_INFO by letting the ptracer modify details of > > > system calls the tracee is blocked in. > > ... > > > > FWIW, I am getting these on s390: > > > > # ./tools/testing/selftests/ptrace/set_syscall_info > > TAP version 13 > > 1..1 > > # Starting 1 tests from 1 test cases. > > # RUN global.set_syscall_info ... > > # set_syscall_info.c:87:set_syscall_info:Expected exp_entry->nr (-1) == info->entry.nr (65535) > > # set_syscall_info.c:88:set_syscall_info:wait #3: PTRACE_GET_SYSCALL_INFO #2: syscall nr mismatch > > # set_syscall_info: Test terminated by assertion > > # FAIL global.set_syscall_info > > not ok 1 global.set_syscall_info > > # FAILED: 0 / 1 tests passed. > > # Totals: pass:0 fail:1 xfail:0 xpass:0 skip:0 error:0 > > > > I remember one of the earlier versions (v1 or v2) was working for me. > > > > Thanks! > > In v3, this test was extended to check whether PTRACE_GET_SYSCALL_INFO > called immediately after PTRACE_SET_SYSCALL_INFO returns the same syscall > number, and on s390 it apparently doesn't, thanks to its implementation > of syscall_get_nr() that returns 0xffff in this case. > > To workaround this, we could either change syscall_get_nr() to return -1 > in this case, or add an #ifdef __s390x__ exception to the test. > > What would you prefer? OK, I'm going to apply the following s390 workaround to the test: diff --git a/tools/testing/selftests/ptrace/set_syscall_info.c b/tools/testing/selftests/ptrace/set_syscall_info.c index 0ec69401c008..4198248ef874 100644 --- a/tools/testing/selftests/ptrace/set_syscall_info.c +++ b/tools/testing/selftests/ptrace/set_syscall_info.c @@ -71,6 +71,11 @@ check_psi_entry(struct __test_metadata *_metadata, const char *text) { unsigned int i; + int exp_nr = exp_entry->nr; +#if defined __s390__ || defined __s390x__ + /* s390 is the only architecture that has 16-bit syscall numbers */ + exp_nr &= 0xffff; +#endif ASSERT_EQ(PTRACE_SYSCALL_INFO_ENTRY, info->op) { LOG_KILL_TRACEE("%s: entry stop mismatch", text); @@ -84,7 +89,7 @@ check_psi_entry(struct __test_metadata *_metadata, ASSERT_TRUE(info->stack_pointer) { LOG_KILL_TRACEE("%s: entry stop mismatch", text); } - ASSERT_EQ(exp_entry->nr, info->entry.nr) { + ASSERT_EQ(exp_nr, info->entry.nr) { LOG_KILL_TRACEE("%s: syscall nr mismatch", text); } for (i = 0; i < ARRAY_SIZE(exp_entry->args); ++i) { -- ldv