From patchwork Mon Jun 19 13:10:57 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Liebler X-Patchwork-Id: 21083 Received: (qmail 5055 invoked by alias); 19 Jun 2017 13:11:02 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 4432 invoked by uid 89); 19 Jun 2017 13:11:01 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-23.6 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, KAM_LAZY_DOMAIN_SECURITY, KHOP_DYNAMIC, RCVD_IN_DNSWL_LOW autolearn=ham version=3.3.2 spammy=986, dmitry X-HELO: mx0a-001b2d01.pphosted.com Subject: Re: [PATCH] S390: Sync ptrace.h with kernel. [BZ #21539] To: libc-alpha@sourceware.org References: <20170613200522.GA14306@altlinux.org> From: Stefan Liebler Date: Mon, 19 Jun 2017 15:10:57 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.1.0 MIME-Version: 1.0 In-Reply-To: <20170613200522.GA14306@altlinux.org> X-TM-AS-GCONF: 00 x-cbid: 17061913-0012-0000-0000-000005508FE7 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17061913-0013-0000-0000-000018C151A6 Message-Id: X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-06-19_08:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=4 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1703280000 definitions=main-1706190221 On 06/13/2017 10:05 PM, Dmitry V. Levin wrote: > On Tue, Jun 06, 2017 at 12:17:33PM +0200, Stefan Liebler wrote: > [...] >> diff --git a/sysdeps/unix/sysv/linux/s390/tst-ptrace-singleblock.c b/sysdeps/unix/sysv/linux/s390/tst-ptrace-singleblock.c >> new file mode 100644 >> [...] >> + /* Get information about tracee: gprs, last breaking address. */ >> + parea.len = sizeof (regs); >> + parea.process_addr = (unsigned long) ®s; >> + parea.kernel_addr = 0; >> + ptrace (PTRACE_PEEKUSR_AREA, pid, &parea); > > Note that you can verify whether PTRACE_PEEKUSR_AREA has returned > the expected result by comparing registers with those returned > by PTRACE_GETREGSET. The latter is implemented on s390 since > linux 2.6.27 so its use in glibc is safe. > Okay. Now the gprs are obtained by PTRACE_PEEKUSR_AREA and PTRACE_GETREGSET. Afterwards I use memcmp to check whether the values are the same. >> + ptrace (PTRACE_GET_LAST_BREAK, pid, NULL, &last_break); > > As these ptrace calls are expected to succeed, > you might want to check their return code. > Done with several usages of TEST_VERIFY_EXIT. >> + >> + printf ("child IA: %p last_break: %p\n", >> + (void *) regs[1], (void *) last_break); >> + >> + /* Execute tracee until next taken branch. >> + >> + Note: >> + Before the commit which introduced this testcase, >> + /sysdeps/unix/sysv/linux/s390/sys/ptrace.h >> + uses ptrace-request 12 for PTRACE_GETREGS, >> + but /include/uapi/linux/ptrace.h >> + uses 12 for PTRACE_SINGLEBLOCK. >> + >> + The s390 kernel has no support for PTRACE_GETREGS! >> + Thus glibc ptrace.h is adjusted to match kernel ptrace.h. >> + >> + This test ensures, that PTRACE_SINGLEBLOCK defined in glibc >> + works as expected. If the kernel would interpret it as >> + PTRACE_GETREGS, then the tracee will not make any progress >> + and this testcase will time out. */ >> + ptrace (req_singleblock, pid, NULL, NULL); > > Likewise. > > I've attached the patch with the mentioned changes and the NEWS entry requested by Andreas. Is this okay? Bye Stefan commit 99d6dcd30803d992b2e82c1edb8db797f4ace846 Author: Stefan Liebler Date: Mon Jun 19 15:02:02 2017 +0200 S390: Sync ptrace.h with kernel. [BZ #21539] This patch removes PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS and PTRACE_SETFPREGS as these requests does not exist on s390 kernel. But the kernel has support for PTRACE_SINGLEBLOCK, PTRACE_SECCOMP_GET_FILTER, PTRACE_PEEKUSR_AREA, PTRACE_POKEUSR_AREA, PTRACE_GET_LAST_BREAK, PTRACE_ENABLE_TE, PTRACE_DISABLE_TE and PTRACE_TE_ABORT_RAND. Thus those are defined now. The current kernel s390 specific ptrace.h file also defines PTRACE_PEEKTEXT_AREA, PTRACE_PEEKDATA_AREA, PTRACE_POKETEXT_AREA, PTRACE_POKEDATA_AREA, PTRACE_PEEK_SYSTEM_CALL, PTRACE_POKE_SYSTEM_CALL and PTRACE_PROT, but those requests are not supported. Thus those defines are skipped in glibc ptrace.h. There were old includes of ptrace.h in sysdeps/s390/fpu/fesetenv.c. The ptrace feature isn't used there anymore, thus I removed the includes. Before this patch, /sysdeps/unix/sysv/linux/s390/sys/ptrace.h uses ptrace-request 12 for PTRACE_GETREGS, but /include/uapi/linux/ptrace.h uses 12 for PTRACE_SINGLEBLOCK. The s390 kernel has never had support for PTRACE_GETREGS! Thus glibc ptrace.h is adjusted to match kernel ptrace.h. The new s390 specific test ensures, that PTRACE_SINGLEBLOCK defined in glibc works as expected. If the kernel would interpret it as PTRACE_GETREGS, then the testcase will not make any progress and will time out. ChangeLog: [BZ #21539] * NEWS: Mention s390 ptrace request changes. * sysdeps/unix/sysv/linux/s390/sys/ptrace.h (PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS, PTRACE_SETFPREGS): Remove enum constant. (PT_GETREGS, PT_SETREGS, PT_GETFPREGS, T_SETFPREGS): Remove defines. (PTRACE_SINGLEBLOCK): New enum constant. (PT_STEPBLOCK): New define. (PTRACE_PEEKUSR_AREA, PTRACE_POKEUSR_AREA, PTRACE_GET_LAST_BREAK, PTRACE_ENABLE_TE, PTRACE_DISABLE_TE, PTRACE_TE_ABORT_RAND): New enum constant and define. * sysdeps/s390/fpu/fesetenv.c: Remove ptrace.h includes. * sysdeps/unix/sysv/linux/s390/tst-ptrace-singleblock.c: New file. * sysdeps/unix/sysv/linux/s390/Makefile: Add test. diff --git a/NEWS b/NEWS index 804c1b9..9ee2218 100644 --- a/NEWS +++ b/NEWS @@ -98,6 +98,15 @@ Version 2.26 * The tunables feature is now enabled by default. This allows users to tweak behavior of the GNU C Library using the GLIBC_TUNABLES environment variable. +* The s390 specific ptrace requests are adjusted to the kernel ones. Request 12 + is now used for PTRACE_SINGLEBLOCK instead of PTRACE_GETREGS. The requests + PTRACE_GETREGS, PTRACE_SETREGS, PTRACE_GETFPREGS and PTRACE_SETFPREGS were + removed as those are not supported by the s390 kernel. The requests + PTRACE_SINGLEBLOCK, PTRACE_SECCOMP_GET_FILTER, PTRACE_PEEKUSR_AREA, + PTRACE_POKEUSR_AREA, PTRACE_GET_LAST_BREAK, PTRACE_ENABLE_TE, + PTRACE_DISABLE_TE and PTRACE_TE_ABORT_RAND were added as those are supported + by the s390 kernel. + Security related changes: * The DNS stub resolver limits the advertised UDP buffer size to 1200 bytes, diff --git a/sysdeps/s390/fpu/fesetenv.c b/sysdeps/s390/fpu/fesetenv.c index 4c9bcf0..0f64a3f 100644 --- a/sysdeps/s390/fpu/fesetenv.c +++ b/sysdeps/s390/fpu/fesetenv.c @@ -20,8 +20,6 @@ #include #include #include -#include -#include #include int diff --git a/sysdeps/unix/sysv/linux/s390/Makefile b/sysdeps/unix/sysv/linux/s390/Makefile index 3867c33..f30a6bb 100644 --- a/sysdeps/unix/sysv/linux/s390/Makefile +++ b/sysdeps/unix/sysv/linux/s390/Makefile @@ -29,3 +29,7 @@ CFLAGS-elision-trylock.c = $(elision-CFLAGS) CFLAGS-elision-unlock.c = $(elision-CFLAGS) endif endif + +ifeq ($(subdir),misc) +tests += tst-ptrace-singleblock +endif diff --git a/sysdeps/unix/sysv/linux/s390/sys/ptrace.h b/sysdeps/unix/sysv/linux/s390/sys/ptrace.h index 7caf101..88079fc 100644 --- a/sysdeps/unix/sysv/linux/s390/sys/ptrace.h +++ b/sysdeps/unix/sysv/linux/s390/sys/ptrace.h @@ -89,25 +89,9 @@ enum __ptrace_request PTRACE_SINGLESTEP = 9, #define PT_STEP PTRACE_SINGLESTEP - /* Get all general purpose registers used by a processes. - This is not supported on all machines. */ - PTRACE_GETREGS = 12, -#define PT_GETREGS PTRACE_GETREGS - - /* Set all general purpose registers used by a processes. - This is not supported on all machines. */ - PTRACE_SETREGS = 13, -#define PT_SETREGS PTRACE_SETREGS - - /* Get all floating point registers used by a processes. - This is not supported on all machines. */ - PTRACE_GETFPREGS = 14, -#define PT_GETFPREGS PTRACE_GETFPREGS - - /* Set all floating point registers used by a processes. - This is not supported on all machines. */ - PTRACE_SETFPREGS = 15, -#define PT_SETFPREGS PTRACE_SETFPREGS + /* Execute process until next taken branch. */ + PTRACE_SINGLEBLOCK = 12, +#define PT_STEPBLOCK PTRACE_SINGLEBLOCK /* Attach to a process that is already running. */ PTRACE_ATTACH = 16, @@ -167,8 +151,26 @@ enum __ptrace_request PTRACE_SETSIGMASK = 0x420b, #define PTRACE_SETSIGMASK PTRACE_SETSIGMASK - PTRACE_SECCOMP_GET_FILTER = 0x420c + PTRACE_SECCOMP_GET_FILTER = 0x420c, #define PTRACE_SECCOMP_GET_FILTER PTRACE_SECCOMP_GET_FILTER + + PTRACE_PEEKUSR_AREA = 0x5000, +#define PTRACE_PEEKUSR_AREA PTRACE_PEEKUSR_AREA + + PTRACE_POKEUSR_AREA = 0x5001, +#define PTRACE_POKEUSR_AREA PTRACE_POKEUSR_AREA + + PTRACE_GET_LAST_BREAK = 0x5006, +#define PTRACE_GET_LAST_BREAK PTRACE_GET_LAST_BREAK + + PTRACE_ENABLE_TE = 0x5009, +#define PTRACE_ENABLE_TE PTRACE_ENABLE_TE + + PTRACE_DISABLE_TE = 0x5010, +#define PTRACE_DISABLE_TE PTRACE_DISABLE_TE + + PTRACE_TE_ABORT_RAND = 0x5011 +#define PTRACE_TE_ABORT_RAND PTRACE_TE_ABORT_RAND }; diff --git a/sysdeps/unix/sysv/linux/s390/tst-ptrace-singleblock.c b/sysdeps/unix/sysv/linux/s390/tst-ptrace-singleblock.c new file mode 100644 index 0000000..95a2f55 --- /dev/null +++ b/sysdeps/unix/sysv/linux/s390/tst-ptrace-singleblock.c @@ -0,0 +1,128 @@ +/* Testing s390x PTRACE_SINGLEBLOCK ptrace request. + Copyright (C) 2017 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + . */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* Ensure that we use the PTRACE_SINGLEBLOCK definition from glibc ptrace.h + in tracer_func. We need the kernel ptrace.h for structs ptrace_area + and gregset_t. */ +#include +static const enum __ptrace_request req_singleblock = PTRACE_SINGLEBLOCK; +#include + +static void +tracee_func (int pid) +{ + /* Dump the mapping information for manual inspection of the printed + tracee addresses. */ + char str[80]; + sprintf (str, "cat /proc/%d/maps", pid); + puts (str); + system (str); + fflush (stdout); + + TEST_VERIFY_EXIT (ptrace (PTRACE_TRACEME) == 0); + /* Stop tracee. Afterwards the tracer_func can operate. */ + kill (pid, SIGSTOP); + + puts ("The PTRACE_SINGLEBLOCK of the tracer will stop after: " + "brasl %r14,!"); +} + +static void +tracer_func (int pid) +{ + unsigned long last_break; + ptrace_area parea; + gregset_t regs; + struct iovec parea2; + gregset_t regs2; + + int status; + + while (1) + { + /* Wait for the tracee to be stopped or exited. */ + wait (&status); + if (WIFEXITED (status)) + break; + + /* Get information about tracee: gprs, last breaking address. */ + parea.len = sizeof (regs); + parea.process_addr = (unsigned long) ®s; + parea.kernel_addr = 0; + TEST_VERIFY_EXIT (ptrace (PTRACE_PEEKUSR_AREA, pid, &parea) == 0); + TEST_VERIFY_EXIT (ptrace (PTRACE_GET_LAST_BREAK, pid, NULL, &last_break) + == 0); + + parea2.iov_len = sizeof (regs2); + parea2.iov_base = ®s2; + TEST_VERIFY_EXIT (ptrace (PTRACE_GETREGSET, pid, NT_PRSTATUS, &parea2) + == 0); + TEST_VERIFY_EXIT (parea2.iov_len == sizeof (regs2)); + + /* Test if gprs obtained by PTRACE_PEEKUSR_AREA and PTRACE_GETREGESET + have the same values. */ + TEST_VERIFY_EXIT (memcmp (®s, ®s2, sizeof (regs)) == 0); + + printf ("child IA: %p last_break: %p\n", + (void *) regs[1], (void *) last_break); + + /* Execute tracee until next taken branch. + + Note: + Before the commit which introduced this testcase, + /sysdeps/unix/sysv/linux/s390/sys/ptrace.h + uses ptrace-request 12 for PTRACE_GETREGS, + but /include/uapi/linux/ptrace.h + uses 12 for PTRACE_SINGLEBLOCK. + + The s390 kernel has no support for PTRACE_GETREGS! + Thus glibc ptrace.h is adjusted to match kernel ptrace.h. + + This test ensures, that PTRACE_SINGLEBLOCK defined in glibc + works as expected. If the kernel would interpret it as + PTRACE_GETREGS, then the tracee will not make any progress + and this testcase will time out. */ + TEST_VERIFY_EXIT (ptrace (req_singleblock, pid, NULL, NULL) == 0); + } +} + +static int +do_test (void) +{ + int pid; + pid = xfork (); + if (pid) + tracer_func (pid); + else + tracee_func (getpid ()); + + return EXIT_SUCCESS; +} + +#include