From: Stefan Liebler <stli@linux.vnet.ibm.com>
To: libc-alpha@sourceware.org
Subject: Re: [PATCH] S390: Sync ptrace.h with kernel. [BZ #21539]
Date: Mon, 19 Jun 2017 13:11:00 -0000 [thread overview]
Message-ID: <a70194fb-d96c-d22f-7aba-36be9685d421@linux.vnet.ibm.com> (raw)
In-Reply-To: <20170613200522.GA14306@altlinux.org>
[-- Attachment #1: Type: text/plain, Size: 2130 bytes --]
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,
>> + <glibc>/sysdeps/unix/sysv/linux/s390/sys/ptrace.h
>> + uses ptrace-request 12 for PTRACE_GETREGS,
>> + but <kernel>/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
[-- Attachment #2: 20170619_s390_ptraceh.patch --]
[-- Type: text/x-patch, Size: 10287 bytes --]
commit 99d6dcd30803d992b2e82c1edb8db797f4ace846
Author: Stefan Liebler <stli@linux.vnet.ibm.com>
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, <glibc>/sysdeps/unix/sysv/linux/s390/sys/ptrace.h
uses ptrace-request 12 for PTRACE_GETREGS,
but <kernel>/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 <fenv_libc.h>
#include <fpu_control.h>
#include <stddef.h>
-#include <asm/ptrace.h>
-#include <sys/ptrace.h>
#include <unistd.h>
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
+ <http://www.gnu.org/licenses/>. */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <sys/uio.h>
+#include <elf.h>
+#include <support/xunistd.h>
+#include <support/check.h>
+
+/* 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 <sys/ptrace.h>
+static const enum __ptrace_request req_singleblock = PTRACE_SINGLEBLOCK;
+#include <asm/ptrace.h>
+
+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,<puts@plt>!");
+}
+
+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,
+ <glibc>/sysdeps/unix/sysv/linux/s390/sys/ptrace.h
+ uses ptrace-request 12 for PTRACE_GETREGS,
+ but <kernel>/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 <support/test-driver.c>
next prev parent reply other threads:[~2017-06-19 13:11 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-06 10:17 Stefan Liebler
2017-06-06 10:44 ` Andreas Schwab
2017-06-06 10:58 ` Dmitry V. Levin
2017-06-06 11:56 ` Stefan Liebler
2017-06-08 12:02 ` Stefan Liebler
2017-06-13 20:05 ` Dmitry V. Levin
2017-06-19 13:11 ` Stefan Liebler [this message]
2017-06-19 13:26 ` Dmitry V. Levin
2017-06-19 14:34 ` Stefan Liebler
2017-06-30 10:09 ` Florian Weimer
2017-07-04 8:22 ` Stefan Liebler
2017-07-04 9:41 ` Florian Weimer
2017-07-04 15:37 ` Stefan Liebler
2017-07-07 10:22 ` Stefan Liebler
2017-07-07 10:45 ` Florian Weimer
2017-07-07 13:54 ` Stefan Liebler
2017-07-11 8:39 ` Stefan Liebler
2017-07-18 10:20 ` Dmitry V. Levin
2017-07-18 13:31 ` Carlos O'Donell
2017-07-18 13:39 ` Dmitry V. Levin
2017-07-18 14:11 ` Carlos O'Donell
2017-07-18 14:28 ` Mark Wielaard
2017-07-18 14:40 ` Mark Wielaard
2017-07-20 7:38 ` Stefan Liebler
2017-07-20 8:07 ` Carlos O'Donell
2017-07-20 8:32 ` Stefan Liebler
2017-07-24 3:51 ` Dmitry V. Levin
2017-07-24 7:18 ` Stefan Liebler
2017-07-18 13:41 ` Stefan Liebler
2017-07-18 14:12 ` Carlos O'Donell
2017-07-18 14:16 ` Dmitry V. Levin
2017-07-19 8:40 ` Stefan Liebler
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