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/* Testing s390x PTRACE_SINGLEBLOCK ptrace request.
Copyright (C) 2017-2022 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
<https://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>
#include <string.h>
#include <errno.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;
int ret;
#define MAX_CHARS_IN_BUF 4096
char buf[MAX_CHARS_IN_BUF + 1];
size_t buf_count;
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.
The glibc sys/ptrace.h header contains the identifier
PTRACE_SINGLEBLOCK in enum __ptrace_request. In contrast, the kernel
asm/ptrace.h header defines PTRACE_SINGLEBLOCK.
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 or the ptrace call will fail with
different errors. */
/* Ptrace request 12 is first done with data argument pointing to
a buffer:
-If request 12 is interpreted as PTRACE_GETREGS, it will store the regs
to buffer without an error.
-If request 12 is interpreted as PTRACE_SINGLEBLOCK, it will fail
as data argument is used as signal-number and the address of
buf is no valid signal.
-If request 12 is not implemented, it will also fail.
Here the test expects that the buffer is untouched and an error is
returned. */
memset (buf, 'a', MAX_CHARS_IN_BUF);
ret = ptrace (req_singleblock, pid, NULL, buf);
buf [MAX_CHARS_IN_BUF] = '\0';
buf_count = strspn (buf, "a");
TEST_VERIFY_EXIT (buf_count == MAX_CHARS_IN_BUF);
TEST_VERIFY_EXIT (ret == -1);
/* If request 12 is interpreted as PTRACE_GETREGS, the first ptrace
call will touch the buffer which is detected by this test. */
errno = 0;
ret = ptrace (req_singleblock, pid, NULL, NULL);
if (ret == 0)
{
/* The kernel has support for PTRACE_SINGLEBLOCK ptrace request. */
TEST_VERIFY_EXIT (errno == 0);
}
else
{
/* The kernel (< 3.15) has no support for PTRACE_SINGLEBLOCK ptrace
request. */
TEST_VERIFY_EXIT (errno == EIO);
TEST_VERIFY_EXIT (ret == -1);
/* Just continue tracee until it exits normally. */
TEST_VERIFY_EXIT (ptrace (PTRACE_CONT, 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>
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