sysdeps/unix/sysv/linux/s390/tst-ptrace-singleblock.c

   1 /* Testing s390x PTRACE_SINGLEBLOCK ptrace request.
   2    Copyright (C) 2017 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <unistd.h>
  23 #include <sys/wait.h>
  24 #include <sys/types.h>
  25 #include <sys/uio.h>
  26 #include <elf.h>
  27 #include <support/xunistd.h>
  28 #include <support/check.h>
  29
  30 /* Ensure that we use the PTRACE_SINGLEBLOCK definition from glibc ptrace.h
  31    in tracer_func.  We need the kernel ptrace.h for structs ptrace_area
  32    and gregset_t.  */
  33 #include <sys/ptrace.h>
  34 static const enum __ptrace_request req_singleblock = PTRACE_SINGLEBLOCK;
  35 #include <asm/ptrace.h>
  36
  37 static void
  38 tracee_func (int pid)
  39 {
  40   /* Dump the mapping information for manual inspection of the printed
  41      tracee addresses.  */
  42   char str[80];
  43   sprintf (str, "cat /proc/%d/maps", pid);
  44   puts (str);
  45   system (str);
  46   fflush (stdout);
  47
  48   TEST_VERIFY_EXIT (ptrace (PTRACE_TRACEME) == 0);
  49   /* Stop tracee.  Afterwards the tracer_func can operate.  */
  50   kill (pid, SIGSTOP);
  51
  52   puts ("The PTRACE_SINGLEBLOCK of the tracer will stop after: "
  53         "brasl %r14,<puts@plt>!");
  54 }
  55
  56 static void
  57 tracer_func (int pid)
  58 {
  59   unsigned long last_break;
  60   ptrace_area parea;
  61   gregset_t regs;
  62   struct iovec parea2;
  63   gregset_t regs2;
  64
  65   int status;
  66
  67   while (1)
  68     {
  69       /* Wait for the tracee to be stopped or exited.  */
  70       wait (&status);
  71       if (WIFEXITED (status))
  72         break;
  73
  74       /* Get information about tracee: gprs, last breaking address.  */
  75       parea.len = sizeof (regs);
  76       parea.process_addr = (unsigned long) &regs;
  77       parea.kernel_addr = 0;
  78       TEST_VERIFY_EXIT (ptrace (PTRACE_PEEKUSR_AREA, pid, &parea) == 0);
  79       TEST_VERIFY_EXIT (ptrace (PTRACE_GET_LAST_BREAK, pid, NULL, &last_break)
  80                         == 0);
  81
  82       parea2.iov_len = sizeof (regs2);
  83       parea2.iov_base = &regs2;
  84       TEST_VERIFY_EXIT (ptrace (PTRACE_GETREGSET, pid, NT_PRSTATUS, &parea2)
  85                         == 0);
  86       TEST_VERIFY_EXIT (parea2.iov_len == sizeof (regs2));
  87
  88       /* Test if gprs obtained by PTRACE_PEEKUSR_AREA and PTRACE_GETREGESET
  89          have the same values.  */
  90       TEST_VERIFY_EXIT (memcmp (&regs, &regs2, sizeof (regs)) == 0);
  91
  92       printf ("child IA: %p last_break: %p\n",
  93               (void *) regs[1], (void *) last_break);
  94
  95       /* Execute tracee until next taken branch.
  96
  97          Note:
  98          Before the commit which introduced this testcase,
  99          <glibc>/sysdeps/unix/sysv/linux/s390/sys/ptrace.h
 100          uses ptrace-request 12 for PTRACE_GETREGS,
 101          but <kernel>/include/uapi/linux/ptrace.h
 102          uses 12 for PTRACE_SINGLEBLOCK.
 103
 104          The s390 kernel has no support for PTRACE_GETREGS!
 105          Thus glibc ptrace.h is adjusted to match kernel ptrace.h.
 106
 107          This test ensures, that PTRACE_SINGLEBLOCK defined in glibc
 108          works as expected.  If the kernel would interpret it as
 109          PTRACE_GETREGS, then the tracee will not make any progress
 110          and this testcase will time out.  */
 111       TEST_VERIFY_EXIT (ptrace (req_singleblock, pid, NULL, NULL) == 0);
 112     }
 113 }
 114
 115 static int
 116 do_test (void)
 117 {
 118   int pid;
 119   pid = xfork ();
 120   if (pid)
 121     tracer_func (pid);
 122   else
 123     tracee_func (getpid ());
 124
 125   return EXIT_SUCCESS;
 126 }
 127
 128 #include <support/test-driver.c>