Attachment 575976 Details for Bug 810668 – Attempt for a reproducer; nothing is reproduced.

Attempt for a reproducer; nothing is reproduced.

fpregs-getset.c (text/plain), 4.23 KB, created by Jan Kratochvil on 2012-04-07 22:28:57 UTC

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Creator: Jan Kratochvil

Created: 2012-04-07 22:28:57 UTC

Size: 4.23 KB

patch

obsolete

>/* This software is provided 'as-is', without any express or implied
>   warranty.  In no event will the authors be held liable for any damages
>   arising from the use of this software.
>
>   Permission is granted to anyone to use this software for any purpose,
>   including commercial applications, and to alter it and redistribute it
>   freely.  */
>
>#define _GNU_SOURCE 1
>#ifdef __ia64__
>#define ia64_fpreg ia64_fpreg_DISABLE
>#define pt_all_user_regs pt_all_user_regs_DISABLE
>#endif	/* __ia64__ */
>#include <sys/ptrace.h>
>#ifdef __ia64__
>#undef ia64_fpreg
>#undef pt_all_user_regs
>#endif	/* __ia64__ */
>#include <linux/ptrace.h>
>#include <sys/types.h>
>#include <sys/user.h>
>#if defined __i386__ || defined __x86_64__
>#include <sys/debugreg.h>
>#endif
>
>#include <unistd.h>
>#include <assert.h>
>#include <stdlib.h>
>#include <signal.h>
>#include <errno.h>
>#include <error.h>
>#include <stdio.h>
>#include <sys/types.h>
>#include <sys/wait.h>
>#include <sys/procfs.h>
>#include <string.h>
>#include <stddef.h>
>
>#define LOOPS 10000
>
>static pid_t child;
>
>static void
>cleanup (void)
>{
>  if (child > 0)
>    kill (child, SIGKILL);
>}
>
>static void
>handler_fail (int signo)
>{
>  cleanup ();
>  signal (SIGABRT, SIG_DFL);
>  assert (0);
>}
>
>static void __attribute__ ((noinline, noclone))
>f (volatile double pi)
>{
>  static double expect = 0;
>
>#if 0
>  printf ("child pi = %f\n",pi);
>#endif
>
>  expect += 3.14;
>  assert (pi == expect);
>}
>
>static void __attribute__ ((noinline, noclone))
>g (volatile double e)
>{
>  assert (e == 2.71);
>}
>
>int main (void)
>{
>  int i, status, loop;
>  volatile double pi;
>  long l, f_long_orig, f_long_bpt;
>
>  setbuf (stdout, NULL);
>  atexit (cleanup);
>  signal (SIGABRT, handler_fail);
>  signal (SIGINT, handler_fail);
>  signal (SIGALRM, handler_fail);
>//  alarm (1);
>
>  child = fork();
>  switch (child)
>    {
>    case -1:
>      perror ("fork()");
>      exit (1);
>      /* NOTREACHED */
>    case 0:
>      l = ptrace (PTRACE_TRACEME, 0, NULL, NULL);
>      assert (l == 0);
>
>      raise (SIGSTOP);
>
>      for (loop = 0; loop < LOOPS; loop++)
>	{
>	  f (0);
>	  g (2.71);
>	}
>      assert (0);
>      /* NOTREACHED */
>    default:;
>      /* PASSTHRU */
>    }
>  /* Parent.  */
>
>  i = waitpid (child, &status, 0);
>  assert_perror (errno);
>  assert (i == child);
>  assert (WIFSTOPPED (status));
>  assert (WSTOPSIG (status) == SIGSTOP);
>
>  f_long_orig = ptrace (PTRACE_PEEKTEXT, child, f, NULL);
>  assert_perror (errno);
>
>  f_long_bpt = (f_long_orig & ~0xFFL) | 0xcc;
>
>  pi = 0;
>  for (loop = 0; loop < LOOPS; loop++)
>    {
>      elf_fpregset_t fpregs;
>
>      l = ptrace (PTRACE_POKETEXT, child, f, (void *) f_long_bpt);
>      assert_perror (errno);
>      assert (l == 0);
>
>      l = ptrace (PTRACE_CONT, child, NULL, NULL);
>      assert_perror (errno);
>      assert (l == 0);
>
>      i = waitpid (child, &status, 0);
>      assert_perror (errno);
>      assert (i == child);
>      assert (WIFSTOPPED (status));
>      assert (WSTOPSIG (status) == SIGTRAP);
>
>      l = ptrace (PTRACE_PEEKUSER, child,
>		  (void *) offsetof (struct user_regs_struct, rip), NULL);
>      assert_perror (errno);
>      assert (l == 1 + (long) f);
>
>      l = ptrace (PTRACE_POKEUSER, child,
>		  (void *) offsetof (struct user_regs_struct, rip), f);
>      assert_perror (errno);
>      assert (l == 0);
>
>      l = ptrace (PTRACE_POKETEXT, child, f, (void *) f_long_orig);
>      assert_perror (errno);
>      assert (l == 0);
>
>      pi += 3.14;
>
>      l = ptrace (PTRACE_GETFPREGS, child, NULL, &fpregs);
>      assert_perror (errno);
>      assert (l == 0);
>
>      assert (sizeof (pi) == 8);
>      assert (sizeof (fpregs.xmm_space) == 16 * 16);
>      assert (sizeof (fpregs.xmm_space[0]) == 4);
>      memcpy (&fpregs.xmm_space[0], (void *) &pi, 8);
>      memset (&fpregs.xmm_space[2], 0, 8);
>
>      l = ptrace (PTRACE_SETFPREGS, child, NULL, &fpregs);
>      assert_perror (errno);
>      assert (l == 0);
>
>      l = ptrace (PTRACE_SINGLESTEP, child, NULL, NULL);
>      assert_perror (errno);
>      assert (l == 0);
>
>      i = waitpid (child, &status, 0);
>      assert_perror (errno);
>      assert (i == child);
>      assert (WIFSTOPPED (status));
>      assert (WSTOPSIG (status) == SIGTRAP);
>
>      l = ptrace (PTRACE_PEEKUSER, child,
>		  (void *) offsetof (struct user_regs_struct, rip), NULL);
>      assert_perror (errno);
>      assert (l == 1 + (long) f);
>    }
>
>  return 0;
>}

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Attachments on bug 810668: 575976 | 577270 | 577491 | 578300