--- old/usr/src/test/os-tests/tests/xsave/proc_xregs_set.c
          +++ new/usr/src/test/os-tests/tests/xsave/proc_xregs_set.c

   1    1  /*
   2    2   * This file and its contents are supplied under the terms of the
   3    3   * Common Development and Distribution License ("CDDL"), version 1.0.
   4    4   * You may only use this file in accordance with the terms of version
   5    5   * 1.0 of the CDDL.
   6    6   *
   7    7   * A full copy of the text of the CDDL should have accompanied this
   8    8   * source.  A copy of the CDDL is also available via the Internet at
   9    9   * http://www.illumos.org/license/CDDL.
  10   10   */
  11   11  
  12   12  /*
  13   13   * Copyright 2023 Oxide Computer Company
  14   14   */
  15   15  
  16   16  /*
  17   17   * This program pairs with the xregs_dump.32 and xregs_dump.64 program. It's
  18   18   * main purpose is to use /proc to overwrite the FPU contents right before our
  19   19   * target program calls xsu_getfpu().
  20   20   *
  21   21   * To accomplish this we end up using libproc for some mischief via support
  22   22   * routines. In particular we go through the following to logically accomplish
  23   23   * this:
  24   24   *
  25   25   *   o Generate the target FPU contents that we'll write (seeded from the CLI)
  26   26   *   o Explicitly create the process, which will be stopped.
  27   27   *   o Set it to be killed if we die.
  28   28   *   o Find the xsu_getfpu() symbol in the target and set a breakpoint.
  29   29   *   o Resume execution of the process.
  30   30   *   o When the break point hits, use libproc to set the FPU.
  31   31   *   o Delete the breakpoint and resume the process, which will print the FPU
  32   32   *     regs to a designated file.
  33   33   *   o Verify the process successfully terminates and returns 0.
  34   34   *
  35   35   * A critical assumption here is that our hardware support is not going to
  36   36   * change between processes (something that may be mucked around with via
  37   37   * environment variables for rtld).
  38   38   */
  39   39  
  40   40  #include <err.h>
  41   41  #include <stdlib.h>
  42   42  #include <errno.h>
  43   43  #include <sys/types.h>
  44   44  #include <sys/wait.h>
  45   45  #include <string.h>
  46   46  
  47   47  #include "xsave_util.h"
  48   48  
  49   49  static xsu_fpu_t fpu;
  50   50  
  51   51  int
  52   52  main(int argc, char *argv[])
  53   53  {
  54   54          uint32_t seed, hwsup;
  55   55          unsigned long ul;
  56   56          char *eptr;
  57   57          prxregset_t *prx;
  58   58          size_t prx_len;
  59   59          xsu_proc_t xp;
  60   60  
  61   61          if (argc != 5) {
  62   62                  errx(EXIT_FAILURE, "missing args: <prog> <output file> "
  63   63                      "<seed> <func>");
  64   64          }
  65   65  
  66   66          errno = 0;
  67   67          ul = strtoul(argv[3], &eptr, 0);
  68   68          if (errno != 0 || *eptr != '\0') {
  69   69                  errx(EXIT_FAILURE, "seed value is bad: %s", argv[3]);
  70   70          }
  71   71  
  72   72  #if defined(_LP64)
  73   73          if (ul > UINT32_MAX) {
  74   74                  errx(EXIT_FAILURE, "seed %s, exceeds [0, UINT32_MAX]", argv[3]);
  75   75          }
  76   76  #endif
  77   77  
  78   78          seed = (uint32_t)ul;
  79   79          hwsup = xsu_hwsupport();
  80   80          xsu_fill(&fpu, hwsup, seed);
  81   81          xsu_fpu_to_xregs(&fpu, hwsup, &prx, &prx_len);
  82   82  
  83   83          (void) memset(&xp, 0, sizeof (xsu_proc_t));
  84   84          xp.xp_prog = argv[1];
  85   85          xp.xp_arg = argv[2];
  86   86          xp.xp_object = "a.out";
  87   87          xp.xp_symname = argv[4];
  88   88  
  89   89          xsu_proc_bkpt(&xp);
  90   90          /* We know that libc always creates a default thread with id of 1 */
  91   91          if (Plwp_setxregs(xp.xp_proc, 1, prx, prx_len) != 0) {
  92   92                  err(EXIT_FAILURE, "failed to set target's xregs");
  93   93          }
  94   94  
  95   95          xsu_proc_finish(&xp);
  96   96  
  97   97          if (WEXITSTATUS(xp.xp_wait) != EXIT_SUCCESS) {
  98   98                  errx(EXIT_FAILURE, "our target process didn't exit non-zero, "
  99   99                      "got %d", WEXITSTATUS(xp.xp_wait));
 100  100          }
 101  101  
 102  102          return (EXIT_SUCCESS);
 103  103  }

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