mdw@git.distorted.org.uk Git - xchg-rax-rax/blob - main.c

   1 #include <ctype.h>
   2 #include <errno.h>
   3 #include <limits.h>
   4 #include <stdarg.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8
   9 union reg {
  10   unsigned char *p;
  11   long i;
  12   long u;
  13 };
  14
  15 struct regs {
  16   union reg
  17     a, b, c, d, si, di, bp, f,
  18     r8, r9, r10, r11, r12, r13, r14, r15;
  19 };
  20
  21 struct seg {
  22   unsigned char *p;
  23   size_t sz;
  24 };
  25
  26 #define N(v) (sizeof(v)/sizeof((v)[0]))
  27
  28 #define CTYPE_HACK(func, ch) func((unsigned char)(ch))
  29 #define ISDIGIT(ch) CTYPE_HACK(isdigit, ch)
  30 #define ISSPACE(ch) CTYPE_HACK(isspace, ch)
  31
  32 #define XCHG(_)                                                         \
  33   _(x00) _(x01) _(x02) _(x03) _(x04) _(x05) _(x06) _(x07)               \
  34   _(x08) _(x09) _(x0a) _(x0b) _(x0c) _(x0d) _(x0e) _(x0f)               \
  35   _(x10) _(x11) _(x12) _(x13) _(x14) _(x15) _(x16) _(x17)               \
  36   _(x18) _(x19) _(x1a) _(x1b) _(x1c) _(x1d) _(x1e) _(x1f)               \
  37   _(x20) _(x21) _(x22) _(x23) _(x24) _(x25) _(x26) _(x27)               \
  38   _(x28) _(x29) _(x2a) _(x2b) _(x2c) _(x2d) _(x2e) _(x2f)               \
  39   _(x30) _(x31) _(x32) _(x33) _(x34) _(x35) _(x36) _(x37)               \
  40   _(x38) _(x39) _(x3a) _(x3b) _(x3c) _(x3d) _(x3e) _(x3f)
  41
  42 #define DECL(x) extern const int x;
  43 XCHG(DECL)
  44 extern const int nop;
  45
  46 static const int *x[] = {
  47 #define SLOT(x) &x,
  48   XCHG(SLOT)
  49 };
  50
  51 extern void call_example(const int *f, struct regs *r);
  52
  53 static const char *prog = "???";
  54
  55 __attribute__((format(printf, 1, 2), noreturn))
  56 static void barf(const char *m, ...)
  57 {
  58   va_list ap;
  59
  60   va_start(ap, m);
  61   fprintf(stderr, "%s: ", prog);
  62   vfprintf(stderr, m, ap);
  63   putc('\n', stderr);
  64   va_end(ap);
  65   exit(127);
  66 }
  67
  68 static void *xmalloc(size_t sz)
  69 {
  70   void *p;
  71
  72   if (!sz) return (0);
  73   p = malloc(sz);
  74   if (!p) barf("malloc failed");
  75   return (p);
  76 }
  77
  78 #define DEF_PARSEINT(name, ty, strto)                                   \
  79   static ty parse_##name(const char *what, const char *p, ty min, ty max) \
  80   {                                                                     \
  81     const char *pp = p;                                                 \
  82     char *q;                                                            \
  83     ty i;                                                               \
  84     int err;                                                            \
  85                                                                         \
  86     if (ISSPACE(*p)) goto bad;                                          \
  87     err = errno; errno = 0;                                             \
  88     i = strto(p, &q, 0);                                                \
  89     if (errno) goto bad;                                                \
  90     if (*q) goto bad;                                                   \
  91     if (i < min || i > max) goto bad;                                   \
  92     errno = err;                                                        \
  93     return (i);                                                         \
  94                                                                         \
  95   bad:                                                                  \
  96     barf("bad %s `%s'", what, pp);                                      \
  97   }
  98 DEF_PARSEINT(long, long, strtol)
  99 DEF_PARSEINT(ulong, unsigned long, strtoul)
 100
 101 static int hex_digit(char ch)
 102 {
 103   if ('0' <= ch && ch <= '9') return (ch - '0');
 104   else if ('A' <= ch && ch <= 'F') return (ch - 'A' + 10);
 105   else if ('a' <= ch && ch <= 'f') return (ch - 'a' + 10);
 106   else return (-1);
 107 }
 108
 109 static void setreg(union reg *r,
 110                    struct seg **seg_inout,
 111                    int *i_inout, int argc, char *argv[])
 112 {
 113   struct seg *seg;
 114   const char *p, *pp;
 115   unsigned char *q;
 116   int hi, lo;
 117   size_t n;
 118
 119 #define LONG_REG(p) (parse_long("signed register", (p), LONG_MIN, LONG_MAX))
 120 #define ULONG_REG(p) (parse_ulong("unsigned register", (p), 0, ULONG_MAX))
 121
 122   p = *i_inout >= argc ? "-" : argv[(*i_inout)++];
 123   switch (*p) {
 124     case '-':
 125       if (p[1]) r->i = LONG_REG(p);
 126       else r->u = 0xdeadbeefdeadbeef;
 127       break;
 128     case 'i':
 129       if (p[1] != ':') goto bad;
 130       r->i = LONG_REG(p + 2);
 131       break;
 132     case 'u':
 133       if (p[1] != ':') goto bad;
 134       r->u = ULONG_REG(p + 2);
 135       break;
 136     case 'c':
 137       if (p[1] != ':' || p[3]) goto bad;
 138       r->u = p[2];
 139       break;
 140     case 's':
 141       if (p[1] != ':') goto bad;
 142       pp = p + 2; n = strlen(pp) + 1;
 143       seg = (*seg_inout)++; seg->p = xmalloc(n); seg->sz = n;
 144       memcpy(seg->p, pp, n); r->p = seg->p;
 145       break;
 146     case 'm':
 147       if (p[1] != ':') goto bad;
 148       pp = p + 2; n = strlen(pp); if (n%2) goto bad;
 149       seg = (*seg_inout)++; seg->p = q = xmalloc(n/2); seg->sz = n/2;
 150       while (n) {
 151         hi = hex_digit(pp[0]); lo = hex_digit(pp[1]);
 152         if (hi < 0 || lo < 0) goto bad;
 153         *q++ = 16*hi + lo; n -= 2; pp += 2;
 154       }
 155       r->p = seg->p;
 156       break;
 157     default:
 158       if (ISDIGIT(*p)) r->u = ULONG_REG(p);
 159       else if (*p == '+') r->i = LONG_REG(p);
 160       else if (*p == '\'' && p[2] == '\'' && !p[3]) r->u = p[1];
 161       else goto bad;
 162       break;
 163     bad:
 164       barf("bad regspec `%s'", p);
 165   }
 166
 167 #undef LONG_REG
 168 #undef ULONG_REG
 169 }
 170
 171 static void dumpreg(const char *name, const union reg *r,
 172                     const struct seg *seg, size_t nseg)
 173 {
 174   size_t i;
 175
 176   printf("%3s = 0x%016lx = %20ld = %20lu", name, r->u, r->i, r->u);
 177   if (r->u >= ' ' && r->u <= '~') printf(" = '%c'", (int)r->u);
 178   for (i = 0; i < nseg; i++) {
 179     if (r->p == seg[i].p)
 180       printf(" = seg[%zu] base", i);
 181     else if (r->p == seg[i].p + seg[i].sz)
 182       printf(" = seg[%zu] limit", i);
 183     else if (seg[i].p < r->p && r->p < seg[i].p + seg[i].sz)
 184       printf(" = seg[%zu] + %zu", i, (size_t)(r->p - seg[i].p));
 185   }
 186   putchar('\n');
 187 }
 188
 189 static void dumpseg(const struct seg *seg)
 190 {
 191   size_t i, j;
 192   unsigned char ch;
 193
 194   for (i = 0; i < seg->sz; i += 8) {
 195     printf("\t%8zx :", i);
 196     for (j = 0; j < 8; j++)
 197       if (i + j >= seg->sz) printf(" **");
 198       else printf(" %02x", seg->p[i + j]);
 199     printf(" : ");
 200     for (j = 0; j < 8; j++)
 201       if (i + j >= seg->sz) putchar('*');
 202       else {
 203         ch = seg->p[i + j];
 204         if (' ' <= ch && ch <= '~') putchar(ch);
 205         else putchar('.');
 206       }
 207     putchar('\n');
 208   }
 209 }
 210
 211 int main(int argc, char *argv[])
 212 {
 213   struct regs r;
 214   struct seg seg[16], *segp = seg;
 215   size_t nseg;
 216   int i, j;
 217
 218   prog = strrchr(argv[0], '/'); if (prog) prog++; else prog = argv[0];
 219
 220   if (argc < 2)
 221     barf("usage: %s I [A B C D SI DI BP R8 R9 R10 R11 R12 R13 R14 R15 F]",
 222          prog);
 223
 224   j = parse_long("program index", argv[1], -1, N(x) - 1);
 225
 226   i = 2;
 227   setreg(&r.a, &segp, &i, argc, argv);
 228   setreg(&r.b, &segp, &i, argc, argv);
 229   setreg(&r.c, &segp, &i, argc, argv);
 230   setreg(&r.d, &segp, &i, argc, argv);
 231   setreg(&r.si, &segp, &i, argc, argv);
 232   setreg(&r.di, &segp, &i, argc, argv);
 233   setreg(&r.bp, &segp, &i, argc, argv);
 234   setreg(&r.r8, &segp, &i, argc, argv);
 235   setreg(&r.r9, &segp, &i, argc, argv);
 236   setreg(&r.r10, &segp, &i, argc, argv);
 237   setreg(&r.r11, &segp, &i, argc, argv);
 238   setreg(&r.r12, &segp, &i, argc, argv);
 239   setreg(&r.r13, &segp, &i, argc, argv);
 240   setreg(&r.r14, &segp, &i, argc, argv);
 241   setreg(&r.r15, &segp, &i, argc, argv);
 242   setreg(&r.f, &segp, &i, argc, argv);
 243   nseg = segp - seg;
 244
 245   call_example(j < 0 ? &nop : x[j], &r);
 246
 247   dumpreg("rax", &r.a, seg, nseg);
 248   dumpreg("rbx", &r.b, seg, nseg);
 249   dumpreg("rcx", &r.c, seg, nseg);
 250   dumpreg("rdx", &r.d, seg, nseg);
 251   dumpreg("rsi", &r.si, seg, nseg);
 252   dumpreg("rdi", &r.di, seg, nseg);
 253   dumpreg("rbp", &r.bp, seg, nseg);
 254   dumpreg("rbp", &r.bp, seg, nseg);
 255   dumpreg("r8", &r.r8, seg, nseg);
 256   dumpreg("r9", &r.r9, seg, nseg);
 257   dumpreg("r10", &r.r10, seg, nseg);
 258   dumpreg("r11", &r.r11, seg, nseg);
 259   dumpreg("r12", &r.r12, seg, nseg);
 260   dumpreg("r13", &r.r13, seg, nseg);
 261   dumpreg("r14", &r.r14, seg, nseg);
 262   dumpreg("r15", &r.r15, seg, nseg);
 263
 264 #define CF (1 <<  0)
 265 #define PF (1 <<  2)
 266 #define ZF (1 <<  6)
 267 #define SF (1 <<  7)
 268 #define OF (1 << 11)
 269
 270   dumpreg("f", &r.f, seg, nseg);
 271   printf("\tstatus: %ccf %cpf %caf %czf %csf %cdf %cof\n",
 272          (r.f.u >>  0)&1u ? '+' : '-',
 273          (r.f.u >>  2)&1u ? '+' : '-',
 274          (r.f.u >>  4)&1u ? '+' : '-',
 275          (r.f.u >>  6)&1u ? '+' : '-',
 276          (r.f.u >>  7)&1u ? '+' : '-',
 277          (r.f.u >> 10)&1u ? '+' : '-',
 278          (r.f.u >> 11)&1u ? '+' : '-');
 279   printf("\tcond:");
 280   if (r.f.u&CF) printf(" c/b/nae"); else printf(" nc/ae/nb");
 281   if (r.f.u&ZF) printf(" e/z"); else printf(" ne/nz");
 282   if (r.f.u&SF) printf(" s"); else printf(" ns");
 283   if (r.f.u&OF) printf(" o"); else printf(" no");
 284   if (r.f.u&PF) printf(" p"); else printf(" np");
 285   if ((r.f.u&CF) || (r.f.u&ZF)) printf(" be/na"); else printf(" a/nbe");
 286   if (!(r.f.u&OF) == !(r.f.u&SF)) printf(" ge/nl"); else printf(" l/nge");
 287   if (!(r.f.u&OF) == !(r.f.u&SF) && !(r.f.u&ZF))
 288     printf(" g/nle"); else printf(" le/ng");
 289   putchar('\n');
 290   printf("\tsystem: %ctf %cif iopl=%d %cnt "
 291                         "%crf %cvm %cac %cvif %cvip %cid\n",
 292          (r.f.u >>  8)&1u ? '+' : '-',
 293          (r.f.u >>  9)&1u ? '+' : '-',
 294          (int)((r.f.u >> 12)&1u),
 295          (r.f.u >> 14)&1u ? '+' : '-',
 296          (r.f.u >> 16)&1u ? '+' : '-',
 297          (r.f.u >> 17)&1u ? '+' : '-',
 298          (r.f.u >> 18)&1u ? '+' : '-',
 299          (r.f.u >> 19)&1u ? '+' : '-',
 300          (r.f.u >> 20)&1u ? '+' : '-',
 301          (r.f.u >> 21)&1u ? '+' : '-');
 302
 303 #undef CF
 304 #undef PF
 305 #undef ZF
 306 #undef SF
 307 #undef OF
 308
 309   for (i = 0; i < nseg; i++)
 310     { printf("seg[%d] (%p):\n", i, seg[i].p); dumpseg(&seg[i]); }
 311
 312   return (0);
 313 }