memcheck/tests/sh-mem-random.c

// This program is a thorough test of the LOADVn/STOREVn shadow memory
// operations.

#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include "memcheck/memcheck.h"

// All the sizes here are in *bytes*, not bits.

typedef unsigned char        U1;
typedef unsigned short       U2;
typedef unsigned int         U4;
typedef unsigned long long   U8;

typedef float                F4;
typedef double               F8;

#define PAGE_SIZE 4096ULL


// XXX: should check the error cases for SET/GET_VBITS also

// For the byte 'x', build a value of 'size' bytes from that byte, eg:
//   size 1 --> x
//   size 2 --> xx
//   size 4 --> xxxx
//   size 8 --> xxxxxxxx
// where the 0 bits are seen by Memcheck as defined, and the 1 bits are
// seen as undefined (ie. the value of each bit matches its V bit, ie. the
// resulting value is the same as its metavalue).
//
U8 build(int size, U1 byte)
{
   int i;
   U8 mask = 0;
   U8 shres;
   U8 res = 0xffffffffffffffffULL, res2;
   VALGRIND_MAKE_WRITABLE(&res, 8);
   assert(1 == size || 2 == size || 4 == size || 8 == size);

   for (i = 0; i < size; i++) {
      mask <<= 8;
      mask |= (U8)byte;
   }

   res &= mask;      
   
   // res is now considered partially defined, but we know exactly what its
   // value is (it happens to be the same as its metavalue).
   
   VALGRIND_GET_VBITS(&res, &shres, 8);
   res2 = res;
   VALGRIND_MAKE_READABLE(&res2, 8);      // avoid the 'undefined' warning
   assert(res2 == shres);
   return res;
}

U1 make_defined ( U1 x )
{
   volatile U1 xx = x;
   VALGRIND_MAKE_READABLE(&xx, 1);
   return xx;
}

void check(U1* arr, int n, char* who)
{
   int i;
   U1* shadow = malloc(n);
   U1 arr_i;
   U8 sum = 0;
   VALGRIND_GET_VBITS(arr, shadow, n);
   for (i = 0; i < n; i++) {
      arr_i = make_defined(arr[i]);
      if (arr_i != shadow[i]) {
          fprintf(stderr, "\n\nFAILURE: %s, byte %d -- "
                          "is 0x%x, should be 0x%x\n\n",
                          who, i, shadow[i], arr[i]);
          exit(1);
      }
      sum += (U8)arr_i;
   }
   free(shadow);
   printf("test passed, sum = %llu (%9.5f per byte)\n", 
	  sum, (F8)sum / (F8)n);
}

static inline U4 randomU4 ( void )
{
   static U4 n = 0;
   /* From "Numerical Recipes in C" 2nd Edition */
   n = 1664525UL * n + 1013904223UL;
   return n;
}

static inline U1 randomU1 ( void )
{
   return 0xFF & (randomU4() >> 13);
}

#define N_BYTES  300000
#define N_EVENTS (5 * N_BYTES)


void do_test_at ( U1* arr )
{
   int i;

   U4 mv1 = 0, mv2 = 0, mv4 = 0, mv8 = 0, mv4f = 0, mv8f = 0;

   /* Fill arr with random bytes whose shadows match them. */
   printf("-------- arr = %p\n", arr);

   printf("initialising\n");
   for (i = 0; i < N_BYTES; i++)
      arr[i] = (U1)build(1, randomU1());

   printf("post-initialisation check\n");
   check(arr, N_BYTES, "after initialisation");

   /* Now do huge numbers of memory copies. */
   printf("doing copies\n");
   for (i = 0; i < N_EVENTS; i++) {
      U4 ty, src, dst;
      ty  = (randomU4() >> 13) % 5;
     tryagain:
      src = (randomU4() >>  1) % N_BYTES;
      dst = (randomU4() >>  3) % N_BYTES;
      switch (ty) {
         case 0: { // U1
            *(U1*)(arr+dst) = *(U1*)(arr+src);
	    mv1++;
            break;
         }
         case 1: { // U2
            if (src+2 >= N_BYTES || dst+2 >= N_BYTES) 
               goto tryagain;
            *(U2*)(arr+dst) = *(U2*)(arr+src);
	    mv2++;
            break;
         }
         case 2: { // U4
            if (src+4 >= N_BYTES || dst+4 >= N_BYTES) 
               goto tryagain;
            *(U4*)(arr+dst) = *(U4*)(arr+src);
	    mv4++;
            break;
         }
         case 3: { // U8
            if (src+8 >= N_BYTES || dst+8 >= N_BYTES) 
               goto tryagain;
            *(U8*)(arr+dst) = *(U8*)(arr+src);
	    mv8++;
            break;
         }
         /* Don't bother with 32-bit floats.  These cause
            horrible complications, as discussed in sh-mem.c. */
         /*
         case 4: { // F4
            if (src+4 >= N_BYTES || dst+4 >= N_BYTES) 
               goto tryagain;
            *(F4*)(arr+dst) = *(F4*)(arr+src);
	    mv4f++;
            break;
         }
         */
         case 4: { // F8
            if (src+8 >= N_BYTES || dst+8 >= N_BYTES) 
               goto tryagain;
            *(F8*)(arr+dst) = *(F8*)(arr+src);
	    mv8f++;
            break;
         }
         default:
	   fprintf(stderr, "sh-mem-random: bad size\n");
	   exit(0);
      }
   }

   printf("final check\n");
   check(arr, N_BYTES, "final check");

   printf("counts 1/2/4/8/F4/F8: %d %d %d %d %d %d\n", 
          mv1, mv2, mv4, mv8, mv4f, mv8f);
}



int main(void)
{
   U1* arr;

   if (0 == RUNNING_ON_VALGRIND) {
      fprintf(stderr, "error: this program only works when run under Valgrind\n");
      exit(1);
   }

   printf("-------- testing non-auxmap range --------\n");

   arr = malloc(N_BYTES);
   assert(arr);
   do_test_at(arr);
   free(arr);

   if (sizeof(void*) == 8) {
      // 64-bit platform.
      int tries;
      int nbytes_p;
      U1* huge_addr = (U1*)0x6600000000;  // 408GB
      // Note, kernel 2.6.? on Athlon64 refuses fixed mmap requests
      // at above 512GB.

      printf("-------- testing auxmap range --------\n");

      nbytes_p = (N_BYTES + PAGE_SIZE) & ~(PAGE_SIZE-1);

      for (tries = 0; tries < 10; tries++) {
         arr = mmap(huge_addr, nbytes_p, PROT_READ|PROT_WRITE, 
                    MAP_FIXED|MAP_PRIVATE|MAP_ANONYMOUS, 0,0);
	 if (arr != MAP_FAILED)
            break;
	 // hmm. fudge the address and try again.
         huge_addr += (randomU4() & ~(PAGE_SIZE-1));
      }

      if (tries >= 10) {
	   fprintf(stderr, "sh-mem-random: can't mmap hi-mem\n");
	   exit(0);
      }
      assert(arr != MAP_FAILED);

      do_test_at(arr);
   }

   return 0;

}