tools/testing/selftests/powerpc/stringloops/memcmp.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <malloc.h>
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <sys/mman.h>
   6 #include <time.h>
   7
   8 #include "utils.h"
   9
  10 #define SIZE 256
  11 #define ITERATIONS 10000
  12
  13 #define LARGE_SIZE (5 * 1024)
  14 #define LARGE_ITERATIONS 1000
  15 #define LARGE_MAX_OFFSET 32
  16 #define LARGE_SIZE_START 4096
  17
  18 /* This is big enough to fit LARGE_SIZE and works on 4K & 64K kernels */
  19 #define MAP_SIZE (64 * 1024)
  20
  21 #define MAX_OFFSET_DIFF_S1_S2 48
  22
  23 int vmx_count;
  24 int enter_vmx_ops(void)
  25 {
  26         vmx_count++;
  27         return 1;
  28 }
  29
  30 void exit_vmx_ops(void)
  31 {
  32         vmx_count--;
  33 }
  34 int test_memcmp(const void *s1, const void *s2, size_t n);
  35
  36 /* test all offsets and lengths */
  37 static void test_one(char *s1, char *s2, unsigned long max_offset,
  38                 unsigned long size_start, unsigned long max_size)
  39 {
  40         unsigned long offset, size;
  41
  42         for (offset = 0; offset < max_offset; offset++) {
  43                 for (size = size_start; size < (max_size - offset); size++) {
  44                         int x, y;
  45                         unsigned long i;
  46
  47                         y = memcmp(s1+offset, s2+offset, size);
  48                         x = test_memcmp(s1+offset, s2+offset, size);
  49
  50                         if (((x ^ y) < 0) &&    /* Trick to compare sign */
  51                                 ((x | y) != 0)) { /* check for zero */
  52                                 printf("memcmp returned %d, should have returned %d (offset %ld size %ld)\n", x, y, offset, size);
  53
  54                                 for (i = offset; i < offset+size; i++)
  55                                         printf("%02x ", s1[i]);
  56                                 printf("\n");
  57
  58                                 for (i = offset; i < offset+size; i++)
  59                                         printf("%02x ", s2[i]);
  60                                 printf("\n");
  61                                 abort();
  62                         }
  63
  64                         if (vmx_count != 0) {
  65                                 printf("vmx enter/exit not paired.(offset:%ld size:%ld s1:%p s2:%p vc:%d\n",
  66                                         offset, size, s1, s2, vmx_count);
  67                                 printf("\n");
  68                                 abort();
  69                         }
  70                 }
  71         }
  72 }
  73
  74 static int testcase(bool islarge)
  75 {
  76         unsigned long i, comp_size, alloc_size;
  77         char *p, *s1, *s2;
  78         int iterations;
  79
  80         comp_size = (islarge ? LARGE_SIZE : SIZE);
  81         alloc_size = comp_size + MAX_OFFSET_DIFF_S1_S2;
  82         iterations = islarge ? LARGE_ITERATIONS : ITERATIONS;
  83
  84         p = mmap(NULL, 4 * MAP_SIZE, PROT_READ | PROT_WRITE,
  85                  MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
  86         FAIL_IF(p == MAP_FAILED);
  87
  88         /* Put s1/s2 at the end of a page */
  89         s1 = p + MAP_SIZE - alloc_size;
  90         s2 = p + 3 * MAP_SIZE - alloc_size;
  91
  92         /* And unmap the subsequent page to force a fault if we overread */
  93         munmap(p + MAP_SIZE, MAP_SIZE);
  94         munmap(p + 3 * MAP_SIZE, MAP_SIZE);
  95
  96         srandom(time(0));
  97
  98         for (i = 0; i < iterations; i++) {
  99                 unsigned long j;
 100                 unsigned long change;
 101                 char *rand_s1 = s1;
 102                 char *rand_s2 = s2;
 103
 104                 for (j = 0; j < alloc_size; j++)
 105                         s1[j] = random();
 106
 107                 rand_s1 += random() % MAX_OFFSET_DIFF_S1_S2;
 108                 rand_s2 += random() % MAX_OFFSET_DIFF_S1_S2;
 109                 memcpy(rand_s2, rand_s1, comp_size);
 110
 111                 /* change one byte */
 112                 change = random() % comp_size;
 113                 rand_s2[change] = random() & 0xff;
 114
 115                 if (islarge)
 116                         test_one(rand_s1, rand_s2, LARGE_MAX_OFFSET,
 117                                         LARGE_SIZE_START, comp_size);
 118                 else
 119                         test_one(rand_s1, rand_s2, SIZE, 0, comp_size);
 120         }
 121
 122         srandom(time(0));
 123
 124         for (i = 0; i < iterations; i++) {
 125                 unsigned long j;
 126                 unsigned long change;
 127                 char *rand_s1 = s1;
 128                 char *rand_s2 = s2;
 129
 130                 for (j = 0; j < alloc_size; j++)
 131                         s1[j] = random();
 132
 133                 rand_s1 += random() % MAX_OFFSET_DIFF_S1_S2;
 134                 rand_s2 += random() % MAX_OFFSET_DIFF_S1_S2;
 135                 memcpy(rand_s2, rand_s1, comp_size);
 136
 137                 /* change multiple bytes, 1/8 of total */
 138                 for (j = 0; j < comp_size / 8; j++) {
 139                         change = random() % comp_size;
 140                         s2[change] = random() & 0xff;
 141                 }
 142
 143                 if (islarge)
 144                         test_one(rand_s1, rand_s2, LARGE_MAX_OFFSET,
 145                                         LARGE_SIZE_START, comp_size);
 146                 else
 147                         test_one(rand_s1, rand_s2, SIZE, 0, comp_size);
 148         }
 149
 150         return 0;
 151 }
 152
 153 static int testcases(void)
 154 {
 155 #ifdef __powerpc64__
 156         // vcmpequd used in memcmp_64.S is v2.07
 157         SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07));
 158 #endif
 159
 160         testcase(0);
 161         testcase(1);
 162         return 0;
 163 }
 164
 165 int main(void)
 166 {
 167         test_harness_set_timeout(300);
 168         return test_harness(testcases, "memcmp");
 169 }