LXR linux/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
  23int vmx_count;
  24int enter_vmx_ops(void)
  25{
  26        vmx_count++;
  27        return 1;
  28}
  29
  30void exit_vmx_ops(void)
  31{
  32        vmx_count--;
  33}
  34int test_memcmp(const void *s1, const void *s2, size_t n);
  35
  36/* test all offsets and lengths */
  37static 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
  74static 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
 153static 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
 165int main(void)
 166{
 167        test_harness_set_timeout(300);
 168        return test_harness(testcases, "memcmp");
 169}
 170