powerpc/stringloops/memcmp.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 #include <malloc.h>
0003 #include <stdlib.h>
0004 #include <string.h>
0005 #include <sys/mman.h>
0006 #include <time.h>
0007
0008 #include "utils.h"
0009
0010 #define SIZE 256
0011 #define ITERATIONS 10000
0012
0013 #define LARGE_SIZE (5 * 1024)
0014 #define LARGE_ITERATIONS 1000
0015 #define LARGE_MAX_OFFSET 32
0016 #define LARGE_SIZE_START 4096
0017
0018 /* This is big enough to fit LARGE_SIZE and works on 4K & 64K kernels */
0019 #define MAP_SIZE (64 * 1024)
0020
0021 #define MAX_OFFSET_DIFF_S1_S2 48
0022
0023 int vmx_count;
0024 int enter_vmx_ops(void)
0025 {
0026     vmx_count++;
0027     return 1;
0028 }
0029
0030 void exit_vmx_ops(void)
0031 {
0032     vmx_count--;
0033 }
0034 int test_memcmp(const void *s1, const void *s2, size_t n);
0035
0036 /* test all offsets and lengths */
0037 static void test_one(char *s1, char *s2, unsigned long max_offset,
0038         unsigned long size_start, unsigned long max_size)
0039 {
0040     unsigned long offset, size;
0041
0042     for (offset = 0; offset < max_offset; offset++) {
0043         for (size = size_start; size < (max_size - offset); size++) {
0044             int x, y;
0045             unsigned long i;
0046
0047             y = memcmp(s1+offset, s2+offset, size);
0048             x = test_memcmp(s1+offset, s2+offset, size);
0049
0050             if (((x ^ y) < 0) &&    /* Trick to compare sign */
0051                 ((x | y) != 0)) { /* check for zero */
0052                 printf("memcmp returned %d, should have returned %d (offset %ld size %ld)\n", x, y, offset, size);
0053
0054                 for (i = offset; i < offset+size; i++)
0055                     printf("%02x ", s1[i]);
0056                 printf("\n");
0057
0058                 for (i = offset; i < offset+size; i++)
0059                     printf("%02x ", s2[i]);
0060                 printf("\n");
0061                 abort();
0062             }
0063
0064             if (vmx_count != 0) {
0065                 printf("vmx enter/exit not paired.(offset:%ld size:%ld s1:%p s2:%p vc:%d\n",
0066                     offset, size, s1, s2, vmx_count);
0067                 printf("\n");
0068                 abort();
0069             }
0070         }
0071     }
0072 }
0073
0074 static int testcase(bool islarge)
0075 {
0076     unsigned long i, comp_size, alloc_size;
0077     char *p, *s1, *s2;
0078     int iterations;
0079
0080     comp_size = (islarge ? LARGE_SIZE : SIZE);
0081     alloc_size = comp_size + MAX_OFFSET_DIFF_S1_S2;
0082     iterations = islarge ? LARGE_ITERATIONS : ITERATIONS;
0083
0084     p = mmap(NULL, 4 * MAP_SIZE, PROT_READ | PROT_WRITE,
0085          MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
0086     FAIL_IF(p == MAP_FAILED);
0087
0088     /* Put s1/s2 at the end of a page */
0089     s1 = p + MAP_SIZE - alloc_size;
0090     s2 = p + 3 * MAP_SIZE - alloc_size;
0091
0092     /* And unmap the subsequent page to force a fault if we overread */
0093     munmap(p + MAP_SIZE, MAP_SIZE);
0094     munmap(p + 3 * MAP_SIZE, MAP_SIZE);
0095
0096     srandom(time(0));
0097
0098     for (i = 0; i < iterations; i++) {
0099         unsigned long j;
0100         unsigned long change;
0101         char *rand_s1 = s1;
0102         char *rand_s2 = s2;
0103
0104         for (j = 0; j < alloc_size; j++)
0105             s1[j] = random();
0106
0107         rand_s1 += random() % MAX_OFFSET_DIFF_S1_S2;
0108         rand_s2 += random() % MAX_OFFSET_DIFF_S1_S2;
0109         memcpy(rand_s2, rand_s1, comp_size);
0110
0111         /* change one byte */
0112         change = random() % comp_size;
0113         rand_s2[change] = random() & 0xff;
0114
0115         if (islarge)
0116             test_one(rand_s1, rand_s2, LARGE_MAX_OFFSET,
0117                     LARGE_SIZE_START, comp_size);
0118         else
0119             test_one(rand_s1, rand_s2, SIZE, 0, comp_size);
0120     }
0121
0122     srandom(time(0));
0123
0124     for (i = 0; i < iterations; i++) {
0125         unsigned long j;
0126         unsigned long change;
0127         char *rand_s1 = s1;
0128         char *rand_s2 = s2;
0129
0130         for (j = 0; j < alloc_size; j++)
0131             s1[j] = random();
0132
0133         rand_s1 += random() % MAX_OFFSET_DIFF_S1_S2;
0134         rand_s2 += random() % MAX_OFFSET_DIFF_S1_S2;
0135         memcpy(rand_s2, rand_s1, comp_size);
0136
0137         /* change multiple bytes, 1/8 of total */
0138         for (j = 0; j < comp_size / 8; j++) {
0139             change = random() % comp_size;
0140             s2[change] = random() & 0xff;
0141         }
0142
0143         if (islarge)
0144             test_one(rand_s1, rand_s2, LARGE_MAX_OFFSET,
0145                     LARGE_SIZE_START, comp_size);
0146         else
0147             test_one(rand_s1, rand_s2, SIZE, 0, comp_size);
0148     }
0149
0150     return 0;
0151 }
0152
0153 static int testcases(void)
0154 {
0155 #ifdef __powerpc64__
0156     // vcmpequd used in memcmp_64.S is v2.07
0157     SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07));
0158 #endif
0159
0160     testcase(0);
0161     testcase(1);
0162     return 0;
0163 }
0164
0165 int main(void)
0166 {
0167     test_harness_set_timeout(300);
0168     return test_harness(testcases, "memcmp");
0169 }