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}