PROSAGA码农传奇-可信计算-分配多维数组后的内存泄漏

我编写了一个简单的程序来读取任何方阵并计算其行列式。但是，根据Valgrind的说法，它似乎正在泄漏内存。会话示例：
<pre><code>./det
4 23 4
2 -5 2
45 2 40
330.000000
</code></pre>这是Valgrind的输出：
<pre><code>valgrind --leak-check=full --track-origins=yes ./det ⏎
==5586== Memcheck, a memory error detector
==5586== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==5586== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==5586== Command: ./det
==5586== 
4 23 4
==5586== Conditional jump or move depends on uninitialised value(s)
==5586== at 0x4C2D1CA: strcat (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400EE6: readline (det.c:132)
==5586== by 0x400B13: parse_into (det.c:53)
==5586== by 0x40084D: main (det.c:20)
==5586== Uninitialised value was created by a heap allocation
==5586== at 0x4C29F90: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x4C2C33F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400EB4: readline (det.c:127)
==5586== by 0x400B13: parse_into (det.c:53)
==5586== by 0x40084D: main (det.c:20)
==5586== 
2 -5 2
==5586== Conditional jump or move depends on uninitialised value(s)
==5586== at 0x4C2D1CA: strcat (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400EE6: readline (det.c:132)
==5586== by 0x400C66: parse_into (det.c:79)
==5586== by 0x40084D: main (det.c:20)
==5586== Uninitialised value was created by a heap allocation
==5586== at 0x4C29F90: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x4C2C33F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400EB4: readline (det.c:127)
==5586== by 0x400C66: parse_into (det.c:79)
==5586== by 0x40084D: main (det.c:20)
==5586== 
45 2 40
==5586== Invalid read of size 8
==5586== at 0x400929: determinant (det.c:37)
==5586== by 0x400864: main (det.c:21)
==5586== Address 0x51d9040 is 0 bytes inside a block of size 64 free'd
==5586== at 0x4C2C29E: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400D39: allocate_matrix (det.c:95)
==5586== by 0x400BFB: parse_into (det.c:72)
==5586== by 0x40084D: main (det.c:20)
==5586== 
==5586== Conditional jump or move depends on uninitialised value(s)
==5586== at 0x400945: determinant (det.c:37)
==5586== by 0x400864: main (det.c:21)
==5586== Uninitialised value was created by a heap allocation
==5586== at 0x4C29F90: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x4C2C33F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400DBD: allocate_matrix (det.c:102)
==5586== by 0x40083D: main (det.c:19)
==5586== 
==5586== Conditional jump or move depends on uninitialised value(s)
==5586== at 0x40094F: determinant (det.c:37)
==5586== by 0x400864: main (det.c:21)
==5586== Uninitialised value was created by a heap allocation
==5586== at 0x4C29F90: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x4C2C33F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400DBD: allocate_matrix (det.c:102)
==5586== by 0x40083D: main (det.c:19)
==5586== 
0.000000
==5586== Invalid read of size 8
==5586== at 0x400E24: free_matrix (det.c:113)
==5586== by 0x40087F: main (det.c:22)
==5586== Address 0x51d9040 is 0 bytes inside a block of size 64 free'd
==5586== at 0x4C2C29E: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400D39: allocate_matrix (det.c:95)
==5586== by 0x400BFB: parse_into (det.c:72)
==5586== by 0x40084D: main (det.c:20)
==5586== 
==5586== Invalid free() / delete / delete[] / realloc()
==5586== at 0x4C2B200: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400E4B: free_matrix (det.c:114)
==5586== by 0x40087F: main (det.c:22)
==5586== Address 0x51d9040 is 0 bytes inside a block of size 64 free'd
==5586== at 0x4C2C29E: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400D39: allocate_matrix (det.c:95)
==5586== by 0x400BFB: parse_into (det.c:72)
==5586== by 0x40084D: main (det.c:20)
==5586== 
==5586== 
==5586== HEAP SUMMARY:
==5586== in use at exit: 624 bytes in 14 blocks
==5586== total heap usage: 17 allocs, 4 frees, 761 bytes allocated
==5586== 
==5586== 8 bytes in 1 blocks are definitely lost in loss record 1 of 6
==5586== at 0x4C29F90: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x4C2C33F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400EB4: readline (det.c:127)
==5586== by 0x400B13: parse_into (det.c:53)
==5586== by 0x40084D: main (det.c:20)
==5586== 
==5586== 8 bytes in 1 blocks are definitely lost in loss record 2 of 6
==5586== at 0x4C29F90: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x4C2C33F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400EB4: readline (det.c:127)
==5586== by 0x400C66: parse_into (det.c:79)
==5586== by 0x40084D: main (det.c:20)
==5586== 
==5586== 64 bytes in 1 blocks are definitely lost in loss record 3 of 6
==5586== at 0x4C29F90: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400B41: parse_into (det.c:59)
==5586== by 0x40084D: main (det.c:20)
==5586== 
==5586== 96 (24 direct, 72 indirect) bytes in 1 blocks are definitely lost in loss record 5 of 6
==5586== at 0x4C2C29E: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400D39: allocate_matrix (det.c:95)
==5586== by 0x400BFB: parse_into (det.c:72)
==5586== by 0x40084D: main (det.c:20)
==5586== 
==5586== 448 bytes in 7 blocks are definitely lost in loss record 6 of 6
==5586== at 0x4C29F90: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x4C2C33F: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==5586== by 0x400DBD: allocate_matrix (det.c:102)
==5586== by 0x40083D: main (det.c:19)
==5586== 
==5586== LEAK SUMMARY:
==5586== definitely lost: 552 bytes in 11 blocks
==5586== indirectly lost: 72 bytes in 3 blocks
==5586== possibly lost: 0 bytes in 0 blocks
==5586== still reachable: 0 bytes in 0 blocks
==5586== suppressed: 0 bytes in 0 blocks
==5586== 
==5586== For counts of detected and suppressed errors, rerun with: -v
==5586== ERROR SUMMARY: 13 errors from 12 contexts (suppressed: 0 from 0)
</code></pre>我不知道为什么，但是在Valgrind会议期间，结果是错误的！怎么能输出330，并0具有相同的输入？是否可以信任Valgrind错误？这是完整的代码。如您所见，我总是free()在使用堆之后调用。
<pre><code>#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>

#define MATRIX 8
#define CHUNK 32

double determinant(double **, size_t);
size_t parse_into(double **);
double **allocate_matrix(double **, size_t);
void free_matrix(double **);
char *readline();

int main(int argc, char *argv[]) {
    double **matrix = NULL;
    size_t N;
    matrix = allocate_matrix(matrix, MATRIX);
    N = parse_into(matrix);
    printf("%lf\n", determinant(matrix, N));
    free_matrix(matrix);
    return 0;
}

double determinant(double **matrix, size_t side) {
    if (side == 1) {
        return matrix[0][0];
    } else if (side == 2) {
        return matrix[0][0] * matrix[1][1] - matrix[0][1] * matrix[1][0];
    }

// Make the matrix triangular
 int i, j, t, r = 1;
 for (j = 0; j < side; j++) {
 if (!matrix[j][j]) return 0;
 for (i = j + 1; i < side; i++) {
 double ratio = matrix[i][j] / matrix[j][j];
 for (t = 0; t < side; t++) {
 matrix[i][t] -= ratio * matrix[j][t];
 }
 }
 }
 for (i = 0; i < side; i++) {
 r *= matrix[i][i];
 }
 return r;
}

size_t parse_into(double **matrix) {
    char *row = readline();
    size_t t;
    size_t N = 0, M = 0;
    size_t i = 1, j = 0;

int *first_row;
 if (!(first_row = malloc(MATRIX * sizeof(first_row)))) {
 puts("Could not allocate memory.");
 exit(EXIT_FAILURE);
 }
 char *number = strtok(row, " ");
 while (number) {
 if (N == MATRIX) {
 first_row = realloc(first_row, 2 * N * sizeof(first_row));
 }
 first_row[N++] = atoi(number);
 number = strtok(NULL, " ");
 }
 M = N;
 matrix = allocate_matrix(matrix, N);
 for (t = 0; t < N; t++) {
 matrix[0][t] = first_row[t];
 }

while (--M) {
        j = 0;
        row = readline();
        char *number = strtok(row, " ");
        while (number) {
            matrix[i][j++] = atoi(number);
            number = strtok(NULL, " ");
        }
        i++;
    }
    free(row);
    return N;
}

double **allocate_matrix(double **matrix, size_t side) {
    size_t i;

if (!(matrix = realloc(matrix, sizeof(*matrix) * side))) {
        puts("Could not allocate memory.");
        exit(EXIT_FAILURE);
    }

for (i = 0; i < side; i++) {
 matrix[i] = NULL;
 if (!(matrix[i] = realloc(matrix[i], sizeof(matrix[i]) * side))) {
 puts("Could not allocate memory.");
 exit(EXIT_FAILURE);
 }
 }
 return matrix;
}

void free_matrix(double **matrix) {
    size_t length = sizeof(matrix[0]) / sizeof(matrix[0][0]);
    while (length--) free(matrix[length]);
    free(matrix);
}

char *readline() {
    char *input = NULL;
    char tmpbuf[CHUNK];
    size_t inputlen = 0, tmplen = 0;

do {
        fgets(tmpbuf, CHUNK, stdin);
        tmplen = strlen(tmpbuf);
        inputlen += tmplen;
        input = realloc(input, inputlen + 1);
        if (!input) {
            puts("Could not allocate memory.");
            exit(EXIT_FAILURE);
        }
        strcat(input, tmpbuf);
    } while (tmplen == CHUNK - 1 && tmpbuf[CHUNK - 2] != '\n');

return input;
}
</code></pre>编辑这是正确且有效的代码，以防万一有人感兴趣：https : //codereview.stackexchange.com/questions/85769/reading-a-matrix-and-computing-the-determinant