Memory leak in Pset4

Question

According to valgrind I have a memory leak in my version of resize.

Here's the valgrind output:

==22900== Memcheck, a memory error detector
==22900== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==22900== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==22900== Command: resize
==22900== 
COLUMNS=250;
LINES=14;
export COLUMNS LINES;
==22900== 
==22900== HEAP SUMMARY:
==22900==     in use at exit: 597 bytes in 4 blocks
==22900==   total heap usage: 4 allocs, 0 frees, 597 bytes allocated
==22900== 
==22900== 8 bytes in 1 blocks are definitely lost in loss record 1 of 4
==22900==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==22900==    by 0x401D3E: ??? (in /usr/bin/resize)
==22900==    by 0x400EDC: ??? (in /usr/bin/resize)
==22900==    by 0x4E58F44: (below main) (libc-start.c:287)
==22900== 
==22900== 10 bytes in 1 blocks are definitely lost in loss record 2 of 4
==22900==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==22900==    by 0x401D3E: ??? (in /usr/bin/resize)
==22900==    by 0x400EA4: ??? (in /usr/bin/resize)
==22900==    by 0x4E58F44: (below main) (libc-start.c:287)
==22900== 
==22900== 11 bytes in 1 blocks are definitely lost in loss record 3 of 4
==22900==    at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==22900==    by 0x401D3E: ??? (in /usr/bin/resize)
==22900==    by 0x400F9C: ??? (in /usr/bin/resize)
==22900==    by 0x4E58F44: (below main) (libc-start.c:287)
==22900== 
==22900== LEAK SUMMARY:
==22900==    definitely lost: 29 bytes in 3 blocks
==22900==    indirectly lost: 0 bytes in 0 blocks
==22900==      possibly lost: 0 bytes in 0 blocks
==22900==    still reachable: 568 bytes in 1 blocks
==22900==         suppressed: 0 bytes in 0 blocks
==22900== Reachable blocks (those to which a pointer was found) are not shown.
==22900== To see them, rerun with: --leak-check=full --show-leak-kinds=all
==22900== 
==22900== For counts of detected and suppressed errors, rerun with: -v
==22900== ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 0 from 0)

And here's my source:

#include <stdio.h>
#include <stdlib.h>

#include "bmp.h"

int main(int argc, char* argv[])
{
        // ensure proper usage
    if (argc != 4)
    {
    printf("Usage: ./resize n infile outfile\n");
    return 1;
}

int foo = atoi(argv[1]);

if(foo > 100 || foo < 1)
{
    printf("Please enter a size-factor between 1 - 100!\n");
    return 1;
}

char* infile = argv[2];
char* outfile = argv[3];

FILE* inptr = fopen(infile, "r");
if (inptr == NULL)
{
    printf("Could not open %s.\n", infile);
    return 2;
}

FILE* outptr = fopen(outfile, "w");
if (outptr == NULL)
{
    fclose(inptr);
    fprintf(stderr, "Could not create %s.\n", outfile);
    return 3;
}

BITMAPFILEHEADER bf;
fread(&bf, sizeof(BITMAPFILEHEADER), 1, inptr);

BITMAPINFOHEADER bi;
fread(&bi, sizeof(BITMAPINFOHEADER), 1, inptr);

if (bf.bfType != 0x4d42 || bf.bfOffBits != 54 || bi.biSize != 40 || 
    bi.biBitCount != 24 || bi.biCompression != 0)
{
    fclose(outptr);
    fclose(inptr);
    fprintf(stderr, "Unsupported file format.\n");
    return 4;
} 

int initWidth = bi.biWidth;
int initHeight = bi.biHeight;

bi.biWidth *= foo;
bi.biHeight     oo;

int initPad =  (4 - (initWidth * sizeof(RGBTRIPLE)) % 4) % 4;
int pad =  (4 - (bi.biWidth * sizeof(RGBTRIPLE)) % 4) % 4;

bi.biSizeImage = abs(bi.biHeight) * ((bi.biWidth * sizeof (RGBTRIPLE)) + pad);

bf.bfSize = bi.biSizeImage + sizeof (BITMAPFILEHEADER) + sizeof (BITMAPINFOHEADER); 

fwrite(&bf, sizeof(BITMAPFILEHEADER), 1, outptr);

fwrite(&bi, sizeof(BITMAPINFOHEADER), 1, outptr);

RGBTRIPLE *buffer = malloc(sizeof(RGBTRIPLE) * (bi.biWidth));

for (int i = 0, biHeight = abs(initHeight); i < biHeight; i++)
{
    int bar = 0;
    for (int j = 0; j < initWidth; j++)
    {
        RGBTRIPLE triple;

        fread(&triple, sizeof(RGBTRIPLE), 1, inptr);

        for(int boo = 0; boo < foo; boo++)
        {
            *(buffer+(bar)) = triple;
            bar++;
        }
    }

    fseek(inptr, initPad, SEEK_CUR);

       for(int r = 0; r < foo; r++)
       {
            fwrite((buffer), sizeof(RGBTRIPLE), bi.biWidth, outptr);

            for (int k = 0; k < pad; k++)
                fputc(0x00, outptr);
       }        
}

free(buffer);

fclose(inptr);

fclose(outptr);

return 0;
}

I absolutely cannot place this memory leak, and it's starting to bug me! Any idea?

Answer 1

Actually, your apparent problem is that you are running valgrind against a different executable binary, also called resize.

~/workspace/ $ which resize
/usr/bin/resize
~/workspace/ $ whatis resize
resize (1)           - set environment and terminal settings to current xterm window size

Try running valgrind against ./resize (in the appropriate pset directory) instead.

Hope this helps!