Invalid read using valgrind - c

Question

After a compilation with no warnings and errors for my file reorg.c, I am running the program using Valgrind and I am getting the following output. I am trying to understand why I am getting a segmentation fault but I can't really find something wrong with line 35:
Memcheck, a memory error detector
==29338== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==29338== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info
==29338== Command: ./reorg /opt/lsde/dataset-sf100/
==29338==
==29338== Invalid read of size 2
==29338== at 0x109398: main (reorg.c:35)
==29338== Address 0x12cb4008 is not stack'd, malloc'd or (recently) free'd
==29338==
==29338==
==29338== Process terminating with default action of signal 11 (SIGSEGV)
==29338== Access not within mapped region at address 0x12CB4008
==29338== at 0x109398: main (reorg.c:35)
==29338== If you believe this happened as a result of a stack
==29338== overflow in your program's main thread (unlikely but
==29338== possible), you can try to increase the size of the
==29338== main thread stack using the --main-stacksize= flag.
==29338== The main thread stack size used in this run was 8388608.
==29338==
==29338== HEAP SUMMARY:
==29338== in use at exit: 15,280 bytes in 10 blocks
==29338== total heap usage: 10 allocs, 0 frees, 15,280 bytes allocated
==29338==
==29338== LEAK SUMMARY:
==29338== definitely lost: 5,120 bytes in 5 blocks
==29338== indirectly lost: 0 bytes in 0 blocks
==29338== possibly lost: 0 bytes in 0 blocks
==29338== still reachable: 10,160 bytes in 5 blocks
==29338== suppressed: 0 bytes in 0 blocks
==29338== Rerun with --leak-check=full to see details of leaked memory
==29338==
==29338== For lists of detected and suppressed errors, rerun with: -s
==29338== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
Segmentation fault (core dumped)
This is the code of the reorg.c program.
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include "utils.h"
Person *person_map;
unsigned int *knows_map;
unsigned short *interest_map;
unsigned long person_num = 0;
int main(int argc, char *argv[]) {
unsigned long file_length;
interest_map = (unsigned short *) mmapr(makepath(argv[1], "interest", "bin"), &file_length);
printf("amin1");
knows_map = (unsigned int *) mmapr(makepath(argv[1], "knows", "bin"), &file_length);
printf("amin2");
person_map = (Person *) mmapr(makepath(argv[1], "person", "bin"), &file_length);
printf("amin3");
knows_map = (unsigned int *) mmapr(makepath(argv[1], "knows", "bin"), &file_length);
printf("knows");
person_map = (Person *) mmapr(makepath(argv[1], "person", "bin"), &file_length);
printf("person");
person_num = file_length/sizeof(person_map);
int counter=0;
FILE* fp_knows2 = fopen(makepath(argv[1], "knows2", "bin"), (char*) "w");
FILE* fp_person2 = fopen(makepath(argv[1], "person2", "bin"), (char*) "w");
long knows2_bytesize;
int *knows2_map;
int *person2_map;
long person2_bytesize;
for(long i=0; i<person_num; i++) {
for(long j = 0; j < person_map[i].knows_n; j++) {
int friend = knows_map[person_map[i].knows_first+j]; // person in my knows-list
if (person_map[friend].location == person_map[i].location) {
counter++;
fwrite(&friend, 1,sizeof(int), fp_knows2);
}
}
if(counter > 0){
fwrite(&person_map[i], 1, sizeof(int), fp_person2);
}
counter=0;
}
fclose(fp_knows2);
fclose(fp_person2);
person2_map = (int*) mmapr(makepath(argv[1], "person2","bin"), &person2_bytesize);
knows2_map = (int*) mmapr(makepath(argv[1], "knows2","bin"), &knows2_bytesize);
return 0;
}
And this is the code of the utils.h program that am including in:
#define REPORTING_N 1000000
#define LINEBUFLEN 1024
typedef unsigned long byteoffset;
typedef unsigned int entrycount;
typedef struct {
unsigned long person_id;
unsigned short birthday;
unsigned short location;
unsigned long knows_first;
unsigned short knows_n;
unsigned long interests_first;
unsigned short interest_n;
} Person;
void parse_csv(char* fname, void (*line_handler)(unsigned char nfields, char** fieldvals)) {
long nlines = 0;
FILE* stream = fopen(fname, "r");
if (stream == NULL) {
fprintf(stderr, "Can't read file at %s\n", fname);
exit(-1);
}
char line[LINEBUFLEN];
char* tokens[10];
unsigned int col, idx;
tokens[0] = line;
while (fgets(line, LINEBUFLEN, stream)) {
col = 0;
// parse the csv line into array of strings
for (idx=0; idx<LINEBUFLEN; idx++) {
if (line[idx] == '|' || line[idx] == '\n') {
line[idx] = '\0';
col++;
tokens[col] = &line[idx+1];
} // lookahead to find end of line
if (line[idx+1] == '\0') {
break;
}
}
(*line_handler)(col, tokens);
nlines++;
if (nlines % REPORTING_N == 0) {
printf("%s: read %lu lines\n", fname, nlines);
}
}
fclose(stream);
}
FILE* open_binout(char* filename) {
FILE* outfile;
outfile = fopen(filename, "wb");
if (outfile == NULL) {
fprintf(stderr, "Could not open %s for writing\n", filename);
exit(-1);
}
return outfile;
}
unsigned short birthday_to_short(char* date) {
unsigned short bdaysht;
char dmbuf[3];
dmbuf[2] = '\0';
dmbuf[0] = *(date + 5);
dmbuf[1] = *(date + 6);
bdaysht = atoi(dmbuf) * 100;
dmbuf[0] = *(date + 8);
dmbuf[1] = *(date + 9);
bdaysht += atoi(dmbuf);
return bdaysht;
}
void* mmapr(char* filename, byteoffset *filelen) {
int fd;
struct stat sbuf;
void *mapaddr;
if ((fd = open(filename, O_RDONLY)) == -1) {
fprintf(stderr, "failed to open %s\n", filename);
exit(1);
}
if (stat(filename, &sbuf) == -1) {
fprintf(stderr, "failed to stat %s\n", filename);
exit(1);
}
mapaddr = mmap(0, sbuf.st_size, PROT_READ, MAP_SHARED, fd, 0);
if (mapaddr == MAP_FAILED) {
fprintf(stderr, "failed to mmap %s\n", filename);
exit(1);
}
*filelen = sbuf.st_size;
return mapaddr;
}
char* makepath(char* dir, const char* file, const char* ext) {
char* out = (char*) malloc(1024), *sep = (char*) "";
if (strlen(dir) && dir[strlen(dir)-1] != '/') sep = (char*) "/";
sprintf(out, "%s%s%s.%s", dir, sep, file, ext);
return out;
}