1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
|
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <unistd.h>
static int child(int argc, char* argv[])
{
char **newargv = malloc(sizeof(char*) * argc);
if (newargv == NULL)
{
perror("malloc");
return 1;
}
for (int i = 0; i < argc; i++)
{
newargv[i] = argv[i];
}
newargv[argc] = NULL;
execvp(newargv[0], newargv);
perror("execvp");
return 1;
}
int main(int argc, char* argv[]) {
if (argc < 2)
{
printf("Usage: %s [-p LD_PRELOAD] [-l LD_LIBRARY_PATH] <cmd> [cmd args]\n", argv[0]);
printf("\tset LD_PRELOAD to ld_preload and call execvp <cmd> [cmd args]\n");
return 1;
}
int status, child_val;
struct rusage r_usage;
int i = 1;
for (; i < argc; i++)
{
// Overwrite LD_PRELOAD.
if (strncmp(argv[i], "-p", 2) == 0)
{
setenv("LD_PRELOAD", argv[i+1], 1);
i++;
// Overwrite LD_LIBRARY_PATH.
} else if (strncmp(argv[i], "-l", 2) == 0)
{
setenv("LD_LIBRARY_PATH", argv[i+1], 1);
i++;
} else
{
break;
}
}
pid_t child_pid = fork();
if (child_pid == 0)
{
return child(argc - i, &argv[i]);
}
else if (child_pid > 0)
{
/* Collect child */
wait4(child_pid, &status, 0, &r_usage);
printf("child memory usage = %ld\n", r_usage.ru_maxrss);
/* Get child status value */
if (WIFEXITED(status))
{
child_val = WEXITSTATUS(status);
exit(child_val);
}
} else
{
perror("fork");
}
return 0;
}
|
