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/* Test that /proc/{self,$PID}/auxv can be opened and read simultaneously
using two different file descriptors. */
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/auxv.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
/* Reads one auxv_t entry from the input file. */
int read_entry(int fi, auxv_t *out)
{
size_t toread = sizeof(*out);
char *ptr = (char*)out;
while (toread) {
ssize_t r;
r = read(fi, ptr, toread);
if (r == 0) {
fprintf(stderr, "unexpected EOF\n");
return 1;
}
if (r == -1) {
perror("read");
return 1;
}
ptr += r;
toread -= r;
assert(toread >= 0);
}
return 0;
}
int main(void)
{
auxv_t vector[2][4];
int fi[2] = {-1, -1};
size_t i;
int res = 1;
/* Open the first input file. */
if ((fi[0] = open("/proc/self/auxv", O_RDONLY)) == -1) {
perror("open");
goto out;
}
/* Read the first two entries from the first file. */
for (i = 0; i < 2; i++)
if (read_entry(fi[0], &vector[0][i]))
goto out;
/* Open the second input file. */
if ((fi[1] = open("/proc/self/auxv", O_RDONLY)) == -1) {
perror("open");
goto out;
}
/* Read the first two entries from the first file. */
for (i = 2; i < 4; i++)
if (read_entry(fi[0], &vector[0][i]))
goto out;
/* Read the first four entries from the second file. */
for (i = 0; i < 4; i++)
if (read_entry(fi[1], &vector[1][i]))
goto out;
/* Compare read vectors. */
if (memcmp(vector[0], vector[1], 4 * sizeof(vector[0][0]))) {
fprintf(stderr, "vectors differ\n");
goto out;
}
res = 0;
out:
for (i = 0; i < 2; i++)
if (fi[i] >= 0)
close(fi[i]);
return res;
}
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