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Subjectclose-exec flag not working in 2.6.9?
As far as I can tell, close-exec is not working correctly in 2.6.9
or 2.6.10-1.741_FC3smp.

The attached program generates a file /tmp/cl_foo.output
which has this data:


[greear@grok ~]$ more /tmp/cl_foo.output
total 5
lrwx------ 1 greear greear 64 Jan 30 23:49 0 -> /dev/pts/3
l-wx------ 1 greear greear 64 Jan 30 23:49 1 -> /tmp/cl_foo.output
l-wx------ 1 greear greear 64 Jan 30 23:49 2 -> /tmp/cl_foo.output
lr-x------ 1 greear greear 64 Jan 30 23:49 3 -> /etc/passwd
lr-x------ 1 greear greear 64 Jan 30 23:49 4 -> /proc/7020/fd


I would not expect to see the /etc/passwd entry since I marked
it close-exec in the parent process before forking and running
the system() command.

Am I confused about things, or is this a real bug?

Thanks,
Ben

--
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc http://www.candelatech.com



#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <fstream>
#include <iostream>
#include <stdlib.h>
#include <errno.h>

using namespace std;

void close_exec(int s) {
int flags;

flags = fcntl(s, F_GETFL);
flags |= (FD_CLOEXEC);
if (fcntl(s, F_SETFL, flags) < 0) {
cerr << "ERROR: fcntl, executing close_exec: " << strerror(errno)
<< endl;
}
}//close_exec

int main() {
ofstream script("/tmp/cl_foo.bash");
script << "#!/bin/bash\nls -l /proc/self/fd > /tmp/cl_foo.output 2>&1\n";
script.close();

if (chmod("/tmp/cl_foo.bash",
S_IRUSR|S_IWUSR|S_IXUSR|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH) < 0) {
cerr << "ERROR: Failed to chmod /tmp/cl_foo.bash, error: "
<< strerror(errno) << endl;
exit(7);
}

int fd = open("/etc/passwd", O_RDONLY);
if (fd < 0) {
cerr << "ERROR: Failed to open /etc/passwd: " << strerror(errno) << endl;
}
else {
close_exec(fd);
}

int rv = fork();
if (rv < 0) {
cerr << "ERROR from fork: " << strerror(errno) << endl;
}
else if (rv == 0) {
// Child
system("/tmp/cl_foo.bash");
exit(7);
}
else {
// parent, done
sleep(5);
}
return 0;
}//main
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