On Thu, Mar 30, 2017 at 09:06:43PM +0700, Nikolay Marchuk wrote:
[...]
> +int
> +nsfs_ioctl(struct tcb *tcp, unsigned int code, kernel_ulong_t arg)
> +{
> + uid_t uid;
> + switch (code) {
> + case NS_GET_USERNS:
> + case NS_GET_PARENT:
> + return 1 + RVAL_FD + RVAL_DECODED;
> + case NS_GET_NSTYPE:
> + if (entering(tcp))
> + return 0;
> + if (!syserror(tcp)) {
> + const char *outstr;
> + outstr = xlookup(setns_types, tcp->u_rval);
> + if (outstr) {
> + tcp->auxstr = outstr;
> + return 1 + RVAL_STR;
> + }
> + }
> + return 1;
> + case NS_GET_OWNER_UID:
> + if (entering(tcp))
> + return 0;
> + tprints(", ");
> + if (!umove_or_printaddr(tcp, arg, &uid)) {
> + printuid("[", uid);
> + tprints("]");
> + }
printuid takes an unsigned int as uid and other parsers except those
defined in uid.c do not use uid_t. As the libc's idea of uid_t may differ
from kernel's, let's use unsigned int so far.
[...]
> +#include "tests.h"
> +
> +#include <fcntl.h>
> +#include <linux/ioctl.h>
> +#include <sched.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <sys/ioctl.h>
> +#include <sys/wait.h>
> +#include <unistd.h>
Please include linux/ headers after libc headers unless necessary.
> +#include "nsfs.h"
> +
> +static void
> +test_no_namespace(void)
> +{
> + ioctl(-1, NS_GET_USERNS);
> + printf("ioctl(-1, NS_GET_USERNS) = -1 EBADF (%m)\n");
> + ioctl(-1, NS_GET_PARENT);
> + printf("ioctl(-1, NS_GET_PARENT) = -1 EBADF (%m)\n");
> + ioctl(-1, NS_GET_NSTYPE);
> + printf("ioctl(-1, NS_GET_NSTYPE) = -1 EBADF (%m)\n");
> + ioctl(-1, NS_GET_OWNER_UID, NULL);
> + printf("ioctl(-1, NS_GET_OWNER_UID, NULL) = -1 EBADF (%m)\n");
> +}
> +
> +static void
> +test_clone(pid_t pid)
> +{
> + int ns_fd, userns_fd, parent_ns_fd, nstype, rc;
> + /* Path length with terminator is less then 22 in any case. */
> + char path[22];
> + TAIL_ALLOC_OBJECT_CONST_PTR(uid_t, uid);
> +
> + snprintf(path, sizeof(path), "/proc/%d/ns/user", pid);
Why 22? Wouldn't it be better to use a sizeof based approach,
e.g. like in implementation of getfdproto()?
> + ns_fd = open(path, O_RDONLY);
> + if (ns_fd == -1)
> + perror_msg_and_skip("open: %s", path);
> +
> + userns_fd = ioctl(ns_fd, NS_GET_USERNS);
> + printf("ioctl(%d, NS_GET_USERNS) = %s\n", ns_fd, sprintrc(userns_fd));
> +
> + parent_ns_fd = ioctl(userns_fd, NS_GET_PARENT);
> + printf("ioctl(%d, NS_GET_PARENT) = %s\n", userns_fd,
> + sprintrc(parent_ns_fd));
When wrapping printf statements, please wrap the line after format
string, it's more readable.
> +
> + nstype = ioctl(userns_fd, NS_GET_NSTYPE);
> + if (nstype == -1) {
> + printf("ioctl(%d, NS_GET_NSTYPE) = %s\n", userns_fd,
> sprintrc(nstype));
The line is too long, please wrap.
> + } else {
> + printf("ioctl(%d, NS_GET_NSTYPE) = %d (CLONE_NEWUSER)\n",
> userns_fd,
> + nstype);
The line is still too long, please wrap it earlier.
> + }
> +
> + rc = ioctl(userns_fd, NS_GET_OWNER_UID, uid);
> + if (rc == -1) {
> + printf("ioctl(%d, NS_GET_OWNER_UID, %p) = %s\n", userns_fd, uid,
> + sprintrc(rc));
When wrapping printf statements, please wrap the line after format
string, it's more readable.
> + } else {
> + printf("ioctl(%d, NS_GET_OWNER_UID, [%u]) = %d\n", userns_fd,
> *uid, rc);
The line is too long, please wrap.
> + }
> +}
> +
> +static int
> +child(void *arg)
> +{
> + int *pipefd = (int *)arg;
Please add a space before arg.
> + close(pipefd[1]);
> + /* Wait for EOF from pipe. */
> + while(read(pipefd[0], &pipefd[1], 1) != 0);
> + return 0;
> +}
> +
> +#define STACK_SIZE (1024 * 1024)
> +
> +static void
> +test_user_namespace(void)
> +{
> + char stack[STACK_SIZE];
Do you really need 1M of stack for child()?
> + pid_t pid;
> + int pipefd[2];
> + int rc, status;
> +
> + rc = pipe(pipefd);
> + if (rc == -1)
> + perror_msg_and_skip("pipe");
> +
> + pid = clone(child, stack + STACK_SIZE, (CLONE_NEWUSER | CLONE_UNTRACED
> + | SIGCHLD), pipefd);
> + close(pipefd[0]);
This potentially clobbers errno used by perror_msg_and_skip.
> + if (pid == -1)
> + perror_msg_and_skip("clone");
User namespaces are not universally available,
let's just skip this part of the test.
--
ldv
signature.asc
Description: PGP signature
------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________ Strace-devel mailing list Strace-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/strace-devel
