SymbX/systemd
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge pull request #34053 from YHNdnzj/follow-ups

Browse Source 
Two follow-ups for recent PRs
This commit is contained in:
Yu Watanabe
2024-08-22 04:34:11 +09:00
committed by GitHub
parent 0452779b00 e06c5be29a
commit 2ddf5bdece
10 changed files with 46 additions and 127 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/basic/process-util.c
+37 -35
View File
@@ -2059,10 +2059,14 @@ int posix_spawn_wrapper(
_unused_ _cleanup_(posix_spawnattr_destroyp) posix_spawnattr_t *attr_destructor = &attr;
#if HAVE_PIDFD_SPAWN
static bool setcgroup_supported = true;
static enum {
CLONE_ONLY_PID,
CLONE_CAN_PIDFD, /* 5.2 */
CLONE_CAN_CGROUP, /* 5.7 */
} clone_support = CLONE_CAN_CGROUP;
_cleanup_close_ int cgroup_fd = -EBADF;
if (cgroup && setcgroup_supported) {
if (cgroup && clone_support >= CLONE_CAN_CGROUP) {
_cleanup_free_ char *resolved_cgroup = NULL;
r = cg_get_path_and_check(
@@ -2093,45 +2097,43 @@ int posix_spawn_wrapper(
return -r;
#if HAVE_PIDFD_SPAWN
_cleanup_close_ int pidfd = -EBADF;
if (clone_support >= CLONE_CAN_PIDFD) {
_cleanup_close_ int pidfd = -EBADF;
r = pidfd_spawn(&pidfd, path, NULL, &attr, argv, envp);
if (r == E2BIG && FLAGS_SET(flags, POSIX_SPAWN_SETCGROUP)) {
/* Some kernels (e.g., 5.4) support clone3 but they do not support CLONE_INTO_CGROUP.
* Retry pidfd_spawn() after removing the flag. */
flags &= ~POSIX_SPAWN_SETCGROUP;
r = posix_spawnattr_setflags(&attr, flags);
if (r != 0)
return -r;
r = pidfd_spawn(&pidfd, path, NULL, &attr, argv, envp);
/* if pidfd_spawn was successful after removing SPAWN_CGROUP,
* mark setcgroup_supported as false so that we do not retry every time */
if (r == 0)
setcgroup_supported = false;
}
if (r == 0) {
r = pidref_set_pidfd_consume(ret_pidref, TAKE_FD(pidfd));
if (r < 0)
return r;
return FLAGS_SET(flags, POSIX_SPAWN_SETCGROUP);
}
if (ERRNO_IS_NOT_SUPPORTED(r)) {
/* clone3() could also return EOPNOTSUPP if the target cgroup is in threaded mode. */
if (cgroup && cg_is_threaded(cgroup) > 0)
if (ERRNO_IS_NOT_SUPPORTED(r) && FLAGS_SET(flags, POSIX_SPAWN_SETCGROUP) &&
cg_is_threaded(cgroup) > 0) /* clone3() could also return EOPNOTSUPP if the target cgroup is in threaded mode. */
return -EUCLEAN;
if ((ERRNO_IS_NOT_SUPPORTED(r) || ERRNO_IS_PRIVILEGE(r) || r == E2BIG) &&
FLAGS_SET(flags, POSIX_SPAWN_SETCGROUP)) {
/* Compiled on a newer host, or seccomp&friends blocking clone3()? Fallback, but
* need to disable POSIX_SPAWN_SETCGROUP, which is what redirects to clone3().
* Note that we might get E2BIG here since some kernels (e.g. 5.4) support clone3()
* but not CLONE_INTO_CGROUP. */
/* clone3() not available? */
} else if (!ERRNO_IS_PRIVILEGE(r))
return -r;
/* CLONE_INTO_CGROUP definitely won't work, hence remember the fact so that we don't
* retry every time. */
assert(clone_support >= CLONE_CAN_CGROUP);
clone_support = CLONE_CAN_PIDFD;
/* Compiled on a newer host, or seccomp&friends blocking clone3()? Fallback, but need to change the
* flags to remove the cgroup one, which is what redirects to clone3() */
if (FLAGS_SET(flags, POSIX_SPAWN_SETCGROUP)) {
flags &= ~POSIX_SPAWN_SETCGROUP;
r = posix_spawnattr_setflags(&attr, flags);
if (r != 0)
flags &= ~POSIX_SPAWN_SETCGROUP;
r = posix_spawnattr_setflags(&attr, flags);
if (r != 0)
return -r;
r = pidfd_spawn(&pidfd, path, NULL, &attr, argv, envp);
}
if (r == 0) {
r = pidref_set_pidfd_consume(ret_pidref, TAKE_FD(pidfd));
if (r < 0)
return r;
return FLAGS_SET(flags, POSIX_SPAWN_SETCGROUP);
}
if (!ERRNO_IS_NOT_SUPPORTED(r) && !ERRNO_IS_PRIVILEGE(r))
return -r;
clone_support = CLONE_ONLY_PID; /* No CLONE_PIDFD either? */
}
#endif