shaba/systemd
1
0
Fork 0
mirror of https://github.com/systemd/systemd.git synced 2025-03-11 20:58:27 +03:00
Code

process-util: introduce namespace_get_leader helper

Browse Source 
For a given PID and namespace type, this helper function gives the PID
of the leader of the namespace containing the given PID. Use this in
systemd-coredump instead of using the existing get_mount_namespace_leader.

This helper will be used again in a later commit.
This commit is contained in:
Nick Rosbrook 2023-09-08 17:03:56 -04:00
parent 9764bca98e
commit ade39d9ab8
3 changed files with 31 additions and 51 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
src/basic/process-util.c
View File

@ -318,6 +318,33 @@ int container_get_leader(const char *machine, pid_t *pid) {
return 0;
}
int namespace_get_leader(pid_t pid, NamespaceType type, pid_t *ret) {
int r;
assert(ret);
for (;;) {
pid_t ppid;
r = get_process_ppid(pid, &ppid);
if (r < 0)
return r;
r = in_same_namespace(pid, ppid, type);
if (r < 0)
return r;
if (r == 0) {
/* If the parent and the child are not in the same
* namespace, then the child is the leader we are
* looking for. */
*ret = pid;
return 0;
}
pid = ppid;
}
}
int is_kernel_thread(pid_t pid) {
_cleanup_free_ char *line = NULL;
unsigned long long flags;

3
src/basic/process-util.h
View File

@ -14,6 +14,7 @@
#include "alloc-util.h"
#include "format-util.h"
#include "macro.h"
#include "namespace-util.h"
#include "time-util.h"
#define procfs_file_alloca(pid, field) \
@ -53,6 +54,8 @@ int get_process_umask(pid_t pid, mode_t *ret);
int container_get_leader(const char *machine, pid_t *pid);
int namespace_get_leader(pid_t pid, NamespaceType type, pid_t *ret);
int wait_for_terminate(pid_t pid, siginfo_t *status);
typedef enum WaitFlags {

52
src/coredump/coredump.c
View File

@ -713,56 +713,6 @@ static int compose_open_fds(pid_t pid, char **ret) {
return memstream_finalize(&m, ret, NULL);
}
static int get_process_ns(pid_t pid, const char *namespace, ino_t *ns) {
const char *p;
struct stat stbuf;
_cleanup_close_ int proc_ns_dir_fd = -EBADF;
p = procfs_file_alloca(pid, "ns");
proc_ns_dir_fd = open(p, O_DIRECTORY | O_CLOEXEC | O_RDONLY);
if (proc_ns_dir_fd < 0)
return -errno;
if (fstatat(proc_ns_dir_fd, namespace, &stbuf, /* flags */0) < 0)
return -errno;
*ns = stbuf.st_ino;
return 0;
}
static int get_mount_namespace_leader(pid_t pid, pid_t *ret) {
ino_t proc_mntns;
int r;
r = get_process_ns(pid, "mnt", &proc_mntns);
if (r < 0)
return r;
for (;;) {
ino_t parent_mntns;
pid_t ppid;
r = get_process_ppid(pid, &ppid);
if (r == -EADDRNOTAVAIL) /* Reached the top (i.e. typically PID 1, but could also be a process
* whose parent is not in our pidns) */
return -ENOENT;
if (r < 0)
return r;
r = get_process_ns(ppid, "mnt", &parent_mntns);
if (r < 0)
return r;
if (proc_mntns != parent_mntns) {
*ret = ppid;
return 0;
}
pid = ppid;
}
}
/* Returns 1 if the parent was found.
* Returns 0 if there is not a process we can call the pid's
* container parent (the pid's process isn't 'containerized').
@ -788,7 +738,7 @@ static int get_process_container_parent_cmdline(pid_t pid, char** cmdline) {
return 0;
}
r = get_mount_namespace_leader(pid, &container_pid);
r = namespace_get_leader(pid, NAMESPACE_MOUNT, &container_pid);
if (r < 0)
return r;