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authorZbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>2016-08-02 13:38:00 -0400
committerGitHub <noreply@github.com>2016-08-02 13:38:00 -0400
commit87edd2b116c107b54c844e88de06be62ab55e29d (patch)
tree7ae20597926f538cd415f601181e23a021b0fe52 /src
parent125918635516491dc8ec1d803c38b9225b3599b9 (diff)
parent7ed03ce69ede34b03107702efd6efb100e9a23bc (diff)
Merge pull request #3858 from jfilak/coredump-containers-v2
Coredump: save information useful for debuging crashes in containers - v2
Diffstat (limited to 'src')
-rw-r--r--src/coredump/coredump.c111
1 files changed, 108 insertions, 3 deletions
diff --git a/src/coredump/coredump.c b/src/coredump/coredump.c
index dcc09fcc6d..e3d17c864d 100644
--- a/src/coredump/coredump.c
+++ b/src/coredump/coredump.c
@@ -558,6 +558,89 @@ static int compose_open_fds(pid_t pid, char **open_fds) {
return 0;
}
+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;
+
+ 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 *container_pid) {
+ pid_t cpid = pid, ppid = 0;
+ ino_t proc_mntns;
+ int r = 0;
+
+ r = get_process_ns(pid, "mnt", &proc_mntns);
+ if (r < 0)
+ return r;
+
+ while (1) {
+ ino_t parent_mntns;
+
+ r = get_process_ppid(cpid, &ppid);
+ if (r < 0)
+ return r;
+
+ r = get_process_ns(ppid, "mnt", &parent_mntns);
+ if (r < 0)
+ return r;
+
+ if (proc_mntns != parent_mntns)
+ break;
+
+ if (ppid == 1)
+ return -ENOENT;
+
+ cpid = ppid;
+ }
+
+ *container_pid = ppid;
+ return 0;
+}
+
+/* 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').
+ * Returns a negative number on errors.
+ */
+static int get_process_container_parent_cmdline(pid_t pid, char** cmdline) {
+ int r = 0;
+ pid_t container_pid;
+ const char *proc_root_path;
+ struct stat root_stat, proc_root_stat;
+
+ /* To compare inodes of / and /proc/[pid]/root */
+ if (stat("/", &root_stat) < 0)
+ return -errno;
+
+ proc_root_path = procfs_file_alloca(pid, "root");
+ if (stat(proc_root_path, &proc_root_stat) < 0)
+ return -errno;
+
+ /* The process uses system root. */
+ if (proc_root_stat.st_ino == root_stat.st_ino) {
+ *cmdline = NULL;
+ return 0;
+ }
+
+ r = get_mount_namespace_leader(pid, &container_pid);
+ if (r < 0)
+ return r;
+
+ return get_process_cmdline(container_pid, 0, false, cmdline);
+}
+
static int change_uid_gid(const char *context[]) {
uid_t uid;
gid_t gid;
@@ -933,11 +1016,13 @@ static int process_kernel(int argc, char* argv[]) {
/* The larger ones we allocate on the heap */
_cleanup_free_ char
*core_owner_uid = NULL, *core_open_fds = NULL, *core_proc_status = NULL,
- *core_proc_maps = NULL, *core_proc_limits = NULL, *core_proc_cgroup = NULL, *core_environ = NULL;
+ *core_proc_maps = NULL, *core_proc_limits = NULL, *core_proc_cgroup = NULL, *core_environ = NULL,
+ *core_proc_mountinfo = NULL, *core_container_cmdline = NULL;
_cleanup_free_ char *exe = NULL, *comm = NULL;
const char *context[_CONTEXT_MAX];
- struct iovec iovec[25];
+ bool proc_self_root_is_slash;
+ struct iovec iovec[27];
size_t n_iovec = 0;
uid_t owner_uid;
const char *p;
@@ -1110,6 +1195,15 @@ static int process_kernel(int argc, char* argv[]) {
IOVEC_SET_STRING(iovec[n_iovec++], core_proc_cgroup);
}
+ p = procfs_file_alloca(pid, "mountinfo");
+ if (read_full_file(p, &t, NULL) >=0) {
+ core_proc_mountinfo = strappend("COREDUMP_PROC_MOUNTINFO=", t);
+ free(t);
+
+ if (core_proc_mountinfo)
+ IOVEC_SET_STRING(iovec[n_iovec++], core_proc_mountinfo);
+ }
+
if (get_process_cwd(pid, &t) >= 0) {
core_cwd = strjoina("COREDUMP_CWD=", t);
free(t);
@@ -1119,9 +1213,20 @@ static int process_kernel(int argc, char* argv[]) {
if (get_process_root(pid, &t) >= 0) {
core_root = strjoina("COREDUMP_ROOT=", t);
- free(t);
IOVEC_SET_STRING(iovec[n_iovec++], core_root);
+
+ /* If the process' root is "/", then there is a chance it has
+ * mounted own root and hence being containerized. */
+ proc_self_root_is_slash = strcmp(t, "/") == 0;
+ free(t);
+ if (proc_self_root_is_slash && get_process_container_parent_cmdline(pid, &t) > 0) {
+ core_container_cmdline = strappend("COREDUMP_CONTAINER_CMDLINE=", t);
+ free(t);
+
+ if (core_container_cmdline)
+ IOVEC_SET_STRING(iovec[n_iovec++], core_container_cmdline);
+ }
}
if (get_process_environ(pid, &t) >= 0) {