Add namespaces statedump
authorMichael Jeanson <mjeanson@efficios.com>
Tue, 12 Feb 2019 14:47:34 +0000 (09:47 -0500)
committerMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fri, 18 Oct 2019 15:16:49 +0000 (11:16 -0400)
Add a statedump event for each type of namespace.

The pid ns was already implemented as part of the lttng_statedump_process_state
event, move the "vtid" and "vpid" fields to the new
lttng_statedump_process_pid_ns event.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
instrumentation/events/lttng-module/lttng-statedump.h
lttng-statedump-impl.c
wrapper/namespace.h
wrapper/user_namespace.h

index 14ec12779199d2762c16b2ac4f942ab9e85783a2..5ce94fa68dfc45a3f0b910428b3c5e0739ec88ed 100644 (file)
@@ -7,15 +7,22 @@
 
 #include <probes/lttng-tracepoint-event.h>
 #include <linux/nsproxy.h>
+#include <linux/cgroup.h>
+#include <linux/ipc_namespace.h>
+#include <net/net_namespace.h>
 #include <linux/pid_namespace.h>
+#include <linux/user_namespace.h>
+#include <linux/utsname.h>
 #include <linux/types.h>
 #include <linux/version.h>
+#include <wrapper/namespace.h>
+#include <wrapper/user_namespace.h>
 
-
-#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,19,0))
-#define lttng_proc_inum ns.inum
-#else
-#define lttng_proc_inum proc_inum
+#ifndef LTTNG_MNT_NS_MISSING_HEADER
+# ifndef ONCE_LTTNG_FS_MOUNT_H
+#  define ONCE_LTTNG_FS_MOUNT_H
+#  include <../fs/mount.h>
+# endif
 #endif
 
 LTTNG_TRACEPOINT_EVENT(lttng_statedump_start,
@@ -76,6 +83,120 @@ LTTNG_TRACEPOINT_EVENT(lttng_statedump_process_state,
        )
 )
 
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0))
+LTTNG_TRACEPOINT_EVENT(lttng_statedump_process_cgroup_ns,
+       TP_PROTO(struct lttng_session *session,
+               struct task_struct *p,
+               struct cgroup_namespace *cgroup_ns),
+       TP_ARGS(session, p, cgroup_ns),
+       TP_FIELDS(
+               ctf_integer(pid_t, tid, p->pid)
+               ctf_integer(unsigned int, ns_inum, cgroup_ns ? cgroup_ns->lttng_ns_inum : 0)
+       )
+)
+#endif
+
+LTTNG_TRACEPOINT_EVENT(lttng_statedump_process_ipc_ns,
+       TP_PROTO(struct lttng_session *session,
+               struct task_struct *p,
+               struct ipc_namespace *ipc_ns),
+       TP_ARGS(session, p, ipc_ns),
+       TP_FIELDS(
+               ctf_integer(pid_t, tid, p->pid)
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0))
+               ctf_integer(unsigned int, ns_inum, ipc_ns ? ipc_ns->lttng_ns_inum : 0)
+#endif
+       )
+)
+
+#if !defined(LTTNG_MNT_NS_MISSING_HEADER)
+LTTNG_TRACEPOINT_EVENT(lttng_statedump_process_mnt_ns,
+       TP_PROTO(struct lttng_session *session,
+               struct task_struct *p,
+               struct mnt_namespace *mnt_ns),
+       TP_ARGS(session, p, mnt_ns),
+       TP_FIELDS(
+               ctf_integer(pid_t, tid, p->pid)
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0))
+               ctf_integer(unsigned int, ns_inum, mnt_ns ? mnt_ns->lttng_ns_inum : 0)
+#endif
+       )
+)
+#endif
+
+LTTNG_TRACEPOINT_EVENT(lttng_statedump_process_net_ns,
+       TP_PROTO(struct lttng_session *session,
+               struct task_struct *p,
+               struct net *net_ns),
+       TP_ARGS(session, p, net_ns),
+       TP_FIELDS(
+               ctf_integer(pid_t, tid, p->pid)
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0))
+               ctf_integer(unsigned int, ns_inum, net_ns ? net_ns->lttng_ns_inum : 0)
+#endif
+       )
+)
+
+LTTNG_TRACEPOINT_EVENT(lttng_statedump_process_pid_ns,
+       TP_PROTO(struct lttng_session *session,
+               struct task_struct *p,
+               struct pid_namespace *pid_ns),
+       TP_ARGS(session, p, pid_ns),
+       TP_FIELDS(
+               ctf_integer(pid_t, tid, p->pid)
+               ctf_integer(pid_t, vtid, pid_ns ? task_pid_nr_ns(p, pid_ns) : 0)
+               ctf_integer(pid_t, vpid, pid_ns ? task_tgid_nr_ns(p, pid_ns) : 0)
+               ctf_integer(pid_t, vppid,
+                       ({
+                               struct task_struct *parent;
+                               pid_t ret = 0;
+
+                               if (pid_ns) {
+                                       rcu_read_lock();
+                                       parent = rcu_dereference(p->real_parent);
+                                       ret = task_tgid_nr_ns(parent, pid_ns);
+                                       rcu_read_unlock();
+                               }
+                               ret;
+                       }))
+               ctf_integer(int, ns_level, pid_ns ? pid_ns->level : 0)
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0))
+               ctf_integer(unsigned int, ns_inum, pid_ns ? pid_ns->lttng_ns_inum : 0)
+#endif
+       )
+)
+
+LTTNG_TRACEPOINT_EVENT(lttng_statedump_process_user_ns,
+       TP_PROTO(struct lttng_session *session,
+               struct task_struct *p,
+               struct user_namespace *user_ns),
+       TP_ARGS(session, p, user_ns),
+       TP_FIELDS(
+               ctf_integer(pid_t, tid, p->pid)
+               ctf_integer(uid_t, vuid, user_ns ? lttng_task_vuid(p, user_ns) : 0)
+               ctf_integer(gid_t, vgid, user_ns ? lttng_task_vgid(p, user_ns) : 0)
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,11,0))
+               ctf_integer(int, ns_level, user_ns ? user_ns->level : 0)
+#endif
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0))
+               ctf_integer(unsigned int, ns_inum, user_ns ? user_ns->lttng_ns_inum : 0)
+#endif
+       )
+)
+
+LTTNG_TRACEPOINT_EVENT(lttng_statedump_process_uts_ns,
+       TP_PROTO(struct lttng_session *session,
+               struct task_struct *p,
+               struct uts_namespace *uts_ns),
+       TP_ARGS(session, p, uts_ns),
+       TP_FIELDS(
+               ctf_integer(pid_t, tid, p->pid)
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,8,0))
+               ctf_integer(unsigned int, ns_inum, uts_ns ? uts_ns->lttng_ns_inum : 0)
+#endif
+       )
+)
+
 LTTNG_TRACEPOINT_EVENT(lttng_statedump_file_descriptor,
        TP_PROTO(struct lttng_session *session,
                struct task_struct *p, int fd, const char *filename,
index dc037508c055b7f61b8c758d581bd0178e26552a..a707c775dd683a8b6dff99b53049349ddea43fdf 100644 (file)
@@ -38,6 +38,7 @@
 #include <lttng-tracer.h>
 #include <wrapper/irqdesc.h>
 #include <wrapper/fdtable.h>
+#include <wrapper/namespace.h>
 #include <wrapper/irq.h>
 #include <wrapper/tracepoint.h>
 #include <wrapper/genhd.h>
@@ -61,6 +62,17 @@ DEFINE_TRACE(lttng_statedump_interrupt);
 DEFINE_TRACE(lttng_statedump_file_descriptor);
 DEFINE_TRACE(lttng_statedump_start);
 DEFINE_TRACE(lttng_statedump_process_state);
+DEFINE_TRACE(lttng_statedump_process_pid_ns);
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0))
+DEFINE_TRACE(lttng_statedump_process_cgroup_ns);
+#endif
+DEFINE_TRACE(lttng_statedump_process_ipc_ns);
+#ifndef LTTNG_MNT_NS_MISSING_HEADER
+DEFINE_TRACE(lttng_statedump_process_mnt_ns);
+#endif
+DEFINE_TRACE(lttng_statedump_process_net_ns);
+DEFINE_TRACE(lttng_statedump_process_user_ns);
+DEFINE_TRACE(lttng_statedump_process_uts_ns);
 DEFINE_TRACE(lttng_statedump_network_interface);
 #ifdef LTTNG_HAVE_STATEDUMP_CPU_TOPOLOGY
 DEFINE_TRACE(lttng_statedump_cpu_topology);
@@ -388,6 +400,10 @@ int lttng_list_interrupts(struct lttng_session *session)
 #endif
 
 /*
+ * Statedump the task's namespaces using the proc filesystem inode number as
+ * the unique identifier. The user and pid ns are nested and will be dumped
+ * recursively.
+ *
  * Called with task lock held.
  */
 static
@@ -398,14 +414,64 @@ void lttng_statedump_process_ns(struct lttng_session *session,
                enum lttng_execution_submode submode,
                enum lttng_process_status status)
 {
+       struct nsproxy *proxy;
        struct pid_namespace *pid_ns;
+       struct user_namespace *user_ns;
 
+       /*
+        * The pid and user namespaces are special, they are nested and
+        * accessed with specific functions instead of the nsproxy struct
+        * like the other namespaces.
+        */
        pid_ns = task_active_pid_ns(p);
        do {
                trace_lttng_statedump_process_state(session,
                        p, type, mode, submode, status, pid_ns);
+               trace_lttng_statedump_process_pid_ns(session, p, pid_ns);
                pid_ns = pid_ns->parent;
        } while (pid_ns);
+
+
+       user_ns = task_cred_xxx(p, user_ns);
+       do {
+               trace_lttng_statedump_process_user_ns(session, p, user_ns);
+               user_ns = user_ns->lttng_user_ns_parent;
+       } while (user_ns);
+
+       /*
+        * Back and forth on locking strategy within Linux upstream for nsproxy.
+        * See Linux upstream commit 728dba3a39c66b3d8ac889ddbe38b5b1c264aec3
+        * "namespaces: Use task_lock and not rcu to protect nsproxy"
+        * for details.
+        */
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0) || \
+               LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \
+               LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \
+               LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0))
+       proxy = p->nsproxy;
+#else
+       rcu_read_lock();
+       proxy = task_nsproxy(p);
+#endif
+       if (proxy) {
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0))
+               trace_lttng_statedump_process_cgroup_ns(session, p, proxy->cgroup_ns);
+#endif
+               trace_lttng_statedump_process_ipc_ns(session, p, proxy->ipc_ns);
+#ifndef LTTNG_MNT_NS_MISSING_HEADER
+               trace_lttng_statedump_process_mnt_ns(session, p, proxy->mnt_ns);
+#endif
+               trace_lttng_statedump_process_net_ns(session, p, proxy->net_ns);
+               trace_lttng_statedump_process_uts_ns(session, p, proxy->uts_ns);
+       }
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,17,0) || \
+               LTTNG_UBUNTU_KERNEL_RANGE(3,13,11,36, 3,14,0,0) || \
+               LTTNG_UBUNTU_KERNEL_RANGE(3,16,1,11, 3,17,0,0) || \
+               LTTNG_RHEL_KERNEL_RANGE(3,10,0,229,13,0, 3,11,0,0,0,0))
+       /* (nothing) */
+#else
+       rcu_read_unlock();
+#endif
 }
 
 static
index 36dbf4c0475081812230a361b7e1090678d506bd..0e7833e1f1e8c528d2ae83a121fae564530c0378 100644 (file)
 #define lttng_ns_inum proc_inum
 #endif
 
+#if (LINUX_VERSION_CODE >= KERNEL_VERSION(3,5,0))
+#define lttng_user_ns_parent parent
+#else
+#define lttng_user_ns_parent creator->user_ns
+#endif
+
 #endif /* _LTTNG_WRAPPER_NAMESPACE_H */
index 701f3189b5c97f8e1f006c175e0bbd755d66b052..851674b06759f91c680c320b8290248dd3df0a13 100644 (file)
 #define lttng_current_vxxgid(xxx)                              \
        (from_kgid_munged(current_user_ns(), current_##xxx()))
 
+static inline
+uid_t lttng_task_vuid(struct task_struct *p, struct user_namespace *ns)
+{
+       uid_t uid;
+       kuid_t kuid;
+
+       kuid = task_cred_xxx(p, uid);
+       uid = from_kuid_munged(ns, kuid);
+
+       return uid;
+}
+
+static inline
+gid_t lttng_task_vgid(struct task_struct *p, struct user_namespace *ns)
+{
+       gid_t gid;
+       kgid_t kgid;
+
+       kgid = task_cred_xxx(p, gid);
+       gid = from_kgid_munged(ns, kgid);
+
+       return gid;
+}
+
 #else
 
 #define lttng_current_xxuid(xxx)       (current_##xxx())
 
 #define lttng_current_vxxgid(xxx)                                      \
        (user_ns_map_gid(current_user_ns(), current_cred(), current_##xxx()))
+
+static inline
+uid_t lttng_task_vuid(struct task_struct *p, struct user_namespace *ns)
+{
+       uid_t uid;
+
+       /*
+        * __task_cred requires the RCU readlock be held
+        */
+       rcu_read_lock();
+       uid = user_ns_map_uid(ns, __task_cred(p), __task_cred(p)->uid);
+       rcu_read_unlock();
+
+       return uid;
+}
+
+static inline
+gid_t lttng_task_vgid(struct task_struct *p, struct user_namespace *ns)
+{
+       gid_t gid;
+
+       /*
+        * __task_cred requires the RCU readlock be held
+        */
+       rcu_read_lock();
+       gid = user_ns_map_gid(ns, __task_cred(p), __task_cred(p)->gid);
+       rcu_read_unlock();
+
+       return gid;
+}
+
 #endif
 
 #define lttng_current_uid()    (lttng_current_xxuid(uid))
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