#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/syscalls.h>
-#include "lttng-events.h"
-#include "wrapper/ringbuffer/frontend_types.h"
-#include "wrapper/vmalloc.h"
-#include "lttng-tracer.h"
+#include <lttng-events.h>
+#include <wrapper/ringbuffer/frontend_types.h>
+#include <wrapper/vmalloc.h>
+#include <lttng-tracer.h>
static
size_t vppid_get_size(size_t offset)
chan->ops->event_write(ctx, &vppid, sizeof(vppid));
}
+static
+void vppid_get_value(struct lttng_ctx_field *field,
+ struct lttng_probe_ctx *lttng_probe_ctx,
+ union lttng_ctx_value *value)
+{
+ struct task_struct *parent;
+ pid_t vppid;
+
+ /*
+ * current nsproxy can be NULL when scheduled out of exit. pid_vnr uses
+ * the current thread nsproxy to perform the lookup.
+ */
+
+ /*
+ * TODO: when we eventually add RCU subsystem instrumentation,
+ * taking the rcu read lock here will trigger RCU tracing
+ * recursively. We should modify the kernel synchronization so
+ * it synchronizes both for RCU and RCU sched, and rely on
+ * rcu_read_lock_sched_notrace.
+ */
+
+ rcu_read_lock();
+ parent = rcu_dereference(current->real_parent);
+ if (!current->nsproxy)
+ vppid = 0;
+ else
+ vppid = task_tgid_vnr(parent);
+ rcu_read_unlock();
+ value->s64 = vppid;
+}
+
int lttng_add_vppid_to_ctx(struct lttng_ctx **ctx)
{
struct lttng_ctx_field *field;
field->event_field.type.u.basic.integer.encoding = lttng_encode_none;
field->get_size = vppid_get_size;
field->record = vppid_record;
+ field->get_value = vppid_get_value;
lttng_context_update(*ctx);
wrapper_vmalloc_sync_all();
return 0;
}
EXPORT_SYMBOL_GPL(lttng_add_vppid_to_ctx);
-
-MODULE_LICENSE("GPL and additional rights");
-MODULE_AUTHOR("Mathieu Desnoyers");
-MODULE_DESCRIPTION("Linux Trace Toolkit vPPID Context");
-MODULE_VERSION(__stringify(LTTNG_MODULES_MAJOR_VERSION) "."
- __stringify(LTTNG_MODULES_MINOR_VERSION) "."
- __stringify(LTTNG_MODULES_PATCHLEVEL_VERSION)
- LTTNG_MODULES_EXTRAVERSION);