-/* SPDX-License-Identifier: (GPL-2.0-only or LGPL-2.1-only)
- *
- * lttng-context-cgroup-ns.c
- *
- * LTTng cgroup namespace context.
- *
- * Copyright (C) 2009-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- * 2019 Michael Jeanson <mjeanson@efficios.com>
- *
- */
-
-#include <linux/module.h>
-#include <linux/slab.h>
-#include <linux/sched.h>
-#include <linux/cgroup.h>
-#include <lttng-events.h>
-#include <wrapper/ringbuffer/frontend_types.h>
-#include <wrapper/vmalloc.h>
-#include <wrapper/namespace.h>
-#include <lttng-tracer.h>
-
-#if defined(CONFIG_CGROUPS) && \
- ((LINUX_VERSION_CODE >= KERNEL_VERSION(4,6,0)) || \
- LTTNG_UBUNTU_KERNEL_RANGE(4,4,0,0, 4,5,0,0))
-
-static
-size_t cgroup_ns_get_size(size_t offset)
-{
- size_t size = 0;
-
- size += lib_ring_buffer_align(offset, lttng_alignof(unsigned int));
- size += sizeof(unsigned int);
- return size;
-}
-
-static
-void cgroup_ns_record(struct lttng_ctx_field *field,
- struct lib_ring_buffer_ctx *ctx,
- struct lttng_channel *chan)
-{
- unsigned int cgroup_ns_inum = 0;
-
- /*
- * nsproxy can be NULL when scheduled out of exit.
- *
- * As documented in 'linux/nsproxy.h' namespaces access rules, no
- * precautions should be taken when accessing the current task's
- * namespaces, just dereference the pointers.
- */
- if (current->nsproxy)
- cgroup_ns_inum = current->nsproxy->cgroup_ns->lttng_ns_inum;
-
- lib_ring_buffer_align_ctx(ctx, lttng_alignof(cgroup_ns_inum));
- chan->ops->event_write(ctx, &cgroup_ns_inum, sizeof(cgroup_ns_inum));
-}
-
-static
-void cgroup_ns_get_value(struct lttng_ctx_field *field,
- struct lttng_probe_ctx *lttng_probe_ctx,
- union lttng_ctx_value *value)
-{
- unsigned int cgroup_ns_inum = 0;
-
- /*
- * nsproxy can be NULL when scheduled out of exit.
- *
- * As documented in 'linux/nsproxy.h' namespaces access rules, no
- * precautions should be taken when accessing the current task's
- * namespaces, just dereference the pointers.
- */
- if (current->nsproxy)
- cgroup_ns_inum = current->nsproxy->cgroup_ns->lttng_ns_inum;
-
- value->s64 = cgroup_ns_inum;
-}
-
-int lttng_add_cgroup_ns_to_ctx(struct lttng_ctx **ctx)
-{
- struct lttng_ctx_field *field;
-
- field = lttng_append_context(ctx);
- if (!field)
- return -ENOMEM;
- if (lttng_find_context(*ctx, "cgroup_ns")) {
- lttng_remove_context_field(ctx, field);
- return -EEXIST;
- }
- field->event_field.name = "cgroup_ns";
- field->event_field.type.atype = atype_integer;
- field->event_field.type.u.integer.size = sizeof(unsigned int) * CHAR_BIT;
- field->event_field.type.u.integer.alignment = lttng_alignof(unsigned int) * CHAR_BIT;
- field->event_field.type.u.integer.signedness = lttng_is_signed_type(unsigned int);
- field->event_field.type.u.integer.reverse_byte_order = 0;
- field->event_field.type.u.integer.base = 10;
- field->event_field.type.u.integer.encoding = lttng_encode_none;
- field->get_size = cgroup_ns_get_size;
- field->record = cgroup_ns_record;
- field->get_value = cgroup_ns_get_value;
- lttng_context_update(*ctx);
- wrapper_vmalloc_sync_all();
- return 0;
-}
-EXPORT_SYMBOL_GPL(lttng_add_cgroup_ns_to_ctx);
-
-#endif