src/bin/lttng-sessiond/ust-registry.cpp

   1 /*
   2  * Copyright (C) 2013 David Goulet <dgoulet@efficios.com>
   3  *
   4  * SPDX-License-Identifier: GPL-2.0-only
   5  *
   6  */
   7
   8 #define _LGPL_SOURCE
   9
  10 #include "ust-registry.hpp"
  11 #include "lttng-sessiond.hpp"
  12 #include "notification-thread-commands.hpp"
  13 #include "ust-app.hpp"
  14 #include "ust-registry-session-pid.hpp"
  15 #include "ust-registry-session-uid.hpp"
  16 #include "utils.hpp"
  17
  18 #include <common/common.hpp>
  19 #include <common/exception.hpp>
  20 #include <common/format.hpp>
  21 #include <common/hashtable/utils.hpp>
  22 #include <common/make-unique-wrapper.hpp>
  23 #include <lttng/lttng.h>
  24 #include <lttng/trace-format-descriptor-internal.hpp>
  25
  26 #include <inttypes.h>
  27
  28 namespace ls = lttng::sessiond;
  29 namespace lst = lttng::sessiond::trace;
  30 namespace lsu = lttng::sessiond::ust;
  31
  32 /*
  33  * Destroy event function call of the call RCU.
  34  */
  35 static void ust_registry_event_destroy_rcu(struct rcu_head *head)
  36 {
  37         DIAGNOSTIC_PUSH
  38         DIAGNOSTIC_IGNORE_INVALID_OFFSETOF
  39         lttng::sessiond::ust::registry_event *event =
  40                         lttng::utils::container_of(head, &lttng::sessiond::ust::registry_event::_head);
  41         DIAGNOSTIC_POP
  42
  43         lttng::sessiond::ust::registry_event_destroy(event);
  44 }
  45
  46 /*
  47  * For a given event in a registry, delete the entry and destroy the event.
  48  * This MUST be called within a RCU read side lock section.
  49  */
  50 void ust_registry_channel_destroy_event(lsu::registry_channel *chan,
  51                 lttng::sessiond::ust::registry_event *event)
  52 {
  53         int ret;
  54         struct lttng_ht_iter iter;
  55
  56         LTTNG_ASSERT(chan);
  57         LTTNG_ASSERT(event);
  58         ASSERT_RCU_READ_LOCKED();
  59
  60         /* Delete the node first. */
  61         iter.iter.node = &event->_node;
  62         ret = lttng_ht_del(chan->_events, &iter);
  63         LTTNG_ASSERT(!ret);
  64
  65         call_rcu(&event->_head, ust_registry_event_destroy_rcu);
  66
  67         return;
  68 }
  69
  70 lsu::registry_session *ust_registry_session_per_uid_create(const lttng::sessiond::trace::abi& abi,
  71                 uint32_t major,
  72                 uint32_t minor,
  73                 const char *root_shm_path,
  74                 const char *shm_path,
  75                 uid_t euid,
  76                 gid_t egid,
  77                 uint64_t tracing_id,
  78                 uid_t tracing_uid,
  79                 const lttng::trace_format_descriptor& trace_format)
  80 {
  81         try {
  82                 return new lsu::registry_session_per_uid(abi, major, minor, root_shm_path, shm_path,
  83                                 euid, egid, tracing_id, tracing_uid, trace_format);
  84         } catch (const std::exception& ex) {
  85                 ERR("Failed to create per-uid registry session: %s", ex.what());
  86                 return nullptr;
  87         }
  88 }
  89
  90 lsu::registry_session *ust_registry_session_per_pid_create(struct ust_app *app,
  91                 const lttng::sessiond::trace::abi& abi,
  92                 uint32_t major,
  93                 uint32_t minor,
  94                 const char *root_shm_path,
  95                 const char *shm_path,
  96                 uid_t euid,
  97                 gid_t egid,
  98                 uint64_t tracing_id,
  99                 const lttng::trace_format_descriptor& trace_format)
 100 {
 101         try {
 102                 return new lsu::registry_session_per_pid(*app, abi, major, minor, root_shm_path,
 103                                 shm_path, euid, egid, tracing_id, trace_format);
 104         } catch (const std::exception& ex) {
 105                 ERR("Failed to create per-pid registry session: %s", ex.what());
 106                 return nullptr;
 107         }
 108 }
 109
 110 /*
 111  * Destroy session registry. This does NOT free the given pointer since it
 112  * might get passed as a reference. The registry lock should NOT be acquired.
 113  */
 114 void ust_registry_session_destroy(lsu::registry_session *reg)
 115 {
 116         delete reg;
 117 }
 118
 119 lsu::registry_enum::registry_enum(
 120                 std::string in_name, enum lst::integer_type::signedness in_signedness) :
 121         name{std::move(in_name)}, signedness{in_signedness}
 122 {
 123         cds_lfht_node_init(&this->node.node);
 124         this->rcu_head = {};
 125 }
 126
 127 bool lsu::operator==(const lsu::registry_enum& lhs, const lsu::registry_enum& rhs) noexcept
 128 {
 129         if (lhs.signedness != rhs.signedness) {
 130                 return false;
 131         }
 132
 133         return lhs._is_equal(rhs);
 134 }