From f9d6cd8bfe9e1183209098bb82542b34d23dc0ed Mon Sep 17 00:00:00 2001 From: Anatoly Burakov Date: Fri, 5 Jul 2019 18:22:44 +0100 Subject: [PATCH] timer: fix resource leak in finalize Currently, whenever timer library is initialized, the memory is leaked because there is no telling when primary or secondary processes get to use the state, and there is no way to initialize/deinitialize timer library state without race conditions [1] because the data itself must live in shared memory. Add a spinlock to the shared mem config to have a way to exclusively initialize/deinitialize the timer library without any races, and implement the synchronization mechanism based on this lock in the timer library. Also, update the API doc. Note that the behavior of the API itself did not change - the requirement to call init in every process was simply not documented explicitly. [1] See the following email thread: https://mails.dpdk.org/archives/dev/2019-May/131498.html Fixes: c0749f7096c7 ("timer: allow management in shared memory") Cc: stable@dpdk.org Signed-off-by: Erik Gabriel Carrillo Signed-off-by: Anatoly Burakov Acked-by: Erik Gabriel Carrillo Reviewed-by: David Marchand --- lib/librte_eal/common/eal_common_mcfg.c | 14 +++++++ lib/librte_eal/common/eal_memcfg.h | 2 + .../common/include/rte_eal_memconfig.h | 22 ++++++++++ lib/librte_eal/rte_eal_version.map | 2 + lib/librte_timer/rte_timer.c | 41 +++++++++++++------ lib/librte_timer/rte_timer.h | 5 ++- 6 files changed, 71 insertions(+), 15 deletions(-) diff --git a/lib/librte_eal/common/eal_common_mcfg.c b/lib/librte_eal/common/eal_common_mcfg.c index 1825d90838..0665494322 100644 --- a/lib/librte_eal/common/eal_common_mcfg.c +++ b/lib/librte_eal/common/eal_common_mcfg.c @@ -147,3 +147,17 @@ rte_mcfg_mempool_write_unlock(void) struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config; rte_rwlock_write_unlock(&mcfg->mplock); } + +void +rte_mcfg_timer_lock(void) +{ + struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config; + rte_spinlock_lock(&mcfg->tlock); +} + +void +rte_mcfg_timer_unlock(void) +{ + struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config; + rte_spinlock_unlock(&mcfg->tlock); +} diff --git a/lib/librte_eal/common/eal_memcfg.h b/lib/librte_eal/common/eal_memcfg.h index 030f903adc..359beb2168 100644 --- a/lib/librte_eal/common/eal_memcfg.h +++ b/lib/librte_eal/common/eal_memcfg.h @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -36,6 +37,7 @@ struct rte_mem_config { rte_rwlock_t mlock; /**< used by memzones for thread safety. */ rte_rwlock_t qlock; /**< used by tailqs for thread safety. */ rte_rwlock_t mplock; /**< used by mempool library for thread safety. */ + rte_spinlock_t tlock; /**< used by timer library for thread safety. */ rte_rwlock_t memory_hotplug_lock; /**< Indicates whether memory hotplug request is in progress. */ diff --git a/lib/librte_eal/common/include/rte_eal_memconfig.h b/lib/librte_eal/common/include/rte_eal_memconfig.h index dc61a6fed7..34b0e44a05 100644 --- a/lib/librte_eal/common/include/rte_eal_memconfig.h +++ b/lib/librte_eal/common/include/rte_eal_memconfig.h @@ -5,6 +5,8 @@ #ifndef _RTE_EAL_MEMCONFIG_H_ #define _RTE_EAL_MEMCONFIG_H_ +#include + /** * @file * @@ -87,6 +89,26 @@ rte_mcfg_mempool_write_lock(void); void rte_mcfg_mempool_write_unlock(void); +/** + * @warning + * @b EXPERIMENTAL: this API may change without prior notice + * + * Lock the internal EAL Timer Library lock for exclusive access. + */ +__rte_experimental +void +rte_mcfg_timer_lock(void); + +/** + * @warning + * @b EXPERIMENTAL: this API may change without prior notice + * + * Unlock the internal EAL Timer Library lock for exclusive access. + */ +__rte_experimental +void +rte_mcfg_timer_unlock(void); + #ifdef __cplusplus } #endif diff --git a/lib/librte_eal/rte_eal_version.map b/lib/librte_eal/rte_eal_version.map index cc4ef04a05..d0ee67dbfd 100644 --- a/lib/librte_eal/rte_eal_version.map +++ b/lib/librte_eal/rte_eal_version.map @@ -405,4 +405,6 @@ EXPERIMENTAL { # added in 19.08 rte_lcore_cpuset; rte_lcore_to_cpu_id; + rte_mcfg_timer_lock; + rte_mcfg_timer_unlock; }; diff --git a/lib/librte_timer/rte_timer.c b/lib/librte_timer/rte_timer.c index eaeafd74fb..71dffd23bf 100644 --- a/lib/librte_timer/rte_timer.c +++ b/lib/librte_timer/rte_timer.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -61,6 +62,8 @@ struct rte_timer_data { }; #define RTE_MAX_DATA_ELS 64 +static const struct rte_memzone *rte_timer_data_mz; +static int *volatile rte_timer_mz_refcnt; static struct rte_timer_data *rte_timer_data_arr; static const uint32_t default_data_id; static uint32_t rte_timer_subsystem_initialized; @@ -157,28 +160,30 @@ rte_timer_subsystem_init_v1905(void) int i, lcore_id; static const char *mz_name = "rte_timer_mz"; const size_t data_arr_size = - RTE_MAX_DATA_ELS * sizeof(*rte_timer_data_arr); + RTE_MAX_DATA_ELS * sizeof(*rte_timer_data_arr); + const size_t mem_size = data_arr_size + sizeof(*rte_timer_mz_refcnt); bool do_full_init = true; if (rte_timer_subsystem_initialized) return -EALREADY; -reserve: - rte_errno = 0; - mz = rte_memzone_reserve_aligned(mz_name, data_arr_size, SOCKET_ID_ANY, - 0, RTE_CACHE_LINE_SIZE); - if (mz == NULL) { - if (rte_errno == EEXIST) { - mz = rte_memzone_lookup(mz_name); - if (mz == NULL) - goto reserve; + rte_mcfg_timer_lock(); - do_full_init = false; - } else + mz = rte_memzone_lookup(mz_name); + if (mz == NULL) { + mz = rte_memzone_reserve_aligned(mz_name, mem_size, + SOCKET_ID_ANY, 0, RTE_CACHE_LINE_SIZE); + if (mz == NULL) { + rte_mcfg_timer_unlock(); return -ENOMEM; - } + } + do_full_init = true; + } else + do_full_init = false; + rte_timer_data_mz = mz; rte_timer_data_arr = mz->addr; + rte_timer_mz_refcnt = (void *)((char *)mz->addr + data_arr_size); if (do_full_init) { for (i = 0; i < RTE_MAX_DATA_ELS; i++) { @@ -195,6 +200,9 @@ reserve: } rte_timer_data_arr[default_data_id].internal_flags |= FL_ALLOCATED; + (*rte_timer_mz_refcnt)++; + + rte_mcfg_timer_unlock(); rte_timer_subsystem_initialized = 1; @@ -210,6 +218,13 @@ rte_timer_subsystem_finalize(void) if (!rte_timer_subsystem_initialized) return; + rte_mcfg_timer_lock(); + + if (--(*rte_timer_mz_refcnt) == 0) + rte_memzone_free(rte_timer_data_mz); + + rte_mcfg_timer_unlock(); + rte_timer_subsystem_initialized = 0; } diff --git a/lib/librte_timer/rte_timer.h b/lib/librte_timer/rte_timer.h index 1b0d5f6a5a..05d287d8f2 100644 --- a/lib/librte_timer/rte_timer.h +++ b/lib/librte_timer/rte_timer.h @@ -172,10 +172,11 @@ int rte_timer_data_dealloc(uint32_t id); * Initializes internal variables (list, locks and so on) for the RTE * timer library. * + * @note + * This function must be called in every process before using the library. + * * @return * - 0: Success - * - -EEXIST: Returned in secondary process when primary process has not - * yet initialized the timer subsystem * - -ENOMEM: Unable to allocate memory needed to initialize timer * subsystem */ -- 2.20.1