Messages in this thread Patch in this message | | | Date | Fri, 24 Nov 2006 17:01:44 -0500 | From | Mathieu Desnoyers <> | Subject | [PATCH 12/16] LTTng 0.6.36 for 2.6.18 : Tracer module |
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LTTng tracer module.
patch12-2.6.18-lttng-core-0.6.36-tracer.diff
Signed-off-by : Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
--BEGIN-- --- /dev/null +++ b/ltt/ltt-tracer.c @@ -0,0 +1,836 @@ +/* + * ltt-tracer.c + * + * (C) Copyright 2005-2006 - + * Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca) + * + * Contains the kernel code for the Linux Trace Toolkit. + * + * Author: + * Mathieu Desnoyers (mathieu.desnoyers@polymtl.ca) + * + * Inspired from LTT : + * Karim Yaghmour (karim@opersys.com) + * Tom Zanussi (zanussi@us.ibm.com) + * Bob Wisniewski (bob@watson.ibm.com) + * And from K42 : + * Bob Wisniewski (bob@watson.ibm.com) + * + * Changelog: + * 22/09/06 Move to the marker/probes mechanism. (Mathieu Desnoyers) + * 19/10/05, Complete lockless mechanism. (Mathieu Desnoyers) + * 27/05/05, Modular redesign and rewrite. (Mathieu Desnoyers) + + * Comments : + * num_active_traces protects the functors. Changing the pointer is an atomic + * operation, but the functions can only be called when in tracing. It is then + * safe to unload a module in which sits a functor when no tracing is active. + * + * filter_control functor is protected by incrementing its module refcount. + * + */ + +#include <linux/config.h> +#include <linux/time.h> +#include <ltt/ltt-tracer.h> +#include <linux/module.h> +#include <linux/string.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/ltt-facilities.h> +#include <linux/rcupdate.h> +#include <linux/sched.h> +#include <linux/bitops.h> +#include <linux/fs.h> +#include <linux/cpu.h> +#include <linux/kref.h> +#include <asm/atomic.h> + +/* Traces list writer locking */ +DECLARE_MUTEX(ltt_traces_sem); + +static struct timer_list ltt_async_wakeup_timer; + +/* Default callbacks for modules */ +int ltt_run_filter_default(void) +{ + return 1; +} + +int ltt_filter_control_default + (enum ltt_filter_control_msg msg, struct ltt_trace_struct *trace) +{ + return 0; +} + +int ltt_statedump_default(struct ltt_trace_struct *trace) +{ + return 0; +} + + + +/* Callbacks for registered modules */ + +int (*ltt_filter_control_functor) + (enum ltt_filter_control_msg msg, struct ltt_trace_struct *trace) = + ltt_filter_control_default; +struct module *ltt_filter_control_owner = NULL; + +/* These function pointers are protected by trace activation check */ + +int (*ltt_run_filter_functor)(void) = ltt_run_filter_default; +struct module *ltt_run_filter_owner = NULL; + +// FIXME : integrate the filter in the logging chain. +// +int (*ltt_statedump_functor)(struct ltt_trace_struct *trace) = + ltt_statedump_default; +struct module *ltt_statedump_owner = NULL; + +/* Module registration methods */ + +int ltt_module_register(enum ltt_module_function name, void *function, + struct module *owner) +{ + int ret = 0; + + switch (name) { + case LTT_FUNCTION_RUN_FILTER: + if (ltt_run_filter_owner != NULL) { + ret = -EEXIST; + goto end; + } + ltt_run_filter_functor = (int (*)(void))function; + ltt_run_filter_owner = owner; + break; + case LTT_FUNCTION_FILTER_CONTROL: + if (ltt_filter_control_owner != NULL) { + ret = -EEXIST; + goto end; + } + ltt_filter_control_functor = + (int (*)(enum ltt_filter_control_msg, + struct ltt_trace_struct *))function; + break; + case LTT_FUNCTION_STATEDUMP: + if (ltt_statedump_owner != NULL) { + ret = -EEXIST; + goto end; + } + ltt_statedump_functor = + (int (*)(struct ltt_trace_struct *))function; + ltt_statedump_owner = owner; + break; + } + +end: + + return ret; +} + + +void ltt_module_unregister(enum ltt_module_function name) +{ + switch (name) { + case LTT_FUNCTION_RUN_FILTER: + ltt_run_filter_functor = ltt_run_filter_default; + ltt_run_filter_owner = NULL; + /* Wait for preempt sections to finish */ + synchronize_sched(); + break; + case LTT_FUNCTION_FILTER_CONTROL: + ltt_filter_control_functor = ltt_filter_control_default; + ltt_filter_control_owner = NULL; + break; + case LTT_FUNCTION_STATEDUMP: + ltt_statedump_functor = ltt_statedump_default; + ltt_statedump_owner = NULL; + break; + } + +} + +EXPORT_SYMBOL_GPL(ltt_module_register); +EXPORT_SYMBOL_GPL(ltt_module_unregister); + +static LIST_HEAD(ltt_transport_list); + +void ltt_transport_register(struct ltt_transport *transport) +{ + down(<t_traces_sem); + list_add_tail(&transport->node, <t_transport_list); + up(<t_traces_sem); +} + +void ltt_transport_unregister(struct ltt_transport *transport) +{ + down(<t_traces_sem); + list_del(&transport->node); + up(<t_traces_sem); +} + +EXPORT_SYMBOL_GPL(ltt_transport_register); +EXPORT_SYMBOL_GPL(ltt_transport_unregister); + + +static inline int is_channel_overwrite(enum ltt_channels chan, + enum trace_mode mode) +{ + switch (mode) { + case LTT_TRACE_NORMAL: + return 0; + case LTT_TRACE_FLIGHT: + switch (chan) { + case LTT_CHANNEL_FACILITIES: + return 0; + default: + return 1; + } + case LTT_TRACE_HYBRID: + switch (chan) { + case LTT_CHANNEL_CPU: + return 1; + default: + return 0; + } + default: + return 0; + } +} + + +void ltt_write_trace_header(struct ltt_trace_struct *trace, + struct ltt_trace_header *header) +{ + header->magic_number = LTT_TRACER_MAGIC_NUMBER; + header->major_version = LTT_TRACER_VERSION_MAJOR; + header->minor_version = LTT_TRACER_VERSION_MINOR; + header->float_word_order = 0; /* Kernel : no floating point */ + header->arch_type = LTT_ARCH_TYPE; + header->arch_size = sizeof(void*); + header->arch_variant = LTT_ARCH_VARIANT; + switch (trace->mode) { + case LTT_TRACE_NORMAL: + header->flight_recorder = 0; + break; + case LTT_TRACE_FLIGHT: + header->flight_recorder = 1; + break; + case LTT_TRACE_HYBRID: + header->flight_recorder = 2; + break; + default: + header->flight_recorder = 0; + } + +#ifdef CONFIG_LTT_HEARTBEAT_EVENT + header->has_heartbeat = 1; +#else + header->has_heartbeat = 0; +#endif //CONFIG_LTT_HEARTBEAT_EVENT + +#ifdef CONFIG_LTT_ALIGNMENT + header->has_alignment = sizeof(void*); +#else + header->has_alignment = 0; +#endif + + header->freq_scale = trace->freq_scale; + header->start_freq = trace->start_freq; + header->start_tsc = trace->start_tsc; + header->start_monotonic = trace->start_monotonic; + header->start_time_sec = trace->start_time.tv_sec; + header->start_time_usec = trace->start_time.tv_usec; +} +EXPORT_SYMBOL_GPL(ltt_write_trace_header); + +static void trace_async_wakeup(struct ltt_trace_struct *trace) +{ + /* Must check each channel for pending read wakeup */ + trace->ops->wakeup_channel(trace->channel.facilities); + trace->ops->wakeup_channel(trace->channel.interrupts); + trace->ops->wakeup_channel(trace->channel.processes); + trace->ops->wakeup_channel(trace->channel.modules); + trace->ops->wakeup_channel(trace->channel.cpu); + trace->ops->wakeup_channel(trace->channel.network); +} + +/* Timer to send async wakeups to the readers */ +static void async_wakeup(unsigned long data) +{ + struct ltt_trace_struct *trace; + preempt_disable(); + list_for_each_entry_rcu(trace, <t_traces.head, list) { + trace_async_wakeup(trace); + } + preempt_enable(); + + del_timer(<t_async_wakeup_timer); + ltt_async_wakeup_timer.expires = jiffies + 1; + add_timer(<t_async_wakeup_timer); +} + + + + +void ltt_wakeup_writers(void *private) +{ + struct ltt_channel_buf_struct *ltt_buf = private; + wake_up_interruptible(<t_buf->write_wait); +} +EXPORT_SYMBOL_GPL(ltt_wakeup_writers); + + +/* _ltt_trace_find : + * find a trace by given name. + * + * Returns a pointer to the trace structure, NULL if not found. */ +static struct ltt_trace_struct *_ltt_trace_find(char *trace_name) +{ + int compare; + struct ltt_trace_struct *trace, *found=NULL; + + list_for_each_entry(trace, <t_traces.head, list) { + compare = strncmp(trace->trace_name, trace_name, NAME_MAX); + + if (compare == 0) { + found = trace; + break; + } + } + + return found; +} + +/* This function must be called with traces semaphore held. */ +static int _ltt_trace_create(char *trace_name, enum trace_mode mode, + struct ltt_trace_struct *new_trace) +{ + int err = EPERM; + + if (_ltt_trace_find(trace_name) != NULL) { + printk(KERN_ERR "LTT : Trace %s already exists\n", trace_name); + err = EEXIST; + goto traces_error; + } + list_add_rcu(&new_trace->list, <t_traces.head); + synchronize_sched(); + /* Everything went fine, finish creation */ + return 0; + + /* Error handling */ +traces_error: + return err; +} + + +void ltt_release_transport(struct kref *kref) +{ + struct ltt_trace_struct *trace = container_of(kref, + struct ltt_trace_struct, ltt_transport_kref); + trace->ops->remove_dirs(trace); +} +EXPORT_SYMBOL_GPL(ltt_release_transport); + + +void ltt_release_trace(struct kref *kref) +{ + struct ltt_trace_struct *trace = container_of(kref, + struct ltt_trace_struct, kref); + kfree(trace); +} +EXPORT_SYMBOL_GPL(ltt_release_trace); + +static inline void prepare_chan_size_num(unsigned *subbuf_size, + unsigned *n_subbufs, unsigned default_size, unsigned default_n_subbufs) +{ + if (*subbuf_size == 0) + *subbuf_size = default_size; + if (*n_subbufs == 0) + *n_subbufs = default_n_subbufs; + *subbuf_size = 1 << get_count_order(*subbuf_size); + *n_subbufs = 1 << get_count_order(*n_subbufs); + + /* Subbuf size and number must both be power of two */ + WARN_ON(hweight32(*subbuf_size) != 1); + WARN_ON(hweight32(*n_subbufs) != 1); +} + +static int ltt_trace_create(char *trace_name, char *trace_type, + enum trace_mode mode, + unsigned subbuf_size_low, unsigned n_subbufs_low, + unsigned subbuf_size_med, unsigned n_subbufs_med, + unsigned subbuf_size_high, unsigned n_subbufs_high) +{ + int err = 0; + struct ltt_trace_struct *new_trace, *trace; + unsigned long flags; + struct ltt_transport *tran, *transport = NULL; + + prepare_chan_size_num(&subbuf_size_low, &n_subbufs_low, + LTT_DEFAULT_SUBBUF_SIZE_LOW, LTT_DEFAULT_N_SUBBUFS_LOW); + + prepare_chan_size_num(&subbuf_size_med, &n_subbufs_med, + LTT_DEFAULT_SUBBUF_SIZE_MED, LTT_DEFAULT_N_SUBBUFS_MED); + + prepare_chan_size_num(&subbuf_size_high, &n_subbufs_high, + LTT_DEFAULT_SUBBUF_SIZE_HIGH, LTT_DEFAULT_N_SUBBUFS_HIGH); + + new_trace = kzalloc(sizeof(struct ltt_trace_struct), GFP_KERNEL); + if (!new_trace) { + printk(KERN_ERR + "LTT : Unable to allocate memory for trace %s\n", + trace_name); + err = ENOMEM; + goto traces_error; + } + + kref_init(&new_trace->kref); + kref_init(&new_trace->ltt_transport_kref); + new_trace->active = 0; + strncpy(new_trace->trace_name, trace_name, NAME_MAX); + new_trace->paused = 0; + new_trace->mode = mode; + new_trace->freq_scale = ltt_freq_scale(); + + down(<t_traces_sem); + list_for_each_entry(tran, <t_transport_list, node) { + if (!strcmp(tran->name, trace_type)) { + transport = tran; + break; + } + } + + if (!transport) { + err = EINVAL; + printk(KERN_ERR "LTT : Transport %s is not present.\n", trace_type); + up(<t_traces_sem); + goto trace_error; + } + + if (!try_module_get(transport->owner)) { + err = ENODEV; + printk(KERN_ERR "LTT : Can't lock transport module.\n"); + up(<t_traces_sem); + goto trace_error; + } + + trace = _ltt_trace_find(trace_name); + if(trace) { + printk(KERN_ERR "LTT : Trace name %s already used.\n", + trace_name); + err = EEXIST; + goto trace_error; + } + + new_trace->transport = transport; + new_trace->ops = &transport->ops; + + err = new_trace->ops->create_dirs(new_trace); + if (err) + goto dirs_error; + + local_irq_save(flags); + new_trace->start_freq = ltt_frequency(); + new_trace->start_tsc = ltt_get_timestamp64(); + do_gettimeofday(&new_trace->start_time); + local_irq_restore(flags); + + /* Always put the facilities channel in non-overwrite mode : + * This is a very low traffic channel and it can't afford to have its + * data overwritten : this data (facilities info) is necessary to be + * able to read the trace. + * + * WARNING : The heartbeat time _shouldn't_ write events in the + * facilities channel as it would make the traffic too high. This is a + * problematic case with flight recorder mode. FIXME + */ + err = new_trace->ops->create_channel(trace_name, new_trace, + new_trace->dentry.control_root, LTT_FACILITIES_CHANNEL, + &new_trace->channel.facilities, subbuf_size_low, + n_subbufs_low, is_channel_overwrite(LTT_CHANNEL_FACILITIES, mode)); + if (err != 0) { + goto facilities_error; + } + err = new_trace->ops->create_channel(trace_name, new_trace, + new_trace->dentry.control_root, LTT_INTERRUPTS_CHANNEL, + &new_trace->channel.interrupts, subbuf_size_low, + n_subbufs_low, is_channel_overwrite(LTT_CHANNEL_INTERRUPTS, mode)); + if (err != 0) { + goto interrupts_error; + } + err = new_trace->ops->create_channel(trace_name, new_trace, + new_trace->dentry.control_root, LTT_PROCESSES_CHANNEL, + &new_trace->channel.processes, subbuf_size_med, + n_subbufs_med, is_channel_overwrite(LTT_CHANNEL_PROCESSES, mode)); + if (err != 0) { + goto processes_error; + } + err = new_trace->ops->create_channel(trace_name, new_trace, + new_trace->dentry.control_root, LTT_MODULES_CHANNEL, + &new_trace->channel.modules, subbuf_size_low, + n_subbufs_low, is_channel_overwrite(LTT_CHANNEL_MODULES, mode)); + if (err != 0) { + goto modules_error; + } + err = new_trace->ops->create_channel(trace_name, new_trace, + new_trace->dentry.trace_root, LTT_CPU_CHANNEL, + &new_trace->channel.cpu, subbuf_size_high, + n_subbufs_high, is_channel_overwrite(LTT_CHANNEL_CPU, mode)); + if (err != 0) { + goto cpu_error; + } + err = new_trace->ops->create_channel(trace_name, new_trace, + new_trace->dentry.control_root, LTT_NETWORK_CHANNEL, + &new_trace->channel.network, subbuf_size_low, + n_subbufs_low, is_channel_overwrite(LTT_CHANNEL_NETWORK, mode)); + if (err != 0) { + goto network_error; + } + + err = _ltt_trace_create(trace_name, mode, new_trace); + + if (err != 0) + goto lock_create_error; + up(<t_traces_sem); + return err; + +lock_create_error: + new_trace->ops->remove_channel(new_trace->channel.network); +network_error: + new_trace->ops->remove_channel(new_trace->channel.cpu); +cpu_error: + new_trace->ops->remove_channel(new_trace->channel.modules); +modules_error: + new_trace->ops->remove_channel(new_trace->channel.processes); +processes_error: + new_trace->ops->remove_channel(new_trace->channel.interrupts); +interrupts_error: + new_trace->ops->remove_channel(new_trace->channel.facilities); +facilities_error: + kref_put(&new_trace->ltt_transport_kref, ltt_release_transport); +dirs_error: + module_put(transport->owner); +trace_error: + kref_put(&new_trace->kref, ltt_release_trace); + up(<t_traces_sem); +traces_error: + return err; +} + +/* Must be called while sure that trace is in the list. */ +static int _ltt_trace_destroy(struct ltt_trace_struct *trace) +{ + int err = EPERM; + + if (trace == NULL) { + err = ENOENT; + goto traces_error; + } + if (trace->active) { + printk(KERN_ERR + "LTT : Can't destroy trace %s : tracer is active\n", + trace->trace_name); + err = EBUSY; + goto active_error; + } + /* Everything went fine */ + list_del_rcu(&trace->list); + synchronize_sched(); + /* If no more trace in the list, we can free the unused facilities */ + if (list_empty(<t_traces.head)) + ltt_facility_free_unused(); + return 0; + + /* error handling */ +active_error: +traces_error: + return err; +} + +/* Sleepable part of the destroy */ +static void __ltt_trace_destroy(struct ltt_trace_struct *trace) +{ + trace->ops->finish_channel(trace->channel.facilities); + trace->ops->finish_channel(trace->channel.interrupts); + trace->ops->finish_channel(trace->channel.processes); + trace->ops->finish_channel(trace->channel.modules); + trace->ops->finish_channel(trace->channel.cpu); + trace->ops->finish_channel(trace->channel.network); + + flush_scheduled_work(); + + if (ltt_traces.num_active_traces == 0) { + /* We stop the asynchronous delivery of reader wakeup, but + * we must make one last check for reader wakeups pending. */ + del_timer(<t_async_wakeup_timer); + } + /* The currently destroyed trace is not in the trace list anymore, + * so it's safe to call the async wakeup ourself. It will deliver + * the last subbuffers. */ + trace_async_wakeup(trace); + + trace->ops->remove_channel(trace->channel.facilities); + trace->ops->remove_channel(trace->channel.interrupts); + trace->ops->remove_channel(trace->channel.processes); + trace->ops->remove_channel(trace->channel.modules); + trace->ops->remove_channel(trace->channel.cpu); + trace->ops->remove_channel(trace->channel.network); + + kref_put(&trace->ltt_transport_kref, ltt_release_transport); + + module_put(trace->transport->owner); + + kref_put(&trace->kref, ltt_release_trace); +} + +static int ltt_trace_destroy(char *trace_name) +{ + int err = 0; + struct ltt_trace_struct* trace; + + down(<t_traces_sem); + trace = _ltt_trace_find(trace_name); + err = _ltt_trace_destroy(trace); + if (err) + goto error; + up(<t_traces_sem); + __ltt_trace_destroy(trace); + return err; + + /* Error handling */ +error: + up(<t_traces_sem); + return err; +} + +/* must be called from within a traces lock. */ +static int _ltt_trace_start(struct ltt_trace_struct* trace) +{ + int err = 0; + + if (trace == NULL) { + err = ENOENT; + goto traces_error; + } + if (trace->active) + printk(KERN_INFO "LTT : Tracing already active for trace %s\n", + trace->trace_name); + if (!try_module_get(ltt_run_filter_owner)) { + err = ENODEV; + printk(KERN_ERR "LTT : Can't lock filter module.\n"); + goto get_ltt_run_filter_error; + } + if (ltt_traces.num_active_traces == 0) { +#ifdef CONFIG_LTT_HEARTBEAT + if (ltt_heartbeat_trigger(LTT_HEARTBEAT_START)) { + err = ENODEV; + printk(KERN_ERR + "LTT : Heartbeat timer module not present.\n"); + goto ltt_heartbeat_error; + } +#endif //CONFIG_LTT_HEARTBEAT + init_timer(<t_async_wakeup_timer); + ltt_async_wakeup_timer.function = async_wakeup; + ltt_async_wakeup_timer.expires = jiffies + 1; + add_timer(<t_async_wakeup_timer); + } + trace->active = 1; + ltt_traces.num_active_traces++; /* Read by trace points without + * protection : be careful */ + return err; + + /* error handling */ +#ifdef CONFIG_LTT_HEARTBEAT +ltt_heartbeat_error: +#endif //CONFIG_LTT_HEARTBEAT + module_put(ltt_run_filter_owner); +get_ltt_run_filter_error: +traces_error: + return err; +} + +static int ltt_trace_start(char *trace_name) +{ + int err = 0; + struct ltt_trace_struct* trace; + + down(<t_traces_sem); + + trace = _ltt_trace_find(trace_name); + if (trace == NULL) + goto no_trace; + err = _ltt_trace_start(trace); + + up(<t_traces_sem); + + /* Call the kernel state dump. + * Events will be mixed with real kernel events, it's ok. + * Notice that there is no protection on the trace : that's exactly + * why we iterate on the list and check for trace equality instead of + * directly using this trace handle inside the logging function. */ + + ltt_facility_state_dump(trace); + + if (!try_module_get(ltt_statedump_owner)) { + err = ENODEV; + printk(KERN_ERR + "LTT : Can't lock state dump module.\n"); + } else { + ltt_statedump_functor(trace); + module_put(ltt_statedump_owner); + } + + return err; + + /* Error handling */ +no_trace: + up(<t_traces_sem); + return err; +} + + +/* must be called from within traces lock */ +static int _ltt_trace_stop(struct ltt_trace_struct* trace) +{ + int err = EPERM; + + if (trace == NULL) { + err = ENOENT; + goto traces_error; + } + if (!trace->active) + printk(KERN_INFO "LTT : Tracing not active for trace %s\n", + trace->trace_name); + if (trace->active) { + trace->active = 0; + ltt_traces.num_active_traces--; + synchronize_sched(); /* Wait for each tracing to be finished */ + } + if (ltt_traces.num_active_traces == 0) { +#ifdef CONFIG_LTT_HEARTBEAT + /* stop the heartbeat if we are the last active trace */ + ltt_heartbeat_trigger(LTT_HEARTBEAT_STOP); +#endif //CONFIG_LTT_HEARTBEAT + } + module_put(ltt_run_filter_owner); + /* Everything went fine */ + return 0; + + /* Error handling */ +traces_error: + return err; +} + +static int ltt_trace_stop(char *trace_name) +{ + int err = 0; + struct ltt_trace_struct* trace; + + down(<t_traces_sem); + trace = _ltt_trace_find(trace_name); + err = _ltt_trace_stop(trace); + up(<t_traces_sem); + return err; +} + + +/* Exported functions */ + +int ltt_control(enum ltt_control_msg msg, char *trace_name, char *trace_type, + union ltt_control_args args) +{ + int err = EPERM; + + printk(KERN_ALERT "ltt_control : trace %s\n", trace_name); + switch (msg) { + case LTT_CONTROL_START: + printk(KERN_DEBUG "Start tracing %s\n", trace_name); + err = ltt_trace_start(trace_name); + break; + case LTT_CONTROL_STOP: + printk(KERN_DEBUG "Stop tracing %s\n", trace_name); + err = ltt_trace_stop(trace_name); + break; + case LTT_CONTROL_CREATE_TRACE: + printk(KERN_DEBUG "Creating trace %s\n", trace_name); + err = ltt_trace_create(trace_name, trace_type, + args.new_trace.mode, + args.new_trace.subbuf_size_low, + args.new_trace.n_subbufs_low, + args.new_trace.subbuf_size_med, + args.new_trace.n_subbufs_med, + args.new_trace.subbuf_size_high, + args.new_trace.n_subbufs_high); + break; + case LTT_CONTROL_DESTROY_TRACE: + printk(KERN_DEBUG "Destroying trace %s\n", trace_name); + err = ltt_trace_destroy(trace_name); + break; + } + return err; +} +EXPORT_SYMBOL_GPL(ltt_control); + +int ltt_filter_control(enum ltt_filter_control_msg msg, char *trace_name) +{ + int err; + struct ltt_trace_struct *trace; + + printk(KERN_DEBUG "ltt_filter_control : trace %s\n", trace_name); + down(<t_traces_sem); + trace = _ltt_trace_find(trace_name); + if (trace == NULL) { + printk(KERN_ALERT + "Trace does not exist. Cannot proxy control request\n"); + err = ENOENT; + goto trace_error; + } + if (!try_module_get(ltt_filter_control_owner)) { + err = ENODEV; + goto get_module_error; + } + switch (msg) { + case LTT_FILTER_DEFAULT_ACCEPT: + printk(KERN_DEBUG + "Proxy filter default accept %s\n", trace_name); + err = (*ltt_filter_control_functor)(msg, trace); + break; + case LTT_FILTER_DEFAULT_REJECT: + printk(KERN_DEBUG + "Proxy filter default reject %s\n", trace_name); + err = (*ltt_filter_control_functor)(msg, trace); + break; + default: + err = EPERM; + } + module_put(ltt_filter_control_owner); + +get_module_error: +trace_error: + up(<t_traces_sem); + return err; +} +EXPORT_SYMBOL_GPL(ltt_filter_control); + +static void __exit ltt_exit(void) +{ + struct ltt_trace_struct *trace; + + down(<t_traces_sem); + /* Stop each trace and destroy them */ + list_for_each_entry_rcu(trace, <t_traces.head, list) { + _ltt_trace_stop(trace); + _ltt_trace_destroy(trace);/* it's doing a synchronize_sched() */ + __ltt_trace_destroy(trace); + } + up(<t_traces_sem); +} + +module_exit(ltt_exit) + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Mathieu Desnoyers"); +MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation Tracer"); + --END-- OpenPGP public key: http://krystal.dyndns.org:8080/key/compudj.gpg Key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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