X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=probes%2Flttng-ftrace.c;h=fe1bfd6652ab837a0911b566b3c5dc6759d28043;hb=HEAD;hp=2a939216ef5e3233edc484b66dcb288837f42a99;hpb=a90917c3f8c4ed79117f1caa333b29a2108084ec;p=lttng-modules.git diff --git a/probes/lttng-ftrace.c b/probes/lttng-ftrace.c deleted file mode 100644 index 2a939216..00000000 --- a/probes/lttng-ftrace.c +++ /dev/null @@ -1,188 +0,0 @@ -/* - * (C) Copyright 2009-2011 - - * Mathieu Desnoyers - * - * LTTng function tracer integration module. - * - * Dual LGPL v2.1/GPL v2 license. - */ - -/* - * Ftrace function tracer does not seem to provide synchronization between probe - * teardown and callback execution. Therefore, we make this module permanently - * loaded (unloadable). - * - * TODO: Move to register_ftrace_function() (which is exported for - * modules) for Linux >= 3.0. It is faster (only enables the selected - * functions), and will stay there. - */ - -#include -#include -#include -#include "../lttng-events.h" -#include "../wrapper/ringbuffer/frontend_types.h" -#include "../wrapper/ftrace.h" -#include "../wrapper/vmalloc.h" -#include "../lttng-tracer.h" - -static -void lttng_ftrace_handler(unsigned long ip, unsigned long parent_ip, void **data) -{ - struct lttng_event *event = *data; - struct lttng_channel *chan = event->chan; - struct lib_ring_buffer_ctx ctx; - struct { - unsigned long ip; - unsigned long parent_ip; - } payload; - int ret; - - if (unlikely(!ACCESS_ONCE(chan->session->active))) - return; - if (unlikely(!ACCESS_ONCE(chan->enabled))) - return; - if (unlikely(!ACCESS_ONCE(event->enabled))) - return; - - lib_ring_buffer_ctx_init(&ctx, chan->chan, event, - sizeof(payload), lttng_alignof(payload), -1); - ret = chan->ops->event_reserve(&ctx, event->id); - if (ret < 0) - return; - payload.ip = ip; - payload.parent_ip = parent_ip; - lib_ring_buffer_align_ctx(&ctx, lttng_alignof(payload)); - chan->ops->event_write(&ctx, &payload, sizeof(payload)); - chan->ops->event_commit(&ctx); - return; -} - -/* - * Create event description - */ -static -int lttng_create_ftrace_event(const char *name, struct lttng_event *event) -{ - struct lttng_event_field *fields; - struct lttng_event_desc *desc; - int ret; - - desc = kzalloc(sizeof(*event->desc), GFP_KERNEL); - if (!desc) - return -ENOMEM; - desc->name = kstrdup(name, GFP_KERNEL); - if (!desc->name) { - ret = -ENOMEM; - goto error_str; - } - desc->nr_fields = 2; - desc->fields = fields = - kzalloc(2 * sizeof(struct lttng_event_field), GFP_KERNEL); - if (!desc->fields) { - ret = -ENOMEM; - goto error_fields; - } - fields[0].name = "ip"; - fields[0].type.atype = atype_integer; - fields[0].type.u.basic.integer.size = sizeof(unsigned long) * CHAR_BIT; - fields[0].type.u.basic.integer.alignment = lttng_alignof(unsigned long) * CHAR_BIT; - fields[0].type.u.basic.integer.signedness = is_signed_type(unsigned long); - fields[0].type.u.basic.integer.reverse_byte_order = 0; - fields[0].type.u.basic.integer.base = 16; - fields[0].type.u.basic.integer.encoding = lttng_encode_none; - - fields[1].name = "parent_ip"; - fields[1].type.atype = atype_integer; - fields[1].type.u.basic.integer.size = sizeof(unsigned long) * CHAR_BIT; - fields[1].type.u.basic.integer.alignment = lttng_alignof(unsigned long) * CHAR_BIT; - fields[1].type.u.basic.integer.signedness = is_signed_type(unsigned long); - fields[1].type.u.basic.integer.reverse_byte_order = 0; - fields[1].type.u.basic.integer.base = 16; - fields[1].type.u.basic.integer.encoding = lttng_encode_none; - - desc->owner = THIS_MODULE; - event->desc = desc; - - return 0; - -error_fields: - kfree(desc->name); -error_str: - kfree(desc); - return ret; -} - -static -struct ftrace_probe_ops lttng_ftrace_ops = { - .func = lttng_ftrace_handler, -}; - -int lttng_ftrace_register(const char *name, - const char *symbol_name, - struct lttng_event *event) -{ - int ret; - - ret = lttng_create_ftrace_event(name, event); - if (ret) - goto error; - - event->u.ftrace.symbol_name = kstrdup(symbol_name, GFP_KERNEL); - if (!event->u.ftrace.symbol_name) - goto name_error; - - /* Ensure the memory we just allocated don't trigger page faults */ - wrapper_vmalloc_sync_all(); - - ret = wrapper_register_ftrace_function_probe(event->u.ftrace.symbol_name, - <tng_ftrace_ops, event); - if (ret < 0) - goto register_error; - return 0; - -register_error: - kfree(event->u.ftrace.symbol_name); -name_error: - kfree(event->desc->name); - kfree(event->desc); -error: - return ret; -} -EXPORT_SYMBOL_GPL(lttng_ftrace_register); - -void lttng_ftrace_unregister(struct lttng_event *event) -{ - wrapper_unregister_ftrace_function_probe(event->u.ftrace.symbol_name, - <tng_ftrace_ops, event); -} -EXPORT_SYMBOL_GPL(lttng_ftrace_unregister); - -void lttng_ftrace_destroy_private(struct lttng_event *event) -{ - kfree(event->u.ftrace.symbol_name); - kfree(event->desc->fields); - kfree(event->desc->name); - kfree(event->desc); -} -EXPORT_SYMBOL_GPL(lttng_ftrace_destroy_private); - -int lttng_ftrace_init(void) -{ - wrapper_vmalloc_sync_all(); - return 0; -} -module_init(lttng_ftrace_init) - -/* - * Ftrace takes care of waiting for a grace period (RCU sched) at probe - * unregistration, and disables preemption around probe call. - */ -void lttng_ftrace_exit(void) -{ -} -module_exit(lttng_ftrace_exit) - -MODULE_LICENSE("GPL and additional rights"); -MODULE_AUTHOR("Mathieu Desnoyers"); -MODULE_DESCRIPTION("Linux Trace Toolkit Ftrace Support");