#include <linux/kprobes.h>
#include "trace.h"
-DEFINE_PER_CPU(struct pt_regs, perf_trace_regs);
-EXPORT_PER_CPU_SYMBOL_GPL(perf_trace_regs);
-
EXPORT_SYMBOL_GPL(perf_arch_fetch_caller_regs);
-static char *perf_trace_buf;
-static char *perf_trace_buf_nmi;
+static char *perf_trace_buf[4];
/*
* Force it to be aligned to unsigned long to avoid misaligned accesses
/* Count the events in use (per event id, not per instance) */
static int total_ref_count;
-static int perf_trace_event_enable(struct ftrace_event_call *event)
+static int perf_trace_event_init(struct ftrace_event_call *tp_event,
+ struct perf_event *p_event)
{
- char *buf;
+ struct hlist_head *list;
int ret = -ENOMEM;
+ int cpu;
- if (event->perf_refcount++ > 0)
+ p_event->tp_event = tp_event;
+ if (tp_event->perf_refcount++ > 0)
return 0;
- if (!total_ref_count) {
- buf = (char *)alloc_percpu(perf_trace_t);
- if (!buf)
- goto fail_buf;
+ list = alloc_percpu(struct hlist_head);
+ if (!list)
+ goto fail;
- rcu_assign_pointer(perf_trace_buf, buf);
+ for_each_possible_cpu(cpu)
+ INIT_HLIST_HEAD(per_cpu_ptr(list, cpu));
- buf = (char *)alloc_percpu(perf_trace_t);
- if (!buf)
- goto fail_buf_nmi;
+ tp_event->perf_events = list;
- rcu_assign_pointer(perf_trace_buf_nmi, buf);
- }
+ if (!total_ref_count) {
+ char *buf;
+ int i;
- ret = event->perf_event_enable(event);
- if (!ret) {
- total_ref_count++;
- return 0;
+ for (i = 0; i < 4; i++) {
+ buf = (char *)alloc_percpu(perf_trace_t);
+ if (!buf)
+ goto fail;
+
+ perf_trace_buf[i] = buf;
+ }
}
-fail_buf_nmi:
+ if (tp_event->class->reg)
+ ret = tp_event->class->reg(tp_event, TRACE_REG_PERF_REGISTER);
+ else
+ ret = tracepoint_probe_register(tp_event->name,
+ tp_event->class->perf_probe,
+ tp_event);
+
+ if (ret)
+ goto fail;
+
+ total_ref_count++;
+ return 0;
+
+fail:
if (!total_ref_count) {
- free_percpu(perf_trace_buf_nmi);
- free_percpu(perf_trace_buf);
- perf_trace_buf_nmi = NULL;
- perf_trace_buf = NULL;
+ int i;
+
+ for (i = 0; i < 4; i++) {
+ free_percpu(perf_trace_buf[i]);
+ perf_trace_buf[i] = NULL;
+ }
+ }
+
+ if (!--tp_event->perf_refcount) {
+ free_percpu(tp_event->perf_events);
+ tp_event->perf_events = NULL;
}
-fail_buf:
- event->perf_refcount--;
return ret;
}
-int perf_trace_enable(int event_id)
+int perf_trace_init(struct perf_event *p_event)
{
- struct ftrace_event_call *event;
+ struct ftrace_event_call *tp_event;
+ int event_id = p_event->attr.config;
int ret = -EINVAL;
mutex_lock(&event_mutex);
- list_for_each_entry(event, &ftrace_events, list) {
- if (event->id == event_id && event->perf_event_enable &&
- try_module_get(event->mod)) {
- ret = perf_trace_event_enable(event);
+ list_for_each_entry(tp_event, &ftrace_events, list) {
+ if (tp_event->event.type == event_id &&
+ tp_event->class && tp_event->class->perf_probe &&
+ try_module_get(tp_event->mod)) {
+ ret = perf_trace_event_init(tp_event, p_event);
break;
}
}
return ret;
}
-static void perf_trace_event_disable(struct ftrace_event_call *event)
+int perf_trace_enable(struct perf_event *p_event)
{
- char *buf, *nmi_buf;
+ struct ftrace_event_call *tp_event = p_event->tp_event;
+ struct hlist_head *list;
- if (--event->perf_refcount > 0)
- return;
+ list = tp_event->perf_events;
+ if (WARN_ON_ONCE(!list))
+ return -EINVAL;
- event->perf_event_disable(event);
-
- if (!--total_ref_count) {
- buf = perf_trace_buf;
- rcu_assign_pointer(perf_trace_buf, NULL);
+ list = this_cpu_ptr(list);
+ hlist_add_head_rcu(&p_event->hlist_entry, list);
- nmi_buf = perf_trace_buf_nmi;
- rcu_assign_pointer(perf_trace_buf_nmi, NULL);
-
- /*
- * Ensure every events in profiling have finished before
- * releasing the buffers
- */
- synchronize_sched();
+ return 0;
+}
- free_percpu(buf);
- free_percpu(nmi_buf);
- }
+void perf_trace_disable(struct perf_event *p_event)
+{
+ hlist_del_rcu(&p_event->hlist_entry);
}
-void perf_trace_disable(int event_id)
+void perf_trace_destroy(struct perf_event *p_event)
{
- struct ftrace_event_call *event;
+ struct ftrace_event_call *tp_event = p_event->tp_event;
+ int i;
mutex_lock(&event_mutex);
- list_for_each_entry(event, &ftrace_events, list) {
- if (event->id == event_id) {
- perf_trace_event_disable(event);
- module_put(event->mod);
- break;
+ if (--tp_event->perf_refcount > 0)
+ goto out;
+
+ if (tp_event->class->reg)
+ tp_event->class->reg(tp_event, TRACE_REG_PERF_UNREGISTER);
+ else
+ tracepoint_probe_unregister(tp_event->name,
+ tp_event->class->perf_probe,
+ tp_event);
+
+ /*
+ * Ensure our callback won't be called anymore. See
+ * tracepoint_probe_unregister() and __DO_TRACE().
+ */
+ synchronize_sched();
+
+ free_percpu(tp_event->perf_events);
+ tp_event->perf_events = NULL;
+
+ if (!--total_ref_count) {
+ for (i = 0; i < 4; i++) {
+ free_percpu(perf_trace_buf[i]);
+ perf_trace_buf[i] = NULL;
}
}
+out:
mutex_unlock(&event_mutex);
}
__kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
- int *rctxp, unsigned long *irq_flags)
+ struct pt_regs *regs, int *rctxp)
{
struct trace_entry *entry;
- char *trace_buf, *raw_data;
- int pc, cpu;
+ unsigned long flags;
+ char *raw_data;
+ int pc;
BUILD_BUG_ON(PERF_MAX_TRACE_SIZE % sizeof(unsigned long));
pc = preempt_count();
- /* Protect the per cpu buffer, begin the rcu read side */
- local_irq_save(*irq_flags);
-
*rctxp = perf_swevent_get_recursion_context();
if (*rctxp < 0)
- goto err_recursion;
-
- cpu = smp_processor_id();
-
- if (in_nmi())
- trace_buf = rcu_dereference_sched(perf_trace_buf_nmi);
- else
- trace_buf = rcu_dereference_sched(perf_trace_buf);
-
- if (!trace_buf)
- goto err;
+ return NULL;
- raw_data = per_cpu_ptr(trace_buf, cpu);
+ raw_data = this_cpu_ptr(perf_trace_buf[*rctxp]);
/* zero the dead bytes from align to not leak stack to user */
memset(&raw_data[size - sizeof(u64)], 0, sizeof(u64));
entry = (struct trace_entry *)raw_data;
- tracing_generic_entry_update(entry, *irq_flags, pc);
+ local_save_flags(flags);
+ tracing_generic_entry_update(entry, flags, pc);
entry->type = type;
return raw_data;
-err:
- perf_swevent_put_recursion_context(*rctxp);
-err_recursion:
- local_irq_restore(*irq_flags);
- return NULL;
}
EXPORT_SYMBOL_GPL(perf_trace_buf_prepare);
projects / linux-flexiantxendom0-3.2.10.git / blobdiff