Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (35 commits)
  perf: Fix unexported generic perf_arch_fetch_caller_regs
  perf record: Don't try to find buildids in a zero sized file
  perf: export perf_trace_regs and perf_arch_fetch_caller_regs
  perf, x86: Fix hw_perf_enable() event assignment
  perf, ppc: Fix compile error due to new cpu notifiers
  perf: Make the install relative to DESTDIR if specified
  kprobes: Calculate the index correctly when freeing the out-of-line execution slot
  perf tools: Fix sparse CPU numbering related bugs
  perf_event: Fix oops triggered by cpu offline/online
  perf: Drop the obsolete profile naming for trace events
  perf: Take a hot regs snapshot for trace events
  perf: Introduce new perf_fetch_caller_regs() for hot regs snapshot
  perf/x86-64: Use frame pointer to walk on irq and process stacks
  lockdep: Move lock events under lockdep recursion protection
  perf report: Print the map table just after samples for which no map was found
  perf report: Add multiple event support
  perf session: Change perf_session post processing functions to take histogram tree
  perf session: Add storage for seperating event types in report
  perf session: Change add_hist_entry to take the tree root instead of session
  perf record: Add ID and to recorded event data when recording multiple events
  ...

1 files changed, 168 insertions, 0 deletions

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
new file mode 100644
index 0000000..81f691e
--- /dev/null
+++ b/kernel/trace/trace_event_perf.c
@@ -0,0 +1,168 @@
+/*
+ * trace event based perf event profiling/tracing
+ *
+ * Copyright (C) 2009 Red Hat Inc, Peter Zijlstra <pzijlstr@redhat.com>
+ * Copyright (C) 2009-2010 Frederic Weisbecker <fweisbec@gmail.com>
+ */
+
+#include <linux/module.h>
+#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;
+
+typedef typeof(char [PERF_MAX_TRACE_SIZE]) perf_trace_t ;
+
+/* 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)
+{
+	char *buf;
+	int ret = -ENOMEM;
+
+	if (event->perf_refcount++ > 0)
+		return 0;
+
+	if (!total_ref_count) {
+		buf = (char *)alloc_percpu(perf_trace_t);
+		if (!buf)
+			goto fail_buf;
+
+		rcu_assign_pointer(perf_trace_buf, buf);
+
+		buf = (char *)alloc_percpu(perf_trace_t);
+		if (!buf)
+			goto fail_buf_nmi;
+
+		rcu_assign_pointer(perf_trace_buf_nmi, buf);
+	}
+
+	ret = event->perf_event_enable(event);
+	if (!ret) {
+		total_ref_count++;
+		return 0;
+	}
+
+fail_buf_nmi:
+	if (!total_ref_count) {
+		free_percpu(perf_trace_buf_nmi);
+		free_percpu(perf_trace_buf);
+		perf_trace_buf_nmi = NULL;
+		perf_trace_buf = NULL;
+	}
+fail_buf:
+	event->perf_refcount--;
+
+	return ret;
+}
+
+int perf_trace_enable(int event_id)
+{
+	struct ftrace_event_call *event;
+	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);
+			break;
+		}
+	}
+	mutex_unlock(&event_mutex);
+
+	return ret;
+}
+
+static void perf_trace_event_disable(struct ftrace_event_call *event)
+{
+	char *buf, *nmi_buf;
+
+	if (--event->perf_refcount > 0)
+		return;
+
+	event->perf_event_disable(event);
+
+	if (!--total_ref_count) {
+		buf = perf_trace_buf;
+		rcu_assign_pointer(perf_trace_buf, NULL);
+
+		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();
+
+		free_percpu(buf);
+		free_percpu(nmi_buf);
+	}
+}
+
+void perf_trace_disable(int event_id)
+{
+	struct ftrace_event_call *event;
+
+	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;
+		}
+	}
+	mutex_unlock(&event_mutex);
+}
+
+__kprobes void *perf_trace_buf_prepare(int size, unsigned short type,
+				       int *rctxp, unsigned long *irq_flags)
+{
+	struct trace_entry *entry;
+	char *trace_buf, *raw_data;
+	int pc, cpu;
+
+	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;
+
+	raw_data = per_cpu_ptr(trace_buf, cpu);
+
+	/* zero the dead bytes from align to not leak stack to user */
+	*(u64 *)(&raw_data[size - sizeof(u64)]) = 0ULL;
+
+	entry = (struct trace_entry *)raw_data;
+	tracing_generic_entry_update(entry, *irq_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);