[PATCH 3/5] uprobes: Kill uprobe_trace_consumer, embed uprobe_consumer into trace_uprobe

[Oleg Nesterov <oleg@redhat.com>]

trace_uprobe->consumer and "struct uprobe_trace_consumer" add the
unnecessary indirection and complicate the code for no reason.

This patch simply embeds uprobe_consumer into "struct trace_uprobe",
all other changes only fix the compilation errors.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
---
 kernel/trace/trace_uprobe.c |   44 ++++++++++--------------------------------
 1 files changed, 11 insertions(+), 33 deletions(-)

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index c430d01..6551b77 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -32,12 +32,6 @@
 /*
  * uprobe event core functions
  */
-struct trace_uprobe;
-struct uprobe_trace_consumer {
-	struct uprobe_consumer		cons;
-	struct trace_uprobe		*tu;
-};
-
 struct trace_uprobe_filter {
 	struct pid *tgid;
 };
@@ -47,7 +41,7 @@ struct trace_uprobe {
 	struct ftrace_event_class	class;
 	struct ftrace_event_call	call;
 	bool				enabled;
-	struct uprobe_trace_consumer	*consumer;
+	struct uprobe_consumer		consumer;
 	struct trace_uprobe_filter	filter;
 	struct inode			*inode;
 	char				*filename;
@@ -122,13 +116,13 @@ static bool trace_uprobe_filter_func(struct uprobe_consumer *uc,
 					enum uprobe_filter_ctx ctx,
 					struct mm_struct *mm)
 {
-	struct uprobe_trace_consumer *utc;
+	struct trace_uprobe *tu;
 	struct trace_uprobe_filter *filter;
 	struct task_struct *p, *t;
 	bool ret;
 
-	utc = container_of(uc, struct uprobe_trace_consumer, cons);
-	filter = &utc->tu->filter;
+	tu = container_of(uc, struct trace_uprobe, consumer);
+	filter = &tu->filter;
 
 	if (ctx == UPROBE_FILTER_MMAP)
 		return trace_uprobe_filter_current(filter);
@@ -645,30 +639,20 @@ partial:
 
 static int probe_event_enable(struct trace_uprobe *tu, int flag)
 {
-	struct uprobe_trace_consumer *utc;
 	int ret = 0;
 
 	if (tu->enabled)
 		return -EINTR;
 
-	utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL);
-	if (!utc)
-		return -EINTR;
-
-	set_trace_uprobe_filter_func(&utc->cons, &tu->filter);
-	utc->cons.handler = uprobe_dispatcher;
-	utc->tu = tu;
-	tu->consumer = utc;
+	set_trace_uprobe_filter_func(&tu->consumer, &tu->filter);
+	tu->consumer.handler = uprobe_dispatcher;
 	tu->flags |= flag;
 
-	ret = uprobe_register(tu->inode, tu->offset, &utc->cons);
-	if (ret) {
-		tu->consumer = NULL;
+	ret = uprobe_register(tu->inode, tu->offset, &tu->consumer);
+	if (ret)
 		tu->flags &= ~flag;
-		kfree(utc);
-	} else {
+	else
 		tu->enabled = true;
-	}
 
 	return ret;
 }
@@ -678,11 +662,9 @@ static void probe_event_disable(struct trace_uprobe *tu, int flag)
 	if (!tu->enabled)
 		return;
 
-	uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons);
+	uprobe_unregister(tu->inode, tu->offset, &tu->consumer);
 	tu->flags &= ~flag;
 	tu->enabled = false;
-	kfree(tu->consumer);
-	tu->consumer = NULL;
 }
 
 static int uprobe_event_define_fields(struct ftrace_event_call *event_call)
@@ -820,13 +802,9 @@ int trace_uprobe_register(struct ftrace_event_call *event, enum trace_reg type,
 
 static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs)
 {
-	struct uprobe_trace_consumer *utc;
 	struct trace_uprobe *tu;
 
-	utc = container_of(con, struct uprobe_trace_consumer, cons);
-	tu = utc->tu;
-	if (!tu || tu->consumer != utc)
-		return 0;
+	tu = container_of(con, struct trace_uprobe, consumer);
 
 	if (!trace_uprobe_filter_current(&tu->filter))
 		return UPROBE_HANDLER_REMOVE;
-- 
1.5.5.1