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Commit ea853e03 authored by Sami Tolvanen's avatar Sami Tolvanen Committed by Alistair Strachan
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ANDROID: ftrace: fix function type mismatches 



This change fixes indirect call mismatches with function and function
graph tracing, which trip Control-Flow Integrity (CFI) checking.

Bug: 79510107
Bug: 67506682
Change-Id: I5de08c113fb970ffefedce93c58e0161f22c7ca2
Signed-off-by: default avatarSami Tolvanen <samitolvanen@google.com>
parent 7dd8055f

include/linux/ftrace.h

+8 −0
Original line number Diff line number Diff line
@@ -224,8 +224,16 @@ extern enum ftrace_tracing_type_t ftrace_tracing_type; 
int register_ftrace_function(struct ftrace_ops *ops);

int unregister_ftrace_function(struct ftrace_ops *ops);



#ifdef CONFIG_CFI_CLANG

/* Use a C stub with the correct type for CFI */

static inline void ftrace_stub(unsigned long a0, unsigned long a1,

			       struct ftrace_ops *op, struct pt_regs *regs)

{

}

#else

extern void ftrace_stub(unsigned long a0, unsigned long a1,

			struct ftrace_ops *op, struct pt_regs *regs);

#endif



#else /* !CONFIG_FUNCTION_TRACER */

/*

kernel/trace/ftrace.c

+11 −6
Original line number Diff line number Diff line
@@ -124,8 +124,9 @@ static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, 
				 struct ftrace_ops *op, struct pt_regs *regs);

#else

/* See comment below, where ftrace_ops_list_func is defined */

static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip);

#define ftrace_ops_list_func ((ftrace_func_t)ftrace_ops_no_ops)

static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip,

			      struct ftrace_ops *op, struct pt_regs *regs);

#define ftrace_ops_list_func ftrace_ops_no_ops

#endif



/*
@@ -6313,7 +6314,8 @@ static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, 
}

NOKPROBE_SYMBOL(ftrace_ops_list_func);

#else

static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip)

static void ftrace_ops_no_ops(unsigned long ip, unsigned long parent_ip,

			      struct ftrace_ops *op, struct pt_regs *regs)

{

	__ftrace_ops_list_func(ip, parent_ip, NULL, NULL);

}
@@ -6776,14 +6778,17 @@ void ftrace_graph_graph_time_control(bool enable) 
	fgraph_graph_time = enable;

}



void ftrace_graph_return_stub(struct ftrace_graph_ret *trace)

{

}



int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)

{

	return 0;

}



/* The callbacks that hook a function */

trace_func_graph_ret_t ftrace_graph_return =

			(trace_func_graph_ret_t)ftrace_stub;

trace_func_graph_ret_t ftrace_graph_return = ftrace_graph_return_stub;

trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;

static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
@@ -7013,7 +7018,7 @@ void unregister_ftrace_graph(void) 
		goto out;



	ftrace_graph_active--;

	ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;

	ftrace_graph_return = ftrace_graph_return_stub;

	ftrace_graph_entry = ftrace_graph_entry_stub;

	__ftrace_graph_entry = ftrace_graph_entry_stub;

	ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);