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: Sami Tolvanen <samitolvanen@google.com>
This commit is contained in:
Sami Tolvanen 2018-05-10 14:56:41 -07:00 committed by Amit Pundir
parent 33395cc5bf
commit 1875563351
2 changed files with 19 additions and 6 deletions

View file

@ -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 */
/*

View file

@ -123,8 +123,9 @@ 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
/*
@ -6310,7 +6311,8 @@ static void ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip,
__ftrace_ops_list_func(ip, parent_ip, NULL, regs);
}
#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);
}
@ -6771,14 +6773,17 @@ 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;
@ -7007,7 +7012,7 @@ 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);