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-rw-r--r--arch/x86/kernel/entry_32.S3
-rw-r--r--arch/x86/kernel/entry_64.S3
-rw-r--r--arch/x86/kernel/ftrace.c7
-rw-r--r--include/linux/ftrace.h2
-rw-r--r--kernel/trace/ftrace.c10
-rw-r--r--kernel/trace/trace.c4
-rw-r--r--kernel/trace/trace.h2
7 files changed, 24 insertions, 7 deletions
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 826682abed1..43ceb3f454b 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -1196,6 +1196,9 @@ ENTRY(mcount)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
cmpl $ftrace_stub, ftrace_graph_return
jnz ftrace_graph_caller
+
+ cmpl $ftrace_graph_entry_stub, ftrace_graph_entry
+ jnz ftrace_graph_caller
#endif
.globl ftrace_stub
ftrace_stub:
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 9060ba6497e..54e0bbdccb9 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -120,6 +120,9 @@ ENTRY(mcount)
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
cmpq $ftrace_stub, ftrace_graph_return
jnz ftrace_graph_caller
+
+ cmpq $ftrace_graph_entry_stub, ftrace_graph_entry
+ jnz ftrace_graph_caller
#endif
.globl ftrace_stub
diff --git a/arch/x86/kernel/ftrace.c b/arch/x86/kernel/ftrace.c
index adba8e9a427..d278ad2ebda 100644
--- a/arch/x86/kernel/ftrace.c
+++ b/arch/x86/kernel/ftrace.c
@@ -425,6 +425,7 @@ static void pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
trace->calltime = current->ret_stack[index].calltime;
trace->overrun = atomic_read(&current->trace_overrun);
trace->depth = index;
+ barrier();
current->curr_ret_stack--;
}
@@ -506,7 +507,11 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
}
trace.func = self_addr;
- ftrace_graph_entry(&trace);
+ /* Only trace if the calling function expects to */
+ if (!ftrace_graph_entry(&trace)) {
+ current->curr_ret_stack--;
+ *parent = old;
+ }
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 58ca1c3a3f4..469ceb3e85b 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -371,7 +371,7 @@ struct ftrace_graph_ret {
#define FTRACE_RETSTACK_ALLOC_SIZE 32
/* Type of the callback handlers for tracing function graph*/
typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
-typedef void (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
+typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
trace_func_graph_ent_t entryfunc);
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index a44af05ae2d..65b9e863056 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1636,11 +1636,15 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
static atomic_t ftrace_graph_active;
+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_ent_t ftrace_graph_entry =
- (trace_func_graph_ent_t)ftrace_stub;
+trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */
static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list)
@@ -1738,7 +1742,7 @@ void unregister_ftrace_graph(void)
atomic_dec(&ftrace_graph_active);
ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
- ftrace_graph_entry = (trace_func_graph_ent_t)ftrace_stub;
+ ftrace_graph_entry = ftrace_graph_entry_stub;
ftrace_shutdown(FTRACE_STOP_FUNC_RET);
mutex_unlock(&ftrace_sysctl_lock);
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 380de630ebc..8b6409a62b5 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1200,7 +1200,7 @@ function_trace_call(unsigned long ip, unsigned long parent_ip)
}
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-void trace_graph_entry(struct ftrace_graph_ent *trace)
+int trace_graph_entry(struct ftrace_graph_ent *trace)
{
struct trace_array *tr = &global_trace;
struct trace_array_cpu *data;
@@ -1219,6 +1219,8 @@ void trace_graph_entry(struct ftrace_graph_ent *trace)
}
atomic_dec(&data->disabled);
local_irq_restore(flags);
+
+ return 1;
}
void trace_graph_return(struct ftrace_graph_ret *trace)
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index f96f4e787ff..0565ae9a221 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -412,7 +412,7 @@ void trace_function(struct trace_array *tr,
unsigned long flags, int pc);
void trace_graph_return(struct ftrace_graph_ret *trace);
-void trace_graph_entry(struct ftrace_graph_ent *trace);
+int trace_graph_entry(struct ftrace_graph_ent *trace);
void trace_bts(struct trace_array *tr,
unsigned long from,
unsigned long to);