Commit 35f88e6b authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt

Merge commit 'ftrace/function-graph' into next

parents 3b7faeb4 712406a6
...@@ -55,29 +55,4 @@ struct dyn_arch_ftrace { ...@@ -55,29 +55,4 @@ struct dyn_arch_ftrace {
#endif /* __ASSEMBLY__ */ #endif /* __ASSEMBLY__ */
#endif /* CONFIG_FUNCTION_TRACER */ #endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
#ifndef __ASSEMBLY__
/*
* Stack of return addresses for functions
* of a thread.
* Used in struct thread_info
*/
struct ftrace_ret_stack {
unsigned long ret;
unsigned long func;
unsigned long long calltime;
};
/*
* Primary handler of a function return.
* It relays on ftrace_return_to_handler.
* Defined in entry_32/64.S
*/
extern void return_to_handler(void);
#endif /* __ASSEMBLY__ */
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#endif /* _ASM_X86_FTRACE_H */ #endif /* _ASM_X86_FTRACE_H */
...@@ -10,6 +10,7 @@ ...@@ -10,6 +10,7 @@
#include <linux/kdebug.h> #include <linux/kdebug.h>
#include <linux/module.h> #include <linux/module.h>
#include <linux/ptrace.h> #include <linux/ptrace.h>
#include <linux/ftrace.h>
#include <linux/kexec.h> #include <linux/kexec.h>
#include <linux/bug.h> #include <linux/bug.h>
#include <linux/nmi.h> #include <linux/nmi.h>
......
...@@ -389,79 +389,6 @@ void ftrace_nmi_exit(void) ...@@ -389,79 +389,6 @@ void ftrace_nmi_exit(void)
#endif /* !CONFIG_DYNAMIC_FTRACE */ #endif /* !CONFIG_DYNAMIC_FTRACE */
/* Add a function return address to the trace stack on thread info.*/
static int push_return_trace(unsigned long ret, unsigned long long time,
unsigned long func, int *depth)
{
int index;
if (!current->ret_stack)
return -EBUSY;
/* The return trace stack is full */
if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
atomic_inc(&current->trace_overrun);
return -EBUSY;
}
index = ++current->curr_ret_stack;
barrier();
current->ret_stack[index].ret = ret;
current->ret_stack[index].func = func;
current->ret_stack[index].calltime = time;
*depth = index;
return 0;
}
/* Retrieve a function return address to the trace stack on thread info.*/
static void pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
{
int index;
index = current->curr_ret_stack;
if (unlikely(index < 0)) {
ftrace_graph_stop();
WARN_ON(1);
/* Might as well panic, otherwise we have no where to go */
*ret = (unsigned long)panic;
return;
}
*ret = current->ret_stack[index].ret;
trace->func = current->ret_stack[index].func;
trace->calltime = current->ret_stack[index].calltime;
trace->overrun = atomic_read(&current->trace_overrun);
trace->depth = index;
barrier();
current->curr_ret_stack--;
}
/*
* Send the trace to the ring-buffer.
* @return the original return address.
*/
unsigned long ftrace_return_to_handler(void)
{
struct ftrace_graph_ret trace;
unsigned long ret;
pop_return_trace(&trace, &ret);
trace.rettime = cpu_clock(raw_smp_processor_id());
ftrace_graph_return(&trace);
if (unlikely(!ret)) {
ftrace_graph_stop();
WARN_ON(1);
/* Might as well panic. What else to do? */
ret = (unsigned long)panic;
}
return ret;
}
/* /*
* Hook the return address and push it in the stack of return addrs * Hook the return address and push it in the stack of return addrs
* in current thread info. * in current thread info.
...@@ -521,7 +448,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr) ...@@ -521,7 +448,7 @@ void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr)
calltime = cpu_clock(raw_smp_processor_id()); calltime = cpu_clock(raw_smp_processor_id());
if (push_return_trace(old, calltime, if (ftrace_push_return_trace(old, calltime,
self_addr, &trace.depth) == -EBUSY) { self_addr, &trace.depth) == -EBUSY) {
*parent = old; *parent = old;
return; return;
......
...@@ -379,6 +379,30 @@ struct ftrace_graph_ret { ...@@ -379,6 +379,30 @@ struct ftrace_graph_ret {
#ifdef CONFIG_FUNCTION_GRAPH_TRACER #ifdef CONFIG_FUNCTION_GRAPH_TRACER
/*
* Stack of return addresses for functions
* of a thread.
* Used in struct thread_info
*/
struct ftrace_ret_stack {
unsigned long ret;
unsigned long func;
unsigned long long calltime;
};
/*
* Primary handler of a function return.
* It relays on ftrace_return_to_handler.
* Defined in entry_32/64.S
*/
extern void return_to_handler(void);
extern int
ftrace_push_return_trace(unsigned long ret, unsigned long long time,
unsigned long func, int *depth);
extern void
ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret);
/* /*
* Sometimes we don't want to trace a function with the function * Sometimes we don't want to trace a function with the function
* graph tracer but we want them to keep traced by the usual function * graph tracer but we want them to keep traced by the usual function
......
...@@ -42,6 +42,81 @@ static struct tracer_flags tracer_flags = { ...@@ -42,6 +42,81 @@ static struct tracer_flags tracer_flags = {
/* pid on the last trace processed */ /* pid on the last trace processed */
static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 }; static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };
/* Add a function return address to the trace stack on thread info.*/
int
ftrace_push_return_trace(unsigned long ret, unsigned long long time,
unsigned long func, int *depth)
{
int index;
if (!current->ret_stack)
return -EBUSY;
/* The return trace stack is full */
if (current->curr_ret_stack == FTRACE_RETFUNC_DEPTH - 1) {
atomic_inc(&current->trace_overrun);
return -EBUSY;
}
index = ++current->curr_ret_stack;
barrier();
current->ret_stack[index].ret = ret;
current->ret_stack[index].func = func;
current->ret_stack[index].calltime = time;
*depth = index;
return 0;
}
/* Retrieve a function return address to the trace stack on thread info.*/
void
ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret)
{
int index;
index = current->curr_ret_stack;
if (unlikely(index < 0)) {
ftrace_graph_stop();
WARN_ON(1);
/* Might as well panic, otherwise we have no where to go */
*ret = (unsigned long)panic;
return;
}
*ret = current->ret_stack[index].ret;
trace->func = current->ret_stack[index].func;
trace->calltime = current->ret_stack[index].calltime;
trace->overrun = atomic_read(&current->trace_overrun);
trace->depth = index;
barrier();
current->curr_ret_stack--;
}
/*
* Send the trace to the ring-buffer.
* @return the original return address.
*/
unsigned long ftrace_return_to_handler(void)
{
struct ftrace_graph_ret trace;
unsigned long ret;
ftrace_pop_return_trace(&trace, &ret);
trace.rettime = cpu_clock(raw_smp_processor_id());
ftrace_graph_return(&trace);
if (unlikely(!ret)) {
ftrace_graph_stop();
WARN_ON(1);
/* Might as well panic. What else to do? */
ret = (unsigned long)panic;
}
return ret;
}
static int graph_trace_init(struct trace_array *tr) static int graph_trace_init(struct trace_array *tr)
{ {
int cpu, ret; int cpu, ret;
......
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