linux_dsm_epyc7002/include/linux/ftrace.h
Steven Rostedt c88fd8634e ftrace: Allow archs to modify code without stop machine
The stop machine method to modify all functions in the kernel
(some 20,000 of them) is the safest way to do so across all archs.
But some archs may not need this big hammer approach to modify code
on SMP machines, and can simply just update the code it needs.

Adding a weak function arch_ftrace_update_code() that now does the
stop machine, will also let any arch override this method.

If the arch needs to check the system and then decide if it can
avoid stop machine, it can still call ftrace_run_stop_machine() to
use the old method.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 07:16:58 -05:00

585 lines
16 KiB
C

/*
* Ftrace header. For implementation details beyond the random comments
* scattered below, see: Documentation/trace/ftrace-design.txt
*/
#ifndef _LINUX_FTRACE_H
#define _LINUX_FTRACE_H
#include <linux/trace_clock.h>
#include <linux/kallsyms.h>
#include <linux/linkage.h>
#include <linux/bitops.h>
#include <linux/ktime.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <asm/ftrace.h>
struct module;
struct ftrace_hash;
#ifdef CONFIG_FUNCTION_TRACER
extern int ftrace_enabled;
extern int
ftrace_enable_sysctl(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos);
typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip);
enum {
FTRACE_OPS_FL_ENABLED = 1 << 0,
FTRACE_OPS_FL_GLOBAL = 1 << 1,
FTRACE_OPS_FL_DYNAMIC = 1 << 2,
};
struct ftrace_ops {
ftrace_func_t func;
struct ftrace_ops *next;
unsigned long flags;
#ifdef CONFIG_DYNAMIC_FTRACE
struct ftrace_hash *notrace_hash;
struct ftrace_hash *filter_hash;
#endif
};
extern int function_trace_stop;
/*
* Type of the current tracing.
*/
enum ftrace_tracing_type_t {
FTRACE_TYPE_ENTER = 0, /* Hook the call of the function */
FTRACE_TYPE_RETURN, /* Hook the return of the function */
};
/* Current tracing type, default is FTRACE_TYPE_ENTER */
extern enum ftrace_tracing_type_t ftrace_tracing_type;
/**
* ftrace_stop - stop function tracer.
*
* A quick way to stop the function tracer. Note this an on off switch,
* it is not something that is recursive like preempt_disable.
* This does not disable the calling of mcount, it only stops the
* calling of functions from mcount.
*/
static inline void ftrace_stop(void)
{
function_trace_stop = 1;
}
/**
* ftrace_start - start the function tracer.
*
* This function is the inverse of ftrace_stop. This does not enable
* the function tracing if the function tracer is disabled. This only
* sets the function tracer flag to continue calling the functions
* from mcount.
*/
static inline void ftrace_start(void)
{
function_trace_stop = 0;
}
/*
* The ftrace_ops must be a static and should also
* be read_mostly. These functions do modify read_mostly variables
* so use them sparely. Never free an ftrace_op or modify the
* next pointer after it has been registered. Even after unregistering
* it, the next pointer may still be used internally.
*/
int register_ftrace_function(struct ftrace_ops *ops);
int unregister_ftrace_function(struct ftrace_ops *ops);
void clear_ftrace_function(void);
extern void ftrace_stub(unsigned long a0, unsigned long a1);
#else /* !CONFIG_FUNCTION_TRACER */
/*
* (un)register_ftrace_function must be a macro since the ops parameter
* must not be evaluated.
*/
#define register_ftrace_function(ops) ({ 0; })
#define unregister_ftrace_function(ops) ({ 0; })
static inline void clear_ftrace_function(void) { }
static inline void ftrace_kill(void) { }
static inline void ftrace_stop(void) { }
static inline void ftrace_start(void) { }
#endif /* CONFIG_FUNCTION_TRACER */
#ifdef CONFIG_STACK_TRACER
extern int stack_tracer_enabled;
int
stack_trace_sysctl(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
loff_t *ppos);
#endif
struct ftrace_func_command {
struct list_head list;
char *name;
int (*func)(struct ftrace_hash *hash,
char *func, char *cmd,
char *params, int enable);
};
#ifdef CONFIG_DYNAMIC_FTRACE
int ftrace_arch_code_modify_prepare(void);
int ftrace_arch_code_modify_post_process(void);
void ftrace_bug(int err, unsigned long ip);
struct seq_file;
struct ftrace_probe_ops {
void (*func)(unsigned long ip,
unsigned long parent_ip,
void **data);
int (*callback)(unsigned long ip, void **data);
void (*free)(void **data);
int (*print)(struct seq_file *m,
unsigned long ip,
struct ftrace_probe_ops *ops,
void *data);
};
extern int
register_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
void *data);
extern void
unregister_ftrace_function_probe(char *glob, struct ftrace_probe_ops *ops,
void *data);
extern void
unregister_ftrace_function_probe_func(char *glob, struct ftrace_probe_ops *ops);
extern void unregister_ftrace_function_probe_all(char *glob);
extern int ftrace_text_reserved(void *start, void *end);
enum {
FTRACE_FL_ENABLED = (1 << 30),
FTRACE_FL_FREE = (1 << 31),
};
#define FTRACE_FL_MASK (0x3UL << 30)
#define FTRACE_REF_MAX ((1 << 30) - 1)
struct dyn_ftrace {
union {
unsigned long ip; /* address of mcount call-site */
struct dyn_ftrace *freelist;
};
union {
unsigned long flags;
struct dyn_ftrace *newlist;
};
struct dyn_arch_ftrace arch;
};
int ftrace_force_update(void);
void ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
int len, int reset);
void ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf,
int len, int reset);
void ftrace_set_global_filter(unsigned char *buf, int len, int reset);
void ftrace_set_global_notrace(unsigned char *buf, int len, int reset);
int register_ftrace_command(struct ftrace_func_command *cmd);
int unregister_ftrace_command(struct ftrace_func_command *cmd);
enum {
FTRACE_UPDATE_CALLS = (1 << 0),
FTRACE_DISABLE_CALLS = (1 << 1),
FTRACE_UPDATE_TRACE_FUNC = (1 << 2),
FTRACE_START_FUNC_RET = (1 << 3),
FTRACE_STOP_FUNC_RET = (1 << 4),
};
enum {
FTRACE_UPDATE_IGNORE,
FTRACE_UPDATE_MAKE_CALL,
FTRACE_UPDATE_MAKE_NOP,
};
void arch_ftrace_update_code(int command);
struct ftrace_rec_iter;
struct ftrace_rec_iter *ftrace_rec_iter_start(void);
struct ftrace_rec_iter *ftrace_rec_iter_next(struct ftrace_rec_iter *iter);
struct dyn_ftrace *ftrace_rec_iter_record(struct ftrace_rec_iter *iter);
int ftrace_update_record(struct dyn_ftrace *rec, int enable);
int ftrace_test_record(struct dyn_ftrace *rec, int enable);
void ftrace_run_stop_machine(int command);
int ftrace_location(unsigned long ip);
extern ftrace_func_t ftrace_trace_function;
/* defined in arch */
extern int ftrace_ip_converted(unsigned long ip);
extern int ftrace_dyn_arch_init(void *data);
extern int ftrace_update_ftrace_func(ftrace_func_t func);
extern void ftrace_caller(void);
extern void ftrace_call(void);
extern void mcount_call(void);
#ifndef FTRACE_ADDR
#define FTRACE_ADDR ((unsigned long)ftrace_caller)
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
extern void ftrace_graph_caller(void);
extern int ftrace_enable_ftrace_graph_caller(void);
extern int ftrace_disable_ftrace_graph_caller(void);
#else
static inline int ftrace_enable_ftrace_graph_caller(void) { return 0; }
static inline int ftrace_disable_ftrace_graph_caller(void) { return 0; }
#endif
/**
* ftrace_make_nop - convert code into nop
* @mod: module structure if called by module load initialization
* @rec: the mcount call site record
* @addr: the address that the call site should be calling
*
* This is a very sensitive operation and great care needs
* to be taken by the arch. The operation should carefully
* read the location, check to see if what is read is indeed
* what we expect it to be, and then on success of the compare,
* it should write to the location.
*
* The code segment at @rec->ip should be a caller to @addr
*
* Return must be:
* 0 on success
* -EFAULT on error reading the location
* -EINVAL on a failed compare of the contents
* -EPERM on error writing to the location
* Any other value will be considered a failure.
*/
extern int ftrace_make_nop(struct module *mod,
struct dyn_ftrace *rec, unsigned long addr);
/**
* ftrace_make_call - convert a nop call site into a call to addr
* @rec: the mcount call site record
* @addr: the address that the call site should call
*
* This is a very sensitive operation and great care needs
* to be taken by the arch. The operation should carefully
* read the location, check to see if what is read is indeed
* what we expect it to be, and then on success of the compare,
* it should write to the location.
*
* The code segment at @rec->ip should be a nop
*
* Return must be:
* 0 on success
* -EFAULT on error reading the location
* -EINVAL on a failed compare of the contents
* -EPERM on error writing to the location
* Any other value will be considered a failure.
*/
extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr);
/* May be defined in arch */
extern int ftrace_arch_read_dyn_info(char *buf, int size);
extern int skip_trace(unsigned long ip);
extern void ftrace_disable_daemon(void);
extern void ftrace_enable_daemon(void);
#else
static inline int skip_trace(unsigned long ip) { return 0; }
static inline int ftrace_force_update(void) { return 0; }
static inline void ftrace_set_filter(unsigned char *buf, int len, int reset)
{
}
static inline void ftrace_disable_daemon(void) { }
static inline void ftrace_enable_daemon(void) { }
static inline void ftrace_release_mod(struct module *mod) {}
static inline int register_ftrace_command(struct ftrace_func_command *cmd)
{
return -EINVAL;
}
static inline int unregister_ftrace_command(char *cmd_name)
{
return -EINVAL;
}
static inline int ftrace_text_reserved(void *start, void *end)
{
return 0;
}
#endif /* CONFIG_DYNAMIC_FTRACE */
/* totally disable ftrace - can not re-enable after this */
void ftrace_kill(void);
static inline void tracer_disable(void)
{
#ifdef CONFIG_FUNCTION_TRACER
ftrace_enabled = 0;
#endif
}
/*
* Ftrace disable/restore without lock. Some synchronization mechanism
* must be used to prevent ftrace_enabled to be changed between
* disable/restore.
*/
static inline int __ftrace_enabled_save(void)
{
#ifdef CONFIG_FUNCTION_TRACER
int saved_ftrace_enabled = ftrace_enabled;
ftrace_enabled = 0;
return saved_ftrace_enabled;
#else
return 0;
#endif
}
static inline void __ftrace_enabled_restore(int enabled)
{
#ifdef CONFIG_FUNCTION_TRACER
ftrace_enabled = enabled;
#endif
}
#ifndef HAVE_ARCH_CALLER_ADDR
# ifdef CONFIG_FRAME_POINTER
# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
# define CALLER_ADDR1 ((unsigned long)__builtin_return_address(1))
# define CALLER_ADDR2 ((unsigned long)__builtin_return_address(2))
# define CALLER_ADDR3 ((unsigned long)__builtin_return_address(3))
# define CALLER_ADDR4 ((unsigned long)__builtin_return_address(4))
# define CALLER_ADDR5 ((unsigned long)__builtin_return_address(5))
# define CALLER_ADDR6 ((unsigned long)__builtin_return_address(6))
# else
# define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
# define CALLER_ADDR1 0UL
# define CALLER_ADDR2 0UL
# define CALLER_ADDR3 0UL
# define CALLER_ADDR4 0UL
# define CALLER_ADDR5 0UL
# define CALLER_ADDR6 0UL
# endif
#endif /* ifndef HAVE_ARCH_CALLER_ADDR */
#ifdef CONFIG_IRQSOFF_TRACER
extern void time_hardirqs_on(unsigned long a0, unsigned long a1);
extern void time_hardirqs_off(unsigned long a0, unsigned long a1);
#else
static inline void time_hardirqs_on(unsigned long a0, unsigned long a1) { }
static inline void time_hardirqs_off(unsigned long a0, unsigned long a1) { }
#endif
#ifdef CONFIG_PREEMPT_TRACER
extern void trace_preempt_on(unsigned long a0, unsigned long a1);
extern void trace_preempt_off(unsigned long a0, unsigned long a1);
#else
static inline void trace_preempt_on(unsigned long a0, unsigned long a1) { }
static inline void trace_preempt_off(unsigned long a0, unsigned long a1) { }
#endif
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
extern void ftrace_init(void);
#else
static inline void ftrace_init(void) { }
#endif
/*
* Structure that defines an entry function trace.
*/
struct ftrace_graph_ent {
unsigned long func; /* Current function */
int depth;
};
/*
* Structure that defines a return function trace.
*/
struct ftrace_graph_ret {
unsigned long func; /* Current function */
unsigned long long calltime;
unsigned long long rettime;
/* Number of functions that overran the depth limit for current task */
unsigned long overrun;
int depth;
};
/* Type of the callback handlers for tracing function graph*/
typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
/* for init task */
#define INIT_FTRACE_GRAPH .ret_stack = NULL,
/*
* 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;
unsigned long long subtime;
unsigned long fp;
};
/*
* 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 func, int *depth,
unsigned long frame_pointer);
/*
* 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
* tracer if the function graph tracer is not configured.
*/
#define __notrace_funcgraph notrace
/*
* We want to which function is an entrypoint of a hardirq.
* That will help us to put a signal on output.
*/
#define __irq_entry __attribute__((__section__(".irqentry.text")))
/* Limits of hardirq entrypoints */
extern char __irqentry_text_start[];
extern char __irqentry_text_end[];
#define FTRACE_RETFUNC_DEPTH 50
#define FTRACE_RETSTACK_ALLOC_SIZE 32
extern int register_ftrace_graph(trace_func_graph_ret_t retfunc,
trace_func_graph_ent_t entryfunc);
extern void ftrace_graph_stop(void);
/* The current handlers in use */
extern trace_func_graph_ret_t ftrace_graph_return;
extern trace_func_graph_ent_t ftrace_graph_entry;
extern void unregister_ftrace_graph(void);
extern void ftrace_graph_init_task(struct task_struct *t);
extern void ftrace_graph_exit_task(struct task_struct *t);
extern void ftrace_graph_init_idle_task(struct task_struct *t, int cpu);
static inline int task_curr_ret_stack(struct task_struct *t)
{
return t->curr_ret_stack;
}
static inline void pause_graph_tracing(void)
{
atomic_inc(&current->tracing_graph_pause);
}
static inline void unpause_graph_tracing(void)
{
atomic_dec(&current->tracing_graph_pause);
}
#else /* !CONFIG_FUNCTION_GRAPH_TRACER */
#define __notrace_funcgraph
#define __irq_entry
#define INIT_FTRACE_GRAPH
static inline void ftrace_graph_init_task(struct task_struct *t) { }
static inline void ftrace_graph_exit_task(struct task_struct *t) { }
static inline void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) { }
static inline int register_ftrace_graph(trace_func_graph_ret_t retfunc,
trace_func_graph_ent_t entryfunc)
{
return -1;
}
static inline void unregister_ftrace_graph(void) { }
static inline int task_curr_ret_stack(struct task_struct *tsk)
{
return -1;
}
static inline void pause_graph_tracing(void) { }
static inline void unpause_graph_tracing(void) { }
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#ifdef CONFIG_TRACING
/* flags for current->trace */
enum {
TSK_TRACE_FL_TRACE_BIT = 0,
TSK_TRACE_FL_GRAPH_BIT = 1,
};
enum {
TSK_TRACE_FL_TRACE = 1 << TSK_TRACE_FL_TRACE_BIT,
TSK_TRACE_FL_GRAPH = 1 << TSK_TRACE_FL_GRAPH_BIT,
};
static inline void set_tsk_trace_trace(struct task_struct *tsk)
{
set_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
}
static inline void clear_tsk_trace_trace(struct task_struct *tsk)
{
clear_bit(TSK_TRACE_FL_TRACE_BIT, &tsk->trace);
}
static inline int test_tsk_trace_trace(struct task_struct *tsk)
{
return tsk->trace & TSK_TRACE_FL_TRACE;
}
static inline void set_tsk_trace_graph(struct task_struct *tsk)
{
set_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
}
static inline void clear_tsk_trace_graph(struct task_struct *tsk)
{
clear_bit(TSK_TRACE_FL_GRAPH_BIT, &tsk->trace);
}
static inline int test_tsk_trace_graph(struct task_struct *tsk)
{
return tsk->trace & TSK_TRACE_FL_GRAPH;
}
enum ftrace_dump_mode;
extern enum ftrace_dump_mode ftrace_dump_on_oops;
#ifdef CONFIG_PREEMPT
#define INIT_TRACE_RECURSION .trace_recursion = 0,
#endif
#endif /* CONFIG_TRACING */
#ifndef INIT_TRACE_RECURSION
#define INIT_TRACE_RECURSION
#endif
#ifdef CONFIG_FTRACE_SYSCALLS
unsigned long arch_syscall_addr(int nr);
#endif /* CONFIG_FTRACE_SYSCALLS */
#endif /* _LINUX_FTRACE_H */