Current File : //proc/self/root/usr/src/linux-headers-5.15.0-43-generic/include/linux/ftrace.h
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Ftrace header. For implementation details beyond the random comments
* scattered below, see: Documentation/trace/ftrace-design.rst
*/
#ifndef _LINUX_FTRACE_H
#define _LINUX_FTRACE_H
#include <linux/trace_recursion.h>
#include <linux/trace_clock.h>
#include <linux/kallsyms.h>
#include <linux/linkage.h>
#include <linux/bitops.h>
#include <linux/ptrace.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>
/*
* If the arch supports passing the variable contents of
* function_trace_op as the third parameter back from the
* mcount call, then the arch should define this as 1.
*/
#ifndef ARCH_SUPPORTS_FTRACE_OPS
#define ARCH_SUPPORTS_FTRACE_OPS 0
#endif
/*
* If the arch's mcount caller does not support all of ftrace's
* features, then it must call an indirect function that
* does. Or at least does enough to prevent any unwelcome side effects.
*/
#if !ARCH_SUPPORTS_FTRACE_OPS
# define FTRACE_FORCE_LIST_FUNC 1
#else
# define FTRACE_FORCE_LIST_FUNC 0
#endif
/* Main tracing buffer and events set up */
#ifdef CONFIG_TRACING
void trace_init(void);
void early_trace_init(void);
#else
static inline void trace_init(void) { }
static inline void early_trace_init(void) { }
#endif
struct module;
struct ftrace_hash;
struct ftrace_direct_func;
#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_MODULES) && \
defined(CONFIG_DYNAMIC_FTRACE)
const char *
ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
unsigned long *off, char **modname, char *sym);
#else
static inline const char *
ftrace_mod_address_lookup(unsigned long addr, unsigned long *size,
unsigned long *off, char **modname, char *sym)
{
return NULL;
}
#endif
#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE)
int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
char *type, char *name,
char *module_name, int *exported);
#else
static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value,
char *type, char *name,
char *module_name, int *exported)
{
return -1;
}
#endif
#ifdef CONFIG_FUNCTION_TRACER
extern int ftrace_enabled;
extern int
ftrace_enable_sysctl(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos);
struct ftrace_ops;
#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS
struct ftrace_regs {
struct pt_regs regs;
};
#define arch_ftrace_get_regs(fregs) (&(fregs)->regs)
/*
* ftrace_instruction_pointer_set() is to be defined by the architecture
* if to allow setting of the instruction pointer from the ftrace_regs
* when HAVE_DYNAMIC_FTRACE_WITH_ARGS is set and it supports
* live kernel patching.
*/
#define ftrace_instruction_pointer_set(fregs, ip) do { } while (0)
#endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS */
static __always_inline struct pt_regs *ftrace_get_regs(struct ftrace_regs *fregs)
{
if (!fregs)
return NULL;
return arch_ftrace_get_regs(fregs);
}
typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct ftrace_regs *fregs);
ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops);
/*
* FTRACE_OPS_FL_* bits denote the state of ftrace_ops struct and are
* set in the flags member.
* CONTROL, SAVE_REGS, SAVE_REGS_IF_SUPPORTED, RECURSION, STUB and
* IPMODIFY are a kind of attribute flags which can be set only before
* registering the ftrace_ops, and can not be modified while registered.
* Changing those attribute flags after registering ftrace_ops will
* cause unexpected results.
*
* ENABLED - set/unset when ftrace_ops is registered/unregistered
* DYNAMIC - set when ftrace_ops is registered to denote dynamically
* allocated ftrace_ops which need special care
* SAVE_REGS - The ftrace_ops wants regs saved at each function called
* and passed to the callback. If this flag is set, but the
* architecture does not support passing regs
* (CONFIG_DYNAMIC_FTRACE_WITH_REGS is not defined), then the
* ftrace_ops will fail to register, unless the next flag
* is set.
* SAVE_REGS_IF_SUPPORTED - This is the same as SAVE_REGS, but if the
* handler can handle an arch that does not save regs
* (the handler tests if regs == NULL), then it can set
* this flag instead. It will not fail registering the ftrace_ops
* but, the regs field will be NULL if the arch does not support
* passing regs to the handler.
* Note, if this flag is set, the SAVE_REGS flag will automatically
* get set upon registering the ftrace_ops, if the arch supports it.
* RECURSION - The ftrace_ops can set this to tell the ftrace infrastructure
* that the call back needs recursion protection. If it does
* not set this, then the ftrace infrastructure will assume
* that the callback can handle recursion on its own.
* STUB - The ftrace_ops is just a place holder.
* INITIALIZED - The ftrace_ops has already been initialized (first use time
* register_ftrace_function() is called, it will initialized the ops)
* DELETED - The ops are being deleted, do not let them be registered again.
* ADDING - The ops is in the process of being added.
* REMOVING - The ops is in the process of being removed.
* MODIFYING - The ops is in the process of changing its filter functions.
* ALLOC_TRAMP - A dynamic trampoline was allocated by the core code.
* The arch specific code sets this flag when it allocated a
* trampoline. This lets the arch know that it can update the
* trampoline in case the callback function changes.
* The ftrace_ops trampoline can be set by the ftrace users, and
* in such cases the arch must not modify it. Only the arch ftrace
* core code should set this flag.
* IPMODIFY - The ops can modify the IP register. This can only be set with
* SAVE_REGS. If another ops with this flag set is already registered
* for any of the functions that this ops will be registered for, then
* this ops will fail to register or set_filter_ip.
* PID - Is affected by set_ftrace_pid (allows filtering on those pids)
* RCU - Set when the ops can only be called when RCU is watching.
* TRACE_ARRAY - The ops->private points to a trace_array descriptor.
* PERMANENT - Set when the ops is permanent and should not be affected by
* ftrace_enabled.
* DIRECT - Used by the direct ftrace_ops helper for direct functions
* (internal ftrace only, should not be used by others)
*/
enum {
FTRACE_OPS_FL_ENABLED = BIT(0),
FTRACE_OPS_FL_DYNAMIC = BIT(1),
FTRACE_OPS_FL_SAVE_REGS = BIT(2),
FTRACE_OPS_FL_SAVE_REGS_IF_SUPPORTED = BIT(3),
FTRACE_OPS_FL_RECURSION = BIT(4),
FTRACE_OPS_FL_STUB = BIT(5),
FTRACE_OPS_FL_INITIALIZED = BIT(6),
FTRACE_OPS_FL_DELETED = BIT(7),
FTRACE_OPS_FL_ADDING = BIT(8),
FTRACE_OPS_FL_REMOVING = BIT(9),
FTRACE_OPS_FL_MODIFYING = BIT(10),
FTRACE_OPS_FL_ALLOC_TRAMP = BIT(11),
FTRACE_OPS_FL_IPMODIFY = BIT(12),
FTRACE_OPS_FL_PID = BIT(13),
FTRACE_OPS_FL_RCU = BIT(14),
FTRACE_OPS_FL_TRACE_ARRAY = BIT(15),
FTRACE_OPS_FL_PERMANENT = BIT(16),
FTRACE_OPS_FL_DIRECT = BIT(17),
};
#ifdef CONFIG_DYNAMIC_FTRACE
/* The hash used to know what functions callbacks trace */
struct ftrace_ops_hash {
struct ftrace_hash __rcu *notrace_hash;
struct ftrace_hash __rcu *filter_hash;
struct mutex regex_lock;
};
void ftrace_free_init_mem(void);
void ftrace_free_mem(struct module *mod, void *start, void *end);
#else
static inline void ftrace_free_init_mem(void) { }
static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
#endif
/*
* Note, ftrace_ops can be referenced outside of RCU protection, unless
* the RCU flag is set. If ftrace_ops is allocated and not part of kernel
* core data, the unregistering of it will perform a scheduling on all CPUs
* to make sure that there are no more users. Depending on the load of the
* system that may take a bit of time.
*
* Any private data added must also take care not to be freed and if private
* data is added to a ftrace_ops that is in core code, the user of the
* ftrace_ops must perform a schedule_on_each_cpu() before freeing it.
*/
struct ftrace_ops {
ftrace_func_t func;
struct ftrace_ops __rcu *next;
unsigned long flags;
void *private;
ftrace_func_t saved_func;
#ifdef CONFIG_DYNAMIC_FTRACE
struct ftrace_ops_hash local_hash;
struct ftrace_ops_hash *func_hash;
struct ftrace_ops_hash old_hash;
unsigned long trampoline;
unsigned long trampoline_size;
struct list_head list;
#endif
};
extern struct ftrace_ops __rcu *ftrace_ops_list;
extern struct ftrace_ops ftrace_list_end;
/*
* Traverse the ftrace_ops_list, invoking all entries. The reason that we
* can use rcu_dereference_raw_check() is that elements removed from this list
* are simply leaked, so there is no need to interact with a grace-period
* mechanism. The rcu_dereference_raw_check() calls are needed to handle
* concurrent insertions into the ftrace_ops_list.
*
* Silly Alpha and silly pointer-speculation compiler optimizations!
*/
#define do_for_each_ftrace_op(op, list) \
op = rcu_dereference_raw_check(list); \
do
/*
* Optimized for just a single item in the list (as that is the normal case).
*/
#define while_for_each_ftrace_op(op) \
while (likely(op = rcu_dereference_raw_check((op)->next)) && \
unlikely((op) != &ftrace_list_end))
/*
* 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;
/*
* 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);
extern void ftrace_stub(unsigned long a0, unsigned long a1,
struct ftrace_ops *op, struct ftrace_regs *fregs);
#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 ftrace_kill(void) { }
static inline void ftrace_free_init_mem(void) { }
static inline void ftrace_free_mem(struct module *mod, void *start, void *end) { }
#endif /* CONFIG_FUNCTION_TRACER */
struct ftrace_func_entry {
struct hlist_node hlist;
unsigned long ip;
unsigned long direct; /* for direct lookup only */
};
struct dyn_ftrace;
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
extern int ftrace_direct_func_count;
int register_ftrace_direct(unsigned long ip, unsigned long addr);
int unregister_ftrace_direct(unsigned long ip, unsigned long addr);
int modify_ftrace_direct(unsigned long ip, unsigned long old_addr, unsigned long new_addr);
struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr);
int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
struct dyn_ftrace *rec,
unsigned long old_addr,
unsigned long new_addr);
unsigned long ftrace_find_rec_direct(unsigned long ip);
#else
# define ftrace_direct_func_count 0
static inline int register_ftrace_direct(unsigned long ip, unsigned long addr)
{
return -ENOTSUPP;
}
static inline int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
{
return -ENOTSUPP;
}
static inline int modify_ftrace_direct(unsigned long ip,
unsigned long old_addr, unsigned long new_addr)
{
return -ENOTSUPP;
}
static inline struct ftrace_direct_func *ftrace_find_direct_func(unsigned long addr)
{
return NULL;
}
static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry,
struct dyn_ftrace *rec,
unsigned long old_addr,
unsigned long new_addr)
{
return -ENODEV;
}
static inline unsigned long ftrace_find_rec_direct(unsigned long ip)
{
return 0;
}
#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
/*
* This must be implemented by the architecture.
* It is the way the ftrace direct_ops helper, when called
* via ftrace (because there's other callbacks besides the
* direct call), can inform the architecture's trampoline that this
* routine has a direct caller, and what the caller is.
*
* For example, in x86, it returns the direct caller
* callback function via the regs->orig_ax parameter.
* Then in the ftrace trampoline, if this is set, it makes
* the return from the trampoline jump to the direct caller
* instead of going back to the function it just traced.
*/
static inline void arch_ftrace_set_direct_caller(struct pt_regs *regs,
unsigned long addr) { }
#endif /* CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
#ifdef CONFIG_STACK_TRACER
extern int stack_tracer_enabled;
int stack_trace_sysctl(struct ctl_table *table, int write, void *buffer,
size_t *lenp, loff_t *ppos);
/* DO NOT MODIFY THIS VARIABLE DIRECTLY! */
DECLARE_PER_CPU(int, disable_stack_tracer);
/**
* stack_tracer_disable - temporarily disable the stack tracer
*
* There's a few locations (namely in RCU) where stack tracing
* cannot be executed. This function is used to disable stack
* tracing during those critical sections.
*
* This function must be called with preemption or interrupts
* disabled and stack_tracer_enable() must be called shortly after
* while preemption or interrupts are still disabled.
*/
static inline void stack_tracer_disable(void)
{
/* Preemption or interrupts must be disabled */
if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
this_cpu_inc(disable_stack_tracer);
}
/**
* stack_tracer_enable - re-enable the stack tracer
*
* After stack_tracer_disable() is called, stack_tracer_enable()
* must be called shortly afterward.
*/
static inline void stack_tracer_enable(void)
{
if (IS_ENABLED(CONFIG_DEBUG_PREEMPT))
WARN_ON_ONCE(!preempt_count() || !irqs_disabled());
this_cpu_dec(disable_stack_tracer);
}
#else
static inline void stack_tracer_disable(void) { }
static inline void stack_tracer_enable(void) { }
#endif
#ifdef CONFIG_DYNAMIC_FTRACE
int ftrace_arch_code_modify_prepare(void);
int ftrace_arch_code_modify_post_process(void);
enum ftrace_bug_type {
FTRACE_BUG_UNKNOWN,
FTRACE_BUG_INIT,
FTRACE_BUG_NOP,
FTRACE_BUG_CALL,
FTRACE_BUG_UPDATE,
};
extern enum ftrace_bug_type ftrace_bug_type;
/*
* Archs can set this to point to a variable that holds the value that was
* expected at the call site before calling ftrace_bug().
*/
extern const void *ftrace_expected;
void ftrace_bug(int err, struct dyn_ftrace *rec);
struct seq_file;
extern int ftrace_text_reserved(const void *start, const void *end);
struct ftrace_ops *ftrace_ops_trampoline(unsigned long addr);
bool is_ftrace_trampoline(unsigned long addr);
/*
* The dyn_ftrace record's flags field is split into two parts.
* the first part which is '0-FTRACE_REF_MAX' is a counter of
* the number of callbacks that have registered the function that
* the dyn_ftrace descriptor represents.
*
* The second part is a mask:
* ENABLED - the function is being traced
* REGS - the record wants the function to save regs
* REGS_EN - the function is set up to save regs.
* IPMODIFY - the record allows for the IP address to be changed.
* DISABLED - the record is not ready to be touched yet
* DIRECT - there is a direct function to call
*
* When a new ftrace_ops is registered and wants a function to save
* pt_regs, the rec->flags REGS is set. When the function has been
* set up to save regs, the REG_EN flag is set. Once a function
* starts saving regs it will do so until all ftrace_ops are removed
* from tracing that function.
*/
enum {
FTRACE_FL_ENABLED = (1UL << 31),
FTRACE_FL_REGS = (1UL << 30),
FTRACE_FL_REGS_EN = (1UL << 29),
FTRACE_FL_TRAMP = (1UL << 28),
FTRACE_FL_TRAMP_EN = (1UL << 27),
FTRACE_FL_IPMODIFY = (1UL << 26),
FTRACE_FL_DISABLED = (1UL << 25),
FTRACE_FL_DIRECT = (1UL << 24),
FTRACE_FL_DIRECT_EN = (1UL << 23),
};
#define FTRACE_REF_MAX_SHIFT 23
#define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
#define ftrace_rec_count(rec) ((rec)->flags & FTRACE_REF_MAX)
struct dyn_ftrace {
unsigned long ip; /* address of mcount call-site */
unsigned long flags;
struct dyn_arch_ftrace arch;
};
int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip,
int remove, int reset);
int ftrace_set_filter(struct ftrace_ops *ops, unsigned char *buf,
int len, int reset);
int 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);
void ftrace_free_filter(struct ftrace_ops *ops);
void ftrace_ops_set_global_filter(struct ftrace_ops *ops);
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),
FTRACE_MAY_SLEEP = (1 << 5),
};
/*
* The FTRACE_UPDATE_* enum is used to pass information back
* from the ftrace_update_record() and ftrace_test_record()
* functions. These are called by the code update routines
* to find out what is to be done for a given function.
*
* IGNORE - The function is already what we want it to be
* MAKE_CALL - Start tracing the function
* MODIFY_CALL - Stop saving regs for the function
* MAKE_NOP - Stop tracing the function
*/
enum {
FTRACE_UPDATE_IGNORE,
FTRACE_UPDATE_MAKE_CALL,
FTRACE_UPDATE_MODIFY_CALL,
FTRACE_UPDATE_MAKE_NOP,
};
enum {
FTRACE_ITER_FILTER = (1 << 0),
FTRACE_ITER_NOTRACE = (1 << 1),
FTRACE_ITER_PRINTALL = (1 << 2),
FTRACE_ITER_DO_PROBES = (1 << 3),
FTRACE_ITER_PROBE = (1 << 4),
FTRACE_ITER_MOD = (1 << 5),
FTRACE_ITER_ENABLED = (1 << 6),
};
void arch_ftrace_update_code(int command);
void arch_ftrace_update_trampoline(struct ftrace_ops *ops);
void *arch_ftrace_trampoline_func(struct ftrace_ops *ops, struct dyn_ftrace *rec);
void arch_ftrace_trampoline_free(struct ftrace_ops *ops);
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);
#define for_ftrace_rec_iter(iter) \
for (iter = ftrace_rec_iter_start(); \
iter; \
iter = ftrace_rec_iter_next(iter))
int ftrace_update_record(struct dyn_ftrace *rec, bool enable);
int ftrace_test_record(struct dyn_ftrace *rec, bool enable);
void ftrace_run_stop_machine(int command);
unsigned long ftrace_location(unsigned long ip);
unsigned long ftrace_location_range(unsigned long start, unsigned long end);
unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec);
unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec);
extern ftrace_func_t ftrace_trace_function;
int ftrace_regex_open(struct ftrace_ops *ops, int flag,
struct inode *inode, struct file *file);
ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
size_t cnt, loff_t *ppos);
ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
size_t cnt, loff_t *ppos);
int ftrace_regex_release(struct inode *inode, struct file *file);
void __init
ftrace_set_early_filter(struct ftrace_ops *ops, char *buf, int enable);
/* defined in arch */
extern int ftrace_ip_converted(unsigned long ip);
extern int ftrace_dyn_arch_init(void);
extern void ftrace_replace_code(int enable);
extern int ftrace_update_ftrace_func(ftrace_func_t func);
extern void ftrace_caller(void);
extern void ftrace_regs_caller(void);
extern void ftrace_call(void);
extern void ftrace_regs_call(void);
extern void mcount_call(void);
void ftrace_modify_all_code(int command);
#ifndef FTRACE_ADDR
#define FTRACE_ADDR ((unsigned long)ftrace_caller)
#endif
#ifndef FTRACE_GRAPH_ADDR
#define FTRACE_GRAPH_ADDR ((unsigned long)ftrace_graph_caller)
#endif
#ifndef FTRACE_REGS_ADDR
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
# define FTRACE_REGS_ADDR ((unsigned long)ftrace_regs_caller)
#else
# define FTRACE_REGS_ADDR FTRACE_ADDR
#endif
#endif
/*
* If an arch would like functions that are only traced
* by the function graph tracer to jump directly to its own
* trampoline, then they can define FTRACE_GRAPH_TRAMP_ADDR
* to be that address to jump to.
*/
#ifndef FTRACE_GRAPH_TRAMP_ADDR
#define FTRACE_GRAPH_TRAMP_ADDR ((unsigned long) 0)
#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 call site record (e.g. mcount/fentry)
* @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_need_init_nop - return whether nop call sites should be initialized
*
* Normally the compiler's -mnop-mcount generates suitable nops, so we don't
* need to call ftrace_init_nop() if the code is built with that flag.
* Architectures where this is not always the case may define their own
* condition.
*
* Return must be:
* 0 if ftrace_init_nop() should be called
* Nonzero if ftrace_init_nop() should not be called
*/
#ifndef ftrace_need_init_nop
#define ftrace_need_init_nop() (!__is_defined(CC_USING_NOP_MCOUNT))
#endif
/**
* ftrace_init_nop - initialize a nop call site
* @mod: module structure if called by module load initialization
* @rec: the call site record (e.g. mcount/fentry)
*
* 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 contain the contents created by
* the compiler
*
* 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.
*/
#ifndef ftrace_init_nop
static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec)
{
return ftrace_make_nop(mod, rec, MCOUNT_ADDR);
}
#endif
/**
* ftrace_make_call - convert a nop call site into a call to addr
* @rec: the call site record (e.g. mcount/fentry)
* @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);
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
/**
* ftrace_modify_call - convert from one addr to another (no nop)
* @rec: the call site record (e.g. mcount/fentry)
* @old_addr: the address expected to be currently called to
* @addr: the address to change to
*
* 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 @old_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_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
unsigned long addr);
#else
/* Should never be called */
static inline int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
unsigned long addr)
{
return -EINVAL;
}
#endif
/* 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_module_init(struct module *mod);
extern void ftrace_module_enable(struct module *mod);
extern void ftrace_release_mod(struct module *mod);
extern void ftrace_disable_daemon(void);
extern void ftrace_enable_daemon(void);
#else /* CONFIG_DYNAMIC_FTRACE */
static inline int skip_trace(unsigned long ip) { return 0; }
static inline void ftrace_disable_daemon(void) { }
static inline void ftrace_enable_daemon(void) { }
static inline void ftrace_module_init(struct module *mod) { }
static inline void ftrace_module_enable(struct module *mod) { }
static inline void ftrace_release_mod(struct module *mod) { }
static inline int ftrace_text_reserved(const void *start, const void *end)
{
return 0;
}
static inline unsigned long ftrace_location(unsigned long ip)
{
return 0;
}
/*
* Again users of functions that have ftrace_ops may not
* have them defined when ftrace is not enabled, but these
* functions may still be called. Use a macro instead of inline.
*/
#define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; })
#define ftrace_set_early_filter(ops, buf, enable) do { } while (0)
#define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; })
#define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; })
#define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; })
#define ftrace_free_filter(ops) do { } while (0)
#define ftrace_ops_set_global_filter(ops) do { } while (0)
static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf,
size_t cnt, loff_t *ppos) { return -ENODEV; }
static inline ssize_t ftrace_notrace_write(struct file *file, const char __user *ubuf,
size_t cnt, loff_t *ppos) { return -ENODEV; }
static inline int
ftrace_regex_release(struct inode *inode, struct file *file) { return -ENODEV; }
static inline bool is_ftrace_trampoline(unsigned long addr)
{
return false;
}
#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
}
/* All archs should have this, but we define it for consistency */
#ifndef ftrace_return_address0
# define ftrace_return_address0 __builtin_return_address(0)
#endif
/* Archs may use other ways for ADDR1 and beyond */
#ifndef ftrace_return_address
# ifdef CONFIG_FRAME_POINTER
# define ftrace_return_address(n) __builtin_return_address(n)
# else
# define ftrace_return_address(n) 0UL
# endif
#endif
#define CALLER_ADDR0 ((unsigned long)ftrace_return_address0)
#define CALLER_ADDR1 ((unsigned long)ftrace_return_address(1))
#define CALLER_ADDR2 ((unsigned long)ftrace_return_address(2))
#define CALLER_ADDR3 ((unsigned long)ftrace_return_address(3))
#define CALLER_ADDR4 ((unsigned long)ftrace_return_address(4))
#define CALLER_ADDR5 ((unsigned long)ftrace_return_address(5))
#define CALLER_ADDR6 ((unsigned long)ftrace_return_address(6))
static inline unsigned long get_lock_parent_ip(void)
{
unsigned long addr = CALLER_ADDR0;
if (!in_lock_functions(addr))
return addr;
addr = CALLER_ADDR1;
if (!in_lock_functions(addr))
return addr;
return CALLER_ADDR2;
}
#ifdef CONFIG_TRACE_PREEMPT_TOGGLE
extern void trace_preempt_on(unsigned long a0, unsigned long a1);
extern void trace_preempt_off(unsigned long a0, unsigned long a1);
#else
/*
* Use defines instead of static inlines because some arches will make code out
* of the CALLER_ADDR, when we really want these to be a real nop.
*/
# define trace_preempt_on(a0, a1) do { } while (0)
# define trace_preempt_off(a0, a1) do { } while (0)
#endif
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
extern void ftrace_init(void);
#ifdef CC_USING_PATCHABLE_FUNCTION_ENTRY
#define FTRACE_CALLSITE_SECTION "__patchable_function_entries"
#else
#define FTRACE_CALLSITE_SECTION "__mcount_loc"
#endif
#else
static inline void ftrace_init(void) { }
#endif
/*
* Structure that defines an entry function trace.
* It's already packed but the attribute "packed" is needed
* to remove extra padding at the end.
*/
struct ftrace_graph_ent {
unsigned long func; /* Current function */
int depth;
} __packed;
/*
* Structure that defines a return function trace.
* It's already packed but the attribute "packed" is needed
* to remove extra padding at the end.
*/
struct ftrace_graph_ret {
unsigned long func; /* Current function */
int depth;
/* Number of functions that overran the depth limit for current task */
unsigned int overrun;
unsigned long long calltime;
unsigned long long rettime;
} __packed;
/* 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 */
extern int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace);
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
struct fgraph_ops {
trace_func_graph_ent_t entryfunc;
trace_func_graph_ret_t retfunc;
};
/*
* 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;
#ifdef CONFIG_FUNCTION_PROFILER
unsigned long long subtime;
#endif
#ifdef HAVE_FUNCTION_GRAPH_FP_TEST
unsigned long fp;
#endif
#ifdef HAVE_FUNCTION_GRAPH_RET_ADDR_PTR
unsigned long *retp;
#endif
};
/*
* 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
function_graph_enter(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp);
struct ftrace_ret_stack *
ftrace_graph_get_ret_stack(struct task_struct *task, int idx);
unsigned long ftrace_graph_ret_addr(struct task_struct *task, int *idx,
unsigned long ret, unsigned long *retp);
/*
* 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
#define FTRACE_RETFUNC_DEPTH 50
#define FTRACE_RETSTACK_ALLOC_SIZE 32
extern int register_ftrace_graph(struct fgraph_ops *ops);
extern void unregister_ftrace_graph(struct fgraph_ops *ops);
extern bool ftrace_graph_is_dead(void);
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 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 void pause_graph_tracing(void)
{
atomic_inc(¤t->tracing_graph_pause);
}
static inline void unpause_graph_tracing(void)
{
atomic_dec(¤t->tracing_graph_pause);
}
#else /* !CONFIG_FUNCTION_GRAPH_TRACER */
#define __notrace_funcgraph
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) { }
/* Define as macros as fgraph_ops may not be defined */
#define register_ftrace_graph(ops) ({ -1; })
#define unregister_ftrace_graph(ops) do { } while (0)
static inline unsigned long
ftrace_graph_ret_addr(struct task_struct *task, int *idx, unsigned long ret,
unsigned long *retp)
{
return ret;
}
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;
extern int tracepoint_printk;
extern void disable_trace_on_warning(void);
extern int __disable_trace_on_warning;
int tracepoint_printk_sysctl(struct ctl_table *table, int write,
void *buffer, size_t *lenp, loff_t *ppos);
#else /* CONFIG_TRACING */
static inline void disable_trace_on_warning(void) { }
#endif /* CONFIG_TRACING */
#ifdef CONFIG_FTRACE_SYSCALLS
unsigned long arch_syscall_addr(int nr);
#endif /* CONFIG_FTRACE_SYSCALLS */
#endif /* _LINUX_FTRACE_H */
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