linux-stable/include/linux/ftrace.h
Adrian Hunter fc0ea795f5 ftrace: Add symbols for ftrace trampolines
Symbols are needed for tools to describe instruction addresses. Pages
allocated for ftrace's purposes need symbols to be created for them.
Add such symbols to be visible via /proc/kallsyms.

Example on x86 with CONFIG_DYNAMIC_FTRACE=y

	# echo function > /sys/kernel/debug/tracing/current_tracer
	# cat /proc/kallsyms | grep '\[__builtin__ftrace\]'
	ffffffffc0238000 t ftrace_trampoline    [__builtin__ftrace]

Note: This patch adds "__builtin__ftrace" as a module name in /proc/kallsyms for
symbols for pages allocated for ftrace's purposes, even though "__builtin__ftrace"
is not a module.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200512121922.8997-7-adrian.hunter@intel.com
2020-06-15 14:09:49 +02:00

1046 lines
34 KiB
C

/* 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_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 unwelcomed 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 __user *buffer, size_t *lenp,
loff_t *ppos);
struct ftrace_ops;
typedef void (*ftrace_func_t)(unsigned long ip, unsigned long parent_ip,
struct ftrace_ops *op, struct pt_regs *regs);
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_SAFE, 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_SAFE - The ftrace_ops can set this to tell the ftrace infrastructure
* that the call back has its own recursion protection. If it does
* not set this, then the ftrace infrastructure will add recursion
* protection for the caller.
* 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_SAFE = 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_global_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_global_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 pt_regs *regs);
#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 interupts 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->flag 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_FL_BITS 9
#define FTRACE_FL_MASKED_BITS ((1UL << FTRACE_FL_BITS) - 1)
#define FTRACE_FL_MASK (FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
#define FTRACE_REF_MAX ((1UL << FTRACE_REF_MAX_SHIFT) - 1)
#define ftrace_rec_count(rec) ((rec)->flags & ~FTRACE_FL_MASK)
struct dyn_ftrace {
unsigned long ip; /* address of mcount call-site */
unsigned long flags;
struct dyn_arch_ftrace arch;
};
int ftrace_force_update(void);
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_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 int ftrace_force_update(void) { 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 */
/* Number of functions that overran the depth limit for current task */
unsigned long overrun;
unsigned long long calltime;
unsigned long long rettime;
int depth;
} __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(&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
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 */