/* 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/jump_label.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 #ifdef CONFIG_TRACING extern void ftrace_boot_snapshot(void); #else static inline void ftrace_boot_snapshot(void) { } #endif #ifdef CONFIG_FUNCTION_TRACER struct ftrace_ops; struct ftrace_regs; /* * 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. * * Also define the function prototype that these architectures use * to call the ftrace_ops_list_func(). */ #if !ARCH_SUPPORTS_FTRACE_OPS # define FTRACE_FORCE_LIST_FUNC 1 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip); #else # define FTRACE_FORCE_LIST_FUNC 0 void arch_ftrace_ops_list_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct ftrace_regs *fregs); #endif #endif /* CONFIG_FUNCTION_TRACER */ /* 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; #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) { ftrace_boot_snapshot(); } 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); int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs); #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) { } static inline int ftrace_lookup_symbols(const char **sorted_syms, size_t cnt, unsigned long *addrs) { return -EOPNOTSUPP; } #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); int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr); #else struct ftrace_ops; # 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; } static inline int register_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) { return -ENODEV; } static inline int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) { return -ENODEV; } static inline int modify_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) { return -ENODEV; } #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 void ftrace_arch_code_modify_prepare(void); void 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_ips(struct ftrace_ops *ops, unsigned long *ips, unsigned int cnt, 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_ips(ops, ips, cnt, 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 */ #ifdef CONFIG_FUNCTION_GRAPH_TRACER #ifndef ftrace_graph_func #define ftrace_graph_func ftrace_stub #define FTRACE_OPS_GRAPH_STUB FTRACE_OPS_FL_STUB #else #define FTRACE_OPS_GRAPH_STUB 0 #endif #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ /* 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); /** * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called * * ftrace_graph_stop() is called when a severe error is detected in * the function graph tracing. This function is called by the critical * paths of function graph to keep those paths from doing any more harm. */ DECLARE_STATIC_KEY_FALSE(kill_ftrace_graph); static inline bool ftrace_graph_is_dead(void) { return static_branch_unlikely(&kill_ftrace_graph); } 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 */