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- /* SPDX-License-Identifier: GPL-2.0-or-later */
- #ifndef _LINUX_KPROBES_H
- #define _LINUX_KPROBES_H
- /*
- * Kernel Probes (KProbes)
- *
- * Copyright (C) IBM Corporation, 2002, 2004
- *
- * 2002-Oct Created by Vamsi Krishna S <[email protected]> Kernel
- * Probes initial implementation ( includes suggestions from
- * Rusty Russell).
- * 2004-July Suparna Bhattacharya <[email protected]> added jumper probes
- * interface to access function arguments.
- * 2005-May Hien Nguyen <[email protected]> and Jim Keniston
- * <[email protected]> and Prasanna S Panchamukhi
- * <[email protected]> added function-return probes.
- */
- #include <linux/compiler.h>
- #include <linux/linkage.h>
- #include <linux/list.h>
- #include <linux/notifier.h>
- #include <linux/smp.h>
- #include <linux/bug.h>
- #include <linux/percpu.h>
- #include <linux/spinlock.h>
- #include <linux/rcupdate.h>
- #include <linux/mutex.h>
- #include <linux/ftrace.h>
- #include <linux/refcount.h>
- #include <linux/freelist.h>
- #include <linux/rethook.h>
- #include <asm/kprobes.h>
- #ifdef CONFIG_KPROBES
- /* kprobe_status settings */
- #define KPROBE_HIT_ACTIVE 0x00000001
- #define KPROBE_HIT_SS 0x00000002
- #define KPROBE_REENTER 0x00000004
- #define KPROBE_HIT_SSDONE 0x00000008
- #else /* !CONFIG_KPROBES */
- #include <asm-generic/kprobes.h>
- typedef int kprobe_opcode_t;
- struct arch_specific_insn {
- int dummy;
- };
- #endif /* CONFIG_KPROBES */
- struct kprobe;
- struct pt_regs;
- struct kretprobe;
- struct kretprobe_instance;
- typedef int (*kprobe_pre_handler_t) (struct kprobe *, struct pt_regs *);
- typedef void (*kprobe_post_handler_t) (struct kprobe *, struct pt_regs *,
- unsigned long flags);
- typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
- struct pt_regs *);
- struct kprobe {
- struct hlist_node hlist;
- /* list of kprobes for multi-handler support */
- struct list_head list;
- /*count the number of times this probe was temporarily disarmed */
- unsigned long nmissed;
- /* location of the probe point */
- kprobe_opcode_t *addr;
- /* Allow user to indicate symbol name of the probe point */
- const char *symbol_name;
- /* Offset into the symbol */
- unsigned int offset;
- /* Called before addr is executed. */
- kprobe_pre_handler_t pre_handler;
- /* Called after addr is executed, unless... */
- kprobe_post_handler_t post_handler;
- /* Saved opcode (which has been replaced with breakpoint) */
- kprobe_opcode_t opcode;
- /* copy of the original instruction */
- struct arch_specific_insn ainsn;
- /*
- * Indicates various status flags.
- * Protected by kprobe_mutex after this kprobe is registered.
- */
- u32 flags;
- };
- /* Kprobe status flags */
- #define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
- #define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
- #define KPROBE_FLAG_OPTIMIZED 4 /*
- * probe is really optimized.
- * NOTE:
- * this flag is only for optimized_kprobe.
- */
- #define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */
- #define KPROBE_FLAG_ON_FUNC_ENTRY 16 /* probe is on the function entry */
- /* Has this kprobe gone ? */
- static inline bool kprobe_gone(struct kprobe *p)
- {
- return p->flags & KPROBE_FLAG_GONE;
- }
- /* Is this kprobe disabled ? */
- static inline bool kprobe_disabled(struct kprobe *p)
- {
- return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
- }
- /* Is this kprobe really running optimized path ? */
- static inline bool kprobe_optimized(struct kprobe *p)
- {
- return p->flags & KPROBE_FLAG_OPTIMIZED;
- }
- /* Is this kprobe uses ftrace ? */
- static inline bool kprobe_ftrace(struct kprobe *p)
- {
- return p->flags & KPROBE_FLAG_FTRACE;
- }
- /*
- * Function-return probe -
- * Note:
- * User needs to provide a handler function, and initialize maxactive.
- * maxactive - The maximum number of instances of the probed function that
- * can be active concurrently.
- * nmissed - tracks the number of times the probed function's return was
- * ignored, due to maxactive being too low.
- *
- */
- struct kretprobe_holder {
- struct kretprobe __rcu *rp;
- refcount_t ref;
- };
- struct kretprobe {
- struct kprobe kp;
- kretprobe_handler_t handler;
- kretprobe_handler_t entry_handler;
- int maxactive;
- int nmissed;
- size_t data_size;
- #ifdef CONFIG_KRETPROBE_ON_RETHOOK
- struct rethook *rh;
- #else
- struct freelist_head freelist;
- struct kretprobe_holder *rph;
- #endif
- };
- #define KRETPROBE_MAX_DATA_SIZE 4096
- struct kretprobe_instance {
- #ifdef CONFIG_KRETPROBE_ON_RETHOOK
- struct rethook_node node;
- #else
- union {
- struct freelist_node freelist;
- struct rcu_head rcu;
- };
- struct llist_node llist;
- struct kretprobe_holder *rph;
- kprobe_opcode_t *ret_addr;
- void *fp;
- #endif
- char data[];
- };
- struct kretprobe_blackpoint {
- const char *name;
- void *addr;
- };
- struct kprobe_blacklist_entry {
- struct list_head list;
- unsigned long start_addr;
- unsigned long end_addr;
- };
- #ifdef CONFIG_KPROBES
- DECLARE_PER_CPU(struct kprobe *, current_kprobe);
- DECLARE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
- extern void kprobe_busy_begin(void);
- extern void kprobe_busy_end(void);
- #ifdef CONFIG_KRETPROBES
- /* Check whether @p is used for implementing a trampoline. */
- extern int arch_trampoline_kprobe(struct kprobe *p);
- #ifdef CONFIG_KRETPROBE_ON_RETHOOK
- static nokprobe_inline struct kretprobe *get_kretprobe(struct kretprobe_instance *ri)
- {
- /* rethook::data is non-changed field, so that you can access it freely. */
- return (struct kretprobe *)ri->node.rethook->data;
- }
- static nokprobe_inline unsigned long get_kretprobe_retaddr(struct kretprobe_instance *ri)
- {
- return ri->node.ret_addr;
- }
- #else
- extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
- struct pt_regs *regs);
- void arch_kretprobe_fixup_return(struct pt_regs *regs,
- kprobe_opcode_t *correct_ret_addr);
- void __kretprobe_trampoline(void);
- /*
- * Since some architecture uses structured function pointer,
- * use dereference_function_descriptor() to get real function address.
- */
- static nokprobe_inline void *kretprobe_trampoline_addr(void)
- {
- return dereference_kernel_function_descriptor(__kretprobe_trampoline);
- }
- /* If the trampoline handler called from a kprobe, use this version */
- unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs,
- void *frame_pointer);
- static nokprobe_inline
- unsigned long kretprobe_trampoline_handler(struct pt_regs *regs,
- void *frame_pointer)
- {
- unsigned long ret;
- /*
- * Set a dummy kprobe for avoiding kretprobe recursion.
- * Since kretprobe never runs in kprobe handler, no kprobe must
- * be running at this point.
- */
- kprobe_busy_begin();
- ret = __kretprobe_trampoline_handler(regs, frame_pointer);
- kprobe_busy_end();
- return ret;
- }
- static nokprobe_inline struct kretprobe *get_kretprobe(struct kretprobe_instance *ri)
- {
- return rcu_dereference_check(ri->rph->rp, rcu_read_lock_any_held());
- }
- static nokprobe_inline unsigned long get_kretprobe_retaddr(struct kretprobe_instance *ri)
- {
- return (unsigned long)ri->ret_addr;
- }
- #endif /* CONFIG_KRETPROBE_ON_RETHOOK */
- #else /* !CONFIG_KRETPROBES */
- static inline void arch_prepare_kretprobe(struct kretprobe *rp,
- struct pt_regs *regs)
- {
- }
- static inline int arch_trampoline_kprobe(struct kprobe *p)
- {
- return 0;
- }
- #endif /* CONFIG_KRETPROBES */
- /* Markers of '_kprobe_blacklist' section */
- extern unsigned long __start_kprobe_blacklist[];
- extern unsigned long __stop_kprobe_blacklist[];
- extern struct kretprobe_blackpoint kretprobe_blacklist[];
- #ifdef CONFIG_KPROBES_SANITY_TEST
- extern int init_test_probes(void);
- #else /* !CONFIG_KPROBES_SANITY_TEST */
- static inline int init_test_probes(void)
- {
- return 0;
- }
- #endif /* CONFIG_KPROBES_SANITY_TEST */
- extern int arch_prepare_kprobe(struct kprobe *p);
- extern void arch_arm_kprobe(struct kprobe *p);
- extern void arch_disarm_kprobe(struct kprobe *p);
- extern int arch_init_kprobes(void);
- extern void kprobes_inc_nmissed_count(struct kprobe *p);
- extern bool arch_within_kprobe_blacklist(unsigned long addr);
- extern int arch_populate_kprobe_blacklist(void);
- extern int kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset);
- extern bool within_kprobe_blacklist(unsigned long addr);
- extern int kprobe_add_ksym_blacklist(unsigned long entry);
- extern int kprobe_add_area_blacklist(unsigned long start, unsigned long end);
- struct kprobe_insn_cache {
- struct mutex mutex;
- void *(*alloc)(void); /* allocate insn page */
- void (*free)(void *); /* free insn page */
- const char *sym; /* symbol for insn pages */
- struct list_head pages; /* list of kprobe_insn_page */
- size_t insn_size; /* size of instruction slot */
- int nr_garbage;
- };
- #ifdef __ARCH_WANT_KPROBES_INSN_SLOT
- extern kprobe_opcode_t *__get_insn_slot(struct kprobe_insn_cache *c);
- extern void __free_insn_slot(struct kprobe_insn_cache *c,
- kprobe_opcode_t *slot, int dirty);
- /* sleep-less address checking routine */
- extern bool __is_insn_slot_addr(struct kprobe_insn_cache *c,
- unsigned long addr);
- #define DEFINE_INSN_CACHE_OPS(__name) \
- extern struct kprobe_insn_cache kprobe_##__name##_slots; \
- \
- static inline kprobe_opcode_t *get_##__name##_slot(void) \
- { \
- return __get_insn_slot(&kprobe_##__name##_slots); \
- } \
- \
- static inline void free_##__name##_slot(kprobe_opcode_t *slot, int dirty)\
- { \
- __free_insn_slot(&kprobe_##__name##_slots, slot, dirty); \
- } \
- \
- static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
- { \
- return __is_insn_slot_addr(&kprobe_##__name##_slots, addr); \
- }
- #define KPROBE_INSN_PAGE_SYM "kprobe_insn_page"
- #define KPROBE_OPTINSN_PAGE_SYM "kprobe_optinsn_page"
- int kprobe_cache_get_kallsym(struct kprobe_insn_cache *c, unsigned int *symnum,
- unsigned long *value, char *type, char *sym);
- #else /* !__ARCH_WANT_KPROBES_INSN_SLOT */
- #define DEFINE_INSN_CACHE_OPS(__name) \
- static inline bool is_kprobe_##__name##_slot(unsigned long addr) \
- { \
- return 0; \
- }
- #endif
- DEFINE_INSN_CACHE_OPS(insn);
- #ifdef CONFIG_OPTPROBES
- /*
- * Internal structure for direct jump optimized probe
- */
- struct optimized_kprobe {
- struct kprobe kp;
- struct list_head list; /* list for optimizing queue */
- struct arch_optimized_insn optinsn;
- };
- /* Architecture dependent functions for direct jump optimization */
- extern int arch_prepared_optinsn(struct arch_optimized_insn *optinsn);
- extern int arch_check_optimized_kprobe(struct optimized_kprobe *op);
- extern int arch_prepare_optimized_kprobe(struct optimized_kprobe *op,
- struct kprobe *orig);
- extern void arch_remove_optimized_kprobe(struct optimized_kprobe *op);
- extern void arch_optimize_kprobes(struct list_head *oplist);
- extern void arch_unoptimize_kprobes(struct list_head *oplist,
- struct list_head *done_list);
- extern void arch_unoptimize_kprobe(struct optimized_kprobe *op);
- extern int arch_within_optimized_kprobe(struct optimized_kprobe *op,
- kprobe_opcode_t *addr);
- extern void opt_pre_handler(struct kprobe *p, struct pt_regs *regs);
- DEFINE_INSN_CACHE_OPS(optinsn);
- extern void wait_for_kprobe_optimizer(void);
- bool optprobe_queued_unopt(struct optimized_kprobe *op);
- bool kprobe_disarmed(struct kprobe *p);
- #else /* !CONFIG_OPTPROBES */
- static inline void wait_for_kprobe_optimizer(void) { }
- #endif /* CONFIG_OPTPROBES */
- #ifdef CONFIG_KPROBES_ON_FTRACE
- extern void kprobe_ftrace_handler(unsigned long ip, unsigned long parent_ip,
- struct ftrace_ops *ops, struct ftrace_regs *fregs);
- extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
- #else
- static inline int arch_prepare_kprobe_ftrace(struct kprobe *p)
- {
- return -EINVAL;
- }
- #endif /* CONFIG_KPROBES_ON_FTRACE */
- /* Get the kprobe at this addr (if any) - called with preemption disabled */
- struct kprobe *get_kprobe(void *addr);
- /* kprobe_running() will just return the current_kprobe on this CPU */
- static inline struct kprobe *kprobe_running(void)
- {
- return __this_cpu_read(current_kprobe);
- }
- static inline void reset_current_kprobe(void)
- {
- __this_cpu_write(current_kprobe, NULL);
- }
- static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
- {
- return this_cpu_ptr(&kprobe_ctlblk);
- }
- kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset);
- kprobe_opcode_t *arch_adjust_kprobe_addr(unsigned long addr, unsigned long offset, bool *on_func_entry);
- int register_kprobe(struct kprobe *p);
- void unregister_kprobe(struct kprobe *p);
- int register_kprobes(struct kprobe **kps, int num);
- void unregister_kprobes(struct kprobe **kps, int num);
- int register_kretprobe(struct kretprobe *rp);
- void unregister_kretprobe(struct kretprobe *rp);
- int register_kretprobes(struct kretprobe **rps, int num);
- void unregister_kretprobes(struct kretprobe **rps, int num);
- #if defined(CONFIG_KRETPROBE_ON_RETHOOK) || !defined(CONFIG_KRETPROBES)
- #define kprobe_flush_task(tk) do {} while (0)
- #else
- void kprobe_flush_task(struct task_struct *tk);
- #endif
- void kprobe_free_init_mem(void);
- int disable_kprobe(struct kprobe *kp);
- int enable_kprobe(struct kprobe *kp);
- void dump_kprobe(struct kprobe *kp);
- void *alloc_insn_page(void);
- void *alloc_optinsn_page(void);
- void free_optinsn_page(void *page);
- int kprobe_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
- char *sym);
- int arch_kprobe_get_kallsym(unsigned int *symnum, unsigned long *value,
- char *type, char *sym);
- #else /* !CONFIG_KPROBES: */
- static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
- {
- return 0;
- }
- static inline struct kprobe *get_kprobe(void *addr)
- {
- return NULL;
- }
- static inline struct kprobe *kprobe_running(void)
- {
- return NULL;
- }
- #define kprobe_busy_begin() do {} while (0)
- #define kprobe_busy_end() do {} while (0)
- static inline int register_kprobe(struct kprobe *p)
- {
- return -EOPNOTSUPP;
- }
- static inline int register_kprobes(struct kprobe **kps, int num)
- {
- return -EOPNOTSUPP;
- }
- static inline void unregister_kprobe(struct kprobe *p)
- {
- }
- static inline void unregister_kprobes(struct kprobe **kps, int num)
- {
- }
- static inline int register_kretprobe(struct kretprobe *rp)
- {
- return -EOPNOTSUPP;
- }
- static inline int register_kretprobes(struct kretprobe **rps, int num)
- {
- return -EOPNOTSUPP;
- }
- static inline void unregister_kretprobe(struct kretprobe *rp)
- {
- }
- static inline void unregister_kretprobes(struct kretprobe **rps, int num)
- {
- }
- static inline void kprobe_flush_task(struct task_struct *tk)
- {
- }
- static inline void kprobe_free_init_mem(void)
- {
- }
- static inline int disable_kprobe(struct kprobe *kp)
- {
- return -EOPNOTSUPP;
- }
- static inline int enable_kprobe(struct kprobe *kp)
- {
- return -EOPNOTSUPP;
- }
- static inline bool within_kprobe_blacklist(unsigned long addr)
- {
- return true;
- }
- static inline int kprobe_get_kallsym(unsigned int symnum, unsigned long *value,
- char *type, char *sym)
- {
- return -ERANGE;
- }
- #endif /* CONFIG_KPROBES */
- static inline int disable_kretprobe(struct kretprobe *rp)
- {
- return disable_kprobe(&rp->kp);
- }
- static inline int enable_kretprobe(struct kretprobe *rp)
- {
- return enable_kprobe(&rp->kp);
- }
- #ifndef CONFIG_KPROBES
- static inline bool is_kprobe_insn_slot(unsigned long addr)
- {
- return false;
- }
- #endif /* !CONFIG_KPROBES */
- #ifndef CONFIG_OPTPROBES
- static inline bool is_kprobe_optinsn_slot(unsigned long addr)
- {
- return false;
- }
- #endif /* !CONFIG_OPTPROBES */
- #ifdef CONFIG_KRETPROBES
- #ifdef CONFIG_KRETPROBE_ON_RETHOOK
- static nokprobe_inline bool is_kretprobe_trampoline(unsigned long addr)
- {
- return is_rethook_trampoline(addr);
- }
- static nokprobe_inline
- unsigned long kretprobe_find_ret_addr(struct task_struct *tsk, void *fp,
- struct llist_node **cur)
- {
- return rethook_find_ret_addr(tsk, (unsigned long)fp, cur);
- }
- #else
- static nokprobe_inline bool is_kretprobe_trampoline(unsigned long addr)
- {
- return (void *)addr == kretprobe_trampoline_addr();
- }
- unsigned long kretprobe_find_ret_addr(struct task_struct *tsk, void *fp,
- struct llist_node **cur);
- #endif
- #else
- static nokprobe_inline bool is_kretprobe_trampoline(unsigned long addr)
- {
- return false;
- }
- static nokprobe_inline
- unsigned long kretprobe_find_ret_addr(struct task_struct *tsk, void *fp,
- struct llist_node **cur)
- {
- return 0;
- }
- #endif
- /* Returns true if kprobes handled the fault */
- static nokprobe_inline bool kprobe_page_fault(struct pt_regs *regs,
- unsigned int trap)
- {
- if (!IS_ENABLED(CONFIG_KPROBES))
- return false;
- if (user_mode(regs))
- return false;
- /*
- * To be potentially processing a kprobe fault and to be allowed
- * to call kprobe_running(), we have to be non-preemptible.
- */
- if (preemptible())
- return false;
- if (!kprobe_running())
- return false;
- return kprobe_fault_handler(regs, trap);
- }
- #endif /* _LINUX_KPROBES_H */
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