| /* 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 <vamsi_krishna@in.ibm.com> Kernel |
| * Probes initial implementation ( includes suggestions from |
| * Rusty Russell). |
| * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes |
| * interface to access function arguments. |
| * 2005-May Hien Nguyen <hien@us.ibm.com> and Jim Keniston |
| * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi |
| * <prasanna@in.ibm.com> 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 <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 */ |
| |
| /* 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 *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; |
| struct freelist_head freelist; |
| struct kretprobe_holder *rph; |
| }; |
| |
| #define KRETPROBE_MAX_DATA_SIZE 4096 |
| |
| struct kretprobe_instance { |
| union { |
| struct freelist_node freelist; |
| struct rcu_head rcu; |
| }; |
| struct llist_node llist; |
| struct kretprobe_holder *rph; |
| kprobe_opcode_t *ret_addr; |
| void *fp; |
| 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 |
| extern void arch_prepare_kretprobe(struct kretprobe_instance *ri, |
| struct pt_regs *regs); |
| extern int arch_trampoline_kprobe(struct kprobe *p); |
| |
| 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) |
| { |
| RCU_LOCKDEP_WARN(!rcu_read_lock_any_held(), |
| "Kretprobe is accessed from instance under preemptive context"); |
| |
| return READ_ONCE(ri->rph->rp); |
| } |
| |
| #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 bool arch_kprobe_on_func_entry(unsigned long offset); |
| 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); |
| |
| #ifdef CONFIG_SYSCTL |
| extern int sysctl_kprobes_optimization; |
| extern int proc_kprobes_optimization_handler(struct ctl_table *table, |
| int write, void *buffer, |
| size_t *length, loff_t *ppos); |
| #endif /* CONFIG_SYSCTL */ |
| extern void wait_for_kprobe_optimizer(void); |
| #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); |
| 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); |
| |
| void kprobe_flush_task(struct task_struct *tk); |
| |
| 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; |
| } |
| 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 |
| 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); |
| #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 */ |