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