1 files changed, 195 insertions, 75 deletions

diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 04bdaf01112c..a0b92be98984 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -3,7 +3,6 @@
 #define _LINUX_KPROBES_H
 /*
  *  Kernel Probes (KProbes)
- *  include/linux/kprobes.h
  *
  * Copyright (C) IBM Corporation, 2002, 2004
  *
@@ -27,6 +26,9 @@
 #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
@@ -37,7 +39,7 @@
 #define KPROBE_REENTER		0x00000004
 #define KPROBE_HIT_SSDONE	0x00000008
 
-#else /* CONFIG_KPROBES */
+#else /* !CONFIG_KPROBES */
 #include <asm-generic/kprobes.h>
 typedef int kprobe_opcode_t;
 struct arch_specific_insn {
@@ -52,8 +54,6 @@ 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 (*kprobe_fault_handler_t) (struct kprobe *, struct pt_regs *,
-				       int trapnr);
 typedef int (*kretprobe_handler_t) (struct kretprobe_instance *,
 				    struct pt_regs *);
 
@@ -81,12 +81,6 @@ struct kprobe {
 	/* Called after addr is executed, unless... */
 	kprobe_post_handler_t post_handler;
 
-	/*
-	 * ... called if executing addr causes a fault (eg. page fault).
-	 * Return 1 if it handled fault, otherwise kernel will see it.
-	 */
-	kprobe_fault_handler_t fault_handler;
-
 	/* Saved opcode (which has been replaced with breakpoint) */
 	kprobe_opcode_t opcode;
 
@@ -109,27 +103,28 @@ struct kprobe {
 				   * 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 int kprobe_gone(struct kprobe *p)
+static inline bool kprobe_gone(struct kprobe *p)
 {
 	return p->flags & KPROBE_FLAG_GONE;
 }
 
 /* Is this kprobe disabled ? */
-static inline int kprobe_disabled(struct kprobe *p)
+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 int kprobe_optimized(struct kprobe *p)
+static inline bool kprobe_optimized(struct kprobe *p)
 {
 	return p->flags & KPROBE_FLAG_OPTIMIZED;
 }
 
 /* Is this kprobe uses ftrace ? */
-static inline int kprobe_ftrace(struct kprobe *p)
+static inline bool kprobe_ftrace(struct kprobe *p)
 {
 	return p->flags & KPROBE_FLAG_FTRACE;
 }
@@ -144,6 +139,11 @@ static inline int kprobe_ftrace(struct kprobe *p)
  * 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;
@@ -151,17 +151,30 @@ struct kretprobe {
 	int maxactive;
 	int nmissed;
 	size_t data_size;
-	struct hlist_head free_instances;
-	raw_spinlock_t lock;
+#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 {
-	struct hlist_node hlist;
-	struct kretprobe *rp;
+#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;
-	struct task_struct *task;
 	void *fp;
-	char data[0];
+#endif
+	char data[];
 };
 
 struct kretprobe_blackpoint {
@@ -179,19 +192,77 @@ struct kprobe_blacklist_entry {
 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)
+{
+	RCU_LOCKDEP_WARN(!rcu_read_lock_any_held(),
+		"Kretprobe is accessed from instance under preemptive context");
+
+	return (struct kretprobe *)READ_ONCE(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);
 /*
- * For #ifdef avoidance:
+ * Since some architecture uses structured function pointer,
+ * use dereference_function_descriptor() to get real function address.
  */
-static inline int kprobes_built_in(void)
+static nokprobe_inline void *kretprobe_trampoline_addr(void)
 {
-	return 1;
+	return dereference_kernel_function_descriptor(__kretprobe_trampoline);
 }
 
-#ifdef CONFIG_KRETPROBES
-extern void arch_prepare_kretprobe(struct kretprobe_instance *ri,
-				   struct pt_regs *regs);
-extern int arch_trampoline_kprobe(struct kprobe *p);
-#else /* CONFIG_KRETPROBES */
+/* 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);
+}
+
+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)
 {
@@ -202,21 +273,15 @@ static inline int arch_trampoline_kprobe(struct kprobe *p)
 }
 #endif /* CONFIG_KRETPROBES */
 
-extern struct kretprobe_blackpoint kretprobe_blacklist[];
+/* Markers of '_kprobe_blacklist' section */
+extern unsigned long __start_kprobe_blacklist[];
+extern unsigned long __stop_kprobe_blacklist[];
 
-static inline void kretprobe_assert(struct kretprobe_instance *ri,
-	unsigned long orig_ret_address, unsigned long trampoline_address)
-{
-	if (!orig_ret_address || (orig_ret_address == trampoline_address)) {
-		printk("kretprobe BUG!: Processing kretprobe %p @ %p\n",
-				ri->rp, ri->rp->kp.addr);
-		BUG();
-	}
-}
+extern struct kretprobe_blackpoint kretprobe_blacklist[];
 
 #ifdef CONFIG_KPROBES_SANITY_TEST
 extern int init_test_probes(void);
-#else
+#else /* !CONFIG_KPROBES_SANITY_TEST */
 static inline int init_test_probes(void)
 {
 	return 0;
@@ -227,12 +292,10 @@ 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 show_registers(struct pt_regs *regs);
 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 bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, 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);
@@ -242,6 +305,7 @@ 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;
@@ -272,7 +336,11 @@ static inline bool is_kprobe_##__name##_slot(unsigned long addr)	\
 {									\
 	return __is_insn_slot_addr(&kprobe_##__name##_slots, addr);	\
 }
-#else /* __ARCH_WANT_KPROBES_INSN_SLOT */
+#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)	\
 {									\
@@ -303,41 +371,35 @@ 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,
-					unsigned long addr);
+					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 __user *buffer,
-					     size_t *length, loff_t *ppos);
-#endif
 extern void wait_for_kprobe_optimizer(void);
-#else
+#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 pt_regs *regs);
+				  struct ftrace_ops *ops, struct ftrace_regs *fregs);
 extern int arch_prepare_kprobe_ftrace(struct kprobe *p);
-#endif
-
-int arch_check_ftrace_location(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);
-void kretprobe_hash_lock(struct task_struct *tsk,
-			 struct hlist_head **head, unsigned long *flags);
-void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags);
-struct hlist_head * kretprobe_inst_table_head(struct task_struct *tsk);
 
 /* kprobe_running() will just return the current_kprobe on this CPU */
 static inline struct kprobe *kprobe_running(void)
 {
-	return (__this_cpu_read(current_kprobe));
+	return __this_cpu_read(current_kprobe);
 }
 
 static inline void reset_current_kprobe(void)
@@ -351,19 +413,25 @@ static inline struct kprobe_ctlblk *get_kprobe_ctlblk(void)
 }
 
 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);
-unsigned long arch_deref_entry_point(void *);
 
 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);
-void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
+#endif
+
+void kprobe_free_init_mem(void);
 
 int disable_kprobe(struct kprobe *kp);
 int enable_kprobe(struct kprobe *kp);
@@ -371,14 +439,17 @@ int enable_kprobe(struct kprobe *kp);
 void dump_kprobe(struct kprobe *kp);
 
 void *alloc_insn_page(void);
-void free_insn_page(void *page);
 
+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 kprobes_built_in(void)
-{
-	return 0;
-}
 static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr)
 {
 	return 0;
@@ -391,13 +462,16 @@ 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 -ENOSYS;
+	return -EOPNOTSUPP;
 }
 static inline int register_kprobes(struct kprobe **kps, int num)
 {
-	return -ENOSYS;
+	return -EOPNOTSUPP;
 }
 static inline void unregister_kprobe(struct kprobe *p)
 {
@@ -407,11 +481,11 @@ static inline void unregister_kprobes(struct kprobe **kps, int num)
 }
 static inline int register_kretprobe(struct kretprobe *rp)
 {
-	return -ENOSYS;
+	return -EOPNOTSUPP;
 }
 static inline int register_kretprobes(struct kretprobe **rps, int num)
 {
-	return -ENOSYS;
+	return -EOPNOTSUPP;
 }
 static inline void unregister_kretprobe(struct kretprobe *rp)
 {
@@ -422,20 +496,29 @@ 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 -ENOSYS;
+	return -EOPNOTSUPP;
 }
 static inline int enable_kprobe(struct kprobe *kp)
 {
-	return -ENOSYS;
+	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);
@@ -450,19 +533,56 @@ static inline bool is_kprobe_insn_slot(unsigned long addr)
 {
 	return false;
 }
-#endif
+#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 (!kprobes_built_in())
+	if (!IS_ENABLED(CONFIG_KPROBES))
 		return false;
 	if (user_mode(regs))
 		return false;