xref: /openbmc/linux/arch/powerpc/include/asm/kprobes.h (revision ecd25094)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 #ifndef _ASM_POWERPC_KPROBES_H
3 #define _ASM_POWERPC_KPROBES_H
4 
5 #include <asm-generic/kprobes.h>
6 
7 #ifdef __KERNEL__
8 /*
9  *  Kernel Probes (KProbes)
10  *
11  * Copyright (C) IBM Corporation, 2002, 2004
12  *
13  * 2002-Oct	Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
14  *		Probes initial implementation ( includes suggestions from
15  *		Rusty Russell).
16  * 2004-Nov	Modified for PPC64 by Ananth N Mavinakayanahalli
17  *		<ananth@in.ibm.com>
18  */
19 #include <linux/types.h>
20 #include <linux/ptrace.h>
21 #include <linux/percpu.h>
22 #include <linux/module.h>
23 #include <asm/probes.h>
24 #include <asm/code-patching.h>
25 
26 #ifdef CONFIG_KPROBES
27 #define  __ARCH_WANT_KPROBES_INSN_SLOT
28 
29 struct pt_regs;
30 struct kprobe;
31 
32 typedef ppc_opcode_t kprobe_opcode_t;
33 
34 extern kprobe_opcode_t optinsn_slot;
35 
36 /* Optinsn template address */
37 extern kprobe_opcode_t optprobe_template_entry[];
38 extern kprobe_opcode_t optprobe_template_op_address[];
39 extern kprobe_opcode_t optprobe_template_call_handler[];
40 extern kprobe_opcode_t optprobe_template_insn[];
41 extern kprobe_opcode_t optprobe_template_call_emulate[];
42 extern kprobe_opcode_t optprobe_template_ret[];
43 extern kprobe_opcode_t optprobe_template_end[];
44 
45 /* Fixed instruction size for powerpc */
46 #define MAX_INSN_SIZE		1
47 #define MAX_OPTIMIZED_LENGTH	sizeof(kprobe_opcode_t)	/* 4 bytes */
48 #define MAX_OPTINSN_SIZE	(optprobe_template_end - optprobe_template_entry)
49 #define RELATIVEJUMP_SIZE	sizeof(kprobe_opcode_t)	/* 4 bytes */
50 
51 #define flush_insn_slot(p)	do { } while (0)
52 #define kretprobe_blacklist_size 0
53 
54 void kretprobe_trampoline(void);
55 extern void arch_remove_kprobe(struct kprobe *p);
56 
57 /* Architecture specific copy of original instruction */
58 struct arch_specific_insn {
59 	/* copy of original instruction */
60 	kprobe_opcode_t *insn;
61 	/*
62 	 * Set in kprobes code, initially to 0. If the instruction can be
63 	 * eumulated, this is set to 1, if not, to -1.
64 	 */
65 	int boostable;
66 };
67 
68 struct prev_kprobe {
69 	struct kprobe *kp;
70 	unsigned long status;
71 	unsigned long saved_msr;
72 };
73 
74 /* per-cpu kprobe control block */
75 struct kprobe_ctlblk {
76 	unsigned long kprobe_status;
77 	unsigned long kprobe_saved_msr;
78 	struct prev_kprobe prev_kprobe;
79 };
80 
81 struct arch_optimized_insn {
82 	kprobe_opcode_t copied_insn[1];
83 	/* detour buffer */
84 	kprobe_opcode_t *insn;
85 };
86 
87 extern int kprobe_exceptions_notify(struct notifier_block *self,
88 					unsigned long val, void *data);
89 extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
90 extern int kprobe_handler(struct pt_regs *regs);
91 extern int kprobe_post_handler(struct pt_regs *regs);
92 #else
93 static inline int kprobe_handler(struct pt_regs *regs) { return 0; }
94 static inline int kprobe_post_handler(struct pt_regs *regs) { return 0; }
95 #endif /* CONFIG_KPROBES */
96 #endif /* __KERNEL__ */
97 #endif	/* _ASM_POWERPC_KPROBES_H */
98