xref: /openbmc/linux/arch/powerpc/include/asm/kprobes.h (revision 275876e2)
1 #ifndef _ASM_POWERPC_KPROBES_H
2 #define _ASM_POWERPC_KPROBES_H
3 #ifdef __KERNEL__
4 /*
5  *  Kernel Probes (KProbes)
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20  *
21  * Copyright (C) IBM Corporation, 2002, 2004
22  *
23  * 2002-Oct	Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
24  *		Probes initial implementation ( includes suggestions from
25  *		Rusty Russell).
26  * 2004-Nov	Modified for PPC64 by Ananth N Mavinakayanahalli
27  *		<ananth@in.ibm.com>
28  */
29 #include <linux/types.h>
30 #include <linux/ptrace.h>
31 #include <linux/percpu.h>
32 #include <asm/probes.h>
33 #include <asm/code-patching.h>
34 
35 #define  __ARCH_WANT_KPROBES_INSN_SLOT
36 
37 struct pt_regs;
38 struct kprobe;
39 
40 typedef ppc_opcode_t kprobe_opcode_t;
41 #define MAX_INSN_SIZE 1
42 
43 #ifdef CONFIG_PPC64
44 /*
45  * 64bit powerpc uses function descriptors.
46  * Handle cases where:
47  * 		- User passes a <.symbol> or <module:.symbol>
48  * 		- User passes a <symbol> or <module:symbol>
49  * 		- User passes a non-existent symbol, kallsyms_lookup_name
50  * 		  returns 0. Don't deref the NULL pointer in that case
51  */
52 #define kprobe_lookup_name(name, addr)					\
53 {									\
54 	addr = (kprobe_opcode_t *)kallsyms_lookup_name(name);		\
55 	if (addr) {							\
56 		char *colon;						\
57 		if ((colon = strchr(name, ':')) != NULL) {		\
58 			colon++;					\
59 			if (*colon != '\0' && *colon != '.')		\
60 				addr = (kprobe_opcode_t *)ppc_function_entry(addr); \
61 		} else if (name[0] != '.')				\
62 			addr = (kprobe_opcode_t *)ppc_function_entry(addr); \
63 	} else {							\
64 		char dot_name[KSYM_NAME_LEN];				\
65 		dot_name[0] = '.';					\
66 		dot_name[1] = '\0';					\
67 		strncat(dot_name, name, KSYM_NAME_LEN - 2);		\
68 		addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name); \
69 	}								\
70 }
71 #endif
72 
73 #define flush_insn_slot(p)	do { } while (0)
74 #define kretprobe_blacklist_size 0
75 
76 void kretprobe_trampoline(void);
77 extern void arch_remove_kprobe(struct kprobe *p);
78 
79 /* Architecture specific copy of original instruction */
80 struct arch_specific_insn {
81 	/* copy of original instruction */
82 	kprobe_opcode_t *insn;
83 	/*
84 	 * Set in kprobes code, initially to 0. If the instruction can be
85 	 * eumulated, this is set to 1, if not, to -1.
86 	 */
87 	int boostable;
88 };
89 
90 struct prev_kprobe {
91 	struct kprobe *kp;
92 	unsigned long status;
93 	unsigned long saved_msr;
94 };
95 
96 /* per-cpu kprobe control block */
97 struct kprobe_ctlblk {
98 	unsigned long kprobe_status;
99 	unsigned long kprobe_saved_msr;
100 	struct pt_regs jprobe_saved_regs;
101 	struct prev_kprobe prev_kprobe;
102 };
103 
104 extern int kprobe_exceptions_notify(struct notifier_block *self,
105 					unsigned long val, void *data);
106 extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
107 #endif /* __KERNEL__ */
108 #endif	/* _ASM_POWERPC_KPROBES_H */
109