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aaddd3ea ME |
1 | #ifndef _ASM_POWERPC_CODE_PATCHING_H |
2 | #define _ASM_POWERPC_CODE_PATCHING_H | |
3 | ||
4 | /* | |
5 | * Copyright 2008, Michael Ellerman, IBM Corporation. | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | */ | |
12 | ||
07630a37 | 13 | #include <asm/types.h> |
16c57b36 | 14 | #include <asm/ppc-opcode.h> |
1b32cd17 NR |
15 | #include <linux/string.h> |
16 | #include <linux/kallsyms.h> | |
b7bcda63 | 17 | |
aaddd3ea ME |
18 | /* Flags for create_branch: |
19 | * "b" == create_branch(addr, target, 0); | |
20 | * "ba" == create_branch(addr, target, BRANCH_ABSOLUTE); | |
21 | * "bl" == create_branch(addr, target, BRANCH_SET_LINK); | |
22 | * "bla" == create_branch(addr, target, BRANCH_ABSOLUTE | BRANCH_SET_LINK); | |
23 | */ | |
24 | #define BRANCH_SET_LINK 0x1 | |
25 | #define BRANCH_ABSOLUTE 0x2 | |
26 | ||
ebfa50df | 27 | bool is_offset_in_branch_range(long offset); |
e7a57273 ME |
28 | unsigned int create_branch(const unsigned int *addr, |
29 | unsigned long target, int flags); | |
411781a2 ME |
30 | unsigned int create_cond_branch(const unsigned int *addr, |
31 | unsigned long target, int flags); | |
b6e37968 SR |
32 | int patch_branch(unsigned int *addr, unsigned long target, int flags); |
33 | int patch_instruction(unsigned int *addr, unsigned int instr); | |
aaddd3ea | 34 | |
411781a2 ME |
35 | int instr_is_relative_branch(unsigned int instr); |
36 | int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr); | |
37 | unsigned long branch_target(const unsigned int *instr); | |
38 | unsigned int translate_branch(const unsigned int *dest, | |
39 | const unsigned int *src); | |
51c9c084 | 40 | extern bool is_conditional_branch(unsigned int instr); |
1e8341ae KH |
41 | #ifdef CONFIG_PPC_BOOK3E_64 |
42 | void __patch_exception(int exc, unsigned long addr); | |
43 | #define patch_exception(exc, name) do { \ | |
44 | extern unsigned int name; \ | |
45 | __patch_exception((exc), (unsigned long)&name); \ | |
46 | } while (0) | |
47 | #endif | |
411781a2 | 48 | |
c71b7eff AB |
49 | #define OP_RT_RA_MASK 0xffff0000UL |
50 | #define LIS_R2 0x3c020000UL | |
51 | #define ADDIS_R2_R12 0x3c4c0000UL | |
52 | #define ADDI_R2_R2 0x38420000UL | |
53 | ||
07630a37 ME |
54 | static inline unsigned long ppc_function_entry(void *func) |
55 | { | |
f55d9665 | 56 | #ifdef PPC64_ELF_ABI_v2 |
c71b7eff AB |
57 | u32 *insn = func; |
58 | ||
59 | /* | |
60 | * A PPC64 ABIv2 function may have a local and a global entry | |
61 | * point. We need to use the local entry point when patching | |
62 | * functions, so identify and step over the global entry point | |
63 | * sequence. | |
64 | * | |
65 | * The global entry point sequence is always of the form: | |
66 | * | |
67 | * addis r2,r12,XXXX | |
68 | * addi r2,r2,XXXX | |
69 | * | |
70 | * A linker optimisation may convert the addis to lis: | |
71 | * | |
72 | * lis r2,XXXX | |
73 | * addi r2,r2,XXXX | |
74 | */ | |
75 | if ((((*insn & OP_RT_RA_MASK) == ADDIS_R2_R12) || | |
76 | ((*insn & OP_RT_RA_MASK) == LIS_R2)) && | |
77 | ((*(insn+1) & OP_RT_RA_MASK) == ADDI_R2_R2)) | |
78 | return (unsigned long)(insn + 2); | |
79 | else | |
80 | return (unsigned long)func; | |
f55d9665 | 81 | #elif defined(PPC64_ELF_ABI_v1) |
07630a37 | 82 | /* |
c71b7eff AB |
83 | * On PPC64 ABIv1 the function pointer actually points to the |
84 | * function's descriptor. The first entry in the descriptor is the | |
85 | * address of the function text. | |
07630a37 | 86 | */ |
63be1a81 | 87 | return ((func_descr_t *)func)->entry; |
07630a37 ME |
88 | #else |
89 | return (unsigned long)func; | |
90 | #endif | |
91 | } | |
92 | ||
d997c00c ME |
93 | static inline unsigned long ppc_global_function_entry(void *func) |
94 | { | |
f55d9665 | 95 | #ifdef PPC64_ELF_ABI_v2 |
d997c00c ME |
96 | /* PPC64 ABIv2 the global entry point is at the address */ |
97 | return (unsigned long)func; | |
98 | #else | |
99 | /* All other cases there is no change vs ppc_function_entry() */ | |
100 | return ppc_function_entry(func); | |
101 | #endif | |
102 | } | |
103 | ||
1b32cd17 NR |
104 | /* |
105 | * Wrapper around kallsyms_lookup() to return function entry address: | |
106 | * - For ABIv1, we lookup the dot variant. | |
107 | * - For ABIv2, we return the local entry point. | |
108 | */ | |
109 | static inline unsigned long ppc_kallsyms_lookup_name(const char *name) | |
110 | { | |
111 | unsigned long addr; | |
112 | #ifdef PPC64_ELF_ABI_v1 | |
113 | /* check for dot variant */ | |
114 | char dot_name[1 + KSYM_NAME_LEN]; | |
115 | bool dot_appended = false; | |
116 | ||
117 | if (strnlen(name, KSYM_NAME_LEN) >= KSYM_NAME_LEN) | |
118 | return 0; | |
119 | ||
120 | if (name[0] != '.') { | |
121 | dot_name[0] = '.'; | |
122 | dot_name[1] = '\0'; | |
123 | strlcat(dot_name, name, sizeof(dot_name)); | |
124 | dot_appended = true; | |
125 | } else { | |
126 | dot_name[0] = '\0'; | |
127 | strlcat(dot_name, name, sizeof(dot_name)); | |
128 | } | |
129 | addr = kallsyms_lookup_name(dot_name); | |
130 | if (!addr && dot_appended) | |
131 | /* Let's try the original non-dot symbol lookup */ | |
132 | addr = kallsyms_lookup_name(name); | |
133 | #elif defined(PPC64_ELF_ABI_v2) | |
134 | addr = kallsyms_lookup_name(name); | |
135 | if (addr) | |
136 | addr = ppc_function_entry((void *)addr); | |
137 | #else | |
138 | addr = kallsyms_lookup_name(name); | |
139 | #endif | |
140 | return addr; | |
141 | } | |
142 | ||
15308664 TD |
143 | #ifdef CONFIG_PPC64 |
144 | /* | |
145 | * Some instruction encodings commonly used in dynamic ftracing | |
146 | * and function live patching. | |
147 | */ | |
148 | ||
149 | /* This must match the definition of STK_GOT in <asm/ppc_asm.h> */ | |
f55d9665 | 150 | #ifdef PPC64_ELF_ABI_v2 |
15308664 TD |
151 | #define R2_STACK_OFFSET 24 |
152 | #else | |
153 | #define R2_STACK_OFFSET 40 | |
154 | #endif | |
155 | ||
156 | #define PPC_INST_LD_TOC (PPC_INST_LD | ___PPC_RT(__REG_R2) | \ | |
157 | ___PPC_RA(__REG_R1) | R2_STACK_OFFSET) | |
158 | ||
159 | /* usually preceded by a mflr r0 */ | |
160 | #define PPC_INST_STD_LR (PPC_INST_STD | ___PPC_RS(__REG_R0) | \ | |
161 | ___PPC_RA(__REG_R1) | PPC_LR_STKOFF) | |
162 | #endif /* CONFIG_PPC64 */ | |
163 | ||
aaddd3ea | 164 | #endif /* _ASM_POWERPC_CODE_PATCHING_H */ |