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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> | |
ec0c464c | 17 | #include <asm/asm-compat.h> |
b7bcda63 | 18 | |
aaddd3ea ME |
19 | /* Flags for create_branch: |
20 | * "b" == create_branch(addr, target, 0); | |
21 | * "ba" == create_branch(addr, target, BRANCH_ABSOLUTE); | |
22 | * "bl" == create_branch(addr, target, BRANCH_SET_LINK); | |
23 | * "bla" == create_branch(addr, target, BRANCH_ABSOLUTE | BRANCH_SET_LINK); | |
24 | */ | |
25 | #define BRANCH_SET_LINK 0x1 | |
26 | #define BRANCH_ABSOLUTE 0x2 | |
27 | ||
ebfa50df | 28 | bool is_offset_in_branch_range(long offset); |
e7a57273 ME |
29 | unsigned int create_branch(const unsigned int *addr, |
30 | unsigned long target, int flags); | |
411781a2 ME |
31 | unsigned int create_cond_branch(const unsigned int *addr, |
32 | unsigned long target, int flags); | |
b6e37968 SR |
33 | int patch_branch(unsigned int *addr, unsigned long target, int flags); |
34 | int patch_instruction(unsigned int *addr, unsigned int instr); | |
8183d99f | 35 | int raw_patch_instruction(unsigned int *addr, unsigned int instr); |
aaddd3ea | 36 | |
082e2869 CL |
37 | static inline unsigned long patch_site_addr(s32 *site) |
38 | { | |
39 | return (unsigned long)site + *site; | |
40 | } | |
41 | ||
45090c26 CL |
42 | static inline int patch_instruction_site(s32 *site, unsigned int instr) |
43 | { | |
44 | return patch_instruction((unsigned int *)patch_site_addr(site), instr); | |
45 | } | |
46 | ||
47 | static inline int patch_branch_site(s32 *site, unsigned long target, int flags) | |
48 | { | |
49 | return patch_branch((unsigned int *)patch_site_addr(site), target, flags); | |
50 | } | |
51 | ||
411781a2 | 52 | int instr_is_relative_branch(unsigned int instr); |
b9eab08d | 53 | int instr_is_relative_link_branch(unsigned int instr); |
411781a2 ME |
54 | int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr); |
55 | unsigned long branch_target(const unsigned int *instr); | |
56 | unsigned int translate_branch(const unsigned int *dest, | |
57 | const unsigned int *src); | |
51c9c084 | 58 | extern bool is_conditional_branch(unsigned int instr); |
1e8341ae KH |
59 | #ifdef CONFIG_PPC_BOOK3E_64 |
60 | void __patch_exception(int exc, unsigned long addr); | |
61 | #define patch_exception(exc, name) do { \ | |
62 | extern unsigned int name; \ | |
63 | __patch_exception((exc), (unsigned long)&name); \ | |
64 | } while (0) | |
65 | #endif | |
411781a2 | 66 | |
c71b7eff AB |
67 | #define OP_RT_RA_MASK 0xffff0000UL |
68 | #define LIS_R2 0x3c020000UL | |
69 | #define ADDIS_R2_R12 0x3c4c0000UL | |
70 | #define ADDI_R2_R2 0x38420000UL | |
71 | ||
07630a37 ME |
72 | static inline unsigned long ppc_function_entry(void *func) |
73 | { | |
f55d9665 | 74 | #ifdef PPC64_ELF_ABI_v2 |
c71b7eff AB |
75 | u32 *insn = func; |
76 | ||
77 | /* | |
78 | * A PPC64 ABIv2 function may have a local and a global entry | |
79 | * point. We need to use the local entry point when patching | |
80 | * functions, so identify and step over the global entry point | |
81 | * sequence. | |
82 | * | |
83 | * The global entry point sequence is always of the form: | |
84 | * | |
85 | * addis r2,r12,XXXX | |
86 | * addi r2,r2,XXXX | |
87 | * | |
88 | * A linker optimisation may convert the addis to lis: | |
89 | * | |
90 | * lis r2,XXXX | |
91 | * addi r2,r2,XXXX | |
92 | */ | |
93 | if ((((*insn & OP_RT_RA_MASK) == ADDIS_R2_R12) || | |
94 | ((*insn & OP_RT_RA_MASK) == LIS_R2)) && | |
95 | ((*(insn+1) & OP_RT_RA_MASK) == ADDI_R2_R2)) | |
96 | return (unsigned long)(insn + 2); | |
97 | else | |
98 | return (unsigned long)func; | |
f55d9665 | 99 | #elif defined(PPC64_ELF_ABI_v1) |
07630a37 | 100 | /* |
c71b7eff AB |
101 | * On PPC64 ABIv1 the function pointer actually points to the |
102 | * function's descriptor. The first entry in the descriptor is the | |
103 | * address of the function text. | |
07630a37 | 104 | */ |
63be1a81 | 105 | return ((func_descr_t *)func)->entry; |
07630a37 ME |
106 | #else |
107 | return (unsigned long)func; | |
108 | #endif | |
109 | } | |
110 | ||
d997c00c ME |
111 | static inline unsigned long ppc_global_function_entry(void *func) |
112 | { | |
f55d9665 | 113 | #ifdef PPC64_ELF_ABI_v2 |
d997c00c ME |
114 | /* PPC64 ABIv2 the global entry point is at the address */ |
115 | return (unsigned long)func; | |
116 | #else | |
117 | /* All other cases there is no change vs ppc_function_entry() */ | |
118 | return ppc_function_entry(func); | |
119 | #endif | |
120 | } | |
121 | ||
1b32cd17 NR |
122 | /* |
123 | * Wrapper around kallsyms_lookup() to return function entry address: | |
124 | * - For ABIv1, we lookup the dot variant. | |
125 | * - For ABIv2, we return the local entry point. | |
126 | */ | |
127 | static inline unsigned long ppc_kallsyms_lookup_name(const char *name) | |
128 | { | |
129 | unsigned long addr; | |
130 | #ifdef PPC64_ELF_ABI_v1 | |
131 | /* check for dot variant */ | |
132 | char dot_name[1 + KSYM_NAME_LEN]; | |
133 | bool dot_appended = false; | |
134 | ||
135 | if (strnlen(name, KSYM_NAME_LEN) >= KSYM_NAME_LEN) | |
136 | return 0; | |
137 | ||
138 | if (name[0] != '.') { | |
139 | dot_name[0] = '.'; | |
140 | dot_name[1] = '\0'; | |
141 | strlcat(dot_name, name, sizeof(dot_name)); | |
142 | dot_appended = true; | |
143 | } else { | |
144 | dot_name[0] = '\0'; | |
145 | strlcat(dot_name, name, sizeof(dot_name)); | |
146 | } | |
147 | addr = kallsyms_lookup_name(dot_name); | |
148 | if (!addr && dot_appended) | |
149 | /* Let's try the original non-dot symbol lookup */ | |
150 | addr = kallsyms_lookup_name(name); | |
151 | #elif defined(PPC64_ELF_ABI_v2) | |
152 | addr = kallsyms_lookup_name(name); | |
153 | if (addr) | |
154 | addr = ppc_function_entry((void *)addr); | |
155 | #else | |
156 | addr = kallsyms_lookup_name(name); | |
157 | #endif | |
158 | return addr; | |
159 | } | |
160 | ||
15308664 TD |
161 | #ifdef CONFIG_PPC64 |
162 | /* | |
163 | * Some instruction encodings commonly used in dynamic ftracing | |
164 | * and function live patching. | |
165 | */ | |
166 | ||
167 | /* This must match the definition of STK_GOT in <asm/ppc_asm.h> */ | |
f55d9665 | 168 | #ifdef PPC64_ELF_ABI_v2 |
15308664 TD |
169 | #define R2_STACK_OFFSET 24 |
170 | #else | |
171 | #define R2_STACK_OFFSET 40 | |
172 | #endif | |
173 | ||
174 | #define PPC_INST_LD_TOC (PPC_INST_LD | ___PPC_RT(__REG_R2) | \ | |
175 | ___PPC_RA(__REG_R1) | R2_STACK_OFFSET) | |
176 | ||
177 | /* usually preceded by a mflr r0 */ | |
178 | #define PPC_INST_STD_LR (PPC_INST_STD | ___PPC_RS(__REG_R0) | \ | |
179 | ___PPC_RA(__REG_R1) | PPC_LR_STKOFF) | |
180 | #endif /* CONFIG_PPC64 */ | |
181 | ||
aaddd3ea | 182 | #endif /* _ASM_POWERPC_CODE_PATCHING_H */ |