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gerrit-public.fairphone.software / kernel / msm-4.9 / f4af6fb2fc942e84612e8c1a80f0727a797a750a / . / arch / mips / kernel / elf.c
blob: c92b15df6893f555549bf3cc51bf6c39f78e1875 [file] [log] [blame]
Paul Burton90cee752014-09-11 08:30:22 +0100[diff] [blame]1/*
2 * Copyright (C) 2014 Imagination Technologies
3 * Author: Paul Burton <paul.burton@imgtec.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License as published by the
7 * Free Software Foundation; either version 2 of the License, or (at your
8 * option) any later version.
9 */
10
11#include <linux/elf.h>
12#include <linux/sched.h>
13
14enum {
15 FP_ERROR = -1,
16 FP_DOUBLE_64A = -2,
17};
18
19int arch_elf_pt_proc(void *_ehdr, void *_phdr, struct file *elf,
20 bool is_interp, struct arch_elf_state *state)
21{
22 struct elfhdr *ehdr = _ehdr;
23 struct elf_phdr *phdr = _phdr;
24 struct mips_elf_abiflags_v0 abiflags;
25 int ret;
26
27 if (config_enabled(CONFIG_64BIT) &&
28 (ehdr->e_ident[EI_CLASS] != ELFCLASS32))
29 return 0;
30 if (phdr->p_type != PT_MIPS_ABIFLAGS)
31 return 0;
32 if (phdr->p_filesz < sizeof(abiflags))
33 return -EINVAL;
34
35 ret = kernel_read(elf, phdr->p_offset, (char *)&abiflags,
36 sizeof(abiflags));
37 if (ret < 0)
38 return ret;
39 if (ret != sizeof(abiflags))
40 return -EIO;
41
42 /* Record the required FP ABIs for use by mips_check_elf */
43 if (is_interp)
44 state->interp_fp_abi = abiflags.fp_abi;
45 else
46 state->fp_abi = abiflags.fp_abi;
47
48 return 0;
49}
50
51static inline unsigned get_fp_abi(struct elfhdr *ehdr, int in_abi)
52{
53 /* If the ABI requirement is provided, simply return that */
54 if (in_abi != -1)
55 return in_abi;
56
57 /* If the EF_MIPS_FP64 flag was set, return MIPS_ABI_FP_64 */
58 if (ehdr->e_flags & EF_MIPS_FP64)
59 return MIPS_ABI_FP_64;
60
61 /* Default to MIPS_ABI_FP_DOUBLE */
62 return MIPS_ABI_FP_DOUBLE;
63}
64
65int arch_check_elf(void *_ehdr, bool has_interpreter,
66 struct arch_elf_state *state)
67{
68 struct elfhdr *ehdr = _ehdr;
69 unsigned fp_abi, interp_fp_abi, abi0, abi1;
70
71 /* Ignore non-O32 binaries */
72 if (config_enabled(CONFIG_64BIT) &&
73 (ehdr->e_ident[EI_CLASS] != ELFCLASS32))
74 return 0;
75
76 fp_abi = get_fp_abi(ehdr, state->fp_abi);
77
78 if (has_interpreter) {
79 interp_fp_abi = get_fp_abi(ehdr, state->interp_fp_abi);
80
81 abi0 = min(fp_abi, interp_fp_abi);
82 abi1 = max(fp_abi, interp_fp_abi);
83 } else {
84 abi0 = abi1 = fp_abi;
85 }
86
87 state->overall_abi = FP_ERROR;
88
89 if (abi0 == abi1) {
90 state->overall_abi = abi0;
91 } else if (abi0 == MIPS_ABI_FP_ANY) {
92 state->overall_abi = abi1;
93 } else if (abi0 == MIPS_ABI_FP_DOUBLE) {
94 switch (abi1) {
95 case MIPS_ABI_FP_XX:
96 state->overall_abi = MIPS_ABI_FP_DOUBLE;
97 break;
98
99 case MIPS_ABI_FP_64A:
100 state->overall_abi = FP_DOUBLE_64A;
101 break;
102 }
103 } else if (abi0 == MIPS_ABI_FP_SINGLE ||
104 abi0 == MIPS_ABI_FP_SOFT) {
105 /* Cannot link with other ABIs */
106 } else if (abi0 == MIPS_ABI_FP_OLD_64) {
107 switch (abi1) {
108 case MIPS_ABI_FP_XX:
109 case MIPS_ABI_FP_64:
110 case MIPS_ABI_FP_64A:
111 state->overall_abi = MIPS_ABI_FP_64;
112 break;
113 }
114 } else if (abi0 == MIPS_ABI_FP_XX ||
115 abi0 == MIPS_ABI_FP_64 ||
116 abi0 == MIPS_ABI_FP_64A) {
117 state->overall_abi = MIPS_ABI_FP_64;
118 }
119
120 switch (state->overall_abi) {
121 case MIPS_ABI_FP_64:
122 case MIPS_ABI_FP_64A:
123 case FP_DOUBLE_64A:
124 if (!config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT))
125 return -ELIBBAD;
126 break;
127
128 case FP_ERROR:
129 return -ELIBBAD;
130 }
131
132 return 0;
133}
134
135void mips_set_personality_fp(struct arch_elf_state *state)
136{
Paul Burtonf4af6fb2014-09-11 08:30:23 +0100[diff] [blame^]137 if (config_enabled(CONFIG_FP32XX_HYBRID_FPRS)) {
138 /*
139 * Use hybrid FPRs for all code which can correctly execute
140 * with that mode.
141 */
142 switch (state->overall_abi) {
143 case MIPS_ABI_FP_DOUBLE:
144 case MIPS_ABI_FP_SINGLE:
145 case MIPS_ABI_FP_SOFT:
146 case MIPS_ABI_FP_XX:
147 case MIPS_ABI_FP_ANY:
148 /* FR=1, FRE=1 */
149 clear_thread_flag(TIF_32BIT_FPREGS);
150 set_thread_flag(TIF_HYBRID_FPREGS);
151 return;
152 }
153 }
154
Paul Burton90cee752014-09-11 08:30:22 +0100[diff] [blame]155 switch (state->overall_abi) {
156 case MIPS_ABI_FP_DOUBLE:
157 case MIPS_ABI_FP_SINGLE:
158 case MIPS_ABI_FP_SOFT:
159 /* FR=0 */
160 set_thread_flag(TIF_32BIT_FPREGS);
161 clear_thread_flag(TIF_HYBRID_FPREGS);
162 break;
163
164 case FP_DOUBLE_64A:
165 /* FR=1, FRE=1 */
166 clear_thread_flag(TIF_32BIT_FPREGS);
167 set_thread_flag(TIF_HYBRID_FPREGS);
168 break;
169
170 case MIPS_ABI_FP_64:
171 case MIPS_ABI_FP_64A:
172 /* FR=1, FRE=0 */
173 clear_thread_flag(TIF_32BIT_FPREGS);
174 clear_thread_flag(TIF_HYBRID_FPREGS);
175 break;
176
177 case MIPS_ABI_FP_XX:
178 case MIPS_ABI_FP_ANY:
179 if (!config_enabled(CONFIG_MIPS_O32_FP64_SUPPORT))
180 set_thread_flag(TIF_32BIT_FPREGS);
181 else
182 clear_thread_flag(TIF_32BIT_FPREGS);
183
184 clear_thread_flag(TIF_HYBRID_FPREGS);
185 break;
186
187 default:
188 case FP_ERROR:
189 BUG();
190 }
191}