xref: /openbmc/linux/arch/arm64/include/asm/elf.h (revision de6da33e)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2012 ARM Ltd.
4  */
5 #ifndef __ASM_ELF_H
6 #define __ASM_ELF_H
7 
8 #include <asm/hwcap.h>
9 
10 /*
11  * ELF register definitions..
12  */
13 #include <asm/ptrace.h>
14 #include <asm/user.h>
15 
16 /*
17  * AArch64 static relocation types.
18  */
19 
20 /* Miscellaneous. */
21 #define R_ARM_NONE			0
22 #define R_AARCH64_NONE			256
23 
24 /* Data. */
25 #define R_AARCH64_ABS64			257
26 #define R_AARCH64_ABS32			258
27 #define R_AARCH64_ABS16			259
28 #define R_AARCH64_PREL64		260
29 #define R_AARCH64_PREL32		261
30 #define R_AARCH64_PREL16		262
31 
32 /* Instructions. */
33 #define R_AARCH64_MOVW_UABS_G0		263
34 #define R_AARCH64_MOVW_UABS_G0_NC	264
35 #define R_AARCH64_MOVW_UABS_G1		265
36 #define R_AARCH64_MOVW_UABS_G1_NC	266
37 #define R_AARCH64_MOVW_UABS_G2		267
38 #define R_AARCH64_MOVW_UABS_G2_NC	268
39 #define R_AARCH64_MOVW_UABS_G3		269
40 
41 #define R_AARCH64_MOVW_SABS_G0		270
42 #define R_AARCH64_MOVW_SABS_G1		271
43 #define R_AARCH64_MOVW_SABS_G2		272
44 
45 #define R_AARCH64_LD_PREL_LO19		273
46 #define R_AARCH64_ADR_PREL_LO21		274
47 #define R_AARCH64_ADR_PREL_PG_HI21	275
48 #define R_AARCH64_ADR_PREL_PG_HI21_NC	276
49 #define R_AARCH64_ADD_ABS_LO12_NC	277
50 #define R_AARCH64_LDST8_ABS_LO12_NC	278
51 
52 #define R_AARCH64_TSTBR14		279
53 #define R_AARCH64_CONDBR19		280
54 #define R_AARCH64_JUMP26		282
55 #define R_AARCH64_CALL26		283
56 #define R_AARCH64_LDST16_ABS_LO12_NC	284
57 #define R_AARCH64_LDST32_ABS_LO12_NC	285
58 #define R_AARCH64_LDST64_ABS_LO12_NC	286
59 #define R_AARCH64_LDST128_ABS_LO12_NC	299
60 
61 #define R_AARCH64_MOVW_PREL_G0		287
62 #define R_AARCH64_MOVW_PREL_G0_NC	288
63 #define R_AARCH64_MOVW_PREL_G1		289
64 #define R_AARCH64_MOVW_PREL_G1_NC	290
65 #define R_AARCH64_MOVW_PREL_G2		291
66 #define R_AARCH64_MOVW_PREL_G2_NC	292
67 #define R_AARCH64_MOVW_PREL_G3		293
68 
69 #define R_AARCH64_RELATIVE		1027
70 
71 /*
72  * These are used to set parameters in the core dumps.
73  */
74 #define ELF_CLASS	ELFCLASS64
75 #ifdef __AARCH64EB__
76 #define ELF_DATA	ELFDATA2MSB
77 #else
78 #define ELF_DATA	ELFDATA2LSB
79 #endif
80 #define ELF_ARCH	EM_AARCH64
81 
82 /*
83  * This yields a string that ld.so will use to load implementation
84  * specific libraries for optimization.  This is more specific in
85  * intent than poking at uname or /proc/cpuinfo.
86  */
87 #define ELF_PLATFORM_SIZE	16
88 #ifdef __AARCH64EB__
89 #define ELF_PLATFORM		("aarch64_be")
90 #else
91 #define ELF_PLATFORM		("aarch64")
92 #endif
93 
94 /*
95  * This is used to ensure we don't load something for the wrong architecture.
96  */
97 #define elf_check_arch(x)		((x)->e_machine == EM_AARCH64)
98 
99 /*
100  * An executable for which elf_read_implies_exec() returns TRUE will
101  * have the READ_IMPLIES_EXEC personality flag set automatically.
102  *
103  * The decision process for determining the results are:
104  *
105  *                CPU*: | arm32      | arm64      |
106  * ELF:                 |            |            |
107  * ---------------------|------------|------------|
108  * missing PT_GNU_STACK | exec-all   | exec-none  |
109  * PT_GNU_STACK == RWX  | exec-stack | exec-stack |
110  * PT_GNU_STACK == RW   | exec-none  | exec-none  |
111  *
112  *  exec-all  : all PROT_READ user mappings are executable, except when
113  *              backed by files on a noexec-filesystem.
114  *  exec-none : only PROT_EXEC user mappings are executable.
115  *  exec-stack: only the stack and PROT_EXEC user mappings are executable.
116  *
117  *  *all arm64 CPUs support NX, so there is no "lacks NX" column.
118  *
119  */
120 #define compat_elf_read_implies_exec(ex, stk)	(stk == EXSTACK_DEFAULT)
121 
122 #define CORE_DUMP_USE_REGSET
123 #define ELF_EXEC_PAGESIZE	PAGE_SIZE
124 
125 /*
126  * This is the base location for PIE (ET_DYN with INTERP) loads. On
127  * 64-bit, this is above 4GB to leave the entire 32-bit address
128  * space open for things that want to use the area for 32-bit pointers.
129  */
130 #ifdef CONFIG_ARM64_FORCE_52BIT
131 #define ELF_ET_DYN_BASE		(2 * TASK_SIZE_64 / 3)
132 #else
133 #define ELF_ET_DYN_BASE		(2 * DEFAULT_MAP_WINDOW_64 / 3)
134 #endif /* CONFIG_ARM64_FORCE_52BIT */
135 
136 #ifndef __ASSEMBLY__
137 
138 #include <uapi/linux/elf.h>
139 #include <linux/bug.h>
140 #include <linux/errno.h>
141 #include <linux/fs.h>
142 #include <linux/types.h>
143 #include <asm/processor.h> /* for signal_minsigstksz, used by ARCH_DLINFO */
144 
145 typedef unsigned long elf_greg_t;
146 
147 #define ELF_NGREG (sizeof(struct user_pt_regs) / sizeof(elf_greg_t))
148 #define ELF_CORE_COPY_REGS(dest, regs)	\
149 	*(struct user_pt_regs *)&(dest) = (regs)->user_regs;
150 
151 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
152 typedef struct user_fpsimd_state elf_fpregset_t;
153 
154 /*
155  * When the program starts, a1 contains a pointer to a function to be
156  * registered with atexit, as per the SVR4 ABI.  A value of 0 means we have no
157  * such handler.
158  */
159 #define ELF_PLAT_INIT(_r, load_addr)	(_r)->regs[0] = 0
160 
161 #define SET_PERSONALITY(ex)						\
162 ({									\
163 	clear_thread_flag(TIF_32BIT);					\
164 	current->personality &= ~READ_IMPLIES_EXEC;			\
165 })
166 
167 /* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
168 #define ARCH_DLINFO							\
169 do {									\
170 	NEW_AUX_ENT(AT_SYSINFO_EHDR,					\
171 		    (elf_addr_t)current->mm->context.vdso);		\
172 									\
173 	/*								\
174 	 * Should always be nonzero unless there's a kernel bug.	\
175 	 * If we haven't determined a sensible value to give to		\
176 	 * userspace, omit the entry:					\
177 	 */								\
178 	if (likely(signal_minsigstksz))					\
179 		NEW_AUX_ENT(AT_MINSIGSTKSZ, signal_minsigstksz);	\
180 	else								\
181 		NEW_AUX_ENT(AT_IGNORE, 0);				\
182 } while (0)
183 
184 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES
185 struct linux_binprm;
186 extern int arch_setup_additional_pages(struct linux_binprm *bprm,
187 				       int uses_interp);
188 
189 /* 1GB of VA */
190 #ifdef CONFIG_COMPAT
191 #define STACK_RND_MASK			(test_thread_flag(TIF_32BIT) ? \
192 						0x7ff >> (PAGE_SHIFT - 12) : \
193 						0x3ffff >> (PAGE_SHIFT - 12))
194 #else
195 #define STACK_RND_MASK			(0x3ffff >> (PAGE_SHIFT - 12))
196 #endif
197 
198 #ifdef __AARCH64EB__
199 #define COMPAT_ELF_PLATFORM		("v8b")
200 #else
201 #define COMPAT_ELF_PLATFORM		("v8l")
202 #endif
203 
204 #ifdef CONFIG_COMPAT
205 
206 /* PIE load location for compat arm. Must match ARM ELF_ET_DYN_BASE. */
207 #define COMPAT_ELF_ET_DYN_BASE		0x000400000UL
208 
209 /* AArch32 registers. */
210 #define COMPAT_ELF_NGREG		18
211 typedef unsigned int			compat_elf_greg_t;
212 typedef compat_elf_greg_t		compat_elf_gregset_t[COMPAT_ELF_NGREG];
213 
214 /* AArch32 EABI. */
215 #define EF_ARM_EABI_MASK		0xff000000
216 int compat_elf_check_arch(const struct elf32_hdr *);
217 #define compat_elf_check_arch		compat_elf_check_arch
218 #define compat_start_thread		compat_start_thread
219 /*
220  * Unlike the native SET_PERSONALITY macro, the compat version maintains
221  * READ_IMPLIES_EXEC across an execve() since this is the behaviour on
222  * arch/arm/.
223  */
224 #define COMPAT_SET_PERSONALITY(ex)					\
225 ({									\
226 	set_thread_flag(TIF_32BIT);					\
227  })
228 #ifdef CONFIG_COMPAT_VDSO
229 #define COMPAT_ARCH_DLINFO						\
230 do {									\
231 	/*								\
232 	 * Note that we use Elf64_Off instead of elf_addr_t because	\
233 	 * elf_addr_t in compat is defined as Elf32_Addr and casting	\
234 	 * current->mm->context.vdso to it triggers a cast warning of	\
235 	 * cast from pointer to integer of different size.		\
236 	 */								\
237 	NEW_AUX_ENT(AT_SYSINFO_EHDR,					\
238 			(Elf64_Off)current->mm->context.vdso);		\
239 } while (0)
240 #else
241 #define COMPAT_ARCH_DLINFO
242 #endif
243 extern int aarch32_setup_additional_pages(struct linux_binprm *bprm,
244 					  int uses_interp);
245 #define compat_arch_setup_additional_pages \
246 					aarch32_setup_additional_pages
247 
248 #endif /* CONFIG_COMPAT */
249 
250 struct arch_elf_state {
251 	int flags;
252 };
253 
254 #define ARM64_ELF_BTI		(1 << 0)
255 
256 #define INIT_ARCH_ELF_STATE {			\
257 	.flags = 0,				\
258 }
259 
260 static inline int arch_parse_elf_property(u32 type, const void *data,
261 					  size_t datasz, bool compat,
262 					  struct arch_elf_state *arch)
263 {
264 	/* No known properties for AArch32 yet */
265 	if (IS_ENABLED(CONFIG_COMPAT) && compat)
266 		return 0;
267 
268 	if (type == GNU_PROPERTY_AARCH64_FEATURE_1_AND) {
269 		const u32 *p = data;
270 
271 		if (datasz != sizeof(*p))
272 			return -ENOEXEC;
273 
274 		if (system_supports_bti() &&
275 		    (*p & GNU_PROPERTY_AARCH64_FEATURE_1_BTI))
276 			arch->flags |= ARM64_ELF_BTI;
277 	}
278 
279 	return 0;
280 }
281 
282 static inline int arch_elf_pt_proc(void *ehdr, void *phdr,
283 				   struct file *f, bool is_interp,
284 				   struct arch_elf_state *state)
285 {
286 	return 0;
287 }
288 
289 static inline int arch_check_elf(void *ehdr, bool has_interp,
290 				 void *interp_ehdr,
291 				 struct arch_elf_state *state)
292 {
293 	return 0;
294 }
295 
296 #endif /* !__ASSEMBLY__ */
297 
298 #endif
299