xref: /openbmc/linux/arch/x86/include/asm/elf.h (revision 1a59d1b8)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_ELF_H
3 #define _ASM_X86_ELF_H
4 
5 /*
6  * ELF register definitions..
7  */
8 #include <linux/thread_info.h>
9 
10 #include <asm/ptrace.h>
11 #include <asm/user.h>
12 #include <asm/auxvec.h>
13 #include <asm/fsgsbase.h>
14 
15 typedef unsigned long elf_greg_t;
16 
17 #define ELF_NGREG (sizeof(struct user_regs_struct) / sizeof(elf_greg_t))
18 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
19 
20 typedef struct user_i387_struct elf_fpregset_t;
21 
22 #ifdef __i386__
23 
24 typedef struct user_fxsr_struct elf_fpxregset_t;
25 
26 #define R_386_NONE	0
27 #define R_386_32	1
28 #define R_386_PC32	2
29 #define R_386_GOT32	3
30 #define R_386_PLT32	4
31 #define R_386_COPY	5
32 #define R_386_GLOB_DAT	6
33 #define R_386_JMP_SLOT	7
34 #define R_386_RELATIVE	8
35 #define R_386_GOTOFF	9
36 #define R_386_GOTPC	10
37 #define R_386_NUM	11
38 
39 /*
40  * These are used to set parameters in the core dumps.
41  */
42 #define ELF_CLASS	ELFCLASS32
43 #define ELF_DATA	ELFDATA2LSB
44 #define ELF_ARCH	EM_386
45 
46 #else
47 
48 /* x86-64 relocation types */
49 #define R_X86_64_NONE		0	/* No reloc */
50 #define R_X86_64_64		1	/* Direct 64 bit  */
51 #define R_X86_64_PC32		2	/* PC relative 32 bit signed */
52 #define R_X86_64_GOT32		3	/* 32 bit GOT entry */
53 #define R_X86_64_PLT32		4	/* 32 bit PLT address */
54 #define R_X86_64_COPY		5	/* Copy symbol at runtime */
55 #define R_X86_64_GLOB_DAT	6	/* Create GOT entry */
56 #define R_X86_64_JUMP_SLOT	7	/* Create PLT entry */
57 #define R_X86_64_RELATIVE	8	/* Adjust by program base */
58 #define R_X86_64_GOTPCREL	9	/* 32 bit signed pc relative
59 					   offset to GOT */
60 #define R_X86_64_32		10	/* Direct 32 bit zero extended */
61 #define R_X86_64_32S		11	/* Direct 32 bit sign extended */
62 #define R_X86_64_16		12	/* Direct 16 bit zero extended */
63 #define R_X86_64_PC16		13	/* 16 bit sign extended pc relative */
64 #define R_X86_64_8		14	/* Direct 8 bit sign extended  */
65 #define R_X86_64_PC8		15	/* 8 bit sign extended pc relative */
66 #define R_X86_64_PC64		24	/* Place relative 64-bit signed */
67 
68 /*
69  * These are used to set parameters in the core dumps.
70  */
71 #define ELF_CLASS	ELFCLASS64
72 #define ELF_DATA	ELFDATA2LSB
73 #define ELF_ARCH	EM_X86_64
74 
75 #endif
76 
77 #include <asm/vdso.h>
78 
79 #ifdef CONFIG_X86_64
80 extern unsigned int vdso64_enabled;
81 #endif
82 #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
83 extern unsigned int vdso32_enabled;
84 #endif
85 
86 /*
87  * This is used to ensure we don't load something for the wrong architecture.
88  */
89 #define elf_check_arch_ia32(x) \
90 	(((x)->e_machine == EM_386) || ((x)->e_machine == EM_486))
91 
92 #include <asm/processor.h>
93 
94 #ifdef CONFIG_X86_32
95 #include <asm/desc.h>
96 
97 #define elf_check_arch(x)	elf_check_arch_ia32(x)
98 
99 /* SVR4/i386 ABI (pages 3-31, 3-32) says that when the program starts %edx
100    contains a pointer to a function which might be registered using `atexit'.
101    This provides a mean for the dynamic linker to call DT_FINI functions for
102    shared libraries that have been loaded before the code runs.
103 
104    A value of 0 tells we have no such handler.
105 
106    We might as well make sure everything else is cleared too (except for %esp),
107    just to make things more deterministic.
108  */
109 #define ELF_PLAT_INIT(_r, load_addr)		\
110 	do {					\
111 	_r->bx = 0; _r->cx = 0; _r->dx = 0;	\
112 	_r->si = 0; _r->di = 0; _r->bp = 0;	\
113 	_r->ax = 0;				\
114 } while (0)
115 
116 /*
117  * regs is struct pt_regs, pr_reg is elf_gregset_t (which is
118  * now struct_user_regs, they are different)
119  */
120 
121 #define ELF_CORE_COPY_REGS_COMMON(pr_reg, regs)	\
122 do {						\
123 	pr_reg[0] = regs->bx;			\
124 	pr_reg[1] = regs->cx;			\
125 	pr_reg[2] = regs->dx;			\
126 	pr_reg[3] = regs->si;			\
127 	pr_reg[4] = regs->di;			\
128 	pr_reg[5] = regs->bp;			\
129 	pr_reg[6] = regs->ax;			\
130 	pr_reg[7] = regs->ds;			\
131 	pr_reg[8] = regs->es;			\
132 	pr_reg[9] = regs->fs;			\
133 	pr_reg[11] = regs->orig_ax;		\
134 	pr_reg[12] = regs->ip;			\
135 	pr_reg[13] = regs->cs;			\
136 	pr_reg[14] = regs->flags;		\
137 	pr_reg[15] = regs->sp;			\
138 	pr_reg[16] = regs->ss;			\
139 } while (0);
140 
141 #define ELF_CORE_COPY_REGS(pr_reg, regs)	\
142 do {						\
143 	ELF_CORE_COPY_REGS_COMMON(pr_reg, regs);\
144 	pr_reg[10] = get_user_gs(regs);		\
145 } while (0);
146 
147 #define ELF_CORE_COPY_KERNEL_REGS(pr_reg, regs)	\
148 do {						\
149 	ELF_CORE_COPY_REGS_COMMON(pr_reg, regs);\
150 	savesegment(gs, pr_reg[10]);		\
151 } while (0);
152 
153 #define ELF_PLATFORM	(utsname()->machine)
154 #define set_personality_64bit()	do { } while (0)
155 
156 #else /* CONFIG_X86_32 */
157 
158 /*
159  * This is used to ensure we don't load something for the wrong architecture.
160  */
161 #define elf_check_arch(x)			\
162 	((x)->e_machine == EM_X86_64)
163 
164 #define compat_elf_check_arch(x)					\
165 	(elf_check_arch_ia32(x) ||					\
166 	 (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine == EM_X86_64))
167 
168 #if __USER32_DS != __USER_DS
169 # error "The following code assumes __USER32_DS == __USER_DS"
170 #endif
171 
172 static inline void elf_common_init(struct thread_struct *t,
173 				   struct pt_regs *regs, const u16 ds)
174 {
175 	/* ax gets execve's return value. */
176 	/*regs->ax = */ regs->bx = regs->cx = regs->dx = 0;
177 	regs->si = regs->di = regs->bp = 0;
178 	regs->r8 = regs->r9 = regs->r10 = regs->r11 = 0;
179 	regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
180 	t->fsbase = t->gsbase = 0;
181 	t->fsindex = t->gsindex = 0;
182 	t->ds = t->es = ds;
183 }
184 
185 #define ELF_PLAT_INIT(_r, load_addr)			\
186 	elf_common_init(&current->thread, _r, 0)
187 
188 #define	COMPAT_ELF_PLAT_INIT(regs, load_addr)		\
189 	elf_common_init(&current->thread, regs, __USER_DS)
190 
191 void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp);
192 #define compat_start_thread compat_start_thread
193 
194 void set_personality_ia32(bool);
195 #define COMPAT_SET_PERSONALITY(ex)			\
196 	set_personality_ia32((ex).e_machine == EM_X86_64)
197 
198 #define COMPAT_ELF_PLATFORM			("i686")
199 
200 /*
201  * regs is struct pt_regs, pr_reg is elf_gregset_t (which is
202  * now struct_user_regs, they are different). Assumes current is the process
203  * getting dumped.
204  */
205 
206 #define ELF_CORE_COPY_REGS(pr_reg, regs)			\
207 do {								\
208 	unsigned v;						\
209 	(pr_reg)[0] = (regs)->r15;				\
210 	(pr_reg)[1] = (regs)->r14;				\
211 	(pr_reg)[2] = (regs)->r13;				\
212 	(pr_reg)[3] = (regs)->r12;				\
213 	(pr_reg)[4] = (regs)->bp;				\
214 	(pr_reg)[5] = (regs)->bx;				\
215 	(pr_reg)[6] = (regs)->r11;				\
216 	(pr_reg)[7] = (regs)->r10;				\
217 	(pr_reg)[8] = (regs)->r9;				\
218 	(pr_reg)[9] = (regs)->r8;				\
219 	(pr_reg)[10] = (regs)->ax;				\
220 	(pr_reg)[11] = (regs)->cx;				\
221 	(pr_reg)[12] = (regs)->dx;				\
222 	(pr_reg)[13] = (regs)->si;				\
223 	(pr_reg)[14] = (regs)->di;				\
224 	(pr_reg)[15] = (regs)->orig_ax;				\
225 	(pr_reg)[16] = (regs)->ip;				\
226 	(pr_reg)[17] = (regs)->cs;				\
227 	(pr_reg)[18] = (regs)->flags;				\
228 	(pr_reg)[19] = (regs)->sp;				\
229 	(pr_reg)[20] = (regs)->ss;				\
230 	(pr_reg)[21] = x86_fsbase_read_cpu();			\
231 	(pr_reg)[22] = x86_gsbase_read_cpu_inactive();		\
232 	asm("movl %%ds,%0" : "=r" (v)); (pr_reg)[23] = v;	\
233 	asm("movl %%es,%0" : "=r" (v)); (pr_reg)[24] = v;	\
234 	asm("movl %%fs,%0" : "=r" (v)); (pr_reg)[25] = v;	\
235 	asm("movl %%gs,%0" : "=r" (v)); (pr_reg)[26] = v;	\
236 } while (0);
237 
238 /* I'm not sure if we can use '-' here */
239 #define ELF_PLATFORM       ("x86_64")
240 extern void set_personality_64bit(void);
241 extern unsigned int sysctl_vsyscall32;
242 extern int force_personality32;
243 
244 #endif /* !CONFIG_X86_32 */
245 
246 #define CORE_DUMP_USE_REGSET
247 #define ELF_EXEC_PAGESIZE	4096
248 
249 /*
250  * This is the base location for PIE (ET_DYN with INTERP) loads. On
251  * 64-bit, this is above 4GB to leave the entire 32-bit address
252  * space open for things that want to use the area for 32-bit pointers.
253  */
254 #define ELF_ET_DYN_BASE		(mmap_is_ia32() ? 0x000400000UL : \
255 						  (DEFAULT_MAP_WINDOW / 3 * 2))
256 
257 /* This yields a mask that user programs can use to figure out what
258    instruction set this CPU supports.  This could be done in user space,
259    but it's not easy, and we've already done it here.  */
260 
261 #define ELF_HWCAP		(boot_cpu_data.x86_capability[CPUID_1_EDX])
262 
263 extern u32 elf_hwcap2;
264 
265 /*
266  * HWCAP2 supplies mask with kernel enabled CPU features, so that
267  * the application can discover that it can safely use them.
268  * The bits are defined in uapi/asm/hwcap2.h.
269  */
270 #define ELF_HWCAP2		(elf_hwcap2)
271 
272 /* This yields a string that ld.so will use to load implementation
273    specific libraries for optimization.  This is more specific in
274    intent than poking at uname or /proc/cpuinfo.
275 
276    For the moment, we have only optimizations for the Intel generations,
277    but that could change... */
278 
279 #define SET_PERSONALITY(ex) set_personality_64bit()
280 
281 /*
282  * An executable for which elf_read_implies_exec() returns TRUE will
283  * have the READ_IMPLIES_EXEC personality flag set automatically.
284  */
285 #define elf_read_implies_exec(ex, executable_stack)	\
286 	(executable_stack != EXSTACK_DISABLE_X)
287 
288 struct task_struct;
289 
290 #define	ARCH_DLINFO_IA32						\
291 do {									\
292 	if (VDSO_CURRENT_BASE) {					\
293 		NEW_AUX_ENT(AT_SYSINFO,	VDSO_ENTRY);			\
294 		NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE);	\
295 	}								\
296 } while (0)
297 
298 /*
299  * True on X86_32 or when emulating IA32 on X86_64
300  */
301 static inline int mmap_is_ia32(void)
302 {
303 	return IS_ENABLED(CONFIG_X86_32) ||
304 	       (IS_ENABLED(CONFIG_COMPAT) &&
305 		test_thread_flag(TIF_ADDR32));
306 }
307 
308 extern unsigned long task_size_32bit(void);
309 extern unsigned long task_size_64bit(int full_addr_space);
310 extern unsigned long get_mmap_base(int is_legacy);
311 extern bool mmap_address_hint_valid(unsigned long addr, unsigned long len);
312 
313 #ifdef CONFIG_X86_32
314 
315 #define __STACK_RND_MASK(is32bit) (0x7ff)
316 #define STACK_RND_MASK (0x7ff)
317 
318 #define ARCH_DLINFO		ARCH_DLINFO_IA32
319 
320 /* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
321 
322 #else /* CONFIG_X86_32 */
323 
324 /* 1GB for 64bit, 8MB for 32bit */
325 #define __STACK_RND_MASK(is32bit) ((is32bit) ? 0x7ff : 0x3fffff)
326 #define STACK_RND_MASK __STACK_RND_MASK(mmap_is_ia32())
327 
328 #define ARCH_DLINFO							\
329 do {									\
330 	if (vdso64_enabled)						\
331 		NEW_AUX_ENT(AT_SYSINFO_EHDR,				\
332 			    (unsigned long __force)current->mm->context.vdso); \
333 } while (0)
334 
335 /* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
336 #define ARCH_DLINFO_X32							\
337 do {									\
338 	if (vdso64_enabled)						\
339 		NEW_AUX_ENT(AT_SYSINFO_EHDR,				\
340 			    (unsigned long __force)current->mm->context.vdso); \
341 } while (0)
342 
343 #define AT_SYSINFO		32
344 
345 #define COMPAT_ARCH_DLINFO						\
346 if (test_thread_flag(TIF_X32))						\
347 	ARCH_DLINFO_X32;						\
348 else									\
349 	ARCH_DLINFO_IA32
350 
351 #define COMPAT_ELF_ET_DYN_BASE	(TASK_UNMAPPED_BASE + 0x1000000)
352 
353 #endif /* !CONFIG_X86_32 */
354 
355 #define VDSO_CURRENT_BASE	((unsigned long)current->mm->context.vdso)
356 
357 #define VDSO_ENTRY							\
358 	((unsigned long)current->mm->context.vdso +			\
359 	 vdso_image_32.sym___kernel_vsyscall)
360 
361 struct linux_binprm;
362 
363 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
364 extern int arch_setup_additional_pages(struct linux_binprm *bprm,
365 				       int uses_interp);
366 extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
367 					      int uses_interp);
368 #define compat_arch_setup_additional_pages compat_arch_setup_additional_pages
369 
370 /* Do not change the values. See get_align_mask() */
371 enum align_flags {
372 	ALIGN_VA_32	= BIT(0),
373 	ALIGN_VA_64	= BIT(1),
374 };
375 
376 struct va_alignment {
377 	int flags;
378 	unsigned long mask;
379 	unsigned long bits;
380 } ____cacheline_aligned;
381 
382 extern struct va_alignment va_align;
383 extern unsigned long align_vdso_addr(unsigned long);
384 #endif /* _ASM_X86_ELF_H */
385