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 #define R_386_NONE	0
25 #define R_386_32	1
26 #define R_386_PC32	2
27 #define R_386_GOT32	3
28 #define R_386_PLT32	4
29 #define R_386_COPY	5
30 #define R_386_GLOB_DAT	6
31 #define R_386_JMP_SLOT	7
32 #define R_386_RELATIVE	8
33 #define R_386_GOTOFF	9
34 #define R_386_GOTPC	10
35 #define R_386_NUM	11
36 
37 /*
38  * These are used to set parameters in the core dumps.
39  */
40 #define ELF_CLASS	ELFCLASS32
41 #define ELF_DATA	ELFDATA2LSB
42 #define ELF_ARCH	EM_386
43 
44 #else
45 
46 /* x86-64 relocation types */
47 #define R_X86_64_NONE		0	/* No reloc */
48 #define R_X86_64_64		1	/* Direct 64 bit  */
49 #define R_X86_64_PC32		2	/* PC relative 32 bit signed */
50 #define R_X86_64_GOT32		3	/* 32 bit GOT entry */
51 #define R_X86_64_PLT32		4	/* 32 bit PLT address */
52 #define R_X86_64_COPY		5	/* Copy symbol at runtime */
53 #define R_X86_64_GLOB_DAT	6	/* Create GOT entry */
54 #define R_X86_64_JUMP_SLOT	7	/* Create PLT entry */
55 #define R_X86_64_RELATIVE	8	/* Adjust by program base */
56 #define R_X86_64_GOTPCREL	9	/* 32 bit signed pc relative
57 					   offset to GOT */
58 #define R_X86_64_32		10	/* Direct 32 bit zero extended */
59 #define R_X86_64_32S		11	/* Direct 32 bit sign extended */
60 #define R_X86_64_16		12	/* Direct 16 bit zero extended */
61 #define R_X86_64_PC16		13	/* 16 bit sign extended pc relative */
62 #define R_X86_64_8		14	/* Direct 8 bit sign extended  */
63 #define R_X86_64_PC8		15	/* 8 bit sign extended pc relative */
64 #define R_X86_64_PC64		24	/* Place relative 64-bit signed */
65 
66 /*
67  * These are used to set parameters in the core dumps.
68  */
69 #define ELF_CLASS	ELFCLASS64
70 #define ELF_DATA	ELFDATA2LSB
71 #define ELF_ARCH	EM_X86_64
72 
73 #endif
74 
75 #include <asm/vdso.h>
76 
77 #ifdef CONFIG_X86_64
78 extern unsigned int vdso64_enabled;
79 #endif
80 #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
81 extern unsigned int vdso32_enabled;
82 #endif
83 
84 /*
85  * This is used to ensure we don't load something for the wrong architecture.
86  */
87 #define elf_check_arch_ia32(x) \
88 	(((x)->e_machine == EM_386) || ((x)->e_machine == EM_486))
89 
90 #include <asm/processor.h>
91 
92 #ifdef CONFIG_X86_32
93 #include <asm/desc.h>
94 
95 #define elf_check_arch(x)	elf_check_arch_ia32(x)
96 
97 /* SVR4/i386 ABI (pages 3-31, 3-32) says that when the program starts %edx
98    contains a pointer to a function which might be registered using `atexit'.
99    This provides a mean for the dynamic linker to call DT_FINI functions for
100    shared libraries that have been loaded before the code runs.
101 
102    A value of 0 tells we have no such handler.
103 
104    We might as well make sure everything else is cleared too (except for %esp),
105    just to make things more deterministic.
106  */
107 #define ELF_PLAT_INIT(_r, load_addr)		\
108 	do {					\
109 	_r->bx = 0; _r->cx = 0; _r->dx = 0;	\
110 	_r->si = 0; _r->di = 0; _r->bp = 0;	\
111 	_r->ax = 0;				\
112 } while (0)
113 
114 /*
115  * regs is struct pt_regs, pr_reg is elf_gregset_t (which is
116  * now struct_user_regs, they are different)
117  */
118 
119 #define ELF_CORE_COPY_REGS(pr_reg, regs)	\
120 do {						\
121 	pr_reg[0] = regs->bx;			\
122 	pr_reg[1] = regs->cx;			\
123 	pr_reg[2] = regs->dx;			\
124 	pr_reg[3] = regs->si;			\
125 	pr_reg[4] = regs->di;			\
126 	pr_reg[5] = regs->bp;			\
127 	pr_reg[6] = regs->ax;			\
128 	pr_reg[7] = regs->ds;			\
129 	pr_reg[8] = regs->es;			\
130 	pr_reg[9] = regs->fs;			\
131 	savesegment(gs, pr_reg[10]);		\
132 	pr_reg[11] = regs->orig_ax;		\
133 	pr_reg[12] = regs->ip;			\
134 	pr_reg[13] = regs->cs;			\
135 	pr_reg[14] = regs->flags;		\
136 	pr_reg[15] = regs->sp;			\
137 	pr_reg[16] = regs->ss;			\
138 } while (0);
139 
140 #define ELF_PLATFORM	(utsname()->machine)
141 #define set_personality_64bit()	do { } while (0)
142 
143 #else /* CONFIG_X86_32 */
144 
145 /*
146  * This is used to ensure we don't load something for the wrong architecture.
147  */
148 #define elf_check_arch(x)			\
149 	((x)->e_machine == EM_X86_64)
150 
151 #define compat_elf_check_arch(x)					\
152 	(elf_check_arch_ia32(x) ||					\
153 	 (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine == EM_X86_64))
154 
155 #if __USER32_DS != __USER_DS
156 # error "The following code assumes __USER32_DS == __USER_DS"
157 #endif
158 
elf_common_init(struct thread_struct * t,struct pt_regs * regs,const u16 ds)159 static inline void elf_common_init(struct thread_struct *t,
160 				   struct pt_regs *regs, const u16 ds)
161 {
162 	/* ax gets execve's return value. */
163 	/*regs->ax = */ regs->bx = regs->cx = regs->dx = 0;
164 	regs->si = regs->di = regs->bp = 0;
165 	regs->r8 = regs->r9 = regs->r10 = regs->r11 = 0;
166 	regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
167 	t->fsbase = t->gsbase = 0;
168 	t->fsindex = t->gsindex = 0;
169 	t->ds = t->es = ds;
170 }
171 
172 #define ELF_PLAT_INIT(_r, load_addr)			\
173 	elf_common_init(&current->thread, _r, 0)
174 
175 #define	COMPAT_ELF_PLAT_INIT(regs, load_addr)		\
176 	elf_common_init(&current->thread, regs, __USER_DS)
177 
178 void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp, bool x32);
179 #define COMPAT_START_THREAD(ex, regs, new_ip, new_sp)	\
180 	compat_start_thread(regs, new_ip, new_sp, ex->e_machine == EM_X86_64)
181 
182 void set_personality_ia32(bool);
183 #define COMPAT_SET_PERSONALITY(ex)			\
184 	set_personality_ia32((ex).e_machine == EM_X86_64)
185 
186 #define COMPAT_ELF_PLATFORM			("i686")
187 
188 /*
189  * regs is struct pt_regs, pr_reg is elf_gregset_t (which is
190  * now struct_user_regs, they are different). Assumes current is the process
191  * getting dumped.
192  */
193 
194 #define ELF_CORE_COPY_REGS(pr_reg, regs)			\
195 do {								\
196 	unsigned v;						\
197 	(pr_reg)[0] = (regs)->r15;				\
198 	(pr_reg)[1] = (regs)->r14;				\
199 	(pr_reg)[2] = (regs)->r13;				\
200 	(pr_reg)[3] = (regs)->r12;				\
201 	(pr_reg)[4] = (regs)->bp;				\
202 	(pr_reg)[5] = (regs)->bx;				\
203 	(pr_reg)[6] = (regs)->r11;				\
204 	(pr_reg)[7] = (regs)->r10;				\
205 	(pr_reg)[8] = (regs)->r9;				\
206 	(pr_reg)[9] = (regs)->r8;				\
207 	(pr_reg)[10] = (regs)->ax;				\
208 	(pr_reg)[11] = (regs)->cx;				\
209 	(pr_reg)[12] = (regs)->dx;				\
210 	(pr_reg)[13] = (regs)->si;				\
211 	(pr_reg)[14] = (regs)->di;				\
212 	(pr_reg)[15] = (regs)->orig_ax;				\
213 	(pr_reg)[16] = (regs)->ip;				\
214 	(pr_reg)[17] = (regs)->cs;				\
215 	(pr_reg)[18] = (regs)->flags;				\
216 	(pr_reg)[19] = (regs)->sp;				\
217 	(pr_reg)[20] = (regs)->ss;				\
218 	(pr_reg)[21] = x86_fsbase_read_cpu();			\
219 	(pr_reg)[22] = x86_gsbase_read_cpu_inactive();		\
220 	asm("movl %%ds,%0" : "=r" (v)); (pr_reg)[23] = v;	\
221 	asm("movl %%es,%0" : "=r" (v)); (pr_reg)[24] = v;	\
222 	asm("movl %%fs,%0" : "=r" (v)); (pr_reg)[25] = v;	\
223 	asm("movl %%gs,%0" : "=r" (v)); (pr_reg)[26] = v;	\
224 } while (0);
225 
226 /* I'm not sure if we can use '-' here */
227 #define ELF_PLATFORM       ("x86_64")
228 extern void set_personality_64bit(void);
229 extern unsigned int sysctl_vsyscall32;
230 extern int force_personality32;
231 
232 #endif /* !CONFIG_X86_32 */
233 
234 #define CORE_DUMP_USE_REGSET
235 #define ELF_EXEC_PAGESIZE	4096
236 
237 /*
238  * This is the base location for PIE (ET_DYN with INTERP) loads. On
239  * 64-bit, this is above 4GB to leave the entire 32-bit address
240  * space open for things that want to use the area for 32-bit pointers.
241  */
242 #define ELF_ET_DYN_BASE		(mmap_is_ia32() ? 0x000400000UL : \
243 						  (DEFAULT_MAP_WINDOW / 3 * 2))
244 
245 /* This yields a mask that user programs can use to figure out what
246    instruction set this CPU supports.  This could be done in user space,
247    but it's not easy, and we've already done it here.  */
248 
249 #define ELF_HWCAP		(boot_cpu_data.x86_capability[CPUID_1_EDX])
250 
251 extern u32 elf_hwcap2;
252 
253 /*
254  * HWCAP2 supplies mask with kernel enabled CPU features, so that
255  * the application can discover that it can safely use them.
256  * The bits are defined in uapi/asm/hwcap2.h.
257  */
258 #define ELF_HWCAP2		(elf_hwcap2)
259 
260 /* This yields a string that ld.so will use to load implementation
261    specific libraries for optimization.  This is more specific in
262    intent than poking at uname or /proc/cpuinfo.
263 
264    For the moment, we have only optimizations for the Intel generations,
265    but that could change... */
266 
267 #define SET_PERSONALITY(ex) set_personality_64bit()
268 
269 /*
270  * An executable for which elf_read_implies_exec() returns TRUE will
271  * have the READ_IMPLIES_EXEC personality flag set automatically.
272  *
273  * The decision process for determining the results are:
274  *
275  *                 CPU: | lacks NX*  | has NX, ia32     | has NX, x86_64 |
276  * ELF:                 |            |                  |                |
277  * ---------------------|------------|------------------|----------------|
278  * missing PT_GNU_STACK | exec-all   | exec-all         | exec-none      |
279  * PT_GNU_STACK == RWX  | exec-stack | exec-stack       | exec-stack     |
280  * PT_GNU_STACK == RW   | exec-none  | exec-none        | exec-none      |
281  *
282  *  exec-all  : all PROT_READ user mappings are executable, except when
283  *              backed by files on a noexec-filesystem.
284  *  exec-none : only PROT_EXEC user mappings are executable.
285  *  exec-stack: only the stack and PROT_EXEC user mappings are executable.
286  *
287  *  *this column has no architectural effect: NX markings are ignored by
288  *   hardware, but may have behavioral effects when "wants X" collides with
289  *   "cannot be X" constraints in memory permission flags, as in
290  *   https://lkml.kernel.org/r/20190418055759.GA3155@mellanox.com
291  *
292  */
293 #define elf_read_implies_exec(ex, executable_stack)	\
294 	(mmap_is_ia32() && executable_stack == EXSTACK_DEFAULT)
295 
296 struct task_struct;
297 
298 #define	ARCH_DLINFO_IA32						\
299 do {									\
300 	if (VDSO_CURRENT_BASE) {					\
301 		NEW_AUX_ENT(AT_SYSINFO,	VDSO_ENTRY);			\
302 		NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE);	\
303 	}								\
304 	NEW_AUX_ENT(AT_MINSIGSTKSZ, get_sigframe_size());		\
305 } while (0)
306 
307 /*
308  * True on X86_32 or when emulating IA32 on X86_64
309  */
mmap_is_ia32(void)310 static inline int mmap_is_ia32(void)
311 {
312 	return IS_ENABLED(CONFIG_X86_32) ||
313 	       (IS_ENABLED(CONFIG_COMPAT) &&
314 		test_thread_flag(TIF_ADDR32));
315 }
316 
317 extern unsigned long task_size_32bit(void);
318 extern unsigned long task_size_64bit(int full_addr_space);
319 extern unsigned long get_mmap_base(int is_legacy);
320 extern bool mmap_address_hint_valid(unsigned long addr, unsigned long len);
321 extern unsigned long get_sigframe_size(void);
322 
323 #ifdef CONFIG_X86_32
324 
325 #define __STACK_RND_MASK(is32bit) (0x7ff)
326 #define STACK_RND_MASK (0x7ff)
327 
328 #define ARCH_DLINFO		ARCH_DLINFO_IA32
329 
330 /* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
331 
332 #else /* CONFIG_X86_32 */
333 
334 /* 1GB for 64bit, 8MB for 32bit */
335 #define __STACK_RND_MASK(is32bit) ((is32bit) ? 0x7ff : 0x3fffff)
336 #define STACK_RND_MASK __STACK_RND_MASK(mmap_is_ia32())
337 
338 #define ARCH_DLINFO							\
339 do {									\
340 	if (vdso64_enabled)						\
341 		NEW_AUX_ENT(AT_SYSINFO_EHDR,				\
342 			    (unsigned long __force)current->mm->context.vdso); \
343 	NEW_AUX_ENT(AT_MINSIGSTKSZ, get_sigframe_size());		\
344 } while (0)
345 
346 /* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
347 #define ARCH_DLINFO_X32							\
348 do {									\
349 	if (vdso64_enabled)						\
350 		NEW_AUX_ENT(AT_SYSINFO_EHDR,				\
351 			    (unsigned long __force)current->mm->context.vdso); \
352 	NEW_AUX_ENT(AT_MINSIGSTKSZ, get_sigframe_size());		\
353 } while (0)
354 
355 #define AT_SYSINFO		32
356 
357 #define COMPAT_ARCH_DLINFO						\
358 if (exec->e_machine == EM_X86_64)					\
359 	ARCH_DLINFO_X32;						\
360 else if (IS_ENABLED(CONFIG_IA32_EMULATION))				\
361 	ARCH_DLINFO_IA32
362 
363 #define COMPAT_ELF_ET_DYN_BASE	(TASK_UNMAPPED_BASE + 0x1000000)
364 
365 #endif /* !CONFIG_X86_32 */
366 
367 #define VDSO_CURRENT_BASE	((unsigned long)current->mm->context.vdso)
368 
369 #define VDSO_ENTRY							\
370 	((unsigned long)current->mm->context.vdso +			\
371 	 vdso_image_32.sym___kernel_vsyscall)
372 
373 struct linux_binprm;
374 
375 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
376 extern int arch_setup_additional_pages(struct linux_binprm *bprm,
377 				       int uses_interp);
378 extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
379 					      int uses_interp, bool x32);
380 #define COMPAT_ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter)	\
381 	compat_arch_setup_additional_pages(bprm, interpreter,		\
382 					   (ex->e_machine == EM_X86_64))
383 
384 extern bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs);
385 
386 /* Do not change the values. See get_align_mask() */
387 enum align_flags {
388 	ALIGN_VA_32	= BIT(0),
389 	ALIGN_VA_64	= BIT(1),
390 };
391 
392 struct va_alignment {
393 	int flags;
394 	unsigned long mask;
395 	unsigned long bits;
396 } ____cacheline_aligned;
397 
398 extern struct va_alignment va_align;
399 extern unsigned long align_vdso_addr(unsigned long);
400 #endif /* _ASM_X86_ELF_H */
401