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
15typedef unsigned long elf_greg_t;
16
17#define ELF_NGREG (sizeof(struct user_regs_struct) / sizeof(elf_greg_t))
18typedef elf_greg_t elf_gregset_t[ELF_NGREG];
19
20typedef 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
78extern unsigned int vdso64_enabled;
79#endif
80#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
81extern 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) \
120do { \
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
159static 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
178void 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
182void 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) \
195do { \
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")
228extern void set_personality_64bit(void);
229extern unsigned int sysctl_vsyscall32;
230extern 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
251extern 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
296struct task_struct;
297
298#define ARCH_DLINFO_IA32 \
299do { \
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 */
310static 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
317extern unsigned long task_size_32bit(void);
318extern unsigned long task_size_64bit(int full_addr_space);
319extern unsigned long get_mmap_base(int is_legacy);
320extern bool mmap_address_hint_valid(unsigned long addr, unsigned long len);
321extern 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 \
339do { \
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 \
348do { \
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 \
358if (exec->e_machine == EM_X86_64) \
359 ARCH_DLINFO_X32; \
360else 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
373struct linux_binprm;
374
375#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
376extern int arch_setup_additional_pages(struct linux_binprm *bprm,
377 int uses_interp);
378extern 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
384extern bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs);
385
386/* Do not change the values. See get_align_mask() */
387enum align_flags {
388 ALIGN_VA_32 = BIT(0),
389 ALIGN_VA_64 = BIT(1),
390};
391
392struct va_alignment {
393 int flags;
394 unsigned long mask;
395 unsigned long bits;
396} ____cacheline_aligned;
397
398extern struct va_alignment va_align;
399extern unsigned long align_vdso_addr(unsigned long);
400#endif /* _ASM_X86_ELF_H */
401

source code of linux/arch/x86/include/asm/elf.h