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_COMMON(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 pr_reg[11] = regs->orig_ax; \
132 pr_reg[12] = regs->ip; \
133 pr_reg[13] = regs->cs; \
134 pr_reg[14] = regs->flags; \
135 pr_reg[15] = regs->sp; \
136 pr_reg[16] = regs->ss; \
137 } while (0);
138
139 #define ELF_CORE_COPY_REGS(pr_reg, regs) \
140 do { \
141 ELF_CORE_COPY_REGS_COMMON(pr_reg, regs);\
142 pr_reg[10] = get_user_gs(regs); \
143 } while (0);
144
145 #define ELF_CORE_COPY_KERNEL_REGS(pr_reg, regs) \
146 do { \
147 ELF_CORE_COPY_REGS_COMMON(pr_reg, regs);\
148 savesegment(gs, pr_reg[10]); \
149 } while (0);
150
151 #define ELF_PLATFORM (utsname()->machine)
152 #define set_personality_64bit() do { } while (0)
153
154 #else /* CONFIG_X86_32 */
155
156 /*
157 * This is used to ensure we don't load something for the wrong architecture.
158 */
159 #define elf_check_arch(x) \
160 ((x)->e_machine == EM_X86_64)
161
162 #define compat_elf_check_arch(x) \
163 (elf_check_arch_ia32(x) || \
164 (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine == EM_X86_64))
165
166 #if __USER32_DS != __USER_DS
167 # error "The following code assumes __USER32_DS == __USER_DS"
168 #endif
169
elf_common_init(struct thread_struct * t,struct pt_regs * regs,const u16 ds)170 static inline void elf_common_init(struct thread_struct *t,
171 struct pt_regs *regs, const u16 ds)
172 {
173 /* ax gets execve's return value. */
174 /*regs->ax = */ regs->bx = regs->cx = regs->dx = 0;
175 regs->si = regs->di = regs->bp = 0;
176 regs->r8 = regs->r9 = regs->r10 = regs->r11 = 0;
177 regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
178 t->fsbase = t->gsbase = 0;
179 t->fsindex = t->gsindex = 0;
180 t->ds = t->es = ds;
181 }
182
183 #define ELF_PLAT_INIT(_r, load_addr) \
184 elf_common_init(¤t->thread, _r, 0)
185
186 #define COMPAT_ELF_PLAT_INIT(regs, load_addr) \
187 elf_common_init(¤t->thread, regs, __USER_DS)
188
189 void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp, bool x32);
190 #define COMPAT_START_THREAD(ex, regs, new_ip, new_sp) \
191 compat_start_thread(regs, new_ip, new_sp, ex->e_machine == EM_X86_64)
192
193 void set_personality_ia32(bool);
194 #define COMPAT_SET_PERSONALITY(ex) \
195 set_personality_ia32((ex).e_machine == EM_X86_64)
196
197 #define COMPAT_ELF_PLATFORM ("i686")
198
199 /*
200 * regs is struct pt_regs, pr_reg is elf_gregset_t (which is
201 * now struct_user_regs, they are different). Assumes current is the process
202 * getting dumped.
203 */
204
205 #define ELF_CORE_COPY_REGS(pr_reg, regs) \
206 do { \
207 unsigned v; \
208 (pr_reg)[0] = (regs)->r15; \
209 (pr_reg)[1] = (regs)->r14; \
210 (pr_reg)[2] = (regs)->r13; \
211 (pr_reg)[3] = (regs)->r12; \
212 (pr_reg)[4] = (regs)->bp; \
213 (pr_reg)[5] = (regs)->bx; \
214 (pr_reg)[6] = (regs)->r11; \
215 (pr_reg)[7] = (regs)->r10; \
216 (pr_reg)[8] = (regs)->r9; \
217 (pr_reg)[9] = (regs)->r8; \
218 (pr_reg)[10] = (regs)->ax; \
219 (pr_reg)[11] = (regs)->cx; \
220 (pr_reg)[12] = (regs)->dx; \
221 (pr_reg)[13] = (regs)->si; \
222 (pr_reg)[14] = (regs)->di; \
223 (pr_reg)[15] = (regs)->orig_ax; \
224 (pr_reg)[16] = (regs)->ip; \
225 (pr_reg)[17] = (regs)->cs; \
226 (pr_reg)[18] = (regs)->flags; \
227 (pr_reg)[19] = (regs)->sp; \
228 (pr_reg)[20] = (regs)->ss; \
229 (pr_reg)[21] = x86_fsbase_read_cpu(); \
230 (pr_reg)[22] = x86_gsbase_read_cpu_inactive(); \
231 asm("movl %%ds,%0" : "=r" (v)); (pr_reg)[23] = v; \
232 asm("movl %%es,%0" : "=r" (v)); (pr_reg)[24] = v; \
233 asm("movl %%fs,%0" : "=r" (v)); (pr_reg)[25] = v; \
234 asm("movl %%gs,%0" : "=r" (v)); (pr_reg)[26] = v; \
235 } while (0);
236
237 /* I'm not sure if we can use '-' here */
238 #define ELF_PLATFORM ("x86_64")
239 extern void set_personality_64bit(void);
240 extern unsigned int sysctl_vsyscall32;
241 extern int force_personality32;
242
243 #endif /* !CONFIG_X86_32 */
244
245 #define CORE_DUMP_USE_REGSET
246 #define ELF_EXEC_PAGESIZE 4096
247
248 /*
249 * This is the base location for PIE (ET_DYN with INTERP) loads. On
250 * 64-bit, this is above 4GB to leave the entire 32-bit address
251 * space open for things that want to use the area for 32-bit pointers.
252 */
253 #define ELF_ET_DYN_BASE (mmap_is_ia32() ? 0x000400000UL : \
254 (DEFAULT_MAP_WINDOW / 3 * 2))
255
256 /* This yields a mask that user programs can use to figure out what
257 instruction set this CPU supports. This could be done in user space,
258 but it's not easy, and we've already done it here. */
259
260 #define ELF_HWCAP (boot_cpu_data.x86_capability[CPUID_1_EDX])
261
262 extern u32 elf_hwcap2;
263
264 /*
265 * HWCAP2 supplies mask with kernel enabled CPU features, so that
266 * the application can discover that it can safely use them.
267 * The bits are defined in uapi/asm/hwcap2.h.
268 */
269 #define ELF_HWCAP2 (elf_hwcap2)
270
271 /* This yields a string that ld.so will use to load implementation
272 specific libraries for optimization. This is more specific in
273 intent than poking at uname or /proc/cpuinfo.
274
275 For the moment, we have only optimizations for the Intel generations,
276 but that could change... */
277
278 #define SET_PERSONALITY(ex) set_personality_64bit()
279
280 /*
281 * An executable for which elf_read_implies_exec() returns TRUE will
282 * have the READ_IMPLIES_EXEC personality flag set automatically.
283 *
284 * The decision process for determining the results are:
285 *
286 * CPU: | lacks NX* | has NX, ia32 | has NX, x86_64 |
287 * ELF: | | | |
288 * ---------------------|------------|------------------|----------------|
289 * missing PT_GNU_STACK | exec-all | exec-all | exec-none |
290 * PT_GNU_STACK == RWX | exec-stack | exec-stack | exec-stack |
291 * PT_GNU_STACK == RW | exec-none | exec-none | exec-none |
292 *
293 * exec-all : all PROT_READ user mappings are executable, except when
294 * backed by files on a noexec-filesystem.
295 * exec-none : only PROT_EXEC user mappings are executable.
296 * exec-stack: only the stack and PROT_EXEC user mappings are executable.
297 *
298 * *this column has no architectural effect: NX markings are ignored by
299 * hardware, but may have behavioral effects when "wants X" collides with
300 * "cannot be X" constraints in memory permission flags, as in
301 * https://lkml.kernel.org/r/20190418055759.GA3155@mellanox.com
302 *
303 */
304 #define elf_read_implies_exec(ex, executable_stack) \
305 (mmap_is_ia32() && executable_stack == EXSTACK_DEFAULT)
306
307 struct task_struct;
308
309 #define ARCH_DLINFO_IA32 \
310 do { \
311 if (VDSO_CURRENT_BASE) { \
312 NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY); \
313 NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE); \
314 } \
315 } while (0)
316
317 /*
318 * True on X86_32 or when emulating IA32 on X86_64
319 */
mmap_is_ia32(void)320 static inline int mmap_is_ia32(void)
321 {
322 return IS_ENABLED(CONFIG_X86_32) ||
323 (IS_ENABLED(CONFIG_COMPAT) &&
324 test_thread_flag(TIF_ADDR32));
325 }
326
327 extern unsigned long task_size_32bit(void);
328 extern unsigned long task_size_64bit(int full_addr_space);
329 extern unsigned long get_mmap_base(int is_legacy);
330 extern bool mmap_address_hint_valid(unsigned long addr, unsigned long len);
331
332 #ifdef CONFIG_X86_32
333
334 #define __STACK_RND_MASK(is32bit) (0x7ff)
335 #define STACK_RND_MASK (0x7ff)
336
337 #define ARCH_DLINFO ARCH_DLINFO_IA32
338
339 /* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
340
341 #else /* CONFIG_X86_32 */
342
343 /* 1GB for 64bit, 8MB for 32bit */
344 #define __STACK_RND_MASK(is32bit) ((is32bit) ? 0x7ff : 0x3fffff)
345 #define STACK_RND_MASK __STACK_RND_MASK(mmap_is_ia32())
346
347 #define ARCH_DLINFO \
348 do { \
349 if (vdso64_enabled) \
350 NEW_AUX_ENT(AT_SYSINFO_EHDR, \
351 (unsigned long __force)current->mm->context.vdso); \
352 } while (0)
353
354 /* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
355 #define ARCH_DLINFO_X32 \
356 do { \
357 if (vdso64_enabled) \
358 NEW_AUX_ENT(AT_SYSINFO_EHDR, \
359 (unsigned long __force)current->mm->context.vdso); \
360 } while (0)
361
362 #define AT_SYSINFO 32
363
364 #define COMPAT_ARCH_DLINFO \
365 if (exec->e_machine == EM_X86_64) \
366 ARCH_DLINFO_X32; \
367 else if (IS_ENABLED(CONFIG_IA32_EMULATION)) \
368 ARCH_DLINFO_IA32
369
370 #define COMPAT_ELF_ET_DYN_BASE (TASK_UNMAPPED_BASE + 0x1000000)
371
372 #endif /* !CONFIG_X86_32 */
373
374 #define VDSO_CURRENT_BASE ((unsigned long)current->mm->context.vdso)
375
376 #define VDSO_ENTRY \
377 ((unsigned long)current->mm->context.vdso + \
378 vdso_image_32.sym___kernel_vsyscall)
379
380 struct linux_binprm;
381
382 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
383 extern int arch_setup_additional_pages(struct linux_binprm *bprm,
384 int uses_interp);
385 extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
386 int uses_interp, bool x32);
387 #define COMPAT_ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter) \
388 compat_arch_setup_additional_pages(bprm, interpreter, \
389 (ex->e_machine == EM_X86_64))
390
391 extern bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs);
392
393 /* Do not change the values. See get_align_mask() */
394 enum align_flags {
395 ALIGN_VA_32 = BIT(0),
396 ALIGN_VA_64 = BIT(1),
397 };
398
399 struct va_alignment {
400 int flags;
401 unsigned long mask;
402 unsigned long bits;
403 } ____cacheline_aligned;
404
405 extern struct va_alignment va_align;
406 extern unsigned long align_vdso_addr(unsigned long);
407 #endif /* _ASM_X86_ELF_H */
408