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