arch/x86/include/asm/elf.h

   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
 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(&current->thread, _r, 0)
 185
 186 #define COMPAT_ELF_PLAT_INIT(regs, load_addr)           \
 187         elf_common_init(&current->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  */
 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                                                                    \
 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 */