LXR linux/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
  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_COMMON(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        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)        \
 140do {                                            \
 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) \
 146do {                                            \
 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
 170static 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
 189void 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
 193void 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)                        \
 206do {                                                            \
 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")
 239extern void set_personality_64bit(void);
 240extern unsigned int sysctl_vsyscall32;
 241extern 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
 262extern 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
 307struct task_struct;
 308
 309#define ARCH_DLINFO_IA32                                                \
 310do {                                                                    \
 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        NEW_AUX_ENT(AT_MINSIGSTKSZ, get_sigframe_size());               \
 316} while (0)
 317
 318/*
 319 * True on X86_32 or when emulating IA32 on X86_64
 320 */
 321static inline int mmap_is_ia32(void)
 322{
 323        return IS_ENABLED(CONFIG_X86_32) ||
 324               (IS_ENABLED(CONFIG_COMPAT) &&
 325                test_thread_flag(TIF_ADDR32));
 326}
 327
 328extern unsigned long task_size_32bit(void);
 329extern unsigned long task_size_64bit(int full_addr_space);
 330extern unsigned long get_mmap_base(int is_legacy);
 331extern bool mmap_address_hint_valid(unsigned long addr, unsigned long len);
 332extern unsigned long get_sigframe_size(void);
 333
 334#ifdef CONFIG_X86_32
 335
 336#define __STACK_RND_MASK(is32bit) (0x7ff)
 337#define STACK_RND_MASK (0x7ff)
 338
 339#define ARCH_DLINFO             ARCH_DLINFO_IA32
 340
 341/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
 342
 343#else /* CONFIG_X86_32 */
 344
 345/* 1GB for 64bit, 8MB for 32bit */
 346#define __STACK_RND_MASK(is32bit) ((is32bit) ? 0x7ff : 0x3fffff)
 347#define STACK_RND_MASK __STACK_RND_MASK(mmap_is_ia32())
 348
 349#define ARCH_DLINFO                                                     \
 350do {                                                                    \
 351        if (vdso64_enabled)                                             \
 352                NEW_AUX_ENT(AT_SYSINFO_EHDR,                            \
 353                            (unsigned long __force)current->mm->context.vdso); \
 354        NEW_AUX_ENT(AT_MINSIGSTKSZ, get_sigframe_size());               \
 355} while (0)
 356
 357/* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
 358#define ARCH_DLINFO_X32                                                 \
 359do {                                                                    \
 360        if (vdso64_enabled)                                             \
 361                NEW_AUX_ENT(AT_SYSINFO_EHDR,                            \
 362                            (unsigned long __force)current->mm->context.vdso); \
 363        NEW_AUX_ENT(AT_MINSIGSTKSZ, get_sigframe_size());               \
 364} while (0)
 365
 366#define AT_SYSINFO              32
 367
 368#define COMPAT_ARCH_DLINFO                                              \
 369if (exec->e_machine == EM_X86_64)                                       \
 370        ARCH_DLINFO_X32;                                                \
 371else if (IS_ENABLED(CONFIG_IA32_EMULATION))                             \
 372        ARCH_DLINFO_IA32
 373
 374#define COMPAT_ELF_ET_DYN_BASE  (TASK_UNMAPPED_BASE + 0x1000000)
 375
 376#endif /* !CONFIG_X86_32 */
 377
 378#define VDSO_CURRENT_BASE       ((unsigned long)current->mm->context.vdso)
 379
 380#define VDSO_ENTRY                                                      \
 381        ((unsigned long)current->mm->context.vdso +                     \
 382         vdso_image_32.sym___kernel_vsyscall)
 383
 384struct linux_binprm;
 385
 386#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 387extern int arch_setup_additional_pages(struct linux_binprm *bprm,
 388                                       int uses_interp);
 389extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
 390                                              int uses_interp, bool x32);
 391#define COMPAT_ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter)       \
 392        compat_arch_setup_additional_pages(bprm, interpreter,           \
 393                                           (ex->e_machine == EM_X86_64))
 394
 395extern bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs);
 396
 397/* Do not change the values. See get_align_mask() */
 398enum align_flags {
 399        ALIGN_VA_32     = BIT(0),
 400        ALIGN_VA_64     = BIT(1),
 401};
 402
 403struct va_alignment {
 404        int flags;
 405        unsigned long mask;
 406        unsigned long bits;
 407} ____cacheline_aligned;
 408
 409extern struct va_alignment va_align;
 410extern unsigned long align_vdso_addr(unsigned long);
 411#endif /* _ASM_X86_ELF_H */
 412