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
  24typedef struct user_fxsr_struct elf_fpxregset_t;
  25
  26#define R_386_NONE      0
  27#define R_386_32        1
  28#define R_386_PC32      2
  29#define R_386_GOT32     3
  30#define R_386_PLT32     4
  31#define R_386_COPY      5
  32#define R_386_GLOB_DAT  6
  33#define R_386_JMP_SLOT  7
  34#define R_386_RELATIVE  8
  35#define R_386_GOTOFF    9
  36#define R_386_GOTPC     10
  37#define R_386_NUM       11
  38
  39/*
  40 * These are used to set parameters in the core dumps.
  41 */
  42#define ELF_CLASS       ELFCLASS32
  43#define ELF_DATA        ELFDATA2LSB
  44#define ELF_ARCH        EM_386
  45
  46#else
  47
  48/* x86-64 relocation types */
  49#define R_X86_64_NONE           0       /* No reloc */
  50#define R_X86_64_64             1       /* Direct 64 bit  */
  51#define R_X86_64_PC32           2       /* PC relative 32 bit signed */
  52#define R_X86_64_GOT32          3       /* 32 bit GOT entry */
  53#define R_X86_64_PLT32          4       /* 32 bit PLT address */
  54#define R_X86_64_COPY           5       /* Copy symbol at runtime */
  55#define R_X86_64_GLOB_DAT       6       /* Create GOT entry */
  56#define R_X86_64_JUMP_SLOT      7       /* Create PLT entry */
  57#define R_X86_64_RELATIVE       8       /* Adjust by program base */
  58#define R_X86_64_GOTPCREL       9       /* 32 bit signed pc relative
  59                                           offset to GOT */
  60#define R_X86_64_32             10      /* Direct 32 bit zero extended */
  61#define R_X86_64_32S            11      /* Direct 32 bit sign extended */
  62#define R_X86_64_16             12      /* Direct 16 bit zero extended */
  63#define R_X86_64_PC16           13      /* 16 bit sign extended pc relative */
  64#define R_X86_64_8              14      /* Direct 8 bit sign extended  */
  65#define R_X86_64_PC8            15      /* 8 bit sign extended pc relative */
  66#define R_X86_64_PC64           24      /* Place relative 64-bit signed */
  67
  68/*
  69 * These are used to set parameters in the core dumps.
  70 */
  71#define ELF_CLASS       ELFCLASS64
  72#define ELF_DATA        ELFDATA2LSB
  73#define ELF_ARCH        EM_X86_64
  74
  75#endif
  76
  77#include <asm/vdso.h>
  78
  79#ifdef CONFIG_X86_64
  80extern unsigned int vdso64_enabled;
  81#endif
  82#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
  83extern unsigned int vdso32_enabled;
  84#endif
  85
  86/*
  87 * This is used to ensure we don't load something for the wrong architecture.
  88 */
  89#define elf_check_arch_ia32(x) \
  90        (((x)->e_machine == EM_386) || ((x)->e_machine == EM_486))
  91
  92#include <asm/processor.h>
  93
  94#ifdef CONFIG_X86_32
  95#include <asm/desc.h>
  96
  97#define elf_check_arch(x)       elf_check_arch_ia32(x)
  98
  99/* SVR4/i386 ABI (pages 3-31, 3-32) says that when the program starts %edx
 100   contains a pointer to a function which might be registered using `atexit'.
 101   This provides a mean for the dynamic linker to call DT_FINI functions for
 102   shared libraries that have been loaded before the code runs.
 103
 104   A value of 0 tells we have no such handler.
 105
 106   We might as well make sure everything else is cleared too (except for %esp),
 107   just to make things more deterministic.
 108 */
 109#define ELF_PLAT_INIT(_r, load_addr)            \
 110        do {                                    \
 111        _r->bx = 0; _r->cx = 0; _r->dx = 0;     \
 112        _r->si = 0; _r->di = 0; _r->bp = 0;     \
 113        _r->ax = 0;                             \
 114} while (0)
 115
 116/*
 117 * regs is struct pt_regs, pr_reg is elf_gregset_t (which is
 118 * now struct_user_regs, they are different)
 119 */
 120
 121#define ELF_CORE_COPY_REGS_COMMON(pr_reg, regs) \
 122do {                                            \
 123        pr_reg[0] = regs->bx;                   \
 124        pr_reg[1] = regs->cx;                   \
 125        pr_reg[2] = regs->dx;                   \
 126        pr_reg[3] = regs->si;                   \
 127        pr_reg[4] = regs->di;                   \
 128        pr_reg[5] = regs->bp;                   \
 129        pr_reg[6] = regs->ax;                   \
 130        pr_reg[7] = regs->ds;                   \
 131        pr_reg[8] = regs->es;                   \
 132        pr_reg[9] = regs->fs;                   \
 133        pr_reg[11] = regs->orig_ax;             \
 134        pr_reg[12] = regs->ip;                  \
 135        pr_reg[13] = regs->cs;                  \
 136        pr_reg[14] = regs->flags;               \
 137        pr_reg[15] = regs->sp;                  \
 138        pr_reg[16] = regs->ss;                  \
 139} while (0);
 140
 141#define ELF_CORE_COPY_REGS(pr_reg, regs)        \
 142do {                                            \
 143        ELF_CORE_COPY_REGS_COMMON(pr_reg, regs);\
 144        pr_reg[10] = get_user_gs(regs);         \
 145} while (0);
 146
 147#define ELF_CORE_COPY_KERNEL_REGS(pr_reg, regs) \
 148do {                                            \
 149        ELF_CORE_COPY_REGS_COMMON(pr_reg, regs);\
 150        savesegment(gs, pr_reg[10]);            \
 151} while (0);
 152
 153#define ELF_PLATFORM    (utsname()->machine)
 154#define set_personality_64bit() do { } while (0)
 155
 156#else /* CONFIG_X86_32 */
 157
 158/*
 159 * This is used to ensure we don't load something for the wrong architecture.
 160 */
 161#define elf_check_arch(x)                       \
 162        ((x)->e_machine == EM_X86_64)
 163
 164#define compat_elf_check_arch(x)                                        \
 165        (elf_check_arch_ia32(x) ||                                      \
 166         (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine == EM_X86_64))
 167
 168#if __USER32_DS != __USER_DS
 169# error "The following code assumes __USER32_DS == __USER_DS"
 170#endif
 171
 172static inline void elf_common_init(struct thread_struct *t,
 173                                   struct pt_regs *regs, const u16 ds)
 174{
 175        /* ax gets execve's return value. */
 176        /*regs->ax = */ regs->bx = regs->cx = regs->dx = 0;
 177        regs->si = regs->di = regs->bp = 0;
 178        regs->r8 = regs->r9 = regs->r10 = regs->r11 = 0;
 179        regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
 180        t->fsbase = t->gsbase = 0;
 181        t->fsindex = t->gsindex = 0;
 182        t->ds = t->es = ds;
 183}
 184
 185#define ELF_PLAT_INIT(_r, load_addr)                    \
 186        elf_common_init(&current->thread, _r, 0)
 187
 188#define COMPAT_ELF_PLAT_INIT(regs, load_addr)           \
 189        elf_common_init(&current->thread, regs, __USER_DS)
 190
 191void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp);
 192#define compat_start_thread compat_start_thread
 193
 194void set_personality_ia32(bool);
 195#define COMPAT_SET_PERSONALITY(ex)                      \
 196        set_personality_ia32((ex).e_machine == EM_X86_64)
 197
 198#define COMPAT_ELF_PLATFORM                     ("i686")
 199
 200/*
 201 * regs is struct pt_regs, pr_reg is elf_gregset_t (which is
 202 * now struct_user_regs, they are different). Assumes current is the process
 203 * getting dumped.
 204 */
 205
 206#define ELF_CORE_COPY_REGS(pr_reg, regs)                        \
 207do {                                                            \
 208        unsigned v;                                             \
 209        (pr_reg)[0] = (regs)->r15;                              \
 210        (pr_reg)[1] = (regs)->r14;                              \
 211        (pr_reg)[2] = (regs)->r13;                              \
 212        (pr_reg)[3] = (regs)->r12;                              \
 213        (pr_reg)[4] = (regs)->bp;                               \
 214        (pr_reg)[5] = (regs)->bx;                               \
 215        (pr_reg)[6] = (regs)->r11;                              \
 216        (pr_reg)[7] = (regs)->r10;                              \
 217        (pr_reg)[8] = (regs)->r9;                               \
 218        (pr_reg)[9] = (regs)->r8;                               \
 219        (pr_reg)[10] = (regs)->ax;                              \
 220        (pr_reg)[11] = (regs)->cx;                              \
 221        (pr_reg)[12] = (regs)->dx;                              \
 222        (pr_reg)[13] = (regs)->si;                              \
 223        (pr_reg)[14] = (regs)->di;                              \
 224        (pr_reg)[15] = (regs)->orig_ax;                         \
 225        (pr_reg)[16] = (regs)->ip;                              \
 226        (pr_reg)[17] = (regs)->cs;                              \
 227        (pr_reg)[18] = (regs)->flags;                           \
 228        (pr_reg)[19] = (regs)->sp;                              \
 229        (pr_reg)[20] = (regs)->ss;                              \
 230        (pr_reg)[21] = x86_fsbase_read_cpu();                   \
 231        (pr_reg)[22] = x86_gsbase_read_cpu_inactive();          \
 232        asm("movl %%ds,%0" : "=r" (v)); (pr_reg)[23] = v;       \
 233        asm("movl %%es,%0" : "=r" (v)); (pr_reg)[24] = v;       \
 234        asm("movl %%fs,%0" : "=r" (v)); (pr_reg)[25] = v;       \
 235        asm("movl %%gs,%0" : "=r" (v)); (pr_reg)[26] = v;       \
 236} while (0);
 237
 238/* I'm not sure if we can use '-' here */
 239#define ELF_PLATFORM       ("x86_64")
 240extern void set_personality_64bit(void);
 241extern unsigned int sysctl_vsyscall32;
 242extern int force_personality32;
 243
 244#endif /* !CONFIG_X86_32 */
 245
 246#define CORE_DUMP_USE_REGSET
 247#define ELF_EXEC_PAGESIZE       4096
 248
 249/*
 250 * This is the base location for PIE (ET_DYN with INTERP) loads. On
 251 * 64-bit, this is above 4GB to leave the entire 32-bit address
 252 * space open for things that want to use the area for 32-bit pointers.
 253 */
 254#define ELF_ET_DYN_BASE         (mmap_is_ia32() ? 0x000400000UL : \
 255                                                  (DEFAULT_MAP_WINDOW / 3 * 2))
 256
 257/* This yields a mask that user programs can use to figure out what
 258   instruction set this CPU supports.  This could be done in user space,
 259   but it's not easy, and we've already done it here.  */
 260
 261#define ELF_HWCAP               (boot_cpu_data.x86_capability[CPUID_1_EDX])
 262
 263extern u32 elf_hwcap2;
 264
 265/*
 266 * HWCAP2 supplies mask with kernel enabled CPU features, so that
 267 * the application can discover that it can safely use them.
 268 * The bits are defined in uapi/asm/hwcap2.h.
 269 */
 270#define ELF_HWCAP2              (elf_hwcap2)
 271
 272/* This yields a string that ld.so will use to load implementation
 273   specific libraries for optimization.  This is more specific in
 274   intent than poking at uname or /proc/cpuinfo.
 275
 276   For the moment, we have only optimizations for the Intel generations,
 277   but that could change... */
 278
 279#define SET_PERSONALITY(ex) set_personality_64bit()
 280
 281/*
 282 * An executable for which elf_read_implies_exec() returns TRUE will
 283 * have the READ_IMPLIES_EXEC personality flag set automatically.
 284 *
 285 * The decision process for determining the results are:
 286 *
 287 *                 CPU: | lacks NX*  | has NX, ia32     | has NX, x86_64 |
 288 * ELF:                 |            |                  |                |
 289 * ---------------------|------------|------------------|----------------|
 290 * missing PT_GNU_STACK | exec-all   | exec-all         | exec-none      |
 291 * PT_GNU_STACK == RWX  | exec-stack | exec-stack       | exec-stack     |
 292 * PT_GNU_STACK == RW   | exec-none  | exec-none        | exec-none      |
 293 *
 294 *  exec-all  : all PROT_READ user mappings are executable, except when
 295 *              backed by files on a noexec-filesystem.
 296 *  exec-none : only PROT_EXEC user mappings are executable.
 297 *  exec-stack: only the stack and PROT_EXEC user mappings are executable.
 298 *
 299 *  *this column has no architectural effect: NX markings are ignored by
 300 *   hardware, but may have behavioral effects when "wants X" collides with
 301 *   "cannot be X" constraints in memory permission flags, as in
 302 *   https://lkml.kernel.org/r/20190418055759.GA3155@mellanox.com
 303 *
 304 */
 305#define elf_read_implies_exec(ex, executable_stack)     \
 306        (mmap_is_ia32() && executable_stack == EXSTACK_DEFAULT)
 307
 308struct task_struct;
 309
 310#define ARCH_DLINFO_IA32                                                \
 311do {                                                                    \
 312        if (VDSO_CURRENT_BASE) {                                        \
 313                NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY);                    \
 314                NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE);        \
 315        }                                                               \
 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);
 332
 333#ifdef CONFIG_X86_32
 334
 335#define __STACK_RND_MASK(is32bit) (0x7ff)
 336#define STACK_RND_MASK (0x7ff)
 337
 338#define ARCH_DLINFO             ARCH_DLINFO_IA32
 339
 340/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
 341
 342#else /* CONFIG_X86_32 */
 343
 344/* 1GB for 64bit, 8MB for 32bit */
 345#define __STACK_RND_MASK(is32bit) ((is32bit) ? 0x7ff : 0x3fffff)
 346#define STACK_RND_MASK __STACK_RND_MASK(mmap_is_ia32())
 347
 348#define ARCH_DLINFO                                                     \
 349do {                                                                    \
 350        if (vdso64_enabled)                                             \
 351                NEW_AUX_ENT(AT_SYSINFO_EHDR,                            \
 352                            (unsigned long __force)current->mm->context.vdso); \
 353} while (0)
 354
 355/* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
 356#define ARCH_DLINFO_X32                                                 \
 357do {                                                                    \
 358        if (vdso64_enabled)                                             \
 359                NEW_AUX_ENT(AT_SYSINFO_EHDR,                            \
 360                            (unsigned long __force)current->mm->context.vdso); \
 361} while (0)
 362
 363#define AT_SYSINFO              32
 364
 365#define COMPAT_ARCH_DLINFO                                              \
 366if (test_thread_flag(TIF_X32))                                          \
 367        ARCH_DLINFO_X32;                                                \
 368else                                                                    \
 369        ARCH_DLINFO_IA32
 370
 371#define COMPAT_ELF_ET_DYN_BASE  (TASK_UNMAPPED_BASE + 0x1000000)
 372
 373#endif /* !CONFIG_X86_32 */
 374
 375#define VDSO_CURRENT_BASE       ((unsigned long)current->mm->context.vdso)
 376
 377#define VDSO_ENTRY                                                      \
 378        ((unsigned long)current->mm->context.vdso +                     \
 379         vdso_image_32.sym___kernel_vsyscall)
 380
 381struct linux_binprm;
 382
 383#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 384extern int arch_setup_additional_pages(struct linux_binprm *bprm,
 385                                       int uses_interp);
 386extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
 387                                              int uses_interp);
 388#define compat_arch_setup_additional_pages compat_arch_setup_additional_pages
 389
 390/* Do not change the values. See get_align_mask() */
 391enum align_flags {
 392        ALIGN_VA_32     = BIT(0),
 393        ALIGN_VA_64     = BIT(1),
 394};
 395
 396struct va_alignment {
 397        int flags;
 398        unsigned long mask;
 399        unsigned long bits;
 400} ____cacheline_aligned;
 401
 402extern struct va_alignment va_align;
 403extern unsigned long align_vdso_addr(unsigned long);
 404#endif /* _ASM_X86_ELF_H */
 405