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