linux/arch/arm64/include/asm/elf.h
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   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * Copyright (C) 2012 ARM Ltd.
   4 */
   5#ifndef __ASM_ELF_H
   6#define __ASM_ELF_H
   7
   8#include <asm/hwcap.h>
   9
  10/*
  11 * ELF register definitions..
  12 */
  13#include <asm/ptrace.h>
  14#include <asm/user.h>
  15
  16/*
  17 * AArch64 static relocation types.
  18 */
  19
  20/* Miscellaneous. */
  21#define R_ARM_NONE                      0
  22#define R_AARCH64_NONE                  256
  23
  24/* Data. */
  25#define R_AARCH64_ABS64                 257
  26#define R_AARCH64_ABS32                 258
  27#define R_AARCH64_ABS16                 259
  28#define R_AARCH64_PREL64                260
  29#define R_AARCH64_PREL32                261
  30#define R_AARCH64_PREL16                262
  31
  32/* Instructions. */
  33#define R_AARCH64_MOVW_UABS_G0          263
  34#define R_AARCH64_MOVW_UABS_G0_NC       264
  35#define R_AARCH64_MOVW_UABS_G1          265
  36#define R_AARCH64_MOVW_UABS_G1_NC       266
  37#define R_AARCH64_MOVW_UABS_G2          267
  38#define R_AARCH64_MOVW_UABS_G2_NC       268
  39#define R_AARCH64_MOVW_UABS_G3          269
  40
  41#define R_AARCH64_MOVW_SABS_G0          270
  42#define R_AARCH64_MOVW_SABS_G1          271
  43#define R_AARCH64_MOVW_SABS_G2          272
  44
  45#define R_AARCH64_LD_PREL_LO19          273
  46#define R_AARCH64_ADR_PREL_LO21         274
  47#define R_AARCH64_ADR_PREL_PG_HI21      275
  48#define R_AARCH64_ADR_PREL_PG_HI21_NC   276
  49#define R_AARCH64_ADD_ABS_LO12_NC       277
  50#define R_AARCH64_LDST8_ABS_LO12_NC     278
  51
  52#define R_AARCH64_TSTBR14               279
  53#define R_AARCH64_CONDBR19              280
  54#define R_AARCH64_JUMP26                282
  55#define R_AARCH64_CALL26                283
  56#define R_AARCH64_LDST16_ABS_LO12_NC    284
  57#define R_AARCH64_LDST32_ABS_LO12_NC    285
  58#define R_AARCH64_LDST64_ABS_LO12_NC    286
  59#define R_AARCH64_LDST128_ABS_LO12_NC   299
  60
  61#define R_AARCH64_MOVW_PREL_G0          287
  62#define R_AARCH64_MOVW_PREL_G0_NC       288
  63#define R_AARCH64_MOVW_PREL_G1          289
  64#define R_AARCH64_MOVW_PREL_G1_NC       290
  65#define R_AARCH64_MOVW_PREL_G2          291
  66#define R_AARCH64_MOVW_PREL_G2_NC       292
  67#define R_AARCH64_MOVW_PREL_G3          293
  68
  69#define R_AARCH64_RELATIVE              1027
  70
  71/*
  72 * These are used to set parameters in the core dumps.
  73 */
  74#define ELF_CLASS       ELFCLASS64
  75#ifdef __AARCH64EB__
  76#define ELF_DATA        ELFDATA2MSB
  77#else
  78#define ELF_DATA        ELFDATA2LSB
  79#endif
  80#define ELF_ARCH        EM_AARCH64
  81
  82/*
  83 * This yields a string that ld.so will use to load implementation
  84 * specific libraries for optimization.  This is more specific in
  85 * intent than poking at uname or /proc/cpuinfo.
  86 */
  87#define ELF_PLATFORM_SIZE       16
  88#ifdef __AARCH64EB__
  89#define ELF_PLATFORM            ("aarch64_be")
  90#else
  91#define ELF_PLATFORM            ("aarch64")
  92#endif
  93
  94/*
  95 * This is used to ensure we don't load something for the wrong architecture.
  96 */
  97#define elf_check_arch(x)               ((x)->e_machine == EM_AARCH64)
  98
  99/*
 100 * An executable for which elf_read_implies_exec() returns TRUE will
 101 * have the READ_IMPLIES_EXEC personality flag set automatically.
 102 *
 103 * The decision process for determining the results are:
 104 *
 105 *                CPU*: | arm32      | arm64      |
 106 * ELF:                 |            |            |
 107 * ---------------------|------------|------------|
 108 * missing PT_GNU_STACK | exec-all   | exec-none  |
 109 * PT_GNU_STACK == RWX  | exec-stack | exec-stack |
 110 * PT_GNU_STACK == RW   | exec-none  | exec-none  |
 111 *
 112 *  exec-all  : all PROT_READ user mappings are executable, except when
 113 *              backed by files on a noexec-filesystem.
 114 *  exec-none : only PROT_EXEC user mappings are executable.
 115 *  exec-stack: only the stack and PROT_EXEC user mappings are executable.
 116 *
 117 *  *all arm64 CPUs support NX, so there is no "lacks NX" column.
 118 *
 119 */
 120#define compat_elf_read_implies_exec(ex, stk)   (stk == EXSTACK_DEFAULT)
 121
 122#define CORE_DUMP_USE_REGSET
 123#define ELF_EXEC_PAGESIZE       PAGE_SIZE
 124
 125/*
 126 * This is the base location for PIE (ET_DYN with INTERP) loads. On
 127 * 64-bit, this is above 4GB to leave the entire 32-bit address
 128 * space open for things that want to use the area for 32-bit pointers.
 129 */
 130#ifdef CONFIG_ARM64_FORCE_52BIT
 131#define ELF_ET_DYN_BASE         (2 * TASK_SIZE_64 / 3)
 132#else
 133#define ELF_ET_DYN_BASE         (2 * DEFAULT_MAP_WINDOW_64 / 3)
 134#endif /* CONFIG_ARM64_FORCE_52BIT */
 135
 136#ifndef __ASSEMBLY__
 137
 138#include <uapi/linux/elf.h>
 139#include <linux/bug.h>
 140#include <linux/errno.h>
 141#include <linux/fs.h>
 142#include <linux/types.h>
 143#include <asm/processor.h> /* for signal_minsigstksz, used by ARCH_DLINFO */
 144
 145typedef unsigned long elf_greg_t;
 146
 147#define ELF_NGREG (sizeof(struct user_pt_regs) / sizeof(elf_greg_t))
 148#define ELF_CORE_COPY_REGS(dest, regs)  \
 149        *(struct user_pt_regs *)&(dest) = (regs)->user_regs;
 150
 151typedef elf_greg_t elf_gregset_t[ELF_NGREG];
 152typedef struct user_fpsimd_state elf_fpregset_t;
 153
 154/*
 155 * When the program starts, a1 contains a pointer to a function to be
 156 * registered with atexit, as per the SVR4 ABI.  A value of 0 means we have no
 157 * such handler.
 158 */
 159#define ELF_PLAT_INIT(_r, load_addr)    (_r)->regs[0] = 0
 160
 161#define SET_PERSONALITY(ex)                                             \
 162({                                                                      \
 163        clear_thread_flag(TIF_32BIT);                                   \
 164        current->personality &= ~READ_IMPLIES_EXEC;                     \
 165})
 166
 167/* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
 168#define ARCH_DLINFO                                                     \
 169do {                                                                    \
 170        NEW_AUX_ENT(AT_SYSINFO_EHDR,                                    \
 171                    (elf_addr_t)current->mm->context.vdso);             \
 172                                                                        \
 173        /*                                                              \
 174         * Should always be nonzero unless there's a kernel bug.        \
 175         * If we haven't determined a sensible value to give to         \
 176         * userspace, omit the entry:                                   \
 177         */                                                             \
 178        if (likely(signal_minsigstksz))                                 \
 179                NEW_AUX_ENT(AT_MINSIGSTKSZ, signal_minsigstksz);        \
 180        else                                                            \
 181                NEW_AUX_ENT(AT_IGNORE, 0);                              \
 182} while (0)
 183
 184#define ARCH_HAS_SETUP_ADDITIONAL_PAGES
 185struct linux_binprm;
 186extern int arch_setup_additional_pages(struct linux_binprm *bprm,
 187                                       int uses_interp);
 188
 189/* 1GB of VA */
 190#ifdef CONFIG_COMPAT
 191#define STACK_RND_MASK                  (test_thread_flag(TIF_32BIT) ? \
 192                                                0x7ff >> (PAGE_SHIFT - 12) : \
 193                                                0x3ffff >> (PAGE_SHIFT - 12))
 194#else
 195#define STACK_RND_MASK                  (0x3ffff >> (PAGE_SHIFT - 12))
 196#endif
 197
 198#ifdef __AARCH64EB__
 199#define COMPAT_ELF_PLATFORM             ("v8b")
 200#else
 201#define COMPAT_ELF_PLATFORM             ("v8l")
 202#endif
 203
 204#ifdef CONFIG_COMPAT
 205
 206/* PIE load location for compat arm. Must match ARM ELF_ET_DYN_BASE. */
 207#define COMPAT_ELF_ET_DYN_BASE          0x000400000UL
 208
 209/* AArch32 registers. */
 210#define COMPAT_ELF_NGREG                18
 211typedef unsigned int                    compat_elf_greg_t;
 212typedef compat_elf_greg_t               compat_elf_gregset_t[COMPAT_ELF_NGREG];
 213
 214/* AArch32 EABI. */
 215#define EF_ARM_EABI_MASK                0xff000000
 216#define compat_elf_check_arch(x)        (system_supports_32bit_el0() && \
 217                                         ((x)->e_machine == EM_ARM) && \
 218                                         ((x)->e_flags & EF_ARM_EABI_MASK))
 219
 220#define compat_start_thread             compat_start_thread
 221/*
 222 * Unlike the native SET_PERSONALITY macro, the compat version maintains
 223 * READ_IMPLIES_EXEC across an execve() since this is the behaviour on
 224 * arch/arm/.
 225 */
 226#define COMPAT_SET_PERSONALITY(ex)                                      \
 227({                                                                      \
 228        set_thread_flag(TIF_32BIT);                                     \
 229 })
 230#ifdef CONFIG_COMPAT_VDSO
 231#define COMPAT_ARCH_DLINFO                                              \
 232do {                                                                    \
 233        /*                                                              \
 234         * Note that we use Elf64_Off instead of elf_addr_t because     \
 235         * elf_addr_t in compat is defined as Elf32_Addr and casting    \
 236         * current->mm->context.vdso to it triggers a cast warning of   \
 237         * cast from pointer to integer of different size.              \
 238         */                                                             \
 239        NEW_AUX_ENT(AT_SYSINFO_EHDR,                                    \
 240                        (Elf64_Off)current->mm->context.vdso);          \
 241} while (0)
 242#else
 243#define COMPAT_ARCH_DLINFO
 244#endif
 245extern int aarch32_setup_additional_pages(struct linux_binprm *bprm,
 246                                          int uses_interp);
 247#define compat_arch_setup_additional_pages \
 248                                        aarch32_setup_additional_pages
 249
 250#endif /* CONFIG_COMPAT */
 251
 252struct arch_elf_state {
 253        int flags;
 254};
 255
 256#define ARM64_ELF_BTI           (1 << 0)
 257
 258#define INIT_ARCH_ELF_STATE {                   \
 259        .flags = 0,                             \
 260}
 261
 262static inline int arch_parse_elf_property(u32 type, const void *data,
 263                                          size_t datasz, bool compat,
 264                                          struct arch_elf_state *arch)
 265{
 266        /* No known properties for AArch32 yet */
 267        if (IS_ENABLED(CONFIG_COMPAT) && compat)
 268                return 0;
 269
 270        if (type == GNU_PROPERTY_AARCH64_FEATURE_1_AND) {
 271                const u32 *p = data;
 272
 273                if (datasz != sizeof(*p))
 274                        return -ENOEXEC;
 275
 276                if (system_supports_bti() &&
 277                    (*p & GNU_PROPERTY_AARCH64_FEATURE_1_BTI))
 278                        arch->flags |= ARM64_ELF_BTI;
 279        }
 280
 281        return 0;
 282}
 283
 284static inline int arch_elf_pt_proc(void *ehdr, void *phdr,
 285                                   struct file *f, bool is_interp,
 286                                   struct arch_elf_state *state)
 287{
 288        return 0;
 289}
 290
 291static inline int arch_check_elf(void *ehdr, bool has_interp,
 292                                 void *interp_ehdr,
 293                                 struct arch_elf_state *state)
 294{
 295        return 0;
 296}
 297
 298#endif /* !__ASSEMBLY__ */
 299
 300#endif
 301