include/asm/elf.h

0001 /* SPDX-License-Identifier: GPL-2.0-only */
0002 /*
0003  * Copyright (C) 2012 ARM Ltd.
0004  */
0005 #ifndef __ASM_ELF_H
0006 #define __ASM_ELF_H
0007
0008 #include <asm/hwcap.h>
0009
0010 /*
0011  * ELF register definitions..
0012  */
0013 #include <asm/ptrace.h>
0014 #include <asm/user.h>
0015
0016 /*
0017  * AArch64 static relocation types.
0018  */
0019
0020 /* Miscellaneous. */
0021 #define R_ARM_NONE          0
0022 #define R_AARCH64_NONE          256
0023
0024 /* Data. */
0025 #define R_AARCH64_ABS64         257
0026 #define R_AARCH64_ABS32         258
0027 #define R_AARCH64_ABS16         259
0028 #define R_AARCH64_PREL64        260
0029 #define R_AARCH64_PREL32        261
0030 #define R_AARCH64_PREL16        262
0031
0032 /* Instructions. */
0033 #define R_AARCH64_MOVW_UABS_G0      263
0034 #define R_AARCH64_MOVW_UABS_G0_NC   264
0035 #define R_AARCH64_MOVW_UABS_G1      265
0036 #define R_AARCH64_MOVW_UABS_G1_NC   266
0037 #define R_AARCH64_MOVW_UABS_G2      267
0038 #define R_AARCH64_MOVW_UABS_G2_NC   268
0039 #define R_AARCH64_MOVW_UABS_G3      269
0040
0041 #define R_AARCH64_MOVW_SABS_G0      270
0042 #define R_AARCH64_MOVW_SABS_G1      271
0043 #define R_AARCH64_MOVW_SABS_G2      272
0044
0045 #define R_AARCH64_LD_PREL_LO19      273
0046 #define R_AARCH64_ADR_PREL_LO21     274
0047 #define R_AARCH64_ADR_PREL_PG_HI21  275
0048 #define R_AARCH64_ADR_PREL_PG_HI21_NC   276
0049 #define R_AARCH64_ADD_ABS_LO12_NC   277
0050 #define R_AARCH64_LDST8_ABS_LO12_NC 278
0051
0052 #define R_AARCH64_TSTBR14       279
0053 #define R_AARCH64_CONDBR19      280
0054 #define R_AARCH64_JUMP26        282
0055 #define R_AARCH64_CALL26        283
0056 #define R_AARCH64_LDST16_ABS_LO12_NC    284
0057 #define R_AARCH64_LDST32_ABS_LO12_NC    285
0058 #define R_AARCH64_LDST64_ABS_LO12_NC    286
0059 #define R_AARCH64_LDST128_ABS_LO12_NC   299
0060
0061 #define R_AARCH64_MOVW_PREL_G0      287
0062 #define R_AARCH64_MOVW_PREL_G0_NC   288
0063 #define R_AARCH64_MOVW_PREL_G1      289
0064 #define R_AARCH64_MOVW_PREL_G1_NC   290
0065 #define R_AARCH64_MOVW_PREL_G2      291
0066 #define R_AARCH64_MOVW_PREL_G2_NC   292
0067 #define R_AARCH64_MOVW_PREL_G3      293
0068
0069 #define R_AARCH64_RELATIVE      1027
0070
0071 /*
0072  * These are used to set parameters in the core dumps.
0073  */
0074 #define ELF_CLASS   ELFCLASS64
0075 #ifdef __AARCH64EB__
0076 #define ELF_DATA    ELFDATA2MSB
0077 #else
0078 #define ELF_DATA    ELFDATA2LSB
0079 #endif
0080 #define ELF_ARCH    EM_AARCH64
0081
0082 /*
0083  * This yields a string that ld.so will use to load implementation
0084  * specific libraries for optimization.  This is more specific in
0085  * intent than poking at uname or /proc/cpuinfo.
0086  */
0087 #define ELF_PLATFORM_SIZE   16
0088 #ifdef __AARCH64EB__
0089 #define ELF_PLATFORM        ("aarch64_be")
0090 #else
0091 #define ELF_PLATFORM        ("aarch64")
0092 #endif
0093
0094 /*
0095  * This is used to ensure we don't load something for the wrong architecture.
0096  */
0097 #define elf_check_arch(x)       ((x)->e_machine == EM_AARCH64)
0098
0099 /*
0100  * An executable for which elf_read_implies_exec() returns TRUE will
0101  * have the READ_IMPLIES_EXEC personality flag set automatically.
0102  *
0103  * The decision process for determining the results are:
0104  *
0105  *                CPU*: | arm32      | arm64      |
0106  * ELF:                 |            |            |
0107  * ---------------------|------------|------------|
0108  * missing PT_GNU_STACK | exec-all   | exec-none  |
0109  * PT_GNU_STACK == RWX  | exec-stack | exec-stack |
0110  * PT_GNU_STACK == RW   | exec-none  | exec-none  |
0111  *
0112  *  exec-all  : all PROT_READ user mappings are executable, except when
0113  *              backed by files on a noexec-filesystem.
0114  *  exec-none : only PROT_EXEC user mappings are executable.
0115  *  exec-stack: only the stack and PROT_EXEC user mappings are executable.
0116  *
0117  *  *all arm64 CPUs support NX, so there is no "lacks NX" column.
0118  *
0119  */
0120 #define compat_elf_read_implies_exec(ex, stk)   (stk == EXSTACK_DEFAULT)
0121
0122 #define CORE_DUMP_USE_REGSET
0123 #define ELF_EXEC_PAGESIZE   PAGE_SIZE
0124
0125 /*
0126  * This is the base location for PIE (ET_DYN with INTERP) loads. On
0127  * 64-bit, this is above 4GB to leave the entire 32-bit address
0128  * space open for things that want to use the area for 32-bit pointers.
0129  */
0130 #ifdef CONFIG_ARM64_FORCE_52BIT
0131 #define ELF_ET_DYN_BASE     (2 * TASK_SIZE_64 / 3)
0132 #else
0133 #define ELF_ET_DYN_BASE     (2 * DEFAULT_MAP_WINDOW_64 / 3)
0134 #endif /* CONFIG_ARM64_FORCE_52BIT */
0135
0136 #ifndef __ASSEMBLY__
0137
0138 #include <uapi/linux/elf.h>
0139 #include <linux/bug.h>
0140 #include <linux/errno.h>
0141 #include <linux/fs.h>
0142 #include <linux/types.h>
0143 #include <asm/processor.h> /* for signal_minsigstksz, used by ARCH_DLINFO */
0144
0145 typedef unsigned long elf_greg_t;
0146
0147 #define ELF_NGREG (sizeof(struct user_pt_regs) / sizeof(elf_greg_t))
0148 #define ELF_CORE_COPY_REGS(dest, regs)  \
0149     *(struct user_pt_regs *)&(dest) = (regs)->user_regs;
0150
0151 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
0152 typedef struct user_fpsimd_state elf_fpregset_t;
0153
0154 /*
0155  * When the program starts, a1 contains a pointer to a function to be
0156  * registered with atexit, as per the SVR4 ABI.  A value of 0 means we have no
0157  * such handler.
0158  */
0159 #define ELF_PLAT_INIT(_r, load_addr)    (_r)->regs[0] = 0
0160
0161 #define SET_PERSONALITY(ex)                     \
0162 ({                                  \
0163     clear_thread_flag(TIF_32BIT);                   \
0164     current->personality &= ~READ_IMPLIES_EXEC;         \
0165 })
0166
0167 /* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
0168 #define ARCH_DLINFO                         \
0169 do {                                    \
0170     NEW_AUX_ENT(AT_SYSINFO_EHDR,                    \
0171             (elf_addr_t)current->mm->context.vdso);     \
0172                                     \
0173     /*                              \
0174      * Should always be nonzero unless there's a kernel bug.    \
0175      * If we haven't determined a sensible value to give to     \
0176      * userspace, omit the entry:                   \
0177      */                             \
0178     if (likely(signal_minsigstksz))                 \
0179         NEW_AUX_ENT(AT_MINSIGSTKSZ, signal_minsigstksz);    \
0180     else                                \
0181         NEW_AUX_ENT(AT_IGNORE, 0);              \
0182 } while (0)
0183
0184 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES
0185 struct linux_binprm;
0186 extern int arch_setup_additional_pages(struct linux_binprm *bprm,
0187                        int uses_interp);
0188
0189 /* 1GB of VA */
0190 #ifdef CONFIG_COMPAT
0191 #define STACK_RND_MASK          (test_thread_flag(TIF_32BIT) ? \
0192                         0x7ff >> (PAGE_SHIFT - 12) : \
0193                         0x3ffff >> (PAGE_SHIFT - 12))
0194 #else
0195 #define STACK_RND_MASK          (0x3ffff >> (PAGE_SHIFT - 12))
0196 #endif
0197
0198 #ifdef __AARCH64EB__
0199 #define COMPAT_ELF_PLATFORM     ("v8b")
0200 #else
0201 #define COMPAT_ELF_PLATFORM     ("v8l")
0202 #endif
0203
0204 #ifdef CONFIG_COMPAT
0205
0206 /* PIE load location for compat arm. Must match ARM ELF_ET_DYN_BASE. */
0207 #define COMPAT_ELF_ET_DYN_BASE      0x000400000UL
0208
0209 /* AArch32 registers. */
0210 #define COMPAT_ELF_NGREG        18
0211 typedef unsigned int            compat_elf_greg_t;
0212 typedef compat_elf_greg_t       compat_elf_gregset_t[COMPAT_ELF_NGREG];
0213
0214 /* AArch32 EABI. */
0215 #define EF_ARM_EABI_MASK        0xff000000
0216 int compat_elf_check_arch(const struct elf32_hdr *);
0217 #define compat_elf_check_arch       compat_elf_check_arch
0218 #define compat_start_thread     compat_start_thread
0219 /*
0220  * Unlike the native SET_PERSONALITY macro, the compat version maintains
0221  * READ_IMPLIES_EXEC across an execve() since this is the behaviour on
0222  * arch/arm/.
0223  */
0224 #define COMPAT_SET_PERSONALITY(ex)                  \
0225 ({                                  \
0226     set_thread_flag(TIF_32BIT);                 \
0227  })
0228 #ifdef CONFIG_COMPAT_VDSO
0229 #define COMPAT_ARCH_DLINFO                      \
0230 do {                                    \
0231     /*                              \
0232      * Note that we use Elf64_Off instead of elf_addr_t because \
0233      * elf_addr_t in compat is defined as Elf32_Addr and casting    \
0234      * current->mm->context.vdso to it triggers a cast warning of   \
0235      * cast from pointer to integer of different size.      \
0236      */                             \
0237     NEW_AUX_ENT(AT_SYSINFO_EHDR,                    \
0238             (Elf64_Off)current->mm->context.vdso);      \
0239 } while (0)
0240 #else
0241 #define COMPAT_ARCH_DLINFO
0242 #endif
0243 extern int aarch32_setup_additional_pages(struct linux_binprm *bprm,
0244                       int uses_interp);
0245 #define compat_arch_setup_additional_pages \
0246                     aarch32_setup_additional_pages
0247
0248 #endif /* CONFIG_COMPAT */
0249
0250 struct arch_elf_state {
0251     int flags;
0252 };
0253
0254 #define ARM64_ELF_BTI       (1 << 0)
0255
0256 #define INIT_ARCH_ELF_STATE {           \
0257     .flags = 0,             \
0258 }
0259
0260 static inline int arch_parse_elf_property(u32 type, const void *data,
0261                       size_t datasz, bool compat,
0262                       struct arch_elf_state *arch)
0263 {
0264     /* No known properties for AArch32 yet */
0265     if (IS_ENABLED(CONFIG_COMPAT) && compat)
0266         return 0;
0267
0268     if (type == GNU_PROPERTY_AARCH64_FEATURE_1_AND) {
0269         const u32 *p = data;
0270
0271         if (datasz != sizeof(*p))
0272             return -ENOEXEC;
0273
0274         if (system_supports_bti() &&
0275             (*p & GNU_PROPERTY_AARCH64_FEATURE_1_BTI))
0276             arch->flags |= ARM64_ELF_BTI;
0277     }
0278
0279     return 0;
0280 }
0281
0282 static inline int arch_elf_pt_proc(void *ehdr, void *phdr,
0283                    struct file *f, bool is_interp,
0284                    struct arch_elf_state *state)
0285 {
0286     return 0;
0287 }
0288
0289 static inline int arch_check_elf(void *ehdr, bool has_interp,
0290                  void *interp_ehdr,
0291                  struct arch_elf_state *state)
0292 {
0293     return 0;
0294 }
0295
0296 #endif /* !__ASSEMBLY__ */
0297
0298 #endif