include/asm/elf.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _ASM_X86_ELF_H
0003 #define _ASM_X86_ELF_H
0004
0005 /*
0006  * ELF register definitions..
0007  */
0008 #include <linux/thread_info.h>
0009
0010 #include <asm/ptrace.h>
0011 #include <asm/user.h>
0012 #include <asm/auxvec.h>
0013 #include <asm/fsgsbase.h>
0014
0015 typedef unsigned long elf_greg_t;
0016
0017 #define ELF_NGREG (sizeof(struct user_regs_struct) / sizeof(elf_greg_t))
0018 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
0019
0020 typedef struct user_i387_struct elf_fpregset_t;
0021
0022 #ifdef __i386__
0023
0024 #define R_386_NONE  0
0025 #define R_386_32    1
0026 #define R_386_PC32  2
0027 #define R_386_GOT32 3
0028 #define R_386_PLT32 4
0029 #define R_386_COPY  5
0030 #define R_386_GLOB_DAT  6
0031 #define R_386_JMP_SLOT  7
0032 #define R_386_RELATIVE  8
0033 #define R_386_GOTOFF    9
0034 #define R_386_GOTPC 10
0035 #define R_386_NUM   11
0036
0037 /*
0038  * These are used to set parameters in the core dumps.
0039  */
0040 #define ELF_CLASS   ELFCLASS32
0041 #define ELF_DATA    ELFDATA2LSB
0042 #define ELF_ARCH    EM_386
0043
0044 #else
0045
0046 /* x86-64 relocation types */
0047 #define R_X86_64_NONE       0   /* No reloc */
0048 #define R_X86_64_64     1   /* Direct 64 bit  */
0049 #define R_X86_64_PC32       2   /* PC relative 32 bit signed */
0050 #define R_X86_64_GOT32      3   /* 32 bit GOT entry */
0051 #define R_X86_64_PLT32      4   /* 32 bit PLT address */
0052 #define R_X86_64_COPY       5   /* Copy symbol at runtime */
0053 #define R_X86_64_GLOB_DAT   6   /* Create GOT entry */
0054 #define R_X86_64_JUMP_SLOT  7   /* Create PLT entry */
0055 #define R_X86_64_RELATIVE   8   /* Adjust by program base */
0056 #define R_X86_64_GOTPCREL   9   /* 32 bit signed pc relative
0057                        offset to GOT */
0058 #define R_X86_64_32     10  /* Direct 32 bit zero extended */
0059 #define R_X86_64_32S        11  /* Direct 32 bit sign extended */
0060 #define R_X86_64_16     12  /* Direct 16 bit zero extended */
0061 #define R_X86_64_PC16       13  /* 16 bit sign extended pc relative */
0062 #define R_X86_64_8      14  /* Direct 8 bit sign extended  */
0063 #define R_X86_64_PC8        15  /* 8 bit sign extended pc relative */
0064 #define R_X86_64_PC64       24  /* Place relative 64-bit signed */
0065
0066 /*
0067  * These are used to set parameters in the core dumps.
0068  */
0069 #define ELF_CLASS   ELFCLASS64
0070 #define ELF_DATA    ELFDATA2LSB
0071 #define ELF_ARCH    EM_X86_64
0072
0073 #endif
0074
0075 #include <asm/vdso.h>
0076
0077 #ifdef CONFIG_X86_64
0078 extern unsigned int vdso64_enabled;
0079 #endif
0080 #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
0081 extern unsigned int vdso32_enabled;
0082 #endif
0083
0084 /*
0085  * This is used to ensure we don't load something for the wrong architecture.
0086  */
0087 #define elf_check_arch_ia32(x) \
0088     (((x)->e_machine == EM_386) || ((x)->e_machine == EM_486))
0089
0090 #include <asm/processor.h>
0091
0092 #ifdef CONFIG_X86_32
0093 #include <asm/desc.h>
0094
0095 #define elf_check_arch(x)   elf_check_arch_ia32(x)
0096
0097 /* SVR4/i386 ABI (pages 3-31, 3-32) says that when the program starts %edx
0098    contains a pointer to a function which might be registered using `atexit'.
0099    This provides a mean for the dynamic linker to call DT_FINI functions for
0100    shared libraries that have been loaded before the code runs.
0101
0102    A value of 0 tells we have no such handler.
0103
0104    We might as well make sure everything else is cleared too (except for %esp),
0105    just to make things more deterministic.
0106  */
0107 #define ELF_PLAT_INIT(_r, load_addr)        \
0108     do {                    \
0109     _r->bx = 0; _r->cx = 0; _r->dx = 0; \
0110     _r->si = 0; _r->di = 0; _r->bp = 0; \
0111     _r->ax = 0;             \
0112 } while (0)
0113
0114 /*
0115  * regs is struct pt_regs, pr_reg is elf_gregset_t (which is
0116  * now struct_user_regs, they are different)
0117  */
0118
0119 #define ELF_CORE_COPY_REGS(pr_reg, regs)    \
0120 do {                        \
0121     pr_reg[0] = regs->bx;           \
0122     pr_reg[1] = regs->cx;           \
0123     pr_reg[2] = regs->dx;           \
0124     pr_reg[3] = regs->si;           \
0125     pr_reg[4] = regs->di;           \
0126     pr_reg[5] = regs->bp;           \
0127     pr_reg[6] = regs->ax;           \
0128     pr_reg[7] = regs->ds;           \
0129     pr_reg[8] = regs->es;           \
0130     pr_reg[9] = regs->fs;           \
0131     savesegment(gs, pr_reg[10]);        \
0132     pr_reg[11] = regs->orig_ax;     \
0133     pr_reg[12] = regs->ip;          \
0134     pr_reg[13] = regs->cs;          \
0135     pr_reg[14] = regs->flags;       \
0136     pr_reg[15] = regs->sp;          \
0137     pr_reg[16] = regs->ss;          \
0138 } while (0);
0139
0140 #define ELF_PLATFORM    (utsname()->machine)
0141 #define set_personality_64bit() do { } while (0)
0142
0143 #else /* CONFIG_X86_32 */
0144
0145 /*
0146  * This is used to ensure we don't load something for the wrong architecture.
0147  */
0148 #define elf_check_arch(x)           \
0149     ((x)->e_machine == EM_X86_64)
0150
0151 #define compat_elf_check_arch(x)                    \
0152     (elf_check_arch_ia32(x) ||                  \
0153      (IS_ENABLED(CONFIG_X86_X32_ABI) && (x)->e_machine == EM_X86_64))
0154
0155 #if __USER32_DS != __USER_DS
0156 # error "The following code assumes __USER32_DS == __USER_DS"
0157 #endif
0158
0159 static inline void elf_common_init(struct thread_struct *t,
0160                    struct pt_regs *regs, const u16 ds)
0161 {
0162     /* ax gets execve's return value. */
0163     /*regs->ax = */ regs->bx = regs->cx = regs->dx = 0;
0164     regs->si = regs->di = regs->bp = 0;
0165     regs->r8 = regs->r9 = regs->r10 = regs->r11 = 0;
0166     regs->r12 = regs->r13 = regs->r14 = regs->r15 = 0;
0167     t->fsbase = t->gsbase = 0;
0168     t->fsindex = t->gsindex = 0;
0169     t->ds = t->es = ds;
0170 }
0171
0172 #define ELF_PLAT_INIT(_r, load_addr)            \
0173     elf_common_init(&current->thread, _r, 0)
0174
0175 #define COMPAT_ELF_PLAT_INIT(regs, load_addr)       \
0176     elf_common_init(&current->thread, regs, __USER_DS)
0177
0178 void compat_start_thread(struct pt_regs *regs, u32 new_ip, u32 new_sp, bool x32);
0179 #define COMPAT_START_THREAD(ex, regs, new_ip, new_sp)   \
0180     compat_start_thread(regs, new_ip, new_sp, ex->e_machine == EM_X86_64)
0181
0182 void set_personality_ia32(bool);
0183 #define COMPAT_SET_PERSONALITY(ex)          \
0184     set_personality_ia32((ex).e_machine == EM_X86_64)
0185
0186 #define COMPAT_ELF_PLATFORM         ("i686")
0187
0188 /*
0189  * regs is struct pt_regs, pr_reg is elf_gregset_t (which is
0190  * now struct_user_regs, they are different). Assumes current is the process
0191  * getting dumped.
0192  */
0193
0194 #define ELF_CORE_COPY_REGS(pr_reg, regs)            \
0195 do {                                \
0196     unsigned v;                     \
0197     (pr_reg)[0] = (regs)->r15;              \
0198     (pr_reg)[1] = (regs)->r14;              \
0199     (pr_reg)[2] = (regs)->r13;              \
0200     (pr_reg)[3] = (regs)->r12;              \
0201     (pr_reg)[4] = (regs)->bp;               \
0202     (pr_reg)[5] = (regs)->bx;               \
0203     (pr_reg)[6] = (regs)->r11;              \
0204     (pr_reg)[7] = (regs)->r10;              \
0205     (pr_reg)[8] = (regs)->r9;               \
0206     (pr_reg)[9] = (regs)->r8;               \
0207     (pr_reg)[10] = (regs)->ax;              \
0208     (pr_reg)[11] = (regs)->cx;              \
0209     (pr_reg)[12] = (regs)->dx;              \
0210     (pr_reg)[13] = (regs)->si;              \
0211     (pr_reg)[14] = (regs)->di;              \
0212     (pr_reg)[15] = (regs)->orig_ax;             \
0213     (pr_reg)[16] = (regs)->ip;              \
0214     (pr_reg)[17] = (regs)->cs;              \
0215     (pr_reg)[18] = (regs)->flags;               \
0216     (pr_reg)[19] = (regs)->sp;              \
0217     (pr_reg)[20] = (regs)->ss;              \
0218     (pr_reg)[21] = x86_fsbase_read_cpu();           \
0219     (pr_reg)[22] = x86_gsbase_read_cpu_inactive();      \
0220     asm("movl %%ds,%0" : "=r" (v)); (pr_reg)[23] = v;   \
0221     asm("movl %%es,%0" : "=r" (v)); (pr_reg)[24] = v;   \
0222     asm("movl %%fs,%0" : "=r" (v)); (pr_reg)[25] = v;   \
0223     asm("movl %%gs,%0" : "=r" (v)); (pr_reg)[26] = v;   \
0224 } while (0);
0225
0226 /* I'm not sure if we can use '-' here */
0227 #define ELF_PLATFORM       ("x86_64")
0228 extern void set_personality_64bit(void);
0229 extern unsigned int sysctl_vsyscall32;
0230 extern int force_personality32;
0231
0232 #endif /* !CONFIG_X86_32 */
0233
0234 #define CORE_DUMP_USE_REGSET
0235 #define ELF_EXEC_PAGESIZE   4096
0236
0237 /*
0238  * This is the base location for PIE (ET_DYN with INTERP) loads. On
0239  * 64-bit, this is above 4GB to leave the entire 32-bit address
0240  * space open for things that want to use the area for 32-bit pointers.
0241  */
0242 #define ELF_ET_DYN_BASE     (mmap_is_ia32() ? 0x000400000UL : \
0243                           (DEFAULT_MAP_WINDOW / 3 * 2))
0244
0245 /* This yields a mask that user programs can use to figure out what
0246    instruction set this CPU supports.  This could be done in user space,
0247    but it's not easy, and we've already done it here.  */
0248
0249 #define ELF_HWCAP       (boot_cpu_data.x86_capability[CPUID_1_EDX])
0250
0251 extern u32 elf_hwcap2;
0252
0253 /*
0254  * HWCAP2 supplies mask with kernel enabled CPU features, so that
0255  * the application can discover that it can safely use them.
0256  * The bits are defined in uapi/asm/hwcap2.h.
0257  */
0258 #define ELF_HWCAP2      (elf_hwcap2)
0259
0260 /* This yields a string that ld.so will use to load implementation
0261    specific libraries for optimization.  This is more specific in
0262    intent than poking at uname or /proc/cpuinfo.
0263
0264    For the moment, we have only optimizations for the Intel generations,
0265    but that could change... */
0266
0267 #define SET_PERSONALITY(ex) set_personality_64bit()
0268
0269 /*
0270  * An executable for which elf_read_implies_exec() returns TRUE will
0271  * have the READ_IMPLIES_EXEC personality flag set automatically.
0272  *
0273  * The decision process for determining the results are:
0274  *
0275  *                 CPU: | lacks NX*  | has NX, ia32     | has NX, x86_64 |
0276  * ELF:                 |            |                  |                |
0277  * ---------------------|------------|------------------|----------------|
0278  * missing PT_GNU_STACK | exec-all   | exec-all         | exec-none      |
0279  * PT_GNU_STACK == RWX  | exec-stack | exec-stack       | exec-stack     |
0280  * PT_GNU_STACK == RW   | exec-none  | exec-none        | exec-none      |
0281  *
0282  *  exec-all  : all PROT_READ user mappings are executable, except when
0283  *              backed by files on a noexec-filesystem.
0284  *  exec-none : only PROT_EXEC user mappings are executable.
0285  *  exec-stack: only the stack and PROT_EXEC user mappings are executable.
0286  *
0287  *  *this column has no architectural effect: NX markings are ignored by
0288  *   hardware, but may have behavioral effects when "wants X" collides with
0289  *   "cannot be X" constraints in memory permission flags, as in
0290  *   https://lkml.kernel.org/r/20190418055759.GA3155@mellanox.com
0291  *
0292  */
0293 #define elf_read_implies_exec(ex, executable_stack) \
0294     (mmap_is_ia32() && executable_stack == EXSTACK_DEFAULT)
0295
0296 struct task_struct;
0297
0298 #define ARCH_DLINFO_IA32                        \
0299 do {                                    \
0300     if (VDSO_CURRENT_BASE) {                    \
0301         NEW_AUX_ENT(AT_SYSINFO, VDSO_ENTRY);            \
0302         NEW_AUX_ENT(AT_SYSINFO_EHDR, VDSO_CURRENT_BASE);    \
0303     }                               \
0304     NEW_AUX_ENT(AT_MINSIGSTKSZ, get_sigframe_size());       \
0305 } while (0)
0306
0307 /*
0308  * True on X86_32 or when emulating IA32 on X86_64
0309  */
0310 static inline int mmap_is_ia32(void)
0311 {
0312     return IS_ENABLED(CONFIG_X86_32) ||
0313            (IS_ENABLED(CONFIG_COMPAT) &&
0314         test_thread_flag(TIF_ADDR32));
0315 }
0316
0317 extern unsigned long task_size_32bit(void);
0318 extern unsigned long task_size_64bit(int full_addr_space);
0319 extern unsigned long get_mmap_base(int is_legacy);
0320 extern bool mmap_address_hint_valid(unsigned long addr, unsigned long len);
0321 extern unsigned long get_sigframe_size(void);
0322
0323 #ifdef CONFIG_X86_32
0324
0325 #define __STACK_RND_MASK(is32bit) (0x7ff)
0326 #define STACK_RND_MASK (0x7ff)
0327
0328 #define ARCH_DLINFO     ARCH_DLINFO_IA32
0329
0330 /* update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT entries changes */
0331
0332 #else /* CONFIG_X86_32 */
0333
0334 /* 1GB for 64bit, 8MB for 32bit */
0335 #define __STACK_RND_MASK(is32bit) ((is32bit) ? 0x7ff : 0x3fffff)
0336 #define STACK_RND_MASK __STACK_RND_MASK(mmap_is_ia32())
0337
0338 #define ARCH_DLINFO                         \
0339 do {                                    \
0340     if (vdso64_enabled)                     \
0341         NEW_AUX_ENT(AT_SYSINFO_EHDR,                \
0342                 (unsigned long __force)current->mm->context.vdso); \
0343     NEW_AUX_ENT(AT_MINSIGSTKSZ, get_sigframe_size());       \
0344 } while (0)
0345
0346 /* As a historical oddity, the x32 and x86_64 vDSOs are controlled together. */
0347 #define ARCH_DLINFO_X32                         \
0348 do {                                    \
0349     if (vdso64_enabled)                     \
0350         NEW_AUX_ENT(AT_SYSINFO_EHDR,                \
0351                 (unsigned long __force)current->mm->context.vdso); \
0352     NEW_AUX_ENT(AT_MINSIGSTKSZ, get_sigframe_size());       \
0353 } while (0)
0354
0355 #define AT_SYSINFO      32
0356
0357 #define COMPAT_ARCH_DLINFO                      \
0358 if (exec->e_machine == EM_X86_64)                   \
0359     ARCH_DLINFO_X32;                        \
0360 else if (IS_ENABLED(CONFIG_IA32_EMULATION))             \
0361     ARCH_DLINFO_IA32
0362
0363 #define COMPAT_ELF_ET_DYN_BASE  (TASK_UNMAPPED_BASE + 0x1000000)
0364
0365 #endif /* !CONFIG_X86_32 */
0366
0367 #define VDSO_CURRENT_BASE   ((unsigned long)current->mm->context.vdso)
0368
0369 #define VDSO_ENTRY                          \
0370     ((unsigned long)current->mm->context.vdso +         \
0371      vdso_image_32.sym___kernel_vsyscall)
0372
0373 struct linux_binprm;
0374
0375 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
0376 extern int arch_setup_additional_pages(struct linux_binprm *bprm,
0377                        int uses_interp);
0378 extern int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
0379                           int uses_interp, bool x32);
0380 #define COMPAT_ARCH_SETUP_ADDITIONAL_PAGES(bprm, ex, interpreter)   \
0381     compat_arch_setup_additional_pages(bprm, interpreter,       \
0382                        (ex->e_machine == EM_X86_64))
0383
0384 extern bool arch_syscall_is_vdso_sigreturn(struct pt_regs *regs);
0385
0386 /* Do not change the values. See get_align_mask() */
0387 enum align_flags {
0388     ALIGN_VA_32 = BIT(0),
0389     ALIGN_VA_64 = BIT(1),
0390 };
0391
0392 struct va_alignment {
0393     int flags;
0394     unsigned long mask;
0395     unsigned long bits;
0396 } ____cacheline_aligned;
0397
0398 extern struct va_alignment va_align;
0399 extern unsigned long align_vdso_addr(unsigned long);
0400 #endif /* _ASM_X86_ELF_H */