arch/x86_64/ia32/ia32_binfmt.c

   1 /*
   2  * Written 2000,2002 by Andi Kleen.
   3  *
   4  * Loosely based on the sparc64 and IA64 32bit emulation loaders.
   5  * This tricks binfmt_elf.c into loading 32bit binaries using lots
   6  * of ugly preprocessor tricks. Talk about very very poor man's inheritance.
   7  */
   8 #include <linux/types.h>
   9 #include <linux/config.h>
  10 #include <linux/stddef.h>
  11 #include <linux/rwsem.h>
  12 #include <linux/sched.h>
  13 #include <linux/compat.h>
  14 #include <linux/string.h>
  15 #include <linux/binfmts.h>
  16 #include <linux/mm.h>
  17 #include <linux/security.h>
  18
  19 #include <asm/segment.h>
  20 #include <asm/ptrace.h>
  21 #include <asm/processor.h>
  22 #include <asm/user32.h>
  23 #include <asm/sigcontext32.h>
  24 #include <asm/fpu32.h>
  25 #include <asm/i387.h>
  26 #include <asm/uaccess.h>
  27 #include <asm/ia32.h>
  28 #include <asm/vsyscall32.h>
  29
  30 #define ELF_NAME "elf/i386"
  31
  32 #define AT_SYSINFO 32
  33 #define AT_SYSINFO_EHDR         33
  34
  35 int sysctl_vsyscall32 = 1;
  36
  37 #define ARCH_DLINFO do {  \
  38         if (sysctl_vsyscall32) { \
  39         NEW_AUX_ENT(AT_SYSINFO, (u32)(u64)VSYSCALL32_VSYSCALL); \
  40         NEW_AUX_ENT(AT_SYSINFO_EHDR, VSYSCALL32_BASE);    \
  41         }       \
  42 } while(0)
  43
  44 struct file;
  45 struct elf_phdr;
  46
  47 #define IA32_EMULATOR 1
  48
  49 #define ELF_ET_DYN_BASE         (TASK_UNMAPPED_BASE + 0x1000000)
  50
  51 #undef ELF_ARCH
  52 #define ELF_ARCH EM_386
  53
  54 #undef ELF_CLASS
  55 #define ELF_CLASS ELFCLASS32
  56
  57 #define ELF_DATA        ELFDATA2LSB
  58
  59 #define USE_ELF_CORE_DUMP 1
  60
  61 /* Override elfcore.h */
  62 #define _LINUX_ELFCORE_H 1
  63 typedef unsigned int elf_greg_t;
  64
  65 #define ELF_NGREG (sizeof (struct user_regs_struct32) / sizeof(elf_greg_t))
  66 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
  67
  68 /*
  69  * These macros parameterize elf_core_dump in fs/binfmt_elf.c to write out
  70  * extra segments containing the vsyscall DSO contents.  Dumping its
  71  * contents makes post-mortem fully interpretable later without matching up
  72  * the same kernel and hardware config to see what PC values meant.
  73  * Dumping its extra ELF program headers includes all the other information
  74  * a debugger needs to easily find how the vsyscall DSO was being used.
  75  */
  76 #define ELF_CORE_EXTRA_PHDRS    (find_vma(current->mm, VSYSCALL32_BASE) ?     \
  77     (VSYSCALL32_EHDR->e_phnum) : 0)
  78 #define ELF_CORE_WRITE_EXTRA_PHDRS                                            \
  79 do {                                                                          \
  80         if (find_vma(current->mm, VSYSCALL32_BASE)) {                         \
  81                 const struct elf32_phdr *const vsyscall_phdrs =               \
  82                         (const struct elf32_phdr *) (VSYSCALL32_BASE          \
  83                                                    + VSYSCALL32_EHDR->e_phoff);\
  84                 int i;                                                        \
  85                 Elf32_Off ofs = 0;                                            \
  86                 for (i = 0; i < VSYSCALL32_EHDR->e_phnum; ++i) {              \
  87                         struct elf32_phdr phdr = vsyscall_phdrs[i];           \
  88                         if (phdr.p_type == PT_LOAD) {                         \
  89                                 BUG_ON(ofs != 0);                             \
  90                                 ofs = phdr.p_offset = offset;                 \
  91                                 phdr.p_memsz = PAGE_ALIGN(phdr.p_memsz);      \
  92                                 phdr.p_filesz = phdr.p_memsz;                 \
  93                                 offset += phdr.p_filesz;                      \
  94                         }                                                     \
  95                         else                                                  \
  96                                 phdr.p_offset += ofs;                         \
  97                         phdr.p_paddr = 0; /* match other core phdrs */        \
  98                         DUMP_WRITE(&phdr, sizeof(phdr));                      \
  99                 }                                                             \
 100         }                                                                     \
 101 } while (0)
 102 #define ELF_CORE_WRITE_EXTRA_DATA                                             \
 103 do {                                                                          \
 104         if (find_vma(current->mm, VSYSCALL32_BASE)) {                         \
 105                 const struct elf32_phdr *const vsyscall_phdrs =               \
 106                         (const struct elf32_phdr *) (VSYSCALL32_BASE          \
 107                                                    + VSYSCALL32_EHDR->e_phoff);      \
 108                 int i;                                                        \
 109                 for (i = 0; i < VSYSCALL32_EHDR->e_phnum; ++i) {              \
 110                         if (vsyscall_phdrs[i].p_type == PT_LOAD)              \
 111                                 DUMP_WRITE((void *) (u64) vsyscall_phdrs[i].p_vaddr,\
 112                                     PAGE_ALIGN(vsyscall_phdrs[i].p_memsz));   \
 113                 }                                                             \
 114         }                                                                     \
 115 } while (0)
 116
 117 struct elf_siginfo
 118 {
 119         int     si_signo;                       /* signal number */
 120         int     si_code;                        /* extra code */
 121         int     si_errno;                       /* errno */
 122 };
 123
 124 #define jiffies_to_timeval(a,b) do { (b)->tv_usec = 0; (b)->tv_sec = (a)/HZ; }while(0)
 125
 126 struct elf_prstatus
 127 {
 128         struct elf_siginfo pr_info;     /* Info associated with signal */
 129         short   pr_cursig;              /* Current signal */
 130         unsigned int pr_sigpend;        /* Set of pending signals */
 131         unsigned int pr_sighold;        /* Set of held signals */
 132         pid_t   pr_pid;
 133         pid_t   pr_ppid;
 134         pid_t   pr_pgrp;
 135         pid_t   pr_sid;
 136         struct compat_timeval pr_utime; /* User time */
 137         struct compat_timeval pr_stime; /* System time */
 138         struct compat_timeval pr_cutime;        /* Cumulative user time */
 139         struct compat_timeval pr_cstime;        /* Cumulative system time */
 140         elf_gregset_t pr_reg;   /* GP registers */
 141         int pr_fpvalid;         /* True if math co-processor being used.  */
 142 };
 143
 144 #define ELF_PRARGSZ     (80)    /* Number of chars for args */
 145
 146 struct elf_prpsinfo
 147 {
 148         char    pr_state;       /* numeric process state */
 149         char    pr_sname;       /* char for pr_state */
 150         char    pr_zomb;        /* zombie */
 151         char    pr_nice;        /* nice val */
 152         unsigned int pr_flag;   /* flags */
 153         __u16   pr_uid;
 154         __u16   pr_gid;
 155         pid_t   pr_pid, pr_ppid, pr_pgrp, pr_sid;
 156         /* Lots missing */
 157         char    pr_fname[16];   /* filename of executable */
 158         char    pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */
 159 };
 160
 161 #define __STR(x) #x
 162 #define STR(x) __STR(x)
 163
 164 #define _GET_SEG(x) \
 165         ({ __u32 seg; asm("movl %%" STR(x) ",%0" : "=r"(seg)); seg; })
 166
 167 /* Assumes current==process to be dumped */
 168 #define ELF_CORE_COPY_REGS(pr_reg, regs)                \
 169         pr_reg[0] = regs->rbx;                          \
 170         pr_reg[1] = regs->rcx;                          \
 171         pr_reg[2] = regs->rdx;                          \
 172         pr_reg[3] = regs->rsi;                          \
 173         pr_reg[4] = regs->rdi;                          \
 174         pr_reg[5] = regs->rbp;                          \
 175         pr_reg[6] = regs->rax;                          \
 176         pr_reg[7] = _GET_SEG(ds);                       \
 177         pr_reg[8] = _GET_SEG(es);                       \
 178         pr_reg[9] = _GET_SEG(fs);                       \
 179         pr_reg[10] = _GET_SEG(gs);                      \
 180         pr_reg[11] = regs->orig_rax;                    \
 181         pr_reg[12] = regs->rip;                         \
 182         pr_reg[13] = regs->cs;                          \
 183         pr_reg[14] = regs->eflags;                      \
 184         pr_reg[15] = regs->rsp;                         \
 185         pr_reg[16] = regs->ss;
 186
 187 #define user user32
 188
 189 #define __ASM_X86_64_ELF_H 1
 190 #define elf_read_implies_exec(ex, executable_stack)     (executable_stack != EXSTACK_DISABLE_X)
 191 //#include <asm/ia32.h>
 192 #include <linux/elf.h>
 193
 194 typedef struct user_i387_ia32_struct elf_fpregset_t;
 195 typedef struct user32_fxsr_struct elf_fpxregset_t;
 196
 197
 198 static inline void elf_core_copy_regs(elf_gregset_t *elfregs, struct pt_regs *regs)
 199 {
 200         ELF_CORE_COPY_REGS((*elfregs), regs)
 201 }
 202
 203 static inline int elf_core_copy_task_regs(struct task_struct *t, elf_gregset_t* elfregs)
 204 {
 205         struct pt_regs *pp = task_pt_regs(t);
 206         ELF_CORE_COPY_REGS((*elfregs), pp);
 207         /* fix wrong segments */
 208         (*elfregs)[7] = t->thread.ds;
 209         (*elfregs)[9] = t->thread.fsindex;
 210         (*elfregs)[10] = t->thread.gsindex;
 211         (*elfregs)[8] = t->thread.es;
 212         return 1;
 213 }
 214
 215 static inline int
 216 elf_core_copy_task_fpregs(struct task_struct *tsk, struct pt_regs *regs, elf_fpregset_t *fpu)
 217 {
 218         struct _fpstate_ia32 *fpstate = (void*)fpu;
 219         mm_segment_t oldfs = get_fs();
 220
 221         if (!tsk_used_math(tsk))
 222                 return 0;
 223         if (!regs)
 224                 regs = task_pt_regs(tsk);
 225         if (tsk == current)
 226                 unlazy_fpu(tsk);
 227         set_fs(KERNEL_DS);
 228         save_i387_ia32(tsk, fpstate, regs, 1);
 229         /* Correct for i386 bug. It puts the fop into the upper 16bits of
 230            the tag word (like FXSAVE), not into the fcs*/
 231         fpstate->cssel |= fpstate->tag & 0xffff0000;
 232         set_fs(oldfs);
 233         return 1;
 234 }
 235
 236 #define ELF_CORE_COPY_XFPREGS 1
 237 static inline int
 238 elf_core_copy_task_xfpregs(struct task_struct *t, elf_fpxregset_t *xfpu)
 239 {
 240         struct pt_regs *regs = task_pt_regs(t);
 241         if (!tsk_used_math(t))
 242                 return 0;
 243         if (t == current)
 244                 unlazy_fpu(t);
 245         memcpy(xfpu, &t->thread.i387.fxsave, sizeof(elf_fpxregset_t));
 246         xfpu->fcs = regs->cs;
 247         xfpu->fos = t->thread.ds; /* right? */
 248         return 1;
 249 }
 250
 251 #undef elf_check_arch
 252 #define elf_check_arch(x) \
 253         ((x)->e_machine == EM_386)
 254
 255 extern int force_personality32;
 256
 257 #define ELF_EXEC_PAGESIZE PAGE_SIZE
 258 #define ELF_HWCAP (boot_cpu_data.x86_capability[0])
 259 #define ELF_PLATFORM  ("i686")
 260 #define SET_PERSONALITY(ex, ibcs2)                      \
 261 do {                                                    \
 262         unsigned long new_flags = 0;                            \
 263         if ((ex).e_ident[EI_CLASS] == ELFCLASS32)               \
 264                 new_flags = _TIF_IA32;                          \
 265         if ((current_thread_info()->flags & _TIF_IA32)          \
 266             != new_flags)                                       \
 267                 set_thread_flag(TIF_ABI_PENDING);               \
 268         else                                                    \
 269                 clear_thread_flag(TIF_ABI_PENDING);             \
 270         /* XXX This overwrites the user set personality */      \
 271         current->personality |= force_personality32;            \
 272 } while (0)
 273
 274 /* Override some function names */
 275 #define elf_format                      elf32_format
 276
 277 #define init_elf_binfmt                 init_elf32_binfmt
 278 #define exit_elf_binfmt                 exit_elf32_binfmt
 279
 280 #define load_elf_binary load_elf32_binary
 281
 282 #define ELF_PLAT_INIT(r, load_addr)     elf32_init(r)
 283 #define setup_arg_pages(bprm, stack_top, exec_stack) \
 284         ia32_setup_arg_pages(bprm, stack_top, exec_stack)
 285 int ia32_setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top, int executable_stack);
 286
 287 #undef start_thread
 288 #define start_thread(regs,new_rip,new_rsp) do { \
 289         asm volatile("movl %0,%%fs" :: "r" (0)); \
 290         asm volatile("movl %0,%%es; movl %0,%%ds": :"r" (__USER32_DS)); \
 291         load_gs_index(0); \
 292         (regs)->rip = (new_rip); \
 293         (regs)->rsp = (new_rsp); \
 294         (regs)->eflags = 0x200; \
 295         (regs)->cs = __USER32_CS; \
 296         (regs)->ss = __USER32_DS; \
 297         set_fs(USER_DS); \
 298 } while(0)
 299
 300
 301 #include <linux/module.h>
 302
 303 MODULE_DESCRIPTION("Binary format loader for compatibility with IA32 ELF binaries.");
 304 MODULE_AUTHOR("Eric Youngdale, Andi Kleen");
 305
 306 #undef MODULE_DESCRIPTION
 307 #undef MODULE_AUTHOR
 308
 309 #define elf_addr_t __u32
 310
 311 static void elf32_init(struct pt_regs *);
 312
 313 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 314 #define arch_setup_additional_pages syscall32_setup_pages
 315 extern int syscall32_setup_pages(struct linux_binprm *, int exstack);
 316
 317 #include "../../../fs/binfmt_elf.c"
 318
 319 static void elf32_init(struct pt_regs *regs)
 320 {
 321         struct task_struct *me = current;
 322         regs->rdi = 0;
 323         regs->rsi = 0;
 324         regs->rdx = 0;
 325         regs->rcx = 0;
 326         regs->rax = 0;
 327         regs->rbx = 0;
 328         regs->rbp = 0;
 329         regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
 330                 regs->r13 = regs->r14 = regs->r15 = 0;
 331     me->thread.fs = 0;
 332         me->thread.gs = 0;
 333         me->thread.fsindex = 0;
 334         me->thread.gsindex = 0;
 335     me->thread.ds = __USER_DS;
 336         me->thread.es = __USER_DS;
 337 }
 338
 339 int ia32_setup_arg_pages(struct linux_binprm *bprm, unsigned long stack_top,
 340                          int executable_stack)
 341 {
 342         unsigned long stack_base;
 343         struct vm_area_struct *mpnt;
 344         struct mm_struct *mm = current->mm;
 345         int i, ret;
 346
 347         stack_base = stack_top - MAX_ARG_PAGES * PAGE_SIZE;
 348         mm->arg_start = bprm->p + stack_base;
 349
 350         bprm->p += stack_base;
 351         if (bprm->loader)
 352                 bprm->loader += stack_base;
 353         bprm->exec += stack_base;
 354
 355         mpnt = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
 356         if (!mpnt)
 357                 return -ENOMEM;
 358
 359         memset(mpnt, 0, sizeof(*mpnt));
 360
 361         down_write(&mm->mmap_sem);
 362         {
 363                 mpnt->vm_mm = mm;
 364                 mpnt->vm_start = PAGE_MASK & (unsigned long) bprm->p;
 365                 mpnt->vm_end = stack_top;
 366                 if (executable_stack == EXSTACK_ENABLE_X)
 367                         mpnt->vm_flags = VM_STACK_FLAGS |  VM_EXEC;
 368                 else if (executable_stack == EXSTACK_DISABLE_X)
 369                         mpnt->vm_flags = VM_STACK_FLAGS & ~VM_EXEC;
 370                 else
 371                         mpnt->vm_flags = VM_STACK_FLAGS;
 372                 mpnt->vm_page_prot = (mpnt->vm_flags & VM_EXEC) ?
 373                         PAGE_COPY_EXEC : PAGE_COPY;
 374                 if ((ret = insert_vm_struct(mm, mpnt))) {
 375                         up_write(&mm->mmap_sem);
 376                         kmem_cache_free(vm_area_cachep, mpnt);
 377                         return ret;
 378                 }
 379                 mm->stack_vm = mm->total_vm = vma_pages(mpnt);
 380         }
 381
 382         for (i = 0 ; i < MAX_ARG_PAGES ; i++) {
 383                 struct page *page = bprm->page[i];
 384                 if (page) {
 385                         bprm->page[i] = NULL;
 386                         install_arg_page(mpnt, page, stack_base);
 387                 }
 388                 stack_base += PAGE_SIZE;
 389         }
 390         up_write(&mm->mmap_sem);
 391
 392         return 0;
 393 }
 394 EXPORT_SYMBOL(ia32_setup_arg_pages);
 395
 396 #ifdef CONFIG_SYSCTL
 397 /* Register vsyscall32 into the ABI table */
 398 #include <linux/sysctl.h>
 399
 400 static ctl_table abi_table2[] = {
 401         { 99, "vsyscall32", &sysctl_vsyscall32, sizeof(int), 0644, NULL,
 402           proc_dointvec },
 403         { 0, }
 404 };
 405
 406 static ctl_table abi_root_table2[] = {
 407         { .ctl_name = CTL_ABI, .procname = "abi", .mode = 0555,
 408           .child = abi_table2 },
 409         { 0 },
 410 };
 411
 412 static __init int ia32_binfmt_init(void)
 413 {
 414         register_sysctl_table(abi_root_table2, 1);
 415         return 0;
 416 }
 417 __initcall(ia32_binfmt_init);
 418 #endif