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