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