arch/x86/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
   9 #include <linux/types.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 #include <linux/elfcore-compat.h>
  19
  20 #include <asm/segment.h>
  21 #include <asm/ptrace.h>
  22 #include <asm/processor.h>
  23 #include <asm/user32.h>
  24 #include <asm/sigcontext32.h>
  25 #include <asm/fpu32.h>
  26 #include <asm/i387.h>
  27 #include <asm/uaccess.h>
  28 #include <asm/ia32.h>
  29 #include <asm/vsyscall32.h>
  30
  31 #undef  ELF_ARCH
  32 #undef  ELF_CLASS
  33 #define ELF_CLASS       ELFCLASS32
  34 #define ELF_ARCH        EM_386
  35
  36 #undef  elfhdr
  37 #undef  elf_phdr
  38 #undef  elf_note
  39 #undef  elf_addr_t
  40 #define elfhdr          elf32_hdr
  41 #define elf_phdr        elf32_phdr
  42 #define elf_note        elf32_note
  43 #define elf_addr_t      Elf32_Off
  44
  45 #define ELF_NAME "elf/i386"
  46
  47 #define AT_SYSINFO 32
  48 #define AT_SYSINFO_EHDR         33
  49
  50 int sysctl_vsyscall32 = 1;
  51
  52 #undef ARCH_DLINFO
  53 #define ARCH_DLINFO do {  \
  54         if (sysctl_vsyscall32) { \
  55                 current->mm->context.vdso = (void *)VSYSCALL32_BASE;    \
  56                 NEW_AUX_ENT(AT_SYSINFO, (u32)(u64)VSYSCALL32_VSYSCALL); \
  57                 NEW_AUX_ENT(AT_SYSINFO_EHDR, VSYSCALL32_BASE);    \
  58         }       \
  59 } while(0)
  60
  61 struct file;
  62
  63 #define IA32_EMULATOR 1
  64
  65 #undef ELF_ET_DYN_BASE
  66
  67 #define ELF_ET_DYN_BASE         (TASK_UNMAPPED_BASE + 0x1000000)
  68
  69 #define jiffies_to_timeval(a,b) do { (b)->tv_usec = 0; (b)->tv_sec = (a)/HZ; }while(0)
  70
  71 #define _GET_SEG(x) \
  72         ({ __u32 seg; asm("movl %%" __stringify(x) ",%0" : "=r"(seg)); seg; })
  73
  74 /* Assumes current==process to be dumped */
  75 #undef  ELF_CORE_COPY_REGS
  76 #define ELF_CORE_COPY_REGS(pr_reg, regs)                \
  77         pr_reg[0] = regs->rbx;                          \
  78         pr_reg[1] = regs->rcx;                          \
  79         pr_reg[2] = regs->rdx;                          \
  80         pr_reg[3] = regs->rsi;                          \
  81         pr_reg[4] = regs->rdi;                          \
  82         pr_reg[5] = regs->rbp;                          \
  83         pr_reg[6] = regs->rax;                          \
  84         pr_reg[7] = _GET_SEG(ds);                       \
  85         pr_reg[8] = _GET_SEG(es);                       \
  86         pr_reg[9] = _GET_SEG(fs);                       \
  87         pr_reg[10] = _GET_SEG(gs);                      \
  88         pr_reg[11] = regs->orig_rax;                    \
  89         pr_reg[12] = regs->rip;                         \
  90         pr_reg[13] = regs->cs;                          \
  91         pr_reg[14] = regs->eflags;                      \
  92         pr_reg[15] = regs->rsp;                         \
  93         pr_reg[16] = regs->ss;
  94
  95
  96 #define elf_prstatus    compat_elf_prstatus
  97 #define elf_prpsinfo    compat_elf_prpsinfo
  98 #define elf_fpregset_t  struct user_i387_ia32_struct
  99 #define elf_fpxregset_t struct user32_fxsr_struct
 100 #define user            user32
 101
 102 #undef elf_read_implies_exec
 103 #define elf_read_implies_exec(ex, executable_stack)     (executable_stack != EXSTACK_DISABLE_X)
 104
 105 #define elf_core_copy_regs              elf32_core_copy_regs
 106 static inline void elf32_core_copy_regs(compat_elf_gregset_t *elfregs,
 107                                         struct pt_regs *regs)
 108 {
 109         ELF_CORE_COPY_REGS((&elfregs->ebx), regs)
 110 }
 111
 112 #define elf_core_copy_task_regs         elf32_core_copy_task_regs
 113 static inline int elf32_core_copy_task_regs(struct task_struct *t,
 114                                             compat_elf_gregset_t* elfregs)
 115 {
 116         struct pt_regs *pp = task_pt_regs(t);
 117         ELF_CORE_COPY_REGS((&elfregs->ebx), pp);
 118         /* fix wrong segments */
 119         elfregs->ds = t->thread.ds;
 120         elfregs->fs = t->thread.fsindex;
 121         elfregs->gs = t->thread.gsindex;
 122         elfregs->es = t->thread.es;
 123         return 1;
 124 }
 125
 126 #define elf_core_copy_task_fpregs       elf32_core_copy_task_fpregs
 127 static inline int
 128 elf32_core_copy_task_fpregs(struct task_struct *tsk, struct pt_regs *regs,
 129                             elf_fpregset_t *fpu)
 130 {
 131         struct _fpstate_ia32 *fpstate = (void*)fpu;
 132         mm_segment_t oldfs = get_fs();
 133
 134         if (!tsk_used_math(tsk))
 135                 return 0;
 136         if (!regs)
 137                 regs = task_pt_regs(tsk);
 138         if (tsk == current)
 139                 unlazy_fpu(tsk);
 140         set_fs(KERNEL_DS);
 141         save_i387_ia32(tsk, fpstate, regs, 1);
 142         /* Correct for i386 bug. It puts the fop into the upper 16bits of
 143            the tag word (like FXSAVE), not into the fcs*/
 144         fpstate->cssel |= fpstate->tag & 0xffff0000;
 145         set_fs(oldfs);
 146         return 1;
 147 }
 148
 149 #define ELF_CORE_COPY_XFPREGS 1
 150 #define ELF_CORE_XFPREG_TYPE NT_PRXFPREG
 151 #define elf_core_copy_task_xfpregs      elf32_core_copy_task_xfpregs
 152 static inline int
 153 elf32_core_copy_task_xfpregs(struct task_struct *t, elf_fpxregset_t *xfpu)
 154 {
 155         struct pt_regs *regs = task_pt_regs(t);
 156         if (!tsk_used_math(t))
 157                 return 0;
 158         if (t == current)
 159                 unlazy_fpu(t);
 160         memcpy(xfpu, &t->thread.i387.fxsave, sizeof(elf_fpxregset_t));
 161         xfpu->fcs = regs->cs;
 162         xfpu->fos = t->thread.ds; /* right? */
 163         return 1;
 164 }
 165
 166 #undef elf_check_arch
 167 #define elf_check_arch(x) \
 168         ((x)->e_machine == EM_386)
 169
 170 extern int force_personality32;
 171
 172 #undef  ELF_EXEC_PAGESIZE
 173 #undef  ELF_HWCAP
 174 #undef  ELF_PLATFORM
 175 #undef  SET_PERSONALITY
 176 #define ELF_EXEC_PAGESIZE PAGE_SIZE
 177 #define ELF_HWCAP (boot_cpu_data.x86_capability[0])
 178 #define ELF_PLATFORM  ("i686")
 179 #define SET_PERSONALITY(ex, ibcs2)                      \
 180 do {                                                    \
 181         unsigned long new_flags = 0;                            \
 182         if ((ex).e_ident[EI_CLASS] == ELFCLASS32)               \
 183                 new_flags = _TIF_IA32;                          \
 184         if ((current_thread_info()->flags & _TIF_IA32)          \
 185             != new_flags)                                       \
 186                 set_thread_flag(TIF_ABI_PENDING);               \
 187         else                                                    \
 188                 clear_thread_flag(TIF_ABI_PENDING);             \
 189         /* XXX This overwrites the user set personality */      \
 190         current->personality |= force_personality32;            \
 191 } while (0)
 192
 193 /* Override some function names */
 194 #define elf_format                      elf32_format
 195
 196 #define init_elf_binfmt                 init_elf32_binfmt
 197 #define exit_elf_binfmt                 exit_elf32_binfmt
 198
 199 #define load_elf_binary load_elf32_binary
 200
 201 #undef  ELF_PLAT_INIT
 202 #define ELF_PLAT_INIT(r, load_addr)     elf32_init(r)
 203
 204 #undef start_thread
 205 #define start_thread(regs,new_rip,new_rsp) do { \
 206         asm volatile("movl %0,%%fs" :: "r" (0)); \
 207         asm volatile("movl %0,%%es; movl %0,%%ds": :"r" (__USER32_DS)); \
 208         load_gs_index(0); \
 209         (regs)->rip = (new_rip); \
 210         (regs)->rsp = (new_rsp); \
 211         (regs)->eflags = 0x200; \
 212         (regs)->cs = __USER32_CS; \
 213         (regs)->ss = __USER32_DS; \
 214         set_fs(USER_DS); \
 215 } while(0)
 216
 217
 218 #include <linux/module.h>
 219
 220 MODULE_DESCRIPTION("Binary format loader for compatibility with IA32 ELF binaries.");
 221 MODULE_AUTHOR("Eric Youngdale, Andi Kleen");
 222
 223 #undef MODULE_DESCRIPTION
 224 #undef MODULE_AUTHOR
 225
 226 static void elf32_init(struct pt_regs *);
 227
 228 #define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
 229 #define arch_setup_additional_pages syscall32_setup_pages
 230 extern int syscall32_setup_pages(struct linux_binprm *, int exstack);
 231
 232 #include "../../../fs/binfmt_elf.c"
 233
 234 static void elf32_init(struct pt_regs *regs)
 235 {
 236         struct task_struct *me = current;
 237         regs->rdi = 0;
 238         regs->rsi = 0;
 239         regs->rdx = 0;
 240         regs->rcx = 0;
 241         regs->rax = 0;
 242         regs->rbx = 0;
 243         regs->rbp = 0;
 244         regs->r8 = regs->r9 = regs->r10 = regs->r11 = regs->r12 =
 245                 regs->r13 = regs->r14 = regs->r15 = 0;
 246     me->thread.fs = 0;
 247         me->thread.gs = 0;
 248         me->thread.fsindex = 0;
 249         me->thread.gsindex = 0;
 250     me->thread.ds = __USER_DS;
 251         me->thread.es = __USER_DS;
 252 }
 253
 254 #ifdef CONFIG_SYSCTL
 255 /* Register vsyscall32 into the ABI table */
 256 #include <linux/sysctl.h>
 257
 258 static ctl_table abi_table2[] = {
 259         {
 260                 .procname       = "vsyscall32",
 261                 .data           = &sysctl_vsyscall32,
 262                 .maxlen         = sizeof(int),
 263                 .mode           = 0644,
 264                 .proc_handler   = proc_dointvec
 265         },
 266         {}
 267 };
 268
 269 static ctl_table abi_root_table2[] = {
 270         {
 271                 .ctl_name = CTL_ABI,
 272                 .procname = "abi",
 273                 .mode = 0555,
 274                 .child = abi_table2
 275         },
 276         {}
 277 };
 278
 279 static __init int ia32_binfmt_init(void)
 280 {
 281         register_sysctl_table(abi_root_table2);
 282         return 0;
 283 }
 284 __initcall(ia32_binfmt_init);
 285 #endif