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