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 #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         NEW_AUX_ENT(AT_SYSINFO, (u32)(u64)VSYSCALL32_VSYSCALL); \
  45         NEW_AUX_ENT(AT_SYSINFO_EHDR, VSYSCALL32_BASE);    \
  46         }       \
  47 } while(0)
  48
  49 struct file;
  50 struct elf_phdr;
  51
  52 #define IA32_EMULATOR 1
  53
  54 #define ELF_ET_DYN_BASE         (TASK_UNMAPPED_BASE + 0x1000000)
  55
  56 #undef ELF_ARCH
  57 #define ELF_ARCH EM_386
  58
  59 #define ELF_DATA        ELFDATA2LSB
  60
  61 #define USE_ELF_CORE_DUMP 1
  62
  63 /* Override elfcore.h */
  64 #define _LINUX_ELFCORE_H 1
  65 typedef unsigned int elf_greg_t;
  66
  67 #define ELF_NGREG (sizeof (struct user_regs_struct32) / sizeof(elf_greg_t))
  68 typedef elf_greg_t elf_gregset_t[ELF_NGREG];
  69
  70 struct elf_siginfo
  71 {
  72         int     si_signo;                       /* signal number */
  73         int     si_code;                        /* extra code */
  74         int     si_errno;                       /* errno */
  75 };
  76
  77 #define jiffies_to_timeval(a,b) do { (b)->tv_usec = 0; (b)->tv_sec = (a)/HZ; }while(0)
  78
  79 struct elf_prstatus
  80 {
  81         struct elf_siginfo pr_info;     /* Info associated with signal */
  82         short   pr_cursig;              /* Current signal */
  83         unsigned int pr_sigpend;        /* Set of pending signals */
  84         unsigned int pr_sighold;        /* Set of held signals */
  85         pid_t   pr_pid;
  86         pid_t   pr_ppid;
  87         pid_t   pr_pgrp;
  88         pid_t   pr_sid;
  89         struct compat_timeval pr_utime; /* User time */
  90         struct compat_timeval pr_stime; /* System time */
  91         struct compat_timeval pr_cutime;        /* Cumulative user time */
  92         struct compat_timeval pr_cstime;        /* Cumulative system time */
  93         elf_gregset_t pr_reg;   /* GP registers */
  94         int pr_fpvalid;         /* True if math co-processor being used.  */
  95 };
  96
  97 #define ELF_PRARGSZ     (80)    /* Number of chars for args */
  98
  99 struct elf_prpsinfo
 100 {
 101         char    pr_state;       /* numeric process state */
 102         char    pr_sname;       /* char for pr_state */
 103         char    pr_zomb;        /* zombie */
 104         char    pr_nice;        /* nice val */
 105         unsigned int pr_flag;   /* flags */
 106         __u16   pr_uid;
 107         __u16   pr_gid;
 108         pid_t   pr_pid, pr_ppid, pr_pgrp, pr_sid;
 109         /* Lots missing */
 110         char    pr_fname[16];   /* filename of executable */
 111         char    pr_psargs[ELF_PRARGSZ]; /* initial part of arg list */
 112 };
 113
 114 #define __STR(x) #x
 115 #define STR(x) __STR(x)
 116
 117 #define _GET_SEG(x) \
 118         ({ __u32 seg; asm("movl %%" STR(x) ",%0" : "=r"(seg)); seg; })
 119
 120 /* Assumes current==process to be dumped */
 121 #define ELF_CORE_COPY_REGS(pr_reg, regs)                \
 122         pr_reg[0] = regs->rbx;                          \
 123         pr_reg[1] = regs->rcx;                          \
 124         pr_reg[2] = regs->rdx;                          \
 125         pr_reg[3] = regs->rsi;                          \
 126         pr_reg[4] = regs->rdi;                          \
 127         pr_reg[5] = regs->rbp;                          \
 128         pr_reg[6] = regs->rax;                          \
 129         pr_reg[7] = _GET_SEG(ds);                       \
 130         pr_reg[8] = _GET_SEG(es);                       \
 131         pr_reg[9] = _GET_SEG(fs);                       \
 132         pr_reg[10] = _GET_SEG(gs);                      \
 133         pr_reg[11] = regs->orig_rax;                    \
 134         pr_reg[12] = regs->rip;                         \
 135         pr_reg[13] = regs->cs;                          \
 136         pr_reg[14] = regs->eflags;                      \
 137         pr_reg[15] = regs->rsp;                         \
 138         pr_reg[16] = regs->ss;
 139
 140 #define user user32
 141
 142 #undef elf_read_implies_exec
 143 #define elf_read_implies_exec(ex, executable_stack)     (executable_stack != EXSTACK_DISABLE_X)
 144 //#include <asm/ia32.h>
 145 #include <linux/elf.h>
 146
 147 typedef struct user_i387_ia32_struct elf_fpregset_t;
 148 typedef struct user32_fxsr_struct elf_fpxregset_t;
 149
 150
 151 static inline void elf_core_copy_regs(elf_gregset_t *elfregs, struct pt_regs *regs)
 152 {
 153         ELF_CORE_COPY_REGS((*elfregs), regs)
 154 }
 155
 156 static inline int elf_core_copy_task_regs(struct task_struct *t, elf_gregset_t* elfregs)
 157 {
 158         struct pt_regs *pp = task_pt_regs(t);
 159         ELF_CORE_COPY_REGS((*elfregs), pp);
 160         /* fix wrong segments */
 161         (*elfregs)[7] = t->thread.ds;
 162         (*elfregs)[9] = t->thread.fsindex;
 163         (*elfregs)[10] = t->thread.gsindex;
 164         (*elfregs)[8] = t->thread.es;
 165         return 1;
 166 }
 167
 168 static inline int
 169 elf_core_copy_task_fpregs(struct task_struct *tsk, struct pt_regs *regs, elf_fpregset_t *fpu)
 170 {
 171         struct _fpstate_ia32 *fpstate = (void*)fpu;
 172         mm_segment_t oldfs = get_fs();
 173
 174         if (!tsk_used_math(tsk))
 175                 return 0;
 176         if (!regs)
 177                 regs = task_pt_regs(tsk);
 178         if (tsk == current)
 179                 unlazy_fpu(tsk);
 180         set_fs(KERNEL_DS);
 181         save_i387_ia32(tsk, fpstate, regs, 1);
 182         /* Correct for i386 bug. It puts the fop into the upper 16bits of
 183            the tag word (like FXSAVE), not into the fcs*/
 184         fpstate->cssel |= fpstate->tag & 0xffff0000;
 185         set_fs(oldfs);
 186         return 1;
 187 }
 188
 189 #define ELF_CORE_COPY_XFPREGS 1
 190 static inline int
 191 elf_core_copy_task_xfpregs(struct task_struct *t, elf_fpxregset_t *xfpu)
 192 {
 193         struct pt_regs *regs = task_pt_regs(t);
 194         if (!tsk_used_math(t))
 195                 return 0;
 196         if (t == current)
 197                 unlazy_fpu(t);
 198         memcpy(xfpu, &t->thread.i387.fxsave, sizeof(elf_fpxregset_t));
 199         xfpu->fcs = regs->cs;
 200         xfpu->fos = t->thread.ds; /* right? */
 201         return 1;
 202 }
 203
 204 #undef elf_check_arch
 205 #define elf_check_arch(x) \
 206         ((x)->e_machine == EM_386)
 207
 208 extern int force_personality32;
 209
 210 #define ELF_EXEC_PAGESIZE PAGE_SIZE
 211 #define ELF_HWCAP (boot_cpu_data.x86_capability[0])
 212 #define ELF_PLATFORM  ("i686")
 213 #define SET_PERSONALITY(ex, ibcs2)                      \
 214 do {                                                    \
 215         unsigned long new_flags = 0;                            \
 216         if ((ex).e_ident[EI_CLASS] == ELFCLASS32)               \
 217                 new_flags = _TIF_IA32;                          \
 218         if ((current_thread_info()->flags & _TIF_IA32)          \
 219             != new_flags)                                       \
 220                 set_thread_flag(TIF_ABI_PENDING);               \
 221         else                                                    \
 222                 clear_thread_flag(TIF_ABI_PENDING);             \
 223         /* XXX This overwrites the user set personality */      \
 224         current->personality |= force_personality32;            \
 225 } while (0)
 226
 227 /* Override some function names */
 228 #define elf_format                      elf32_format
 229
 230 #define init_elf_binfmt                 init_elf32_binfmt
 231 #define exit_elf_binfmt                 exit_elf32_binfmt
 232
 233 #define load_elf_binary load_elf32_binary
 234
 235 #define ELF_PLAT_INIT(r, load_addr)     elf32_init(r)
 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 #ifdef CONFIG_SYSCTL
 288 /* Register vsyscall32 into the ABI table */
 289 #include <linux/sysctl.h>
 290
 291 static ctl_table abi_table2[] = {
 292         {
 293                 .ctl_name       = 99,
 294                 .procname       = "vsyscall32",
 295                 .data           = &sysctl_vsyscall32,
 296                 .maxlen         = sizeof(int),
 297                 .mode           = 0644,
 298                 .proc_handler   = proc_dointvec
 299         },
 300         {}
 301 };
 302
 303 static ctl_table abi_root_table2[] = {
 304         {
 305                 .ctl_name = CTL_ABI,
 306                 .procname = "abi",
 307                 .mode = 0555,
 308                 .child = abi_table2
 309         },
 310         {}
 311 };
 312
 313 static __init int ia32_binfmt_init(void)
 314 {
 315         register_sysctl_table(abi_root_table2);
 316         return 0;
 317 }
 318 __initcall(ia32_binfmt_init);
 319 #endif