linux/fs/binfmt_som.c
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   1/*
   2 * linux/fs/binfmt_som.c
   3 *
   4 * These are the functions used to load SOM format executables as used
   5 * by HP-UX.  
   6 *
   7 * Copyright 1999 Matthew Wilcox <willy@bofh.ai>
   8 * based on binfmt_elf which is
   9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
  10 */
  11
  12#include <linux/module.h>
  13
  14#include <linux/fs.h>
  15#include <linux/stat.h>
  16#include <linux/sched.h>
  17#include <linux/mm.h>
  18#include <linux/mman.h>
  19#include <linux/errno.h>
  20#include <linux/signal.h>
  21#include <linux/binfmts.h>
  22#include <linux/som.h>
  23#include <linux/string.h>
  24#include <linux/file.h>
  25#include <linux/fcntl.h>
  26#include <linux/ptrace.h>
  27#include <linux/slab.h>
  28#include <linux/shm.h>
  29#include <linux/personality.h>
  30#include <linux/init.h>
  31
  32#include <asm/uaccess.h>
  33#include <asm/pgtable.h>
  34
  35
  36#include <linux/elf.h>
  37
  38static int load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs);
  39static int load_som_library(struct file *);
  40
  41/*
  42 * If we don't support core dumping, then supply a NULL so we
  43 * don't even try.
  44 */
  45#if 0
  46static int som_core_dump(struct coredump_params *cprm);
  47#else
  48#define som_core_dump   NULL
  49#endif
  50
  51#define SOM_PAGESTART(_v) ((_v) & ~(unsigned long)(SOM_PAGESIZE-1))
  52#define SOM_PAGEOFFSET(_v) ((_v) & (SOM_PAGESIZE-1))
  53#define SOM_PAGEALIGN(_v) (((_v) + SOM_PAGESIZE - 1) & ~(SOM_PAGESIZE - 1))
  54
  55static struct linux_binfmt som_format = {
  56        .module         = THIS_MODULE,
  57        .load_binary    = load_som_binary,
  58        .load_shlib     = load_som_library,
  59        .core_dump      = som_core_dump,
  60        .min_coredump   = SOM_PAGESIZE
  61};
  62
  63/*
  64 * create_som_tables() parses the env- and arg-strings in new user
  65 * memory and creates the pointer tables from them, and puts their
  66 * addresses on the "stack", returning the new stack pointer value.
  67 */
  68static void create_som_tables(struct linux_binprm *bprm)
  69{
  70        char **argv, **envp;
  71        int argc = bprm->argc;
  72        int envc = bprm->envc;
  73        unsigned long p;
  74        unsigned long *sp;
  75
  76        /* Word-align the stack pointer */
  77        sp = (unsigned long *)((bprm->p + 3) & ~3);
  78
  79        envp = (char **) sp;
  80        sp += envc + 1;
  81        argv = (char **) sp;
  82        sp += argc + 1;
  83
  84        __put_user((unsigned long) envp,++sp);
  85        __put_user((unsigned long) argv,++sp);
  86
  87        __put_user(argc, ++sp);
  88
  89        bprm->p = (unsigned long) sp;
  90
  91        p = current->mm->arg_start;
  92        while (argc-- > 0) {
  93                __put_user((char *)p,argv++);
  94                p += strlen_user((char *)p);
  95        }
  96        __put_user(NULL, argv);
  97        current->mm->arg_end = current->mm->env_start = p;
  98        while (envc-- > 0) {
  99                __put_user((char *)p,envp++);
 100                p += strlen_user((char *)p);
 101        }
 102        __put_user(NULL, envp);
 103        current->mm->env_end = p;
 104}
 105
 106static int check_som_header(struct som_hdr *som_ex)
 107{
 108        int *buf = (int *)som_ex;
 109        int i, ck;
 110
 111        if (som_ex->system_id != SOM_SID_PARISC_1_0 &&
 112            som_ex->system_id != SOM_SID_PARISC_1_1 &&
 113            som_ex->system_id != SOM_SID_PARISC_2_0)
 114                return -ENOEXEC;
 115
 116        if (som_ex->a_magic != SOM_EXEC_NONSHARE &&
 117            som_ex->a_magic != SOM_EXEC_SHARE &&
 118            som_ex->a_magic != SOM_EXEC_DEMAND)
 119                return -ENOEXEC;
 120
 121        if (som_ex->version_id != SOM_ID_OLD &&
 122            som_ex->version_id != SOM_ID_NEW)
 123                return -ENOEXEC;
 124
 125        ck = 0;
 126        for (i=0; i<32; i++)
 127                ck ^= buf[i];
 128        if (ck != 0)
 129                return -ENOEXEC;
 130
 131        return 0;
 132}
 133
 134static int map_som_binary(struct file *file,
 135                const struct som_exec_auxhdr *hpuxhdr)
 136{
 137        unsigned long code_start, code_size, data_start, data_size;
 138        unsigned long bss_start, som_brk;
 139        int retval;
 140        int prot = PROT_READ | PROT_EXEC;
 141        int flags = MAP_FIXED|MAP_PRIVATE|MAP_DENYWRITE|MAP_EXECUTABLE;
 142
 143        mm_segment_t old_fs = get_fs();
 144        set_fs(get_ds());
 145
 146        code_start = SOM_PAGESTART(hpuxhdr->exec_tmem);
 147        code_size = SOM_PAGEALIGN(hpuxhdr->exec_tsize);
 148        current->mm->start_code = code_start;
 149        current->mm->end_code = code_start + code_size;
 150        retval = vm_mmap(file, code_start, code_size, prot,
 151                        flags, SOM_PAGESTART(hpuxhdr->exec_tfile));
 152        if (retval < 0 && retval > -1024)
 153                goto out;
 154
 155        data_start = SOM_PAGESTART(hpuxhdr->exec_dmem);
 156        data_size = SOM_PAGEALIGN(hpuxhdr->exec_dsize);
 157        current->mm->start_data = data_start;
 158        current->mm->end_data = bss_start = data_start + data_size;
 159        retval = vm_mmap(file, data_start, data_size,
 160                        prot | PROT_WRITE, flags,
 161                        SOM_PAGESTART(hpuxhdr->exec_dfile));
 162        if (retval < 0 && retval > -1024)
 163                goto out;
 164
 165        som_brk = bss_start + SOM_PAGEALIGN(hpuxhdr->exec_bsize);
 166        current->mm->start_brk = current->mm->brk = som_brk;
 167        retval = vm_mmap(NULL, bss_start, som_brk - bss_start,
 168                        prot | PROT_WRITE, MAP_FIXED | MAP_PRIVATE, 0);
 169        if (retval > 0 || retval < -1024)
 170                retval = 0;
 171out:
 172        set_fs(old_fs);
 173        return retval;
 174}
 175
 176
 177/*
 178 * These are the functions used to load SOM executables and shared
 179 * libraries.  There is no binary dependent code anywhere else.
 180 */
 181
 182static int
 183load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 184{
 185        int retval;
 186        unsigned int size;
 187        unsigned long som_entry;
 188        struct som_hdr *som_ex;
 189        struct som_exec_auxhdr *hpuxhdr;
 190
 191        /* Get the exec-header */
 192        som_ex = (struct som_hdr *) bprm->buf;
 193
 194        retval = check_som_header(som_ex);
 195        if (retval != 0)
 196                goto out;
 197
 198        /* Now read in the auxiliary header information */
 199
 200        retval = -ENOMEM;
 201        size = som_ex->aux_header_size;
 202        if (size > SOM_PAGESIZE)
 203                goto out;
 204        hpuxhdr = kmalloc(size, GFP_KERNEL);
 205        if (!hpuxhdr)
 206                goto out;
 207
 208        retval = kernel_read(bprm->file, som_ex->aux_header_location,
 209                        (char *) hpuxhdr, size);
 210        if (retval != size) {
 211                if (retval >= 0)
 212                        retval = -EIO;
 213                goto out_free;
 214        }
 215
 216        /* Flush all traces of the currently running executable */
 217        retval = flush_old_exec(bprm);
 218        if (retval)
 219                goto out_free;
 220
 221        /* OK, This is the point of no return */
 222        current->personality = PER_HPUX;
 223        setup_new_exec(bprm);
 224
 225        /* Set the task size for HP-UX processes such that
 226         * the gateway page is outside the address space.
 227         * This can be fixed later, but for now, this is much
 228         * easier.
 229         */
 230
 231        current->thread.task_size = 0xc0000000;
 232
 233        /* Set map base to allow enough room for hp-ux heap growth */
 234
 235        current->thread.map_base = 0x80000000;
 236
 237        retval = map_som_binary(bprm->file, hpuxhdr);
 238        if (retval < 0)
 239                goto out_free;
 240
 241        som_entry = hpuxhdr->exec_entry;
 242        kfree(hpuxhdr);
 243
 244        set_binfmt(&som_format);
 245        install_exec_creds(bprm);
 246        setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
 247
 248        create_som_tables(bprm);
 249
 250        current->mm->start_stack = bprm->p;
 251
 252#if 0
 253        printk("(start_brk) %08lx\n" , (unsigned long) current->mm->start_brk);
 254        printk("(end_code) %08lx\n" , (unsigned long) current->mm->end_code);
 255        printk("(start_code) %08lx\n" , (unsigned long) current->mm->start_code);
 256        printk("(end_data) %08lx\n" , (unsigned long) current->mm->end_data);
 257        printk("(start_stack) %08lx\n" , (unsigned long) current->mm->start_stack);
 258        printk("(brk) %08lx\n" , (unsigned long) current->mm->brk);
 259#endif
 260
 261        map_hpux_gateway_page(current,current->mm);
 262
 263        start_thread_som(regs, som_entry, bprm->p);
 264        return 0;
 265
 266        /* error cleanup */
 267out_free:
 268        kfree(hpuxhdr);
 269out:
 270        return retval;
 271}
 272
 273static int load_som_library(struct file *f)
 274{
 275/* No lib support in SOM yet.  gizza chance.. */
 276        return -ENOEXEC;
 277}
 278        /* Install the SOM loader.
 279         * N.B. We *rely* on the table being the right size with the
 280         * right number of free slots...
 281         */
 282
 283static int __init init_som_binfmt(void)
 284{
 285        register_binfmt(&som_format);
 286        return 0;
 287}
 288
 289static void __exit exit_som_binfmt(void)
 290{
 291        /* Remove the SOM loader. */
 292        unregister_binfmt(&som_format);
 293}
 294
 295core_initcall(init_som_binfmt);
 296module_exit(exit_som_binfmt);
 297
 298MODULE_LICENSE("GPL");
 299
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