Root/fs/binfmt_som.c

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(long signr, struct pt_regs *regs, unsigned long limit);
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    down_write(&current->mm->mmap_sem);
151    retval = do_mmap(file, code_start, code_size, prot,
152            flags, SOM_PAGESTART(hpuxhdr->exec_tfile));
153    up_write(&current->mm->mmap_sem);
154    if (retval < 0 && retval > -1024)
155        goto out;
156
157    data_start = SOM_PAGESTART(hpuxhdr->exec_dmem);
158    data_size = SOM_PAGEALIGN(hpuxhdr->exec_dsize);
159    current->mm->start_data = data_start;
160    current->mm->end_data = bss_start = data_start + data_size;
161    down_write(&current->mm->mmap_sem);
162    retval = do_mmap(file, data_start, data_size,
163            prot | PROT_WRITE, flags,
164            SOM_PAGESTART(hpuxhdr->exec_dfile));
165    up_write(&current->mm->mmap_sem);
166    if (retval < 0 && retval > -1024)
167        goto out;
168
169    som_brk = bss_start + SOM_PAGEALIGN(hpuxhdr->exec_bsize);
170    current->mm->start_brk = current->mm->brk = som_brk;
171    down_write(&current->mm->mmap_sem);
172    retval = do_mmap(NULL, bss_start, som_brk - bss_start,
173            prot | PROT_WRITE, MAP_FIXED | MAP_PRIVATE, 0);
174    up_write(&current->mm->mmap_sem);
175    if (retval > 0 || retval < -1024)
176        retval = 0;
177out:
178    set_fs(old_fs);
179    return retval;
180}
181
182
183/*
184 * These are the functions used to load SOM executables and shared
185 * libraries. There is no binary dependent code anywhere else.
186 */
187
188static int
189load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs)
190{
191    int retval;
192    unsigned int size;
193    unsigned long som_entry;
194    struct som_hdr *som_ex;
195    struct som_exec_auxhdr *hpuxhdr;
196
197    /* Get the exec-header */
198    som_ex = (struct som_hdr *) bprm->buf;
199
200    retval = check_som_header(som_ex);
201    if (retval != 0)
202        goto out;
203
204    /* Now read in the auxiliary header information */
205
206    retval = -ENOMEM;
207    size = som_ex->aux_header_size;
208    if (size > SOM_PAGESIZE)
209        goto out;
210    hpuxhdr = kmalloc(size, GFP_KERNEL);
211    if (!hpuxhdr)
212        goto out;
213
214    retval = kernel_read(bprm->file, som_ex->aux_header_location,
215            (char *) hpuxhdr, size);
216    if (retval != size) {
217        if (retval >= 0)
218            retval = -EIO;
219        goto out_free;
220    }
221
222    /* Flush all traces of the currently running executable */
223    retval = flush_old_exec(bprm);
224    if (retval)
225        goto out_free;
226
227    /* OK, This is the point of no return */
228    current->flags &= ~PF_FORKNOEXEC;
229    current->personality = PER_HPUX;
230
231    /* Set the task size for HP-UX processes such that
232     * the gateway page is outside the address space.
233     * This can be fixed later, but for now, this is much
234     * easier.
235     */
236
237    current->thread.task_size = 0xc0000000;
238
239    /* Set map base to allow enough room for hp-ux heap growth */
240
241    current->thread.map_base = 0x80000000;
242
243    retval = map_som_binary(bprm->file, hpuxhdr);
244    if (retval < 0)
245        goto out_free;
246
247    som_entry = hpuxhdr->exec_entry;
248    kfree(hpuxhdr);
249
250    set_binfmt(&som_format);
251    install_exec_creds(bprm);
252    setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
253
254    create_som_tables(bprm);
255
256    current->mm->start_stack = bprm->p;
257
258#if 0
259    printk("(start_brk) %08lx\n" , (unsigned long) current->mm->start_brk);
260    printk("(end_code) %08lx\n" , (unsigned long) current->mm->end_code);
261    printk("(start_code) %08lx\n" , (unsigned long) current->mm->start_code);
262    printk("(end_data) %08lx\n" , (unsigned long) current->mm->end_data);
263    printk("(start_stack) %08lx\n" , (unsigned long) current->mm->start_stack);
264    printk("(brk) %08lx\n" , (unsigned long) current->mm->brk);
265#endif
266
267    map_hpux_gateway_page(current,current->mm);
268
269    start_thread_som(regs, som_entry, bprm->p);
270    return 0;
271
272    /* error cleanup */
273out_free:
274    kfree(hpuxhdr);
275out:
276    return retval;
277}
278
279static int load_som_library(struct file *f)
280{
281/* No lib support in SOM yet. gizza chance.. */
282    return -ENOEXEC;
283}
284    /* Install the SOM loader.
285     * N.B. We *rely* on the table being the right size with the
286     * right number of free slots...
287     */
288
289static int __init init_som_binfmt(void)
290{
291    return register_binfmt(&som_format);
292}
293
294static void __exit exit_som_binfmt(void)
295{
296    /* Remove the SOM loader. */
297    unregister_binfmt(&som_format);
298}
299
300core_initcall(init_som_binfmt);
301module_exit(exit_som_binfmt);
302
303MODULE_LICENSE("GPL");
304

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