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
38 static int load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs);
39 static 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
46 static 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
55 static 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 */
create_som_tables(struct linux_binprm * bprm)68 static 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
check_som_header(struct som_hdr * som_ex)106 static 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
map_som_binary(struct file * file,const struct som_exec_auxhdr * hpuxhdr)134 static 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(¤t->mm->mmap_sem);
151 retval = do_mmap(file, code_start, code_size, prot,
152 flags, SOM_PAGESTART(hpuxhdr->exec_tfile));
153 up_write(¤t->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(¤t->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(¤t->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(¤t->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(¤t->mm->mmap_sem);
175 if (retval > 0 || retval < -1024)
176 retval = 0;
177 out:
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
188 static int
load_som_binary(struct linux_binprm * bprm,struct pt_regs * regs)189 load_som_binary(struct linux_binprm * bprm, struct pt_regs * regs)
190 {
191 int som_exec_fileno;
192 int retval;
193 unsigned int size;
194 unsigned long som_entry;
195 struct som_hdr *som_ex;
196 struct som_exec_auxhdr *hpuxhdr;
197
198 /* Get the exec-header */
199 som_ex = (struct som_hdr *) bprm->buf;
200
201 retval = check_som_header(som_ex);
202 if (retval != 0)
203 goto out;
204
205 /* Now read in the auxiliary header information */
206
207 retval = -ENOMEM;
208 size = som_ex->aux_header_size;
209 if (size > SOM_PAGESIZE)
210 goto out;
211 hpuxhdr = kmalloc(size, GFP_KERNEL);
212 if (!hpuxhdr)
213 goto out;
214
215 retval = kernel_read(bprm->file, som_ex->aux_header_location,
216 (char *) hpuxhdr, size);
217 if (retval != size) {
218 if (retval >= 0)
219 retval = -EIO;
220 goto out_free;
221 }
222
223 retval = get_unused_fd();
224 if (retval < 0)
225 goto out_free;
226 get_file(bprm->file);
227 fd_install(som_exec_fileno = retval, bprm->file);
228
229 /* Flush all traces of the currently running executable */
230 retval = flush_old_exec(bprm);
231 if (retval)
232 goto out_free;
233
234 /* OK, This is the point of no return */
235 current->flags &= ~PF_FORKNOEXEC;
236 current->personality = PER_HPUX;
237
238 /* Set the task size for HP-UX processes such that
239 * the gateway page is outside the address space.
240 * This can be fixed later, but for now, this is much
241 * easier.
242 */
243
244 current->thread.task_size = 0xc0000000;
245
246 /* Set map base to allow enough room for hp-ux heap growth */
247
248 current->thread.map_base = 0x80000000;
249
250 retval = map_som_binary(bprm->file, hpuxhdr);
251 if (retval < 0)
252 goto out_free;
253
254 som_entry = hpuxhdr->exec_entry;
255 kfree(hpuxhdr);
256
257 set_binfmt(&som_format);
258 install_exec_creds(bprm);
259 setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
260
261 create_som_tables(bprm);
262
263 current->mm->start_stack = bprm->p;
264
265 #if 0
266 printk("(start_brk) %08lx\n" , (unsigned long) current->mm->start_brk);
267 printk("(end_code) %08lx\n" , (unsigned long) current->mm->end_code);
268 printk("(start_code) %08lx\n" , (unsigned long) current->mm->start_code);
269 printk("(end_data) %08lx\n" , (unsigned long) current->mm->end_data);
270 printk("(start_stack) %08lx\n" , (unsigned long) current->mm->start_stack);
271 printk("(brk) %08lx\n" , (unsigned long) current->mm->brk);
272 #endif
273
274 map_hpux_gateway_page(current,current->mm);
275
276 start_thread_som(regs, som_entry, bprm->p);
277 return 0;
278
279 /* error cleanup */
280 out_free:
281 kfree(hpuxhdr);
282 out:
283 return retval;
284 }
285
load_som_library(struct file * f)286 static int load_som_library(struct file *f)
287 {
288 /* No lib support in SOM yet. gizza chance.. */
289 return -ENOEXEC;
290 }
291 /* Install the SOM loader.
292 * N.B. We *rely* on the table being the right size with the
293 * right number of free slots...
294 */
295
init_som_binfmt(void)296 static int __init init_som_binfmt(void)
297 {
298 return register_binfmt(&som_format);
299 }
300
exit_som_binfmt(void)301 static void __exit exit_som_binfmt(void)
302 {
303 /* Remove the SOM loader. */
304 unregister_binfmt(&som_format);
305 }
306
307 core_initcall(init_som_binfmt);
308 module_exit(exit_som_binfmt);
309
310 MODULE_LICENSE("GPL");
311