[PATCH] mm: mm_init set_mm_counters
[linux-2.6.git] / fs / binfmt_elf_fdpic.c
1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
2  *
3  * Copyright (C) 2003, 2004 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  * Derived from binfmt_elf.c
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version
10  * 2 of the License, or (at your option) any later version.
11  */
12
13 #include <linux/module.h>
14
15 #include <linux/fs.h>
16 #include <linux/stat.h>
17 #include <linux/sched.h>
18 #include <linux/mm.h>
19 #include <linux/mman.h>
20 #include <linux/errno.h>
21 #include <linux/signal.h>
22 #include <linux/binfmts.h>
23 #include <linux/string.h>
24 #include <linux/file.h>
25 #include <linux/fcntl.h>
26 #include <linux/slab.h>
27 #include <linux/highmem.h>
28 #include <linux/personality.h>
29 #include <linux/ptrace.h>
30 #include <linux/init.h>
31 #include <linux/smp_lock.h>
32 #include <linux/elf.h>
33 #include <linux/elf-fdpic.h>
34 #include <linux/elfcore.h>
35
36 #include <asm/uaccess.h>
37 #include <asm/param.h>
38 #include <asm/pgalloc.h>
39
40 typedef char *elf_caddr_t;
41 #ifndef elf_addr_t
42 #define elf_addr_t unsigned long
43 #endif
44
45 #if 0
46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
47 #else
48 #define kdebug(fmt, ...) do {} while(0)
49 #endif
50
51 MODULE_LICENSE("GPL");
52
53 static int load_elf_fdpic_binary(struct linux_binprm *bprm, struct pt_regs *regs);
54 //static int load_elf_fdpic_library(struct file *);
55 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, struct file *file);
56 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
57                               struct file *file,
58                               struct mm_struct *mm,
59                               const char *what);
60
61 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
62                                    struct mm_struct *mm,
63                                    struct elf_fdpic_params *exec_params,
64                                    struct elf_fdpic_params *interp_params);
65
66 #ifndef CONFIG_MMU
67 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, unsigned long *_sp);
68 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *params,
69                                                    struct file *file,
70                                                    struct mm_struct *mm);
71 #endif
72
73 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
74                                              struct file *file,
75                                              struct mm_struct *mm);
76
77 static struct linux_binfmt elf_fdpic_format = {
78         .module         = THIS_MODULE,
79         .load_binary    = load_elf_fdpic_binary,
80 //      .load_shlib     = load_elf_fdpic_library,
81 //      .core_dump      = elf_fdpic_core_dump,
82         .min_coredump   = ELF_EXEC_PAGESIZE,
83 };
84
85 static int __init init_elf_fdpic_binfmt(void)  { return register_binfmt(&elf_fdpic_format); }
86 static void __exit exit_elf_fdpic_binfmt(void) { unregister_binfmt(&elf_fdpic_format); }
87
88 module_init(init_elf_fdpic_binfmt)
89 module_exit(exit_elf_fdpic_binfmt)
90
91 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
92 {
93         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
94                 return 0;
95         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
96                 return 0;
97         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
98                 return 0;
99         if (!file->f_op || !file->f_op->mmap)
100                 return 0;
101         return 1;
102 }
103
104 /*****************************************************************************/
105 /*
106  * read the program headers table into memory
107  */
108 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params, struct file *file)
109 {
110         struct elf32_phdr *phdr;
111         unsigned long size;
112         int retval, loop;
113
114         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
115                 return -ENOMEM;
116         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
117                 return -ENOMEM;
118
119         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
120         params->phdrs = kmalloc(size, GFP_KERNEL);
121         if (!params->phdrs)
122                 return -ENOMEM;
123
124         retval = kernel_read(file, params->hdr.e_phoff, (char *) params->phdrs, size);
125         if (retval < 0)
126                 return retval;
127
128         /* determine stack size for this binary */
129         phdr = params->phdrs;
130         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
131                 if (phdr->p_type != PT_GNU_STACK)
132                         continue;
133
134                 if (phdr->p_flags & PF_X)
135                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
136                 else
137                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
138
139                 params->stack_size = phdr->p_memsz;
140                 break;
141         }
142
143         return 0;
144 } /* end elf_fdpic_fetch_phdrs() */
145
146 /*****************************************************************************/
147 /*
148  * load an fdpic binary into various bits of memory
149  */
150 static int load_elf_fdpic_binary(struct linux_binprm *bprm, struct pt_regs *regs)
151 {
152         struct elf_fdpic_params exec_params, interp_params;
153         struct elf_phdr *phdr;
154         unsigned long stack_size;
155         struct file *interpreter = NULL; /* to shut gcc up */
156         char *interpreter_name = NULL;
157         int executable_stack;
158         int retval, i;
159
160         memset(&exec_params, 0, sizeof(exec_params));
161         memset(&interp_params, 0, sizeof(interp_params));
162
163         exec_params.hdr = *(struct elfhdr *) bprm->buf;
164         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
165
166         /* check that this is a binary we know how to deal with */
167         retval = -ENOEXEC;
168         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
169                 goto error;
170
171         /* read the program header table */
172         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
173         if (retval < 0)
174                 goto error;
175
176         /* scan for a program header that specifies an interpreter */
177         phdr = exec_params.phdrs;
178
179         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
180                 switch (phdr->p_type) {
181                 case PT_INTERP:
182                         retval = -ENOMEM;
183                         if (phdr->p_filesz > PATH_MAX)
184                                 goto error;
185                         retval = -ENOENT;
186                         if (phdr->p_filesz < 2)
187                                 goto error;
188
189                         /* read the name of the interpreter into memory */
190                         interpreter_name = (char *) kmalloc(phdr->p_filesz, GFP_KERNEL);
191                         if (!interpreter_name)
192                                 goto error;
193
194                         retval = kernel_read(bprm->file,
195                                              phdr->p_offset,
196                                              interpreter_name,
197                                              phdr->p_filesz);
198                         if (retval < 0)
199                                 goto error;
200
201                         retval = -ENOENT;
202                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
203                                 goto error;
204
205                         kdebug("Using ELF interpreter %s", interpreter_name);
206
207                         /* replace the program with the interpreter */
208                         interpreter = open_exec(interpreter_name);
209                         retval = PTR_ERR(interpreter);
210                         if (IS_ERR(interpreter)) {
211                                 interpreter = NULL;
212                                 goto error;
213                         }
214
215                         retval = kernel_read(interpreter, 0, bprm->buf, BINPRM_BUF_SIZE);
216                         if (retval < 0)
217                                 goto error;
218
219                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
220                         break;
221
222                 case PT_LOAD:
223 #ifdef CONFIG_MMU
224                         if (exec_params.load_addr == 0)
225                                 exec_params.load_addr = phdr->p_vaddr;
226 #endif
227                         break;
228                 }
229
230         }
231
232         if (elf_check_const_displacement(&exec_params.hdr))
233                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
234
235         /* perform insanity checks on the interpreter */
236         if (interpreter_name) {
237                 retval = -ELIBBAD;
238                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
239                         goto error;
240
241                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
242
243                 /* read the interpreter's program header table */
244                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
245                 if (retval < 0)
246                         goto error;
247         }
248
249         stack_size = exec_params.stack_size;
250         if (stack_size < interp_params.stack_size)
251                 stack_size = interp_params.stack_size;
252
253         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
254                 executable_stack = EXSTACK_ENABLE_X;
255         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
256                 executable_stack = EXSTACK_DISABLE_X;
257         else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
258                 executable_stack = EXSTACK_ENABLE_X;
259         else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
260                 executable_stack = EXSTACK_DISABLE_X;
261         else
262                 executable_stack = EXSTACK_DEFAULT;
263
264         retval = -ENOEXEC;
265         if (stack_size == 0)
266                 goto error;
267
268         if (elf_check_const_displacement(&interp_params.hdr))
269                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
270
271         /* flush all traces of the currently running executable */
272         retval = flush_old_exec(bprm);
273         if (retval)
274                 goto error;
275
276         /* there's now no turning back... the old userspace image is dead,
277          * defunct, deceased, etc. after this point we have to exit via
278          * error_kill */
279         set_personality(PER_LINUX_FDPIC);
280         set_binfmt(&elf_fdpic_format);
281
282         current->mm->start_code = 0;
283         current->mm->end_code = 0;
284         current->mm->start_stack = 0;
285         current->mm->start_data = 0;
286         current->mm->end_data = 0;
287         current->mm->context.exec_fdpic_loadmap = 0;
288         current->mm->context.interp_fdpic_loadmap = 0;
289
290         current->flags &= ~PF_FORKNOEXEC;
291
292 #ifdef CONFIG_MMU
293         elf_fdpic_arch_lay_out_mm(&exec_params,
294                                   &interp_params,
295                                   &current->mm->start_stack,
296                                   &current->mm->start_brk);
297
298         retval = setup_arg_pages(bprm, current->mm->start_stack, executable_stack);
299         if (retval < 0) {
300                 send_sig(SIGKILL, current, 0);
301                 goto error_kill;
302         }
303 #endif
304
305         /* load the executable and interpreter into memory */
306         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm, "executable");
307         if (retval < 0)
308                 goto error_kill;
309
310         if (interpreter_name) {
311                 retval = elf_fdpic_map_file(&interp_params, interpreter,
312                                             current->mm, "interpreter");
313                 if (retval < 0) {
314                         printk(KERN_ERR "Unable to load interpreter\n");
315                         goto error_kill;
316                 }
317
318                 allow_write_access(interpreter);
319                 fput(interpreter);
320                 interpreter = NULL;
321         }
322
323 #ifdef CONFIG_MMU
324         if (!current->mm->start_brk)
325                 current->mm->start_brk = current->mm->end_data;
326
327         current->mm->brk = current->mm->start_brk = PAGE_ALIGN(current->mm->start_brk);
328
329 #else
330         /* create a stack and brk area big enough for everyone
331          * - the brk heap starts at the bottom and works up
332          * - the stack starts at the top and works down
333          */
334         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
335         if (stack_size < PAGE_SIZE * 2)
336                 stack_size = PAGE_SIZE * 2;
337
338         down_write(&current->mm->mmap_sem);
339         current->mm->start_brk = do_mmap(NULL,
340                                          0,
341                                          stack_size,
342                                          PROT_READ | PROT_WRITE | PROT_EXEC,
343                                          MAP_PRIVATE | MAP_ANON | MAP_GROWSDOWN,
344                                          0);
345
346         if (IS_ERR((void *) current->mm->start_brk)) {
347                 up_write(&current->mm->mmap_sem);
348                 retval = current->mm->start_brk;
349                 current->mm->start_brk = 0;
350                 goto error_kill;
351         }
352
353         if (do_mremap(current->mm->start_brk,
354                       stack_size,
355                       ksize((char *) current->mm->start_brk),
356                       0, 0
357                       ) == current->mm->start_brk
358             )
359                 stack_size = ksize((char *) current->mm->start_brk);
360         up_write(&current->mm->mmap_sem);
361
362         current->mm->brk = current->mm->start_brk;
363         current->mm->context.end_brk = current->mm->start_brk;
364         current->mm->context.end_brk += (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
365         current->mm->start_stack = current->mm->start_brk + stack_size;
366 #endif
367
368         compute_creds(bprm);
369         current->flags &= ~PF_FORKNOEXEC;
370         if (create_elf_fdpic_tables(bprm, current->mm, &exec_params, &interp_params) < 0)
371                 goto error_kill;
372
373         kdebug("- start_code  %lx",     (long) current->mm->start_code);
374         kdebug("- end_code    %lx",     (long) current->mm->end_code);
375         kdebug("- start_data  %lx",     (long) current->mm->start_data);
376         kdebug("- end_data    %lx",     (long) current->mm->end_data);
377         kdebug("- start_brk   %lx",     (long) current->mm->start_brk);
378         kdebug("- brk         %lx",     (long) current->mm->brk);
379         kdebug("- start_stack %lx",     (long) current->mm->start_stack);
380
381 #ifdef ELF_FDPIC_PLAT_INIT
382         /*
383          * The ABI may specify that certain registers be set up in special
384          * ways (on i386 %edx is the address of a DT_FINI function, for
385          * example.  This macro performs whatever initialization to
386          * the regs structure is required.
387          */
388         ELF_FDPIC_PLAT_INIT(regs,
389                             exec_params.map_addr,
390                             interp_params.map_addr,
391                             interp_params.dynamic_addr ?: exec_params.dynamic_addr
392                             );
393 #endif
394
395         /* everything is now ready... get the userspace context ready to roll */
396         start_thread(regs,
397                      interp_params.entry_addr ?: exec_params.entry_addr,
398                      current->mm->start_stack);
399
400         if (unlikely(current->ptrace & PT_PTRACED)) {
401                 if (current->ptrace & PT_TRACE_EXEC)
402                         ptrace_notify ((PTRACE_EVENT_EXEC << 8) | SIGTRAP);
403                 else
404                         send_sig(SIGTRAP, current, 0);
405         }
406
407         retval = 0;
408
409 error:
410         if (interpreter) {
411                 allow_write_access(interpreter);
412                 fput(interpreter);
413         }
414         if (interpreter_name)
415                 kfree(interpreter_name);
416         if (exec_params.phdrs)
417                 kfree(exec_params.phdrs);
418         if (exec_params.loadmap)
419                 kfree(exec_params.loadmap);
420         if (interp_params.phdrs)
421                 kfree(interp_params.phdrs);
422         if (interp_params.loadmap)
423                 kfree(interp_params.loadmap);
424         return retval;
425
426         /* unrecoverable error - kill the process */
427  error_kill:
428         send_sig(SIGSEGV, current, 0);
429         goto error;
430
431 } /* end load_elf_fdpic_binary() */
432
433 /*****************************************************************************/
434 /*
435  * present useful information to the program
436  */
437 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
438                                    struct mm_struct *mm,
439                                    struct elf_fdpic_params *exec_params,
440                                    struct elf_fdpic_params *interp_params)
441 {
442         unsigned long sp, csp, nitems;
443         elf_caddr_t *argv, *envp;
444         size_t platform_len = 0, len;
445         char *k_platform, *u_platform, *p;
446         long hwcap;
447         int loop;
448
449         /* we're going to shovel a whole load of stuff onto the stack */
450 #ifdef CONFIG_MMU
451         sp = bprm->p;
452 #else
453         sp = mm->start_stack;
454
455         /* stack the program arguments and environment */
456         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
457                 return -EFAULT;
458 #endif
459
460         /* get hold of platform and hardware capabilities masks for the machine
461          * we are running on.  In some cases (Sparc), this info is impossible
462          * to get, in others (i386) it is merely difficult.
463          */
464         hwcap = ELF_HWCAP;
465         k_platform = ELF_PLATFORM;
466
467         if (k_platform) {
468                 platform_len = strlen(k_platform) + 1;
469                 sp -= platform_len;
470                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
471                         return -EFAULT;
472         }
473
474         u_platform = (char *) sp;
475
476 #if defined(__i386__) && defined(CONFIG_SMP)
477         /* in some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
478          * by the processes running on the same package. One thing we can do
479          * is to shuffle the initial stack for them.
480          *
481          * the conditionals here are unneeded, but kept in to make the
482          * code behaviour the same as pre change unless we have hyperthreaded
483          * processors. This keeps Mr Marcelo Person happier but should be
484          * removed for 2.5
485          */
486         if (smp_num_siblings > 1)
487                 sp = sp - ((current->pid % 64) << 7);
488 #endif
489
490         sp &= ~7UL;
491
492         /* stack the load map(s) */
493         len = sizeof(struct elf32_fdpic_loadmap);
494         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
495         sp = (sp - len) & ~7UL;
496         exec_params->map_addr = sp;
497
498         if (copy_to_user((void *) sp, exec_params->loadmap, len) != 0)
499                 return -EFAULT;
500
501         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
502
503         if (interp_params->loadmap) {
504                 len = sizeof(struct elf32_fdpic_loadmap);
505                 len += sizeof(struct elf32_fdpic_loadseg) * interp_params->loadmap->nsegs;
506                 sp = (sp - len) & ~7UL;
507                 interp_params->map_addr = sp;
508
509                 if (copy_to_user((void *) sp, interp_params->loadmap, len) != 0)
510                         return -EFAULT;
511
512                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
513         }
514
515         /* force 16 byte _final_ alignment here for generality */
516 #define DLINFO_ITEMS 13
517
518         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0);
519 #ifdef DLINFO_ARCH_ITEMS
520         nitems += DLINFO_ARCH_ITEMS;
521 #endif
522
523         csp = sp;
524         sp -= nitems * 2 * sizeof(unsigned long);
525         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
526         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
527         sp -= 1 * sizeof(unsigned long);                /* argc */
528
529         csp -= sp & 15UL;
530         sp -= sp & 15UL;
531
532         /* put the ELF interpreter info on the stack */
533 #define NEW_AUX_ENT(nr, id, val)                                                \
534         do {                                                                    \
535                 struct { unsigned long _id, _val; } *ent = (void *) csp;        \
536                 __put_user((id), &ent[nr]._id);                                 \
537                 __put_user((val), &ent[nr]._val);                               \
538         } while (0)
539
540         csp -= 2 * sizeof(unsigned long);
541         NEW_AUX_ENT(0, AT_NULL, 0);
542         if (k_platform) {
543                 csp -= 2 * sizeof(unsigned long);
544                 NEW_AUX_ENT(0, AT_PLATFORM, (elf_addr_t)(unsigned long) u_platform);
545         }
546
547         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
548         NEW_AUX_ENT( 0, AT_HWCAP,               hwcap);
549         NEW_AUX_ENT( 1, AT_PAGESZ,              PAGE_SIZE);
550         NEW_AUX_ENT( 2, AT_CLKTCK,              CLOCKS_PER_SEC);
551         NEW_AUX_ENT( 3, AT_PHDR,                exec_params->ph_addr);
552         NEW_AUX_ENT( 4, AT_PHENT,               sizeof(struct elf_phdr));
553         NEW_AUX_ENT( 5, AT_PHNUM,               exec_params->hdr.e_phnum);
554         NEW_AUX_ENT( 6, AT_BASE,                interp_params->elfhdr_addr);
555         NEW_AUX_ENT( 7, AT_FLAGS,               0);
556         NEW_AUX_ENT( 8, AT_ENTRY,               exec_params->entry_addr);
557         NEW_AUX_ENT( 9, AT_UID,                 (elf_addr_t) current->uid);
558         NEW_AUX_ENT(10, AT_EUID,                (elf_addr_t) current->euid);
559         NEW_AUX_ENT(11, AT_GID,                 (elf_addr_t) current->gid);
560         NEW_AUX_ENT(12, AT_EGID,                (elf_addr_t) current->egid);
561
562 #ifdef ARCH_DLINFO
563         /* ARCH_DLINFO must come last so platform specific code can enforce
564          * special alignment requirements on the AUXV if necessary (eg. PPC).
565          */
566         ARCH_DLINFO;
567 #endif
568 #undef NEW_AUX_ENT
569
570         /* allocate room for argv[] and envv[] */
571         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
572         envp = (elf_caddr_t *) csp;
573         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
574         argv = (elf_caddr_t *) csp;
575
576         /* stack argc */
577         csp -= sizeof(unsigned long);
578         __put_user(bprm->argc, (unsigned long *) csp);
579
580         if (csp != sp)
581                 BUG();
582
583         /* fill in the argv[] array */
584 #ifdef CONFIG_MMU
585         current->mm->arg_start = bprm->p;
586 #else
587         current->mm->arg_start = current->mm->start_stack - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
588 #endif
589
590         p = (char *) current->mm->arg_start;
591         for (loop = bprm->argc; loop > 0; loop--) {
592                 __put_user((elf_caddr_t) p, argv++);
593                 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
594                 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
595                         return -EINVAL;
596                 p += len;
597         }
598         __put_user(NULL, argv);
599         current->mm->arg_end = (unsigned long) p;
600
601         /* fill in the envv[] array */
602         current->mm->env_start = (unsigned long) p;
603         for (loop = bprm->envc; loop > 0; loop--) {
604                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
605                 len = strnlen_user(p, PAGE_SIZE * MAX_ARG_PAGES);
606                 if (!len || len > PAGE_SIZE * MAX_ARG_PAGES)
607                         return -EINVAL;
608                 p += len;
609         }
610         __put_user(NULL, envp);
611         current->mm->env_end = (unsigned long) p;
612
613         mm->start_stack = (unsigned long) sp;
614         return 0;
615 } /* end create_elf_fdpic_tables() */
616
617 /*****************************************************************************/
618 /*
619  * transfer the program arguments and environment from the holding pages onto
620  * the stack
621  */
622 #ifndef CONFIG_MMU
623 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm, unsigned long *_sp)
624 {
625         unsigned long index, stop, sp;
626         char *src;
627         int ret = 0;
628
629         stop = bprm->p >> PAGE_SHIFT;
630         sp = *_sp;
631
632         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
633                 src = kmap(bprm->page[index]);
634                 sp -= PAGE_SIZE;
635                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
636                         ret = -EFAULT;
637                 kunmap(bprm->page[index]);
638                 if (ret < 0)
639                         goto out;
640         }
641
642         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
643
644  out:
645         return ret;
646 } /* end elf_fdpic_transfer_args_to_stack() */
647 #endif
648
649 /*****************************************************************************/
650 /*
651  * load the appropriate binary image (executable or interpreter) into memory
652  * - we assume no MMU is available
653  * - if no other PIC bits are set in params->hdr->e_flags
654  *   - we assume that the LOADable segments in the binary are independently relocatable
655  *   - we assume R/O executable segments are shareable
656  * - else
657  *   - we assume the loadable parts of the image to require fixed displacement
658  *   - the image is not shareable
659  */
660 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
661                               struct file *file,
662                               struct mm_struct *mm,
663                               const char *what)
664 {
665         struct elf32_fdpic_loadmap *loadmap;
666 #ifdef CONFIG_MMU
667         struct elf32_fdpic_loadseg *mseg;
668 #endif
669         struct elf32_fdpic_loadseg *seg;
670         struct elf32_phdr *phdr;
671         unsigned long load_addr, stop;
672         unsigned nloads, tmp;
673         size_t size;
674         int loop, ret;
675
676         /* allocate a load map table */
677         nloads = 0;
678         for (loop = 0; loop < params->hdr.e_phnum; loop++)
679                 if (params->phdrs[loop].p_type == PT_LOAD)
680                         nloads++;
681
682         if (nloads == 0)
683                 return -ELIBBAD;
684
685         size = sizeof(*loadmap) + nloads * sizeof(*seg);
686         loadmap = kmalloc(size, GFP_KERNEL);
687         if (!loadmap)
688                 return -ENOMEM;
689
690         params->loadmap = loadmap;
691         memset(loadmap, 0, size);
692
693         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
694         loadmap->nsegs = nloads;
695
696         load_addr = params->load_addr;
697         seg = loadmap->segs;
698
699         /* map the requested LOADs into the memory space */
700         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
701         case ELF_FDPIC_FLAG_CONSTDISP:
702         case ELF_FDPIC_FLAG_CONTIGUOUS:
703 #ifndef CONFIG_MMU
704                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
705                 if (ret < 0)
706                         return ret;
707                 break;
708 #endif
709         default:
710                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
711                 if (ret < 0)
712                         return ret;
713                 break;
714         }
715
716         /* map the entry point */
717         if (params->hdr.e_entry) {
718                 seg = loadmap->segs;
719                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
720                         if (params->hdr.e_entry >= seg->p_vaddr &&
721                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz
722                             ) {
723                                 params->entry_addr =
724                                         (params->hdr.e_entry - seg->p_vaddr) + seg->addr;
725                                 break;
726                         }
727                 }
728         }
729
730         /* determine where the program header table has wound up if mapped */
731         stop = params->hdr.e_phoff + params->hdr.e_phnum * sizeof (struct elf_phdr);
732         phdr = params->phdrs;
733
734         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
735                 if (phdr->p_type != PT_LOAD)
736                         continue;
737
738                 if (phdr->p_offset > params->hdr.e_phoff ||
739                     phdr->p_offset + phdr->p_filesz < stop)
740                         continue;
741
742                 seg = loadmap->segs;
743                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
744                         if (phdr->p_vaddr >= seg->p_vaddr &&
745                             phdr->p_vaddr + phdr->p_filesz <= seg->p_vaddr + seg->p_memsz
746                             ) {
747                                 params->ph_addr = (phdr->p_vaddr - seg->p_vaddr) + seg->addr +
748                                         params->hdr.e_phoff - phdr->p_offset;
749                                 break;
750                         }
751                 }
752                 break;
753         }
754
755         /* determine where the dynamic section has wound up if there is one */
756         phdr = params->phdrs;
757         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
758                 if (phdr->p_type != PT_DYNAMIC)
759                         continue;
760
761                 seg = loadmap->segs;
762                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
763                         if (phdr->p_vaddr >= seg->p_vaddr &&
764                             phdr->p_vaddr + phdr->p_memsz <= seg->p_vaddr + seg->p_memsz
765                             ) {
766                                 params->dynamic_addr = (phdr->p_vaddr - seg->p_vaddr) + seg->addr;
767
768                                 /* check the dynamic section contains at least one item, and that
769                                  * the last item is a NULL entry */
770                                 if (phdr->p_memsz == 0 ||
771                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
772                                         goto dynamic_error;
773
774                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
775                                 if (((Elf32_Dyn *) params->dynamic_addr)[tmp - 1].d_tag != 0)
776                                         goto dynamic_error;
777                                 break;
778                         }
779                 }
780                 break;
781         }
782
783         /* now elide adjacent segments in the load map on MMU linux
784          * - on uClinux the holes between may actually be filled with system stuff or stuff from
785          *   other processes
786          */
787 #ifdef CONFIG_MMU
788         nloads = loadmap->nsegs;
789         mseg = loadmap->segs;
790         seg = mseg + 1;
791         for (loop = 1; loop < nloads; loop++) {
792                 /* see if we have a candidate for merging */
793                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
794                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
795                         if (load_addr == (seg->addr & PAGE_MASK)) {
796                                 mseg->p_memsz += load_addr - (mseg->addr + mseg->p_memsz);
797                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
798                                 mseg->p_memsz += seg->p_memsz;
799                                 loadmap->nsegs--;
800                                 continue;
801                         }
802                 }
803
804                 mseg++;
805                 if (mseg != seg)
806                         *mseg = *seg;
807         }
808 #endif
809
810         kdebug("Mapped Object [%s]:", what);
811         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
812         kdebug("- entry    : %lx", params->entry_addr);
813         kdebug("- PHDR[]   : %lx", params->ph_addr);
814         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
815         seg = loadmap->segs;
816         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
817                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
818                        loop,
819                        seg->addr, seg->addr + seg->p_memsz - 1,
820                        seg->p_vaddr, seg->p_memsz);
821
822         return 0;
823
824  dynamic_error:
825         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
826                what, file->f_dentry->d_inode->i_ino);
827         return -ELIBBAD;
828 } /* end elf_fdpic_map_file() */
829
830 /*****************************************************************************/
831 /*
832  * map a file with constant displacement under uClinux
833  */
834 #ifndef CONFIG_MMU
835 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *params,
836                                                    struct file *file,
837                                                    struct mm_struct *mm)
838 {
839         struct elf32_fdpic_loadseg *seg;
840         struct elf32_phdr *phdr;
841         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
842         loff_t fpos;
843         int loop, ret;
844
845         load_addr = params->load_addr;
846         seg = params->loadmap->segs;
847
848         /* determine the bounds of the contiguous overall allocation we must make */
849         phdr = params->phdrs;
850         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
851                 if (params->phdrs[loop].p_type != PT_LOAD)
852                         continue;
853
854                 if (base > phdr->p_vaddr)
855                         base = phdr->p_vaddr;
856                 if (top < phdr->p_vaddr + phdr->p_memsz)
857                         top = phdr->p_vaddr + phdr->p_memsz;
858         }
859
860         /* allocate one big anon block for everything */
861         mflags = MAP_PRIVATE;
862         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
863                 mflags |= MAP_EXECUTABLE;
864
865         down_write(&mm->mmap_sem);
866         maddr = do_mmap(NULL, load_addr, top - base,
867                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
868         up_write(&mm->mmap_sem);
869         if (IS_ERR((void *) maddr))
870                 return (int) maddr;
871
872         if (load_addr != 0)
873                 load_addr += PAGE_ALIGN(top - base);
874
875         /* and then load the file segments into it */
876         phdr = params->phdrs;
877         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
878                 if (params->phdrs[loop].p_type != PT_LOAD)
879                         continue;
880
881                 fpos = phdr->p_offset;
882
883                 seg->addr = maddr + (phdr->p_vaddr - base);
884                 seg->p_vaddr = phdr->p_vaddr;
885                 seg->p_memsz = phdr->p_memsz;
886
887                 ret = file->f_op->read(file, (void *) seg->addr, phdr->p_filesz, &fpos);
888                 if (ret < 0)
889                         return ret;
890
891                 /* map the ELF header address if in this segment */
892                 if (phdr->p_offset == 0)
893                         params->elfhdr_addr = seg->addr;
894
895                 /* clear any space allocated but not loaded */
896                 if (phdr->p_filesz < phdr->p_memsz)
897                         clear_user((void *) (seg->addr + phdr->p_filesz),
898                                    phdr->p_memsz - phdr->p_filesz);
899
900                 if (mm) {
901                         if (phdr->p_flags & PF_X) {
902                                 mm->start_code = seg->addr;
903                                 mm->end_code = seg->addr + phdr->p_memsz;
904                         }
905                         else if (!mm->start_data) {
906                                 mm->start_data = seg->addr;
907 #ifndef CONFIG_MMU
908                                 mm->end_data = seg->addr + phdr->p_memsz;
909 #endif
910                         }
911
912 #ifdef CONFIG_MMU
913                         if (seg->addr + phdr->p_memsz > mm->end_data)
914                                 mm->end_data = seg->addr + phdr->p_memsz;
915 #endif
916                 }
917
918                 seg++;
919         }
920
921         return 0;
922 } /* end elf_fdpic_map_file_constdisp_on_uclinux() */
923 #endif
924
925 /*****************************************************************************/
926 /*
927  * map a binary by direct mmap() of the individual PT_LOAD segments
928  */
929 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
930                                              struct file *file,
931                                              struct mm_struct *mm)
932 {
933         struct elf32_fdpic_loadseg *seg;
934         struct elf32_phdr *phdr;
935         unsigned long load_addr, delta_vaddr;
936         int loop, dvset;
937
938         load_addr = params->load_addr;
939         delta_vaddr = 0;
940         dvset = 0;
941
942         seg = params->loadmap->segs;
943
944         /* deal with each load segment separately */
945         phdr = params->phdrs;
946         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
947                 unsigned long maddr, disp, excess, excess1;
948                 int prot = 0, flags;
949
950                 if (phdr->p_type != PT_LOAD)
951                         continue;
952
953                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
954                        (unsigned long) phdr->p_vaddr,
955                        (unsigned long) phdr->p_offset,
956                        (unsigned long) phdr->p_filesz,
957                        (unsigned long) phdr->p_memsz);
958
959                 /* determine the mapping parameters */
960                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
961                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
962                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
963
964                 flags = MAP_PRIVATE | MAP_DENYWRITE;
965                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
966                         flags |= MAP_EXECUTABLE;
967
968                 maddr = 0;
969
970                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
971                 case ELF_FDPIC_FLAG_INDEPENDENT:
972                         /* PT_LOADs are independently locatable */
973                         break;
974
975                 case ELF_FDPIC_FLAG_HONOURVADDR:
976                         /* the specified virtual address must be honoured */
977                         maddr = phdr->p_vaddr;
978                         flags |= MAP_FIXED;
979                         break;
980
981                 case ELF_FDPIC_FLAG_CONSTDISP:
982                         /* constant displacement
983                          * - can be mapped anywhere, but must be mapped as a unit
984                          */
985                         if (!dvset) {
986                                 maddr = load_addr;
987                                 delta_vaddr = phdr->p_vaddr;
988                                 dvset = 1;
989                         }
990                         else {
991                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
992                                 flags |= MAP_FIXED;
993                         }
994                         break;
995
996                 case ELF_FDPIC_FLAG_CONTIGUOUS:
997                         /* contiguity handled later */
998                         break;
999
1000                 default:
1001                         BUG();
1002                 }
1003
1004                 maddr &= PAGE_MASK;
1005
1006                 /* create the mapping */
1007                 disp = phdr->p_vaddr & ~PAGE_MASK;
1008                 down_write(&mm->mmap_sem);
1009                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1010                                 phdr->p_offset - disp);
1011                 up_write(&mm->mmap_sem);
1012
1013                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1014                        loop, phdr->p_memsz + disp, prot, flags, phdr->p_offset - disp,
1015                        maddr);
1016
1017                 if (IS_ERR((void *) maddr))
1018                         return (int) maddr;
1019
1020                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == ELF_FDPIC_FLAG_CONTIGUOUS)
1021                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1022
1023                 seg->addr = maddr + disp;
1024                 seg->p_vaddr = phdr->p_vaddr;
1025                 seg->p_memsz = phdr->p_memsz;
1026
1027                 /* map the ELF header address if in this segment */
1028                 if (phdr->p_offset == 0)
1029                         params->elfhdr_addr = seg->addr;
1030
1031                 /* clear the bit between beginning of mapping and beginning of PT_LOAD */
1032                 if (prot & PROT_WRITE && disp > 0) {
1033                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1034                         clear_user((void *) maddr, disp);
1035                         maddr += disp;
1036                 }
1037
1038                 /* clear any space allocated but not loaded
1039                  * - on uClinux we can just clear the lot
1040                  * - on MMU linux we'll get a SIGBUS beyond the last page
1041                  *   extant in the file
1042                  */
1043                 excess = phdr->p_memsz - phdr->p_filesz;
1044                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1045
1046 #ifdef CONFIG_MMU
1047
1048                 if (excess > excess1) {
1049                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1050                         unsigned long xmaddr;
1051
1052                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1053                         down_write(&mm->mmap_sem);
1054                         xmaddr = do_mmap(NULL, xaddr, excess - excess1, prot, flags, 0);
1055                         up_write(&mm->mmap_sem);
1056
1057                         kdebug("mmap[%d] <anon>"
1058                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1059                                loop, xaddr, excess - excess1, prot, flags, xmaddr);
1060
1061                         if (xmaddr != xaddr)
1062                                 return -ENOMEM;
1063                 }
1064
1065                 if (prot & PROT_WRITE && excess1 > 0) {
1066                         kdebug("clear[%d] ad=%lx sz=%lx",
1067                                loop, maddr + phdr->p_filesz, excess1);
1068                         clear_user((void *) maddr + phdr->p_filesz, excess1);
1069                 }
1070
1071 #else
1072                 if (excess > 0) {
1073                         kdebug("clear[%d] ad=%lx sz=%lx",
1074                                loop, maddr + phdr->p_filesz, excess);
1075                         clear_user((void *) maddr + phdr->p_filesz, excess);
1076                 }
1077 #endif
1078
1079                 if (mm) {
1080                         if (phdr->p_flags & PF_X) {
1081                                 mm->start_code = maddr;
1082                                 mm->end_code = maddr + phdr->p_memsz;
1083                         }
1084                         else if (!mm->start_data) {
1085                                 mm->start_data = maddr;
1086                                 mm->end_data = maddr + phdr->p_memsz;
1087                         }
1088                 }
1089
1090                 seg++;
1091         }
1092
1093         return 0;
1094 } /* end elf_fdpic_map_file_by_direct_mmap() */