GFS2: Wait for unlock completion on umount
[linux-2.6.git] / fs / binfmt_elf_fdpic.c
1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
2  *
3  * Copyright (C) 2003, 2004, 2006 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/pagemap.h>
28 #include <linux/security.h>
29 #include <linux/highmem.h>
30 #include <linux/highuid.h>
31 #include <linux/personality.h>
32 #include <linux/ptrace.h>
33 #include <linux/init.h>
34 #include <linux/elf.h>
35 #include <linux/elf-fdpic.h>
36 #include <linux/elfcore.h>
37
38 #include <asm/uaccess.h>
39 #include <asm/param.h>
40 #include <asm/pgalloc.h>
41
42 typedef char *elf_caddr_t;
43
44 #if 0
45 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
46 #else
47 #define kdebug(fmt, ...) do {} while(0)
48 #endif
49
50 #if 0
51 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
52 #else
53 #define kdcore(fmt, ...) do {} while(0)
54 #endif
55
56 MODULE_LICENSE("GPL");
57
58 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
59 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
60 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
61                               struct mm_struct *, const char *);
62
63 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
64                                    struct elf_fdpic_params *,
65                                    struct elf_fdpic_params *);
66
67 #ifndef CONFIG_MMU
68 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
69                                             unsigned long *);
70 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
71                                                    struct file *,
72                                                    struct mm_struct *);
73 #endif
74
75 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
76                                              struct file *, struct mm_struct *);
77
78 #ifdef CONFIG_ELF_CORE
79 static int elf_fdpic_core_dump(struct coredump_params *cprm);
80 #endif
81
82 static struct linux_binfmt elf_fdpic_format = {
83         .module         = THIS_MODULE,
84         .load_binary    = load_elf_fdpic_binary,
85 #ifdef CONFIG_ELF_CORE
86         .core_dump      = elf_fdpic_core_dump,
87 #endif
88         .min_coredump   = ELF_EXEC_PAGESIZE,
89 };
90
91 static int __init init_elf_fdpic_binfmt(void)
92 {
93         return register_binfmt(&elf_fdpic_format);
94 }
95
96 static void __exit exit_elf_fdpic_binfmt(void)
97 {
98         unregister_binfmt(&elf_fdpic_format);
99 }
100
101 core_initcall(init_elf_fdpic_binfmt);
102 module_exit(exit_elf_fdpic_binfmt);
103
104 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
105 {
106         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
107                 return 0;
108         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
109                 return 0;
110         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
111                 return 0;
112         if (!file->f_op || !file->f_op->mmap)
113                 return 0;
114         return 1;
115 }
116
117 /*****************************************************************************/
118 /*
119  * read the program headers table into memory
120  */
121 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
122                                  struct file *file)
123 {
124         struct elf32_phdr *phdr;
125         unsigned long size;
126         int retval, loop;
127
128         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
129                 return -ENOMEM;
130         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
131                 return -ENOMEM;
132
133         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
134         params->phdrs = kmalloc(size, GFP_KERNEL);
135         if (!params->phdrs)
136                 return -ENOMEM;
137
138         retval = kernel_read(file, params->hdr.e_phoff,
139                              (char *) params->phdrs, size);
140         if (unlikely(retval != size))
141                 return retval < 0 ? retval : -ENOEXEC;
142
143         /* determine stack size for this binary */
144         phdr = params->phdrs;
145         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
146                 if (phdr->p_type != PT_GNU_STACK)
147                         continue;
148
149                 if (phdr->p_flags & PF_X)
150                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
151                 else
152                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
153
154                 params->stack_size = phdr->p_memsz;
155                 break;
156         }
157
158         return 0;
159 }
160
161 /*****************************************************************************/
162 /*
163  * load an fdpic binary into various bits of memory
164  */
165 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
166                                  struct pt_regs *regs)
167 {
168         struct elf_fdpic_params exec_params, interp_params;
169         struct elf_phdr *phdr;
170         unsigned long stack_size, entryaddr;
171 #ifdef ELF_FDPIC_PLAT_INIT
172         unsigned long dynaddr;
173 #endif
174 #ifndef CONFIG_MMU
175         unsigned long stack_prot;
176 #endif
177         struct file *interpreter = NULL; /* to shut gcc up */
178         char *interpreter_name = NULL;
179         int executable_stack;
180         int retval, i;
181
182         kdebug("____ LOAD %d ____", current->pid);
183
184         memset(&exec_params, 0, sizeof(exec_params));
185         memset(&interp_params, 0, sizeof(interp_params));
186
187         exec_params.hdr = *(struct elfhdr *) bprm->buf;
188         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
189
190         /* check that this is a binary we know how to deal with */
191         retval = -ENOEXEC;
192         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
193                 goto error;
194
195         /* read the program header table */
196         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
197         if (retval < 0)
198                 goto error;
199
200         /* scan for a program header that specifies an interpreter */
201         phdr = exec_params.phdrs;
202
203         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
204                 switch (phdr->p_type) {
205                 case PT_INTERP:
206                         retval = -ENOMEM;
207                         if (phdr->p_filesz > PATH_MAX)
208                                 goto error;
209                         retval = -ENOENT;
210                         if (phdr->p_filesz < 2)
211                                 goto error;
212
213                         /* read the name of the interpreter into memory */
214                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
215                         if (!interpreter_name)
216                                 goto error;
217
218                         retval = kernel_read(bprm->file,
219                                              phdr->p_offset,
220                                              interpreter_name,
221                                              phdr->p_filesz);
222                         if (unlikely(retval != phdr->p_filesz)) {
223                                 if (retval >= 0)
224                                         retval = -ENOEXEC;
225                                 goto error;
226                         }
227
228                         retval = -ENOENT;
229                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
230                                 goto error;
231
232                         kdebug("Using ELF interpreter %s", interpreter_name);
233
234                         /* replace the program with the interpreter */
235                         interpreter = open_exec(interpreter_name);
236                         retval = PTR_ERR(interpreter);
237                         if (IS_ERR(interpreter)) {
238                                 interpreter = NULL;
239                                 goto error;
240                         }
241
242                         /*
243                          * If the binary is not readable then enforce
244                          * mm->dumpable = 0 regardless of the interpreter's
245                          * permissions.
246                          */
247                         if (file_permission(interpreter, MAY_READ) < 0)
248                                 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
249
250                         retval = kernel_read(interpreter, 0, bprm->buf,
251                                              BINPRM_BUF_SIZE);
252                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
253                                 if (retval >= 0)
254                                         retval = -ENOEXEC;
255                                 goto error;
256                         }
257
258                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
259                         break;
260
261                 case PT_LOAD:
262 #ifdef CONFIG_MMU
263                         if (exec_params.load_addr == 0)
264                                 exec_params.load_addr = phdr->p_vaddr;
265 #endif
266                         break;
267                 }
268
269         }
270
271         if (elf_check_const_displacement(&exec_params.hdr))
272                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
273
274         /* perform insanity checks on the interpreter */
275         if (interpreter_name) {
276                 retval = -ELIBBAD;
277                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
278                         goto error;
279
280                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
281
282                 /* read the interpreter's program header table */
283                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
284                 if (retval < 0)
285                         goto error;
286         }
287
288         stack_size = exec_params.stack_size;
289         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
290                 executable_stack = EXSTACK_ENABLE_X;
291         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
292                 executable_stack = EXSTACK_DISABLE_X;
293         else
294                 executable_stack = EXSTACK_DEFAULT;
295
296         if (stack_size == 0) {
297                 stack_size = interp_params.stack_size;
298                 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
299                         executable_stack = EXSTACK_ENABLE_X;
300                 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
301                         executable_stack = EXSTACK_DISABLE_X;
302                 else
303                         executable_stack = EXSTACK_DEFAULT;
304         }
305
306         retval = -ENOEXEC;
307         if (stack_size == 0)
308                 goto error;
309
310         if (elf_check_const_displacement(&interp_params.hdr))
311                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
312
313         /* flush all traces of the currently running executable */
314         retval = flush_old_exec(bprm);
315         if (retval)
316                 goto error;
317
318         /* there's now no turning back... the old userspace image is dead,
319          * defunct, deceased, etc. after this point we have to exit via
320          * error_kill */
321         set_personality(PER_LINUX_FDPIC);
322         if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
323                 current->personality |= READ_IMPLIES_EXEC;
324
325         setup_new_exec(bprm);
326
327         set_binfmt(&elf_fdpic_format);
328
329         current->mm->start_code = 0;
330         current->mm->end_code = 0;
331         current->mm->start_stack = 0;
332         current->mm->start_data = 0;
333         current->mm->end_data = 0;
334         current->mm->context.exec_fdpic_loadmap = 0;
335         current->mm->context.interp_fdpic_loadmap = 0;
336
337         current->flags &= ~PF_FORKNOEXEC;
338
339 #ifdef CONFIG_MMU
340         elf_fdpic_arch_lay_out_mm(&exec_params,
341                                   &interp_params,
342                                   &current->mm->start_stack,
343                                   &current->mm->start_brk);
344
345         retval = setup_arg_pages(bprm, current->mm->start_stack,
346                                  executable_stack);
347         if (retval < 0) {
348                 send_sig(SIGKILL, current, 0);
349                 goto error_kill;
350         }
351 #endif
352
353         /* load the executable and interpreter into memory */
354         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
355                                     "executable");
356         if (retval < 0)
357                 goto error_kill;
358
359         if (interpreter_name) {
360                 retval = elf_fdpic_map_file(&interp_params, interpreter,
361                                             current->mm, "interpreter");
362                 if (retval < 0) {
363                         printk(KERN_ERR "Unable to load interpreter\n");
364                         goto error_kill;
365                 }
366
367                 allow_write_access(interpreter);
368                 fput(interpreter);
369                 interpreter = NULL;
370         }
371
372 #ifdef CONFIG_MMU
373         if (!current->mm->start_brk)
374                 current->mm->start_brk = current->mm->end_data;
375
376         current->mm->brk = current->mm->start_brk =
377                 PAGE_ALIGN(current->mm->start_brk);
378
379 #else
380         /* create a stack and brk area big enough for everyone
381          * - the brk heap starts at the bottom and works up
382          * - the stack starts at the top and works down
383          */
384         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
385         if (stack_size < PAGE_SIZE * 2)
386                 stack_size = PAGE_SIZE * 2;
387
388         stack_prot = PROT_READ | PROT_WRITE;
389         if (executable_stack == EXSTACK_ENABLE_X ||
390             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
391                 stack_prot |= PROT_EXEC;
392
393         down_write(&current->mm->mmap_sem);
394         current->mm->start_brk = do_mmap(NULL, 0, stack_size, stack_prot,
395                                          MAP_PRIVATE | MAP_ANONYMOUS |
396                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
397                                          0);
398
399         if (IS_ERR_VALUE(current->mm->start_brk)) {
400                 up_write(&current->mm->mmap_sem);
401                 retval = current->mm->start_brk;
402                 current->mm->start_brk = 0;
403                 goto error_kill;
404         }
405
406         up_write(&current->mm->mmap_sem);
407
408         current->mm->brk = current->mm->start_brk;
409         current->mm->context.end_brk = current->mm->start_brk;
410         current->mm->context.end_brk +=
411                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
412         current->mm->start_stack = current->mm->start_brk + stack_size;
413 #endif
414
415         install_exec_creds(bprm);
416         current->flags &= ~PF_FORKNOEXEC;
417         if (create_elf_fdpic_tables(bprm, current->mm,
418                                     &exec_params, &interp_params) < 0)
419                 goto error_kill;
420
421         kdebug("- start_code  %lx", current->mm->start_code);
422         kdebug("- end_code    %lx", current->mm->end_code);
423         kdebug("- start_data  %lx", current->mm->start_data);
424         kdebug("- end_data    %lx", current->mm->end_data);
425         kdebug("- start_brk   %lx", current->mm->start_brk);
426         kdebug("- brk         %lx", current->mm->brk);
427         kdebug("- start_stack %lx", current->mm->start_stack);
428
429 #ifdef ELF_FDPIC_PLAT_INIT
430         /*
431          * The ABI may specify that certain registers be set up in special
432          * ways (on i386 %edx is the address of a DT_FINI function, for
433          * example.  This macro performs whatever initialization to
434          * the regs structure is required.
435          */
436         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
437         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
438                             dynaddr);
439 #endif
440
441         /* everything is now ready... get the userspace context ready to roll */
442         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
443         start_thread(regs, entryaddr, current->mm->start_stack);
444
445         retval = 0;
446
447 error:
448         if (interpreter) {
449                 allow_write_access(interpreter);
450                 fput(interpreter);
451         }
452         kfree(interpreter_name);
453         kfree(exec_params.phdrs);
454         kfree(exec_params.loadmap);
455         kfree(interp_params.phdrs);
456         kfree(interp_params.loadmap);
457         return retval;
458
459         /* unrecoverable error - kill the process */
460 error_kill:
461         send_sig(SIGSEGV, current, 0);
462         goto error;
463
464 }
465
466 /*****************************************************************************/
467
468 #ifndef ELF_BASE_PLATFORM
469 /*
470  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
471  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
472  * will be copied to the user stack in the same manner as AT_PLATFORM.
473  */
474 #define ELF_BASE_PLATFORM NULL
475 #endif
476
477 /*
478  * present useful information to the program by shovelling it onto the new
479  * process's stack
480  */
481 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
482                                    struct mm_struct *mm,
483                                    struct elf_fdpic_params *exec_params,
484                                    struct elf_fdpic_params *interp_params)
485 {
486         const struct cred *cred = current_cred();
487         unsigned long sp, csp, nitems;
488         elf_caddr_t __user *argv, *envp;
489         size_t platform_len = 0, len;
490         char *k_platform, *k_base_platform;
491         char __user *u_platform, *u_base_platform, *p;
492         long hwcap;
493         int loop;
494         int nr; /* reset for each csp adjustment */
495
496 #ifdef CONFIG_MMU
497         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
498          * by the processes running on the same package. One thing we can do is
499          * to shuffle the initial stack for them, so we give the architecture
500          * an opportunity to do so here.
501          */
502         sp = arch_align_stack(bprm->p);
503 #else
504         sp = mm->start_stack;
505
506         /* stack the program arguments and environment */
507         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
508                 return -EFAULT;
509 #endif
510
511         hwcap = ELF_HWCAP;
512
513         /*
514          * If this architecture has a platform capability string, copy it
515          * to userspace.  In some cases (Sparc), this info is impossible
516          * for userspace to get any other way, in others (i386) it is
517          * merely difficult.
518          */
519         k_platform = ELF_PLATFORM;
520         u_platform = NULL;
521
522         if (k_platform) {
523                 platform_len = strlen(k_platform) + 1;
524                 sp -= platform_len;
525                 u_platform = (char __user *) sp;
526                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
527                         return -EFAULT;
528         }
529
530         /*
531          * If this architecture has a "base" platform capability
532          * string, copy it to userspace.
533          */
534         k_base_platform = ELF_BASE_PLATFORM;
535         u_base_platform = NULL;
536
537         if (k_base_platform) {
538                 platform_len = strlen(k_base_platform) + 1;
539                 sp -= platform_len;
540                 u_base_platform = (char __user *) sp;
541                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
542                         return -EFAULT;
543         }
544
545         sp &= ~7UL;
546
547         /* stack the load map(s) */
548         len = sizeof(struct elf32_fdpic_loadmap);
549         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
550         sp = (sp - len) & ~7UL;
551         exec_params->map_addr = sp;
552
553         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
554                 return -EFAULT;
555
556         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
557
558         if (interp_params->loadmap) {
559                 len = sizeof(struct elf32_fdpic_loadmap);
560                 len += sizeof(struct elf32_fdpic_loadseg) *
561                         interp_params->loadmap->nsegs;
562                 sp = (sp - len) & ~7UL;
563                 interp_params->map_addr = sp;
564
565                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
566                                  len) != 0)
567                         return -EFAULT;
568
569                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
570         }
571
572         /* force 16 byte _final_ alignment here for generality */
573 #define DLINFO_ITEMS 15
574
575         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
576                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
577
578         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
579                 nitems++;
580
581         csp = sp;
582         sp -= nitems * 2 * sizeof(unsigned long);
583         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
584         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
585         sp -= 1 * sizeof(unsigned long);                /* argc */
586
587         csp -= sp & 15UL;
588         sp -= sp & 15UL;
589
590         /* put the ELF interpreter info on the stack */
591 #define NEW_AUX_ENT(id, val)                                            \
592         do {                                                            \
593                 struct { unsigned long _id, _val; } __user *ent;        \
594                                                                         \
595                 ent = (void __user *) csp;                              \
596                 __put_user((id), &ent[nr]._id);                         \
597                 __put_user((val), &ent[nr]._val);                       \
598                 nr++;                                                   \
599         } while (0)
600
601         nr = 0;
602         csp -= 2 * sizeof(unsigned long);
603         NEW_AUX_ENT(AT_NULL, 0);
604         if (k_platform) {
605                 nr = 0;
606                 csp -= 2 * sizeof(unsigned long);
607                 NEW_AUX_ENT(AT_PLATFORM,
608                             (elf_addr_t) (unsigned long) u_platform);
609         }
610
611         if (k_base_platform) {
612                 nr = 0;
613                 csp -= 2 * sizeof(unsigned long);
614                 NEW_AUX_ENT(AT_BASE_PLATFORM,
615                             (elf_addr_t) (unsigned long) u_base_platform);
616         }
617
618         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
619                 nr = 0;
620                 csp -= 2 * sizeof(unsigned long);
621                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
622         }
623
624         nr = 0;
625         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
626         NEW_AUX_ENT(AT_HWCAP,   hwcap);
627         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
628         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
629         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
630         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
631         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
632         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
633         NEW_AUX_ENT(AT_FLAGS,   0);
634         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
635         NEW_AUX_ENT(AT_UID,     (elf_addr_t) cred->uid);
636         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) cred->euid);
637         NEW_AUX_ENT(AT_GID,     (elf_addr_t) cred->gid);
638         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) cred->egid);
639         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
640         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
641
642 #ifdef ARCH_DLINFO
643         nr = 0;
644         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
645
646         /* ARCH_DLINFO must come last so platform specific code can enforce
647          * special alignment requirements on the AUXV if necessary (eg. PPC).
648          */
649         ARCH_DLINFO;
650 #endif
651 #undef NEW_AUX_ENT
652
653         /* allocate room for argv[] and envv[] */
654         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
655         envp = (elf_caddr_t __user *) csp;
656         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
657         argv = (elf_caddr_t __user *) csp;
658
659         /* stack argc */
660         csp -= sizeof(unsigned long);
661         __put_user(bprm->argc, (unsigned long __user *) csp);
662
663         BUG_ON(csp != sp);
664
665         /* fill in the argv[] array */
666 #ifdef CONFIG_MMU
667         current->mm->arg_start = bprm->p;
668 #else
669         current->mm->arg_start = current->mm->start_stack -
670                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
671 #endif
672
673         p = (char __user *) current->mm->arg_start;
674         for (loop = bprm->argc; loop > 0; loop--) {
675                 __put_user((elf_caddr_t) p, argv++);
676                 len = strnlen_user(p, MAX_ARG_STRLEN);
677                 if (!len || len > MAX_ARG_STRLEN)
678                         return -EINVAL;
679                 p += len;
680         }
681         __put_user(NULL, argv);
682         current->mm->arg_end = (unsigned long) p;
683
684         /* fill in the envv[] array */
685         current->mm->env_start = (unsigned long) p;
686         for (loop = bprm->envc; loop > 0; loop--) {
687                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
688                 len = strnlen_user(p, MAX_ARG_STRLEN);
689                 if (!len || len > MAX_ARG_STRLEN)
690                         return -EINVAL;
691                 p += len;
692         }
693         __put_user(NULL, envp);
694         current->mm->env_end = (unsigned long) p;
695
696         mm->start_stack = (unsigned long) sp;
697         return 0;
698 }
699
700 /*****************************************************************************/
701 /*
702  * transfer the program arguments and environment from the holding pages onto
703  * the stack
704  */
705 #ifndef CONFIG_MMU
706 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
707                                             unsigned long *_sp)
708 {
709         unsigned long index, stop, sp;
710         char *src;
711         int ret = 0;
712
713         stop = bprm->p >> PAGE_SHIFT;
714         sp = *_sp;
715
716         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
717                 src = kmap(bprm->page[index]);
718                 sp -= PAGE_SIZE;
719                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
720                         ret = -EFAULT;
721                 kunmap(bprm->page[index]);
722                 if (ret < 0)
723                         goto out;
724         }
725
726         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
727
728 out:
729         return ret;
730 }
731 #endif
732
733 /*****************************************************************************/
734 /*
735  * load the appropriate binary image (executable or interpreter) into memory
736  * - we assume no MMU is available
737  * - if no other PIC bits are set in params->hdr->e_flags
738  *   - we assume that the LOADable segments in the binary are independently relocatable
739  *   - we assume R/O executable segments are shareable
740  * - else
741  *   - we assume the loadable parts of the image to require fixed displacement
742  *   - the image is not shareable
743  */
744 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
745                               struct file *file,
746                               struct mm_struct *mm,
747                               const char *what)
748 {
749         struct elf32_fdpic_loadmap *loadmap;
750 #ifdef CONFIG_MMU
751         struct elf32_fdpic_loadseg *mseg;
752 #endif
753         struct elf32_fdpic_loadseg *seg;
754         struct elf32_phdr *phdr;
755         unsigned long load_addr, stop;
756         unsigned nloads, tmp;
757         size_t size;
758         int loop, ret;
759
760         /* allocate a load map table */
761         nloads = 0;
762         for (loop = 0; loop < params->hdr.e_phnum; loop++)
763                 if (params->phdrs[loop].p_type == PT_LOAD)
764                         nloads++;
765
766         if (nloads == 0)
767                 return -ELIBBAD;
768
769         size = sizeof(*loadmap) + nloads * sizeof(*seg);
770         loadmap = kzalloc(size, GFP_KERNEL);
771         if (!loadmap)
772                 return -ENOMEM;
773
774         params->loadmap = loadmap;
775
776         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
777         loadmap->nsegs = nloads;
778
779         load_addr = params->load_addr;
780         seg = loadmap->segs;
781
782         /* map the requested LOADs into the memory space */
783         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
784         case ELF_FDPIC_FLAG_CONSTDISP:
785         case ELF_FDPIC_FLAG_CONTIGUOUS:
786 #ifndef CONFIG_MMU
787                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
788                 if (ret < 0)
789                         return ret;
790                 break;
791 #endif
792         default:
793                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
794                 if (ret < 0)
795                         return ret;
796                 break;
797         }
798
799         /* map the entry point */
800         if (params->hdr.e_entry) {
801                 seg = loadmap->segs;
802                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
803                         if (params->hdr.e_entry >= seg->p_vaddr &&
804                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
805                                 params->entry_addr =
806                                         (params->hdr.e_entry - seg->p_vaddr) +
807                                         seg->addr;
808                                 break;
809                         }
810                 }
811         }
812
813         /* determine where the program header table has wound up if mapped */
814         stop = params->hdr.e_phoff;
815         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
816         phdr = params->phdrs;
817
818         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
819                 if (phdr->p_type != PT_LOAD)
820                         continue;
821
822                 if (phdr->p_offset > params->hdr.e_phoff ||
823                     phdr->p_offset + phdr->p_filesz < stop)
824                         continue;
825
826                 seg = loadmap->segs;
827                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
828                         if (phdr->p_vaddr >= seg->p_vaddr &&
829                             phdr->p_vaddr + phdr->p_filesz <=
830                             seg->p_vaddr + seg->p_memsz) {
831                                 params->ph_addr =
832                                         (phdr->p_vaddr - seg->p_vaddr) +
833                                         seg->addr +
834                                         params->hdr.e_phoff - phdr->p_offset;
835                                 break;
836                         }
837                 }
838                 break;
839         }
840
841         /* determine where the dynamic section has wound up if there is one */
842         phdr = params->phdrs;
843         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
844                 if (phdr->p_type != PT_DYNAMIC)
845                         continue;
846
847                 seg = loadmap->segs;
848                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
849                         if (phdr->p_vaddr >= seg->p_vaddr &&
850                             phdr->p_vaddr + phdr->p_memsz <=
851                             seg->p_vaddr + seg->p_memsz) {
852                                 params->dynamic_addr =
853                                         (phdr->p_vaddr - seg->p_vaddr) +
854                                         seg->addr;
855
856                                 /* check the dynamic section contains at least
857                                  * one item, and that the last item is a NULL
858                                  * entry */
859                                 if (phdr->p_memsz == 0 ||
860                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
861                                         goto dynamic_error;
862
863                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
864                                 if (((Elf32_Dyn *)
865                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
866                                         goto dynamic_error;
867                                 break;
868                         }
869                 }
870                 break;
871         }
872
873         /* now elide adjacent segments in the load map on MMU linux
874          * - on uClinux the holes between may actually be filled with system
875          *   stuff or stuff from other processes
876          */
877 #ifdef CONFIG_MMU
878         nloads = loadmap->nsegs;
879         mseg = loadmap->segs;
880         seg = mseg + 1;
881         for (loop = 1; loop < nloads; loop++) {
882                 /* see if we have a candidate for merging */
883                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
884                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
885                         if (load_addr == (seg->addr & PAGE_MASK)) {
886                                 mseg->p_memsz +=
887                                         load_addr -
888                                         (mseg->addr + mseg->p_memsz);
889                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
890                                 mseg->p_memsz += seg->p_memsz;
891                                 loadmap->nsegs--;
892                                 continue;
893                         }
894                 }
895
896                 mseg++;
897                 if (mseg != seg)
898                         *mseg = *seg;
899         }
900 #endif
901
902         kdebug("Mapped Object [%s]:", what);
903         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
904         kdebug("- entry    : %lx", params->entry_addr);
905         kdebug("- PHDR[]   : %lx", params->ph_addr);
906         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
907         seg = loadmap->segs;
908         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
909                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
910                        loop,
911                        seg->addr, seg->addr + seg->p_memsz - 1,
912                        seg->p_vaddr, seg->p_memsz);
913
914         return 0;
915
916 dynamic_error:
917         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
918                what, file->f_path.dentry->d_inode->i_ino);
919         return -ELIBBAD;
920 }
921
922 /*****************************************************************************/
923 /*
924  * map a file with constant displacement under uClinux
925  */
926 #ifndef CONFIG_MMU
927 static int elf_fdpic_map_file_constdisp_on_uclinux(
928         struct elf_fdpic_params *params,
929         struct file *file,
930         struct mm_struct *mm)
931 {
932         struct elf32_fdpic_loadseg *seg;
933         struct elf32_phdr *phdr;
934         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
935         loff_t fpos;
936         int loop, ret;
937
938         load_addr = params->load_addr;
939         seg = params->loadmap->segs;
940
941         /* determine the bounds of the contiguous overall allocation we must
942          * make */
943         phdr = params->phdrs;
944         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
945                 if (params->phdrs[loop].p_type != PT_LOAD)
946                         continue;
947
948                 if (base > phdr->p_vaddr)
949                         base = phdr->p_vaddr;
950                 if (top < phdr->p_vaddr + phdr->p_memsz)
951                         top = phdr->p_vaddr + phdr->p_memsz;
952         }
953
954         /* allocate one big anon block for everything */
955         mflags = MAP_PRIVATE;
956         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
957                 mflags |= MAP_EXECUTABLE;
958
959         down_write(&mm->mmap_sem);
960         maddr = do_mmap(NULL, load_addr, top - base,
961                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
962         up_write(&mm->mmap_sem);
963         if (IS_ERR_VALUE(maddr))
964                 return (int) maddr;
965
966         if (load_addr != 0)
967                 load_addr += PAGE_ALIGN(top - base);
968
969         /* and then load the file segments into it */
970         phdr = params->phdrs;
971         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
972                 if (params->phdrs[loop].p_type != PT_LOAD)
973                         continue;
974
975                 fpos = phdr->p_offset;
976
977                 seg->addr = maddr + (phdr->p_vaddr - base);
978                 seg->p_vaddr = phdr->p_vaddr;
979                 seg->p_memsz = phdr->p_memsz;
980
981                 ret = file->f_op->read(file, (void *) seg->addr,
982                                        phdr->p_filesz, &fpos);
983                 if (ret < 0)
984                         return ret;
985
986                 /* map the ELF header address if in this segment */
987                 if (phdr->p_offset == 0)
988                         params->elfhdr_addr = seg->addr;
989
990                 /* clear any space allocated but not loaded */
991                 if (phdr->p_filesz < phdr->p_memsz) {
992                         ret = clear_user((void *) (seg->addr + phdr->p_filesz),
993                                          phdr->p_memsz - phdr->p_filesz);
994                         if (ret)
995                                 return ret;
996                 }
997
998                 if (mm) {
999                         if (phdr->p_flags & PF_X) {
1000                                 if (!mm->start_code) {
1001                                         mm->start_code = seg->addr;
1002                                         mm->end_code = seg->addr +
1003                                                 phdr->p_memsz;
1004                                 }
1005                         } else if (!mm->start_data) {
1006                                 mm->start_data = seg->addr;
1007 #ifndef CONFIG_MMU
1008                                 mm->end_data = seg->addr + phdr->p_memsz;
1009 #endif
1010                         }
1011
1012 #ifdef CONFIG_MMU
1013                         if (seg->addr + phdr->p_memsz > mm->end_data)
1014                                 mm->end_data = seg->addr + phdr->p_memsz;
1015 #endif
1016                 }
1017
1018                 seg++;
1019         }
1020
1021         return 0;
1022 }
1023 #endif
1024
1025 /*****************************************************************************/
1026 /*
1027  * map a binary by direct mmap() of the individual PT_LOAD segments
1028  */
1029 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1030                                              struct file *file,
1031                                              struct mm_struct *mm)
1032 {
1033         struct elf32_fdpic_loadseg *seg;
1034         struct elf32_phdr *phdr;
1035         unsigned long load_addr, delta_vaddr;
1036         int loop, dvset, ret;
1037
1038         load_addr = params->load_addr;
1039         delta_vaddr = 0;
1040         dvset = 0;
1041
1042         seg = params->loadmap->segs;
1043
1044         /* deal with each load segment separately */
1045         phdr = params->phdrs;
1046         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1047                 unsigned long maddr, disp, excess, excess1;
1048                 int prot = 0, flags;
1049
1050                 if (phdr->p_type != PT_LOAD)
1051                         continue;
1052
1053                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1054                        (unsigned long) phdr->p_vaddr,
1055                        (unsigned long) phdr->p_offset,
1056                        (unsigned long) phdr->p_filesz,
1057                        (unsigned long) phdr->p_memsz);
1058
1059                 /* determine the mapping parameters */
1060                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1061                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1062                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1063
1064                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1065                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1066                         flags |= MAP_EXECUTABLE;
1067
1068                 maddr = 0;
1069
1070                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1071                 case ELF_FDPIC_FLAG_INDEPENDENT:
1072                         /* PT_LOADs are independently locatable */
1073                         break;
1074
1075                 case ELF_FDPIC_FLAG_HONOURVADDR:
1076                         /* the specified virtual address must be honoured */
1077                         maddr = phdr->p_vaddr;
1078                         flags |= MAP_FIXED;
1079                         break;
1080
1081                 case ELF_FDPIC_FLAG_CONSTDISP:
1082                         /* constant displacement
1083                          * - can be mapped anywhere, but must be mapped as a
1084                          *   unit
1085                          */
1086                         if (!dvset) {
1087                                 maddr = load_addr;
1088                                 delta_vaddr = phdr->p_vaddr;
1089                                 dvset = 1;
1090                         } else {
1091                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1092                                 flags |= MAP_FIXED;
1093                         }
1094                         break;
1095
1096                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1097                         /* contiguity handled later */
1098                         break;
1099
1100                 default:
1101                         BUG();
1102                 }
1103
1104                 maddr &= PAGE_MASK;
1105
1106                 /* create the mapping */
1107                 disp = phdr->p_vaddr & ~PAGE_MASK;
1108                 down_write(&mm->mmap_sem);
1109                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1110                                 phdr->p_offset - disp);
1111                 up_write(&mm->mmap_sem);
1112
1113                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1114                        loop, phdr->p_memsz + disp, prot, flags,
1115                        phdr->p_offset - disp, maddr);
1116
1117                 if (IS_ERR_VALUE(maddr))
1118                         return (int) maddr;
1119
1120                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1121                     ELF_FDPIC_FLAG_CONTIGUOUS)
1122                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1123
1124                 seg->addr = maddr + disp;
1125                 seg->p_vaddr = phdr->p_vaddr;
1126                 seg->p_memsz = phdr->p_memsz;
1127
1128                 /* map the ELF header address if in this segment */
1129                 if (phdr->p_offset == 0)
1130                         params->elfhdr_addr = seg->addr;
1131
1132                 /* clear the bit between beginning of mapping and beginning of
1133                  * PT_LOAD */
1134                 if (prot & PROT_WRITE && disp > 0) {
1135                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1136                         ret = clear_user((void __user *) maddr, disp);
1137                         if (ret)
1138                                 return ret;
1139                         maddr += disp;
1140                 }
1141
1142                 /* clear any space allocated but not loaded
1143                  * - on uClinux we can just clear the lot
1144                  * - on MMU linux we'll get a SIGBUS beyond the last page
1145                  *   extant in the file
1146                  */
1147                 excess = phdr->p_memsz - phdr->p_filesz;
1148                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1149
1150 #ifdef CONFIG_MMU
1151                 if (excess > excess1) {
1152                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1153                         unsigned long xmaddr;
1154
1155                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1156                         down_write(&mm->mmap_sem);
1157                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1158                                          prot, flags, 0);
1159                         up_write(&mm->mmap_sem);
1160
1161                         kdebug("mmap[%d] <anon>"
1162                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1163                                loop, xaddr, excess - excess1, prot, flags,
1164                                xmaddr);
1165
1166                         if (xmaddr != xaddr)
1167                                 return -ENOMEM;
1168                 }
1169
1170                 if (prot & PROT_WRITE && excess1 > 0) {
1171                         kdebug("clear[%d] ad=%lx sz=%lx",
1172                                loop, maddr + phdr->p_filesz, excess1);
1173                         ret = clear_user((void __user *) maddr + phdr->p_filesz,
1174                                          excess1);
1175                         if (ret)
1176                                 return ret;
1177                 }
1178
1179 #else
1180                 if (excess > 0) {
1181                         kdebug("clear[%d] ad=%lx sz=%lx",
1182                                loop, maddr + phdr->p_filesz, excess);
1183                         ret = clear_user((void *) maddr + phdr->p_filesz, excess);
1184                         if (ret)
1185                                 return ret;
1186                 }
1187 #endif
1188
1189                 if (mm) {
1190                         if (phdr->p_flags & PF_X) {
1191                                 if (!mm->start_code) {
1192                                         mm->start_code = maddr;
1193                                         mm->end_code = maddr + phdr->p_memsz;
1194                                 }
1195                         } else if (!mm->start_data) {
1196                                 mm->start_data = maddr;
1197                                 mm->end_data = maddr + phdr->p_memsz;
1198                         }
1199                 }
1200
1201                 seg++;
1202         }
1203
1204         return 0;
1205 }
1206
1207 /*****************************************************************************/
1208 /*
1209  * ELF-FDPIC core dumper
1210  *
1211  * Modelled on fs/exec.c:aout_core_dump()
1212  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1213  *
1214  * Modelled on fs/binfmt_elf.c core dumper
1215  */
1216 #ifdef CONFIG_ELF_CORE
1217
1218 /*
1219  * These are the only things you should do on a core-file: use only these
1220  * functions to write out all the necessary info.
1221  */
1222 static int dump_write(struct file *file, const void *addr, int nr)
1223 {
1224         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1225 }
1226
1227 static int dump_seek(struct file *file, loff_t off)
1228 {
1229         if (file->f_op->llseek) {
1230                 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1231                         return 0;
1232         } else {
1233                 file->f_pos = off;
1234         }
1235         return 1;
1236 }
1237
1238 /*
1239  * Decide whether a segment is worth dumping; default is yes to be
1240  * sure (missing info is worse than too much; etc).
1241  * Personally I'd include everything, and use the coredump limit...
1242  *
1243  * I think we should skip something. But I am not sure how. H.J.
1244  */
1245 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1246 {
1247         int dump_ok;
1248
1249         /* Do not dump I/O mapped devices or special mappings */
1250         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1251                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1252                 return 0;
1253         }
1254
1255         /* If we may not read the contents, don't allow us to dump
1256          * them either. "dump_write()" can't handle it anyway.
1257          */
1258         if (!(vma->vm_flags & VM_READ)) {
1259                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1260                 return 0;
1261         }
1262
1263         /* By default, dump shared memory if mapped from an anonymous file. */
1264         if (vma->vm_flags & VM_SHARED) {
1265                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1266                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1267                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1268                                vma->vm_flags, dump_ok ? "yes" : "no");
1269                         return dump_ok;
1270                 }
1271
1272                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1273                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1274                        vma->vm_flags, dump_ok ? "yes" : "no");
1275                 return dump_ok;
1276         }
1277
1278 #ifdef CONFIG_MMU
1279         /* By default, if it hasn't been written to, don't write it out */
1280         if (!vma->anon_vma) {
1281                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1282                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1283                        vma->vm_flags, dump_ok ? "yes" : "no");
1284                 return dump_ok;
1285         }
1286 #endif
1287
1288         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1289         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1290                dump_ok ? "yes" : "no");
1291         return dump_ok;
1292 }
1293
1294 /* An ELF note in memory */
1295 struct memelfnote
1296 {
1297         const char *name;
1298         int type;
1299         unsigned int datasz;
1300         void *data;
1301 };
1302
1303 static int notesize(struct memelfnote *en)
1304 {
1305         int sz;
1306
1307         sz = sizeof(struct elf_note);
1308         sz += roundup(strlen(en->name) + 1, 4);
1309         sz += roundup(en->datasz, 4);
1310
1311         return sz;
1312 }
1313
1314 /* #define DEBUG */
1315
1316 #define DUMP_WRITE(addr, nr)    \
1317         do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1318 #define DUMP_SEEK(off)  \
1319         do { if (!dump_seek(file, (off))) return 0; } while(0)
1320
1321 static int writenote(struct memelfnote *men, struct file *file)
1322 {
1323         struct elf_note en;
1324
1325         en.n_namesz = strlen(men->name) + 1;
1326         en.n_descsz = men->datasz;
1327         en.n_type = men->type;
1328
1329         DUMP_WRITE(&en, sizeof(en));
1330         DUMP_WRITE(men->name, en.n_namesz);
1331         /* XXX - cast from long long to long to avoid need for libgcc.a */
1332         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1333         DUMP_WRITE(men->data, men->datasz);
1334         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1335
1336         return 1;
1337 }
1338 #undef DUMP_WRITE
1339 #undef DUMP_SEEK
1340
1341 #define DUMP_WRITE(addr, nr)                            \
1342         if ((size += (nr)) > cprm->limit ||             \
1343             !dump_write(cprm->file, (addr), (nr)))      \
1344                 goto end_coredump;
1345
1346 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1347 {
1348         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1349         elf->e_ident[EI_CLASS] = ELF_CLASS;
1350         elf->e_ident[EI_DATA] = ELF_DATA;
1351         elf->e_ident[EI_VERSION] = EV_CURRENT;
1352         elf->e_ident[EI_OSABI] = ELF_OSABI;
1353         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1354
1355         elf->e_type = ET_CORE;
1356         elf->e_machine = ELF_ARCH;
1357         elf->e_version = EV_CURRENT;
1358         elf->e_entry = 0;
1359         elf->e_phoff = sizeof(struct elfhdr);
1360         elf->e_shoff = 0;
1361         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1362         elf->e_ehsize = sizeof(struct elfhdr);
1363         elf->e_phentsize = sizeof(struct elf_phdr);
1364         elf->e_phnum = segs;
1365         elf->e_shentsize = 0;
1366         elf->e_shnum = 0;
1367         elf->e_shstrndx = 0;
1368         return;
1369 }
1370
1371 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1372 {
1373         phdr->p_type = PT_NOTE;
1374         phdr->p_offset = offset;
1375         phdr->p_vaddr = 0;
1376         phdr->p_paddr = 0;
1377         phdr->p_filesz = sz;
1378         phdr->p_memsz = 0;
1379         phdr->p_flags = 0;
1380         phdr->p_align = 0;
1381         return;
1382 }
1383
1384 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1385                 unsigned int sz, void *data)
1386 {
1387         note->name = name;
1388         note->type = type;
1389         note->datasz = sz;
1390         note->data = data;
1391         return;
1392 }
1393
1394 /*
1395  * fill up all the fields in prstatus from the given task struct, except
1396  * registers which need to be filled up seperately.
1397  */
1398 static void fill_prstatus(struct elf_prstatus *prstatus,
1399                           struct task_struct *p, long signr)
1400 {
1401         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1402         prstatus->pr_sigpend = p->pending.signal.sig[0];
1403         prstatus->pr_sighold = p->blocked.sig[0];
1404         rcu_read_lock();
1405         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1406         rcu_read_unlock();
1407         prstatus->pr_pid = task_pid_vnr(p);
1408         prstatus->pr_pgrp = task_pgrp_vnr(p);
1409         prstatus->pr_sid = task_session_vnr(p);
1410         if (thread_group_leader(p)) {
1411                 struct task_cputime cputime;
1412
1413                 /*
1414                  * This is the record for the group leader.  It shows the
1415                  * group-wide total, not its individual thread total.
1416                  */
1417                 thread_group_cputime(p, &cputime);
1418                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1419                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1420         } else {
1421                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1422                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1423         }
1424         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1425         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1426
1427         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1428         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1429 }
1430
1431 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1432                        struct mm_struct *mm)
1433 {
1434         const struct cred *cred;
1435         unsigned int i, len;
1436
1437         /* first copy the parameters from user space */
1438         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1439
1440         len = mm->arg_end - mm->arg_start;
1441         if (len >= ELF_PRARGSZ)
1442                 len = ELF_PRARGSZ - 1;
1443         if (copy_from_user(&psinfo->pr_psargs,
1444                            (const char __user *) mm->arg_start, len))
1445                 return -EFAULT;
1446         for (i = 0; i < len; i++)
1447                 if (psinfo->pr_psargs[i] == 0)
1448                         psinfo->pr_psargs[i] = ' ';
1449         psinfo->pr_psargs[len] = 0;
1450
1451         rcu_read_lock();
1452         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1453         rcu_read_unlock();
1454         psinfo->pr_pid = task_pid_vnr(p);
1455         psinfo->pr_pgrp = task_pgrp_vnr(p);
1456         psinfo->pr_sid = task_session_vnr(p);
1457
1458         i = p->state ? ffz(~p->state) + 1 : 0;
1459         psinfo->pr_state = i;
1460         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1461         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1462         psinfo->pr_nice = task_nice(p);
1463         psinfo->pr_flag = p->flags;
1464         rcu_read_lock();
1465         cred = __task_cred(p);
1466         SET_UID(psinfo->pr_uid, cred->uid);
1467         SET_GID(psinfo->pr_gid, cred->gid);
1468         rcu_read_unlock();
1469         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1470
1471         return 0;
1472 }
1473
1474 /* Here is the structure in which status of each thread is captured. */
1475 struct elf_thread_status
1476 {
1477         struct list_head list;
1478         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1479         elf_fpregset_t fpu;             /* NT_PRFPREG */
1480         struct task_struct *thread;
1481 #ifdef ELF_CORE_COPY_XFPREGS
1482         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1483 #endif
1484         struct memelfnote notes[3];
1485         int num_notes;
1486 };
1487
1488 /*
1489  * In order to add the specific thread information for the elf file format,
1490  * we need to keep a linked list of every thread's pr_status and then create
1491  * a single section for them in the final core file.
1492  */
1493 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1494 {
1495         struct task_struct *p = t->thread;
1496         int sz = 0;
1497
1498         t->num_notes = 0;
1499
1500         fill_prstatus(&t->prstatus, p, signr);
1501         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1502
1503         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1504                   &t->prstatus);
1505         t->num_notes++;
1506         sz += notesize(&t->notes[0]);
1507
1508         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1509         if (t->prstatus.pr_fpvalid) {
1510                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1511                           &t->fpu);
1512                 t->num_notes++;
1513                 sz += notesize(&t->notes[1]);
1514         }
1515
1516 #ifdef ELF_CORE_COPY_XFPREGS
1517         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1518                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1519                           sizeof(t->xfpu), &t->xfpu);
1520                 t->num_notes++;
1521                 sz += notesize(&t->notes[2]);
1522         }
1523 #endif
1524         return sz;
1525 }
1526
1527 /*
1528  * dump the segments for an MMU process
1529  */
1530 #ifdef CONFIG_MMU
1531 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1532                            unsigned long *limit, unsigned long mm_flags)
1533 {
1534         struct vm_area_struct *vma;
1535         int err = 0;
1536
1537         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1538                 unsigned long addr;
1539
1540                 if (!maydump(vma, mm_flags))
1541                         continue;
1542
1543                 for (addr = vma->vm_start; addr < vma->vm_end;
1544                                                         addr += PAGE_SIZE) {
1545                         struct page *page = get_dump_page(addr);
1546                         if (page) {
1547                                 void *kaddr = kmap(page);
1548                                 *size += PAGE_SIZE;
1549                                 if (*size > *limit)
1550                                         err = -EFBIG;
1551                                 else if (!dump_write(file, kaddr, PAGE_SIZE))
1552                                         err = -EIO;
1553                                 kunmap(page);
1554                                 page_cache_release(page);
1555                         } else if (!dump_seek(file, file->f_pos + PAGE_SIZE))
1556                                 err = -EFBIG;
1557                         if (err)
1558                                 goto out;
1559                 }
1560         }
1561 out:
1562         return err;
1563 }
1564 #endif
1565
1566 /*
1567  * dump the segments for a NOMMU process
1568  */
1569 #ifndef CONFIG_MMU
1570 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1571                            unsigned long *limit, unsigned long mm_flags)
1572 {
1573         struct vm_area_struct *vma;
1574
1575         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1576                 if (!maydump(vma, mm_flags))
1577                         continue;
1578
1579                 if ((*size += PAGE_SIZE) > *limit)
1580                         return -EFBIG;
1581
1582                 if (!dump_write(file, (void *) vma->vm_start,
1583                                 vma->vm_end - vma->vm_start))
1584                         return -EIO;
1585         }
1586
1587         return 0;
1588 }
1589 #endif
1590
1591 /*
1592  * Actual dumper
1593  *
1594  * This is a two-pass process; first we find the offsets of the bits,
1595  * and then they are actually written out.  If we run out of core limit
1596  * we just truncate.
1597  */
1598 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1599 {
1600 #define NUM_NOTES       6
1601         int has_dumped = 0;
1602         mm_segment_t fs;
1603         int segs;
1604         size_t size = 0;
1605         int i;
1606         struct vm_area_struct *vma;
1607         struct elfhdr *elf = NULL;
1608         loff_t offset = 0, dataoff;
1609         int numnote;
1610         struct memelfnote *notes = NULL;
1611         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1612         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1613         LIST_HEAD(thread_list);
1614         struct list_head *t;
1615         elf_fpregset_t *fpu = NULL;
1616 #ifdef ELF_CORE_COPY_XFPREGS
1617         elf_fpxregset_t *xfpu = NULL;
1618 #endif
1619         int thread_status_size = 0;
1620         elf_addr_t *auxv;
1621         unsigned long mm_flags;
1622
1623         /*
1624          * We no longer stop all VM operations.
1625          *
1626          * This is because those proceses that could possibly change map_count
1627          * or the mmap / vma pages are now blocked in do_exit on current
1628          * finishing this core dump.
1629          *
1630          * Only ptrace can touch these memory addresses, but it doesn't change
1631          * the map_count or the pages allocated. So no possibility of crashing
1632          * exists while dumping the mm->vm_next areas to the core file.
1633          */
1634
1635         /* alloc memory for large data structures: too large to be on stack */
1636         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1637         if (!elf)
1638                 goto cleanup;
1639         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1640         if (!prstatus)
1641                 goto cleanup;
1642         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1643         if (!psinfo)
1644                 goto cleanup;
1645         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1646         if (!notes)
1647                 goto cleanup;
1648         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1649         if (!fpu)
1650                 goto cleanup;
1651 #ifdef ELF_CORE_COPY_XFPREGS
1652         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1653         if (!xfpu)
1654                 goto cleanup;
1655 #endif
1656
1657         if (cprm->signr) {
1658                 struct core_thread *ct;
1659                 struct elf_thread_status *tmp;
1660
1661                 for (ct = current->mm->core_state->dumper.next;
1662                                                 ct; ct = ct->next) {
1663                         tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1664                         if (!tmp)
1665                                 goto cleanup;
1666
1667                         tmp->thread = ct->task;
1668                         list_add(&tmp->list, &thread_list);
1669                 }
1670
1671                 list_for_each(t, &thread_list) {
1672                         struct elf_thread_status *tmp;
1673                         int sz;
1674
1675                         tmp = list_entry(t, struct elf_thread_status, list);
1676                         sz = elf_dump_thread_status(cprm->signr, tmp);
1677                         thread_status_size += sz;
1678                 }
1679         }
1680
1681         /* now collect the dump for the current */
1682         fill_prstatus(prstatus, current, cprm->signr);
1683         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1684
1685         segs = current->mm->map_count;
1686 #ifdef ELF_CORE_EXTRA_PHDRS
1687         segs += ELF_CORE_EXTRA_PHDRS;
1688 #endif
1689
1690         /* Set up header */
1691         fill_elf_fdpic_header(elf, segs + 1);   /* including notes section */
1692
1693         has_dumped = 1;
1694         current->flags |= PF_DUMPCORE;
1695
1696         /*
1697          * Set up the notes in similar form to SVR4 core dumps made
1698          * with info from their /proc.
1699          */
1700
1701         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1702         fill_psinfo(psinfo, current->group_leader, current->mm);
1703         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1704
1705         numnote = 2;
1706
1707         auxv = (elf_addr_t *) current->mm->saved_auxv;
1708
1709         i = 0;
1710         do
1711                 i += 2;
1712         while (auxv[i - 2] != AT_NULL);
1713         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1714                   i * sizeof(elf_addr_t), auxv);
1715
1716         /* Try to dump the FPU. */
1717         if ((prstatus->pr_fpvalid =
1718              elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1719                 fill_note(notes + numnote++,
1720                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1721 #ifdef ELF_CORE_COPY_XFPREGS
1722         if (elf_core_copy_task_xfpregs(current, xfpu))
1723                 fill_note(notes + numnote++,
1724                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1725 #endif
1726
1727         fs = get_fs();
1728         set_fs(KERNEL_DS);
1729
1730         DUMP_WRITE(elf, sizeof(*elf));
1731         offset += sizeof(*elf);                         /* Elf header */
1732         offset += (segs+1) * sizeof(struct elf_phdr);   /* Program headers */
1733
1734         /* Write notes phdr entry */
1735         {
1736                 struct elf_phdr phdr;
1737                 int sz = 0;
1738
1739                 for (i = 0; i < numnote; i++)
1740                         sz += notesize(notes + i);
1741
1742                 sz += thread_status_size;
1743
1744                 fill_elf_note_phdr(&phdr, sz, offset);
1745                 offset += sz;
1746                 DUMP_WRITE(&phdr, sizeof(phdr));
1747         }
1748
1749         /* Page-align dumped data */
1750         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1751
1752         /*
1753          * We must use the same mm->flags while dumping core to avoid
1754          * inconsistency between the program headers and bodies, otherwise an
1755          * unusable core file can be generated.
1756          */
1757         mm_flags = current->mm->flags;
1758
1759         /* write program headers for segments dump */
1760         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1761                 struct elf_phdr phdr;
1762                 size_t sz;
1763
1764                 sz = vma->vm_end - vma->vm_start;
1765
1766                 phdr.p_type = PT_LOAD;
1767                 phdr.p_offset = offset;
1768                 phdr.p_vaddr = vma->vm_start;
1769                 phdr.p_paddr = 0;
1770                 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1771                 phdr.p_memsz = sz;
1772                 offset += phdr.p_filesz;
1773                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1774                 if (vma->vm_flags & VM_WRITE)
1775                         phdr.p_flags |= PF_W;
1776                 if (vma->vm_flags & VM_EXEC)
1777                         phdr.p_flags |= PF_X;
1778                 phdr.p_align = ELF_EXEC_PAGESIZE;
1779
1780                 DUMP_WRITE(&phdr, sizeof(phdr));
1781         }
1782
1783 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1784         ELF_CORE_WRITE_EXTRA_PHDRS;
1785 #endif
1786
1787         /* write out the notes section */
1788         for (i = 0; i < numnote; i++)
1789                 if (!writenote(notes + i, cprm->file))
1790                         goto end_coredump;
1791
1792         /* write out the thread status notes section */
1793         list_for_each(t, &thread_list) {
1794                 struct elf_thread_status *tmp =
1795                                 list_entry(t, struct elf_thread_status, list);
1796
1797                 for (i = 0; i < tmp->num_notes; i++)
1798                         if (!writenote(&tmp->notes[i], cprm->file))
1799                                 goto end_coredump;
1800         }
1801
1802         if (!dump_seek(cprm->file, dataoff))
1803                 goto end_coredump;
1804
1805         if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit,
1806                                     mm_flags) < 0)
1807                 goto end_coredump;
1808
1809 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1810         ELF_CORE_WRITE_EXTRA_DATA;
1811 #endif
1812
1813         if (cprm->file->f_pos != offset) {
1814                 /* Sanity check */
1815                 printk(KERN_WARNING
1816                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1817                        cprm->file->f_pos, offset);
1818         }
1819
1820 end_coredump:
1821         set_fs(fs);
1822
1823 cleanup:
1824         while (!list_empty(&thread_list)) {
1825                 struct list_head *tmp = thread_list.next;
1826                 list_del(tmp);
1827                 kfree(list_entry(tmp, struct elf_thread_status, list));
1828         }
1829
1830         kfree(elf);
1831         kfree(prstatus);
1832         kfree(psinfo);
1833         kfree(notes);
1834         kfree(fpu);
1835 #ifdef ELF_CORE_COPY_XFPREGS
1836         kfree(xfpu);
1837 #endif
1838         return has_dumped;
1839 #undef NUM_NOTES
1840 }
1841
1842 #endif          /* CONFIG_ELF_CORE */