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Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab...
[karo-tx-linux.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 #include <linux/coredump.h>
38
39 #include <asm/uaccess.h>
40 #include <asm/param.h>
41 #include <asm/pgalloc.h>
42
43 typedef char *elf_caddr_t;
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 #if 0
52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
53 #else
54 #define kdcore(fmt, ...) do {} while(0)
55 #endif
56
57 MODULE_LICENSE("GPL");
58
59 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
62                               struct mm_struct *, const char *);
63
64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
65                                    struct elf_fdpic_params *,
66                                    struct elf_fdpic_params *);
67
68 #ifndef CONFIG_MMU
69 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
70                                             unsigned long *);
71 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
72                                                    struct file *,
73                                                    struct mm_struct *);
74 #endif
75
76 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
77                                              struct file *, struct mm_struct *);
78
79 #ifdef CONFIG_ELF_CORE
80 static int elf_fdpic_core_dump(struct coredump_params *cprm);
81 #endif
82
83 static struct linux_binfmt elf_fdpic_format = {
84         .module         = THIS_MODULE,
85         .load_binary    = load_elf_fdpic_binary,
86 #ifdef CONFIG_ELF_CORE
87         .core_dump      = elf_fdpic_core_dump,
88 #endif
89         .min_coredump   = ELF_EXEC_PAGESIZE,
90 };
91
92 static int __init init_elf_fdpic_binfmt(void)
93 {
94         register_binfmt(&elf_fdpic_format);
95         return 0;
96 }
97
98 static void __exit exit_elf_fdpic_binfmt(void)
99 {
100         unregister_binfmt(&elf_fdpic_format);
101 }
102
103 core_initcall(init_elf_fdpic_binfmt);
104 module_exit(exit_elf_fdpic_binfmt);
105
106 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
107 {
108         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
109                 return 0;
110         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
111                 return 0;
112         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
113                 return 0;
114         if (!file->f_op || !file->f_op->mmap)
115                 return 0;
116         return 1;
117 }
118
119 /*****************************************************************************/
120 /*
121  * read the program headers table into memory
122  */
123 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
124                                  struct file *file)
125 {
126         struct elf32_phdr *phdr;
127         unsigned long size;
128         int retval, loop;
129
130         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
131                 return -ENOMEM;
132         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
133                 return -ENOMEM;
134
135         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
136         params->phdrs = kmalloc(size, GFP_KERNEL);
137         if (!params->phdrs)
138                 return -ENOMEM;
139
140         retval = kernel_read(file, params->hdr.e_phoff,
141                              (char *) params->phdrs, size);
142         if (unlikely(retval != size))
143                 return retval < 0 ? retval : -ENOEXEC;
144
145         /* determine stack size for this binary */
146         phdr = params->phdrs;
147         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
148                 if (phdr->p_type != PT_GNU_STACK)
149                         continue;
150
151                 if (phdr->p_flags & PF_X)
152                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
153                 else
154                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
155
156                 params->stack_size = phdr->p_memsz;
157                 break;
158         }
159
160         return 0;
161 }
162
163 /*****************************************************************************/
164 /*
165  * load an fdpic binary into various bits of memory
166  */
167 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
168                                  struct pt_regs *regs)
169 {
170         struct elf_fdpic_params exec_params, interp_params;
171         struct elf_phdr *phdr;
172         unsigned long stack_size, entryaddr;
173 #ifdef ELF_FDPIC_PLAT_INIT
174         unsigned long dynaddr;
175 #endif
176 #ifndef CONFIG_MMU
177         unsigned long stack_prot;
178 #endif
179         struct file *interpreter = NULL; /* to shut gcc up */
180         char *interpreter_name = NULL;
181         int executable_stack;
182         int retval, i;
183
184         kdebug("____ LOAD %d ____", current->pid);
185
186         memset(&exec_params, 0, sizeof(exec_params));
187         memset(&interp_params, 0, sizeof(interp_params));
188
189         exec_params.hdr = *(struct elfhdr *) bprm->buf;
190         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
191
192         /* check that this is a binary we know how to deal with */
193         retval = -ENOEXEC;
194         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
195                 goto error;
196
197         /* read the program header table */
198         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
199         if (retval < 0)
200                 goto error;
201
202         /* scan for a program header that specifies an interpreter */
203         phdr = exec_params.phdrs;
204
205         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
206                 switch (phdr->p_type) {
207                 case PT_INTERP:
208                         retval = -ENOMEM;
209                         if (phdr->p_filesz > PATH_MAX)
210                                 goto error;
211                         retval = -ENOENT;
212                         if (phdr->p_filesz < 2)
213                                 goto error;
214
215                         /* read the name of the interpreter into memory */
216                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
217                         if (!interpreter_name)
218                                 goto error;
219
220                         retval = kernel_read(bprm->file,
221                                              phdr->p_offset,
222                                              interpreter_name,
223                                              phdr->p_filesz);
224                         if (unlikely(retval != phdr->p_filesz)) {
225                                 if (retval >= 0)
226                                         retval = -ENOEXEC;
227                                 goto error;
228                         }
229
230                         retval = -ENOENT;
231                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
232                                 goto error;
233
234                         kdebug("Using ELF interpreter %s", interpreter_name);
235
236                         /* replace the program with the interpreter */
237                         interpreter = open_exec(interpreter_name);
238                         retval = PTR_ERR(interpreter);
239                         if (IS_ERR(interpreter)) {
240                                 interpreter = NULL;
241                                 goto error;
242                         }
243
244                         /*
245                          * If the binary is not readable then enforce
246                          * mm->dumpable = 0 regardless of the interpreter's
247                          * permissions.
248                          */
249                         would_dump(bprm, interpreter);
250
251                         retval = kernel_read(interpreter, 0, bprm->buf,
252                                              BINPRM_BUF_SIZE);
253                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
254                                 if (retval >= 0)
255                                         retval = -ENOEXEC;
256                                 goto error;
257                         }
258
259                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
260                         break;
261
262                 case PT_LOAD:
263 #ifdef CONFIG_MMU
264                         if (exec_params.load_addr == 0)
265                                 exec_params.load_addr = phdr->p_vaddr;
266 #endif
267                         break;
268                 }
269
270         }
271
272         if (elf_check_const_displacement(&exec_params.hdr))
273                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
274
275         /* perform insanity checks on the interpreter */
276         if (interpreter_name) {
277                 retval = -ELIBBAD;
278                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
279                         goto error;
280
281                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
282
283                 /* read the interpreter's program header table */
284                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
285                 if (retval < 0)
286                         goto error;
287         }
288
289         stack_size = exec_params.stack_size;
290         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
291                 executable_stack = EXSTACK_ENABLE_X;
292         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
293                 executable_stack = EXSTACK_DISABLE_X;
294         else
295                 executable_stack = EXSTACK_DEFAULT;
296
297         if (stack_size == 0) {
298                 stack_size = interp_params.stack_size;
299                 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
300                         executable_stack = EXSTACK_ENABLE_X;
301                 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
302                         executable_stack = EXSTACK_DISABLE_X;
303                 else
304                         executable_stack = EXSTACK_DEFAULT;
305         }
306
307         retval = -ENOEXEC;
308         if (stack_size == 0)
309                 goto error;
310
311         if (elf_check_const_displacement(&interp_params.hdr))
312                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
313
314         /* flush all traces of the currently running executable */
315         retval = flush_old_exec(bprm);
316         if (retval)
317                 goto error;
318
319         /* there's now no turning back... the old userspace image is dead,
320          * defunct, deceased, etc. after this point we have to exit via
321          * error_kill */
322         set_personality(PER_LINUX_FDPIC);
323         if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
324                 current->personality |= READ_IMPLIES_EXEC;
325
326         setup_new_exec(bprm);
327
328         set_binfmt(&elf_fdpic_format);
329
330         current->mm->start_code = 0;
331         current->mm->end_code = 0;
332         current->mm->start_stack = 0;
333         current->mm->start_data = 0;
334         current->mm->end_data = 0;
335         current->mm->context.exec_fdpic_loadmap = 0;
336         current->mm->context.interp_fdpic_loadmap = 0;
337
338 #ifdef CONFIG_MMU
339         elf_fdpic_arch_lay_out_mm(&exec_params,
340                                   &interp_params,
341                                   &current->mm->start_stack,
342                                   &current->mm->start_brk);
343
344         retval = setup_arg_pages(bprm, current->mm->start_stack,
345                                  executable_stack);
346         if (retval < 0) {
347                 send_sig(SIGKILL, current, 0);
348                 goto error_kill;
349         }
350 #endif
351
352         /* load the executable and interpreter into memory */
353         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
354                                     "executable");
355         if (retval < 0)
356                 goto error_kill;
357
358         if (interpreter_name) {
359                 retval = elf_fdpic_map_file(&interp_params, interpreter,
360                                             current->mm, "interpreter");
361                 if (retval < 0) {
362                         printk(KERN_ERR "Unable to load interpreter\n");
363                         goto error_kill;
364                 }
365
366                 allow_write_access(interpreter);
367                 fput(interpreter);
368                 interpreter = NULL;
369         }
370
371 #ifdef CONFIG_MMU
372         if (!current->mm->start_brk)
373                 current->mm->start_brk = current->mm->end_data;
374
375         current->mm->brk = current->mm->start_brk =
376                 PAGE_ALIGN(current->mm->start_brk);
377
378 #else
379         /* create a stack and brk area big enough for everyone
380          * - the brk heap starts at the bottom and works up
381          * - the stack starts at the top and works down
382          */
383         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
384         if (stack_size < PAGE_SIZE * 2)
385                 stack_size = PAGE_SIZE * 2;
386
387         stack_prot = PROT_READ | PROT_WRITE;
388         if (executable_stack == EXSTACK_ENABLE_X ||
389             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
390                 stack_prot |= PROT_EXEC;
391
392         down_write(&current->mm->mmap_sem);
393         current->mm->start_brk = do_mmap(NULL, 0, stack_size, stack_prot,
394                                          MAP_PRIVATE | MAP_ANONYMOUS |
395                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
396                                          0);
397
398         if (IS_ERR_VALUE(current->mm->start_brk)) {
399                 up_write(&current->mm->mmap_sem);
400                 retval = current->mm->start_brk;
401                 current->mm->start_brk = 0;
402                 goto error_kill;
403         }
404
405         up_write(&current->mm->mmap_sem);
406
407         current->mm->brk = current->mm->start_brk;
408         current->mm->context.end_brk = current->mm->start_brk;
409         current->mm->context.end_brk +=
410                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
411         current->mm->start_stack = current->mm->start_brk + stack_size;
412 #endif
413
414         install_exec_creds(bprm);
415         if (create_elf_fdpic_tables(bprm, current->mm,
416                                     &exec_params, &interp_params) < 0)
417                 goto error_kill;
418
419         kdebug("- start_code  %lx", current->mm->start_code);
420         kdebug("- end_code    %lx", current->mm->end_code);
421         kdebug("- start_data  %lx", current->mm->start_data);
422         kdebug("- end_data    %lx", current->mm->end_data);
423         kdebug("- start_brk   %lx", current->mm->start_brk);
424         kdebug("- brk         %lx", current->mm->brk);
425         kdebug("- start_stack %lx", current->mm->start_stack);
426
427 #ifdef ELF_FDPIC_PLAT_INIT
428         /*
429          * The ABI may specify that certain registers be set up in special
430          * ways (on i386 %edx is the address of a DT_FINI function, for
431          * example.  This macro performs whatever initialization to
432          * the regs structure is required.
433          */
434         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
435         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
436                             dynaddr);
437 #endif
438
439         /* everything is now ready... get the userspace context ready to roll */
440         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
441         start_thread(regs, entryaddr, current->mm->start_stack);
442
443         retval = 0;
444
445 error:
446         if (interpreter) {
447                 allow_write_access(interpreter);
448                 fput(interpreter);
449         }
450         kfree(interpreter_name);
451         kfree(exec_params.phdrs);
452         kfree(exec_params.loadmap);
453         kfree(interp_params.phdrs);
454         kfree(interp_params.loadmap);
455         return retval;
456
457         /* unrecoverable error - kill the process */
458 error_kill:
459         send_sig(SIGSEGV, current, 0);
460         goto error;
461
462 }
463
464 /*****************************************************************************/
465
466 #ifndef ELF_BASE_PLATFORM
467 /*
468  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
469  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
470  * will be copied to the user stack in the same manner as AT_PLATFORM.
471  */
472 #define ELF_BASE_PLATFORM NULL
473 #endif
474
475 /*
476  * present useful information to the program by shovelling it onto the new
477  * process's stack
478  */
479 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
480                                    struct mm_struct *mm,
481                                    struct elf_fdpic_params *exec_params,
482                                    struct elf_fdpic_params *interp_params)
483 {
484         const struct cred *cred = current_cred();
485         unsigned long sp, csp, nitems;
486         elf_caddr_t __user *argv, *envp;
487         size_t platform_len = 0, len;
488         char *k_platform, *k_base_platform;
489         char __user *u_platform, *u_base_platform, *p;
490         long hwcap;
491         int loop;
492         int nr; /* reset for each csp adjustment */
493
494 #ifdef CONFIG_MMU
495         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
496          * by the processes running on the same package. One thing we can do is
497          * to shuffle the initial stack for them, so we give the architecture
498          * an opportunity to do so here.
499          */
500         sp = arch_align_stack(bprm->p);
501 #else
502         sp = mm->start_stack;
503
504         /* stack the program arguments and environment */
505         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
506                 return -EFAULT;
507 #endif
508
509         hwcap = ELF_HWCAP;
510
511         /*
512          * If this architecture has a platform capability string, copy it
513          * to userspace.  In some cases (Sparc), this info is impossible
514          * for userspace to get any other way, in others (i386) it is
515          * merely difficult.
516          */
517         k_platform = ELF_PLATFORM;
518         u_platform = NULL;
519
520         if (k_platform) {
521                 platform_len = strlen(k_platform) + 1;
522                 sp -= platform_len;
523                 u_platform = (char __user *) sp;
524                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
525                         return -EFAULT;
526         }
527
528         /*
529          * If this architecture has a "base" platform capability
530          * string, copy it to userspace.
531          */
532         k_base_platform = ELF_BASE_PLATFORM;
533         u_base_platform = NULL;
534
535         if (k_base_platform) {
536                 platform_len = strlen(k_base_platform) + 1;
537                 sp -= platform_len;
538                 u_base_platform = (char __user *) sp;
539                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
540                         return -EFAULT;
541         }
542
543         sp &= ~7UL;
544
545         /* stack the load map(s) */
546         len = sizeof(struct elf32_fdpic_loadmap);
547         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
548         sp = (sp - len) & ~7UL;
549         exec_params->map_addr = sp;
550
551         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
552                 return -EFAULT;
553
554         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
555
556         if (interp_params->loadmap) {
557                 len = sizeof(struct elf32_fdpic_loadmap);
558                 len += sizeof(struct elf32_fdpic_loadseg) *
559                         interp_params->loadmap->nsegs;
560                 sp = (sp - len) & ~7UL;
561                 interp_params->map_addr = sp;
562
563                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
564                                  len) != 0)
565                         return -EFAULT;
566
567                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
568         }
569
570         /* force 16 byte _final_ alignment here for generality */
571 #define DLINFO_ITEMS 15
572
573         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
574                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
575
576         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
577                 nitems++;
578
579         csp = sp;
580         sp -= nitems * 2 * sizeof(unsigned long);
581         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
582         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
583         sp -= 1 * sizeof(unsigned long);                /* argc */
584
585         csp -= sp & 15UL;
586         sp -= sp & 15UL;
587
588         /* put the ELF interpreter info on the stack */
589 #define NEW_AUX_ENT(id, val)                                            \
590         do {                                                            \
591                 struct { unsigned long _id, _val; } __user *ent;        \
592                                                                         \
593                 ent = (void __user *) csp;                              \
594                 __put_user((id), &ent[nr]._id);                         \
595                 __put_user((val), &ent[nr]._val);                       \
596                 nr++;                                                   \
597         } while (0)
598
599         nr = 0;
600         csp -= 2 * sizeof(unsigned long);
601         NEW_AUX_ENT(AT_NULL, 0);
602         if (k_platform) {
603                 nr = 0;
604                 csp -= 2 * sizeof(unsigned long);
605                 NEW_AUX_ENT(AT_PLATFORM,
606                             (elf_addr_t) (unsigned long) u_platform);
607         }
608
609         if (k_base_platform) {
610                 nr = 0;
611                 csp -= 2 * sizeof(unsigned long);
612                 NEW_AUX_ENT(AT_BASE_PLATFORM,
613                             (elf_addr_t) (unsigned long) u_base_platform);
614         }
615
616         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
617                 nr = 0;
618                 csp -= 2 * sizeof(unsigned long);
619                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
620         }
621
622         nr = 0;
623         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
624         NEW_AUX_ENT(AT_HWCAP,   hwcap);
625         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
626         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
627         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
628         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
629         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
630         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
631         NEW_AUX_ENT(AT_FLAGS,   0);
632         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
633         NEW_AUX_ENT(AT_UID,     (elf_addr_t) cred->uid);
634         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) cred->euid);
635         NEW_AUX_ENT(AT_GID,     (elf_addr_t) cred->gid);
636         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) cred->egid);
637         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
638         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
639
640 #ifdef ARCH_DLINFO
641         nr = 0;
642         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
643
644         /* ARCH_DLINFO must come last so platform specific code can enforce
645          * special alignment requirements on the AUXV if necessary (eg. PPC).
646          */
647         ARCH_DLINFO;
648 #endif
649 #undef NEW_AUX_ENT
650
651         /* allocate room for argv[] and envv[] */
652         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
653         envp = (elf_caddr_t __user *) csp;
654         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
655         argv = (elf_caddr_t __user *) csp;
656
657         /* stack argc */
658         csp -= sizeof(unsigned long);
659         __put_user(bprm->argc, (unsigned long __user *) csp);
660
661         BUG_ON(csp != sp);
662
663         /* fill in the argv[] array */
664 #ifdef CONFIG_MMU
665         current->mm->arg_start = bprm->p;
666 #else
667         current->mm->arg_start = current->mm->start_stack -
668                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
669 #endif
670
671         p = (char __user *) current->mm->arg_start;
672         for (loop = bprm->argc; loop > 0; loop--) {
673                 __put_user((elf_caddr_t) p, argv++);
674                 len = strnlen_user(p, MAX_ARG_STRLEN);
675                 if (!len || len > MAX_ARG_STRLEN)
676                         return -EINVAL;
677                 p += len;
678         }
679         __put_user(NULL, argv);
680         current->mm->arg_end = (unsigned long) p;
681
682         /* fill in the envv[] array */
683         current->mm->env_start = (unsigned long) p;
684         for (loop = bprm->envc; loop > 0; loop--) {
685                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
686                 len = strnlen_user(p, MAX_ARG_STRLEN);
687                 if (!len || len > MAX_ARG_STRLEN)
688                         return -EINVAL;
689                 p += len;
690         }
691         __put_user(NULL, envp);
692         current->mm->env_end = (unsigned long) p;
693
694         mm->start_stack = (unsigned long) sp;
695         return 0;
696 }
697
698 /*****************************************************************************/
699 /*
700  * transfer the program arguments and environment from the holding pages onto
701  * the stack
702  */
703 #ifndef CONFIG_MMU
704 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
705                                             unsigned long *_sp)
706 {
707         unsigned long index, stop, sp;
708         char *src;
709         int ret = 0;
710
711         stop = bprm->p >> PAGE_SHIFT;
712         sp = *_sp;
713
714         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
715                 src = kmap(bprm->page[index]);
716                 sp -= PAGE_SIZE;
717                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
718                         ret = -EFAULT;
719                 kunmap(bprm->page[index]);
720                 if (ret < 0)
721                         goto out;
722         }
723
724         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
725
726 out:
727         return ret;
728 }
729 #endif
730
731 /*****************************************************************************/
732 /*
733  * load the appropriate binary image (executable or interpreter) into memory
734  * - we assume no MMU is available
735  * - if no other PIC bits are set in params->hdr->e_flags
736  *   - we assume that the LOADable segments in the binary are independently relocatable
737  *   - we assume R/O executable segments are shareable
738  * - else
739  *   - we assume the loadable parts of the image to require fixed displacement
740  *   - the image is not shareable
741  */
742 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
743                               struct file *file,
744                               struct mm_struct *mm,
745                               const char *what)
746 {
747         struct elf32_fdpic_loadmap *loadmap;
748 #ifdef CONFIG_MMU
749         struct elf32_fdpic_loadseg *mseg;
750 #endif
751         struct elf32_fdpic_loadseg *seg;
752         struct elf32_phdr *phdr;
753         unsigned long load_addr, stop;
754         unsigned nloads, tmp;
755         size_t size;
756         int loop, ret;
757
758         /* allocate a load map table */
759         nloads = 0;
760         for (loop = 0; loop < params->hdr.e_phnum; loop++)
761                 if (params->phdrs[loop].p_type == PT_LOAD)
762                         nloads++;
763
764         if (nloads == 0)
765                 return -ELIBBAD;
766
767         size = sizeof(*loadmap) + nloads * sizeof(*seg);
768         loadmap = kzalloc(size, GFP_KERNEL);
769         if (!loadmap)
770                 return -ENOMEM;
771
772         params->loadmap = loadmap;
773
774         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
775         loadmap->nsegs = nloads;
776
777         load_addr = params->load_addr;
778         seg = loadmap->segs;
779
780         /* map the requested LOADs into the memory space */
781         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
782         case ELF_FDPIC_FLAG_CONSTDISP:
783         case ELF_FDPIC_FLAG_CONTIGUOUS:
784 #ifndef CONFIG_MMU
785                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
786                 if (ret < 0)
787                         return ret;
788                 break;
789 #endif
790         default:
791                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
792                 if (ret < 0)
793                         return ret;
794                 break;
795         }
796
797         /* map the entry point */
798         if (params->hdr.e_entry) {
799                 seg = loadmap->segs;
800                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
801                         if (params->hdr.e_entry >= seg->p_vaddr &&
802                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
803                                 params->entry_addr =
804                                         (params->hdr.e_entry - seg->p_vaddr) +
805                                         seg->addr;
806                                 break;
807                         }
808                 }
809         }
810
811         /* determine where the program header table has wound up if mapped */
812         stop = params->hdr.e_phoff;
813         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
814         phdr = params->phdrs;
815
816         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
817                 if (phdr->p_type != PT_LOAD)
818                         continue;
819
820                 if (phdr->p_offset > params->hdr.e_phoff ||
821                     phdr->p_offset + phdr->p_filesz < stop)
822                         continue;
823
824                 seg = loadmap->segs;
825                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
826                         if (phdr->p_vaddr >= seg->p_vaddr &&
827                             phdr->p_vaddr + phdr->p_filesz <=
828                             seg->p_vaddr + seg->p_memsz) {
829                                 params->ph_addr =
830                                         (phdr->p_vaddr - seg->p_vaddr) +
831                                         seg->addr +
832                                         params->hdr.e_phoff - phdr->p_offset;
833                                 break;
834                         }
835                 }
836                 break;
837         }
838
839         /* determine where the dynamic section has wound up if there is one */
840         phdr = params->phdrs;
841         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
842                 if (phdr->p_type != PT_DYNAMIC)
843                         continue;
844
845                 seg = loadmap->segs;
846                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
847                         if (phdr->p_vaddr >= seg->p_vaddr &&
848                             phdr->p_vaddr + phdr->p_memsz <=
849                             seg->p_vaddr + seg->p_memsz) {
850                                 params->dynamic_addr =
851                                         (phdr->p_vaddr - seg->p_vaddr) +
852                                         seg->addr;
853
854                                 /* check the dynamic section contains at least
855                                  * one item, and that the last item is a NULL
856                                  * entry */
857                                 if (phdr->p_memsz == 0 ||
858                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
859                                         goto dynamic_error;
860
861                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
862                                 if (((Elf32_Dyn *)
863                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
864                                         goto dynamic_error;
865                                 break;
866                         }
867                 }
868                 break;
869         }
870
871         /* now elide adjacent segments in the load map on MMU linux
872          * - on uClinux the holes between may actually be filled with system
873          *   stuff or stuff from other processes
874          */
875 #ifdef CONFIG_MMU
876         nloads = loadmap->nsegs;
877         mseg = loadmap->segs;
878         seg = mseg + 1;
879         for (loop = 1; loop < nloads; loop++) {
880                 /* see if we have a candidate for merging */
881                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
882                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
883                         if (load_addr == (seg->addr & PAGE_MASK)) {
884                                 mseg->p_memsz +=
885                                         load_addr -
886                                         (mseg->addr + mseg->p_memsz);
887                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
888                                 mseg->p_memsz += seg->p_memsz;
889                                 loadmap->nsegs--;
890                                 continue;
891                         }
892                 }
893
894                 mseg++;
895                 if (mseg != seg)
896                         *mseg = *seg;
897         }
898 #endif
899
900         kdebug("Mapped Object [%s]:", what);
901         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
902         kdebug("- entry    : %lx", params->entry_addr);
903         kdebug("- PHDR[]   : %lx", params->ph_addr);
904         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
905         seg = loadmap->segs;
906         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
907                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
908                        loop,
909                        seg->addr, seg->addr + seg->p_memsz - 1,
910                        seg->p_vaddr, seg->p_memsz);
911
912         return 0;
913
914 dynamic_error:
915         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
916                what, file->f_path.dentry->d_inode->i_ino);
917         return -ELIBBAD;
918 }
919
920 /*****************************************************************************/
921 /*
922  * map a file with constant displacement under uClinux
923  */
924 #ifndef CONFIG_MMU
925 static int elf_fdpic_map_file_constdisp_on_uclinux(
926         struct elf_fdpic_params *params,
927         struct file *file,
928         struct mm_struct *mm)
929 {
930         struct elf32_fdpic_loadseg *seg;
931         struct elf32_phdr *phdr;
932         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
933         loff_t fpos;
934         int loop, ret;
935
936         load_addr = params->load_addr;
937         seg = params->loadmap->segs;
938
939         /* determine the bounds of the contiguous overall allocation we must
940          * make */
941         phdr = params->phdrs;
942         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
943                 if (params->phdrs[loop].p_type != PT_LOAD)
944                         continue;
945
946                 if (base > phdr->p_vaddr)
947                         base = phdr->p_vaddr;
948                 if (top < phdr->p_vaddr + phdr->p_memsz)
949                         top = phdr->p_vaddr + phdr->p_memsz;
950         }
951
952         /* allocate one big anon block for everything */
953         mflags = MAP_PRIVATE;
954         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
955                 mflags |= MAP_EXECUTABLE;
956
957         down_write(&mm->mmap_sem);
958         maddr = do_mmap(NULL, load_addr, top - base,
959                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
960         up_write(&mm->mmap_sem);
961         if (IS_ERR_VALUE(maddr))
962                 return (int) maddr;
963
964         if (load_addr != 0)
965                 load_addr += PAGE_ALIGN(top - base);
966
967         /* and then load the file segments into it */
968         phdr = params->phdrs;
969         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
970                 if (params->phdrs[loop].p_type != PT_LOAD)
971                         continue;
972
973                 fpos = phdr->p_offset;
974
975                 seg->addr = maddr + (phdr->p_vaddr - base);
976                 seg->p_vaddr = phdr->p_vaddr;
977                 seg->p_memsz = phdr->p_memsz;
978
979                 ret = file->f_op->read(file, (void *) seg->addr,
980                                        phdr->p_filesz, &fpos);
981                 if (ret < 0)
982                         return ret;
983
984                 /* map the ELF header address if in this segment */
985                 if (phdr->p_offset == 0)
986                         params->elfhdr_addr = seg->addr;
987
988                 /* clear any space allocated but not loaded */
989                 if (phdr->p_filesz < phdr->p_memsz) {
990                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
991                                        phdr->p_memsz - phdr->p_filesz))
992                                 return -EFAULT;
993                 }
994
995                 if (mm) {
996                         if (phdr->p_flags & PF_X) {
997                                 if (!mm->start_code) {
998                                         mm->start_code = seg->addr;
999                                         mm->end_code = seg->addr +
1000                                                 phdr->p_memsz;
1001                                 }
1002                         } else if (!mm->start_data) {
1003                                 mm->start_data = seg->addr;
1004                                 mm->end_data = seg->addr + phdr->p_memsz;
1005                         }
1006                 }
1007
1008                 seg++;
1009         }
1010
1011         return 0;
1012 }
1013 #endif
1014
1015 /*****************************************************************************/
1016 /*
1017  * map a binary by direct mmap() of the individual PT_LOAD segments
1018  */
1019 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1020                                              struct file *file,
1021                                              struct mm_struct *mm)
1022 {
1023         struct elf32_fdpic_loadseg *seg;
1024         struct elf32_phdr *phdr;
1025         unsigned long load_addr, delta_vaddr;
1026         int loop, dvset;
1027
1028         load_addr = params->load_addr;
1029         delta_vaddr = 0;
1030         dvset = 0;
1031
1032         seg = params->loadmap->segs;
1033
1034         /* deal with each load segment separately */
1035         phdr = params->phdrs;
1036         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1037                 unsigned long maddr, disp, excess, excess1;
1038                 int prot = 0, flags;
1039
1040                 if (phdr->p_type != PT_LOAD)
1041                         continue;
1042
1043                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1044                        (unsigned long) phdr->p_vaddr,
1045                        (unsigned long) phdr->p_offset,
1046                        (unsigned long) phdr->p_filesz,
1047                        (unsigned long) phdr->p_memsz);
1048
1049                 /* determine the mapping parameters */
1050                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1051                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1052                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1053
1054                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1055                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1056                         flags |= MAP_EXECUTABLE;
1057
1058                 maddr = 0;
1059
1060                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1061                 case ELF_FDPIC_FLAG_INDEPENDENT:
1062                         /* PT_LOADs are independently locatable */
1063                         break;
1064
1065                 case ELF_FDPIC_FLAG_HONOURVADDR:
1066                         /* the specified virtual address must be honoured */
1067                         maddr = phdr->p_vaddr;
1068                         flags |= MAP_FIXED;
1069                         break;
1070
1071                 case ELF_FDPIC_FLAG_CONSTDISP:
1072                         /* constant displacement
1073                          * - can be mapped anywhere, but must be mapped as a
1074                          *   unit
1075                          */
1076                         if (!dvset) {
1077                                 maddr = load_addr;
1078                                 delta_vaddr = phdr->p_vaddr;
1079                                 dvset = 1;
1080                         } else {
1081                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1082                                 flags |= MAP_FIXED;
1083                         }
1084                         break;
1085
1086                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1087                         /* contiguity handled later */
1088                         break;
1089
1090                 default:
1091                         BUG();
1092                 }
1093
1094                 maddr &= PAGE_MASK;
1095
1096                 /* create the mapping */
1097                 disp = phdr->p_vaddr & ~PAGE_MASK;
1098                 down_write(&mm->mmap_sem);
1099                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1100                                 phdr->p_offset - disp);
1101                 up_write(&mm->mmap_sem);
1102
1103                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1104                        loop, phdr->p_memsz + disp, prot, flags,
1105                        phdr->p_offset - disp, maddr);
1106
1107                 if (IS_ERR_VALUE(maddr))
1108                         return (int) maddr;
1109
1110                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1111                     ELF_FDPIC_FLAG_CONTIGUOUS)
1112                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1113
1114                 seg->addr = maddr + disp;
1115                 seg->p_vaddr = phdr->p_vaddr;
1116                 seg->p_memsz = phdr->p_memsz;
1117
1118                 /* map the ELF header address if in this segment */
1119                 if (phdr->p_offset == 0)
1120                         params->elfhdr_addr = seg->addr;
1121
1122                 /* clear the bit between beginning of mapping and beginning of
1123                  * PT_LOAD */
1124                 if (prot & PROT_WRITE && disp > 0) {
1125                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1126                         if (clear_user((void __user *) maddr, disp))
1127                                 return -EFAULT;
1128                         maddr += disp;
1129                 }
1130
1131                 /* clear any space allocated but not loaded
1132                  * - on uClinux we can just clear the lot
1133                  * - on MMU linux we'll get a SIGBUS beyond the last page
1134                  *   extant in the file
1135                  */
1136                 excess = phdr->p_memsz - phdr->p_filesz;
1137                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1138
1139 #ifdef CONFIG_MMU
1140                 if (excess > excess1) {
1141                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1142                         unsigned long xmaddr;
1143
1144                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1145                         down_write(&mm->mmap_sem);
1146                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1147                                          prot, flags, 0);
1148                         up_write(&mm->mmap_sem);
1149
1150                         kdebug("mmap[%d] <anon>"
1151                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1152                                loop, xaddr, excess - excess1, prot, flags,
1153                                xmaddr);
1154
1155                         if (xmaddr != xaddr)
1156                                 return -ENOMEM;
1157                 }
1158
1159                 if (prot & PROT_WRITE && excess1 > 0) {
1160                         kdebug("clear[%d] ad=%lx sz=%lx",
1161                                loop, maddr + phdr->p_filesz, excess1);
1162                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1163                                        excess1))
1164                                 return -EFAULT;
1165                 }
1166
1167 #else
1168                 if (excess > 0) {
1169                         kdebug("clear[%d] ad=%lx sz=%lx",
1170                                loop, maddr + phdr->p_filesz, excess);
1171                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1172                                 return -EFAULT;
1173                 }
1174 #endif
1175
1176                 if (mm) {
1177                         if (phdr->p_flags & PF_X) {
1178                                 if (!mm->start_code) {
1179                                         mm->start_code = maddr;
1180                                         mm->end_code = maddr + phdr->p_memsz;
1181                                 }
1182                         } else if (!mm->start_data) {
1183                                 mm->start_data = maddr;
1184                                 mm->end_data = maddr + phdr->p_memsz;
1185                         }
1186                 }
1187
1188                 seg++;
1189         }
1190
1191         return 0;
1192 }
1193
1194 /*****************************************************************************/
1195 /*
1196  * ELF-FDPIC core dumper
1197  *
1198  * Modelled on fs/exec.c:aout_core_dump()
1199  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1200  *
1201  * Modelled on fs/binfmt_elf.c core dumper
1202  */
1203 #ifdef CONFIG_ELF_CORE
1204
1205 /*
1206  * Decide whether a segment is worth dumping; default is yes to be
1207  * sure (missing info is worse than too much; etc).
1208  * Personally I'd include everything, and use the coredump limit...
1209  *
1210  * I think we should skip something. But I am not sure how. H.J.
1211  */
1212 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1213 {
1214         int dump_ok;
1215
1216         /* Do not dump I/O mapped devices or special mappings */
1217         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1218                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1219                 return 0;
1220         }
1221
1222         /* If we may not read the contents, don't allow us to dump
1223          * them either. "dump_write()" can't handle it anyway.
1224          */
1225         if (!(vma->vm_flags & VM_READ)) {
1226                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1227                 return 0;
1228         }
1229
1230         /* By default, dump shared memory if mapped from an anonymous file. */
1231         if (vma->vm_flags & VM_SHARED) {
1232                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1233                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1234                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1235                                vma->vm_flags, dump_ok ? "yes" : "no");
1236                         return dump_ok;
1237                 }
1238
1239                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1240                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1241                        vma->vm_flags, dump_ok ? "yes" : "no");
1242                 return dump_ok;
1243         }
1244
1245 #ifdef CONFIG_MMU
1246         /* By default, if it hasn't been written to, don't write it out */
1247         if (!vma->anon_vma) {
1248                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1249                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1250                        vma->vm_flags, dump_ok ? "yes" : "no");
1251                 return dump_ok;
1252         }
1253 #endif
1254
1255         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1256         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1257                dump_ok ? "yes" : "no");
1258         return dump_ok;
1259 }
1260
1261 /* An ELF note in memory */
1262 struct memelfnote
1263 {
1264         const char *name;
1265         int type;
1266         unsigned int datasz;
1267         void *data;
1268 };
1269
1270 static int notesize(struct memelfnote *en)
1271 {
1272         int sz;
1273
1274         sz = sizeof(struct elf_note);
1275         sz += roundup(strlen(en->name) + 1, 4);
1276         sz += roundup(en->datasz, 4);
1277
1278         return sz;
1279 }
1280
1281 /* #define DEBUG */
1282
1283 #define DUMP_WRITE(addr, nr, foffset)   \
1284         do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1285
1286 static int alignfile(struct file *file, loff_t *foffset)
1287 {
1288         static const char buf[4] = { 0, };
1289         DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1290         return 1;
1291 }
1292
1293 static int writenote(struct memelfnote *men, struct file *file,
1294                         loff_t *foffset)
1295 {
1296         struct elf_note en;
1297         en.n_namesz = strlen(men->name) + 1;
1298         en.n_descsz = men->datasz;
1299         en.n_type = men->type;
1300
1301         DUMP_WRITE(&en, sizeof(en), foffset);
1302         DUMP_WRITE(men->name, en.n_namesz, foffset);
1303         if (!alignfile(file, foffset))
1304                 return 0;
1305         DUMP_WRITE(men->data, men->datasz, foffset);
1306         if (!alignfile(file, foffset))
1307                 return 0;
1308
1309         return 1;
1310 }
1311 #undef DUMP_WRITE
1312
1313 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1314 {
1315         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1316         elf->e_ident[EI_CLASS] = ELF_CLASS;
1317         elf->e_ident[EI_DATA] = ELF_DATA;
1318         elf->e_ident[EI_VERSION] = EV_CURRENT;
1319         elf->e_ident[EI_OSABI] = ELF_OSABI;
1320         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1321
1322         elf->e_type = ET_CORE;
1323         elf->e_machine = ELF_ARCH;
1324         elf->e_version = EV_CURRENT;
1325         elf->e_entry = 0;
1326         elf->e_phoff = sizeof(struct elfhdr);
1327         elf->e_shoff = 0;
1328         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1329         elf->e_ehsize = sizeof(struct elfhdr);
1330         elf->e_phentsize = sizeof(struct elf_phdr);
1331         elf->e_phnum = segs;
1332         elf->e_shentsize = 0;
1333         elf->e_shnum = 0;
1334         elf->e_shstrndx = 0;
1335         return;
1336 }
1337
1338 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1339 {
1340         phdr->p_type = PT_NOTE;
1341         phdr->p_offset = offset;
1342         phdr->p_vaddr = 0;
1343         phdr->p_paddr = 0;
1344         phdr->p_filesz = sz;
1345         phdr->p_memsz = 0;
1346         phdr->p_flags = 0;
1347         phdr->p_align = 0;
1348         return;
1349 }
1350
1351 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1352                 unsigned int sz, void *data)
1353 {
1354         note->name = name;
1355         note->type = type;
1356         note->datasz = sz;
1357         note->data = data;
1358         return;
1359 }
1360
1361 /*
1362  * fill up all the fields in prstatus from the given task struct, except
1363  * registers which need to be filled up separately.
1364  */
1365 static void fill_prstatus(struct elf_prstatus *prstatus,
1366                           struct task_struct *p, long signr)
1367 {
1368         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1369         prstatus->pr_sigpend = p->pending.signal.sig[0];
1370         prstatus->pr_sighold = p->blocked.sig[0];
1371         rcu_read_lock();
1372         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1373         rcu_read_unlock();
1374         prstatus->pr_pid = task_pid_vnr(p);
1375         prstatus->pr_pgrp = task_pgrp_vnr(p);
1376         prstatus->pr_sid = task_session_vnr(p);
1377         if (thread_group_leader(p)) {
1378                 struct task_cputime cputime;
1379
1380                 /*
1381                  * This is the record for the group leader.  It shows the
1382                  * group-wide total, not its individual thread total.
1383                  */
1384                 thread_group_cputime(p, &cputime);
1385                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1386                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1387         } else {
1388                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1389                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1390         }
1391         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1392         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1393
1394         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1395         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1396 }
1397
1398 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1399                        struct mm_struct *mm)
1400 {
1401         const struct cred *cred;
1402         unsigned int i, len;
1403
1404         /* first copy the parameters from user space */
1405         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1406
1407         len = mm->arg_end - mm->arg_start;
1408         if (len >= ELF_PRARGSZ)
1409                 len = ELF_PRARGSZ - 1;
1410         if (copy_from_user(&psinfo->pr_psargs,
1411                            (const char __user *) mm->arg_start, len))
1412                 return -EFAULT;
1413         for (i = 0; i < len; i++)
1414                 if (psinfo->pr_psargs[i] == 0)
1415                         psinfo->pr_psargs[i] = ' ';
1416         psinfo->pr_psargs[len] = 0;
1417
1418         rcu_read_lock();
1419         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1420         rcu_read_unlock();
1421         psinfo->pr_pid = task_pid_vnr(p);
1422         psinfo->pr_pgrp = task_pgrp_vnr(p);
1423         psinfo->pr_sid = task_session_vnr(p);
1424
1425         i = p->state ? ffz(~p->state) + 1 : 0;
1426         psinfo->pr_state = i;
1427         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1428         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1429         psinfo->pr_nice = task_nice(p);
1430         psinfo->pr_flag = p->flags;
1431         rcu_read_lock();
1432         cred = __task_cred(p);
1433         SET_UID(psinfo->pr_uid, cred->uid);
1434         SET_GID(psinfo->pr_gid, cred->gid);
1435         rcu_read_unlock();
1436         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1437
1438         return 0;
1439 }
1440
1441 /* Here is the structure in which status of each thread is captured. */
1442 struct elf_thread_status
1443 {
1444         struct list_head list;
1445         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1446         elf_fpregset_t fpu;             /* NT_PRFPREG */
1447         struct task_struct *thread;
1448 #ifdef ELF_CORE_COPY_XFPREGS
1449         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1450 #endif
1451         struct memelfnote notes[3];
1452         int num_notes;
1453 };
1454
1455 /*
1456  * In order to add the specific thread information for the elf file format,
1457  * we need to keep a linked list of every thread's pr_status and then create
1458  * a single section for them in the final core file.
1459  */
1460 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1461 {
1462         struct task_struct *p = t->thread;
1463         int sz = 0;
1464
1465         t->num_notes = 0;
1466
1467         fill_prstatus(&t->prstatus, p, signr);
1468         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1469
1470         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1471                   &t->prstatus);
1472         t->num_notes++;
1473         sz += notesize(&t->notes[0]);
1474
1475         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1476         if (t->prstatus.pr_fpvalid) {
1477                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1478                           &t->fpu);
1479                 t->num_notes++;
1480                 sz += notesize(&t->notes[1]);
1481         }
1482
1483 #ifdef ELF_CORE_COPY_XFPREGS
1484         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1485                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1486                           sizeof(t->xfpu), &t->xfpu);
1487                 t->num_notes++;
1488                 sz += notesize(&t->notes[2]);
1489         }
1490 #endif
1491         return sz;
1492 }
1493
1494 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1495                              elf_addr_t e_shoff, int segs)
1496 {
1497         elf->e_shoff = e_shoff;
1498         elf->e_shentsize = sizeof(*shdr4extnum);
1499         elf->e_shnum = 1;
1500         elf->e_shstrndx = SHN_UNDEF;
1501
1502         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1503
1504         shdr4extnum->sh_type = SHT_NULL;
1505         shdr4extnum->sh_size = elf->e_shnum;
1506         shdr4extnum->sh_link = elf->e_shstrndx;
1507         shdr4extnum->sh_info = segs;
1508 }
1509
1510 /*
1511  * dump the segments for an MMU process
1512  */
1513 #ifdef CONFIG_MMU
1514 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1515                            unsigned long *limit, unsigned long mm_flags)
1516 {
1517         struct vm_area_struct *vma;
1518         int err = 0;
1519
1520         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1521                 unsigned long addr;
1522
1523                 if (!maydump(vma, mm_flags))
1524                         continue;
1525
1526                 for (addr = vma->vm_start; addr < vma->vm_end;
1527                                                         addr += PAGE_SIZE) {
1528                         struct page *page = get_dump_page(addr);
1529                         if (page) {
1530                                 void *kaddr = kmap(page);
1531                                 *size += PAGE_SIZE;
1532                                 if (*size > *limit)
1533                                         err = -EFBIG;
1534                                 else if (!dump_write(file, kaddr, PAGE_SIZE))
1535                                         err = -EIO;
1536                                 kunmap(page);
1537                                 page_cache_release(page);
1538                         } else if (!dump_seek(file, PAGE_SIZE))
1539                                 err = -EFBIG;
1540                         if (err)
1541                                 goto out;
1542                 }
1543         }
1544 out:
1545         return err;
1546 }
1547 #endif
1548
1549 /*
1550  * dump the segments for a NOMMU process
1551  */
1552 #ifndef CONFIG_MMU
1553 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1554                            unsigned long *limit, unsigned long mm_flags)
1555 {
1556         struct vm_area_struct *vma;
1557
1558         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1559                 if (!maydump(vma, mm_flags))
1560                         continue;
1561
1562                 if ((*size += PAGE_SIZE) > *limit)
1563                         return -EFBIG;
1564
1565                 if (!dump_write(file, (void *) vma->vm_start,
1566                                 vma->vm_end - vma->vm_start))
1567                         return -EIO;
1568         }
1569
1570         return 0;
1571 }
1572 #endif
1573
1574 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1575 {
1576         struct vm_area_struct *vma;
1577         size_t size = 0;
1578
1579         for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1580                 if (maydump(vma, mm_flags))
1581                         size += vma->vm_end - vma->vm_start;
1582         return size;
1583 }
1584
1585 /*
1586  * Actual dumper
1587  *
1588  * This is a two-pass process; first we find the offsets of the bits,
1589  * and then they are actually written out.  If we run out of core limit
1590  * we just truncate.
1591  */
1592 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1593 {
1594 #define NUM_NOTES       6
1595         int has_dumped = 0;
1596         mm_segment_t fs;
1597         int segs;
1598         size_t size = 0;
1599         int i;
1600         struct vm_area_struct *vma;
1601         struct elfhdr *elf = NULL;
1602         loff_t offset = 0, dataoff, foffset;
1603         int numnote;
1604         struct memelfnote *notes = NULL;
1605         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1606         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1607         LIST_HEAD(thread_list);
1608         struct list_head *t;
1609         elf_fpregset_t *fpu = NULL;
1610 #ifdef ELF_CORE_COPY_XFPREGS
1611         elf_fpxregset_t *xfpu = NULL;
1612 #endif
1613         int thread_status_size = 0;
1614         elf_addr_t *auxv;
1615         struct elf_phdr *phdr4note = NULL;
1616         struct elf_shdr *shdr4extnum = NULL;
1617         Elf_Half e_phnum;
1618         elf_addr_t e_shoff;
1619
1620         /*
1621          * We no longer stop all VM operations.
1622          *
1623          * This is because those proceses that could possibly change map_count
1624          * or the mmap / vma pages are now blocked in do_exit on current
1625          * finishing this core dump.
1626          *
1627          * Only ptrace can touch these memory addresses, but it doesn't change
1628          * the map_count or the pages allocated. So no possibility of crashing
1629          * exists while dumping the mm->vm_next areas to the core file.
1630          */
1631
1632         /* alloc memory for large data structures: too large to be on stack */
1633         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1634         if (!elf)
1635                 goto cleanup;
1636         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1637         if (!prstatus)
1638                 goto cleanup;
1639         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1640         if (!psinfo)
1641                 goto cleanup;
1642         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1643         if (!notes)
1644                 goto cleanup;
1645         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1646         if (!fpu)
1647                 goto cleanup;
1648 #ifdef ELF_CORE_COPY_XFPREGS
1649         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1650         if (!xfpu)
1651                 goto cleanup;
1652 #endif
1653
1654         if (cprm->signr) {
1655                 struct core_thread *ct;
1656                 struct elf_thread_status *tmp;
1657
1658                 for (ct = current->mm->core_state->dumper.next;
1659                                                 ct; ct = ct->next) {
1660                         tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1661                         if (!tmp)
1662                                 goto cleanup;
1663
1664                         tmp->thread = ct->task;
1665                         list_add(&tmp->list, &thread_list);
1666                 }
1667
1668                 list_for_each(t, &thread_list) {
1669                         struct elf_thread_status *tmp;
1670                         int sz;
1671
1672                         tmp = list_entry(t, struct elf_thread_status, list);
1673                         sz = elf_dump_thread_status(cprm->signr, tmp);
1674                         thread_status_size += sz;
1675                 }
1676         }
1677
1678         /* now collect the dump for the current */
1679         fill_prstatus(prstatus, current, cprm->signr);
1680         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1681
1682         segs = current->mm->map_count;
1683         segs += elf_core_extra_phdrs();
1684
1685         /* for notes section */
1686         segs++;
1687
1688         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1689          * this, kernel supports extended numbering. Have a look at
1690          * include/linux/elf.h for further information. */
1691         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1692
1693         /* Set up header */
1694         fill_elf_fdpic_header(elf, e_phnum);
1695
1696         has_dumped = 1;
1697         current->flags |= PF_DUMPCORE;
1698
1699         /*
1700          * Set up the notes in similar form to SVR4 core dumps made
1701          * with info from their /proc.
1702          */
1703
1704         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1705         fill_psinfo(psinfo, current->group_leader, current->mm);
1706         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1707
1708         numnote = 2;
1709
1710         auxv = (elf_addr_t *) current->mm->saved_auxv;
1711
1712         i = 0;
1713         do
1714                 i += 2;
1715         while (auxv[i - 2] != AT_NULL);
1716         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1717                   i * sizeof(elf_addr_t), auxv);
1718
1719         /* Try to dump the FPU. */
1720         if ((prstatus->pr_fpvalid =
1721              elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1722                 fill_note(notes + numnote++,
1723                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1724 #ifdef ELF_CORE_COPY_XFPREGS
1725         if (elf_core_copy_task_xfpregs(current, xfpu))
1726                 fill_note(notes + numnote++,
1727                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1728 #endif
1729
1730         fs = get_fs();
1731         set_fs(KERNEL_DS);
1732
1733         offset += sizeof(*elf);                         /* Elf header */
1734         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1735         foffset = offset;
1736
1737         /* Write notes phdr entry */
1738         {
1739                 int sz = 0;
1740
1741                 for (i = 0; i < numnote; i++)
1742                         sz += notesize(notes + i);
1743
1744                 sz += thread_status_size;
1745
1746                 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1747                 if (!phdr4note)
1748                         goto end_coredump;
1749
1750                 fill_elf_note_phdr(phdr4note, sz, offset);
1751                 offset += sz;
1752         }
1753
1754         /* Page-align dumped data */
1755         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1756
1757         offset += elf_core_vma_data_size(cprm->mm_flags);
1758         offset += elf_core_extra_data_size();
1759         e_shoff = offset;
1760
1761         if (e_phnum == PN_XNUM) {
1762                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1763                 if (!shdr4extnum)
1764                         goto end_coredump;
1765                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1766         }
1767
1768         offset = dataoff;
1769
1770         size += sizeof(*elf);
1771         if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
1772                 goto end_coredump;
1773
1774         size += sizeof(*phdr4note);
1775         if (size > cprm->limit
1776             || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
1777                 goto end_coredump;
1778
1779         /* write program headers for segments dump */
1780         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1781                 struct elf_phdr phdr;
1782                 size_t sz;
1783
1784                 sz = vma->vm_end - vma->vm_start;
1785
1786                 phdr.p_type = PT_LOAD;
1787                 phdr.p_offset = offset;
1788                 phdr.p_vaddr = vma->vm_start;
1789                 phdr.p_paddr = 0;
1790                 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1791                 phdr.p_memsz = sz;
1792                 offset += phdr.p_filesz;
1793                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1794                 if (vma->vm_flags & VM_WRITE)
1795                         phdr.p_flags |= PF_W;
1796                 if (vma->vm_flags & VM_EXEC)
1797                         phdr.p_flags |= PF_X;
1798                 phdr.p_align = ELF_EXEC_PAGESIZE;
1799
1800                 size += sizeof(phdr);
1801                 if (size > cprm->limit
1802                     || !dump_write(cprm->file, &phdr, sizeof(phdr)))
1803                         goto end_coredump;
1804         }
1805
1806         if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
1807                 goto end_coredump;
1808
1809         /* write out the notes section */
1810         for (i = 0; i < numnote; i++)
1811                 if (!writenote(notes + i, cprm->file, &foffset))
1812                         goto end_coredump;
1813
1814         /* write out the thread status notes section */
1815         list_for_each(t, &thread_list) {
1816                 struct elf_thread_status *tmp =
1817                                 list_entry(t, struct elf_thread_status, list);
1818
1819                 for (i = 0; i < tmp->num_notes; i++)
1820                         if (!writenote(&tmp->notes[i], cprm->file, &foffset))
1821                                 goto end_coredump;
1822         }
1823
1824         if (!dump_seek(cprm->file, dataoff - foffset))
1825                 goto end_coredump;
1826
1827         if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit,
1828                                     cprm->mm_flags) < 0)
1829                 goto end_coredump;
1830
1831         if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
1832                 goto end_coredump;
1833
1834         if (e_phnum == PN_XNUM) {
1835                 size += sizeof(*shdr4extnum);
1836                 if (size > cprm->limit
1837                     || !dump_write(cprm->file, shdr4extnum,
1838                                    sizeof(*shdr4extnum)))
1839                         goto end_coredump;
1840         }
1841
1842         if (cprm->file->f_pos != offset) {
1843                 /* Sanity check */
1844                 printk(KERN_WARNING
1845                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1846                        cprm->file->f_pos, offset);
1847         }
1848
1849 end_coredump:
1850         set_fs(fs);
1851
1852 cleanup:
1853         while (!list_empty(&thread_list)) {
1854                 struct list_head *tmp = thread_list.next;
1855                 list_del(tmp);
1856                 kfree(list_entry(tmp, struct elf_thread_status, list));
1857         }
1858         kfree(phdr4note);
1859         kfree(elf);
1860         kfree(prstatus);
1861         kfree(psinfo);
1862         kfree(notes);
1863         kfree(fpu);
1864         kfree(shdr4extnum);
1865 #ifdef ELF_CORE_COPY_XFPREGS
1866         kfree(xfpu);
1867 #endif
1868         return has_dumped;
1869 #undef NUM_NOTES
1870 }
1871
1872 #endif          /* CONFIG_ELF_CORE */