ext4: Properly count journal credits for long symlinks
[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 #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         return register_binfmt(&elf_fdpic_format);
95 }
96
97 static void __exit exit_elf_fdpic_binfmt(void)
98 {
99         unregister_binfmt(&elf_fdpic_format);
100 }
101
102 core_initcall(init_elf_fdpic_binfmt);
103 module_exit(exit_elf_fdpic_binfmt);
104
105 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
106 {
107         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
108                 return 0;
109         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
110                 return 0;
111         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
112                 return 0;
113         if (!file->f_op || !file->f_op->mmap)
114                 return 0;
115         return 1;
116 }
117
118 /*****************************************************************************/
119 /*
120  * read the program headers table into memory
121  */
122 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
123                                  struct file *file)
124 {
125         struct elf32_phdr *phdr;
126         unsigned long size;
127         int retval, loop;
128
129         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
130                 return -ENOMEM;
131         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
132                 return -ENOMEM;
133
134         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
135         params->phdrs = kmalloc(size, GFP_KERNEL);
136         if (!params->phdrs)
137                 return -ENOMEM;
138
139         retval = kernel_read(file, params->hdr.e_phoff,
140                              (char *) params->phdrs, size);
141         if (unlikely(retval != size))
142                 return retval < 0 ? retval : -ENOEXEC;
143
144         /* determine stack size for this binary */
145         phdr = params->phdrs;
146         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
147                 if (phdr->p_type != PT_GNU_STACK)
148                         continue;
149
150                 if (phdr->p_flags & PF_X)
151                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
152                 else
153                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
154
155                 params->stack_size = phdr->p_memsz;
156                 break;
157         }
158
159         return 0;
160 }
161
162 /*****************************************************************************/
163 /*
164  * load an fdpic binary into various bits of memory
165  */
166 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
167                                  struct pt_regs *regs)
168 {
169         struct elf_fdpic_params exec_params, interp_params;
170         struct elf_phdr *phdr;
171         unsigned long stack_size, entryaddr;
172 #ifdef ELF_FDPIC_PLAT_INIT
173         unsigned long dynaddr;
174 #endif
175 #ifndef CONFIG_MMU
176         unsigned long stack_prot;
177 #endif
178         struct file *interpreter = NULL; /* to shut gcc up */
179         char *interpreter_name = NULL;
180         int executable_stack;
181         int retval, i;
182
183         kdebug("____ LOAD %d ____", current->pid);
184
185         memset(&exec_params, 0, sizeof(exec_params));
186         memset(&interp_params, 0, sizeof(interp_params));
187
188         exec_params.hdr = *(struct elfhdr *) bprm->buf;
189         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
190
191         /* check that this is a binary we know how to deal with */
192         retval = -ENOEXEC;
193         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
194                 goto error;
195
196         /* read the program header table */
197         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
198         if (retval < 0)
199                 goto error;
200
201         /* scan for a program header that specifies an interpreter */
202         phdr = exec_params.phdrs;
203
204         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
205                 switch (phdr->p_type) {
206                 case PT_INTERP:
207                         retval = -ENOMEM;
208                         if (phdr->p_filesz > PATH_MAX)
209                                 goto error;
210                         retval = -ENOENT;
211                         if (phdr->p_filesz < 2)
212                                 goto error;
213
214                         /* read the name of the interpreter into memory */
215                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
216                         if (!interpreter_name)
217                                 goto error;
218
219                         retval = kernel_read(bprm->file,
220                                              phdr->p_offset,
221                                              interpreter_name,
222                                              phdr->p_filesz);
223                         if (unlikely(retval != phdr->p_filesz)) {
224                                 if (retval >= 0)
225                                         retval = -ENOEXEC;
226                                 goto error;
227                         }
228
229                         retval = -ENOENT;
230                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
231                                 goto error;
232
233                         kdebug("Using ELF interpreter %s", interpreter_name);
234
235                         /* replace the program with the interpreter */
236                         interpreter = open_exec(interpreter_name);
237                         retval = PTR_ERR(interpreter);
238                         if (IS_ERR(interpreter)) {
239                                 interpreter = NULL;
240                                 goto error;
241                         }
242
243                         /*
244                          * If the binary is not readable then enforce
245                          * mm->dumpable = 0 regardless of the interpreter's
246                          * permissions.
247                          */
248                         would_dump(bprm, interpreter);
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                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
993                                        phdr->p_memsz - phdr->p_filesz))
994                                 return -EFAULT;
995                 }
996
997                 if (mm) {
998                         if (phdr->p_flags & PF_X) {
999                                 if (!mm->start_code) {
1000                                         mm->start_code = seg->addr;
1001                                         mm->end_code = seg->addr +
1002                                                 phdr->p_memsz;
1003                                 }
1004                         } else if (!mm->start_data) {
1005                                 mm->start_data = seg->addr;
1006                                 mm->end_data = seg->addr + phdr->p_memsz;
1007                         }
1008                 }
1009
1010                 seg++;
1011         }
1012
1013         return 0;
1014 }
1015 #endif
1016
1017 /*****************************************************************************/
1018 /*
1019  * map a binary by direct mmap() of the individual PT_LOAD segments
1020  */
1021 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1022                                              struct file *file,
1023                                              struct mm_struct *mm)
1024 {
1025         struct elf32_fdpic_loadseg *seg;
1026         struct elf32_phdr *phdr;
1027         unsigned long load_addr, delta_vaddr;
1028         int loop, dvset;
1029
1030         load_addr = params->load_addr;
1031         delta_vaddr = 0;
1032         dvset = 0;
1033
1034         seg = params->loadmap->segs;
1035
1036         /* deal with each load segment separately */
1037         phdr = params->phdrs;
1038         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1039                 unsigned long maddr, disp, excess, excess1;
1040                 int prot = 0, flags;
1041
1042                 if (phdr->p_type != PT_LOAD)
1043                         continue;
1044
1045                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1046                        (unsigned long) phdr->p_vaddr,
1047                        (unsigned long) phdr->p_offset,
1048                        (unsigned long) phdr->p_filesz,
1049                        (unsigned long) phdr->p_memsz);
1050
1051                 /* determine the mapping parameters */
1052                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1053                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1054                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1055
1056                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1057                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1058                         flags |= MAP_EXECUTABLE;
1059
1060                 maddr = 0;
1061
1062                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1063                 case ELF_FDPIC_FLAG_INDEPENDENT:
1064                         /* PT_LOADs are independently locatable */
1065                         break;
1066
1067                 case ELF_FDPIC_FLAG_HONOURVADDR:
1068                         /* the specified virtual address must be honoured */
1069                         maddr = phdr->p_vaddr;
1070                         flags |= MAP_FIXED;
1071                         break;
1072
1073                 case ELF_FDPIC_FLAG_CONSTDISP:
1074                         /* constant displacement
1075                          * - can be mapped anywhere, but must be mapped as a
1076                          *   unit
1077                          */
1078                         if (!dvset) {
1079                                 maddr = load_addr;
1080                                 delta_vaddr = phdr->p_vaddr;
1081                                 dvset = 1;
1082                         } else {
1083                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1084                                 flags |= MAP_FIXED;
1085                         }
1086                         break;
1087
1088                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1089                         /* contiguity handled later */
1090                         break;
1091
1092                 default:
1093                         BUG();
1094                 }
1095
1096                 maddr &= PAGE_MASK;
1097
1098                 /* create the mapping */
1099                 disp = phdr->p_vaddr & ~PAGE_MASK;
1100                 down_write(&mm->mmap_sem);
1101                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1102                                 phdr->p_offset - disp);
1103                 up_write(&mm->mmap_sem);
1104
1105                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1106                        loop, phdr->p_memsz + disp, prot, flags,
1107                        phdr->p_offset - disp, maddr);
1108
1109                 if (IS_ERR_VALUE(maddr))
1110                         return (int) maddr;
1111
1112                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1113                     ELF_FDPIC_FLAG_CONTIGUOUS)
1114                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1115
1116                 seg->addr = maddr + disp;
1117                 seg->p_vaddr = phdr->p_vaddr;
1118                 seg->p_memsz = phdr->p_memsz;
1119
1120                 /* map the ELF header address if in this segment */
1121                 if (phdr->p_offset == 0)
1122                         params->elfhdr_addr = seg->addr;
1123
1124                 /* clear the bit between beginning of mapping and beginning of
1125                  * PT_LOAD */
1126                 if (prot & PROT_WRITE && disp > 0) {
1127                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1128                         if (clear_user((void __user *) maddr, disp))
1129                                 return -EFAULT;
1130                         maddr += disp;
1131                 }
1132
1133                 /* clear any space allocated but not loaded
1134                  * - on uClinux we can just clear the lot
1135                  * - on MMU linux we'll get a SIGBUS beyond the last page
1136                  *   extant in the file
1137                  */
1138                 excess = phdr->p_memsz - phdr->p_filesz;
1139                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1140
1141 #ifdef CONFIG_MMU
1142                 if (excess > excess1) {
1143                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1144                         unsigned long xmaddr;
1145
1146                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1147                         down_write(&mm->mmap_sem);
1148                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1149                                          prot, flags, 0);
1150                         up_write(&mm->mmap_sem);
1151
1152                         kdebug("mmap[%d] <anon>"
1153                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1154                                loop, xaddr, excess - excess1, prot, flags,
1155                                xmaddr);
1156
1157                         if (xmaddr != xaddr)
1158                                 return -ENOMEM;
1159                 }
1160
1161                 if (prot & PROT_WRITE && excess1 > 0) {
1162                         kdebug("clear[%d] ad=%lx sz=%lx",
1163                                loop, maddr + phdr->p_filesz, excess1);
1164                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1165                                        excess1))
1166                                 return -EFAULT;
1167                 }
1168
1169 #else
1170                 if (excess > 0) {
1171                         kdebug("clear[%d] ad=%lx sz=%lx",
1172                                loop, maddr + phdr->p_filesz, excess);
1173                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1174                                 return -EFAULT;
1175                 }
1176 #endif
1177
1178                 if (mm) {
1179                         if (phdr->p_flags & PF_X) {
1180                                 if (!mm->start_code) {
1181                                         mm->start_code = maddr;
1182                                         mm->end_code = maddr + phdr->p_memsz;
1183                                 }
1184                         } else if (!mm->start_data) {
1185                                 mm->start_data = maddr;
1186                                 mm->end_data = maddr + phdr->p_memsz;
1187                         }
1188                 }
1189
1190                 seg++;
1191         }
1192
1193         return 0;
1194 }
1195
1196 /*****************************************************************************/
1197 /*
1198  * ELF-FDPIC core dumper
1199  *
1200  * Modelled on fs/exec.c:aout_core_dump()
1201  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1202  *
1203  * Modelled on fs/binfmt_elf.c core dumper
1204  */
1205 #ifdef CONFIG_ELF_CORE
1206
1207 /*
1208  * Decide whether a segment is worth dumping; default is yes to be
1209  * sure (missing info is worse than too much; etc).
1210  * Personally I'd include everything, and use the coredump limit...
1211  *
1212  * I think we should skip something. But I am not sure how. H.J.
1213  */
1214 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1215 {
1216         int dump_ok;
1217
1218         /* Do not dump I/O mapped devices or special mappings */
1219         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1220                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1221                 return 0;
1222         }
1223
1224         /* If we may not read the contents, don't allow us to dump
1225          * them either. "dump_write()" can't handle it anyway.
1226          */
1227         if (!(vma->vm_flags & VM_READ)) {
1228                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1229                 return 0;
1230         }
1231
1232         /* By default, dump shared memory if mapped from an anonymous file. */
1233         if (vma->vm_flags & VM_SHARED) {
1234                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1235                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1236                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1237                                vma->vm_flags, dump_ok ? "yes" : "no");
1238                         return dump_ok;
1239                 }
1240
1241                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1242                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1243                        vma->vm_flags, dump_ok ? "yes" : "no");
1244                 return dump_ok;
1245         }
1246
1247 #ifdef CONFIG_MMU
1248         /* By default, if it hasn't been written to, don't write it out */
1249         if (!vma->anon_vma) {
1250                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1251                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1252                        vma->vm_flags, dump_ok ? "yes" : "no");
1253                 return dump_ok;
1254         }
1255 #endif
1256
1257         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1258         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1259                dump_ok ? "yes" : "no");
1260         return dump_ok;
1261 }
1262
1263 /* An ELF note in memory */
1264 struct memelfnote
1265 {
1266         const char *name;
1267         int type;
1268         unsigned int datasz;
1269         void *data;
1270 };
1271
1272 static int notesize(struct memelfnote *en)
1273 {
1274         int sz;
1275
1276         sz = sizeof(struct elf_note);
1277         sz += roundup(strlen(en->name) + 1, 4);
1278         sz += roundup(en->datasz, 4);
1279
1280         return sz;
1281 }
1282
1283 /* #define DEBUG */
1284
1285 #define DUMP_WRITE(addr, nr, foffset)   \
1286         do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1287
1288 static int alignfile(struct file *file, loff_t *foffset)
1289 {
1290         static const char buf[4] = { 0, };
1291         DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1292         return 1;
1293 }
1294
1295 static int writenote(struct memelfnote *men, struct file *file,
1296                         loff_t *foffset)
1297 {
1298         struct elf_note en;
1299         en.n_namesz = strlen(men->name) + 1;
1300         en.n_descsz = men->datasz;
1301         en.n_type = men->type;
1302
1303         DUMP_WRITE(&en, sizeof(en), foffset);
1304         DUMP_WRITE(men->name, en.n_namesz, foffset);
1305         if (!alignfile(file, foffset))
1306                 return 0;
1307         DUMP_WRITE(men->data, men->datasz, foffset);
1308         if (!alignfile(file, foffset))
1309                 return 0;
1310
1311         return 1;
1312 }
1313 #undef DUMP_WRITE
1314
1315 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1316 {
1317         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1318         elf->e_ident[EI_CLASS] = ELF_CLASS;
1319         elf->e_ident[EI_DATA] = ELF_DATA;
1320         elf->e_ident[EI_VERSION] = EV_CURRENT;
1321         elf->e_ident[EI_OSABI] = ELF_OSABI;
1322         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1323
1324         elf->e_type = ET_CORE;
1325         elf->e_machine = ELF_ARCH;
1326         elf->e_version = EV_CURRENT;
1327         elf->e_entry = 0;
1328         elf->e_phoff = sizeof(struct elfhdr);
1329         elf->e_shoff = 0;
1330         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1331         elf->e_ehsize = sizeof(struct elfhdr);
1332         elf->e_phentsize = sizeof(struct elf_phdr);
1333         elf->e_phnum = segs;
1334         elf->e_shentsize = 0;
1335         elf->e_shnum = 0;
1336         elf->e_shstrndx = 0;
1337         return;
1338 }
1339
1340 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1341 {
1342         phdr->p_type = PT_NOTE;
1343         phdr->p_offset = offset;
1344         phdr->p_vaddr = 0;
1345         phdr->p_paddr = 0;
1346         phdr->p_filesz = sz;
1347         phdr->p_memsz = 0;
1348         phdr->p_flags = 0;
1349         phdr->p_align = 0;
1350         return;
1351 }
1352
1353 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1354                 unsigned int sz, void *data)
1355 {
1356         note->name = name;
1357         note->type = type;
1358         note->datasz = sz;
1359         note->data = data;
1360         return;
1361 }
1362
1363 /*
1364  * fill up all the fields in prstatus from the given task struct, except
1365  * registers which need to be filled up separately.
1366  */
1367 static void fill_prstatus(struct elf_prstatus *prstatus,
1368                           struct task_struct *p, long signr)
1369 {
1370         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1371         prstatus->pr_sigpend = p->pending.signal.sig[0];
1372         prstatus->pr_sighold = p->blocked.sig[0];
1373         rcu_read_lock();
1374         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1375         rcu_read_unlock();
1376         prstatus->pr_pid = task_pid_vnr(p);
1377         prstatus->pr_pgrp = task_pgrp_vnr(p);
1378         prstatus->pr_sid = task_session_vnr(p);
1379         if (thread_group_leader(p)) {
1380                 struct task_cputime cputime;
1381
1382                 /*
1383                  * This is the record for the group leader.  It shows the
1384                  * group-wide total, not its individual thread total.
1385                  */
1386                 thread_group_cputime(p, &cputime);
1387                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1388                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1389         } else {
1390                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1391                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1392         }
1393         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1394         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1395
1396         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1397         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1398 }
1399
1400 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1401                        struct mm_struct *mm)
1402 {
1403         const struct cred *cred;
1404         unsigned int i, len;
1405
1406         /* first copy the parameters from user space */
1407         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1408
1409         len = mm->arg_end - mm->arg_start;
1410         if (len >= ELF_PRARGSZ)
1411                 len = ELF_PRARGSZ - 1;
1412         if (copy_from_user(&psinfo->pr_psargs,
1413                            (const char __user *) mm->arg_start, len))
1414                 return -EFAULT;
1415         for (i = 0; i < len; i++)
1416                 if (psinfo->pr_psargs[i] == 0)
1417                         psinfo->pr_psargs[i] = ' ';
1418         psinfo->pr_psargs[len] = 0;
1419
1420         rcu_read_lock();
1421         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1422         rcu_read_unlock();
1423         psinfo->pr_pid = task_pid_vnr(p);
1424         psinfo->pr_pgrp = task_pgrp_vnr(p);
1425         psinfo->pr_sid = task_session_vnr(p);
1426
1427         i = p->state ? ffz(~p->state) + 1 : 0;
1428         psinfo->pr_state = i;
1429         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1430         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1431         psinfo->pr_nice = task_nice(p);
1432         psinfo->pr_flag = p->flags;
1433         rcu_read_lock();
1434         cred = __task_cred(p);
1435         SET_UID(psinfo->pr_uid, cred->uid);
1436         SET_GID(psinfo->pr_gid, cred->gid);
1437         rcu_read_unlock();
1438         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1439
1440         return 0;
1441 }
1442
1443 /* Here is the structure in which status of each thread is captured. */
1444 struct elf_thread_status
1445 {
1446         struct list_head list;
1447         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1448         elf_fpregset_t fpu;             /* NT_PRFPREG */
1449         struct task_struct *thread;
1450 #ifdef ELF_CORE_COPY_XFPREGS
1451         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1452 #endif
1453         struct memelfnote notes[3];
1454         int num_notes;
1455 };
1456
1457 /*
1458  * In order to add the specific thread information for the elf file format,
1459  * we need to keep a linked list of every thread's pr_status and then create
1460  * a single section for them in the final core file.
1461  */
1462 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1463 {
1464         struct task_struct *p = t->thread;
1465         int sz = 0;
1466
1467         t->num_notes = 0;
1468
1469         fill_prstatus(&t->prstatus, p, signr);
1470         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1471
1472         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1473                   &t->prstatus);
1474         t->num_notes++;
1475         sz += notesize(&t->notes[0]);
1476
1477         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1478         if (t->prstatus.pr_fpvalid) {
1479                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1480                           &t->fpu);
1481                 t->num_notes++;
1482                 sz += notesize(&t->notes[1]);
1483         }
1484
1485 #ifdef ELF_CORE_COPY_XFPREGS
1486         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1487                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1488                           sizeof(t->xfpu), &t->xfpu);
1489                 t->num_notes++;
1490                 sz += notesize(&t->notes[2]);
1491         }
1492 #endif
1493         return sz;
1494 }
1495
1496 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1497                              elf_addr_t e_shoff, int segs)
1498 {
1499         elf->e_shoff = e_shoff;
1500         elf->e_shentsize = sizeof(*shdr4extnum);
1501         elf->e_shnum = 1;
1502         elf->e_shstrndx = SHN_UNDEF;
1503
1504         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1505
1506         shdr4extnum->sh_type = SHT_NULL;
1507         shdr4extnum->sh_size = elf->e_shnum;
1508         shdr4extnum->sh_link = elf->e_shstrndx;
1509         shdr4extnum->sh_info = segs;
1510 }
1511
1512 /*
1513  * dump the segments for an MMU process
1514  */
1515 #ifdef CONFIG_MMU
1516 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1517                            unsigned long *limit, unsigned long mm_flags)
1518 {
1519         struct vm_area_struct *vma;
1520         int err = 0;
1521
1522         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1523                 unsigned long addr;
1524
1525                 if (!maydump(vma, mm_flags))
1526                         continue;
1527
1528                 for (addr = vma->vm_start; addr < vma->vm_end;
1529                                                         addr += PAGE_SIZE) {
1530                         struct page *page = get_dump_page(addr);
1531                         if (page) {
1532                                 void *kaddr = kmap(page);
1533                                 *size += PAGE_SIZE;
1534                                 if (*size > *limit)
1535                                         err = -EFBIG;
1536                                 else if (!dump_write(file, kaddr, PAGE_SIZE))
1537                                         err = -EIO;
1538                                 kunmap(page);
1539                                 page_cache_release(page);
1540                         } else if (!dump_seek(file, PAGE_SIZE))
1541                                 err = -EFBIG;
1542                         if (err)
1543                                 goto out;
1544                 }
1545         }
1546 out:
1547         return err;
1548 }
1549 #endif
1550
1551 /*
1552  * dump the segments for a NOMMU process
1553  */
1554 #ifndef CONFIG_MMU
1555 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1556                            unsigned long *limit, unsigned long mm_flags)
1557 {
1558         struct vm_area_struct *vma;
1559
1560         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1561                 if (!maydump(vma, mm_flags))
1562                         continue;
1563
1564                 if ((*size += PAGE_SIZE) > *limit)
1565                         return -EFBIG;
1566
1567                 if (!dump_write(file, (void *) vma->vm_start,
1568                                 vma->vm_end - vma->vm_start))
1569                         return -EIO;
1570         }
1571
1572         return 0;
1573 }
1574 #endif
1575
1576 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1577 {
1578         struct vm_area_struct *vma;
1579         size_t size = 0;
1580
1581         for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1582                 if (maydump(vma, mm_flags))
1583                         size += vma->vm_end - vma->vm_start;
1584         return size;
1585 }
1586
1587 /*
1588  * Actual dumper
1589  *
1590  * This is a two-pass process; first we find the offsets of the bits,
1591  * and then they are actually written out.  If we run out of core limit
1592  * we just truncate.
1593  */
1594 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1595 {
1596 #define NUM_NOTES       6
1597         int has_dumped = 0;
1598         mm_segment_t fs;
1599         int segs;
1600         size_t size = 0;
1601         int i;
1602         struct vm_area_struct *vma;
1603         struct elfhdr *elf = NULL;
1604         loff_t offset = 0, dataoff, foffset;
1605         int numnote;
1606         struct memelfnote *notes = NULL;
1607         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1608         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1609         LIST_HEAD(thread_list);
1610         struct list_head *t;
1611         elf_fpregset_t *fpu = NULL;
1612 #ifdef ELF_CORE_COPY_XFPREGS
1613         elf_fpxregset_t *xfpu = NULL;
1614 #endif
1615         int thread_status_size = 0;
1616         elf_addr_t *auxv;
1617         struct elf_phdr *phdr4note = NULL;
1618         struct elf_shdr *shdr4extnum = NULL;
1619         Elf_Half e_phnum;
1620         elf_addr_t e_shoff;
1621
1622         /*
1623          * We no longer stop all VM operations.
1624          *
1625          * This is because those proceses that could possibly change map_count
1626          * or the mmap / vma pages are now blocked in do_exit on current
1627          * finishing this core dump.
1628          *
1629          * Only ptrace can touch these memory addresses, but it doesn't change
1630          * the map_count or the pages allocated. So no possibility of crashing
1631          * exists while dumping the mm->vm_next areas to the core file.
1632          */
1633
1634         /* alloc memory for large data structures: too large to be on stack */
1635         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1636         if (!elf)
1637                 goto cleanup;
1638         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1639         if (!prstatus)
1640                 goto cleanup;
1641         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1642         if (!psinfo)
1643                 goto cleanup;
1644         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1645         if (!notes)
1646                 goto cleanup;
1647         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1648         if (!fpu)
1649                 goto cleanup;
1650 #ifdef ELF_CORE_COPY_XFPREGS
1651         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1652         if (!xfpu)
1653                 goto cleanup;
1654 #endif
1655
1656         if (cprm->signr) {
1657                 struct core_thread *ct;
1658                 struct elf_thread_status *tmp;
1659
1660                 for (ct = current->mm->core_state->dumper.next;
1661                                                 ct; ct = ct->next) {
1662                         tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1663                         if (!tmp)
1664                                 goto cleanup;
1665
1666                         tmp->thread = ct->task;
1667                         list_add(&tmp->list, &thread_list);
1668                 }
1669
1670                 list_for_each(t, &thread_list) {
1671                         struct elf_thread_status *tmp;
1672                         int sz;
1673
1674                         tmp = list_entry(t, struct elf_thread_status, list);
1675                         sz = elf_dump_thread_status(cprm->signr, tmp);
1676                         thread_status_size += sz;
1677                 }
1678         }
1679
1680         /* now collect the dump for the current */
1681         fill_prstatus(prstatus, current, cprm->signr);
1682         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1683
1684         segs = current->mm->map_count;
1685         segs += elf_core_extra_phdrs();
1686
1687         /* for notes section */
1688         segs++;
1689
1690         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1691          * this, kernel supports extended numbering. Have a look at
1692          * include/linux/elf.h for further information. */
1693         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1694
1695         /* Set up header */
1696         fill_elf_fdpic_header(elf, e_phnum);
1697
1698         has_dumped = 1;
1699         current->flags |= PF_DUMPCORE;
1700
1701         /*
1702          * Set up the notes in similar form to SVR4 core dumps made
1703          * with info from their /proc.
1704          */
1705
1706         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1707         fill_psinfo(psinfo, current->group_leader, current->mm);
1708         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1709
1710         numnote = 2;
1711
1712         auxv = (elf_addr_t *) current->mm->saved_auxv;
1713
1714         i = 0;
1715         do
1716                 i += 2;
1717         while (auxv[i - 2] != AT_NULL);
1718         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1719                   i * sizeof(elf_addr_t), auxv);
1720
1721         /* Try to dump the FPU. */
1722         if ((prstatus->pr_fpvalid =
1723              elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1724                 fill_note(notes + numnote++,
1725                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1726 #ifdef ELF_CORE_COPY_XFPREGS
1727         if (elf_core_copy_task_xfpregs(current, xfpu))
1728                 fill_note(notes + numnote++,
1729                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1730 #endif
1731
1732         fs = get_fs();
1733         set_fs(KERNEL_DS);
1734
1735         offset += sizeof(*elf);                         /* Elf header */
1736         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1737         foffset = offset;
1738
1739         /* Write notes phdr entry */
1740         {
1741                 int sz = 0;
1742
1743                 for (i = 0; i < numnote; i++)
1744                         sz += notesize(notes + i);
1745
1746                 sz += thread_status_size;
1747
1748                 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1749                 if (!phdr4note)
1750                         goto end_coredump;
1751
1752                 fill_elf_note_phdr(phdr4note, sz, offset);
1753                 offset += sz;
1754         }
1755
1756         /* Page-align dumped data */
1757         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1758
1759         offset += elf_core_vma_data_size(cprm->mm_flags);
1760         offset += elf_core_extra_data_size();
1761         e_shoff = offset;
1762
1763         if (e_phnum == PN_XNUM) {
1764                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1765                 if (!shdr4extnum)
1766                         goto end_coredump;
1767                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1768         }
1769
1770         offset = dataoff;
1771
1772         size += sizeof(*elf);
1773         if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
1774                 goto end_coredump;
1775
1776         size += sizeof(*phdr4note);
1777         if (size > cprm->limit
1778             || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
1779                 goto end_coredump;
1780
1781         /* write program headers for segments dump */
1782         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1783                 struct elf_phdr phdr;
1784                 size_t sz;
1785
1786                 sz = vma->vm_end - vma->vm_start;
1787
1788                 phdr.p_type = PT_LOAD;
1789                 phdr.p_offset = offset;
1790                 phdr.p_vaddr = vma->vm_start;
1791                 phdr.p_paddr = 0;
1792                 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1793                 phdr.p_memsz = sz;
1794                 offset += phdr.p_filesz;
1795                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1796                 if (vma->vm_flags & VM_WRITE)
1797                         phdr.p_flags |= PF_W;
1798                 if (vma->vm_flags & VM_EXEC)
1799                         phdr.p_flags |= PF_X;
1800                 phdr.p_align = ELF_EXEC_PAGESIZE;
1801
1802                 size += sizeof(phdr);
1803                 if (size > cprm->limit
1804                     || !dump_write(cprm->file, &phdr, sizeof(phdr)))
1805                         goto end_coredump;
1806         }
1807
1808         if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
1809                 goto end_coredump;
1810
1811         /* write out the notes section */
1812         for (i = 0; i < numnote; i++)
1813                 if (!writenote(notes + i, cprm->file, &foffset))
1814                         goto end_coredump;
1815
1816         /* write out the thread status notes section */
1817         list_for_each(t, &thread_list) {
1818                 struct elf_thread_status *tmp =
1819                                 list_entry(t, struct elf_thread_status, list);
1820
1821                 for (i = 0; i < tmp->num_notes; i++)
1822                         if (!writenote(&tmp->notes[i], cprm->file, &foffset))
1823                                 goto end_coredump;
1824         }
1825
1826         if (!dump_seek(cprm->file, dataoff - foffset))
1827                 goto end_coredump;
1828
1829         if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit,
1830                                     cprm->mm_flags) < 0)
1831                 goto end_coredump;
1832
1833         if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
1834                 goto end_coredump;
1835
1836         if (e_phnum == PN_XNUM) {
1837                 size += sizeof(*shdr4extnum);
1838                 if (size > cprm->limit
1839                     || !dump_write(cprm->file, shdr4extnum,
1840                                    sizeof(*shdr4extnum)))
1841                         goto end_coredump;
1842         }
1843
1844         if (cprm->file->f_pos != offset) {
1845                 /* Sanity check */
1846                 printk(KERN_WARNING
1847                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1848                        cprm->file->f_pos, offset);
1849         }
1850
1851 end_coredump:
1852         set_fs(fs);
1853
1854 cleanup:
1855         while (!list_empty(&thread_list)) {
1856                 struct list_head *tmp = thread_list.next;
1857                 list_del(tmp);
1858                 kfree(list_entry(tmp, struct elf_thread_status, list));
1859         }
1860         kfree(phdr4note);
1861         kfree(elf);
1862         kfree(prstatus);
1863         kfree(psinfo);
1864         kfree(notes);
1865         kfree(fpu);
1866         kfree(shdr4extnum);
1867 #ifdef ELF_CORE_COPY_XFPREGS
1868         kfree(xfpu);
1869 #endif
1870         return has_dumped;
1871 #undef NUM_NOTES
1872 }
1873
1874 #endif          /* CONFIG_ELF_CORE */