CRED: Separate task security context from task_struct
[linux-3.10.git] / fs / binfmt_elf_fdpic.c
1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
2  *
3  * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  * Derived from binfmt_elf.c
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version
10  * 2 of the License, or (at your option) any later version.
11  */
12
13 #include <linux/module.h>
14
15 #include <linux/fs.h>
16 #include <linux/stat.h>
17 #include <linux/sched.h>
18 #include <linux/mm.h>
19 #include <linux/mman.h>
20 #include <linux/errno.h>
21 #include <linux/signal.h>
22 #include <linux/binfmts.h>
23 #include <linux/string.h>
24 #include <linux/file.h>
25 #include <linux/fcntl.h>
26 #include <linux/slab.h>
27 #include <linux/pagemap.h>
28 #include <linux/security.h>
29 #include <linux/highmem.h>
30 #include <linux/highuid.h>
31 #include <linux/personality.h>
32 #include <linux/ptrace.h>
33 #include <linux/init.h>
34 #include <linux/elf.h>
35 #include <linux/elf-fdpic.h>
36 #include <linux/elfcore.h>
37
38 #include <asm/uaccess.h>
39 #include <asm/param.h>
40 #include <asm/pgalloc.h>
41
42 typedef char *elf_caddr_t;
43
44 #if 0
45 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
46 #else
47 #define kdebug(fmt, ...) do {} while(0)
48 #endif
49
50 #if 0
51 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
52 #else
53 #define kdcore(fmt, ...) do {} while(0)
54 #endif
55
56 MODULE_LICENSE("GPL");
57
58 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
59 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
60 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
61                               struct mm_struct *, const char *);
62
63 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
64                                    struct elf_fdpic_params *,
65                                    struct elf_fdpic_params *);
66
67 #ifndef CONFIG_MMU
68 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
69                                             unsigned long *);
70 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
71                                                    struct file *,
72                                                    struct mm_struct *);
73 #endif
74
75 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
76                                              struct file *, struct mm_struct *);
77
78 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
79 static int elf_fdpic_core_dump(long, struct pt_regs *, struct file *, unsigned long limit);
80 #endif
81
82 static struct linux_binfmt elf_fdpic_format = {
83         .module         = THIS_MODULE,
84         .load_binary    = load_elf_fdpic_binary,
85 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
86         .core_dump      = elf_fdpic_core_dump,
87 #endif
88         .min_coredump   = ELF_EXEC_PAGESIZE,
89 };
90
91 static int __init init_elf_fdpic_binfmt(void)
92 {
93         return register_binfmt(&elf_fdpic_format);
94 }
95
96 static void __exit exit_elf_fdpic_binfmt(void)
97 {
98         unregister_binfmt(&elf_fdpic_format);
99 }
100
101 core_initcall(init_elf_fdpic_binfmt);
102 module_exit(exit_elf_fdpic_binfmt);
103
104 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
105 {
106         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
107                 return 0;
108         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
109                 return 0;
110         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
111                 return 0;
112         if (!file->f_op || !file->f_op->mmap)
113                 return 0;
114         return 1;
115 }
116
117 /*****************************************************************************/
118 /*
119  * read the program headers table into memory
120  */
121 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
122                                  struct file *file)
123 {
124         struct elf32_phdr *phdr;
125         unsigned long size;
126         int retval, loop;
127
128         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
129                 return -ENOMEM;
130         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
131                 return -ENOMEM;
132
133         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
134         params->phdrs = kmalloc(size, GFP_KERNEL);
135         if (!params->phdrs)
136                 return -ENOMEM;
137
138         retval = kernel_read(file, params->hdr.e_phoff,
139                              (char *) params->phdrs, size);
140         if (unlikely(retval != size))
141                 return retval < 0 ? retval : -ENOEXEC;
142
143         /* determine stack size for this binary */
144         phdr = params->phdrs;
145         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
146                 if (phdr->p_type != PT_GNU_STACK)
147                         continue;
148
149                 if (phdr->p_flags & PF_X)
150                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
151                 else
152                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
153
154                 params->stack_size = phdr->p_memsz;
155                 break;
156         }
157
158         return 0;
159 }
160
161 /*****************************************************************************/
162 /*
163  * load an fdpic binary into various bits of memory
164  */
165 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
166                                  struct pt_regs *regs)
167 {
168         struct elf_fdpic_params exec_params, interp_params;
169         struct elf_phdr *phdr;
170         unsigned long stack_size, entryaddr;
171 #ifndef CONFIG_MMU
172         unsigned long fullsize;
173 #endif
174 #ifdef ELF_FDPIC_PLAT_INIT
175         unsigned long dynaddr;
176 #endif
177         struct file *interpreter = NULL; /* to shut gcc up */
178         char *interpreter_name = NULL;
179         int executable_stack;
180         int retval, i;
181
182         kdebug("____ LOAD %d ____", current->pid);
183
184         memset(&exec_params, 0, sizeof(exec_params));
185         memset(&interp_params, 0, sizeof(interp_params));
186
187         exec_params.hdr = *(struct elfhdr *) bprm->buf;
188         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
189
190         /* check that this is a binary we know how to deal with */
191         retval = -ENOEXEC;
192         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
193                 goto error;
194
195         /* read the program header table */
196         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
197         if (retval < 0)
198                 goto error;
199
200         /* scan for a program header that specifies an interpreter */
201         phdr = exec_params.phdrs;
202
203         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
204                 switch (phdr->p_type) {
205                 case PT_INTERP:
206                         retval = -ENOMEM;
207                         if (phdr->p_filesz > PATH_MAX)
208                                 goto error;
209                         retval = -ENOENT;
210                         if (phdr->p_filesz < 2)
211                                 goto error;
212
213                         /* read the name of the interpreter into memory */
214                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
215                         if (!interpreter_name)
216                                 goto error;
217
218                         retval = kernel_read(bprm->file,
219                                              phdr->p_offset,
220                                              interpreter_name,
221                                              phdr->p_filesz);
222                         if (unlikely(retval != phdr->p_filesz)) {
223                                 if (retval >= 0)
224                                         retval = -ENOEXEC;
225                                 goto error;
226                         }
227
228                         retval = -ENOENT;
229                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
230                                 goto error;
231
232                         kdebug("Using ELF interpreter %s", interpreter_name);
233
234                         /* replace the program with the interpreter */
235                         interpreter = open_exec(interpreter_name);
236                         retval = PTR_ERR(interpreter);
237                         if (IS_ERR(interpreter)) {
238                                 interpreter = NULL;
239                                 goto error;
240                         }
241
242                         /*
243                          * If the binary is not readable then enforce
244                          * mm->dumpable = 0 regardless of the interpreter's
245                          * permissions.
246                          */
247                         if (file_permission(interpreter, MAY_READ) < 0)
248                                 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
249
250                         retval = kernel_read(interpreter, 0, bprm->buf,
251                                              BINPRM_BUF_SIZE);
252                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
253                                 if (retval >= 0)
254                                         retval = -ENOEXEC;
255                                 goto error;
256                         }
257
258                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
259                         break;
260
261                 case PT_LOAD:
262 #ifdef CONFIG_MMU
263                         if (exec_params.load_addr == 0)
264                                 exec_params.load_addr = phdr->p_vaddr;
265 #endif
266                         break;
267                 }
268
269         }
270
271         if (elf_check_const_displacement(&exec_params.hdr))
272                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
273
274         /* perform insanity checks on the interpreter */
275         if (interpreter_name) {
276                 retval = -ELIBBAD;
277                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
278                         goto error;
279
280                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
281
282                 /* read the interpreter's program header table */
283                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
284                 if (retval < 0)
285                         goto error;
286         }
287
288         stack_size = exec_params.stack_size;
289         if (stack_size < interp_params.stack_size)
290                 stack_size = interp_params.stack_size;
291
292         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
293                 executable_stack = EXSTACK_ENABLE_X;
294         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
295                 executable_stack = EXSTACK_DISABLE_X;
296         else if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
297                 executable_stack = EXSTACK_ENABLE_X;
298         else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
299                 executable_stack = EXSTACK_DISABLE_X;
300         else
301                 executable_stack = EXSTACK_DEFAULT;
302
303         retval = -ENOEXEC;
304         if (stack_size == 0)
305                 goto error;
306
307         if (elf_check_const_displacement(&interp_params.hdr))
308                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
309
310         /* flush all traces of the currently running executable */
311         retval = flush_old_exec(bprm);
312         if (retval)
313                 goto error;
314
315         /* there's now no turning back... the old userspace image is dead,
316          * defunct, deceased, etc. after this point we have to exit via
317          * error_kill */
318         set_personality(PER_LINUX_FDPIC);
319         set_binfmt(&elf_fdpic_format);
320
321         current->mm->start_code = 0;
322         current->mm->end_code = 0;
323         current->mm->start_stack = 0;
324         current->mm->start_data = 0;
325         current->mm->end_data = 0;
326         current->mm->context.exec_fdpic_loadmap = 0;
327         current->mm->context.interp_fdpic_loadmap = 0;
328
329         current->flags &= ~PF_FORKNOEXEC;
330
331 #ifdef CONFIG_MMU
332         elf_fdpic_arch_lay_out_mm(&exec_params,
333                                   &interp_params,
334                                   &current->mm->start_stack,
335                                   &current->mm->start_brk);
336
337         retval = setup_arg_pages(bprm, current->mm->start_stack,
338                                  executable_stack);
339         if (retval < 0) {
340                 send_sig(SIGKILL, current, 0);
341                 goto error_kill;
342         }
343 #endif
344
345         /* load the executable and interpreter into memory */
346         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
347                                     "executable");
348         if (retval < 0)
349                 goto error_kill;
350
351         if (interpreter_name) {
352                 retval = elf_fdpic_map_file(&interp_params, interpreter,
353                                             current->mm, "interpreter");
354                 if (retval < 0) {
355                         printk(KERN_ERR "Unable to load interpreter\n");
356                         goto error_kill;
357                 }
358
359                 allow_write_access(interpreter);
360                 fput(interpreter);
361                 interpreter = NULL;
362         }
363
364 #ifdef CONFIG_MMU
365         if (!current->mm->start_brk)
366                 current->mm->start_brk = current->mm->end_data;
367
368         current->mm->brk = current->mm->start_brk =
369                 PAGE_ALIGN(current->mm->start_brk);
370
371 #else
372         /* create a stack and brk area big enough for everyone
373          * - the brk heap starts at the bottom and works up
374          * - the stack starts at the top and works down
375          */
376         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
377         if (stack_size < PAGE_SIZE * 2)
378                 stack_size = PAGE_SIZE * 2;
379
380         down_write(&current->mm->mmap_sem);
381         current->mm->start_brk = do_mmap(NULL, 0, stack_size,
382                                          PROT_READ | PROT_WRITE | PROT_EXEC,
383                                          MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
384                                          0);
385
386         if (IS_ERR_VALUE(current->mm->start_brk)) {
387                 up_write(&current->mm->mmap_sem);
388                 retval = current->mm->start_brk;
389                 current->mm->start_brk = 0;
390                 goto error_kill;
391         }
392
393         /* expand the stack mapping to use up the entire allocation granule */
394         fullsize = kobjsize((char *) current->mm->start_brk);
395         if (!IS_ERR_VALUE(do_mremap(current->mm->start_brk, stack_size,
396                                     fullsize, 0, 0)))
397                 stack_size = fullsize;
398         up_write(&current->mm->mmap_sem);
399
400         current->mm->brk = current->mm->start_brk;
401         current->mm->context.end_brk = current->mm->start_brk;
402         current->mm->context.end_brk +=
403                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
404         current->mm->start_stack = current->mm->start_brk + stack_size;
405 #endif
406
407         compute_creds(bprm);
408         current->flags &= ~PF_FORKNOEXEC;
409         if (create_elf_fdpic_tables(bprm, current->mm,
410                                     &exec_params, &interp_params) < 0)
411                 goto error_kill;
412
413         kdebug("- start_code  %lx", current->mm->start_code);
414         kdebug("- end_code    %lx", current->mm->end_code);
415         kdebug("- start_data  %lx", current->mm->start_data);
416         kdebug("- end_data    %lx", current->mm->end_data);
417         kdebug("- start_brk   %lx", current->mm->start_brk);
418         kdebug("- brk         %lx", current->mm->brk);
419         kdebug("- start_stack %lx", current->mm->start_stack);
420
421 #ifdef ELF_FDPIC_PLAT_INIT
422         /*
423          * The ABI may specify that certain registers be set up in special
424          * ways (on i386 %edx is the address of a DT_FINI function, for
425          * example.  This macro performs whatever initialization to
426          * the regs structure is required.
427          */
428         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
429         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
430                             dynaddr);
431 #endif
432
433         /* everything is now ready... get the userspace context ready to roll */
434         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
435         start_thread(regs, entryaddr, current->mm->start_stack);
436
437         retval = 0;
438
439 error:
440         if (interpreter) {
441                 allow_write_access(interpreter);
442                 fput(interpreter);
443         }
444         kfree(interpreter_name);
445         kfree(exec_params.phdrs);
446         kfree(exec_params.loadmap);
447         kfree(interp_params.phdrs);
448         kfree(interp_params.loadmap);
449         return retval;
450
451         /* unrecoverable error - kill the process */
452 error_kill:
453         send_sig(SIGSEGV, current, 0);
454         goto error;
455
456 }
457
458 /*****************************************************************************/
459
460 #ifndef ELF_BASE_PLATFORM
461 /*
462  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
463  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
464  * will be copied to the user stack in the same manner as AT_PLATFORM.
465  */
466 #define ELF_BASE_PLATFORM NULL
467 #endif
468
469 /*
470  * present useful information to the program by shovelling it onto the new
471  * process's stack
472  */
473 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
474                                    struct mm_struct *mm,
475                                    struct elf_fdpic_params *exec_params,
476                                    struct elf_fdpic_params *interp_params)
477 {
478         unsigned long sp, csp, nitems;
479         elf_caddr_t __user *argv, *envp;
480         size_t platform_len = 0, len;
481         char *k_platform, *k_base_platform;
482         char __user *u_platform, *u_base_platform, *p;
483         long hwcap;
484         int loop;
485         int nr; /* reset for each csp adjustment */
486
487 #ifdef CONFIG_MMU
488         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
489          * by the processes running on the same package. One thing we can do is
490          * to shuffle the initial stack for them, so we give the architecture
491          * an opportunity to do so here.
492          */
493         sp = arch_align_stack(bprm->p);
494 #else
495         sp = mm->start_stack;
496
497         /* stack the program arguments and environment */
498         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
499                 return -EFAULT;
500 #endif
501
502         hwcap = ELF_HWCAP;
503
504         /*
505          * If this architecture has a platform capability string, copy it
506          * to userspace.  In some cases (Sparc), this info is impossible
507          * for userspace to get any other way, in others (i386) it is
508          * merely difficult.
509          */
510         k_platform = ELF_PLATFORM;
511         u_platform = NULL;
512
513         if (k_platform) {
514                 platform_len = strlen(k_platform) + 1;
515                 sp -= platform_len;
516                 u_platform = (char __user *) sp;
517                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
518                         return -EFAULT;
519         }
520
521         /*
522          * If this architecture has a "base" platform capability
523          * string, copy it to userspace.
524          */
525         k_base_platform = ELF_BASE_PLATFORM;
526         u_base_platform = NULL;
527
528         if (k_base_platform) {
529                 platform_len = strlen(k_base_platform) + 1;
530                 sp -= platform_len;
531                 u_base_platform = (char __user *) sp;
532                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
533                         return -EFAULT;
534         }
535
536         sp &= ~7UL;
537
538         /* stack the load map(s) */
539         len = sizeof(struct elf32_fdpic_loadmap);
540         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
541         sp = (sp - len) & ~7UL;
542         exec_params->map_addr = sp;
543
544         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
545                 return -EFAULT;
546
547         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
548
549         if (interp_params->loadmap) {
550                 len = sizeof(struct elf32_fdpic_loadmap);
551                 len += sizeof(struct elf32_fdpic_loadseg) *
552                         interp_params->loadmap->nsegs;
553                 sp = (sp - len) & ~7UL;
554                 interp_params->map_addr = sp;
555
556                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
557                                  len) != 0)
558                         return -EFAULT;
559
560                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
561         }
562
563         /* force 16 byte _final_ alignment here for generality */
564 #define DLINFO_ITEMS 15
565
566         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
567                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
568
569         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
570                 nitems++;
571
572         csp = sp;
573         sp -= nitems * 2 * sizeof(unsigned long);
574         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
575         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
576         sp -= 1 * sizeof(unsigned long);                /* argc */
577
578         csp -= sp & 15UL;
579         sp -= sp & 15UL;
580
581         /* put the ELF interpreter info on the stack */
582 #define NEW_AUX_ENT(id, val)                                            \
583         do {                                                            \
584                 struct { unsigned long _id, _val; } __user *ent;        \
585                                                                         \
586                 ent = (void __user *) csp;                              \
587                 __put_user((id), &ent[nr]._id);                         \
588                 __put_user((val), &ent[nr]._val);                       \
589                 nr++;                                                   \
590         } while (0)
591
592         nr = 0;
593         csp -= 2 * sizeof(unsigned long);
594         NEW_AUX_ENT(AT_NULL, 0);
595         if (k_platform) {
596                 nr = 0;
597                 csp -= 2 * sizeof(unsigned long);
598                 NEW_AUX_ENT(AT_PLATFORM,
599                             (elf_addr_t) (unsigned long) u_platform);
600         }
601
602         if (k_base_platform) {
603                 nr = 0;
604                 csp -= 2 * sizeof(unsigned long);
605                 NEW_AUX_ENT(AT_BASE_PLATFORM,
606                             (elf_addr_t) (unsigned long) u_base_platform);
607         }
608
609         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
610                 nr = 0;
611                 csp -= 2 * sizeof(unsigned long);
612                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
613         }
614
615         nr = 0;
616         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
617         NEW_AUX_ENT(AT_HWCAP,   hwcap);
618         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
619         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
620         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
621         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
622         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
623         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
624         NEW_AUX_ENT(AT_FLAGS,   0);
625         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
626         NEW_AUX_ENT(AT_UID,     (elf_addr_t) current->cred->uid);
627         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) current->cred->euid);
628         NEW_AUX_ENT(AT_GID,     (elf_addr_t) current->cred->gid);
629         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) current->cred->egid);
630         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
631         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
632
633 #ifdef ARCH_DLINFO
634         nr = 0;
635         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
636
637         /* ARCH_DLINFO must come last so platform specific code can enforce
638          * special alignment requirements on the AUXV if necessary (eg. PPC).
639          */
640         ARCH_DLINFO;
641 #endif
642 #undef NEW_AUX_ENT
643
644         /* allocate room for argv[] and envv[] */
645         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
646         envp = (elf_caddr_t __user *) csp;
647         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
648         argv = (elf_caddr_t __user *) csp;
649
650         /* stack argc */
651         csp -= sizeof(unsigned long);
652         __put_user(bprm->argc, (unsigned long __user *) csp);
653
654         BUG_ON(csp != sp);
655
656         /* fill in the argv[] array */
657 #ifdef CONFIG_MMU
658         current->mm->arg_start = bprm->p;
659 #else
660         current->mm->arg_start = current->mm->start_stack -
661                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
662 #endif
663
664         p = (char __user *) current->mm->arg_start;
665         for (loop = bprm->argc; loop > 0; loop--) {
666                 __put_user((elf_caddr_t) p, argv++);
667                 len = strnlen_user(p, MAX_ARG_STRLEN);
668                 if (!len || len > MAX_ARG_STRLEN)
669                         return -EINVAL;
670                 p += len;
671         }
672         __put_user(NULL, argv);
673         current->mm->arg_end = (unsigned long) p;
674
675         /* fill in the envv[] array */
676         current->mm->env_start = (unsigned long) p;
677         for (loop = bprm->envc; loop > 0; loop--) {
678                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
679                 len = strnlen_user(p, MAX_ARG_STRLEN);
680                 if (!len || len > MAX_ARG_STRLEN)
681                         return -EINVAL;
682                 p += len;
683         }
684         __put_user(NULL, envp);
685         current->mm->env_end = (unsigned long) p;
686
687         mm->start_stack = (unsigned long) sp;
688         return 0;
689 }
690
691 /*****************************************************************************/
692 /*
693  * transfer the program arguments and environment from the holding pages onto
694  * the stack
695  */
696 #ifndef CONFIG_MMU
697 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
698                                             unsigned long *_sp)
699 {
700         unsigned long index, stop, sp;
701         char *src;
702         int ret = 0;
703
704         stop = bprm->p >> PAGE_SHIFT;
705         sp = *_sp;
706
707         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
708                 src = kmap(bprm->page[index]);
709                 sp -= PAGE_SIZE;
710                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
711                         ret = -EFAULT;
712                 kunmap(bprm->page[index]);
713                 if (ret < 0)
714                         goto out;
715         }
716
717         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
718
719 out:
720         return ret;
721 }
722 #endif
723
724 /*****************************************************************************/
725 /*
726  * load the appropriate binary image (executable or interpreter) into memory
727  * - we assume no MMU is available
728  * - if no other PIC bits are set in params->hdr->e_flags
729  *   - we assume that the LOADable segments in the binary are independently relocatable
730  *   - we assume R/O executable segments are shareable
731  * - else
732  *   - we assume the loadable parts of the image to require fixed displacement
733  *   - the image is not shareable
734  */
735 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
736                               struct file *file,
737                               struct mm_struct *mm,
738                               const char *what)
739 {
740         struct elf32_fdpic_loadmap *loadmap;
741 #ifdef CONFIG_MMU
742         struct elf32_fdpic_loadseg *mseg;
743 #endif
744         struct elf32_fdpic_loadseg *seg;
745         struct elf32_phdr *phdr;
746         unsigned long load_addr, stop;
747         unsigned nloads, tmp;
748         size_t size;
749         int loop, ret;
750
751         /* allocate a load map table */
752         nloads = 0;
753         for (loop = 0; loop < params->hdr.e_phnum; loop++)
754                 if (params->phdrs[loop].p_type == PT_LOAD)
755                         nloads++;
756
757         if (nloads == 0)
758                 return -ELIBBAD;
759
760         size = sizeof(*loadmap) + nloads * sizeof(*seg);
761         loadmap = kzalloc(size, GFP_KERNEL);
762         if (!loadmap)
763                 return -ENOMEM;
764
765         params->loadmap = loadmap;
766
767         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
768         loadmap->nsegs = nloads;
769
770         load_addr = params->load_addr;
771         seg = loadmap->segs;
772
773         /* map the requested LOADs into the memory space */
774         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
775         case ELF_FDPIC_FLAG_CONSTDISP:
776         case ELF_FDPIC_FLAG_CONTIGUOUS:
777 #ifndef CONFIG_MMU
778                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
779                 if (ret < 0)
780                         return ret;
781                 break;
782 #endif
783         default:
784                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
785                 if (ret < 0)
786                         return ret;
787                 break;
788         }
789
790         /* map the entry point */
791         if (params->hdr.e_entry) {
792                 seg = loadmap->segs;
793                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
794                         if (params->hdr.e_entry >= seg->p_vaddr &&
795                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
796                                 params->entry_addr =
797                                         (params->hdr.e_entry - seg->p_vaddr) +
798                                         seg->addr;
799                                 break;
800                         }
801                 }
802         }
803
804         /* determine where the program header table has wound up if mapped */
805         stop = params->hdr.e_phoff;
806         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
807         phdr = params->phdrs;
808
809         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
810                 if (phdr->p_type != PT_LOAD)
811                         continue;
812
813                 if (phdr->p_offset > params->hdr.e_phoff ||
814                     phdr->p_offset + phdr->p_filesz < stop)
815                         continue;
816
817                 seg = loadmap->segs;
818                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
819                         if (phdr->p_vaddr >= seg->p_vaddr &&
820                             phdr->p_vaddr + phdr->p_filesz <=
821                             seg->p_vaddr + seg->p_memsz) {
822                                 params->ph_addr =
823                                         (phdr->p_vaddr - seg->p_vaddr) +
824                                         seg->addr +
825                                         params->hdr.e_phoff - phdr->p_offset;
826                                 break;
827                         }
828                 }
829                 break;
830         }
831
832         /* determine where the dynamic section has wound up if there is one */
833         phdr = params->phdrs;
834         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
835                 if (phdr->p_type != PT_DYNAMIC)
836                         continue;
837
838                 seg = loadmap->segs;
839                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
840                         if (phdr->p_vaddr >= seg->p_vaddr &&
841                             phdr->p_vaddr + phdr->p_memsz <=
842                             seg->p_vaddr + seg->p_memsz) {
843                                 params->dynamic_addr =
844                                         (phdr->p_vaddr - seg->p_vaddr) +
845                                         seg->addr;
846
847                                 /* check the dynamic section contains at least
848                                  * one item, and that the last item is a NULL
849                                  * entry */
850                                 if (phdr->p_memsz == 0 ||
851                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
852                                         goto dynamic_error;
853
854                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
855                                 if (((Elf32_Dyn *)
856                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
857                                         goto dynamic_error;
858                                 break;
859                         }
860                 }
861                 break;
862         }
863
864         /* now elide adjacent segments in the load map on MMU linux
865          * - on uClinux the holes between may actually be filled with system
866          *   stuff or stuff from other processes
867          */
868 #ifdef CONFIG_MMU
869         nloads = loadmap->nsegs;
870         mseg = loadmap->segs;
871         seg = mseg + 1;
872         for (loop = 1; loop < nloads; loop++) {
873                 /* see if we have a candidate for merging */
874                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
875                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
876                         if (load_addr == (seg->addr & PAGE_MASK)) {
877                                 mseg->p_memsz +=
878                                         load_addr -
879                                         (mseg->addr + mseg->p_memsz);
880                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
881                                 mseg->p_memsz += seg->p_memsz;
882                                 loadmap->nsegs--;
883                                 continue;
884                         }
885                 }
886
887                 mseg++;
888                 if (mseg != seg)
889                         *mseg = *seg;
890         }
891 #endif
892
893         kdebug("Mapped Object [%s]:", what);
894         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
895         kdebug("- entry    : %lx", params->entry_addr);
896         kdebug("- PHDR[]   : %lx", params->ph_addr);
897         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
898         seg = loadmap->segs;
899         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
900                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
901                        loop,
902                        seg->addr, seg->addr + seg->p_memsz - 1,
903                        seg->p_vaddr, seg->p_memsz);
904
905         return 0;
906
907 dynamic_error:
908         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
909                what, file->f_path.dentry->d_inode->i_ino);
910         return -ELIBBAD;
911 }
912
913 /*****************************************************************************/
914 /*
915  * map a file with constant displacement under uClinux
916  */
917 #ifndef CONFIG_MMU
918 static int elf_fdpic_map_file_constdisp_on_uclinux(
919         struct elf_fdpic_params *params,
920         struct file *file,
921         struct mm_struct *mm)
922 {
923         struct elf32_fdpic_loadseg *seg;
924         struct elf32_phdr *phdr;
925         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
926         loff_t fpos;
927         int loop, ret;
928
929         load_addr = params->load_addr;
930         seg = params->loadmap->segs;
931
932         /* determine the bounds of the contiguous overall allocation we must
933          * make */
934         phdr = params->phdrs;
935         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
936                 if (params->phdrs[loop].p_type != PT_LOAD)
937                         continue;
938
939                 if (base > phdr->p_vaddr)
940                         base = phdr->p_vaddr;
941                 if (top < phdr->p_vaddr + phdr->p_memsz)
942                         top = phdr->p_vaddr + phdr->p_memsz;
943         }
944
945         /* allocate one big anon block for everything */
946         mflags = MAP_PRIVATE;
947         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
948                 mflags |= MAP_EXECUTABLE;
949
950         down_write(&mm->mmap_sem);
951         maddr = do_mmap(NULL, load_addr, top - base,
952                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
953         up_write(&mm->mmap_sem);
954         if (IS_ERR_VALUE(maddr))
955                 return (int) maddr;
956
957         if (load_addr != 0)
958                 load_addr += PAGE_ALIGN(top - base);
959
960         /* and then load the file segments into it */
961         phdr = params->phdrs;
962         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
963                 if (params->phdrs[loop].p_type != PT_LOAD)
964                         continue;
965
966                 fpos = phdr->p_offset;
967
968                 seg->addr = maddr + (phdr->p_vaddr - base);
969                 seg->p_vaddr = phdr->p_vaddr;
970                 seg->p_memsz = phdr->p_memsz;
971
972                 ret = file->f_op->read(file, (void *) seg->addr,
973                                        phdr->p_filesz, &fpos);
974                 if (ret < 0)
975                         return ret;
976
977                 /* map the ELF header address if in this segment */
978                 if (phdr->p_offset == 0)
979                         params->elfhdr_addr = seg->addr;
980
981                 /* clear any space allocated but not loaded */
982                 if (phdr->p_filesz < phdr->p_memsz)
983                         clear_user((void *) (seg->addr + phdr->p_filesz),
984                                    phdr->p_memsz - phdr->p_filesz);
985
986                 if (mm) {
987                         if (phdr->p_flags & PF_X) {
988                                 if (!mm->start_code) {
989                                         mm->start_code = seg->addr;
990                                         mm->end_code = seg->addr +
991                                                 phdr->p_memsz;
992                                 }
993                         } else if (!mm->start_data) {
994                                 mm->start_data = seg->addr;
995 #ifndef CONFIG_MMU
996                                 mm->end_data = seg->addr + phdr->p_memsz;
997 #endif
998                         }
999
1000 #ifdef CONFIG_MMU
1001                         if (seg->addr + phdr->p_memsz > mm->end_data)
1002                                 mm->end_data = seg->addr + phdr->p_memsz;
1003 #endif
1004                 }
1005
1006                 seg++;
1007         }
1008
1009         return 0;
1010 }
1011 #endif
1012
1013 /*****************************************************************************/
1014 /*
1015  * map a binary by direct mmap() of the individual PT_LOAD segments
1016  */
1017 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1018                                              struct file *file,
1019                                              struct mm_struct *mm)
1020 {
1021         struct elf32_fdpic_loadseg *seg;
1022         struct elf32_phdr *phdr;
1023         unsigned long load_addr, delta_vaddr;
1024         int loop, dvset;
1025
1026         load_addr = params->load_addr;
1027         delta_vaddr = 0;
1028         dvset = 0;
1029
1030         seg = params->loadmap->segs;
1031
1032         /* deal with each load segment separately */
1033         phdr = params->phdrs;
1034         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1035                 unsigned long maddr, disp, excess, excess1;
1036                 int prot = 0, flags;
1037
1038                 if (phdr->p_type != PT_LOAD)
1039                         continue;
1040
1041                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1042                        (unsigned long) phdr->p_vaddr,
1043                        (unsigned long) phdr->p_offset,
1044                        (unsigned long) phdr->p_filesz,
1045                        (unsigned long) phdr->p_memsz);
1046
1047                 /* determine the mapping parameters */
1048                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1049                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1050                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1051
1052                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1053                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1054                         flags |= MAP_EXECUTABLE;
1055
1056                 maddr = 0;
1057
1058                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1059                 case ELF_FDPIC_FLAG_INDEPENDENT:
1060                         /* PT_LOADs are independently locatable */
1061                         break;
1062
1063                 case ELF_FDPIC_FLAG_HONOURVADDR:
1064                         /* the specified virtual address must be honoured */
1065                         maddr = phdr->p_vaddr;
1066                         flags |= MAP_FIXED;
1067                         break;
1068
1069                 case ELF_FDPIC_FLAG_CONSTDISP:
1070                         /* constant displacement
1071                          * - can be mapped anywhere, but must be mapped as a
1072                          *   unit
1073                          */
1074                         if (!dvset) {
1075                                 maddr = load_addr;
1076                                 delta_vaddr = phdr->p_vaddr;
1077                                 dvset = 1;
1078                         } else {
1079                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1080                                 flags |= MAP_FIXED;
1081                         }
1082                         break;
1083
1084                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1085                         /* contiguity handled later */
1086                         break;
1087
1088                 default:
1089                         BUG();
1090                 }
1091
1092                 maddr &= PAGE_MASK;
1093
1094                 /* create the mapping */
1095                 disp = phdr->p_vaddr & ~PAGE_MASK;
1096                 down_write(&mm->mmap_sem);
1097                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1098                                 phdr->p_offset - disp);
1099                 up_write(&mm->mmap_sem);
1100
1101                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1102                        loop, phdr->p_memsz + disp, prot, flags,
1103                        phdr->p_offset - disp, maddr);
1104
1105                 if (IS_ERR_VALUE(maddr))
1106                         return (int) maddr;
1107
1108                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1109                     ELF_FDPIC_FLAG_CONTIGUOUS)
1110                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1111
1112                 seg->addr = maddr + disp;
1113                 seg->p_vaddr = phdr->p_vaddr;
1114                 seg->p_memsz = phdr->p_memsz;
1115
1116                 /* map the ELF header address if in this segment */
1117                 if (phdr->p_offset == 0)
1118                         params->elfhdr_addr = seg->addr;
1119
1120                 /* clear the bit between beginning of mapping and beginning of
1121                  * PT_LOAD */
1122                 if (prot & PROT_WRITE && disp > 0) {
1123                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1124                         clear_user((void __user *) maddr, disp);
1125                         maddr += disp;
1126                 }
1127
1128                 /* clear any space allocated but not loaded
1129                  * - on uClinux we can just clear the lot
1130                  * - on MMU linux we'll get a SIGBUS beyond the last page
1131                  *   extant in the file
1132                  */
1133                 excess = phdr->p_memsz - phdr->p_filesz;
1134                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1135
1136 #ifdef CONFIG_MMU
1137                 if (excess > excess1) {
1138                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1139                         unsigned long xmaddr;
1140
1141                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1142                         down_write(&mm->mmap_sem);
1143                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1144                                          prot, flags, 0);
1145                         up_write(&mm->mmap_sem);
1146
1147                         kdebug("mmap[%d] <anon>"
1148                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1149                                loop, xaddr, excess - excess1, prot, flags,
1150                                xmaddr);
1151
1152                         if (xmaddr != xaddr)
1153                                 return -ENOMEM;
1154                 }
1155
1156                 if (prot & PROT_WRITE && excess1 > 0) {
1157                         kdebug("clear[%d] ad=%lx sz=%lx",
1158                                loop, maddr + phdr->p_filesz, excess1);
1159                         clear_user((void __user *) maddr + phdr->p_filesz,
1160                                    excess1);
1161                 }
1162
1163 #else
1164                 if (excess > 0) {
1165                         kdebug("clear[%d] ad=%lx sz=%lx",
1166                                loop, maddr + phdr->p_filesz, excess);
1167                         clear_user((void *) maddr + phdr->p_filesz, excess);
1168                 }
1169 #endif
1170
1171                 if (mm) {
1172                         if (phdr->p_flags & PF_X) {
1173                                 if (!mm->start_code) {
1174                                         mm->start_code = maddr;
1175                                         mm->end_code = maddr + phdr->p_memsz;
1176                                 }
1177                         } else if (!mm->start_data) {
1178                                 mm->start_data = maddr;
1179                                 mm->end_data = maddr + phdr->p_memsz;
1180                         }
1181                 }
1182
1183                 seg++;
1184         }
1185
1186         return 0;
1187 }
1188
1189 /*****************************************************************************/
1190 /*
1191  * ELF-FDPIC core dumper
1192  *
1193  * Modelled on fs/exec.c:aout_core_dump()
1194  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1195  *
1196  * Modelled on fs/binfmt_elf.c core dumper
1197  */
1198 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1199
1200 /*
1201  * These are the only things you should do on a core-file: use only these
1202  * functions to write out all the necessary info.
1203  */
1204 static int dump_write(struct file *file, const void *addr, int nr)
1205 {
1206         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1207 }
1208
1209 static int dump_seek(struct file *file, loff_t off)
1210 {
1211         if (file->f_op->llseek) {
1212                 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1213                         return 0;
1214         } else {
1215                 file->f_pos = off;
1216         }
1217         return 1;
1218 }
1219
1220 /*
1221  * Decide whether a segment is worth dumping; default is yes to be
1222  * sure (missing info is worse than too much; etc).
1223  * Personally I'd include everything, and use the coredump limit...
1224  *
1225  * I think we should skip something. But I am not sure how. H.J.
1226  */
1227 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1228 {
1229         int dump_ok;
1230
1231         /* Do not dump I/O mapped devices or special mappings */
1232         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1233                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1234                 return 0;
1235         }
1236
1237         /* If we may not read the contents, don't allow us to dump
1238          * them either. "dump_write()" can't handle it anyway.
1239          */
1240         if (!(vma->vm_flags & VM_READ)) {
1241                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1242                 return 0;
1243         }
1244
1245         /* By default, dump shared memory if mapped from an anonymous file. */
1246         if (vma->vm_flags & VM_SHARED) {
1247                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1248                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1249                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1250                                vma->vm_flags, dump_ok ? "yes" : "no");
1251                         return dump_ok;
1252                 }
1253
1254                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1255                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1256                        vma->vm_flags, dump_ok ? "yes" : "no");
1257                 return dump_ok;
1258         }
1259
1260 #ifdef CONFIG_MMU
1261         /* By default, if it hasn't been written to, don't write it out */
1262         if (!vma->anon_vma) {
1263                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1264                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1265                        vma->vm_flags, dump_ok ? "yes" : "no");
1266                 return dump_ok;
1267         }
1268 #endif
1269
1270         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1271         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1272                dump_ok ? "yes" : "no");
1273         return dump_ok;
1274 }
1275
1276 /* An ELF note in memory */
1277 struct memelfnote
1278 {
1279         const char *name;
1280         int type;
1281         unsigned int datasz;
1282         void *data;
1283 };
1284
1285 static int notesize(struct memelfnote *en)
1286 {
1287         int sz;
1288
1289         sz = sizeof(struct elf_note);
1290         sz += roundup(strlen(en->name) + 1, 4);
1291         sz += roundup(en->datasz, 4);
1292
1293         return sz;
1294 }
1295
1296 /* #define DEBUG */
1297
1298 #define DUMP_WRITE(addr, nr)    \
1299         do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1300 #define DUMP_SEEK(off)  \
1301         do { if (!dump_seek(file, (off))) return 0; } while(0)
1302
1303 static int writenote(struct memelfnote *men, struct file *file)
1304 {
1305         struct elf_note en;
1306
1307         en.n_namesz = strlen(men->name) + 1;
1308         en.n_descsz = men->datasz;
1309         en.n_type = men->type;
1310
1311         DUMP_WRITE(&en, sizeof(en));
1312         DUMP_WRITE(men->name, en.n_namesz);
1313         /* XXX - cast from long long to long to avoid need for libgcc.a */
1314         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1315         DUMP_WRITE(men->data, men->datasz);
1316         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1317
1318         return 1;
1319 }
1320 #undef DUMP_WRITE
1321 #undef DUMP_SEEK
1322
1323 #define DUMP_WRITE(addr, nr)    \
1324         if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1325                 goto end_coredump;
1326 #define DUMP_SEEK(off)  \
1327         if (!dump_seek(file, (off))) \
1328                 goto end_coredump;
1329
1330 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1331 {
1332         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1333         elf->e_ident[EI_CLASS] = ELF_CLASS;
1334         elf->e_ident[EI_DATA] = ELF_DATA;
1335         elf->e_ident[EI_VERSION] = EV_CURRENT;
1336         elf->e_ident[EI_OSABI] = ELF_OSABI;
1337         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1338
1339         elf->e_type = ET_CORE;
1340         elf->e_machine = ELF_ARCH;
1341         elf->e_version = EV_CURRENT;
1342         elf->e_entry = 0;
1343         elf->e_phoff = sizeof(struct elfhdr);
1344         elf->e_shoff = 0;
1345         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1346         elf->e_ehsize = sizeof(struct elfhdr);
1347         elf->e_phentsize = sizeof(struct elf_phdr);
1348         elf->e_phnum = segs;
1349         elf->e_shentsize = 0;
1350         elf->e_shnum = 0;
1351         elf->e_shstrndx = 0;
1352         return;
1353 }
1354
1355 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1356 {
1357         phdr->p_type = PT_NOTE;
1358         phdr->p_offset = offset;
1359         phdr->p_vaddr = 0;
1360         phdr->p_paddr = 0;
1361         phdr->p_filesz = sz;
1362         phdr->p_memsz = 0;
1363         phdr->p_flags = 0;
1364         phdr->p_align = 0;
1365         return;
1366 }
1367
1368 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1369                 unsigned int sz, void *data)
1370 {
1371         note->name = name;
1372         note->type = type;
1373         note->datasz = sz;
1374         note->data = data;
1375         return;
1376 }
1377
1378 /*
1379  * fill up all the fields in prstatus from the given task struct, except
1380  * registers which need to be filled up seperately.
1381  */
1382 static void fill_prstatus(struct elf_prstatus *prstatus,
1383                           struct task_struct *p, long signr)
1384 {
1385         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1386         prstatus->pr_sigpend = p->pending.signal.sig[0];
1387         prstatus->pr_sighold = p->blocked.sig[0];
1388         prstatus->pr_pid = task_pid_vnr(p);
1389         prstatus->pr_ppid = task_pid_vnr(p->parent);
1390         prstatus->pr_pgrp = task_pgrp_vnr(p);
1391         prstatus->pr_sid = task_session_vnr(p);
1392         if (thread_group_leader(p)) {
1393                 struct task_cputime cputime;
1394
1395                 /*
1396                  * This is the record for the group leader.  It shows the
1397                  * group-wide total, not its individual thread total.
1398                  */
1399                 thread_group_cputime(p, &cputime);
1400                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1401                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1402         } else {
1403                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1404                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1405         }
1406         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1407         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1408
1409         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1410         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1411 }
1412
1413 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1414                        struct mm_struct *mm)
1415 {
1416         unsigned int i, len;
1417
1418         /* first copy the parameters from user space */
1419         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1420
1421         len = mm->arg_end - mm->arg_start;
1422         if (len >= ELF_PRARGSZ)
1423                 len = ELF_PRARGSZ - 1;
1424         if (copy_from_user(&psinfo->pr_psargs,
1425                            (const char __user *) mm->arg_start, len))
1426                 return -EFAULT;
1427         for (i = 0; i < len; i++)
1428                 if (psinfo->pr_psargs[i] == 0)
1429                         psinfo->pr_psargs[i] = ' ';
1430         psinfo->pr_psargs[len] = 0;
1431
1432         psinfo->pr_pid = task_pid_vnr(p);
1433         psinfo->pr_ppid = task_pid_vnr(p->parent);
1434         psinfo->pr_pgrp = task_pgrp_vnr(p);
1435         psinfo->pr_sid = task_session_vnr(p);
1436
1437         i = p->state ? ffz(~p->state) + 1 : 0;
1438         psinfo->pr_state = i;
1439         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1440         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1441         psinfo->pr_nice = task_nice(p);
1442         psinfo->pr_flag = p->flags;
1443         SET_UID(psinfo->pr_uid, p->cred->uid);
1444         SET_GID(psinfo->pr_gid, p->cred->gid);
1445         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1446
1447         return 0;
1448 }
1449
1450 /* Here is the structure in which status of each thread is captured. */
1451 struct elf_thread_status
1452 {
1453         struct list_head list;
1454         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1455         elf_fpregset_t fpu;             /* NT_PRFPREG */
1456         struct task_struct *thread;
1457 #ifdef ELF_CORE_COPY_XFPREGS
1458         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1459 #endif
1460         struct memelfnote notes[3];
1461         int num_notes;
1462 };
1463
1464 /*
1465  * In order to add the specific thread information for the elf file format,
1466  * we need to keep a linked list of every thread's pr_status and then create
1467  * a single section for them in the final core file.
1468  */
1469 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1470 {
1471         struct task_struct *p = t->thread;
1472         int sz = 0;
1473
1474         t->num_notes = 0;
1475
1476         fill_prstatus(&t->prstatus, p, signr);
1477         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1478
1479         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1480                   &t->prstatus);
1481         t->num_notes++;
1482         sz += notesize(&t->notes[0]);
1483
1484         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1485         if (t->prstatus.pr_fpvalid) {
1486                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1487                           &t->fpu);
1488                 t->num_notes++;
1489                 sz += notesize(&t->notes[1]);
1490         }
1491
1492 #ifdef ELF_CORE_COPY_XFPREGS
1493         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1494                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1495                           sizeof(t->xfpu), &t->xfpu);
1496                 t->num_notes++;
1497                 sz += notesize(&t->notes[2]);
1498         }
1499 #endif
1500         return sz;
1501 }
1502
1503 /*
1504  * dump the segments for an MMU process
1505  */
1506 #ifdef CONFIG_MMU
1507 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1508                            unsigned long *limit, unsigned long mm_flags)
1509 {
1510         struct vm_area_struct *vma;
1511
1512         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1513                 unsigned long addr;
1514
1515                 if (!maydump(vma, mm_flags))
1516                         continue;
1517
1518                 for (addr = vma->vm_start;
1519                      addr < vma->vm_end;
1520                      addr += PAGE_SIZE
1521                      ) {
1522                         struct vm_area_struct *vma;
1523                         struct page *page;
1524
1525                         if (get_user_pages(current, current->mm, addr, 1, 0, 1,
1526                                            &page, &vma) <= 0) {
1527                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1528                         }
1529                         else if (page == ZERO_PAGE(0)) {
1530                                 page_cache_release(page);
1531                                 DUMP_SEEK(file->f_pos + PAGE_SIZE);
1532                         }
1533                         else {
1534                                 void *kaddr;
1535
1536                                 flush_cache_page(vma, addr, page_to_pfn(page));
1537                                 kaddr = kmap(page);
1538                                 if ((*size += PAGE_SIZE) > *limit ||
1539                                     !dump_write(file, kaddr, PAGE_SIZE)
1540                                     ) {
1541                                         kunmap(page);
1542                                         page_cache_release(page);
1543                                         return -EIO;
1544                                 }
1545                                 kunmap(page);
1546                                 page_cache_release(page);
1547                         }
1548                 }
1549         }
1550
1551         return 0;
1552
1553 end_coredump:
1554         return -EFBIG;
1555 }
1556 #endif
1557
1558 /*
1559  * dump the segments for a NOMMU process
1560  */
1561 #ifndef CONFIG_MMU
1562 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1563                            unsigned long *limit, unsigned long mm_flags)
1564 {
1565         struct vm_list_struct *vml;
1566
1567         for (vml = current->mm->context.vmlist; vml; vml = vml->next) {
1568         struct vm_area_struct *vma = vml->vma;
1569
1570                 if (!maydump(vma, mm_flags))
1571                         continue;
1572
1573                 if ((*size += PAGE_SIZE) > *limit)
1574                         return -EFBIG;
1575
1576                 if (!dump_write(file, (void *) vma->vm_start,
1577                                 vma->vm_end - vma->vm_start))
1578                         return -EIO;
1579         }
1580
1581         return 0;
1582 }
1583 #endif
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(long signr, struct pt_regs *regs,
1593                                struct file *file, unsigned long limit)
1594 {
1595 #define NUM_NOTES       6
1596         int has_dumped = 0;
1597         mm_segment_t fs;
1598         int segs;
1599         size_t size = 0;
1600         int i;
1601         struct vm_area_struct *vma;
1602         struct elfhdr *elf = NULL;
1603         loff_t offset = 0, dataoff;
1604         int numnote;
1605         struct memelfnote *notes = NULL;
1606         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1607         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1608         LIST_HEAD(thread_list);
1609         struct list_head *t;
1610         elf_fpregset_t *fpu = NULL;
1611 #ifdef ELF_CORE_COPY_XFPREGS
1612         elf_fpxregset_t *xfpu = NULL;
1613 #endif
1614         int thread_status_size = 0;
1615 #ifndef CONFIG_MMU
1616         struct vm_list_struct *vml;
1617 #endif
1618         elf_addr_t *auxv;
1619         unsigned long mm_flags;
1620
1621         /*
1622          * We no longer stop all VM operations.
1623          *
1624          * This is because those proceses that could possibly change map_count
1625          * or the mmap / vma pages are now blocked in do_exit on current
1626          * finishing this core dump.
1627          *
1628          * Only ptrace can touch these memory addresses, but it doesn't change
1629          * the map_count or the pages allocated. So no possibility of crashing
1630          * exists while dumping the mm->vm_next areas to the core file.
1631          */
1632
1633         /* alloc memory for large data structures: too large to be on stack */
1634         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1635         if (!elf)
1636                 goto cleanup;
1637         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1638         if (!prstatus)
1639                 goto cleanup;
1640         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1641         if (!psinfo)
1642                 goto cleanup;
1643         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1644         if (!notes)
1645                 goto cleanup;
1646         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1647         if (!fpu)
1648                 goto cleanup;
1649 #ifdef ELF_CORE_COPY_XFPREGS
1650         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1651         if (!xfpu)
1652                 goto cleanup;
1653 #endif
1654
1655         if (signr) {
1656                 struct core_thread *ct;
1657                 struct elf_thread_status *tmp;
1658
1659                 for (ct = current->mm->core_state->dumper.next;
1660                                                 ct; ct = ct->next) {
1661                         tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1662                         if (!tmp)
1663                                 goto cleanup;
1664
1665                         tmp->thread = ct->task;
1666                         list_add(&tmp->list, &thread_list);
1667                 }
1668
1669                 list_for_each(t, &thread_list) {
1670                         struct elf_thread_status *tmp;
1671                         int sz;
1672
1673                         tmp = list_entry(t, struct elf_thread_status, list);
1674                         sz = elf_dump_thread_status(signr, tmp);
1675                         thread_status_size += sz;
1676                 }
1677         }
1678
1679         /* now collect the dump for the current */
1680         fill_prstatus(prstatus, current, signr);
1681         elf_core_copy_regs(&prstatus->pr_reg, regs);
1682
1683 #ifdef CONFIG_MMU
1684         segs = current->mm->map_count;
1685 #else
1686         segs = 0;
1687         for (vml = current->mm->context.vmlist; vml; vml = vml->next)
1688             segs++;
1689 #endif
1690 #ifdef ELF_CORE_EXTRA_PHDRS
1691         segs += ELF_CORE_EXTRA_PHDRS;
1692 #endif
1693
1694         /* Set up header */
1695         fill_elf_fdpic_header(elf, segs + 1);   /* including notes section */
1696
1697         has_dumped = 1;
1698         current->flags |= PF_DUMPCORE;
1699
1700         /*
1701          * Set up the notes in similar form to SVR4 core dumps made
1702          * with info from their /proc.
1703          */
1704
1705         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1706         fill_psinfo(psinfo, current->group_leader, current->mm);
1707         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1708
1709         numnote = 2;
1710
1711         auxv = (elf_addr_t *) current->mm->saved_auxv;
1712
1713         i = 0;
1714         do
1715                 i += 2;
1716         while (auxv[i - 2] != AT_NULL);
1717         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1718                   i * sizeof(elf_addr_t), auxv);
1719
1720         /* Try to dump the FPU. */
1721         if ((prstatus->pr_fpvalid =
1722              elf_core_copy_task_fpregs(current, regs, fpu)))
1723                 fill_note(notes + numnote++,
1724                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1725 #ifdef ELF_CORE_COPY_XFPREGS
1726         if (elf_core_copy_task_xfpregs(current, xfpu))
1727                 fill_note(notes + numnote++,
1728                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1729 #endif
1730
1731         fs = get_fs();
1732         set_fs(KERNEL_DS);
1733
1734         DUMP_WRITE(elf, sizeof(*elf));
1735         offset += sizeof(*elf);                         /* Elf header */
1736         offset += (segs+1) * sizeof(struct elf_phdr);   /* Program headers */
1737
1738         /* Write notes phdr entry */
1739         {
1740                 struct elf_phdr phdr;
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                 fill_elf_note_phdr(&phdr, sz, offset);
1749                 offset += sz;
1750                 DUMP_WRITE(&phdr, sizeof(phdr));
1751         }
1752
1753         /* Page-align dumped data */
1754         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1755
1756         /*
1757          * We must use the same mm->flags while dumping core to avoid
1758          * inconsistency between the program headers and bodies, otherwise an
1759          * unusable core file can be generated.
1760          */
1761         mm_flags = current->mm->flags;
1762
1763         /* write program headers for segments dump */
1764         for (
1765 #ifdef CONFIG_MMU
1766                 vma = current->mm->mmap; vma; vma = vma->vm_next
1767 #else
1768                         vml = current->mm->context.vmlist; vml; vml = vml->next
1769 #endif
1770              ) {
1771                 struct elf_phdr phdr;
1772                 size_t sz;
1773
1774 #ifndef CONFIG_MMU
1775                 vma = vml->vma;
1776 #endif
1777
1778                 sz = vma->vm_end - vma->vm_start;
1779
1780                 phdr.p_type = PT_LOAD;
1781                 phdr.p_offset = offset;
1782                 phdr.p_vaddr = vma->vm_start;
1783                 phdr.p_paddr = 0;
1784                 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1785                 phdr.p_memsz = sz;
1786                 offset += phdr.p_filesz;
1787                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1788                 if (vma->vm_flags & VM_WRITE)
1789                         phdr.p_flags |= PF_W;
1790                 if (vma->vm_flags & VM_EXEC)
1791                         phdr.p_flags |= PF_X;
1792                 phdr.p_align = ELF_EXEC_PAGESIZE;
1793
1794                 DUMP_WRITE(&phdr, sizeof(phdr));
1795         }
1796
1797 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1798         ELF_CORE_WRITE_EXTRA_PHDRS;
1799 #endif
1800
1801         /* write out the notes section */
1802         for (i = 0; i < numnote; i++)
1803                 if (!writenote(notes + i, file))
1804                         goto end_coredump;
1805
1806         /* write out the thread status notes section */
1807         list_for_each(t, &thread_list) {
1808                 struct elf_thread_status *tmp =
1809                                 list_entry(t, struct elf_thread_status, list);
1810
1811                 for (i = 0; i < tmp->num_notes; i++)
1812                         if (!writenote(&tmp->notes[i], file))
1813                                 goto end_coredump;
1814         }
1815
1816         DUMP_SEEK(dataoff);
1817
1818         if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
1819                 goto end_coredump;
1820
1821 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1822         ELF_CORE_WRITE_EXTRA_DATA;
1823 #endif
1824
1825         if (file->f_pos != offset) {
1826                 /* Sanity check */
1827                 printk(KERN_WARNING
1828                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1829                        file->f_pos, offset);
1830         }
1831
1832 end_coredump:
1833         set_fs(fs);
1834
1835 cleanup:
1836         while (!list_empty(&thread_list)) {
1837                 struct list_head *tmp = thread_list.next;
1838                 list_del(tmp);
1839                 kfree(list_entry(tmp, struct elf_thread_status, list));
1840         }
1841
1842         kfree(elf);
1843         kfree(prstatus);
1844         kfree(psinfo);
1845         kfree(notes);
1846         kfree(fpu);
1847 #ifdef ELF_CORE_COPY_XFPREGS
1848         kfree(xfpu);
1849 #endif
1850         return has_dumped;
1851 #undef NUM_NOTES
1852 }
1853
1854 #endif          /* USE_ELF_CORE_DUMP */