mm: add get_dump_page
[linux-2.6.git] / fs / binfmt_elf_fdpic.c
1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
2  *
3  * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  * Derived from binfmt_elf.c
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version
10  * 2 of the License, or (at your option) any later version.
11  */
12
13 #include <linux/module.h>
14
15 #include <linux/fs.h>
16 #include <linux/stat.h>
17 #include <linux/sched.h>
18 #include <linux/mm.h>
19 #include <linux/mman.h>
20 #include <linux/errno.h>
21 #include <linux/signal.h>
22 #include <linux/binfmts.h>
23 #include <linux/string.h>
24 #include <linux/file.h>
25 #include <linux/fcntl.h>
26 #include <linux/slab.h>
27 #include <linux/pagemap.h>
28 #include <linux/security.h>
29 #include <linux/highmem.h>
30 #include <linux/highuid.h>
31 #include <linux/personality.h>
32 #include <linux/ptrace.h>
33 #include <linux/init.h>
34 #include <linux/elf.h>
35 #include <linux/elf-fdpic.h>
36 #include <linux/elfcore.h>
37
38 #include <asm/uaccess.h>
39 #include <asm/param.h>
40 #include <asm/pgalloc.h>
41
42 typedef char *elf_caddr_t;
43
44 #if 0
45 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
46 #else
47 #define kdebug(fmt, ...) do {} while(0)
48 #endif
49
50 #if 0
51 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
52 #else
53 #define kdcore(fmt, ...) do {} while(0)
54 #endif
55
56 MODULE_LICENSE("GPL");
57
58 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
59 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
60 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
61                               struct mm_struct *, const char *);
62
63 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
64                                    struct elf_fdpic_params *,
65                                    struct elf_fdpic_params *);
66
67 #ifndef CONFIG_MMU
68 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
69                                             unsigned long *);
70 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
71                                                    struct file *,
72                                                    struct mm_struct *);
73 #endif
74
75 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
76                                              struct file *, struct mm_struct *);
77
78 #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 #ifdef ELF_FDPIC_PLAT_INIT
172         unsigned long dynaddr;
173 #endif
174         struct file *interpreter = NULL; /* to shut gcc up */
175         char *interpreter_name = NULL;
176         int executable_stack;
177         int retval, i;
178
179         kdebug("____ LOAD %d ____", current->pid);
180
181         memset(&exec_params, 0, sizeof(exec_params));
182         memset(&interp_params, 0, sizeof(interp_params));
183
184         exec_params.hdr = *(struct elfhdr *) bprm->buf;
185         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
186
187         /* check that this is a binary we know how to deal with */
188         retval = -ENOEXEC;
189         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
190                 goto error;
191
192         /* read the program header table */
193         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
194         if (retval < 0)
195                 goto error;
196
197         /* scan for a program header that specifies an interpreter */
198         phdr = exec_params.phdrs;
199
200         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
201                 switch (phdr->p_type) {
202                 case PT_INTERP:
203                         retval = -ENOMEM;
204                         if (phdr->p_filesz > PATH_MAX)
205                                 goto error;
206                         retval = -ENOENT;
207                         if (phdr->p_filesz < 2)
208                                 goto error;
209
210                         /* read the name of the interpreter into memory */
211                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
212                         if (!interpreter_name)
213                                 goto error;
214
215                         retval = kernel_read(bprm->file,
216                                              phdr->p_offset,
217                                              interpreter_name,
218                                              phdr->p_filesz);
219                         if (unlikely(retval != phdr->p_filesz)) {
220                                 if (retval >= 0)
221                                         retval = -ENOEXEC;
222                                 goto error;
223                         }
224
225                         retval = -ENOENT;
226                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
227                                 goto error;
228
229                         kdebug("Using ELF interpreter %s", interpreter_name);
230
231                         /* replace the program with the interpreter */
232                         interpreter = open_exec(interpreter_name);
233                         retval = PTR_ERR(interpreter);
234                         if (IS_ERR(interpreter)) {
235                                 interpreter = NULL;
236                                 goto error;
237                         }
238
239                         /*
240                          * If the binary is not readable then enforce
241                          * mm->dumpable = 0 regardless of the interpreter's
242                          * permissions.
243                          */
244                         if (file_permission(interpreter, MAY_READ) < 0)
245                                 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
246
247                         retval = kernel_read(interpreter, 0, bprm->buf,
248                                              BINPRM_BUF_SIZE);
249                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
250                                 if (retval >= 0)
251                                         retval = -ENOEXEC;
252                                 goto error;
253                         }
254
255                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
256                         break;
257
258                 case PT_LOAD:
259 #ifdef CONFIG_MMU
260                         if (exec_params.load_addr == 0)
261                                 exec_params.load_addr = phdr->p_vaddr;
262 #endif
263                         break;
264                 }
265
266         }
267
268         if (elf_check_const_displacement(&exec_params.hdr))
269                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
270
271         /* perform insanity checks on the interpreter */
272         if (interpreter_name) {
273                 retval = -ELIBBAD;
274                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
275                         goto error;
276
277                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
278
279                 /* read the interpreter's program header table */
280                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
281                 if (retval < 0)
282                         goto error;
283         }
284
285         stack_size = exec_params.stack_size;
286         if (stack_size < interp_params.stack_size)
287                 stack_size = interp_params.stack_size;
288
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 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
294                 executable_stack = EXSTACK_ENABLE_X;
295         else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
296                 executable_stack = EXSTACK_DISABLE_X;
297         else
298                 executable_stack = EXSTACK_DEFAULT;
299
300         retval = -ENOEXEC;
301         if (stack_size == 0)
302                 goto error;
303
304         if (elf_check_const_displacement(&interp_params.hdr))
305                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
306
307         /* flush all traces of the currently running executable */
308         retval = flush_old_exec(bprm);
309         if (retval)
310                 goto error;
311
312         /* there's now no turning back... the old userspace image is dead,
313          * defunct, deceased, etc. after this point we have to exit via
314          * error_kill */
315         set_personality(PER_LINUX_FDPIC);
316         set_binfmt(&elf_fdpic_format);
317
318         current->mm->start_code = 0;
319         current->mm->end_code = 0;
320         current->mm->start_stack = 0;
321         current->mm->start_data = 0;
322         current->mm->end_data = 0;
323         current->mm->context.exec_fdpic_loadmap = 0;
324         current->mm->context.interp_fdpic_loadmap = 0;
325
326         current->flags &= ~PF_FORKNOEXEC;
327
328 #ifdef CONFIG_MMU
329         elf_fdpic_arch_lay_out_mm(&exec_params,
330                                   &interp_params,
331                                   &current->mm->start_stack,
332                                   &current->mm->start_brk);
333
334         retval = setup_arg_pages(bprm, current->mm->start_stack,
335                                  executable_stack);
336         if (retval < 0) {
337                 send_sig(SIGKILL, current, 0);
338                 goto error_kill;
339         }
340 #endif
341
342         /* load the executable and interpreter into memory */
343         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
344                                     "executable");
345         if (retval < 0)
346                 goto error_kill;
347
348         if (interpreter_name) {
349                 retval = elf_fdpic_map_file(&interp_params, interpreter,
350                                             current->mm, "interpreter");
351                 if (retval < 0) {
352                         printk(KERN_ERR "Unable to load interpreter\n");
353                         goto error_kill;
354                 }
355
356                 allow_write_access(interpreter);
357                 fput(interpreter);
358                 interpreter = NULL;
359         }
360
361 #ifdef CONFIG_MMU
362         if (!current->mm->start_brk)
363                 current->mm->start_brk = current->mm->end_data;
364
365         current->mm->brk = current->mm->start_brk =
366                 PAGE_ALIGN(current->mm->start_brk);
367
368 #else
369         /* create a stack and brk area big enough for everyone
370          * - the brk heap starts at the bottom and works up
371          * - the stack starts at the top and works down
372          */
373         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
374         if (stack_size < PAGE_SIZE * 2)
375                 stack_size = PAGE_SIZE * 2;
376
377         down_write(&current->mm->mmap_sem);
378         current->mm->start_brk = do_mmap(NULL, 0, stack_size,
379                                          PROT_READ | PROT_WRITE | PROT_EXEC,
380                                          MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN,
381                                          0);
382
383         if (IS_ERR_VALUE(current->mm->start_brk)) {
384                 up_write(&current->mm->mmap_sem);
385                 retval = current->mm->start_brk;
386                 current->mm->start_brk = 0;
387                 goto error_kill;
388         }
389
390         up_write(&current->mm->mmap_sem);
391
392         current->mm->brk = current->mm->start_brk;
393         current->mm->context.end_brk = current->mm->start_brk;
394         current->mm->context.end_brk +=
395                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
396         current->mm->start_stack = current->mm->start_brk + stack_size;
397 #endif
398
399         install_exec_creds(bprm);
400         current->flags &= ~PF_FORKNOEXEC;
401         if (create_elf_fdpic_tables(bprm, current->mm,
402                                     &exec_params, &interp_params) < 0)
403                 goto error_kill;
404
405         kdebug("- start_code  %lx", current->mm->start_code);
406         kdebug("- end_code    %lx", current->mm->end_code);
407         kdebug("- start_data  %lx", current->mm->start_data);
408         kdebug("- end_data    %lx", current->mm->end_data);
409         kdebug("- start_brk   %lx", current->mm->start_brk);
410         kdebug("- brk         %lx", current->mm->brk);
411         kdebug("- start_stack %lx", current->mm->start_stack);
412
413 #ifdef ELF_FDPIC_PLAT_INIT
414         /*
415          * The ABI may specify that certain registers be set up in special
416          * ways (on i386 %edx is the address of a DT_FINI function, for
417          * example.  This macro performs whatever initialization to
418          * the regs structure is required.
419          */
420         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
421         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
422                             dynaddr);
423 #endif
424
425         /* everything is now ready... get the userspace context ready to roll */
426         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
427         start_thread(regs, entryaddr, current->mm->start_stack);
428
429         retval = 0;
430
431 error:
432         if (interpreter) {
433                 allow_write_access(interpreter);
434                 fput(interpreter);
435         }
436         kfree(interpreter_name);
437         kfree(exec_params.phdrs);
438         kfree(exec_params.loadmap);
439         kfree(interp_params.phdrs);
440         kfree(interp_params.loadmap);
441         return retval;
442
443         /* unrecoverable error - kill the process */
444 error_kill:
445         send_sig(SIGSEGV, current, 0);
446         goto error;
447
448 }
449
450 /*****************************************************************************/
451
452 #ifndef ELF_BASE_PLATFORM
453 /*
454  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
455  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
456  * will be copied to the user stack in the same manner as AT_PLATFORM.
457  */
458 #define ELF_BASE_PLATFORM NULL
459 #endif
460
461 /*
462  * present useful information to the program by shovelling it onto the new
463  * process's stack
464  */
465 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
466                                    struct mm_struct *mm,
467                                    struct elf_fdpic_params *exec_params,
468                                    struct elf_fdpic_params *interp_params)
469 {
470         const struct cred *cred = current_cred();
471         unsigned long sp, csp, nitems;
472         elf_caddr_t __user *argv, *envp;
473         size_t platform_len = 0, len;
474         char *k_platform, *k_base_platform;
475         char __user *u_platform, *u_base_platform, *p;
476         long hwcap;
477         int loop;
478         int nr; /* reset for each csp adjustment */
479
480 #ifdef CONFIG_MMU
481         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
482          * by the processes running on the same package. One thing we can do is
483          * to shuffle the initial stack for them, so we give the architecture
484          * an opportunity to do so here.
485          */
486         sp = arch_align_stack(bprm->p);
487 #else
488         sp = mm->start_stack;
489
490         /* stack the program arguments and environment */
491         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
492                 return -EFAULT;
493 #endif
494
495         hwcap = ELF_HWCAP;
496
497         /*
498          * If this architecture has a platform capability string, copy it
499          * to userspace.  In some cases (Sparc), this info is impossible
500          * for userspace to get any other way, in others (i386) it is
501          * merely difficult.
502          */
503         k_platform = ELF_PLATFORM;
504         u_platform = NULL;
505
506         if (k_platform) {
507                 platform_len = strlen(k_platform) + 1;
508                 sp -= platform_len;
509                 u_platform = (char __user *) sp;
510                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
511                         return -EFAULT;
512         }
513
514         /*
515          * If this architecture has a "base" platform capability
516          * string, copy it to userspace.
517          */
518         k_base_platform = ELF_BASE_PLATFORM;
519         u_base_platform = NULL;
520
521         if (k_base_platform) {
522                 platform_len = strlen(k_base_platform) + 1;
523                 sp -= platform_len;
524                 u_base_platform = (char __user *) sp;
525                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
526                         return -EFAULT;
527         }
528
529         sp &= ~7UL;
530
531         /* stack the load map(s) */
532         len = sizeof(struct elf32_fdpic_loadmap);
533         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
534         sp = (sp - len) & ~7UL;
535         exec_params->map_addr = sp;
536
537         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
538                 return -EFAULT;
539
540         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
541
542         if (interp_params->loadmap) {
543                 len = sizeof(struct elf32_fdpic_loadmap);
544                 len += sizeof(struct elf32_fdpic_loadseg) *
545                         interp_params->loadmap->nsegs;
546                 sp = (sp - len) & ~7UL;
547                 interp_params->map_addr = sp;
548
549                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
550                                  len) != 0)
551                         return -EFAULT;
552
553                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
554         }
555
556         /* force 16 byte _final_ alignment here for generality */
557 #define DLINFO_ITEMS 15
558
559         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
560                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
561
562         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
563                 nitems++;
564
565         csp = sp;
566         sp -= nitems * 2 * sizeof(unsigned long);
567         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
568         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
569         sp -= 1 * sizeof(unsigned long);                /* argc */
570
571         csp -= sp & 15UL;
572         sp -= sp & 15UL;
573
574         /* put the ELF interpreter info on the stack */
575 #define NEW_AUX_ENT(id, val)                                            \
576         do {                                                            \
577                 struct { unsigned long _id, _val; } __user *ent;        \
578                                                                         \
579                 ent = (void __user *) csp;                              \
580                 __put_user((id), &ent[nr]._id);                         \
581                 __put_user((val), &ent[nr]._val);                       \
582                 nr++;                                                   \
583         } while (0)
584
585         nr = 0;
586         csp -= 2 * sizeof(unsigned long);
587         NEW_AUX_ENT(AT_NULL, 0);
588         if (k_platform) {
589                 nr = 0;
590                 csp -= 2 * sizeof(unsigned long);
591                 NEW_AUX_ENT(AT_PLATFORM,
592                             (elf_addr_t) (unsigned long) u_platform);
593         }
594
595         if (k_base_platform) {
596                 nr = 0;
597                 csp -= 2 * sizeof(unsigned long);
598                 NEW_AUX_ENT(AT_BASE_PLATFORM,
599                             (elf_addr_t) (unsigned long) u_base_platform);
600         }
601
602         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
603                 nr = 0;
604                 csp -= 2 * sizeof(unsigned long);
605                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
606         }
607
608         nr = 0;
609         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
610         NEW_AUX_ENT(AT_HWCAP,   hwcap);
611         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
612         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
613         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
614         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
615         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
616         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
617         NEW_AUX_ENT(AT_FLAGS,   0);
618         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
619         NEW_AUX_ENT(AT_UID,     (elf_addr_t) cred->uid);
620         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) cred->euid);
621         NEW_AUX_ENT(AT_GID,     (elf_addr_t) cred->gid);
622         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) cred->egid);
623         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
624         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
625
626 #ifdef ARCH_DLINFO
627         nr = 0;
628         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
629
630         /* ARCH_DLINFO must come last so platform specific code can enforce
631          * special alignment requirements on the AUXV if necessary (eg. PPC).
632          */
633         ARCH_DLINFO;
634 #endif
635 #undef NEW_AUX_ENT
636
637         /* allocate room for argv[] and envv[] */
638         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
639         envp = (elf_caddr_t __user *) csp;
640         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
641         argv = (elf_caddr_t __user *) csp;
642
643         /* stack argc */
644         csp -= sizeof(unsigned long);
645         __put_user(bprm->argc, (unsigned long __user *) csp);
646
647         BUG_ON(csp != sp);
648
649         /* fill in the argv[] array */
650 #ifdef CONFIG_MMU
651         current->mm->arg_start = bprm->p;
652 #else
653         current->mm->arg_start = current->mm->start_stack -
654                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
655 #endif
656
657         p = (char __user *) current->mm->arg_start;
658         for (loop = bprm->argc; loop > 0; loop--) {
659                 __put_user((elf_caddr_t) p, argv++);
660                 len = strnlen_user(p, MAX_ARG_STRLEN);
661                 if (!len || len > MAX_ARG_STRLEN)
662                         return -EINVAL;
663                 p += len;
664         }
665         __put_user(NULL, argv);
666         current->mm->arg_end = (unsigned long) p;
667
668         /* fill in the envv[] array */
669         current->mm->env_start = (unsigned long) p;
670         for (loop = bprm->envc; loop > 0; loop--) {
671                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
672                 len = strnlen_user(p, MAX_ARG_STRLEN);
673                 if (!len || len > MAX_ARG_STRLEN)
674                         return -EINVAL;
675                 p += len;
676         }
677         __put_user(NULL, envp);
678         current->mm->env_end = (unsigned long) p;
679
680         mm->start_stack = (unsigned long) sp;
681         return 0;
682 }
683
684 /*****************************************************************************/
685 /*
686  * transfer the program arguments and environment from the holding pages onto
687  * the stack
688  */
689 #ifndef CONFIG_MMU
690 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
691                                             unsigned long *_sp)
692 {
693         unsigned long index, stop, sp;
694         char *src;
695         int ret = 0;
696
697         stop = bprm->p >> PAGE_SHIFT;
698         sp = *_sp;
699
700         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
701                 src = kmap(bprm->page[index]);
702                 sp -= PAGE_SIZE;
703                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
704                         ret = -EFAULT;
705                 kunmap(bprm->page[index]);
706                 if (ret < 0)
707                         goto out;
708         }
709
710         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
711
712 out:
713         return ret;
714 }
715 #endif
716
717 /*****************************************************************************/
718 /*
719  * load the appropriate binary image (executable or interpreter) into memory
720  * - we assume no MMU is available
721  * - if no other PIC bits are set in params->hdr->e_flags
722  *   - we assume that the LOADable segments in the binary are independently relocatable
723  *   - we assume R/O executable segments are shareable
724  * - else
725  *   - we assume the loadable parts of the image to require fixed displacement
726  *   - the image is not shareable
727  */
728 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
729                               struct file *file,
730                               struct mm_struct *mm,
731                               const char *what)
732 {
733         struct elf32_fdpic_loadmap *loadmap;
734 #ifdef CONFIG_MMU
735         struct elf32_fdpic_loadseg *mseg;
736 #endif
737         struct elf32_fdpic_loadseg *seg;
738         struct elf32_phdr *phdr;
739         unsigned long load_addr, stop;
740         unsigned nloads, tmp;
741         size_t size;
742         int loop, ret;
743
744         /* allocate a load map table */
745         nloads = 0;
746         for (loop = 0; loop < params->hdr.e_phnum; loop++)
747                 if (params->phdrs[loop].p_type == PT_LOAD)
748                         nloads++;
749
750         if (nloads == 0)
751                 return -ELIBBAD;
752
753         size = sizeof(*loadmap) + nloads * sizeof(*seg);
754         loadmap = kzalloc(size, GFP_KERNEL);
755         if (!loadmap)
756                 return -ENOMEM;
757
758         params->loadmap = loadmap;
759
760         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
761         loadmap->nsegs = nloads;
762
763         load_addr = params->load_addr;
764         seg = loadmap->segs;
765
766         /* map the requested LOADs into the memory space */
767         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
768         case ELF_FDPIC_FLAG_CONSTDISP:
769         case ELF_FDPIC_FLAG_CONTIGUOUS:
770 #ifndef CONFIG_MMU
771                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
772                 if (ret < 0)
773                         return ret;
774                 break;
775 #endif
776         default:
777                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
778                 if (ret < 0)
779                         return ret;
780                 break;
781         }
782
783         /* map the entry point */
784         if (params->hdr.e_entry) {
785                 seg = loadmap->segs;
786                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
787                         if (params->hdr.e_entry >= seg->p_vaddr &&
788                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
789                                 params->entry_addr =
790                                         (params->hdr.e_entry - seg->p_vaddr) +
791                                         seg->addr;
792                                 break;
793                         }
794                 }
795         }
796
797         /* determine where the program header table has wound up if mapped */
798         stop = params->hdr.e_phoff;
799         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
800         phdr = params->phdrs;
801
802         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
803                 if (phdr->p_type != PT_LOAD)
804                         continue;
805
806                 if (phdr->p_offset > params->hdr.e_phoff ||
807                     phdr->p_offset + phdr->p_filesz < stop)
808                         continue;
809
810                 seg = loadmap->segs;
811                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
812                         if (phdr->p_vaddr >= seg->p_vaddr &&
813                             phdr->p_vaddr + phdr->p_filesz <=
814                             seg->p_vaddr + seg->p_memsz) {
815                                 params->ph_addr =
816                                         (phdr->p_vaddr - seg->p_vaddr) +
817                                         seg->addr +
818                                         params->hdr.e_phoff - phdr->p_offset;
819                                 break;
820                         }
821                 }
822                 break;
823         }
824
825         /* determine where the dynamic section has wound up if there is one */
826         phdr = params->phdrs;
827         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
828                 if (phdr->p_type != PT_DYNAMIC)
829                         continue;
830
831                 seg = loadmap->segs;
832                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
833                         if (phdr->p_vaddr >= seg->p_vaddr &&
834                             phdr->p_vaddr + phdr->p_memsz <=
835                             seg->p_vaddr + seg->p_memsz) {
836                                 params->dynamic_addr =
837                                         (phdr->p_vaddr - seg->p_vaddr) +
838                                         seg->addr;
839
840                                 /* check the dynamic section contains at least
841                                  * one item, and that the last item is a NULL
842                                  * entry */
843                                 if (phdr->p_memsz == 0 ||
844                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
845                                         goto dynamic_error;
846
847                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
848                                 if (((Elf32_Dyn *)
849                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
850                                         goto dynamic_error;
851                                 break;
852                         }
853                 }
854                 break;
855         }
856
857         /* now elide adjacent segments in the load map on MMU linux
858          * - on uClinux the holes between may actually be filled with system
859          *   stuff or stuff from other processes
860          */
861 #ifdef CONFIG_MMU
862         nloads = loadmap->nsegs;
863         mseg = loadmap->segs;
864         seg = mseg + 1;
865         for (loop = 1; loop < nloads; loop++) {
866                 /* see if we have a candidate for merging */
867                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
868                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
869                         if (load_addr == (seg->addr & PAGE_MASK)) {
870                                 mseg->p_memsz +=
871                                         load_addr -
872                                         (mseg->addr + mseg->p_memsz);
873                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
874                                 mseg->p_memsz += seg->p_memsz;
875                                 loadmap->nsegs--;
876                                 continue;
877                         }
878                 }
879
880                 mseg++;
881                 if (mseg != seg)
882                         *mseg = *seg;
883         }
884 #endif
885
886         kdebug("Mapped Object [%s]:", what);
887         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
888         kdebug("- entry    : %lx", params->entry_addr);
889         kdebug("- PHDR[]   : %lx", params->ph_addr);
890         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
891         seg = loadmap->segs;
892         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
893                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
894                        loop,
895                        seg->addr, seg->addr + seg->p_memsz - 1,
896                        seg->p_vaddr, seg->p_memsz);
897
898         return 0;
899
900 dynamic_error:
901         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
902                what, file->f_path.dentry->d_inode->i_ino);
903         return -ELIBBAD;
904 }
905
906 /*****************************************************************************/
907 /*
908  * map a file with constant displacement under uClinux
909  */
910 #ifndef CONFIG_MMU
911 static int elf_fdpic_map_file_constdisp_on_uclinux(
912         struct elf_fdpic_params *params,
913         struct file *file,
914         struct mm_struct *mm)
915 {
916         struct elf32_fdpic_loadseg *seg;
917         struct elf32_phdr *phdr;
918         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
919         loff_t fpos;
920         int loop, ret;
921
922         load_addr = params->load_addr;
923         seg = params->loadmap->segs;
924
925         /* determine the bounds of the contiguous overall allocation we must
926          * make */
927         phdr = params->phdrs;
928         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
929                 if (params->phdrs[loop].p_type != PT_LOAD)
930                         continue;
931
932                 if (base > phdr->p_vaddr)
933                         base = phdr->p_vaddr;
934                 if (top < phdr->p_vaddr + phdr->p_memsz)
935                         top = phdr->p_vaddr + phdr->p_memsz;
936         }
937
938         /* allocate one big anon block for everything */
939         mflags = MAP_PRIVATE;
940         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
941                 mflags |= MAP_EXECUTABLE;
942
943         down_write(&mm->mmap_sem);
944         maddr = do_mmap(NULL, load_addr, top - base,
945                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
946         up_write(&mm->mmap_sem);
947         if (IS_ERR_VALUE(maddr))
948                 return (int) maddr;
949
950         if (load_addr != 0)
951                 load_addr += PAGE_ALIGN(top - base);
952
953         /* and then load the file segments into it */
954         phdr = params->phdrs;
955         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
956                 if (params->phdrs[loop].p_type != PT_LOAD)
957                         continue;
958
959                 fpos = phdr->p_offset;
960
961                 seg->addr = maddr + (phdr->p_vaddr - base);
962                 seg->p_vaddr = phdr->p_vaddr;
963                 seg->p_memsz = phdr->p_memsz;
964
965                 ret = file->f_op->read(file, (void *) seg->addr,
966                                        phdr->p_filesz, &fpos);
967                 if (ret < 0)
968                         return ret;
969
970                 /* map the ELF header address if in this segment */
971                 if (phdr->p_offset == 0)
972                         params->elfhdr_addr = seg->addr;
973
974                 /* clear any space allocated but not loaded */
975                 if (phdr->p_filesz < phdr->p_memsz) {
976                         ret = clear_user((void *) (seg->addr + phdr->p_filesz),
977                                          phdr->p_memsz - phdr->p_filesz);
978                         if (ret)
979                                 return ret;
980                 }
981
982                 if (mm) {
983                         if (phdr->p_flags & PF_X) {
984                                 if (!mm->start_code) {
985                                         mm->start_code = seg->addr;
986                                         mm->end_code = seg->addr +
987                                                 phdr->p_memsz;
988                                 }
989                         } else if (!mm->start_data) {
990                                 mm->start_data = seg->addr;
991 #ifndef CONFIG_MMU
992                                 mm->end_data = seg->addr + phdr->p_memsz;
993 #endif
994                         }
995
996 #ifdef CONFIG_MMU
997                         if (seg->addr + phdr->p_memsz > mm->end_data)
998                                 mm->end_data = seg->addr + phdr->p_memsz;
999 #endif
1000                 }
1001
1002                 seg++;
1003         }
1004
1005         return 0;
1006 }
1007 #endif
1008
1009 /*****************************************************************************/
1010 /*
1011  * map a binary by direct mmap() of the individual PT_LOAD segments
1012  */
1013 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1014                                              struct file *file,
1015                                              struct mm_struct *mm)
1016 {
1017         struct elf32_fdpic_loadseg *seg;
1018         struct elf32_phdr *phdr;
1019         unsigned long load_addr, delta_vaddr;
1020         int loop, dvset, ret;
1021
1022         load_addr = params->load_addr;
1023         delta_vaddr = 0;
1024         dvset = 0;
1025
1026         seg = params->loadmap->segs;
1027
1028         /* deal with each load segment separately */
1029         phdr = params->phdrs;
1030         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1031                 unsigned long maddr, disp, excess, excess1;
1032                 int prot = 0, flags;
1033
1034                 if (phdr->p_type != PT_LOAD)
1035                         continue;
1036
1037                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1038                        (unsigned long) phdr->p_vaddr,
1039                        (unsigned long) phdr->p_offset,
1040                        (unsigned long) phdr->p_filesz,
1041                        (unsigned long) phdr->p_memsz);
1042
1043                 /* determine the mapping parameters */
1044                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1045                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1046                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1047
1048                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1049                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1050                         flags |= MAP_EXECUTABLE;
1051
1052                 maddr = 0;
1053
1054                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1055                 case ELF_FDPIC_FLAG_INDEPENDENT:
1056                         /* PT_LOADs are independently locatable */
1057                         break;
1058
1059                 case ELF_FDPIC_FLAG_HONOURVADDR:
1060                         /* the specified virtual address must be honoured */
1061                         maddr = phdr->p_vaddr;
1062                         flags |= MAP_FIXED;
1063                         break;
1064
1065                 case ELF_FDPIC_FLAG_CONSTDISP:
1066                         /* constant displacement
1067                          * - can be mapped anywhere, but must be mapped as a
1068                          *   unit
1069                          */
1070                         if (!dvset) {
1071                                 maddr = load_addr;
1072                                 delta_vaddr = phdr->p_vaddr;
1073                                 dvset = 1;
1074                         } else {
1075                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1076                                 flags |= MAP_FIXED;
1077                         }
1078                         break;
1079
1080                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1081                         /* contiguity handled later */
1082                         break;
1083
1084                 default:
1085                         BUG();
1086                 }
1087
1088                 maddr &= PAGE_MASK;
1089
1090                 /* create the mapping */
1091                 disp = phdr->p_vaddr & ~PAGE_MASK;
1092                 down_write(&mm->mmap_sem);
1093                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1094                                 phdr->p_offset - disp);
1095                 up_write(&mm->mmap_sem);
1096
1097                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1098                        loop, phdr->p_memsz + disp, prot, flags,
1099                        phdr->p_offset - disp, maddr);
1100
1101                 if (IS_ERR_VALUE(maddr))
1102                         return (int) maddr;
1103
1104                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1105                     ELF_FDPIC_FLAG_CONTIGUOUS)
1106                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1107
1108                 seg->addr = maddr + disp;
1109                 seg->p_vaddr = phdr->p_vaddr;
1110                 seg->p_memsz = phdr->p_memsz;
1111
1112                 /* map the ELF header address if in this segment */
1113                 if (phdr->p_offset == 0)
1114                         params->elfhdr_addr = seg->addr;
1115
1116                 /* clear the bit between beginning of mapping and beginning of
1117                  * PT_LOAD */
1118                 if (prot & PROT_WRITE && disp > 0) {
1119                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1120                         ret = clear_user((void __user *) maddr, disp);
1121                         if (ret)
1122                                 return ret;
1123                         maddr += disp;
1124                 }
1125
1126                 /* clear any space allocated but not loaded
1127                  * - on uClinux we can just clear the lot
1128                  * - on MMU linux we'll get a SIGBUS beyond the last page
1129                  *   extant in the file
1130                  */
1131                 excess = phdr->p_memsz - phdr->p_filesz;
1132                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1133
1134 #ifdef CONFIG_MMU
1135                 if (excess > excess1) {
1136                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1137                         unsigned long xmaddr;
1138
1139                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1140                         down_write(&mm->mmap_sem);
1141                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1142                                          prot, flags, 0);
1143                         up_write(&mm->mmap_sem);
1144
1145                         kdebug("mmap[%d] <anon>"
1146                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1147                                loop, xaddr, excess - excess1, prot, flags,
1148                                xmaddr);
1149
1150                         if (xmaddr != xaddr)
1151                                 return -ENOMEM;
1152                 }
1153
1154                 if (prot & PROT_WRITE && excess1 > 0) {
1155                         kdebug("clear[%d] ad=%lx sz=%lx",
1156                                loop, maddr + phdr->p_filesz, excess1);
1157                         ret = clear_user((void __user *) maddr + phdr->p_filesz,
1158                                          excess1);
1159                         if (ret)
1160                                 return ret;
1161                 }
1162
1163 #else
1164                 if (excess > 0) {
1165                         kdebug("clear[%d] ad=%lx sz=%lx",
1166                                loop, maddr + phdr->p_filesz, excess);
1167                         ret = clear_user((void *) maddr + phdr->p_filesz, excess);
1168                         if (ret)
1169                                 return ret;
1170                 }
1171 #endif
1172
1173                 if (mm) {
1174                         if (phdr->p_flags & PF_X) {
1175                                 if (!mm->start_code) {
1176                                         mm->start_code = maddr;
1177                                         mm->end_code = maddr + phdr->p_memsz;
1178                                 }
1179                         } else if (!mm->start_data) {
1180                                 mm->start_data = maddr;
1181                                 mm->end_data = maddr + phdr->p_memsz;
1182                         }
1183                 }
1184
1185                 seg++;
1186         }
1187
1188         return 0;
1189 }
1190
1191 /*****************************************************************************/
1192 /*
1193  * ELF-FDPIC core dumper
1194  *
1195  * Modelled on fs/exec.c:aout_core_dump()
1196  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1197  *
1198  * Modelled on fs/binfmt_elf.c core dumper
1199  */
1200 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1201
1202 /*
1203  * These are the only things you should do on a core-file: use only these
1204  * functions to write out all the necessary info.
1205  */
1206 static int dump_write(struct file *file, const void *addr, int nr)
1207 {
1208         return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1209 }
1210
1211 static int dump_seek(struct file *file, loff_t off)
1212 {
1213         if (file->f_op->llseek) {
1214                 if (file->f_op->llseek(file, off, SEEK_SET) != off)
1215                         return 0;
1216         } else {
1217                 file->f_pos = off;
1218         }
1219         return 1;
1220 }
1221
1222 /*
1223  * Decide whether a segment is worth dumping; default is yes to be
1224  * sure (missing info is worse than too much; etc).
1225  * Personally I'd include everything, and use the coredump limit...
1226  *
1227  * I think we should skip something. But I am not sure how. H.J.
1228  */
1229 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1230 {
1231         int dump_ok;
1232
1233         /* Do not dump I/O mapped devices or special mappings */
1234         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1235                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1236                 return 0;
1237         }
1238
1239         /* If we may not read the contents, don't allow us to dump
1240          * them either. "dump_write()" can't handle it anyway.
1241          */
1242         if (!(vma->vm_flags & VM_READ)) {
1243                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1244                 return 0;
1245         }
1246
1247         /* By default, dump shared memory if mapped from an anonymous file. */
1248         if (vma->vm_flags & VM_SHARED) {
1249                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1250                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1251                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1252                                vma->vm_flags, dump_ok ? "yes" : "no");
1253                         return dump_ok;
1254                 }
1255
1256                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1257                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1258                        vma->vm_flags, dump_ok ? "yes" : "no");
1259                 return dump_ok;
1260         }
1261
1262 #ifdef CONFIG_MMU
1263         /* By default, if it hasn't been written to, don't write it out */
1264         if (!vma->anon_vma) {
1265                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1266                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1267                        vma->vm_flags, dump_ok ? "yes" : "no");
1268                 return dump_ok;
1269         }
1270 #endif
1271
1272         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1273         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1274                dump_ok ? "yes" : "no");
1275         return dump_ok;
1276 }
1277
1278 /* An ELF note in memory */
1279 struct memelfnote
1280 {
1281         const char *name;
1282         int type;
1283         unsigned int datasz;
1284         void *data;
1285 };
1286
1287 static int notesize(struct memelfnote *en)
1288 {
1289         int sz;
1290
1291         sz = sizeof(struct elf_note);
1292         sz += roundup(strlen(en->name) + 1, 4);
1293         sz += roundup(en->datasz, 4);
1294
1295         return sz;
1296 }
1297
1298 /* #define DEBUG */
1299
1300 #define DUMP_WRITE(addr, nr)    \
1301         do { if (!dump_write(file, (addr), (nr))) return 0; } while(0)
1302 #define DUMP_SEEK(off)  \
1303         do { if (!dump_seek(file, (off))) return 0; } while(0)
1304
1305 static int writenote(struct memelfnote *men, struct file *file)
1306 {
1307         struct elf_note en;
1308
1309         en.n_namesz = strlen(men->name) + 1;
1310         en.n_descsz = men->datasz;
1311         en.n_type = men->type;
1312
1313         DUMP_WRITE(&en, sizeof(en));
1314         DUMP_WRITE(men->name, en.n_namesz);
1315         /* XXX - cast from long long to long to avoid need for libgcc.a */
1316         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1317         DUMP_WRITE(men->data, men->datasz);
1318         DUMP_SEEK(roundup((unsigned long)file->f_pos, 4));      /* XXX */
1319
1320         return 1;
1321 }
1322 #undef DUMP_WRITE
1323 #undef DUMP_SEEK
1324
1325 #define DUMP_WRITE(addr, nr)    \
1326         if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1327                 goto end_coredump;
1328
1329 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1330 {
1331         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1332         elf->e_ident[EI_CLASS] = ELF_CLASS;
1333         elf->e_ident[EI_DATA] = ELF_DATA;
1334         elf->e_ident[EI_VERSION] = EV_CURRENT;
1335         elf->e_ident[EI_OSABI] = ELF_OSABI;
1336         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1337
1338         elf->e_type = ET_CORE;
1339         elf->e_machine = ELF_ARCH;
1340         elf->e_version = EV_CURRENT;
1341         elf->e_entry = 0;
1342         elf->e_phoff = sizeof(struct elfhdr);
1343         elf->e_shoff = 0;
1344         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1345         elf->e_ehsize = sizeof(struct elfhdr);
1346         elf->e_phentsize = sizeof(struct elf_phdr);
1347         elf->e_phnum = segs;
1348         elf->e_shentsize = 0;
1349         elf->e_shnum = 0;
1350         elf->e_shstrndx = 0;
1351         return;
1352 }
1353
1354 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1355 {
1356         phdr->p_type = PT_NOTE;
1357         phdr->p_offset = offset;
1358         phdr->p_vaddr = 0;
1359         phdr->p_paddr = 0;
1360         phdr->p_filesz = sz;
1361         phdr->p_memsz = 0;
1362         phdr->p_flags = 0;
1363         phdr->p_align = 0;
1364         return;
1365 }
1366
1367 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1368                 unsigned int sz, void *data)
1369 {
1370         note->name = name;
1371         note->type = type;
1372         note->datasz = sz;
1373         note->data = data;
1374         return;
1375 }
1376
1377 /*
1378  * fill up all the fields in prstatus from the given task struct, except
1379  * registers which need to be filled up seperately.
1380  */
1381 static void fill_prstatus(struct elf_prstatus *prstatus,
1382                           struct task_struct *p, long signr)
1383 {
1384         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1385         prstatus->pr_sigpend = p->pending.signal.sig[0];
1386         prstatus->pr_sighold = p->blocked.sig[0];
1387         rcu_read_lock();
1388         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1389         rcu_read_unlock();
1390         prstatus->pr_pid = task_pid_vnr(p);
1391         prstatus->pr_pgrp = task_pgrp_vnr(p);
1392         prstatus->pr_sid = task_session_vnr(p);
1393         if (thread_group_leader(p)) {
1394                 struct task_cputime cputime;
1395
1396                 /*
1397                  * This is the record for the group leader.  It shows the
1398                  * group-wide total, not its individual thread total.
1399                  */
1400                 thread_group_cputime(p, &cputime);
1401                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1402                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1403         } else {
1404                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1405                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1406         }
1407         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1408         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1409
1410         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1411         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1412 }
1413
1414 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1415                        struct mm_struct *mm)
1416 {
1417         const struct cred *cred;
1418         unsigned int i, len;
1419
1420         /* first copy the parameters from user space */
1421         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1422
1423         len = mm->arg_end - mm->arg_start;
1424         if (len >= ELF_PRARGSZ)
1425                 len = ELF_PRARGSZ - 1;
1426         if (copy_from_user(&psinfo->pr_psargs,
1427                            (const char __user *) mm->arg_start, len))
1428                 return -EFAULT;
1429         for (i = 0; i < len; i++)
1430                 if (psinfo->pr_psargs[i] == 0)
1431                         psinfo->pr_psargs[i] = ' ';
1432         psinfo->pr_psargs[len] = 0;
1433
1434         rcu_read_lock();
1435         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1436         rcu_read_unlock();
1437         psinfo->pr_pid = task_pid_vnr(p);
1438         psinfo->pr_pgrp = task_pgrp_vnr(p);
1439         psinfo->pr_sid = task_session_vnr(p);
1440
1441         i = p->state ? ffz(~p->state) + 1 : 0;
1442         psinfo->pr_state = i;
1443         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1444         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1445         psinfo->pr_nice = task_nice(p);
1446         psinfo->pr_flag = p->flags;
1447         rcu_read_lock();
1448         cred = __task_cred(p);
1449         SET_UID(psinfo->pr_uid, cred->uid);
1450         SET_GID(psinfo->pr_gid, cred->gid);
1451         rcu_read_unlock();
1452         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1453
1454         return 0;
1455 }
1456
1457 /* Here is the structure in which status of each thread is captured. */
1458 struct elf_thread_status
1459 {
1460         struct list_head list;
1461         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1462         elf_fpregset_t fpu;             /* NT_PRFPREG */
1463         struct task_struct *thread;
1464 #ifdef ELF_CORE_COPY_XFPREGS
1465         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1466 #endif
1467         struct memelfnote notes[3];
1468         int num_notes;
1469 };
1470
1471 /*
1472  * In order to add the specific thread information for the elf file format,
1473  * we need to keep a linked list of every thread's pr_status and then create
1474  * a single section for them in the final core file.
1475  */
1476 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1477 {
1478         struct task_struct *p = t->thread;
1479         int sz = 0;
1480
1481         t->num_notes = 0;
1482
1483         fill_prstatus(&t->prstatus, p, signr);
1484         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1485
1486         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1487                   &t->prstatus);
1488         t->num_notes++;
1489         sz += notesize(&t->notes[0]);
1490
1491         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1492         if (t->prstatus.pr_fpvalid) {
1493                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1494                           &t->fpu);
1495                 t->num_notes++;
1496                 sz += notesize(&t->notes[1]);
1497         }
1498
1499 #ifdef ELF_CORE_COPY_XFPREGS
1500         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1501                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1502                           sizeof(t->xfpu), &t->xfpu);
1503                 t->num_notes++;
1504                 sz += notesize(&t->notes[2]);
1505         }
1506 #endif
1507         return sz;
1508 }
1509
1510 /*
1511  * dump the segments for an MMU process
1512  */
1513 #ifdef CONFIG_MMU
1514 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1515                            unsigned long *limit, unsigned long mm_flags)
1516 {
1517         struct vm_area_struct *vma;
1518         int err = 0;
1519
1520         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1521                 unsigned long addr;
1522
1523                 if (!maydump(vma, mm_flags))
1524                         continue;
1525
1526                 for (addr = vma->vm_start; addr < vma->vm_end;
1527                                                         addr += PAGE_SIZE) {
1528                         struct page *page = get_dump_page(addr);
1529                         if (page) {
1530                                 void *kaddr = kmap(page);
1531                                 *size += PAGE_SIZE;
1532                                 if (*size > *limit)
1533                                         err = -EFBIG;
1534                                 else if (!dump_write(file, kaddr, PAGE_SIZE))
1535                                         err = -EIO;
1536                                 kunmap(page);
1537                                 page_cache_release(page);
1538                         } else if (!dump_seek(file, file->f_pos + PAGE_SIZE))
1539                                 err = -EFBIG;
1540                         if (err)
1541                                 goto out;
1542                 }
1543         }
1544 out:
1545         return err;
1546 }
1547 #endif
1548
1549 /*
1550  * dump the segments for a NOMMU process
1551  */
1552 #ifndef CONFIG_MMU
1553 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1554                            unsigned long *limit, unsigned long mm_flags)
1555 {
1556         struct vm_area_struct *vma;
1557
1558         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1559                 if (!maydump(vma, mm_flags))
1560                         continue;
1561
1562                 if ((*size += PAGE_SIZE) > *limit)
1563                         return -EFBIG;
1564
1565                 if (!dump_write(file, (void *) vma->vm_start,
1566                                 vma->vm_end - vma->vm_start))
1567                         return -EIO;
1568         }
1569
1570         return 0;
1571 }
1572 #endif
1573
1574 /*
1575  * Actual dumper
1576  *
1577  * This is a two-pass process; first we find the offsets of the bits,
1578  * and then they are actually written out.  If we run out of core limit
1579  * we just truncate.
1580  */
1581 static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
1582                                struct file *file, unsigned long limit)
1583 {
1584 #define NUM_NOTES       6
1585         int has_dumped = 0;
1586         mm_segment_t fs;
1587         int segs;
1588         size_t size = 0;
1589         int i;
1590         struct vm_area_struct *vma;
1591         struct elfhdr *elf = NULL;
1592         loff_t offset = 0, dataoff;
1593         int numnote;
1594         struct memelfnote *notes = NULL;
1595         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1596         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1597         LIST_HEAD(thread_list);
1598         struct list_head *t;
1599         elf_fpregset_t *fpu = NULL;
1600 #ifdef ELF_CORE_COPY_XFPREGS
1601         elf_fpxregset_t *xfpu = NULL;
1602 #endif
1603         int thread_status_size = 0;
1604         elf_addr_t *auxv;
1605         unsigned long mm_flags;
1606
1607         /*
1608          * We no longer stop all VM operations.
1609          *
1610          * This is because those proceses that could possibly change map_count
1611          * or the mmap / vma pages are now blocked in do_exit on current
1612          * finishing this core dump.
1613          *
1614          * Only ptrace can touch these memory addresses, but it doesn't change
1615          * the map_count or the pages allocated. So no possibility of crashing
1616          * exists while dumping the mm->vm_next areas to the core file.
1617          */
1618
1619         /* alloc memory for large data structures: too large to be on stack */
1620         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1621         if (!elf)
1622                 goto cleanup;
1623         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1624         if (!prstatus)
1625                 goto cleanup;
1626         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1627         if (!psinfo)
1628                 goto cleanup;
1629         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1630         if (!notes)
1631                 goto cleanup;
1632         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1633         if (!fpu)
1634                 goto cleanup;
1635 #ifdef ELF_CORE_COPY_XFPREGS
1636         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1637         if (!xfpu)
1638                 goto cleanup;
1639 #endif
1640
1641         if (signr) {
1642                 struct core_thread *ct;
1643                 struct elf_thread_status *tmp;
1644
1645                 for (ct = current->mm->core_state->dumper.next;
1646                                                 ct; ct = ct->next) {
1647                         tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1648                         if (!tmp)
1649                                 goto cleanup;
1650
1651                         tmp->thread = ct->task;
1652                         list_add(&tmp->list, &thread_list);
1653                 }
1654
1655                 list_for_each(t, &thread_list) {
1656                         struct elf_thread_status *tmp;
1657                         int sz;
1658
1659                         tmp = list_entry(t, struct elf_thread_status, list);
1660                         sz = elf_dump_thread_status(signr, tmp);
1661                         thread_status_size += sz;
1662                 }
1663         }
1664
1665         /* now collect the dump for the current */
1666         fill_prstatus(prstatus, current, signr);
1667         elf_core_copy_regs(&prstatus->pr_reg, regs);
1668
1669         segs = current->mm->map_count;
1670 #ifdef ELF_CORE_EXTRA_PHDRS
1671         segs += ELF_CORE_EXTRA_PHDRS;
1672 #endif
1673
1674         /* Set up header */
1675         fill_elf_fdpic_header(elf, segs + 1);   /* including notes section */
1676
1677         has_dumped = 1;
1678         current->flags |= PF_DUMPCORE;
1679
1680         /*
1681          * Set up the notes in similar form to SVR4 core dumps made
1682          * with info from their /proc.
1683          */
1684
1685         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1686         fill_psinfo(psinfo, current->group_leader, current->mm);
1687         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1688
1689         numnote = 2;
1690
1691         auxv = (elf_addr_t *) current->mm->saved_auxv;
1692
1693         i = 0;
1694         do
1695                 i += 2;
1696         while (auxv[i - 2] != AT_NULL);
1697         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1698                   i * sizeof(elf_addr_t), auxv);
1699
1700         /* Try to dump the FPU. */
1701         if ((prstatus->pr_fpvalid =
1702              elf_core_copy_task_fpregs(current, regs, fpu)))
1703                 fill_note(notes + numnote++,
1704                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1705 #ifdef ELF_CORE_COPY_XFPREGS
1706         if (elf_core_copy_task_xfpregs(current, xfpu))
1707                 fill_note(notes + numnote++,
1708                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1709 #endif
1710
1711         fs = get_fs();
1712         set_fs(KERNEL_DS);
1713
1714         DUMP_WRITE(elf, sizeof(*elf));
1715         offset += sizeof(*elf);                         /* Elf header */
1716         offset += (segs+1) * sizeof(struct elf_phdr);   /* Program headers */
1717
1718         /* Write notes phdr entry */
1719         {
1720                 struct elf_phdr phdr;
1721                 int sz = 0;
1722
1723                 for (i = 0; i < numnote; i++)
1724                         sz += notesize(notes + i);
1725
1726                 sz += thread_status_size;
1727
1728                 fill_elf_note_phdr(&phdr, sz, offset);
1729                 offset += sz;
1730                 DUMP_WRITE(&phdr, sizeof(phdr));
1731         }
1732
1733         /* Page-align dumped data */
1734         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1735
1736         /*
1737          * We must use the same mm->flags while dumping core to avoid
1738          * inconsistency between the program headers and bodies, otherwise an
1739          * unusable core file can be generated.
1740          */
1741         mm_flags = current->mm->flags;
1742
1743         /* write program headers for segments dump */
1744         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1745                 struct elf_phdr phdr;
1746                 size_t sz;
1747
1748                 sz = vma->vm_end - vma->vm_start;
1749
1750                 phdr.p_type = PT_LOAD;
1751                 phdr.p_offset = offset;
1752                 phdr.p_vaddr = vma->vm_start;
1753                 phdr.p_paddr = 0;
1754                 phdr.p_filesz = maydump(vma, mm_flags) ? sz : 0;
1755                 phdr.p_memsz = sz;
1756                 offset += phdr.p_filesz;
1757                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1758                 if (vma->vm_flags & VM_WRITE)
1759                         phdr.p_flags |= PF_W;
1760                 if (vma->vm_flags & VM_EXEC)
1761                         phdr.p_flags |= PF_X;
1762                 phdr.p_align = ELF_EXEC_PAGESIZE;
1763
1764                 DUMP_WRITE(&phdr, sizeof(phdr));
1765         }
1766
1767 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1768         ELF_CORE_WRITE_EXTRA_PHDRS;
1769 #endif
1770
1771         /* write out the notes section */
1772         for (i = 0; i < numnote; i++)
1773                 if (!writenote(notes + i, file))
1774                         goto end_coredump;
1775
1776         /* write out the thread status notes section */
1777         list_for_each(t, &thread_list) {
1778                 struct elf_thread_status *tmp =
1779                                 list_entry(t, struct elf_thread_status, list);
1780
1781                 for (i = 0; i < tmp->num_notes; i++)
1782                         if (!writenote(&tmp->notes[i], file))
1783                                 goto end_coredump;
1784         }
1785
1786         if (!dump_seek(file, dataoff))
1787                 goto end_coredump;
1788
1789         if (elf_fdpic_dump_segments(file, &size, &limit, mm_flags) < 0)
1790                 goto end_coredump;
1791
1792 #ifdef ELF_CORE_WRITE_EXTRA_DATA
1793         ELF_CORE_WRITE_EXTRA_DATA;
1794 #endif
1795
1796         if (file->f_pos != offset) {
1797                 /* Sanity check */
1798                 printk(KERN_WARNING
1799                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1800                        file->f_pos, offset);
1801         }
1802
1803 end_coredump:
1804         set_fs(fs);
1805
1806 cleanup:
1807         while (!list_empty(&thread_list)) {
1808                 struct list_head *tmp = thread_list.next;
1809                 list_del(tmp);
1810                 kfree(list_entry(tmp, struct elf_thread_status, list));
1811         }
1812
1813         kfree(elf);
1814         kfree(prstatus);
1815         kfree(psinfo);
1816         kfree(notes);
1817         kfree(fpu);
1818 #ifdef ELF_CORE_COPY_XFPREGS
1819         kfree(xfpu);
1820 #endif
1821         return has_dumped;
1822 #undef NUM_NOTES
1823 }
1824
1825 #endif          /* USE_ELF_CORE_DUMP */