coredump: factor out the setting of PF_DUMPCORE
[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 #include <linux/coredump.h>
38
39 #include <asm/uaccess.h>
40 #include <asm/param.h>
41 #include <asm/pgalloc.h>
42
43 typedef char *elf_caddr_t;
44
45 #if 0
46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
47 #else
48 #define kdebug(fmt, ...) do {} while(0)
49 #endif
50
51 #if 0
52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
53 #else
54 #define kdcore(fmt, ...) do {} while(0)
55 #endif
56
57 MODULE_LICENSE("GPL");
58
59 static int load_elf_fdpic_binary(struct linux_binprm *);
60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
62                               struct mm_struct *, const char *);
63
64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
65                                    struct elf_fdpic_params *,
66                                    struct elf_fdpic_params *);
67
68 #ifndef CONFIG_MMU
69 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
70                                             unsigned long *);
71 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
72                                                    struct file *,
73                                                    struct mm_struct *);
74 #endif
75
76 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
77                                              struct file *, struct mm_struct *);
78
79 #ifdef CONFIG_ELF_CORE
80 static int elf_fdpic_core_dump(struct coredump_params *cprm);
81 #endif
82
83 static struct linux_binfmt elf_fdpic_format = {
84         .module         = THIS_MODULE,
85         .load_binary    = load_elf_fdpic_binary,
86 #ifdef CONFIG_ELF_CORE
87         .core_dump      = elf_fdpic_core_dump,
88 #endif
89         .min_coredump   = ELF_EXEC_PAGESIZE,
90 };
91
92 static int __init init_elf_fdpic_binfmt(void)
93 {
94         register_binfmt(&elf_fdpic_format);
95         return 0;
96 }
97
98 static void __exit exit_elf_fdpic_binfmt(void)
99 {
100         unregister_binfmt(&elf_fdpic_format);
101 }
102
103 core_initcall(init_elf_fdpic_binfmt);
104 module_exit(exit_elf_fdpic_binfmt);
105
106 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
107 {
108         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
109                 return 0;
110         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
111                 return 0;
112         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
113                 return 0;
114         if (!file->f_op || !file->f_op->mmap)
115                 return 0;
116         return 1;
117 }
118
119 /*****************************************************************************/
120 /*
121  * read the program headers table into memory
122  */
123 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
124                                  struct file *file)
125 {
126         struct elf32_phdr *phdr;
127         unsigned long size;
128         int retval, loop;
129
130         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
131                 return -ENOMEM;
132         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
133                 return -ENOMEM;
134
135         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
136         params->phdrs = kmalloc(size, GFP_KERNEL);
137         if (!params->phdrs)
138                 return -ENOMEM;
139
140         retval = kernel_read(file, params->hdr.e_phoff,
141                              (char *) params->phdrs, size);
142         if (unlikely(retval != size))
143                 return retval < 0 ? retval : -ENOEXEC;
144
145         /* determine stack size for this binary */
146         phdr = params->phdrs;
147         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
148                 if (phdr->p_type != PT_GNU_STACK)
149                         continue;
150
151                 if (phdr->p_flags & PF_X)
152                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
153                 else
154                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
155
156                 params->stack_size = phdr->p_memsz;
157                 break;
158         }
159
160         return 0;
161 }
162
163 /*****************************************************************************/
164 /*
165  * load an fdpic binary into various bits of memory
166  */
167 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
168 {
169         struct elf_fdpic_params exec_params, interp_params;
170         struct pt_regs *regs = current_pt_regs();
171         struct elf_phdr *phdr;
172         unsigned long stack_size, entryaddr;
173 #ifdef ELF_FDPIC_PLAT_INIT
174         unsigned long dynaddr;
175 #endif
176 #ifndef CONFIG_MMU
177         unsigned long stack_prot;
178 #endif
179         struct file *interpreter = NULL; /* to shut gcc up */
180         char *interpreter_name = NULL;
181         int executable_stack;
182         int retval, i;
183
184         kdebug("____ LOAD %d ____", current->pid);
185
186         memset(&exec_params, 0, sizeof(exec_params));
187         memset(&interp_params, 0, sizeof(interp_params));
188
189         exec_params.hdr = *(struct elfhdr *) bprm->buf;
190         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
191
192         /* check that this is a binary we know how to deal with */
193         retval = -ENOEXEC;
194         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
195                 goto error;
196
197         /* read the program header table */
198         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
199         if (retval < 0)
200                 goto error;
201
202         /* scan for a program header that specifies an interpreter */
203         phdr = exec_params.phdrs;
204
205         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
206                 switch (phdr->p_type) {
207                 case PT_INTERP:
208                         retval = -ENOMEM;
209                         if (phdr->p_filesz > PATH_MAX)
210                                 goto error;
211                         retval = -ENOENT;
212                         if (phdr->p_filesz < 2)
213                                 goto error;
214
215                         /* read the name of the interpreter into memory */
216                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
217                         if (!interpreter_name)
218                                 goto error;
219
220                         retval = kernel_read(bprm->file,
221                                              phdr->p_offset,
222                                              interpreter_name,
223                                              phdr->p_filesz);
224                         if (unlikely(retval != phdr->p_filesz)) {
225                                 if (retval >= 0)
226                                         retval = -ENOEXEC;
227                                 goto error;
228                         }
229
230                         retval = -ENOENT;
231                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
232                                 goto error;
233
234                         kdebug("Using ELF interpreter %s", interpreter_name);
235
236                         /* replace the program with the interpreter */
237                         interpreter = open_exec(interpreter_name);
238                         retval = PTR_ERR(interpreter);
239                         if (IS_ERR(interpreter)) {
240                                 interpreter = NULL;
241                                 goto error;
242                         }
243
244                         /*
245                          * If the binary is not readable then enforce
246                          * mm->dumpable = 0 regardless of the interpreter's
247                          * permissions.
248                          */
249                         would_dump(bprm, interpreter);
250
251                         retval = kernel_read(interpreter, 0, bprm->buf,
252                                              BINPRM_BUF_SIZE);
253                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
254                                 if (retval >= 0)
255                                         retval = -ENOEXEC;
256                                 goto error;
257                         }
258
259                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
260                         break;
261
262                 case PT_LOAD:
263 #ifdef CONFIG_MMU
264                         if (exec_params.load_addr == 0)
265                                 exec_params.load_addr = phdr->p_vaddr;
266 #endif
267                         break;
268                 }
269
270         }
271
272         if (elf_check_const_displacement(&exec_params.hdr))
273                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
274
275         /* perform insanity checks on the interpreter */
276         if (interpreter_name) {
277                 retval = -ELIBBAD;
278                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
279                         goto error;
280
281                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
282
283                 /* read the interpreter's program header table */
284                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
285                 if (retval < 0)
286                         goto error;
287         }
288
289         stack_size = exec_params.stack_size;
290         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
291                 executable_stack = EXSTACK_ENABLE_X;
292         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
293                 executable_stack = EXSTACK_DISABLE_X;
294         else
295                 executable_stack = EXSTACK_DEFAULT;
296
297         if (stack_size == 0) {
298                 stack_size = interp_params.stack_size;
299                 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
300                         executable_stack = EXSTACK_ENABLE_X;
301                 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
302                         executable_stack = EXSTACK_DISABLE_X;
303                 else
304                         executable_stack = EXSTACK_DEFAULT;
305         }
306
307         retval = -ENOEXEC;
308         if (stack_size == 0)
309                 goto error;
310
311         if (elf_check_const_displacement(&interp_params.hdr))
312                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
313
314         /* flush all traces of the currently running executable */
315         retval = flush_old_exec(bprm);
316         if (retval)
317                 goto error;
318
319         /* there's now no turning back... the old userspace image is dead,
320          * defunct, deceased, etc. after this point we have to exit via
321          * error_kill */
322         set_personality(PER_LINUX_FDPIC);
323         if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
324                 current->personality |= READ_IMPLIES_EXEC;
325
326         setup_new_exec(bprm);
327
328         set_binfmt(&elf_fdpic_format);
329
330         current->mm->start_code = 0;
331         current->mm->end_code = 0;
332         current->mm->start_stack = 0;
333         current->mm->start_data = 0;
334         current->mm->end_data = 0;
335         current->mm->context.exec_fdpic_loadmap = 0;
336         current->mm->context.interp_fdpic_loadmap = 0;
337
338 #ifdef CONFIG_MMU
339         elf_fdpic_arch_lay_out_mm(&exec_params,
340                                   &interp_params,
341                                   &current->mm->start_stack,
342                                   &current->mm->start_brk);
343
344         retval = setup_arg_pages(bprm, current->mm->start_stack,
345                                  executable_stack);
346         if (retval < 0) {
347                 send_sig(SIGKILL, current, 0);
348                 goto error_kill;
349         }
350 #endif
351
352         /* load the executable and interpreter into memory */
353         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
354                                     "executable");
355         if (retval < 0)
356                 goto error_kill;
357
358         if (interpreter_name) {
359                 retval = elf_fdpic_map_file(&interp_params, interpreter,
360                                             current->mm, "interpreter");
361                 if (retval < 0) {
362                         printk(KERN_ERR "Unable to load interpreter\n");
363                         goto error_kill;
364                 }
365
366                 allow_write_access(interpreter);
367                 fput(interpreter);
368                 interpreter = NULL;
369         }
370
371 #ifdef CONFIG_MMU
372         if (!current->mm->start_brk)
373                 current->mm->start_brk = current->mm->end_data;
374
375         current->mm->brk = current->mm->start_brk =
376                 PAGE_ALIGN(current->mm->start_brk);
377
378 #else
379         /* create a stack and brk area big enough for everyone
380          * - the brk heap starts at the bottom and works up
381          * - the stack starts at the top and works down
382          */
383         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
384         if (stack_size < PAGE_SIZE * 2)
385                 stack_size = PAGE_SIZE * 2;
386
387         stack_prot = PROT_READ | PROT_WRITE;
388         if (executable_stack == EXSTACK_ENABLE_X ||
389             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
390                 stack_prot |= PROT_EXEC;
391
392         current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
393                                          MAP_PRIVATE | MAP_ANONYMOUS |
394                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
395                                          0);
396
397         if (IS_ERR_VALUE(current->mm->start_brk)) {
398                 retval = current->mm->start_brk;
399                 current->mm->start_brk = 0;
400                 goto error_kill;
401         }
402
403         current->mm->brk = current->mm->start_brk;
404         current->mm->context.end_brk = current->mm->start_brk;
405         current->mm->context.end_brk +=
406                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
407         current->mm->start_stack = current->mm->start_brk + stack_size;
408 #endif
409
410         install_exec_creds(bprm);
411         if (create_elf_fdpic_tables(bprm, current->mm,
412                                     &exec_params, &interp_params) < 0)
413                 goto error_kill;
414
415         kdebug("- start_code  %lx", current->mm->start_code);
416         kdebug("- end_code    %lx", current->mm->end_code);
417         kdebug("- start_data  %lx", current->mm->start_data);
418         kdebug("- end_data    %lx", current->mm->end_data);
419         kdebug("- start_brk   %lx", current->mm->start_brk);
420         kdebug("- brk         %lx", current->mm->brk);
421         kdebug("- start_stack %lx", current->mm->start_stack);
422
423 #ifdef ELF_FDPIC_PLAT_INIT
424         /*
425          * The ABI may specify that certain registers be set up in special
426          * ways (on i386 %edx is the address of a DT_FINI function, for
427          * example.  This macro performs whatever initialization to
428          * the regs structure is required.
429          */
430         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
431         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
432                             dynaddr);
433 #endif
434
435         /* everything is now ready... get the userspace context ready to roll */
436         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
437         start_thread(regs, entryaddr, current->mm->start_stack);
438
439         retval = 0;
440
441 error:
442         if (interpreter) {
443                 allow_write_access(interpreter);
444                 fput(interpreter);
445         }
446         kfree(interpreter_name);
447         kfree(exec_params.phdrs);
448         kfree(exec_params.loadmap);
449         kfree(interp_params.phdrs);
450         kfree(interp_params.loadmap);
451         return retval;
452
453         /* unrecoverable error - kill the process */
454 error_kill:
455         send_sig(SIGSEGV, current, 0);
456         goto error;
457
458 }
459
460 /*****************************************************************************/
461
462 #ifndef ELF_BASE_PLATFORM
463 /*
464  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
465  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
466  * will be copied to the user stack in the same manner as AT_PLATFORM.
467  */
468 #define ELF_BASE_PLATFORM NULL
469 #endif
470
471 /*
472  * present useful information to the program by shovelling it onto the new
473  * process's stack
474  */
475 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
476                                    struct mm_struct *mm,
477                                    struct elf_fdpic_params *exec_params,
478                                    struct elf_fdpic_params *interp_params)
479 {
480         const struct cred *cred = current_cred();
481         unsigned long sp, csp, nitems;
482         elf_caddr_t __user *argv, *envp;
483         size_t platform_len = 0, len;
484         char *k_platform, *k_base_platform;
485         char __user *u_platform, *u_base_platform, *p;
486         long hwcap;
487         int loop;
488         int nr; /* reset for each csp adjustment */
489
490 #ifdef CONFIG_MMU
491         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
492          * by the processes running on the same package. One thing we can do is
493          * to shuffle the initial stack for them, so we give the architecture
494          * an opportunity to do so here.
495          */
496         sp = arch_align_stack(bprm->p);
497 #else
498         sp = mm->start_stack;
499
500         /* stack the program arguments and environment */
501         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
502                 return -EFAULT;
503 #endif
504
505         hwcap = ELF_HWCAP;
506
507         /*
508          * If this architecture has a platform capability string, copy it
509          * to userspace.  In some cases (Sparc), this info is impossible
510          * for userspace to get any other way, in others (i386) it is
511          * merely difficult.
512          */
513         k_platform = ELF_PLATFORM;
514         u_platform = NULL;
515
516         if (k_platform) {
517                 platform_len = strlen(k_platform) + 1;
518                 sp -= platform_len;
519                 u_platform = (char __user *) sp;
520                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
521                         return -EFAULT;
522         }
523
524         /*
525          * If this architecture has a "base" platform capability
526          * string, copy it to userspace.
527          */
528         k_base_platform = ELF_BASE_PLATFORM;
529         u_base_platform = NULL;
530
531         if (k_base_platform) {
532                 platform_len = strlen(k_base_platform) + 1;
533                 sp -= platform_len;
534                 u_base_platform = (char __user *) sp;
535                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
536                         return -EFAULT;
537         }
538
539         sp &= ~7UL;
540
541         /* stack the load map(s) */
542         len = sizeof(struct elf32_fdpic_loadmap);
543         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
544         sp = (sp - len) & ~7UL;
545         exec_params->map_addr = sp;
546
547         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
548                 return -EFAULT;
549
550         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
551
552         if (interp_params->loadmap) {
553                 len = sizeof(struct elf32_fdpic_loadmap);
554                 len += sizeof(struct elf32_fdpic_loadseg) *
555                         interp_params->loadmap->nsegs;
556                 sp = (sp - len) & ~7UL;
557                 interp_params->map_addr = sp;
558
559                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
560                                  len) != 0)
561                         return -EFAULT;
562
563                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
564         }
565
566         /* force 16 byte _final_ alignment here for generality */
567 #define DLINFO_ITEMS 15
568
569         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
570                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
571
572         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
573                 nitems++;
574
575         csp = sp;
576         sp -= nitems * 2 * sizeof(unsigned long);
577         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
578         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
579         sp -= 1 * sizeof(unsigned long);                /* argc */
580
581         csp -= sp & 15UL;
582         sp -= sp & 15UL;
583
584         /* put the ELF interpreter info on the stack */
585 #define NEW_AUX_ENT(id, val)                                            \
586         do {                                                            \
587                 struct { unsigned long _id, _val; } __user *ent;        \
588                                                                         \
589                 ent = (void __user *) csp;                              \
590                 __put_user((id), &ent[nr]._id);                         \
591                 __put_user((val), &ent[nr]._val);                       \
592                 nr++;                                                   \
593         } while (0)
594
595         nr = 0;
596         csp -= 2 * sizeof(unsigned long);
597         NEW_AUX_ENT(AT_NULL, 0);
598         if (k_platform) {
599                 nr = 0;
600                 csp -= 2 * sizeof(unsigned long);
601                 NEW_AUX_ENT(AT_PLATFORM,
602                             (elf_addr_t) (unsigned long) u_platform);
603         }
604
605         if (k_base_platform) {
606                 nr = 0;
607                 csp -= 2 * sizeof(unsigned long);
608                 NEW_AUX_ENT(AT_BASE_PLATFORM,
609                             (elf_addr_t) (unsigned long) u_base_platform);
610         }
611
612         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
613                 nr = 0;
614                 csp -= 2 * sizeof(unsigned long);
615                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
616         }
617
618         nr = 0;
619         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
620         NEW_AUX_ENT(AT_HWCAP,   hwcap);
621         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
622         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
623         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
624         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
625         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
626         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
627         NEW_AUX_ENT(AT_FLAGS,   0);
628         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
629         NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
630         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
631         NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
632         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
633         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
634         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
635
636 #ifdef ARCH_DLINFO
637         nr = 0;
638         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
639
640         /* ARCH_DLINFO must come last so platform specific code can enforce
641          * special alignment requirements on the AUXV if necessary (eg. PPC).
642          */
643         ARCH_DLINFO;
644 #endif
645 #undef NEW_AUX_ENT
646
647         /* allocate room for argv[] and envv[] */
648         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
649         envp = (elf_caddr_t __user *) csp;
650         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
651         argv = (elf_caddr_t __user *) csp;
652
653         /* stack argc */
654         csp -= sizeof(unsigned long);
655         __put_user(bprm->argc, (unsigned long __user *) csp);
656
657         BUG_ON(csp != sp);
658
659         /* fill in the argv[] array */
660 #ifdef CONFIG_MMU
661         current->mm->arg_start = bprm->p;
662 #else
663         current->mm->arg_start = current->mm->start_stack -
664                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
665 #endif
666
667         p = (char __user *) current->mm->arg_start;
668         for (loop = bprm->argc; loop > 0; loop--) {
669                 __put_user((elf_caddr_t) p, argv++);
670                 len = strnlen_user(p, MAX_ARG_STRLEN);
671                 if (!len || len > MAX_ARG_STRLEN)
672                         return -EINVAL;
673                 p += len;
674         }
675         __put_user(NULL, argv);
676         current->mm->arg_end = (unsigned long) p;
677
678         /* fill in the envv[] array */
679         current->mm->env_start = (unsigned long) p;
680         for (loop = bprm->envc; loop > 0; loop--) {
681                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
682                 len = strnlen_user(p, MAX_ARG_STRLEN);
683                 if (!len || len > MAX_ARG_STRLEN)
684                         return -EINVAL;
685                 p += len;
686         }
687         __put_user(NULL, envp);
688         current->mm->env_end = (unsigned long) p;
689
690         mm->start_stack = (unsigned long) sp;
691         return 0;
692 }
693
694 /*****************************************************************************/
695 /*
696  * transfer the program arguments and environment from the holding pages onto
697  * the stack
698  */
699 #ifndef CONFIG_MMU
700 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
701                                             unsigned long *_sp)
702 {
703         unsigned long index, stop, sp;
704         char *src;
705         int ret = 0;
706
707         stop = bprm->p >> PAGE_SHIFT;
708         sp = *_sp;
709
710         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
711                 src = kmap(bprm->page[index]);
712                 sp -= PAGE_SIZE;
713                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
714                         ret = -EFAULT;
715                 kunmap(bprm->page[index]);
716                 if (ret < 0)
717                         goto out;
718         }
719
720         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
721
722 out:
723         return ret;
724 }
725 #endif
726
727 /*****************************************************************************/
728 /*
729  * load the appropriate binary image (executable or interpreter) into memory
730  * - we assume no MMU is available
731  * - if no other PIC bits are set in params->hdr->e_flags
732  *   - we assume that the LOADable segments in the binary are independently relocatable
733  *   - we assume R/O executable segments are shareable
734  * - else
735  *   - we assume the loadable parts of the image to require fixed displacement
736  *   - the image is not shareable
737  */
738 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
739                               struct file *file,
740                               struct mm_struct *mm,
741                               const char *what)
742 {
743         struct elf32_fdpic_loadmap *loadmap;
744 #ifdef CONFIG_MMU
745         struct elf32_fdpic_loadseg *mseg;
746 #endif
747         struct elf32_fdpic_loadseg *seg;
748         struct elf32_phdr *phdr;
749         unsigned long load_addr, stop;
750         unsigned nloads, tmp;
751         size_t size;
752         int loop, ret;
753
754         /* allocate a load map table */
755         nloads = 0;
756         for (loop = 0; loop < params->hdr.e_phnum; loop++)
757                 if (params->phdrs[loop].p_type == PT_LOAD)
758                         nloads++;
759
760         if (nloads == 0)
761                 return -ELIBBAD;
762
763         size = sizeof(*loadmap) + nloads * sizeof(*seg);
764         loadmap = kzalloc(size, GFP_KERNEL);
765         if (!loadmap)
766                 return -ENOMEM;
767
768         params->loadmap = loadmap;
769
770         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
771         loadmap->nsegs = nloads;
772
773         load_addr = params->load_addr;
774         seg = loadmap->segs;
775
776         /* map the requested LOADs into the memory space */
777         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
778         case ELF_FDPIC_FLAG_CONSTDISP:
779         case ELF_FDPIC_FLAG_CONTIGUOUS:
780 #ifndef CONFIG_MMU
781                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
782                 if (ret < 0)
783                         return ret;
784                 break;
785 #endif
786         default:
787                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
788                 if (ret < 0)
789                         return ret;
790                 break;
791         }
792
793         /* map the entry point */
794         if (params->hdr.e_entry) {
795                 seg = loadmap->segs;
796                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
797                         if (params->hdr.e_entry >= seg->p_vaddr &&
798                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
799                                 params->entry_addr =
800                                         (params->hdr.e_entry - seg->p_vaddr) +
801                                         seg->addr;
802                                 break;
803                         }
804                 }
805         }
806
807         /* determine where the program header table has wound up if mapped */
808         stop = params->hdr.e_phoff;
809         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
810         phdr = params->phdrs;
811
812         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
813                 if (phdr->p_type != PT_LOAD)
814                         continue;
815
816                 if (phdr->p_offset > params->hdr.e_phoff ||
817                     phdr->p_offset + phdr->p_filesz < stop)
818                         continue;
819
820                 seg = loadmap->segs;
821                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
822                         if (phdr->p_vaddr >= seg->p_vaddr &&
823                             phdr->p_vaddr + phdr->p_filesz <=
824                             seg->p_vaddr + seg->p_memsz) {
825                                 params->ph_addr =
826                                         (phdr->p_vaddr - seg->p_vaddr) +
827                                         seg->addr +
828                                         params->hdr.e_phoff - phdr->p_offset;
829                                 break;
830                         }
831                 }
832                 break;
833         }
834
835         /* determine where the dynamic section has wound up if there is one */
836         phdr = params->phdrs;
837         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
838                 if (phdr->p_type != PT_DYNAMIC)
839                         continue;
840
841                 seg = loadmap->segs;
842                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
843                         if (phdr->p_vaddr >= seg->p_vaddr &&
844                             phdr->p_vaddr + phdr->p_memsz <=
845                             seg->p_vaddr + seg->p_memsz) {
846                                 params->dynamic_addr =
847                                         (phdr->p_vaddr - seg->p_vaddr) +
848                                         seg->addr;
849
850                                 /* check the dynamic section contains at least
851                                  * one item, and that the last item is a NULL
852                                  * entry */
853                                 if (phdr->p_memsz == 0 ||
854                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
855                                         goto dynamic_error;
856
857                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
858                                 if (((Elf32_Dyn *)
859                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
860                                         goto dynamic_error;
861                                 break;
862                         }
863                 }
864                 break;
865         }
866
867         /* now elide adjacent segments in the load map on MMU linux
868          * - on uClinux the holes between may actually be filled with system
869          *   stuff or stuff from other processes
870          */
871 #ifdef CONFIG_MMU
872         nloads = loadmap->nsegs;
873         mseg = loadmap->segs;
874         seg = mseg + 1;
875         for (loop = 1; loop < nloads; loop++) {
876                 /* see if we have a candidate for merging */
877                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
878                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
879                         if (load_addr == (seg->addr & PAGE_MASK)) {
880                                 mseg->p_memsz +=
881                                         load_addr -
882                                         (mseg->addr + mseg->p_memsz);
883                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
884                                 mseg->p_memsz += seg->p_memsz;
885                                 loadmap->nsegs--;
886                                 continue;
887                         }
888                 }
889
890                 mseg++;
891                 if (mseg != seg)
892                         *mseg = *seg;
893         }
894 #endif
895
896         kdebug("Mapped Object [%s]:", what);
897         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
898         kdebug("- entry    : %lx", params->entry_addr);
899         kdebug("- PHDR[]   : %lx", params->ph_addr);
900         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
901         seg = loadmap->segs;
902         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
903                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
904                        loop,
905                        seg->addr, seg->addr + seg->p_memsz - 1,
906                        seg->p_vaddr, seg->p_memsz);
907
908         return 0;
909
910 dynamic_error:
911         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
912                what, file_inode(file)->i_ino);
913         return -ELIBBAD;
914 }
915
916 /*****************************************************************************/
917 /*
918  * map a file with constant displacement under uClinux
919  */
920 #ifndef CONFIG_MMU
921 static int elf_fdpic_map_file_constdisp_on_uclinux(
922         struct elf_fdpic_params *params,
923         struct file *file,
924         struct mm_struct *mm)
925 {
926         struct elf32_fdpic_loadseg *seg;
927         struct elf32_phdr *phdr;
928         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
929         loff_t fpos;
930         int loop, ret;
931
932         load_addr = params->load_addr;
933         seg = params->loadmap->segs;
934
935         /* determine the bounds of the contiguous overall allocation we must
936          * make */
937         phdr = params->phdrs;
938         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
939                 if (params->phdrs[loop].p_type != PT_LOAD)
940                         continue;
941
942                 if (base > phdr->p_vaddr)
943                         base = phdr->p_vaddr;
944                 if (top < phdr->p_vaddr + phdr->p_memsz)
945                         top = phdr->p_vaddr + phdr->p_memsz;
946         }
947
948         /* allocate one big anon block for everything */
949         mflags = MAP_PRIVATE;
950         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
951                 mflags |= MAP_EXECUTABLE;
952
953         maddr = vm_mmap(NULL, load_addr, top - base,
954                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
955         if (IS_ERR_VALUE(maddr))
956                 return (int) maddr;
957
958         if (load_addr != 0)
959                 load_addr += PAGE_ALIGN(top - base);
960
961         /* and then load the file segments into it */
962         phdr = params->phdrs;
963         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
964                 if (params->phdrs[loop].p_type != PT_LOAD)
965                         continue;
966
967                 fpos = phdr->p_offset;
968
969                 seg->addr = maddr + (phdr->p_vaddr - base);
970                 seg->p_vaddr = phdr->p_vaddr;
971                 seg->p_memsz = phdr->p_memsz;
972
973                 ret = file->f_op->read(file, (void *) seg->addr,
974                                        phdr->p_filesz, &fpos);
975                 if (ret < 0)
976                         return ret;
977
978                 /* map the ELF header address if in this segment */
979                 if (phdr->p_offset == 0)
980                         params->elfhdr_addr = seg->addr;
981
982                 /* clear any space allocated but not loaded */
983                 if (phdr->p_filesz < phdr->p_memsz) {
984                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
985                                        phdr->p_memsz - phdr->p_filesz))
986                                 return -EFAULT;
987                 }
988
989                 if (mm) {
990                         if (phdr->p_flags & PF_X) {
991                                 if (!mm->start_code) {
992                                         mm->start_code = seg->addr;
993                                         mm->end_code = seg->addr +
994                                                 phdr->p_memsz;
995                                 }
996                         } else if (!mm->start_data) {
997                                 mm->start_data = seg->addr;
998                                 mm->end_data = seg->addr + phdr->p_memsz;
999                         }
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;
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                 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1093                                 phdr->p_offset - disp);
1094
1095                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1096                        loop, phdr->p_memsz + disp, prot, flags,
1097                        phdr->p_offset - disp, maddr);
1098
1099                 if (IS_ERR_VALUE(maddr))
1100                         return (int) maddr;
1101
1102                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1103                     ELF_FDPIC_FLAG_CONTIGUOUS)
1104                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1105
1106                 seg->addr = maddr + disp;
1107                 seg->p_vaddr = phdr->p_vaddr;
1108                 seg->p_memsz = phdr->p_memsz;
1109
1110                 /* map the ELF header address if in this segment */
1111                 if (phdr->p_offset == 0)
1112                         params->elfhdr_addr = seg->addr;
1113
1114                 /* clear the bit between beginning of mapping and beginning of
1115                  * PT_LOAD */
1116                 if (prot & PROT_WRITE && disp > 0) {
1117                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1118                         if (clear_user((void __user *) maddr, disp))
1119                                 return -EFAULT;
1120                         maddr += disp;
1121                 }
1122
1123                 /* clear any space allocated but not loaded
1124                  * - on uClinux we can just clear the lot
1125                  * - on MMU linux we'll get a SIGBUS beyond the last page
1126                  *   extant in the file
1127                  */
1128                 excess = phdr->p_memsz - phdr->p_filesz;
1129                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1130
1131 #ifdef CONFIG_MMU
1132                 if (excess > excess1) {
1133                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1134                         unsigned long xmaddr;
1135
1136                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1137                         xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1138                                          prot, flags, 0);
1139
1140                         kdebug("mmap[%d] <anon>"
1141                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1142                                loop, xaddr, excess - excess1, prot, flags,
1143                                xmaddr);
1144
1145                         if (xmaddr != xaddr)
1146                                 return -ENOMEM;
1147                 }
1148
1149                 if (prot & PROT_WRITE && excess1 > 0) {
1150                         kdebug("clear[%d] ad=%lx sz=%lx",
1151                                loop, maddr + phdr->p_filesz, excess1);
1152                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1153                                        excess1))
1154                                 return -EFAULT;
1155                 }
1156
1157 #else
1158                 if (excess > 0) {
1159                         kdebug("clear[%d] ad=%lx sz=%lx",
1160                                loop, maddr + phdr->p_filesz, excess);
1161                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1162                                 return -EFAULT;
1163                 }
1164 #endif
1165
1166                 if (mm) {
1167                         if (phdr->p_flags & PF_X) {
1168                                 if (!mm->start_code) {
1169                                         mm->start_code = maddr;
1170                                         mm->end_code = maddr + phdr->p_memsz;
1171                                 }
1172                         } else if (!mm->start_data) {
1173                                 mm->start_data = maddr;
1174                                 mm->end_data = maddr + phdr->p_memsz;
1175                         }
1176                 }
1177
1178                 seg++;
1179         }
1180
1181         return 0;
1182 }
1183
1184 /*****************************************************************************/
1185 /*
1186  * ELF-FDPIC core dumper
1187  *
1188  * Modelled on fs/exec.c:aout_core_dump()
1189  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1190  *
1191  * Modelled on fs/binfmt_elf.c core dumper
1192  */
1193 #ifdef CONFIG_ELF_CORE
1194
1195 /*
1196  * Decide whether a segment is worth dumping; default is yes to be
1197  * sure (missing info is worse than too much; etc).
1198  * Personally I'd include everything, and use the coredump limit...
1199  *
1200  * I think we should skip something. But I am not sure how. H.J.
1201  */
1202 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1203 {
1204         int dump_ok;
1205
1206         /* Do not dump I/O mapped devices or special mappings */
1207         if (vma->vm_flags & VM_IO) {
1208                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1209                 return 0;
1210         }
1211
1212         /* If we may not read the contents, don't allow us to dump
1213          * them either. "dump_write()" can't handle it anyway.
1214          */
1215         if (!(vma->vm_flags & VM_READ)) {
1216                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1217                 return 0;
1218         }
1219
1220         /* By default, dump shared memory if mapped from an anonymous file. */
1221         if (vma->vm_flags & VM_SHARED) {
1222                 if (file_inode(vma->vm_file)->i_nlink == 0) {
1223                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1224                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1225                                vma->vm_flags, dump_ok ? "yes" : "no");
1226                         return dump_ok;
1227                 }
1228
1229                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1230                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1231                        vma->vm_flags, dump_ok ? "yes" : "no");
1232                 return dump_ok;
1233         }
1234
1235 #ifdef CONFIG_MMU
1236         /* By default, if it hasn't been written to, don't write it out */
1237         if (!vma->anon_vma) {
1238                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1239                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1240                        vma->vm_flags, dump_ok ? "yes" : "no");
1241                 return dump_ok;
1242         }
1243 #endif
1244
1245         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1246         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1247                dump_ok ? "yes" : "no");
1248         return dump_ok;
1249 }
1250
1251 /* An ELF note in memory */
1252 struct memelfnote
1253 {
1254         const char *name;
1255         int type;
1256         unsigned int datasz;
1257         void *data;
1258 };
1259
1260 static int notesize(struct memelfnote *en)
1261 {
1262         int sz;
1263
1264         sz = sizeof(struct elf_note);
1265         sz += roundup(strlen(en->name) + 1, 4);
1266         sz += roundup(en->datasz, 4);
1267
1268         return sz;
1269 }
1270
1271 /* #define DEBUG */
1272
1273 #define DUMP_WRITE(addr, nr, foffset)   \
1274         do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1275
1276 static int alignfile(struct file *file, loff_t *foffset)
1277 {
1278         static const char buf[4] = { 0, };
1279         DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1280         return 1;
1281 }
1282
1283 static int writenote(struct memelfnote *men, struct file *file,
1284                         loff_t *foffset)
1285 {
1286         struct elf_note en;
1287         en.n_namesz = strlen(men->name) + 1;
1288         en.n_descsz = men->datasz;
1289         en.n_type = men->type;
1290
1291         DUMP_WRITE(&en, sizeof(en), foffset);
1292         DUMP_WRITE(men->name, en.n_namesz, foffset);
1293         if (!alignfile(file, foffset))
1294                 return 0;
1295         DUMP_WRITE(men->data, men->datasz, foffset);
1296         if (!alignfile(file, foffset))
1297                 return 0;
1298
1299         return 1;
1300 }
1301 #undef DUMP_WRITE
1302
1303 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1304 {
1305         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1306         elf->e_ident[EI_CLASS] = ELF_CLASS;
1307         elf->e_ident[EI_DATA] = ELF_DATA;
1308         elf->e_ident[EI_VERSION] = EV_CURRENT;
1309         elf->e_ident[EI_OSABI] = ELF_OSABI;
1310         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1311
1312         elf->e_type = ET_CORE;
1313         elf->e_machine = ELF_ARCH;
1314         elf->e_version = EV_CURRENT;
1315         elf->e_entry = 0;
1316         elf->e_phoff = sizeof(struct elfhdr);
1317         elf->e_shoff = 0;
1318         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1319         elf->e_ehsize = sizeof(struct elfhdr);
1320         elf->e_phentsize = sizeof(struct elf_phdr);
1321         elf->e_phnum = segs;
1322         elf->e_shentsize = 0;
1323         elf->e_shnum = 0;
1324         elf->e_shstrndx = 0;
1325         return;
1326 }
1327
1328 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1329 {
1330         phdr->p_type = PT_NOTE;
1331         phdr->p_offset = offset;
1332         phdr->p_vaddr = 0;
1333         phdr->p_paddr = 0;
1334         phdr->p_filesz = sz;
1335         phdr->p_memsz = 0;
1336         phdr->p_flags = 0;
1337         phdr->p_align = 0;
1338         return;
1339 }
1340
1341 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1342                 unsigned int sz, void *data)
1343 {
1344         note->name = name;
1345         note->type = type;
1346         note->datasz = sz;
1347         note->data = data;
1348         return;
1349 }
1350
1351 /*
1352  * fill up all the fields in prstatus from the given task struct, except
1353  * registers which need to be filled up separately.
1354  */
1355 static void fill_prstatus(struct elf_prstatus *prstatus,
1356                           struct task_struct *p, long signr)
1357 {
1358         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1359         prstatus->pr_sigpend = p->pending.signal.sig[0];
1360         prstatus->pr_sighold = p->blocked.sig[0];
1361         rcu_read_lock();
1362         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1363         rcu_read_unlock();
1364         prstatus->pr_pid = task_pid_vnr(p);
1365         prstatus->pr_pgrp = task_pgrp_vnr(p);
1366         prstatus->pr_sid = task_session_vnr(p);
1367         if (thread_group_leader(p)) {
1368                 struct task_cputime cputime;
1369
1370                 /*
1371                  * This is the record for the group leader.  It shows the
1372                  * group-wide total, not its individual thread total.
1373                  */
1374                 thread_group_cputime(p, &cputime);
1375                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1376                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1377         } else {
1378                 cputime_t utime, stime;
1379
1380                 task_cputime(p, &utime, &stime);
1381                 cputime_to_timeval(utime, &prstatus->pr_utime);
1382                 cputime_to_timeval(stime, &prstatus->pr_stime);
1383         }
1384         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1385         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1386
1387         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1388         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1389 }
1390
1391 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1392                        struct mm_struct *mm)
1393 {
1394         const struct cred *cred;
1395         unsigned int i, len;
1396
1397         /* first copy the parameters from user space */
1398         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1399
1400         len = mm->arg_end - mm->arg_start;
1401         if (len >= ELF_PRARGSZ)
1402                 len = ELF_PRARGSZ - 1;
1403         if (copy_from_user(&psinfo->pr_psargs,
1404                            (const char __user *) mm->arg_start, len))
1405                 return -EFAULT;
1406         for (i = 0; i < len; i++)
1407                 if (psinfo->pr_psargs[i] == 0)
1408                         psinfo->pr_psargs[i] = ' ';
1409         psinfo->pr_psargs[len] = 0;
1410
1411         rcu_read_lock();
1412         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1413         rcu_read_unlock();
1414         psinfo->pr_pid = task_pid_vnr(p);
1415         psinfo->pr_pgrp = task_pgrp_vnr(p);
1416         psinfo->pr_sid = task_session_vnr(p);
1417
1418         i = p->state ? ffz(~p->state) + 1 : 0;
1419         psinfo->pr_state = i;
1420         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1421         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1422         psinfo->pr_nice = task_nice(p);
1423         psinfo->pr_flag = p->flags;
1424         rcu_read_lock();
1425         cred = __task_cred(p);
1426         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1427         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1428         rcu_read_unlock();
1429         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1430
1431         return 0;
1432 }
1433
1434 /* Here is the structure in which status of each thread is captured. */
1435 struct elf_thread_status
1436 {
1437         struct list_head list;
1438         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1439         elf_fpregset_t fpu;             /* NT_PRFPREG */
1440         struct task_struct *thread;
1441 #ifdef ELF_CORE_COPY_XFPREGS
1442         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1443 #endif
1444         struct memelfnote notes[3];
1445         int num_notes;
1446 };
1447
1448 /*
1449  * In order to add the specific thread information for the elf file format,
1450  * we need to keep a linked list of every thread's pr_status and then create
1451  * a single section for them in the final core file.
1452  */
1453 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1454 {
1455         struct task_struct *p = t->thread;
1456         int sz = 0;
1457
1458         t->num_notes = 0;
1459
1460         fill_prstatus(&t->prstatus, p, signr);
1461         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1462
1463         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1464                   &t->prstatus);
1465         t->num_notes++;
1466         sz += notesize(&t->notes[0]);
1467
1468         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1469         if (t->prstatus.pr_fpvalid) {
1470                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1471                           &t->fpu);
1472                 t->num_notes++;
1473                 sz += notesize(&t->notes[1]);
1474         }
1475
1476 #ifdef ELF_CORE_COPY_XFPREGS
1477         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1478                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1479                           sizeof(t->xfpu), &t->xfpu);
1480                 t->num_notes++;
1481                 sz += notesize(&t->notes[2]);
1482         }
1483 #endif
1484         return sz;
1485 }
1486
1487 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1488                              elf_addr_t e_shoff, int segs)
1489 {
1490         elf->e_shoff = e_shoff;
1491         elf->e_shentsize = sizeof(*shdr4extnum);
1492         elf->e_shnum = 1;
1493         elf->e_shstrndx = SHN_UNDEF;
1494
1495         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1496
1497         shdr4extnum->sh_type = SHT_NULL;
1498         shdr4extnum->sh_size = elf->e_shnum;
1499         shdr4extnum->sh_link = elf->e_shstrndx;
1500         shdr4extnum->sh_info = segs;
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         int err = 0;
1512
1513         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1514                 unsigned long addr;
1515
1516                 if (!maydump(vma, mm_flags))
1517                         continue;
1518
1519                 for (addr = vma->vm_start; addr < vma->vm_end;
1520                                                         addr += PAGE_SIZE) {
1521                         struct page *page = get_dump_page(addr);
1522                         if (page) {
1523                                 void *kaddr = kmap(page);
1524                                 *size += PAGE_SIZE;
1525                                 if (*size > *limit)
1526                                         err = -EFBIG;
1527                                 else if (!dump_write(file, kaddr, PAGE_SIZE))
1528                                         err = -EIO;
1529                                 kunmap(page);
1530                                 page_cache_release(page);
1531                         } else if (!dump_seek(file, PAGE_SIZE))
1532                                 err = -EFBIG;
1533                         if (err)
1534                                 goto out;
1535                 }
1536         }
1537 out:
1538         return err;
1539 }
1540 #endif
1541
1542 /*
1543  * dump the segments for a NOMMU process
1544  */
1545 #ifndef CONFIG_MMU
1546 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1547                            unsigned long *limit, unsigned long mm_flags)
1548 {
1549         struct vm_area_struct *vma;
1550
1551         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1552                 if (!maydump(vma, mm_flags))
1553                         continue;
1554
1555                 if ((*size += PAGE_SIZE) > *limit)
1556                         return -EFBIG;
1557
1558                 if (!dump_write(file, (void *) vma->vm_start,
1559                                 vma->vm_end - vma->vm_start))
1560                         return -EIO;
1561         }
1562
1563         return 0;
1564 }
1565 #endif
1566
1567 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1568 {
1569         struct vm_area_struct *vma;
1570         size_t size = 0;
1571
1572         for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1573                 if (maydump(vma, mm_flags))
1574                         size += vma->vm_end - vma->vm_start;
1575         return size;
1576 }
1577
1578 /*
1579  * Actual dumper
1580  *
1581  * This is a two-pass process; first we find the offsets of the bits,
1582  * and then they are actually written out.  If we run out of core limit
1583  * we just truncate.
1584  */
1585 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1586 {
1587 #define NUM_NOTES       6
1588         int has_dumped = 0;
1589         mm_segment_t fs;
1590         int segs;
1591         size_t size = 0;
1592         int i;
1593         struct vm_area_struct *vma;
1594         struct elfhdr *elf = NULL;
1595         loff_t offset = 0, dataoff, foffset;
1596         int numnote;
1597         struct memelfnote *notes = NULL;
1598         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1599         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1600         LIST_HEAD(thread_list);
1601         struct list_head *t;
1602         elf_fpregset_t *fpu = NULL;
1603 #ifdef ELF_CORE_COPY_XFPREGS
1604         elf_fpxregset_t *xfpu = NULL;
1605 #endif
1606         int thread_status_size = 0;
1607         elf_addr_t *auxv;
1608         struct elf_phdr *phdr4note = NULL;
1609         struct elf_shdr *shdr4extnum = NULL;
1610         Elf_Half e_phnum;
1611         elf_addr_t e_shoff;
1612
1613         /*
1614          * We no longer stop all VM operations.
1615          *
1616          * This is because those proceses that could possibly change map_count
1617          * or the mmap / vma pages are now blocked in do_exit on current
1618          * finishing this core dump.
1619          *
1620          * Only ptrace can touch these memory addresses, but it doesn't change
1621          * the map_count or the pages allocated. So no possibility of crashing
1622          * exists while dumping the mm->vm_next areas to the core file.
1623          */
1624
1625         /* alloc memory for large data structures: too large to be on stack */
1626         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1627         if (!elf)
1628                 goto cleanup;
1629         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1630         if (!prstatus)
1631                 goto cleanup;
1632         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1633         if (!psinfo)
1634                 goto cleanup;
1635         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1636         if (!notes)
1637                 goto cleanup;
1638         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1639         if (!fpu)
1640                 goto cleanup;
1641 #ifdef ELF_CORE_COPY_XFPREGS
1642         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1643         if (!xfpu)
1644                 goto cleanup;
1645 #endif
1646
1647         if (cprm->siginfo->si_signo) {
1648                 struct core_thread *ct;
1649                 struct elf_thread_status *tmp;
1650
1651                 for (ct = current->mm->core_state->dumper.next;
1652                                                 ct; ct = ct->next) {
1653                         tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1654                         if (!tmp)
1655                                 goto cleanup;
1656
1657                         tmp->thread = ct->task;
1658                         list_add(&tmp->list, &thread_list);
1659                 }
1660
1661                 list_for_each(t, &thread_list) {
1662                         struct elf_thread_status *tmp;
1663                         int sz;
1664
1665                         tmp = list_entry(t, struct elf_thread_status, list);
1666                         sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1667                         thread_status_size += sz;
1668                 }
1669         }
1670
1671         /* now collect the dump for the current */
1672         fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1673         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1674
1675         segs = current->mm->map_count;
1676         segs += elf_core_extra_phdrs();
1677
1678         /* for notes section */
1679         segs++;
1680
1681         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1682          * this, kernel supports extended numbering. Have a look at
1683          * include/linux/elf.h for further information. */
1684         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1685
1686         /* Set up header */
1687         fill_elf_fdpic_header(elf, e_phnum);
1688
1689         has_dumped = 1;
1690         /*
1691          * Set up the notes in similar form to SVR4 core dumps made
1692          * with info from their /proc.
1693          */
1694
1695         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1696         fill_psinfo(psinfo, current->group_leader, current->mm);
1697         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1698
1699         numnote = 2;
1700
1701         auxv = (elf_addr_t *) current->mm->saved_auxv;
1702
1703         i = 0;
1704         do
1705                 i += 2;
1706         while (auxv[i - 2] != AT_NULL);
1707         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1708                   i * sizeof(elf_addr_t), auxv);
1709
1710         /* Try to dump the FPU. */
1711         if ((prstatus->pr_fpvalid =
1712              elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1713                 fill_note(notes + numnote++,
1714                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1715 #ifdef ELF_CORE_COPY_XFPREGS
1716         if (elf_core_copy_task_xfpregs(current, xfpu))
1717                 fill_note(notes + numnote++,
1718                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1719 #endif
1720
1721         fs = get_fs();
1722         set_fs(KERNEL_DS);
1723
1724         offset += sizeof(*elf);                         /* Elf header */
1725         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1726         foffset = offset;
1727
1728         /* Write notes phdr entry */
1729         {
1730                 int sz = 0;
1731
1732                 for (i = 0; i < numnote; i++)
1733                         sz += notesize(notes + i);
1734
1735                 sz += thread_status_size;
1736
1737                 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1738                 if (!phdr4note)
1739                         goto end_coredump;
1740
1741                 fill_elf_note_phdr(phdr4note, sz, offset);
1742                 offset += sz;
1743         }
1744
1745         /* Page-align dumped data */
1746         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1747
1748         offset += elf_core_vma_data_size(cprm->mm_flags);
1749         offset += elf_core_extra_data_size();
1750         e_shoff = offset;
1751
1752         if (e_phnum == PN_XNUM) {
1753                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1754                 if (!shdr4extnum)
1755                         goto end_coredump;
1756                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1757         }
1758
1759         offset = dataoff;
1760
1761         size += sizeof(*elf);
1762         if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
1763                 goto end_coredump;
1764
1765         size += sizeof(*phdr4note);
1766         if (size > cprm->limit
1767             || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
1768                 goto end_coredump;
1769
1770         /* write program headers for segments dump */
1771         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1772                 struct elf_phdr phdr;
1773                 size_t sz;
1774
1775                 sz = vma->vm_end - vma->vm_start;
1776
1777                 phdr.p_type = PT_LOAD;
1778                 phdr.p_offset = offset;
1779                 phdr.p_vaddr = vma->vm_start;
1780                 phdr.p_paddr = 0;
1781                 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1782                 phdr.p_memsz = sz;
1783                 offset += phdr.p_filesz;
1784                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1785                 if (vma->vm_flags & VM_WRITE)
1786                         phdr.p_flags |= PF_W;
1787                 if (vma->vm_flags & VM_EXEC)
1788                         phdr.p_flags |= PF_X;
1789                 phdr.p_align = ELF_EXEC_PAGESIZE;
1790
1791                 size += sizeof(phdr);
1792                 if (size > cprm->limit
1793                     || !dump_write(cprm->file, &phdr, sizeof(phdr)))
1794                         goto end_coredump;
1795         }
1796
1797         if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
1798                 goto end_coredump;
1799
1800         /* write out the notes section */
1801         for (i = 0; i < numnote; i++)
1802                 if (!writenote(notes + i, cprm->file, &foffset))
1803                         goto end_coredump;
1804
1805         /* write out the thread status notes section */
1806         list_for_each(t, &thread_list) {
1807                 struct elf_thread_status *tmp =
1808                                 list_entry(t, struct elf_thread_status, list);
1809
1810                 for (i = 0; i < tmp->num_notes; i++)
1811                         if (!writenote(&tmp->notes[i], cprm->file, &foffset))
1812                                 goto end_coredump;
1813         }
1814
1815         if (!dump_seek(cprm->file, dataoff - foffset))
1816                 goto end_coredump;
1817
1818         if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit,
1819                                     cprm->mm_flags) < 0)
1820                 goto end_coredump;
1821
1822         if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
1823                 goto end_coredump;
1824
1825         if (e_phnum == PN_XNUM) {
1826                 size += sizeof(*shdr4extnum);
1827                 if (size > cprm->limit
1828                     || !dump_write(cprm->file, shdr4extnum,
1829                                    sizeof(*shdr4extnum)))
1830                         goto end_coredump;
1831         }
1832
1833         if (cprm->file->f_pos != offset) {
1834                 /* Sanity check */
1835                 printk(KERN_WARNING
1836                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1837                        cprm->file->f_pos, offset);
1838         }
1839
1840 end_coredump:
1841         set_fs(fs);
1842
1843 cleanup:
1844         while (!list_empty(&thread_list)) {
1845                 struct list_head *tmp = thread_list.next;
1846                 list_del(tmp);
1847                 kfree(list_entry(tmp, struct elf_thread_status, list));
1848         }
1849         kfree(phdr4note);
1850         kfree(elf);
1851         kfree(prstatus);
1852         kfree(psinfo);
1853         kfree(notes);
1854         kfree(fpu);
1855         kfree(shdr4extnum);
1856 #ifdef ELF_CORE_COPY_XFPREGS
1857         kfree(xfpu);
1858 #endif
1859         return has_dumped;
1860 #undef NUM_NOTES
1861 }
1862
1863 #endif          /* CONFIG_ELF_CORE */