microblaze: Fix "kstack=" parsing
[linux-2.6.git] / fs / binfmt_elf_fdpic.c
1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
2  *
3  * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  * Derived from binfmt_elf.c
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * as published by the Free Software Foundation; either version
10  * 2 of the License, or (at your option) any later version.
11  */
12
13 #include <linux/module.h>
14
15 #include <linux/fs.h>
16 #include <linux/stat.h>
17 #include <linux/sched.h>
18 #include <linux/mm.h>
19 #include <linux/mman.h>
20 #include <linux/errno.h>
21 #include <linux/signal.h>
22 #include <linux/binfmts.h>
23 #include <linux/string.h>
24 #include <linux/file.h>
25 #include <linux/fcntl.h>
26 #include <linux/slab.h>
27 #include <linux/pagemap.h>
28 #include <linux/security.h>
29 #include <linux/highmem.h>
30 #include <linux/highuid.h>
31 #include <linux/personality.h>
32 #include <linux/ptrace.h>
33 #include <linux/init.h>
34 #include <linux/elf.h>
35 #include <linux/elf-fdpic.h>
36 #include <linux/elfcore.h>
37 #include <linux/coredump.h>
38
39 #include <asm/uaccess.h>
40 #include <asm/param.h>
41 #include <asm/pgalloc.h>
42
43 typedef char *elf_caddr_t;
44
45 #if 0
46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
47 #else
48 #define kdebug(fmt, ...) do {} while(0)
49 #endif
50
51 #if 0
52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
53 #else
54 #define kdcore(fmt, ...) do {} while(0)
55 #endif
56
57 MODULE_LICENSE("GPL");
58
59 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
62                               struct mm_struct *, const char *);
63
64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
65                                    struct elf_fdpic_params *,
66                                    struct elf_fdpic_params *);
67
68 #ifndef CONFIG_MMU
69 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
70                                             unsigned long *);
71 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
72                                                    struct file *,
73                                                    struct mm_struct *);
74 #endif
75
76 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
77                                              struct file *, struct mm_struct *);
78
79 #ifdef CONFIG_ELF_CORE
80 static int elf_fdpic_core_dump(struct coredump_params *cprm);
81 #endif
82
83 static struct linux_binfmt elf_fdpic_format = {
84         .module         = THIS_MODULE,
85         .load_binary    = load_elf_fdpic_binary,
86 #ifdef CONFIG_ELF_CORE
87         .core_dump      = elf_fdpic_core_dump,
88 #endif
89         .min_coredump   = ELF_EXEC_PAGESIZE,
90 };
91
92 static int __init init_elf_fdpic_binfmt(void)
93 {
94         return register_binfmt(&elf_fdpic_format);
95 }
96
97 static void __exit exit_elf_fdpic_binfmt(void)
98 {
99         unregister_binfmt(&elf_fdpic_format);
100 }
101
102 core_initcall(init_elf_fdpic_binfmt);
103 module_exit(exit_elf_fdpic_binfmt);
104
105 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
106 {
107         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
108                 return 0;
109         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
110                 return 0;
111         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
112                 return 0;
113         if (!file->f_op || !file->f_op->mmap)
114                 return 0;
115         return 1;
116 }
117
118 /*****************************************************************************/
119 /*
120  * read the program headers table into memory
121  */
122 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
123                                  struct file *file)
124 {
125         struct elf32_phdr *phdr;
126         unsigned long size;
127         int retval, loop;
128
129         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
130                 return -ENOMEM;
131         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
132                 return -ENOMEM;
133
134         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
135         params->phdrs = kmalloc(size, GFP_KERNEL);
136         if (!params->phdrs)
137                 return -ENOMEM;
138
139         retval = kernel_read(file, params->hdr.e_phoff,
140                              (char *) params->phdrs, size);
141         if (unlikely(retval != size))
142                 return retval < 0 ? retval : -ENOEXEC;
143
144         /* determine stack size for this binary */
145         phdr = params->phdrs;
146         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
147                 if (phdr->p_type != PT_GNU_STACK)
148                         continue;
149
150                 if (phdr->p_flags & PF_X)
151                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
152                 else
153                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
154
155                 params->stack_size = phdr->p_memsz;
156                 break;
157         }
158
159         return 0;
160 }
161
162 /*****************************************************************************/
163 /*
164  * load an fdpic binary into various bits of memory
165  */
166 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
167                                  struct pt_regs *regs)
168 {
169         struct elf_fdpic_params exec_params, interp_params;
170         struct elf_phdr *phdr;
171         unsigned long stack_size, entryaddr;
172 #ifdef ELF_FDPIC_PLAT_INIT
173         unsigned long dynaddr;
174 #endif
175 #ifndef CONFIG_MMU
176         unsigned long stack_prot;
177 #endif
178         struct file *interpreter = NULL; /* to shut gcc up */
179         char *interpreter_name = NULL;
180         int executable_stack;
181         int retval, i;
182
183         kdebug("____ LOAD %d ____", current->pid);
184
185         memset(&exec_params, 0, sizeof(exec_params));
186         memset(&interp_params, 0, sizeof(interp_params));
187
188         exec_params.hdr = *(struct elfhdr *) bprm->buf;
189         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
190
191         /* check that this is a binary we know how to deal with */
192         retval = -ENOEXEC;
193         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
194                 goto error;
195
196         /* read the program header table */
197         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
198         if (retval < 0)
199                 goto error;
200
201         /* scan for a program header that specifies an interpreter */
202         phdr = exec_params.phdrs;
203
204         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
205                 switch (phdr->p_type) {
206                 case PT_INTERP:
207                         retval = -ENOMEM;
208                         if (phdr->p_filesz > PATH_MAX)
209                                 goto error;
210                         retval = -ENOENT;
211                         if (phdr->p_filesz < 2)
212                                 goto error;
213
214                         /* read the name of the interpreter into memory */
215                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
216                         if (!interpreter_name)
217                                 goto error;
218
219                         retval = kernel_read(bprm->file,
220                                              phdr->p_offset,
221                                              interpreter_name,
222                                              phdr->p_filesz);
223                         if (unlikely(retval != phdr->p_filesz)) {
224                                 if (retval >= 0)
225                                         retval = -ENOEXEC;
226                                 goto error;
227                         }
228
229                         retval = -ENOENT;
230                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
231                                 goto error;
232
233                         kdebug("Using ELF interpreter %s", interpreter_name);
234
235                         /* replace the program with the interpreter */
236                         interpreter = open_exec(interpreter_name);
237                         retval = PTR_ERR(interpreter);
238                         if (IS_ERR(interpreter)) {
239                                 interpreter = NULL;
240                                 goto error;
241                         }
242
243                         /*
244                          * If the binary is not readable then enforce
245                          * mm->dumpable = 0 regardless of the interpreter's
246                          * permissions.
247                          */
248                         if (file_permission(interpreter, MAY_READ) < 0)
249                                 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
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         current->flags &= ~PF_FORKNOEXEC;
339
340 #ifdef CONFIG_MMU
341         elf_fdpic_arch_lay_out_mm(&exec_params,
342                                   &interp_params,
343                                   &current->mm->start_stack,
344                                   &current->mm->start_brk);
345
346         retval = setup_arg_pages(bprm, current->mm->start_stack,
347                                  executable_stack);
348         if (retval < 0) {
349                 send_sig(SIGKILL, current, 0);
350                 goto error_kill;
351         }
352 #endif
353
354         /* load the executable and interpreter into memory */
355         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
356                                     "executable");
357         if (retval < 0)
358                 goto error_kill;
359
360         if (interpreter_name) {
361                 retval = elf_fdpic_map_file(&interp_params, interpreter,
362                                             current->mm, "interpreter");
363                 if (retval < 0) {
364                         printk(KERN_ERR "Unable to load interpreter\n");
365                         goto error_kill;
366                 }
367
368                 allow_write_access(interpreter);
369                 fput(interpreter);
370                 interpreter = NULL;
371         }
372
373 #ifdef CONFIG_MMU
374         if (!current->mm->start_brk)
375                 current->mm->start_brk = current->mm->end_data;
376
377         current->mm->brk = current->mm->start_brk =
378                 PAGE_ALIGN(current->mm->start_brk);
379
380 #else
381         /* create a stack and brk area big enough for everyone
382          * - the brk heap starts at the bottom and works up
383          * - the stack starts at the top and works down
384          */
385         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
386         if (stack_size < PAGE_SIZE * 2)
387                 stack_size = PAGE_SIZE * 2;
388
389         stack_prot = PROT_READ | PROT_WRITE;
390         if (executable_stack == EXSTACK_ENABLE_X ||
391             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
392                 stack_prot |= PROT_EXEC;
393
394         down_write(&current->mm->mmap_sem);
395         current->mm->start_brk = do_mmap(NULL, 0, stack_size, stack_prot,
396                                          MAP_PRIVATE | MAP_ANONYMOUS |
397                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
398                                          0);
399
400         if (IS_ERR_VALUE(current->mm->start_brk)) {
401                 up_write(&current->mm->mmap_sem);
402                 retval = current->mm->start_brk;
403                 current->mm->start_brk = 0;
404                 goto error_kill;
405         }
406
407         up_write(&current->mm->mmap_sem);
408
409         current->mm->brk = current->mm->start_brk;
410         current->mm->context.end_brk = current->mm->start_brk;
411         current->mm->context.end_brk +=
412                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
413         current->mm->start_stack = current->mm->start_brk + stack_size;
414 #endif
415
416         install_exec_creds(bprm);
417         current->flags &= ~PF_FORKNOEXEC;
418         if (create_elf_fdpic_tables(bprm, current->mm,
419                                     &exec_params, &interp_params) < 0)
420                 goto error_kill;
421
422         kdebug("- start_code  %lx", current->mm->start_code);
423         kdebug("- end_code    %lx", current->mm->end_code);
424         kdebug("- start_data  %lx", current->mm->start_data);
425         kdebug("- end_data    %lx", current->mm->end_data);
426         kdebug("- start_brk   %lx", current->mm->start_brk);
427         kdebug("- brk         %lx", current->mm->brk);
428         kdebug("- start_stack %lx", current->mm->start_stack);
429
430 #ifdef ELF_FDPIC_PLAT_INIT
431         /*
432          * The ABI may specify that certain registers be set up in special
433          * ways (on i386 %edx is the address of a DT_FINI function, for
434          * example.  This macro performs whatever initialization to
435          * the regs structure is required.
436          */
437         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
438         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
439                             dynaddr);
440 #endif
441
442         /* everything is now ready... get the userspace context ready to roll */
443         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
444         start_thread(regs, entryaddr, current->mm->start_stack);
445
446         retval = 0;
447
448 error:
449         if (interpreter) {
450                 allow_write_access(interpreter);
451                 fput(interpreter);
452         }
453         kfree(interpreter_name);
454         kfree(exec_params.phdrs);
455         kfree(exec_params.loadmap);
456         kfree(interp_params.phdrs);
457         kfree(interp_params.loadmap);
458         return retval;
459
460         /* unrecoverable error - kill the process */
461 error_kill:
462         send_sig(SIGSEGV, current, 0);
463         goto error;
464
465 }
466
467 /*****************************************************************************/
468
469 #ifndef ELF_BASE_PLATFORM
470 /*
471  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
472  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
473  * will be copied to the user stack in the same manner as AT_PLATFORM.
474  */
475 #define ELF_BASE_PLATFORM NULL
476 #endif
477
478 /*
479  * present useful information to the program by shovelling it onto the new
480  * process's stack
481  */
482 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
483                                    struct mm_struct *mm,
484                                    struct elf_fdpic_params *exec_params,
485                                    struct elf_fdpic_params *interp_params)
486 {
487         const struct cred *cred = current_cred();
488         unsigned long sp, csp, nitems;
489         elf_caddr_t __user *argv, *envp;
490         size_t platform_len = 0, len;
491         char *k_platform, *k_base_platform;
492         char __user *u_platform, *u_base_platform, *p;
493         long hwcap;
494         int loop;
495         int nr; /* reset for each csp adjustment */
496
497 #ifdef CONFIG_MMU
498         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
499          * by the processes running on the same package. One thing we can do is
500          * to shuffle the initial stack for them, so we give the architecture
501          * an opportunity to do so here.
502          */
503         sp = arch_align_stack(bprm->p);
504 #else
505         sp = mm->start_stack;
506
507         /* stack the program arguments and environment */
508         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
509                 return -EFAULT;
510 #endif
511
512         hwcap = ELF_HWCAP;
513
514         /*
515          * If this architecture has a platform capability string, copy it
516          * to userspace.  In some cases (Sparc), this info is impossible
517          * for userspace to get any other way, in others (i386) it is
518          * merely difficult.
519          */
520         k_platform = ELF_PLATFORM;
521         u_platform = NULL;
522
523         if (k_platform) {
524                 platform_len = strlen(k_platform) + 1;
525                 sp -= platform_len;
526                 u_platform = (char __user *) sp;
527                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
528                         return -EFAULT;
529         }
530
531         /*
532          * If this architecture has a "base" platform capability
533          * string, copy it to userspace.
534          */
535         k_base_platform = ELF_BASE_PLATFORM;
536         u_base_platform = NULL;
537
538         if (k_base_platform) {
539                 platform_len = strlen(k_base_platform) + 1;
540                 sp -= platform_len;
541                 u_base_platform = (char __user *) sp;
542                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
543                         return -EFAULT;
544         }
545
546         sp &= ~7UL;
547
548         /* stack the load map(s) */
549         len = sizeof(struct elf32_fdpic_loadmap);
550         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
551         sp = (sp - len) & ~7UL;
552         exec_params->map_addr = sp;
553
554         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
555                 return -EFAULT;
556
557         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
558
559         if (interp_params->loadmap) {
560                 len = sizeof(struct elf32_fdpic_loadmap);
561                 len += sizeof(struct elf32_fdpic_loadseg) *
562                         interp_params->loadmap->nsegs;
563                 sp = (sp - len) & ~7UL;
564                 interp_params->map_addr = sp;
565
566                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
567                                  len) != 0)
568                         return -EFAULT;
569
570                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
571         }
572
573         /* force 16 byte _final_ alignment here for generality */
574 #define DLINFO_ITEMS 15
575
576         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
577                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
578
579         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
580                 nitems++;
581
582         csp = sp;
583         sp -= nitems * 2 * sizeof(unsigned long);
584         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
585         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
586         sp -= 1 * sizeof(unsigned long);                /* argc */
587
588         csp -= sp & 15UL;
589         sp -= sp & 15UL;
590
591         /* put the ELF interpreter info on the stack */
592 #define NEW_AUX_ENT(id, val)                                            \
593         do {                                                            \
594                 struct { unsigned long _id, _val; } __user *ent;        \
595                                                                         \
596                 ent = (void __user *) csp;                              \
597                 __put_user((id), &ent[nr]._id);                         \
598                 __put_user((val), &ent[nr]._val);                       \
599                 nr++;                                                   \
600         } while (0)
601
602         nr = 0;
603         csp -= 2 * sizeof(unsigned long);
604         NEW_AUX_ENT(AT_NULL, 0);
605         if (k_platform) {
606                 nr = 0;
607                 csp -= 2 * sizeof(unsigned long);
608                 NEW_AUX_ENT(AT_PLATFORM,
609                             (elf_addr_t) (unsigned long) u_platform);
610         }
611
612         if (k_base_platform) {
613                 nr = 0;
614                 csp -= 2 * sizeof(unsigned long);
615                 NEW_AUX_ENT(AT_BASE_PLATFORM,
616                             (elf_addr_t) (unsigned long) u_base_platform);
617         }
618
619         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
620                 nr = 0;
621                 csp -= 2 * sizeof(unsigned long);
622                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
623         }
624
625         nr = 0;
626         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
627         NEW_AUX_ENT(AT_HWCAP,   hwcap);
628         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
629         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
630         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
631         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
632         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
633         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
634         NEW_AUX_ENT(AT_FLAGS,   0);
635         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
636         NEW_AUX_ENT(AT_UID,     (elf_addr_t) cred->uid);
637         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) cred->euid);
638         NEW_AUX_ENT(AT_GID,     (elf_addr_t) cred->gid);
639         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) cred->egid);
640         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
641         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
642
643 #ifdef ARCH_DLINFO
644         nr = 0;
645         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
646
647         /* ARCH_DLINFO must come last so platform specific code can enforce
648          * special alignment requirements on the AUXV if necessary (eg. PPC).
649          */
650         ARCH_DLINFO;
651 #endif
652 #undef NEW_AUX_ENT
653
654         /* allocate room for argv[] and envv[] */
655         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
656         envp = (elf_caddr_t __user *) csp;
657         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
658         argv = (elf_caddr_t __user *) csp;
659
660         /* stack argc */
661         csp -= sizeof(unsigned long);
662         __put_user(bprm->argc, (unsigned long __user *) csp);
663
664         BUG_ON(csp != sp);
665
666         /* fill in the argv[] array */
667 #ifdef CONFIG_MMU
668         current->mm->arg_start = bprm->p;
669 #else
670         current->mm->arg_start = current->mm->start_stack -
671                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
672 #endif
673
674         p = (char __user *) current->mm->arg_start;
675         for (loop = bprm->argc; loop > 0; loop--) {
676                 __put_user((elf_caddr_t) p, argv++);
677                 len = strnlen_user(p, MAX_ARG_STRLEN);
678                 if (!len || len > MAX_ARG_STRLEN)
679                         return -EINVAL;
680                 p += len;
681         }
682         __put_user(NULL, argv);
683         current->mm->arg_end = (unsigned long) p;
684
685         /* fill in the envv[] array */
686         current->mm->env_start = (unsigned long) p;
687         for (loop = bprm->envc; loop > 0; loop--) {
688                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
689                 len = strnlen_user(p, MAX_ARG_STRLEN);
690                 if (!len || len > MAX_ARG_STRLEN)
691                         return -EINVAL;
692                 p += len;
693         }
694         __put_user(NULL, envp);
695         current->mm->env_end = (unsigned long) p;
696
697         mm->start_stack = (unsigned long) sp;
698         return 0;
699 }
700
701 /*****************************************************************************/
702 /*
703  * transfer the program arguments and environment from the holding pages onto
704  * the stack
705  */
706 #ifndef CONFIG_MMU
707 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
708                                             unsigned long *_sp)
709 {
710         unsigned long index, stop, sp;
711         char *src;
712         int ret = 0;
713
714         stop = bprm->p >> PAGE_SHIFT;
715         sp = *_sp;
716
717         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
718                 src = kmap(bprm->page[index]);
719                 sp -= PAGE_SIZE;
720                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
721                         ret = -EFAULT;
722                 kunmap(bprm->page[index]);
723                 if (ret < 0)
724                         goto out;
725         }
726
727         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
728
729 out:
730         return ret;
731 }
732 #endif
733
734 /*****************************************************************************/
735 /*
736  * load the appropriate binary image (executable or interpreter) into memory
737  * - we assume no MMU is available
738  * - if no other PIC bits are set in params->hdr->e_flags
739  *   - we assume that the LOADable segments in the binary are independently relocatable
740  *   - we assume R/O executable segments are shareable
741  * - else
742  *   - we assume the loadable parts of the image to require fixed displacement
743  *   - the image is not shareable
744  */
745 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
746                               struct file *file,
747                               struct mm_struct *mm,
748                               const char *what)
749 {
750         struct elf32_fdpic_loadmap *loadmap;
751 #ifdef CONFIG_MMU
752         struct elf32_fdpic_loadseg *mseg;
753 #endif
754         struct elf32_fdpic_loadseg *seg;
755         struct elf32_phdr *phdr;
756         unsigned long load_addr, stop;
757         unsigned nloads, tmp;
758         size_t size;
759         int loop, ret;
760
761         /* allocate a load map table */
762         nloads = 0;
763         for (loop = 0; loop < params->hdr.e_phnum; loop++)
764                 if (params->phdrs[loop].p_type == PT_LOAD)
765                         nloads++;
766
767         if (nloads == 0)
768                 return -ELIBBAD;
769
770         size = sizeof(*loadmap) + nloads * sizeof(*seg);
771         loadmap = kzalloc(size, GFP_KERNEL);
772         if (!loadmap)
773                 return -ENOMEM;
774
775         params->loadmap = loadmap;
776
777         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
778         loadmap->nsegs = nloads;
779
780         load_addr = params->load_addr;
781         seg = loadmap->segs;
782
783         /* map the requested LOADs into the memory space */
784         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
785         case ELF_FDPIC_FLAG_CONSTDISP:
786         case ELF_FDPIC_FLAG_CONTIGUOUS:
787 #ifndef CONFIG_MMU
788                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
789                 if (ret < 0)
790                         return ret;
791                 break;
792 #endif
793         default:
794                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
795                 if (ret < 0)
796                         return ret;
797                 break;
798         }
799
800         /* map the entry point */
801         if (params->hdr.e_entry) {
802                 seg = loadmap->segs;
803                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
804                         if (params->hdr.e_entry >= seg->p_vaddr &&
805                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
806                                 params->entry_addr =
807                                         (params->hdr.e_entry - seg->p_vaddr) +
808                                         seg->addr;
809                                 break;
810                         }
811                 }
812         }
813
814         /* determine where the program header table has wound up if mapped */
815         stop = params->hdr.e_phoff;
816         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
817         phdr = params->phdrs;
818
819         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
820                 if (phdr->p_type != PT_LOAD)
821                         continue;
822
823                 if (phdr->p_offset > params->hdr.e_phoff ||
824                     phdr->p_offset + phdr->p_filesz < stop)
825                         continue;
826
827                 seg = loadmap->segs;
828                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
829                         if (phdr->p_vaddr >= seg->p_vaddr &&
830                             phdr->p_vaddr + phdr->p_filesz <=
831                             seg->p_vaddr + seg->p_memsz) {
832                                 params->ph_addr =
833                                         (phdr->p_vaddr - seg->p_vaddr) +
834                                         seg->addr +
835                                         params->hdr.e_phoff - phdr->p_offset;
836                                 break;
837                         }
838                 }
839                 break;
840         }
841
842         /* determine where the dynamic section has wound up if there is one */
843         phdr = params->phdrs;
844         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
845                 if (phdr->p_type != PT_DYNAMIC)
846                         continue;
847
848                 seg = loadmap->segs;
849                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
850                         if (phdr->p_vaddr >= seg->p_vaddr &&
851                             phdr->p_vaddr + phdr->p_memsz <=
852                             seg->p_vaddr + seg->p_memsz) {
853                                 params->dynamic_addr =
854                                         (phdr->p_vaddr - seg->p_vaddr) +
855                                         seg->addr;
856
857                                 /* check the dynamic section contains at least
858                                  * one item, and that the last item is a NULL
859                                  * entry */
860                                 if (phdr->p_memsz == 0 ||
861                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
862                                         goto dynamic_error;
863
864                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
865                                 if (((Elf32_Dyn *)
866                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
867                                         goto dynamic_error;
868                                 break;
869                         }
870                 }
871                 break;
872         }
873
874         /* now elide adjacent segments in the load map on MMU linux
875          * - on uClinux the holes between may actually be filled with system
876          *   stuff or stuff from other processes
877          */
878 #ifdef CONFIG_MMU
879         nloads = loadmap->nsegs;
880         mseg = loadmap->segs;
881         seg = mseg + 1;
882         for (loop = 1; loop < nloads; loop++) {
883                 /* see if we have a candidate for merging */
884                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
885                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
886                         if (load_addr == (seg->addr & PAGE_MASK)) {
887                                 mseg->p_memsz +=
888                                         load_addr -
889                                         (mseg->addr + mseg->p_memsz);
890                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
891                                 mseg->p_memsz += seg->p_memsz;
892                                 loadmap->nsegs--;
893                                 continue;
894                         }
895                 }
896
897                 mseg++;
898                 if (mseg != seg)
899                         *mseg = *seg;
900         }
901 #endif
902
903         kdebug("Mapped Object [%s]:", what);
904         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
905         kdebug("- entry    : %lx", params->entry_addr);
906         kdebug("- PHDR[]   : %lx", params->ph_addr);
907         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
908         seg = loadmap->segs;
909         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
910                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
911                        loop,
912                        seg->addr, seg->addr + seg->p_memsz - 1,
913                        seg->p_vaddr, seg->p_memsz);
914
915         return 0;
916
917 dynamic_error:
918         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
919                what, file->f_path.dentry->d_inode->i_ino);
920         return -ELIBBAD;
921 }
922
923 /*****************************************************************************/
924 /*
925  * map a file with constant displacement under uClinux
926  */
927 #ifndef CONFIG_MMU
928 static int elf_fdpic_map_file_constdisp_on_uclinux(
929         struct elf_fdpic_params *params,
930         struct file *file,
931         struct mm_struct *mm)
932 {
933         struct elf32_fdpic_loadseg *seg;
934         struct elf32_phdr *phdr;
935         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
936         loff_t fpos;
937         int loop, ret;
938
939         load_addr = params->load_addr;
940         seg = params->loadmap->segs;
941
942         /* determine the bounds of the contiguous overall allocation we must
943          * make */
944         phdr = params->phdrs;
945         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
946                 if (params->phdrs[loop].p_type != PT_LOAD)
947                         continue;
948
949                 if (base > phdr->p_vaddr)
950                         base = phdr->p_vaddr;
951                 if (top < phdr->p_vaddr + phdr->p_memsz)
952                         top = phdr->p_vaddr + phdr->p_memsz;
953         }
954
955         /* allocate one big anon block for everything */
956         mflags = MAP_PRIVATE;
957         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
958                 mflags |= MAP_EXECUTABLE;
959
960         down_write(&mm->mmap_sem);
961         maddr = do_mmap(NULL, load_addr, top - base,
962                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
963         up_write(&mm->mmap_sem);
964         if (IS_ERR_VALUE(maddr))
965                 return (int) maddr;
966
967         if (load_addr != 0)
968                 load_addr += PAGE_ALIGN(top - base);
969
970         /* and then load the file segments into it */
971         phdr = params->phdrs;
972         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
973                 if (params->phdrs[loop].p_type != PT_LOAD)
974                         continue;
975
976                 fpos = phdr->p_offset;
977
978                 seg->addr = maddr + (phdr->p_vaddr - base);
979                 seg->p_vaddr = phdr->p_vaddr;
980                 seg->p_memsz = phdr->p_memsz;
981
982                 ret = file->f_op->read(file, (void *) seg->addr,
983                                        phdr->p_filesz, &fpos);
984                 if (ret < 0)
985                         return ret;
986
987                 /* map the ELF header address if in this segment */
988                 if (phdr->p_offset == 0)
989                         params->elfhdr_addr = seg->addr;
990
991                 /* clear any space allocated but not loaded */
992                 if (phdr->p_filesz < phdr->p_memsz) {
993                         ret = clear_user((void *) (seg->addr + phdr->p_filesz),
994                                          phdr->p_memsz - phdr->p_filesz);
995                         if (ret)
996                                 return ret;
997                 }
998
999                 if (mm) {
1000                         if (phdr->p_flags & PF_X) {
1001                                 if (!mm->start_code) {
1002                                         mm->start_code = seg->addr;
1003                                         mm->end_code = seg->addr +
1004                                                 phdr->p_memsz;
1005                                 }
1006                         } else if (!mm->start_data) {
1007                                 mm->start_data = seg->addr;
1008 #ifndef CONFIG_MMU
1009                                 mm->end_data = seg->addr + phdr->p_memsz;
1010 #endif
1011                         }
1012
1013 #ifdef CONFIG_MMU
1014                         if (seg->addr + phdr->p_memsz > mm->end_data)
1015                                 mm->end_data = seg->addr + phdr->p_memsz;
1016 #endif
1017                 }
1018
1019                 seg++;
1020         }
1021
1022         return 0;
1023 }
1024 #endif
1025
1026 /*****************************************************************************/
1027 /*
1028  * map a binary by direct mmap() of the individual PT_LOAD segments
1029  */
1030 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1031                                              struct file *file,
1032                                              struct mm_struct *mm)
1033 {
1034         struct elf32_fdpic_loadseg *seg;
1035         struct elf32_phdr *phdr;
1036         unsigned long load_addr, delta_vaddr;
1037         int loop, dvset, ret;
1038
1039         load_addr = params->load_addr;
1040         delta_vaddr = 0;
1041         dvset = 0;
1042
1043         seg = params->loadmap->segs;
1044
1045         /* deal with each load segment separately */
1046         phdr = params->phdrs;
1047         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1048                 unsigned long maddr, disp, excess, excess1;
1049                 int prot = 0, flags;
1050
1051                 if (phdr->p_type != PT_LOAD)
1052                         continue;
1053
1054                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1055                        (unsigned long) phdr->p_vaddr,
1056                        (unsigned long) phdr->p_offset,
1057                        (unsigned long) phdr->p_filesz,
1058                        (unsigned long) phdr->p_memsz);
1059
1060                 /* determine the mapping parameters */
1061                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1062                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1063                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1064
1065                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1066                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1067                         flags |= MAP_EXECUTABLE;
1068
1069                 maddr = 0;
1070
1071                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1072                 case ELF_FDPIC_FLAG_INDEPENDENT:
1073                         /* PT_LOADs are independently locatable */
1074                         break;
1075
1076                 case ELF_FDPIC_FLAG_HONOURVADDR:
1077                         /* the specified virtual address must be honoured */
1078                         maddr = phdr->p_vaddr;
1079                         flags |= MAP_FIXED;
1080                         break;
1081
1082                 case ELF_FDPIC_FLAG_CONSTDISP:
1083                         /* constant displacement
1084                          * - can be mapped anywhere, but must be mapped as a
1085                          *   unit
1086                          */
1087                         if (!dvset) {
1088                                 maddr = load_addr;
1089                                 delta_vaddr = phdr->p_vaddr;
1090                                 dvset = 1;
1091                         } else {
1092                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1093                                 flags |= MAP_FIXED;
1094                         }
1095                         break;
1096
1097                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1098                         /* contiguity handled later */
1099                         break;
1100
1101                 default:
1102                         BUG();
1103                 }
1104
1105                 maddr &= PAGE_MASK;
1106
1107                 /* create the mapping */
1108                 disp = phdr->p_vaddr & ~PAGE_MASK;
1109                 down_write(&mm->mmap_sem);
1110                 maddr = do_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1111                                 phdr->p_offset - disp);
1112                 up_write(&mm->mmap_sem);
1113
1114                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1115                        loop, phdr->p_memsz + disp, prot, flags,
1116                        phdr->p_offset - disp, maddr);
1117
1118                 if (IS_ERR_VALUE(maddr))
1119                         return (int) maddr;
1120
1121                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1122                     ELF_FDPIC_FLAG_CONTIGUOUS)
1123                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1124
1125                 seg->addr = maddr + disp;
1126                 seg->p_vaddr = phdr->p_vaddr;
1127                 seg->p_memsz = phdr->p_memsz;
1128
1129                 /* map the ELF header address if in this segment */
1130                 if (phdr->p_offset == 0)
1131                         params->elfhdr_addr = seg->addr;
1132
1133                 /* clear the bit between beginning of mapping and beginning of
1134                  * PT_LOAD */
1135                 if (prot & PROT_WRITE && disp > 0) {
1136                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1137                         ret = clear_user((void __user *) maddr, disp);
1138                         if (ret)
1139                                 return ret;
1140                         maddr += disp;
1141                 }
1142
1143                 /* clear any space allocated but not loaded
1144                  * - on uClinux we can just clear the lot
1145                  * - on MMU linux we'll get a SIGBUS beyond the last page
1146                  *   extant in the file
1147                  */
1148                 excess = phdr->p_memsz - phdr->p_filesz;
1149                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1150
1151 #ifdef CONFIG_MMU
1152                 if (excess > excess1) {
1153                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1154                         unsigned long xmaddr;
1155
1156                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1157                         down_write(&mm->mmap_sem);
1158                         xmaddr = do_mmap(NULL, xaddr, excess - excess1,
1159                                          prot, flags, 0);
1160                         up_write(&mm->mmap_sem);
1161
1162                         kdebug("mmap[%d] <anon>"
1163                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1164                                loop, xaddr, excess - excess1, prot, flags,
1165                                xmaddr);
1166
1167                         if (xmaddr != xaddr)
1168                                 return -ENOMEM;
1169                 }
1170
1171                 if (prot & PROT_WRITE && excess1 > 0) {
1172                         kdebug("clear[%d] ad=%lx sz=%lx",
1173                                loop, maddr + phdr->p_filesz, excess1);
1174                         ret = clear_user((void __user *) maddr + phdr->p_filesz,
1175                                          excess1);
1176                         if (ret)
1177                                 return ret;
1178                 }
1179
1180 #else
1181                 if (excess > 0) {
1182                         kdebug("clear[%d] ad=%lx sz=%lx",
1183                                loop, maddr + phdr->p_filesz, excess);
1184                         ret = clear_user((void *) maddr + phdr->p_filesz, excess);
1185                         if (ret)
1186                                 return ret;
1187                 }
1188 #endif
1189
1190                 if (mm) {
1191                         if (phdr->p_flags & PF_X) {
1192                                 if (!mm->start_code) {
1193                                         mm->start_code = maddr;
1194                                         mm->end_code = maddr + phdr->p_memsz;
1195                                 }
1196                         } else if (!mm->start_data) {
1197                                 mm->start_data = maddr;
1198                                 mm->end_data = maddr + phdr->p_memsz;
1199                         }
1200                 }
1201
1202                 seg++;
1203         }
1204
1205         return 0;
1206 }
1207
1208 /*****************************************************************************/
1209 /*
1210  * ELF-FDPIC core dumper
1211  *
1212  * Modelled on fs/exec.c:aout_core_dump()
1213  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1214  *
1215  * Modelled on fs/binfmt_elf.c core dumper
1216  */
1217 #ifdef CONFIG_ELF_CORE
1218
1219 /*
1220  * Decide whether a segment is worth dumping; default is yes to be
1221  * sure (missing info is worse than too much; etc).
1222  * Personally I'd include everything, and use the coredump limit...
1223  *
1224  * I think we should skip something. But I am not sure how. H.J.
1225  */
1226 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1227 {
1228         int dump_ok;
1229
1230         /* Do not dump I/O mapped devices or special mappings */
1231         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1232                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1233                 return 0;
1234         }
1235
1236         /* If we may not read the contents, don't allow us to dump
1237          * them either. "dump_write()" can't handle it anyway.
1238          */
1239         if (!(vma->vm_flags & VM_READ)) {
1240                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1241                 return 0;
1242         }
1243
1244         /* By default, dump shared memory if mapped from an anonymous file. */
1245         if (vma->vm_flags & VM_SHARED) {
1246                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1247                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1248                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1249                                vma->vm_flags, dump_ok ? "yes" : "no");
1250                         return dump_ok;
1251                 }
1252
1253                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1254                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1255                        vma->vm_flags, dump_ok ? "yes" : "no");
1256                 return dump_ok;
1257         }
1258
1259 #ifdef CONFIG_MMU
1260         /* By default, if it hasn't been written to, don't write it out */
1261         if (!vma->anon_vma) {
1262                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1263                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1264                        vma->vm_flags, dump_ok ? "yes" : "no");
1265                 return dump_ok;
1266         }
1267 #endif
1268
1269         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1270         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1271                dump_ok ? "yes" : "no");
1272         return dump_ok;
1273 }
1274
1275 /* An ELF note in memory */
1276 struct memelfnote
1277 {
1278         const char *name;
1279         int type;
1280         unsigned int datasz;
1281         void *data;
1282 };
1283
1284 static int notesize(struct memelfnote *en)
1285 {
1286         int sz;
1287
1288         sz = sizeof(struct elf_note);
1289         sz += roundup(strlen(en->name) + 1, 4);
1290         sz += roundup(en->datasz, 4);
1291
1292         return sz;
1293 }
1294
1295 /* #define DEBUG */
1296
1297 #define DUMP_WRITE(addr, nr, foffset)   \
1298         do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1299
1300 static int alignfile(struct file *file, loff_t *foffset)
1301 {
1302         static const char buf[4] = { 0, };
1303         DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1304         return 1;
1305 }
1306
1307 static int writenote(struct memelfnote *men, struct file *file,
1308                         loff_t *foffset)
1309 {
1310         struct elf_note en;
1311         en.n_namesz = strlen(men->name) + 1;
1312         en.n_descsz = men->datasz;
1313         en.n_type = men->type;
1314
1315         DUMP_WRITE(&en, sizeof(en), foffset);
1316         DUMP_WRITE(men->name, en.n_namesz, foffset);
1317         if (!alignfile(file, foffset))
1318                 return 0;
1319         DUMP_WRITE(men->data, men->datasz, foffset);
1320         if (!alignfile(file, foffset))
1321                 return 0;
1322
1323         return 1;
1324 }
1325 #undef DUMP_WRITE
1326
1327 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1328 {
1329         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1330         elf->e_ident[EI_CLASS] = ELF_CLASS;
1331         elf->e_ident[EI_DATA] = ELF_DATA;
1332         elf->e_ident[EI_VERSION] = EV_CURRENT;
1333         elf->e_ident[EI_OSABI] = ELF_OSABI;
1334         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1335
1336         elf->e_type = ET_CORE;
1337         elf->e_machine = ELF_ARCH;
1338         elf->e_version = EV_CURRENT;
1339         elf->e_entry = 0;
1340         elf->e_phoff = sizeof(struct elfhdr);
1341         elf->e_shoff = 0;
1342         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1343         elf->e_ehsize = sizeof(struct elfhdr);
1344         elf->e_phentsize = sizeof(struct elf_phdr);
1345         elf->e_phnum = segs;
1346         elf->e_shentsize = 0;
1347         elf->e_shnum = 0;
1348         elf->e_shstrndx = 0;
1349         return;
1350 }
1351
1352 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1353 {
1354         phdr->p_type = PT_NOTE;
1355         phdr->p_offset = offset;
1356         phdr->p_vaddr = 0;
1357         phdr->p_paddr = 0;
1358         phdr->p_filesz = sz;
1359         phdr->p_memsz = 0;
1360         phdr->p_flags = 0;
1361         phdr->p_align = 0;
1362         return;
1363 }
1364
1365 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1366                 unsigned int sz, void *data)
1367 {
1368         note->name = name;
1369         note->type = type;
1370         note->datasz = sz;
1371         note->data = data;
1372         return;
1373 }
1374
1375 /*
1376  * fill up all the fields in prstatus from the given task struct, except
1377  * registers which need to be filled up separately.
1378  */
1379 static void fill_prstatus(struct elf_prstatus *prstatus,
1380                           struct task_struct *p, long signr)
1381 {
1382         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1383         prstatus->pr_sigpend = p->pending.signal.sig[0];
1384         prstatus->pr_sighold = p->blocked.sig[0];
1385         rcu_read_lock();
1386         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1387         rcu_read_unlock();
1388         prstatus->pr_pid = task_pid_vnr(p);
1389         prstatus->pr_pgrp = task_pgrp_vnr(p);
1390         prstatus->pr_sid = task_session_vnr(p);
1391         if (thread_group_leader(p)) {
1392                 struct task_cputime cputime;
1393
1394                 /*
1395                  * This is the record for the group leader.  It shows the
1396                  * group-wide total, not its individual thread total.
1397                  */
1398                 thread_group_cputime(p, &cputime);
1399                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1400                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1401         } else {
1402                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1403                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1404         }
1405         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1406         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1407
1408         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1409         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1410 }
1411
1412 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1413                        struct mm_struct *mm)
1414 {
1415         const struct cred *cred;
1416         unsigned int i, len;
1417
1418         /* first copy the parameters from user space */
1419         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1420
1421         len = mm->arg_end - mm->arg_start;
1422         if (len >= ELF_PRARGSZ)
1423                 len = ELF_PRARGSZ - 1;
1424         if (copy_from_user(&psinfo->pr_psargs,
1425                            (const char __user *) mm->arg_start, len))
1426                 return -EFAULT;
1427         for (i = 0; i < len; i++)
1428                 if (psinfo->pr_psargs[i] == 0)
1429                         psinfo->pr_psargs[i] = ' ';
1430         psinfo->pr_psargs[len] = 0;
1431
1432         rcu_read_lock();
1433         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1434         rcu_read_unlock();
1435         psinfo->pr_pid = task_pid_vnr(p);
1436         psinfo->pr_pgrp = task_pgrp_vnr(p);
1437         psinfo->pr_sid = task_session_vnr(p);
1438
1439         i = p->state ? ffz(~p->state) + 1 : 0;
1440         psinfo->pr_state = i;
1441         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1442         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1443         psinfo->pr_nice = task_nice(p);
1444         psinfo->pr_flag = p->flags;
1445         rcu_read_lock();
1446         cred = __task_cred(p);
1447         SET_UID(psinfo->pr_uid, cred->uid);
1448         SET_GID(psinfo->pr_gid, cred->gid);
1449         rcu_read_unlock();
1450         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1451
1452         return 0;
1453 }
1454
1455 /* Here is the structure in which status of each thread is captured. */
1456 struct elf_thread_status
1457 {
1458         struct list_head list;
1459         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1460         elf_fpregset_t fpu;             /* NT_PRFPREG */
1461         struct task_struct *thread;
1462 #ifdef ELF_CORE_COPY_XFPREGS
1463         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1464 #endif
1465         struct memelfnote notes[3];
1466         int num_notes;
1467 };
1468
1469 /*
1470  * In order to add the specific thread information for the elf file format,
1471  * we need to keep a linked list of every thread's pr_status and then create
1472  * a single section for them in the final core file.
1473  */
1474 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1475 {
1476         struct task_struct *p = t->thread;
1477         int sz = 0;
1478
1479         t->num_notes = 0;
1480
1481         fill_prstatus(&t->prstatus, p, signr);
1482         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1483
1484         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1485                   &t->prstatus);
1486         t->num_notes++;
1487         sz += notesize(&t->notes[0]);
1488
1489         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1490         if (t->prstatus.pr_fpvalid) {
1491                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1492                           &t->fpu);
1493                 t->num_notes++;
1494                 sz += notesize(&t->notes[1]);
1495         }
1496
1497 #ifdef ELF_CORE_COPY_XFPREGS
1498         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1499                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1500                           sizeof(t->xfpu), &t->xfpu);
1501                 t->num_notes++;
1502                 sz += notesize(&t->notes[2]);
1503         }
1504 #endif
1505         return sz;
1506 }
1507
1508 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1509                              elf_addr_t e_shoff, int segs)
1510 {
1511         elf->e_shoff = e_shoff;
1512         elf->e_shentsize = sizeof(*shdr4extnum);
1513         elf->e_shnum = 1;
1514         elf->e_shstrndx = SHN_UNDEF;
1515
1516         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1517
1518         shdr4extnum->sh_type = SHT_NULL;
1519         shdr4extnum->sh_size = elf->e_shnum;
1520         shdr4extnum->sh_link = elf->e_shstrndx;
1521         shdr4extnum->sh_info = segs;
1522 }
1523
1524 /*
1525  * dump the segments for an MMU process
1526  */
1527 #ifdef CONFIG_MMU
1528 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1529                            unsigned long *limit, unsigned long mm_flags)
1530 {
1531         struct vm_area_struct *vma;
1532         int err = 0;
1533
1534         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1535                 unsigned long addr;
1536
1537                 if (!maydump(vma, mm_flags))
1538                         continue;
1539
1540                 for (addr = vma->vm_start; addr < vma->vm_end;
1541                                                         addr += PAGE_SIZE) {
1542                         struct page *page = get_dump_page(addr);
1543                         if (page) {
1544                                 void *kaddr = kmap(page);
1545                                 *size += PAGE_SIZE;
1546                                 if (*size > *limit)
1547                                         err = -EFBIG;
1548                                 else if (!dump_write(file, kaddr, PAGE_SIZE))
1549                                         err = -EIO;
1550                                 kunmap(page);
1551                                 page_cache_release(page);
1552                         } else if (!dump_seek(file, PAGE_SIZE))
1553                                 err = -EFBIG;
1554                         if (err)
1555                                 goto out;
1556                 }
1557         }
1558 out:
1559         return err;
1560 }
1561 #endif
1562
1563 /*
1564  * dump the segments for a NOMMU process
1565  */
1566 #ifndef CONFIG_MMU
1567 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1568                            unsigned long *limit, unsigned long mm_flags)
1569 {
1570         struct vm_area_struct *vma;
1571
1572         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1573                 if (!maydump(vma, mm_flags))
1574                         continue;
1575
1576                 if ((*size += PAGE_SIZE) > *limit)
1577                         return -EFBIG;
1578
1579                 if (!dump_write(file, (void *) vma->vm_start,
1580                                 vma->vm_end - vma->vm_start))
1581                         return -EIO;
1582         }
1583
1584         return 0;
1585 }
1586 #endif
1587
1588 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1589 {
1590         struct vm_area_struct *vma;
1591         size_t size = 0;
1592
1593         for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1594                 if (maydump(vma, mm_flags))
1595                         size += vma->vm_end - vma->vm_start;
1596         return size;
1597 }
1598
1599 /*
1600  * Actual dumper
1601  *
1602  * This is a two-pass process; first we find the offsets of the bits,
1603  * and then they are actually written out.  If we run out of core limit
1604  * we just truncate.
1605  */
1606 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1607 {
1608 #define NUM_NOTES       6
1609         int has_dumped = 0;
1610         mm_segment_t fs;
1611         int segs;
1612         size_t size = 0;
1613         int i;
1614         struct vm_area_struct *vma;
1615         struct elfhdr *elf = NULL;
1616         loff_t offset = 0, dataoff, foffset;
1617         int numnote;
1618         struct memelfnote *notes = NULL;
1619         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1620         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1621         LIST_HEAD(thread_list);
1622         struct list_head *t;
1623         elf_fpregset_t *fpu = NULL;
1624 #ifdef ELF_CORE_COPY_XFPREGS
1625         elf_fpxregset_t *xfpu = NULL;
1626 #endif
1627         int thread_status_size = 0;
1628         elf_addr_t *auxv;
1629         struct elf_phdr *phdr4note = NULL;
1630         struct elf_shdr *shdr4extnum = NULL;
1631         Elf_Half e_phnum;
1632         elf_addr_t e_shoff;
1633
1634         /*
1635          * We no longer stop all VM operations.
1636          *
1637          * This is because those proceses that could possibly change map_count
1638          * or the mmap / vma pages are now blocked in do_exit on current
1639          * finishing this core dump.
1640          *
1641          * Only ptrace can touch these memory addresses, but it doesn't change
1642          * the map_count or the pages allocated. So no possibility of crashing
1643          * exists while dumping the mm->vm_next areas to the core file.
1644          */
1645
1646         /* alloc memory for large data structures: too large to be on stack */
1647         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1648         if (!elf)
1649                 goto cleanup;
1650         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1651         if (!prstatus)
1652                 goto cleanup;
1653         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1654         if (!psinfo)
1655                 goto cleanup;
1656         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1657         if (!notes)
1658                 goto cleanup;
1659         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1660         if (!fpu)
1661                 goto cleanup;
1662 #ifdef ELF_CORE_COPY_XFPREGS
1663         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1664         if (!xfpu)
1665                 goto cleanup;
1666 #endif
1667
1668         if (cprm->signr) {
1669                 struct core_thread *ct;
1670                 struct elf_thread_status *tmp;
1671
1672                 for (ct = current->mm->core_state->dumper.next;
1673                                                 ct; ct = ct->next) {
1674                         tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1675                         if (!tmp)
1676                                 goto cleanup;
1677
1678                         tmp->thread = ct->task;
1679                         list_add(&tmp->list, &thread_list);
1680                 }
1681
1682                 list_for_each(t, &thread_list) {
1683                         struct elf_thread_status *tmp;
1684                         int sz;
1685
1686                         tmp = list_entry(t, struct elf_thread_status, list);
1687                         sz = elf_dump_thread_status(cprm->signr, tmp);
1688                         thread_status_size += sz;
1689                 }
1690         }
1691
1692         /* now collect the dump for the current */
1693         fill_prstatus(prstatus, current, cprm->signr);
1694         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1695
1696         segs = current->mm->map_count;
1697         segs += elf_core_extra_phdrs();
1698
1699         /* for notes section */
1700         segs++;
1701
1702         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1703          * this, kernel supports extended numbering. Have a look at
1704          * include/linux/elf.h for further information. */
1705         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1706
1707         /* Set up header */
1708         fill_elf_fdpic_header(elf, e_phnum);
1709
1710         has_dumped = 1;
1711         current->flags |= PF_DUMPCORE;
1712
1713         /*
1714          * Set up the notes in similar form to SVR4 core dumps made
1715          * with info from their /proc.
1716          */
1717
1718         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1719         fill_psinfo(psinfo, current->group_leader, current->mm);
1720         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1721
1722         numnote = 2;
1723
1724         auxv = (elf_addr_t *) current->mm->saved_auxv;
1725
1726         i = 0;
1727         do
1728                 i += 2;
1729         while (auxv[i - 2] != AT_NULL);
1730         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1731                   i * sizeof(elf_addr_t), auxv);
1732
1733         /* Try to dump the FPU. */
1734         if ((prstatus->pr_fpvalid =
1735              elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1736                 fill_note(notes + numnote++,
1737                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1738 #ifdef ELF_CORE_COPY_XFPREGS
1739         if (elf_core_copy_task_xfpregs(current, xfpu))
1740                 fill_note(notes + numnote++,
1741                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1742 #endif
1743
1744         fs = get_fs();
1745         set_fs(KERNEL_DS);
1746
1747         offset += sizeof(*elf);                         /* Elf header */
1748         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1749         foffset = offset;
1750
1751         /* Write notes phdr entry */
1752         {
1753                 int sz = 0;
1754
1755                 for (i = 0; i < numnote; i++)
1756                         sz += notesize(notes + i);
1757
1758                 sz += thread_status_size;
1759
1760                 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1761                 if (!phdr4note)
1762                         goto end_coredump;
1763
1764                 fill_elf_note_phdr(phdr4note, sz, offset);
1765                 offset += sz;
1766         }
1767
1768         /* Page-align dumped data */
1769         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1770
1771         offset += elf_core_vma_data_size(cprm->mm_flags);
1772         offset += elf_core_extra_data_size();
1773         e_shoff = offset;
1774
1775         if (e_phnum == PN_XNUM) {
1776                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1777                 if (!shdr4extnum)
1778                         goto end_coredump;
1779                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1780         }
1781
1782         offset = dataoff;
1783
1784         size += sizeof(*elf);
1785         if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
1786                 goto end_coredump;
1787
1788         size += sizeof(*phdr4note);
1789         if (size > cprm->limit
1790             || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
1791                 goto end_coredump;
1792
1793         /* write program headers for segments dump */
1794         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1795                 struct elf_phdr phdr;
1796                 size_t sz;
1797
1798                 sz = vma->vm_end - vma->vm_start;
1799
1800                 phdr.p_type = PT_LOAD;
1801                 phdr.p_offset = offset;
1802                 phdr.p_vaddr = vma->vm_start;
1803                 phdr.p_paddr = 0;
1804                 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1805                 phdr.p_memsz = sz;
1806                 offset += phdr.p_filesz;
1807                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1808                 if (vma->vm_flags & VM_WRITE)
1809                         phdr.p_flags |= PF_W;
1810                 if (vma->vm_flags & VM_EXEC)
1811                         phdr.p_flags |= PF_X;
1812                 phdr.p_align = ELF_EXEC_PAGESIZE;
1813
1814                 size += sizeof(phdr);
1815                 if (size > cprm->limit
1816                     || !dump_write(cprm->file, &phdr, sizeof(phdr)))
1817                         goto end_coredump;
1818         }
1819
1820         if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
1821                 goto end_coredump;
1822
1823         /* write out the notes section */
1824         for (i = 0; i < numnote; i++)
1825                 if (!writenote(notes + i, cprm->file, &foffset))
1826                         goto end_coredump;
1827
1828         /* write out the thread status notes section */
1829         list_for_each(t, &thread_list) {
1830                 struct elf_thread_status *tmp =
1831                                 list_entry(t, struct elf_thread_status, list);
1832
1833                 for (i = 0; i < tmp->num_notes; i++)
1834                         if (!writenote(&tmp->notes[i], cprm->file, &foffset))
1835                                 goto end_coredump;
1836         }
1837
1838         if (!dump_seek(cprm->file, dataoff - foffset))
1839                 goto end_coredump;
1840
1841         if (elf_fdpic_dump_segments(cprm->file, &size, &cprm->limit,
1842                                     cprm->mm_flags) < 0)
1843                 goto end_coredump;
1844
1845         if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
1846                 goto end_coredump;
1847
1848         if (e_phnum == PN_XNUM) {
1849                 size += sizeof(*shdr4extnum);
1850                 if (size > cprm->limit
1851                     || !dump_write(cprm->file, shdr4extnum,
1852                                    sizeof(*shdr4extnum)))
1853                         goto end_coredump;
1854         }
1855
1856         if (cprm->file->f_pos != offset) {
1857                 /* Sanity check */
1858                 printk(KERN_WARNING
1859                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1860                        cprm->file->f_pos, offset);
1861         }
1862
1863 end_coredump:
1864         set_fs(fs);
1865
1866 cleanup:
1867         while (!list_empty(&thread_list)) {
1868                 struct list_head *tmp = thread_list.next;
1869                 list_del(tmp);
1870                 kfree(list_entry(tmp, struct elf_thread_status, list));
1871         }
1872         kfree(phdr4note);
1873         kfree(elf);
1874         kfree(prstatus);
1875         kfree(psinfo);
1876         kfree(notes);
1877         kfree(fpu);
1878 #ifdef ELF_CORE_COPY_XFPREGS
1879         kfree(xfpu);
1880 #endif
1881         return has_dumped;
1882 #undef NUM_NOTES
1883 }
1884
1885 #endif          /* CONFIG_ELF_CORE */