inotify: invalid mask should return a error number but not set it
[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 #include <asm/exec.h>
43
44 typedef char *elf_caddr_t;
45
46 #if 0
47 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
48 #else
49 #define kdebug(fmt, ...) do {} while(0)
50 #endif
51
52 #if 0
53 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
54 #else
55 #define kdcore(fmt, ...) do {} while(0)
56 #endif
57
58 MODULE_LICENSE("GPL");
59
60 static int load_elf_fdpic_binary(struct linux_binprm *, struct pt_regs *);
61 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
62 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
63                               struct mm_struct *, const char *);
64
65 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
66                                    struct elf_fdpic_params *,
67                                    struct elf_fdpic_params *);
68
69 #ifndef CONFIG_MMU
70 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
71                                             unsigned long *);
72 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
73                                                    struct file *,
74                                                    struct mm_struct *);
75 #endif
76
77 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
78                                              struct file *, struct mm_struct *);
79
80 #ifdef CONFIG_ELF_CORE
81 static int elf_fdpic_core_dump(struct coredump_params *cprm);
82 #endif
83
84 static struct linux_binfmt elf_fdpic_format = {
85         .module         = THIS_MODULE,
86         .load_binary    = load_elf_fdpic_binary,
87 #ifdef CONFIG_ELF_CORE
88         .core_dump      = elf_fdpic_core_dump,
89 #endif
90         .min_coredump   = ELF_EXEC_PAGESIZE,
91 };
92
93 static int __init init_elf_fdpic_binfmt(void)
94 {
95         register_binfmt(&elf_fdpic_format);
96         return 0;
97 }
98
99 static void __exit exit_elf_fdpic_binfmt(void)
100 {
101         unregister_binfmt(&elf_fdpic_format);
102 }
103
104 core_initcall(init_elf_fdpic_binfmt);
105 module_exit(exit_elf_fdpic_binfmt);
106
107 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
108 {
109         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
110                 return 0;
111         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
112                 return 0;
113         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
114                 return 0;
115         if (!file->f_op || !file->f_op->mmap)
116                 return 0;
117         return 1;
118 }
119
120 /*****************************************************************************/
121 /*
122  * read the program headers table into memory
123  */
124 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
125                                  struct file *file)
126 {
127         struct elf32_phdr *phdr;
128         unsigned long size;
129         int retval, loop;
130
131         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
132                 return -ENOMEM;
133         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
134                 return -ENOMEM;
135
136         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
137         params->phdrs = kmalloc(size, GFP_KERNEL);
138         if (!params->phdrs)
139                 return -ENOMEM;
140
141         retval = kernel_read(file, params->hdr.e_phoff,
142                              (char *) params->phdrs, size);
143         if (unlikely(retval != size))
144                 return retval < 0 ? retval : -ENOEXEC;
145
146         /* determine stack size for this binary */
147         phdr = params->phdrs;
148         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
149                 if (phdr->p_type != PT_GNU_STACK)
150                         continue;
151
152                 if (phdr->p_flags & PF_X)
153                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
154                 else
155                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
156
157                 params->stack_size = phdr->p_memsz;
158                 break;
159         }
160
161         return 0;
162 }
163
164 /*****************************************************************************/
165 /*
166  * load an fdpic binary into various bits of memory
167  */
168 static int load_elf_fdpic_binary(struct linux_binprm *bprm,
169                                  struct pt_regs *regs)
170 {
171         struct elf_fdpic_params exec_params, interp_params;
172         struct elf_phdr *phdr;
173         unsigned long stack_size, entryaddr;
174 #ifdef ELF_FDPIC_PLAT_INIT
175         unsigned long dynaddr;
176 #endif
177 #ifndef CONFIG_MMU
178         unsigned long stack_prot;
179 #endif
180         struct file *interpreter = NULL; /* to shut gcc up */
181         char *interpreter_name = NULL;
182         int executable_stack;
183         int retval, i;
184
185         kdebug("____ LOAD %d ____", current->pid);
186
187         memset(&exec_params, 0, sizeof(exec_params));
188         memset(&interp_params, 0, sizeof(interp_params));
189
190         exec_params.hdr = *(struct elfhdr *) bprm->buf;
191         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
192
193         /* check that this is a binary we know how to deal with */
194         retval = -ENOEXEC;
195         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
196                 goto error;
197
198         /* read the program header table */
199         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
200         if (retval < 0)
201                 goto error;
202
203         /* scan for a program header that specifies an interpreter */
204         phdr = exec_params.phdrs;
205
206         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
207                 switch (phdr->p_type) {
208                 case PT_INTERP:
209                         retval = -ENOMEM;
210                         if (phdr->p_filesz > PATH_MAX)
211                                 goto error;
212                         retval = -ENOENT;
213                         if (phdr->p_filesz < 2)
214                                 goto error;
215
216                         /* read the name of the interpreter into memory */
217                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
218                         if (!interpreter_name)
219                                 goto error;
220
221                         retval = kernel_read(bprm->file,
222                                              phdr->p_offset,
223                                              interpreter_name,
224                                              phdr->p_filesz);
225                         if (unlikely(retval != phdr->p_filesz)) {
226                                 if (retval >= 0)
227                                         retval = -ENOEXEC;
228                                 goto error;
229                         }
230
231                         retval = -ENOENT;
232                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
233                                 goto error;
234
235                         kdebug("Using ELF interpreter %s", interpreter_name);
236
237                         /* replace the program with the interpreter */
238                         interpreter = open_exec(interpreter_name);
239                         retval = PTR_ERR(interpreter);
240                         if (IS_ERR(interpreter)) {
241                                 interpreter = NULL;
242                                 goto error;
243                         }
244
245                         /*
246                          * If the binary is not readable then enforce
247                          * mm->dumpable = 0 regardless of the interpreter's
248                          * permissions.
249                          */
250                         would_dump(bprm, interpreter);
251
252                         retval = kernel_read(interpreter, 0, bprm->buf,
253                                              BINPRM_BUF_SIZE);
254                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
255                                 if (retval >= 0)
256                                         retval = -ENOEXEC;
257                                 goto error;
258                         }
259
260                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
261                         break;
262
263                 case PT_LOAD:
264 #ifdef CONFIG_MMU
265                         if (exec_params.load_addr == 0)
266                                 exec_params.load_addr = phdr->p_vaddr;
267 #endif
268                         break;
269                 }
270
271         }
272
273         if (elf_check_const_displacement(&exec_params.hdr))
274                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
275
276         /* perform insanity checks on the interpreter */
277         if (interpreter_name) {
278                 retval = -ELIBBAD;
279                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
280                         goto error;
281
282                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
283
284                 /* read the interpreter's program header table */
285                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
286                 if (retval < 0)
287                         goto error;
288         }
289
290         stack_size = exec_params.stack_size;
291         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
292                 executable_stack = EXSTACK_ENABLE_X;
293         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
294                 executable_stack = EXSTACK_DISABLE_X;
295         else
296                 executable_stack = EXSTACK_DEFAULT;
297
298         if (stack_size == 0) {
299                 stack_size = interp_params.stack_size;
300                 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
301                         executable_stack = EXSTACK_ENABLE_X;
302                 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
303                         executable_stack = EXSTACK_DISABLE_X;
304                 else
305                         executable_stack = EXSTACK_DEFAULT;
306         }
307
308         retval = -ENOEXEC;
309         if (stack_size == 0)
310                 goto error;
311
312         if (elf_check_const_displacement(&interp_params.hdr))
313                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
314
315         /* flush all traces of the currently running executable */
316         retval = flush_old_exec(bprm);
317         if (retval)
318                 goto error;
319
320         /* there's now no turning back... the old userspace image is dead,
321          * defunct, deceased, etc. after this point we have to exit via
322          * error_kill */
323         set_personality(PER_LINUX_FDPIC);
324         if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
325                 current->personality |= READ_IMPLIES_EXEC;
326
327         setup_new_exec(bprm);
328
329         set_binfmt(&elf_fdpic_format);
330
331         current->mm->start_code = 0;
332         current->mm->end_code = 0;
333         current->mm->start_stack = 0;
334         current->mm->start_data = 0;
335         current->mm->end_data = 0;
336         current->mm->context.exec_fdpic_loadmap = 0;
337         current->mm->context.interp_fdpic_loadmap = 0;
338
339 #ifdef CONFIG_MMU
340         elf_fdpic_arch_lay_out_mm(&exec_params,
341                                   &interp_params,
342                                   &current->mm->start_stack,
343                                   &current->mm->start_brk);
344
345         retval = setup_arg_pages(bprm, current->mm->start_stack,
346                                  executable_stack);
347         if (retval < 0) {
348                 send_sig(SIGKILL, current, 0);
349                 goto error_kill;
350         }
351 #endif
352
353         /* load the executable and interpreter into memory */
354         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
355                                     "executable");
356         if (retval < 0)
357                 goto error_kill;
358
359         if (interpreter_name) {
360                 retval = elf_fdpic_map_file(&interp_params, interpreter,
361                                             current->mm, "interpreter");
362                 if (retval < 0) {
363                         printk(KERN_ERR "Unable to load interpreter\n");
364                         goto error_kill;
365                 }
366
367                 allow_write_access(interpreter);
368                 fput(interpreter);
369                 interpreter = NULL;
370         }
371
372 #ifdef CONFIG_MMU
373         if (!current->mm->start_brk)
374                 current->mm->start_brk = current->mm->end_data;
375
376         current->mm->brk = current->mm->start_brk =
377                 PAGE_ALIGN(current->mm->start_brk);
378
379 #else
380         /* create a stack and brk area big enough for everyone
381          * - the brk heap starts at the bottom and works up
382          * - the stack starts at the top and works down
383          */
384         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
385         if (stack_size < PAGE_SIZE * 2)
386                 stack_size = PAGE_SIZE * 2;
387
388         stack_prot = PROT_READ | PROT_WRITE;
389         if (executable_stack == EXSTACK_ENABLE_X ||
390             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
391                 stack_prot |= PROT_EXEC;
392
393         current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
394                                          MAP_PRIVATE | MAP_ANONYMOUS |
395                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
396                                          0);
397
398         if (IS_ERR_VALUE(current->mm->start_brk)) {
399                 retval = current->mm->start_brk;
400                 current->mm->start_brk = 0;
401                 goto error_kill;
402         }
403
404         current->mm->brk = current->mm->start_brk;
405         current->mm->context.end_brk = current->mm->start_brk;
406         current->mm->context.end_brk +=
407                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
408         current->mm->start_stack = current->mm->start_brk + stack_size;
409 #endif
410
411         install_exec_creds(bprm);
412         if (create_elf_fdpic_tables(bprm, current->mm,
413                                     &exec_params, &interp_params) < 0)
414                 goto error_kill;
415
416         kdebug("- start_code  %lx", current->mm->start_code);
417         kdebug("- end_code    %lx", current->mm->end_code);
418         kdebug("- start_data  %lx", current->mm->start_data);
419         kdebug("- end_data    %lx", current->mm->end_data);
420         kdebug("- start_brk   %lx", current->mm->start_brk);
421         kdebug("- brk         %lx", current->mm->brk);
422         kdebug("- start_stack %lx", current->mm->start_stack);
423
424 #ifdef ELF_FDPIC_PLAT_INIT
425         /*
426          * The ABI may specify that certain registers be set up in special
427          * ways (on i386 %edx is the address of a DT_FINI function, for
428          * example.  This macro performs whatever initialization to
429          * the regs structure is required.
430          */
431         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
432         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
433                             dynaddr);
434 #endif
435
436         /* everything is now ready... get the userspace context ready to roll */
437         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
438         start_thread(regs, entryaddr, current->mm->start_stack);
439
440         retval = 0;
441
442 error:
443         if (interpreter) {
444                 allow_write_access(interpreter);
445                 fput(interpreter);
446         }
447         kfree(interpreter_name);
448         kfree(exec_params.phdrs);
449         kfree(exec_params.loadmap);
450         kfree(interp_params.phdrs);
451         kfree(interp_params.loadmap);
452         return retval;
453
454         /* unrecoverable error - kill the process */
455 error_kill:
456         send_sig(SIGSEGV, current, 0);
457         goto error;
458
459 }
460
461 /*****************************************************************************/
462
463 #ifndef ELF_BASE_PLATFORM
464 /*
465  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
466  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
467  * will be copied to the user stack in the same manner as AT_PLATFORM.
468  */
469 #define ELF_BASE_PLATFORM NULL
470 #endif
471
472 /*
473  * present useful information to the program by shovelling it onto the new
474  * process's stack
475  */
476 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
477                                    struct mm_struct *mm,
478                                    struct elf_fdpic_params *exec_params,
479                                    struct elf_fdpic_params *interp_params)
480 {
481         const struct cred *cred = current_cred();
482         unsigned long sp, csp, nitems;
483         elf_caddr_t __user *argv, *envp;
484         size_t platform_len = 0, len;
485         char *k_platform, *k_base_platform;
486         char __user *u_platform, *u_base_platform, *p;
487         long hwcap;
488         int loop;
489         int nr; /* reset for each csp adjustment */
490
491 #ifdef CONFIG_MMU
492         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
493          * by the processes running on the same package. One thing we can do is
494          * to shuffle the initial stack for them, so we give the architecture
495          * an opportunity to do so here.
496          */
497         sp = arch_align_stack(bprm->p);
498 #else
499         sp = mm->start_stack;
500
501         /* stack the program arguments and environment */
502         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
503                 return -EFAULT;
504 #endif
505
506         hwcap = ELF_HWCAP;
507
508         /*
509          * If this architecture has a platform capability string, copy it
510          * to userspace.  In some cases (Sparc), this info is impossible
511          * for userspace to get any other way, in others (i386) it is
512          * merely difficult.
513          */
514         k_platform = ELF_PLATFORM;
515         u_platform = NULL;
516
517         if (k_platform) {
518                 platform_len = strlen(k_platform) + 1;
519                 sp -= platform_len;
520                 u_platform = (char __user *) sp;
521                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
522                         return -EFAULT;
523         }
524
525         /*
526          * If this architecture has a "base" platform capability
527          * string, copy it to userspace.
528          */
529         k_base_platform = ELF_BASE_PLATFORM;
530         u_base_platform = NULL;
531
532         if (k_base_platform) {
533                 platform_len = strlen(k_base_platform) + 1;
534                 sp -= platform_len;
535                 u_base_platform = (char __user *) sp;
536                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
537                         return -EFAULT;
538         }
539
540         sp &= ~7UL;
541
542         /* stack the load map(s) */
543         len = sizeof(struct elf32_fdpic_loadmap);
544         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
545         sp = (sp - len) & ~7UL;
546         exec_params->map_addr = sp;
547
548         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
549                 return -EFAULT;
550
551         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
552
553         if (interp_params->loadmap) {
554                 len = sizeof(struct elf32_fdpic_loadmap);
555                 len += sizeof(struct elf32_fdpic_loadseg) *
556                         interp_params->loadmap->nsegs;
557                 sp = (sp - len) & ~7UL;
558                 interp_params->map_addr = sp;
559
560                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
561                                  len) != 0)
562                         return -EFAULT;
563
564                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
565         }
566
567         /* force 16 byte _final_ alignment here for generality */
568 #define DLINFO_ITEMS 15
569
570         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
571                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
572
573         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
574                 nitems++;
575
576         csp = sp;
577         sp -= nitems * 2 * sizeof(unsigned long);
578         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
579         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
580         sp -= 1 * sizeof(unsigned long);                /* argc */
581
582         csp -= sp & 15UL;
583         sp -= sp & 15UL;
584
585         /* put the ELF interpreter info on the stack */
586 #define NEW_AUX_ENT(id, val)                                            \
587         do {                                                            \
588                 struct { unsigned long _id, _val; } __user *ent;        \
589                                                                         \
590                 ent = (void __user *) csp;                              \
591                 __put_user((id), &ent[nr]._id);                         \
592                 __put_user((val), &ent[nr]._val);                       \
593                 nr++;                                                   \
594         } while (0)
595
596         nr = 0;
597         csp -= 2 * sizeof(unsigned long);
598         NEW_AUX_ENT(AT_NULL, 0);
599         if (k_platform) {
600                 nr = 0;
601                 csp -= 2 * sizeof(unsigned long);
602                 NEW_AUX_ENT(AT_PLATFORM,
603                             (elf_addr_t) (unsigned long) u_platform);
604         }
605
606         if (k_base_platform) {
607                 nr = 0;
608                 csp -= 2 * sizeof(unsigned long);
609                 NEW_AUX_ENT(AT_BASE_PLATFORM,
610                             (elf_addr_t) (unsigned long) u_base_platform);
611         }
612
613         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
614                 nr = 0;
615                 csp -= 2 * sizeof(unsigned long);
616                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
617         }
618
619         nr = 0;
620         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
621         NEW_AUX_ENT(AT_HWCAP,   hwcap);
622         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
623         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
624         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
625         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
626         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
627         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
628         NEW_AUX_ENT(AT_FLAGS,   0);
629         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
630         NEW_AUX_ENT(AT_UID,     (elf_addr_t) cred->uid);
631         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) cred->euid);
632         NEW_AUX_ENT(AT_GID,     (elf_addr_t) cred->gid);
633         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) cred->egid);
634         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
635         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
636
637 #ifdef ARCH_DLINFO
638         nr = 0;
639         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
640
641         /* ARCH_DLINFO must come last so platform specific code can enforce
642          * special alignment requirements on the AUXV if necessary (eg. PPC).
643          */
644         ARCH_DLINFO;
645 #endif
646 #undef NEW_AUX_ENT
647
648         /* allocate room for argv[] and envv[] */
649         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
650         envp = (elf_caddr_t __user *) csp;
651         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
652         argv = (elf_caddr_t __user *) csp;
653
654         /* stack argc */
655         csp -= sizeof(unsigned long);
656         __put_user(bprm->argc, (unsigned long __user *) csp);
657
658         BUG_ON(csp != sp);
659
660         /* fill in the argv[] array */
661 #ifdef CONFIG_MMU
662         current->mm->arg_start = bprm->p;
663 #else
664         current->mm->arg_start = current->mm->start_stack -
665                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
666 #endif
667
668         p = (char __user *) current->mm->arg_start;
669         for (loop = bprm->argc; loop > 0; loop--) {
670                 __put_user((elf_caddr_t) p, argv++);
671                 len = strnlen_user(p, MAX_ARG_STRLEN);
672                 if (!len || len > MAX_ARG_STRLEN)
673                         return -EINVAL;
674                 p += len;
675         }
676         __put_user(NULL, argv);
677         current->mm->arg_end = (unsigned long) p;
678
679         /* fill in the envv[] array */
680         current->mm->env_start = (unsigned long) p;
681         for (loop = bprm->envc; loop > 0; loop--) {
682                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
683                 len = strnlen_user(p, MAX_ARG_STRLEN);
684                 if (!len || len > MAX_ARG_STRLEN)
685                         return -EINVAL;
686                 p += len;
687         }
688         __put_user(NULL, envp);
689         current->mm->env_end = (unsigned long) p;
690
691         mm->start_stack = (unsigned long) sp;
692         return 0;
693 }
694
695 /*****************************************************************************/
696 /*
697  * transfer the program arguments and environment from the holding pages onto
698  * the stack
699  */
700 #ifndef CONFIG_MMU
701 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
702                                             unsigned long *_sp)
703 {
704         unsigned long index, stop, sp;
705         char *src;
706         int ret = 0;
707
708         stop = bprm->p >> PAGE_SHIFT;
709         sp = *_sp;
710
711         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
712                 src = kmap(bprm->page[index]);
713                 sp -= PAGE_SIZE;
714                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
715                         ret = -EFAULT;
716                 kunmap(bprm->page[index]);
717                 if (ret < 0)
718                         goto out;
719         }
720
721         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
722
723 out:
724         return ret;
725 }
726 #endif
727
728 /*****************************************************************************/
729 /*
730  * load the appropriate binary image (executable or interpreter) into memory
731  * - we assume no MMU is available
732  * - if no other PIC bits are set in params->hdr->e_flags
733  *   - we assume that the LOADable segments in the binary are independently relocatable
734  *   - we assume R/O executable segments are shareable
735  * - else
736  *   - we assume the loadable parts of the image to require fixed displacement
737  *   - the image is not shareable
738  */
739 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
740                               struct file *file,
741                               struct mm_struct *mm,
742                               const char *what)
743 {
744         struct elf32_fdpic_loadmap *loadmap;
745 #ifdef CONFIG_MMU
746         struct elf32_fdpic_loadseg *mseg;
747 #endif
748         struct elf32_fdpic_loadseg *seg;
749         struct elf32_phdr *phdr;
750         unsigned long load_addr, stop;
751         unsigned nloads, tmp;
752         size_t size;
753         int loop, ret;
754
755         /* allocate a load map table */
756         nloads = 0;
757         for (loop = 0; loop < params->hdr.e_phnum; loop++)
758                 if (params->phdrs[loop].p_type == PT_LOAD)
759                         nloads++;
760
761         if (nloads == 0)
762                 return -ELIBBAD;
763
764         size = sizeof(*loadmap) + nloads * sizeof(*seg);
765         loadmap = kzalloc(size, GFP_KERNEL);
766         if (!loadmap)
767                 return -ENOMEM;
768
769         params->loadmap = loadmap;
770
771         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
772         loadmap->nsegs = nloads;
773
774         load_addr = params->load_addr;
775         seg = loadmap->segs;
776
777         /* map the requested LOADs into the memory space */
778         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
779         case ELF_FDPIC_FLAG_CONSTDISP:
780         case ELF_FDPIC_FLAG_CONTIGUOUS:
781 #ifndef CONFIG_MMU
782                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
783                 if (ret < 0)
784                         return ret;
785                 break;
786 #endif
787         default:
788                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
789                 if (ret < 0)
790                         return ret;
791                 break;
792         }
793
794         /* map the entry point */
795         if (params->hdr.e_entry) {
796                 seg = loadmap->segs;
797                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
798                         if (params->hdr.e_entry >= seg->p_vaddr &&
799                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
800                                 params->entry_addr =
801                                         (params->hdr.e_entry - seg->p_vaddr) +
802                                         seg->addr;
803                                 break;
804                         }
805                 }
806         }
807
808         /* determine where the program header table has wound up if mapped */
809         stop = params->hdr.e_phoff;
810         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
811         phdr = params->phdrs;
812
813         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
814                 if (phdr->p_type != PT_LOAD)
815                         continue;
816
817                 if (phdr->p_offset > params->hdr.e_phoff ||
818                     phdr->p_offset + phdr->p_filesz < stop)
819                         continue;
820
821                 seg = loadmap->segs;
822                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
823                         if (phdr->p_vaddr >= seg->p_vaddr &&
824                             phdr->p_vaddr + phdr->p_filesz <=
825                             seg->p_vaddr + seg->p_memsz) {
826                                 params->ph_addr =
827                                         (phdr->p_vaddr - seg->p_vaddr) +
828                                         seg->addr +
829                                         params->hdr.e_phoff - phdr->p_offset;
830                                 break;
831                         }
832                 }
833                 break;
834         }
835
836         /* determine where the dynamic section has wound up if there is one */
837         phdr = params->phdrs;
838         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
839                 if (phdr->p_type != PT_DYNAMIC)
840                         continue;
841
842                 seg = loadmap->segs;
843                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
844                         if (phdr->p_vaddr >= seg->p_vaddr &&
845                             phdr->p_vaddr + phdr->p_memsz <=
846                             seg->p_vaddr + seg->p_memsz) {
847                                 params->dynamic_addr =
848                                         (phdr->p_vaddr - seg->p_vaddr) +
849                                         seg->addr;
850
851                                 /* check the dynamic section contains at least
852                                  * one item, and that the last item is a NULL
853                                  * entry */
854                                 if (phdr->p_memsz == 0 ||
855                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
856                                         goto dynamic_error;
857
858                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
859                                 if (((Elf32_Dyn *)
860                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
861                                         goto dynamic_error;
862                                 break;
863                         }
864                 }
865                 break;
866         }
867
868         /* now elide adjacent segments in the load map on MMU linux
869          * - on uClinux the holes between may actually be filled with system
870          *   stuff or stuff from other processes
871          */
872 #ifdef CONFIG_MMU
873         nloads = loadmap->nsegs;
874         mseg = loadmap->segs;
875         seg = mseg + 1;
876         for (loop = 1; loop < nloads; loop++) {
877                 /* see if we have a candidate for merging */
878                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
879                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
880                         if (load_addr == (seg->addr & PAGE_MASK)) {
881                                 mseg->p_memsz +=
882                                         load_addr -
883                                         (mseg->addr + mseg->p_memsz);
884                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
885                                 mseg->p_memsz += seg->p_memsz;
886                                 loadmap->nsegs--;
887                                 continue;
888                         }
889                 }
890
891                 mseg++;
892                 if (mseg != seg)
893                         *mseg = *seg;
894         }
895 #endif
896
897         kdebug("Mapped Object [%s]:", what);
898         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
899         kdebug("- entry    : %lx", params->entry_addr);
900         kdebug("- PHDR[]   : %lx", params->ph_addr);
901         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
902         seg = loadmap->segs;
903         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
904                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
905                        loop,
906                        seg->addr, seg->addr + seg->p_memsz - 1,
907                        seg->p_vaddr, seg->p_memsz);
908
909         return 0;
910
911 dynamic_error:
912         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
913                what, file->f_path.dentry->d_inode->i_ino);
914         return -ELIBBAD;
915 }
916
917 /*****************************************************************************/
918 /*
919  * map a file with constant displacement under uClinux
920  */
921 #ifndef CONFIG_MMU
922 static int elf_fdpic_map_file_constdisp_on_uclinux(
923         struct elf_fdpic_params *params,
924         struct file *file,
925         struct mm_struct *mm)
926 {
927         struct elf32_fdpic_loadseg *seg;
928         struct elf32_phdr *phdr;
929         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
930         loff_t fpos;
931         int loop, ret;
932
933         load_addr = params->load_addr;
934         seg = params->loadmap->segs;
935
936         /* determine the bounds of the contiguous overall allocation we must
937          * make */
938         phdr = params->phdrs;
939         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
940                 if (params->phdrs[loop].p_type != PT_LOAD)
941                         continue;
942
943                 if (base > phdr->p_vaddr)
944                         base = phdr->p_vaddr;
945                 if (top < phdr->p_vaddr + phdr->p_memsz)
946                         top = phdr->p_vaddr + phdr->p_memsz;
947         }
948
949         /* allocate one big anon block for everything */
950         mflags = MAP_PRIVATE;
951         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
952                 mflags |= MAP_EXECUTABLE;
953
954         maddr = vm_mmap(NULL, load_addr, top - base,
955                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
956         if (IS_ERR_VALUE(maddr))
957                 return (int) maddr;
958
959         if (load_addr != 0)
960                 load_addr += PAGE_ALIGN(top - base);
961
962         /* and then load the file segments into it */
963         phdr = params->phdrs;
964         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
965                 if (params->phdrs[loop].p_type != PT_LOAD)
966                         continue;
967
968                 fpos = phdr->p_offset;
969
970                 seg->addr = maddr + (phdr->p_vaddr - base);
971                 seg->p_vaddr = phdr->p_vaddr;
972                 seg->p_memsz = phdr->p_memsz;
973
974                 ret = file->f_op->read(file, (void *) seg->addr,
975                                        phdr->p_filesz, &fpos);
976                 if (ret < 0)
977                         return ret;
978
979                 /* map the ELF header address if in this segment */
980                 if (phdr->p_offset == 0)
981                         params->elfhdr_addr = seg->addr;
982
983                 /* clear any space allocated but not loaded */
984                 if (phdr->p_filesz < phdr->p_memsz) {
985                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
986                                        phdr->p_memsz - phdr->p_filesz))
987                                 return -EFAULT;
988                 }
989
990                 if (mm) {
991                         if (phdr->p_flags & PF_X) {
992                                 if (!mm->start_code) {
993                                         mm->start_code = seg->addr;
994                                         mm->end_code = seg->addr +
995                                                 phdr->p_memsz;
996                                 }
997                         } else if (!mm->start_data) {
998                                 mm->start_data = seg->addr;
999                                 mm->end_data = seg->addr + phdr->p_memsz;
1000                         }
1001                 }
1002
1003                 seg++;
1004         }
1005
1006         return 0;
1007 }
1008 #endif
1009
1010 /*****************************************************************************/
1011 /*
1012  * map a binary by direct mmap() of the individual PT_LOAD segments
1013  */
1014 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1015                                              struct file *file,
1016                                              struct mm_struct *mm)
1017 {
1018         struct elf32_fdpic_loadseg *seg;
1019         struct elf32_phdr *phdr;
1020         unsigned long load_addr, delta_vaddr;
1021         int loop, dvset;
1022
1023         load_addr = params->load_addr;
1024         delta_vaddr = 0;
1025         dvset = 0;
1026
1027         seg = params->loadmap->segs;
1028
1029         /* deal with each load segment separately */
1030         phdr = params->phdrs;
1031         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1032                 unsigned long maddr, disp, excess, excess1;
1033                 int prot = 0, flags;
1034
1035                 if (phdr->p_type != PT_LOAD)
1036                         continue;
1037
1038                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1039                        (unsigned long) phdr->p_vaddr,
1040                        (unsigned long) phdr->p_offset,
1041                        (unsigned long) phdr->p_filesz,
1042                        (unsigned long) phdr->p_memsz);
1043
1044                 /* determine the mapping parameters */
1045                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1046                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1047                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1048
1049                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1050                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1051                         flags |= MAP_EXECUTABLE;
1052
1053                 maddr = 0;
1054
1055                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1056                 case ELF_FDPIC_FLAG_INDEPENDENT:
1057                         /* PT_LOADs are independently locatable */
1058                         break;
1059
1060                 case ELF_FDPIC_FLAG_HONOURVADDR:
1061                         /* the specified virtual address must be honoured */
1062                         maddr = phdr->p_vaddr;
1063                         flags |= MAP_FIXED;
1064                         break;
1065
1066                 case ELF_FDPIC_FLAG_CONSTDISP:
1067                         /* constant displacement
1068                          * - can be mapped anywhere, but must be mapped as a
1069                          *   unit
1070                          */
1071                         if (!dvset) {
1072                                 maddr = load_addr;
1073                                 delta_vaddr = phdr->p_vaddr;
1074                                 dvset = 1;
1075                         } else {
1076                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1077                                 flags |= MAP_FIXED;
1078                         }
1079                         break;
1080
1081                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1082                         /* contiguity handled later */
1083                         break;
1084
1085                 default:
1086                         BUG();
1087                 }
1088
1089                 maddr &= PAGE_MASK;
1090
1091                 /* create the mapping */
1092                 disp = phdr->p_vaddr & ~PAGE_MASK;
1093                 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1094                                 phdr->p_offset - disp);
1095
1096                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1097                        loop, phdr->p_memsz + disp, prot, flags,
1098                        phdr->p_offset - disp, maddr);
1099
1100                 if (IS_ERR_VALUE(maddr))
1101                         return (int) maddr;
1102
1103                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1104                     ELF_FDPIC_FLAG_CONTIGUOUS)
1105                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1106
1107                 seg->addr = maddr + disp;
1108                 seg->p_vaddr = phdr->p_vaddr;
1109                 seg->p_memsz = phdr->p_memsz;
1110
1111                 /* map the ELF header address if in this segment */
1112                 if (phdr->p_offset == 0)
1113                         params->elfhdr_addr = seg->addr;
1114
1115                 /* clear the bit between beginning of mapping and beginning of
1116                  * PT_LOAD */
1117                 if (prot & PROT_WRITE && disp > 0) {
1118                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1119                         if (clear_user((void __user *) maddr, disp))
1120                                 return -EFAULT;
1121                         maddr += disp;
1122                 }
1123
1124                 /* clear any space allocated but not loaded
1125                  * - on uClinux we can just clear the lot
1126                  * - on MMU linux we'll get a SIGBUS beyond the last page
1127                  *   extant in the file
1128                  */
1129                 excess = phdr->p_memsz - phdr->p_filesz;
1130                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1131
1132 #ifdef CONFIG_MMU
1133                 if (excess > excess1) {
1134                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1135                         unsigned long xmaddr;
1136
1137                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1138                         xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1139                                          prot, flags, 0);
1140
1141                         kdebug("mmap[%d] <anon>"
1142                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1143                                loop, xaddr, excess - excess1, prot, flags,
1144                                xmaddr);
1145
1146                         if (xmaddr != xaddr)
1147                                 return -ENOMEM;
1148                 }
1149
1150                 if (prot & PROT_WRITE && excess1 > 0) {
1151                         kdebug("clear[%d] ad=%lx sz=%lx",
1152                                loop, maddr + phdr->p_filesz, excess1);
1153                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1154                                        excess1))
1155                                 return -EFAULT;
1156                 }
1157
1158 #else
1159                 if (excess > 0) {
1160                         kdebug("clear[%d] ad=%lx sz=%lx",
1161                                loop, maddr + phdr->p_filesz, excess);
1162                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1163                                 return -EFAULT;
1164                 }
1165 #endif
1166
1167                 if (mm) {
1168                         if (phdr->p_flags & PF_X) {
1169                                 if (!mm->start_code) {
1170                                         mm->start_code = maddr;
1171                                         mm->end_code = maddr + phdr->p_memsz;
1172                                 }
1173                         } else if (!mm->start_data) {
1174                                 mm->start_data = maddr;
1175                                 mm->end_data = maddr + phdr->p_memsz;
1176                         }
1177                 }
1178
1179                 seg++;
1180         }
1181
1182         return 0;
1183 }
1184
1185 /*****************************************************************************/
1186 /*
1187  * ELF-FDPIC core dumper
1188  *
1189  * Modelled on fs/exec.c:aout_core_dump()
1190  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1191  *
1192  * Modelled on fs/binfmt_elf.c core dumper
1193  */
1194 #ifdef CONFIG_ELF_CORE
1195
1196 /*
1197  * Decide whether a segment is worth dumping; default is yes to be
1198  * sure (missing info is worse than too much; etc).
1199  * Personally I'd include everything, and use the coredump limit...
1200  *
1201  * I think we should skip something. But I am not sure how. H.J.
1202  */
1203 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1204 {
1205         int dump_ok;
1206
1207         /* Do not dump I/O mapped devices or special mappings */
1208         if (vma->vm_flags & (VM_IO | VM_RESERVED)) {
1209                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1210                 return 0;
1211         }
1212
1213         /* If we may not read the contents, don't allow us to dump
1214          * them either. "dump_write()" can't handle it anyway.
1215          */
1216         if (!(vma->vm_flags & VM_READ)) {
1217                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1218                 return 0;
1219         }
1220
1221         /* By default, dump shared memory if mapped from an anonymous file. */
1222         if (vma->vm_flags & VM_SHARED) {
1223                 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0) {
1224                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1225                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1226                                vma->vm_flags, dump_ok ? "yes" : "no");
1227                         return dump_ok;
1228                 }
1229
1230                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1231                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1232                        vma->vm_flags, dump_ok ? "yes" : "no");
1233                 return dump_ok;
1234         }
1235
1236 #ifdef CONFIG_MMU
1237         /* By default, if it hasn't been written to, don't write it out */
1238         if (!vma->anon_vma) {
1239                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1240                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1241                        vma->vm_flags, dump_ok ? "yes" : "no");
1242                 return dump_ok;
1243         }
1244 #endif
1245
1246         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1247         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1248                dump_ok ? "yes" : "no");
1249         return dump_ok;
1250 }
1251
1252 /* An ELF note in memory */
1253 struct memelfnote
1254 {
1255         const char *name;
1256         int type;
1257         unsigned int datasz;
1258         void *data;
1259 };
1260
1261 static int notesize(struct memelfnote *en)
1262 {
1263         int sz;
1264
1265         sz = sizeof(struct elf_note);
1266         sz += roundup(strlen(en->name) + 1, 4);
1267         sz += roundup(en->datasz, 4);
1268
1269         return sz;
1270 }
1271
1272 /* #define DEBUG */
1273
1274 #define DUMP_WRITE(addr, nr, foffset)   \
1275         do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1276
1277 static int alignfile(struct file *file, loff_t *foffset)
1278 {
1279         static const char buf[4] = { 0, };
1280         DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1281         return 1;
1282 }
1283
1284 static int writenote(struct memelfnote *men, struct file *file,
1285                         loff_t *foffset)
1286 {
1287         struct elf_note en;
1288         en.n_namesz = strlen(men->name) + 1;
1289         en.n_descsz = men->datasz;
1290         en.n_type = men->type;
1291
1292         DUMP_WRITE(&en, sizeof(en), foffset);
1293         DUMP_WRITE(men->name, en.n_namesz, foffset);
1294         if (!alignfile(file, foffset))
1295                 return 0;
1296         DUMP_WRITE(men->data, men->datasz, foffset);
1297         if (!alignfile(file, foffset))
1298                 return 0;
1299
1300         return 1;
1301 }
1302 #undef DUMP_WRITE
1303
1304 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1305 {
1306         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1307         elf->e_ident[EI_CLASS] = ELF_CLASS;
1308         elf->e_ident[EI_DATA] = ELF_DATA;
1309         elf->e_ident[EI_VERSION] = EV_CURRENT;
1310         elf->e_ident[EI_OSABI] = ELF_OSABI;
1311         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1312
1313         elf->e_type = ET_CORE;
1314         elf->e_machine = ELF_ARCH;
1315         elf->e_version = EV_CURRENT;
1316         elf->e_entry = 0;
1317         elf->e_phoff = sizeof(struct elfhdr);
1318         elf->e_shoff = 0;
1319         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1320         elf->e_ehsize = sizeof(struct elfhdr);
1321         elf->e_phentsize = sizeof(struct elf_phdr);
1322         elf->e_phnum = segs;
1323         elf->e_shentsize = 0;
1324         elf->e_shnum = 0;
1325         elf->e_shstrndx = 0;
1326         return;
1327 }
1328
1329 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1330 {
1331         phdr->p_type = PT_NOTE;
1332         phdr->p_offset = offset;
1333         phdr->p_vaddr = 0;
1334         phdr->p_paddr = 0;
1335         phdr->p_filesz = sz;
1336         phdr->p_memsz = 0;
1337         phdr->p_flags = 0;
1338         phdr->p_align = 0;
1339         return;
1340 }
1341
1342 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1343                 unsigned int sz, void *data)
1344 {
1345         note->name = name;
1346         note->type = type;
1347         note->datasz = sz;
1348         note->data = data;
1349         return;
1350 }
1351
1352 /*
1353  * fill up all the fields in prstatus from the given task struct, except
1354  * registers which need to be filled up separately.
1355  */
1356 static void fill_prstatus(struct elf_prstatus *prstatus,
1357                           struct task_struct *p, long signr)
1358 {
1359         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1360         prstatus->pr_sigpend = p->pending.signal.sig[0];
1361         prstatus->pr_sighold = p->blocked.sig[0];
1362         rcu_read_lock();
1363         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1364         rcu_read_unlock();
1365         prstatus->pr_pid = task_pid_vnr(p);
1366         prstatus->pr_pgrp = task_pgrp_vnr(p);
1367         prstatus->pr_sid = task_session_vnr(p);
1368         if (thread_group_leader(p)) {
1369                 struct task_cputime cputime;
1370
1371                 /*
1372                  * This is the record for the group leader.  It shows the
1373                  * group-wide total, not its individual thread total.
1374                  */
1375                 thread_group_cputime(p, &cputime);
1376                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1377                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1378         } else {
1379                 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1380                 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1381         }
1382         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1383         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1384
1385         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1386         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1387 }
1388
1389 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1390                        struct mm_struct *mm)
1391 {
1392         const struct cred *cred;
1393         unsigned int i, len;
1394
1395         /* first copy the parameters from user space */
1396         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1397
1398         len = mm->arg_end - mm->arg_start;
1399         if (len >= ELF_PRARGSZ)
1400                 len = ELF_PRARGSZ - 1;
1401         if (copy_from_user(&psinfo->pr_psargs,
1402                            (const char __user *) mm->arg_start, len))
1403                 return -EFAULT;
1404         for (i = 0; i < len; i++)
1405                 if (psinfo->pr_psargs[i] == 0)
1406                         psinfo->pr_psargs[i] = ' ';
1407         psinfo->pr_psargs[len] = 0;
1408
1409         rcu_read_lock();
1410         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1411         rcu_read_unlock();
1412         psinfo->pr_pid = task_pid_vnr(p);
1413         psinfo->pr_pgrp = task_pgrp_vnr(p);
1414         psinfo->pr_sid = task_session_vnr(p);
1415
1416         i = p->state ? ffz(~p->state) + 1 : 0;
1417         psinfo->pr_state = i;
1418         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1419         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1420         psinfo->pr_nice = task_nice(p);
1421         psinfo->pr_flag = p->flags;
1422         rcu_read_lock();
1423         cred = __task_cred(p);
1424         SET_UID(psinfo->pr_uid, cred->uid);
1425         SET_GID(psinfo->pr_gid, cred->gid);
1426         rcu_read_unlock();
1427         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1428
1429         return 0;
1430 }
1431
1432 /* Here is the structure in which status of each thread is captured. */
1433 struct elf_thread_status
1434 {
1435         struct list_head list;
1436         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1437         elf_fpregset_t fpu;             /* NT_PRFPREG */
1438         struct task_struct *thread;
1439 #ifdef ELF_CORE_COPY_XFPREGS
1440         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1441 #endif
1442         struct memelfnote notes[3];
1443         int num_notes;
1444 };
1445
1446 /*
1447  * In order to add the specific thread information for the elf file format,
1448  * we need to keep a linked list of every thread's pr_status and then create
1449  * a single section for them in the final core file.
1450  */
1451 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1452 {
1453         struct task_struct *p = t->thread;
1454         int sz = 0;
1455
1456         t->num_notes = 0;
1457
1458         fill_prstatus(&t->prstatus, p, signr);
1459         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1460
1461         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1462                   &t->prstatus);
1463         t->num_notes++;
1464         sz += notesize(&t->notes[0]);
1465
1466         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1467         if (t->prstatus.pr_fpvalid) {
1468                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1469                           &t->fpu);
1470                 t->num_notes++;
1471                 sz += notesize(&t->notes[1]);
1472         }
1473
1474 #ifdef ELF_CORE_COPY_XFPREGS
1475         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1476                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1477                           sizeof(t->xfpu), &t->xfpu);
1478                 t->num_notes++;
1479                 sz += notesize(&t->notes[2]);
1480         }
1481 #endif
1482         return sz;
1483 }
1484
1485 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1486                              elf_addr_t e_shoff, int segs)
1487 {
1488         elf->e_shoff = e_shoff;
1489         elf->e_shentsize = sizeof(*shdr4extnum);
1490         elf->e_shnum = 1;
1491         elf->e_shstrndx = SHN_UNDEF;
1492
1493         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1494
1495         shdr4extnum->sh_type = SHT_NULL;
1496         shdr4extnum->sh_size = elf->e_shnum;
1497         shdr4extnum->sh_link = elf->e_shstrndx;
1498         shdr4extnum->sh_info = segs;
1499 }
1500
1501 /*
1502  * dump the segments for an MMU process
1503  */
1504 #ifdef CONFIG_MMU
1505 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1506                            unsigned long *limit, unsigned long mm_flags)
1507 {
1508         struct vm_area_struct *vma;
1509         int err = 0;
1510
1511         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1512                 unsigned long addr;
1513
1514                 if (!maydump(vma, mm_flags))
1515                         continue;
1516
1517                 for (addr = vma->vm_start; addr < vma->vm_end;
1518                                                         addr += PAGE_SIZE) {
1519                         struct page *page = get_dump_page(addr);
1520                         if (page) {
1521                                 void *kaddr = kmap(page);
1522                                 *size += PAGE_SIZE;
1523                                 if (*size > *limit)
1524                                         err = -EFBIG;
1525                                 else if (!dump_write(file, kaddr, PAGE_SIZE))
1526                                         err = -EIO;
1527                                 kunmap(page);
1528                                 page_cache_release(page);
1529                         } else if (!dump_seek(file, PAGE_SIZE))
1530                                 err = -EFBIG;
1531                         if (err)
1532                                 goto out;
1533                 }
1534         }
1535 out:
1536         return err;
1537 }
1538 #endif
1539
1540 /*
1541  * dump the segments for a NOMMU process
1542  */
1543 #ifndef CONFIG_MMU
1544 static int elf_fdpic_dump_segments(struct file *file, size_t *size,
1545                            unsigned long *limit, unsigned long mm_flags)
1546 {
1547         struct vm_area_struct *vma;
1548
1549         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1550                 if (!maydump(vma, mm_flags))
1551                         continue;
1552
1553                 if ((*size += PAGE_SIZE) > *limit)
1554                         return -EFBIG;
1555
1556                 if (!dump_write(file, (void *) vma->vm_start,
1557                                 vma->vm_end - vma->vm_start))
1558                         return -EIO;
1559         }
1560
1561         return 0;
1562 }
1563 #endif
1564
1565 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1566 {
1567         struct vm_area_struct *vma;
1568         size_t size = 0;
1569
1570         for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1571                 if (maydump(vma, mm_flags))
1572                         size += vma->vm_end - vma->vm_start;
1573         return size;
1574 }
1575
1576 /*
1577  * Actual dumper
1578  *
1579  * This is a two-pass process; first we find the offsets of the bits,
1580  * and then they are actually written out.  If we run out of core limit
1581  * we just truncate.
1582  */
1583 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1584 {
1585 #define NUM_NOTES       6
1586         int has_dumped = 0;
1587         mm_segment_t fs;
1588         int segs;
1589         size_t size = 0;
1590         int i;
1591         struct vm_area_struct *vma;
1592         struct elfhdr *elf = NULL;
1593         loff_t offset = 0, dataoff, foffset;
1594         int numnote;
1595         struct memelfnote *notes = NULL;
1596         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1597         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1598         LIST_HEAD(thread_list);
1599         struct list_head *t;
1600         elf_fpregset_t *fpu = NULL;
1601 #ifdef ELF_CORE_COPY_XFPREGS
1602         elf_fpxregset_t *xfpu = NULL;
1603 #endif
1604         int thread_status_size = 0;
1605         elf_addr_t *auxv;
1606         struct elf_phdr *phdr4note = NULL;
1607         struct elf_shdr *shdr4extnum = NULL;
1608         Elf_Half e_phnum;
1609         elf_addr_t e_shoff;
1610
1611         /*
1612          * We no longer stop all VM operations.
1613          *
1614          * This is because those proceses that could possibly change map_count
1615          * or the mmap / vma pages are now blocked in do_exit on current
1616          * finishing this core dump.
1617          *
1618          * Only ptrace can touch these memory addresses, but it doesn't change
1619          * the map_count or the pages allocated. So no possibility of crashing
1620          * exists while dumping the mm->vm_next areas to the core file.
1621          */
1622
1623         /* alloc memory for large data structures: too large to be on stack */
1624         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1625         if (!elf)
1626                 goto cleanup;
1627         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1628         if (!prstatus)
1629                 goto cleanup;
1630         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1631         if (!psinfo)
1632                 goto cleanup;
1633         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1634         if (!notes)
1635                 goto cleanup;
1636         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1637         if (!fpu)
1638                 goto cleanup;
1639 #ifdef ELF_CORE_COPY_XFPREGS
1640         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1641         if (!xfpu)
1642                 goto cleanup;
1643 #endif
1644
1645         if (cprm->signr) {
1646                 struct core_thread *ct;
1647                 struct elf_thread_status *tmp;
1648
1649                 for (ct = current->mm->core_state->dumper.next;
1650                                                 ct; ct = ct->next) {
1651                         tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1652                         if (!tmp)
1653                                 goto cleanup;
1654
1655                         tmp->thread = ct->task;
1656                         list_add(&tmp->list, &thread_list);
1657                 }
1658
1659                 list_for_each(t, &thread_list) {
1660                         struct elf_thread_status *tmp;
1661                         int sz;
1662
1663                         tmp = list_entry(t, struct elf_thread_status, list);
1664                         sz = elf_dump_thread_status(cprm->signr, tmp);
1665                         thread_status_size += sz;
1666                 }
1667         }
1668
1669         /* now collect the dump for the current */
1670         fill_prstatus(prstatus, current, cprm->signr);
1671         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1672
1673         segs = current->mm->map_count;
1674         segs += elf_core_extra_phdrs();
1675
1676         /* for notes section */
1677         segs++;
1678
1679         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1680          * this, kernel supports extended numbering. Have a look at
1681          * include/linux/elf.h for further information. */
1682         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1683
1684         /* Set up header */
1685         fill_elf_fdpic_header(elf, e_phnum);
1686
1687         has_dumped = 1;
1688         current->flags |= PF_DUMPCORE;
1689
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 */