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Merge tag 'rtc-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
[deliverable/linux.git] / fs / binfmt_elf_fdpic.c
1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
2 *
3 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * Derived from binfmt_elf.c
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
13 #include <linux/module.h>
14
15 #include <linux/fs.h>
16 #include <linux/stat.h>
17 #include <linux/sched.h>
18 #include <linux/mm.h>
19 #include <linux/mman.h>
20 #include <linux/errno.h>
21 #include <linux/signal.h>
22 #include <linux/binfmts.h>
23 #include <linux/string.h>
24 #include <linux/file.h>
25 #include <linux/fcntl.h>
26 #include <linux/slab.h>
27 #include <linux/pagemap.h>
28 #include <linux/security.h>
29 #include <linux/highmem.h>
30 #include <linux/highuid.h>
31 #include <linux/personality.h>
32 #include <linux/ptrace.h>
33 #include <linux/init.h>
34 #include <linux/elf.h>
35 #include <linux/elf-fdpic.h>
36 #include <linux/elfcore.h>
37 #include <linux/coredump.h>
38
39 #include <asm/uaccess.h>
40 #include <asm/param.h>
41 #include <asm/pgalloc.h>
42
43 typedef char *elf_caddr_t;
44
45 #if 0
46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
47 #else
48 #define kdebug(fmt, ...) do {} while(0)
49 #endif
50
51 #if 0
52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
53 #else
54 #define kdcore(fmt, ...) do {} while(0)
55 #endif
56
57 MODULE_LICENSE("GPL");
58
59 static int load_elf_fdpic_binary(struct linux_binprm *);
60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
62 struct mm_struct *, const char *);
63
64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
65 struct elf_fdpic_params *,
66 struct elf_fdpic_params *);
67
68 #ifndef CONFIG_MMU
69 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
70 unsigned long *);
71 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
72 struct file *,
73 struct mm_struct *);
74 #endif
75
76 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
77 struct file *, struct mm_struct *);
78
79 #ifdef CONFIG_ELF_CORE
80 static int elf_fdpic_core_dump(struct coredump_params *cprm);
81 #endif
82
83 static struct linux_binfmt elf_fdpic_format = {
84 .module = THIS_MODULE,
85 .load_binary = load_elf_fdpic_binary,
86 #ifdef CONFIG_ELF_CORE
87 .core_dump = elf_fdpic_core_dump,
88 #endif
89 .min_coredump = ELF_EXEC_PAGESIZE,
90 };
91
92 static int __init init_elf_fdpic_binfmt(void)
93 {
94 register_binfmt(&elf_fdpic_format);
95 return 0;
96 }
97
98 static void __exit exit_elf_fdpic_binfmt(void)
99 {
100 unregister_binfmt(&elf_fdpic_format);
101 }
102
103 core_initcall(init_elf_fdpic_binfmt);
104 module_exit(exit_elf_fdpic_binfmt);
105
106 static int is_elf(struct elfhdr *hdr, struct file *file)
107 {
108 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
109 return 0;
110 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
111 return 0;
112 if (!elf_check_arch(hdr))
113 return 0;
114 if (!file->f_op->mmap)
115 return 0;
116 return 1;
117 }
118
119 #ifndef elf_check_fdpic
120 #define elf_check_fdpic(x) 0
121 #endif
122
123 #ifndef elf_check_const_displacement
124 #define elf_check_const_displacement(x) 0
125 #endif
126
127 static int is_constdisp(struct elfhdr *hdr)
128 {
129 if (!elf_check_fdpic(hdr))
130 return 1;
131 if (elf_check_const_displacement(hdr))
132 return 1;
133 return 0;
134 }
135
136 /*****************************************************************************/
137 /*
138 * read the program headers table into memory
139 */
140 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
141 struct file *file)
142 {
143 struct elf32_phdr *phdr;
144 unsigned long size;
145 int retval, loop;
146
147 if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
148 return -ENOMEM;
149 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
150 return -ENOMEM;
151
152 size = params->hdr.e_phnum * sizeof(struct elf_phdr);
153 params->phdrs = kmalloc(size, GFP_KERNEL);
154 if (!params->phdrs)
155 return -ENOMEM;
156
157 retval = kernel_read(file, params->hdr.e_phoff,
158 (char *) params->phdrs, size);
159 if (unlikely(retval != size))
160 return retval < 0 ? retval : -ENOEXEC;
161
162 /* determine stack size for this binary */
163 phdr = params->phdrs;
164 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
165 if (phdr->p_type != PT_GNU_STACK)
166 continue;
167
168 if (phdr->p_flags & PF_X)
169 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
170 else
171 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
172
173 params->stack_size = phdr->p_memsz;
174 break;
175 }
176
177 return 0;
178 }
179
180 /*****************************************************************************/
181 /*
182 * load an fdpic binary into various bits of memory
183 */
184 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
185 {
186 struct elf_fdpic_params exec_params, interp_params;
187 struct pt_regs *regs = current_pt_regs();
188 struct elf_phdr *phdr;
189 unsigned long stack_size, entryaddr;
190 #ifdef ELF_FDPIC_PLAT_INIT
191 unsigned long dynaddr;
192 #endif
193 #ifndef CONFIG_MMU
194 unsigned long stack_prot;
195 #endif
196 struct file *interpreter = NULL; /* to shut gcc up */
197 char *interpreter_name = NULL;
198 int executable_stack;
199 int retval, i;
200
201 kdebug("____ LOAD %d ____", current->pid);
202
203 memset(&exec_params, 0, sizeof(exec_params));
204 memset(&interp_params, 0, sizeof(interp_params));
205
206 exec_params.hdr = *(struct elfhdr *) bprm->buf;
207 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
208
209 /* check that this is a binary we know how to deal with */
210 retval = -ENOEXEC;
211 if (!is_elf(&exec_params.hdr, bprm->file))
212 goto error;
213 if (!elf_check_fdpic(&exec_params.hdr)) {
214 #ifdef CONFIG_MMU
215 /* binfmt_elf handles non-fdpic elf except on nommu */
216 goto error;
217 #else
218 /* nommu can only load ET_DYN (PIE) ELF */
219 if (exec_params.hdr.e_type != ET_DYN)
220 goto error;
221 #endif
222 }
223
224 /* read the program header table */
225 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
226 if (retval < 0)
227 goto error;
228
229 /* scan for a program header that specifies an interpreter */
230 phdr = exec_params.phdrs;
231
232 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
233 switch (phdr->p_type) {
234 case PT_INTERP:
235 retval = -ENOMEM;
236 if (phdr->p_filesz > PATH_MAX)
237 goto error;
238 retval = -ENOENT;
239 if (phdr->p_filesz < 2)
240 goto error;
241
242 /* read the name of the interpreter into memory */
243 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
244 if (!interpreter_name)
245 goto error;
246
247 retval = kernel_read(bprm->file,
248 phdr->p_offset,
249 interpreter_name,
250 phdr->p_filesz);
251 if (unlikely(retval != phdr->p_filesz)) {
252 if (retval >= 0)
253 retval = -ENOEXEC;
254 goto error;
255 }
256
257 retval = -ENOENT;
258 if (interpreter_name[phdr->p_filesz - 1] != '\0')
259 goto error;
260
261 kdebug("Using ELF interpreter %s", interpreter_name);
262
263 /* replace the program with the interpreter */
264 interpreter = open_exec(interpreter_name);
265 retval = PTR_ERR(interpreter);
266 if (IS_ERR(interpreter)) {
267 interpreter = NULL;
268 goto error;
269 }
270
271 /*
272 * If the binary is not readable then enforce
273 * mm->dumpable = 0 regardless of the interpreter's
274 * permissions.
275 */
276 would_dump(bprm, interpreter);
277
278 retval = kernel_read(interpreter, 0, bprm->buf,
279 BINPRM_BUF_SIZE);
280 if (unlikely(retval != BINPRM_BUF_SIZE)) {
281 if (retval >= 0)
282 retval = -ENOEXEC;
283 goto error;
284 }
285
286 interp_params.hdr = *((struct elfhdr *) bprm->buf);
287 break;
288
289 case PT_LOAD:
290 #ifdef CONFIG_MMU
291 if (exec_params.load_addr == 0)
292 exec_params.load_addr = phdr->p_vaddr;
293 #endif
294 break;
295 }
296
297 }
298
299 if (is_constdisp(&exec_params.hdr))
300 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
301
302 /* perform insanity checks on the interpreter */
303 if (interpreter_name) {
304 retval = -ELIBBAD;
305 if (!is_elf(&interp_params.hdr, interpreter))
306 goto error;
307
308 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
309
310 /* read the interpreter's program header table */
311 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
312 if (retval < 0)
313 goto error;
314 }
315
316 stack_size = exec_params.stack_size;
317 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
318 executable_stack = EXSTACK_ENABLE_X;
319 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
320 executable_stack = EXSTACK_DISABLE_X;
321 else
322 executable_stack = EXSTACK_DEFAULT;
323
324 if (stack_size == 0) {
325 stack_size = interp_params.stack_size;
326 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
327 executable_stack = EXSTACK_ENABLE_X;
328 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
329 executable_stack = EXSTACK_DISABLE_X;
330 else
331 executable_stack = EXSTACK_DEFAULT;
332 }
333
334 retval = -ENOEXEC;
335 if (stack_size == 0)
336 stack_size = 131072UL; /* same as exec.c's default commit */
337
338 if (is_constdisp(&interp_params.hdr))
339 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
340
341 /* flush all traces of the currently running executable */
342 retval = flush_old_exec(bprm);
343 if (retval)
344 goto error;
345
346 /* there's now no turning back... the old userspace image is dead,
347 * defunct, deceased, etc.
348 */
349 if (elf_check_fdpic(&exec_params.hdr))
350 set_personality(PER_LINUX_FDPIC);
351 else
352 set_personality(PER_LINUX);
353 if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
354 current->personality |= READ_IMPLIES_EXEC;
355
356 setup_new_exec(bprm);
357
358 set_binfmt(&elf_fdpic_format);
359
360 current->mm->start_code = 0;
361 current->mm->end_code = 0;
362 current->mm->start_stack = 0;
363 current->mm->start_data = 0;
364 current->mm->end_data = 0;
365 current->mm->context.exec_fdpic_loadmap = 0;
366 current->mm->context.interp_fdpic_loadmap = 0;
367
368 #ifdef CONFIG_MMU
369 elf_fdpic_arch_lay_out_mm(&exec_params,
370 &interp_params,
371 &current->mm->start_stack,
372 &current->mm->start_brk);
373
374 retval = setup_arg_pages(bprm, current->mm->start_stack,
375 executable_stack);
376 if (retval < 0)
377 goto error;
378 #endif
379
380 /* load the executable and interpreter into memory */
381 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
382 "executable");
383 if (retval < 0)
384 goto error;
385
386 if (interpreter_name) {
387 retval = elf_fdpic_map_file(&interp_params, interpreter,
388 current->mm, "interpreter");
389 if (retval < 0) {
390 printk(KERN_ERR "Unable to load interpreter\n");
391 goto error;
392 }
393
394 allow_write_access(interpreter);
395 fput(interpreter);
396 interpreter = NULL;
397 }
398
399 #ifdef CONFIG_MMU
400 if (!current->mm->start_brk)
401 current->mm->start_brk = current->mm->end_data;
402
403 current->mm->brk = current->mm->start_brk =
404 PAGE_ALIGN(current->mm->start_brk);
405
406 #else
407 /* create a stack area and zero-size brk area */
408 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
409 if (stack_size < PAGE_SIZE * 2)
410 stack_size = PAGE_SIZE * 2;
411
412 stack_prot = PROT_READ | PROT_WRITE;
413 if (executable_stack == EXSTACK_ENABLE_X ||
414 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
415 stack_prot |= PROT_EXEC;
416
417 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
418 MAP_PRIVATE | MAP_ANONYMOUS |
419 MAP_UNINITIALIZED | MAP_GROWSDOWN,
420 0);
421
422 if (IS_ERR_VALUE(current->mm->start_brk)) {
423 retval = current->mm->start_brk;
424 current->mm->start_brk = 0;
425 goto error;
426 }
427
428 current->mm->brk = current->mm->start_brk;
429 current->mm->context.end_brk = current->mm->start_brk;
430 current->mm->start_stack = current->mm->start_brk + stack_size;
431 #endif
432
433 install_exec_creds(bprm);
434 if (create_elf_fdpic_tables(bprm, current->mm,
435 &exec_params, &interp_params) < 0)
436 goto error;
437
438 kdebug("- start_code %lx", current->mm->start_code);
439 kdebug("- end_code %lx", current->mm->end_code);
440 kdebug("- start_data %lx", current->mm->start_data);
441 kdebug("- end_data %lx", current->mm->end_data);
442 kdebug("- start_brk %lx", current->mm->start_brk);
443 kdebug("- brk %lx", current->mm->brk);
444 kdebug("- start_stack %lx", current->mm->start_stack);
445
446 #ifdef ELF_FDPIC_PLAT_INIT
447 /*
448 * The ABI may specify that certain registers be set up in special
449 * ways (on i386 %edx is the address of a DT_FINI function, for
450 * example. This macro performs whatever initialization to
451 * the regs structure is required.
452 */
453 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
454 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
455 dynaddr);
456 #endif
457
458 /* everything is now ready... get the userspace context ready to roll */
459 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
460 start_thread(regs, entryaddr, current->mm->start_stack);
461
462 retval = 0;
463
464 error:
465 if (interpreter) {
466 allow_write_access(interpreter);
467 fput(interpreter);
468 }
469 kfree(interpreter_name);
470 kfree(exec_params.phdrs);
471 kfree(exec_params.loadmap);
472 kfree(interp_params.phdrs);
473 kfree(interp_params.loadmap);
474 return retval;
475 }
476
477 /*****************************************************************************/
478
479 #ifndef ELF_BASE_PLATFORM
480 /*
481 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
482 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
483 * will be copied to the user stack in the same manner as AT_PLATFORM.
484 */
485 #define ELF_BASE_PLATFORM NULL
486 #endif
487
488 /*
489 * present useful information to the program by shovelling it onto the new
490 * process's stack
491 */
492 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
493 struct mm_struct *mm,
494 struct elf_fdpic_params *exec_params,
495 struct elf_fdpic_params *interp_params)
496 {
497 const struct cred *cred = current_cred();
498 unsigned long sp, csp, nitems;
499 elf_caddr_t __user *argv, *envp;
500 size_t platform_len = 0, len;
501 char *k_platform, *k_base_platform;
502 char __user *u_platform, *u_base_platform, *p;
503 int loop;
504 int nr; /* reset for each csp adjustment */
505
506 #ifdef CONFIG_MMU
507 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
508 * by the processes running on the same package. One thing we can do is
509 * to shuffle the initial stack for them, so we give the architecture
510 * an opportunity to do so here.
511 */
512 sp = arch_align_stack(bprm->p);
513 #else
514 sp = mm->start_stack;
515
516 /* stack the program arguments and environment */
517 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
518 return -EFAULT;
519 #endif
520
521 /*
522 * If this architecture has a platform capability string, copy it
523 * to userspace. In some cases (Sparc), this info is impossible
524 * for userspace to get any other way, in others (i386) it is
525 * merely difficult.
526 */
527 k_platform = ELF_PLATFORM;
528 u_platform = NULL;
529
530 if (k_platform) {
531 platform_len = strlen(k_platform) + 1;
532 sp -= platform_len;
533 u_platform = (char __user *) sp;
534 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
535 return -EFAULT;
536 }
537
538 /*
539 * If this architecture has a "base" platform capability
540 * string, copy it to userspace.
541 */
542 k_base_platform = ELF_BASE_PLATFORM;
543 u_base_platform = NULL;
544
545 if (k_base_platform) {
546 platform_len = strlen(k_base_platform) + 1;
547 sp -= platform_len;
548 u_base_platform = (char __user *) sp;
549 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
550 return -EFAULT;
551 }
552
553 sp &= ~7UL;
554
555 /* stack the load map(s) */
556 len = sizeof(struct elf32_fdpic_loadmap);
557 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
558 sp = (sp - len) & ~7UL;
559 exec_params->map_addr = sp;
560
561 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
562 return -EFAULT;
563
564 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
565
566 if (interp_params->loadmap) {
567 len = sizeof(struct elf32_fdpic_loadmap);
568 len += sizeof(struct elf32_fdpic_loadseg) *
569 interp_params->loadmap->nsegs;
570 sp = (sp - len) & ~7UL;
571 interp_params->map_addr = sp;
572
573 if (copy_to_user((void __user *) sp, interp_params->loadmap,
574 len) != 0)
575 return -EFAULT;
576
577 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
578 }
579
580 /* force 16 byte _final_ alignment here for generality */
581 #define DLINFO_ITEMS 15
582
583 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
584 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
585
586 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
587 nitems++;
588
589 csp = sp;
590 sp -= nitems * 2 * sizeof(unsigned long);
591 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
592 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
593 sp -= 1 * sizeof(unsigned long); /* argc */
594
595 csp -= sp & 15UL;
596 sp -= sp & 15UL;
597
598 /* put the ELF interpreter info on the stack */
599 #define NEW_AUX_ENT(id, val) \
600 do { \
601 struct { unsigned long _id, _val; } __user *ent; \
602 \
603 ent = (void __user *) csp; \
604 __put_user((id), &ent[nr]._id); \
605 __put_user((val), &ent[nr]._val); \
606 nr++; \
607 } while (0)
608
609 nr = 0;
610 csp -= 2 * sizeof(unsigned long);
611 NEW_AUX_ENT(AT_NULL, 0);
612 if (k_platform) {
613 nr = 0;
614 csp -= 2 * sizeof(unsigned long);
615 NEW_AUX_ENT(AT_PLATFORM,
616 (elf_addr_t) (unsigned long) u_platform);
617 }
618
619 if (k_base_platform) {
620 nr = 0;
621 csp -= 2 * sizeof(unsigned long);
622 NEW_AUX_ENT(AT_BASE_PLATFORM,
623 (elf_addr_t) (unsigned long) u_base_platform);
624 }
625
626 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
627 nr = 0;
628 csp -= 2 * sizeof(unsigned long);
629 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
630 }
631
632 nr = 0;
633 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
634 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
635 #ifdef ELF_HWCAP2
636 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
637 #endif
638 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
639 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
640 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
641 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
642 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
643 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
644 NEW_AUX_ENT(AT_FLAGS, 0);
645 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
646 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
647 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
648 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
649 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
650 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
651 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
652
653 #ifdef ARCH_DLINFO
654 nr = 0;
655 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
656
657 /* ARCH_DLINFO must come last so platform specific code can enforce
658 * special alignment requirements on the AUXV if necessary (eg. PPC).
659 */
660 ARCH_DLINFO;
661 #endif
662 #undef NEW_AUX_ENT
663
664 /* allocate room for argv[] and envv[] */
665 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
666 envp = (elf_caddr_t __user *) csp;
667 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
668 argv = (elf_caddr_t __user *) csp;
669
670 /* stack argc */
671 csp -= sizeof(unsigned long);
672 __put_user(bprm->argc, (unsigned long __user *) csp);
673
674 BUG_ON(csp != sp);
675
676 /* fill in the argv[] array */
677 #ifdef CONFIG_MMU
678 current->mm->arg_start = bprm->p;
679 #else
680 current->mm->arg_start = current->mm->start_stack -
681 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
682 #endif
683
684 p = (char __user *) current->mm->arg_start;
685 for (loop = bprm->argc; loop > 0; loop--) {
686 __put_user((elf_caddr_t) p, argv++);
687 len = strnlen_user(p, MAX_ARG_STRLEN);
688 if (!len || len > MAX_ARG_STRLEN)
689 return -EINVAL;
690 p += len;
691 }
692 __put_user(NULL, argv);
693 current->mm->arg_end = (unsigned long) p;
694
695 /* fill in the envv[] array */
696 current->mm->env_start = (unsigned long) p;
697 for (loop = bprm->envc; loop > 0; loop--) {
698 __put_user((elf_caddr_t)(unsigned long) p, envp++);
699 len = strnlen_user(p, MAX_ARG_STRLEN);
700 if (!len || len > MAX_ARG_STRLEN)
701 return -EINVAL;
702 p += len;
703 }
704 __put_user(NULL, envp);
705 current->mm->env_end = (unsigned long) p;
706
707 mm->start_stack = (unsigned long) sp;
708 return 0;
709 }
710
711 /*****************************************************************************/
712 /*
713 * transfer the program arguments and environment from the holding pages onto
714 * the stack
715 */
716 #ifndef CONFIG_MMU
717 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
718 unsigned long *_sp)
719 {
720 unsigned long index, stop, sp;
721 char *src;
722 int ret = 0;
723
724 stop = bprm->p >> PAGE_SHIFT;
725 sp = *_sp;
726
727 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
728 src = kmap(bprm->page[index]);
729 sp -= PAGE_SIZE;
730 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
731 ret = -EFAULT;
732 kunmap(bprm->page[index]);
733 if (ret < 0)
734 goto out;
735 }
736
737 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
738
739 out:
740 return ret;
741 }
742 #endif
743
744 /*****************************************************************************/
745 /*
746 * load the appropriate binary image (executable or interpreter) into memory
747 * - we assume no MMU is available
748 * - if no other PIC bits are set in params->hdr->e_flags
749 * - we assume that the LOADable segments in the binary are independently relocatable
750 * - we assume R/O executable segments are shareable
751 * - else
752 * - we assume the loadable parts of the image to require fixed displacement
753 * - the image is not shareable
754 */
755 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
756 struct file *file,
757 struct mm_struct *mm,
758 const char *what)
759 {
760 struct elf32_fdpic_loadmap *loadmap;
761 #ifdef CONFIG_MMU
762 struct elf32_fdpic_loadseg *mseg;
763 #endif
764 struct elf32_fdpic_loadseg *seg;
765 struct elf32_phdr *phdr;
766 unsigned long load_addr, stop;
767 unsigned nloads, tmp;
768 size_t size;
769 int loop, ret;
770
771 /* allocate a load map table */
772 nloads = 0;
773 for (loop = 0; loop < params->hdr.e_phnum; loop++)
774 if (params->phdrs[loop].p_type == PT_LOAD)
775 nloads++;
776
777 if (nloads == 0)
778 return -ELIBBAD;
779
780 size = sizeof(*loadmap) + nloads * sizeof(*seg);
781 loadmap = kzalloc(size, GFP_KERNEL);
782 if (!loadmap)
783 return -ENOMEM;
784
785 params->loadmap = loadmap;
786
787 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
788 loadmap->nsegs = nloads;
789
790 load_addr = params->load_addr;
791 seg = loadmap->segs;
792
793 /* map the requested LOADs into the memory space */
794 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
795 case ELF_FDPIC_FLAG_CONSTDISP:
796 case ELF_FDPIC_FLAG_CONTIGUOUS:
797 #ifndef CONFIG_MMU
798 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
799 if (ret < 0)
800 return ret;
801 break;
802 #endif
803 default:
804 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
805 if (ret < 0)
806 return ret;
807 break;
808 }
809
810 /* map the entry point */
811 if (params->hdr.e_entry) {
812 seg = loadmap->segs;
813 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
814 if (params->hdr.e_entry >= seg->p_vaddr &&
815 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
816 params->entry_addr =
817 (params->hdr.e_entry - seg->p_vaddr) +
818 seg->addr;
819 break;
820 }
821 }
822 }
823
824 /* determine where the program header table has wound up if mapped */
825 stop = params->hdr.e_phoff;
826 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
827 phdr = params->phdrs;
828
829 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
830 if (phdr->p_type != PT_LOAD)
831 continue;
832
833 if (phdr->p_offset > params->hdr.e_phoff ||
834 phdr->p_offset + phdr->p_filesz < stop)
835 continue;
836
837 seg = loadmap->segs;
838 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
839 if (phdr->p_vaddr >= seg->p_vaddr &&
840 phdr->p_vaddr + phdr->p_filesz <=
841 seg->p_vaddr + seg->p_memsz) {
842 params->ph_addr =
843 (phdr->p_vaddr - seg->p_vaddr) +
844 seg->addr +
845 params->hdr.e_phoff - phdr->p_offset;
846 break;
847 }
848 }
849 break;
850 }
851
852 /* determine where the dynamic section has wound up if there is one */
853 phdr = params->phdrs;
854 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
855 if (phdr->p_type != PT_DYNAMIC)
856 continue;
857
858 seg = loadmap->segs;
859 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
860 if (phdr->p_vaddr >= seg->p_vaddr &&
861 phdr->p_vaddr + phdr->p_memsz <=
862 seg->p_vaddr + seg->p_memsz) {
863 params->dynamic_addr =
864 (phdr->p_vaddr - seg->p_vaddr) +
865 seg->addr;
866
867 /* check the dynamic section contains at least
868 * one item, and that the last item is a NULL
869 * entry */
870 if (phdr->p_memsz == 0 ||
871 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
872 goto dynamic_error;
873
874 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
875 if (((Elf32_Dyn *)
876 params->dynamic_addr)[tmp - 1].d_tag != 0)
877 goto dynamic_error;
878 break;
879 }
880 }
881 break;
882 }
883
884 /* now elide adjacent segments in the load map on MMU linux
885 * - on uClinux the holes between may actually be filled with system
886 * stuff or stuff from other processes
887 */
888 #ifdef CONFIG_MMU
889 nloads = loadmap->nsegs;
890 mseg = loadmap->segs;
891 seg = mseg + 1;
892 for (loop = 1; loop < nloads; loop++) {
893 /* see if we have a candidate for merging */
894 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
895 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
896 if (load_addr == (seg->addr & PAGE_MASK)) {
897 mseg->p_memsz +=
898 load_addr -
899 (mseg->addr + mseg->p_memsz);
900 mseg->p_memsz += seg->addr & ~PAGE_MASK;
901 mseg->p_memsz += seg->p_memsz;
902 loadmap->nsegs--;
903 continue;
904 }
905 }
906
907 mseg++;
908 if (mseg != seg)
909 *mseg = *seg;
910 }
911 #endif
912
913 kdebug("Mapped Object [%s]:", what);
914 kdebug("- elfhdr : %lx", params->elfhdr_addr);
915 kdebug("- entry : %lx", params->entry_addr);
916 kdebug("- PHDR[] : %lx", params->ph_addr);
917 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
918 seg = loadmap->segs;
919 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
920 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
921 loop,
922 seg->addr, seg->addr + seg->p_memsz - 1,
923 seg->p_vaddr, seg->p_memsz);
924
925 return 0;
926
927 dynamic_error:
928 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
929 what, file_inode(file)->i_ino);
930 return -ELIBBAD;
931 }
932
933 /*****************************************************************************/
934 /*
935 * map a file with constant displacement under uClinux
936 */
937 #ifndef CONFIG_MMU
938 static int elf_fdpic_map_file_constdisp_on_uclinux(
939 struct elf_fdpic_params *params,
940 struct file *file,
941 struct mm_struct *mm)
942 {
943 struct elf32_fdpic_loadseg *seg;
944 struct elf32_phdr *phdr;
945 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
946 int loop, ret;
947
948 load_addr = params->load_addr;
949 seg = params->loadmap->segs;
950
951 /* determine the bounds of the contiguous overall allocation we must
952 * make */
953 phdr = params->phdrs;
954 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
955 if (params->phdrs[loop].p_type != PT_LOAD)
956 continue;
957
958 if (base > phdr->p_vaddr)
959 base = phdr->p_vaddr;
960 if (top < phdr->p_vaddr + phdr->p_memsz)
961 top = phdr->p_vaddr + phdr->p_memsz;
962 }
963
964 /* allocate one big anon block for everything */
965 mflags = MAP_PRIVATE;
966 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
967 mflags |= MAP_EXECUTABLE;
968
969 maddr = vm_mmap(NULL, load_addr, top - base,
970 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
971 if (IS_ERR_VALUE(maddr))
972 return (int) maddr;
973
974 if (load_addr != 0)
975 load_addr += PAGE_ALIGN(top - base);
976
977 /* and then load the file segments into it */
978 phdr = params->phdrs;
979 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
980 if (params->phdrs[loop].p_type != PT_LOAD)
981 continue;
982
983 seg->addr = maddr + (phdr->p_vaddr - base);
984 seg->p_vaddr = phdr->p_vaddr;
985 seg->p_memsz = phdr->p_memsz;
986
987 ret = read_code(file, seg->addr, phdr->p_offset,
988 phdr->p_filesz);
989 if (ret < 0)
990 return ret;
991
992 /* map the ELF header address if in this segment */
993 if (phdr->p_offset == 0)
994 params->elfhdr_addr = seg->addr;
995
996 /* clear any space allocated but not loaded */
997 if (phdr->p_filesz < phdr->p_memsz) {
998 if (clear_user((void *) (seg->addr + phdr->p_filesz),
999 phdr->p_memsz - phdr->p_filesz))
1000 return -EFAULT;
1001 }
1002
1003 if (mm) {
1004 if (phdr->p_flags & PF_X) {
1005 if (!mm->start_code) {
1006 mm->start_code = seg->addr;
1007 mm->end_code = seg->addr +
1008 phdr->p_memsz;
1009 }
1010 } else if (!mm->start_data) {
1011 mm->start_data = seg->addr;
1012 mm->end_data = seg->addr + phdr->p_memsz;
1013 }
1014 }
1015
1016 seg++;
1017 }
1018
1019 return 0;
1020 }
1021 #endif
1022
1023 /*****************************************************************************/
1024 /*
1025 * map a binary by direct mmap() of the individual PT_LOAD segments
1026 */
1027 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1028 struct file *file,
1029 struct mm_struct *mm)
1030 {
1031 struct elf32_fdpic_loadseg *seg;
1032 struct elf32_phdr *phdr;
1033 unsigned long load_addr, delta_vaddr;
1034 int loop, dvset;
1035
1036 load_addr = params->load_addr;
1037 delta_vaddr = 0;
1038 dvset = 0;
1039
1040 seg = params->loadmap->segs;
1041
1042 /* deal with each load segment separately */
1043 phdr = params->phdrs;
1044 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1045 unsigned long maddr, disp, excess, excess1;
1046 int prot = 0, flags;
1047
1048 if (phdr->p_type != PT_LOAD)
1049 continue;
1050
1051 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1052 (unsigned long) phdr->p_vaddr,
1053 (unsigned long) phdr->p_offset,
1054 (unsigned long) phdr->p_filesz,
1055 (unsigned long) phdr->p_memsz);
1056
1057 /* determine the mapping parameters */
1058 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1059 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1060 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1061
1062 flags = MAP_PRIVATE | MAP_DENYWRITE;
1063 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1064 flags |= MAP_EXECUTABLE;
1065
1066 maddr = 0;
1067
1068 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1069 case ELF_FDPIC_FLAG_INDEPENDENT:
1070 /* PT_LOADs are independently locatable */
1071 break;
1072
1073 case ELF_FDPIC_FLAG_HONOURVADDR:
1074 /* the specified virtual address must be honoured */
1075 maddr = phdr->p_vaddr;
1076 flags |= MAP_FIXED;
1077 break;
1078
1079 case ELF_FDPIC_FLAG_CONSTDISP:
1080 /* constant displacement
1081 * - can be mapped anywhere, but must be mapped as a
1082 * unit
1083 */
1084 if (!dvset) {
1085 maddr = load_addr;
1086 delta_vaddr = phdr->p_vaddr;
1087 dvset = 1;
1088 } else {
1089 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1090 flags |= MAP_FIXED;
1091 }
1092 break;
1093
1094 case ELF_FDPIC_FLAG_CONTIGUOUS:
1095 /* contiguity handled later */
1096 break;
1097
1098 default:
1099 BUG();
1100 }
1101
1102 maddr &= PAGE_MASK;
1103
1104 /* create the mapping */
1105 disp = phdr->p_vaddr & ~PAGE_MASK;
1106 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1107 phdr->p_offset - disp);
1108
1109 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1110 loop, phdr->p_memsz + disp, prot, flags,
1111 phdr->p_offset - disp, maddr);
1112
1113 if (IS_ERR_VALUE(maddr))
1114 return (int) maddr;
1115
1116 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1117 ELF_FDPIC_FLAG_CONTIGUOUS)
1118 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1119
1120 seg->addr = maddr + disp;
1121 seg->p_vaddr = phdr->p_vaddr;
1122 seg->p_memsz = phdr->p_memsz;
1123
1124 /* map the ELF header address if in this segment */
1125 if (phdr->p_offset == 0)
1126 params->elfhdr_addr = seg->addr;
1127
1128 /* clear the bit between beginning of mapping and beginning of
1129 * PT_LOAD */
1130 if (prot & PROT_WRITE && disp > 0) {
1131 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1132 if (clear_user((void __user *) maddr, disp))
1133 return -EFAULT;
1134 maddr += disp;
1135 }
1136
1137 /* clear any space allocated but not loaded
1138 * - on uClinux we can just clear the lot
1139 * - on MMU linux we'll get a SIGBUS beyond the last page
1140 * extant in the file
1141 */
1142 excess = phdr->p_memsz - phdr->p_filesz;
1143 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1144
1145 #ifdef CONFIG_MMU
1146 if (excess > excess1) {
1147 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1148 unsigned long xmaddr;
1149
1150 flags |= MAP_FIXED | MAP_ANONYMOUS;
1151 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1152 prot, flags, 0);
1153
1154 kdebug("mmap[%d] <anon>"
1155 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1156 loop, xaddr, excess - excess1, prot, flags,
1157 xmaddr);
1158
1159 if (xmaddr != xaddr)
1160 return -ENOMEM;
1161 }
1162
1163 if (prot & PROT_WRITE && excess1 > 0) {
1164 kdebug("clear[%d] ad=%lx sz=%lx",
1165 loop, maddr + phdr->p_filesz, excess1);
1166 if (clear_user((void __user *) maddr + phdr->p_filesz,
1167 excess1))
1168 return -EFAULT;
1169 }
1170
1171 #else
1172 if (excess > 0) {
1173 kdebug("clear[%d] ad=%lx sz=%lx",
1174 loop, maddr + phdr->p_filesz, excess);
1175 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1176 return -EFAULT;
1177 }
1178 #endif
1179
1180 if (mm) {
1181 if (phdr->p_flags & PF_X) {
1182 if (!mm->start_code) {
1183 mm->start_code = maddr;
1184 mm->end_code = maddr + phdr->p_memsz;
1185 }
1186 } else if (!mm->start_data) {
1187 mm->start_data = maddr;
1188 mm->end_data = maddr + phdr->p_memsz;
1189 }
1190 }
1191
1192 seg++;
1193 }
1194
1195 return 0;
1196 }
1197
1198 /*****************************************************************************/
1199 /*
1200 * ELF-FDPIC core dumper
1201 *
1202 * Modelled on fs/exec.c:aout_core_dump()
1203 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1204 *
1205 * Modelled on fs/binfmt_elf.c core dumper
1206 */
1207 #ifdef CONFIG_ELF_CORE
1208
1209 /*
1210 * Decide whether a segment is worth dumping; default is yes to be
1211 * sure (missing info is worse than too much; etc).
1212 * Personally I'd include everything, and use the coredump limit...
1213 *
1214 * I think we should skip something. But I am not sure how. H.J.
1215 */
1216 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1217 {
1218 int dump_ok;
1219
1220 /* Do not dump I/O mapped devices or special mappings */
1221 if (vma->vm_flags & VM_IO) {
1222 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1223 return 0;
1224 }
1225
1226 /* If we may not read the contents, don't allow us to dump
1227 * them either. "dump_write()" can't handle it anyway.
1228 */
1229 if (!(vma->vm_flags & VM_READ)) {
1230 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1231 return 0;
1232 }
1233
1234 /* By default, dump shared memory if mapped from an anonymous file. */
1235 if (vma->vm_flags & VM_SHARED) {
1236 if (file_inode(vma->vm_file)->i_nlink == 0) {
1237 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1238 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1239 vma->vm_flags, dump_ok ? "yes" : "no");
1240 return dump_ok;
1241 }
1242
1243 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1244 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1245 vma->vm_flags, dump_ok ? "yes" : "no");
1246 return dump_ok;
1247 }
1248
1249 #ifdef CONFIG_MMU
1250 /* By default, if it hasn't been written to, don't write it out */
1251 if (!vma->anon_vma) {
1252 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1253 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1254 vma->vm_flags, dump_ok ? "yes" : "no");
1255 return dump_ok;
1256 }
1257 #endif
1258
1259 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1260 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1261 dump_ok ? "yes" : "no");
1262 return dump_ok;
1263 }
1264
1265 /* An ELF note in memory */
1266 struct memelfnote
1267 {
1268 const char *name;
1269 int type;
1270 unsigned int datasz;
1271 void *data;
1272 };
1273
1274 static int notesize(struct memelfnote *en)
1275 {
1276 int sz;
1277
1278 sz = sizeof(struct elf_note);
1279 sz += roundup(strlen(en->name) + 1, 4);
1280 sz += roundup(en->datasz, 4);
1281
1282 return sz;
1283 }
1284
1285 /* #define DEBUG */
1286
1287 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1288 {
1289 struct elf_note en;
1290 en.n_namesz = strlen(men->name) + 1;
1291 en.n_descsz = men->datasz;
1292 en.n_type = men->type;
1293
1294 return dump_emit(cprm, &en, sizeof(en)) &&
1295 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1296 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1297 }
1298
1299 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1300 {
1301 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1302 elf->e_ident[EI_CLASS] = ELF_CLASS;
1303 elf->e_ident[EI_DATA] = ELF_DATA;
1304 elf->e_ident[EI_VERSION] = EV_CURRENT;
1305 elf->e_ident[EI_OSABI] = ELF_OSABI;
1306 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1307
1308 elf->e_type = ET_CORE;
1309 elf->e_machine = ELF_ARCH;
1310 elf->e_version = EV_CURRENT;
1311 elf->e_entry = 0;
1312 elf->e_phoff = sizeof(struct elfhdr);
1313 elf->e_shoff = 0;
1314 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1315 elf->e_ehsize = sizeof(struct elfhdr);
1316 elf->e_phentsize = sizeof(struct elf_phdr);
1317 elf->e_phnum = segs;
1318 elf->e_shentsize = 0;
1319 elf->e_shnum = 0;
1320 elf->e_shstrndx = 0;
1321 return;
1322 }
1323
1324 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1325 {
1326 phdr->p_type = PT_NOTE;
1327 phdr->p_offset = offset;
1328 phdr->p_vaddr = 0;
1329 phdr->p_paddr = 0;
1330 phdr->p_filesz = sz;
1331 phdr->p_memsz = 0;
1332 phdr->p_flags = 0;
1333 phdr->p_align = 0;
1334 return;
1335 }
1336
1337 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1338 unsigned int sz, void *data)
1339 {
1340 note->name = name;
1341 note->type = type;
1342 note->datasz = sz;
1343 note->data = data;
1344 return;
1345 }
1346
1347 /*
1348 * fill up all the fields in prstatus from the given task struct, except
1349 * registers which need to be filled up separately.
1350 */
1351 static void fill_prstatus(struct elf_prstatus *prstatus,
1352 struct task_struct *p, long signr)
1353 {
1354 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1355 prstatus->pr_sigpend = p->pending.signal.sig[0];
1356 prstatus->pr_sighold = p->blocked.sig[0];
1357 rcu_read_lock();
1358 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1359 rcu_read_unlock();
1360 prstatus->pr_pid = task_pid_vnr(p);
1361 prstatus->pr_pgrp = task_pgrp_vnr(p);
1362 prstatus->pr_sid = task_session_vnr(p);
1363 if (thread_group_leader(p)) {
1364 struct task_cputime cputime;
1365
1366 /*
1367 * This is the record for the group leader. It shows the
1368 * group-wide total, not its individual thread total.
1369 */
1370 thread_group_cputime(p, &cputime);
1371 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1372 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1373 } else {
1374 cputime_t utime, stime;
1375
1376 task_cputime(p, &utime, &stime);
1377 cputime_to_timeval(utime, &prstatus->pr_utime);
1378 cputime_to_timeval(stime, &prstatus->pr_stime);
1379 }
1380 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1381 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1382
1383 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1384 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1385 }
1386
1387 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1388 struct mm_struct *mm)
1389 {
1390 const struct cred *cred;
1391 unsigned int i, len;
1392
1393 /* first copy the parameters from user space */
1394 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1395
1396 len = mm->arg_end - mm->arg_start;
1397 if (len >= ELF_PRARGSZ)
1398 len = ELF_PRARGSZ - 1;
1399 if (copy_from_user(&psinfo->pr_psargs,
1400 (const char __user *) mm->arg_start, len))
1401 return -EFAULT;
1402 for (i = 0; i < len; i++)
1403 if (psinfo->pr_psargs[i] == 0)
1404 psinfo->pr_psargs[i] = ' ';
1405 psinfo->pr_psargs[len] = 0;
1406
1407 rcu_read_lock();
1408 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1409 rcu_read_unlock();
1410 psinfo->pr_pid = task_pid_vnr(p);
1411 psinfo->pr_pgrp = task_pgrp_vnr(p);
1412 psinfo->pr_sid = task_session_vnr(p);
1413
1414 i = p->state ? ffz(~p->state) + 1 : 0;
1415 psinfo->pr_state = i;
1416 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1417 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1418 psinfo->pr_nice = task_nice(p);
1419 psinfo->pr_flag = p->flags;
1420 rcu_read_lock();
1421 cred = __task_cred(p);
1422 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1423 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1424 rcu_read_unlock();
1425 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1426
1427 return 0;
1428 }
1429
1430 /* Here is the structure in which status of each thread is captured. */
1431 struct elf_thread_status
1432 {
1433 struct list_head list;
1434 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1435 elf_fpregset_t fpu; /* NT_PRFPREG */
1436 struct task_struct *thread;
1437 #ifdef ELF_CORE_COPY_XFPREGS
1438 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1439 #endif
1440 struct memelfnote notes[3];
1441 int num_notes;
1442 };
1443
1444 /*
1445 * In order to add the specific thread information for the elf file format,
1446 * we need to keep a linked list of every thread's pr_status and then create
1447 * a single section for them in the final core file.
1448 */
1449 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1450 {
1451 struct task_struct *p = t->thread;
1452 int sz = 0;
1453
1454 t->num_notes = 0;
1455
1456 fill_prstatus(&t->prstatus, p, signr);
1457 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1458
1459 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1460 &t->prstatus);
1461 t->num_notes++;
1462 sz += notesize(&t->notes[0]);
1463
1464 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1465 if (t->prstatus.pr_fpvalid) {
1466 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1467 &t->fpu);
1468 t->num_notes++;
1469 sz += notesize(&t->notes[1]);
1470 }
1471
1472 #ifdef ELF_CORE_COPY_XFPREGS
1473 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1474 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1475 sizeof(t->xfpu), &t->xfpu);
1476 t->num_notes++;
1477 sz += notesize(&t->notes[2]);
1478 }
1479 #endif
1480 return sz;
1481 }
1482
1483 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1484 elf_addr_t e_shoff, int segs)
1485 {
1486 elf->e_shoff = e_shoff;
1487 elf->e_shentsize = sizeof(*shdr4extnum);
1488 elf->e_shnum = 1;
1489 elf->e_shstrndx = SHN_UNDEF;
1490
1491 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1492
1493 shdr4extnum->sh_type = SHT_NULL;
1494 shdr4extnum->sh_size = elf->e_shnum;
1495 shdr4extnum->sh_link = elf->e_shstrndx;
1496 shdr4extnum->sh_info = segs;
1497 }
1498
1499 /*
1500 * dump the segments for an MMU process
1501 */
1502 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1503 {
1504 struct vm_area_struct *vma;
1505
1506 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1507 unsigned long addr;
1508
1509 if (!maydump(vma, cprm->mm_flags))
1510 continue;
1511
1512 #ifdef CONFIG_MMU
1513 for (addr = vma->vm_start; addr < vma->vm_end;
1514 addr += PAGE_SIZE) {
1515 bool res;
1516 struct page *page = get_dump_page(addr);
1517 if (page) {
1518 void *kaddr = kmap(page);
1519 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1520 kunmap(page);
1521 page_cache_release(page);
1522 } else {
1523 res = dump_skip(cprm, PAGE_SIZE);
1524 }
1525 if (!res)
1526 return false;
1527 }
1528 #else
1529 if (!dump_emit(cprm, (void *) vma->vm_start,
1530 vma->vm_end - vma->vm_start))
1531 return false;
1532 #endif
1533 }
1534 return true;
1535 }
1536
1537 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1538 {
1539 struct vm_area_struct *vma;
1540 size_t size = 0;
1541
1542 for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1543 if (maydump(vma, mm_flags))
1544 size += vma->vm_end - vma->vm_start;
1545 return size;
1546 }
1547
1548 /*
1549 * Actual dumper
1550 *
1551 * This is a two-pass process; first we find the offsets of the bits,
1552 * and then they are actually written out. If we run out of core limit
1553 * we just truncate.
1554 */
1555 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1556 {
1557 #define NUM_NOTES 6
1558 int has_dumped = 0;
1559 mm_segment_t fs;
1560 int segs;
1561 int i;
1562 struct vm_area_struct *vma;
1563 struct elfhdr *elf = NULL;
1564 loff_t offset = 0, dataoff;
1565 int numnote;
1566 struct memelfnote *notes = NULL;
1567 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1568 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1569 LIST_HEAD(thread_list);
1570 struct list_head *t;
1571 elf_fpregset_t *fpu = NULL;
1572 #ifdef ELF_CORE_COPY_XFPREGS
1573 elf_fpxregset_t *xfpu = NULL;
1574 #endif
1575 int thread_status_size = 0;
1576 elf_addr_t *auxv;
1577 struct elf_phdr *phdr4note = NULL;
1578 struct elf_shdr *shdr4extnum = NULL;
1579 Elf_Half e_phnum;
1580 elf_addr_t e_shoff;
1581 struct core_thread *ct;
1582 struct elf_thread_status *tmp;
1583
1584 /*
1585 * We no longer stop all VM operations.
1586 *
1587 * This is because those proceses that could possibly change map_count
1588 * or the mmap / vma pages are now blocked in do_exit on current
1589 * finishing this core dump.
1590 *
1591 * Only ptrace can touch these memory addresses, but it doesn't change
1592 * the map_count or the pages allocated. So no possibility of crashing
1593 * exists while dumping the mm->vm_next areas to the core file.
1594 */
1595
1596 /* alloc memory for large data structures: too large to be on stack */
1597 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1598 if (!elf)
1599 goto cleanup;
1600 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1601 if (!prstatus)
1602 goto cleanup;
1603 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1604 if (!psinfo)
1605 goto cleanup;
1606 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1607 if (!notes)
1608 goto cleanup;
1609 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1610 if (!fpu)
1611 goto cleanup;
1612 #ifdef ELF_CORE_COPY_XFPREGS
1613 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1614 if (!xfpu)
1615 goto cleanup;
1616 #endif
1617
1618 for (ct = current->mm->core_state->dumper.next;
1619 ct; ct = ct->next) {
1620 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1621 if (!tmp)
1622 goto cleanup;
1623
1624 tmp->thread = ct->task;
1625 list_add(&tmp->list, &thread_list);
1626 }
1627
1628 list_for_each(t, &thread_list) {
1629 struct elf_thread_status *tmp;
1630 int sz;
1631
1632 tmp = list_entry(t, struct elf_thread_status, list);
1633 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1634 thread_status_size += sz;
1635 }
1636
1637 /* now collect the dump for the current */
1638 fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1639 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1640
1641 segs = current->mm->map_count;
1642 segs += elf_core_extra_phdrs();
1643
1644 /* for notes section */
1645 segs++;
1646
1647 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1648 * this, kernel supports extended numbering. Have a look at
1649 * include/linux/elf.h for further information. */
1650 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1651
1652 /* Set up header */
1653 fill_elf_fdpic_header(elf, e_phnum);
1654
1655 has_dumped = 1;
1656 /*
1657 * Set up the notes in similar form to SVR4 core dumps made
1658 * with info from their /proc.
1659 */
1660
1661 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1662 fill_psinfo(psinfo, current->group_leader, current->mm);
1663 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1664
1665 numnote = 2;
1666
1667 auxv = (elf_addr_t *) current->mm->saved_auxv;
1668
1669 i = 0;
1670 do
1671 i += 2;
1672 while (auxv[i - 2] != AT_NULL);
1673 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1674 i * sizeof(elf_addr_t), auxv);
1675
1676 /* Try to dump the FPU. */
1677 if ((prstatus->pr_fpvalid =
1678 elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1679 fill_note(notes + numnote++,
1680 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1681 #ifdef ELF_CORE_COPY_XFPREGS
1682 if (elf_core_copy_task_xfpregs(current, xfpu))
1683 fill_note(notes + numnote++,
1684 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1685 #endif
1686
1687 fs = get_fs();
1688 set_fs(KERNEL_DS);
1689
1690 offset += sizeof(*elf); /* Elf header */
1691 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1692
1693 /* Write notes phdr entry */
1694 {
1695 int sz = 0;
1696
1697 for (i = 0; i < numnote; i++)
1698 sz += notesize(notes + i);
1699
1700 sz += thread_status_size;
1701
1702 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1703 if (!phdr4note)
1704 goto end_coredump;
1705
1706 fill_elf_note_phdr(phdr4note, sz, offset);
1707 offset += sz;
1708 }
1709
1710 /* Page-align dumped data */
1711 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1712
1713 offset += elf_core_vma_data_size(cprm->mm_flags);
1714 offset += elf_core_extra_data_size();
1715 e_shoff = offset;
1716
1717 if (e_phnum == PN_XNUM) {
1718 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1719 if (!shdr4extnum)
1720 goto end_coredump;
1721 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1722 }
1723
1724 offset = dataoff;
1725
1726 if (!dump_emit(cprm, elf, sizeof(*elf)))
1727 goto end_coredump;
1728
1729 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1730 goto end_coredump;
1731
1732 /* write program headers for segments dump */
1733 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1734 struct elf_phdr phdr;
1735 size_t sz;
1736
1737 sz = vma->vm_end - vma->vm_start;
1738
1739 phdr.p_type = PT_LOAD;
1740 phdr.p_offset = offset;
1741 phdr.p_vaddr = vma->vm_start;
1742 phdr.p_paddr = 0;
1743 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1744 phdr.p_memsz = sz;
1745 offset += phdr.p_filesz;
1746 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1747 if (vma->vm_flags & VM_WRITE)
1748 phdr.p_flags |= PF_W;
1749 if (vma->vm_flags & VM_EXEC)
1750 phdr.p_flags |= PF_X;
1751 phdr.p_align = ELF_EXEC_PAGESIZE;
1752
1753 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1754 goto end_coredump;
1755 }
1756
1757 if (!elf_core_write_extra_phdrs(cprm, offset))
1758 goto end_coredump;
1759
1760 /* write out the notes section */
1761 for (i = 0; i < numnote; i++)
1762 if (!writenote(notes + i, cprm))
1763 goto end_coredump;
1764
1765 /* write out the thread status notes section */
1766 list_for_each(t, &thread_list) {
1767 struct elf_thread_status *tmp =
1768 list_entry(t, struct elf_thread_status, list);
1769
1770 for (i = 0; i < tmp->num_notes; i++)
1771 if (!writenote(&tmp->notes[i], cprm))
1772 goto end_coredump;
1773 }
1774
1775 if (!dump_skip(cprm, dataoff - cprm->written))
1776 goto end_coredump;
1777
1778 if (!elf_fdpic_dump_segments(cprm))
1779 goto end_coredump;
1780
1781 if (!elf_core_write_extra_data(cprm))
1782 goto end_coredump;
1783
1784 if (e_phnum == PN_XNUM) {
1785 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1786 goto end_coredump;
1787 }
1788
1789 if (cprm->file->f_pos != offset) {
1790 /* Sanity check */
1791 printk(KERN_WARNING
1792 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1793 cprm->file->f_pos, offset);
1794 }
1795
1796 end_coredump:
1797 set_fs(fs);
1798
1799 cleanup:
1800 while (!list_empty(&thread_list)) {
1801 struct list_head *tmp = thread_list.next;
1802 list_del(tmp);
1803 kfree(list_entry(tmp, struct elf_thread_status, list));
1804 }
1805 kfree(phdr4note);
1806 kfree(elf);
1807 kfree(prstatus);
1808 kfree(psinfo);
1809 kfree(notes);
1810 kfree(fpu);
1811 kfree(shdr4extnum);
1812 #ifdef ELF_CORE_COPY_XFPREGS
1813 kfree(xfpu);
1814 #endif
1815 return has_dumped;
1816 #undef NUM_NOTES
1817 }
1818
1819 #endif /* CONFIG_ELF_CORE */
Linux kernel - Deliverables
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