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Linux 4.2.1
[linux/fpc-iii.git] / fs / binfmt_elf_fdpic.c
blobd3634bfb7fe187b4de899e809188319c08b6ac23
1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
2 *
3 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 * Derived from binfmt_elf.c
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
13 #include <linux/module.h>
14
15 #include <linux/fs.h>
16 #include <linux/stat.h>
17 #include <linux/sched.h>
18 #include <linux/mm.h>
19 #include <linux/mman.h>
20 #include <linux/errno.h>
21 #include <linux/signal.h>
22 #include <linux/binfmts.h>
23 #include <linux/string.h>
24 #include <linux/file.h>
25 #include <linux/fcntl.h>
26 #include <linux/slab.h>
27 #include <linux/pagemap.h>
28 #include <linux/security.h>
29 #include <linux/highmem.h>
30 #include <linux/highuid.h>
31 #include <linux/personality.h>
32 #include <linux/ptrace.h>
33 #include <linux/init.h>
34 #include <linux/elf.h>
35 #include <linux/elf-fdpic.h>
36 #include <linux/elfcore.h>
37 #include <linux/coredump.h>
38
39 #include <asm/uaccess.h>
40 #include <asm/param.h>
41 #include <asm/pgalloc.h>
42
43 typedef char *elf_caddr_t;
44
45 #if 0
46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
47 #else
48 #define kdebug(fmt, ...) do {} while(0)
49 #endif
50
51 #if 0
52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
53 #else
54 #define kdcore(fmt, ...) do {} while(0)
55 #endif
56
57 MODULE_LICENSE("GPL");
58
59 static int load_elf_fdpic_binary(struct linux_binprm *);
60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
62 struct mm_struct *, const char *);
63
64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
65 struct elf_fdpic_params *,
66 struct elf_fdpic_params *);
67
68 #ifndef CONFIG_MMU
69 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
70 unsigned long *);
71 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
72 struct file *,
73 struct mm_struct *);
74 #endif
75
76 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
77 struct file *, struct mm_struct *);
78
79 #ifdef CONFIG_ELF_CORE
80 static int elf_fdpic_core_dump(struct coredump_params *cprm);
81 #endif
82
83 static struct linux_binfmt elf_fdpic_format = {
84 .module = THIS_MODULE,
85 .load_binary = load_elf_fdpic_binary,
86 #ifdef CONFIG_ELF_CORE
87 .core_dump = elf_fdpic_core_dump,
88 #endif
89 .min_coredump = ELF_EXEC_PAGESIZE,
90 };
91
92 static int __init init_elf_fdpic_binfmt(void)
93 {
94 register_binfmt(&elf_fdpic_format);
95 return 0;
96 }
97
98 static void __exit exit_elf_fdpic_binfmt(void)
99 {
100 unregister_binfmt(&elf_fdpic_format);
101 }
102
103 core_initcall(init_elf_fdpic_binfmt);
104 module_exit(exit_elf_fdpic_binfmt);
105
106 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
107 {
108 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
109 return 0;
110 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
111 return 0;
112 if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
113 return 0;
114 if (!file->f_op->mmap)
115 return 0;
116 return 1;
117 }
118
119 /*****************************************************************************/
120 /*
121 * read the program headers table into memory
122 */
123 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
124 struct file *file)
125 {
126 struct elf32_phdr *phdr;
127 unsigned long size;
128 int retval, loop;
129
130 if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
131 return -ENOMEM;
132 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
133 return -ENOMEM;
134
135 size = params->hdr.e_phnum * sizeof(struct elf_phdr);
136 params->phdrs = kmalloc(size, GFP_KERNEL);
137 if (!params->phdrs)
138 return -ENOMEM;
139
140 retval = kernel_read(file, params->hdr.e_phoff,
141 (char *) params->phdrs, size);
142 if (unlikely(retval != size))
143 return retval < 0 ? retval : -ENOEXEC;
144
145 /* determine stack size for this binary */
146 phdr = params->phdrs;
147 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
148 if (phdr->p_type != PT_GNU_STACK)
149 continue;
150
151 if (phdr->p_flags & PF_X)
152 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
153 else
154 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
155
156 params->stack_size = phdr->p_memsz;
157 break;
158 }
159
160 return 0;
161 }
162
163 /*****************************************************************************/
164 /*
165 * load an fdpic binary into various bits of memory
166 */
167 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
168 {
169 struct elf_fdpic_params exec_params, interp_params;
170 struct pt_regs *regs = current_pt_regs();
171 struct elf_phdr *phdr;
172 unsigned long stack_size, entryaddr;
173 #ifdef ELF_FDPIC_PLAT_INIT
174 unsigned long dynaddr;
175 #endif
176 #ifndef CONFIG_MMU
177 unsigned long stack_prot;
178 #endif
179 struct file *interpreter = NULL; /* to shut gcc up */
180 char *interpreter_name = NULL;
181 int executable_stack;
182 int retval, i;
183
184 kdebug("____ LOAD %d ____", current->pid);
185
186 memset(&exec_params, 0, sizeof(exec_params));
187 memset(&interp_params, 0, sizeof(interp_params));
188
189 exec_params.hdr = *(struct elfhdr *) bprm->buf;
190 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
191
192 /* check that this is a binary we know how to deal with */
193 retval = -ENOEXEC;
194 if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
195 goto error;
196
197 /* read the program header table */
198 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
199 if (retval < 0)
200 goto error;
201
202 /* scan for a program header that specifies an interpreter */
203 phdr = exec_params.phdrs;
204
205 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
206 switch (phdr->p_type) {
207 case PT_INTERP:
208 retval = -ENOMEM;
209 if (phdr->p_filesz > PATH_MAX)
210 goto error;
211 retval = -ENOENT;
212 if (phdr->p_filesz < 2)
213 goto error;
214
215 /* read the name of the interpreter into memory */
216 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
217 if (!interpreter_name)
218 goto error;
219
220 retval = kernel_read(bprm->file,
221 phdr->p_offset,
222 interpreter_name,
223 phdr->p_filesz);
224 if (unlikely(retval != phdr->p_filesz)) {
225 if (retval >= 0)
226 retval = -ENOEXEC;
227 goto error;
228 }
229
230 retval = -ENOENT;
231 if (interpreter_name[phdr->p_filesz - 1] != '\0')
232 goto error;
233
234 kdebug("Using ELF interpreter %s", interpreter_name);
235
236 /* replace the program with the interpreter */
237 interpreter = open_exec(interpreter_name);
238 retval = PTR_ERR(interpreter);
239 if (IS_ERR(interpreter)) {
240 interpreter = NULL;
241 goto error;
242 }
243
244 /*
245 * If the binary is not readable then enforce
246 * mm->dumpable = 0 regardless of the interpreter's
247 * permissions.
248 */
249 would_dump(bprm, interpreter);
250
251 retval = kernel_read(interpreter, 0, bprm->buf,
252 BINPRM_BUF_SIZE);
253 if (unlikely(retval != BINPRM_BUF_SIZE)) {
254 if (retval >= 0)
255 retval = -ENOEXEC;
256 goto error;
257 }
258
259 interp_params.hdr = *((struct elfhdr *) bprm->buf);
260 break;
261
262 case PT_LOAD:
263 #ifdef CONFIG_MMU
264 if (exec_params.load_addr == 0)
265 exec_params.load_addr = phdr->p_vaddr;
266 #endif
267 break;
268 }
269
270 }
271
272 if (elf_check_const_displacement(&exec_params.hdr))
273 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
274
275 /* perform insanity checks on the interpreter */
276 if (interpreter_name) {
277 retval = -ELIBBAD;
278 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
279 goto error;
280
281 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
282
283 /* read the interpreter's program header table */
284 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
285 if (retval < 0)
286 goto error;
287 }
288
289 stack_size = exec_params.stack_size;
290 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
291 executable_stack = EXSTACK_ENABLE_X;
292 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
293 executable_stack = EXSTACK_DISABLE_X;
294 else
295 executable_stack = EXSTACK_DEFAULT;
296
297 if (stack_size == 0) {
298 stack_size = interp_params.stack_size;
299 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
300 executable_stack = EXSTACK_ENABLE_X;
301 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
302 executable_stack = EXSTACK_DISABLE_X;
303 else
304 executable_stack = EXSTACK_DEFAULT;
305 }
306
307 retval = -ENOEXEC;
308 if (stack_size == 0)
309 goto error;
310
311 if (elf_check_const_displacement(&interp_params.hdr))
312 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
313
314 /* flush all traces of the currently running executable */
315 retval = flush_old_exec(bprm);
316 if (retval)
317 goto error;
318
319 /* there's now no turning back... the old userspace image is dead,
320 * defunct, deceased, etc.
321 */
322 set_personality(PER_LINUX_FDPIC);
323 if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
324 current->personality |= READ_IMPLIES_EXEC;
325
326 setup_new_exec(bprm);
327
328 set_binfmt(&elf_fdpic_format);
329
330 current->mm->start_code = 0;
331 current->mm->end_code = 0;
332 current->mm->start_stack = 0;
333 current->mm->start_data = 0;
334 current->mm->end_data = 0;
335 current->mm->context.exec_fdpic_loadmap = 0;
336 current->mm->context.interp_fdpic_loadmap = 0;
337
338 #ifdef CONFIG_MMU
339 elf_fdpic_arch_lay_out_mm(&exec_params,
340 &interp_params,
341 &current->mm->start_stack,
342 &current->mm->start_brk);
343
344 retval = setup_arg_pages(bprm, current->mm->start_stack,
345 executable_stack);
346 if (retval < 0)
347 goto error;
348 #endif
349
350 /* load the executable and interpreter into memory */
351 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
352 "executable");
353 if (retval < 0)
354 goto error;
355
356 if (interpreter_name) {
357 retval = elf_fdpic_map_file(&interp_params, interpreter,
358 current->mm, "interpreter");
359 if (retval < 0) {
360 printk(KERN_ERR "Unable to load interpreter\n");
361 goto error;
362 }
363
364 allow_write_access(interpreter);
365 fput(interpreter);
366 interpreter = NULL;
367 }
368
369 #ifdef CONFIG_MMU
370 if (!current->mm->start_brk)
371 current->mm->start_brk = current->mm->end_data;
372
373 current->mm->brk = current->mm->start_brk =
374 PAGE_ALIGN(current->mm->start_brk);
375
376 #else
377 /* create a stack and brk area big enough for everyone
378 * - the brk heap starts at the bottom and works up
379 * - the stack starts at the top and works down
380 */
381 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
382 if (stack_size < PAGE_SIZE * 2)
383 stack_size = PAGE_SIZE * 2;
384
385 stack_prot = PROT_READ | PROT_WRITE;
386 if (executable_stack == EXSTACK_ENABLE_X ||
387 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
388 stack_prot |= PROT_EXEC;
389
390 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
391 MAP_PRIVATE | MAP_ANONYMOUS |
392 MAP_UNINITIALIZED | MAP_GROWSDOWN,
393 0);
394
395 if (IS_ERR_VALUE(current->mm->start_brk)) {
396 retval = current->mm->start_brk;
397 current->mm->start_brk = 0;
398 goto error;
399 }
400
401 current->mm->brk = current->mm->start_brk;
402 current->mm->context.end_brk = current->mm->start_brk;
403 current->mm->context.end_brk +=
404 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
405 current->mm->start_stack = current->mm->start_brk + stack_size;
406 #endif
407
408 install_exec_creds(bprm);
409 if (create_elf_fdpic_tables(bprm, current->mm,
410 &exec_params, &interp_params) < 0)
411 goto error;
412
413 kdebug("- start_code %lx", current->mm->start_code);
414 kdebug("- end_code %lx", current->mm->end_code);
415 kdebug("- start_data %lx", current->mm->start_data);
416 kdebug("- end_data %lx", current->mm->end_data);
417 kdebug("- start_brk %lx", current->mm->start_brk);
418 kdebug("- brk %lx", current->mm->brk);
419 kdebug("- start_stack %lx", current->mm->start_stack);
420
421 #ifdef ELF_FDPIC_PLAT_INIT
422 /*
423 * The ABI may specify that certain registers be set up in special
424 * ways (on i386 %edx is the address of a DT_FINI function, for
425 * example. This macro performs whatever initialization to
426 * the regs structure is required.
427 */
428 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
429 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
430 dynaddr);
431 #endif
432
433 /* everything is now ready... get the userspace context ready to roll */
434 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
435 start_thread(regs, entryaddr, current->mm->start_stack);
436
437 retval = 0;
438
439 error:
440 if (interpreter) {
441 allow_write_access(interpreter);
442 fput(interpreter);
443 }
444 kfree(interpreter_name);
445 kfree(exec_params.phdrs);
446 kfree(exec_params.loadmap);
447 kfree(interp_params.phdrs);
448 kfree(interp_params.loadmap);
449 return retval;
450 }
451
452 /*****************************************************************************/
453
454 #ifndef ELF_BASE_PLATFORM
455 /*
456 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
457 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
458 * will be copied to the user stack in the same manner as AT_PLATFORM.
459 */
460 #define ELF_BASE_PLATFORM NULL
461 #endif
462
463 /*
464 * present useful information to the program by shovelling it onto the new
465 * process's stack
466 */
467 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
468 struct mm_struct *mm,
469 struct elf_fdpic_params *exec_params,
470 struct elf_fdpic_params *interp_params)
471 {
472 const struct cred *cred = current_cred();
473 unsigned long sp, csp, nitems;
474 elf_caddr_t __user *argv, *envp;
475 size_t platform_len = 0, len;
476 char *k_platform, *k_base_platform;
477 char __user *u_platform, *u_base_platform, *p;
478 int loop;
479 int nr; /* reset for each csp adjustment */
480
481 #ifdef CONFIG_MMU
482 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
483 * by the processes running on the same package. One thing we can do is
484 * to shuffle the initial stack for them, so we give the architecture
485 * an opportunity to do so here.
486 */
487 sp = arch_align_stack(bprm->p);
488 #else
489 sp = mm->start_stack;
490
491 /* stack the program arguments and environment */
492 if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
493 return -EFAULT;
494 #endif
495
496 /*
497 * If this architecture has a platform capability string, copy it
498 * to userspace. In some cases (Sparc), this info is impossible
499 * for userspace to get any other way, in others (i386) it is
500 * merely difficult.
501 */
502 k_platform = ELF_PLATFORM;
503 u_platform = NULL;
504
505 if (k_platform) {
506 platform_len = strlen(k_platform) + 1;
507 sp -= platform_len;
508 u_platform = (char __user *) sp;
509 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
510 return -EFAULT;
511 }
512
513 /*
514 * If this architecture has a "base" platform capability
515 * string, copy it to userspace.
516 */
517 k_base_platform = ELF_BASE_PLATFORM;
518 u_base_platform = NULL;
519
520 if (k_base_platform) {
521 platform_len = strlen(k_base_platform) + 1;
522 sp -= platform_len;
523 u_base_platform = (char __user *) sp;
524 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
525 return -EFAULT;
526 }
527
528 sp &= ~7UL;
529
530 /* stack the load map(s) */
531 len = sizeof(struct elf32_fdpic_loadmap);
532 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
533 sp = (sp - len) & ~7UL;
534 exec_params->map_addr = sp;
535
536 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
537 return -EFAULT;
538
539 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
540
541 if (interp_params->loadmap) {
542 len = sizeof(struct elf32_fdpic_loadmap);
543 len += sizeof(struct elf32_fdpic_loadseg) *
544 interp_params->loadmap->nsegs;
545 sp = (sp - len) & ~7UL;
546 interp_params->map_addr = sp;
547
548 if (copy_to_user((void __user *) sp, interp_params->loadmap,
549 len) != 0)
550 return -EFAULT;
551
552 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
553 }
554
555 /* force 16 byte _final_ alignment here for generality */
556 #define DLINFO_ITEMS 15
557
558 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
559 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
560
561 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
562 nitems++;
563
564 csp = sp;
565 sp -= nitems * 2 * sizeof(unsigned long);
566 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
567 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
568 sp -= 1 * sizeof(unsigned long); /* argc */
569
570 csp -= sp & 15UL;
571 sp -= sp & 15UL;
572
573 /* put the ELF interpreter info on the stack */
574 #define NEW_AUX_ENT(id, val) \
575 do { \
576 struct { unsigned long _id, _val; } __user *ent; \
577 \
578 ent = (void __user *) csp; \
579 __put_user((id), &ent[nr]._id); \
580 __put_user((val), &ent[nr]._val); \
581 nr++; \
582 } while (0)
583
584 nr = 0;
585 csp -= 2 * sizeof(unsigned long);
586 NEW_AUX_ENT(AT_NULL, 0);
587 if (k_platform) {
588 nr = 0;
589 csp -= 2 * sizeof(unsigned long);
590 NEW_AUX_ENT(AT_PLATFORM,
591 (elf_addr_t) (unsigned long) u_platform);
592 }
593
594 if (k_base_platform) {
595 nr = 0;
596 csp -= 2 * sizeof(unsigned long);
597 NEW_AUX_ENT(AT_BASE_PLATFORM,
598 (elf_addr_t) (unsigned long) u_base_platform);
599 }
600
601 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
602 nr = 0;
603 csp -= 2 * sizeof(unsigned long);
604 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
605 }
606
607 nr = 0;
608 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
609 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
610 #ifdef ELF_HWCAP2
611 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
612 #endif
613 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
614 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
615 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
616 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
617 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
618 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
619 NEW_AUX_ENT(AT_FLAGS, 0);
620 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
621 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
622 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
623 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
624 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
625 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
626 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
627
628 #ifdef ARCH_DLINFO
629 nr = 0;
630 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
631
632 /* ARCH_DLINFO must come last so platform specific code can enforce
633 * special alignment requirements on the AUXV if necessary (eg. PPC).
634 */
635 ARCH_DLINFO;
636 #endif
637 #undef NEW_AUX_ENT
638
639 /* allocate room for argv[] and envv[] */
640 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
641 envp = (elf_caddr_t __user *) csp;
642 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
643 argv = (elf_caddr_t __user *) csp;
644
645 /* stack argc */
646 csp -= sizeof(unsigned long);
647 __put_user(bprm->argc, (unsigned long __user *) csp);
648
649 BUG_ON(csp != sp);
650
651 /* fill in the argv[] array */
652 #ifdef CONFIG_MMU
653 current->mm->arg_start = bprm->p;
654 #else
655 current->mm->arg_start = current->mm->start_stack -
656 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
657 #endif
658
659 p = (char __user *) current->mm->arg_start;
660 for (loop = bprm->argc; loop > 0; loop--) {
661 __put_user((elf_caddr_t) p, argv++);
662 len = strnlen_user(p, MAX_ARG_STRLEN);
663 if (!len || len > MAX_ARG_STRLEN)
664 return -EINVAL;
665 p += len;
666 }
667 __put_user(NULL, argv);
668 current->mm->arg_end = (unsigned long) p;
669
670 /* fill in the envv[] array */
671 current->mm->env_start = (unsigned long) p;
672 for (loop = bprm->envc; loop > 0; loop--) {
673 __put_user((elf_caddr_t)(unsigned long) p, envp++);
674 len = strnlen_user(p, MAX_ARG_STRLEN);
675 if (!len || len > MAX_ARG_STRLEN)
676 return -EINVAL;
677 p += len;
678 }
679 __put_user(NULL, envp);
680 current->mm->env_end = (unsigned long) p;
681
682 mm->start_stack = (unsigned long) sp;
683 return 0;
684 }
685
686 /*****************************************************************************/
687 /*
688 * transfer the program arguments and environment from the holding pages onto
689 * the stack
690 */
691 #ifndef CONFIG_MMU
692 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
693 unsigned long *_sp)
694 {
695 unsigned long index, stop, sp;
696 char *src;
697 int ret = 0;
698
699 stop = bprm->p >> PAGE_SHIFT;
700 sp = *_sp;
701
702 for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
703 src = kmap(bprm->page[index]);
704 sp -= PAGE_SIZE;
705 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
706 ret = -EFAULT;
707 kunmap(bprm->page[index]);
708 if (ret < 0)
709 goto out;
710 }
711
712 *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
713
714 out:
715 return ret;
716 }
717 #endif
718
719 /*****************************************************************************/
720 /*
721 * load the appropriate binary image (executable or interpreter) into memory
722 * - we assume no MMU is available
723 * - if no other PIC bits are set in params->hdr->e_flags
724 * - we assume that the LOADable segments in the binary are independently relocatable
725 * - we assume R/O executable segments are shareable
726 * - else
727 * - we assume the loadable parts of the image to require fixed displacement
728 * - the image is not shareable
729 */
730 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
731 struct file *file,
732 struct mm_struct *mm,
733 const char *what)
734 {
735 struct elf32_fdpic_loadmap *loadmap;
736 #ifdef CONFIG_MMU
737 struct elf32_fdpic_loadseg *mseg;
738 #endif
739 struct elf32_fdpic_loadseg *seg;
740 struct elf32_phdr *phdr;
741 unsigned long load_addr, stop;
742 unsigned nloads, tmp;
743 size_t size;
744 int loop, ret;
745
746 /* allocate a load map table */
747 nloads = 0;
748 for (loop = 0; loop < params->hdr.e_phnum; loop++)
749 if (params->phdrs[loop].p_type == PT_LOAD)
750 nloads++;
751
752 if (nloads == 0)
753 return -ELIBBAD;
754
755 size = sizeof(*loadmap) + nloads * sizeof(*seg);
756 loadmap = kzalloc(size, GFP_KERNEL);
757 if (!loadmap)
758 return -ENOMEM;
759
760 params->loadmap = loadmap;
761
762 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
763 loadmap->nsegs = nloads;
764
765 load_addr = params->load_addr;
766 seg = loadmap->segs;
767
768 /* map the requested LOADs into the memory space */
769 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
770 case ELF_FDPIC_FLAG_CONSTDISP:
771 case ELF_FDPIC_FLAG_CONTIGUOUS:
772 #ifndef CONFIG_MMU
773 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
774 if (ret < 0)
775 return ret;
776 break;
777 #endif
778 default:
779 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
780 if (ret < 0)
781 return ret;
782 break;
783 }
784
785 /* map the entry point */
786 if (params->hdr.e_entry) {
787 seg = loadmap->segs;
788 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
789 if (params->hdr.e_entry >= seg->p_vaddr &&
790 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
791 params->entry_addr =
792 (params->hdr.e_entry - seg->p_vaddr) +
793 seg->addr;
794 break;
795 }
796 }
797 }
798
799 /* determine where the program header table has wound up if mapped */
800 stop = params->hdr.e_phoff;
801 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
802 phdr = params->phdrs;
803
804 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
805 if (phdr->p_type != PT_LOAD)
806 continue;
807
808 if (phdr->p_offset > params->hdr.e_phoff ||
809 phdr->p_offset + phdr->p_filesz < stop)
810 continue;
811
812 seg = loadmap->segs;
813 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
814 if (phdr->p_vaddr >= seg->p_vaddr &&
815 phdr->p_vaddr + phdr->p_filesz <=
816 seg->p_vaddr + seg->p_memsz) {
817 params->ph_addr =
818 (phdr->p_vaddr - seg->p_vaddr) +
819 seg->addr +
820 params->hdr.e_phoff - phdr->p_offset;
821 break;
822 }
823 }
824 break;
825 }
826
827 /* determine where the dynamic section has wound up if there is one */
828 phdr = params->phdrs;
829 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
830 if (phdr->p_type != PT_DYNAMIC)
831 continue;
832
833 seg = loadmap->segs;
834 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
835 if (phdr->p_vaddr >= seg->p_vaddr &&
836 phdr->p_vaddr + phdr->p_memsz <=
837 seg->p_vaddr + seg->p_memsz) {
838 params->dynamic_addr =
839 (phdr->p_vaddr - seg->p_vaddr) +
840 seg->addr;
841
842 /* check the dynamic section contains at least
843 * one item, and that the last item is a NULL
844 * entry */
845 if (phdr->p_memsz == 0 ||
846 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
847 goto dynamic_error;
848
849 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
850 if (((Elf32_Dyn *)
851 params->dynamic_addr)[tmp - 1].d_tag != 0)
852 goto dynamic_error;
853 break;
854 }
855 }
856 break;
857 }
858
859 /* now elide adjacent segments in the load map on MMU linux
860 * - on uClinux the holes between may actually be filled with system
861 * stuff or stuff from other processes
862 */
863 #ifdef CONFIG_MMU
864 nloads = loadmap->nsegs;
865 mseg = loadmap->segs;
866 seg = mseg + 1;
867 for (loop = 1; loop < nloads; loop++) {
868 /* see if we have a candidate for merging */
869 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
870 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
871 if (load_addr == (seg->addr & PAGE_MASK)) {
872 mseg->p_memsz +=
873 load_addr -
874 (mseg->addr + mseg->p_memsz);
875 mseg->p_memsz += seg->addr & ~PAGE_MASK;
876 mseg->p_memsz += seg->p_memsz;
877 loadmap->nsegs--;
878 continue;
879 }
880 }
881
882 mseg++;
883 if (mseg != seg)
884 *mseg = *seg;
885 }
886 #endif
887
888 kdebug("Mapped Object [%s]:", what);
889 kdebug("- elfhdr : %lx", params->elfhdr_addr);
890 kdebug("- entry : %lx", params->entry_addr);
891 kdebug("- PHDR[] : %lx", params->ph_addr);
892 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
893 seg = loadmap->segs;
894 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
895 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
896 loop,
897 seg->addr, seg->addr + seg->p_memsz - 1,
898 seg->p_vaddr, seg->p_memsz);
899
900 return 0;
901
902 dynamic_error:
903 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
904 what, file_inode(file)->i_ino);
905 return -ELIBBAD;
906 }
907
908 /*****************************************************************************/
909 /*
910 * map a file with constant displacement under uClinux
911 */
912 #ifndef CONFIG_MMU
913 static int elf_fdpic_map_file_constdisp_on_uclinux(
914 struct elf_fdpic_params *params,
915 struct file *file,
916 struct mm_struct *mm)
917 {
918 struct elf32_fdpic_loadseg *seg;
919 struct elf32_phdr *phdr;
920 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
921 int loop, ret;
922
923 load_addr = params->load_addr;
924 seg = params->loadmap->segs;
925
926 /* determine the bounds of the contiguous overall allocation we must
927 * make */
928 phdr = params->phdrs;
929 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
930 if (params->phdrs[loop].p_type != PT_LOAD)
931 continue;
932
933 if (base > phdr->p_vaddr)
934 base = phdr->p_vaddr;
935 if (top < phdr->p_vaddr + phdr->p_memsz)
936 top = phdr->p_vaddr + phdr->p_memsz;
937 }
938
939 /* allocate one big anon block for everything */
940 mflags = MAP_PRIVATE;
941 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
942 mflags |= MAP_EXECUTABLE;
943
944 maddr = vm_mmap(NULL, load_addr, top - base,
945 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
946 if (IS_ERR_VALUE(maddr))
947 return (int) maddr;
948
949 if (load_addr != 0)
950 load_addr += PAGE_ALIGN(top - base);
951
952 /* and then load the file segments into it */
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 seg->addr = maddr + (phdr->p_vaddr - base);
959 seg->p_vaddr = phdr->p_vaddr;
960 seg->p_memsz = phdr->p_memsz;
961
962 ret = read_code(file, seg->addr, phdr->p_offset,
963 phdr->p_filesz);
964 if (ret < 0)
965 return ret;
966
967 /* map the ELF header address if in this segment */
968 if (phdr->p_offset == 0)
969 params->elfhdr_addr = seg->addr;
970
971 /* clear any space allocated but not loaded */
972 if (phdr->p_filesz < phdr->p_memsz) {
973 if (clear_user((void *) (seg->addr + phdr->p_filesz),
974 phdr->p_memsz - phdr->p_filesz))
975 return -EFAULT;
976 }
977
978 if (mm) {
979 if (phdr->p_flags & PF_X) {
980 if (!mm->start_code) {
981 mm->start_code = seg->addr;
982 mm->end_code = seg->addr +
983 phdr->p_memsz;
984 }
985 } else if (!mm->start_data) {
986 mm->start_data = seg->addr;
987 mm->end_data = seg->addr + phdr->p_memsz;
988 }
989 }
990
991 seg++;
992 }
993
994 return 0;
995 }
996 #endif
997
998 /*****************************************************************************/
999 /*
1000 * map a binary by direct mmap() of the individual PT_LOAD segments
1001 */
1002 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1003 struct file *file,
1004 struct mm_struct *mm)
1005 {
1006 struct elf32_fdpic_loadseg *seg;
1007 struct elf32_phdr *phdr;
1008 unsigned long load_addr, delta_vaddr;
1009 int loop, dvset;
1010
1011 load_addr = params->load_addr;
1012 delta_vaddr = 0;
1013 dvset = 0;
1014
1015 seg = params->loadmap->segs;
1016
1017 /* deal with each load segment separately */
1018 phdr = params->phdrs;
1019 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1020 unsigned long maddr, disp, excess, excess1;
1021 int prot = 0, flags;
1022
1023 if (phdr->p_type != PT_LOAD)
1024 continue;
1025
1026 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1027 (unsigned long) phdr->p_vaddr,
1028 (unsigned long) phdr->p_offset,
1029 (unsigned long) phdr->p_filesz,
1030 (unsigned long) phdr->p_memsz);
1031
1032 /* determine the mapping parameters */
1033 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1034 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1035 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1036
1037 flags = MAP_PRIVATE | MAP_DENYWRITE;
1038 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1039 flags |= MAP_EXECUTABLE;
1040
1041 maddr = 0;
1042
1043 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1044 case ELF_FDPIC_FLAG_INDEPENDENT:
1045 /* PT_LOADs are independently locatable */
1046 break;
1047
1048 case ELF_FDPIC_FLAG_HONOURVADDR:
1049 /* the specified virtual address must be honoured */
1050 maddr = phdr->p_vaddr;
1051 flags |= MAP_FIXED;
1052 break;
1053
1054 case ELF_FDPIC_FLAG_CONSTDISP:
1055 /* constant displacement
1056 * - can be mapped anywhere, but must be mapped as a
1057 * unit
1058 */
1059 if (!dvset) {
1060 maddr = load_addr;
1061 delta_vaddr = phdr->p_vaddr;
1062 dvset = 1;
1063 } else {
1064 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1065 flags |= MAP_FIXED;
1066 }
1067 break;
1068
1069 case ELF_FDPIC_FLAG_CONTIGUOUS:
1070 /* contiguity handled later */
1071 break;
1072
1073 default:
1074 BUG();
1075 }
1076
1077 maddr &= PAGE_MASK;
1078
1079 /* create the mapping */
1080 disp = phdr->p_vaddr & ~PAGE_MASK;
1081 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1082 phdr->p_offset - disp);
1083
1084 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1085 loop, phdr->p_memsz + disp, prot, flags,
1086 phdr->p_offset - disp, maddr);
1087
1088 if (IS_ERR_VALUE(maddr))
1089 return (int) maddr;
1090
1091 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1092 ELF_FDPIC_FLAG_CONTIGUOUS)
1093 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1094
1095 seg->addr = maddr + disp;
1096 seg->p_vaddr = phdr->p_vaddr;
1097 seg->p_memsz = phdr->p_memsz;
1098
1099 /* map the ELF header address if in this segment */
1100 if (phdr->p_offset == 0)
1101 params->elfhdr_addr = seg->addr;
1102
1103 /* clear the bit between beginning of mapping and beginning of
1104 * PT_LOAD */
1105 if (prot & PROT_WRITE && disp > 0) {
1106 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1107 if (clear_user((void __user *) maddr, disp))
1108 return -EFAULT;
1109 maddr += disp;
1110 }
1111
1112 /* clear any space allocated but not loaded
1113 * - on uClinux we can just clear the lot
1114 * - on MMU linux we'll get a SIGBUS beyond the last page
1115 * extant in the file
1116 */
1117 excess = phdr->p_memsz - phdr->p_filesz;
1118 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1119
1120 #ifdef CONFIG_MMU
1121 if (excess > excess1) {
1122 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1123 unsigned long xmaddr;
1124
1125 flags |= MAP_FIXED | MAP_ANONYMOUS;
1126 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1127 prot, flags, 0);
1128
1129 kdebug("mmap[%d] <anon>"
1130 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1131 loop, xaddr, excess - excess1, prot, flags,
1132 xmaddr);
1133
1134 if (xmaddr != xaddr)
1135 return -ENOMEM;
1136 }
1137
1138 if (prot & PROT_WRITE && excess1 > 0) {
1139 kdebug("clear[%d] ad=%lx sz=%lx",
1140 loop, maddr + phdr->p_filesz, excess1);
1141 if (clear_user((void __user *) maddr + phdr->p_filesz,
1142 excess1))
1143 return -EFAULT;
1144 }
1145
1146 #else
1147 if (excess > 0) {
1148 kdebug("clear[%d] ad=%lx sz=%lx",
1149 loop, maddr + phdr->p_filesz, excess);
1150 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1151 return -EFAULT;
1152 }
1153 #endif
1154
1155 if (mm) {
1156 if (phdr->p_flags & PF_X) {
1157 if (!mm->start_code) {
1158 mm->start_code = maddr;
1159 mm->end_code = maddr + phdr->p_memsz;
1160 }
1161 } else if (!mm->start_data) {
1162 mm->start_data = maddr;
1163 mm->end_data = maddr + phdr->p_memsz;
1164 }
1165 }
1166
1167 seg++;
1168 }
1169
1170 return 0;
1171 }
1172
1173 /*****************************************************************************/
1174 /*
1175 * ELF-FDPIC core dumper
1176 *
1177 * Modelled on fs/exec.c:aout_core_dump()
1178 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1179 *
1180 * Modelled on fs/binfmt_elf.c core dumper
1181 */
1182 #ifdef CONFIG_ELF_CORE
1183
1184 /*
1185 * Decide whether a segment is worth dumping; default is yes to be
1186 * sure (missing info is worse than too much; etc).
1187 * Personally I'd include everything, and use the coredump limit...
1188 *
1189 * I think we should skip something. But I am not sure how. H.J.
1190 */
1191 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1192 {
1193 int dump_ok;
1194
1195 /* Do not dump I/O mapped devices or special mappings */
1196 if (vma->vm_flags & VM_IO) {
1197 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1198 return 0;
1199 }
1200
1201 /* If we may not read the contents, don't allow us to dump
1202 * them either. "dump_write()" can't handle it anyway.
1203 */
1204 if (!(vma->vm_flags & VM_READ)) {
1205 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1206 return 0;
1207 }
1208
1209 /* By default, dump shared memory if mapped from an anonymous file. */
1210 if (vma->vm_flags & VM_SHARED) {
1211 if (file_inode(vma->vm_file)->i_nlink == 0) {
1212 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1213 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1214 vma->vm_flags, dump_ok ? "yes" : "no");
1215 return dump_ok;
1216 }
1217
1218 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1219 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1220 vma->vm_flags, dump_ok ? "yes" : "no");
1221 return dump_ok;
1222 }
1223
1224 #ifdef CONFIG_MMU
1225 /* By default, if it hasn't been written to, don't write it out */
1226 if (!vma->anon_vma) {
1227 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1228 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1229 vma->vm_flags, dump_ok ? "yes" : "no");
1230 return dump_ok;
1231 }
1232 #endif
1233
1234 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1235 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1236 dump_ok ? "yes" : "no");
1237 return dump_ok;
1238 }
1239
1240 /* An ELF note in memory */
1241 struct memelfnote
1242 {
1243 const char *name;
1244 int type;
1245 unsigned int datasz;
1246 void *data;
1247 };
1248
1249 static int notesize(struct memelfnote *en)
1250 {
1251 int sz;
1252
1253 sz = sizeof(struct elf_note);
1254 sz += roundup(strlen(en->name) + 1, 4);
1255 sz += roundup(en->datasz, 4);
1256
1257 return sz;
1258 }
1259
1260 /* #define DEBUG */
1261
1262 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1263 {
1264 struct elf_note en;
1265 en.n_namesz = strlen(men->name) + 1;
1266 en.n_descsz = men->datasz;
1267 en.n_type = men->type;
1268
1269 return dump_emit(cprm, &en, sizeof(en)) &&
1270 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1271 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1272 }
1273
1274 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1275 {
1276 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1277 elf->e_ident[EI_CLASS] = ELF_CLASS;
1278 elf->e_ident[EI_DATA] = ELF_DATA;
1279 elf->e_ident[EI_VERSION] = EV_CURRENT;
1280 elf->e_ident[EI_OSABI] = ELF_OSABI;
1281 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1282
1283 elf->e_type = ET_CORE;
1284 elf->e_machine = ELF_ARCH;
1285 elf->e_version = EV_CURRENT;
1286 elf->e_entry = 0;
1287 elf->e_phoff = sizeof(struct elfhdr);
1288 elf->e_shoff = 0;
1289 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1290 elf->e_ehsize = sizeof(struct elfhdr);
1291 elf->e_phentsize = sizeof(struct elf_phdr);
1292 elf->e_phnum = segs;
1293 elf->e_shentsize = 0;
1294 elf->e_shnum = 0;
1295 elf->e_shstrndx = 0;
1296 return;
1297 }
1298
1299 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1300 {
1301 phdr->p_type = PT_NOTE;
1302 phdr->p_offset = offset;
1303 phdr->p_vaddr = 0;
1304 phdr->p_paddr = 0;
1305 phdr->p_filesz = sz;
1306 phdr->p_memsz = 0;
1307 phdr->p_flags = 0;
1308 phdr->p_align = 0;
1309 return;
1310 }
1311
1312 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1313 unsigned int sz, void *data)
1314 {
1315 note->name = name;
1316 note->type = type;
1317 note->datasz = sz;
1318 note->data = data;
1319 return;
1320 }
1321
1322 /*
1323 * fill up all the fields in prstatus from the given task struct, except
1324 * registers which need to be filled up separately.
1325 */
1326 static void fill_prstatus(struct elf_prstatus *prstatus,
1327 struct task_struct *p, long signr)
1328 {
1329 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1330 prstatus->pr_sigpend = p->pending.signal.sig[0];
1331 prstatus->pr_sighold = p->blocked.sig[0];
1332 rcu_read_lock();
1333 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1334 rcu_read_unlock();
1335 prstatus->pr_pid = task_pid_vnr(p);
1336 prstatus->pr_pgrp = task_pgrp_vnr(p);
1337 prstatus->pr_sid = task_session_vnr(p);
1338 if (thread_group_leader(p)) {
1339 struct task_cputime cputime;
1340
1341 /*
1342 * This is the record for the group leader. It shows the
1343 * group-wide total, not its individual thread total.
1344 */
1345 thread_group_cputime(p, &cputime);
1346 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1347 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1348 } else {
1349 cputime_t utime, stime;
1350
1351 task_cputime(p, &utime, &stime);
1352 cputime_to_timeval(utime, &prstatus->pr_utime);
1353 cputime_to_timeval(stime, &prstatus->pr_stime);
1354 }
1355 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1356 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1357
1358 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1359 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1360 }
1361
1362 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1363 struct mm_struct *mm)
1364 {
1365 const struct cred *cred;
1366 unsigned int i, len;
1367
1368 /* first copy the parameters from user space */
1369 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1370
1371 len = mm->arg_end - mm->arg_start;
1372 if (len >= ELF_PRARGSZ)
1373 len = ELF_PRARGSZ - 1;
1374 if (copy_from_user(&psinfo->pr_psargs,
1375 (const char __user *) mm->arg_start, len))
1376 return -EFAULT;
1377 for (i = 0; i < len; i++)
1378 if (psinfo->pr_psargs[i] == 0)
1379 psinfo->pr_psargs[i] = ' ';
1380 psinfo->pr_psargs[len] = 0;
1381
1382 rcu_read_lock();
1383 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1384 rcu_read_unlock();
1385 psinfo->pr_pid = task_pid_vnr(p);
1386 psinfo->pr_pgrp = task_pgrp_vnr(p);
1387 psinfo->pr_sid = task_session_vnr(p);
1388
1389 i = p->state ? ffz(~p->state) + 1 : 0;
1390 psinfo->pr_state = i;
1391 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1392 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1393 psinfo->pr_nice = task_nice(p);
1394 psinfo->pr_flag = p->flags;
1395 rcu_read_lock();
1396 cred = __task_cred(p);
1397 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1398 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1399 rcu_read_unlock();
1400 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1401
1402 return 0;
1403 }
1404
1405 /* Here is the structure in which status of each thread is captured. */
1406 struct elf_thread_status
1407 {
1408 struct list_head list;
1409 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1410 elf_fpregset_t fpu; /* NT_PRFPREG */
1411 struct task_struct *thread;
1412 #ifdef ELF_CORE_COPY_XFPREGS
1413 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1414 #endif
1415 struct memelfnote notes[3];
1416 int num_notes;
1417 };
1418
1419 /*
1420 * In order to add the specific thread information for the elf file format,
1421 * we need to keep a linked list of every thread's pr_status and then create
1422 * a single section for them in the final core file.
1423 */
1424 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1425 {
1426 struct task_struct *p = t->thread;
1427 int sz = 0;
1428
1429 t->num_notes = 0;
1430
1431 fill_prstatus(&t->prstatus, p, signr);
1432 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1433
1434 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1435 &t->prstatus);
1436 t->num_notes++;
1437 sz += notesize(&t->notes[0]);
1438
1439 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1440 if (t->prstatus.pr_fpvalid) {
1441 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1442 &t->fpu);
1443 t->num_notes++;
1444 sz += notesize(&t->notes[1]);
1445 }
1446
1447 #ifdef ELF_CORE_COPY_XFPREGS
1448 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1449 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1450 sizeof(t->xfpu), &t->xfpu);
1451 t->num_notes++;
1452 sz += notesize(&t->notes[2]);
1453 }
1454 #endif
1455 return sz;
1456 }
1457
1458 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1459 elf_addr_t e_shoff, int segs)
1460 {
1461 elf->e_shoff = e_shoff;
1462 elf->e_shentsize = sizeof(*shdr4extnum);
1463 elf->e_shnum = 1;
1464 elf->e_shstrndx = SHN_UNDEF;
1465
1466 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1467
1468 shdr4extnum->sh_type = SHT_NULL;
1469 shdr4extnum->sh_size = elf->e_shnum;
1470 shdr4extnum->sh_link = elf->e_shstrndx;
1471 shdr4extnum->sh_info = segs;
1472 }
1473
1474 /*
1475 * dump the segments for an MMU process
1476 */
1477 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1478 {
1479 struct vm_area_struct *vma;
1480
1481 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1482 unsigned long addr;
1483
1484 if (!maydump(vma, cprm->mm_flags))
1485 continue;
1486
1487 #ifdef CONFIG_MMU
1488 for (addr = vma->vm_start; addr < vma->vm_end;
1489 addr += PAGE_SIZE) {
1490 bool res;
1491 struct page *page = get_dump_page(addr);
1492 if (page) {
1493 void *kaddr = kmap(page);
1494 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1495 kunmap(page);
1496 page_cache_release(page);
1497 } else {
1498 res = dump_skip(cprm, PAGE_SIZE);
1499 }
1500 if (!res)
1501 return false;
1502 }
1503 #else
1504 if (!dump_emit(cprm, (void *) vma->vm_start,
1505 vma->vm_end - vma->vm_start))
1506 return false;
1507 #endif
1508 }
1509 return true;
1510 }
1511
1512 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1513 {
1514 struct vm_area_struct *vma;
1515 size_t size = 0;
1516
1517 for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1518 if (maydump(vma, mm_flags))
1519 size += vma->vm_end - vma->vm_start;
1520 return size;
1521 }
1522
1523 /*
1524 * Actual dumper
1525 *
1526 * This is a two-pass process; first we find the offsets of the bits,
1527 * and then they are actually written out. If we run out of core limit
1528 * we just truncate.
1529 */
1530 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1531 {
1532 #define NUM_NOTES 6
1533 int has_dumped = 0;
1534 mm_segment_t fs;
1535 int segs;
1536 int i;
1537 struct vm_area_struct *vma;
1538 struct elfhdr *elf = NULL;
1539 loff_t offset = 0, dataoff;
1540 int numnote;
1541 struct memelfnote *notes = NULL;
1542 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1543 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1544 LIST_HEAD(thread_list);
1545 struct list_head *t;
1546 elf_fpregset_t *fpu = NULL;
1547 #ifdef ELF_CORE_COPY_XFPREGS
1548 elf_fpxregset_t *xfpu = NULL;
1549 #endif
1550 int thread_status_size = 0;
1551 elf_addr_t *auxv;
1552 struct elf_phdr *phdr4note = NULL;
1553 struct elf_shdr *shdr4extnum = NULL;
1554 Elf_Half e_phnum;
1555 elf_addr_t e_shoff;
1556 struct core_thread *ct;
1557 struct elf_thread_status *tmp;
1558
1559 /*
1560 * We no longer stop all VM operations.
1561 *
1562 * This is because those proceses that could possibly change map_count
1563 * or the mmap / vma pages are now blocked in do_exit on current
1564 * finishing this core dump.
1565 *
1566 * Only ptrace can touch these memory addresses, but it doesn't change
1567 * the map_count or the pages allocated. So no possibility of crashing
1568 * exists while dumping the mm->vm_next areas to the core file.
1569 */
1570
1571 /* alloc memory for large data structures: too large to be on stack */
1572 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1573 if (!elf)
1574 goto cleanup;
1575 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1576 if (!prstatus)
1577 goto cleanup;
1578 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1579 if (!psinfo)
1580 goto cleanup;
1581 notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1582 if (!notes)
1583 goto cleanup;
1584 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1585 if (!fpu)
1586 goto cleanup;
1587 #ifdef ELF_CORE_COPY_XFPREGS
1588 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1589 if (!xfpu)
1590 goto cleanup;
1591 #endif
1592
1593 for (ct = current->mm->core_state->dumper.next;
1594 ct; ct = ct->next) {
1595 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1596 if (!tmp)
1597 goto cleanup;
1598
1599 tmp->thread = ct->task;
1600 list_add(&tmp->list, &thread_list);
1601 }
1602
1603 list_for_each(t, &thread_list) {
1604 struct elf_thread_status *tmp;
1605 int sz;
1606
1607 tmp = list_entry(t, struct elf_thread_status, list);
1608 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1609 thread_status_size += sz;
1610 }
1611
1612 /* now collect the dump for the current */
1613 fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1614 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1615
1616 segs = current->mm->map_count;
1617 segs += elf_core_extra_phdrs();
1618
1619 /* for notes section */
1620 segs++;
1621
1622 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1623 * this, kernel supports extended numbering. Have a look at
1624 * include/linux/elf.h for further information. */
1625 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1626
1627 /* Set up header */
1628 fill_elf_fdpic_header(elf, e_phnum);
1629
1630 has_dumped = 1;
1631 /*
1632 * Set up the notes in similar form to SVR4 core dumps made
1633 * with info from their /proc.
1634 */
1635
1636 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1637 fill_psinfo(psinfo, current->group_leader, current->mm);
1638 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1639
1640 numnote = 2;
1641
1642 auxv = (elf_addr_t *) current->mm->saved_auxv;
1643
1644 i = 0;
1645 do
1646 i += 2;
1647 while (auxv[i - 2] != AT_NULL);
1648 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1649 i * sizeof(elf_addr_t), auxv);
1650
1651 /* Try to dump the FPU. */
1652 if ((prstatus->pr_fpvalid =
1653 elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1654 fill_note(notes + numnote++,
1655 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1656 #ifdef ELF_CORE_COPY_XFPREGS
1657 if (elf_core_copy_task_xfpregs(current, xfpu))
1658 fill_note(notes + numnote++,
1659 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1660 #endif
1661
1662 fs = get_fs();
1663 set_fs(KERNEL_DS);
1664
1665 offset += sizeof(*elf); /* Elf header */
1666 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1667
1668 /* Write notes phdr entry */
1669 {
1670 int sz = 0;
1671
1672 for (i = 0; i < numnote; i++)
1673 sz += notesize(notes + i);
1674
1675 sz += thread_status_size;
1676
1677 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1678 if (!phdr4note)
1679 goto end_coredump;
1680
1681 fill_elf_note_phdr(phdr4note, sz, offset);
1682 offset += sz;
1683 }
1684
1685 /* Page-align dumped data */
1686 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1687
1688 offset += elf_core_vma_data_size(cprm->mm_flags);
1689 offset += elf_core_extra_data_size();
1690 e_shoff = offset;
1691
1692 if (e_phnum == PN_XNUM) {
1693 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1694 if (!shdr4extnum)
1695 goto end_coredump;
1696 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1697 }
1698
1699 offset = dataoff;
1700
1701 if (!dump_emit(cprm, elf, sizeof(*elf)))
1702 goto end_coredump;
1703
1704 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1705 goto end_coredump;
1706
1707 /* write program headers for segments dump */
1708 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1709 struct elf_phdr phdr;
1710 size_t sz;
1711
1712 sz = vma->vm_end - vma->vm_start;
1713
1714 phdr.p_type = PT_LOAD;
1715 phdr.p_offset = offset;
1716 phdr.p_vaddr = vma->vm_start;
1717 phdr.p_paddr = 0;
1718 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1719 phdr.p_memsz = sz;
1720 offset += phdr.p_filesz;
1721 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1722 if (vma->vm_flags & VM_WRITE)
1723 phdr.p_flags |= PF_W;
1724 if (vma->vm_flags & VM_EXEC)
1725 phdr.p_flags |= PF_X;
1726 phdr.p_align = ELF_EXEC_PAGESIZE;
1727
1728 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1729 goto end_coredump;
1730 }
1731
1732 if (!elf_core_write_extra_phdrs(cprm, offset))
1733 goto end_coredump;
1734
1735 /* write out the notes section */
1736 for (i = 0; i < numnote; i++)
1737 if (!writenote(notes + i, cprm))
1738 goto end_coredump;
1739
1740 /* write out the thread status notes section */
1741 list_for_each(t, &thread_list) {
1742 struct elf_thread_status *tmp =
1743 list_entry(t, struct elf_thread_status, list);
1744
1745 for (i = 0; i < tmp->num_notes; i++)
1746 if (!writenote(&tmp->notes[i], cprm))
1747 goto end_coredump;
1748 }
1749
1750 if (!dump_skip(cprm, dataoff - cprm->written))
1751 goto end_coredump;
1752
1753 if (!elf_fdpic_dump_segments(cprm))
1754 goto end_coredump;
1755
1756 if (!elf_core_write_extra_data(cprm))
1757 goto end_coredump;
1758
1759 if (e_phnum == PN_XNUM) {
1760 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1761 goto end_coredump;
1762 }
1763
1764 if (cprm->file->f_pos != offset) {
1765 /* Sanity check */
1766 printk(KERN_WARNING
1767 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1768 cprm->file->f_pos, offset);
1769 }
1770
1771 end_coredump:
1772 set_fs(fs);
1773
1774 cleanup:
1775 while (!list_empty(&thread_list)) {
1776 struct list_head *tmp = thread_list.next;
1777 list_del(tmp);
1778 kfree(list_entry(tmp, struct elf_thread_status, list));
1779 }
1780 kfree(phdr4note);
1781 kfree(elf);
1782 kfree(prstatus);
1783 kfree(psinfo);
1784 kfree(notes);
1785 kfree(fpu);
1786 kfree(shdr4extnum);
1787 #ifdef ELF_CORE_COPY_XFPREGS
1788 kfree(xfpu);
1789 #endif
1790 return has_dumped;
1791 #undef NUM_NOTES
1792 }
1793
1794 #endif /* CONFIG_ELF_CORE */
Linux with added FPC-III support