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Merge tag 'for-5.8/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device...
[linux/fpc-iii.git] / fs / binfmt_elf_fdpic.c
blob0f45521b237cd0ab8998f46d27554af585baaae1
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
3 *
4 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 * Derived from binfmt_elf.c
7 */
8
9 #include <linux/module.h>
10
11 #include <linux/fs.h>
12 #include <linux/stat.h>
13 #include <linux/sched.h>
14 #include <linux/sched/coredump.h>
15 #include <linux/sched/task_stack.h>
16 #include <linux/sched/cputime.h>
17 #include <linux/mm.h>
18 #include <linux/mman.h>
19 #include <linux/errno.h>
20 #include <linux/signal.h>
21 #include <linux/binfmts.h>
22 #include <linux/string.h>
23 #include <linux/file.h>
24 #include <linux/fcntl.h>
25 #include <linux/slab.h>
26 #include <linux/pagemap.h>
27 #include <linux/security.h>
28 #include <linux/highmem.h>
29 #include <linux/highuid.h>
30 #include <linux/personality.h>
31 #include <linux/ptrace.h>
32 #include <linux/init.h>
33 #include <linux/elf.h>
34 #include <linux/elf-fdpic.h>
35 #include <linux/elfcore.h>
36 #include <linux/coredump.h>
37 #include <linux/dax.h>
38
39 #include <linux/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_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
70 struct file *,
71 struct mm_struct *);
72 #endif
73
74 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
75 struct file *, struct mm_struct *);
76
77 #ifdef CONFIG_ELF_CORE
78 static int elf_fdpic_core_dump(struct coredump_params *cprm);
79 #endif
80
81 static struct linux_binfmt elf_fdpic_format = {
82 .module = THIS_MODULE,
83 .load_binary = load_elf_fdpic_binary,
84 #ifdef CONFIG_ELF_CORE
85 .core_dump = elf_fdpic_core_dump,
86 #endif
87 .min_coredump = ELF_EXEC_PAGESIZE,
88 };
89
90 static int __init init_elf_fdpic_binfmt(void)
91 {
92 register_binfmt(&elf_fdpic_format);
93 return 0;
94 }
95
96 static void __exit exit_elf_fdpic_binfmt(void)
97 {
98 unregister_binfmt(&elf_fdpic_format);
99 }
100
101 core_initcall(init_elf_fdpic_binfmt);
102 module_exit(exit_elf_fdpic_binfmt);
103
104 static int is_elf(struct elfhdr *hdr, struct file *file)
105 {
106 if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
107 return 0;
108 if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
109 return 0;
110 if (!elf_check_arch(hdr))
111 return 0;
112 if (!file->f_op->mmap)
113 return 0;
114 return 1;
115 }
116
117 #ifndef elf_check_fdpic
118 #define elf_check_fdpic(x) 0
119 #endif
120
121 #ifndef elf_check_const_displacement
122 #define elf_check_const_displacement(x) 0
123 #endif
124
125 static int is_constdisp(struct elfhdr *hdr)
126 {
127 if (!elf_check_fdpic(hdr))
128 return 1;
129 if (elf_check_const_displacement(hdr))
130 return 1;
131 return 0;
132 }
133
134 /*****************************************************************************/
135 /*
136 * read the program headers table into memory
137 */
138 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
139 struct file *file)
140 {
141 struct elf32_phdr *phdr;
142 unsigned long size;
143 int retval, loop;
144 loff_t pos = params->hdr.e_phoff;
145
146 if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
147 return -ENOMEM;
148 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
149 return -ENOMEM;
150
151 size = params->hdr.e_phnum * sizeof(struct elf_phdr);
152 params->phdrs = kmalloc(size, GFP_KERNEL);
153 if (!params->phdrs)
154 return -ENOMEM;
155
156 retval = kernel_read(file, params->phdrs, size, &pos);
157 if (unlikely(retval != size))
158 return retval < 0 ? retval : -ENOEXEC;
159
160 /* determine stack size for this binary */
161 phdr = params->phdrs;
162 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
163 if (phdr->p_type != PT_GNU_STACK)
164 continue;
165
166 if (phdr->p_flags & PF_X)
167 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
168 else
169 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
170
171 params->stack_size = phdr->p_memsz;
172 break;
173 }
174
175 return 0;
176 }
177
178 /*****************************************************************************/
179 /*
180 * load an fdpic binary into various bits of memory
181 */
182 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
183 {
184 struct elf_fdpic_params exec_params, interp_params;
185 struct pt_regs *regs = current_pt_regs();
186 struct elf_phdr *phdr;
187 unsigned long stack_size, entryaddr;
188 #ifdef ELF_FDPIC_PLAT_INIT
189 unsigned long dynaddr;
190 #endif
191 #ifndef CONFIG_MMU
192 unsigned long stack_prot;
193 #endif
194 struct file *interpreter = NULL; /* to shut gcc up */
195 char *interpreter_name = NULL;
196 int executable_stack;
197 int retval, i;
198 loff_t pos;
199
200 kdebug("____ LOAD %d ____", current->pid);
201
202 memset(&exec_params, 0, sizeof(exec_params));
203 memset(&interp_params, 0, sizeof(interp_params));
204
205 exec_params.hdr = *(struct elfhdr *) bprm->buf;
206 exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
207
208 /* check that this is a binary we know how to deal with */
209 retval = -ENOEXEC;
210 if (!is_elf(&exec_params.hdr, bprm->file))
211 goto error;
212 if (!elf_check_fdpic(&exec_params.hdr)) {
213 #ifdef CONFIG_MMU
214 /* binfmt_elf handles non-fdpic elf except on nommu */
215 goto error;
216 #else
217 /* nommu can only load ET_DYN (PIE) ELF */
218 if (exec_params.hdr.e_type != ET_DYN)
219 goto error;
220 #endif
221 }
222
223 /* read the program header table */
224 retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
225 if (retval < 0)
226 goto error;
227
228 /* scan for a program header that specifies an interpreter */
229 phdr = exec_params.phdrs;
230
231 for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
232 switch (phdr->p_type) {
233 case PT_INTERP:
234 retval = -ENOMEM;
235 if (phdr->p_filesz > PATH_MAX)
236 goto error;
237 retval = -ENOENT;
238 if (phdr->p_filesz < 2)
239 goto error;
240
241 /* read the name of the interpreter into memory */
242 interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
243 if (!interpreter_name)
244 goto error;
245
246 pos = phdr->p_offset;
247 retval = kernel_read(bprm->file, interpreter_name,
248 phdr->p_filesz, &pos);
249 if (unlikely(retval != phdr->p_filesz)) {
250 if (retval >= 0)
251 retval = -ENOEXEC;
252 goto error;
253 }
254
255 retval = -ENOENT;
256 if (interpreter_name[phdr->p_filesz - 1] != '\0')
257 goto error;
258
259 kdebug("Using ELF interpreter %s", interpreter_name);
260
261 /* replace the program with the interpreter */
262 interpreter = open_exec(interpreter_name);
263 retval = PTR_ERR(interpreter);
264 if (IS_ERR(interpreter)) {
265 interpreter = NULL;
266 goto error;
267 }
268
269 /*
270 * If the binary is not readable then enforce
271 * mm->dumpable = 0 regardless of the interpreter's
272 * permissions.
273 */
274 would_dump(bprm, interpreter);
275
276 pos = 0;
277 retval = kernel_read(interpreter, bprm->buf,
278 BINPRM_BUF_SIZE, &pos);
279 if (unlikely(retval != BINPRM_BUF_SIZE)) {
280 if (retval >= 0)
281 retval = -ENOEXEC;
282 goto error;
283 }
284
285 interp_params.hdr = *((struct elfhdr *) bprm->buf);
286 break;
287
288 case PT_LOAD:
289 #ifdef CONFIG_MMU
290 if (exec_params.load_addr == 0)
291 exec_params.load_addr = phdr->p_vaddr;
292 #endif
293 break;
294 }
295
296 }
297
298 if (is_constdisp(&exec_params.hdr))
299 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
300
301 /* perform insanity checks on the interpreter */
302 if (interpreter_name) {
303 retval = -ELIBBAD;
304 if (!is_elf(&interp_params.hdr, interpreter))
305 goto error;
306
307 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
308
309 /* read the interpreter's program header table */
310 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
311 if (retval < 0)
312 goto error;
313 }
314
315 stack_size = exec_params.stack_size;
316 if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
317 executable_stack = EXSTACK_ENABLE_X;
318 else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
319 executable_stack = EXSTACK_DISABLE_X;
320 else
321 executable_stack = EXSTACK_DEFAULT;
322
323 if (stack_size == 0) {
324 stack_size = interp_params.stack_size;
325 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
326 executable_stack = EXSTACK_ENABLE_X;
327 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
328 executable_stack = EXSTACK_DISABLE_X;
329 else
330 executable_stack = EXSTACK_DEFAULT;
331 }
332
333 retval = -ENOEXEC;
334 if (stack_size == 0)
335 stack_size = 131072UL; /* same as exec.c's default commit */
336
337 if (is_constdisp(&interp_params.hdr))
338 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
339
340 /* flush all traces of the currently running executable */
341 retval = begin_new_exec(bprm);
342 if (retval)
343 goto error;
344
345 /* there's now no turning back... the old userspace image is dead,
346 * defunct, deceased, etc.
347 */
348 if (elf_check_fdpic(&exec_params.hdr))
349 set_personality(PER_LINUX_FDPIC);
350 else
351 set_personality(PER_LINUX);
352 if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
353 current->personality |= READ_IMPLIES_EXEC;
354
355 setup_new_exec(bprm);
356
357 set_binfmt(&elf_fdpic_format);
358
359 current->mm->start_code = 0;
360 current->mm->end_code = 0;
361 current->mm->start_stack = 0;
362 current->mm->start_data = 0;
363 current->mm->end_data = 0;
364 current->mm->context.exec_fdpic_loadmap = 0;
365 current->mm->context.interp_fdpic_loadmap = 0;
366
367 #ifdef CONFIG_MMU
368 elf_fdpic_arch_lay_out_mm(&exec_params,
369 &interp_params,
370 &current->mm->start_stack,
371 &current->mm->start_brk);
372
373 retval = setup_arg_pages(bprm, current->mm->start_stack,
374 executable_stack);
375 if (retval < 0)
376 goto error;
377 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
378 retval = arch_setup_additional_pages(bprm, !!interpreter_name);
379 if (retval < 0)
380 goto error;
381 #endif
382 #endif
383
384 /* load the executable and interpreter into memory */
385 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
386 "executable");
387 if (retval < 0)
388 goto error;
389
390 if (interpreter_name) {
391 retval = elf_fdpic_map_file(&interp_params, interpreter,
392 current->mm, "interpreter");
393 if (retval < 0) {
394 printk(KERN_ERR "Unable to load interpreter\n");
395 goto error;
396 }
397
398 allow_write_access(interpreter);
399 fput(interpreter);
400 interpreter = NULL;
401 }
402
403 #ifdef CONFIG_MMU
404 if (!current->mm->start_brk)
405 current->mm->start_brk = current->mm->end_data;
406
407 current->mm->brk = current->mm->start_brk =
408 PAGE_ALIGN(current->mm->start_brk);
409
410 #else
411 /* create a stack area and zero-size brk area */
412 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
413 if (stack_size < PAGE_SIZE * 2)
414 stack_size = PAGE_SIZE * 2;
415
416 stack_prot = PROT_READ | PROT_WRITE;
417 if (executable_stack == EXSTACK_ENABLE_X ||
418 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
419 stack_prot |= PROT_EXEC;
420
421 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
422 MAP_PRIVATE | MAP_ANONYMOUS |
423 MAP_UNINITIALIZED | MAP_GROWSDOWN,
424 0);
425
426 if (IS_ERR_VALUE(current->mm->start_brk)) {
427 retval = current->mm->start_brk;
428 current->mm->start_brk = 0;
429 goto error;
430 }
431
432 current->mm->brk = current->mm->start_brk;
433 current->mm->context.end_brk = current->mm->start_brk;
434 current->mm->start_stack = current->mm->start_brk + stack_size;
435 #endif
436
437 if (create_elf_fdpic_tables(bprm, current->mm,
438 &exec_params, &interp_params) < 0)
439 goto error;
440
441 kdebug("- start_code %lx", current->mm->start_code);
442 kdebug("- end_code %lx", current->mm->end_code);
443 kdebug("- start_data %lx", current->mm->start_data);
444 kdebug("- end_data %lx", current->mm->end_data);
445 kdebug("- start_brk %lx", current->mm->start_brk);
446 kdebug("- brk %lx", current->mm->brk);
447 kdebug("- start_stack %lx", current->mm->start_stack);
448
449 #ifdef ELF_FDPIC_PLAT_INIT
450 /*
451 * The ABI may specify that certain registers be set up in special
452 * ways (on i386 %edx is the address of a DT_FINI function, for
453 * example. This macro performs whatever initialization to
454 * the regs structure is required.
455 */
456 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
457 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
458 dynaddr);
459 #endif
460
461 finalize_exec(bprm);
462 /* everything is now ready... get the userspace context ready to roll */
463 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
464 start_thread(regs, entryaddr, current->mm->start_stack);
465
466 retval = 0;
467
468 error:
469 if (interpreter) {
470 allow_write_access(interpreter);
471 fput(interpreter);
472 }
473 kfree(interpreter_name);
474 kfree(exec_params.phdrs);
475 kfree(exec_params.loadmap);
476 kfree(interp_params.phdrs);
477 kfree(interp_params.loadmap);
478 return retval;
479 }
480
481 /*****************************************************************************/
482
483 #ifndef ELF_BASE_PLATFORM
484 /*
485 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
486 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
487 * will be copied to the user stack in the same manner as AT_PLATFORM.
488 */
489 #define ELF_BASE_PLATFORM NULL
490 #endif
491
492 /*
493 * present useful information to the program by shovelling it onto the new
494 * process's stack
495 */
496 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
497 struct mm_struct *mm,
498 struct elf_fdpic_params *exec_params,
499 struct elf_fdpic_params *interp_params)
500 {
501 const struct cred *cred = current_cred();
502 unsigned long sp, csp, nitems;
503 elf_caddr_t __user *argv, *envp;
504 size_t platform_len = 0, len;
505 char *k_platform, *k_base_platform;
506 char __user *u_platform, *u_base_platform, *p;
507 int loop;
508 int nr; /* reset for each csp adjustment */
509
510 #ifdef CONFIG_MMU
511 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
512 * by the processes running on the same package. One thing we can do is
513 * to shuffle the initial stack for them, so we give the architecture
514 * an opportunity to do so here.
515 */
516 sp = arch_align_stack(bprm->p);
517 #else
518 sp = mm->start_stack;
519
520 /* stack the program arguments and environment */
521 if (transfer_args_to_stack(bprm, &sp) < 0)
522 return -EFAULT;
523 sp &= ~15;
524 #endif
525
526 /*
527 * If this architecture has a platform capability string, copy it
528 * to userspace. In some cases (Sparc), this info is impossible
529 * for userspace to get any other way, in others (i386) it is
530 * merely difficult.
531 */
532 k_platform = ELF_PLATFORM;
533 u_platform = NULL;
534
535 if (k_platform) {
536 platform_len = strlen(k_platform) + 1;
537 sp -= platform_len;
538 u_platform = (char __user *) sp;
539 if (copy_to_user(u_platform, k_platform, platform_len) != 0)
540 return -EFAULT;
541 }
542
543 /*
544 * If this architecture has a "base" platform capability
545 * string, copy it to userspace.
546 */
547 k_base_platform = ELF_BASE_PLATFORM;
548 u_base_platform = NULL;
549
550 if (k_base_platform) {
551 platform_len = strlen(k_base_platform) + 1;
552 sp -= platform_len;
553 u_base_platform = (char __user *) sp;
554 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
555 return -EFAULT;
556 }
557
558 sp &= ~7UL;
559
560 /* stack the load map(s) */
561 len = sizeof(struct elf32_fdpic_loadmap);
562 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
563 sp = (sp - len) & ~7UL;
564 exec_params->map_addr = sp;
565
566 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
567 return -EFAULT;
568
569 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
570
571 if (interp_params->loadmap) {
572 len = sizeof(struct elf32_fdpic_loadmap);
573 len += sizeof(struct elf32_fdpic_loadseg) *
574 interp_params->loadmap->nsegs;
575 sp = (sp - len) & ~7UL;
576 interp_params->map_addr = sp;
577
578 if (copy_to_user((void __user *) sp, interp_params->loadmap,
579 len) != 0)
580 return -EFAULT;
581
582 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
583 }
584
585 /* force 16 byte _final_ alignment here for generality */
586 #define DLINFO_ITEMS 15
587
588 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
589 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
590
591 if (bprm->have_execfd)
592 nitems++;
593
594 csp = sp;
595 sp -= nitems * 2 * sizeof(unsigned long);
596 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
597 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
598 sp -= 1 * sizeof(unsigned long); /* argc */
599
600 csp -= sp & 15UL;
601 sp -= sp & 15UL;
602
603 /* put the ELF interpreter info on the stack */
604 #define NEW_AUX_ENT(id, val) \
605 do { \
606 struct { unsigned long _id, _val; } __user *ent, v; \
607 \
608 ent = (void __user *) csp; \
609 v._id = (id); \
610 v._val = (val); \
611 if (copy_to_user(ent + nr, &v, sizeof(v))) \
612 return -EFAULT; \
613 nr++; \
614 } while (0)
615
616 nr = 0;
617 csp -= 2 * sizeof(unsigned long);
618 NEW_AUX_ENT(AT_NULL, 0);
619 if (k_platform) {
620 nr = 0;
621 csp -= 2 * sizeof(unsigned long);
622 NEW_AUX_ENT(AT_PLATFORM,
623 (elf_addr_t) (unsigned long) u_platform);
624 }
625
626 if (k_base_platform) {
627 nr = 0;
628 csp -= 2 * sizeof(unsigned long);
629 NEW_AUX_ENT(AT_BASE_PLATFORM,
630 (elf_addr_t) (unsigned long) u_base_platform);
631 }
632
633 if (bprm->have_execfd) {
634 nr = 0;
635 csp -= 2 * sizeof(unsigned long);
636 NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
637 }
638
639 nr = 0;
640 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
641 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
642 #ifdef ELF_HWCAP2
643 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
644 #endif
645 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
646 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
647 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
648 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
649 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
650 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
651 NEW_AUX_ENT(AT_FLAGS, 0);
652 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
653 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
654 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
655 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
656 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
657 NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
658 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
659
660 #ifdef ARCH_DLINFO
661 nr = 0;
662 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
663
664 /* ARCH_DLINFO must come last so platform specific code can enforce
665 * special alignment requirements on the AUXV if necessary (eg. PPC).
666 */
667 ARCH_DLINFO;
668 #endif
669 #undef NEW_AUX_ENT
670
671 /* allocate room for argv[] and envv[] */
672 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
673 envp = (elf_caddr_t __user *) csp;
674 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
675 argv = (elf_caddr_t __user *) csp;
676
677 /* stack argc */
678 csp -= sizeof(unsigned long);
679 if (put_user(bprm->argc, (unsigned long __user *) csp))
680 return -EFAULT;
681
682 BUG_ON(csp != sp);
683
684 /* fill in the argv[] array */
685 #ifdef CONFIG_MMU
686 current->mm->arg_start = bprm->p;
687 #else
688 current->mm->arg_start = current->mm->start_stack -
689 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
690 #endif
691
692 p = (char __user *) current->mm->arg_start;
693 for (loop = bprm->argc; loop > 0; loop--) {
694 if (put_user((elf_caddr_t) p, argv++))
695 return -EFAULT;
696 len = strnlen_user(p, MAX_ARG_STRLEN);
697 if (!len || len > MAX_ARG_STRLEN)
698 return -EINVAL;
699 p += len;
700 }
701 if (put_user(NULL, argv))
702 return -EFAULT;
703 current->mm->arg_end = (unsigned long) p;
704
705 /* fill in the envv[] array */
706 current->mm->env_start = (unsigned long) p;
707 for (loop = bprm->envc; loop > 0; loop--) {
708 if (put_user((elf_caddr_t)(unsigned long) p, envp++))
709 return -EFAULT;
710 len = strnlen_user(p, MAX_ARG_STRLEN);
711 if (!len || len > MAX_ARG_STRLEN)
712 return -EINVAL;
713 p += len;
714 }
715 if (put_user(NULL, envp))
716 return -EFAULT;
717 current->mm->env_end = (unsigned long) p;
718
719 mm->start_stack = (unsigned long) sp;
720 return 0;
721 }
722
723 /*****************************************************************************/
724 /*
725 * load the appropriate binary image (executable or interpreter) into memory
726 * - we assume no MMU is available
727 * - if no other PIC bits are set in params->hdr->e_flags
728 * - we assume that the LOADable segments in the binary are independently relocatable
729 * - we assume R/O executable segments are shareable
730 * - else
731 * - we assume the loadable parts of the image to require fixed displacement
732 * - the image is not shareable
733 */
734 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
735 struct file *file,
736 struct mm_struct *mm,
737 const char *what)
738 {
739 struct elf32_fdpic_loadmap *loadmap;
740 #ifdef CONFIG_MMU
741 struct elf32_fdpic_loadseg *mseg;
742 #endif
743 struct elf32_fdpic_loadseg *seg;
744 struct elf32_phdr *phdr;
745 unsigned long load_addr, stop;
746 unsigned nloads, tmp;
747 size_t size;
748 int loop, ret;
749
750 /* allocate a load map table */
751 nloads = 0;
752 for (loop = 0; loop < params->hdr.e_phnum; loop++)
753 if (params->phdrs[loop].p_type == PT_LOAD)
754 nloads++;
755
756 if (nloads == 0)
757 return -ELIBBAD;
758
759 size = sizeof(*loadmap) + nloads * sizeof(*seg);
760 loadmap = kzalloc(size, GFP_KERNEL);
761 if (!loadmap)
762 return -ENOMEM;
763
764 params->loadmap = loadmap;
765
766 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
767 loadmap->nsegs = nloads;
768
769 load_addr = params->load_addr;
770 seg = loadmap->segs;
771
772 /* map the requested LOADs into the memory space */
773 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
774 case ELF_FDPIC_FLAG_CONSTDISP:
775 case ELF_FDPIC_FLAG_CONTIGUOUS:
776 #ifndef CONFIG_MMU
777 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
778 if (ret < 0)
779 return ret;
780 break;
781 #endif
782 default:
783 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
784 if (ret < 0)
785 return ret;
786 break;
787 }
788
789 /* map the entry point */
790 if (params->hdr.e_entry) {
791 seg = loadmap->segs;
792 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
793 if (params->hdr.e_entry >= seg->p_vaddr &&
794 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
795 params->entry_addr =
796 (params->hdr.e_entry - seg->p_vaddr) +
797 seg->addr;
798 break;
799 }
800 }
801 }
802
803 /* determine where the program header table has wound up if mapped */
804 stop = params->hdr.e_phoff;
805 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
806 phdr = params->phdrs;
807
808 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
809 if (phdr->p_type != PT_LOAD)
810 continue;
811
812 if (phdr->p_offset > params->hdr.e_phoff ||
813 phdr->p_offset + phdr->p_filesz < stop)
814 continue;
815
816 seg = loadmap->segs;
817 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
818 if (phdr->p_vaddr >= seg->p_vaddr &&
819 phdr->p_vaddr + phdr->p_filesz <=
820 seg->p_vaddr + seg->p_memsz) {
821 params->ph_addr =
822 (phdr->p_vaddr - seg->p_vaddr) +
823 seg->addr +
824 params->hdr.e_phoff - phdr->p_offset;
825 break;
826 }
827 }
828 break;
829 }
830
831 /* determine where the dynamic section has wound up if there is one */
832 phdr = params->phdrs;
833 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
834 if (phdr->p_type != PT_DYNAMIC)
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_memsz <=
841 seg->p_vaddr + seg->p_memsz) {
842 Elf32_Dyn __user *dyn;
843 Elf32_Sword d_tag;
844
845 params->dynamic_addr =
846 (phdr->p_vaddr - seg->p_vaddr) +
847 seg->addr;
848
849 /* check the dynamic section contains at least
850 * one item, and that the last item is a NULL
851 * entry */
852 if (phdr->p_memsz == 0 ||
853 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
854 goto dynamic_error;
855
856 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
857 dyn = (Elf32_Dyn __user *)params->dynamic_addr;
858 if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
859 d_tag != 0)
860 goto dynamic_error;
861 break;
862 }
863 }
864 break;
865 }
866
867 /* now elide adjacent segments in the load map on MMU linux
868 * - on uClinux the holes between may actually be filled with system
869 * stuff or stuff from other processes
870 */
871 #ifdef CONFIG_MMU
872 nloads = loadmap->nsegs;
873 mseg = loadmap->segs;
874 seg = mseg + 1;
875 for (loop = 1; loop < nloads; loop++) {
876 /* see if we have a candidate for merging */
877 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
878 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
879 if (load_addr == (seg->addr & PAGE_MASK)) {
880 mseg->p_memsz +=
881 load_addr -
882 (mseg->addr + mseg->p_memsz);
883 mseg->p_memsz += seg->addr & ~PAGE_MASK;
884 mseg->p_memsz += seg->p_memsz;
885 loadmap->nsegs--;
886 continue;
887 }
888 }
889
890 mseg++;
891 if (mseg != seg)
892 *mseg = *seg;
893 }
894 #endif
895
896 kdebug("Mapped Object [%s]:", what);
897 kdebug("- elfhdr : %lx", params->elfhdr_addr);
898 kdebug("- entry : %lx", params->entry_addr);
899 kdebug("- PHDR[] : %lx", params->ph_addr);
900 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
901 seg = loadmap->segs;
902 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
903 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
904 loop,
905 seg->addr, seg->addr + seg->p_memsz - 1,
906 seg->p_vaddr, seg->p_memsz);
907
908 return 0;
909
910 dynamic_error:
911 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
912 what, file_inode(file)->i_ino);
913 return -ELIBBAD;
914 }
915
916 /*****************************************************************************/
917 /*
918 * map a file with constant displacement under uClinux
919 */
920 #ifndef CONFIG_MMU
921 static int elf_fdpic_map_file_constdisp_on_uclinux(
922 struct elf_fdpic_params *params,
923 struct file *file,
924 struct mm_struct *mm)
925 {
926 struct elf32_fdpic_loadseg *seg;
927 struct elf32_phdr *phdr;
928 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
929 int loop, ret;
930
931 load_addr = params->load_addr;
932 seg = params->loadmap->segs;
933
934 /* determine the bounds of the contiguous overall allocation we must
935 * make */
936 phdr = params->phdrs;
937 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
938 if (params->phdrs[loop].p_type != PT_LOAD)
939 continue;
940
941 if (base > phdr->p_vaddr)
942 base = phdr->p_vaddr;
943 if (top < phdr->p_vaddr + phdr->p_memsz)
944 top = phdr->p_vaddr + phdr->p_memsz;
945 }
946
947 /* allocate one big anon block for everything */
948 mflags = MAP_PRIVATE;
949 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
950 mflags |= MAP_EXECUTABLE;
951
952 maddr = vm_mmap(NULL, load_addr, top - base,
953 PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
954 if (IS_ERR_VALUE(maddr))
955 return (int) maddr;
956
957 if (load_addr != 0)
958 load_addr += PAGE_ALIGN(top - base);
959
960 /* and then load the file segments into it */
961 phdr = params->phdrs;
962 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
963 if (params->phdrs[loop].p_type != PT_LOAD)
964 continue;
965
966 seg->addr = maddr + (phdr->p_vaddr - base);
967 seg->p_vaddr = phdr->p_vaddr;
968 seg->p_memsz = phdr->p_memsz;
969
970 ret = read_code(file, seg->addr, phdr->p_offset,
971 phdr->p_filesz);
972 if (ret < 0)
973 return ret;
974
975 /* map the ELF header address if in this segment */
976 if (phdr->p_offset == 0)
977 params->elfhdr_addr = seg->addr;
978
979 /* clear any space allocated but not loaded */
980 if (phdr->p_filesz < phdr->p_memsz) {
981 if (clear_user((void *) (seg->addr + phdr->p_filesz),
982 phdr->p_memsz - phdr->p_filesz))
983 return -EFAULT;
984 }
985
986 if (mm) {
987 if (phdr->p_flags & PF_X) {
988 if (!mm->start_code) {
989 mm->start_code = seg->addr;
990 mm->end_code = seg->addr +
991 phdr->p_memsz;
992 }
993 } else if (!mm->start_data) {
994 mm->start_data = seg->addr;
995 mm->end_data = seg->addr + phdr->p_memsz;
996 }
997 }
998
999 seg++;
1000 }
1001
1002 return 0;
1003 }
1004 #endif
1005
1006 /*****************************************************************************/
1007 /*
1008 * map a binary by direct mmap() of the individual PT_LOAD segments
1009 */
1010 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1011 struct file *file,
1012 struct mm_struct *mm)
1013 {
1014 struct elf32_fdpic_loadseg *seg;
1015 struct elf32_phdr *phdr;
1016 unsigned long load_addr, delta_vaddr;
1017 int loop, dvset;
1018
1019 load_addr = params->load_addr;
1020 delta_vaddr = 0;
1021 dvset = 0;
1022
1023 seg = params->loadmap->segs;
1024
1025 /* deal with each load segment separately */
1026 phdr = params->phdrs;
1027 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1028 unsigned long maddr, disp, excess, excess1;
1029 int prot = 0, flags;
1030
1031 if (phdr->p_type != PT_LOAD)
1032 continue;
1033
1034 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1035 (unsigned long) phdr->p_vaddr,
1036 (unsigned long) phdr->p_offset,
1037 (unsigned long) phdr->p_filesz,
1038 (unsigned long) phdr->p_memsz);
1039
1040 /* determine the mapping parameters */
1041 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1042 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1043 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1044
1045 flags = MAP_PRIVATE | MAP_DENYWRITE;
1046 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1047 flags |= MAP_EXECUTABLE;
1048
1049 maddr = 0;
1050
1051 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1052 case ELF_FDPIC_FLAG_INDEPENDENT:
1053 /* PT_LOADs are independently locatable */
1054 break;
1055
1056 case ELF_FDPIC_FLAG_HONOURVADDR:
1057 /* the specified virtual address must be honoured */
1058 maddr = phdr->p_vaddr;
1059 flags |= MAP_FIXED;
1060 break;
1061
1062 case ELF_FDPIC_FLAG_CONSTDISP:
1063 /* constant displacement
1064 * - can be mapped anywhere, but must be mapped as a
1065 * unit
1066 */
1067 if (!dvset) {
1068 maddr = load_addr;
1069 delta_vaddr = phdr->p_vaddr;
1070 dvset = 1;
1071 } else {
1072 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1073 flags |= MAP_FIXED;
1074 }
1075 break;
1076
1077 case ELF_FDPIC_FLAG_CONTIGUOUS:
1078 /* contiguity handled later */
1079 break;
1080
1081 default:
1082 BUG();
1083 }
1084
1085 maddr &= PAGE_MASK;
1086
1087 /* create the mapping */
1088 disp = phdr->p_vaddr & ~PAGE_MASK;
1089 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1090 phdr->p_offset - disp);
1091
1092 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1093 loop, phdr->p_memsz + disp, prot, flags,
1094 phdr->p_offset - disp, maddr);
1095
1096 if (IS_ERR_VALUE(maddr))
1097 return (int) maddr;
1098
1099 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1100 ELF_FDPIC_FLAG_CONTIGUOUS)
1101 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1102
1103 seg->addr = maddr + disp;
1104 seg->p_vaddr = phdr->p_vaddr;
1105 seg->p_memsz = phdr->p_memsz;
1106
1107 /* map the ELF header address if in this segment */
1108 if (phdr->p_offset == 0)
1109 params->elfhdr_addr = seg->addr;
1110
1111 /* clear the bit between beginning of mapping and beginning of
1112 * PT_LOAD */
1113 if (prot & PROT_WRITE && disp > 0) {
1114 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1115 if (clear_user((void __user *) maddr, disp))
1116 return -EFAULT;
1117 maddr += disp;
1118 }
1119
1120 /* clear any space allocated but not loaded
1121 * - on uClinux we can just clear the lot
1122 * - on MMU linux we'll get a SIGBUS beyond the last page
1123 * extant in the file
1124 */
1125 excess = phdr->p_memsz - phdr->p_filesz;
1126 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1127
1128 #ifdef CONFIG_MMU
1129 if (excess > excess1) {
1130 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1131 unsigned long xmaddr;
1132
1133 flags |= MAP_FIXED | MAP_ANONYMOUS;
1134 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1135 prot, flags, 0);
1136
1137 kdebug("mmap[%d] <anon>"
1138 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1139 loop, xaddr, excess - excess1, prot, flags,
1140 xmaddr);
1141
1142 if (xmaddr != xaddr)
1143 return -ENOMEM;
1144 }
1145
1146 if (prot & PROT_WRITE && excess1 > 0) {
1147 kdebug("clear[%d] ad=%lx sz=%lx",
1148 loop, maddr + phdr->p_filesz, excess1);
1149 if (clear_user((void __user *) maddr + phdr->p_filesz,
1150 excess1))
1151 return -EFAULT;
1152 }
1153
1154 #else
1155 if (excess > 0) {
1156 kdebug("clear[%d] ad=%lx sz=%lx",
1157 loop, maddr + phdr->p_filesz, excess);
1158 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1159 return -EFAULT;
1160 }
1161 #endif
1162
1163 if (mm) {
1164 if (phdr->p_flags & PF_X) {
1165 if (!mm->start_code) {
1166 mm->start_code = maddr;
1167 mm->end_code = maddr + phdr->p_memsz;
1168 }
1169 } else if (!mm->start_data) {
1170 mm->start_data = maddr;
1171 mm->end_data = maddr + phdr->p_memsz;
1172 }
1173 }
1174
1175 seg++;
1176 }
1177
1178 return 0;
1179 }
1180
1181 /*****************************************************************************/
1182 /*
1183 * ELF-FDPIC core dumper
1184 *
1185 * Modelled on fs/exec.c:aout_core_dump()
1186 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1187 *
1188 * Modelled on fs/binfmt_elf.c core dumper
1189 */
1190 #ifdef CONFIG_ELF_CORE
1191
1192 /*
1193 * Decide whether a segment is worth dumping; default is yes to be
1194 * sure (missing info is worse than too much; etc).
1195 * Personally I'd include everything, and use the coredump limit...
1196 *
1197 * I think we should skip something. But I am not sure how. H.J.
1198 */
1199 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1200 {
1201 int dump_ok;
1202
1203 /* Do not dump I/O mapped devices or special mappings */
1204 if (vma->vm_flags & VM_IO) {
1205 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1206 return 0;
1207 }
1208
1209 /* If we may not read the contents, don't allow us to dump
1210 * them either. "dump_write()" can't handle it anyway.
1211 */
1212 if (!(vma->vm_flags & VM_READ)) {
1213 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1214 return 0;
1215 }
1216
1217 /* support for DAX */
1218 if (vma_is_dax(vma)) {
1219 if (vma->vm_flags & VM_SHARED) {
1220 dump_ok = test_bit(MMF_DUMP_DAX_SHARED, &mm_flags);
1221 kdcore("%08lx: %08lx: %s (DAX shared)", vma->vm_start,
1222 vma->vm_flags, dump_ok ? "yes" : "no");
1223 } else {
1224 dump_ok = test_bit(MMF_DUMP_DAX_PRIVATE, &mm_flags);
1225 kdcore("%08lx: %08lx: %s (DAX private)", vma->vm_start,
1226 vma->vm_flags, dump_ok ? "yes" : "no");
1227 }
1228 return dump_ok;
1229 }
1230
1231 /* By default, dump shared memory if mapped from an anonymous file. */
1232 if (vma->vm_flags & VM_SHARED) {
1233 if (file_inode(vma->vm_file)->i_nlink == 0) {
1234 dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1235 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1236 vma->vm_flags, dump_ok ? "yes" : "no");
1237 return dump_ok;
1238 }
1239
1240 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1241 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1242 vma->vm_flags, dump_ok ? "yes" : "no");
1243 return dump_ok;
1244 }
1245
1246 #ifdef CONFIG_MMU
1247 /* By default, if it hasn't been written to, don't write it out */
1248 if (!vma->anon_vma) {
1249 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1250 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1251 vma->vm_flags, dump_ok ? "yes" : "no");
1252 return dump_ok;
1253 }
1254 #endif
1255
1256 dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1257 kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1258 dump_ok ? "yes" : "no");
1259 return dump_ok;
1260 }
1261
1262 /* An ELF note in memory */
1263 struct memelfnote
1264 {
1265 const char *name;
1266 int type;
1267 unsigned int datasz;
1268 void *data;
1269 };
1270
1271 static int notesize(struct memelfnote *en)
1272 {
1273 int sz;
1274
1275 sz = sizeof(struct elf_note);
1276 sz += roundup(strlen(en->name) + 1, 4);
1277 sz += roundup(en->datasz, 4);
1278
1279 return sz;
1280 }
1281
1282 /* #define DEBUG */
1283
1284 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1285 {
1286 struct elf_note en;
1287 en.n_namesz = strlen(men->name) + 1;
1288 en.n_descsz = men->datasz;
1289 en.n_type = men->type;
1290
1291 return dump_emit(cprm, &en, sizeof(en)) &&
1292 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1293 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1294 }
1295
1296 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1297 {
1298 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1299 elf->e_ident[EI_CLASS] = ELF_CLASS;
1300 elf->e_ident[EI_DATA] = ELF_DATA;
1301 elf->e_ident[EI_VERSION] = EV_CURRENT;
1302 elf->e_ident[EI_OSABI] = ELF_OSABI;
1303 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1304
1305 elf->e_type = ET_CORE;
1306 elf->e_machine = ELF_ARCH;
1307 elf->e_version = EV_CURRENT;
1308 elf->e_entry = 0;
1309 elf->e_phoff = sizeof(struct elfhdr);
1310 elf->e_shoff = 0;
1311 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1312 elf->e_ehsize = sizeof(struct elfhdr);
1313 elf->e_phentsize = sizeof(struct elf_phdr);
1314 elf->e_phnum = segs;
1315 elf->e_shentsize = 0;
1316 elf->e_shnum = 0;
1317 elf->e_shstrndx = 0;
1318 return;
1319 }
1320
1321 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1322 {
1323 phdr->p_type = PT_NOTE;
1324 phdr->p_offset = offset;
1325 phdr->p_vaddr = 0;
1326 phdr->p_paddr = 0;
1327 phdr->p_filesz = sz;
1328 phdr->p_memsz = 0;
1329 phdr->p_flags = 0;
1330 phdr->p_align = 0;
1331 return;
1332 }
1333
1334 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1335 unsigned int sz, void *data)
1336 {
1337 note->name = name;
1338 note->type = type;
1339 note->datasz = sz;
1340 note->data = data;
1341 return;
1342 }
1343
1344 /*
1345 * fill up all the fields in prstatus from the given task struct, except
1346 * registers which need to be filled up separately.
1347 */
1348 static void fill_prstatus(struct elf_prstatus *prstatus,
1349 struct task_struct *p, long signr)
1350 {
1351 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1352 prstatus->pr_sigpend = p->pending.signal.sig[0];
1353 prstatus->pr_sighold = p->blocked.sig[0];
1354 rcu_read_lock();
1355 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1356 rcu_read_unlock();
1357 prstatus->pr_pid = task_pid_vnr(p);
1358 prstatus->pr_pgrp = task_pgrp_vnr(p);
1359 prstatus->pr_sid = task_session_vnr(p);
1360 if (thread_group_leader(p)) {
1361 struct task_cputime cputime;
1362
1363 /*
1364 * This is the record for the group leader. It shows the
1365 * group-wide total, not its individual thread total.
1366 */
1367 thread_group_cputime(p, &cputime);
1368 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1369 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1370 } else {
1371 u64 utime, stime;
1372
1373 task_cputime(p, &utime, &stime);
1374 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1375 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1376 }
1377 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1378 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1379
1380 prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1381 prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1382 }
1383
1384 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1385 struct mm_struct *mm)
1386 {
1387 const struct cred *cred;
1388 unsigned int i, len;
1389
1390 /* first copy the parameters from user space */
1391 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1392
1393 len = mm->arg_end - mm->arg_start;
1394 if (len >= ELF_PRARGSZ)
1395 len = ELF_PRARGSZ - 1;
1396 if (copy_from_user(&psinfo->pr_psargs,
1397 (const char __user *) mm->arg_start, len))
1398 return -EFAULT;
1399 for (i = 0; i < len; i++)
1400 if (psinfo->pr_psargs[i] == 0)
1401 psinfo->pr_psargs[i] = ' ';
1402 psinfo->pr_psargs[len] = 0;
1403
1404 rcu_read_lock();
1405 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1406 rcu_read_unlock();
1407 psinfo->pr_pid = task_pid_vnr(p);
1408 psinfo->pr_pgrp = task_pgrp_vnr(p);
1409 psinfo->pr_sid = task_session_vnr(p);
1410
1411 i = p->state ? ffz(~p->state) + 1 : 0;
1412 psinfo->pr_state = i;
1413 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1414 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1415 psinfo->pr_nice = task_nice(p);
1416 psinfo->pr_flag = p->flags;
1417 rcu_read_lock();
1418 cred = __task_cred(p);
1419 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1420 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1421 rcu_read_unlock();
1422 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1423
1424 return 0;
1425 }
1426
1427 /* Here is the structure in which status of each thread is captured. */
1428 struct elf_thread_status
1429 {
1430 struct list_head list;
1431 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1432 elf_fpregset_t fpu; /* NT_PRFPREG */
1433 struct task_struct *thread;
1434 #ifdef ELF_CORE_COPY_XFPREGS
1435 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1436 #endif
1437 struct memelfnote notes[3];
1438 int num_notes;
1439 };
1440
1441 /*
1442 * In order to add the specific thread information for the elf file format,
1443 * we need to keep a linked list of every thread's pr_status and then create
1444 * a single section for them in the final core file.
1445 */
1446 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1447 {
1448 struct task_struct *p = t->thread;
1449 int sz = 0;
1450
1451 t->num_notes = 0;
1452
1453 fill_prstatus(&t->prstatus, p, signr);
1454 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1455
1456 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1457 &t->prstatus);
1458 t->num_notes++;
1459 sz += notesize(&t->notes[0]);
1460
1461 t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1462 if (t->prstatus.pr_fpvalid) {
1463 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1464 &t->fpu);
1465 t->num_notes++;
1466 sz += notesize(&t->notes[1]);
1467 }
1468
1469 #ifdef ELF_CORE_COPY_XFPREGS
1470 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1471 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1472 sizeof(t->xfpu), &t->xfpu);
1473 t->num_notes++;
1474 sz += notesize(&t->notes[2]);
1475 }
1476 #endif
1477 return sz;
1478 }
1479
1480 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1481 elf_addr_t e_shoff, int segs)
1482 {
1483 elf->e_shoff = e_shoff;
1484 elf->e_shentsize = sizeof(*shdr4extnum);
1485 elf->e_shnum = 1;
1486 elf->e_shstrndx = SHN_UNDEF;
1487
1488 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1489
1490 shdr4extnum->sh_type = SHT_NULL;
1491 shdr4extnum->sh_size = elf->e_shnum;
1492 shdr4extnum->sh_link = elf->e_shstrndx;
1493 shdr4extnum->sh_info = segs;
1494 }
1495
1496 /*
1497 * dump the segments for an MMU process
1498 */
1499 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1500 {
1501 struct vm_area_struct *vma;
1502
1503 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1504 #ifdef CONFIG_MMU
1505 unsigned long addr;
1506 #endif
1507
1508 if (!maydump(vma, cprm->mm_flags))
1509 continue;
1510
1511 #ifdef CONFIG_MMU
1512 for (addr = vma->vm_start; addr < vma->vm_end;
1513 addr += PAGE_SIZE) {
1514 bool res;
1515 struct page *page = get_dump_page(addr);
1516 if (page) {
1517 void *kaddr = kmap(page);
1518 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1519 kunmap(page);
1520 put_page(page);
1521 } else {
1522 res = dump_skip(cprm, PAGE_SIZE);
1523 }
1524 if (!res)
1525 return false;
1526 }
1527 #else
1528 if (!dump_emit(cprm, (void *) vma->vm_start,
1529 vma->vm_end - vma->vm_start))
1530 return false;
1531 #endif
1532 }
1533 return true;
1534 }
1535
1536 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1537 {
1538 struct vm_area_struct *vma;
1539 size_t size = 0;
1540
1541 for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1542 if (maydump(vma, mm_flags))
1543 size += vma->vm_end - vma->vm_start;
1544 return size;
1545 }
1546
1547 /*
1548 * Actual dumper
1549 *
1550 * This is a two-pass process; first we find the offsets of the bits,
1551 * and then they are actually written out. If we run out of core limit
1552 * we just truncate.
1553 */
1554 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1555 {
1556 #define NUM_NOTES 6
1557 int has_dumped = 0;
1558 int segs;
1559 int i;
1560 struct vm_area_struct *vma;
1561 struct elfhdr *elf = NULL;
1562 loff_t offset = 0, dataoff;
1563 int numnote;
1564 struct memelfnote *notes = NULL;
1565 struct elf_prstatus *prstatus = NULL; /* NT_PRSTATUS */
1566 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1567 LIST_HEAD(thread_list);
1568 struct list_head *t;
1569 elf_fpregset_t *fpu = NULL;
1570 #ifdef ELF_CORE_COPY_XFPREGS
1571 elf_fpxregset_t *xfpu = NULL;
1572 #endif
1573 int thread_status_size = 0;
1574 elf_addr_t *auxv;
1575 struct elf_phdr *phdr4note = NULL;
1576 struct elf_shdr *shdr4extnum = NULL;
1577 Elf_Half e_phnum;
1578 elf_addr_t e_shoff;
1579 struct core_thread *ct;
1580 struct elf_thread_status *tmp;
1581
1582 /*
1583 * We no longer stop all VM operations.
1584 *
1585 * This is because those proceses that could possibly change map_count
1586 * or the mmap / vma pages are now blocked in do_exit on current
1587 * finishing this core dump.
1588 *
1589 * Only ptrace can touch these memory addresses, but it doesn't change
1590 * the map_count or the pages allocated. So no possibility of crashing
1591 * exists while dumping the mm->vm_next areas to the core file.
1592 */
1593
1594 /* alloc memory for large data structures: too large to be on stack */
1595 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1596 if (!elf)
1597 goto end_coredump;
1598 prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1599 if (!prstatus)
1600 goto end_coredump;
1601 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1602 if (!psinfo)
1603 goto end_coredump;
1604 notes = kmalloc_array(NUM_NOTES, sizeof(struct memelfnote),
1605 GFP_KERNEL);
1606 if (!notes)
1607 goto end_coredump;
1608 fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1609 if (!fpu)
1610 goto end_coredump;
1611 #ifdef ELF_CORE_COPY_XFPREGS
1612 xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1613 if (!xfpu)
1614 goto end_coredump;
1615 #endif
1616
1617 for (ct = current->mm->core_state->dumper.next;
1618 ct; ct = ct->next) {
1619 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1620 if (!tmp)
1621 goto end_coredump;
1622
1623 tmp->thread = ct->task;
1624 list_add(&tmp->list, &thread_list);
1625 }
1626
1627 list_for_each(t, &thread_list) {
1628 struct elf_thread_status *tmp;
1629 int sz;
1630
1631 tmp = list_entry(t, struct elf_thread_status, list);
1632 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1633 thread_status_size += sz;
1634 }
1635
1636 /* now collect the dump for the current */
1637 fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1638 elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1639
1640 segs = current->mm->map_count;
1641 segs += elf_core_extra_phdrs();
1642
1643 /* for notes section */
1644 segs++;
1645
1646 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1647 * this, kernel supports extended numbering. Have a look at
1648 * include/linux/elf.h for further information. */
1649 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1650
1651 /* Set up header */
1652 fill_elf_fdpic_header(elf, e_phnum);
1653
1654 has_dumped = 1;
1655 /*
1656 * Set up the notes in similar form to SVR4 core dumps made
1657 * with info from their /proc.
1658 */
1659
1660 fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1661 fill_psinfo(psinfo, current->group_leader, current->mm);
1662 fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1663
1664 numnote = 2;
1665
1666 auxv = (elf_addr_t *) current->mm->saved_auxv;
1667
1668 i = 0;
1669 do
1670 i += 2;
1671 while (auxv[i - 2] != AT_NULL);
1672 fill_note(&notes[numnote++], "CORE", NT_AUXV,
1673 i * sizeof(elf_addr_t), auxv);
1674
1675 /* Try to dump the FPU. */
1676 if ((prstatus->pr_fpvalid =
1677 elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1678 fill_note(notes + numnote++,
1679 "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1680 #ifdef ELF_CORE_COPY_XFPREGS
1681 if (elf_core_copy_task_xfpregs(current, xfpu))
1682 fill_note(notes + numnote++,
1683 "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1684 #endif
1685
1686 offset += sizeof(*elf); /* Elf header */
1687 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1688
1689 /* Write notes phdr entry */
1690 {
1691 int sz = 0;
1692
1693 for (i = 0; i < numnote; i++)
1694 sz += notesize(notes + i);
1695
1696 sz += thread_status_size;
1697
1698 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1699 if (!phdr4note)
1700 goto end_coredump;
1701
1702 fill_elf_note_phdr(phdr4note, sz, offset);
1703 offset += sz;
1704 }
1705
1706 /* Page-align dumped data */
1707 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1708
1709 offset += elf_core_vma_data_size(cprm->mm_flags);
1710 offset += elf_core_extra_data_size();
1711 e_shoff = offset;
1712
1713 if (e_phnum == PN_XNUM) {
1714 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1715 if (!shdr4extnum)
1716 goto end_coredump;
1717 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1718 }
1719
1720 offset = dataoff;
1721
1722 if (!dump_emit(cprm, elf, sizeof(*elf)))
1723 goto end_coredump;
1724
1725 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1726 goto end_coredump;
1727
1728 /* write program headers for segments dump */
1729 for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1730 struct elf_phdr phdr;
1731 size_t sz;
1732
1733 sz = vma->vm_end - vma->vm_start;
1734
1735 phdr.p_type = PT_LOAD;
1736 phdr.p_offset = offset;
1737 phdr.p_vaddr = vma->vm_start;
1738 phdr.p_paddr = 0;
1739 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1740 phdr.p_memsz = sz;
1741 offset += phdr.p_filesz;
1742 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1743 if (vma->vm_flags & VM_WRITE)
1744 phdr.p_flags |= PF_W;
1745 if (vma->vm_flags & VM_EXEC)
1746 phdr.p_flags |= PF_X;
1747 phdr.p_align = ELF_EXEC_PAGESIZE;
1748
1749 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1750 goto end_coredump;
1751 }
1752
1753 if (!elf_core_write_extra_phdrs(cprm, offset))
1754 goto end_coredump;
1755
1756 /* write out the notes section */
1757 for (i = 0; i < numnote; i++)
1758 if (!writenote(notes + i, cprm))
1759 goto end_coredump;
1760
1761 /* write out the thread status notes section */
1762 list_for_each(t, &thread_list) {
1763 struct elf_thread_status *tmp =
1764 list_entry(t, struct elf_thread_status, list);
1765
1766 for (i = 0; i < tmp->num_notes; i++)
1767 if (!writenote(&tmp->notes[i], cprm))
1768 goto end_coredump;
1769 }
1770
1771 if (!dump_skip(cprm, dataoff - cprm->pos))
1772 goto end_coredump;
1773
1774 if (!elf_fdpic_dump_segments(cprm))
1775 goto end_coredump;
1776
1777 if (!elf_core_write_extra_data(cprm))
1778 goto end_coredump;
1779
1780 if (e_phnum == PN_XNUM) {
1781 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1782 goto end_coredump;
1783 }
1784
1785 if (cprm->file->f_pos != offset) {
1786 /* Sanity check */
1787 printk(KERN_WARNING
1788 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1789 cprm->file->f_pos, offset);
1790 }
1791
1792 end_coredump:
1793 while (!list_empty(&thread_list)) {
1794 struct list_head *tmp = thread_list.next;
1795 list_del(tmp);
1796 kfree(list_entry(tmp, struct elf_thread_status, list));
1797 }
1798 kfree(phdr4note);
1799 kfree(elf);
1800 kfree(prstatus);
1801 kfree(psinfo);
1802 kfree(notes);
1803 kfree(fpu);
1804 kfree(shdr4extnum);
1805 #ifdef ELF_CORE_COPY_XFPREGS
1806 kfree(xfpu);
1807 #endif
1808 return has_dumped;
1809 #undef NUM_NOTES
1810 }
1811
1812 #endif /* CONFIG_ELF_CORE */
Linux with added FPC-III support