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 #include <linux/regset.h>
39
40 #include <linux/uaccess.h>
41 #include <asm/param.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 .min_coredump = ELF_EXEC_PAGESIZE,
87 #endif
88 };
89
init_elf_fdpic_binfmt(void)90 static int __init init_elf_fdpic_binfmt(void)
91 {
92 register_binfmt(&elf_fdpic_format);
93 return 0;
94 }
95
exit_elf_fdpic_binfmt(void)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
is_elf(struct elfhdr * hdr,struct file * file)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
is_constdisp(struct elfhdr * hdr)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 */
elf_fdpic_fetch_phdrs(struct elf_fdpic_params * params,struct file * file)138 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
139 struct file *file)
140 {
141 struct elf_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 */
load_elf_fdpic_binary(struct linux_binprm * bprm)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 && interp_params.flags & ELF_FDPIC_FLAG_PRESENT) {
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 SET_PERSONALITY(exec_params.hdr);
349 if (elf_check_fdpic(&exec_params.hdr))
350 current->personality |= PER_LINUX_FDPIC;
351 if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
352 current->personality |= READ_IMPLIES_EXEC;
353
354 setup_new_exec(bprm);
355
356 set_binfmt(&elf_fdpic_format);
357
358 current->mm->start_code = 0;
359 current->mm->end_code = 0;
360 current->mm->start_stack = 0;
361 current->mm->start_data = 0;
362 current->mm->end_data = 0;
363 current->mm->context.exec_fdpic_loadmap = 0;
364 current->mm->context.interp_fdpic_loadmap = 0;
365
366 #ifdef CONFIG_MMU
367 elf_fdpic_arch_lay_out_mm(&exec_params,
368 &interp_params,
369 ¤t->mm->start_stack,
370 ¤t->mm->start_brk);
371
372 retval = setup_arg_pages(bprm, current->mm->start_stack,
373 executable_stack);
374 if (retval < 0)
375 goto error;
376 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
377 retval = arch_setup_additional_pages(bprm, !!interpreter_name);
378 if (retval < 0)
379 goto error;
380 #endif
381 #endif
382
383 /* load the executable and interpreter into memory */
384 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
385 "executable");
386 if (retval < 0)
387 goto error;
388
389 if (interpreter_name) {
390 retval = elf_fdpic_map_file(&interp_params, interpreter,
391 current->mm, "interpreter");
392 if (retval < 0) {
393 printk(KERN_ERR "Unable to load interpreter\n");
394 goto error;
395 }
396
397 fput(interpreter);
398 interpreter = NULL;
399 }
400
401 #ifdef CONFIG_MMU
402 if (!current->mm->start_brk)
403 current->mm->start_brk = current->mm->end_data;
404
405 current->mm->brk = current->mm->start_brk =
406 PAGE_ALIGN(current->mm->start_brk);
407
408 #else
409 /* create a stack area and zero-size brk area */
410 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
411 if (stack_size < PAGE_SIZE * 2)
412 stack_size = PAGE_SIZE * 2;
413
414 stack_prot = PROT_READ | PROT_WRITE;
415 if (executable_stack == EXSTACK_ENABLE_X ||
416 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
417 stack_prot |= PROT_EXEC;
418
419 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
420 MAP_PRIVATE | MAP_ANONYMOUS |
421 MAP_UNINITIALIZED | MAP_GROWSDOWN,
422 0);
423
424 if (IS_ERR_VALUE(current->mm->start_brk)) {
425 retval = current->mm->start_brk;
426 current->mm->start_brk = 0;
427 goto error;
428 }
429
430 current->mm->brk = current->mm->start_brk;
431 current->mm->context.end_brk = current->mm->start_brk;
432 current->mm->start_stack = current->mm->start_brk + stack_size;
433 #endif
434
435 retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params,
436 &interp_params);
437 if (retval < 0)
438 goto error;
439
440 kdebug("- start_code %lx", current->mm->start_code);
441 kdebug("- end_code %lx", current->mm->end_code);
442 kdebug("- start_data %lx", current->mm->start_data);
443 kdebug("- end_data %lx", current->mm->end_data);
444 kdebug("- start_brk %lx", current->mm->start_brk);
445 kdebug("- brk %lx", current->mm->brk);
446 kdebug("- start_stack %lx", current->mm->start_stack);
447
448 #ifdef ELF_FDPIC_PLAT_INIT
449 /*
450 * The ABI may specify that certain registers be set up in special
451 * ways (on i386 %edx is the address of a DT_FINI function, for
452 * example. This macro performs whatever initialization to
453 * the regs structure is required.
454 */
455 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
456 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
457 dynaddr);
458 #endif
459
460 finalize_exec(bprm);
461 /* everything is now ready... get the userspace context ready to roll */
462 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
463 start_thread(regs, entryaddr, current->mm->start_stack);
464
465 retval = 0;
466
467 error:
468 if (interpreter)
469 fput(interpreter);
470 kfree(interpreter_name);
471 kfree(exec_params.phdrs);
472 kfree(exec_params.loadmap);
473 kfree(interp_params.phdrs);
474 kfree(interp_params.loadmap);
475 return retval;
476 }
477
478 /*****************************************************************************/
479
480 #ifndef ELF_BASE_PLATFORM
481 /*
482 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
483 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
484 * will be copied to the user stack in the same manner as AT_PLATFORM.
485 */
486 #define ELF_BASE_PLATFORM NULL
487 #endif
488
489 /*
490 * present useful information to the program by shovelling it onto the new
491 * process's stack
492 */
create_elf_fdpic_tables(struct linux_binprm * bprm,struct mm_struct * mm,struct elf_fdpic_params * exec_params,struct elf_fdpic_params * interp_params)493 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
494 struct mm_struct *mm,
495 struct elf_fdpic_params *exec_params,
496 struct elf_fdpic_params *interp_params)
497 {
498 const struct cred *cred = current_cred();
499 unsigned long sp, csp, nitems;
500 elf_caddr_t __user *argv, *envp;
501 size_t platform_len = 0, len;
502 char *k_platform, *k_base_platform;
503 char __user *u_platform, *u_base_platform, *p;
504 int loop;
505 unsigned long flags = 0;
506 int ei_index;
507 elf_addr_t *elf_info;
508
509 #ifdef CONFIG_MMU
510 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
511 * by the processes running on the same package. One thing we can do is
512 * to shuffle the initial stack for them, so we give the architecture
513 * an opportunity to do so here.
514 */
515 sp = arch_align_stack(bprm->p);
516 #else
517 sp = mm->start_stack;
518
519 /* stack the program arguments and environment */
520 if (transfer_args_to_stack(bprm, &sp) < 0)
521 return -EFAULT;
522 sp &= ~15;
523 #endif
524
525 /*
526 * If this architecture has a platform capability string, copy it
527 * to userspace. In some cases (Sparc), this info is impossible
528 * for userspace to get any other way, in others (i386) it is
529 * merely difficult.
530 */
531 k_platform = ELF_PLATFORM;
532 u_platform = NULL;
533
534 if (k_platform) {
535 platform_len = strlen(k_platform) + 1;
536 sp -= platform_len;
537 u_platform = (char __user *) sp;
538 if (copy_to_user(u_platform, k_platform, platform_len) != 0)
539 return -EFAULT;
540 }
541
542 /*
543 * If this architecture has a "base" platform capability
544 * string, copy it to userspace.
545 */
546 k_base_platform = ELF_BASE_PLATFORM;
547 u_base_platform = NULL;
548
549 if (k_base_platform) {
550 platform_len = strlen(k_base_platform) + 1;
551 sp -= platform_len;
552 u_base_platform = (char __user *) sp;
553 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
554 return -EFAULT;
555 }
556
557 sp &= ~7UL;
558
559 /* stack the load map(s) */
560 len = sizeof(struct elf_fdpic_loadmap);
561 len += sizeof(struct elf_fdpic_loadseg) * exec_params->loadmap->nsegs;
562 sp = (sp - len) & ~7UL;
563 exec_params->map_addr = sp;
564
565 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
566 return -EFAULT;
567
568 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
569
570 if (interp_params->loadmap) {
571 len = sizeof(struct elf_fdpic_loadmap);
572 len += sizeof(struct elf_fdpic_loadseg) *
573 interp_params->loadmap->nsegs;
574 sp = (sp - len) & ~7UL;
575 interp_params->map_addr = sp;
576
577 if (copy_to_user((void __user *) sp, interp_params->loadmap,
578 len) != 0)
579 return -EFAULT;
580
581 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
582 }
583
584 /* force 16 byte _final_ alignment here for generality */
585 #define DLINFO_ITEMS 15
586
587 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
588 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
589
590 if (bprm->have_execfd)
591 nitems++;
592 #ifdef ELF_HWCAP2
593 nitems++;
594 #endif
595
596 csp = sp;
597 sp -= nitems * 2 * sizeof(unsigned long);
598 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
599 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
600 sp -= 1 * sizeof(unsigned long); /* argc */
601
602 csp -= sp & 15UL;
603 sp -= sp & 15UL;
604
605 /* Create the ELF interpreter info */
606 elf_info = (elf_addr_t *)mm->saved_auxv;
607 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
608 #define NEW_AUX_ENT(id, val) \
609 do { \
610 *elf_info++ = id; \
611 *elf_info++ = val; \
612 } while (0)
613
614 #ifdef ARCH_DLINFO
615 /*
616 * ARCH_DLINFO must come first so PPC can do its special alignment of
617 * AUXV.
618 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
619 * ARCH_DLINFO changes
620 */
621 ARCH_DLINFO;
622 #endif
623 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
624 #ifdef ELF_HWCAP2
625 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
626 #endif
627 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
628 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
629 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
630 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
631 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
632 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
633 if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
634 flags |= AT_FLAGS_PRESERVE_ARGV0;
635 NEW_AUX_ENT(AT_FLAGS, flags);
636 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
637 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
638 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
639 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
640 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
641 NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
642 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
643 if (k_platform)
644 NEW_AUX_ENT(AT_PLATFORM,
645 (elf_addr_t)(unsigned long)u_platform);
646 if (k_base_platform)
647 NEW_AUX_ENT(AT_BASE_PLATFORM,
648 (elf_addr_t)(unsigned long)u_base_platform);
649 if (bprm->have_execfd)
650 NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
651 #undef NEW_AUX_ENT
652 /* AT_NULL is zero; clear the rest too */
653 memset(elf_info, 0, (char *)mm->saved_auxv +
654 sizeof(mm->saved_auxv) - (char *)elf_info);
655
656 /* And advance past the AT_NULL entry. */
657 elf_info += 2;
658
659 ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
660 csp -= ei_index * sizeof(elf_addr_t);
661
662 /* Put the elf_info on the stack in the right place. */
663 if (copy_to_user((void __user *)csp, mm->saved_auxv,
664 ei_index * sizeof(elf_addr_t)))
665 return -EFAULT;
666
667 /* allocate room for argv[] and envv[] */
668 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
669 envp = (elf_caddr_t __user *) csp;
670 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
671 argv = (elf_caddr_t __user *) csp;
672
673 /* stack argc */
674 csp -= sizeof(unsigned long);
675 if (put_user(bprm->argc, (unsigned long __user *) csp))
676 return -EFAULT;
677
678 BUG_ON(csp != sp);
679
680 /* fill in the argv[] array */
681 #ifdef CONFIG_MMU
682 current->mm->arg_start = bprm->p;
683 #else
684 current->mm->arg_start = current->mm->start_stack -
685 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
686 #endif
687
688 p = (char __user *) current->mm->arg_start;
689 for (loop = bprm->argc; loop > 0; loop--) {
690 if (put_user((elf_caddr_t) p, argv++))
691 return -EFAULT;
692 len = strnlen_user(p, MAX_ARG_STRLEN);
693 if (!len || len > MAX_ARG_STRLEN)
694 return -EINVAL;
695 p += len;
696 }
697 if (put_user(NULL, argv))
698 return -EFAULT;
699 current->mm->arg_end = (unsigned long) p;
700
701 /* fill in the envv[] array */
702 current->mm->env_start = (unsigned long) p;
703 for (loop = bprm->envc; loop > 0; loop--) {
704 if (put_user((elf_caddr_t)(unsigned long) p, envp++))
705 return -EFAULT;
706 len = strnlen_user(p, MAX_ARG_STRLEN);
707 if (!len || len > MAX_ARG_STRLEN)
708 return -EINVAL;
709 p += len;
710 }
711 if (put_user(NULL, envp))
712 return -EFAULT;
713 current->mm->env_end = (unsigned long) p;
714
715 mm->start_stack = (unsigned long) sp;
716 return 0;
717 }
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 */
elf_fdpic_map_file(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm,const char * what)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 elf_fdpic_loadmap *loadmap;
736 #ifdef CONFIG_MMU
737 struct elf_fdpic_loadseg *mseg;
738 unsigned long load_addr;
739 #endif
740 struct elf_fdpic_loadseg *seg;
741 struct elf_phdr *phdr;
742 unsigned nloads, tmp;
743 unsigned long stop;
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 loadmap = kzalloc(struct_size(loadmap, segs, nloads), GFP_KERNEL);
756 if (!loadmap)
757 return -ENOMEM;
758
759 params->loadmap = loadmap;
760
761 loadmap->version = ELF_FDPIC_LOADMAP_VERSION;
762 loadmap->nsegs = nloads;
763
764 /* map the requested LOADs into the memory space */
765 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
766 case ELF_FDPIC_FLAG_CONSTDISP:
767 case ELF_FDPIC_FLAG_CONTIGUOUS:
768 #ifndef CONFIG_MMU
769 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
770 if (ret < 0)
771 return ret;
772 break;
773 #endif
774 default:
775 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
776 if (ret < 0)
777 return ret;
778 break;
779 }
780
781 /* map the entry point */
782 if (params->hdr.e_entry) {
783 seg = loadmap->segs;
784 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
785 if (params->hdr.e_entry >= seg->p_vaddr &&
786 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
787 params->entry_addr =
788 (params->hdr.e_entry - seg->p_vaddr) +
789 seg->addr;
790 break;
791 }
792 }
793 }
794
795 /* determine where the program header table has wound up if mapped */
796 stop = params->hdr.e_phoff;
797 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
798 phdr = params->phdrs;
799
800 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
801 if (phdr->p_type != PT_LOAD)
802 continue;
803
804 if (phdr->p_offset > params->hdr.e_phoff ||
805 phdr->p_offset + phdr->p_filesz < stop)
806 continue;
807
808 seg = loadmap->segs;
809 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
810 if (phdr->p_vaddr >= seg->p_vaddr &&
811 phdr->p_vaddr + phdr->p_filesz <=
812 seg->p_vaddr + seg->p_memsz) {
813 params->ph_addr =
814 (phdr->p_vaddr - seg->p_vaddr) +
815 seg->addr +
816 params->hdr.e_phoff - phdr->p_offset;
817 break;
818 }
819 }
820 break;
821 }
822
823 /* determine where the dynamic section has wound up if there is one */
824 phdr = params->phdrs;
825 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
826 if (phdr->p_type != PT_DYNAMIC)
827 continue;
828
829 seg = loadmap->segs;
830 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
831 if (phdr->p_vaddr >= seg->p_vaddr &&
832 phdr->p_vaddr + phdr->p_memsz <=
833 seg->p_vaddr + seg->p_memsz) {
834 Elf_Dyn __user *dyn;
835 Elf_Sword d_tag;
836
837 params->dynamic_addr =
838 (phdr->p_vaddr - seg->p_vaddr) +
839 seg->addr;
840
841 /* check the dynamic section contains at least
842 * one item, and that the last item is a NULL
843 * entry */
844 if (phdr->p_memsz == 0 ||
845 phdr->p_memsz % sizeof(Elf_Dyn) != 0)
846 goto dynamic_error;
847
848 tmp = phdr->p_memsz / sizeof(Elf_Dyn);
849 dyn = (Elf_Dyn __user *)params->dynamic_addr;
850 if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
851 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] : %08llx-%08llx [va=%llx ms=%llx]",
896 loop,
897 (unsigned long long) seg->addr,
898 (unsigned long long) seg->addr + seg->p_memsz - 1,
899 (unsigned long long) seg->p_vaddr,
900 (unsigned long long) seg->p_memsz);
901
902 return 0;
903
904 dynamic_error:
905 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
906 what, file_inode(file)->i_ino);
907 return -ELIBBAD;
908 }
909
910 /*****************************************************************************/
911 /*
912 * map a file with constant displacement under uClinux
913 */
914 #ifndef CONFIG_MMU
elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm)915 static int elf_fdpic_map_file_constdisp_on_uclinux(
916 struct elf_fdpic_params *params,
917 struct file *file,
918 struct mm_struct *mm)
919 {
920 struct elf_fdpic_loadseg *seg;
921 struct elf_phdr *phdr;
922 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
923 int loop, ret;
924
925 load_addr = params->load_addr;
926 seg = params->loadmap->segs;
927
928 /* determine the bounds of the contiguous overall allocation we must
929 * make */
930 phdr = params->phdrs;
931 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
932 if (params->phdrs[loop].p_type != PT_LOAD)
933 continue;
934
935 if (base > phdr->p_vaddr)
936 base = phdr->p_vaddr;
937 if (top < phdr->p_vaddr + phdr->p_memsz)
938 top = phdr->p_vaddr + phdr->p_memsz;
939 }
940
941 /* allocate one big anon block for everything */
942 maddr = vm_mmap(NULL, load_addr, top - base,
943 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0);
944 if (IS_ERR_VALUE(maddr))
945 return (int) maddr;
946
947 if (load_addr != 0)
948 load_addr += PAGE_ALIGN(top - base);
949
950 /* and then load the file segments into it */
951 phdr = params->phdrs;
952 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
953 if (params->phdrs[loop].p_type != PT_LOAD)
954 continue;
955
956 seg->addr = maddr + (phdr->p_vaddr - base);
957 seg->p_vaddr = phdr->p_vaddr;
958 seg->p_memsz = phdr->p_memsz;
959
960 ret = read_code(file, seg->addr, phdr->p_offset,
961 phdr->p_filesz);
962 if (ret < 0)
963 return ret;
964
965 /* map the ELF header address if in this segment */
966 if (phdr->p_offset == 0)
967 params->elfhdr_addr = seg->addr;
968
969 /* clear any space allocated but not loaded */
970 if (phdr->p_filesz < phdr->p_memsz) {
971 if (clear_user((void *) (seg->addr + phdr->p_filesz),
972 phdr->p_memsz - phdr->p_filesz))
973 return -EFAULT;
974 }
975
976 if (mm) {
977 if (phdr->p_flags & PF_X) {
978 if (!mm->start_code) {
979 mm->start_code = seg->addr;
980 mm->end_code = seg->addr +
981 phdr->p_memsz;
982 }
983 } else if (!mm->start_data) {
984 mm->start_data = seg->addr;
985 mm->end_data = seg->addr + phdr->p_memsz;
986 }
987 }
988
989 seg++;
990 }
991
992 return 0;
993 }
994 #endif
995
996 /*****************************************************************************/
997 /*
998 * map a binary by direct mmap() of the individual PT_LOAD segments
999 */
elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm)1000 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1001 struct file *file,
1002 struct mm_struct *mm)
1003 {
1004 struct elf_fdpic_loadseg *seg;
1005 struct elf_phdr *phdr;
1006 unsigned long load_addr, delta_vaddr;
1007 int loop, dvset;
1008
1009 load_addr = params->load_addr;
1010 delta_vaddr = 0;
1011 dvset = 0;
1012
1013 seg = params->loadmap->segs;
1014
1015 /* deal with each load segment separately */
1016 phdr = params->phdrs;
1017 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1018 unsigned long maddr, disp, excess, excess1;
1019 int prot = 0, flags;
1020
1021 if (phdr->p_type != PT_LOAD)
1022 continue;
1023
1024 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1025 (unsigned long) phdr->p_vaddr,
1026 (unsigned long) phdr->p_offset,
1027 (unsigned long) phdr->p_filesz,
1028 (unsigned long) phdr->p_memsz);
1029
1030 /* determine the mapping parameters */
1031 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1032 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1033 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1034
1035 flags = MAP_PRIVATE;
1036 maddr = 0;
1037
1038 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1039 case ELF_FDPIC_FLAG_INDEPENDENT:
1040 /* PT_LOADs are independently locatable */
1041 break;
1042
1043 case ELF_FDPIC_FLAG_HONOURVADDR:
1044 /* the specified virtual address must be honoured */
1045 maddr = phdr->p_vaddr;
1046 flags |= MAP_FIXED;
1047 break;
1048
1049 case ELF_FDPIC_FLAG_CONSTDISP:
1050 /* constant displacement
1051 * - can be mapped anywhere, but must be mapped as a
1052 * unit
1053 */
1054 if (!dvset) {
1055 maddr = load_addr;
1056 delta_vaddr = phdr->p_vaddr;
1057 dvset = 1;
1058 } else {
1059 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1060 flags |= MAP_FIXED;
1061 }
1062 break;
1063
1064 case ELF_FDPIC_FLAG_CONTIGUOUS:
1065 /* contiguity handled later */
1066 break;
1067
1068 default:
1069 BUG();
1070 }
1071
1072 maddr &= PAGE_MASK;
1073
1074 /* create the mapping */
1075 disp = phdr->p_vaddr & ~PAGE_MASK;
1076 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1077 phdr->p_offset - disp);
1078
1079 kdebug("mmap[%d] <file> sz=%llx pr=%x fl=%x of=%llx --> %08lx",
1080 loop, (unsigned long long) phdr->p_memsz + disp,
1081 prot, flags, (unsigned long long) phdr->p_offset - disp,
1082 maddr);
1083
1084 if (IS_ERR_VALUE(maddr))
1085 return (int) maddr;
1086
1087 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1088 ELF_FDPIC_FLAG_CONTIGUOUS)
1089 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1090
1091 seg->addr = maddr + disp;
1092 seg->p_vaddr = phdr->p_vaddr;
1093 seg->p_memsz = phdr->p_memsz;
1094
1095 /* map the ELF header address if in this segment */
1096 if (phdr->p_offset == 0)
1097 params->elfhdr_addr = seg->addr;
1098
1099 /* clear the bit between beginning of mapping and beginning of
1100 * PT_LOAD */
1101 if (prot & PROT_WRITE && disp > 0) {
1102 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1103 if (clear_user((void __user *) maddr, disp))
1104 return -EFAULT;
1105 maddr += disp;
1106 }
1107
1108 /* clear any space allocated but not loaded
1109 * - on uClinux we can just clear the lot
1110 * - on MMU linux we'll get a SIGBUS beyond the last page
1111 * extant in the file
1112 */
1113 excess = phdr->p_memsz - phdr->p_filesz;
1114 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1115
1116 #ifdef CONFIG_MMU
1117 if (excess > excess1) {
1118 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1119 unsigned long xmaddr;
1120
1121 flags |= MAP_FIXED | MAP_ANONYMOUS;
1122 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1123 prot, flags, 0);
1124
1125 kdebug("mmap[%d] <anon>"
1126 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1127 loop, xaddr, excess - excess1, prot, flags,
1128 xmaddr);
1129
1130 if (xmaddr != xaddr)
1131 return -ENOMEM;
1132 }
1133
1134 if (prot & PROT_WRITE && excess1 > 0) {
1135 kdebug("clear[%d] ad=%lx sz=%lx",
1136 loop, maddr + phdr->p_filesz, excess1);
1137 if (clear_user((void __user *) maddr + phdr->p_filesz,
1138 excess1))
1139 return -EFAULT;
1140 }
1141
1142 #else
1143 if (excess > 0) {
1144 kdebug("clear[%d] ad=%llx sz=%lx", loop,
1145 (unsigned long long) maddr + phdr->p_filesz,
1146 excess);
1147 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1148 return -EFAULT;
1149 }
1150 #endif
1151
1152 if (mm) {
1153 if (phdr->p_flags & PF_X) {
1154 if (!mm->start_code) {
1155 mm->start_code = maddr;
1156 mm->end_code = maddr + phdr->p_memsz;
1157 }
1158 } else if (!mm->start_data) {
1159 mm->start_data = maddr;
1160 mm->end_data = maddr + phdr->p_memsz;
1161 }
1162 }
1163
1164 seg++;
1165 }
1166
1167 return 0;
1168 }
1169
1170 /*****************************************************************************/
1171 /*
1172 * ELF-FDPIC core dumper
1173 *
1174 * Modelled on fs/exec.c:aout_core_dump()
1175 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1176 *
1177 * Modelled on fs/binfmt_elf.c core dumper
1178 */
1179 #ifdef CONFIG_ELF_CORE
1180
1181 struct elf_prstatus_fdpic
1182 {
1183 struct elf_prstatus_common common;
1184 elf_gregset_t pr_reg; /* GP registers */
1185 /* When using FDPIC, the loadmap addresses need to be communicated
1186 * to GDB in order for GDB to do the necessary relocations. The
1187 * fields (below) used to communicate this information are placed
1188 * immediately after ``pr_reg'', so that the loadmap addresses may
1189 * be viewed as part of the register set if so desired.
1190 */
1191 unsigned long pr_exec_fdpic_loadmap;
1192 unsigned long pr_interp_fdpic_loadmap;
1193 int pr_fpvalid; /* True if math co-processor being used. */
1194 };
1195
1196 /* An ELF note in memory */
1197 struct memelfnote
1198 {
1199 const char *name;
1200 int type;
1201 unsigned int datasz;
1202 void *data;
1203 };
1204
notesize(struct memelfnote * en)1205 static int notesize(struct memelfnote *en)
1206 {
1207 int sz;
1208
1209 sz = sizeof(struct elf_note);
1210 sz += roundup(strlen(en->name) + 1, 4);
1211 sz += roundup(en->datasz, 4);
1212
1213 return sz;
1214 }
1215
1216 /* #define DEBUG */
1217
writenote(struct memelfnote * men,struct coredump_params * cprm)1218 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1219 {
1220 struct elf_note en;
1221 en.n_namesz = strlen(men->name) + 1;
1222 en.n_descsz = men->datasz;
1223 en.n_type = men->type;
1224
1225 return dump_emit(cprm, &en, sizeof(en)) &&
1226 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1227 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1228 }
1229
fill_elf_fdpic_header(struct elfhdr * elf,int segs)1230 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1231 {
1232 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1233 elf->e_ident[EI_CLASS] = ELF_CLASS;
1234 elf->e_ident[EI_DATA] = ELF_DATA;
1235 elf->e_ident[EI_VERSION] = EV_CURRENT;
1236 elf->e_ident[EI_OSABI] = ELF_OSABI;
1237 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1238
1239 elf->e_type = ET_CORE;
1240 elf->e_machine = ELF_ARCH;
1241 elf->e_version = EV_CURRENT;
1242 elf->e_entry = 0;
1243 elf->e_phoff = sizeof(struct elfhdr);
1244 elf->e_shoff = 0;
1245 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1246 elf->e_ehsize = sizeof(struct elfhdr);
1247 elf->e_phentsize = sizeof(struct elf_phdr);
1248 elf->e_phnum = segs;
1249 elf->e_shentsize = 0;
1250 elf->e_shnum = 0;
1251 elf->e_shstrndx = 0;
1252 return;
1253 }
1254
fill_elf_note_phdr(struct elf_phdr * phdr,int sz,loff_t offset)1255 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1256 {
1257 phdr->p_type = PT_NOTE;
1258 phdr->p_offset = offset;
1259 phdr->p_vaddr = 0;
1260 phdr->p_paddr = 0;
1261 phdr->p_filesz = sz;
1262 phdr->p_memsz = 0;
1263 phdr->p_flags = 0;
1264 phdr->p_align = 4;
1265 return;
1266 }
1267
fill_note(struct memelfnote * note,const char * name,int type,unsigned int sz,void * data)1268 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1269 unsigned int sz, void *data)
1270 {
1271 note->name = name;
1272 note->type = type;
1273 note->datasz = sz;
1274 note->data = data;
1275 return;
1276 }
1277
1278 /*
1279 * fill up all the fields in prstatus from the given task struct, except
1280 * registers which need to be filled up separately.
1281 */
fill_prstatus(struct elf_prstatus_common * prstatus,struct task_struct * p,long signr)1282 static void fill_prstatus(struct elf_prstatus_common *prstatus,
1283 struct task_struct *p, long signr)
1284 {
1285 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1286 prstatus->pr_sigpend = p->pending.signal.sig[0];
1287 prstatus->pr_sighold = p->blocked.sig[0];
1288 rcu_read_lock();
1289 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1290 rcu_read_unlock();
1291 prstatus->pr_pid = task_pid_vnr(p);
1292 prstatus->pr_pgrp = task_pgrp_vnr(p);
1293 prstatus->pr_sid = task_session_vnr(p);
1294 if (thread_group_leader(p)) {
1295 struct task_cputime cputime;
1296
1297 /*
1298 * This is the record for the group leader. It shows the
1299 * group-wide total, not its individual thread total.
1300 */
1301 thread_group_cputime(p, &cputime);
1302 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1303 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1304 } else {
1305 u64 utime, stime;
1306
1307 task_cputime(p, &utime, &stime);
1308 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1309 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1310 }
1311 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1312 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1313 }
1314
fill_psinfo(struct elf_prpsinfo * psinfo,struct task_struct * p,struct mm_struct * mm)1315 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1316 struct mm_struct *mm)
1317 {
1318 const struct cred *cred;
1319 unsigned int i, len;
1320 unsigned int state;
1321
1322 /* first copy the parameters from user space */
1323 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1324
1325 len = mm->arg_end - mm->arg_start;
1326 if (len >= ELF_PRARGSZ)
1327 len = ELF_PRARGSZ - 1;
1328 if (copy_from_user(&psinfo->pr_psargs,
1329 (const char __user *) mm->arg_start, len))
1330 return -EFAULT;
1331 for (i = 0; i < len; i++)
1332 if (psinfo->pr_psargs[i] == 0)
1333 psinfo->pr_psargs[i] = ' ';
1334 psinfo->pr_psargs[len] = 0;
1335
1336 rcu_read_lock();
1337 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1338 rcu_read_unlock();
1339 psinfo->pr_pid = task_pid_vnr(p);
1340 psinfo->pr_pgrp = task_pgrp_vnr(p);
1341 psinfo->pr_sid = task_session_vnr(p);
1342
1343 state = READ_ONCE(p->__state);
1344 i = state ? ffz(~state) + 1 : 0;
1345 psinfo->pr_state = i;
1346 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1347 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1348 psinfo->pr_nice = task_nice(p);
1349 psinfo->pr_flag = p->flags;
1350 rcu_read_lock();
1351 cred = __task_cred(p);
1352 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1353 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1354 rcu_read_unlock();
1355 get_task_comm(psinfo->pr_fname, p);
1356
1357 return 0;
1358 }
1359
1360 /* Here is the structure in which status of each thread is captured. */
1361 struct elf_thread_status
1362 {
1363 struct elf_thread_status *next;
1364 struct elf_prstatus_fdpic prstatus; /* NT_PRSTATUS */
1365 elf_fpregset_t fpu; /* NT_PRFPREG */
1366 struct memelfnote notes[2];
1367 int num_notes;
1368 };
1369
1370 /*
1371 * In order to add the specific thread information for the elf file format,
1372 * we need to keep a linked list of every thread's pr_status and then create
1373 * a single section for them in the final core file.
1374 */
elf_dump_thread_status(long signr,struct task_struct * p,int * sz)1375 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
1376 {
1377 const struct user_regset_view *view = task_user_regset_view(p);
1378 struct elf_thread_status *t;
1379 int i, ret;
1380
1381 t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
1382 if (!t)
1383 return t;
1384
1385 fill_prstatus(&t->prstatus.common, p, signr);
1386 t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1387 t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1388 regset_get(p, &view->regsets[0],
1389 sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1390
1391 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1392 &t->prstatus);
1393 t->num_notes++;
1394 *sz += notesize(&t->notes[0]);
1395
1396 for (i = 1; i < view->n; ++i) {
1397 const struct user_regset *regset = &view->regsets[i];
1398 if (regset->core_note_type != NT_PRFPREG)
1399 continue;
1400 if (regset->active && regset->active(p, regset) <= 0)
1401 continue;
1402 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
1403 if (ret >= 0)
1404 t->prstatus.pr_fpvalid = 1;
1405 break;
1406 }
1407
1408 if (t->prstatus.pr_fpvalid) {
1409 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1410 &t->fpu);
1411 t->num_notes++;
1412 *sz += notesize(&t->notes[1]);
1413 }
1414 return t;
1415 }
1416
fill_extnum_info(struct elfhdr * elf,struct elf_shdr * shdr4extnum,elf_addr_t e_shoff,int segs)1417 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1418 elf_addr_t e_shoff, int segs)
1419 {
1420 elf->e_shoff = e_shoff;
1421 elf->e_shentsize = sizeof(*shdr4extnum);
1422 elf->e_shnum = 1;
1423 elf->e_shstrndx = SHN_UNDEF;
1424
1425 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1426
1427 shdr4extnum->sh_type = SHT_NULL;
1428 shdr4extnum->sh_size = elf->e_shnum;
1429 shdr4extnum->sh_link = elf->e_shstrndx;
1430 shdr4extnum->sh_info = segs;
1431 }
1432
1433 /*
1434 * dump the segments for an MMU process
1435 */
elf_fdpic_dump_segments(struct coredump_params * cprm,struct core_vma_metadata * vma_meta,int vma_count)1436 static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
1437 struct core_vma_metadata *vma_meta,
1438 int vma_count)
1439 {
1440 int i;
1441
1442 for (i = 0; i < vma_count; i++) {
1443 struct core_vma_metadata *meta = vma_meta + i;
1444
1445 if (!dump_user_range(cprm, meta->start, meta->dump_size))
1446 return false;
1447 }
1448 return true;
1449 }
1450
1451 /*
1452 * Actual dumper
1453 *
1454 * This is a two-pass process; first we find the offsets of the bits,
1455 * and then they are actually written out. If we run out of core limit
1456 * we just truncate.
1457 */
elf_fdpic_core_dump(struct coredump_params * cprm)1458 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1459 {
1460 int has_dumped = 0;
1461 int segs;
1462 int i;
1463 struct elfhdr *elf = NULL;
1464 loff_t offset = 0, dataoff;
1465 struct memelfnote psinfo_note, auxv_note;
1466 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1467 struct elf_thread_status *thread_list = NULL;
1468 int thread_status_size = 0;
1469 elf_addr_t *auxv;
1470 struct elf_phdr *phdr4note = NULL;
1471 struct elf_shdr *shdr4extnum = NULL;
1472 Elf_Half e_phnum;
1473 elf_addr_t e_shoff;
1474 struct core_thread *ct;
1475 struct elf_thread_status *tmp;
1476
1477 /* alloc memory for large data structures: too large to be on stack */
1478 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1479 if (!elf)
1480 goto end_coredump;
1481 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1482 if (!psinfo)
1483 goto end_coredump;
1484
1485 for (ct = current->signal->core_state->dumper.next;
1486 ct; ct = ct->next) {
1487 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1488 ct->task, &thread_status_size);
1489 if (!tmp)
1490 goto end_coredump;
1491
1492 tmp->next = thread_list;
1493 thread_list = tmp;
1494 }
1495
1496 /* now collect the dump for the current */
1497 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1498 current, &thread_status_size);
1499 if (!tmp)
1500 goto end_coredump;
1501 tmp->next = thread_list;
1502 thread_list = tmp;
1503
1504 segs = cprm->vma_count + elf_core_extra_phdrs(cprm);
1505
1506 /* for notes section */
1507 segs++;
1508
1509 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1510 * this, kernel supports extended numbering. Have a look at
1511 * include/linux/elf.h for further information. */
1512 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1513
1514 /* Set up header */
1515 fill_elf_fdpic_header(elf, e_phnum);
1516
1517 has_dumped = 1;
1518 /*
1519 * Set up the notes in similar form to SVR4 core dumps made
1520 * with info from their /proc.
1521 */
1522
1523 fill_psinfo(psinfo, current->group_leader, current->mm);
1524 fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1525 thread_status_size += notesize(&psinfo_note);
1526
1527 auxv = (elf_addr_t *) current->mm->saved_auxv;
1528 i = 0;
1529 do
1530 i += 2;
1531 while (auxv[i - 2] != AT_NULL);
1532 fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1533 thread_status_size += notesize(&auxv_note);
1534
1535 offset = sizeof(*elf); /* ELF header */
1536 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1537
1538 /* Write notes phdr entry */
1539 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1540 if (!phdr4note)
1541 goto end_coredump;
1542
1543 fill_elf_note_phdr(phdr4note, thread_status_size, offset);
1544 offset += thread_status_size;
1545
1546 /* Page-align dumped data */
1547 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1548
1549 offset += cprm->vma_data_size;
1550 offset += elf_core_extra_data_size(cprm);
1551 e_shoff = offset;
1552
1553 if (e_phnum == PN_XNUM) {
1554 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1555 if (!shdr4extnum)
1556 goto end_coredump;
1557 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1558 }
1559
1560 offset = dataoff;
1561
1562 if (!dump_emit(cprm, elf, sizeof(*elf)))
1563 goto end_coredump;
1564
1565 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1566 goto end_coredump;
1567
1568 /* write program headers for segments dump */
1569 for (i = 0; i < cprm->vma_count; i++) {
1570 struct core_vma_metadata *meta = cprm->vma_meta + i;
1571 struct elf_phdr phdr;
1572 size_t sz;
1573
1574 sz = meta->end - meta->start;
1575
1576 phdr.p_type = PT_LOAD;
1577 phdr.p_offset = offset;
1578 phdr.p_vaddr = meta->start;
1579 phdr.p_paddr = 0;
1580 phdr.p_filesz = meta->dump_size;
1581 phdr.p_memsz = sz;
1582 offset += phdr.p_filesz;
1583 phdr.p_flags = 0;
1584 if (meta->flags & VM_READ)
1585 phdr.p_flags |= PF_R;
1586 if (meta->flags & VM_WRITE)
1587 phdr.p_flags |= PF_W;
1588 if (meta->flags & VM_EXEC)
1589 phdr.p_flags |= PF_X;
1590 phdr.p_align = ELF_EXEC_PAGESIZE;
1591
1592 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1593 goto end_coredump;
1594 }
1595
1596 if (!elf_core_write_extra_phdrs(cprm, offset))
1597 goto end_coredump;
1598
1599 /* write out the notes section */
1600 if (!writenote(thread_list->notes, cprm))
1601 goto end_coredump;
1602 if (!writenote(&psinfo_note, cprm))
1603 goto end_coredump;
1604 if (!writenote(&auxv_note, cprm))
1605 goto end_coredump;
1606 for (i = 1; i < thread_list->num_notes; i++)
1607 if (!writenote(thread_list->notes + i, cprm))
1608 goto end_coredump;
1609
1610 /* write out the thread status notes section */
1611 for (tmp = thread_list->next; tmp; tmp = tmp->next) {
1612 for (i = 0; i < tmp->num_notes; i++)
1613 if (!writenote(&tmp->notes[i], cprm))
1614 goto end_coredump;
1615 }
1616
1617 dump_skip_to(cprm, dataoff);
1618
1619 if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count))
1620 goto end_coredump;
1621
1622 if (!elf_core_write_extra_data(cprm))
1623 goto end_coredump;
1624
1625 if (e_phnum == PN_XNUM) {
1626 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1627 goto end_coredump;
1628 }
1629
1630 if (cprm->file->f_pos != offset) {
1631 /* Sanity check */
1632 printk(KERN_WARNING
1633 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1634 cprm->file->f_pos, offset);
1635 }
1636
1637 end_coredump:
1638 while (thread_list) {
1639 tmp = thread_list;
1640 thread_list = thread_list->next;
1641 kfree(tmp);
1642 }
1643 kfree(phdr4note);
1644 kfree(elf);
1645 kfree(psinfo);
1646 kfree(shdr4extnum);
1647 return has_dumped;
1648 }
1649
1650 #endif /* CONFIG_ELF_CORE */
1651