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 allow_write_access(interpreter);
398 fput(interpreter);
399 interpreter = NULL;
400 }
401
402 #ifdef CONFIG_MMU
403 if (!current->mm->start_brk)
404 current->mm->start_brk = current->mm->end_data;
405
406 current->mm->brk = current->mm->start_brk =
407 PAGE_ALIGN(current->mm->start_brk);
408
409 #else
410 /* create a stack area and zero-size brk area */
411 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
412 if (stack_size < PAGE_SIZE * 2)
413 stack_size = PAGE_SIZE * 2;
414
415 stack_prot = PROT_READ | PROT_WRITE;
416 if (executable_stack == EXSTACK_ENABLE_X ||
417 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
418 stack_prot |= PROT_EXEC;
419
420 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
421 MAP_PRIVATE | MAP_ANONYMOUS |
422 MAP_UNINITIALIZED | MAP_GROWSDOWN,
423 0);
424
425 if (IS_ERR_VALUE(current->mm->start_brk)) {
426 retval = current->mm->start_brk;
427 current->mm->start_brk = 0;
428 goto error;
429 }
430
431 current->mm->brk = current->mm->start_brk;
432 current->mm->context.end_brk = current->mm->start_brk;
433 current->mm->start_stack = current->mm->start_brk + stack_size;
434 #endif
435
436 retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params,
437 &interp_params);
438 if (retval < 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 */
create_elf_fdpic_tables(struct linux_binprm * bprm,struct mm_struct * mm,struct elf_fdpic_params * exec_params,struct elf_fdpic_params * interp_params)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 unsigned long flags = 0;
509 int ei_index;
510 elf_addr_t *elf_info;
511
512 #ifdef CONFIG_MMU
513 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
514 * by the processes running on the same package. One thing we can do is
515 * to shuffle the initial stack for them, so we give the architecture
516 * an opportunity to do so here.
517 */
518 sp = arch_align_stack(bprm->p);
519 #else
520 sp = mm->start_stack;
521
522 /* stack the program arguments and environment */
523 if (transfer_args_to_stack(bprm, &sp) < 0)
524 return -EFAULT;
525 sp &= ~15;
526 #endif
527
528 /*
529 * If this architecture has a platform capability string, copy it
530 * to userspace. In some cases (Sparc), this info is impossible
531 * for userspace to get any other way, in others (i386) it is
532 * merely difficult.
533 */
534 k_platform = ELF_PLATFORM;
535 u_platform = NULL;
536
537 if (k_platform) {
538 platform_len = strlen(k_platform) + 1;
539 sp -= platform_len;
540 u_platform = (char __user *) sp;
541 if (copy_to_user(u_platform, k_platform, platform_len) != 0)
542 return -EFAULT;
543 }
544
545 /*
546 * If this architecture has a "base" platform capability
547 * string, copy it to userspace.
548 */
549 k_base_platform = ELF_BASE_PLATFORM;
550 u_base_platform = NULL;
551
552 if (k_base_platform) {
553 platform_len = strlen(k_base_platform) + 1;
554 sp -= platform_len;
555 u_base_platform = (char __user *) sp;
556 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
557 return -EFAULT;
558 }
559
560 sp &= ~7UL;
561
562 /* stack the load map(s) */
563 len = sizeof(struct elf_fdpic_loadmap);
564 len += sizeof(struct elf_fdpic_loadseg) * exec_params->loadmap->nsegs;
565 sp = (sp - len) & ~7UL;
566 exec_params->map_addr = sp;
567
568 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
569 return -EFAULT;
570
571 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
572
573 if (interp_params->loadmap) {
574 len = sizeof(struct elf_fdpic_loadmap);
575 len += sizeof(struct elf_fdpic_loadseg) *
576 interp_params->loadmap->nsegs;
577 sp = (sp - len) & ~7UL;
578 interp_params->map_addr = sp;
579
580 if (copy_to_user((void __user *) sp, interp_params->loadmap,
581 len) != 0)
582 return -EFAULT;
583
584 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
585 }
586
587 /* force 16 byte _final_ alignment here for generality */
588 #define DLINFO_ITEMS 15
589
590 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
591 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
592
593 if (bprm->have_execfd)
594 nitems++;
595 #ifdef ELF_HWCAP2
596 nitems++;
597 #endif
598
599 csp = sp;
600 sp -= nitems * 2 * sizeof(unsigned long);
601 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
602 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
603 sp -= 1 * sizeof(unsigned long); /* argc */
604
605 csp -= sp & 15UL;
606 sp -= sp & 15UL;
607
608 /* Create the ELF interpreter info */
609 elf_info = (elf_addr_t *)mm->saved_auxv;
610 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
611 #define NEW_AUX_ENT(id, val) \
612 do { \
613 *elf_info++ = id; \
614 *elf_info++ = val; \
615 } while (0)
616
617 #ifdef ARCH_DLINFO
618 /*
619 * ARCH_DLINFO must come first so PPC can do its special alignment of
620 * AUXV.
621 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
622 * ARCH_DLINFO changes
623 */
624 ARCH_DLINFO;
625 #endif
626 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
627 #ifdef ELF_HWCAP2
628 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
629 #endif
630 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
631 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
632 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
633 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
634 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
635 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
636 if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
637 flags |= AT_FLAGS_PRESERVE_ARGV0;
638 NEW_AUX_ENT(AT_FLAGS, flags);
639 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
640 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
641 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
642 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
643 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
644 NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
645 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
646 if (k_platform)
647 NEW_AUX_ENT(AT_PLATFORM,
648 (elf_addr_t)(unsigned long)u_platform);
649 if (k_base_platform)
650 NEW_AUX_ENT(AT_BASE_PLATFORM,
651 (elf_addr_t)(unsigned long)u_base_platform);
652 if (bprm->have_execfd)
653 NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
654 #undef NEW_AUX_ENT
655 /* AT_NULL is zero; clear the rest too */
656 memset(elf_info, 0, (char *)mm->saved_auxv +
657 sizeof(mm->saved_auxv) - (char *)elf_info);
658
659 /* And advance past the AT_NULL entry. */
660 elf_info += 2;
661
662 ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
663 csp -= ei_index * sizeof(elf_addr_t);
664
665 /* Put the elf_info on the stack in the right place. */
666 if (copy_to_user((void __user *)csp, mm->saved_auxv,
667 ei_index * sizeof(elf_addr_t)))
668 return -EFAULT;
669
670 /* allocate room for argv[] and envv[] */
671 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
672 envp = (elf_caddr_t __user *) csp;
673 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
674 argv = (elf_caddr_t __user *) csp;
675
676 /* stack argc */
677 csp -= sizeof(unsigned long);
678 if (put_user(bprm->argc, (unsigned long __user *) csp))
679 return -EFAULT;
680
681 BUG_ON(csp != sp);
682
683 /* fill in the argv[] array */
684 #ifdef CONFIG_MMU
685 current->mm->arg_start = bprm->p;
686 #else
687 current->mm->arg_start = current->mm->start_stack -
688 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
689 #endif
690
691 p = (char __user *) current->mm->arg_start;
692 for (loop = bprm->argc; loop > 0; loop--) {
693 if (put_user((elf_caddr_t) p, argv++))
694 return -EFAULT;
695 len = strnlen_user(p, MAX_ARG_STRLEN);
696 if (!len || len > MAX_ARG_STRLEN)
697 return -EINVAL;
698 p += len;
699 }
700 if (put_user(NULL, argv))
701 return -EFAULT;
702 current->mm->arg_end = (unsigned long) p;
703
704 /* fill in the envv[] array */
705 current->mm->env_start = (unsigned long) p;
706 for (loop = bprm->envc; loop > 0; loop--) {
707 if (put_user((elf_caddr_t)(unsigned long) p, envp++))
708 return -EFAULT;
709 len = strnlen_user(p, MAX_ARG_STRLEN);
710 if (!len || len > MAX_ARG_STRLEN)
711 return -EINVAL;
712 p += len;
713 }
714 if (put_user(NULL, envp))
715 return -EFAULT;
716 current->mm->env_end = (unsigned long) p;
717
718 mm->start_stack = (unsigned long) sp;
719 return 0;
720 }
721
722 /*****************************************************************************/
723 /*
724 * load the appropriate binary image (executable or interpreter) into memory
725 * - we assume no MMU is available
726 * - if no other PIC bits are set in params->hdr->e_flags
727 * - we assume that the LOADable segments in the binary are independently relocatable
728 * - we assume R/O executable segments are shareable
729 * - else
730 * - we assume the loadable parts of the image to require fixed displacement
731 * - the image is not shareable
732 */
elf_fdpic_map_file(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm,const char * what)733 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
734 struct file *file,
735 struct mm_struct *mm,
736 const char *what)
737 {
738 struct elf_fdpic_loadmap *loadmap;
739 #ifdef CONFIG_MMU
740 struct elf_fdpic_loadseg *mseg;
741 unsigned long load_addr;
742 #endif
743 struct elf_fdpic_loadseg *seg;
744 struct elf_phdr *phdr;
745 unsigned nloads, tmp;
746 unsigned long stop;
747 int loop, ret;
748
749 /* allocate a load map table */
750 nloads = 0;
751 for (loop = 0; loop < params->hdr.e_phnum; loop++)
752 if (params->phdrs[loop].p_type == PT_LOAD)
753 nloads++;
754
755 if (nloads == 0)
756 return -ELIBBAD;
757
758 loadmap = kzalloc(struct_size(loadmap, segs, nloads), GFP_KERNEL);
759 if (!loadmap)
760 return -ENOMEM;
761
762 params->loadmap = loadmap;
763
764 loadmap->version = ELF_FDPIC_LOADMAP_VERSION;
765 loadmap->nsegs = nloads;
766
767 /* map the requested LOADs into the memory space */
768 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
769 case ELF_FDPIC_FLAG_CONSTDISP:
770 case ELF_FDPIC_FLAG_CONTIGUOUS:
771 #ifndef CONFIG_MMU
772 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
773 if (ret < 0)
774 return ret;
775 break;
776 #endif
777 default:
778 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
779 if (ret < 0)
780 return ret;
781 break;
782 }
783
784 /* map the entry point */
785 if (params->hdr.e_entry) {
786 seg = loadmap->segs;
787 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
788 if (params->hdr.e_entry >= seg->p_vaddr &&
789 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
790 params->entry_addr =
791 (params->hdr.e_entry - seg->p_vaddr) +
792 seg->addr;
793 break;
794 }
795 }
796 }
797
798 /* determine where the program header table has wound up if mapped */
799 stop = params->hdr.e_phoff;
800 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
801 phdr = params->phdrs;
802
803 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
804 if (phdr->p_type != PT_LOAD)
805 continue;
806
807 if (phdr->p_offset > params->hdr.e_phoff ||
808 phdr->p_offset + phdr->p_filesz < stop)
809 continue;
810
811 seg = loadmap->segs;
812 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
813 if (phdr->p_vaddr >= seg->p_vaddr &&
814 phdr->p_vaddr + phdr->p_filesz <=
815 seg->p_vaddr + seg->p_memsz) {
816 params->ph_addr =
817 (phdr->p_vaddr - seg->p_vaddr) +
818 seg->addr +
819 params->hdr.e_phoff - phdr->p_offset;
820 break;
821 }
822 }
823 break;
824 }
825
826 /* determine where the dynamic section has wound up if there is one */
827 phdr = params->phdrs;
828 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
829 if (phdr->p_type != PT_DYNAMIC)
830 continue;
831
832 seg = loadmap->segs;
833 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
834 if (phdr->p_vaddr >= seg->p_vaddr &&
835 phdr->p_vaddr + phdr->p_memsz <=
836 seg->p_vaddr + seg->p_memsz) {
837 Elf_Dyn __user *dyn;
838 Elf_Sword d_tag;
839
840 params->dynamic_addr =
841 (phdr->p_vaddr - seg->p_vaddr) +
842 seg->addr;
843
844 /* check the dynamic section contains at least
845 * one item, and that the last item is a NULL
846 * entry */
847 if (phdr->p_memsz == 0 ||
848 phdr->p_memsz % sizeof(Elf_Dyn) != 0)
849 goto dynamic_error;
850
851 tmp = phdr->p_memsz / sizeof(Elf_Dyn);
852 dyn = (Elf_Dyn __user *)params->dynamic_addr;
853 if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
854 d_tag != 0)
855 goto dynamic_error;
856 break;
857 }
858 }
859 break;
860 }
861
862 /* now elide adjacent segments in the load map on MMU linux
863 * - on uClinux the holes between may actually be filled with system
864 * stuff or stuff from other processes
865 */
866 #ifdef CONFIG_MMU
867 nloads = loadmap->nsegs;
868 mseg = loadmap->segs;
869 seg = mseg + 1;
870 for (loop = 1; loop < nloads; loop++) {
871 /* see if we have a candidate for merging */
872 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
873 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
874 if (load_addr == (seg->addr & PAGE_MASK)) {
875 mseg->p_memsz +=
876 load_addr -
877 (mseg->addr + mseg->p_memsz);
878 mseg->p_memsz += seg->addr & ~PAGE_MASK;
879 mseg->p_memsz += seg->p_memsz;
880 loadmap->nsegs--;
881 continue;
882 }
883 }
884
885 mseg++;
886 if (mseg != seg)
887 *mseg = *seg;
888 }
889 #endif
890
891 kdebug("Mapped Object [%s]:", what);
892 kdebug("- elfhdr : %lx", params->elfhdr_addr);
893 kdebug("- entry : %lx", params->entry_addr);
894 kdebug("- PHDR[] : %lx", params->ph_addr);
895 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
896 seg = loadmap->segs;
897 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
898 kdebug("- LOAD[%d] : %08llx-%08llx [va=%llx ms=%llx]",
899 loop,
900 (unsigned long long) seg->addr,
901 (unsigned long long) seg->addr + seg->p_memsz - 1,
902 (unsigned long long) seg->p_vaddr,
903 (unsigned long long) seg->p_memsz);
904
905 return 0;
906
907 dynamic_error:
908 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
909 what, file_inode(file)->i_ino);
910 return -ELIBBAD;
911 }
912
913 /*****************************************************************************/
914 /*
915 * map a file with constant displacement under uClinux
916 */
917 #ifndef CONFIG_MMU
elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm)918 static int elf_fdpic_map_file_constdisp_on_uclinux(
919 struct elf_fdpic_params *params,
920 struct file *file,
921 struct mm_struct *mm)
922 {
923 struct elf_fdpic_loadseg *seg;
924 struct elf_phdr *phdr;
925 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
926 int loop, ret;
927
928 load_addr = params->load_addr;
929 seg = params->loadmap->segs;
930
931 /* determine the bounds of the contiguous overall allocation we must
932 * make */
933 phdr = params->phdrs;
934 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
935 if (params->phdrs[loop].p_type != PT_LOAD)
936 continue;
937
938 if (base > phdr->p_vaddr)
939 base = phdr->p_vaddr;
940 if (top < phdr->p_vaddr + phdr->p_memsz)
941 top = phdr->p_vaddr + phdr->p_memsz;
942 }
943
944 /* allocate one big anon block for everything */
945 maddr = vm_mmap(NULL, load_addr, top - base,
946 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0);
947 if (IS_ERR_VALUE(maddr))
948 return (int) maddr;
949
950 if (load_addr != 0)
951 load_addr += PAGE_ALIGN(top - base);
952
953 /* and then load the file segments into it */
954 phdr = params->phdrs;
955 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
956 if (params->phdrs[loop].p_type != PT_LOAD)
957 continue;
958
959 seg->addr = maddr + (phdr->p_vaddr - base);
960 seg->p_vaddr = phdr->p_vaddr;
961 seg->p_memsz = phdr->p_memsz;
962
963 ret = read_code(file, seg->addr, phdr->p_offset,
964 phdr->p_filesz);
965 if (ret < 0)
966 return ret;
967
968 /* map the ELF header address if in this segment */
969 if (phdr->p_offset == 0)
970 params->elfhdr_addr = seg->addr;
971
972 /* clear any space allocated but not loaded */
973 if (phdr->p_filesz < phdr->p_memsz) {
974 if (clear_user((void *) (seg->addr + phdr->p_filesz),
975 phdr->p_memsz - phdr->p_filesz))
976 return -EFAULT;
977 }
978
979 if (mm) {
980 if (phdr->p_flags & PF_X) {
981 if (!mm->start_code) {
982 mm->start_code = seg->addr;
983 mm->end_code = seg->addr +
984 phdr->p_memsz;
985 }
986 } else if (!mm->start_data) {
987 mm->start_data = seg->addr;
988 mm->end_data = seg->addr + phdr->p_memsz;
989 }
990 }
991
992 seg++;
993 }
994
995 return 0;
996 }
997 #endif
998
999 /*****************************************************************************/
1000 /*
1001 * map a binary by direct mmap() of the individual PT_LOAD segments
1002 */
elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm)1003 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1004 struct file *file,
1005 struct mm_struct *mm)
1006 {
1007 struct elf_fdpic_loadseg *seg;
1008 struct elf_phdr *phdr;
1009 unsigned long load_addr, delta_vaddr;
1010 int loop, dvset;
1011
1012 load_addr = params->load_addr;
1013 delta_vaddr = 0;
1014 dvset = 0;
1015
1016 seg = params->loadmap->segs;
1017
1018 /* deal with each load segment separately */
1019 phdr = params->phdrs;
1020 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1021 unsigned long maddr, disp, excess, excess1;
1022 int prot = 0, flags;
1023
1024 if (phdr->p_type != PT_LOAD)
1025 continue;
1026
1027 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1028 (unsigned long) phdr->p_vaddr,
1029 (unsigned long) phdr->p_offset,
1030 (unsigned long) phdr->p_filesz,
1031 (unsigned long) phdr->p_memsz);
1032
1033 /* determine the mapping parameters */
1034 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1035 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1036 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1037
1038 flags = MAP_PRIVATE;
1039 maddr = 0;
1040
1041 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1042 case ELF_FDPIC_FLAG_INDEPENDENT:
1043 /* PT_LOADs are independently locatable */
1044 break;
1045
1046 case ELF_FDPIC_FLAG_HONOURVADDR:
1047 /* the specified virtual address must be honoured */
1048 maddr = phdr->p_vaddr;
1049 flags |= MAP_FIXED;
1050 break;
1051
1052 case ELF_FDPIC_FLAG_CONSTDISP:
1053 /* constant displacement
1054 * - can be mapped anywhere, but must be mapped as a
1055 * unit
1056 */
1057 if (!dvset) {
1058 maddr = load_addr;
1059 delta_vaddr = phdr->p_vaddr;
1060 dvset = 1;
1061 } else {
1062 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1063 flags |= MAP_FIXED;
1064 }
1065 break;
1066
1067 case ELF_FDPIC_FLAG_CONTIGUOUS:
1068 /* contiguity handled later */
1069 break;
1070
1071 default:
1072 BUG();
1073 }
1074
1075 maddr &= PAGE_MASK;
1076
1077 /* create the mapping */
1078 disp = phdr->p_vaddr & ~PAGE_MASK;
1079 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1080 phdr->p_offset - disp);
1081
1082 kdebug("mmap[%d] <file> sz=%llx pr=%x fl=%x of=%llx --> %08lx",
1083 loop, (unsigned long long) phdr->p_memsz + disp,
1084 prot, flags, (unsigned long long) phdr->p_offset - disp,
1085 maddr);
1086
1087 if (IS_ERR_VALUE(maddr))
1088 return (int) maddr;
1089
1090 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1091 ELF_FDPIC_FLAG_CONTIGUOUS)
1092 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1093
1094 seg->addr = maddr + disp;
1095 seg->p_vaddr = phdr->p_vaddr;
1096 seg->p_memsz = phdr->p_memsz;
1097
1098 /* map the ELF header address if in this segment */
1099 if (phdr->p_offset == 0)
1100 params->elfhdr_addr = seg->addr;
1101
1102 /* clear the bit between beginning of mapping and beginning of
1103 * PT_LOAD */
1104 if (prot & PROT_WRITE && disp > 0) {
1105 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1106 if (clear_user((void __user *) maddr, disp))
1107 return -EFAULT;
1108 maddr += disp;
1109 }
1110
1111 /* clear any space allocated but not loaded
1112 * - on uClinux we can just clear the lot
1113 * - on MMU linux we'll get a SIGBUS beyond the last page
1114 * extant in the file
1115 */
1116 excess = phdr->p_memsz - phdr->p_filesz;
1117 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1118
1119 #ifdef CONFIG_MMU
1120 if (excess > excess1) {
1121 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1122 unsigned long xmaddr;
1123
1124 flags |= MAP_FIXED | MAP_ANONYMOUS;
1125 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1126 prot, flags, 0);
1127
1128 kdebug("mmap[%d] <anon>"
1129 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1130 loop, xaddr, excess - excess1, prot, flags,
1131 xmaddr);
1132
1133 if (xmaddr != xaddr)
1134 return -ENOMEM;
1135 }
1136
1137 if (prot & PROT_WRITE && excess1 > 0) {
1138 kdebug("clear[%d] ad=%lx sz=%lx",
1139 loop, maddr + phdr->p_filesz, excess1);
1140 if (clear_user((void __user *) maddr + phdr->p_filesz,
1141 excess1))
1142 return -EFAULT;
1143 }
1144
1145 #else
1146 if (excess > 0) {
1147 kdebug("clear[%d] ad=%llx sz=%lx", loop,
1148 (unsigned long long) maddr + phdr->p_filesz,
1149 excess);
1150 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1151 return -EFAULT;
1152 }
1153 #endif
1154
1155 if (mm) {
1156 if (phdr->p_flags & PF_X) {
1157 if (!mm->start_code) {
1158 mm->start_code = maddr;
1159 mm->end_code = maddr + phdr->p_memsz;
1160 }
1161 } else if (!mm->start_data) {
1162 mm->start_data = maddr;
1163 mm->end_data = maddr + phdr->p_memsz;
1164 }
1165 }
1166
1167 seg++;
1168 }
1169
1170 return 0;
1171 }
1172
1173 /*****************************************************************************/
1174 /*
1175 * ELF-FDPIC core dumper
1176 *
1177 * Modelled on fs/exec.c:aout_core_dump()
1178 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1179 *
1180 * Modelled on fs/binfmt_elf.c core dumper
1181 */
1182 #ifdef CONFIG_ELF_CORE
1183
1184 struct elf_prstatus_fdpic
1185 {
1186 struct elf_prstatus_common common;
1187 elf_gregset_t pr_reg; /* GP registers */
1188 /* When using FDPIC, the loadmap addresses need to be communicated
1189 * to GDB in order for GDB to do the necessary relocations. The
1190 * fields (below) used to communicate this information are placed
1191 * immediately after ``pr_reg'', so that the loadmap addresses may
1192 * be viewed as part of the register set if so desired.
1193 */
1194 unsigned long pr_exec_fdpic_loadmap;
1195 unsigned long pr_interp_fdpic_loadmap;
1196 int pr_fpvalid; /* True if math co-processor being used. */
1197 };
1198
1199 /* An ELF note in memory */
1200 struct memelfnote
1201 {
1202 const char *name;
1203 int type;
1204 unsigned int datasz;
1205 void *data;
1206 };
1207
notesize(struct memelfnote * en)1208 static int notesize(struct memelfnote *en)
1209 {
1210 int sz;
1211
1212 sz = sizeof(struct elf_note);
1213 sz += roundup(strlen(en->name) + 1, 4);
1214 sz += roundup(en->datasz, 4);
1215
1216 return sz;
1217 }
1218
1219 /* #define DEBUG */
1220
writenote(struct memelfnote * men,struct coredump_params * cprm)1221 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1222 {
1223 struct elf_note en;
1224 en.n_namesz = strlen(men->name) + 1;
1225 en.n_descsz = men->datasz;
1226 en.n_type = men->type;
1227
1228 return dump_emit(cprm, &en, sizeof(en)) &&
1229 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1230 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1231 }
1232
fill_elf_fdpic_header(struct elfhdr * elf,int segs)1233 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1234 {
1235 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1236 elf->e_ident[EI_CLASS] = ELF_CLASS;
1237 elf->e_ident[EI_DATA] = ELF_DATA;
1238 elf->e_ident[EI_VERSION] = EV_CURRENT;
1239 elf->e_ident[EI_OSABI] = ELF_OSABI;
1240 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1241
1242 elf->e_type = ET_CORE;
1243 elf->e_machine = ELF_ARCH;
1244 elf->e_version = EV_CURRENT;
1245 elf->e_entry = 0;
1246 elf->e_phoff = sizeof(struct elfhdr);
1247 elf->e_shoff = 0;
1248 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1249 elf->e_ehsize = sizeof(struct elfhdr);
1250 elf->e_phentsize = sizeof(struct elf_phdr);
1251 elf->e_phnum = segs;
1252 elf->e_shentsize = 0;
1253 elf->e_shnum = 0;
1254 elf->e_shstrndx = 0;
1255 return;
1256 }
1257
fill_elf_note_phdr(struct elf_phdr * phdr,int sz,loff_t offset)1258 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1259 {
1260 phdr->p_type = PT_NOTE;
1261 phdr->p_offset = offset;
1262 phdr->p_vaddr = 0;
1263 phdr->p_paddr = 0;
1264 phdr->p_filesz = sz;
1265 phdr->p_memsz = 0;
1266 phdr->p_flags = 0;
1267 phdr->p_align = 4;
1268 return;
1269 }
1270
fill_note(struct memelfnote * note,const char * name,int type,unsigned int sz,void * data)1271 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1272 unsigned int sz, void *data)
1273 {
1274 note->name = name;
1275 note->type = type;
1276 note->datasz = sz;
1277 note->data = data;
1278 return;
1279 }
1280
1281 /*
1282 * fill up all the fields in prstatus from the given task struct, except
1283 * registers which need to be filled up separately.
1284 */
fill_prstatus(struct elf_prstatus_common * prstatus,struct task_struct * p,long signr)1285 static void fill_prstatus(struct elf_prstatus_common *prstatus,
1286 struct task_struct *p, long signr)
1287 {
1288 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1289 prstatus->pr_sigpend = p->pending.signal.sig[0];
1290 prstatus->pr_sighold = p->blocked.sig[0];
1291 rcu_read_lock();
1292 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1293 rcu_read_unlock();
1294 prstatus->pr_pid = task_pid_vnr(p);
1295 prstatus->pr_pgrp = task_pgrp_vnr(p);
1296 prstatus->pr_sid = task_session_vnr(p);
1297 if (thread_group_leader(p)) {
1298 struct task_cputime cputime;
1299
1300 /*
1301 * This is the record for the group leader. It shows the
1302 * group-wide total, not its individual thread total.
1303 */
1304 thread_group_cputime(p, &cputime);
1305 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1306 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1307 } else {
1308 u64 utime, stime;
1309
1310 task_cputime(p, &utime, &stime);
1311 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1312 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1313 }
1314 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1315 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1316 }
1317
fill_psinfo(struct elf_prpsinfo * psinfo,struct task_struct * p,struct mm_struct * mm)1318 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1319 struct mm_struct *mm)
1320 {
1321 const struct cred *cred;
1322 unsigned int i, len;
1323 unsigned int state;
1324
1325 /* first copy the parameters from user space */
1326 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1327
1328 len = mm->arg_end - mm->arg_start;
1329 if (len >= ELF_PRARGSZ)
1330 len = ELF_PRARGSZ - 1;
1331 if (copy_from_user(&psinfo->pr_psargs,
1332 (const char __user *) mm->arg_start, len))
1333 return -EFAULT;
1334 for (i = 0; i < len; i++)
1335 if (psinfo->pr_psargs[i] == 0)
1336 psinfo->pr_psargs[i] = ' ';
1337 psinfo->pr_psargs[len] = 0;
1338
1339 rcu_read_lock();
1340 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1341 rcu_read_unlock();
1342 psinfo->pr_pid = task_pid_vnr(p);
1343 psinfo->pr_pgrp = task_pgrp_vnr(p);
1344 psinfo->pr_sid = task_session_vnr(p);
1345
1346 state = READ_ONCE(p->__state);
1347 i = state ? ffz(~state) + 1 : 0;
1348 psinfo->pr_state = i;
1349 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1350 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1351 psinfo->pr_nice = task_nice(p);
1352 psinfo->pr_flag = p->flags;
1353 rcu_read_lock();
1354 cred = __task_cred(p);
1355 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1356 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1357 rcu_read_unlock();
1358 get_task_comm(psinfo->pr_fname, p);
1359
1360 return 0;
1361 }
1362
1363 /* Here is the structure in which status of each thread is captured. */
1364 struct elf_thread_status
1365 {
1366 struct elf_thread_status *next;
1367 struct elf_prstatus_fdpic prstatus; /* NT_PRSTATUS */
1368 elf_fpregset_t fpu; /* NT_PRFPREG */
1369 struct memelfnote notes[2];
1370 int num_notes;
1371 };
1372
1373 /*
1374 * In order to add the specific thread information for the elf file format,
1375 * we need to keep a linked list of every thread's pr_status and then create
1376 * a single section for them in the final core file.
1377 */
elf_dump_thread_status(long signr,struct task_struct * p,int * sz)1378 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
1379 {
1380 const struct user_regset_view *view = task_user_regset_view(p);
1381 struct elf_thread_status *t;
1382 int i, ret;
1383
1384 t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
1385 if (!t)
1386 return t;
1387
1388 fill_prstatus(&t->prstatus.common, p, signr);
1389 t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1390 t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1391 regset_get(p, &view->regsets[0],
1392 sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1393
1394 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1395 &t->prstatus);
1396 t->num_notes++;
1397 *sz += notesize(&t->notes[0]);
1398
1399 for (i = 1; i < view->n; ++i) {
1400 const struct user_regset *regset = &view->regsets[i];
1401 if (regset->core_note_type != NT_PRFPREG)
1402 continue;
1403 if (regset->active && regset->active(p, regset) <= 0)
1404 continue;
1405 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
1406 if (ret >= 0)
1407 t->prstatus.pr_fpvalid = 1;
1408 break;
1409 }
1410
1411 if (t->prstatus.pr_fpvalid) {
1412 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1413 &t->fpu);
1414 t->num_notes++;
1415 *sz += notesize(&t->notes[1]);
1416 }
1417 return t;
1418 }
1419
fill_extnum_info(struct elfhdr * elf,struct elf_shdr * shdr4extnum,elf_addr_t e_shoff,int segs)1420 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1421 elf_addr_t e_shoff, int segs)
1422 {
1423 elf->e_shoff = e_shoff;
1424 elf->e_shentsize = sizeof(*shdr4extnum);
1425 elf->e_shnum = 1;
1426 elf->e_shstrndx = SHN_UNDEF;
1427
1428 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1429
1430 shdr4extnum->sh_type = SHT_NULL;
1431 shdr4extnum->sh_size = elf->e_shnum;
1432 shdr4extnum->sh_link = elf->e_shstrndx;
1433 shdr4extnum->sh_info = segs;
1434 }
1435
1436 /*
1437 * dump the segments for an MMU process
1438 */
elf_fdpic_dump_segments(struct coredump_params * cprm,struct core_vma_metadata * vma_meta,int vma_count)1439 static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
1440 struct core_vma_metadata *vma_meta,
1441 int vma_count)
1442 {
1443 int i;
1444
1445 for (i = 0; i < vma_count; i++) {
1446 struct core_vma_metadata *meta = vma_meta + i;
1447
1448 if (!dump_user_range(cprm, meta->start, meta->dump_size))
1449 return false;
1450 }
1451 return true;
1452 }
1453
1454 /*
1455 * Actual dumper
1456 *
1457 * This is a two-pass process; first we find the offsets of the bits,
1458 * and then they are actually written out. If we run out of core limit
1459 * we just truncate.
1460 */
elf_fdpic_core_dump(struct coredump_params * cprm)1461 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1462 {
1463 int has_dumped = 0;
1464 int segs;
1465 int i;
1466 struct elfhdr *elf = NULL;
1467 loff_t offset = 0, dataoff;
1468 struct memelfnote psinfo_note, auxv_note;
1469 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1470 struct elf_thread_status *thread_list = NULL;
1471 int thread_status_size = 0;
1472 elf_addr_t *auxv;
1473 struct elf_phdr *phdr4note = NULL;
1474 struct elf_shdr *shdr4extnum = NULL;
1475 Elf_Half e_phnum;
1476 elf_addr_t e_shoff;
1477 struct core_thread *ct;
1478 struct elf_thread_status *tmp;
1479
1480 /* alloc memory for large data structures: too large to be on stack */
1481 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1482 if (!elf)
1483 goto end_coredump;
1484 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1485 if (!psinfo)
1486 goto end_coredump;
1487
1488 for (ct = current->signal->core_state->dumper.next;
1489 ct; ct = ct->next) {
1490 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1491 ct->task, &thread_status_size);
1492 if (!tmp)
1493 goto end_coredump;
1494
1495 tmp->next = thread_list;
1496 thread_list = tmp;
1497 }
1498
1499 /* now collect the dump for the current */
1500 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1501 current, &thread_status_size);
1502 if (!tmp)
1503 goto end_coredump;
1504 tmp->next = thread_list;
1505 thread_list = tmp;
1506
1507 segs = cprm->vma_count + elf_core_extra_phdrs(cprm);
1508
1509 /* for notes section */
1510 segs++;
1511
1512 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1513 * this, kernel supports extended numbering. Have a look at
1514 * include/linux/elf.h for further information. */
1515 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1516
1517 /* Set up header */
1518 fill_elf_fdpic_header(elf, e_phnum);
1519
1520 has_dumped = 1;
1521 /*
1522 * Set up the notes in similar form to SVR4 core dumps made
1523 * with info from their /proc.
1524 */
1525
1526 fill_psinfo(psinfo, current->group_leader, current->mm);
1527 fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1528 thread_status_size += notesize(&psinfo_note);
1529
1530 auxv = (elf_addr_t *) current->mm->saved_auxv;
1531 i = 0;
1532 do
1533 i += 2;
1534 while (auxv[i - 2] != AT_NULL);
1535 fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1536 thread_status_size += notesize(&auxv_note);
1537
1538 offset = sizeof(*elf); /* ELF header */
1539 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1540
1541 /* Write notes phdr entry */
1542 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1543 if (!phdr4note)
1544 goto end_coredump;
1545
1546 fill_elf_note_phdr(phdr4note, thread_status_size, offset);
1547 offset += thread_status_size;
1548
1549 /* Page-align dumped data */
1550 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1551
1552 offset += cprm->vma_data_size;
1553 offset += elf_core_extra_data_size(cprm);
1554 e_shoff = offset;
1555
1556 if (e_phnum == PN_XNUM) {
1557 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1558 if (!shdr4extnum)
1559 goto end_coredump;
1560 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1561 }
1562
1563 offset = dataoff;
1564
1565 if (!dump_emit(cprm, elf, sizeof(*elf)))
1566 goto end_coredump;
1567
1568 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1569 goto end_coredump;
1570
1571 /* write program headers for segments dump */
1572 for (i = 0; i < cprm->vma_count; i++) {
1573 struct core_vma_metadata *meta = cprm->vma_meta + i;
1574 struct elf_phdr phdr;
1575 size_t sz;
1576
1577 sz = meta->end - meta->start;
1578
1579 phdr.p_type = PT_LOAD;
1580 phdr.p_offset = offset;
1581 phdr.p_vaddr = meta->start;
1582 phdr.p_paddr = 0;
1583 phdr.p_filesz = meta->dump_size;
1584 phdr.p_memsz = sz;
1585 offset += phdr.p_filesz;
1586 phdr.p_flags = 0;
1587 if (meta->flags & VM_READ)
1588 phdr.p_flags |= PF_R;
1589 if (meta->flags & VM_WRITE)
1590 phdr.p_flags |= PF_W;
1591 if (meta->flags & VM_EXEC)
1592 phdr.p_flags |= PF_X;
1593 phdr.p_align = ELF_EXEC_PAGESIZE;
1594
1595 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1596 goto end_coredump;
1597 }
1598
1599 if (!elf_core_write_extra_phdrs(cprm, offset))
1600 goto end_coredump;
1601
1602 /* write out the notes section */
1603 if (!writenote(thread_list->notes, cprm))
1604 goto end_coredump;
1605 if (!writenote(&psinfo_note, cprm))
1606 goto end_coredump;
1607 if (!writenote(&auxv_note, cprm))
1608 goto end_coredump;
1609 for (i = 1; i < thread_list->num_notes; i++)
1610 if (!writenote(thread_list->notes + i, cprm))
1611 goto end_coredump;
1612
1613 /* write out the thread status notes section */
1614 for (tmp = thread_list->next; tmp; tmp = tmp->next) {
1615 for (i = 0; i < tmp->num_notes; i++)
1616 if (!writenote(&tmp->notes[i], cprm))
1617 goto end_coredump;
1618 }
1619
1620 dump_skip_to(cprm, dataoff);
1621
1622 if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count))
1623 goto end_coredump;
1624
1625 if (!elf_core_write_extra_data(cprm))
1626 goto end_coredump;
1627
1628 if (e_phnum == PN_XNUM) {
1629 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1630 goto end_coredump;
1631 }
1632
1633 if (cprm->file->f_pos != offset) {
1634 /* Sanity check */
1635 printk(KERN_WARNING
1636 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1637 cprm->file->f_pos, offset);
1638 }
1639
1640 end_coredump:
1641 while (thread_list) {
1642 tmp = thread_list;
1643 thread_list = thread_list->next;
1644 kfree(tmp);
1645 }
1646 kfree(phdr4note);
1647 kfree(elf);
1648 kfree(psinfo);
1649 kfree(shdr4extnum);
1650 return has_dumped;
1651 }
1652
1653 #endif /* CONFIG_ELF_CORE */
1654