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 elf32_phdr *phdr;
142 unsigned long size;
143 int retval, loop;
144 loff_t pos = params->hdr.e_phoff;
145
146 if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
147 return -ENOMEM;
148 if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
149 return -ENOMEM;
150
151 size = params->hdr.e_phnum * sizeof(struct elf_phdr);
152 params->phdrs = kmalloc(size, GFP_KERNEL);
153 if (!params->phdrs)
154 return -ENOMEM;
155
156 retval = kernel_read(file, params->phdrs, size, &pos);
157 if (unlikely(retval != size))
158 return retval < 0 ? retval : -ENOEXEC;
159
160 /* determine stack size for this binary */
161 phdr = params->phdrs;
162 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
163 if (phdr->p_type != PT_GNU_STACK)
164 continue;
165
166 if (phdr->p_flags & PF_X)
167 params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
168 else
169 params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
170
171 params->stack_size = phdr->p_memsz;
172 break;
173 }
174
175 return 0;
176 }
177
178 /*****************************************************************************/
179 /*
180 * load an fdpic binary into various bits of memory
181 */
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) {
324 stack_size = interp_params.stack_size;
325 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
326 executable_stack = EXSTACK_ENABLE_X;
327 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
328 executable_stack = EXSTACK_DISABLE_X;
329 else
330 executable_stack = EXSTACK_DEFAULT;
331 }
332
333 retval = -ENOEXEC;
334 if (stack_size == 0)
335 stack_size = 131072UL; /* same as exec.c's default commit */
336
337 if (is_constdisp(&interp_params.hdr))
338 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
339
340 /* flush all traces of the currently running executable */
341 retval = begin_new_exec(bprm);
342 if (retval)
343 goto error;
344
345 /* there's now no turning back... the old userspace image is dead,
346 * defunct, deceased, etc.
347 */
348 if (elf_check_fdpic(&exec_params.hdr))
349 set_personality(PER_LINUX_FDPIC);
350 else
351 set_personality(PER_LINUX);
352 if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
353 current->personality |= READ_IMPLIES_EXEC;
354
355 setup_new_exec(bprm);
356
357 set_binfmt(&elf_fdpic_format);
358
359 current->mm->start_code = 0;
360 current->mm->end_code = 0;
361 current->mm->start_stack = 0;
362 current->mm->start_data = 0;
363 current->mm->end_data = 0;
364 current->mm->context.exec_fdpic_loadmap = 0;
365 current->mm->context.interp_fdpic_loadmap = 0;
366
367 #ifdef CONFIG_MMU
368 elf_fdpic_arch_lay_out_mm(&exec_params,
369 &interp_params,
370 ¤t->mm->start_stack,
371 ¤t->mm->start_brk);
372
373 retval = setup_arg_pages(bprm, current->mm->start_stack,
374 executable_stack);
375 if (retval < 0)
376 goto error;
377 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
378 retval = arch_setup_additional_pages(bprm, !!interpreter_name);
379 if (retval < 0)
380 goto error;
381 #endif
382 #endif
383
384 /* load the executable and interpreter into memory */
385 retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
386 "executable");
387 if (retval < 0)
388 goto error;
389
390 if (interpreter_name) {
391 retval = elf_fdpic_map_file(&interp_params, interpreter,
392 current->mm, "interpreter");
393 if (retval < 0) {
394 printk(KERN_ERR "Unable to load interpreter\n");
395 goto error;
396 }
397
398 allow_write_access(interpreter);
399 fput(interpreter);
400 interpreter = NULL;
401 }
402
403 #ifdef CONFIG_MMU
404 if (!current->mm->start_brk)
405 current->mm->start_brk = current->mm->end_data;
406
407 current->mm->brk = current->mm->start_brk =
408 PAGE_ALIGN(current->mm->start_brk);
409
410 #else
411 /* create a stack area and zero-size brk area */
412 stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
413 if (stack_size < PAGE_SIZE * 2)
414 stack_size = PAGE_SIZE * 2;
415
416 stack_prot = PROT_READ | PROT_WRITE;
417 if (executable_stack == EXSTACK_ENABLE_X ||
418 (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
419 stack_prot |= PROT_EXEC;
420
421 current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
422 MAP_PRIVATE | MAP_ANONYMOUS |
423 MAP_UNINITIALIZED | MAP_GROWSDOWN,
424 0);
425
426 if (IS_ERR_VALUE(current->mm->start_brk)) {
427 retval = current->mm->start_brk;
428 current->mm->start_brk = 0;
429 goto error;
430 }
431
432 current->mm->brk = current->mm->start_brk;
433 current->mm->context.end_brk = current->mm->start_brk;
434 current->mm->start_stack = current->mm->start_brk + stack_size;
435 #endif
436
437 if (create_elf_fdpic_tables(bprm, current->mm,
438 &exec_params, &interp_params) < 0)
439 goto error;
440
441 kdebug("- start_code %lx", current->mm->start_code);
442 kdebug("- end_code %lx", current->mm->end_code);
443 kdebug("- start_data %lx", current->mm->start_data);
444 kdebug("- end_data %lx", current->mm->end_data);
445 kdebug("- start_brk %lx", current->mm->start_brk);
446 kdebug("- brk %lx", current->mm->brk);
447 kdebug("- start_stack %lx", current->mm->start_stack);
448
449 #ifdef ELF_FDPIC_PLAT_INIT
450 /*
451 * The ABI may specify that certain registers be set up in special
452 * ways (on i386 %edx is the address of a DT_FINI function, for
453 * example. This macro performs whatever initialization to
454 * the regs structure is required.
455 */
456 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
457 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
458 dynaddr);
459 #endif
460
461 finalize_exec(bprm);
462 /* everything is now ready... get the userspace context ready to roll */
463 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
464 start_thread(regs, entryaddr, current->mm->start_stack);
465
466 retval = 0;
467
468 error:
469 if (interpreter) {
470 allow_write_access(interpreter);
471 fput(interpreter);
472 }
473 kfree(interpreter_name);
474 kfree(exec_params.phdrs);
475 kfree(exec_params.loadmap);
476 kfree(interp_params.phdrs);
477 kfree(interp_params.loadmap);
478 return retval;
479 }
480
481 /*****************************************************************************/
482
483 #ifndef ELF_BASE_PLATFORM
484 /*
485 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
486 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
487 * will be copied to the user stack in the same manner as AT_PLATFORM.
488 */
489 #define ELF_BASE_PLATFORM NULL
490 #endif
491
492 /*
493 * present useful information to the program by shovelling it onto the new
494 * process's stack
495 */
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 int nr; /* reset for each csp adjustment */
509 unsigned long flags = 0;
510
511 #ifdef CONFIG_MMU
512 /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
513 * by the processes running on the same package. One thing we can do is
514 * to shuffle the initial stack for them, so we give the architecture
515 * an opportunity to do so here.
516 */
517 sp = arch_align_stack(bprm->p);
518 #else
519 sp = mm->start_stack;
520
521 /* stack the program arguments and environment */
522 if (transfer_args_to_stack(bprm, &sp) < 0)
523 return -EFAULT;
524 sp &= ~15;
525 #endif
526
527 /*
528 * If this architecture has a platform capability string, copy it
529 * to userspace. In some cases (Sparc), this info is impossible
530 * for userspace to get any other way, in others (i386) it is
531 * merely difficult.
532 */
533 k_platform = ELF_PLATFORM;
534 u_platform = NULL;
535
536 if (k_platform) {
537 platform_len = strlen(k_platform) + 1;
538 sp -= platform_len;
539 u_platform = (char __user *) sp;
540 if (copy_to_user(u_platform, k_platform, platform_len) != 0)
541 return -EFAULT;
542 }
543
544 /*
545 * If this architecture has a "base" platform capability
546 * string, copy it to userspace.
547 */
548 k_base_platform = ELF_BASE_PLATFORM;
549 u_base_platform = NULL;
550
551 if (k_base_platform) {
552 platform_len = strlen(k_base_platform) + 1;
553 sp -= platform_len;
554 u_base_platform = (char __user *) sp;
555 if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
556 return -EFAULT;
557 }
558
559 sp &= ~7UL;
560
561 /* stack the load map(s) */
562 len = sizeof(struct elf32_fdpic_loadmap);
563 len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
564 sp = (sp - len) & ~7UL;
565 exec_params->map_addr = sp;
566
567 if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
568 return -EFAULT;
569
570 current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
571
572 if (interp_params->loadmap) {
573 len = sizeof(struct elf32_fdpic_loadmap);
574 len += sizeof(struct elf32_fdpic_loadseg) *
575 interp_params->loadmap->nsegs;
576 sp = (sp - len) & ~7UL;
577 interp_params->map_addr = sp;
578
579 if (copy_to_user((void __user *) sp, interp_params->loadmap,
580 len) != 0)
581 return -EFAULT;
582
583 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
584 }
585
586 /* force 16 byte _final_ alignment here for generality */
587 #define DLINFO_ITEMS 15
588
589 nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
590 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
591
592 if (bprm->have_execfd)
593 nitems++;
594
595 csp = sp;
596 sp -= nitems * 2 * sizeof(unsigned long);
597 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
598 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
599 sp -= 1 * sizeof(unsigned long); /* argc */
600
601 csp -= sp & 15UL;
602 sp -= sp & 15UL;
603
604 /* put the ELF interpreter info on the stack */
605 #define NEW_AUX_ENT(id, val) \
606 do { \
607 struct { unsigned long _id, _val; } __user *ent, v; \
608 \
609 ent = (void __user *) csp; \
610 v._id = (id); \
611 v._val = (val); \
612 if (copy_to_user(ent + nr, &v, sizeof(v))) \
613 return -EFAULT; \
614 nr++; \
615 } while (0)
616
617 nr = 0;
618 csp -= 2 * sizeof(unsigned long);
619 NEW_AUX_ENT(AT_NULL, 0);
620 if (k_platform) {
621 nr = 0;
622 csp -= 2 * sizeof(unsigned long);
623 NEW_AUX_ENT(AT_PLATFORM,
624 (elf_addr_t) (unsigned long) u_platform);
625 }
626
627 if (k_base_platform) {
628 nr = 0;
629 csp -= 2 * sizeof(unsigned long);
630 NEW_AUX_ENT(AT_BASE_PLATFORM,
631 (elf_addr_t) (unsigned long) u_base_platform);
632 }
633
634 if (bprm->have_execfd) {
635 nr = 0;
636 csp -= 2 * sizeof(unsigned long);
637 NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
638 }
639
640 nr = 0;
641 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
642 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
643 #ifdef ELF_HWCAP2
644 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
645 #endif
646 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
647 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
648 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
649 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
650 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
651 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
652 if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
653 flags |= AT_FLAGS_PRESERVE_ARGV0;
654 NEW_AUX_ENT(AT_FLAGS, flags);
655 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
656 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
657 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
658 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
659 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
660 NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
661 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
662
663 #ifdef ARCH_DLINFO
664 nr = 0;
665 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
666
667 /* ARCH_DLINFO must come last so platform specific code can enforce
668 * special alignment requirements on the AUXV if necessary (eg. PPC).
669 */
670 ARCH_DLINFO;
671 #endif
672 #undef NEW_AUX_ENT
673
674 /* allocate room for argv[] and envv[] */
675 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
676 envp = (elf_caddr_t __user *) csp;
677 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
678 argv = (elf_caddr_t __user *) csp;
679
680 /* stack argc */
681 csp -= sizeof(unsigned long);
682 if (put_user(bprm->argc, (unsigned long __user *) csp))
683 return -EFAULT;
684
685 BUG_ON(csp != sp);
686
687 /* fill in the argv[] array */
688 #ifdef CONFIG_MMU
689 current->mm->arg_start = bprm->p;
690 #else
691 current->mm->arg_start = current->mm->start_stack -
692 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
693 #endif
694
695 p = (char __user *) current->mm->arg_start;
696 for (loop = bprm->argc; loop > 0; loop--) {
697 if (put_user((elf_caddr_t) p, argv++))
698 return -EFAULT;
699 len = strnlen_user(p, MAX_ARG_STRLEN);
700 if (!len || len > MAX_ARG_STRLEN)
701 return -EINVAL;
702 p += len;
703 }
704 if (put_user(NULL, argv))
705 return -EFAULT;
706 current->mm->arg_end = (unsigned long) p;
707
708 /* fill in the envv[] array */
709 current->mm->env_start = (unsigned long) p;
710 for (loop = bprm->envc; loop > 0; loop--) {
711 if (put_user((elf_caddr_t)(unsigned long) p, envp++))
712 return -EFAULT;
713 len = strnlen_user(p, MAX_ARG_STRLEN);
714 if (!len || len > MAX_ARG_STRLEN)
715 return -EINVAL;
716 p += len;
717 }
718 if (put_user(NULL, envp))
719 return -EFAULT;
720 current->mm->env_end = (unsigned long) p;
721
722 mm->start_stack = (unsigned long) sp;
723 return 0;
724 }
725
726 /*****************************************************************************/
727 /*
728 * load the appropriate binary image (executable or interpreter) into memory
729 * - we assume no MMU is available
730 * - if no other PIC bits are set in params->hdr->e_flags
731 * - we assume that the LOADable segments in the binary are independently relocatable
732 * - we assume R/O executable segments are shareable
733 * - else
734 * - we assume the loadable parts of the image to require fixed displacement
735 * - the image is not shareable
736 */
elf_fdpic_map_file(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm,const char * what)737 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
738 struct file *file,
739 struct mm_struct *mm,
740 const char *what)
741 {
742 struct elf32_fdpic_loadmap *loadmap;
743 #ifdef CONFIG_MMU
744 struct elf32_fdpic_loadseg *mseg;
745 #endif
746 struct elf32_fdpic_loadseg *seg;
747 struct elf32_phdr *phdr;
748 unsigned long load_addr, stop;
749 unsigned nloads, tmp;
750 size_t size;
751 int loop, ret;
752
753 /* allocate a load map table */
754 nloads = 0;
755 for (loop = 0; loop < params->hdr.e_phnum; loop++)
756 if (params->phdrs[loop].p_type == PT_LOAD)
757 nloads++;
758
759 if (nloads == 0)
760 return -ELIBBAD;
761
762 size = sizeof(*loadmap) + nloads * sizeof(*seg);
763 loadmap = kzalloc(size, GFP_KERNEL);
764 if (!loadmap)
765 return -ENOMEM;
766
767 params->loadmap = loadmap;
768
769 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
770 loadmap->nsegs = nloads;
771
772 load_addr = params->load_addr;
773 seg = loadmap->segs;
774
775 /* map the requested LOADs into the memory space */
776 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
777 case ELF_FDPIC_FLAG_CONSTDISP:
778 case ELF_FDPIC_FLAG_CONTIGUOUS:
779 #ifndef CONFIG_MMU
780 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
781 if (ret < 0)
782 return ret;
783 break;
784 #endif
785 default:
786 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
787 if (ret < 0)
788 return ret;
789 break;
790 }
791
792 /* map the entry point */
793 if (params->hdr.e_entry) {
794 seg = loadmap->segs;
795 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
796 if (params->hdr.e_entry >= seg->p_vaddr &&
797 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
798 params->entry_addr =
799 (params->hdr.e_entry - seg->p_vaddr) +
800 seg->addr;
801 break;
802 }
803 }
804 }
805
806 /* determine where the program header table has wound up if mapped */
807 stop = params->hdr.e_phoff;
808 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
809 phdr = params->phdrs;
810
811 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
812 if (phdr->p_type != PT_LOAD)
813 continue;
814
815 if (phdr->p_offset > params->hdr.e_phoff ||
816 phdr->p_offset + phdr->p_filesz < stop)
817 continue;
818
819 seg = loadmap->segs;
820 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
821 if (phdr->p_vaddr >= seg->p_vaddr &&
822 phdr->p_vaddr + phdr->p_filesz <=
823 seg->p_vaddr + seg->p_memsz) {
824 params->ph_addr =
825 (phdr->p_vaddr - seg->p_vaddr) +
826 seg->addr +
827 params->hdr.e_phoff - phdr->p_offset;
828 break;
829 }
830 }
831 break;
832 }
833
834 /* determine where the dynamic section has wound up if there is one */
835 phdr = params->phdrs;
836 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
837 if (phdr->p_type != PT_DYNAMIC)
838 continue;
839
840 seg = loadmap->segs;
841 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
842 if (phdr->p_vaddr >= seg->p_vaddr &&
843 phdr->p_vaddr + phdr->p_memsz <=
844 seg->p_vaddr + seg->p_memsz) {
845 Elf32_Dyn __user *dyn;
846 Elf32_Sword d_tag;
847
848 params->dynamic_addr =
849 (phdr->p_vaddr - seg->p_vaddr) +
850 seg->addr;
851
852 /* check the dynamic section contains at least
853 * one item, and that the last item is a NULL
854 * entry */
855 if (phdr->p_memsz == 0 ||
856 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
857 goto dynamic_error;
858
859 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
860 dyn = (Elf32_Dyn __user *)params->dynamic_addr;
861 if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
862 d_tag != 0)
863 goto dynamic_error;
864 break;
865 }
866 }
867 break;
868 }
869
870 /* now elide adjacent segments in the load map on MMU linux
871 * - on uClinux the holes between may actually be filled with system
872 * stuff or stuff from other processes
873 */
874 #ifdef CONFIG_MMU
875 nloads = loadmap->nsegs;
876 mseg = loadmap->segs;
877 seg = mseg + 1;
878 for (loop = 1; loop < nloads; loop++) {
879 /* see if we have a candidate for merging */
880 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
881 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
882 if (load_addr == (seg->addr & PAGE_MASK)) {
883 mseg->p_memsz +=
884 load_addr -
885 (mseg->addr + mseg->p_memsz);
886 mseg->p_memsz += seg->addr & ~PAGE_MASK;
887 mseg->p_memsz += seg->p_memsz;
888 loadmap->nsegs--;
889 continue;
890 }
891 }
892
893 mseg++;
894 if (mseg != seg)
895 *mseg = *seg;
896 }
897 #endif
898
899 kdebug("Mapped Object [%s]:", what);
900 kdebug("- elfhdr : %lx", params->elfhdr_addr);
901 kdebug("- entry : %lx", params->entry_addr);
902 kdebug("- PHDR[] : %lx", params->ph_addr);
903 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
904 seg = loadmap->segs;
905 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
906 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
907 loop,
908 seg->addr, seg->addr + seg->p_memsz - 1,
909 seg->p_vaddr, seg->p_memsz);
910
911 return 0;
912
913 dynamic_error:
914 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
915 what, file_inode(file)->i_ino);
916 return -ELIBBAD;
917 }
918
919 /*****************************************************************************/
920 /*
921 * map a file with constant displacement under uClinux
922 */
923 #ifndef CONFIG_MMU
elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm)924 static int elf_fdpic_map_file_constdisp_on_uclinux(
925 struct elf_fdpic_params *params,
926 struct file *file,
927 struct mm_struct *mm)
928 {
929 struct elf32_fdpic_loadseg *seg;
930 struct elf32_phdr *phdr;
931 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
932 int loop, ret;
933
934 load_addr = params->load_addr;
935 seg = params->loadmap->segs;
936
937 /* determine the bounds of the contiguous overall allocation we must
938 * make */
939 phdr = params->phdrs;
940 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
941 if (params->phdrs[loop].p_type != PT_LOAD)
942 continue;
943
944 if (base > phdr->p_vaddr)
945 base = phdr->p_vaddr;
946 if (top < phdr->p_vaddr + phdr->p_memsz)
947 top = phdr->p_vaddr + phdr->p_memsz;
948 }
949
950 /* allocate one big anon block for everything */
951 maddr = vm_mmap(NULL, load_addr, top - base,
952 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0);
953 if (IS_ERR_VALUE(maddr))
954 return (int) maddr;
955
956 if (load_addr != 0)
957 load_addr += PAGE_ALIGN(top - base);
958
959 /* and then load the file segments into it */
960 phdr = params->phdrs;
961 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
962 if (params->phdrs[loop].p_type != PT_LOAD)
963 continue;
964
965 seg->addr = maddr + (phdr->p_vaddr - base);
966 seg->p_vaddr = phdr->p_vaddr;
967 seg->p_memsz = phdr->p_memsz;
968
969 ret = read_code(file, seg->addr, phdr->p_offset,
970 phdr->p_filesz);
971 if (ret < 0)
972 return ret;
973
974 /* map the ELF header address if in this segment */
975 if (phdr->p_offset == 0)
976 params->elfhdr_addr = seg->addr;
977
978 /* clear any space allocated but not loaded */
979 if (phdr->p_filesz < phdr->p_memsz) {
980 if (clear_user((void *) (seg->addr + phdr->p_filesz),
981 phdr->p_memsz - phdr->p_filesz))
982 return -EFAULT;
983 }
984
985 if (mm) {
986 if (phdr->p_flags & PF_X) {
987 if (!mm->start_code) {
988 mm->start_code = seg->addr;
989 mm->end_code = seg->addr +
990 phdr->p_memsz;
991 }
992 } else if (!mm->start_data) {
993 mm->start_data = seg->addr;
994 mm->end_data = seg->addr + phdr->p_memsz;
995 }
996 }
997
998 seg++;
999 }
1000
1001 return 0;
1002 }
1003 #endif
1004
1005 /*****************************************************************************/
1006 /*
1007 * map a binary by direct mmap() of the individual PT_LOAD segments
1008 */
elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm)1009 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1010 struct file *file,
1011 struct mm_struct *mm)
1012 {
1013 struct elf32_fdpic_loadseg *seg;
1014 struct elf32_phdr *phdr;
1015 unsigned long load_addr, delta_vaddr;
1016 int loop, dvset;
1017
1018 load_addr = params->load_addr;
1019 delta_vaddr = 0;
1020 dvset = 0;
1021
1022 seg = params->loadmap->segs;
1023
1024 /* deal with each load segment separately */
1025 phdr = params->phdrs;
1026 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1027 unsigned long maddr, disp, excess, excess1;
1028 int prot = 0, flags;
1029
1030 if (phdr->p_type != PT_LOAD)
1031 continue;
1032
1033 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1034 (unsigned long) phdr->p_vaddr,
1035 (unsigned long) phdr->p_offset,
1036 (unsigned long) phdr->p_filesz,
1037 (unsigned long) phdr->p_memsz);
1038
1039 /* determine the mapping parameters */
1040 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1041 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1042 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1043
1044 flags = MAP_PRIVATE;
1045 maddr = 0;
1046
1047 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1048 case ELF_FDPIC_FLAG_INDEPENDENT:
1049 /* PT_LOADs are independently locatable */
1050 break;
1051
1052 case ELF_FDPIC_FLAG_HONOURVADDR:
1053 /* the specified virtual address must be honoured */
1054 maddr = phdr->p_vaddr;
1055 flags |= MAP_FIXED;
1056 break;
1057
1058 case ELF_FDPIC_FLAG_CONSTDISP:
1059 /* constant displacement
1060 * - can be mapped anywhere, but must be mapped as a
1061 * unit
1062 */
1063 if (!dvset) {
1064 maddr = load_addr;
1065 delta_vaddr = phdr->p_vaddr;
1066 dvset = 1;
1067 } else {
1068 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1069 flags |= MAP_FIXED;
1070 }
1071 break;
1072
1073 case ELF_FDPIC_FLAG_CONTIGUOUS:
1074 /* contiguity handled later */
1075 break;
1076
1077 default:
1078 BUG();
1079 }
1080
1081 maddr &= PAGE_MASK;
1082
1083 /* create the mapping */
1084 disp = phdr->p_vaddr & ~PAGE_MASK;
1085 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1086 phdr->p_offset - disp);
1087
1088 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1089 loop, phdr->p_memsz + disp, prot, flags,
1090 phdr->p_offset - disp, maddr);
1091
1092 if (IS_ERR_VALUE(maddr))
1093 return (int) maddr;
1094
1095 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1096 ELF_FDPIC_FLAG_CONTIGUOUS)
1097 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1098
1099 seg->addr = maddr + disp;
1100 seg->p_vaddr = phdr->p_vaddr;
1101 seg->p_memsz = phdr->p_memsz;
1102
1103 /* map the ELF header address if in this segment */
1104 if (phdr->p_offset == 0)
1105 params->elfhdr_addr = seg->addr;
1106
1107 /* clear the bit between beginning of mapping and beginning of
1108 * PT_LOAD */
1109 if (prot & PROT_WRITE && disp > 0) {
1110 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1111 if (clear_user((void __user *) maddr, disp))
1112 return -EFAULT;
1113 maddr += disp;
1114 }
1115
1116 /* clear any space allocated but not loaded
1117 * - on uClinux we can just clear the lot
1118 * - on MMU linux we'll get a SIGBUS beyond the last page
1119 * extant in the file
1120 */
1121 excess = phdr->p_memsz - phdr->p_filesz;
1122 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1123
1124 #ifdef CONFIG_MMU
1125 if (excess > excess1) {
1126 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1127 unsigned long xmaddr;
1128
1129 flags |= MAP_FIXED | MAP_ANONYMOUS;
1130 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1131 prot, flags, 0);
1132
1133 kdebug("mmap[%d] <anon>"
1134 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1135 loop, xaddr, excess - excess1, prot, flags,
1136 xmaddr);
1137
1138 if (xmaddr != xaddr)
1139 return -ENOMEM;
1140 }
1141
1142 if (prot & PROT_WRITE && excess1 > 0) {
1143 kdebug("clear[%d] ad=%lx sz=%lx",
1144 loop, maddr + phdr->p_filesz, excess1);
1145 if (clear_user((void __user *) maddr + phdr->p_filesz,
1146 excess1))
1147 return -EFAULT;
1148 }
1149
1150 #else
1151 if (excess > 0) {
1152 kdebug("clear[%d] ad=%lx sz=%lx",
1153 loop, maddr + phdr->p_filesz, excess);
1154 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1155 return -EFAULT;
1156 }
1157 #endif
1158
1159 if (mm) {
1160 if (phdr->p_flags & PF_X) {
1161 if (!mm->start_code) {
1162 mm->start_code = maddr;
1163 mm->end_code = maddr + phdr->p_memsz;
1164 }
1165 } else if (!mm->start_data) {
1166 mm->start_data = maddr;
1167 mm->end_data = maddr + phdr->p_memsz;
1168 }
1169 }
1170
1171 seg++;
1172 }
1173
1174 return 0;
1175 }
1176
1177 /*****************************************************************************/
1178 /*
1179 * ELF-FDPIC core dumper
1180 *
1181 * Modelled on fs/exec.c:aout_core_dump()
1182 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1183 *
1184 * Modelled on fs/binfmt_elf.c core dumper
1185 */
1186 #ifdef CONFIG_ELF_CORE
1187
1188 struct elf_prstatus_fdpic
1189 {
1190 struct elf_prstatus_common common;
1191 elf_gregset_t pr_reg; /* GP registers */
1192 /* When using FDPIC, the loadmap addresses need to be communicated
1193 * to GDB in order for GDB to do the necessary relocations. The
1194 * fields (below) used to communicate this information are placed
1195 * immediately after ``pr_reg'', so that the loadmap addresses may
1196 * be viewed as part of the register set if so desired.
1197 */
1198 unsigned long pr_exec_fdpic_loadmap;
1199 unsigned long pr_interp_fdpic_loadmap;
1200 int pr_fpvalid; /* True if math co-processor being used. */
1201 };
1202
1203 /* An ELF note in memory */
1204 struct memelfnote
1205 {
1206 const char *name;
1207 int type;
1208 unsigned int datasz;
1209 void *data;
1210 };
1211
notesize(struct memelfnote * en)1212 static int notesize(struct memelfnote *en)
1213 {
1214 int sz;
1215
1216 sz = sizeof(struct elf_note);
1217 sz += roundup(strlen(en->name) + 1, 4);
1218 sz += roundup(en->datasz, 4);
1219
1220 return sz;
1221 }
1222
1223 /* #define DEBUG */
1224
writenote(struct memelfnote * men,struct coredump_params * cprm)1225 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1226 {
1227 struct elf_note en;
1228 en.n_namesz = strlen(men->name) + 1;
1229 en.n_descsz = men->datasz;
1230 en.n_type = men->type;
1231
1232 return dump_emit(cprm, &en, sizeof(en)) &&
1233 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1234 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1235 }
1236
fill_elf_fdpic_header(struct elfhdr * elf,int segs)1237 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1238 {
1239 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1240 elf->e_ident[EI_CLASS] = ELF_CLASS;
1241 elf->e_ident[EI_DATA] = ELF_DATA;
1242 elf->e_ident[EI_VERSION] = EV_CURRENT;
1243 elf->e_ident[EI_OSABI] = ELF_OSABI;
1244 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1245
1246 elf->e_type = ET_CORE;
1247 elf->e_machine = ELF_ARCH;
1248 elf->e_version = EV_CURRENT;
1249 elf->e_entry = 0;
1250 elf->e_phoff = sizeof(struct elfhdr);
1251 elf->e_shoff = 0;
1252 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1253 elf->e_ehsize = sizeof(struct elfhdr);
1254 elf->e_phentsize = sizeof(struct elf_phdr);
1255 elf->e_phnum = segs;
1256 elf->e_shentsize = 0;
1257 elf->e_shnum = 0;
1258 elf->e_shstrndx = 0;
1259 return;
1260 }
1261
fill_elf_note_phdr(struct elf_phdr * phdr,int sz,loff_t offset)1262 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1263 {
1264 phdr->p_type = PT_NOTE;
1265 phdr->p_offset = offset;
1266 phdr->p_vaddr = 0;
1267 phdr->p_paddr = 0;
1268 phdr->p_filesz = sz;
1269 phdr->p_memsz = 0;
1270 phdr->p_flags = 0;
1271 phdr->p_align = 0;
1272 return;
1273 }
1274
fill_note(struct memelfnote * note,const char * name,int type,unsigned int sz,void * data)1275 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1276 unsigned int sz, void *data)
1277 {
1278 note->name = name;
1279 note->type = type;
1280 note->datasz = sz;
1281 note->data = data;
1282 return;
1283 }
1284
1285 /*
1286 * fill up all the fields in prstatus from the given task struct, except
1287 * registers which need to be filled up separately.
1288 */
fill_prstatus(struct elf_prstatus_common * prstatus,struct task_struct * p,long signr)1289 static void fill_prstatus(struct elf_prstatus_common *prstatus,
1290 struct task_struct *p, long signr)
1291 {
1292 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1293 prstatus->pr_sigpend = p->pending.signal.sig[0];
1294 prstatus->pr_sighold = p->blocked.sig[0];
1295 rcu_read_lock();
1296 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1297 rcu_read_unlock();
1298 prstatus->pr_pid = task_pid_vnr(p);
1299 prstatus->pr_pgrp = task_pgrp_vnr(p);
1300 prstatus->pr_sid = task_session_vnr(p);
1301 if (thread_group_leader(p)) {
1302 struct task_cputime cputime;
1303
1304 /*
1305 * This is the record for the group leader. It shows the
1306 * group-wide total, not its individual thread total.
1307 */
1308 thread_group_cputime(p, &cputime);
1309 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1310 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1311 } else {
1312 u64 utime, stime;
1313
1314 task_cputime(p, &utime, &stime);
1315 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1316 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1317 }
1318 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1319 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1320 }
1321
fill_psinfo(struct elf_prpsinfo * psinfo,struct task_struct * p,struct mm_struct * mm)1322 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1323 struct mm_struct *mm)
1324 {
1325 const struct cred *cred;
1326 unsigned int i, len;
1327 unsigned int state;
1328
1329 /* first copy the parameters from user space */
1330 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1331
1332 len = mm->arg_end - mm->arg_start;
1333 if (len >= ELF_PRARGSZ)
1334 len = ELF_PRARGSZ - 1;
1335 if (copy_from_user(&psinfo->pr_psargs,
1336 (const char __user *) mm->arg_start, len))
1337 return -EFAULT;
1338 for (i = 0; i < len; i++)
1339 if (psinfo->pr_psargs[i] == 0)
1340 psinfo->pr_psargs[i] = ' ';
1341 psinfo->pr_psargs[len] = 0;
1342
1343 rcu_read_lock();
1344 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1345 rcu_read_unlock();
1346 psinfo->pr_pid = task_pid_vnr(p);
1347 psinfo->pr_pgrp = task_pgrp_vnr(p);
1348 psinfo->pr_sid = task_session_vnr(p);
1349
1350 state = READ_ONCE(p->__state);
1351 i = state ? ffz(~state) + 1 : 0;
1352 psinfo->pr_state = i;
1353 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1354 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1355 psinfo->pr_nice = task_nice(p);
1356 psinfo->pr_flag = p->flags;
1357 rcu_read_lock();
1358 cred = __task_cred(p);
1359 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1360 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1361 rcu_read_unlock();
1362 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1363
1364 return 0;
1365 }
1366
1367 /* Here is the structure in which status of each thread is captured. */
1368 struct elf_thread_status
1369 {
1370 struct elf_thread_status *next;
1371 struct elf_prstatus_fdpic prstatus; /* NT_PRSTATUS */
1372 elf_fpregset_t fpu; /* NT_PRFPREG */
1373 struct memelfnote notes[2];
1374 int num_notes;
1375 };
1376
1377 /*
1378 * In order to add the specific thread information for the elf file format,
1379 * we need to keep a linked list of every thread's pr_status and then create
1380 * a single section for them in the final core file.
1381 */
elf_dump_thread_status(long signr,struct task_struct * p,int * sz)1382 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
1383 {
1384 const struct user_regset_view *view = task_user_regset_view(p);
1385 struct elf_thread_status *t;
1386 int i, ret;
1387
1388 t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
1389 if (!t)
1390 return t;
1391
1392 fill_prstatus(&t->prstatus.common, p, signr);
1393 t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1394 t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1395 regset_get(p, &view->regsets[0],
1396 sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1397
1398 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1399 &t->prstatus);
1400 t->num_notes++;
1401 *sz += notesize(&t->notes[0]);
1402
1403 for (i = 1; i < view->n; ++i) {
1404 const struct user_regset *regset = &view->regsets[i];
1405 if (regset->core_note_type != NT_PRFPREG)
1406 continue;
1407 if (regset->active && regset->active(p, regset) <= 0)
1408 continue;
1409 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
1410 if (ret >= 0)
1411 t->prstatus.pr_fpvalid = 1;
1412 break;
1413 }
1414
1415 if (t->prstatus.pr_fpvalid) {
1416 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1417 &t->fpu);
1418 t->num_notes++;
1419 *sz += notesize(&t->notes[1]);
1420 }
1421 return t;
1422 }
1423
fill_extnum_info(struct elfhdr * elf,struct elf_shdr * shdr4extnum,elf_addr_t e_shoff,int segs)1424 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1425 elf_addr_t e_shoff, int segs)
1426 {
1427 elf->e_shoff = e_shoff;
1428 elf->e_shentsize = sizeof(*shdr4extnum);
1429 elf->e_shnum = 1;
1430 elf->e_shstrndx = SHN_UNDEF;
1431
1432 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1433
1434 shdr4extnum->sh_type = SHT_NULL;
1435 shdr4extnum->sh_size = elf->e_shnum;
1436 shdr4extnum->sh_link = elf->e_shstrndx;
1437 shdr4extnum->sh_info = segs;
1438 }
1439
1440 /*
1441 * dump the segments for an MMU process
1442 */
elf_fdpic_dump_segments(struct coredump_params * cprm,struct core_vma_metadata * vma_meta,int vma_count)1443 static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
1444 struct core_vma_metadata *vma_meta,
1445 int vma_count)
1446 {
1447 int i;
1448
1449 for (i = 0; i < vma_count; i++) {
1450 struct core_vma_metadata *meta = vma_meta + i;
1451
1452 if (!dump_user_range(cprm, meta->start, meta->dump_size))
1453 return false;
1454 }
1455 return true;
1456 }
1457
1458 /*
1459 * Actual dumper
1460 *
1461 * This is a two-pass process; first we find the offsets of the bits,
1462 * and then they are actually written out. If we run out of core limit
1463 * we just truncate.
1464 */
elf_fdpic_core_dump(struct coredump_params * cprm)1465 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1466 {
1467 int has_dumped = 0;
1468 int segs;
1469 int i;
1470 struct elfhdr *elf = NULL;
1471 loff_t offset = 0, dataoff;
1472 struct memelfnote psinfo_note, auxv_note;
1473 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1474 struct elf_thread_status *thread_list = NULL;
1475 int thread_status_size = 0;
1476 elf_addr_t *auxv;
1477 struct elf_phdr *phdr4note = NULL;
1478 struct elf_shdr *shdr4extnum = NULL;
1479 Elf_Half e_phnum;
1480 elf_addr_t e_shoff;
1481 struct core_thread *ct;
1482 struct elf_thread_status *tmp;
1483
1484 /* alloc memory for large data structures: too large to be on stack */
1485 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1486 if (!elf)
1487 goto end_coredump;
1488 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1489 if (!psinfo)
1490 goto end_coredump;
1491
1492 for (ct = current->signal->core_state->dumper.next;
1493 ct; ct = ct->next) {
1494 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1495 ct->task, &thread_status_size);
1496 if (!tmp)
1497 goto end_coredump;
1498
1499 tmp->next = thread_list;
1500 thread_list = tmp;
1501 }
1502
1503 /* now collect the dump for the current */
1504 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1505 current, &thread_status_size);
1506 if (!tmp)
1507 goto end_coredump;
1508 tmp->next = thread_list;
1509 thread_list = tmp;
1510
1511 segs = cprm->vma_count + elf_core_extra_phdrs();
1512
1513 /* for notes section */
1514 segs++;
1515
1516 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1517 * this, kernel supports extended numbering. Have a look at
1518 * include/linux/elf.h for further information. */
1519 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1520
1521 /* Set up header */
1522 fill_elf_fdpic_header(elf, e_phnum);
1523
1524 has_dumped = 1;
1525 /*
1526 * Set up the notes in similar form to SVR4 core dumps made
1527 * with info from their /proc.
1528 */
1529
1530 fill_psinfo(psinfo, current->group_leader, current->mm);
1531 fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1532 thread_status_size += notesize(&psinfo_note);
1533
1534 auxv = (elf_addr_t *) current->mm->saved_auxv;
1535 i = 0;
1536 do
1537 i += 2;
1538 while (auxv[i - 2] != AT_NULL);
1539 fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1540 thread_status_size += notesize(&auxv_note);
1541
1542 offset = sizeof(*elf); /* Elf header */
1543 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1544
1545 /* Write notes phdr entry */
1546 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1547 if (!phdr4note)
1548 goto end_coredump;
1549
1550 fill_elf_note_phdr(phdr4note, thread_status_size, offset);
1551 offset += thread_status_size;
1552
1553 /* Page-align dumped data */
1554 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1555
1556 offset += cprm->vma_data_size;
1557 offset += elf_core_extra_data_size();
1558 e_shoff = offset;
1559
1560 if (e_phnum == PN_XNUM) {
1561 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1562 if (!shdr4extnum)
1563 goto end_coredump;
1564 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1565 }
1566
1567 offset = dataoff;
1568
1569 if (!dump_emit(cprm, elf, sizeof(*elf)))
1570 goto end_coredump;
1571
1572 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1573 goto end_coredump;
1574
1575 /* write program headers for segments dump */
1576 for (i = 0; i < cprm->vma_count; i++) {
1577 struct core_vma_metadata *meta = cprm->vma_meta + i;
1578 struct elf_phdr phdr;
1579 size_t sz;
1580
1581 sz = meta->end - meta->start;
1582
1583 phdr.p_type = PT_LOAD;
1584 phdr.p_offset = offset;
1585 phdr.p_vaddr = meta->start;
1586 phdr.p_paddr = 0;
1587 phdr.p_filesz = meta->dump_size;
1588 phdr.p_memsz = sz;
1589 offset += phdr.p_filesz;
1590 phdr.p_flags = 0;
1591 if (meta->flags & VM_READ)
1592 phdr.p_flags |= PF_R;
1593 if (meta->flags & VM_WRITE)
1594 phdr.p_flags |= PF_W;
1595 if (meta->flags & VM_EXEC)
1596 phdr.p_flags |= PF_X;
1597 phdr.p_align = ELF_EXEC_PAGESIZE;
1598
1599 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1600 goto end_coredump;
1601 }
1602
1603 if (!elf_core_write_extra_phdrs(cprm, offset))
1604 goto end_coredump;
1605
1606 /* write out the notes section */
1607 if (!writenote(thread_list->notes, cprm))
1608 goto end_coredump;
1609 if (!writenote(&psinfo_note, cprm))
1610 goto end_coredump;
1611 if (!writenote(&auxv_note, cprm))
1612 goto end_coredump;
1613 for (i = 1; i < thread_list->num_notes; i++)
1614 if (!writenote(thread_list->notes + i, cprm))
1615 goto end_coredump;
1616
1617 /* write out the thread status notes section */
1618 for (tmp = thread_list->next; tmp; tmp = tmp->next) {
1619 for (i = 0; i < tmp->num_notes; i++)
1620 if (!writenote(&tmp->notes[i], cprm))
1621 goto end_coredump;
1622 }
1623
1624 dump_skip_to(cprm, dataoff);
1625
1626 if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count))
1627 goto end_coredump;
1628
1629 if (!elf_core_write_extra_data(cprm))
1630 goto end_coredump;
1631
1632 if (e_phnum == PN_XNUM) {
1633 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1634 goto end_coredump;
1635 }
1636
1637 if (cprm->file->f_pos != offset) {
1638 /* Sanity check */
1639 printk(KERN_WARNING
1640 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1641 cprm->file->f_pos, offset);
1642 }
1643
1644 end_coredump:
1645 while (thread_list) {
1646 tmp = thread_list;
1647 thread_list = thread_list->next;
1648 kfree(tmp);
1649 }
1650 kfree(phdr4note);
1651 kfree(elf);
1652 kfree(psinfo);
1653 kfree(shdr4extnum);
1654 return has_dumped;
1655 }
1656
1657 #endif /* CONFIG_ELF_CORE */
1658
