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 retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params,
438 &interp_params);
439 if (retval < 0)
440 goto error;
441
442 kdebug("- start_code %lx", current->mm->start_code);
443 kdebug("- end_code %lx", current->mm->end_code);
444 kdebug("- start_data %lx", current->mm->start_data);
445 kdebug("- end_data %lx", current->mm->end_data);
446 kdebug("- start_brk %lx", current->mm->start_brk);
447 kdebug("- brk %lx", current->mm->brk);
448 kdebug("- start_stack %lx", current->mm->start_stack);
449
450 #ifdef ELF_FDPIC_PLAT_INIT
451 /*
452 * The ABI may specify that certain registers be set up in special
453 * ways (on i386 %edx is the address of a DT_FINI function, for
454 * example. This macro performs whatever initialization to
455 * the regs structure is required.
456 */
457 dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
458 ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
459 dynaddr);
460 #endif
461
462 finalize_exec(bprm);
463 /* everything is now ready... get the userspace context ready to roll */
464 entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
465 start_thread(regs, entryaddr, current->mm->start_stack);
466
467 retval = 0;
468
469 error:
470 if (interpreter) {
471 allow_write_access(interpreter);
472 fput(interpreter);
473 }
474 kfree(interpreter_name);
475 kfree(exec_params.phdrs);
476 kfree(exec_params.loadmap);
477 kfree(interp_params.phdrs);
478 kfree(interp_params.loadmap);
479 return retval;
480 }
481
482 /*****************************************************************************/
483
484 #ifndef ELF_BASE_PLATFORM
485 /*
486 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
487 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
488 * will be copied to the user stack in the same manner as AT_PLATFORM.
489 */
490 #define ELF_BASE_PLATFORM NULL
491 #endif
492
493 /*
494 * present useful information to the program by shovelling it onto the new
495 * process's stack
496 */
create_elf_fdpic_tables(struct linux_binprm * bprm,struct mm_struct * mm,struct elf_fdpic_params * exec_params,struct elf_fdpic_params * interp_params)497 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
498 struct mm_struct *mm,
499 struct elf_fdpic_params *exec_params,
500 struct elf_fdpic_params *interp_params)
501 {
502 const struct cred *cred = current_cred();
503 unsigned long sp, csp, nitems;
504 elf_caddr_t __user *argv, *envp;
505 size_t platform_len = 0, len;
506 char *k_platform, *k_base_platform;
507 char __user *u_platform, *u_base_platform, *p;
508 int loop;
509 int nr; /* reset for each csp adjustment */
510 unsigned long flags = 0;
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 elf32_fdpic_loadmap);
564 len += sizeof(struct elf32_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 elf32_fdpic_loadmap);
575 len += sizeof(struct elf32_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
596 csp = sp;
597 sp -= nitems * 2 * sizeof(unsigned long);
598 sp -= (bprm->envc + 1) * sizeof(char *); /* envv[] */
599 sp -= (bprm->argc + 1) * sizeof(char *); /* argv[] */
600 sp -= 1 * sizeof(unsigned long); /* argc */
601
602 csp -= sp & 15UL;
603 sp -= sp & 15UL;
604
605 /* put the ELF interpreter info on the stack */
606 #define NEW_AUX_ENT(id, val) \
607 do { \
608 struct { unsigned long _id, _val; } __user *ent, v; \
609 \
610 ent = (void __user *) csp; \
611 v._id = (id); \
612 v._val = (val); \
613 if (copy_to_user(ent + nr, &v, sizeof(v))) \
614 return -EFAULT; \
615 nr++; \
616 } while (0)
617
618 nr = 0;
619 csp -= 2 * sizeof(unsigned long);
620 NEW_AUX_ENT(AT_NULL, 0);
621 if (k_platform) {
622 nr = 0;
623 csp -= 2 * sizeof(unsigned long);
624 NEW_AUX_ENT(AT_PLATFORM,
625 (elf_addr_t) (unsigned long) u_platform);
626 }
627
628 if (k_base_platform) {
629 nr = 0;
630 csp -= 2 * sizeof(unsigned long);
631 NEW_AUX_ENT(AT_BASE_PLATFORM,
632 (elf_addr_t) (unsigned long) u_base_platform);
633 }
634
635 if (bprm->have_execfd) {
636 nr = 0;
637 csp -= 2 * sizeof(unsigned long);
638 NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
639 }
640
641 nr = 0;
642 csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
643 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
644 #ifdef ELF_HWCAP2
645 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
646 #endif
647 NEW_AUX_ENT(AT_PAGESZ, PAGE_SIZE);
648 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
649 NEW_AUX_ENT(AT_PHDR, exec_params->ph_addr);
650 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
651 NEW_AUX_ENT(AT_PHNUM, exec_params->hdr.e_phnum);
652 NEW_AUX_ENT(AT_BASE, interp_params->elfhdr_addr);
653 if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
654 flags |= AT_FLAGS_PRESERVE_ARGV0;
655 NEW_AUX_ENT(AT_FLAGS, flags);
656 NEW_AUX_ENT(AT_ENTRY, exec_params->entry_addr);
657 NEW_AUX_ENT(AT_UID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
658 NEW_AUX_ENT(AT_EUID, (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
659 NEW_AUX_ENT(AT_GID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
660 NEW_AUX_ENT(AT_EGID, (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
661 NEW_AUX_ENT(AT_SECURE, bprm->secureexec);
662 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
663
664 #ifdef ARCH_DLINFO
665 nr = 0;
666 csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
667
668 /* ARCH_DLINFO must come last so platform specific code can enforce
669 * special alignment requirements on the AUXV if necessary (eg. PPC).
670 */
671 ARCH_DLINFO;
672 #endif
673 #undef NEW_AUX_ENT
674
675 /* allocate room for argv[] and envv[] */
676 csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
677 envp = (elf_caddr_t __user *) csp;
678 csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
679 argv = (elf_caddr_t __user *) csp;
680
681 /* stack argc */
682 csp -= sizeof(unsigned long);
683 if (put_user(bprm->argc, (unsigned long __user *) csp))
684 return -EFAULT;
685
686 BUG_ON(csp != sp);
687
688 /* fill in the argv[] array */
689 #ifdef CONFIG_MMU
690 current->mm->arg_start = bprm->p;
691 #else
692 current->mm->arg_start = current->mm->start_stack -
693 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
694 #endif
695
696 p = (char __user *) current->mm->arg_start;
697 for (loop = bprm->argc; loop > 0; loop--) {
698 if (put_user((elf_caddr_t) p, argv++))
699 return -EFAULT;
700 len = strnlen_user(p, MAX_ARG_STRLEN);
701 if (!len || len > MAX_ARG_STRLEN)
702 return -EINVAL;
703 p += len;
704 }
705 if (put_user(NULL, argv))
706 return -EFAULT;
707 current->mm->arg_end = (unsigned long) p;
708
709 /* fill in the envv[] array */
710 current->mm->env_start = (unsigned long) p;
711 for (loop = bprm->envc; loop > 0; loop--) {
712 if (put_user((elf_caddr_t)(unsigned long) p, envp++))
713 return -EFAULT;
714 len = strnlen_user(p, MAX_ARG_STRLEN);
715 if (!len || len > MAX_ARG_STRLEN)
716 return -EINVAL;
717 p += len;
718 }
719 if (put_user(NULL, envp))
720 return -EFAULT;
721 current->mm->env_end = (unsigned long) p;
722
723 mm->start_stack = (unsigned long) sp;
724 return 0;
725 }
726
727 /*****************************************************************************/
728 /*
729 * load the appropriate binary image (executable or interpreter) into memory
730 * - we assume no MMU is available
731 * - if no other PIC bits are set in params->hdr->e_flags
732 * - we assume that the LOADable segments in the binary are independently relocatable
733 * - we assume R/O executable segments are shareable
734 * - else
735 * - we assume the loadable parts of the image to require fixed displacement
736 * - the image is not shareable
737 */
elf_fdpic_map_file(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm,const char * what)738 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
739 struct file *file,
740 struct mm_struct *mm,
741 const char *what)
742 {
743 struct elf32_fdpic_loadmap *loadmap;
744 #ifdef CONFIG_MMU
745 struct elf32_fdpic_loadseg *mseg;
746 #endif
747 struct elf32_fdpic_loadseg *seg;
748 struct elf32_phdr *phdr;
749 unsigned long load_addr, stop;
750 unsigned nloads, tmp;
751 size_t size;
752 int loop, ret;
753
754 /* allocate a load map table */
755 nloads = 0;
756 for (loop = 0; loop < params->hdr.e_phnum; loop++)
757 if (params->phdrs[loop].p_type == PT_LOAD)
758 nloads++;
759
760 if (nloads == 0)
761 return -ELIBBAD;
762
763 size = sizeof(*loadmap) + nloads * sizeof(*seg);
764 loadmap = kzalloc(size, GFP_KERNEL);
765 if (!loadmap)
766 return -ENOMEM;
767
768 params->loadmap = loadmap;
769
770 loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
771 loadmap->nsegs = nloads;
772
773 load_addr = params->load_addr;
774 seg = loadmap->segs;
775
776 /* map the requested LOADs into the memory space */
777 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
778 case ELF_FDPIC_FLAG_CONSTDISP:
779 case ELF_FDPIC_FLAG_CONTIGUOUS:
780 #ifndef CONFIG_MMU
781 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
782 if (ret < 0)
783 return ret;
784 break;
785 #endif
786 default:
787 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
788 if (ret < 0)
789 return ret;
790 break;
791 }
792
793 /* map the entry point */
794 if (params->hdr.e_entry) {
795 seg = loadmap->segs;
796 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
797 if (params->hdr.e_entry >= seg->p_vaddr &&
798 params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
799 params->entry_addr =
800 (params->hdr.e_entry - seg->p_vaddr) +
801 seg->addr;
802 break;
803 }
804 }
805 }
806
807 /* determine where the program header table has wound up if mapped */
808 stop = params->hdr.e_phoff;
809 stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
810 phdr = params->phdrs;
811
812 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
813 if (phdr->p_type != PT_LOAD)
814 continue;
815
816 if (phdr->p_offset > params->hdr.e_phoff ||
817 phdr->p_offset + phdr->p_filesz < stop)
818 continue;
819
820 seg = loadmap->segs;
821 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
822 if (phdr->p_vaddr >= seg->p_vaddr &&
823 phdr->p_vaddr + phdr->p_filesz <=
824 seg->p_vaddr + seg->p_memsz) {
825 params->ph_addr =
826 (phdr->p_vaddr - seg->p_vaddr) +
827 seg->addr +
828 params->hdr.e_phoff - phdr->p_offset;
829 break;
830 }
831 }
832 break;
833 }
834
835 /* determine where the dynamic section has wound up if there is one */
836 phdr = params->phdrs;
837 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
838 if (phdr->p_type != PT_DYNAMIC)
839 continue;
840
841 seg = loadmap->segs;
842 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
843 if (phdr->p_vaddr >= seg->p_vaddr &&
844 phdr->p_vaddr + phdr->p_memsz <=
845 seg->p_vaddr + seg->p_memsz) {
846 Elf32_Dyn __user *dyn;
847 Elf32_Sword d_tag;
848
849 params->dynamic_addr =
850 (phdr->p_vaddr - seg->p_vaddr) +
851 seg->addr;
852
853 /* check the dynamic section contains at least
854 * one item, and that the last item is a NULL
855 * entry */
856 if (phdr->p_memsz == 0 ||
857 phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
858 goto dynamic_error;
859
860 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
861 dyn = (Elf32_Dyn __user *)params->dynamic_addr;
862 if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
863 d_tag != 0)
864 goto dynamic_error;
865 break;
866 }
867 }
868 break;
869 }
870
871 /* now elide adjacent segments in the load map on MMU linux
872 * - on uClinux the holes between may actually be filled with system
873 * stuff or stuff from other processes
874 */
875 #ifdef CONFIG_MMU
876 nloads = loadmap->nsegs;
877 mseg = loadmap->segs;
878 seg = mseg + 1;
879 for (loop = 1; loop < nloads; loop++) {
880 /* see if we have a candidate for merging */
881 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
882 load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
883 if (load_addr == (seg->addr & PAGE_MASK)) {
884 mseg->p_memsz +=
885 load_addr -
886 (mseg->addr + mseg->p_memsz);
887 mseg->p_memsz += seg->addr & ~PAGE_MASK;
888 mseg->p_memsz += seg->p_memsz;
889 loadmap->nsegs--;
890 continue;
891 }
892 }
893
894 mseg++;
895 if (mseg != seg)
896 *mseg = *seg;
897 }
898 #endif
899
900 kdebug("Mapped Object [%s]:", what);
901 kdebug("- elfhdr : %lx", params->elfhdr_addr);
902 kdebug("- entry : %lx", params->entry_addr);
903 kdebug("- PHDR[] : %lx", params->ph_addr);
904 kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
905 seg = loadmap->segs;
906 for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
907 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
908 loop,
909 seg->addr, seg->addr + seg->p_memsz - 1,
910 seg->p_vaddr, seg->p_memsz);
911
912 return 0;
913
914 dynamic_error:
915 printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
916 what, file_inode(file)->i_ino);
917 return -ELIBBAD;
918 }
919
920 /*****************************************************************************/
921 /*
922 * map a file with constant displacement under uClinux
923 */
924 #ifndef CONFIG_MMU
elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm)925 static int elf_fdpic_map_file_constdisp_on_uclinux(
926 struct elf_fdpic_params *params,
927 struct file *file,
928 struct mm_struct *mm)
929 {
930 struct elf32_fdpic_loadseg *seg;
931 struct elf32_phdr *phdr;
932 unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
933 int loop, ret;
934
935 load_addr = params->load_addr;
936 seg = params->loadmap->segs;
937
938 /* determine the bounds of the contiguous overall allocation we must
939 * make */
940 phdr = params->phdrs;
941 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
942 if (params->phdrs[loop].p_type != PT_LOAD)
943 continue;
944
945 if (base > phdr->p_vaddr)
946 base = phdr->p_vaddr;
947 if (top < phdr->p_vaddr + phdr->p_memsz)
948 top = phdr->p_vaddr + phdr->p_memsz;
949 }
950
951 /* allocate one big anon block for everything */
952 maddr = vm_mmap(NULL, load_addr, top - base,
953 PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0);
954 if (IS_ERR_VALUE(maddr))
955 return (int) maddr;
956
957 if (load_addr != 0)
958 load_addr += PAGE_ALIGN(top - base);
959
960 /* and then load the file segments into it */
961 phdr = params->phdrs;
962 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
963 if (params->phdrs[loop].p_type != PT_LOAD)
964 continue;
965
966 seg->addr = maddr + (phdr->p_vaddr - base);
967 seg->p_vaddr = phdr->p_vaddr;
968 seg->p_memsz = phdr->p_memsz;
969
970 ret = read_code(file, seg->addr, phdr->p_offset,
971 phdr->p_filesz);
972 if (ret < 0)
973 return ret;
974
975 /* map the ELF header address if in this segment */
976 if (phdr->p_offset == 0)
977 params->elfhdr_addr = seg->addr;
978
979 /* clear any space allocated but not loaded */
980 if (phdr->p_filesz < phdr->p_memsz) {
981 if (clear_user((void *) (seg->addr + phdr->p_filesz),
982 phdr->p_memsz - phdr->p_filesz))
983 return -EFAULT;
984 }
985
986 if (mm) {
987 if (phdr->p_flags & PF_X) {
988 if (!mm->start_code) {
989 mm->start_code = seg->addr;
990 mm->end_code = seg->addr +
991 phdr->p_memsz;
992 }
993 } else if (!mm->start_data) {
994 mm->start_data = seg->addr;
995 mm->end_data = seg->addr + phdr->p_memsz;
996 }
997 }
998
999 seg++;
1000 }
1001
1002 return 0;
1003 }
1004 #endif
1005
1006 /*****************************************************************************/
1007 /*
1008 * map a binary by direct mmap() of the individual PT_LOAD segments
1009 */
elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params * params,struct file * file,struct mm_struct * mm)1010 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1011 struct file *file,
1012 struct mm_struct *mm)
1013 {
1014 struct elf32_fdpic_loadseg *seg;
1015 struct elf32_phdr *phdr;
1016 unsigned long load_addr, delta_vaddr;
1017 int loop, dvset;
1018
1019 load_addr = params->load_addr;
1020 delta_vaddr = 0;
1021 dvset = 0;
1022
1023 seg = params->loadmap->segs;
1024
1025 /* deal with each load segment separately */
1026 phdr = params->phdrs;
1027 for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1028 unsigned long maddr, disp, excess, excess1;
1029 int prot = 0, flags;
1030
1031 if (phdr->p_type != PT_LOAD)
1032 continue;
1033
1034 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1035 (unsigned long) phdr->p_vaddr,
1036 (unsigned long) phdr->p_offset,
1037 (unsigned long) phdr->p_filesz,
1038 (unsigned long) phdr->p_memsz);
1039
1040 /* determine the mapping parameters */
1041 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1042 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1043 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1044
1045 flags = MAP_PRIVATE;
1046 maddr = 0;
1047
1048 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1049 case ELF_FDPIC_FLAG_INDEPENDENT:
1050 /* PT_LOADs are independently locatable */
1051 break;
1052
1053 case ELF_FDPIC_FLAG_HONOURVADDR:
1054 /* the specified virtual address must be honoured */
1055 maddr = phdr->p_vaddr;
1056 flags |= MAP_FIXED;
1057 break;
1058
1059 case ELF_FDPIC_FLAG_CONSTDISP:
1060 /* constant displacement
1061 * - can be mapped anywhere, but must be mapped as a
1062 * unit
1063 */
1064 if (!dvset) {
1065 maddr = load_addr;
1066 delta_vaddr = phdr->p_vaddr;
1067 dvset = 1;
1068 } else {
1069 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1070 flags |= MAP_FIXED;
1071 }
1072 break;
1073
1074 case ELF_FDPIC_FLAG_CONTIGUOUS:
1075 /* contiguity handled later */
1076 break;
1077
1078 default:
1079 BUG();
1080 }
1081
1082 maddr &= PAGE_MASK;
1083
1084 /* create the mapping */
1085 disp = phdr->p_vaddr & ~PAGE_MASK;
1086 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1087 phdr->p_offset - disp);
1088
1089 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1090 loop, phdr->p_memsz + disp, prot, flags,
1091 phdr->p_offset - disp, maddr);
1092
1093 if (IS_ERR_VALUE(maddr))
1094 return (int) maddr;
1095
1096 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1097 ELF_FDPIC_FLAG_CONTIGUOUS)
1098 load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1099
1100 seg->addr = maddr + disp;
1101 seg->p_vaddr = phdr->p_vaddr;
1102 seg->p_memsz = phdr->p_memsz;
1103
1104 /* map the ELF header address if in this segment */
1105 if (phdr->p_offset == 0)
1106 params->elfhdr_addr = seg->addr;
1107
1108 /* clear the bit between beginning of mapping and beginning of
1109 * PT_LOAD */
1110 if (prot & PROT_WRITE && disp > 0) {
1111 kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1112 if (clear_user((void __user *) maddr, disp))
1113 return -EFAULT;
1114 maddr += disp;
1115 }
1116
1117 /* clear any space allocated but not loaded
1118 * - on uClinux we can just clear the lot
1119 * - on MMU linux we'll get a SIGBUS beyond the last page
1120 * extant in the file
1121 */
1122 excess = phdr->p_memsz - phdr->p_filesz;
1123 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1124
1125 #ifdef CONFIG_MMU
1126 if (excess > excess1) {
1127 unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1128 unsigned long xmaddr;
1129
1130 flags |= MAP_FIXED | MAP_ANONYMOUS;
1131 xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1132 prot, flags, 0);
1133
1134 kdebug("mmap[%d] <anon>"
1135 " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1136 loop, xaddr, excess - excess1, prot, flags,
1137 xmaddr);
1138
1139 if (xmaddr != xaddr)
1140 return -ENOMEM;
1141 }
1142
1143 if (prot & PROT_WRITE && excess1 > 0) {
1144 kdebug("clear[%d] ad=%lx sz=%lx",
1145 loop, maddr + phdr->p_filesz, excess1);
1146 if (clear_user((void __user *) maddr + phdr->p_filesz,
1147 excess1))
1148 return -EFAULT;
1149 }
1150
1151 #else
1152 if (excess > 0) {
1153 kdebug("clear[%d] ad=%lx sz=%lx",
1154 loop, maddr + phdr->p_filesz, excess);
1155 if (clear_user((void *) maddr + phdr->p_filesz, excess))
1156 return -EFAULT;
1157 }
1158 #endif
1159
1160 if (mm) {
1161 if (phdr->p_flags & PF_X) {
1162 if (!mm->start_code) {
1163 mm->start_code = maddr;
1164 mm->end_code = maddr + phdr->p_memsz;
1165 }
1166 } else if (!mm->start_data) {
1167 mm->start_data = maddr;
1168 mm->end_data = maddr + phdr->p_memsz;
1169 }
1170 }
1171
1172 seg++;
1173 }
1174
1175 return 0;
1176 }
1177
1178 /*****************************************************************************/
1179 /*
1180 * ELF-FDPIC core dumper
1181 *
1182 * Modelled on fs/exec.c:aout_core_dump()
1183 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1184 *
1185 * Modelled on fs/binfmt_elf.c core dumper
1186 */
1187 #ifdef CONFIG_ELF_CORE
1188
1189 struct elf_prstatus_fdpic
1190 {
1191 struct elf_prstatus_common common;
1192 elf_gregset_t pr_reg; /* GP registers */
1193 /* When using FDPIC, the loadmap addresses need to be communicated
1194 * to GDB in order for GDB to do the necessary relocations. The
1195 * fields (below) used to communicate this information are placed
1196 * immediately after ``pr_reg'', so that the loadmap addresses may
1197 * be viewed as part of the register set if so desired.
1198 */
1199 unsigned long pr_exec_fdpic_loadmap;
1200 unsigned long pr_interp_fdpic_loadmap;
1201 int pr_fpvalid; /* True if math co-processor being used. */
1202 };
1203
1204 /* An ELF note in memory */
1205 struct memelfnote
1206 {
1207 const char *name;
1208 int type;
1209 unsigned int datasz;
1210 void *data;
1211 };
1212
notesize(struct memelfnote * en)1213 static int notesize(struct memelfnote *en)
1214 {
1215 int sz;
1216
1217 sz = sizeof(struct elf_note);
1218 sz += roundup(strlen(en->name) + 1, 4);
1219 sz += roundup(en->datasz, 4);
1220
1221 return sz;
1222 }
1223
1224 /* #define DEBUG */
1225
writenote(struct memelfnote * men,struct coredump_params * cprm)1226 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1227 {
1228 struct elf_note en;
1229 en.n_namesz = strlen(men->name) + 1;
1230 en.n_descsz = men->datasz;
1231 en.n_type = men->type;
1232
1233 return dump_emit(cprm, &en, sizeof(en)) &&
1234 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1235 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1236 }
1237
fill_elf_fdpic_header(struct elfhdr * elf,int segs)1238 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1239 {
1240 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1241 elf->e_ident[EI_CLASS] = ELF_CLASS;
1242 elf->e_ident[EI_DATA] = ELF_DATA;
1243 elf->e_ident[EI_VERSION] = EV_CURRENT;
1244 elf->e_ident[EI_OSABI] = ELF_OSABI;
1245 memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1246
1247 elf->e_type = ET_CORE;
1248 elf->e_machine = ELF_ARCH;
1249 elf->e_version = EV_CURRENT;
1250 elf->e_entry = 0;
1251 elf->e_phoff = sizeof(struct elfhdr);
1252 elf->e_shoff = 0;
1253 elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1254 elf->e_ehsize = sizeof(struct elfhdr);
1255 elf->e_phentsize = sizeof(struct elf_phdr);
1256 elf->e_phnum = segs;
1257 elf->e_shentsize = 0;
1258 elf->e_shnum = 0;
1259 elf->e_shstrndx = 0;
1260 return;
1261 }
1262
fill_elf_note_phdr(struct elf_phdr * phdr,int sz,loff_t offset)1263 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1264 {
1265 phdr->p_type = PT_NOTE;
1266 phdr->p_offset = offset;
1267 phdr->p_vaddr = 0;
1268 phdr->p_paddr = 0;
1269 phdr->p_filesz = sz;
1270 phdr->p_memsz = 0;
1271 phdr->p_flags = 0;
1272 phdr->p_align = 0;
1273 return;
1274 }
1275
fill_note(struct memelfnote * note,const char * name,int type,unsigned int sz,void * data)1276 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1277 unsigned int sz, void *data)
1278 {
1279 note->name = name;
1280 note->type = type;
1281 note->datasz = sz;
1282 note->data = data;
1283 return;
1284 }
1285
1286 /*
1287 * fill up all the fields in prstatus from the given task struct, except
1288 * registers which need to be filled up separately.
1289 */
fill_prstatus(struct elf_prstatus_common * prstatus,struct task_struct * p,long signr)1290 static void fill_prstatus(struct elf_prstatus_common *prstatus,
1291 struct task_struct *p, long signr)
1292 {
1293 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1294 prstatus->pr_sigpend = p->pending.signal.sig[0];
1295 prstatus->pr_sighold = p->blocked.sig[0];
1296 rcu_read_lock();
1297 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1298 rcu_read_unlock();
1299 prstatus->pr_pid = task_pid_vnr(p);
1300 prstatus->pr_pgrp = task_pgrp_vnr(p);
1301 prstatus->pr_sid = task_session_vnr(p);
1302 if (thread_group_leader(p)) {
1303 struct task_cputime cputime;
1304
1305 /*
1306 * This is the record for the group leader. It shows the
1307 * group-wide total, not its individual thread total.
1308 */
1309 thread_group_cputime(p, &cputime);
1310 prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1311 prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1312 } else {
1313 u64 utime, stime;
1314
1315 task_cputime(p, &utime, &stime);
1316 prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1317 prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1318 }
1319 prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1320 prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1321 }
1322
fill_psinfo(struct elf_prpsinfo * psinfo,struct task_struct * p,struct mm_struct * mm)1323 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1324 struct mm_struct *mm)
1325 {
1326 const struct cred *cred;
1327 unsigned int i, len;
1328 unsigned int state;
1329
1330 /* first copy the parameters from user space */
1331 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1332
1333 len = mm->arg_end - mm->arg_start;
1334 if (len >= ELF_PRARGSZ)
1335 len = ELF_PRARGSZ - 1;
1336 if (copy_from_user(&psinfo->pr_psargs,
1337 (const char __user *) mm->arg_start, len))
1338 return -EFAULT;
1339 for (i = 0; i < len; i++)
1340 if (psinfo->pr_psargs[i] == 0)
1341 psinfo->pr_psargs[i] = ' ';
1342 psinfo->pr_psargs[len] = 0;
1343
1344 rcu_read_lock();
1345 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1346 rcu_read_unlock();
1347 psinfo->pr_pid = task_pid_vnr(p);
1348 psinfo->pr_pgrp = task_pgrp_vnr(p);
1349 psinfo->pr_sid = task_session_vnr(p);
1350
1351 state = READ_ONCE(p->__state);
1352 i = state ? ffz(~state) + 1 : 0;
1353 psinfo->pr_state = i;
1354 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1355 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1356 psinfo->pr_nice = task_nice(p);
1357 psinfo->pr_flag = p->flags;
1358 rcu_read_lock();
1359 cred = __task_cred(p);
1360 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1361 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1362 rcu_read_unlock();
1363 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1364
1365 return 0;
1366 }
1367
1368 /* Here is the structure in which status of each thread is captured. */
1369 struct elf_thread_status
1370 {
1371 struct elf_thread_status *next;
1372 struct elf_prstatus_fdpic prstatus; /* NT_PRSTATUS */
1373 elf_fpregset_t fpu; /* NT_PRFPREG */
1374 struct memelfnote notes[2];
1375 int num_notes;
1376 };
1377
1378 /*
1379 * In order to add the specific thread information for the elf file format,
1380 * we need to keep a linked list of every thread's pr_status and then create
1381 * a single section for them in the final core file.
1382 */
elf_dump_thread_status(long signr,struct task_struct * p,int * sz)1383 static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
1384 {
1385 const struct user_regset_view *view = task_user_regset_view(p);
1386 struct elf_thread_status *t;
1387 int i, ret;
1388
1389 t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
1390 if (!t)
1391 return t;
1392
1393 fill_prstatus(&t->prstatus.common, p, signr);
1394 t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1395 t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1396 regset_get(p, &view->regsets[0],
1397 sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1398
1399 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1400 &t->prstatus);
1401 t->num_notes++;
1402 *sz += notesize(&t->notes[0]);
1403
1404 for (i = 1; i < view->n; ++i) {
1405 const struct user_regset *regset = &view->regsets[i];
1406 if (regset->core_note_type != NT_PRFPREG)
1407 continue;
1408 if (regset->active && regset->active(p, regset) <= 0)
1409 continue;
1410 ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
1411 if (ret >= 0)
1412 t->prstatus.pr_fpvalid = 1;
1413 break;
1414 }
1415
1416 if (t->prstatus.pr_fpvalid) {
1417 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1418 &t->fpu);
1419 t->num_notes++;
1420 *sz += notesize(&t->notes[1]);
1421 }
1422 return t;
1423 }
1424
fill_extnum_info(struct elfhdr * elf,struct elf_shdr * shdr4extnum,elf_addr_t e_shoff,int segs)1425 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1426 elf_addr_t e_shoff, int segs)
1427 {
1428 elf->e_shoff = e_shoff;
1429 elf->e_shentsize = sizeof(*shdr4extnum);
1430 elf->e_shnum = 1;
1431 elf->e_shstrndx = SHN_UNDEF;
1432
1433 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1434
1435 shdr4extnum->sh_type = SHT_NULL;
1436 shdr4extnum->sh_size = elf->e_shnum;
1437 shdr4extnum->sh_link = elf->e_shstrndx;
1438 shdr4extnum->sh_info = segs;
1439 }
1440
1441 /*
1442 * dump the segments for an MMU process
1443 */
elf_fdpic_dump_segments(struct coredump_params * cprm,struct core_vma_metadata * vma_meta,int vma_count)1444 static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
1445 struct core_vma_metadata *vma_meta,
1446 int vma_count)
1447 {
1448 int i;
1449
1450 for (i = 0; i < vma_count; i++) {
1451 struct core_vma_metadata *meta = vma_meta + i;
1452
1453 if (!dump_user_range(cprm, meta->start, meta->dump_size))
1454 return false;
1455 }
1456 return true;
1457 }
1458
1459 /*
1460 * Actual dumper
1461 *
1462 * This is a two-pass process; first we find the offsets of the bits,
1463 * and then they are actually written out. If we run out of core limit
1464 * we just truncate.
1465 */
elf_fdpic_core_dump(struct coredump_params * cprm)1466 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1467 {
1468 int has_dumped = 0;
1469 int segs;
1470 int i;
1471 struct elfhdr *elf = NULL;
1472 loff_t offset = 0, dataoff;
1473 struct memelfnote psinfo_note, auxv_note;
1474 struct elf_prpsinfo *psinfo = NULL; /* NT_PRPSINFO */
1475 struct elf_thread_status *thread_list = NULL;
1476 int thread_status_size = 0;
1477 elf_addr_t *auxv;
1478 struct elf_phdr *phdr4note = NULL;
1479 struct elf_shdr *shdr4extnum = NULL;
1480 Elf_Half e_phnum;
1481 elf_addr_t e_shoff;
1482 struct core_thread *ct;
1483 struct elf_thread_status *tmp;
1484
1485 /* alloc memory for large data structures: too large to be on stack */
1486 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1487 if (!elf)
1488 goto end_coredump;
1489 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1490 if (!psinfo)
1491 goto end_coredump;
1492
1493 for (ct = current->signal->core_state->dumper.next;
1494 ct; ct = ct->next) {
1495 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1496 ct->task, &thread_status_size);
1497 if (!tmp)
1498 goto end_coredump;
1499
1500 tmp->next = thread_list;
1501 thread_list = tmp;
1502 }
1503
1504 /* now collect the dump for the current */
1505 tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1506 current, &thread_status_size);
1507 if (!tmp)
1508 goto end_coredump;
1509 tmp->next = thread_list;
1510 thread_list = tmp;
1511
1512 segs = cprm->vma_count + elf_core_extra_phdrs(cprm);
1513
1514 /* for notes section */
1515 segs++;
1516
1517 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1518 * this, kernel supports extended numbering. Have a look at
1519 * include/linux/elf.h for further information. */
1520 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1521
1522 /* Set up header */
1523 fill_elf_fdpic_header(elf, e_phnum);
1524
1525 has_dumped = 1;
1526 /*
1527 * Set up the notes in similar form to SVR4 core dumps made
1528 * with info from their /proc.
1529 */
1530
1531 fill_psinfo(psinfo, current->group_leader, current->mm);
1532 fill_note(&psinfo_note, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1533 thread_status_size += notesize(&psinfo_note);
1534
1535 auxv = (elf_addr_t *) current->mm->saved_auxv;
1536 i = 0;
1537 do
1538 i += 2;
1539 while (auxv[i - 2] != AT_NULL);
1540 fill_note(&auxv_note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1541 thread_status_size += notesize(&auxv_note);
1542
1543 offset = sizeof(*elf); /* Elf header */
1544 offset += segs * sizeof(struct elf_phdr); /* Program headers */
1545
1546 /* Write notes phdr entry */
1547 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1548 if (!phdr4note)
1549 goto end_coredump;
1550
1551 fill_elf_note_phdr(phdr4note, thread_status_size, offset);
1552 offset += thread_status_size;
1553
1554 /* Page-align dumped data */
1555 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1556
1557 offset += cprm->vma_data_size;
1558 offset += elf_core_extra_data_size(cprm);
1559 e_shoff = offset;
1560
1561 if (e_phnum == PN_XNUM) {
1562 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1563 if (!shdr4extnum)
1564 goto end_coredump;
1565 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1566 }
1567
1568 offset = dataoff;
1569
1570 if (!dump_emit(cprm, elf, sizeof(*elf)))
1571 goto end_coredump;
1572
1573 if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1574 goto end_coredump;
1575
1576 /* write program headers for segments dump */
1577 for (i = 0; i < cprm->vma_count; i++) {
1578 struct core_vma_metadata *meta = cprm->vma_meta + i;
1579 struct elf_phdr phdr;
1580 size_t sz;
1581
1582 sz = meta->end - meta->start;
1583
1584 phdr.p_type = PT_LOAD;
1585 phdr.p_offset = offset;
1586 phdr.p_vaddr = meta->start;
1587 phdr.p_paddr = 0;
1588 phdr.p_filesz = meta->dump_size;
1589 phdr.p_memsz = sz;
1590 offset += phdr.p_filesz;
1591 phdr.p_flags = 0;
1592 if (meta->flags & VM_READ)
1593 phdr.p_flags |= PF_R;
1594 if (meta->flags & VM_WRITE)
1595 phdr.p_flags |= PF_W;
1596 if (meta->flags & VM_EXEC)
1597 phdr.p_flags |= PF_X;
1598 phdr.p_align = ELF_EXEC_PAGESIZE;
1599
1600 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1601 goto end_coredump;
1602 }
1603
1604 if (!elf_core_write_extra_phdrs(cprm, offset))
1605 goto end_coredump;
1606
1607 /* write out the notes section */
1608 if (!writenote(thread_list->notes, cprm))
1609 goto end_coredump;
1610 if (!writenote(&psinfo_note, cprm))
1611 goto end_coredump;
1612 if (!writenote(&auxv_note, cprm))
1613 goto end_coredump;
1614 for (i = 1; i < thread_list->num_notes; i++)
1615 if (!writenote(thread_list->notes + i, cprm))
1616 goto end_coredump;
1617
1618 /* write out the thread status notes section */
1619 for (tmp = thread_list->next; tmp; tmp = tmp->next) {
1620 for (i = 0; i < tmp->num_notes; i++)
1621 if (!writenote(&tmp->notes[i], cprm))
1622 goto end_coredump;
1623 }
1624
1625 dump_skip_to(cprm, dataoff);
1626
1627 if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count))
1628 goto end_coredump;
1629
1630 if (!elf_core_write_extra_data(cprm))
1631 goto end_coredump;
1632
1633 if (e_phnum == PN_XNUM) {
1634 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1635 goto end_coredump;
1636 }
1637
1638 if (cprm->file->f_pos != offset) {
1639 /* Sanity check */
1640 printk(KERN_WARNING
1641 "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1642 cprm->file->f_pos, offset);
1643 }
1644
1645 end_coredump:
1646 while (thread_list) {
1647 tmp = thread_list;
1648 thread_list = thread_list->next;
1649 kfree(tmp);
1650 }
1651 kfree(phdr4note);
1652 kfree(elf);
1653 kfree(psinfo);
1654 kfree(shdr4extnum);
1655 return has_dumped;
1656 }
1657
1658 #endif /* CONFIG_ELF_CORE */
1659