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powerpc: Add HWCAP2 aux entry
[deliverable/linux.git] / fs / binfmt_elf.c
1 /*
2 * linux/fs/binfmt_elf.c
3 *
4 * These are the functions used to load ELF format executables as used
5 * on SVr4 machines. Information on the format may be found in the book
6 * "UNIX SYSTEM V RELEASE 4 Programmers Guide: Ansi C and Programming Support
7 * Tools".
8 *
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
10 */
11
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/fs.h>
15 #include <linux/mm.h>
16 #include <linux/mman.h>
17 #include <linux/errno.h>
18 #include <linux/signal.h>
19 #include <linux/binfmts.h>
20 #include <linux/string.h>
21 #include <linux/file.h>
22 #include <linux/slab.h>
23 #include <linux/personality.h>
24 #include <linux/elfcore.h>
25 #include <linux/init.h>
26 #include <linux/highuid.h>
27 #include <linux/compiler.h>
28 #include <linux/highmem.h>
29 #include <linux/pagemap.h>
30 #include <linux/vmalloc.h>
31 #include <linux/security.h>
32 #include <linux/random.h>
33 #include <linux/elf.h>
34 #include <linux/utsname.h>
35 #include <linux/coredump.h>
36 #include <linux/sched.h>
37 #include <asm/uaccess.h>
38 #include <asm/param.h>
39 #include <asm/page.h>
40
41 #ifndef user_long_t
42 #define user_long_t long
43 #endif
44 #ifndef user_siginfo_t
45 #define user_siginfo_t siginfo_t
46 #endif
47
48 static int load_elf_binary(struct linux_binprm *bprm);
49 static int load_elf_library(struct file *);
50 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
51 int, int, unsigned long);
52
53 /*
54 * If we don't support core dumping, then supply a NULL so we
55 * don't even try.
56 */
57 #ifdef CONFIG_ELF_CORE
58 static int elf_core_dump(struct coredump_params *cprm);
59 #else
60 #define elf_core_dump NULL
61 #endif
62
63 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
64 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
65 #else
66 #define ELF_MIN_ALIGN PAGE_SIZE
67 #endif
68
69 #ifndef ELF_CORE_EFLAGS
70 #define ELF_CORE_EFLAGS 0
71 #endif
72
73 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
74 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
75 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
76
77 static struct linux_binfmt elf_format = {
78 .module = THIS_MODULE,
79 .load_binary = load_elf_binary,
80 .load_shlib = load_elf_library,
81 .core_dump = elf_core_dump,
82 .min_coredump = ELF_EXEC_PAGESIZE,
83 };
84
85 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
86
87 static int set_brk(unsigned long start, unsigned long end)
88 {
89 start = ELF_PAGEALIGN(start);
90 end = ELF_PAGEALIGN(end);
91 if (end > start) {
92 unsigned long addr;
93 addr = vm_brk(start, end - start);
94 if (BAD_ADDR(addr))
95 return addr;
96 }
97 current->mm->start_brk = current->mm->brk = end;
98 return 0;
99 }
100
101 /* We need to explicitly zero any fractional pages
102 after the data section (i.e. bss). This would
103 contain the junk from the file that should not
104 be in memory
105 */
106 static int padzero(unsigned long elf_bss)
107 {
108 unsigned long nbyte;
109
110 nbyte = ELF_PAGEOFFSET(elf_bss);
111 if (nbyte) {
112 nbyte = ELF_MIN_ALIGN - nbyte;
113 if (clear_user((void __user *) elf_bss, nbyte))
114 return -EFAULT;
115 }
116 return 0;
117 }
118
119 /* Let's use some macros to make this stack manipulation a little clearer */
120 #ifdef CONFIG_STACK_GROWSUP
121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
122 #define STACK_ROUND(sp, items) \
123 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
124 #define STACK_ALLOC(sp, len) ({ \
125 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
126 old_sp; })
127 #else
128 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
129 #define STACK_ROUND(sp, items) \
130 (((unsigned long) (sp - items)) &~ 15UL)
131 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
132 #endif
133
134 #ifndef ELF_BASE_PLATFORM
135 /*
136 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
137 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
138 * will be copied to the user stack in the same manner as AT_PLATFORM.
139 */
140 #define ELF_BASE_PLATFORM NULL
141 #endif
142
143 static int
144 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
145 unsigned long load_addr, unsigned long interp_load_addr)
146 {
147 unsigned long p = bprm->p;
148 int argc = bprm->argc;
149 int envc = bprm->envc;
150 elf_addr_t __user *argv;
151 elf_addr_t __user *envp;
152 elf_addr_t __user *sp;
153 elf_addr_t __user *u_platform;
154 elf_addr_t __user *u_base_platform;
155 elf_addr_t __user *u_rand_bytes;
156 const char *k_platform = ELF_PLATFORM;
157 const char *k_base_platform = ELF_BASE_PLATFORM;
158 unsigned char k_rand_bytes[16];
159 int items;
160 elf_addr_t *elf_info;
161 int ei_index = 0;
162 const struct cred *cred = current_cred();
163 struct vm_area_struct *vma;
164
165 /*
166 * In some cases (e.g. Hyper-Threading), we want to avoid L1
167 * evictions by the processes running on the same package. One
168 * thing we can do is to shuffle the initial stack for them.
169 */
170
171 p = arch_align_stack(p);
172
173 /*
174 * If this architecture has a platform capability string, copy it
175 * to userspace. In some cases (Sparc), this info is impossible
176 * for userspace to get any other way, in others (i386) it is
177 * merely difficult.
178 */
179 u_platform = NULL;
180 if (k_platform) {
181 size_t len = strlen(k_platform) + 1;
182
183 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
184 if (__copy_to_user(u_platform, k_platform, len))
185 return -EFAULT;
186 }
187
188 /*
189 * If this architecture has a "base" platform capability
190 * string, copy it to userspace.
191 */
192 u_base_platform = NULL;
193 if (k_base_platform) {
194 size_t len = strlen(k_base_platform) + 1;
195
196 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
197 if (__copy_to_user(u_base_platform, k_base_platform, len))
198 return -EFAULT;
199 }
200
201 /*
202 * Generate 16 random bytes for userspace PRNG seeding.
203 */
204 get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes));
205 u_rand_bytes = (elf_addr_t __user *)
206 STACK_ALLOC(p, sizeof(k_rand_bytes));
207 if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes)))
208 return -EFAULT;
209
210 /* Create the ELF interpreter info */
211 elf_info = (elf_addr_t *)current->mm->saved_auxv;
212 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
213 #define NEW_AUX_ENT(id, val) \
214 do { \
215 elf_info[ei_index++] = id; \
216 elf_info[ei_index++] = val; \
217 } while (0)
218
219 #ifdef ARCH_DLINFO
220 /*
221 * ARCH_DLINFO must come first so PPC can do its special alignment of
222 * AUXV.
223 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
224 * ARCH_DLINFO changes
225 */
226 ARCH_DLINFO;
227 #endif
228 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
229 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
230 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
231 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
232 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
233 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
234 NEW_AUX_ENT(AT_BASE, interp_load_addr);
235 NEW_AUX_ENT(AT_FLAGS, 0);
236 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
237 NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid));
238 NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid));
239 NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid));
240 NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid));
241 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
242 NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes);
243 #ifdef ELF_HWCAP2
244 NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2);
245 #endif
246 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
247 if (k_platform) {
248 NEW_AUX_ENT(AT_PLATFORM,
249 (elf_addr_t)(unsigned long)u_platform);
250 }
251 if (k_base_platform) {
252 NEW_AUX_ENT(AT_BASE_PLATFORM,
253 (elf_addr_t)(unsigned long)u_base_platform);
254 }
255 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
256 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
257 }
258 #undef NEW_AUX_ENT
259 /* AT_NULL is zero; clear the rest too */
260 memset(&elf_info[ei_index], 0,
261 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
262
263 /* And advance past the AT_NULL entry. */
264 ei_index += 2;
265
266 sp = STACK_ADD(p, ei_index);
267
268 items = (argc + 1) + (envc + 1) + 1;
269 bprm->p = STACK_ROUND(sp, items);
270
271 /* Point sp at the lowest address on the stack */
272 #ifdef CONFIG_STACK_GROWSUP
273 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
274 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
275 #else
276 sp = (elf_addr_t __user *)bprm->p;
277 #endif
278
279
280 /*
281 * Grow the stack manually; some architectures have a limit on how
282 * far ahead a user-space access may be in order to grow the stack.
283 */
284 vma = find_extend_vma(current->mm, bprm->p);
285 if (!vma)
286 return -EFAULT;
287
288 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
289 if (__put_user(argc, sp++))
290 return -EFAULT;
291 argv = sp;
292 envp = argv + argc + 1;
293
294 /* Populate argv and envp */
295 p = current->mm->arg_end = current->mm->arg_start;
296 while (argc-- > 0) {
297 size_t len;
298 if (__put_user((elf_addr_t)p, argv++))
299 return -EFAULT;
300 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
301 if (!len || len > MAX_ARG_STRLEN)
302 return -EINVAL;
303 p += len;
304 }
305 if (__put_user(0, argv))
306 return -EFAULT;
307 current->mm->arg_end = current->mm->env_start = p;
308 while (envc-- > 0) {
309 size_t len;
310 if (__put_user((elf_addr_t)p, envp++))
311 return -EFAULT;
312 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
313 if (!len || len > MAX_ARG_STRLEN)
314 return -EINVAL;
315 p += len;
316 }
317 if (__put_user(0, envp))
318 return -EFAULT;
319 current->mm->env_end = p;
320
321 /* Put the elf_info on the stack in the right place. */
322 sp = (elf_addr_t __user *)envp + 1;
323 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
324 return -EFAULT;
325 return 0;
326 }
327
328 #ifndef elf_map
329
330 static unsigned long elf_map(struct file *filep, unsigned long addr,
331 struct elf_phdr *eppnt, int prot, int type,
332 unsigned long total_size)
333 {
334 unsigned long map_addr;
335 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
336 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
337 addr = ELF_PAGESTART(addr);
338 size = ELF_PAGEALIGN(size);
339
340 /* mmap() will return -EINVAL if given a zero size, but a
341 * segment with zero filesize is perfectly valid */
342 if (!size)
343 return addr;
344
345 /*
346 * total_size is the size of the ELF (interpreter) image.
347 * The _first_ mmap needs to know the full size, otherwise
348 * randomization might put this image into an overlapping
349 * position with the ELF binary image. (since size < total_size)
350 * So we first map the 'big' image - and unmap the remainder at
351 * the end. (which unmap is needed for ELF images with holes.)
352 */
353 if (total_size) {
354 total_size = ELF_PAGEALIGN(total_size);
355 map_addr = vm_mmap(filep, addr, total_size, prot, type, off);
356 if (!BAD_ADDR(map_addr))
357 vm_munmap(map_addr+size, total_size-size);
358 } else
359 map_addr = vm_mmap(filep, addr, size, prot, type, off);
360
361 return(map_addr);
362 }
363
364 #endif /* !elf_map */
365
366 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
367 {
368 int i, first_idx = -1, last_idx = -1;
369
370 for (i = 0; i < nr; i++) {
371 if (cmds[i].p_type == PT_LOAD) {
372 last_idx = i;
373 if (first_idx == -1)
374 first_idx = i;
375 }
376 }
377 if (first_idx == -1)
378 return 0;
379
380 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
381 ELF_PAGESTART(cmds[first_idx].p_vaddr);
382 }
383
384
385 /* This is much more generalized than the library routine read function,
386 so we keep this separate. Technically the library read function
387 is only provided so that we can read a.out libraries that have
388 an ELF header */
389
390 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
391 struct file *interpreter, unsigned long *interp_map_addr,
392 unsigned long no_base)
393 {
394 struct elf_phdr *elf_phdata;
395 struct elf_phdr *eppnt;
396 unsigned long load_addr = 0;
397 int load_addr_set = 0;
398 unsigned long last_bss = 0, elf_bss = 0;
399 unsigned long error = ~0UL;
400 unsigned long total_size;
401 int retval, i, size;
402
403 /* First of all, some simple consistency checks */
404 if (interp_elf_ex->e_type != ET_EXEC &&
405 interp_elf_ex->e_type != ET_DYN)
406 goto out;
407 if (!elf_check_arch(interp_elf_ex))
408 goto out;
409 if (!interpreter->f_op || !interpreter->f_op->mmap)
410 goto out;
411
412 /*
413 * If the size of this structure has changed, then punt, since
414 * we will be doing the wrong thing.
415 */
416 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
417 goto out;
418 if (interp_elf_ex->e_phnum < 1 ||
419 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
420 goto out;
421
422 /* Now read in all of the header information */
423 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
424 if (size > ELF_MIN_ALIGN)
425 goto out;
426 elf_phdata = kmalloc(size, GFP_KERNEL);
427 if (!elf_phdata)
428 goto out;
429
430 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
431 (char *)elf_phdata, size);
432 error = -EIO;
433 if (retval != size) {
434 if (retval < 0)
435 error = retval;
436 goto out_close;
437 }
438
439 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
440 if (!total_size) {
441 error = -EINVAL;
442 goto out_close;
443 }
444
445 eppnt = elf_phdata;
446 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
447 if (eppnt->p_type == PT_LOAD) {
448 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
449 int elf_prot = 0;
450 unsigned long vaddr = 0;
451 unsigned long k, map_addr;
452
453 if (eppnt->p_flags & PF_R)
454 elf_prot = PROT_READ;
455 if (eppnt->p_flags & PF_W)
456 elf_prot |= PROT_WRITE;
457 if (eppnt->p_flags & PF_X)
458 elf_prot |= PROT_EXEC;
459 vaddr = eppnt->p_vaddr;
460 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
461 elf_type |= MAP_FIXED;
462 else if (no_base && interp_elf_ex->e_type == ET_DYN)
463 load_addr = -vaddr;
464
465 map_addr = elf_map(interpreter, load_addr + vaddr,
466 eppnt, elf_prot, elf_type, total_size);
467 total_size = 0;
468 if (!*interp_map_addr)
469 *interp_map_addr = map_addr;
470 error = map_addr;
471 if (BAD_ADDR(map_addr))
472 goto out_close;
473
474 if (!load_addr_set &&
475 interp_elf_ex->e_type == ET_DYN) {
476 load_addr = map_addr - ELF_PAGESTART(vaddr);
477 load_addr_set = 1;
478 }
479
480 /*
481 * Check to see if the section's size will overflow the
482 * allowed task size. Note that p_filesz must always be
483 * <= p_memsize so it's only necessary to check p_memsz.
484 */
485 k = load_addr + eppnt->p_vaddr;
486 if (BAD_ADDR(k) ||
487 eppnt->p_filesz > eppnt->p_memsz ||
488 eppnt->p_memsz > TASK_SIZE ||
489 TASK_SIZE - eppnt->p_memsz < k) {
490 error = -ENOMEM;
491 goto out_close;
492 }
493
494 /*
495 * Find the end of the file mapping for this phdr, and
496 * keep track of the largest address we see for this.
497 */
498 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
499 if (k > elf_bss)
500 elf_bss = k;
501
502 /*
503 * Do the same thing for the memory mapping - between
504 * elf_bss and last_bss is the bss section.
505 */
506 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
507 if (k > last_bss)
508 last_bss = k;
509 }
510 }
511
512 if (last_bss > elf_bss) {
513 /*
514 * Now fill out the bss section. First pad the last page up
515 * to the page boundary, and then perform a mmap to make sure
516 * that there are zero-mapped pages up to and including the
517 * last bss page.
518 */
519 if (padzero(elf_bss)) {
520 error = -EFAULT;
521 goto out_close;
522 }
523
524 /* What we have mapped so far */
525 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
526
527 /* Map the last of the bss segment */
528 error = vm_brk(elf_bss, last_bss - elf_bss);
529 if (BAD_ADDR(error))
530 goto out_close;
531 }
532
533 error = load_addr;
534
535 out_close:
536 kfree(elf_phdata);
537 out:
538 return error;
539 }
540
541 /*
542 * These are the functions used to load ELF style executables and shared
543 * libraries. There is no binary dependent code anywhere else.
544 */
545
546 #define INTERPRETER_NONE 0
547 #define INTERPRETER_ELF 2
548
549 #ifndef STACK_RND_MASK
550 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
551 #endif
552
553 static unsigned long randomize_stack_top(unsigned long stack_top)
554 {
555 unsigned int random_variable = 0;
556
557 if ((current->flags & PF_RANDOMIZE) &&
558 !(current->personality & ADDR_NO_RANDOMIZE)) {
559 random_variable = get_random_int() & STACK_RND_MASK;
560 random_variable <<= PAGE_SHIFT;
561 }
562 #ifdef CONFIG_STACK_GROWSUP
563 return PAGE_ALIGN(stack_top) + random_variable;
564 #else
565 return PAGE_ALIGN(stack_top) - random_variable;
566 #endif
567 }
568
569 static int load_elf_binary(struct linux_binprm *bprm)
570 {
571 struct file *interpreter = NULL; /* to shut gcc up */
572 unsigned long load_addr = 0, load_bias = 0;
573 int load_addr_set = 0;
574 char * elf_interpreter = NULL;
575 unsigned long error;
576 struct elf_phdr *elf_ppnt, *elf_phdata;
577 unsigned long elf_bss, elf_brk;
578 int retval, i;
579 unsigned int size;
580 unsigned long elf_entry;
581 unsigned long interp_load_addr = 0;
582 unsigned long start_code, end_code, start_data, end_data;
583 unsigned long reloc_func_desc __maybe_unused = 0;
584 int executable_stack = EXSTACK_DEFAULT;
585 unsigned long def_flags = 0;
586 struct pt_regs *regs = current_pt_regs();
587 struct {
588 struct elfhdr elf_ex;
589 struct elfhdr interp_elf_ex;
590 } *loc;
591
592 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
593 if (!loc) {
594 retval = -ENOMEM;
595 goto out_ret;
596 }
597
598 /* Get the exec-header */
599 loc->elf_ex = *((struct elfhdr *)bprm->buf);
600
601 retval = -ENOEXEC;
602 /* First of all, some simple consistency checks */
603 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
604 goto out;
605
606 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
607 goto out;
608 if (!elf_check_arch(&loc->elf_ex))
609 goto out;
610 if (!bprm->file->f_op || !bprm->file->f_op->mmap)
611 goto out;
612
613 /* Now read in all of the header information */
614 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
615 goto out;
616 if (loc->elf_ex.e_phnum < 1 ||
617 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
618 goto out;
619 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
620 retval = -ENOMEM;
621 elf_phdata = kmalloc(size, GFP_KERNEL);
622 if (!elf_phdata)
623 goto out;
624
625 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
626 (char *)elf_phdata, size);
627 if (retval != size) {
628 if (retval >= 0)
629 retval = -EIO;
630 goto out_free_ph;
631 }
632
633 elf_ppnt = elf_phdata;
634 elf_bss = 0;
635 elf_brk = 0;
636
637 start_code = ~0UL;
638 end_code = 0;
639 start_data = 0;
640 end_data = 0;
641
642 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
643 if (elf_ppnt->p_type == PT_INTERP) {
644 /* This is the program interpreter used for
645 * shared libraries - for now assume that this
646 * is an a.out format binary
647 */
648 retval = -ENOEXEC;
649 if (elf_ppnt->p_filesz > PATH_MAX ||
650 elf_ppnt->p_filesz < 2)
651 goto out_free_ph;
652
653 retval = -ENOMEM;
654 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
655 GFP_KERNEL);
656 if (!elf_interpreter)
657 goto out_free_ph;
658
659 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
660 elf_interpreter,
661 elf_ppnt->p_filesz);
662 if (retval != elf_ppnt->p_filesz) {
663 if (retval >= 0)
664 retval = -EIO;
665 goto out_free_interp;
666 }
667 /* make sure path is NULL terminated */
668 retval = -ENOEXEC;
669 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
670 goto out_free_interp;
671
672 interpreter = open_exec(elf_interpreter);
673 retval = PTR_ERR(interpreter);
674 if (IS_ERR(interpreter))
675 goto out_free_interp;
676
677 /*
678 * If the binary is not readable then enforce
679 * mm->dumpable = 0 regardless of the interpreter's
680 * permissions.
681 */
682 would_dump(bprm, interpreter);
683
684 retval = kernel_read(interpreter, 0, bprm->buf,
685 BINPRM_BUF_SIZE);
686 if (retval != BINPRM_BUF_SIZE) {
687 if (retval >= 0)
688 retval = -EIO;
689 goto out_free_dentry;
690 }
691
692 /* Get the exec headers */
693 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
694 break;
695 }
696 elf_ppnt++;
697 }
698
699 elf_ppnt = elf_phdata;
700 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
701 if (elf_ppnt->p_type == PT_GNU_STACK) {
702 if (elf_ppnt->p_flags & PF_X)
703 executable_stack = EXSTACK_ENABLE_X;
704 else
705 executable_stack = EXSTACK_DISABLE_X;
706 break;
707 }
708
709 /* Some simple consistency checks for the interpreter */
710 if (elf_interpreter) {
711 retval = -ELIBBAD;
712 /* Not an ELF interpreter */
713 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
714 goto out_free_dentry;
715 /* Verify the interpreter has a valid arch */
716 if (!elf_check_arch(&loc->interp_elf_ex))
717 goto out_free_dentry;
718 }
719
720 /* Flush all traces of the currently running executable */
721 retval = flush_old_exec(bprm);
722 if (retval)
723 goto out_free_dentry;
724
725 /* OK, This is the point of no return */
726 current->mm->def_flags = def_flags;
727
728 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
729 may depend on the personality. */
730 SET_PERSONALITY(loc->elf_ex);
731 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
732 current->personality |= READ_IMPLIES_EXEC;
733
734 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
735 current->flags |= PF_RANDOMIZE;
736
737 setup_new_exec(bprm);
738
739 /* Do this so that we can load the interpreter, if need be. We will
740 change some of these later */
741 current->mm->free_area_cache = current->mm->mmap_base;
742 current->mm->cached_hole_size = 0;
743 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
744 executable_stack);
745 if (retval < 0) {
746 send_sig(SIGKILL, current, 0);
747 goto out_free_dentry;
748 }
749
750 current->mm->start_stack = bprm->p;
751
752 /* Now we do a little grungy work by mmapping the ELF image into
753 the correct location in memory. */
754 for(i = 0, elf_ppnt = elf_phdata;
755 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
756 int elf_prot = 0, elf_flags;
757 unsigned long k, vaddr;
758
759 if (elf_ppnt->p_type != PT_LOAD)
760 continue;
761
762 if (unlikely (elf_brk > elf_bss)) {
763 unsigned long nbyte;
764
765 /* There was a PT_LOAD segment with p_memsz > p_filesz
766 before this one. Map anonymous pages, if needed,
767 and clear the area. */
768 retval = set_brk(elf_bss + load_bias,
769 elf_brk + load_bias);
770 if (retval) {
771 send_sig(SIGKILL, current, 0);
772 goto out_free_dentry;
773 }
774 nbyte = ELF_PAGEOFFSET(elf_bss);
775 if (nbyte) {
776 nbyte = ELF_MIN_ALIGN - nbyte;
777 if (nbyte > elf_brk - elf_bss)
778 nbyte = elf_brk - elf_bss;
779 if (clear_user((void __user *)elf_bss +
780 load_bias, nbyte)) {
781 /*
782 * This bss-zeroing can fail if the ELF
783 * file specifies odd protections. So
784 * we don't check the return value
785 */
786 }
787 }
788 }
789
790 if (elf_ppnt->p_flags & PF_R)
791 elf_prot |= PROT_READ;
792 if (elf_ppnt->p_flags & PF_W)
793 elf_prot |= PROT_WRITE;
794 if (elf_ppnt->p_flags & PF_X)
795 elf_prot |= PROT_EXEC;
796
797 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
798
799 vaddr = elf_ppnt->p_vaddr;
800 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
801 elf_flags |= MAP_FIXED;
802 } else if (loc->elf_ex.e_type == ET_DYN) {
803 /* Try and get dynamic programs out of the way of the
804 * default mmap base, as well as whatever program they
805 * might try to exec. This is because the brk will
806 * follow the loader, and is not movable. */
807 #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
808 /* Memory randomization might have been switched off
809 * in runtime via sysctl.
810 * If that is the case, retain the original non-zero
811 * load_bias value in order to establish proper
812 * non-randomized mappings.
813 */
814 if (current->flags & PF_RANDOMIZE)
815 load_bias = 0;
816 else
817 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
818 #else
819 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
820 #endif
821 }
822
823 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
824 elf_prot, elf_flags, 0);
825 if (BAD_ADDR(error)) {
826 send_sig(SIGKILL, current, 0);
827 retval = IS_ERR((void *)error) ?
828 PTR_ERR((void*)error) : -EINVAL;
829 goto out_free_dentry;
830 }
831
832 if (!load_addr_set) {
833 load_addr_set = 1;
834 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
835 if (loc->elf_ex.e_type == ET_DYN) {
836 load_bias += error -
837 ELF_PAGESTART(load_bias + vaddr);
838 load_addr += load_bias;
839 reloc_func_desc = load_bias;
840 }
841 }
842 k = elf_ppnt->p_vaddr;
843 if (k < start_code)
844 start_code = k;
845 if (start_data < k)
846 start_data = k;
847
848 /*
849 * Check to see if the section's size will overflow the
850 * allowed task size. Note that p_filesz must always be
851 * <= p_memsz so it is only necessary to check p_memsz.
852 */
853 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
854 elf_ppnt->p_memsz > TASK_SIZE ||
855 TASK_SIZE - elf_ppnt->p_memsz < k) {
856 /* set_brk can never work. Avoid overflows. */
857 send_sig(SIGKILL, current, 0);
858 retval = -EINVAL;
859 goto out_free_dentry;
860 }
861
862 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
863
864 if (k > elf_bss)
865 elf_bss = k;
866 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
867 end_code = k;
868 if (end_data < k)
869 end_data = k;
870 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
871 if (k > elf_brk)
872 elf_brk = k;
873 }
874
875 loc->elf_ex.e_entry += load_bias;
876 elf_bss += load_bias;
877 elf_brk += load_bias;
878 start_code += load_bias;
879 end_code += load_bias;
880 start_data += load_bias;
881 end_data += load_bias;
882
883 /* Calling set_brk effectively mmaps the pages that we need
884 * for the bss and break sections. We must do this before
885 * mapping in the interpreter, to make sure it doesn't wind
886 * up getting placed where the bss needs to go.
887 */
888 retval = set_brk(elf_bss, elf_brk);
889 if (retval) {
890 send_sig(SIGKILL, current, 0);
891 goto out_free_dentry;
892 }
893 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
894 send_sig(SIGSEGV, current, 0);
895 retval = -EFAULT; /* Nobody gets to see this, but.. */
896 goto out_free_dentry;
897 }
898
899 if (elf_interpreter) {
900 unsigned long interp_map_addr = 0;
901
902 elf_entry = load_elf_interp(&loc->interp_elf_ex,
903 interpreter,
904 &interp_map_addr,
905 load_bias);
906 if (!IS_ERR((void *)elf_entry)) {
907 /*
908 * load_elf_interp() returns relocation
909 * adjustment
910 */
911 interp_load_addr = elf_entry;
912 elf_entry += loc->interp_elf_ex.e_entry;
913 }
914 if (BAD_ADDR(elf_entry)) {
915 force_sig(SIGSEGV, current);
916 retval = IS_ERR((void *)elf_entry) ?
917 (int)elf_entry : -EINVAL;
918 goto out_free_dentry;
919 }
920 reloc_func_desc = interp_load_addr;
921
922 allow_write_access(interpreter);
923 fput(interpreter);
924 kfree(elf_interpreter);
925 } else {
926 elf_entry = loc->elf_ex.e_entry;
927 if (BAD_ADDR(elf_entry)) {
928 force_sig(SIGSEGV, current);
929 retval = -EINVAL;
930 goto out_free_dentry;
931 }
932 }
933
934 kfree(elf_phdata);
935
936 set_binfmt(&elf_format);
937
938 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
939 retval = arch_setup_additional_pages(bprm, !!elf_interpreter);
940 if (retval < 0) {
941 send_sig(SIGKILL, current, 0);
942 goto out;
943 }
944 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
945
946 install_exec_creds(bprm);
947 retval = create_elf_tables(bprm, &loc->elf_ex,
948 load_addr, interp_load_addr);
949 if (retval < 0) {
950 send_sig(SIGKILL, current, 0);
951 goto out;
952 }
953 /* N.B. passed_fileno might not be initialized? */
954 current->mm->end_code = end_code;
955 current->mm->start_code = start_code;
956 current->mm->start_data = start_data;
957 current->mm->end_data = end_data;
958 current->mm->start_stack = bprm->p;
959
960 #ifdef arch_randomize_brk
961 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) {
962 current->mm->brk = current->mm->start_brk =
963 arch_randomize_brk(current->mm);
964 #ifdef CONFIG_COMPAT_BRK
965 current->brk_randomized = 1;
966 #endif
967 }
968 #endif
969
970 if (current->personality & MMAP_PAGE_ZERO) {
971 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
972 and some applications "depend" upon this behavior.
973 Since we do not have the power to recompile these, we
974 emulate the SVr4 behavior. Sigh. */
975 error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
976 MAP_FIXED | MAP_PRIVATE, 0);
977 }
978
979 #ifdef ELF_PLAT_INIT
980 /*
981 * The ABI may specify that certain registers be set up in special
982 * ways (on i386 %edx is the address of a DT_FINI function, for
983 * example. In addition, it may also specify (eg, PowerPC64 ELF)
984 * that the e_entry field is the address of the function descriptor
985 * for the startup routine, rather than the address of the startup
986 * routine itself. This macro performs whatever initialization to
987 * the regs structure is required as well as any relocations to the
988 * function descriptor entries when executing dynamically links apps.
989 */
990 ELF_PLAT_INIT(regs, reloc_func_desc);
991 #endif
992
993 start_thread(regs, elf_entry, bprm->p);
994 retval = 0;
995 out:
996 kfree(loc);
997 out_ret:
998 return retval;
999
1000 /* error cleanup */
1001 out_free_dentry:
1002 allow_write_access(interpreter);
1003 if (interpreter)
1004 fput(interpreter);
1005 out_free_interp:
1006 kfree(elf_interpreter);
1007 out_free_ph:
1008 kfree(elf_phdata);
1009 goto out;
1010 }
1011
1012 /* This is really simpleminded and specialized - we are loading an
1013 a.out library that is given an ELF header. */
1014 static int load_elf_library(struct file *file)
1015 {
1016 struct elf_phdr *elf_phdata;
1017 struct elf_phdr *eppnt;
1018 unsigned long elf_bss, bss, len;
1019 int retval, error, i, j;
1020 struct elfhdr elf_ex;
1021
1022 error = -ENOEXEC;
1023 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1024 if (retval != sizeof(elf_ex))
1025 goto out;
1026
1027 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1028 goto out;
1029
1030 /* First of all, some simple consistency checks */
1031 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1032 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1033 goto out;
1034
1035 /* Now read in all of the header information */
1036
1037 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1038 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1039
1040 error = -ENOMEM;
1041 elf_phdata = kmalloc(j, GFP_KERNEL);
1042 if (!elf_phdata)
1043 goto out;
1044
1045 eppnt = elf_phdata;
1046 error = -ENOEXEC;
1047 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1048 if (retval != j)
1049 goto out_free_ph;
1050
1051 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1052 if ((eppnt + i)->p_type == PT_LOAD)
1053 j++;
1054 if (j != 1)
1055 goto out_free_ph;
1056
1057 while (eppnt->p_type != PT_LOAD)
1058 eppnt++;
1059
1060 /* Now use mmap to map the library into memory. */
1061 error = vm_mmap(file,
1062 ELF_PAGESTART(eppnt->p_vaddr),
1063 (eppnt->p_filesz +
1064 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1065 PROT_READ | PROT_WRITE | PROT_EXEC,
1066 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1067 (eppnt->p_offset -
1068 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1069 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1070 goto out_free_ph;
1071
1072 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1073 if (padzero(elf_bss)) {
1074 error = -EFAULT;
1075 goto out_free_ph;
1076 }
1077
1078 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1079 ELF_MIN_ALIGN - 1);
1080 bss = eppnt->p_memsz + eppnt->p_vaddr;
1081 if (bss > len)
1082 vm_brk(len, bss - len);
1083 error = 0;
1084
1085 out_free_ph:
1086 kfree(elf_phdata);
1087 out:
1088 return error;
1089 }
1090
1091 #ifdef CONFIG_ELF_CORE
1092 /*
1093 * ELF core dumper
1094 *
1095 * Modelled on fs/exec.c:aout_core_dump()
1096 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1097 */
1098
1099 /*
1100 * The purpose of always_dump_vma() is to make sure that special kernel mappings
1101 * that are useful for post-mortem analysis are included in every core dump.
1102 * In that way we ensure that the core dump is fully interpretable later
1103 * without matching up the same kernel and hardware config to see what PC values
1104 * meant. These special mappings include - vDSO, vsyscall, and other
1105 * architecture specific mappings
1106 */
1107 static bool always_dump_vma(struct vm_area_struct *vma)
1108 {
1109 /* Any vsyscall mappings? */
1110 if (vma == get_gate_vma(vma->vm_mm))
1111 return true;
1112 /*
1113 * arch_vma_name() returns non-NULL for special architecture mappings,
1114 * such as vDSO sections.
1115 */
1116 if (arch_vma_name(vma))
1117 return true;
1118
1119 return false;
1120 }
1121
1122 /*
1123 * Decide what to dump of a segment, part, all or none.
1124 */
1125 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1126 unsigned long mm_flags)
1127 {
1128 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1129
1130 /* always dump the vdso and vsyscall sections */
1131 if (always_dump_vma(vma))
1132 goto whole;
1133
1134 if (vma->vm_flags & VM_DONTDUMP)
1135 return 0;
1136
1137 /* Hugetlb memory check */
1138 if (vma->vm_flags & VM_HUGETLB) {
1139 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1140 goto whole;
1141 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1142 goto whole;
1143 return 0;
1144 }
1145
1146 /* Do not dump I/O mapped devices or special mappings */
1147 if (vma->vm_flags & VM_IO)
1148 return 0;
1149
1150 /* By default, dump shared memory if mapped from an anonymous file. */
1151 if (vma->vm_flags & VM_SHARED) {
1152 if (file_inode(vma->vm_file)->i_nlink == 0 ?
1153 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1154 goto whole;
1155 return 0;
1156 }
1157
1158 /* Dump segments that have been written to. */
1159 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1160 goto whole;
1161 if (vma->vm_file == NULL)
1162 return 0;
1163
1164 if (FILTER(MAPPED_PRIVATE))
1165 goto whole;
1166
1167 /*
1168 * If this looks like the beginning of a DSO or executable mapping,
1169 * check for an ELF header. If we find one, dump the first page to
1170 * aid in determining what was mapped here.
1171 */
1172 if (FILTER(ELF_HEADERS) &&
1173 vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) {
1174 u32 __user *header = (u32 __user *) vma->vm_start;
1175 u32 word;
1176 mm_segment_t fs = get_fs();
1177 /*
1178 * Doing it this way gets the constant folded by GCC.
1179 */
1180 union {
1181 u32 cmp;
1182 char elfmag[SELFMAG];
1183 } magic;
1184 BUILD_BUG_ON(SELFMAG != sizeof word);
1185 magic.elfmag[EI_MAG0] = ELFMAG0;
1186 magic.elfmag[EI_MAG1] = ELFMAG1;
1187 magic.elfmag[EI_MAG2] = ELFMAG2;
1188 magic.elfmag[EI_MAG3] = ELFMAG3;
1189 /*
1190 * Switch to the user "segment" for get_user(),
1191 * then put back what elf_core_dump() had in place.
1192 */
1193 set_fs(USER_DS);
1194 if (unlikely(get_user(word, header)))
1195 word = 0;
1196 set_fs(fs);
1197 if (word == magic.cmp)
1198 return PAGE_SIZE;
1199 }
1200
1201 #undef FILTER
1202
1203 return 0;
1204
1205 whole:
1206 return vma->vm_end - vma->vm_start;
1207 }
1208
1209 /* An ELF note in memory */
1210 struct memelfnote
1211 {
1212 const char *name;
1213 int type;
1214 unsigned int datasz;
1215 void *data;
1216 };
1217
1218 static int notesize(struct memelfnote *en)
1219 {
1220 int sz;
1221
1222 sz = sizeof(struct elf_note);
1223 sz += roundup(strlen(en->name) + 1, 4);
1224 sz += roundup(en->datasz, 4);
1225
1226 return sz;
1227 }
1228
1229 #define DUMP_WRITE(addr, nr, foffset) \
1230 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1231
1232 static int alignfile(struct file *file, loff_t *foffset)
1233 {
1234 static const char buf[4] = { 0, };
1235 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1236 return 1;
1237 }
1238
1239 static int writenote(struct memelfnote *men, struct file *file,
1240 loff_t *foffset)
1241 {
1242 struct elf_note en;
1243 en.n_namesz = strlen(men->name) + 1;
1244 en.n_descsz = men->datasz;
1245 en.n_type = men->type;
1246
1247 DUMP_WRITE(&en, sizeof(en), foffset);
1248 DUMP_WRITE(men->name, en.n_namesz, foffset);
1249 if (!alignfile(file, foffset))
1250 return 0;
1251 DUMP_WRITE(men->data, men->datasz, foffset);
1252 if (!alignfile(file, foffset))
1253 return 0;
1254
1255 return 1;
1256 }
1257 #undef DUMP_WRITE
1258
1259 static void fill_elf_header(struct elfhdr *elf, int segs,
1260 u16 machine, u32 flags)
1261 {
1262 memset(elf, 0, sizeof(*elf));
1263
1264 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1265 elf->e_ident[EI_CLASS] = ELF_CLASS;
1266 elf->e_ident[EI_DATA] = ELF_DATA;
1267 elf->e_ident[EI_VERSION] = EV_CURRENT;
1268 elf->e_ident[EI_OSABI] = ELF_OSABI;
1269
1270 elf->e_type = ET_CORE;
1271 elf->e_machine = machine;
1272 elf->e_version = EV_CURRENT;
1273 elf->e_phoff = sizeof(struct elfhdr);
1274 elf->e_flags = flags;
1275 elf->e_ehsize = sizeof(struct elfhdr);
1276 elf->e_phentsize = sizeof(struct elf_phdr);
1277 elf->e_phnum = segs;
1278
1279 return;
1280 }
1281
1282 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1283 {
1284 phdr->p_type = PT_NOTE;
1285 phdr->p_offset = offset;
1286 phdr->p_vaddr = 0;
1287 phdr->p_paddr = 0;
1288 phdr->p_filesz = sz;
1289 phdr->p_memsz = 0;
1290 phdr->p_flags = 0;
1291 phdr->p_align = 0;
1292 return;
1293 }
1294
1295 static void fill_note(struct memelfnote *note, const char *name, int type,
1296 unsigned int sz, void *data)
1297 {
1298 note->name = name;
1299 note->type = type;
1300 note->datasz = sz;
1301 note->data = data;
1302 return;
1303 }
1304
1305 /*
1306 * fill up all the fields in prstatus from the given task struct, except
1307 * registers which need to be filled up separately.
1308 */
1309 static void fill_prstatus(struct elf_prstatus *prstatus,
1310 struct task_struct *p, long signr)
1311 {
1312 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1313 prstatus->pr_sigpend = p->pending.signal.sig[0];
1314 prstatus->pr_sighold = p->blocked.sig[0];
1315 rcu_read_lock();
1316 prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1317 rcu_read_unlock();
1318 prstatus->pr_pid = task_pid_vnr(p);
1319 prstatus->pr_pgrp = task_pgrp_vnr(p);
1320 prstatus->pr_sid = task_session_vnr(p);
1321 if (thread_group_leader(p)) {
1322 struct task_cputime cputime;
1323
1324 /*
1325 * This is the record for the group leader. It shows the
1326 * group-wide total, not its individual thread total.
1327 */
1328 thread_group_cputime(p, &cputime);
1329 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1330 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1331 } else {
1332 cputime_t utime, stime;
1333
1334 task_cputime(p, &utime, &stime);
1335 cputime_to_timeval(utime, &prstatus->pr_utime);
1336 cputime_to_timeval(stime, &prstatus->pr_stime);
1337 }
1338 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1339 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1340 }
1341
1342 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1343 struct mm_struct *mm)
1344 {
1345 const struct cred *cred;
1346 unsigned int i, len;
1347
1348 /* first copy the parameters from user space */
1349 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1350
1351 len = mm->arg_end - mm->arg_start;
1352 if (len >= ELF_PRARGSZ)
1353 len = ELF_PRARGSZ-1;
1354 if (copy_from_user(&psinfo->pr_psargs,
1355 (const char __user *)mm->arg_start, len))
1356 return -EFAULT;
1357 for(i = 0; i < len; i++)
1358 if (psinfo->pr_psargs[i] == 0)
1359 psinfo->pr_psargs[i] = ' ';
1360 psinfo->pr_psargs[len] = 0;
1361
1362 rcu_read_lock();
1363 psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1364 rcu_read_unlock();
1365 psinfo->pr_pid = task_pid_vnr(p);
1366 psinfo->pr_pgrp = task_pgrp_vnr(p);
1367 psinfo->pr_sid = task_session_vnr(p);
1368
1369 i = p->state ? ffz(~p->state) + 1 : 0;
1370 psinfo->pr_state = i;
1371 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1372 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1373 psinfo->pr_nice = task_nice(p);
1374 psinfo->pr_flag = p->flags;
1375 rcu_read_lock();
1376 cred = __task_cred(p);
1377 SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1378 SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1379 rcu_read_unlock();
1380 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1381
1382 return 0;
1383 }
1384
1385 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1386 {
1387 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1388 int i = 0;
1389 do
1390 i += 2;
1391 while (auxv[i - 2] != AT_NULL);
1392 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1393 }
1394
1395 static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata,
1396 siginfo_t *siginfo)
1397 {
1398 mm_segment_t old_fs = get_fs();
1399 set_fs(KERNEL_DS);
1400 copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo);
1401 set_fs(old_fs);
1402 fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata);
1403 }
1404
1405 #define MAX_FILE_NOTE_SIZE (4*1024*1024)
1406 /*
1407 * Format of NT_FILE note:
1408 *
1409 * long count -- how many files are mapped
1410 * long page_size -- units for file_ofs
1411 * array of [COUNT] elements of
1412 * long start
1413 * long end
1414 * long file_ofs
1415 * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL...
1416 */
1417 static void fill_files_note(struct memelfnote *note)
1418 {
1419 struct vm_area_struct *vma;
1420 unsigned count, size, names_ofs, remaining, n;
1421 user_long_t *data;
1422 user_long_t *start_end_ofs;
1423 char *name_base, *name_curpos;
1424
1425 /* *Estimated* file count and total data size needed */
1426 count = current->mm->map_count;
1427 size = count * 64;
1428
1429 names_ofs = (2 + 3 * count) * sizeof(data[0]);
1430 alloc:
1431 if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */
1432 goto err;
1433 size = round_up(size, PAGE_SIZE);
1434 data = vmalloc(size);
1435 if (!data)
1436 goto err;
1437
1438 start_end_ofs = data + 2;
1439 name_base = name_curpos = ((char *)data) + names_ofs;
1440 remaining = size - names_ofs;
1441 count = 0;
1442 for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) {
1443 struct file *file;
1444 const char *filename;
1445
1446 file = vma->vm_file;
1447 if (!file)
1448 continue;
1449 filename = d_path(&file->f_path, name_curpos, remaining);
1450 if (IS_ERR(filename)) {
1451 if (PTR_ERR(filename) == -ENAMETOOLONG) {
1452 vfree(data);
1453 size = size * 5 / 4;
1454 goto alloc;
1455 }
1456 continue;
1457 }
1458
1459 /* d_path() fills at the end, move name down */
1460 /* n = strlen(filename) + 1: */
1461 n = (name_curpos + remaining) - filename;
1462 remaining = filename - name_curpos;
1463 memmove(name_curpos, filename, n);
1464 name_curpos += n;
1465
1466 *start_end_ofs++ = vma->vm_start;
1467 *start_end_ofs++ = vma->vm_end;
1468 *start_end_ofs++ = vma->vm_pgoff;
1469 count++;
1470 }
1471
1472 /* Now we know exact count of files, can store it */
1473 data[0] = count;
1474 data[1] = PAGE_SIZE;
1475 /*
1476 * Count usually is less than current->mm->map_count,
1477 * we need to move filenames down.
1478 */
1479 n = current->mm->map_count - count;
1480 if (n != 0) {
1481 unsigned shift_bytes = n * 3 * sizeof(data[0]);
1482 memmove(name_base - shift_bytes, name_base,
1483 name_curpos - name_base);
1484 name_curpos -= shift_bytes;
1485 }
1486
1487 size = name_curpos - (char *)data;
1488 fill_note(note, "CORE", NT_FILE, size, data);
1489 err: ;
1490 }
1491
1492 #ifdef CORE_DUMP_USE_REGSET
1493 #include <linux/regset.h>
1494
1495 struct elf_thread_core_info {
1496 struct elf_thread_core_info *next;
1497 struct task_struct *task;
1498 struct elf_prstatus prstatus;
1499 struct memelfnote notes[0];
1500 };
1501
1502 struct elf_note_info {
1503 struct elf_thread_core_info *thread;
1504 struct memelfnote psinfo;
1505 struct memelfnote signote;
1506 struct memelfnote auxv;
1507 struct memelfnote files;
1508 user_siginfo_t csigdata;
1509 size_t size;
1510 int thread_notes;
1511 };
1512
1513 /*
1514 * When a regset has a writeback hook, we call it on each thread before
1515 * dumping user memory. On register window machines, this makes sure the
1516 * user memory backing the register data is up to date before we read it.
1517 */
1518 static void do_thread_regset_writeback(struct task_struct *task,
1519 const struct user_regset *regset)
1520 {
1521 if (regset->writeback)
1522 regset->writeback(task, regset, 1);
1523 }
1524
1525 #ifndef PR_REG_SIZE
1526 #define PR_REG_SIZE(S) sizeof(S)
1527 #endif
1528
1529 #ifndef PRSTATUS_SIZE
1530 #define PRSTATUS_SIZE(S) sizeof(S)
1531 #endif
1532
1533 #ifndef PR_REG_PTR
1534 #define PR_REG_PTR(S) (&((S)->pr_reg))
1535 #endif
1536
1537 #ifndef SET_PR_FPVALID
1538 #define SET_PR_FPVALID(S, V) ((S)->pr_fpvalid = (V))
1539 #endif
1540
1541 static int fill_thread_core_info(struct elf_thread_core_info *t,
1542 const struct user_regset_view *view,
1543 long signr, size_t *total)
1544 {
1545 unsigned int i;
1546
1547 /*
1548 * NT_PRSTATUS is the one special case, because the regset data
1549 * goes into the pr_reg field inside the note contents, rather
1550 * than being the whole note contents. We fill the reset in here.
1551 * We assume that regset 0 is NT_PRSTATUS.
1552 */
1553 fill_prstatus(&t->prstatus, t->task, signr);
1554 (void) view->regsets[0].get(t->task, &view->regsets[0],
1555 0, PR_REG_SIZE(t->prstatus.pr_reg),
1556 PR_REG_PTR(&t->prstatus), NULL);
1557
1558 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1559 PRSTATUS_SIZE(t->prstatus), &t->prstatus);
1560 *total += notesize(&t->notes[0]);
1561
1562 do_thread_regset_writeback(t->task, &view->regsets[0]);
1563
1564 /*
1565 * Each other regset might generate a note too. For each regset
1566 * that has no core_note_type or is inactive, we leave t->notes[i]
1567 * all zero and we'll know to skip writing it later.
1568 */
1569 for (i = 1; i < view->n; ++i) {
1570 const struct user_regset *regset = &view->regsets[i];
1571 do_thread_regset_writeback(t->task, regset);
1572 if (regset->core_note_type && regset->get &&
1573 (!regset->active || regset->active(t->task, regset))) {
1574 int ret;
1575 size_t size = regset->n * regset->size;
1576 void *data = kmalloc(size, GFP_KERNEL);
1577 if (unlikely(!data))
1578 return 0;
1579 ret = regset->get(t->task, regset,
1580 0, size, data, NULL);
1581 if (unlikely(ret))
1582 kfree(data);
1583 else {
1584 if (regset->core_note_type != NT_PRFPREG)
1585 fill_note(&t->notes[i], "LINUX",
1586 regset->core_note_type,
1587 size, data);
1588 else {
1589 SET_PR_FPVALID(&t->prstatus, 1);
1590 fill_note(&t->notes[i], "CORE",
1591 NT_PRFPREG, size, data);
1592 }
1593 *total += notesize(&t->notes[i]);
1594 }
1595 }
1596 }
1597
1598 return 1;
1599 }
1600
1601 static int fill_note_info(struct elfhdr *elf, int phdrs,
1602 struct elf_note_info *info,
1603 siginfo_t *siginfo, struct pt_regs *regs)
1604 {
1605 struct task_struct *dump_task = current;
1606 const struct user_regset_view *view = task_user_regset_view(dump_task);
1607 struct elf_thread_core_info *t;
1608 struct elf_prpsinfo *psinfo;
1609 struct core_thread *ct;
1610 unsigned int i;
1611
1612 info->size = 0;
1613 info->thread = NULL;
1614
1615 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1616 if (psinfo == NULL) {
1617 info->psinfo.data = NULL; /* So we don't free this wrongly */
1618 return 0;
1619 }
1620
1621 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1622
1623 /*
1624 * Figure out how many notes we're going to need for each thread.
1625 */
1626 info->thread_notes = 0;
1627 for (i = 0; i < view->n; ++i)
1628 if (view->regsets[i].core_note_type != 0)
1629 ++info->thread_notes;
1630
1631 /*
1632 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1633 * since it is our one special case.
1634 */
1635 if (unlikely(info->thread_notes == 0) ||
1636 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1637 WARN_ON(1);
1638 return 0;
1639 }
1640
1641 /*
1642 * Initialize the ELF file header.
1643 */
1644 fill_elf_header(elf, phdrs,
1645 view->e_machine, view->e_flags);
1646
1647 /*
1648 * Allocate a structure for each thread.
1649 */
1650 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1651 t = kzalloc(offsetof(struct elf_thread_core_info,
1652 notes[info->thread_notes]),
1653 GFP_KERNEL);
1654 if (unlikely(!t))
1655 return 0;
1656
1657 t->task = ct->task;
1658 if (ct->task == dump_task || !info->thread) {
1659 t->next = info->thread;
1660 info->thread = t;
1661 } else {
1662 /*
1663 * Make sure to keep the original task at
1664 * the head of the list.
1665 */
1666 t->next = info->thread->next;
1667 info->thread->next = t;
1668 }
1669 }
1670
1671 /*
1672 * Now fill in each thread's information.
1673 */
1674 for (t = info->thread; t != NULL; t = t->next)
1675 if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size))
1676 return 0;
1677
1678 /*
1679 * Fill in the two process-wide notes.
1680 */
1681 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1682 info->size += notesize(&info->psinfo);
1683
1684 fill_siginfo_note(&info->signote, &info->csigdata, siginfo);
1685 info->size += notesize(&info->signote);
1686
1687 fill_auxv_note(&info->auxv, current->mm);
1688 info->size += notesize(&info->auxv);
1689
1690 fill_files_note(&info->files);
1691 info->size += notesize(&info->files);
1692
1693 return 1;
1694 }
1695
1696 static size_t get_note_info_size(struct elf_note_info *info)
1697 {
1698 return info->size;
1699 }
1700
1701 /*
1702 * Write all the notes for each thread. When writing the first thread, the
1703 * process-wide notes are interleaved after the first thread-specific note.
1704 */
1705 static int write_note_info(struct elf_note_info *info,
1706 struct file *file, loff_t *foffset)
1707 {
1708 bool first = 1;
1709 struct elf_thread_core_info *t = info->thread;
1710
1711 do {
1712 int i;
1713
1714 if (!writenote(&t->notes[0], file, foffset))
1715 return 0;
1716
1717 if (first && !writenote(&info->psinfo, file, foffset))
1718 return 0;
1719 if (first && !writenote(&info->signote, file, foffset))
1720 return 0;
1721 if (first && !writenote(&info->auxv, file, foffset))
1722 return 0;
1723 if (first && !writenote(&info->files, file, foffset))
1724 return 0;
1725
1726 for (i = 1; i < info->thread_notes; ++i)
1727 if (t->notes[i].data &&
1728 !writenote(&t->notes[i], file, foffset))
1729 return 0;
1730
1731 first = 0;
1732 t = t->next;
1733 } while (t);
1734
1735 return 1;
1736 }
1737
1738 static void free_note_info(struct elf_note_info *info)
1739 {
1740 struct elf_thread_core_info *threads = info->thread;
1741 while (threads) {
1742 unsigned int i;
1743 struct elf_thread_core_info *t = threads;
1744 threads = t->next;
1745 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1746 for (i = 1; i < info->thread_notes; ++i)
1747 kfree(t->notes[i].data);
1748 kfree(t);
1749 }
1750 kfree(info->psinfo.data);
1751 vfree(info->files.data);
1752 }
1753
1754 #else
1755
1756 /* Here is the structure in which status of each thread is captured. */
1757 struct elf_thread_status
1758 {
1759 struct list_head list;
1760 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1761 elf_fpregset_t fpu; /* NT_PRFPREG */
1762 struct task_struct *thread;
1763 #ifdef ELF_CORE_COPY_XFPREGS
1764 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1765 #endif
1766 struct memelfnote notes[3];
1767 int num_notes;
1768 };
1769
1770 /*
1771 * In order to add the specific thread information for the elf file format,
1772 * we need to keep a linked list of every threads pr_status and then create
1773 * a single section for them in the final core file.
1774 */
1775 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1776 {
1777 int sz = 0;
1778 struct task_struct *p = t->thread;
1779 t->num_notes = 0;
1780
1781 fill_prstatus(&t->prstatus, p, signr);
1782 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1783
1784 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1785 &(t->prstatus));
1786 t->num_notes++;
1787 sz += notesize(&t->notes[0]);
1788
1789 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1790 &t->fpu))) {
1791 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1792 &(t->fpu));
1793 t->num_notes++;
1794 sz += notesize(&t->notes[1]);
1795 }
1796
1797 #ifdef ELF_CORE_COPY_XFPREGS
1798 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1799 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1800 sizeof(t->xfpu), &t->xfpu);
1801 t->num_notes++;
1802 sz += notesize(&t->notes[2]);
1803 }
1804 #endif
1805 return sz;
1806 }
1807
1808 struct elf_note_info {
1809 struct memelfnote *notes;
1810 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1811 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1812 struct list_head thread_list;
1813 elf_fpregset_t *fpu;
1814 #ifdef ELF_CORE_COPY_XFPREGS
1815 elf_fpxregset_t *xfpu;
1816 #endif
1817 user_siginfo_t csigdata;
1818 int thread_status_size;
1819 int numnote;
1820 };
1821
1822 static int elf_note_info_init(struct elf_note_info *info)
1823 {
1824 memset(info, 0, sizeof(*info));
1825 INIT_LIST_HEAD(&info->thread_list);
1826
1827 /* Allocate space for ELF notes */
1828 info->notes = kmalloc(8 * sizeof(struct memelfnote), GFP_KERNEL);
1829 if (!info->notes)
1830 return 0;
1831 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1832 if (!info->psinfo)
1833 return 0;
1834 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1835 if (!info->prstatus)
1836 return 0;
1837 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1838 if (!info->fpu)
1839 return 0;
1840 #ifdef ELF_CORE_COPY_XFPREGS
1841 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1842 if (!info->xfpu)
1843 return 0;
1844 #endif
1845 return 1;
1846 }
1847
1848 static int fill_note_info(struct elfhdr *elf, int phdrs,
1849 struct elf_note_info *info,
1850 siginfo_t *siginfo, struct pt_regs *regs)
1851 {
1852 struct list_head *t;
1853
1854 if (!elf_note_info_init(info))
1855 return 0;
1856
1857 if (siginfo->si_signo) {
1858 struct core_thread *ct;
1859 struct elf_thread_status *ets;
1860
1861 for (ct = current->mm->core_state->dumper.next;
1862 ct; ct = ct->next) {
1863 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1864 if (!ets)
1865 return 0;
1866
1867 ets->thread = ct->task;
1868 list_add(&ets->list, &info->thread_list);
1869 }
1870
1871 list_for_each(t, &info->thread_list) {
1872 int sz;
1873
1874 ets = list_entry(t, struct elf_thread_status, list);
1875 sz = elf_dump_thread_status(siginfo->si_signo, ets);
1876 info->thread_status_size += sz;
1877 }
1878 }
1879 /* now collect the dump for the current */
1880 memset(info->prstatus, 0, sizeof(*info->prstatus));
1881 fill_prstatus(info->prstatus, current, siginfo->si_signo);
1882 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1883
1884 /* Set up header */
1885 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS);
1886
1887 /*
1888 * Set up the notes in similar form to SVR4 core dumps made
1889 * with info from their /proc.
1890 */
1891
1892 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1893 sizeof(*info->prstatus), info->prstatus);
1894 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1895 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1896 sizeof(*info->psinfo), info->psinfo);
1897
1898 fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo);
1899 fill_auxv_note(info->notes + 3, current->mm);
1900 fill_files_note(info->notes + 4);
1901
1902 info->numnote = 5;
1903
1904 /* Try to dump the FPU. */
1905 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1906 info->fpu);
1907 if (info->prstatus->pr_fpvalid)
1908 fill_note(info->notes + info->numnote++,
1909 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1910 #ifdef ELF_CORE_COPY_XFPREGS
1911 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1912 fill_note(info->notes + info->numnote++,
1913 "LINUX", ELF_CORE_XFPREG_TYPE,
1914 sizeof(*info->xfpu), info->xfpu);
1915 #endif
1916
1917 return 1;
1918 }
1919
1920 static size_t get_note_info_size(struct elf_note_info *info)
1921 {
1922 int sz = 0;
1923 int i;
1924
1925 for (i = 0; i < info->numnote; i++)
1926 sz += notesize(info->notes + i);
1927
1928 sz += info->thread_status_size;
1929
1930 return sz;
1931 }
1932
1933 static int write_note_info(struct elf_note_info *info,
1934 struct file *file, loff_t *foffset)
1935 {
1936 int i;
1937 struct list_head *t;
1938
1939 for (i = 0; i < info->numnote; i++)
1940 if (!writenote(info->notes + i, file, foffset))
1941 return 0;
1942
1943 /* write out the thread status notes section */
1944 list_for_each(t, &info->thread_list) {
1945 struct elf_thread_status *tmp =
1946 list_entry(t, struct elf_thread_status, list);
1947
1948 for (i = 0; i < tmp->num_notes; i++)
1949 if (!writenote(&tmp->notes[i], file, foffset))
1950 return 0;
1951 }
1952
1953 return 1;
1954 }
1955
1956 static void free_note_info(struct elf_note_info *info)
1957 {
1958 while (!list_empty(&info->thread_list)) {
1959 struct list_head *tmp = info->thread_list.next;
1960 list_del(tmp);
1961 kfree(list_entry(tmp, struct elf_thread_status, list));
1962 }
1963
1964 /* Free data allocated by fill_files_note(): */
1965 vfree(info->notes[4].data);
1966
1967 kfree(info->prstatus);
1968 kfree(info->psinfo);
1969 kfree(info->notes);
1970 kfree(info->fpu);
1971 #ifdef ELF_CORE_COPY_XFPREGS
1972 kfree(info->xfpu);
1973 #endif
1974 }
1975
1976 #endif
1977
1978 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1979 struct vm_area_struct *gate_vma)
1980 {
1981 struct vm_area_struct *ret = tsk->mm->mmap;
1982
1983 if (ret)
1984 return ret;
1985 return gate_vma;
1986 }
1987 /*
1988 * Helper function for iterating across a vma list. It ensures that the caller
1989 * will visit `gate_vma' prior to terminating the search.
1990 */
1991 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1992 struct vm_area_struct *gate_vma)
1993 {
1994 struct vm_area_struct *ret;
1995
1996 ret = this_vma->vm_next;
1997 if (ret)
1998 return ret;
1999 if (this_vma == gate_vma)
2000 return NULL;
2001 return gate_vma;
2002 }
2003
2004 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
2005 elf_addr_t e_shoff, int segs)
2006 {
2007 elf->e_shoff = e_shoff;
2008 elf->e_shentsize = sizeof(*shdr4extnum);
2009 elf->e_shnum = 1;
2010 elf->e_shstrndx = SHN_UNDEF;
2011
2012 memset(shdr4extnum, 0, sizeof(*shdr4extnum));
2013
2014 shdr4extnum->sh_type = SHT_NULL;
2015 shdr4extnum->sh_size = elf->e_shnum;
2016 shdr4extnum->sh_link = elf->e_shstrndx;
2017 shdr4extnum->sh_info = segs;
2018 }
2019
2020 static size_t elf_core_vma_data_size(struct vm_area_struct *gate_vma,
2021 unsigned long mm_flags)
2022 {
2023 struct vm_area_struct *vma;
2024 size_t size = 0;
2025
2026 for (vma = first_vma(current, gate_vma); vma != NULL;
2027 vma = next_vma(vma, gate_vma))
2028 size += vma_dump_size(vma, mm_flags);
2029 return size;
2030 }
2031
2032 /*
2033 * Actual dumper
2034 *
2035 * This is a two-pass process; first we find the offsets of the bits,
2036 * and then they are actually written out. If we run out of core limit
2037 * we just truncate.
2038 */
2039 static int elf_core_dump(struct coredump_params *cprm)
2040 {
2041 int has_dumped = 0;
2042 mm_segment_t fs;
2043 int segs;
2044 size_t size = 0;
2045 struct vm_area_struct *vma, *gate_vma;
2046 struct elfhdr *elf = NULL;
2047 loff_t offset = 0, dataoff, foffset;
2048 struct elf_note_info info;
2049 struct elf_phdr *phdr4note = NULL;
2050 struct elf_shdr *shdr4extnum = NULL;
2051 Elf_Half e_phnum;
2052 elf_addr_t e_shoff;
2053
2054 /*
2055 * We no longer stop all VM operations.
2056 *
2057 * This is because those proceses that could possibly change map_count
2058 * or the mmap / vma pages are now blocked in do_exit on current
2059 * finishing this core dump.
2060 *
2061 * Only ptrace can touch these memory addresses, but it doesn't change
2062 * the map_count or the pages allocated. So no possibility of crashing
2063 * exists while dumping the mm->vm_next areas to the core file.
2064 */
2065
2066 /* alloc memory for large data structures: too large to be on stack */
2067 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
2068 if (!elf)
2069 goto out;
2070 /*
2071 * The number of segs are recored into ELF header as 16bit value.
2072 * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here.
2073 */
2074 segs = current->mm->map_count;
2075 segs += elf_core_extra_phdrs();
2076
2077 gate_vma = get_gate_vma(current->mm);
2078 if (gate_vma != NULL)
2079 segs++;
2080
2081 /* for notes section */
2082 segs++;
2083
2084 /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
2085 * this, kernel supports extended numbering. Have a look at
2086 * include/linux/elf.h for further information. */
2087 e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
2088
2089 /*
2090 * Collect all the non-memory information about the process for the
2091 * notes. This also sets up the file header.
2092 */
2093 if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs))
2094 goto cleanup;
2095
2096 has_dumped = 1;
2097 current->flags |= PF_DUMPCORE;
2098
2099 fs = get_fs();
2100 set_fs(KERNEL_DS);
2101
2102 offset += sizeof(*elf); /* Elf header */
2103 offset += segs * sizeof(struct elf_phdr); /* Program headers */
2104 foffset = offset;
2105
2106 /* Write notes phdr entry */
2107 {
2108 size_t sz = get_note_info_size(&info);
2109
2110 sz += elf_coredump_extra_notes_size();
2111
2112 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
2113 if (!phdr4note)
2114 goto end_coredump;
2115
2116 fill_elf_note_phdr(phdr4note, sz, offset);
2117 offset += sz;
2118 }
2119
2120 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
2121
2122 offset += elf_core_vma_data_size(gate_vma, cprm->mm_flags);
2123 offset += elf_core_extra_data_size();
2124 e_shoff = offset;
2125
2126 if (e_phnum == PN_XNUM) {
2127 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
2128 if (!shdr4extnum)
2129 goto end_coredump;
2130 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
2131 }
2132
2133 offset = dataoff;
2134
2135 size += sizeof(*elf);
2136 if (size > cprm->limit || !dump_write(cprm->file, elf, sizeof(*elf)))
2137 goto end_coredump;
2138
2139 size += sizeof(*phdr4note);
2140 if (size > cprm->limit
2141 || !dump_write(cprm->file, phdr4note, sizeof(*phdr4note)))
2142 goto end_coredump;
2143
2144 /* Write program headers for segments dump */
2145 for (vma = first_vma(current, gate_vma); vma != NULL;
2146 vma = next_vma(vma, gate_vma)) {
2147 struct elf_phdr phdr;
2148
2149 phdr.p_type = PT_LOAD;
2150 phdr.p_offset = offset;
2151 phdr.p_vaddr = vma->vm_start;
2152 phdr.p_paddr = 0;
2153 phdr.p_filesz = vma_dump_size(vma, cprm->mm_flags);
2154 phdr.p_memsz = vma->vm_end - vma->vm_start;
2155 offset += phdr.p_filesz;
2156 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
2157 if (vma->vm_flags & VM_WRITE)
2158 phdr.p_flags |= PF_W;
2159 if (vma->vm_flags & VM_EXEC)
2160 phdr.p_flags |= PF_X;
2161 phdr.p_align = ELF_EXEC_PAGESIZE;
2162
2163 size += sizeof(phdr);
2164 if (size > cprm->limit
2165 || !dump_write(cprm->file, &phdr, sizeof(phdr)))
2166 goto end_coredump;
2167 }
2168
2169 if (!elf_core_write_extra_phdrs(cprm->file, offset, &size, cprm->limit))
2170 goto end_coredump;
2171
2172 /* write out the notes section */
2173 if (!write_note_info(&info, cprm->file, &foffset))
2174 goto end_coredump;
2175
2176 if (elf_coredump_extra_notes_write(cprm->file, &foffset))
2177 goto end_coredump;
2178
2179 /* Align to page */
2180 if (!dump_seek(cprm->file, dataoff - foffset))
2181 goto end_coredump;
2182
2183 for (vma = first_vma(current, gate_vma); vma != NULL;
2184 vma = next_vma(vma, gate_vma)) {
2185 unsigned long addr;
2186 unsigned long end;
2187
2188 end = vma->vm_start + vma_dump_size(vma, cprm->mm_flags);
2189
2190 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2191 struct page *page;
2192 int stop;
2193
2194 page = get_dump_page(addr);
2195 if (page) {
2196 void *kaddr = kmap(page);
2197 stop = ((size += PAGE_SIZE) > cprm->limit) ||
2198 !dump_write(cprm->file, kaddr,
2199 PAGE_SIZE);
2200 kunmap(page);
2201 page_cache_release(page);
2202 } else
2203 stop = !dump_seek(cprm->file, PAGE_SIZE);
2204 if (stop)
2205 goto end_coredump;
2206 }
2207 }
2208
2209 if (!elf_core_write_extra_data(cprm->file, &size, cprm->limit))
2210 goto end_coredump;
2211
2212 if (e_phnum == PN_XNUM) {
2213 size += sizeof(*shdr4extnum);
2214 if (size > cprm->limit
2215 || !dump_write(cprm->file, shdr4extnum,
2216 sizeof(*shdr4extnum)))
2217 goto end_coredump;
2218 }
2219
2220 end_coredump:
2221 set_fs(fs);
2222
2223 cleanup:
2224 free_note_info(&info);
2225 kfree(shdr4extnum);
2226 kfree(phdr4note);
2227 kfree(elf);
2228 out:
2229 return has_dumped;
2230 }
2231
2232 #endif /* CONFIG_ELF_CORE */
2233
2234 static int __init init_elf_binfmt(void)
2235 {
2236 register_binfmt(&elf_format);
2237 return 0;
2238 }
2239
2240 static void __exit exit_elf_binfmt(void)
2241 {
2242 /* Remove the COFF and ELF loaders. */
2243 unregister_binfmt(&elf_format);
2244 }
2245
2246 core_initcall(init_elf_binfmt);
2247 module_exit(exit_elf_binfmt);
2248 MODULE_LICENSE("GPL");
Linux kernel - Deliverables
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