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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/elf-randomize.h> | |
35 | #include <linux/utsname.h> | |
36 | #include <linux/coredump.h> | |
37 | #include <linux/sched.h> | |
38 | #include <linux/sched/coredump.h> | |
39 | #include <linux/sched/task_stack.h> | |
40 | #include <linux/sched/cputime.h> | |
41 | #include <linux/cred.h> | |
42 | #include <linux/dax.h> | |
43 | #include <linux/uaccess.h> | |
44 | #include <asm/param.h> | |
45 | #include <asm/page.h> | |
46 | ||
47 | #ifndef user_long_t | |
48 | #define user_long_t long | |
49 | #endif | |
50 | #ifndef user_siginfo_t | |
51 | #define user_siginfo_t siginfo_t | |
52 | #endif | |
53 | ||
54 | /* That's for binfmt_elf_fdpic to deal with */ | |
55 | #ifndef elf_check_fdpic | |
56 | #define elf_check_fdpic(ex) false | |
57 | #endif | |
58 | ||
59 | static int load_elf_binary(struct linux_binprm *bprm); | |
60 | static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *, | |
61 | int, int, unsigned long); | |
62 | ||
63 | #ifdef CONFIG_USELIB | |
64 | static int load_elf_library(struct file *); | |
65 | #else | |
66 | #define load_elf_library NULL | |
67 | #endif | |
68 | ||
69 | /* | |
70 | * If we don't support core dumping, then supply a NULL so we | |
71 | * don't even try. | |
72 | */ | |
73 | #ifdef CONFIG_ELF_CORE | |
74 | static int elf_core_dump(struct coredump_params *cprm); | |
75 | #else | |
76 | #define elf_core_dump NULL | |
77 | #endif | |
78 | ||
79 | #if ELF_EXEC_PAGESIZE > PAGE_SIZE | |
80 | #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE | |
81 | #else | |
82 | #define ELF_MIN_ALIGN PAGE_SIZE | |
83 | #endif | |
84 | ||
85 | #ifndef ELF_CORE_EFLAGS | |
86 | #define ELF_CORE_EFLAGS 0 | |
87 | #endif | |
88 | ||
89 | #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1)) | |
90 | #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1)) | |
91 | #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1)) | |
92 | ||
93 | static struct linux_binfmt elf_format = { | |
94 | .module = THIS_MODULE, | |
95 | .load_binary = load_elf_binary, | |
96 | .load_shlib = load_elf_library, | |
97 | .core_dump = elf_core_dump, | |
98 | .min_coredump = ELF_EXEC_PAGESIZE, | |
99 | }; | |
100 | ||
101 | #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE) | |
102 | ||
103 | static int set_brk(unsigned long start, unsigned long end, int prot) | |
104 | { | |
105 | start = ELF_PAGEALIGN(start); | |
106 | end = ELF_PAGEALIGN(end); | |
107 | if (end > start) { | |
108 | /* | |
109 | * Map the last of the bss segment. | |
110 | * If the header is requesting these pages to be | |
111 | * executable, honour that (ppc32 needs this). | |
112 | */ | |
113 | int error = vm_brk_flags(start, end - start, | |
114 | prot & PROT_EXEC ? VM_EXEC : 0); | |
115 | if (error) | |
116 | return error; | |
117 | } | |
118 | current->mm->start_brk = current->mm->brk = end; | |
119 | return 0; | |
120 | } | |
121 | ||
122 | /* We need to explicitly zero any fractional pages | |
123 | after the data section (i.e. bss). This would | |
124 | contain the junk from the file that should not | |
125 | be in memory | |
126 | */ | |
127 | static int padzero(unsigned long elf_bss) | |
128 | { | |
129 | unsigned long nbyte; | |
130 | ||
131 | nbyte = ELF_PAGEOFFSET(elf_bss); | |
132 | if (nbyte) { | |
133 | nbyte = ELF_MIN_ALIGN - nbyte; | |
134 | if (clear_user((void __user *) elf_bss, nbyte)) | |
135 | return -EFAULT; | |
136 | } | |
137 | return 0; | |
138 | } | |
139 | ||
140 | /* Let's use some macros to make this stack manipulation a little clearer */ | |
141 | #ifdef CONFIG_STACK_GROWSUP | |
142 | #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items)) | |
143 | #define STACK_ROUND(sp, items) \ | |
144 | ((15 + (unsigned long) ((sp) + (items))) &~ 15UL) | |
145 | #define STACK_ALLOC(sp, len) ({ \ | |
146 | elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \ | |
147 | old_sp; }) | |
148 | #else | |
149 | #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items)) | |
150 | #define STACK_ROUND(sp, items) \ | |
151 | (((unsigned long) (sp - items)) &~ 15UL) | |
152 | #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; }) | |
153 | #endif | |
154 | ||
155 | #ifndef ELF_BASE_PLATFORM | |
156 | /* | |
157 | * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture. | |
158 | * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value | |
159 | * will be copied to the user stack in the same manner as AT_PLATFORM. | |
160 | */ | |
161 | #define ELF_BASE_PLATFORM NULL | |
162 | #endif | |
163 | ||
164 | static int | |
165 | create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec, | |
166 | unsigned long load_addr, unsigned long interp_load_addr) | |
167 | { | |
168 | unsigned long p = bprm->p; | |
169 | int argc = bprm->argc; | |
170 | int envc = bprm->envc; | |
171 | elf_addr_t __user *sp; | |
172 | elf_addr_t __user *u_platform; | |
173 | elf_addr_t __user *u_base_platform; | |
174 | elf_addr_t __user *u_rand_bytes; | |
175 | const char *k_platform = ELF_PLATFORM; | |
176 | const char *k_base_platform = ELF_BASE_PLATFORM; | |
177 | unsigned char k_rand_bytes[16]; | |
178 | int items; | |
179 | elf_addr_t *elf_info; | |
180 | int ei_index = 0; | |
181 | const struct cred *cred = current_cred(); | |
182 | struct vm_area_struct *vma; | |
183 | ||
184 | /* | |
185 | * In some cases (e.g. Hyper-Threading), we want to avoid L1 | |
186 | * evictions by the processes running on the same package. One | |
187 | * thing we can do is to shuffle the initial stack for them. | |
188 | */ | |
189 | ||
190 | p = arch_align_stack(p); | |
191 | ||
192 | /* | |
193 | * If this architecture has a platform capability string, copy it | |
194 | * to userspace. In some cases (Sparc), this info is impossible | |
195 | * for userspace to get any other way, in others (i386) it is | |
196 | * merely difficult. | |
197 | */ | |
198 | u_platform = NULL; | |
199 | if (k_platform) { | |
200 | size_t len = strlen(k_platform) + 1; | |
201 | ||
202 | u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); | |
203 | if (__copy_to_user(u_platform, k_platform, len)) | |
204 | return -EFAULT; | |
205 | } | |
206 | ||
207 | /* | |
208 | * If this architecture has a "base" platform capability | |
209 | * string, copy it to userspace. | |
210 | */ | |
211 | u_base_platform = NULL; | |
212 | if (k_base_platform) { | |
213 | size_t len = strlen(k_base_platform) + 1; | |
214 | ||
215 | u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len); | |
216 | if (__copy_to_user(u_base_platform, k_base_platform, len)) | |
217 | return -EFAULT; | |
218 | } | |
219 | ||
220 | /* | |
221 | * Generate 16 random bytes for userspace PRNG seeding. | |
222 | */ | |
223 | get_random_bytes(k_rand_bytes, sizeof(k_rand_bytes)); | |
224 | u_rand_bytes = (elf_addr_t __user *) | |
225 | STACK_ALLOC(p, sizeof(k_rand_bytes)); | |
226 | if (__copy_to_user(u_rand_bytes, k_rand_bytes, sizeof(k_rand_bytes))) | |
227 | return -EFAULT; | |
228 | ||
229 | /* Create the ELF interpreter info */ | |
230 | elf_info = (elf_addr_t *)current->mm->saved_auxv; | |
231 | /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */ | |
232 | #define NEW_AUX_ENT(id, val) \ | |
233 | do { \ | |
234 | elf_info[ei_index++] = id; \ | |
235 | elf_info[ei_index++] = val; \ | |
236 | } while (0) | |
237 | ||
238 | #ifdef ARCH_DLINFO | |
239 | /* | |
240 | * ARCH_DLINFO must come first so PPC can do its special alignment of | |
241 | * AUXV. | |
242 | * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in | |
243 | * ARCH_DLINFO changes | |
244 | */ | |
245 | ARCH_DLINFO; | |
246 | #endif | |
247 | NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP); | |
248 | NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE); | |
249 | NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC); | |
250 | NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff); | |
251 | NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr)); | |
252 | NEW_AUX_ENT(AT_PHNUM, exec->e_phnum); | |
253 | NEW_AUX_ENT(AT_BASE, interp_load_addr); | |
254 | NEW_AUX_ENT(AT_FLAGS, 0); | |
255 | NEW_AUX_ENT(AT_ENTRY, exec->e_entry); | |
256 | NEW_AUX_ENT(AT_UID, from_kuid_munged(cred->user_ns, cred->uid)); | |
257 | NEW_AUX_ENT(AT_EUID, from_kuid_munged(cred->user_ns, cred->euid)); | |
258 | NEW_AUX_ENT(AT_GID, from_kgid_munged(cred->user_ns, cred->gid)); | |
259 | NEW_AUX_ENT(AT_EGID, from_kgid_munged(cred->user_ns, cred->egid)); | |
260 | NEW_AUX_ENT(AT_SECURE, bprm->secureexec); | |
261 | NEW_AUX_ENT(AT_RANDOM, (elf_addr_t)(unsigned long)u_rand_bytes); | |
262 | #ifdef ELF_HWCAP2 | |
263 | NEW_AUX_ENT(AT_HWCAP2, ELF_HWCAP2); | |
264 | #endif | |
265 | NEW_AUX_ENT(AT_EXECFN, bprm->exec); | |
266 | if (k_platform) { | |
267 | NEW_AUX_ENT(AT_PLATFORM, | |
268 | (elf_addr_t)(unsigned long)u_platform); | |
269 | } | |
270 | if (k_base_platform) { | |
271 | NEW_AUX_ENT(AT_BASE_PLATFORM, | |
272 | (elf_addr_t)(unsigned long)u_base_platform); | |
273 | } | |
274 | if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) { | |
275 | NEW_AUX_ENT(AT_EXECFD, bprm->interp_data); | |
276 | } | |
277 | #undef NEW_AUX_ENT | |
278 | /* AT_NULL is zero; clear the rest too */ | |
279 | memset(&elf_info[ei_index], 0, | |
280 | sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]); | |
281 | ||
282 | /* And advance past the AT_NULL entry. */ | |
283 | ei_index += 2; | |
284 | ||
285 | sp = STACK_ADD(p, ei_index); | |
286 | ||
287 | items = (argc + 1) + (envc + 1) + 1; | |
288 | bprm->p = STACK_ROUND(sp, items); | |
289 | ||
290 | /* Point sp at the lowest address on the stack */ | |
291 | #ifdef CONFIG_STACK_GROWSUP | |
292 | sp = (elf_addr_t __user *)bprm->p - items - ei_index; | |
293 | bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */ | |
294 | #else | |
295 | sp = (elf_addr_t __user *)bprm->p; | |
296 | #endif | |
297 | ||
298 | ||
299 | /* | |
300 | * Grow the stack manually; some architectures have a limit on how | |
301 | * far ahead a user-space access may be in order to grow the stack. | |
302 | */ | |
303 | vma = find_extend_vma(current->mm, bprm->p); | |
304 | if (!vma) | |
305 | return -EFAULT; | |
306 | ||
307 | /* Now, let's put argc (and argv, envp if appropriate) on the stack */ | |
308 | if (__put_user(argc, sp++)) | |
309 | return -EFAULT; | |
310 | ||
311 | /* Populate list of argv pointers back to argv strings. */ | |
312 | p = current->mm->arg_end = current->mm->arg_start; | |
313 | while (argc-- > 0) { | |
314 | size_t len; | |
315 | if (__put_user((elf_addr_t)p, sp++)) | |
316 | return -EFAULT; | |
317 | len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); | |
318 | if (!len || len > MAX_ARG_STRLEN) | |
319 | return -EINVAL; | |
320 | p += len; | |
321 | } | |
322 | if (__put_user(0, sp++)) | |
323 | return -EFAULT; | |
324 | current->mm->arg_end = p; | |
325 | ||
326 | /* Populate list of envp pointers back to envp strings. */ | |
327 | current->mm->env_end = current->mm->env_start = p; | |
328 | while (envc-- > 0) { | |
329 | size_t len; | |
330 | if (__put_user((elf_addr_t)p, sp++)) | |
331 | return -EFAULT; | |
332 | len = strnlen_user((void __user *)p, MAX_ARG_STRLEN); | |
333 | if (!len || len > MAX_ARG_STRLEN) | |
334 | return -EINVAL; | |
335 | p += len; | |
336 | } | |
337 | if (__put_user(0, sp++)) | |
338 | return -EFAULT; | |
339 | current->mm->env_end = p; | |
340 | ||
341 | /* Put the elf_info on the stack in the right place. */ | |
342 | if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t))) | |
343 | return -EFAULT; | |
344 | return 0; | |
345 | } | |
346 | ||
347 | #ifndef elf_map | |
348 | ||
349 | static unsigned long elf_map(struct file *filep, unsigned long addr, | |
350 | struct elf_phdr *eppnt, int prot, int type, | |
351 | unsigned long total_size) | |
352 | { | |
353 | unsigned long map_addr; | |
354 | unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr); | |
355 | unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr); | |
356 | addr = ELF_PAGESTART(addr); | |
357 | size = ELF_PAGEALIGN(size); | |
358 | ||
359 | /* mmap() will return -EINVAL if given a zero size, but a | |
360 | * segment with zero filesize is perfectly valid */ | |
361 | if (!size) | |
362 | return addr; | |
363 | ||
364 | /* | |
365 | * total_size is the size of the ELF (interpreter) image. | |
366 | * The _first_ mmap needs to know the full size, otherwise | |
367 | * randomization might put this image into an overlapping | |
368 | * position with the ELF binary image. (since size < total_size) | |
369 | * So we first map the 'big' image - and unmap the remainder at | |
370 | * the end. (which unmap is needed for ELF images with holes.) | |
371 | */ | |
372 | if (total_size) { | |
373 | total_size = ELF_PAGEALIGN(total_size); | |
374 | map_addr = vm_mmap(filep, addr, total_size, prot, type, off); | |
375 | if (!BAD_ADDR(map_addr)) | |
376 | vm_munmap(map_addr+size, total_size-size); | |
377 | } else | |
378 | map_addr = vm_mmap(filep, addr, size, prot, type, off); | |
379 | ||
380 | if ((type & MAP_FIXED_NOREPLACE) && | |
381 | PTR_ERR((void *)map_addr) == -EEXIST) | |
382 | pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n", | |
383 | task_pid_nr(current), current->comm, (void *)addr); | |
384 | ||
385 | return(map_addr); | |
386 | } | |
387 | ||
388 | #endif /* !elf_map */ | |
389 | ||
390 | static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr) | |
391 | { | |
392 | int i, first_idx = -1, last_idx = -1; | |
393 | ||
394 | for (i = 0; i < nr; i++) { | |
395 | if (cmds[i].p_type == PT_LOAD) { | |
396 | last_idx = i; | |
397 | if (first_idx == -1) | |
398 | first_idx = i; | |
399 | } | |
400 | } | |
401 | if (first_idx == -1) | |
402 | return 0; | |
403 | ||
404 | return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz - | |
405 | ELF_PAGESTART(cmds[first_idx].p_vaddr); | |
406 | } | |
407 | ||
408 | /** | |
409 | * load_elf_phdrs() - load ELF program headers | |
410 | * @elf_ex: ELF header of the binary whose program headers should be loaded | |
411 | * @elf_file: the opened ELF binary file | |
412 | * | |
413 | * Loads ELF program headers from the binary file elf_file, which has the ELF | |
414 | * header pointed to by elf_ex, into a newly allocated array. The caller is | |
415 | * responsible for freeing the allocated data. Returns an ERR_PTR upon failure. | |
416 | */ | |
417 | static struct elf_phdr *load_elf_phdrs(struct elfhdr *elf_ex, | |
418 | struct file *elf_file) | |
419 | { | |
420 | struct elf_phdr *elf_phdata = NULL; | |
421 | int retval, size, err = -1; | |
422 | loff_t pos = elf_ex->e_phoff; | |
423 | ||
424 | /* | |
425 | * If the size of this structure has changed, then punt, since | |
426 | * we will be doing the wrong thing. | |
427 | */ | |
428 | if (elf_ex->e_phentsize != sizeof(struct elf_phdr)) | |
429 | goto out; | |
430 | ||
431 | /* Sanity check the number of program headers... */ | |
432 | if (elf_ex->e_phnum < 1 || | |
433 | elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr)) | |
434 | goto out; | |
435 | ||
436 | /* ...and their total size. */ | |
437 | size = sizeof(struct elf_phdr) * elf_ex->e_phnum; | |
438 | if (size > ELF_MIN_ALIGN) | |
439 | goto out; | |
440 | ||
441 | elf_phdata = kmalloc(size, GFP_KERNEL); | |
442 | if (!elf_phdata) | |
443 | goto out; | |
444 | ||
445 | /* Read in the program headers */ | |
446 | retval = kernel_read(elf_file, elf_phdata, size, &pos); | |
447 | if (retval != size) { | |
448 | err = (retval < 0) ? retval : -EIO; | |
449 | goto out; | |
450 | } | |
451 | ||
452 | /* Success! */ | |
453 | err = 0; | |
454 | out: | |
455 | if (err) { | |
456 | kfree(elf_phdata); | |
457 | elf_phdata = NULL; | |
458 | } | |
459 | return elf_phdata; | |
460 | } | |
461 | ||
462 | #ifndef CONFIG_ARCH_BINFMT_ELF_STATE | |
463 | ||
464 | /** | |
465 | * struct arch_elf_state - arch-specific ELF loading state | |
466 | * | |
467 | * This structure is used to preserve architecture specific data during | |
468 | * the loading of an ELF file, throughout the checking of architecture | |
469 | * specific ELF headers & through to the point where the ELF load is | |
470 | * known to be proceeding (ie. SET_PERSONALITY). | |
471 | * | |
472 | * This implementation is a dummy for architectures which require no | |
473 | * specific state. | |
474 | */ | |
475 | struct arch_elf_state { | |
476 | }; | |
477 | ||
478 | #define INIT_ARCH_ELF_STATE {} | |
479 | ||
480 | /** | |
481 | * arch_elf_pt_proc() - check a PT_LOPROC..PT_HIPROC ELF program header | |
482 | * @ehdr: The main ELF header | |
483 | * @phdr: The program header to check | |
484 | * @elf: The open ELF file | |
485 | * @is_interp: True if the phdr is from the interpreter of the ELF being | |
486 | * loaded, else false. | |
487 | * @state: Architecture-specific state preserved throughout the process | |
488 | * of loading the ELF. | |
489 | * | |
490 | * Inspects the program header phdr to validate its correctness and/or | |
491 | * suitability for the system. Called once per ELF program header in the | |
492 | * range PT_LOPROC to PT_HIPROC, for both the ELF being loaded and its | |
493 | * interpreter. | |
494 | * | |
495 | * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load | |
496 | * with that return code. | |
497 | */ | |
498 | static inline int arch_elf_pt_proc(struct elfhdr *ehdr, | |
499 | struct elf_phdr *phdr, | |
500 | struct file *elf, bool is_interp, | |
501 | struct arch_elf_state *state) | |
502 | { | |
503 | /* Dummy implementation, always proceed */ | |
504 | return 0; | |
505 | } | |
506 | ||
507 | /** | |
508 | * arch_check_elf() - check an ELF executable | |
509 | * @ehdr: The main ELF header | |
510 | * @has_interp: True if the ELF has an interpreter, else false. | |
511 | * @interp_ehdr: The interpreter's ELF header | |
512 | * @state: Architecture-specific state preserved throughout the process | |
513 | * of loading the ELF. | |
514 | * | |
515 | * Provides a final opportunity for architecture code to reject the loading | |
516 | * of the ELF & cause an exec syscall to return an error. This is called after | |
517 | * all program headers to be checked by arch_elf_pt_proc have been. | |
518 | * | |
519 | * Return: Zero to proceed with the ELF load, non-zero to fail the ELF load | |
520 | * with that return code. | |
521 | */ | |
522 | static inline int arch_check_elf(struct elfhdr *ehdr, bool has_interp, | |
523 | struct elfhdr *interp_ehdr, | |
524 | struct arch_elf_state *state) | |
525 | { | |
526 | /* Dummy implementation, always proceed */ | |
527 | return 0; | |
528 | } | |
529 | ||
530 | #endif /* !CONFIG_ARCH_BINFMT_ELF_STATE */ | |
531 | ||
532 | /* This is much more generalized than the library routine read function, | |
533 | so we keep this separate. Technically the library read function | |
534 | is only provided so that we can read a.out libraries that have | |
535 | an ELF header */ | |
536 | ||
537 | static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex, | |
538 | struct file *interpreter, unsigned long *interp_map_addr, | |
539 | unsigned long no_base, struct elf_phdr *interp_elf_phdata) | |
540 | { | |
541 | struct elf_phdr *eppnt; | |
542 | unsigned long load_addr = 0; | |
543 | int load_addr_set = 0; | |
544 | unsigned long last_bss = 0, elf_bss = 0; | |
545 | int bss_prot = 0; | |
546 | unsigned long error = ~0UL; | |
547 | unsigned long total_size; | |
548 | int i; | |
549 | ||
550 | /* First of all, some simple consistency checks */ | |
551 | if (interp_elf_ex->e_type != ET_EXEC && | |
552 | interp_elf_ex->e_type != ET_DYN) | |
553 | goto out; | |
554 | if (!elf_check_arch(interp_elf_ex) || | |
555 | elf_check_fdpic(interp_elf_ex)) | |
556 | goto out; | |
557 | if (!interpreter->f_op->mmap) | |
558 | goto out; | |
559 | ||
560 | total_size = total_mapping_size(interp_elf_phdata, | |
561 | interp_elf_ex->e_phnum); | |
562 | if (!total_size) { | |
563 | error = -EINVAL; | |
564 | goto out; | |
565 | } | |
566 | ||
567 | eppnt = interp_elf_phdata; | |
568 | for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) { | |
569 | if (eppnt->p_type == PT_LOAD) { | |
570 | int elf_type = MAP_PRIVATE | MAP_DENYWRITE; | |
571 | int elf_prot = 0; | |
572 | unsigned long vaddr = 0; | |
573 | unsigned long k, map_addr; | |
574 | ||
575 | if (eppnt->p_flags & PF_R) | |
576 | elf_prot = PROT_READ; | |
577 | if (eppnt->p_flags & PF_W) | |
578 | elf_prot |= PROT_WRITE; | |
579 | if (eppnt->p_flags & PF_X) | |
580 | elf_prot |= PROT_EXEC; | |
581 | vaddr = eppnt->p_vaddr; | |
582 | if (interp_elf_ex->e_type == ET_EXEC || load_addr_set) | |
583 | elf_type |= MAP_FIXED_NOREPLACE; | |
584 | else if (no_base && interp_elf_ex->e_type == ET_DYN) | |
585 | load_addr = -vaddr; | |
586 | ||
587 | map_addr = elf_map(interpreter, load_addr + vaddr, | |
588 | eppnt, elf_prot, elf_type, total_size); | |
589 | total_size = 0; | |
590 | if (!*interp_map_addr) | |
591 | *interp_map_addr = map_addr; | |
592 | error = map_addr; | |
593 | if (BAD_ADDR(map_addr)) | |
594 | goto out; | |
595 | ||
596 | if (!load_addr_set && | |
597 | interp_elf_ex->e_type == ET_DYN) { | |
598 | load_addr = map_addr - ELF_PAGESTART(vaddr); | |
599 | load_addr_set = 1; | |
600 | } | |
601 | ||
602 | /* | |
603 | * Check to see if the section's size will overflow the | |
604 | * allowed task size. Note that p_filesz must always be | |
605 | * <= p_memsize so it's only necessary to check p_memsz. | |
606 | */ | |
607 | k = load_addr + eppnt->p_vaddr; | |
608 | if (BAD_ADDR(k) || | |
609 | eppnt->p_filesz > eppnt->p_memsz || | |
610 | eppnt->p_memsz > TASK_SIZE || | |
611 | TASK_SIZE - eppnt->p_memsz < k) { | |
612 | error = -ENOMEM; | |
613 | goto out; | |
614 | } | |
615 | ||
616 | /* | |
617 | * Find the end of the file mapping for this phdr, and | |
618 | * keep track of the largest address we see for this. | |
619 | */ | |
620 | k = load_addr + eppnt->p_vaddr + eppnt->p_filesz; | |
621 | if (k > elf_bss) | |
622 | elf_bss = k; | |
623 | ||
624 | /* | |
625 | * Do the same thing for the memory mapping - between | |
626 | * elf_bss and last_bss is the bss section. | |
627 | */ | |
628 | k = load_addr + eppnt->p_vaddr + eppnt->p_memsz; | |
629 | if (k > last_bss) { | |
630 | last_bss = k; | |
631 | bss_prot = elf_prot; | |
632 | } | |
633 | } | |
634 | } | |
635 | ||
636 | /* | |
637 | * Now fill out the bss section: first pad the last page from | |
638 | * the file up to the page boundary, and zero it from elf_bss | |
639 | * up to the end of the page. | |
640 | */ | |
641 | if (padzero(elf_bss)) { | |
642 | error = -EFAULT; | |
643 | goto out; | |
644 | } | |
645 | /* | |
646 | * Next, align both the file and mem bss up to the page size, | |
647 | * since this is where elf_bss was just zeroed up to, and where | |
648 | * last_bss will end after the vm_brk_flags() below. | |
649 | */ | |
650 | elf_bss = ELF_PAGEALIGN(elf_bss); | |
651 | last_bss = ELF_PAGEALIGN(last_bss); | |
652 | /* Finally, if there is still more bss to allocate, do it. */ | |
653 | if (last_bss > elf_bss) { | |
654 | error = vm_brk_flags(elf_bss, last_bss - elf_bss, | |
655 | bss_prot & PROT_EXEC ? VM_EXEC : 0); | |
656 | if (error) | |
657 | goto out; | |
658 | } | |
659 | ||
660 | error = load_addr; | |
661 | out: | |
662 | return error; | |
663 | } | |
664 | ||
665 | /* | |
666 | * These are the functions used to load ELF style executables and shared | |
667 | * libraries. There is no binary dependent code anywhere else. | |
668 | */ | |
669 | ||
670 | #ifndef STACK_RND_MASK | |
671 | #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */ | |
672 | #endif | |
673 | ||
674 | static unsigned long randomize_stack_top(unsigned long stack_top) | |
675 | { | |
676 | unsigned long random_variable = 0; | |
677 | ||
678 | if (current->flags & PF_RANDOMIZE) { | |
679 | random_variable = get_random_long(); | |
680 | random_variable &= STACK_RND_MASK; | |
681 | random_variable <<= PAGE_SHIFT; | |
682 | } | |
683 | #ifdef CONFIG_STACK_GROWSUP | |
684 | return PAGE_ALIGN(stack_top) + random_variable; | |
685 | #else | |
686 | return PAGE_ALIGN(stack_top) - random_variable; | |
687 | #endif | |
688 | } | |
689 | ||
690 | static int load_elf_binary(struct linux_binprm *bprm) | |
691 | { | |
692 | struct file *interpreter = NULL; /* to shut gcc up */ | |
693 | unsigned long load_addr = 0, load_bias = 0; | |
694 | int load_addr_set = 0; | |
695 | char * elf_interpreter = NULL; | |
696 | unsigned long error; | |
697 | struct elf_phdr *elf_ppnt, *elf_phdata, *interp_elf_phdata = NULL; | |
698 | unsigned long elf_bss, elf_brk; | |
699 | int bss_prot = 0; | |
700 | int retval, i; | |
701 | unsigned long elf_entry; | |
702 | unsigned long interp_load_addr = 0; | |
703 | unsigned long start_code, end_code, start_data, end_data; | |
704 | unsigned long reloc_func_desc __maybe_unused = 0; | |
705 | int executable_stack = EXSTACK_DEFAULT; | |
706 | struct pt_regs *regs = current_pt_regs(); | |
707 | struct { | |
708 | struct elfhdr elf_ex; | |
709 | struct elfhdr interp_elf_ex; | |
710 | } *loc; | |
711 | struct arch_elf_state arch_state = INIT_ARCH_ELF_STATE; | |
712 | loff_t pos; | |
713 | ||
714 | loc = kmalloc(sizeof(*loc), GFP_KERNEL); | |
715 | if (!loc) { | |
716 | retval = -ENOMEM; | |
717 | goto out_ret; | |
718 | } | |
719 | ||
720 | /* Get the exec-header */ | |
721 | loc->elf_ex = *((struct elfhdr *)bprm->buf); | |
722 | ||
723 | retval = -ENOEXEC; | |
724 | /* First of all, some simple consistency checks */ | |
725 | if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0) | |
726 | goto out; | |
727 | ||
728 | if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN) | |
729 | goto out; | |
730 | if (!elf_check_arch(&loc->elf_ex)) | |
731 | goto out; | |
732 | if (elf_check_fdpic(&loc->elf_ex)) | |
733 | goto out; | |
734 | if (!bprm->file->f_op->mmap) | |
735 | goto out; | |
736 | ||
737 | elf_phdata = load_elf_phdrs(&loc->elf_ex, bprm->file); | |
738 | if (!elf_phdata) | |
739 | goto out; | |
740 | ||
741 | elf_ppnt = elf_phdata; | |
742 | elf_bss = 0; | |
743 | elf_brk = 0; | |
744 | ||
745 | start_code = ~0UL; | |
746 | end_code = 0; | |
747 | start_data = 0; | |
748 | end_data = 0; | |
749 | ||
750 | for (i = 0; i < loc->elf_ex.e_phnum; i++) { | |
751 | if (elf_ppnt->p_type == PT_INTERP) { | |
752 | /* This is the program interpreter used for | |
753 | * shared libraries - for now assume that this | |
754 | * is an a.out format binary | |
755 | */ | |
756 | retval = -ENOEXEC; | |
757 | if (elf_ppnt->p_filesz > PATH_MAX || | |
758 | elf_ppnt->p_filesz < 2) | |
759 | goto out_free_ph; | |
760 | ||
761 | retval = -ENOMEM; | |
762 | elf_interpreter = kmalloc(elf_ppnt->p_filesz, | |
763 | GFP_KERNEL); | |
764 | if (!elf_interpreter) | |
765 | goto out_free_ph; | |
766 | ||
767 | pos = elf_ppnt->p_offset; | |
768 | retval = kernel_read(bprm->file, elf_interpreter, | |
769 | elf_ppnt->p_filesz, &pos); | |
770 | if (retval != elf_ppnt->p_filesz) { | |
771 | if (retval >= 0) | |
772 | retval = -EIO; | |
773 | goto out_free_interp; | |
774 | } | |
775 | /* make sure path is NULL terminated */ | |
776 | retval = -ENOEXEC; | |
777 | if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0') | |
778 | goto out_free_interp; | |
779 | ||
780 | interpreter = open_exec(elf_interpreter); | |
781 | retval = PTR_ERR(interpreter); | |
782 | if (IS_ERR(interpreter)) | |
783 | goto out_free_interp; | |
784 | ||
785 | /* | |
786 | * If the binary is not readable then enforce | |
787 | * mm->dumpable = 0 regardless of the interpreter's | |
788 | * permissions. | |
789 | */ | |
790 | would_dump(bprm, interpreter); | |
791 | ||
792 | /* Get the exec headers */ | |
793 | pos = 0; | |
794 | retval = kernel_read(interpreter, &loc->interp_elf_ex, | |
795 | sizeof(loc->interp_elf_ex), &pos); | |
796 | if (retval != sizeof(loc->interp_elf_ex)) { | |
797 | if (retval >= 0) | |
798 | retval = -EIO; | |
799 | goto out_free_dentry; | |
800 | } | |
801 | ||
802 | break; | |
803 | } | |
804 | elf_ppnt++; | |
805 | } | |
806 | ||
807 | elf_ppnt = elf_phdata; | |
808 | for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++) | |
809 | switch (elf_ppnt->p_type) { | |
810 | case PT_GNU_STACK: | |
811 | if (elf_ppnt->p_flags & PF_X) | |
812 | executable_stack = EXSTACK_ENABLE_X; | |
813 | else | |
814 | executable_stack = EXSTACK_DISABLE_X; | |
815 | break; | |
816 | ||
817 | case PT_LOPROC ... PT_HIPROC: | |
818 | retval = arch_elf_pt_proc(&loc->elf_ex, elf_ppnt, | |
819 | bprm->file, false, | |
820 | &arch_state); | |
821 | if (retval) | |
822 | goto out_free_dentry; | |
823 | break; | |
824 | } | |
825 | ||
826 | /* Some simple consistency checks for the interpreter */ | |
827 | if (elf_interpreter) { | |
828 | retval = -ELIBBAD; | |
829 | /* Not an ELF interpreter */ | |
830 | if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0) | |
831 | goto out_free_dentry; | |
832 | /* Verify the interpreter has a valid arch */ | |
833 | if (!elf_check_arch(&loc->interp_elf_ex) || | |
834 | elf_check_fdpic(&loc->interp_elf_ex)) | |
835 | goto out_free_dentry; | |
836 | ||
837 | /* Load the interpreter program headers */ | |
838 | interp_elf_phdata = load_elf_phdrs(&loc->interp_elf_ex, | |
839 | interpreter); | |
840 | if (!interp_elf_phdata) | |
841 | goto out_free_dentry; | |
842 | ||
843 | /* Pass PT_LOPROC..PT_HIPROC headers to arch code */ | |
844 | elf_ppnt = interp_elf_phdata; | |
845 | for (i = 0; i < loc->interp_elf_ex.e_phnum; i++, elf_ppnt++) | |
846 | switch (elf_ppnt->p_type) { | |
847 | case PT_LOPROC ... PT_HIPROC: | |
848 | retval = arch_elf_pt_proc(&loc->interp_elf_ex, | |
849 | elf_ppnt, interpreter, | |
850 | true, &arch_state); | |
851 | if (retval) | |
852 | goto out_free_dentry; | |
853 | break; | |
854 | } | |
855 | } | |
856 | ||
857 | /* | |
858 | * Allow arch code to reject the ELF at this point, whilst it's | |
859 | * still possible to return an error to the code that invoked | |
860 | * the exec syscall. | |
861 | */ | |
862 | retval = arch_check_elf(&loc->elf_ex, | |
863 | !!interpreter, &loc->interp_elf_ex, | |
864 | &arch_state); | |
865 | if (retval) | |
866 | goto out_free_dentry; | |
867 | ||
868 | /* Flush all traces of the currently running executable */ | |
869 | retval = flush_old_exec(bprm); | |
870 | if (retval) | |
871 | goto out_free_dentry; | |
872 | ||
873 | /* Do this immediately, since STACK_TOP as used in setup_arg_pages | |
874 | may depend on the personality. */ | |
875 | SET_PERSONALITY2(loc->elf_ex, &arch_state); | |
876 | if (elf_read_implies_exec(loc->elf_ex, executable_stack)) | |
877 | current->personality |= READ_IMPLIES_EXEC; | |
878 | ||
879 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) | |
880 | current->flags |= PF_RANDOMIZE; | |
881 | ||
882 | setup_new_exec(bprm); | |
883 | install_exec_creds(bprm); | |
884 | ||
885 | /* Do this so that we can load the interpreter, if need be. We will | |
886 | change some of these later */ | |
887 | retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP), | |
888 | executable_stack); | |
889 | if (retval < 0) | |
890 | goto out_free_dentry; | |
891 | ||
892 | current->mm->start_stack = bprm->p; | |
893 | ||
894 | /* Now we do a little grungy work by mmapping the ELF image into | |
895 | the correct location in memory. */ | |
896 | for(i = 0, elf_ppnt = elf_phdata; | |
897 | i < loc->elf_ex.e_phnum; i++, elf_ppnt++) { | |
898 | int elf_prot = 0, elf_flags, elf_fixed = MAP_FIXED_NOREPLACE; | |
899 | unsigned long k, vaddr; | |
900 | unsigned long total_size = 0; | |
901 | ||
902 | if (elf_ppnt->p_type != PT_LOAD) | |
903 | continue; | |
904 | ||
905 | if (unlikely (elf_brk > elf_bss)) { | |
906 | unsigned long nbyte; | |
907 | ||
908 | /* There was a PT_LOAD segment with p_memsz > p_filesz | |
909 | before this one. Map anonymous pages, if needed, | |
910 | and clear the area. */ | |
911 | retval = set_brk(elf_bss + load_bias, | |
912 | elf_brk + load_bias, | |
913 | bss_prot); | |
914 | if (retval) | |
915 | goto out_free_dentry; | |
916 | nbyte = ELF_PAGEOFFSET(elf_bss); | |
917 | if (nbyte) { | |
918 | nbyte = ELF_MIN_ALIGN - nbyte; | |
919 | if (nbyte > elf_brk - elf_bss) | |
920 | nbyte = elf_brk - elf_bss; | |
921 | if (clear_user((void __user *)elf_bss + | |
922 | load_bias, nbyte)) { | |
923 | /* | |
924 | * This bss-zeroing can fail if the ELF | |
925 | * file specifies odd protections. So | |
926 | * we don't check the return value | |
927 | */ | |
928 | } | |
929 | } | |
930 | ||
931 | /* | |
932 | * Some binaries have overlapping elf segments and then | |
933 | * we have to forcefully map over an existing mapping | |
934 | * e.g. over this newly established brk mapping. | |
935 | */ | |
936 | elf_fixed = MAP_FIXED; | |
937 | } | |
938 | ||
939 | if (elf_ppnt->p_flags & PF_R) | |
940 | elf_prot |= PROT_READ; | |
941 | if (elf_ppnt->p_flags & PF_W) | |
942 | elf_prot |= PROT_WRITE; | |
943 | if (elf_ppnt->p_flags & PF_X) | |
944 | elf_prot |= PROT_EXEC; | |
945 | ||
946 | elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE; | |
947 | ||
948 | vaddr = elf_ppnt->p_vaddr; | |
949 | /* | |
950 | * If we are loading ET_EXEC or we have already performed | |
951 | * the ET_DYN load_addr calculations, proceed normally. | |
952 | */ | |
953 | if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) { | |
954 | elf_flags |= elf_fixed; | |
955 | } else if (loc->elf_ex.e_type == ET_DYN) { | |
956 | /* | |
957 | * This logic is run once for the first LOAD Program | |
958 | * Header for ET_DYN binaries to calculate the | |
959 | * randomization (load_bias) for all the LOAD | |
960 | * Program Headers, and to calculate the entire | |
961 | * size of the ELF mapping (total_size). (Note that | |
962 | * load_addr_set is set to true later once the | |
963 | * initial mapping is performed.) | |
964 | * | |
965 | * There are effectively two types of ET_DYN | |
966 | * binaries: programs (i.e. PIE: ET_DYN with INTERP) | |
967 | * and loaders (ET_DYN without INTERP, since they | |
968 | * _are_ the ELF interpreter). The loaders must | |
969 | * be loaded away from programs since the program | |
970 | * may otherwise collide with the loader (especially | |
971 | * for ET_EXEC which does not have a randomized | |
972 | * position). For example to handle invocations of | |
973 | * "./ld.so someprog" to test out a new version of | |
974 | * the loader, the subsequent program that the | |
975 | * loader loads must avoid the loader itself, so | |
976 | * they cannot share the same load range. Sufficient | |
977 | * room for the brk must be allocated with the | |
978 | * loader as well, since brk must be available with | |
979 | * the loader. | |
980 | * | |
981 | * Therefore, programs are loaded offset from | |
982 | * ELF_ET_DYN_BASE and loaders are loaded into the | |
983 | * independently randomized mmap region (0 load_bias | |
984 | * without MAP_FIXED). | |
985 | */ | |
986 | if (elf_interpreter) { | |
987 | load_bias = ELF_ET_DYN_BASE; | |
988 | if (current->flags & PF_RANDOMIZE) | |
989 | load_bias += arch_mmap_rnd(); | |
990 | elf_flags |= elf_fixed; | |
991 | } else | |
992 | load_bias = 0; | |
993 | ||
994 | /* | |
995 | * Since load_bias is used for all subsequent loading | |
996 | * calculations, we must lower it by the first vaddr | |
997 | * so that the remaining calculations based on the | |
998 | * ELF vaddrs will be correctly offset. The result | |
999 | * is then page aligned. | |
1000 | */ | |
1001 | load_bias = ELF_PAGESTART(load_bias - vaddr); | |
1002 | ||
1003 | total_size = total_mapping_size(elf_phdata, | |
1004 | loc->elf_ex.e_phnum); | |
1005 | if (!total_size) { | |
1006 | retval = -EINVAL; | |
1007 | goto out_free_dentry; | |
1008 | } | |
1009 | } | |
1010 | ||
1011 | error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt, | |
1012 | elf_prot, elf_flags, total_size); | |
1013 | if (BAD_ADDR(error)) { | |
1014 | retval = IS_ERR((void *)error) ? | |
1015 | PTR_ERR((void*)error) : -EINVAL; | |
1016 | goto out_free_dentry; | |
1017 | } | |
1018 | ||
1019 | if (!load_addr_set) { | |
1020 | load_addr_set = 1; | |
1021 | load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset); | |
1022 | if (loc->elf_ex.e_type == ET_DYN) { | |
1023 | load_bias += error - | |
1024 | ELF_PAGESTART(load_bias + vaddr); | |
1025 | load_addr += load_bias; | |
1026 | reloc_func_desc = load_bias; | |
1027 | } | |
1028 | } | |
1029 | k = elf_ppnt->p_vaddr; | |
1030 | if (k < start_code) | |
1031 | start_code = k; | |
1032 | if (start_data < k) | |
1033 | start_data = k; | |
1034 | ||
1035 | /* | |
1036 | * Check to see if the section's size will overflow the | |
1037 | * allowed task size. Note that p_filesz must always be | |
1038 | * <= p_memsz so it is only necessary to check p_memsz. | |
1039 | */ | |
1040 | if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz || | |
1041 | elf_ppnt->p_memsz > TASK_SIZE || | |
1042 | TASK_SIZE - elf_ppnt->p_memsz < k) { | |
1043 | /* set_brk can never work. Avoid overflows. */ | |
1044 | retval = -EINVAL; | |
1045 | goto out_free_dentry; | |
1046 | } | |
1047 | ||
1048 | k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz; | |
1049 | ||
1050 | if (k > elf_bss) | |
1051 | elf_bss = k; | |
1052 | if ((elf_ppnt->p_flags & PF_X) && end_code < k) | |
1053 | end_code = k; | |
1054 | if (end_data < k) | |
1055 | end_data = k; | |
1056 | k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz; | |
1057 | if (k > elf_brk) { | |
1058 | bss_prot = elf_prot; | |
1059 | elf_brk = k; | |
1060 | } | |
1061 | } | |
1062 | ||
1063 | loc->elf_ex.e_entry += load_bias; | |
1064 | elf_bss += load_bias; | |
1065 | elf_brk += load_bias; | |
1066 | start_code += load_bias; | |
1067 | end_code += load_bias; | |
1068 | start_data += load_bias; | |
1069 | end_data += load_bias; | |
1070 | ||
1071 | /* Calling set_brk effectively mmaps the pages that we need | |
1072 | * for the bss and break sections. We must do this before | |
1073 | * mapping in the interpreter, to make sure it doesn't wind | |
1074 | * up getting placed where the bss needs to go. | |
1075 | */ | |
1076 | retval = set_brk(elf_bss, elf_brk, bss_prot); | |
1077 | if (retval) | |
1078 | goto out_free_dentry; | |
1079 | if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) { | |
1080 | retval = -EFAULT; /* Nobody gets to see this, but.. */ | |
1081 | goto out_free_dentry; | |
1082 | } | |
1083 | ||
1084 | if (elf_interpreter) { | |
1085 | unsigned long interp_map_addr = 0; | |
1086 | ||
1087 | elf_entry = load_elf_interp(&loc->interp_elf_ex, | |
1088 | interpreter, | |
1089 | &interp_map_addr, | |
1090 | load_bias, interp_elf_phdata); | |
1091 | if (!IS_ERR((void *)elf_entry)) { | |
1092 | /* | |
1093 | * load_elf_interp() returns relocation | |
1094 | * adjustment | |
1095 | */ | |
1096 | interp_load_addr = elf_entry; | |
1097 | elf_entry += loc->interp_elf_ex.e_entry; | |
1098 | } | |
1099 | if (BAD_ADDR(elf_entry)) { | |
1100 | retval = IS_ERR((void *)elf_entry) ? | |
1101 | (int)elf_entry : -EINVAL; | |
1102 | goto out_free_dentry; | |
1103 | } | |
1104 | reloc_func_desc = interp_load_addr; | |
1105 | ||
1106 | allow_write_access(interpreter); | |
1107 | fput(interpreter); | |
1108 | kfree(elf_interpreter); | |
1109 | } else { | |
1110 | elf_entry = loc->elf_ex.e_entry; | |
1111 | if (BAD_ADDR(elf_entry)) { | |
1112 | retval = -EINVAL; | |
1113 | goto out_free_dentry; | |
1114 | } | |
1115 | } | |
1116 | ||
1117 | kfree(interp_elf_phdata); | |
1118 | kfree(elf_phdata); | |
1119 | ||
1120 | set_binfmt(&elf_format); | |
1121 | ||
1122 | #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES | |
1123 | retval = arch_setup_additional_pages(bprm, !!elf_interpreter); | |
1124 | if (retval < 0) | |
1125 | goto out; | |
1126 | #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */ | |
1127 | ||
1128 | retval = create_elf_tables(bprm, &loc->elf_ex, | |
1129 | load_addr, interp_load_addr); | |
1130 | if (retval < 0) | |
1131 | goto out; | |
1132 | /* N.B. passed_fileno might not be initialized? */ | |
1133 | current->mm->end_code = end_code; | |
1134 | current->mm->start_code = start_code; | |
1135 | current->mm->start_data = start_data; | |
1136 | current->mm->end_data = end_data; | |
1137 | current->mm->start_stack = bprm->p; | |
1138 | ||
1139 | if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1)) { | |
1140 | current->mm->brk = current->mm->start_brk = | |
1141 | arch_randomize_brk(current->mm); | |
1142 | #ifdef compat_brk_randomized | |
1143 | current->brk_randomized = 1; | |
1144 | #endif | |
1145 | } | |
1146 | ||
1147 | if (current->personality & MMAP_PAGE_ZERO) { | |
1148 | /* Why this, you ask??? Well SVr4 maps page 0 as read-only, | |
1149 | and some applications "depend" upon this behavior. | |
1150 | Since we do not have the power to recompile these, we | |
1151 | emulate the SVr4 behavior. Sigh. */ | |
1152 | error = vm_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC, | |
1153 | MAP_FIXED | MAP_PRIVATE, 0); | |
1154 | } | |
1155 | ||
1156 | #ifdef ELF_PLAT_INIT | |
1157 | /* | |
1158 | * The ABI may specify that certain registers be set up in special | |
1159 | * ways (on i386 %edx is the address of a DT_FINI function, for | |
1160 | * example. In addition, it may also specify (eg, PowerPC64 ELF) | |
1161 | * that the e_entry field is the address of the function descriptor | |
1162 | * for the startup routine, rather than the address of the startup | |
1163 | * routine itself. This macro performs whatever initialization to | |
1164 | * the regs structure is required as well as any relocations to the | |
1165 | * function descriptor entries when executing dynamically links apps. | |
1166 | */ | |
1167 | ELF_PLAT_INIT(regs, reloc_func_desc); | |
1168 | #endif | |
1169 | ||
1170 | finalize_exec(bprm); | |
1171 | start_thread(regs, elf_entry, bprm->p); | |
1172 | retval = 0; | |
1173 | out: | |
1174 | kfree(loc); | |
1175 | out_ret: | |
1176 | return retval; | |
1177 | ||
1178 | /* error cleanup */ | |
1179 | out_free_dentry: | |
1180 | kfree(interp_elf_phdata); | |
1181 | allow_write_access(interpreter); | |
1182 | if (interpreter) | |
1183 | fput(interpreter); | |
1184 | out_free_interp: | |
1185 | kfree(elf_interpreter); | |
1186 | out_free_ph: | |
1187 | kfree(elf_phdata); | |
1188 | goto out; | |
1189 | } | |
1190 | ||
1191 | #ifdef CONFIG_USELIB | |
1192 | /* This is really simpleminded and specialized - we are loading an | |
1193 | a.out library that is given an ELF header. */ | |
1194 | static int load_elf_library(struct file *file) | |
1195 | { | |
1196 | struct elf_phdr *elf_phdata; | |
1197 | struct elf_phdr *eppnt; | |
1198 | unsigned long elf_bss, bss, len; | |
1199 | int retval, error, i, j; | |
1200 | struct elfhdr elf_ex; | |
1201 | loff_t pos = 0; | |
1202 | ||
1203 | error = -ENOEXEC; | |
1204 | retval = kernel_read(file, &elf_ex, sizeof(elf_ex), &pos); | |
1205 | if (retval != sizeof(elf_ex)) | |
1206 | goto out; | |
1207 | ||
1208 | if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0) | |
1209 | goto out; | |
1210 | ||
1211 | /* First of all, some simple consistency checks */ | |
1212 | if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 || | |
1213 | !elf_check_arch(&elf_ex) || !file->f_op->mmap) | |
1214 | goto out; | |
1215 | if (elf_check_fdpic(&elf_ex)) | |
1216 | goto out; | |
1217 | ||
1218 | /* Now read in all of the header information */ | |
1219 | ||
1220 | j = sizeof(struct elf_phdr) * elf_ex.e_phnum; | |
1221 | /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */ | |
1222 | ||
1223 | error = -ENOMEM; | |
1224 | elf_phdata = kmalloc(j, GFP_KERNEL); | |
1225 | if (!elf_phdata) | |
1226 | goto out; | |
1227 | ||
1228 | eppnt = elf_phdata; | |
1229 | error = -ENOEXEC; | |
1230 | pos = elf_ex.e_phoff; | |
1231 | retval = kernel_read(file, eppnt, j, &pos); | |
1232 | if (retval != j) | |
1233 | goto out_free_ph; | |
1234 | ||
1235 | for (j = 0, i = 0; i<elf_ex.e_phnum; i++) | |
1236 | if ((eppnt + i)->p_type == PT_LOAD) | |
1237 | j++; | |
1238 | if (j != 1) | |
1239 | goto out_free_ph; | |
1240 | ||
1241 | while (eppnt->p_type != PT_LOAD) | |
1242 | eppnt++; | |
1243 | ||
1244 | /* Now use mmap to map the library into memory. */ | |
1245 | error = vm_mmap(file, | |
1246 | ELF_PAGESTART(eppnt->p_vaddr), | |
1247 | (eppnt->p_filesz + | |
1248 | ELF_PAGEOFFSET(eppnt->p_vaddr)), | |
1249 | PROT_READ | PROT_WRITE | PROT_EXEC, | |
1250 | MAP_FIXED_NOREPLACE | MAP_PRIVATE | MAP_DENYWRITE, | |
1251 | (eppnt->p_offset - | |
1252 | ELF_PAGEOFFSET(eppnt->p_vaddr))); | |
1253 | if (error != ELF_PAGESTART(eppnt->p_vaddr)) | |
1254 | goto out_free_ph; | |
1255 | ||
1256 | elf_bss = eppnt->p_vaddr + eppnt->p_filesz; | |
1257 | if (padzero(elf_bss)) { | |
1258 | error = -EFAULT; | |
1259 | goto out_free_ph; | |
1260 | } | |
1261 | ||
1262 | len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr + | |
1263 | ELF_MIN_ALIGN - 1); | |
1264 | bss = eppnt->p_memsz + eppnt->p_vaddr; | |
1265 | if (bss > len) { | |
1266 | error = vm_brk(len, bss - len); | |
1267 | if (error) | |
1268 | goto out_free_ph; | |
1269 | } | |
1270 | error = 0; | |
1271 | ||
1272 | out_free_ph: | |
1273 | kfree(elf_phdata); | |
1274 | out: | |
1275 | return error; | |
1276 | } | |
1277 | #endif /* #ifdef CONFIG_USELIB */ | |
1278 | ||
1279 | #ifdef CONFIG_ELF_CORE | |
1280 | /* | |
1281 | * ELF core dumper | |
1282 | * | |
1283 | * Modelled on fs/exec.c:aout_core_dump() | |
1284 | * Jeremy Fitzhardinge <jeremy@sw.oz.au> | |
1285 | */ | |
1286 | ||
1287 | /* | |
1288 | * The purpose of always_dump_vma() is to make sure that special kernel mappings | |
1289 | * that are useful for post-mortem analysis are included in every core dump. | |
1290 | * In that way we ensure that the core dump is fully interpretable later | |
1291 | * without matching up the same kernel and hardware config to see what PC values | |
1292 | * meant. These special mappings include - vDSO, vsyscall, and other | |
1293 | * architecture specific mappings | |
1294 | */ | |
1295 | static bool always_dump_vma(struct vm_area_struct *vma) | |
1296 | { | |
1297 | /* Any vsyscall mappings? */ | |
1298 | if (vma == get_gate_vma(vma->vm_mm)) | |
1299 | return true; | |
1300 | ||
1301 | /* | |
1302 | * Assume that all vmas with a .name op should always be dumped. | |
1303 | * If this changes, a new vm_ops field can easily be added. | |
1304 | */ | |
1305 | if (vma->vm_ops && vma->vm_ops->name && vma->vm_ops->name(vma)) | |
1306 | return true; | |
1307 | ||
1308 | /* | |
1309 | * arch_vma_name() returns non-NULL for special architecture mappings, | |
1310 | * such as vDSO sections. | |
1311 | */ | |
1312 | if (arch_vma_name(vma)) | |
1313 | return true; | |
1314 | ||
1315 | return false; | |
1316 | } | |
1317 | ||
1318 | /* | |
1319 | * Decide what to dump of a segment, part, all or none. | |
1320 | */ | |
1321 | static unsigned long vma_dump_size(struct vm_area_struct *vma, | |
1322 | unsigned long mm_flags) | |
1323 | { | |
1324 | #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type)) | |
1325 | ||
1326 | /* always dump the vdso and vsyscall sections */ | |
1327 | if (always_dump_vma(vma)) | |
1328 | goto whole; | |
1329 | ||
1330 | if (vma->vm_flags & VM_DONTDUMP) | |
1331 | return 0; | |
1332 | ||
1333 | /* support for DAX */ | |
1334 | if (vma_is_dax(vma)) { | |
1335 | if ((vma->vm_flags & VM_SHARED) && FILTER(DAX_SHARED)) | |
1336 | goto whole; | |
1337 | if (!(vma->vm_flags & VM_SHARED) && FILTER(DAX_PRIVATE)) | |
1338 | goto whole; | |
1339 | return 0; | |
1340 | } | |
1341 | ||
1342 | /* Hugetlb memory check */ | |
1343 | if (vma->vm_flags & VM_HUGETLB) { | |
1344 | if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED)) | |
1345 | goto whole; | |
1346 | if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE)) | |
1347 | goto whole; | |
1348 | return 0; | |
1349 | } | |
1350 | ||
1351 | /* Do not dump I/O mapped devices or special mappings */ | |
1352 | if (vma->vm_flags & VM_IO) | |
1353 | return 0; | |
1354 | ||
1355 | /* By default, dump shared memory if mapped from an anonymous file. */ | |
1356 | if (vma->vm_flags & VM_SHARED) { | |
1357 | if (file_inode(vma->vm_file)->i_nlink == 0 ? | |
1358 | FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED)) | |
1359 | goto whole; | |
1360 | return 0; | |
1361 | } | |
1362 | ||
1363 | /* Dump segments that have been written to. */ | |
1364 | if (vma->anon_vma && FILTER(ANON_PRIVATE)) | |
1365 | goto whole; | |
1366 | if (vma->vm_file == NULL) | |
1367 | return 0; | |
1368 | ||
1369 | if (FILTER(MAPPED_PRIVATE)) | |
1370 | goto whole; | |
1371 | ||
1372 | /* | |
1373 | * If this looks like the beginning of a DSO or executable mapping, | |
1374 | * check for an ELF header. If we find one, dump the first page to | |
1375 | * aid in determining what was mapped here. | |
1376 | */ | |
1377 | if (FILTER(ELF_HEADERS) && | |
1378 | vma->vm_pgoff == 0 && (vma->vm_flags & VM_READ)) { | |
1379 | u32 __user *header = (u32 __user *) vma->vm_start; | |
1380 | u32 word; | |
1381 | mm_segment_t fs = get_fs(); | |
1382 | /* | |
1383 | * Doing it this way gets the constant folded by GCC. | |
1384 | */ | |
1385 | union { | |
1386 | u32 cmp; | |
1387 | char elfmag[SELFMAG]; | |
1388 | } magic; | |
1389 | BUILD_BUG_ON(SELFMAG != sizeof word); | |
1390 | magic.elfmag[EI_MAG0] = ELFMAG0; | |
1391 | magic.elfmag[EI_MAG1] = ELFMAG1; | |
1392 | magic.elfmag[EI_MAG2] = ELFMAG2; | |
1393 | magic.elfmag[EI_MAG3] = ELFMAG3; | |
1394 | /* | |
1395 | * Switch to the user "segment" for get_user(), | |
1396 | * then put back what elf_core_dump() had in place. | |
1397 | */ | |
1398 | set_fs(USER_DS); | |
1399 | if (unlikely(get_user(word, header))) | |
1400 | word = 0; | |
1401 | set_fs(fs); | |
1402 | if (word == magic.cmp) | |
1403 | return PAGE_SIZE; | |
1404 | } | |
1405 | ||
1406 | #undef FILTER | |
1407 | ||
1408 | return 0; | |
1409 | ||
1410 | whole: | |
1411 | return vma->vm_end - vma->vm_start; | |
1412 | } | |
1413 | ||
1414 | /* An ELF note in memory */ | |
1415 | struct memelfnote | |
1416 | { | |
1417 | const char *name; | |
1418 | int type; | |
1419 | unsigned int datasz; | |
1420 | void *data; | |
1421 | }; | |
1422 | ||
1423 | static int notesize(struct memelfnote *en) | |
1424 | { | |
1425 | int sz; | |
1426 | ||
1427 | sz = sizeof(struct elf_note); | |
1428 | sz += roundup(strlen(en->name) + 1, 4); | |
1429 | sz += roundup(en->datasz, 4); | |
1430 | ||
1431 | return sz; | |
1432 | } | |
1433 | ||
1434 | static int writenote(struct memelfnote *men, struct coredump_params *cprm) | |
1435 | { | |
1436 | struct elf_note en; | |
1437 | en.n_namesz = strlen(men->name) + 1; | |
1438 | en.n_descsz = men->datasz; | |
1439 | en.n_type = men->type; | |
1440 | ||
1441 | return dump_emit(cprm, &en, sizeof(en)) && | |
1442 | dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) && | |
1443 | dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4); | |
1444 | } | |
1445 | ||
1446 | static void fill_elf_header(struct elfhdr *elf, int segs, | |
1447 | u16 machine, u32 flags) | |
1448 | { | |
1449 | memset(elf, 0, sizeof(*elf)); | |
1450 | ||
1451 | memcpy(elf->e_ident, ELFMAG, SELFMAG); | |
1452 | elf->e_ident[EI_CLASS] = ELF_CLASS; | |
1453 | elf->e_ident[EI_DATA] = ELF_DATA; | |
1454 | elf->e_ident[EI_VERSION] = EV_CURRENT; | |
1455 | elf->e_ident[EI_OSABI] = ELF_OSABI; | |
1456 | ||
1457 | elf->e_type = ET_CORE; | |
1458 | elf->e_machine = machine; | |
1459 | elf->e_version = EV_CURRENT; | |
1460 | elf->e_phoff = sizeof(struct elfhdr); | |
1461 | elf->e_flags = flags; | |
1462 | elf->e_ehsize = sizeof(struct elfhdr); | |
1463 | elf->e_phentsize = sizeof(struct elf_phdr); | |
1464 | elf->e_phnum = segs; | |
1465 | ||
1466 | return; | |
1467 | } | |
1468 | ||
1469 | static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset) | |
1470 | { | |
1471 | phdr->p_type = PT_NOTE; | |
1472 | phdr->p_offset = offset; | |
1473 | phdr->p_vaddr = 0; | |
1474 | phdr->p_paddr = 0; | |
1475 | phdr->p_filesz = sz; | |
1476 | phdr->p_memsz = 0; | |
1477 | phdr->p_flags = 0; | |
1478 | phdr->p_align = 0; | |
1479 | return; | |
1480 | } | |
1481 | ||
1482 | static void fill_note(struct memelfnote *note, const char *name, int type, | |
1483 | unsigned int sz, void *data) | |
1484 | { | |
1485 | note->name = name; | |
1486 | note->type = type; | |
1487 | note->datasz = sz; | |
1488 | note->data = data; | |
1489 | return; | |
1490 | } | |
1491 | ||
1492 | /* | |
1493 | * fill up all the fields in prstatus from the given task struct, except | |
1494 | * registers which need to be filled up separately. | |
1495 | */ | |
1496 | static void fill_prstatus(struct elf_prstatus *prstatus, | |
1497 | struct task_struct *p, long signr) | |
1498 | { | |
1499 | prstatus->pr_info.si_signo = prstatus->pr_cursig = signr; | |
1500 | prstatus->pr_sigpend = p->pending.signal.sig[0]; | |
1501 | prstatus->pr_sighold = p->blocked.sig[0]; | |
1502 | rcu_read_lock(); | |
1503 | prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); | |
1504 | rcu_read_unlock(); | |
1505 | prstatus->pr_pid = task_pid_vnr(p); | |
1506 | prstatus->pr_pgrp = task_pgrp_vnr(p); | |
1507 | prstatus->pr_sid = task_session_vnr(p); | |
1508 | if (thread_group_leader(p)) { | |
1509 | struct task_cputime cputime; | |
1510 | ||
1511 | /* | |
1512 | * This is the record for the group leader. It shows the | |
1513 | * group-wide total, not its individual thread total. | |
1514 | */ | |
1515 | thread_group_cputime(p, &cputime); | |
1516 | prstatus->pr_utime = ns_to_timeval(cputime.utime); | |
1517 | prstatus->pr_stime = ns_to_timeval(cputime.stime); | |
1518 | } else { | |
1519 | u64 utime, stime; | |
1520 | ||
1521 | task_cputime(p, &utime, &stime); | |
1522 | prstatus->pr_utime = ns_to_timeval(utime); | |
1523 | prstatus->pr_stime = ns_to_timeval(stime); | |
1524 | } | |
1525 | ||
1526 | prstatus->pr_cutime = ns_to_timeval(p->signal->cutime); | |
1527 | prstatus->pr_cstime = ns_to_timeval(p->signal->cstime); | |
1528 | } | |
1529 | ||
1530 | static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p, | |
1531 | struct mm_struct *mm) | |
1532 | { | |
1533 | const struct cred *cred; | |
1534 | unsigned int i, len; | |
1535 | ||
1536 | /* first copy the parameters from user space */ | |
1537 | memset(psinfo, 0, sizeof(struct elf_prpsinfo)); | |
1538 | ||
1539 | len = mm->arg_end - mm->arg_start; | |
1540 | if (len >= ELF_PRARGSZ) | |
1541 | len = ELF_PRARGSZ-1; | |
1542 | if (copy_from_user(&psinfo->pr_psargs, | |
1543 | (const char __user *)mm->arg_start, len)) | |
1544 | return -EFAULT; | |
1545 | for(i = 0; i < len; i++) | |
1546 | if (psinfo->pr_psargs[i] == 0) | |
1547 | psinfo->pr_psargs[i] = ' '; | |
1548 | psinfo->pr_psargs[len] = 0; | |
1549 | ||
1550 | rcu_read_lock(); | |
1551 | psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent)); | |
1552 | rcu_read_unlock(); | |
1553 | psinfo->pr_pid = task_pid_vnr(p); | |
1554 | psinfo->pr_pgrp = task_pgrp_vnr(p); | |
1555 | psinfo->pr_sid = task_session_vnr(p); | |
1556 | ||
1557 | i = p->state ? ffz(~p->state) + 1 : 0; | |
1558 | psinfo->pr_state = i; | |
1559 | psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i]; | |
1560 | psinfo->pr_zomb = psinfo->pr_sname == 'Z'; | |
1561 | psinfo->pr_nice = task_nice(p); | |
1562 | psinfo->pr_flag = p->flags; | |
1563 | rcu_read_lock(); | |
1564 | cred = __task_cred(p); | |
1565 | SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid)); | |
1566 | SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid)); | |
1567 | rcu_read_unlock(); | |
1568 | strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname)); | |
1569 | ||
1570 | return 0; | |
1571 | } | |
1572 | ||
1573 | static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm) | |
1574 | { | |
1575 | elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv; | |
1576 | int i = 0; | |
1577 | do | |
1578 | i += 2; | |
1579 | while (auxv[i - 2] != AT_NULL); | |
1580 | fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv); | |
1581 | } | |
1582 | ||
1583 | static void fill_siginfo_note(struct memelfnote *note, user_siginfo_t *csigdata, | |
1584 | const siginfo_t *siginfo) | |
1585 | { | |
1586 | mm_segment_t old_fs = get_fs(); | |
1587 | set_fs(KERNEL_DS); | |
1588 | copy_siginfo_to_user((user_siginfo_t __user *) csigdata, siginfo); | |
1589 | set_fs(old_fs); | |
1590 | fill_note(note, "CORE", NT_SIGINFO, sizeof(*csigdata), csigdata); | |
1591 | } | |
1592 | ||
1593 | #define MAX_FILE_NOTE_SIZE (4*1024*1024) | |
1594 | /* | |
1595 | * Format of NT_FILE note: | |
1596 | * | |
1597 | * long count -- how many files are mapped | |
1598 | * long page_size -- units for file_ofs | |
1599 | * array of [COUNT] elements of | |
1600 | * long start | |
1601 | * long end | |
1602 | * long file_ofs | |
1603 | * followed by COUNT filenames in ASCII: "FILE1" NUL "FILE2" NUL... | |
1604 | */ | |
1605 | static int fill_files_note(struct memelfnote *note) | |
1606 | { | |
1607 | struct vm_area_struct *vma; | |
1608 | unsigned count, size, names_ofs, remaining, n; | |
1609 | user_long_t *data; | |
1610 | user_long_t *start_end_ofs; | |
1611 | char *name_base, *name_curpos; | |
1612 | ||
1613 | /* *Estimated* file count and total data size needed */ | |
1614 | count = current->mm->map_count; | |
1615 | if (count > UINT_MAX / 64) | |
1616 | return -EINVAL; | |
1617 | size = count * 64; | |
1618 | ||
1619 | names_ofs = (2 + 3 * count) * sizeof(data[0]); | |
1620 | alloc: | |
1621 | if (size >= MAX_FILE_NOTE_SIZE) /* paranoia check */ | |
1622 | return -EINVAL; | |
1623 | size = round_up(size, PAGE_SIZE); | |
1624 | data = kvmalloc(size, GFP_KERNEL); | |
1625 | if (ZERO_OR_NULL_PTR(data)) | |
1626 | return -ENOMEM; | |
1627 | ||
1628 | start_end_ofs = data + 2; | |
1629 | name_base = name_curpos = ((char *)data) + names_ofs; | |
1630 | remaining = size - names_ofs; | |
1631 | count = 0; | |
1632 | for (vma = current->mm->mmap; vma != NULL; vma = vma->vm_next) { | |
1633 | struct file *file; | |
1634 | const char *filename; | |
1635 | ||
1636 | file = vma->vm_file; | |
1637 | if (!file) | |
1638 | continue; | |
1639 | filename = file_path(file, name_curpos, remaining); | |
1640 | if (IS_ERR(filename)) { | |
1641 | if (PTR_ERR(filename) == -ENAMETOOLONG) { | |
1642 | kvfree(data); | |
1643 | size = size * 5 / 4; | |
1644 | goto alloc; | |
1645 | } | |
1646 | continue; | |
1647 | } | |
1648 | ||
1649 | /* file_path() fills at the end, move name down */ | |
1650 | /* n = strlen(filename) + 1: */ | |
1651 | n = (name_curpos + remaining) - filename; | |
1652 | remaining = filename - name_curpos; | |
1653 | memmove(name_curpos, filename, n); | |
1654 | name_curpos += n; | |
1655 | ||
1656 | *start_end_ofs++ = vma->vm_start; | |
1657 | *start_end_ofs++ = vma->vm_end; | |
1658 | *start_end_ofs++ = vma->vm_pgoff; | |
1659 | count++; | |
1660 | } | |
1661 | ||
1662 | /* Now we know exact count of files, can store it */ | |
1663 | data[0] = count; | |
1664 | data[1] = PAGE_SIZE; | |
1665 | /* | |
1666 | * Count usually is less than current->mm->map_count, | |
1667 | * we need to move filenames down. | |
1668 | */ | |
1669 | n = current->mm->map_count - count; | |
1670 | if (n != 0) { | |
1671 | unsigned shift_bytes = n * 3 * sizeof(data[0]); | |
1672 | memmove(name_base - shift_bytes, name_base, | |
1673 | name_curpos - name_base); | |
1674 | name_curpos -= shift_bytes; | |
1675 | } | |
1676 | ||
1677 | size = name_curpos - (char *)data; | |
1678 | fill_note(note, "CORE", NT_FILE, size, data); | |
1679 | return 0; | |
1680 | } | |
1681 | ||
1682 | #ifdef CORE_DUMP_USE_REGSET | |
1683 | #include <linux/regset.h> | |
1684 | ||
1685 | struct elf_thread_core_info { | |
1686 | struct elf_thread_core_info *next; | |
1687 | struct task_struct *task; | |
1688 | struct elf_prstatus prstatus; | |
1689 | struct memelfnote notes[0]; | |
1690 | }; | |
1691 | ||
1692 | struct elf_note_info { | |
1693 | struct elf_thread_core_info *thread; | |
1694 | struct memelfnote psinfo; | |
1695 | struct memelfnote signote; | |
1696 | struct memelfnote auxv; | |
1697 | struct memelfnote files; | |
1698 | user_siginfo_t csigdata; | |
1699 | size_t size; | |
1700 | int thread_notes; | |
1701 | }; | |
1702 | ||
1703 | /* | |
1704 | * When a regset has a writeback hook, we call it on each thread before | |
1705 | * dumping user memory. On register window machines, this makes sure the | |
1706 | * user memory backing the register data is up to date before we read it. | |
1707 | */ | |
1708 | static void do_thread_regset_writeback(struct task_struct *task, | |
1709 | const struct user_regset *regset) | |
1710 | { | |
1711 | if (regset->writeback) | |
1712 | regset->writeback(task, regset, 1); | |
1713 | } | |
1714 | ||
1715 | #ifndef PRSTATUS_SIZE | |
1716 | #define PRSTATUS_SIZE(S, R) sizeof(S) | |
1717 | #endif | |
1718 | ||
1719 | #ifndef SET_PR_FPVALID | |
1720 | #define SET_PR_FPVALID(S, V, R) ((S)->pr_fpvalid = (V)) | |
1721 | #endif | |
1722 | ||
1723 | static int fill_thread_core_info(struct elf_thread_core_info *t, | |
1724 | const struct user_regset_view *view, | |
1725 | long signr, size_t *total) | |
1726 | { | |
1727 | unsigned int i; | |
1728 | unsigned int regset0_size = regset_size(t->task, &view->regsets[0]); | |
1729 | ||
1730 | /* | |
1731 | * NT_PRSTATUS is the one special case, because the regset data | |
1732 | * goes into the pr_reg field inside the note contents, rather | |
1733 | * than being the whole note contents. We fill the reset in here. | |
1734 | * We assume that regset 0 is NT_PRSTATUS. | |
1735 | */ | |
1736 | fill_prstatus(&t->prstatus, t->task, signr); | |
1737 | (void) view->regsets[0].get(t->task, &view->regsets[0], 0, regset0_size, | |
1738 | &t->prstatus.pr_reg, NULL); | |
1739 | ||
1740 | fill_note(&t->notes[0], "CORE", NT_PRSTATUS, | |
1741 | PRSTATUS_SIZE(t->prstatus, regset0_size), &t->prstatus); | |
1742 | *total += notesize(&t->notes[0]); | |
1743 | ||
1744 | do_thread_regset_writeback(t->task, &view->regsets[0]); | |
1745 | ||
1746 | /* | |
1747 | * Each other regset might generate a note too. For each regset | |
1748 | * that has no core_note_type or is inactive, we leave t->notes[i] | |
1749 | * all zero and we'll know to skip writing it later. | |
1750 | */ | |
1751 | for (i = 1; i < view->n; ++i) { | |
1752 | const struct user_regset *regset = &view->regsets[i]; | |
1753 | do_thread_regset_writeback(t->task, regset); | |
1754 | if (regset->core_note_type && regset->get && | |
1755 | (!regset->active || regset->active(t->task, regset))) { | |
1756 | int ret; | |
1757 | size_t size = regset_size(t->task, regset); | |
1758 | void *data = kmalloc(size, GFP_KERNEL); | |
1759 | if (unlikely(!data)) | |
1760 | return 0; | |
1761 | ret = regset->get(t->task, regset, | |
1762 | 0, size, data, NULL); | |
1763 | if (unlikely(ret)) | |
1764 | kfree(data); | |
1765 | else { | |
1766 | if (regset->core_note_type != NT_PRFPREG) | |
1767 | fill_note(&t->notes[i], "LINUX", | |
1768 | regset->core_note_type, | |
1769 | size, data); | |
1770 | else { | |
1771 | SET_PR_FPVALID(&t->prstatus, | |
1772 | 1, regset0_size); | |
1773 | fill_note(&t->notes[i], "CORE", | |
1774 | NT_PRFPREG, size, data); | |
1775 | } | |
1776 | *total += notesize(&t->notes[i]); | |
1777 | } | |
1778 | } | |
1779 | } | |
1780 | ||
1781 | return 1; | |
1782 | } | |
1783 | ||
1784 | static int fill_note_info(struct elfhdr *elf, int phdrs, | |
1785 | struct elf_note_info *info, | |
1786 | const siginfo_t *siginfo, struct pt_regs *regs) | |
1787 | { | |
1788 | struct task_struct *dump_task = current; | |
1789 | const struct user_regset_view *view = task_user_regset_view(dump_task); | |
1790 | struct elf_thread_core_info *t; | |
1791 | struct elf_prpsinfo *psinfo; | |
1792 | struct core_thread *ct; | |
1793 | unsigned int i; | |
1794 | ||
1795 | info->size = 0; | |
1796 | info->thread = NULL; | |
1797 | ||
1798 | psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL); | |
1799 | if (psinfo == NULL) { | |
1800 | info->psinfo.data = NULL; /* So we don't free this wrongly */ | |
1801 | return 0; | |
1802 | } | |
1803 | ||
1804 | fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo); | |
1805 | ||
1806 | /* | |
1807 | * Figure out how many notes we're going to need for each thread. | |
1808 | */ | |
1809 | info->thread_notes = 0; | |
1810 | for (i = 0; i < view->n; ++i) | |
1811 | if (view->regsets[i].core_note_type != 0) | |
1812 | ++info->thread_notes; | |
1813 | ||
1814 | /* | |
1815 | * Sanity check. We rely on regset 0 being in NT_PRSTATUS, | |
1816 | * since it is our one special case. | |
1817 | */ | |
1818 | if (unlikely(info->thread_notes == 0) || | |
1819 | unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) { | |
1820 | WARN_ON(1); | |
1821 | return 0; | |
1822 | } | |
1823 | ||
1824 | /* | |
1825 | * Initialize the ELF file header. | |
1826 | */ | |
1827 | fill_elf_header(elf, phdrs, | |
1828 | view->e_machine, view->e_flags); | |
1829 | ||
1830 | /* | |
1831 | * Allocate a structure for each thread. | |
1832 | */ | |
1833 | for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) { | |
1834 | t = kzalloc(offsetof(struct elf_thread_core_info, | |
1835 | notes[info->thread_notes]), | |
1836 | GFP_KERNEL); | |
1837 | if (unlikely(!t)) | |
1838 | return 0; | |
1839 | ||
1840 | t->task = ct->task; | |
1841 | if (ct->task == dump_task || !info->thread) { | |
1842 | t->next = info->thread; | |
1843 | info->thread = t; | |
1844 | } else { | |
1845 | /* | |
1846 | * Make sure to keep the original task at | |
1847 | * the head of the list. | |
1848 | */ | |
1849 | t->next = info->thread->next; | |
1850 | info->thread->next = t; | |
1851 | } | |
1852 | } | |
1853 | ||
1854 | /* | |
1855 | * Now fill in each thread's information. | |
1856 | */ | |
1857 | for (t = info->thread; t != NULL; t = t->next) | |
1858 | if (!fill_thread_core_info(t, view, siginfo->si_signo, &info->size)) | |
1859 | return 0; | |
1860 | ||
1861 | /* | |
1862 | * Fill in the two process-wide notes. | |
1863 | */ | |
1864 | fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm); | |
1865 | info->size += notesize(&info->psinfo); | |
1866 | ||
1867 | fill_siginfo_note(&info->signote, &info->csigdata, siginfo); | |
1868 | info->size += notesize(&info->signote); | |
1869 | ||
1870 | fill_auxv_note(&info->auxv, current->mm); | |
1871 | info->size += notesize(&info->auxv); | |
1872 | ||
1873 | if (fill_files_note(&info->files) == 0) | |
1874 | info->size += notesize(&info->files); | |
1875 | ||
1876 | return 1; | |
1877 | } | |
1878 | ||
1879 | static size_t get_note_info_size(struct elf_note_info *info) | |
1880 | { | |
1881 | return info->size; | |
1882 | } | |
1883 | ||
1884 | /* | |
1885 | * Write all the notes for each thread. When writing the first thread, the | |
1886 | * process-wide notes are interleaved after the first thread-specific note. | |
1887 | */ | |
1888 | static int write_note_info(struct elf_note_info *info, | |
1889 | struct coredump_params *cprm) | |
1890 | { | |
1891 | bool first = true; | |
1892 | struct elf_thread_core_info *t = info->thread; | |
1893 | ||
1894 | do { | |
1895 | int i; | |
1896 | ||
1897 | if (!writenote(&t->notes[0], cprm)) | |
1898 | return 0; | |
1899 | ||
1900 | if (first && !writenote(&info->psinfo, cprm)) | |
1901 | return 0; | |
1902 | if (first && !writenote(&info->signote, cprm)) | |
1903 | return 0; | |
1904 | if (first && !writenote(&info->auxv, cprm)) | |
1905 | return 0; | |
1906 | if (first && info->files.data && | |
1907 | !writenote(&info->files, cprm)) | |
1908 | return 0; | |
1909 | ||
1910 | for (i = 1; i < info->thread_notes; ++i) | |
1911 | if (t->notes[i].data && | |
1912 | !writenote(&t->notes[i], cprm)) | |
1913 | return 0; | |
1914 | ||
1915 | first = false; | |
1916 | t = t->next; | |
1917 | } while (t); | |
1918 | ||
1919 | return 1; | |
1920 | } | |
1921 | ||
1922 | static void free_note_info(struct elf_note_info *info) | |
1923 | { | |
1924 | struct elf_thread_core_info *threads = info->thread; | |
1925 | while (threads) { | |
1926 | unsigned int i; | |
1927 | struct elf_thread_core_info *t = threads; | |
1928 | threads = t->next; | |
1929 | WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus); | |
1930 | for (i = 1; i < info->thread_notes; ++i) | |
1931 | kfree(t->notes[i].data); | |
1932 | kfree(t); | |
1933 | } | |
1934 | kfree(info->psinfo.data); | |
1935 | kvfree(info->files.data); | |
1936 | } | |
1937 | ||
1938 | #else | |
1939 | ||
1940 | /* Here is the structure in which status of each thread is captured. */ | |
1941 | struct elf_thread_status | |
1942 | { | |
1943 | struct list_head list; | |
1944 | struct elf_prstatus prstatus; /* NT_PRSTATUS */ | |
1945 | elf_fpregset_t fpu; /* NT_PRFPREG */ | |
1946 | struct task_struct *thread; | |
1947 | #ifdef ELF_CORE_COPY_XFPREGS | |
1948 | elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */ | |
1949 | #endif | |
1950 | struct memelfnote notes[3]; | |
1951 | int num_notes; | |
1952 | }; | |
1953 | ||
1954 | /* | |
1955 | * In order to add the specific thread information for the elf file format, | |
1956 | * we need to keep a linked list of every threads pr_status and then create | |
1957 | * a single section for them in the final core file. | |
1958 | */ | |
1959 | static int elf_dump_thread_status(long signr, struct elf_thread_status *t) | |
1960 | { | |
1961 | int sz = 0; | |
1962 | struct task_struct *p = t->thread; | |
1963 | t->num_notes = 0; | |
1964 | ||
1965 | fill_prstatus(&t->prstatus, p, signr); | |
1966 | elf_core_copy_task_regs(p, &t->prstatus.pr_reg); | |
1967 | ||
1968 | fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus), | |
1969 | &(t->prstatus)); | |
1970 | t->num_notes++; | |
1971 | sz += notesize(&t->notes[0]); | |
1972 | ||
1973 | if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, | |
1974 | &t->fpu))) { | |
1975 | fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu), | |
1976 | &(t->fpu)); | |
1977 | t->num_notes++; | |
1978 | sz += notesize(&t->notes[1]); | |
1979 | } | |
1980 | ||
1981 | #ifdef ELF_CORE_COPY_XFPREGS | |
1982 | if (elf_core_copy_task_xfpregs(p, &t->xfpu)) { | |
1983 | fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE, | |
1984 | sizeof(t->xfpu), &t->xfpu); | |
1985 | t->num_notes++; | |
1986 | sz += notesize(&t->notes[2]); | |
1987 | } | |
1988 | #endif | |
1989 | return sz; | |
1990 | } | |
1991 | ||
1992 | struct elf_note_info { | |
1993 | struct memelfnote *notes; | |
1994 | struct memelfnote *notes_files; | |
1995 | struct elf_prstatus *prstatus; /* NT_PRSTATUS */ | |
1996 | struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */ | |
1997 | struct list_head thread_list; | |
1998 | elf_fpregset_t *fpu; | |
1999 | #ifdef ELF_CORE_COPY_XFPREGS | |
2000 | elf_fpxregset_t *xfpu; | |
2001 | #endif | |
2002 | user_siginfo_t csigdata; | |
2003 | int thread_status_size; | |
2004 | int numnote; | |
2005 | }; | |
2006 | ||
2007 | static int elf_note_info_init(struct elf_note_info *info) | |
2008 | { | |
2009 | memset(info, 0, sizeof(*info)); | |
2010 | INIT_LIST_HEAD(&info->thread_list); | |
2011 | ||
2012 | /* Allocate space for ELF notes */ | |
2013 | info->notes = kmalloc_array(8, sizeof(struct memelfnote), GFP_KERNEL); | |
2014 | if (!info->notes) | |
2015 | return 0; | |
2016 | info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL); | |
2017 | if (!info->psinfo) | |
2018 | return 0; | |
2019 | info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL); | |
2020 | if (!info->prstatus) | |
2021 | return 0; | |
2022 | info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL); | |
2023 | if (!info->fpu) | |
2024 | return 0; | |
2025 | #ifdef ELF_CORE_COPY_XFPREGS | |
2026 | info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL); | |
2027 | if (!info->xfpu) | |
2028 | return 0; | |
2029 | #endif | |
2030 | return 1; | |
2031 | } | |
2032 | ||
2033 | static int fill_note_info(struct elfhdr *elf, int phdrs, | |
2034 | struct elf_note_info *info, | |
2035 | const siginfo_t *siginfo, struct pt_regs *regs) | |
2036 | { | |
2037 | struct list_head *t; | |
2038 | struct core_thread *ct; | |
2039 | struct elf_thread_status *ets; | |
2040 | ||
2041 | if (!elf_note_info_init(info)) | |
2042 | return 0; | |
2043 | ||
2044 | for (ct = current->mm->core_state->dumper.next; | |
2045 | ct; ct = ct->next) { | |
2046 | ets = kzalloc(sizeof(*ets), GFP_KERNEL); | |
2047 | if (!ets) | |
2048 | return 0; | |
2049 | ||
2050 | ets->thread = ct->task; | |
2051 | list_add(&ets->list, &info->thread_list); | |
2052 | } | |
2053 | ||
2054 | list_for_each(t, &info->thread_list) { | |
2055 | int sz; | |
2056 | ||
2057 | ets = list_entry(t, struct elf_thread_status, list); | |
2058 | sz = elf_dump_thread_status(siginfo->si_signo, ets); | |
2059 | info->thread_status_size += sz; | |
2060 | } | |
2061 | /* now collect the dump for the current */ | |
2062 | memset(info->prstatus, 0, sizeof(*info->prstatus)); | |
2063 | fill_prstatus(info->prstatus, current, siginfo->si_signo); | |
2064 | elf_core_copy_regs(&info->prstatus->pr_reg, regs); | |
2065 | ||
2066 | /* Set up header */ | |
2067 | fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS); | |
2068 | ||
2069 | /* | |
2070 | * Set up the notes in similar form to SVR4 core dumps made | |
2071 | * with info from their /proc. | |
2072 | */ | |
2073 | ||
2074 | fill_note(info->notes + 0, "CORE", NT_PRSTATUS, | |
2075 | sizeof(*info->prstatus), info->prstatus); | |
2076 | fill_psinfo(info->psinfo, current->group_leader, current->mm); | |
2077 | fill_note(info->notes + 1, "CORE", NT_PRPSINFO, | |
2078 | sizeof(*info->psinfo), info->psinfo); | |
2079 | ||
2080 | fill_siginfo_note(info->notes + 2, &info->csigdata, siginfo); | |
2081 | fill_auxv_note(info->notes + 3, current->mm); | |
2082 | info->numnote = 4; | |
2083 | ||
2084 | if (fill_files_note(info->notes + info->numnote) == 0) { | |
2085 | info->notes_files = info->notes + info->numnote; | |
2086 | info->numnote++; | |
2087 | } | |
2088 | ||
2089 | /* Try to dump the FPU. */ | |
2090 | info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs, | |
2091 | info->fpu); | |
2092 | if (info->prstatus->pr_fpvalid) | |
2093 | fill_note(info->notes + info->numnote++, | |
2094 | "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu); | |
2095 | #ifdef ELF_CORE_COPY_XFPREGS | |
2096 | if (elf_core_copy_task_xfpregs(current, info->xfpu)) | |
2097 | fill_note(info->notes + info->numnote++, | |
2098 | "LINUX", ELF_CORE_XFPREG_TYPE, | |
2099 | sizeof(*info->xfpu), info->xfpu); | |
2100 | #endif | |
2101 | ||
2102 | return 1; | |
2103 | } | |
2104 | ||
2105 | static size_t get_note_info_size(struct elf_note_info *info) | |
2106 | { | |
2107 | int sz = 0; | |
2108 | int i; | |
2109 | ||
2110 | for (i = 0; i < info->numnote; i++) | |
2111 | sz += notesize(info->notes + i); | |
2112 | ||
2113 | sz += info->thread_status_size; | |
2114 | ||
2115 | return sz; | |
2116 | } | |
2117 | ||
2118 | static int write_note_info(struct elf_note_info *info, | |
2119 | struct coredump_params *cprm) | |
2120 | { | |
2121 | int i; | |
2122 | struct list_head *t; | |
2123 | ||
2124 | for (i = 0; i < info->numnote; i++) | |
2125 | if (!writenote(info->notes + i, cprm)) | |
2126 | return 0; | |
2127 | ||
2128 | /* write out the thread status notes section */ | |
2129 | list_for_each(t, &info->thread_list) { | |
2130 | struct elf_thread_status *tmp = | |
2131 | list_entry(t, struct elf_thread_status, list); | |
2132 | ||
2133 | for (i = 0; i < tmp->num_notes; i++) | |
2134 | if (!writenote(&tmp->notes[i], cprm)) | |
2135 | return 0; | |
2136 | } | |
2137 | ||
2138 | return 1; | |
2139 | } | |
2140 | ||
2141 | static void free_note_info(struct elf_note_info *info) | |
2142 | { | |
2143 | while (!list_empty(&info->thread_list)) { | |
2144 | struct list_head *tmp = info->thread_list.next; | |
2145 | list_del(tmp); | |
2146 | kfree(list_entry(tmp, struct elf_thread_status, list)); | |
2147 | } | |
2148 | ||
2149 | /* Free data possibly allocated by fill_files_note(): */ | |
2150 | if (info->notes_files) | |
2151 | kvfree(info->notes_files->data); | |
2152 | ||
2153 | kfree(info->prstatus); | |
2154 | kfree(info->psinfo); | |
2155 | kfree(info->notes); | |
2156 | kfree(info->fpu); | |
2157 | #ifdef ELF_CORE_COPY_XFPREGS | |
2158 | kfree(info->xfpu); | |
2159 | #endif | |
2160 | } | |
2161 | ||
2162 | #endif | |
2163 | ||
2164 | static struct vm_area_struct *first_vma(struct task_struct *tsk, | |
2165 | struct vm_area_struct *gate_vma) | |
2166 | { | |
2167 | struct vm_area_struct *ret = tsk->mm->mmap; | |
2168 | ||
2169 | if (ret) | |
2170 | return ret; | |
2171 | return gate_vma; | |
2172 | } | |
2173 | /* | |
2174 | * Helper function for iterating across a vma list. It ensures that the caller | |
2175 | * will visit `gate_vma' prior to terminating the search. | |
2176 | */ | |
2177 | static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma, | |
2178 | struct vm_area_struct *gate_vma) | |
2179 | { | |
2180 | struct vm_area_struct *ret; | |
2181 | ||
2182 | ret = this_vma->vm_next; | |
2183 | if (ret) | |
2184 | return ret; | |
2185 | if (this_vma == gate_vma) | |
2186 | return NULL; | |
2187 | return gate_vma; | |
2188 | } | |
2189 | ||
2190 | static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum, | |
2191 | elf_addr_t e_shoff, int segs) | |
2192 | { | |
2193 | elf->e_shoff = e_shoff; | |
2194 | elf->e_shentsize = sizeof(*shdr4extnum); | |
2195 | elf->e_shnum = 1; | |
2196 | elf->e_shstrndx = SHN_UNDEF; | |
2197 | ||
2198 | memset(shdr4extnum, 0, sizeof(*shdr4extnum)); | |
2199 | ||
2200 | shdr4extnum->sh_type = SHT_NULL; | |
2201 | shdr4extnum->sh_size = elf->e_shnum; | |
2202 | shdr4extnum->sh_link = elf->e_shstrndx; | |
2203 | shdr4extnum->sh_info = segs; | |
2204 | } | |
2205 | ||
2206 | /* | |
2207 | * Actual dumper | |
2208 | * | |
2209 | * This is a two-pass process; first we find the offsets of the bits, | |
2210 | * and then they are actually written out. If we run out of core limit | |
2211 | * we just truncate. | |
2212 | */ | |
2213 | static int elf_core_dump(struct coredump_params *cprm) | |
2214 | { | |
2215 | int has_dumped = 0; | |
2216 | mm_segment_t fs; | |
2217 | int segs, i; | |
2218 | size_t vma_data_size = 0; | |
2219 | struct vm_area_struct *vma, *gate_vma; | |
2220 | struct elfhdr *elf = NULL; | |
2221 | loff_t offset = 0, dataoff; | |
2222 | struct elf_note_info info = { }; | |
2223 | struct elf_phdr *phdr4note = NULL; | |
2224 | struct elf_shdr *shdr4extnum = NULL; | |
2225 | Elf_Half e_phnum; | |
2226 | elf_addr_t e_shoff; | |
2227 | elf_addr_t *vma_filesz = NULL; | |
2228 | ||
2229 | /* | |
2230 | * We no longer stop all VM operations. | |
2231 | * | |
2232 | * This is because those proceses that could possibly change map_count | |
2233 | * or the mmap / vma pages are now blocked in do_exit on current | |
2234 | * finishing this core dump. | |
2235 | * | |
2236 | * Only ptrace can touch these memory addresses, but it doesn't change | |
2237 | * the map_count or the pages allocated. So no possibility of crashing | |
2238 | * exists while dumping the mm->vm_next areas to the core file. | |
2239 | */ | |
2240 | ||
2241 | /* alloc memory for large data structures: too large to be on stack */ | |
2242 | elf = kmalloc(sizeof(*elf), GFP_KERNEL); | |
2243 | if (!elf) | |
2244 | goto out; | |
2245 | /* | |
2246 | * The number of segs are recored into ELF header as 16bit value. | |
2247 | * Please check DEFAULT_MAX_MAP_COUNT definition when you modify here. | |
2248 | */ | |
2249 | segs = current->mm->map_count; | |
2250 | segs += elf_core_extra_phdrs(); | |
2251 | ||
2252 | gate_vma = get_gate_vma(current->mm); | |
2253 | if (gate_vma != NULL) | |
2254 | segs++; | |
2255 | ||
2256 | /* for notes section */ | |
2257 | segs++; | |
2258 | ||
2259 | /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid | |
2260 | * this, kernel supports extended numbering. Have a look at | |
2261 | * include/linux/elf.h for further information. */ | |
2262 | e_phnum = segs > PN_XNUM ? PN_XNUM : segs; | |
2263 | ||
2264 | /* | |
2265 | * Collect all the non-memory information about the process for the | |
2266 | * notes. This also sets up the file header. | |
2267 | */ | |
2268 | if (!fill_note_info(elf, e_phnum, &info, cprm->siginfo, cprm->regs)) | |
2269 | goto cleanup; | |
2270 | ||
2271 | has_dumped = 1; | |
2272 | ||
2273 | fs = get_fs(); | |
2274 | set_fs(KERNEL_DS); | |
2275 | ||
2276 | offset += sizeof(*elf); /* Elf header */ | |
2277 | offset += segs * sizeof(struct elf_phdr); /* Program headers */ | |
2278 | ||
2279 | /* Write notes phdr entry */ | |
2280 | { | |
2281 | size_t sz = get_note_info_size(&info); | |
2282 | ||
2283 | sz += elf_coredump_extra_notes_size(); | |
2284 | ||
2285 | phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL); | |
2286 | if (!phdr4note) | |
2287 | goto end_coredump; | |
2288 | ||
2289 | fill_elf_note_phdr(phdr4note, sz, offset); | |
2290 | offset += sz; | |
2291 | } | |
2292 | ||
2293 | dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE); | |
2294 | ||
2295 | if (segs - 1 > ULONG_MAX / sizeof(*vma_filesz)) | |
2296 | goto end_coredump; | |
2297 | vma_filesz = kvmalloc(array_size(sizeof(*vma_filesz), (segs - 1)), | |
2298 | GFP_KERNEL); | |
2299 | if (ZERO_OR_NULL_PTR(vma_filesz)) | |
2300 | goto end_coredump; | |
2301 | ||
2302 | for (i = 0, vma = first_vma(current, gate_vma); vma != NULL; | |
2303 | vma = next_vma(vma, gate_vma)) { | |
2304 | unsigned long dump_size; | |
2305 | ||
2306 | dump_size = vma_dump_size(vma, cprm->mm_flags); | |
2307 | vma_filesz[i++] = dump_size; | |
2308 | vma_data_size += dump_size; | |
2309 | } | |
2310 | ||
2311 | offset += vma_data_size; | |
2312 | offset += elf_core_extra_data_size(); | |
2313 | e_shoff = offset; | |
2314 | ||
2315 | if (e_phnum == PN_XNUM) { | |
2316 | shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL); | |
2317 | if (!shdr4extnum) | |
2318 | goto end_coredump; | |
2319 | fill_extnum_info(elf, shdr4extnum, e_shoff, segs); | |
2320 | } | |
2321 | ||
2322 | offset = dataoff; | |
2323 | ||
2324 | if (!dump_emit(cprm, elf, sizeof(*elf))) | |
2325 | goto end_coredump; | |
2326 | ||
2327 | if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note))) | |
2328 | goto end_coredump; | |
2329 | ||
2330 | /* Write program headers for segments dump */ | |
2331 | for (i = 0, vma = first_vma(current, gate_vma); vma != NULL; | |
2332 | vma = next_vma(vma, gate_vma)) { | |
2333 | struct elf_phdr phdr; | |
2334 | ||
2335 | phdr.p_type = PT_LOAD; | |
2336 | phdr.p_offset = offset; | |
2337 | phdr.p_vaddr = vma->vm_start; | |
2338 | phdr.p_paddr = 0; | |
2339 | phdr.p_filesz = vma_filesz[i++]; | |
2340 | phdr.p_memsz = vma->vm_end - vma->vm_start; | |
2341 | offset += phdr.p_filesz; | |
2342 | phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0; | |
2343 | if (vma->vm_flags & VM_WRITE) | |
2344 | phdr.p_flags |= PF_W; | |
2345 | if (vma->vm_flags & VM_EXEC) | |
2346 | phdr.p_flags |= PF_X; | |
2347 | phdr.p_align = ELF_EXEC_PAGESIZE; | |
2348 | ||
2349 | if (!dump_emit(cprm, &phdr, sizeof(phdr))) | |
2350 | goto end_coredump; | |
2351 | } | |
2352 | ||
2353 | if (!elf_core_write_extra_phdrs(cprm, offset)) | |
2354 | goto end_coredump; | |
2355 | ||
2356 | /* write out the notes section */ | |
2357 | if (!write_note_info(&info, cprm)) | |
2358 | goto end_coredump; | |
2359 | ||
2360 | if (elf_coredump_extra_notes_write(cprm)) | |
2361 | goto end_coredump; | |
2362 | ||
2363 | /* Align to page */ | |
2364 | if (!dump_skip(cprm, dataoff - cprm->pos)) | |
2365 | goto end_coredump; | |
2366 | ||
2367 | for (i = 0, vma = first_vma(current, gate_vma); vma != NULL; | |
2368 | vma = next_vma(vma, gate_vma)) { | |
2369 | unsigned long addr; | |
2370 | unsigned long end; | |
2371 | ||
2372 | end = vma->vm_start + vma_filesz[i++]; | |
2373 | ||
2374 | for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) { | |
2375 | struct page *page; | |
2376 | int stop; | |
2377 | ||
2378 | page = get_dump_page(addr); | |
2379 | if (page) { | |
2380 | void *kaddr = kmap(page); | |
2381 | stop = !dump_emit(cprm, kaddr, PAGE_SIZE); | |
2382 | kunmap(page); | |
2383 | put_page(page); | |
2384 | } else | |
2385 | stop = !dump_skip(cprm, PAGE_SIZE); | |
2386 | if (stop) | |
2387 | goto end_coredump; | |
2388 | } | |
2389 | } | |
2390 | dump_truncate(cprm); | |
2391 | ||
2392 | if (!elf_core_write_extra_data(cprm)) | |
2393 | goto end_coredump; | |
2394 | ||
2395 | if (e_phnum == PN_XNUM) { | |
2396 | if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum))) | |
2397 | goto end_coredump; | |
2398 | } | |
2399 | ||
2400 | end_coredump: | |
2401 | set_fs(fs); | |
2402 | ||
2403 | cleanup: | |
2404 | free_note_info(&info); | |
2405 | kfree(shdr4extnum); | |
2406 | kvfree(vma_filesz); | |
2407 | kfree(phdr4note); | |
2408 | kfree(elf); | |
2409 | out: | |
2410 | return has_dumped; | |
2411 | } | |
2412 | ||
2413 | #endif /* CONFIG_ELF_CORE */ | |
2414 | ||
2415 | static int __init init_elf_binfmt(void) | |
2416 | { | |
2417 | register_binfmt(&elf_format); | |
2418 | return 0; | |
2419 | } | |
2420 | ||
2421 | static void __exit exit_elf_binfmt(void) | |
2422 | { | |
2423 | /* Remove the COFF and ELF loaders. */ | |
2424 | unregister_binfmt(&elf_format); | |
2425 | } | |
2426 | ||
2427 | core_initcall(init_elf_binfmt); | |
2428 | module_exit(exit_elf_binfmt); | |
2429 | MODULE_LICENSE("GPL"); |