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