Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb-2.6
[linux-2.6/sactl.git] / fs / binfmt_elf.c
blob8fcfa398d35075e1e149b70d62226a6095524ad3
1 /*
2 * linux/fs/binfmt_elf.c
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".
9 * Copyright 1993, 1994: Eric Youngdale (ericy@cais.com).
12 #include <linux/module.h>
13 #include <linux/kernel.h>
14 #include <linux/fs.h>
15 #include <linux/stat.h>
16 #include <linux/time.h>
17 #include <linux/mm.h>
18 #include <linux/mman.h>
19 #include <linux/errno.h>
20 #include <linux/signal.h>
21 #include <linux/binfmts.h>
22 #include <linux/string.h>
23 #include <linux/file.h>
24 #include <linux/fcntl.h>
25 #include <linux/ptrace.h>
26 #include <linux/slab.h>
27 #include <linux/shm.h>
28 #include <linux/personality.h>
29 #include <linux/elfcore.h>
30 #include <linux/init.h>
31 #include <linux/highuid.h>
32 #include <linux/smp.h>
33 #include <linux/compiler.h>
34 #include <linux/highmem.h>
35 #include <linux/pagemap.h>
36 #include <linux/security.h>
37 #include <linux/syscalls.h>
38 #include <linux/random.h>
39 #include <linux/elf.h>
40 #include <linux/utsname.h>
41 #include <asm/uaccess.h>
42 #include <asm/param.h>
43 #include <asm/page.h>
45 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs);
46 static int load_elf_library(struct file *);
47 static unsigned long elf_map(struct file *, unsigned long, struct elf_phdr *,
48 int, int, unsigned long);
51 * If we don't support core dumping, then supply a NULL so we
52 * don't even try.
54 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
55 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);
56 #else
57 #define elf_core_dump NULL
58 #endif
60 #if ELF_EXEC_PAGESIZE > PAGE_SIZE
61 #define ELF_MIN_ALIGN ELF_EXEC_PAGESIZE
62 #else
63 #define ELF_MIN_ALIGN PAGE_SIZE
64 #endif
66 #ifndef ELF_CORE_EFLAGS
67 #define ELF_CORE_EFLAGS 0
68 #endif
70 #define ELF_PAGESTART(_v) ((_v) & ~(unsigned long)(ELF_MIN_ALIGN-1))
71 #define ELF_PAGEOFFSET(_v) ((_v) & (ELF_MIN_ALIGN-1))
72 #define ELF_PAGEALIGN(_v) (((_v) + ELF_MIN_ALIGN - 1) & ~(ELF_MIN_ALIGN - 1))
74 static struct linux_binfmt elf_format = {
75 .module = THIS_MODULE,
76 .load_binary = load_elf_binary,
77 .load_shlib = load_elf_library,
78 .core_dump = elf_core_dump,
79 .min_coredump = ELF_EXEC_PAGESIZE,
80 .hasvdso = 1
83 #define BAD_ADDR(x) ((unsigned long)(x) >= TASK_SIZE)
85 static int set_brk(unsigned long start, unsigned long end)
87 start = ELF_PAGEALIGN(start);
88 end = ELF_PAGEALIGN(end);
89 if (end > start) {
90 unsigned long addr;
91 down_write(&current->mm->mmap_sem);
92 addr = do_brk(start, end - start);
93 up_write(&current->mm->mmap_sem);
94 if (BAD_ADDR(addr))
95 return addr;
97 current->mm->start_brk = current->mm->brk = end;
98 return 0;
101 /* We need to explicitly zero any fractional pages
102 after the data section (i.e. bss). This would
103 contain the junk from the file that should not
104 be in memory
106 static int padzero(unsigned long elf_bss)
108 unsigned long nbyte;
110 nbyte = ELF_PAGEOFFSET(elf_bss);
111 if (nbyte) {
112 nbyte = ELF_MIN_ALIGN - nbyte;
113 if (clear_user((void __user *) elf_bss, nbyte))
114 return -EFAULT;
116 return 0;
119 /* Let's use some macros to make this stack manipulation a little clearer */
120 #ifdef CONFIG_STACK_GROWSUP
121 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) + (items))
122 #define STACK_ROUND(sp, items) \
123 ((15 + (unsigned long) ((sp) + (items))) &~ 15UL)
124 #define STACK_ALLOC(sp, len) ({ \
125 elf_addr_t __user *old_sp = (elf_addr_t __user *)sp; sp += len; \
126 old_sp; })
127 #else
128 #define STACK_ADD(sp, items) ((elf_addr_t __user *)(sp) - (items))
129 #define STACK_ROUND(sp, items) \
130 (((unsigned long) (sp - items)) &~ 15UL)
131 #define STACK_ALLOC(sp, len) ({ sp -= len ; sp; })
132 #endif
134 #ifndef ELF_BASE_PLATFORM
136 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
137 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
138 * will be copied to the user stack in the same manner as AT_PLATFORM.
140 #define ELF_BASE_PLATFORM NULL
141 #endif
143 static int
144 create_elf_tables(struct linux_binprm *bprm, struct elfhdr *exec,
145 unsigned long load_addr, unsigned long interp_load_addr)
147 unsigned long p = bprm->p;
148 int argc = bprm->argc;
149 int envc = bprm->envc;
150 elf_addr_t __user *argv;
151 elf_addr_t __user *envp;
152 elf_addr_t __user *sp;
153 elf_addr_t __user *u_platform;
154 elf_addr_t __user *u_base_platform;
155 const char *k_platform = ELF_PLATFORM;
156 const char *k_base_platform = ELF_BASE_PLATFORM;
157 int items;
158 elf_addr_t *elf_info;
159 int ei_index = 0;
160 struct task_struct *tsk = current;
161 struct vm_area_struct *vma;
164 * In some cases (e.g. Hyper-Threading), we want to avoid L1
165 * evictions by the processes running on the same package. One
166 * thing we can do is to shuffle the initial stack for them.
169 p = arch_align_stack(p);
172 * If this architecture has a platform capability string, copy it
173 * to userspace. In some cases (Sparc), this info is impossible
174 * for userspace to get any other way, in others (i386) it is
175 * merely difficult.
177 u_platform = NULL;
178 if (k_platform) {
179 size_t len = strlen(k_platform) + 1;
181 u_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
182 if (__copy_to_user(u_platform, k_platform, len))
183 return -EFAULT;
187 * If this architecture has a "base" platform capability
188 * string, copy it to userspace.
190 u_base_platform = NULL;
191 if (k_base_platform) {
192 size_t len = strlen(k_base_platform) + 1;
194 u_base_platform = (elf_addr_t __user *)STACK_ALLOC(p, len);
195 if (__copy_to_user(u_base_platform, k_base_platform, len))
196 return -EFAULT;
199 /* Create the ELF interpreter info */
200 elf_info = (elf_addr_t *)current->mm->saved_auxv;
201 /* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
202 #define NEW_AUX_ENT(id, val) \
203 do { \
204 elf_info[ei_index++] = id; \
205 elf_info[ei_index++] = val; \
206 } while (0)
208 #ifdef ARCH_DLINFO
210 * ARCH_DLINFO must come first so PPC can do its special alignment of
211 * AUXV.
212 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
213 * ARCH_DLINFO changes
215 ARCH_DLINFO;
216 #endif
217 NEW_AUX_ENT(AT_HWCAP, ELF_HWCAP);
218 NEW_AUX_ENT(AT_PAGESZ, ELF_EXEC_PAGESIZE);
219 NEW_AUX_ENT(AT_CLKTCK, CLOCKS_PER_SEC);
220 NEW_AUX_ENT(AT_PHDR, load_addr + exec->e_phoff);
221 NEW_AUX_ENT(AT_PHENT, sizeof(struct elf_phdr));
222 NEW_AUX_ENT(AT_PHNUM, exec->e_phnum);
223 NEW_AUX_ENT(AT_BASE, interp_load_addr);
224 NEW_AUX_ENT(AT_FLAGS, 0);
225 NEW_AUX_ENT(AT_ENTRY, exec->e_entry);
226 NEW_AUX_ENT(AT_UID, tsk->uid);
227 NEW_AUX_ENT(AT_EUID, tsk->euid);
228 NEW_AUX_ENT(AT_GID, tsk->gid);
229 NEW_AUX_ENT(AT_EGID, tsk->egid);
230 NEW_AUX_ENT(AT_SECURE, security_bprm_secureexec(bprm));
231 NEW_AUX_ENT(AT_EXECFN, bprm->exec);
232 if (k_platform) {
233 NEW_AUX_ENT(AT_PLATFORM,
234 (elf_addr_t)(unsigned long)u_platform);
236 if (k_base_platform) {
237 NEW_AUX_ENT(AT_BASE_PLATFORM,
238 (elf_addr_t)(unsigned long)u_base_platform);
240 if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
241 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
243 #undef NEW_AUX_ENT
244 /* AT_NULL is zero; clear the rest too */
245 memset(&elf_info[ei_index], 0,
246 sizeof current->mm->saved_auxv - ei_index * sizeof elf_info[0]);
248 /* And advance past the AT_NULL entry. */
249 ei_index += 2;
251 sp = STACK_ADD(p, ei_index);
253 items = (argc + 1) + (envc + 1) + 1;
254 bprm->p = STACK_ROUND(sp, items);
256 /* Point sp at the lowest address on the stack */
257 #ifdef CONFIG_STACK_GROWSUP
258 sp = (elf_addr_t __user *)bprm->p - items - ei_index;
259 bprm->exec = (unsigned long)sp; /* XXX: PARISC HACK */
260 #else
261 sp = (elf_addr_t __user *)bprm->p;
262 #endif
266 * Grow the stack manually; some architectures have a limit on how
267 * far ahead a user-space access may be in order to grow the stack.
269 vma = find_extend_vma(current->mm, bprm->p);
270 if (!vma)
271 return -EFAULT;
273 /* Now, let's put argc (and argv, envp if appropriate) on the stack */
274 if (__put_user(argc, sp++))
275 return -EFAULT;
276 argv = sp;
277 envp = argv + argc + 1;
279 /* Populate argv and envp */
280 p = current->mm->arg_end = current->mm->arg_start;
281 while (argc-- > 0) {
282 size_t len;
283 if (__put_user((elf_addr_t)p, argv++))
284 return -EFAULT;
285 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
286 if (!len || len > MAX_ARG_STRLEN)
287 return -EINVAL;
288 p += len;
290 if (__put_user(0, argv))
291 return -EFAULT;
292 current->mm->arg_end = current->mm->env_start = p;
293 while (envc-- > 0) {
294 size_t len;
295 if (__put_user((elf_addr_t)p, envp++))
296 return -EFAULT;
297 len = strnlen_user((void __user *)p, MAX_ARG_STRLEN);
298 if (!len || len > MAX_ARG_STRLEN)
299 return -EINVAL;
300 p += len;
302 if (__put_user(0, envp))
303 return -EFAULT;
304 current->mm->env_end = p;
306 /* Put the elf_info on the stack in the right place. */
307 sp = (elf_addr_t __user *)envp + 1;
308 if (copy_to_user(sp, elf_info, ei_index * sizeof(elf_addr_t)))
309 return -EFAULT;
310 return 0;
313 #ifndef elf_map
315 static unsigned long elf_map(struct file *filep, unsigned long addr,
316 struct elf_phdr *eppnt, int prot, int type,
317 unsigned long total_size)
319 unsigned long map_addr;
320 unsigned long size = eppnt->p_filesz + ELF_PAGEOFFSET(eppnt->p_vaddr);
321 unsigned long off = eppnt->p_offset - ELF_PAGEOFFSET(eppnt->p_vaddr);
322 addr = ELF_PAGESTART(addr);
323 size = ELF_PAGEALIGN(size);
325 /* mmap() will return -EINVAL if given a zero size, but a
326 * segment with zero filesize is perfectly valid */
327 if (!size)
328 return addr;
330 down_write(&current->mm->mmap_sem);
332 * total_size is the size of the ELF (interpreter) image.
333 * The _first_ mmap needs to know the full size, otherwise
334 * randomization might put this image into an overlapping
335 * position with the ELF binary image. (since size < total_size)
336 * So we first map the 'big' image - and unmap the remainder at
337 * the end. (which unmap is needed for ELF images with holes.)
339 if (total_size) {
340 total_size = ELF_PAGEALIGN(total_size);
341 map_addr = do_mmap(filep, addr, total_size, prot, type, off);
342 if (!BAD_ADDR(map_addr))
343 do_munmap(current->mm, map_addr+size, total_size-size);
344 } else
345 map_addr = do_mmap(filep, addr, size, prot, type, off);
347 up_write(&current->mm->mmap_sem);
348 return(map_addr);
351 #endif /* !elf_map */
353 static unsigned long total_mapping_size(struct elf_phdr *cmds, int nr)
355 int i, first_idx = -1, last_idx = -1;
357 for (i = 0; i < nr; i++) {
358 if (cmds[i].p_type == PT_LOAD) {
359 last_idx = i;
360 if (first_idx == -1)
361 first_idx = i;
364 if (first_idx == -1)
365 return 0;
367 return cmds[last_idx].p_vaddr + cmds[last_idx].p_memsz -
368 ELF_PAGESTART(cmds[first_idx].p_vaddr);
372 /* This is much more generalized than the library routine read function,
373 so we keep this separate. Technically the library read function
374 is only provided so that we can read a.out libraries that have
375 an ELF header */
377 static unsigned long load_elf_interp(struct elfhdr *interp_elf_ex,
378 struct file *interpreter, unsigned long *interp_map_addr,
379 unsigned long no_base)
381 struct elf_phdr *elf_phdata;
382 struct elf_phdr *eppnt;
383 unsigned long load_addr = 0;
384 int load_addr_set = 0;
385 unsigned long last_bss = 0, elf_bss = 0;
386 unsigned long error = ~0UL;
387 unsigned long total_size;
388 int retval, i, size;
390 /* First of all, some simple consistency checks */
391 if (interp_elf_ex->e_type != ET_EXEC &&
392 interp_elf_ex->e_type != ET_DYN)
393 goto out;
394 if (!elf_check_arch(interp_elf_ex))
395 goto out;
396 if (!interpreter->f_op || !interpreter->f_op->mmap)
397 goto out;
400 * If the size of this structure has changed, then punt, since
401 * we will be doing the wrong thing.
403 if (interp_elf_ex->e_phentsize != sizeof(struct elf_phdr))
404 goto out;
405 if (interp_elf_ex->e_phnum < 1 ||
406 interp_elf_ex->e_phnum > 65536U / sizeof(struct elf_phdr))
407 goto out;
409 /* Now read in all of the header information */
410 size = sizeof(struct elf_phdr) * interp_elf_ex->e_phnum;
411 if (size > ELF_MIN_ALIGN)
412 goto out;
413 elf_phdata = kmalloc(size, GFP_KERNEL);
414 if (!elf_phdata)
415 goto out;
417 retval = kernel_read(interpreter, interp_elf_ex->e_phoff,
418 (char *)elf_phdata,size);
419 error = -EIO;
420 if (retval != size) {
421 if (retval < 0)
422 error = retval;
423 goto out_close;
426 total_size = total_mapping_size(elf_phdata, interp_elf_ex->e_phnum);
427 if (!total_size) {
428 error = -EINVAL;
429 goto out_close;
432 eppnt = elf_phdata;
433 for (i = 0; i < interp_elf_ex->e_phnum; i++, eppnt++) {
434 if (eppnt->p_type == PT_LOAD) {
435 int elf_type = MAP_PRIVATE | MAP_DENYWRITE;
436 int elf_prot = 0;
437 unsigned long vaddr = 0;
438 unsigned long k, map_addr;
440 if (eppnt->p_flags & PF_R)
441 elf_prot = PROT_READ;
442 if (eppnt->p_flags & PF_W)
443 elf_prot |= PROT_WRITE;
444 if (eppnt->p_flags & PF_X)
445 elf_prot |= PROT_EXEC;
446 vaddr = eppnt->p_vaddr;
447 if (interp_elf_ex->e_type == ET_EXEC || load_addr_set)
448 elf_type |= MAP_FIXED;
449 else if (no_base && interp_elf_ex->e_type == ET_DYN)
450 load_addr = -vaddr;
452 map_addr = elf_map(interpreter, load_addr + vaddr,
453 eppnt, elf_prot, elf_type, total_size);
454 total_size = 0;
455 if (!*interp_map_addr)
456 *interp_map_addr = map_addr;
457 error = map_addr;
458 if (BAD_ADDR(map_addr))
459 goto out_close;
461 if (!load_addr_set &&
462 interp_elf_ex->e_type == ET_DYN) {
463 load_addr = map_addr - ELF_PAGESTART(vaddr);
464 load_addr_set = 1;
468 * Check to see if the section's size will overflow the
469 * allowed task size. Note that p_filesz must always be
470 * <= p_memsize so it's only necessary to check p_memsz.
472 k = load_addr + eppnt->p_vaddr;
473 if (BAD_ADDR(k) ||
474 eppnt->p_filesz > eppnt->p_memsz ||
475 eppnt->p_memsz > TASK_SIZE ||
476 TASK_SIZE - eppnt->p_memsz < k) {
477 error = -ENOMEM;
478 goto out_close;
482 * Find the end of the file mapping for this phdr, and
483 * keep track of the largest address we see for this.
485 k = load_addr + eppnt->p_vaddr + eppnt->p_filesz;
486 if (k > elf_bss)
487 elf_bss = k;
490 * Do the same thing for the memory mapping - between
491 * elf_bss and last_bss is the bss section.
493 k = load_addr + eppnt->p_memsz + eppnt->p_vaddr;
494 if (k > last_bss)
495 last_bss = k;
500 * Now fill out the bss section. First pad the last page up
501 * to the page boundary, and then perform a mmap to make sure
502 * that there are zero-mapped pages up to and including the
503 * last bss page.
505 if (padzero(elf_bss)) {
506 error = -EFAULT;
507 goto out_close;
510 /* What we have mapped so far */
511 elf_bss = ELF_PAGESTART(elf_bss + ELF_MIN_ALIGN - 1);
513 /* Map the last of the bss segment */
514 if (last_bss > elf_bss) {
515 down_write(&current->mm->mmap_sem);
516 error = do_brk(elf_bss, last_bss - elf_bss);
517 up_write(&current->mm->mmap_sem);
518 if (BAD_ADDR(error))
519 goto out_close;
522 error = load_addr;
524 out_close:
525 kfree(elf_phdata);
526 out:
527 return error;
531 * These are the functions used to load ELF style executables and shared
532 * libraries. There is no binary dependent code anywhere else.
535 #define INTERPRETER_NONE 0
536 #define INTERPRETER_ELF 2
538 #ifndef STACK_RND_MASK
539 #define STACK_RND_MASK (0x7ff >> (PAGE_SHIFT - 12)) /* 8MB of VA */
540 #endif
542 static unsigned long randomize_stack_top(unsigned long stack_top)
544 unsigned int random_variable = 0;
546 if ((current->flags & PF_RANDOMIZE) &&
547 !(current->personality & ADDR_NO_RANDOMIZE)) {
548 random_variable = get_random_int() & STACK_RND_MASK;
549 random_variable <<= PAGE_SHIFT;
551 #ifdef CONFIG_STACK_GROWSUP
552 return PAGE_ALIGN(stack_top) + random_variable;
553 #else
554 return PAGE_ALIGN(stack_top) - random_variable;
555 #endif
558 static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
560 struct file *interpreter = NULL; /* to shut gcc up */
561 unsigned long load_addr = 0, load_bias = 0;
562 int load_addr_set = 0;
563 char * elf_interpreter = NULL;
564 unsigned long error;
565 struct elf_phdr *elf_ppnt, *elf_phdata;
566 unsigned long elf_bss, elf_brk;
567 int elf_exec_fileno;
568 int retval, i;
569 unsigned int size;
570 unsigned long elf_entry;
571 unsigned long interp_load_addr = 0;
572 unsigned long start_code, end_code, start_data, end_data;
573 unsigned long reloc_func_desc = 0;
574 int executable_stack = EXSTACK_DEFAULT;
575 unsigned long def_flags = 0;
576 struct {
577 struct elfhdr elf_ex;
578 struct elfhdr interp_elf_ex;
579 } *loc;
581 loc = kmalloc(sizeof(*loc), GFP_KERNEL);
582 if (!loc) {
583 retval = -ENOMEM;
584 goto out_ret;
587 /* Get the exec-header */
588 loc->elf_ex = *((struct elfhdr *)bprm->buf);
590 retval = -ENOEXEC;
591 /* First of all, some simple consistency checks */
592 if (memcmp(loc->elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
593 goto out;
595 if (loc->elf_ex.e_type != ET_EXEC && loc->elf_ex.e_type != ET_DYN)
596 goto out;
597 if (!elf_check_arch(&loc->elf_ex))
598 goto out;
599 if (!bprm->file->f_op||!bprm->file->f_op->mmap)
600 goto out;
602 /* Now read in all of the header information */
603 if (loc->elf_ex.e_phentsize != sizeof(struct elf_phdr))
604 goto out;
605 if (loc->elf_ex.e_phnum < 1 ||
606 loc->elf_ex.e_phnum > 65536U / sizeof(struct elf_phdr))
607 goto out;
608 size = loc->elf_ex.e_phnum * sizeof(struct elf_phdr);
609 retval = -ENOMEM;
610 elf_phdata = kmalloc(size, GFP_KERNEL);
611 if (!elf_phdata)
612 goto out;
614 retval = kernel_read(bprm->file, loc->elf_ex.e_phoff,
615 (char *)elf_phdata, size);
616 if (retval != size) {
617 if (retval >= 0)
618 retval = -EIO;
619 goto out_free_ph;
622 retval = get_unused_fd();
623 if (retval < 0)
624 goto out_free_ph;
625 get_file(bprm->file);
626 fd_install(elf_exec_fileno = retval, bprm->file);
628 elf_ppnt = elf_phdata;
629 elf_bss = 0;
630 elf_brk = 0;
632 start_code = ~0UL;
633 end_code = 0;
634 start_data = 0;
635 end_data = 0;
637 for (i = 0; i < loc->elf_ex.e_phnum; i++) {
638 if (elf_ppnt->p_type == PT_INTERP) {
639 /* This is the program interpreter used for
640 * shared libraries - for now assume that this
641 * is an a.out format binary
643 retval = -ENOEXEC;
644 if (elf_ppnt->p_filesz > PATH_MAX ||
645 elf_ppnt->p_filesz < 2)
646 goto out_free_file;
648 retval = -ENOMEM;
649 elf_interpreter = kmalloc(elf_ppnt->p_filesz,
650 GFP_KERNEL);
651 if (!elf_interpreter)
652 goto out_free_file;
654 retval = kernel_read(bprm->file, elf_ppnt->p_offset,
655 elf_interpreter,
656 elf_ppnt->p_filesz);
657 if (retval != elf_ppnt->p_filesz) {
658 if (retval >= 0)
659 retval = -EIO;
660 goto out_free_interp;
662 /* make sure path is NULL terminated */
663 retval = -ENOEXEC;
664 if (elf_interpreter[elf_ppnt->p_filesz - 1] != '\0')
665 goto out_free_interp;
668 * The early SET_PERSONALITY here is so that the lookup
669 * for the interpreter happens in the namespace of the
670 * to-be-execed image. SET_PERSONALITY can select an
671 * alternate root.
673 * However, SET_PERSONALITY is NOT allowed to switch
674 * this task into the new images's memory mapping
675 * policy - that is, TASK_SIZE must still evaluate to
676 * that which is appropriate to the execing application.
677 * This is because exit_mmap() needs to have TASK_SIZE
678 * evaluate to the size of the old image.
680 * So if (say) a 64-bit application is execing a 32-bit
681 * application it is the architecture's responsibility
682 * to defer changing the value of TASK_SIZE until the
683 * switch really is going to happen - do this in
684 * flush_thread(). - akpm
686 SET_PERSONALITY(loc->elf_ex);
688 interpreter = open_exec(elf_interpreter);
689 retval = PTR_ERR(interpreter);
690 if (IS_ERR(interpreter))
691 goto out_free_interp;
694 * If the binary is not readable then enforce
695 * mm->dumpable = 0 regardless of the interpreter's
696 * permissions.
698 if (file_permission(interpreter, MAY_READ) < 0)
699 bprm->interp_flags |= BINPRM_FLAGS_ENFORCE_NONDUMP;
701 retval = kernel_read(interpreter, 0, bprm->buf,
702 BINPRM_BUF_SIZE);
703 if (retval != BINPRM_BUF_SIZE) {
704 if (retval >= 0)
705 retval = -EIO;
706 goto out_free_dentry;
709 /* Get the exec headers */
710 loc->interp_elf_ex = *((struct elfhdr *)bprm->buf);
711 break;
713 elf_ppnt++;
716 elf_ppnt = elf_phdata;
717 for (i = 0; i < loc->elf_ex.e_phnum; i++, elf_ppnt++)
718 if (elf_ppnt->p_type == PT_GNU_STACK) {
719 if (elf_ppnt->p_flags & PF_X)
720 executable_stack = EXSTACK_ENABLE_X;
721 else
722 executable_stack = EXSTACK_DISABLE_X;
723 break;
726 /* Some simple consistency checks for the interpreter */
727 if (elf_interpreter) {
728 retval = -ELIBBAD;
729 /* Not an ELF interpreter */
730 if (memcmp(loc->interp_elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
731 goto out_free_dentry;
732 /* Verify the interpreter has a valid arch */
733 if (!elf_check_arch(&loc->interp_elf_ex))
734 goto out_free_dentry;
735 } else {
736 /* Executables without an interpreter also need a personality */
737 SET_PERSONALITY(loc->elf_ex);
740 /* Flush all traces of the currently running executable */
741 retval = flush_old_exec(bprm);
742 if (retval)
743 goto out_free_dentry;
745 /* OK, This is the point of no return */
746 current->flags &= ~PF_FORKNOEXEC;
747 current->mm->def_flags = def_flags;
749 /* Do this immediately, since STACK_TOP as used in setup_arg_pages
750 may depend on the personality. */
751 SET_PERSONALITY(loc->elf_ex);
752 if (elf_read_implies_exec(loc->elf_ex, executable_stack))
753 current->personality |= READ_IMPLIES_EXEC;
755 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
756 current->flags |= PF_RANDOMIZE;
757 arch_pick_mmap_layout(current->mm);
759 /* Do this so that we can load the interpreter, if need be. We will
760 change some of these later */
761 current->mm->free_area_cache = current->mm->mmap_base;
762 current->mm->cached_hole_size = 0;
763 retval = setup_arg_pages(bprm, randomize_stack_top(STACK_TOP),
764 executable_stack);
765 if (retval < 0) {
766 send_sig(SIGKILL, current, 0);
767 goto out_free_dentry;
770 current->mm->start_stack = bprm->p;
772 /* Now we do a little grungy work by mmaping the ELF image into
773 the correct location in memory. */
774 for(i = 0, elf_ppnt = elf_phdata;
775 i < loc->elf_ex.e_phnum; i++, elf_ppnt++) {
776 int elf_prot = 0, elf_flags;
777 unsigned long k, vaddr;
779 if (elf_ppnt->p_type != PT_LOAD)
780 continue;
782 if (unlikely (elf_brk > elf_bss)) {
783 unsigned long nbyte;
785 /* There was a PT_LOAD segment with p_memsz > p_filesz
786 before this one. Map anonymous pages, if needed,
787 and clear the area. */
788 retval = set_brk (elf_bss + load_bias,
789 elf_brk + load_bias);
790 if (retval) {
791 send_sig(SIGKILL, current, 0);
792 goto out_free_dentry;
794 nbyte = ELF_PAGEOFFSET(elf_bss);
795 if (nbyte) {
796 nbyte = ELF_MIN_ALIGN - nbyte;
797 if (nbyte > elf_brk - elf_bss)
798 nbyte = elf_brk - elf_bss;
799 if (clear_user((void __user *)elf_bss +
800 load_bias, nbyte)) {
802 * This bss-zeroing can fail if the ELF
803 * file specifies odd protections. So
804 * we don't check the return value
810 if (elf_ppnt->p_flags & PF_R)
811 elf_prot |= PROT_READ;
812 if (elf_ppnt->p_flags & PF_W)
813 elf_prot |= PROT_WRITE;
814 if (elf_ppnt->p_flags & PF_X)
815 elf_prot |= PROT_EXEC;
817 elf_flags = MAP_PRIVATE | MAP_DENYWRITE | MAP_EXECUTABLE;
819 vaddr = elf_ppnt->p_vaddr;
820 if (loc->elf_ex.e_type == ET_EXEC || load_addr_set) {
821 elf_flags |= MAP_FIXED;
822 } else if (loc->elf_ex.e_type == ET_DYN) {
823 /* Try and get dynamic programs out of the way of the
824 * default mmap base, as well as whatever program they
825 * might try to exec. This is because the brk will
826 * follow the loader, and is not movable. */
827 #ifdef CONFIG_X86
828 load_bias = 0;
829 #else
830 load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
831 #endif
834 error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
835 elf_prot, elf_flags, 0);
836 if (BAD_ADDR(error)) {
837 send_sig(SIGKILL, current, 0);
838 retval = IS_ERR((void *)error) ?
839 PTR_ERR((void*)error) : -EINVAL;
840 goto out_free_dentry;
843 if (!load_addr_set) {
844 load_addr_set = 1;
845 load_addr = (elf_ppnt->p_vaddr - elf_ppnt->p_offset);
846 if (loc->elf_ex.e_type == ET_DYN) {
847 load_bias += error -
848 ELF_PAGESTART(load_bias + vaddr);
849 load_addr += load_bias;
850 reloc_func_desc = load_bias;
853 k = elf_ppnt->p_vaddr;
854 if (k < start_code)
855 start_code = k;
856 if (start_data < k)
857 start_data = k;
860 * Check to see if the section's size will overflow the
861 * allowed task size. Note that p_filesz must always be
862 * <= p_memsz so it is only necessary to check p_memsz.
864 if (BAD_ADDR(k) || elf_ppnt->p_filesz > elf_ppnt->p_memsz ||
865 elf_ppnt->p_memsz > TASK_SIZE ||
866 TASK_SIZE - elf_ppnt->p_memsz < k) {
867 /* set_brk can never work. Avoid overflows. */
868 send_sig(SIGKILL, current, 0);
869 retval = -EINVAL;
870 goto out_free_dentry;
873 k = elf_ppnt->p_vaddr + elf_ppnt->p_filesz;
875 if (k > elf_bss)
876 elf_bss = k;
877 if ((elf_ppnt->p_flags & PF_X) && end_code < k)
878 end_code = k;
879 if (end_data < k)
880 end_data = k;
881 k = elf_ppnt->p_vaddr + elf_ppnt->p_memsz;
882 if (k > elf_brk)
883 elf_brk = k;
886 loc->elf_ex.e_entry += load_bias;
887 elf_bss += load_bias;
888 elf_brk += load_bias;
889 start_code += load_bias;
890 end_code += load_bias;
891 start_data += load_bias;
892 end_data += load_bias;
894 /* Calling set_brk effectively mmaps the pages that we need
895 * for the bss and break sections. We must do this before
896 * mapping in the interpreter, to make sure it doesn't wind
897 * up getting placed where the bss needs to go.
899 retval = set_brk(elf_bss, elf_brk);
900 if (retval) {
901 send_sig(SIGKILL, current, 0);
902 goto out_free_dentry;
904 if (likely(elf_bss != elf_brk) && unlikely(padzero(elf_bss))) {
905 send_sig(SIGSEGV, current, 0);
906 retval = -EFAULT; /* Nobody gets to see this, but.. */
907 goto out_free_dentry;
910 if (elf_interpreter) {
911 unsigned long uninitialized_var(interp_map_addr);
913 elf_entry = load_elf_interp(&loc->interp_elf_ex,
914 interpreter,
915 &interp_map_addr,
916 load_bias);
917 if (!IS_ERR((void *)elf_entry)) {
919 * load_elf_interp() returns relocation
920 * adjustment
922 interp_load_addr = elf_entry;
923 elf_entry += loc->interp_elf_ex.e_entry;
925 if (BAD_ADDR(elf_entry)) {
926 force_sig(SIGSEGV, current);
927 retval = IS_ERR((void *)elf_entry) ?
928 (int)elf_entry : -EINVAL;
929 goto out_free_dentry;
931 reloc_func_desc = interp_load_addr;
933 allow_write_access(interpreter);
934 fput(interpreter);
935 kfree(elf_interpreter);
936 } else {
937 elf_entry = loc->elf_ex.e_entry;
938 if (BAD_ADDR(elf_entry)) {
939 force_sig(SIGSEGV, current);
940 retval = -EINVAL;
941 goto out_free_dentry;
945 kfree(elf_phdata);
947 sys_close(elf_exec_fileno);
949 set_binfmt(&elf_format);
951 #ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
952 retval = arch_setup_additional_pages(bprm, executable_stack);
953 if (retval < 0) {
954 send_sig(SIGKILL, current, 0);
955 goto out;
957 #endif /* ARCH_HAS_SETUP_ADDITIONAL_PAGES */
959 compute_creds(bprm);
960 current->flags &= ~PF_FORKNOEXEC;
961 retval = create_elf_tables(bprm, &loc->elf_ex,
962 load_addr, interp_load_addr);
963 if (retval < 0) {
964 send_sig(SIGKILL, current, 0);
965 goto out;
967 /* N.B. passed_fileno might not be initialized? */
968 current->mm->end_code = end_code;
969 current->mm->start_code = start_code;
970 current->mm->start_data = start_data;
971 current->mm->end_data = end_data;
972 current->mm->start_stack = bprm->p;
974 #ifdef arch_randomize_brk
975 if ((current->flags & PF_RANDOMIZE) && (randomize_va_space > 1))
976 current->mm->brk = current->mm->start_brk =
977 arch_randomize_brk(current->mm);
978 #endif
980 if (current->personality & MMAP_PAGE_ZERO) {
981 /* Why this, you ask??? Well SVr4 maps page 0 as read-only,
982 and some applications "depend" upon this behavior.
983 Since we do not have the power to recompile these, we
984 emulate the SVr4 behavior. Sigh. */
985 down_write(&current->mm->mmap_sem);
986 error = do_mmap(NULL, 0, PAGE_SIZE, PROT_READ | PROT_EXEC,
987 MAP_FIXED | MAP_PRIVATE, 0);
988 up_write(&current->mm->mmap_sem);
991 #ifdef ELF_PLAT_INIT
993 * The ABI may specify that certain registers be set up in special
994 * ways (on i386 %edx is the address of a DT_FINI function, for
995 * example. In addition, it may also specify (eg, PowerPC64 ELF)
996 * that the e_entry field is the address of the function descriptor
997 * for the startup routine, rather than the address of the startup
998 * routine itself. This macro performs whatever initialization to
999 * the regs structure is required as well as any relocations to the
1000 * function descriptor entries when executing dynamically links apps.
1002 ELF_PLAT_INIT(regs, reloc_func_desc);
1003 #endif
1005 start_thread(regs, elf_entry, bprm->p);
1006 retval = 0;
1007 out:
1008 kfree(loc);
1009 out_ret:
1010 return retval;
1012 /* error cleanup */
1013 out_free_dentry:
1014 allow_write_access(interpreter);
1015 if (interpreter)
1016 fput(interpreter);
1017 out_free_interp:
1018 kfree(elf_interpreter);
1019 out_free_file:
1020 sys_close(elf_exec_fileno);
1021 out_free_ph:
1022 kfree(elf_phdata);
1023 goto out;
1026 /* This is really simpleminded and specialized - we are loading an
1027 a.out library that is given an ELF header. */
1028 static int load_elf_library(struct file *file)
1030 struct elf_phdr *elf_phdata;
1031 struct elf_phdr *eppnt;
1032 unsigned long elf_bss, bss, len;
1033 int retval, error, i, j;
1034 struct elfhdr elf_ex;
1036 error = -ENOEXEC;
1037 retval = kernel_read(file, 0, (char *)&elf_ex, sizeof(elf_ex));
1038 if (retval != sizeof(elf_ex))
1039 goto out;
1041 if (memcmp(elf_ex.e_ident, ELFMAG, SELFMAG) != 0)
1042 goto out;
1044 /* First of all, some simple consistency checks */
1045 if (elf_ex.e_type != ET_EXEC || elf_ex.e_phnum > 2 ||
1046 !elf_check_arch(&elf_ex) || !file->f_op || !file->f_op->mmap)
1047 goto out;
1049 /* Now read in all of the header information */
1051 j = sizeof(struct elf_phdr) * elf_ex.e_phnum;
1052 /* j < ELF_MIN_ALIGN because elf_ex.e_phnum <= 2 */
1054 error = -ENOMEM;
1055 elf_phdata = kmalloc(j, GFP_KERNEL);
1056 if (!elf_phdata)
1057 goto out;
1059 eppnt = elf_phdata;
1060 error = -ENOEXEC;
1061 retval = kernel_read(file, elf_ex.e_phoff, (char *)eppnt, j);
1062 if (retval != j)
1063 goto out_free_ph;
1065 for (j = 0, i = 0; i<elf_ex.e_phnum; i++)
1066 if ((eppnt + i)->p_type == PT_LOAD)
1067 j++;
1068 if (j != 1)
1069 goto out_free_ph;
1071 while (eppnt->p_type != PT_LOAD)
1072 eppnt++;
1074 /* Now use mmap to map the library into memory. */
1075 down_write(&current->mm->mmap_sem);
1076 error = do_mmap(file,
1077 ELF_PAGESTART(eppnt->p_vaddr),
1078 (eppnt->p_filesz +
1079 ELF_PAGEOFFSET(eppnt->p_vaddr)),
1080 PROT_READ | PROT_WRITE | PROT_EXEC,
1081 MAP_FIXED | MAP_PRIVATE | MAP_DENYWRITE,
1082 (eppnt->p_offset -
1083 ELF_PAGEOFFSET(eppnt->p_vaddr)));
1084 up_write(&current->mm->mmap_sem);
1085 if (error != ELF_PAGESTART(eppnt->p_vaddr))
1086 goto out_free_ph;
1088 elf_bss = eppnt->p_vaddr + eppnt->p_filesz;
1089 if (padzero(elf_bss)) {
1090 error = -EFAULT;
1091 goto out_free_ph;
1094 len = ELF_PAGESTART(eppnt->p_filesz + eppnt->p_vaddr +
1095 ELF_MIN_ALIGN - 1);
1096 bss = eppnt->p_memsz + eppnt->p_vaddr;
1097 if (bss > len) {
1098 down_write(&current->mm->mmap_sem);
1099 do_brk(len, bss - len);
1100 up_write(&current->mm->mmap_sem);
1102 error = 0;
1104 out_free_ph:
1105 kfree(elf_phdata);
1106 out:
1107 return error;
1111 * Note that some platforms still use traditional core dumps and not
1112 * the ELF core dump. Each platform can select it as appropriate.
1114 #if defined(USE_ELF_CORE_DUMP) && defined(CONFIG_ELF_CORE)
1117 * ELF core dumper
1119 * Modelled on fs/exec.c:aout_core_dump()
1120 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1123 * These are the only things you should do on a core-file: use only these
1124 * functions to write out all the necessary info.
1126 static int dump_write(struct file *file, const void *addr, int nr)
1128 return file->f_op->write(file, addr, nr, &file->f_pos) == nr;
1131 static int dump_seek(struct file *file, loff_t off)
1133 if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
1134 if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
1135 return 0;
1136 } else {
1137 char *buf = (char *)get_zeroed_page(GFP_KERNEL);
1138 if (!buf)
1139 return 0;
1140 while (off > 0) {
1141 unsigned long n = off;
1142 if (n > PAGE_SIZE)
1143 n = PAGE_SIZE;
1144 if (!dump_write(file, buf, n))
1145 return 0;
1146 off -= n;
1148 free_page((unsigned long)buf);
1150 return 1;
1154 * Decide what to dump of a segment, part, all or none.
1156 static unsigned long vma_dump_size(struct vm_area_struct *vma,
1157 unsigned long mm_flags)
1159 #define FILTER(type) (mm_flags & (1UL << MMF_DUMP_##type))
1161 /* The vma can be set up to tell us the answer directly. */
1162 if (vma->vm_flags & VM_ALWAYSDUMP)
1163 goto whole;
1165 /* Hugetlb memory check */
1166 if (vma->vm_flags & VM_HUGETLB) {
1167 if ((vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_SHARED))
1168 goto whole;
1169 if (!(vma->vm_flags & VM_SHARED) && FILTER(HUGETLB_PRIVATE))
1170 goto whole;
1173 /* Do not dump I/O mapped devices or special mappings */
1174 if (vma->vm_flags & (VM_IO | VM_RESERVED))
1175 return 0;
1177 /* By default, dump shared memory if mapped from an anonymous file. */
1178 if (vma->vm_flags & VM_SHARED) {
1179 if (vma->vm_file->f_path.dentry->d_inode->i_nlink == 0 ?
1180 FILTER(ANON_SHARED) : FILTER(MAPPED_SHARED))
1181 goto whole;
1182 return 0;
1185 /* Dump segments that have been written to. */
1186 if (vma->anon_vma && FILTER(ANON_PRIVATE))
1187 goto whole;
1188 if (vma->vm_file == NULL)
1189 return 0;
1191 if (FILTER(MAPPED_PRIVATE))
1192 goto whole;
1195 * If this looks like the beginning of a DSO or executable mapping,
1196 * check for an ELF header. If we find one, dump the first page to
1197 * aid in determining what was mapped here.
1199 if (FILTER(ELF_HEADERS) && vma->vm_file != NULL && vma->vm_pgoff == 0) {
1200 u32 __user *header = (u32 __user *) vma->vm_start;
1201 u32 word;
1203 * Doing it this way gets the constant folded by GCC.
1205 union {
1206 u32 cmp;
1207 char elfmag[SELFMAG];
1208 } magic;
1209 BUILD_BUG_ON(SELFMAG != sizeof word);
1210 magic.elfmag[EI_MAG0] = ELFMAG0;
1211 magic.elfmag[EI_MAG1] = ELFMAG1;
1212 magic.elfmag[EI_MAG2] = ELFMAG2;
1213 magic.elfmag[EI_MAG3] = ELFMAG3;
1214 if (get_user(word, header) == 0 && word == magic.cmp)
1215 return PAGE_SIZE;
1218 #undef FILTER
1220 return 0;
1222 whole:
1223 return vma->vm_end - vma->vm_start;
1226 /* An ELF note in memory */
1227 struct memelfnote
1229 const char *name;
1230 int type;
1231 unsigned int datasz;
1232 void *data;
1235 static int notesize(struct memelfnote *en)
1237 int sz;
1239 sz = sizeof(struct elf_note);
1240 sz += roundup(strlen(en->name) + 1, 4);
1241 sz += roundup(en->datasz, 4);
1243 return sz;
1246 #define DUMP_WRITE(addr, nr, foffset) \
1247 do { if (!dump_write(file, (addr), (nr))) return 0; *foffset += (nr); } while(0)
1249 static int alignfile(struct file *file, loff_t *foffset)
1251 static const char buf[4] = { 0, };
1252 DUMP_WRITE(buf, roundup(*foffset, 4) - *foffset, foffset);
1253 return 1;
1256 static int writenote(struct memelfnote *men, struct file *file,
1257 loff_t *foffset)
1259 struct elf_note en;
1260 en.n_namesz = strlen(men->name) + 1;
1261 en.n_descsz = men->datasz;
1262 en.n_type = men->type;
1264 DUMP_WRITE(&en, sizeof(en), foffset);
1265 DUMP_WRITE(men->name, en.n_namesz, foffset);
1266 if (!alignfile(file, foffset))
1267 return 0;
1268 DUMP_WRITE(men->data, men->datasz, foffset);
1269 if (!alignfile(file, foffset))
1270 return 0;
1272 return 1;
1274 #undef DUMP_WRITE
1276 #define DUMP_WRITE(addr, nr) \
1277 if ((size += (nr)) > limit || !dump_write(file, (addr), (nr))) \
1278 goto end_coredump;
1279 #define DUMP_SEEK(off) \
1280 if (!dump_seek(file, (off))) \
1281 goto end_coredump;
1283 static void fill_elf_header(struct elfhdr *elf, int segs,
1284 u16 machine, u32 flags, u8 osabi)
1286 memset(elf, 0, sizeof(*elf));
1288 memcpy(elf->e_ident, ELFMAG, SELFMAG);
1289 elf->e_ident[EI_CLASS] = ELF_CLASS;
1290 elf->e_ident[EI_DATA] = ELF_DATA;
1291 elf->e_ident[EI_VERSION] = EV_CURRENT;
1292 elf->e_ident[EI_OSABI] = ELF_OSABI;
1294 elf->e_type = ET_CORE;
1295 elf->e_machine = machine;
1296 elf->e_version = EV_CURRENT;
1297 elf->e_phoff = sizeof(struct elfhdr);
1298 elf->e_flags = flags;
1299 elf->e_ehsize = sizeof(struct elfhdr);
1300 elf->e_phentsize = sizeof(struct elf_phdr);
1301 elf->e_phnum = segs;
1303 return;
1306 static void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1308 phdr->p_type = PT_NOTE;
1309 phdr->p_offset = offset;
1310 phdr->p_vaddr = 0;
1311 phdr->p_paddr = 0;
1312 phdr->p_filesz = sz;
1313 phdr->p_memsz = 0;
1314 phdr->p_flags = 0;
1315 phdr->p_align = 0;
1316 return;
1319 static void fill_note(struct memelfnote *note, const char *name, int type,
1320 unsigned int sz, void *data)
1322 note->name = name;
1323 note->type = type;
1324 note->datasz = sz;
1325 note->data = data;
1326 return;
1330 * fill up all the fields in prstatus from the given task struct, except
1331 * registers which need to be filled up separately.
1333 static void fill_prstatus(struct elf_prstatus *prstatus,
1334 struct task_struct *p, long signr)
1336 prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1337 prstatus->pr_sigpend = p->pending.signal.sig[0];
1338 prstatus->pr_sighold = p->blocked.sig[0];
1339 prstatus->pr_pid = task_pid_vnr(p);
1340 prstatus->pr_ppid = task_pid_vnr(p->real_parent);
1341 prstatus->pr_pgrp = task_pgrp_vnr(p);
1342 prstatus->pr_sid = task_session_vnr(p);
1343 if (thread_group_leader(p)) {
1344 struct task_cputime cputime;
1347 * This is the record for the group leader. It shows the
1348 * group-wide total, not its individual thread total.
1350 thread_group_cputime(p, &cputime);
1351 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1352 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1353 } else {
1354 cputime_to_timeval(p->utime, &prstatus->pr_utime);
1355 cputime_to_timeval(p->stime, &prstatus->pr_stime);
1357 cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1358 cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1361 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1362 struct mm_struct *mm)
1364 unsigned int i, len;
1366 /* first copy the parameters from user space */
1367 memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1369 len = mm->arg_end - mm->arg_start;
1370 if (len >= ELF_PRARGSZ)
1371 len = ELF_PRARGSZ-1;
1372 if (copy_from_user(&psinfo->pr_psargs,
1373 (const char __user *)mm->arg_start, len))
1374 return -EFAULT;
1375 for(i = 0; i < len; i++)
1376 if (psinfo->pr_psargs[i] == 0)
1377 psinfo->pr_psargs[i] = ' ';
1378 psinfo->pr_psargs[len] = 0;
1380 psinfo->pr_pid = task_pid_vnr(p);
1381 psinfo->pr_ppid = task_pid_vnr(p->real_parent);
1382 psinfo->pr_pgrp = task_pgrp_vnr(p);
1383 psinfo->pr_sid = task_session_vnr(p);
1385 i = p->state ? ffz(~p->state) + 1 : 0;
1386 psinfo->pr_state = i;
1387 psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1388 psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1389 psinfo->pr_nice = task_nice(p);
1390 psinfo->pr_flag = p->flags;
1391 SET_UID(psinfo->pr_uid, p->uid);
1392 SET_GID(psinfo->pr_gid, p->gid);
1393 strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1395 return 0;
1398 static void fill_auxv_note(struct memelfnote *note, struct mm_struct *mm)
1400 elf_addr_t *auxv = (elf_addr_t *) mm->saved_auxv;
1401 int i = 0;
1403 i += 2;
1404 while (auxv[i - 2] != AT_NULL);
1405 fill_note(note, "CORE", NT_AUXV, i * sizeof(elf_addr_t), auxv);
1408 #ifdef CORE_DUMP_USE_REGSET
1409 #include <linux/regset.h>
1411 struct elf_thread_core_info {
1412 struct elf_thread_core_info *next;
1413 struct task_struct *task;
1414 struct elf_prstatus prstatus;
1415 struct memelfnote notes[0];
1418 struct elf_note_info {
1419 struct elf_thread_core_info *thread;
1420 struct memelfnote psinfo;
1421 struct memelfnote auxv;
1422 size_t size;
1423 int thread_notes;
1427 * When a regset has a writeback hook, we call it on each thread before
1428 * dumping user memory. On register window machines, this makes sure the
1429 * user memory backing the register data is up to date before we read it.
1431 static void do_thread_regset_writeback(struct task_struct *task,
1432 const struct user_regset *regset)
1434 if (regset->writeback)
1435 regset->writeback(task, regset, 1);
1438 static int fill_thread_core_info(struct elf_thread_core_info *t,
1439 const struct user_regset_view *view,
1440 long signr, size_t *total)
1442 unsigned int i;
1445 * NT_PRSTATUS is the one special case, because the regset data
1446 * goes into the pr_reg field inside the note contents, rather
1447 * than being the whole note contents. We fill the reset in here.
1448 * We assume that regset 0 is NT_PRSTATUS.
1450 fill_prstatus(&t->prstatus, t->task, signr);
1451 (void) view->regsets[0].get(t->task, &view->regsets[0],
1452 0, sizeof(t->prstatus.pr_reg),
1453 &t->prstatus.pr_reg, NULL);
1455 fill_note(&t->notes[0], "CORE", NT_PRSTATUS,
1456 sizeof(t->prstatus), &t->prstatus);
1457 *total += notesize(&t->notes[0]);
1459 do_thread_regset_writeback(t->task, &view->regsets[0]);
1462 * Each other regset might generate a note too. For each regset
1463 * that has no core_note_type or is inactive, we leave t->notes[i]
1464 * all zero and we'll know to skip writing it later.
1466 for (i = 1; i < view->n; ++i) {
1467 const struct user_regset *regset = &view->regsets[i];
1468 do_thread_regset_writeback(t->task, regset);
1469 if (regset->core_note_type &&
1470 (!regset->active || regset->active(t->task, regset))) {
1471 int ret;
1472 size_t size = regset->n * regset->size;
1473 void *data = kmalloc(size, GFP_KERNEL);
1474 if (unlikely(!data))
1475 return 0;
1476 ret = regset->get(t->task, regset,
1477 0, size, data, NULL);
1478 if (unlikely(ret))
1479 kfree(data);
1480 else {
1481 if (regset->core_note_type != NT_PRFPREG)
1482 fill_note(&t->notes[i], "LINUX",
1483 regset->core_note_type,
1484 size, data);
1485 else {
1486 t->prstatus.pr_fpvalid = 1;
1487 fill_note(&t->notes[i], "CORE",
1488 NT_PRFPREG, size, data);
1490 *total += notesize(&t->notes[i]);
1495 return 1;
1498 static int fill_note_info(struct elfhdr *elf, int phdrs,
1499 struct elf_note_info *info,
1500 long signr, struct pt_regs *regs)
1502 struct task_struct *dump_task = current;
1503 const struct user_regset_view *view = task_user_regset_view(dump_task);
1504 struct elf_thread_core_info *t;
1505 struct elf_prpsinfo *psinfo;
1506 struct core_thread *ct;
1507 unsigned int i;
1509 info->size = 0;
1510 info->thread = NULL;
1512 psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1513 fill_note(&info->psinfo, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1515 if (psinfo == NULL)
1516 return 0;
1519 * Figure out how many notes we're going to need for each thread.
1521 info->thread_notes = 0;
1522 for (i = 0; i < view->n; ++i)
1523 if (view->regsets[i].core_note_type != 0)
1524 ++info->thread_notes;
1527 * Sanity check. We rely on regset 0 being in NT_PRSTATUS,
1528 * since it is our one special case.
1530 if (unlikely(info->thread_notes == 0) ||
1531 unlikely(view->regsets[0].core_note_type != NT_PRSTATUS)) {
1532 WARN_ON(1);
1533 return 0;
1537 * Initialize the ELF file header.
1539 fill_elf_header(elf, phdrs,
1540 view->e_machine, view->e_flags, view->ei_osabi);
1543 * Allocate a structure for each thread.
1545 for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {
1546 t = kzalloc(offsetof(struct elf_thread_core_info,
1547 notes[info->thread_notes]),
1548 GFP_KERNEL);
1549 if (unlikely(!t))
1550 return 0;
1552 t->task = ct->task;
1553 if (ct->task == dump_task || !info->thread) {
1554 t->next = info->thread;
1555 info->thread = t;
1556 } else {
1558 * Make sure to keep the original task at
1559 * the head of the list.
1561 t->next = info->thread->next;
1562 info->thread->next = t;
1567 * Now fill in each thread's information.
1569 for (t = info->thread; t != NULL; t = t->next)
1570 if (!fill_thread_core_info(t, view, signr, &info->size))
1571 return 0;
1574 * Fill in the two process-wide notes.
1576 fill_psinfo(psinfo, dump_task->group_leader, dump_task->mm);
1577 info->size += notesize(&info->psinfo);
1579 fill_auxv_note(&info->auxv, current->mm);
1580 info->size += notesize(&info->auxv);
1582 return 1;
1585 static size_t get_note_info_size(struct elf_note_info *info)
1587 return info->size;
1591 * Write all the notes for each thread. When writing the first thread, the
1592 * process-wide notes are interleaved after the first thread-specific note.
1594 static int write_note_info(struct elf_note_info *info,
1595 struct file *file, loff_t *foffset)
1597 bool first = 1;
1598 struct elf_thread_core_info *t = info->thread;
1600 do {
1601 int i;
1603 if (!writenote(&t->notes[0], file, foffset))
1604 return 0;
1606 if (first && !writenote(&info->psinfo, file, foffset))
1607 return 0;
1608 if (first && !writenote(&info->auxv, file, foffset))
1609 return 0;
1611 for (i = 1; i < info->thread_notes; ++i)
1612 if (t->notes[i].data &&
1613 !writenote(&t->notes[i], file, foffset))
1614 return 0;
1616 first = 0;
1617 t = t->next;
1618 } while (t);
1620 return 1;
1623 static void free_note_info(struct elf_note_info *info)
1625 struct elf_thread_core_info *threads = info->thread;
1626 while (threads) {
1627 unsigned int i;
1628 struct elf_thread_core_info *t = threads;
1629 threads = t->next;
1630 WARN_ON(t->notes[0].data && t->notes[0].data != &t->prstatus);
1631 for (i = 1; i < info->thread_notes; ++i)
1632 kfree(t->notes[i].data);
1633 kfree(t);
1635 kfree(info->psinfo.data);
1638 #else
1640 /* Here is the structure in which status of each thread is captured. */
1641 struct elf_thread_status
1643 struct list_head list;
1644 struct elf_prstatus prstatus; /* NT_PRSTATUS */
1645 elf_fpregset_t fpu; /* NT_PRFPREG */
1646 struct task_struct *thread;
1647 #ifdef ELF_CORE_COPY_XFPREGS
1648 elf_fpxregset_t xfpu; /* ELF_CORE_XFPREG_TYPE */
1649 #endif
1650 struct memelfnote notes[3];
1651 int num_notes;
1655 * In order to add the specific thread information for the elf file format,
1656 * we need to keep a linked list of every threads pr_status and then create
1657 * a single section for them in the final core file.
1659 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1661 int sz = 0;
1662 struct task_struct *p = t->thread;
1663 t->num_notes = 0;
1665 fill_prstatus(&t->prstatus, p, signr);
1666 elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1668 fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1669 &(t->prstatus));
1670 t->num_notes++;
1671 sz += notesize(&t->notes[0]);
1673 if ((t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL,
1674 &t->fpu))) {
1675 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1676 &(t->fpu));
1677 t->num_notes++;
1678 sz += notesize(&t->notes[1]);
1681 #ifdef ELF_CORE_COPY_XFPREGS
1682 if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1683 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1684 sizeof(t->xfpu), &t->xfpu);
1685 t->num_notes++;
1686 sz += notesize(&t->notes[2]);
1688 #endif
1689 return sz;
1692 struct elf_note_info {
1693 struct memelfnote *notes;
1694 struct elf_prstatus *prstatus; /* NT_PRSTATUS */
1695 struct elf_prpsinfo *psinfo; /* NT_PRPSINFO */
1696 struct list_head thread_list;
1697 elf_fpregset_t *fpu;
1698 #ifdef ELF_CORE_COPY_XFPREGS
1699 elf_fpxregset_t *xfpu;
1700 #endif
1701 int thread_status_size;
1702 int numnote;
1705 static int fill_note_info(struct elfhdr *elf, int phdrs,
1706 struct elf_note_info *info,
1707 long signr, struct pt_regs *regs)
1709 #define NUM_NOTES 6
1710 struct list_head *t;
1712 info->notes = NULL;
1713 info->prstatus = NULL;
1714 info->psinfo = NULL;
1715 info->fpu = NULL;
1716 #ifdef ELF_CORE_COPY_XFPREGS
1717 info->xfpu = NULL;
1718 #endif
1719 INIT_LIST_HEAD(&info->thread_list);
1721 info->notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote),
1722 GFP_KERNEL);
1723 if (!info->notes)
1724 return 0;
1725 info->psinfo = kmalloc(sizeof(*info->psinfo), GFP_KERNEL);
1726 if (!info->psinfo)
1727 return 0;
1728 info->prstatus = kmalloc(sizeof(*info->prstatus), GFP_KERNEL);
1729 if (!info->prstatus)
1730 return 0;
1731 info->fpu = kmalloc(sizeof(*info->fpu), GFP_KERNEL);
1732 if (!info->fpu)
1733 return 0;
1734 #ifdef ELF_CORE_COPY_XFPREGS
1735 info->xfpu = kmalloc(sizeof(*info->xfpu), GFP_KERNEL);
1736 if (!info->xfpu)
1737 return 0;
1738 #endif
1740 info->thread_status_size = 0;
1741 if (signr) {
1742 struct core_thread *ct;
1743 struct elf_thread_status *ets;
1745 for (ct = current->mm->core_state->dumper.next;
1746 ct; ct = ct->next) {
1747 ets = kzalloc(sizeof(*ets), GFP_KERNEL);
1748 if (!ets)
1749 return 0;
1751 ets->thread = ct->task;
1752 list_add(&ets->list, &info->thread_list);
1755 list_for_each(t, &info->thread_list) {
1756 int sz;
1758 ets = list_entry(t, struct elf_thread_status, list);
1759 sz = elf_dump_thread_status(signr, ets);
1760 info->thread_status_size += sz;
1763 /* now collect the dump for the current */
1764 memset(info->prstatus, 0, sizeof(*info->prstatus));
1765 fill_prstatus(info->prstatus, current, signr);
1766 elf_core_copy_regs(&info->prstatus->pr_reg, regs);
1768 /* Set up header */
1769 fill_elf_header(elf, phdrs, ELF_ARCH, ELF_CORE_EFLAGS, ELF_OSABI);
1772 * Set up the notes in similar form to SVR4 core dumps made
1773 * with info from their /proc.
1776 fill_note(info->notes + 0, "CORE", NT_PRSTATUS,
1777 sizeof(*info->prstatus), info->prstatus);
1778 fill_psinfo(info->psinfo, current->group_leader, current->mm);
1779 fill_note(info->notes + 1, "CORE", NT_PRPSINFO,
1780 sizeof(*info->psinfo), info->psinfo);
1782 info->numnote = 2;
1784 fill_auxv_note(&info->notes[info->numnote++], current->mm);
1786 /* Try to dump the FPU. */
1787 info->prstatus->pr_fpvalid = elf_core_copy_task_fpregs(current, regs,
1788 info->fpu);
1789 if (info->prstatus->pr_fpvalid)
1790 fill_note(info->notes + info->numnote++,
1791 "CORE", NT_PRFPREG, sizeof(*info->fpu), info->fpu);
1792 #ifdef ELF_CORE_COPY_XFPREGS
1793 if (elf_core_copy_task_xfpregs(current, info->xfpu))
1794 fill_note(info->notes + info->numnote++,
1795 "LINUX", ELF_CORE_XFPREG_TYPE,
1796 sizeof(*info->xfpu), info->xfpu);
1797 #endif
1799 return 1;
1801 #undef NUM_NOTES
1804 static size_t get_note_info_size(struct elf_note_info *info)
1806 int sz = 0;
1807 int i;
1809 for (i = 0; i < info->numnote; i++)
1810 sz += notesize(info->notes + i);
1812 sz += info->thread_status_size;
1814 return sz;
1817 static int write_note_info(struct elf_note_info *info,
1818 struct file *file, loff_t *foffset)
1820 int i;
1821 struct list_head *t;
1823 for (i = 0; i < info->numnote; i++)
1824 if (!writenote(info->notes + i, file, foffset))
1825 return 0;
1827 /* write out the thread status notes section */
1828 list_for_each(t, &info->thread_list) {
1829 struct elf_thread_status *tmp =
1830 list_entry(t, struct elf_thread_status, list);
1832 for (i = 0; i < tmp->num_notes; i++)
1833 if (!writenote(&tmp->notes[i], file, foffset))
1834 return 0;
1837 return 1;
1840 static void free_note_info(struct elf_note_info *info)
1842 while (!list_empty(&info->thread_list)) {
1843 struct list_head *tmp = info->thread_list.next;
1844 list_del(tmp);
1845 kfree(list_entry(tmp, struct elf_thread_status, list));
1848 kfree(info->prstatus);
1849 kfree(info->psinfo);
1850 kfree(info->notes);
1851 kfree(info->fpu);
1852 #ifdef ELF_CORE_COPY_XFPREGS
1853 kfree(info->xfpu);
1854 #endif
1857 #endif
1859 static struct vm_area_struct *first_vma(struct task_struct *tsk,
1860 struct vm_area_struct *gate_vma)
1862 struct vm_area_struct *ret = tsk->mm->mmap;
1864 if (ret)
1865 return ret;
1866 return gate_vma;
1869 * Helper function for iterating across a vma list. It ensures that the caller
1870 * will visit `gate_vma' prior to terminating the search.
1872 static struct vm_area_struct *next_vma(struct vm_area_struct *this_vma,
1873 struct vm_area_struct *gate_vma)
1875 struct vm_area_struct *ret;
1877 ret = this_vma->vm_next;
1878 if (ret)
1879 return ret;
1880 if (this_vma == gate_vma)
1881 return NULL;
1882 return gate_vma;
1886 * Actual dumper
1888 * This is a two-pass process; first we find the offsets of the bits,
1889 * and then they are actually written out. If we run out of core limit
1890 * we just truncate.
1892 static int elf_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
1894 int has_dumped = 0;
1895 mm_segment_t fs;
1896 int segs;
1897 size_t size = 0;
1898 struct vm_area_struct *vma, *gate_vma;
1899 struct elfhdr *elf = NULL;
1900 loff_t offset = 0, dataoff, foffset;
1901 unsigned long mm_flags;
1902 struct elf_note_info info;
1905 * We no longer stop all VM operations.
1907 * This is because those proceses that could possibly change map_count
1908 * or the mmap / vma pages are now blocked in do_exit on current
1909 * finishing this core dump.
1911 * Only ptrace can touch these memory addresses, but it doesn't change
1912 * the map_count or the pages allocated. So no possibility of crashing
1913 * exists while dumping the mm->vm_next areas to the core file.
1916 /* alloc memory for large data structures: too large to be on stack */
1917 elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1918 if (!elf)
1919 goto out;
1921 segs = current->mm->map_count;
1922 #ifdef ELF_CORE_EXTRA_PHDRS
1923 segs += ELF_CORE_EXTRA_PHDRS;
1924 #endif
1926 gate_vma = get_gate_vma(current);
1927 if (gate_vma != NULL)
1928 segs++;
1931 * Collect all the non-memory information about the process for the
1932 * notes. This also sets up the file header.
1934 if (!fill_note_info(elf, segs + 1, /* including notes section */
1935 &info, signr, regs))
1936 goto cleanup;
1938 has_dumped = 1;
1939 current->flags |= PF_DUMPCORE;
1941 fs = get_fs();
1942 set_fs(KERNEL_DS);
1944 DUMP_WRITE(elf, sizeof(*elf));
1945 offset += sizeof(*elf); /* Elf header */
1946 offset += (segs + 1) * sizeof(struct elf_phdr); /* Program headers */
1947 foffset = offset;
1949 /* Write notes phdr entry */
1951 struct elf_phdr phdr;
1952 size_t sz = get_note_info_size(&info);
1954 sz += elf_coredump_extra_notes_size();
1956 fill_elf_note_phdr(&phdr, sz, offset);
1957 offset += sz;
1958 DUMP_WRITE(&phdr, sizeof(phdr));
1961 dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1964 * We must use the same mm->flags while dumping core to avoid
1965 * inconsistency between the program headers and bodies, otherwise an
1966 * unusable core file can be generated.
1968 mm_flags = current->mm->flags;
1970 /* Write program headers for segments dump */
1971 for (vma = first_vma(current, gate_vma); vma != NULL;
1972 vma = next_vma(vma, gate_vma)) {
1973 struct elf_phdr phdr;
1975 phdr.p_type = PT_LOAD;
1976 phdr.p_offset = offset;
1977 phdr.p_vaddr = vma->vm_start;
1978 phdr.p_paddr = 0;
1979 phdr.p_filesz = vma_dump_size(vma, mm_flags);
1980 phdr.p_memsz = vma->vm_end - vma->vm_start;
1981 offset += phdr.p_filesz;
1982 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1983 if (vma->vm_flags & VM_WRITE)
1984 phdr.p_flags |= PF_W;
1985 if (vma->vm_flags & VM_EXEC)
1986 phdr.p_flags |= PF_X;
1987 phdr.p_align = ELF_EXEC_PAGESIZE;
1989 DUMP_WRITE(&phdr, sizeof(phdr));
1992 #ifdef ELF_CORE_WRITE_EXTRA_PHDRS
1993 ELF_CORE_WRITE_EXTRA_PHDRS;
1994 #endif
1996 /* write out the notes section */
1997 if (!write_note_info(&info, file, &foffset))
1998 goto end_coredump;
2000 if (elf_coredump_extra_notes_write(file, &foffset))
2001 goto end_coredump;
2003 /* Align to page */
2004 DUMP_SEEK(dataoff - foffset);
2006 for (vma = first_vma(current, gate_vma); vma != NULL;
2007 vma = next_vma(vma, gate_vma)) {
2008 unsigned long addr;
2009 unsigned long end;
2011 end = vma->vm_start + vma_dump_size(vma, mm_flags);
2013 for (addr = vma->vm_start; addr < end; addr += PAGE_SIZE) {
2014 struct page *page;
2015 struct vm_area_struct *tmp_vma;
2017 if (get_user_pages(current, current->mm, addr, 1, 0, 1,
2018 &page, &tmp_vma) <= 0) {
2019 DUMP_SEEK(PAGE_SIZE);
2020 } else {
2021 if (page == ZERO_PAGE(0)) {
2022 if (!dump_seek(file, PAGE_SIZE)) {
2023 page_cache_release(page);
2024 goto end_coredump;
2026 } else {
2027 void *kaddr;
2028 flush_cache_page(tmp_vma, addr,
2029 page_to_pfn(page));
2030 kaddr = kmap(page);
2031 if ((size += PAGE_SIZE) > limit ||
2032 !dump_write(file, kaddr,
2033 PAGE_SIZE)) {
2034 kunmap(page);
2035 page_cache_release(page);
2036 goto end_coredump;
2038 kunmap(page);
2040 page_cache_release(page);
2045 #ifdef ELF_CORE_WRITE_EXTRA_DATA
2046 ELF_CORE_WRITE_EXTRA_DATA;
2047 #endif
2049 end_coredump:
2050 set_fs(fs);
2052 cleanup:
2053 free_note_info(&info);
2054 kfree(elf);
2055 out:
2056 return has_dumped;
2059 #endif /* USE_ELF_CORE_DUMP */
2061 static int __init init_elf_binfmt(void)
2063 return register_binfmt(&elf_format);
2066 static void __exit exit_elf_binfmt(void)
2068 /* Remove the COFF and ELF loaders. */
2069 unregister_binfmt(&elf_format);
2072 core_initcall(init_elf_binfmt);
2073 module_exit(exit_elf_binfmt);
2074 MODULE_LICENSE("GPL");