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Linux/fs/binfmt_elf_fdpic.c

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  1 /* binfmt_elf_fdpic.c: FDPIC ELF binary format
  2  *
  3  * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
  4  * Written by David Howells (dhowells@redhat.com)
  5  * Derived from binfmt_elf.c
  6  *
  7  * This program is free software; you can redistribute it and/or
  8  * modify it under the terms of the GNU General Public License
  9  * as published by the Free Software Foundation; either version
 10  * 2 of the License, or (at your option) any later version.
 11  */
 12 
 13 #include <linux/module.h>
 14 
 15 #include <linux/fs.h>
 16 #include <linux/stat.h>
 17 #include <linux/sched.h>
 18 #include <linux/mm.h>
 19 #include <linux/mman.h>
 20 #include <linux/errno.h>
 21 #include <linux/signal.h>
 22 #include <linux/binfmts.h>
 23 #include <linux/string.h>
 24 #include <linux/file.h>
 25 #include <linux/fcntl.h>
 26 #include <linux/slab.h>
 27 #include <linux/pagemap.h>
 28 #include <linux/security.h>
 29 #include <linux/highmem.h>
 30 #include <linux/highuid.h>
 31 #include <linux/personality.h>
 32 #include <linux/ptrace.h>
 33 #include <linux/init.h>
 34 #include <linux/elf.h>
 35 #include <linux/elf-fdpic.h>
 36 #include <linux/elfcore.h>
 37 #include <linux/coredump.h>
 38 
 39 #include <asm/uaccess.h>
 40 #include <asm/param.h>
 41 #include <asm/pgalloc.h>
 42 
 43 typedef char *elf_caddr_t;
 44 
 45 #if 0
 46 #define kdebug(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
 47 #else
 48 #define kdebug(fmt, ...) do {} while(0)
 49 #endif
 50 
 51 #if 0
 52 #define kdcore(fmt, ...) printk("FDPIC "fmt"\n" ,##__VA_ARGS__ )
 53 #else
 54 #define kdcore(fmt, ...) do {} while(0)
 55 #endif
 56 
 57 MODULE_LICENSE("GPL");
 58 
 59 static int load_elf_fdpic_binary(struct linux_binprm *);
 60 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
 61 static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
 62                               struct mm_struct *, const char *);
 63 
 64 static int create_elf_fdpic_tables(struct linux_binprm *, struct mm_struct *,
 65                                    struct elf_fdpic_params *,
 66                                    struct elf_fdpic_params *);
 67 
 68 #ifndef CONFIG_MMU
 69 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *,
 70                                             unsigned long *);
 71 static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
 72                                                    struct file *,
 73                                                    struct mm_struct *);
 74 #endif
 75 
 76 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
 77                                              struct file *, struct mm_struct *);
 78 
 79 #ifdef CONFIG_ELF_CORE
 80 static int elf_fdpic_core_dump(struct coredump_params *cprm);
 81 #endif
 82 
 83 static struct linux_binfmt elf_fdpic_format = {
 84         .module         = THIS_MODULE,
 85         .load_binary    = load_elf_fdpic_binary,
 86 #ifdef CONFIG_ELF_CORE
 87         .core_dump      = elf_fdpic_core_dump,
 88 #endif
 89         .min_coredump   = ELF_EXEC_PAGESIZE,
 90 };
 91 
 92 static int __init init_elf_fdpic_binfmt(void)
 93 {
 94         register_binfmt(&elf_fdpic_format);
 95         return 0;
 96 }
 97 
 98 static void __exit exit_elf_fdpic_binfmt(void)
 99 {
100         unregister_binfmt(&elf_fdpic_format);
101 }
102 
103 core_initcall(init_elf_fdpic_binfmt);
104 module_exit(exit_elf_fdpic_binfmt);
105 
106 static int is_elf_fdpic(struct elfhdr *hdr, struct file *file)
107 {
108         if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
109                 return 0;
110         if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
111                 return 0;
112         if (!elf_check_arch(hdr) || !elf_check_fdpic(hdr))
113                 return 0;
114         if (!file->f_op->mmap)
115                 return 0;
116         return 1;
117 }
118 
119 /*****************************************************************************/
120 /*
121  * read the program headers table into memory
122  */
123 static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
124                                  struct file *file)
125 {
126         struct elf32_phdr *phdr;
127         unsigned long size;
128         int retval, loop;
129 
130         if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
131                 return -ENOMEM;
132         if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
133                 return -ENOMEM;
134 
135         size = params->hdr.e_phnum * sizeof(struct elf_phdr);
136         params->phdrs = kmalloc(size, GFP_KERNEL);
137         if (!params->phdrs)
138                 return -ENOMEM;
139 
140         retval = kernel_read(file, params->hdr.e_phoff,
141                              (char *) params->phdrs, size);
142         if (unlikely(retval != size))
143                 return retval < 0 ? retval : -ENOEXEC;
144 
145         /* determine stack size for this binary */
146         phdr = params->phdrs;
147         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
148                 if (phdr->p_type != PT_GNU_STACK)
149                         continue;
150 
151                 if (phdr->p_flags & PF_X)
152                         params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
153                 else
154                         params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
155 
156                 params->stack_size = phdr->p_memsz;
157                 break;
158         }
159 
160         return 0;
161 }
162 
163 /*****************************************************************************/
164 /*
165  * load an fdpic binary into various bits of memory
166  */
167 static int load_elf_fdpic_binary(struct linux_binprm *bprm)
168 {
169         struct elf_fdpic_params exec_params, interp_params;
170         struct pt_regs *regs = current_pt_regs();
171         struct elf_phdr *phdr;
172         unsigned long stack_size, entryaddr;
173 #ifdef ELF_FDPIC_PLAT_INIT
174         unsigned long dynaddr;
175 #endif
176 #ifndef CONFIG_MMU
177         unsigned long stack_prot;
178 #endif
179         struct file *interpreter = NULL; /* to shut gcc up */
180         char *interpreter_name = NULL;
181         int executable_stack;
182         int retval, i;
183 
184         kdebug("____ LOAD %d ____", current->pid);
185 
186         memset(&exec_params, 0, sizeof(exec_params));
187         memset(&interp_params, 0, sizeof(interp_params));
188 
189         exec_params.hdr = *(struct elfhdr *) bprm->buf;
190         exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
191 
192         /* check that this is a binary we know how to deal with */
193         retval = -ENOEXEC;
194         if (!is_elf_fdpic(&exec_params.hdr, bprm->file))
195                 goto error;
196 
197         /* read the program header table */
198         retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
199         if (retval < 0)
200                 goto error;
201 
202         /* scan for a program header that specifies an interpreter */
203         phdr = exec_params.phdrs;
204 
205         for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
206                 switch (phdr->p_type) {
207                 case PT_INTERP:
208                         retval = -ENOMEM;
209                         if (phdr->p_filesz > PATH_MAX)
210                                 goto error;
211                         retval = -ENOENT;
212                         if (phdr->p_filesz < 2)
213                                 goto error;
214 
215                         /* read the name of the interpreter into memory */
216                         interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
217                         if (!interpreter_name)
218                                 goto error;
219 
220                         retval = kernel_read(bprm->file,
221                                              phdr->p_offset,
222                                              interpreter_name,
223                                              phdr->p_filesz);
224                         if (unlikely(retval != phdr->p_filesz)) {
225                                 if (retval >= 0)
226                                         retval = -ENOEXEC;
227                                 goto error;
228                         }
229 
230                         retval = -ENOENT;
231                         if (interpreter_name[phdr->p_filesz - 1] != '\0')
232                                 goto error;
233 
234                         kdebug("Using ELF interpreter %s", interpreter_name);
235 
236                         /* replace the program with the interpreter */
237                         interpreter = open_exec(interpreter_name);
238                         retval = PTR_ERR(interpreter);
239                         if (IS_ERR(interpreter)) {
240                                 interpreter = NULL;
241                                 goto error;
242                         }
243 
244                         /*
245                          * If the binary is not readable then enforce
246                          * mm->dumpable = 0 regardless of the interpreter's
247                          * permissions.
248                          */
249                         would_dump(bprm, interpreter);
250 
251                         retval = kernel_read(interpreter, 0, bprm->buf,
252                                              BINPRM_BUF_SIZE);
253                         if (unlikely(retval != BINPRM_BUF_SIZE)) {
254                                 if (retval >= 0)
255                                         retval = -ENOEXEC;
256                                 goto error;
257                         }
258 
259                         interp_params.hdr = *((struct elfhdr *) bprm->buf);
260                         break;
261 
262                 case PT_LOAD:
263 #ifdef CONFIG_MMU
264                         if (exec_params.load_addr == 0)
265                                 exec_params.load_addr = phdr->p_vaddr;
266 #endif
267                         break;
268                 }
269 
270         }
271 
272         if (elf_check_const_displacement(&exec_params.hdr))
273                 exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
274 
275         /* perform insanity checks on the interpreter */
276         if (interpreter_name) {
277                 retval = -ELIBBAD;
278                 if (!is_elf_fdpic(&interp_params.hdr, interpreter))
279                         goto error;
280 
281                 interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
282 
283                 /* read the interpreter's program header table */
284                 retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
285                 if (retval < 0)
286                         goto error;
287         }
288 
289         stack_size = exec_params.stack_size;
290         if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
291                 executable_stack = EXSTACK_ENABLE_X;
292         else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
293                 executable_stack = EXSTACK_DISABLE_X;
294         else
295                 executable_stack = EXSTACK_DEFAULT;
296 
297         if (stack_size == 0) {
298                 stack_size = interp_params.stack_size;
299                 if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
300                         executable_stack = EXSTACK_ENABLE_X;
301                 else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
302                         executable_stack = EXSTACK_DISABLE_X;
303                 else
304                         executable_stack = EXSTACK_DEFAULT;
305         }
306 
307         retval = -ENOEXEC;
308         if (stack_size == 0)
309                 goto error;
310 
311         if (elf_check_const_displacement(&interp_params.hdr))
312                 interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
313 
314         /* flush all traces of the currently running executable */
315         retval = flush_old_exec(bprm);
316         if (retval)
317                 goto error;
318 
319         /* there's now no turning back... the old userspace image is dead,
320          * defunct, deceased, etc.
321          */
322         set_personality(PER_LINUX_FDPIC);
323         if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
324                 current->personality |= READ_IMPLIES_EXEC;
325 
326         setup_new_exec(bprm);
327 
328         set_binfmt(&elf_fdpic_format);
329 
330         current->mm->start_code = 0;
331         current->mm->end_code = 0;
332         current->mm->start_stack = 0;
333         current->mm->start_data = 0;
334         current->mm->end_data = 0;
335         current->mm->context.exec_fdpic_loadmap = 0;
336         current->mm->context.interp_fdpic_loadmap = 0;
337 
338 #ifdef CONFIG_MMU
339         elf_fdpic_arch_lay_out_mm(&exec_params,
340                                   &interp_params,
341                                   &current->mm->start_stack,
342                                   &current->mm->start_brk);
343 
344         retval = setup_arg_pages(bprm, current->mm->start_stack,
345                                  executable_stack);
346         if (retval < 0)
347                 goto error;
348 #endif
349 
350         /* load the executable and interpreter into memory */
351         retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
352                                     "executable");
353         if (retval < 0)
354                 goto error;
355 
356         if (interpreter_name) {
357                 retval = elf_fdpic_map_file(&interp_params, interpreter,
358                                             current->mm, "interpreter");
359                 if (retval < 0) {
360                         printk(KERN_ERR "Unable to load interpreter\n");
361                         goto error;
362                 }
363 
364                 allow_write_access(interpreter);
365                 fput(interpreter);
366                 interpreter = NULL;
367         }
368 
369 #ifdef CONFIG_MMU
370         if (!current->mm->start_brk)
371                 current->mm->start_brk = current->mm->end_data;
372 
373         current->mm->brk = current->mm->start_brk =
374                 PAGE_ALIGN(current->mm->start_brk);
375 
376 #else
377         /* create a stack and brk area big enough for everyone
378          * - the brk heap starts at the bottom and works up
379          * - the stack starts at the top and works down
380          */
381         stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
382         if (stack_size < PAGE_SIZE * 2)
383                 stack_size = PAGE_SIZE * 2;
384 
385         stack_prot = PROT_READ | PROT_WRITE;
386         if (executable_stack == EXSTACK_ENABLE_X ||
387             (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
388                 stack_prot |= PROT_EXEC;
389 
390         current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
391                                          MAP_PRIVATE | MAP_ANONYMOUS |
392                                          MAP_UNINITIALIZED | MAP_GROWSDOWN,
393                                          0);
394 
395         if (IS_ERR_VALUE(current->mm->start_brk)) {
396                 retval = current->mm->start_brk;
397                 current->mm->start_brk = 0;
398                 goto error;
399         }
400 
401         current->mm->brk = current->mm->start_brk;
402         current->mm->context.end_brk = current->mm->start_brk;
403         current->mm->context.end_brk +=
404                 (stack_size > PAGE_SIZE) ? (stack_size - PAGE_SIZE) : 0;
405         current->mm->start_stack = current->mm->start_brk + stack_size;
406 #endif
407 
408         install_exec_creds(bprm);
409         if (create_elf_fdpic_tables(bprm, current->mm,
410                                     &exec_params, &interp_params) < 0)
411                 goto error;
412 
413         kdebug("- start_code  %lx", current->mm->start_code);
414         kdebug("- end_code    %lx", current->mm->end_code);
415         kdebug("- start_data  %lx", current->mm->start_data);
416         kdebug("- end_data    %lx", current->mm->end_data);
417         kdebug("- start_brk   %lx", current->mm->start_brk);
418         kdebug("- brk         %lx", current->mm->brk);
419         kdebug("- start_stack %lx", current->mm->start_stack);
420 
421 #ifdef ELF_FDPIC_PLAT_INIT
422         /*
423          * The ABI may specify that certain registers be set up in special
424          * ways (on i386 %edx is the address of a DT_FINI function, for
425          * example.  This macro performs whatever initialization to
426          * the regs structure is required.
427          */
428         dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
429         ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
430                             dynaddr);
431 #endif
432 
433         /* everything is now ready... get the userspace context ready to roll */
434         entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
435         start_thread(regs, entryaddr, current->mm->start_stack);
436 
437         retval = 0;
438 
439 error:
440         if (interpreter) {
441                 allow_write_access(interpreter);
442                 fput(interpreter);
443         }
444         kfree(interpreter_name);
445         kfree(exec_params.phdrs);
446         kfree(exec_params.loadmap);
447         kfree(interp_params.phdrs);
448         kfree(interp_params.loadmap);
449         return retval;
450 }
451 
452 /*****************************************************************************/
453 
454 #ifndef ELF_BASE_PLATFORM
455 /*
456  * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
457  * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
458  * will be copied to the user stack in the same manner as AT_PLATFORM.
459  */
460 #define ELF_BASE_PLATFORM NULL
461 #endif
462 
463 /*
464  * present useful information to the program by shovelling it onto the new
465  * process's stack
466  */
467 static int create_elf_fdpic_tables(struct linux_binprm *bprm,
468                                    struct mm_struct *mm,
469                                    struct elf_fdpic_params *exec_params,
470                                    struct elf_fdpic_params *interp_params)
471 {
472         const struct cred *cred = current_cred();
473         unsigned long sp, csp, nitems;
474         elf_caddr_t __user *argv, *envp;
475         size_t platform_len = 0, len;
476         char *k_platform, *k_base_platform;
477         char __user *u_platform, *u_base_platform, *p;
478         int loop;
479         int nr; /* reset for each csp adjustment */
480 
481 #ifdef CONFIG_MMU
482         /* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
483          * by the processes running on the same package. One thing we can do is
484          * to shuffle the initial stack for them, so we give the architecture
485          * an opportunity to do so here.
486          */
487         sp = arch_align_stack(bprm->p);
488 #else
489         sp = mm->start_stack;
490 
491         /* stack the program arguments and environment */
492         if (elf_fdpic_transfer_args_to_stack(bprm, &sp) < 0)
493                 return -EFAULT;
494 #endif
495 
496         /*
497          * If this architecture has a platform capability string, copy it
498          * to userspace.  In some cases (Sparc), this info is impossible
499          * for userspace to get any other way, in others (i386) it is
500          * merely difficult.
501          */
502         k_platform = ELF_PLATFORM;
503         u_platform = NULL;
504 
505         if (k_platform) {
506                 platform_len = strlen(k_platform) + 1;
507                 sp -= platform_len;
508                 u_platform = (char __user *) sp;
509                 if (__copy_to_user(u_platform, k_platform, platform_len) != 0)
510                         return -EFAULT;
511         }
512 
513         /*
514          * If this architecture has a "base" platform capability
515          * string, copy it to userspace.
516          */
517         k_base_platform = ELF_BASE_PLATFORM;
518         u_base_platform = NULL;
519 
520         if (k_base_platform) {
521                 platform_len = strlen(k_base_platform) + 1;
522                 sp -= platform_len;
523                 u_base_platform = (char __user *) sp;
524                 if (__copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
525                         return -EFAULT;
526         }
527 
528         sp &= ~7UL;
529 
530         /* stack the load map(s) */
531         len = sizeof(struct elf32_fdpic_loadmap);
532         len += sizeof(struct elf32_fdpic_loadseg) * exec_params->loadmap->nsegs;
533         sp = (sp - len) & ~7UL;
534         exec_params->map_addr = sp;
535 
536         if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
537                 return -EFAULT;
538 
539         current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
540 
541         if (interp_params->loadmap) {
542                 len = sizeof(struct elf32_fdpic_loadmap);
543                 len += sizeof(struct elf32_fdpic_loadseg) *
544                         interp_params->loadmap->nsegs;
545                 sp = (sp - len) & ~7UL;
546                 interp_params->map_addr = sp;
547 
548                 if (copy_to_user((void __user *) sp, interp_params->loadmap,
549                                  len) != 0)
550                         return -EFAULT;
551 
552                 current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
553         }
554 
555         /* force 16 byte _final_ alignment here for generality */
556 #define DLINFO_ITEMS 15
557 
558         nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
559                 (k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
560 
561         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD)
562                 nitems++;
563 
564         csp = sp;
565         sp -= nitems * 2 * sizeof(unsigned long);
566         sp -= (bprm->envc + 1) * sizeof(char *);        /* envv[] */
567         sp -= (bprm->argc + 1) * sizeof(char *);        /* argv[] */
568         sp -= 1 * sizeof(unsigned long);                /* argc */
569 
570         csp -= sp & 15UL;
571         sp -= sp & 15UL;
572 
573         /* put the ELF interpreter info on the stack */
574 #define NEW_AUX_ENT(id, val)                                            \
575         do {                                                            \
576                 struct { unsigned long _id, _val; } __user *ent;        \
577                                                                         \
578                 ent = (void __user *) csp;                              \
579                 __put_user((id), &ent[nr]._id);                         \
580                 __put_user((val), &ent[nr]._val);                       \
581                 nr++;                                                   \
582         } while (0)
583 
584         nr = 0;
585         csp -= 2 * sizeof(unsigned long);
586         NEW_AUX_ENT(AT_NULL, 0);
587         if (k_platform) {
588                 nr = 0;
589                 csp -= 2 * sizeof(unsigned long);
590                 NEW_AUX_ENT(AT_PLATFORM,
591                             (elf_addr_t) (unsigned long) u_platform);
592         }
593 
594         if (k_base_platform) {
595                 nr = 0;
596                 csp -= 2 * sizeof(unsigned long);
597                 NEW_AUX_ENT(AT_BASE_PLATFORM,
598                             (elf_addr_t) (unsigned long) u_base_platform);
599         }
600 
601         if (bprm->interp_flags & BINPRM_FLAGS_EXECFD) {
602                 nr = 0;
603                 csp -= 2 * sizeof(unsigned long);
604                 NEW_AUX_ENT(AT_EXECFD, bprm->interp_data);
605         }
606 
607         nr = 0;
608         csp -= DLINFO_ITEMS * 2 * sizeof(unsigned long);
609         NEW_AUX_ENT(AT_HWCAP,   ELF_HWCAP);
610 #ifdef ELF_HWCAP2
611         NEW_AUX_ENT(AT_HWCAP2,  ELF_HWCAP2);
612 #endif
613         NEW_AUX_ENT(AT_PAGESZ,  PAGE_SIZE);
614         NEW_AUX_ENT(AT_CLKTCK,  CLOCKS_PER_SEC);
615         NEW_AUX_ENT(AT_PHDR,    exec_params->ph_addr);
616         NEW_AUX_ENT(AT_PHENT,   sizeof(struct elf_phdr));
617         NEW_AUX_ENT(AT_PHNUM,   exec_params->hdr.e_phnum);
618         NEW_AUX_ENT(AT_BASE,    interp_params->elfhdr_addr);
619         NEW_AUX_ENT(AT_FLAGS,   0);
620         NEW_AUX_ENT(AT_ENTRY,   exec_params->entry_addr);
621         NEW_AUX_ENT(AT_UID,     (elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
622         NEW_AUX_ENT(AT_EUID,    (elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
623         NEW_AUX_ENT(AT_GID,     (elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
624         NEW_AUX_ENT(AT_EGID,    (elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
625         NEW_AUX_ENT(AT_SECURE,  security_bprm_secureexec(bprm));
626         NEW_AUX_ENT(AT_EXECFN,  bprm->exec);
627 
628 #ifdef ARCH_DLINFO
629         nr = 0;
630         csp -= AT_VECTOR_SIZE_ARCH * 2 * sizeof(unsigned long);
631 
632         /* ARCH_DLINFO must come last so platform specific code can enforce
633          * special alignment requirements on the AUXV if necessary (eg. PPC).
634          */
635         ARCH_DLINFO;
636 #endif
637 #undef NEW_AUX_ENT
638 
639         /* allocate room for argv[] and envv[] */
640         csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
641         envp = (elf_caddr_t __user *) csp;
642         csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
643         argv = (elf_caddr_t __user *) csp;
644 
645         /* stack argc */
646         csp -= sizeof(unsigned long);
647         __put_user(bprm->argc, (unsigned long __user *) csp);
648 
649         BUG_ON(csp != sp);
650 
651         /* fill in the argv[] array */
652 #ifdef CONFIG_MMU
653         current->mm->arg_start = bprm->p;
654 #else
655         current->mm->arg_start = current->mm->start_stack -
656                 (MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
657 #endif
658 
659         p = (char __user *) current->mm->arg_start;
660         for (loop = bprm->argc; loop > 0; loop--) {
661                 __put_user((elf_caddr_t) p, argv++);
662                 len = strnlen_user(p, MAX_ARG_STRLEN);
663                 if (!len || len > MAX_ARG_STRLEN)
664                         return -EINVAL;
665                 p += len;
666         }
667         __put_user(NULL, argv);
668         current->mm->arg_end = (unsigned long) p;
669 
670         /* fill in the envv[] array */
671         current->mm->env_start = (unsigned long) p;
672         for (loop = bprm->envc; loop > 0; loop--) {
673                 __put_user((elf_caddr_t)(unsigned long) p, envp++);
674                 len = strnlen_user(p, MAX_ARG_STRLEN);
675                 if (!len || len > MAX_ARG_STRLEN)
676                         return -EINVAL;
677                 p += len;
678         }
679         __put_user(NULL, envp);
680         current->mm->env_end = (unsigned long) p;
681 
682         mm->start_stack = (unsigned long) sp;
683         return 0;
684 }
685 
686 /*****************************************************************************/
687 /*
688  * transfer the program arguments and environment from the holding pages onto
689  * the stack
690  */
691 #ifndef CONFIG_MMU
692 static int elf_fdpic_transfer_args_to_stack(struct linux_binprm *bprm,
693                                             unsigned long *_sp)
694 {
695         unsigned long index, stop, sp;
696         char *src;
697         int ret = 0;
698 
699         stop = bprm->p >> PAGE_SHIFT;
700         sp = *_sp;
701 
702         for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
703                 src = kmap(bprm->page[index]);
704                 sp -= PAGE_SIZE;
705                 if (copy_to_user((void *) sp, src, PAGE_SIZE) != 0)
706                         ret = -EFAULT;
707                 kunmap(bprm->page[index]);
708                 if (ret < 0)
709                         goto out;
710         }
711 
712         *_sp = (*_sp - (MAX_ARG_PAGES * PAGE_SIZE - bprm->p)) & ~15;
713 
714 out:
715         return ret;
716 }
717 #endif
718 
719 /*****************************************************************************/
720 /*
721  * load the appropriate binary image (executable or interpreter) into memory
722  * - we assume no MMU is available
723  * - if no other PIC bits are set in params->hdr->e_flags
724  *   - we assume that the LOADable segments in the binary are independently relocatable
725  *   - we assume R/O executable segments are shareable
726  * - else
727  *   - we assume the loadable parts of the image to require fixed displacement
728  *   - the image is not shareable
729  */
730 static int elf_fdpic_map_file(struct elf_fdpic_params *params,
731                               struct file *file,
732                               struct mm_struct *mm,
733                               const char *what)
734 {
735         struct elf32_fdpic_loadmap *loadmap;
736 #ifdef CONFIG_MMU
737         struct elf32_fdpic_loadseg *mseg;
738 #endif
739         struct elf32_fdpic_loadseg *seg;
740         struct elf32_phdr *phdr;
741         unsigned long load_addr, stop;
742         unsigned nloads, tmp;
743         size_t size;
744         int loop, ret;
745 
746         /* allocate a load map table */
747         nloads = 0;
748         for (loop = 0; loop < params->hdr.e_phnum; loop++)
749                 if (params->phdrs[loop].p_type == PT_LOAD)
750                         nloads++;
751 
752         if (nloads == 0)
753                 return -ELIBBAD;
754 
755         size = sizeof(*loadmap) + nloads * sizeof(*seg);
756         loadmap = kzalloc(size, GFP_KERNEL);
757         if (!loadmap)
758                 return -ENOMEM;
759 
760         params->loadmap = loadmap;
761 
762         loadmap->version = ELF32_FDPIC_LOADMAP_VERSION;
763         loadmap->nsegs = nloads;
764 
765         load_addr = params->load_addr;
766         seg = loadmap->segs;
767 
768         /* map the requested LOADs into the memory space */
769         switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
770         case ELF_FDPIC_FLAG_CONSTDISP:
771         case ELF_FDPIC_FLAG_CONTIGUOUS:
772 #ifndef CONFIG_MMU
773                 ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
774                 if (ret < 0)
775                         return ret;
776                 break;
777 #endif
778         default:
779                 ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
780                 if (ret < 0)
781                         return ret;
782                 break;
783         }
784 
785         /* map the entry point */
786         if (params->hdr.e_entry) {
787                 seg = loadmap->segs;
788                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
789                         if (params->hdr.e_entry >= seg->p_vaddr &&
790                             params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
791                                 params->entry_addr =
792                                         (params->hdr.e_entry - seg->p_vaddr) +
793                                         seg->addr;
794                                 break;
795                         }
796                 }
797         }
798 
799         /* determine where the program header table has wound up if mapped */
800         stop = params->hdr.e_phoff;
801         stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
802         phdr = params->phdrs;
803 
804         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
805                 if (phdr->p_type != PT_LOAD)
806                         continue;
807 
808                 if (phdr->p_offset > params->hdr.e_phoff ||
809                     phdr->p_offset + phdr->p_filesz < stop)
810                         continue;
811 
812                 seg = loadmap->segs;
813                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
814                         if (phdr->p_vaddr >= seg->p_vaddr &&
815                             phdr->p_vaddr + phdr->p_filesz <=
816                             seg->p_vaddr + seg->p_memsz) {
817                                 params->ph_addr =
818                                         (phdr->p_vaddr - seg->p_vaddr) +
819                                         seg->addr +
820                                         params->hdr.e_phoff - phdr->p_offset;
821                                 break;
822                         }
823                 }
824                 break;
825         }
826 
827         /* determine where the dynamic section has wound up if there is one */
828         phdr = params->phdrs;
829         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
830                 if (phdr->p_type != PT_DYNAMIC)
831                         continue;
832 
833                 seg = loadmap->segs;
834                 for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
835                         if (phdr->p_vaddr >= seg->p_vaddr &&
836                             phdr->p_vaddr + phdr->p_memsz <=
837                             seg->p_vaddr + seg->p_memsz) {
838                                 params->dynamic_addr =
839                                         (phdr->p_vaddr - seg->p_vaddr) +
840                                         seg->addr;
841 
842                                 /* check the dynamic section contains at least
843                                  * one item, and that the last item is a NULL
844                                  * entry */
845                                 if (phdr->p_memsz == 0 ||
846                                     phdr->p_memsz % sizeof(Elf32_Dyn) != 0)
847                                         goto dynamic_error;
848 
849                                 tmp = phdr->p_memsz / sizeof(Elf32_Dyn);
850                                 if (((Elf32_Dyn *)
851                                      params->dynamic_addr)[tmp - 1].d_tag != 0)
852                                         goto dynamic_error;
853                                 break;
854                         }
855                 }
856                 break;
857         }
858 
859         /* now elide adjacent segments in the load map on MMU linux
860          * - on uClinux the holes between may actually be filled with system
861          *   stuff or stuff from other processes
862          */
863 #ifdef CONFIG_MMU
864         nloads = loadmap->nsegs;
865         mseg = loadmap->segs;
866         seg = mseg + 1;
867         for (loop = 1; loop < nloads; loop++) {
868                 /* see if we have a candidate for merging */
869                 if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
870                         load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
871                         if (load_addr == (seg->addr & PAGE_MASK)) {
872                                 mseg->p_memsz +=
873                                         load_addr -
874                                         (mseg->addr + mseg->p_memsz);
875                                 mseg->p_memsz += seg->addr & ~PAGE_MASK;
876                                 mseg->p_memsz += seg->p_memsz;
877                                 loadmap->nsegs--;
878                                 continue;
879                         }
880                 }
881 
882                 mseg++;
883                 if (mseg != seg)
884                         *mseg = *seg;
885         }
886 #endif
887 
888         kdebug("Mapped Object [%s]:", what);
889         kdebug("- elfhdr   : %lx", params->elfhdr_addr);
890         kdebug("- entry    : %lx", params->entry_addr);
891         kdebug("- PHDR[]   : %lx", params->ph_addr);
892         kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
893         seg = loadmap->segs;
894         for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
895                 kdebug("- LOAD[%d] : %08x-%08x [va=%x ms=%x]",
896                        loop,
897                        seg->addr, seg->addr + seg->p_memsz - 1,
898                        seg->p_vaddr, seg->p_memsz);
899 
900         return 0;
901 
902 dynamic_error:
903         printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
904                what, file_inode(file)->i_ino);
905         return -ELIBBAD;
906 }
907 
908 /*****************************************************************************/
909 /*
910  * map a file with constant displacement under uClinux
911  */
912 #ifndef CONFIG_MMU
913 static int elf_fdpic_map_file_constdisp_on_uclinux(
914         struct elf_fdpic_params *params,
915         struct file *file,
916         struct mm_struct *mm)
917 {
918         struct elf32_fdpic_loadseg *seg;
919         struct elf32_phdr *phdr;
920         unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0, mflags;
921         int loop, ret;
922 
923         load_addr = params->load_addr;
924         seg = params->loadmap->segs;
925 
926         /* determine the bounds of the contiguous overall allocation we must
927          * make */
928         phdr = params->phdrs;
929         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
930                 if (params->phdrs[loop].p_type != PT_LOAD)
931                         continue;
932 
933                 if (base > phdr->p_vaddr)
934                         base = phdr->p_vaddr;
935                 if (top < phdr->p_vaddr + phdr->p_memsz)
936                         top = phdr->p_vaddr + phdr->p_memsz;
937         }
938 
939         /* allocate one big anon block for everything */
940         mflags = MAP_PRIVATE;
941         if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
942                 mflags |= MAP_EXECUTABLE;
943 
944         maddr = vm_mmap(NULL, load_addr, top - base,
945                         PROT_READ | PROT_WRITE | PROT_EXEC, mflags, 0);
946         if (IS_ERR_VALUE(maddr))
947                 return (int) maddr;
948 
949         if (load_addr != 0)
950                 load_addr += PAGE_ALIGN(top - base);
951 
952         /* and then load the file segments into it */
953         phdr = params->phdrs;
954         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
955                 if (params->phdrs[loop].p_type != PT_LOAD)
956                         continue;
957 
958                 seg->addr = maddr + (phdr->p_vaddr - base);
959                 seg->p_vaddr = phdr->p_vaddr;
960                 seg->p_memsz = phdr->p_memsz;
961 
962                 ret = read_code(file, seg->addr, phdr->p_offset,
963                                        phdr->p_filesz);
964                 if (ret < 0)
965                         return ret;
966 
967                 /* map the ELF header address if in this segment */
968                 if (phdr->p_offset == 0)
969                         params->elfhdr_addr = seg->addr;
970 
971                 /* clear any space allocated but not loaded */
972                 if (phdr->p_filesz < phdr->p_memsz) {
973                         if (clear_user((void *) (seg->addr + phdr->p_filesz),
974                                        phdr->p_memsz - phdr->p_filesz))
975                                 return -EFAULT;
976                 }
977 
978                 if (mm) {
979                         if (phdr->p_flags & PF_X) {
980                                 if (!mm->start_code) {
981                                         mm->start_code = seg->addr;
982                                         mm->end_code = seg->addr +
983                                                 phdr->p_memsz;
984                                 }
985                         } else if (!mm->start_data) {
986                                 mm->start_data = seg->addr;
987                                 mm->end_data = seg->addr + phdr->p_memsz;
988                         }
989                 }
990 
991                 seg++;
992         }
993 
994         return 0;
995 }
996 #endif
997 
998 /*****************************************************************************/
999 /*
1000  * map a binary by direct mmap() of the individual PT_LOAD segments
1001  */
1002 static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1003                                              struct file *file,
1004                                              struct mm_struct *mm)
1005 {
1006         struct elf32_fdpic_loadseg *seg;
1007         struct elf32_phdr *phdr;
1008         unsigned long load_addr, delta_vaddr;
1009         int loop, dvset;
1010 
1011         load_addr = params->load_addr;
1012         delta_vaddr = 0;
1013         dvset = 0;
1014 
1015         seg = params->loadmap->segs;
1016 
1017         /* deal with each load segment separately */
1018         phdr = params->phdrs;
1019         for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1020                 unsigned long maddr, disp, excess, excess1;
1021                 int prot = 0, flags;
1022 
1023                 if (phdr->p_type != PT_LOAD)
1024                         continue;
1025 
1026                 kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1027                        (unsigned long) phdr->p_vaddr,
1028                        (unsigned long) phdr->p_offset,
1029                        (unsigned long) phdr->p_filesz,
1030                        (unsigned long) phdr->p_memsz);
1031 
1032                 /* determine the mapping parameters */
1033                 if (phdr->p_flags & PF_R) prot |= PROT_READ;
1034                 if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1035                 if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1036 
1037                 flags = MAP_PRIVATE | MAP_DENYWRITE;
1038                 if (params->flags & ELF_FDPIC_FLAG_EXECUTABLE)
1039                         flags |= MAP_EXECUTABLE;
1040 
1041                 maddr = 0;
1042 
1043                 switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1044                 case ELF_FDPIC_FLAG_INDEPENDENT:
1045                         /* PT_LOADs are independently locatable */
1046                         break;
1047 
1048                 case ELF_FDPIC_FLAG_HONOURVADDR:
1049                         /* the specified virtual address must be honoured */
1050                         maddr = phdr->p_vaddr;
1051                         flags |= MAP_FIXED;
1052                         break;
1053 
1054                 case ELF_FDPIC_FLAG_CONSTDISP:
1055                         /* constant displacement
1056                          * - can be mapped anywhere, but must be mapped as a
1057                          *   unit
1058                          */
1059                         if (!dvset) {
1060                                 maddr = load_addr;
1061                                 delta_vaddr = phdr->p_vaddr;
1062                                 dvset = 1;
1063                         } else {
1064                                 maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1065                                 flags |= MAP_FIXED;
1066                         }
1067                         break;
1068 
1069                 case ELF_FDPIC_FLAG_CONTIGUOUS:
1070                         /* contiguity handled later */
1071                         break;
1072 
1073                 default:
1074                         BUG();
1075                 }
1076 
1077                 maddr &= PAGE_MASK;
1078 
1079                 /* create the mapping */
1080                 disp = phdr->p_vaddr & ~PAGE_MASK;
1081                 maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1082                                 phdr->p_offset - disp);
1083 
1084                 kdebug("mmap[%d] <file> sz=%lx pr=%x fl=%x of=%lx --> %08lx",
1085                        loop, phdr->p_memsz + disp, prot, flags,
1086                        phdr->p_offset - disp, maddr);
1087 
1088                 if (IS_ERR_VALUE(maddr))
1089                         return (int) maddr;
1090 
1091                 if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1092                     ELF_FDPIC_FLAG_CONTIGUOUS)
1093                         load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1094 
1095                 seg->addr = maddr + disp;
1096                 seg->p_vaddr = phdr->p_vaddr;
1097                 seg->p_memsz = phdr->p_memsz;
1098 
1099                 /* map the ELF header address if in this segment */
1100                 if (phdr->p_offset == 0)
1101                         params->elfhdr_addr = seg->addr;
1102 
1103                 /* clear the bit between beginning of mapping and beginning of
1104                  * PT_LOAD */
1105                 if (prot & PROT_WRITE && disp > 0) {
1106                         kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1107                         if (clear_user((void __user *) maddr, disp))
1108                                 return -EFAULT;
1109                         maddr += disp;
1110                 }
1111 
1112                 /* clear any space allocated but not loaded
1113                  * - on uClinux we can just clear the lot
1114                  * - on MMU linux we'll get a SIGBUS beyond the last page
1115                  *   extant in the file
1116                  */
1117                 excess = phdr->p_memsz - phdr->p_filesz;
1118                 excess1 = PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1119 
1120 #ifdef CONFIG_MMU
1121                 if (excess > excess1) {
1122                         unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1123                         unsigned long xmaddr;
1124 
1125                         flags |= MAP_FIXED | MAP_ANONYMOUS;
1126                         xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1127                                          prot, flags, 0);
1128 
1129                         kdebug("mmap[%d] <anon>"
1130                                " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1131                                loop, xaddr, excess - excess1, prot, flags,
1132                                xmaddr);
1133 
1134                         if (xmaddr != xaddr)
1135                                 return -ENOMEM;
1136                 }
1137 
1138                 if (prot & PROT_WRITE && excess1 > 0) {
1139                         kdebug("clear[%d] ad=%lx sz=%lx",
1140                                loop, maddr + phdr->p_filesz, excess1);
1141                         if (clear_user((void __user *) maddr + phdr->p_filesz,
1142                                        excess1))
1143                                 return -EFAULT;
1144                 }
1145 
1146 #else
1147                 if (excess > 0) {
1148                         kdebug("clear[%d] ad=%lx sz=%lx",
1149                                loop, maddr + phdr->p_filesz, excess);
1150                         if (clear_user((void *) maddr + phdr->p_filesz, excess))
1151                                 return -EFAULT;
1152                 }
1153 #endif
1154 
1155                 if (mm) {
1156                         if (phdr->p_flags & PF_X) {
1157                                 if (!mm->start_code) {
1158                                         mm->start_code = maddr;
1159                                         mm->end_code = maddr + phdr->p_memsz;
1160                                 }
1161                         } else if (!mm->start_data) {
1162                                 mm->start_data = maddr;
1163                                 mm->end_data = maddr + phdr->p_memsz;
1164                         }
1165                 }
1166 
1167                 seg++;
1168         }
1169 
1170         return 0;
1171 }
1172 
1173 /*****************************************************************************/
1174 /*
1175  * ELF-FDPIC core dumper
1176  *
1177  * Modelled on fs/exec.c:aout_core_dump()
1178  * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1179  *
1180  * Modelled on fs/binfmt_elf.c core dumper
1181  */
1182 #ifdef CONFIG_ELF_CORE
1183 
1184 /*
1185  * Decide whether a segment is worth dumping; default is yes to be
1186  * sure (missing info is worse than too much; etc).
1187  * Personally I'd include everything, and use the coredump limit...
1188  *
1189  * I think we should skip something. But I am not sure how. H.J.
1190  */
1191 static int maydump(struct vm_area_struct *vma, unsigned long mm_flags)
1192 {
1193         int dump_ok;
1194 
1195         /* Do not dump I/O mapped devices or special mappings */
1196         if (vma->vm_flags & VM_IO) {
1197                 kdcore("%08lx: %08lx: no (IO)", vma->vm_start, vma->vm_flags);
1198                 return 0;
1199         }
1200 
1201         /* If we may not read the contents, don't allow us to dump
1202          * them either. "dump_write()" can't handle it anyway.
1203          */
1204         if (!(vma->vm_flags & VM_READ)) {
1205                 kdcore("%08lx: %08lx: no (!read)", vma->vm_start, vma->vm_flags);
1206                 return 0;
1207         }
1208 
1209         /* By default, dump shared memory if mapped from an anonymous file. */
1210         if (vma->vm_flags & VM_SHARED) {
1211                 if (file_inode(vma->vm_file)->i_nlink == 0) {
1212                         dump_ok = test_bit(MMF_DUMP_ANON_SHARED, &mm_flags);
1213                         kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1214                                vma->vm_flags, dump_ok ? "yes" : "no");
1215                         return dump_ok;
1216                 }
1217 
1218                 dump_ok = test_bit(MMF_DUMP_MAPPED_SHARED, &mm_flags);
1219                 kdcore("%08lx: %08lx: %s (share)", vma->vm_start,
1220                        vma->vm_flags, dump_ok ? "yes" : "no");
1221                 return dump_ok;
1222         }
1223 
1224 #ifdef CONFIG_MMU
1225         /* By default, if it hasn't been written to, don't write it out */
1226         if (!vma->anon_vma) {
1227                 dump_ok = test_bit(MMF_DUMP_MAPPED_PRIVATE, &mm_flags);
1228                 kdcore("%08lx: %08lx: %s (!anon)", vma->vm_start,
1229                        vma->vm_flags, dump_ok ? "yes" : "no");
1230                 return dump_ok;
1231         }
1232 #endif
1233 
1234         dump_ok = test_bit(MMF_DUMP_ANON_PRIVATE, &mm_flags);
1235         kdcore("%08lx: %08lx: %s", vma->vm_start, vma->vm_flags,
1236                dump_ok ? "yes" : "no");
1237         return dump_ok;
1238 }
1239 
1240 /* An ELF note in memory */
1241 struct memelfnote
1242 {
1243         const char *name;
1244         int type;
1245         unsigned int datasz;
1246         void *data;
1247 };
1248 
1249 static int notesize(struct memelfnote *en)
1250 {
1251         int sz;
1252 
1253         sz = sizeof(struct elf_note);
1254         sz += roundup(strlen(en->name) + 1, 4);
1255         sz += roundup(en->datasz, 4);
1256 
1257         return sz;
1258 }
1259 
1260 /* #define DEBUG */
1261 
1262 static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1263 {
1264         struct elf_note en;
1265         en.n_namesz = strlen(men->name) + 1;
1266         en.n_descsz = men->datasz;
1267         en.n_type = men->type;
1268 
1269         return dump_emit(cprm, &en, sizeof(en)) &&
1270                 dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1271                 dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1272 }
1273 
1274 static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1275 {
1276         memcpy(elf->e_ident, ELFMAG, SELFMAG);
1277         elf->e_ident[EI_CLASS] = ELF_CLASS;
1278         elf->e_ident[EI_DATA] = ELF_DATA;
1279         elf->e_ident[EI_VERSION] = EV_CURRENT;
1280         elf->e_ident[EI_OSABI] = ELF_OSABI;
1281         memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1282 
1283         elf->e_type = ET_CORE;
1284         elf->e_machine = ELF_ARCH;
1285         elf->e_version = EV_CURRENT;
1286         elf->e_entry = 0;
1287         elf->e_phoff = sizeof(struct elfhdr);
1288         elf->e_shoff = 0;
1289         elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1290         elf->e_ehsize = sizeof(struct elfhdr);
1291         elf->e_phentsize = sizeof(struct elf_phdr);
1292         elf->e_phnum = segs;
1293         elf->e_shentsize = 0;
1294         elf->e_shnum = 0;
1295         elf->e_shstrndx = 0;
1296         return;
1297 }
1298 
1299 static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1300 {
1301         phdr->p_type = PT_NOTE;
1302         phdr->p_offset = offset;
1303         phdr->p_vaddr = 0;
1304         phdr->p_paddr = 0;
1305         phdr->p_filesz = sz;
1306         phdr->p_memsz = 0;
1307         phdr->p_flags = 0;
1308         phdr->p_align = 0;
1309         return;
1310 }
1311 
1312 static inline void fill_note(struct memelfnote *note, const char *name, int type,
1313                 unsigned int sz, void *data)
1314 {
1315         note->name = name;
1316         note->type = type;
1317         note->datasz = sz;
1318         note->data = data;
1319         return;
1320 }
1321 
1322 /*
1323  * fill up all the fields in prstatus from the given task struct, except
1324  * registers which need to be filled up separately.
1325  */
1326 static void fill_prstatus(struct elf_prstatus *prstatus,
1327                           struct task_struct *p, long signr)
1328 {
1329         prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1330         prstatus->pr_sigpend = p->pending.signal.sig[0];
1331         prstatus->pr_sighold = p->blocked.sig[0];
1332         rcu_read_lock();
1333         prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1334         rcu_read_unlock();
1335         prstatus->pr_pid = task_pid_vnr(p);
1336         prstatus->pr_pgrp = task_pgrp_vnr(p);
1337         prstatus->pr_sid = task_session_vnr(p);
1338         if (thread_group_leader(p)) {
1339                 struct task_cputime cputime;
1340 
1341                 /*
1342                  * This is the record for the group leader.  It shows the
1343                  * group-wide total, not its individual thread total.
1344                  */
1345                 thread_group_cputime(p, &cputime);
1346                 cputime_to_timeval(cputime.utime, &prstatus->pr_utime);
1347                 cputime_to_timeval(cputime.stime, &prstatus->pr_stime);
1348         } else {
1349                 cputime_t utime, stime;
1350 
1351                 task_cputime(p, &utime, &stime);
1352                 cputime_to_timeval(utime, &prstatus->pr_utime);
1353                 cputime_to_timeval(stime, &prstatus->pr_stime);
1354         }
1355         cputime_to_timeval(p->signal->cutime, &prstatus->pr_cutime);
1356         cputime_to_timeval(p->signal->cstime, &prstatus->pr_cstime);
1357 
1358         prstatus->pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1359         prstatus->pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1360 }
1361 
1362 static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1363                        struct mm_struct *mm)
1364 {
1365         const struct cred *cred;
1366         unsigned int i, len;
1367 
1368         /* first copy the parameters from user space */
1369         memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1370 
1371         len = mm->arg_end - mm->arg_start;
1372         if (len >= ELF_PRARGSZ)
1373                 len = ELF_PRARGSZ - 1;
1374         if (copy_from_user(&psinfo->pr_psargs,
1375                            (const char __user *) mm->arg_start, len))
1376                 return -EFAULT;
1377         for (i = 0; i < len; i++)
1378                 if (psinfo->pr_psargs[i] == 0)
1379                         psinfo->pr_psargs[i] = ' ';
1380         psinfo->pr_psargs[len] = 0;
1381 
1382         rcu_read_lock();
1383         psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1384         rcu_read_unlock();
1385         psinfo->pr_pid = task_pid_vnr(p);
1386         psinfo->pr_pgrp = task_pgrp_vnr(p);
1387         psinfo->pr_sid = task_session_vnr(p);
1388 
1389         i = p->state ? ffz(~p->state) + 1 : 0;
1390         psinfo->pr_state = i;
1391         psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1392         psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1393         psinfo->pr_nice = task_nice(p);
1394         psinfo->pr_flag = p->flags;
1395         rcu_read_lock();
1396         cred = __task_cred(p);
1397         SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1398         SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1399         rcu_read_unlock();
1400         strncpy(psinfo->pr_fname, p->comm, sizeof(psinfo->pr_fname));
1401 
1402         return 0;
1403 }
1404 
1405 /* Here is the structure in which status of each thread is captured. */
1406 struct elf_thread_status
1407 {
1408         struct list_head list;
1409         struct elf_prstatus prstatus;   /* NT_PRSTATUS */
1410         elf_fpregset_t fpu;             /* NT_PRFPREG */
1411         struct task_struct *thread;
1412 #ifdef ELF_CORE_COPY_XFPREGS
1413         elf_fpxregset_t xfpu;           /* ELF_CORE_XFPREG_TYPE */
1414 #endif
1415         struct memelfnote notes[3];
1416         int num_notes;
1417 };
1418 
1419 /*
1420  * In order to add the specific thread information for the elf file format,
1421  * we need to keep a linked list of every thread's pr_status and then create
1422  * a single section for them in the final core file.
1423  */
1424 static int elf_dump_thread_status(long signr, struct elf_thread_status *t)
1425 {
1426         struct task_struct *p = t->thread;
1427         int sz = 0;
1428 
1429         t->num_notes = 0;
1430 
1431         fill_prstatus(&t->prstatus, p, signr);
1432         elf_core_copy_task_regs(p, &t->prstatus.pr_reg);
1433 
1434         fill_note(&t->notes[0], "CORE", NT_PRSTATUS, sizeof(t->prstatus),
1435                   &t->prstatus);
1436         t->num_notes++;
1437         sz += notesize(&t->notes[0]);
1438 
1439         t->prstatus.pr_fpvalid = elf_core_copy_task_fpregs(p, NULL, &t->fpu);
1440         if (t->prstatus.pr_fpvalid) {
1441                 fill_note(&t->notes[1], "CORE", NT_PRFPREG, sizeof(t->fpu),
1442                           &t->fpu);
1443                 t->num_notes++;
1444                 sz += notesize(&t->notes[1]);
1445         }
1446 
1447 #ifdef ELF_CORE_COPY_XFPREGS
1448         if (elf_core_copy_task_xfpregs(p, &t->xfpu)) {
1449                 fill_note(&t->notes[2], "LINUX", ELF_CORE_XFPREG_TYPE,
1450                           sizeof(t->xfpu), &t->xfpu);
1451                 t->num_notes++;
1452                 sz += notesize(&t->notes[2]);
1453         }
1454 #endif
1455         return sz;
1456 }
1457 
1458 static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1459                              elf_addr_t e_shoff, int segs)
1460 {
1461         elf->e_shoff = e_shoff;
1462         elf->e_shentsize = sizeof(*shdr4extnum);
1463         elf->e_shnum = 1;
1464         elf->e_shstrndx = SHN_UNDEF;
1465 
1466         memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1467 
1468         shdr4extnum->sh_type = SHT_NULL;
1469         shdr4extnum->sh_size = elf->e_shnum;
1470         shdr4extnum->sh_link = elf->e_shstrndx;
1471         shdr4extnum->sh_info = segs;
1472 }
1473 
1474 /*
1475  * dump the segments for an MMU process
1476  */
1477 static bool elf_fdpic_dump_segments(struct coredump_params *cprm)
1478 {
1479         struct vm_area_struct *vma;
1480 
1481         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1482                 unsigned long addr;
1483 
1484                 if (!maydump(vma, cprm->mm_flags))
1485                         continue;
1486 
1487 #ifdef CONFIG_MMU
1488                 for (addr = vma->vm_start; addr < vma->vm_end;
1489                                                         addr += PAGE_SIZE) {
1490                         bool res;
1491                         struct page *page = get_dump_page(addr);
1492                         if (page) {
1493                                 void *kaddr = kmap(page);
1494                                 res = dump_emit(cprm, kaddr, PAGE_SIZE);
1495                                 kunmap(page);
1496                                 page_cache_release(page);
1497                         } else {
1498                                 res = dump_skip(cprm, PAGE_SIZE);
1499                         }
1500                         if (!res)
1501                                 return false;
1502                 }
1503 #else
1504                 if (!dump_emit(cprm, (void *) vma->vm_start,
1505                                 vma->vm_end - vma->vm_start))
1506                         return false;
1507 #endif
1508         }
1509         return true;
1510 }
1511 
1512 static size_t elf_core_vma_data_size(unsigned long mm_flags)
1513 {
1514         struct vm_area_struct *vma;
1515         size_t size = 0;
1516 
1517         for (vma = current->mm->mmap; vma; vma = vma->vm_next)
1518                 if (maydump(vma, mm_flags))
1519                         size += vma->vm_end - vma->vm_start;
1520         return size;
1521 }
1522 
1523 /*
1524  * Actual dumper
1525  *
1526  * This is a two-pass process; first we find the offsets of the bits,
1527  * and then they are actually written out.  If we run out of core limit
1528  * we just truncate.
1529  */
1530 static int elf_fdpic_core_dump(struct coredump_params *cprm)
1531 {
1532 #define NUM_NOTES       6
1533         int has_dumped = 0;
1534         mm_segment_t fs;
1535         int segs;
1536         int i;
1537         struct vm_area_struct *vma;
1538         struct elfhdr *elf = NULL;
1539         loff_t offset = 0, dataoff;
1540         int numnote;
1541         struct memelfnote *notes = NULL;
1542         struct elf_prstatus *prstatus = NULL;   /* NT_PRSTATUS */
1543         struct elf_prpsinfo *psinfo = NULL;     /* NT_PRPSINFO */
1544         LIST_HEAD(thread_list);
1545         struct list_head *t;
1546         elf_fpregset_t *fpu = NULL;
1547 #ifdef ELF_CORE_COPY_XFPREGS
1548         elf_fpxregset_t *xfpu = NULL;
1549 #endif
1550         int thread_status_size = 0;
1551         elf_addr_t *auxv;
1552         struct elf_phdr *phdr4note = NULL;
1553         struct elf_shdr *shdr4extnum = NULL;
1554         Elf_Half e_phnum;
1555         elf_addr_t e_shoff;
1556         struct core_thread *ct;
1557         struct elf_thread_status *tmp;
1558 
1559         /*
1560          * We no longer stop all VM operations.
1561          *
1562          * This is because those proceses that could possibly change map_count
1563          * or the mmap / vma pages are now blocked in do_exit on current
1564          * finishing this core dump.
1565          *
1566          * Only ptrace can touch these memory addresses, but it doesn't change
1567          * the map_count or the pages allocated. So no possibility of crashing
1568          * exists while dumping the mm->vm_next areas to the core file.
1569          */
1570 
1571         /* alloc memory for large data structures: too large to be on stack */
1572         elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1573         if (!elf)
1574                 goto cleanup;
1575         prstatus = kzalloc(sizeof(*prstatus), GFP_KERNEL);
1576         if (!prstatus)
1577                 goto cleanup;
1578         psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1579         if (!psinfo)
1580                 goto cleanup;
1581         notes = kmalloc(NUM_NOTES * sizeof(struct memelfnote), GFP_KERNEL);
1582         if (!notes)
1583                 goto cleanup;
1584         fpu = kmalloc(sizeof(*fpu), GFP_KERNEL);
1585         if (!fpu)
1586                 goto cleanup;
1587 #ifdef ELF_CORE_COPY_XFPREGS
1588         xfpu = kmalloc(sizeof(*xfpu), GFP_KERNEL);
1589         if (!xfpu)
1590                 goto cleanup;
1591 #endif
1592 
1593         for (ct = current->mm->core_state->dumper.next;
1594                                         ct; ct = ct->next) {
1595                 tmp = kzalloc(sizeof(*tmp), GFP_KERNEL);
1596                 if (!tmp)
1597                         goto cleanup;
1598 
1599                 tmp->thread = ct->task;
1600                 list_add(&tmp->list, &thread_list);
1601         }
1602 
1603         list_for_each(t, &thread_list) {
1604                 struct elf_thread_status *tmp;
1605                 int sz;
1606 
1607                 tmp = list_entry(t, struct elf_thread_status, list);
1608                 sz = elf_dump_thread_status(cprm->siginfo->si_signo, tmp);
1609                 thread_status_size += sz;
1610         }
1611 
1612         /* now collect the dump for the current */
1613         fill_prstatus(prstatus, current, cprm->siginfo->si_signo);
1614         elf_core_copy_regs(&prstatus->pr_reg, cprm->regs);
1615 
1616         segs = current->mm->map_count;
1617         segs += elf_core_extra_phdrs();
1618 
1619         /* for notes section */
1620         segs++;
1621 
1622         /* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1623          * this, kernel supports extended numbering. Have a look at
1624          * include/linux/elf.h for further information. */
1625         e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1626 
1627         /* Set up header */
1628         fill_elf_fdpic_header(elf, e_phnum);
1629 
1630         has_dumped = 1;
1631         /*
1632          * Set up the notes in similar form to SVR4 core dumps made
1633          * with info from their /proc.
1634          */
1635 
1636         fill_note(notes + 0, "CORE", NT_PRSTATUS, sizeof(*prstatus), prstatus);
1637         fill_psinfo(psinfo, current->group_leader, current->mm);
1638         fill_note(notes + 1, "CORE", NT_PRPSINFO, sizeof(*psinfo), psinfo);
1639 
1640         numnote = 2;
1641 
1642         auxv = (elf_addr_t *) current->mm->saved_auxv;
1643 
1644         i = 0;
1645         do
1646                 i += 2;
1647         while (auxv[i - 2] != AT_NULL);
1648         fill_note(&notes[numnote++], "CORE", NT_AUXV,
1649                   i * sizeof(elf_addr_t), auxv);
1650 
1651         /* Try to dump the FPU. */
1652         if ((prstatus->pr_fpvalid =
1653              elf_core_copy_task_fpregs(current, cprm->regs, fpu)))
1654                 fill_note(notes + numnote++,
1655                           "CORE", NT_PRFPREG, sizeof(*fpu), fpu);
1656 #ifdef ELF_CORE_COPY_XFPREGS
1657         if (elf_core_copy_task_xfpregs(current, xfpu))
1658                 fill_note(notes + numnote++,
1659                           "LINUX", ELF_CORE_XFPREG_TYPE, sizeof(*xfpu), xfpu);
1660 #endif
1661 
1662         fs = get_fs();
1663         set_fs(KERNEL_DS);
1664 
1665         offset += sizeof(*elf);                         /* Elf header */
1666         offset += segs * sizeof(struct elf_phdr);       /* Program headers */
1667 
1668         /* Write notes phdr entry */
1669         {
1670                 int sz = 0;
1671 
1672                 for (i = 0; i < numnote; i++)
1673                         sz += notesize(notes + i);
1674 
1675                 sz += thread_status_size;
1676 
1677                 phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1678                 if (!phdr4note)
1679                         goto end_coredump;
1680 
1681                 fill_elf_note_phdr(phdr4note, sz, offset);
1682                 offset += sz;
1683         }
1684 
1685         /* Page-align dumped data */
1686         dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1687 
1688         offset += elf_core_vma_data_size(cprm->mm_flags);
1689         offset += elf_core_extra_data_size();
1690         e_shoff = offset;
1691 
1692         if (e_phnum == PN_XNUM) {
1693                 shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1694                 if (!shdr4extnum)
1695                         goto end_coredump;
1696                 fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1697         }
1698 
1699         offset = dataoff;
1700 
1701         if (!dump_emit(cprm, elf, sizeof(*elf)))
1702                 goto end_coredump;
1703 
1704         if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1705                 goto end_coredump;
1706 
1707         /* write program headers for segments dump */
1708         for (vma = current->mm->mmap; vma; vma = vma->vm_next) {
1709                 struct elf_phdr phdr;
1710                 size_t sz;
1711 
1712                 sz = vma->vm_end - vma->vm_start;
1713 
1714                 phdr.p_type = PT_LOAD;
1715                 phdr.p_offset = offset;
1716                 phdr.p_vaddr = vma->vm_start;
1717                 phdr.p_paddr = 0;
1718                 phdr.p_filesz = maydump(vma, cprm->mm_flags) ? sz : 0;
1719                 phdr.p_memsz = sz;
1720                 offset += phdr.p_filesz;
1721                 phdr.p_flags = vma->vm_flags & VM_READ ? PF_R : 0;
1722                 if (vma->vm_flags & VM_WRITE)
1723                         phdr.p_flags |= PF_W;
1724                 if (vma->vm_flags & VM_EXEC)
1725                         phdr.p_flags |= PF_X;
1726                 phdr.p_align = ELF_EXEC_PAGESIZE;
1727 
1728                 if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1729                         goto end_coredump;
1730         }
1731 
1732         if (!elf_core_write_extra_phdrs(cprm, offset))
1733                 goto end_coredump;
1734 
1735         /* write out the notes section */
1736         for (i = 0; i < numnote; i++)
1737                 if (!writenote(notes + i, cprm))
1738                         goto end_coredump;
1739 
1740         /* write out the thread status notes section */
1741         list_for_each(t, &thread_list) {
1742                 struct elf_thread_status *tmp =
1743                                 list_entry(t, struct elf_thread_status, list);
1744 
1745                 for (i = 0; i < tmp->num_notes; i++)
1746                         if (!writenote(&tmp->notes[i], cprm))
1747                                 goto end_coredump;
1748         }
1749 
1750         if (!dump_skip(cprm, dataoff - cprm->written))
1751                 goto end_coredump;
1752 
1753         if (!elf_fdpic_dump_segments(cprm))
1754                 goto end_coredump;
1755 
1756         if (!elf_core_write_extra_data(cprm))
1757                 goto end_coredump;
1758 
1759         if (e_phnum == PN_XNUM) {
1760                 if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1761                         goto end_coredump;
1762         }
1763 
1764         if (cprm->file->f_pos != offset) {
1765                 /* Sanity check */
1766                 printk(KERN_WARNING
1767                        "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1768                        cprm->file->f_pos, offset);
1769         }
1770 
1771 end_coredump:
1772         set_fs(fs);
1773 
1774 cleanup:
1775         while (!list_empty(&thread_list)) {
1776                 struct list_head *tmp = thread_list.next;
1777                 list_del(tmp);
1778                 kfree(list_entry(tmp, struct elf_thread_status, list));
1779         }
1780         kfree(phdr4note);
1781         kfree(elf);
1782         kfree(prstatus);
1783         kfree(psinfo);
1784         kfree(notes);
1785         kfree(fpu);
1786         kfree(shdr4extnum);
1787 #ifdef ELF_CORE_COPY_XFPREGS
1788         kfree(xfpu);
1789 #endif
1790         return has_dumped;
1791 #undef NUM_NOTES
1792 }
1793 
1794 #endif          /* CONFIG_ELF_CORE */
1795 

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