binfmt_elf_fdpic.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* binfmt_elf_fdpic.c: FDPIC ELF binary format
   3 *
   4 * Copyright (C) 2003, 2004, 2006 Red Hat, Inc. All Rights Reserved.
   5 * Written by David Howells (dhowells@redhat.com)
   6 * Derived from binfmt_elf.c
   7 */
   8
   9#include <linux/module.h>
  10
  11#include <linux/fs.h>
  12#include <linux/stat.h>
  13#include <linux/sched.h>
  14#include <linux/sched/coredump.h>
  15#include <linux/sched/task_stack.h>
  16#include <linux/sched/cputime.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/slab.h>
  26#include <linux/pagemap.h>
  27#include <linux/security.h>
  28#include <linux/highmem.h>
  29#include <linux/highuid.h>
  30#include <linux/personality.h>
  31#include <linux/ptrace.h>
  32#include <linux/init.h>
  33#include <linux/elf.h>
  34#include <linux/elf-fdpic.h>
  35#include <linux/elfcore.h>
  36#include <linux/coredump.h>
  37#include <linux/dax.h>
  38#include <linux/regset.h>
  39
  40#include <linux/uaccess.h>
  41#include <asm/param.h>
  42
  43typedef 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
  57MODULE_LICENSE("GPL");
  58
  59static int load_elf_fdpic_binary(struct linux_binprm *);
  60static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *, struct file *);
  61static int elf_fdpic_map_file(struct elf_fdpic_params *, struct file *,
  62			      struct mm_struct *, const char *);
  63
  64static 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
  69static int elf_fdpic_map_file_constdisp_on_uclinux(struct elf_fdpic_params *,
  70						   struct file *,
  71						   struct mm_struct *);
  72#endif
  73
  74static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *,
  75					     struct file *, struct mm_struct *);
  76
  77#ifdef CONFIG_ELF_CORE
  78static int elf_fdpic_core_dump(struct coredump_params *cprm);
  79#endif
  80
  81static struct linux_binfmt elf_fdpic_format = {
  82	.module		= THIS_MODULE,
  83	.load_binary	= load_elf_fdpic_binary,
  84#ifdef CONFIG_ELF_CORE
  85	.core_dump	= elf_fdpic_core_dump,
  86	.min_coredump	= ELF_EXEC_PAGESIZE,
  87#endif
  88};
  89
  90static int __init init_elf_fdpic_binfmt(void)
  91{
  92	register_binfmt(&elf_fdpic_format);
  93	return 0;
  94}
  95
  96static void __exit exit_elf_fdpic_binfmt(void)
  97{
  98	unregister_binfmt(&elf_fdpic_format);
  99}
 100
 101core_initcall(init_elf_fdpic_binfmt);
 102module_exit(exit_elf_fdpic_binfmt);
 103
 104static int is_elf(struct elfhdr *hdr, struct file *file)
 105{
 106	if (memcmp(hdr->e_ident, ELFMAG, SELFMAG) != 0)
 107		return 0;
 108	if (hdr->e_type != ET_EXEC && hdr->e_type != ET_DYN)
 109		return 0;
 110	if (!elf_check_arch(hdr))
 111		return 0;
 112	if (!can_mmap_file(file))
 113		return 0;
 114	return 1;
 115}
 116
 117#ifndef elf_check_fdpic
 118#define elf_check_fdpic(x) 0
 119#endif
 120
 121#ifndef elf_check_const_displacement
 122#define elf_check_const_displacement(x) 0
 123#endif
 124
 125static int is_constdisp(struct elfhdr *hdr)
 126{
 127	if (!elf_check_fdpic(hdr))
 128		return 1;
 129	if (elf_check_const_displacement(hdr))
 130		return 1;
 131	return 0;
 132}
 133
 134/*****************************************************************************/
 135/*
 136 * read the program headers table into memory
 137 */
 138static int elf_fdpic_fetch_phdrs(struct elf_fdpic_params *params,
 139				 struct file *file)
 140{
 141	struct elf_phdr *phdr;
 142	unsigned long size;
 143	int retval, loop;
 144	loff_t pos = params->hdr.e_phoff;
 145
 146	if (params->hdr.e_phentsize != sizeof(struct elf_phdr))
 147		return -ENOMEM;
 148	if (params->hdr.e_phnum > 65536U / sizeof(struct elf_phdr))
 149		return -ENOMEM;
 150
 151	size = params->hdr.e_phnum * sizeof(struct elf_phdr);
 152	params->phdrs = kmalloc(size, GFP_KERNEL);
 153	if (!params->phdrs)
 154		return -ENOMEM;
 155
 156	retval = kernel_read(file, params->phdrs, size, &pos);
 157	if (unlikely(retval != size))
 158		return retval < 0 ? retval : -ENOEXEC;
 159
 160	/* determine stack size for this binary */
 161	phdr = params->phdrs;
 162	for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 163		if (phdr->p_type != PT_GNU_STACK)
 164			continue;
 165
 166		if (phdr->p_flags & PF_X)
 167			params->flags |= ELF_FDPIC_FLAG_EXEC_STACK;
 168		else
 169			params->flags |= ELF_FDPIC_FLAG_NOEXEC_STACK;
 170
 171		params->stack_size = phdr->p_memsz;
 172		break;
 173	}
 174
 175	return 0;
 176}
 177
 178/*****************************************************************************/
 179/*
 180 * load an fdpic binary into various bits of memory
 181 */
 182static int load_elf_fdpic_binary(struct linux_binprm *bprm)
 183{
 184	struct elf_fdpic_params exec_params, interp_params;
 185	struct pt_regs *regs = current_pt_regs();
 186	struct elf_phdr *phdr;
 187	unsigned long stack_size, entryaddr;
 188#ifdef ELF_FDPIC_PLAT_INIT
 189	unsigned long dynaddr;
 190#endif
 191#ifndef CONFIG_MMU
 192	unsigned long stack_prot;
 193#endif
 194	struct file *interpreter = NULL; /* to shut gcc up */
 195	char *interpreter_name = NULL;
 196	int executable_stack;
 197	int retval, i;
 198	loff_t pos;
 199
 200	kdebug("____ LOAD %d ____", current->pid);
 201
 202	memset(&exec_params, 0, sizeof(exec_params));
 203	memset(&interp_params, 0, sizeof(interp_params));
 204
 205	exec_params.hdr = *(struct elfhdr *) bprm->buf;
 206	exec_params.flags = ELF_FDPIC_FLAG_PRESENT | ELF_FDPIC_FLAG_EXECUTABLE;
 207
 208	/* check that this is a binary we know how to deal with */
 209	retval = -ENOEXEC;
 210	if (!is_elf(&exec_params.hdr, bprm->file))
 211		goto error;
 212	if (!elf_check_fdpic(&exec_params.hdr)) {
 213#ifdef CONFIG_MMU
 214		/* binfmt_elf handles non-fdpic elf except on nommu */
 215		goto error;
 216#else
 217		/* nommu can only load ET_DYN (PIE) ELF */
 218		if (exec_params.hdr.e_type != ET_DYN)
 219			goto error;
 220#endif
 221	}
 222
 223	/* read the program header table */
 224	retval = elf_fdpic_fetch_phdrs(&exec_params, bprm->file);
 225	if (retval < 0)
 226		goto error;
 227
 228	/* scan for a program header that specifies an interpreter */
 229	phdr = exec_params.phdrs;
 230
 231	for (i = 0; i < exec_params.hdr.e_phnum; i++, phdr++) {
 232		switch (phdr->p_type) {
 233		case PT_INTERP:
 234			retval = -ENOMEM;
 235			if (phdr->p_filesz > PATH_MAX)
 236				goto error;
 237			retval = -ENOENT;
 238			if (phdr->p_filesz < 2)
 239				goto error;
 240
 241			/* read the name of the interpreter into memory */
 242			interpreter_name = kmalloc(phdr->p_filesz, GFP_KERNEL);
 243			if (!interpreter_name)
 244				goto error;
 245
 246			pos = phdr->p_offset;
 247			retval = kernel_read(bprm->file, interpreter_name,
 248					     phdr->p_filesz, &pos);
 249			if (unlikely(retval != phdr->p_filesz)) {
 250				if (retval >= 0)
 251					retval = -ENOEXEC;
 252				goto error;
 253			}
 254
 255			retval = -ENOENT;
 256			if (interpreter_name[phdr->p_filesz - 1] != '\0')
 257				goto error;
 258
 259			kdebug("Using ELF interpreter %s", interpreter_name);
 260
 261			/* replace the program with the interpreter */
 262			interpreter = open_exec(interpreter_name);
 263			retval = PTR_ERR(interpreter);
 264			if (IS_ERR(interpreter)) {
 265				interpreter = NULL;
 266				goto error;
 267			}
 268
 269			/*
 270			 * If the binary is not readable then enforce
 271			 * mm->dumpable = 0 regardless of the interpreter's
 272			 * permissions.
 273			 */
 274			would_dump(bprm, interpreter);
 275
 276			pos = 0;
 277			retval = kernel_read(interpreter, bprm->buf,
 278					BINPRM_BUF_SIZE, &pos);
 279			if (unlikely(retval != BINPRM_BUF_SIZE)) {
 280				if (retval >= 0)
 281					retval = -ENOEXEC;
 282				goto error;
 283			}
 284
 285			interp_params.hdr = *((struct elfhdr *) bprm->buf);
 286			break;
 287
 288		case PT_LOAD:
 289#ifdef CONFIG_MMU
 290			if (exec_params.load_addr == 0)
 291				exec_params.load_addr = phdr->p_vaddr;
 292#endif
 293			break;
 294		}
 295
 296	}
 297
 298	if (is_constdisp(&exec_params.hdr))
 299		exec_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 300
 301	/* perform insanity checks on the interpreter */
 302	if (interpreter_name) {
 303		retval = -ELIBBAD;
 304		if (!is_elf(&interp_params.hdr, interpreter))
 305			goto error;
 306
 307		interp_params.flags = ELF_FDPIC_FLAG_PRESENT;
 308
 309		/* read the interpreter's program header table */
 310		retval = elf_fdpic_fetch_phdrs(&interp_params, interpreter);
 311		if (retval < 0)
 312			goto error;
 313	}
 314
 315	stack_size = exec_params.stack_size;
 316	if (exec_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 317		executable_stack = EXSTACK_ENABLE_X;
 318	else if (exec_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 319		executable_stack = EXSTACK_DISABLE_X;
 320	else
 321		executable_stack = EXSTACK_DEFAULT;
 322
 323	if (stack_size == 0 && interp_params.flags & ELF_FDPIC_FLAG_PRESENT) {
 324		stack_size = interp_params.stack_size;
 325		if (interp_params.flags & ELF_FDPIC_FLAG_EXEC_STACK)
 326			executable_stack = EXSTACK_ENABLE_X;
 327		else if (interp_params.flags & ELF_FDPIC_FLAG_NOEXEC_STACK)
 328			executable_stack = EXSTACK_DISABLE_X;
 329		else
 330			executable_stack = EXSTACK_DEFAULT;
 331	}
 332
 333	retval = -ENOEXEC;
 334	if (stack_size == 0)
 335		stack_size = 131072UL; /* same as exec.c's default commit */
 336
 337	if (is_constdisp(&interp_params.hdr))
 338		interp_params.flags |= ELF_FDPIC_FLAG_CONSTDISP;
 339
 340	/* flush all traces of the currently running executable */
 341	retval = begin_new_exec(bprm);
 342	if (retval)
 343		goto error;
 344
 345	/* there's now no turning back... the old userspace image is dead,
 346	 * defunct, deceased, etc.
 347	 */
 348	SET_PERSONALITY(exec_params.hdr);
 349	if (elf_check_fdpic(&exec_params.hdr))
 350		current->personality |= PER_LINUX_FDPIC;
 351	if (elf_read_implies_exec(&exec_params.hdr, executable_stack))
 352		current->personality |= READ_IMPLIES_EXEC;
 353
 354	setup_new_exec(bprm);
 355
 356	set_binfmt(&elf_fdpic_format);
 357
 358	current->mm->start_code = 0;
 359	current->mm->end_code = 0;
 360	current->mm->start_stack = 0;
 361	current->mm->start_data = 0;
 362	current->mm->end_data = 0;
 363	current->mm->context.exec_fdpic_loadmap = 0;
 364	current->mm->context.interp_fdpic_loadmap = 0;
 365
 366#ifdef CONFIG_MMU
 367	elf_fdpic_arch_lay_out_mm(&exec_params,
 368				  &interp_params,
 369				  &current->mm->start_stack,
 370				  &current->mm->start_brk);
 371
 372	retval = setup_arg_pages(bprm, current->mm->start_stack,
 373				 executable_stack);
 374	if (retval < 0)
 375		goto error;
 376#ifdef ARCH_HAS_SETUP_ADDITIONAL_PAGES
 377	retval = arch_setup_additional_pages(bprm, !!interpreter_name);
 378	if (retval < 0)
 379		goto error;
 380#endif
 381#endif
 382
 383	/* load the executable and interpreter into memory */
 384	retval = elf_fdpic_map_file(&exec_params, bprm->file, current->mm,
 385				    "executable");
 386	if (retval < 0)
 387		goto error;
 388
 389	if (interpreter_name) {
 390		retval = elf_fdpic_map_file(&interp_params, interpreter,
 391					    current->mm, "interpreter");
 392		if (retval < 0) {
 393			printk(KERN_ERR "Unable to load interpreter\n");
 394			goto error;
 395		}
 396
 397		exe_file_allow_write_access(interpreter);
 398		fput(interpreter);
 399		interpreter = NULL;
 400	}
 401
 402#ifdef CONFIG_MMU
 403	if (!current->mm->start_brk)
 404		current->mm->start_brk = current->mm->end_data;
 405
 406	current->mm->brk = current->mm->start_brk =
 407		PAGE_ALIGN(current->mm->start_brk);
 408
 409#else
 410	/* create a stack area and zero-size brk area */
 411	stack_size = (stack_size + PAGE_SIZE - 1) & PAGE_MASK;
 412	if (stack_size < PAGE_SIZE * 2)
 413		stack_size = PAGE_SIZE * 2;
 414
 415	stack_prot = PROT_READ | PROT_WRITE;
 416	if (executable_stack == EXSTACK_ENABLE_X ||
 417	    (executable_stack == EXSTACK_DEFAULT && VM_STACK_FLAGS & VM_EXEC))
 418		stack_prot |= PROT_EXEC;
 419
 420	current->mm->start_brk = vm_mmap(NULL, 0, stack_size, stack_prot,
 421					 MAP_PRIVATE | MAP_ANONYMOUS |
 422					 MAP_UNINITIALIZED | MAP_GROWSDOWN,
 423					 0);
 424
 425	if (IS_ERR_VALUE(current->mm->start_brk)) {
 426		retval = current->mm->start_brk;
 427		current->mm->start_brk = 0;
 428		goto error;
 429	}
 430
 431	current->mm->brk = current->mm->start_brk;
 432	current->mm->context.end_brk = current->mm->start_brk;
 433	current->mm->start_stack = current->mm->start_brk + stack_size;
 434#endif
 435
 436	retval = create_elf_fdpic_tables(bprm, current->mm, &exec_params,
 437					 &interp_params);
 438	if (retval < 0)
 439		goto error;
 440
 441	kdebug("- start_code  %lx", current->mm->start_code);
 442	kdebug("- end_code    %lx", current->mm->end_code);
 443	kdebug("- start_data  %lx", current->mm->start_data);
 444	kdebug("- end_data    %lx", current->mm->end_data);
 445	kdebug("- start_brk   %lx", current->mm->start_brk);
 446	kdebug("- brk         %lx", current->mm->brk);
 447	kdebug("- start_stack %lx", current->mm->start_stack);
 448
 449#ifdef ELF_FDPIC_PLAT_INIT
 450	/*
 451	 * The ABI may specify that certain registers be set up in special
 452	 * ways (on i386 %edx is the address of a DT_FINI function, for
 453	 * example.  This macro performs whatever initialization to
 454	 * the regs structure is required.
 455	 */
 456	dynaddr = interp_params.dynamic_addr ?: exec_params.dynamic_addr;
 457	ELF_FDPIC_PLAT_INIT(regs, exec_params.map_addr, interp_params.map_addr,
 458			    dynaddr);
 459#endif
 460
 461	finalize_exec(bprm);
 462	/* everything is now ready... get the userspace context ready to roll */
 463	entryaddr = interp_params.entry_addr ?: exec_params.entry_addr;
 464	start_thread(regs, entryaddr, current->mm->start_stack);
 465
 466	retval = 0;
 467
 468error:
 469	if (interpreter) {
 470		exe_file_allow_write_access(interpreter);
 471		fput(interpreter);
 472	}
 473	kfree(interpreter_name);
 474	kfree(exec_params.phdrs);
 475	kfree(exec_params.loadmap);
 476	kfree(interp_params.phdrs);
 477	kfree(interp_params.loadmap);
 478	return retval;
 479}
 480
 481/*****************************************************************************/
 482
 483#ifndef ELF_BASE_PLATFORM
 484/*
 485 * AT_BASE_PLATFORM indicates the "real" hardware/microarchitecture.
 486 * If the arch defines ELF_BASE_PLATFORM (in asm/elf.h), the value
 487 * will be copied to the user stack in the same manner as AT_PLATFORM.
 488 */
 489#define ELF_BASE_PLATFORM NULL
 490#endif
 491
 492/*
 493 * present useful information to the program by shovelling it onto the new
 494 * process's stack
 495 */
 496static int create_elf_fdpic_tables(struct linux_binprm *bprm,
 497				   struct mm_struct *mm,
 498				   struct elf_fdpic_params *exec_params,
 499				   struct elf_fdpic_params *interp_params)
 500{
 501	const struct cred *cred = current_cred();
 502	unsigned long sp, csp, nitems;
 503	elf_caddr_t __user *argv, *envp;
 504	size_t platform_len = 0, len;
 505	char *k_platform, *k_base_platform;
 506	char __user *u_platform, *u_base_platform, *p;
 507	int loop;
 508	unsigned long flags = 0;
 509	int ei_index;
 510	elf_addr_t *elf_info;
 511
 512#ifdef CONFIG_MMU
 513	/* In some cases (e.g. Hyper-Threading), we want to avoid L1 evictions
 514	 * by the processes running on the same package. One thing we can do is
 515	 * to shuffle the initial stack for them, so we give the architecture
 516	 * an opportunity to do so here.
 517	 */
 518	sp = arch_align_stack(bprm->p);
 519#else
 520	sp = mm->start_stack;
 521
 522	/* stack the program arguments and environment */
 523	if (transfer_args_to_stack(bprm, &sp) < 0)
 524		return -EFAULT;
 525	sp &= ~15;
 526#endif
 527
 528	/*
 529	 * If this architecture has a platform capability string, copy it
 530	 * to userspace.  In some cases (Sparc), this info is impossible
 531	 * for userspace to get any other way, in others (i386) it is
 532	 * merely difficult.
 533	 */
 534	k_platform = ELF_PLATFORM;
 535	u_platform = NULL;
 536
 537	if (k_platform) {
 538		platform_len = strlen(k_platform) + 1;
 539		sp -= platform_len;
 540		u_platform = (char __user *) sp;
 541		if (copy_to_user(u_platform, k_platform, platform_len) != 0)
 542			return -EFAULT;
 543	}
 544
 545	/*
 546	 * If this architecture has a "base" platform capability
 547	 * string, copy it to userspace.
 548	 */
 549	k_base_platform = ELF_BASE_PLATFORM;
 550	u_base_platform = NULL;
 551
 552	if (k_base_platform) {
 553		platform_len = strlen(k_base_platform) + 1;
 554		sp -= platform_len;
 555		u_base_platform = (char __user *) sp;
 556		if (copy_to_user(u_base_platform, k_base_platform, platform_len) != 0)
 557			return -EFAULT;
 558	}
 559
 560	sp &= ~7UL;
 561
 562	/* stack the load map(s) */
 563	len = sizeof(struct elf_fdpic_loadmap);
 564	len += sizeof(struct elf_fdpic_loadseg) * exec_params->loadmap->nsegs;
 565	sp = (sp - len) & ~7UL;
 566	exec_params->map_addr = sp;
 567
 568	if (copy_to_user((void __user *) sp, exec_params->loadmap, len) != 0)
 569		return -EFAULT;
 570
 571	current->mm->context.exec_fdpic_loadmap = (unsigned long) sp;
 572
 573	if (interp_params->loadmap) {
 574		len = sizeof(struct elf_fdpic_loadmap);
 575		len += sizeof(struct elf_fdpic_loadseg) *
 576			interp_params->loadmap->nsegs;
 577		sp = (sp - len) & ~7UL;
 578		interp_params->map_addr = sp;
 579
 580		if (copy_to_user((void __user *) sp, interp_params->loadmap,
 581				 len) != 0)
 582			return -EFAULT;
 583
 584		current->mm->context.interp_fdpic_loadmap = (unsigned long) sp;
 585	}
 586
 587	/* force 16 byte _final_ alignment here for generality */
 588#define DLINFO_ITEMS 15
 589
 590	nitems = 1 + DLINFO_ITEMS + (k_platform ? 1 : 0) +
 591		(k_base_platform ? 1 : 0) + AT_VECTOR_SIZE_ARCH;
 592
 593	if (bprm->have_execfd)
 594		nitems++;
 595#ifdef ELF_HWCAP2
 596	nitems++;
 597#endif
 598#ifdef ELF_HWCAP3
 599	nitems++;
 600#endif
 601#ifdef ELF_HWCAP4
 602	nitems++;
 603#endif
 604
 605	csp = sp;
 606	sp -= nitems * 2 * sizeof(unsigned long);
 607	sp -= (bprm->envc + 1) * sizeof(char *);	/* envv[] */
 608	sp -= (bprm->argc + 1) * sizeof(char *);	/* argv[] */
 609	sp -= 1 * sizeof(unsigned long);		/* argc */
 610
 611	csp -= sp & 15UL;
 612	sp -= sp & 15UL;
 613
 614	/* Create the ELF interpreter info */
 615	elf_info = (elf_addr_t *)mm->saved_auxv;
 616	/* update AT_VECTOR_SIZE_BASE if the number of NEW_AUX_ENT() changes */
 617#define NEW_AUX_ENT(id, val) \
 618	do { \
 619		*elf_info++ = id; \
 620		*elf_info++ = val; \
 621	} while (0)
 622
 623#ifdef ARCH_DLINFO
 624	/*
 625	 * ARCH_DLINFO must come first so PPC can do its special alignment of
 626	 * AUXV.
 627	 * update AT_VECTOR_SIZE_ARCH if the number of NEW_AUX_ENT() in
 628	 * ARCH_DLINFO changes
 629	 */
 630	ARCH_DLINFO;
 631#endif
 632	NEW_AUX_ENT(AT_HWCAP,	ELF_HWCAP);
 633#ifdef ELF_HWCAP2
 634	NEW_AUX_ENT(AT_HWCAP2,	ELF_HWCAP2);
 635#endif
 636#ifdef ELF_HWCAP3
 637	NEW_AUX_ENT(AT_HWCAP3,	ELF_HWCAP3);
 638#endif
 639#ifdef ELF_HWCAP4
 640	NEW_AUX_ENT(AT_HWCAP4,	ELF_HWCAP4);
 641#endif
 642	NEW_AUX_ENT(AT_PAGESZ,	PAGE_SIZE);
 643	NEW_AUX_ENT(AT_CLKTCK,	CLOCKS_PER_SEC);
 644	NEW_AUX_ENT(AT_PHDR,	exec_params->ph_addr);
 645	NEW_AUX_ENT(AT_PHENT,	sizeof(struct elf_phdr));
 646	NEW_AUX_ENT(AT_PHNUM,	exec_params->hdr.e_phnum);
 647	NEW_AUX_ENT(AT_BASE,	interp_params->elfhdr_addr);
 648	if (bprm->interp_flags & BINPRM_FLAGS_PRESERVE_ARGV0)
 649		flags |= AT_FLAGS_PRESERVE_ARGV0;
 650	NEW_AUX_ENT(AT_FLAGS,	flags);
 651	NEW_AUX_ENT(AT_ENTRY,	exec_params->entry_addr);
 652	NEW_AUX_ENT(AT_UID,	(elf_addr_t) from_kuid_munged(cred->user_ns, cred->uid));
 653	NEW_AUX_ENT(AT_EUID,	(elf_addr_t) from_kuid_munged(cred->user_ns, cred->euid));
 654	NEW_AUX_ENT(AT_GID,	(elf_addr_t) from_kgid_munged(cred->user_ns, cred->gid));
 655	NEW_AUX_ENT(AT_EGID,	(elf_addr_t) from_kgid_munged(cred->user_ns, cred->egid));
 656	NEW_AUX_ENT(AT_SECURE,	bprm->secureexec);
 657	NEW_AUX_ENT(AT_EXECFN,	bprm->exec);
 658	if (k_platform)
 659		NEW_AUX_ENT(AT_PLATFORM,
 660			    (elf_addr_t)(unsigned long)u_platform);
 661	if (k_base_platform)
 662		NEW_AUX_ENT(AT_BASE_PLATFORM,
 663			    (elf_addr_t)(unsigned long)u_base_platform);
 664	if (bprm->have_execfd)
 665		NEW_AUX_ENT(AT_EXECFD, bprm->execfd);
 666#undef NEW_AUX_ENT
 667	/* AT_NULL is zero; clear the rest too */
 668	memset(elf_info, 0, (char *)mm->saved_auxv +
 669	       sizeof(mm->saved_auxv) - (char *)elf_info);
 670
 671	/* And advance past the AT_NULL entry.  */
 672	elf_info += 2;
 673
 674	ei_index = elf_info - (elf_addr_t *)mm->saved_auxv;
 675	csp -= ei_index * sizeof(elf_addr_t);
 676
 677	/* Put the elf_info on the stack in the right place.  */
 678	if (copy_to_user((void __user *)csp, mm->saved_auxv,
 679			 ei_index * sizeof(elf_addr_t)))
 680		return -EFAULT;
 681
 682	/* allocate room for argv[] and envv[] */
 683	csp -= (bprm->envc + 1) * sizeof(elf_caddr_t);
 684	envp = (elf_caddr_t __user *) csp;
 685	csp -= (bprm->argc + 1) * sizeof(elf_caddr_t);
 686	argv = (elf_caddr_t __user *) csp;
 687
 688	/* stack argc */
 689	csp -= sizeof(unsigned long);
 690	if (put_user(bprm->argc, (unsigned long __user *) csp))
 691		return -EFAULT;
 692
 693	BUG_ON(csp != sp);
 694
 695	/* fill in the argv[] array */
 696#ifdef CONFIG_MMU
 697	current->mm->arg_start = bprm->p;
 698#else
 699	current->mm->arg_start = current->mm->start_stack -
 700		(MAX_ARG_PAGES * PAGE_SIZE - bprm->p);
 701#endif
 702
 703	p = (char __user *) current->mm->arg_start;
 704	for (loop = bprm->argc; loop > 0; loop--) {
 705		if (put_user((elf_caddr_t) p, argv++))
 706			return -EFAULT;
 707		len = strnlen_user(p, MAX_ARG_STRLEN);
 708		if (!len || len > MAX_ARG_STRLEN)
 709			return -EINVAL;
 710		p += len;
 711	}
 712	if (put_user(NULL, argv))
 713		return -EFAULT;
 714	current->mm->arg_end = (unsigned long) p;
 715
 716	/* fill in the envv[] array */
 717	current->mm->env_start = (unsigned long) p;
 718	for (loop = bprm->envc; loop > 0; loop--) {
 719		if (put_user((elf_caddr_t)(unsigned long) p, envp++))
 720			return -EFAULT;
 721		len = strnlen_user(p, MAX_ARG_STRLEN);
 722		if (!len || len > MAX_ARG_STRLEN)
 723			return -EINVAL;
 724		p += len;
 725	}
 726	if (put_user(NULL, envp))
 727		return -EFAULT;
 728	current->mm->env_end = (unsigned long) p;
 729
 730	mm->start_stack = (unsigned long) sp;
 731	return 0;
 732}
 733
 734/*****************************************************************************/
 735/*
 736 * load the appropriate binary image (executable or interpreter) into memory
 737 * - we assume no MMU is available
 738 * - if no other PIC bits are set in params->hdr->e_flags
 739 *   - we assume that the LOADable segments in the binary are independently relocatable
 740 *   - we assume R/O executable segments are shareable
 741 * - else
 742 *   - we assume the loadable parts of the image to require fixed displacement
 743 *   - the image is not shareable
 744 */
 745static int elf_fdpic_map_file(struct elf_fdpic_params *params,
 746			      struct file *file,
 747			      struct mm_struct *mm,
 748			      const char *what)
 749{
 750	struct elf_fdpic_loadmap *loadmap;
 751#ifdef CONFIG_MMU
 752	struct elf_fdpic_loadseg *mseg;
 753	unsigned long load_addr;
 754#endif
 755	struct elf_fdpic_loadseg *seg;
 756	struct elf_phdr *phdr;
 757	unsigned nloads, tmp;
 758	unsigned long stop;
 759	int loop, ret;
 760
 761	/* allocate a load map table */
 762	nloads = 0;
 763	for (loop = 0; loop < params->hdr.e_phnum; loop++)
 764		if (params->phdrs[loop].p_type == PT_LOAD)
 765			nloads++;
 766
 767	if (nloads == 0)
 768		return -ELIBBAD;
 769
 770	loadmap = kzalloc(struct_size(loadmap, segs, nloads), GFP_KERNEL);
 771	if (!loadmap)
 772		return -ENOMEM;
 773
 774	params->loadmap = loadmap;
 775
 776	loadmap->version = ELF_FDPIC_LOADMAP_VERSION;
 777	loadmap->nsegs = nloads;
 778
 779	/* map the requested LOADs into the memory space */
 780	switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
 781	case ELF_FDPIC_FLAG_CONSTDISP:
 782	case ELF_FDPIC_FLAG_CONTIGUOUS:
 783#ifndef CONFIG_MMU
 784		ret = elf_fdpic_map_file_constdisp_on_uclinux(params, file, mm);
 785		if (ret < 0)
 786			return ret;
 787		break;
 788#endif
 789	default:
 790		ret = elf_fdpic_map_file_by_direct_mmap(params, file, mm);
 791		if (ret < 0)
 792			return ret;
 793		break;
 794	}
 795
 796	/* map the entry point */
 797	if (params->hdr.e_entry) {
 798		seg = loadmap->segs;
 799		for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 800			if (params->hdr.e_entry >= seg->p_vaddr &&
 801			    params->hdr.e_entry < seg->p_vaddr + seg->p_memsz) {
 802				params->entry_addr =
 803					(params->hdr.e_entry - seg->p_vaddr) +
 804					seg->addr;
 805				break;
 806			}
 807		}
 808	}
 809
 810	/* determine where the program header table has wound up if mapped */
 811	stop = params->hdr.e_phoff;
 812	stop += params->hdr.e_phnum * sizeof (struct elf_phdr);
 813	phdr = params->phdrs;
 814
 815	for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 816		if (phdr->p_type != PT_LOAD)
 817			continue;
 818
 819		if (phdr->p_offset > params->hdr.e_phoff ||
 820		    phdr->p_offset + phdr->p_filesz < stop)
 821			continue;
 822
 823		seg = loadmap->segs;
 824		for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 825			if (phdr->p_vaddr >= seg->p_vaddr &&
 826			    phdr->p_vaddr + phdr->p_filesz <=
 827			    seg->p_vaddr + seg->p_memsz) {
 828				params->ph_addr =
 829					(phdr->p_vaddr - seg->p_vaddr) +
 830					seg->addr +
 831					params->hdr.e_phoff - phdr->p_offset;
 832				break;
 833			}
 834		}
 835		break;
 836	}
 837
 838	/* determine where the dynamic section has wound up if there is one */
 839	phdr = params->phdrs;
 840	for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 841		if (phdr->p_type != PT_DYNAMIC)
 842			continue;
 843
 844		seg = loadmap->segs;
 845		for (loop = loadmap->nsegs; loop > 0; loop--, seg++) {
 846			if (phdr->p_vaddr >= seg->p_vaddr &&
 847			    phdr->p_vaddr + phdr->p_memsz <=
 848			    seg->p_vaddr + seg->p_memsz) {
 849				Elf_Dyn __user *dyn;
 850				Elf_Sword d_tag;
 851
 852				params->dynamic_addr =
 853					(phdr->p_vaddr - seg->p_vaddr) +
 854					seg->addr;
 855
 856				/* check the dynamic section contains at least
 857				 * one item, and that the last item is a NULL
 858				 * entry */
 859				if (phdr->p_memsz == 0 ||
 860				    phdr->p_memsz % sizeof(Elf_Dyn) != 0)
 861					goto dynamic_error;
 862
 863				tmp = phdr->p_memsz / sizeof(Elf_Dyn);
 864				dyn = (Elf_Dyn __user *)params->dynamic_addr;
 865				if (get_user(d_tag, &dyn[tmp - 1].d_tag) ||
 866				    d_tag != 0)
 867					goto dynamic_error;
 868				break;
 869			}
 870		}
 871		break;
 872	}
 873
 874	/* now elide adjacent segments in the load map on MMU linux
 875	 * - on uClinux the holes between may actually be filled with system
 876	 *   stuff or stuff from other processes
 877	 */
 878#ifdef CONFIG_MMU
 879	nloads = loadmap->nsegs;
 880	mseg = loadmap->segs;
 881	seg = mseg + 1;
 882	for (loop = 1; loop < nloads; loop++) {
 883		/* see if we have a candidate for merging */
 884		if (seg->p_vaddr - mseg->p_vaddr == seg->addr - mseg->addr) {
 885			load_addr = PAGE_ALIGN(mseg->addr + mseg->p_memsz);
 886			if (load_addr == (seg->addr & PAGE_MASK)) {
 887				mseg->p_memsz +=
 888					load_addr -
 889					(mseg->addr + mseg->p_memsz);
 890				mseg->p_memsz += seg->addr & ~PAGE_MASK;
 891				mseg->p_memsz += seg->p_memsz;
 892				loadmap->nsegs--;
 893				continue;
 894			}
 895		}
 896
 897		mseg++;
 898		if (mseg != seg)
 899			*mseg = *seg;
 900	}
 901#endif
 902
 903	kdebug("Mapped Object [%s]:", what);
 904	kdebug("- elfhdr   : %lx", params->elfhdr_addr);
 905	kdebug("- entry    : %lx", params->entry_addr);
 906	kdebug("- PHDR[]   : %lx", params->ph_addr);
 907	kdebug("- DYNAMIC[]: %lx", params->dynamic_addr);
 908	seg = loadmap->segs;
 909	for (loop = 0; loop < loadmap->nsegs; loop++, seg++)
 910		kdebug("- LOAD[%d] : %08llx-%08llx [va=%llx ms=%llx]",
 911		       loop,
 912		       (unsigned long long) seg->addr,
 913		       (unsigned long long) seg->addr + seg->p_memsz - 1,
 914		       (unsigned long long) seg->p_vaddr,
 915		       (unsigned long long) seg->p_memsz);
 916
 917	return 0;
 918
 919dynamic_error:
 920	printk("ELF FDPIC %s with invalid DYNAMIC section (inode=%lu)\n",
 921	       what, file_inode(file)->i_ino);
 922	return -ELIBBAD;
 923}
 924
 925/*****************************************************************************/
 926/*
 927 * map a file with constant displacement under uClinux
 928 */
 929#ifndef CONFIG_MMU
 930static int elf_fdpic_map_file_constdisp_on_uclinux(
 931	struct elf_fdpic_params *params,
 932	struct file *file,
 933	struct mm_struct *mm)
 934{
 935	struct elf_fdpic_loadseg *seg;
 936	struct elf_phdr *phdr;
 937	unsigned long load_addr, base = ULONG_MAX, top = 0, maddr = 0;
 938	int loop, ret;
 939
 940	load_addr = params->load_addr;
 941	seg = params->loadmap->segs;
 942
 943	/* determine the bounds of the contiguous overall allocation we must
 944	 * make */
 945	phdr = params->phdrs;
 946	for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 947		if (params->phdrs[loop].p_type != PT_LOAD)
 948			continue;
 949
 950		if (base > phdr->p_vaddr)
 951			base = phdr->p_vaddr;
 952		if (top < phdr->p_vaddr + phdr->p_memsz)
 953			top = phdr->p_vaddr + phdr->p_memsz;
 954	}
 955
 956	/* allocate one big anon block for everything */
 957	maddr = vm_mmap(NULL, load_addr, top - base,
 958			PROT_READ | PROT_WRITE | PROT_EXEC, MAP_PRIVATE, 0);
 959	if (IS_ERR_VALUE(maddr))
 960		return (int) maddr;
 961
 962	if (load_addr != 0)
 963		load_addr += PAGE_ALIGN(top - base);
 964
 965	/* and then load the file segments into it */
 966	phdr = params->phdrs;
 967	for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
 968		if (params->phdrs[loop].p_type != PT_LOAD)
 969			continue;
 970
 971		seg->addr = maddr + (phdr->p_vaddr - base);
 972		seg->p_vaddr = phdr->p_vaddr;
 973		seg->p_memsz = phdr->p_memsz;
 974
 975		ret = read_code(file, seg->addr, phdr->p_offset,
 976				       phdr->p_filesz);
 977		if (ret < 0)
 978			return ret;
 979
 980		/* map the ELF header address if in this segment */
 981		if (phdr->p_offset == 0)
 982			params->elfhdr_addr = seg->addr;
 983
 984		/* clear any space allocated but not loaded */
 985		if (phdr->p_filesz < phdr->p_memsz) {
 986			if (clear_user((void *) (seg->addr + phdr->p_filesz),
 987				       phdr->p_memsz - phdr->p_filesz))
 988				return -EFAULT;
 989		}
 990
 991		if (mm) {
 992			if (phdr->p_flags & PF_X) {
 993				if (!mm->start_code) {
 994					mm->start_code = seg->addr;
 995					mm->end_code = seg->addr +
 996						phdr->p_memsz;
 997				}
 998			} else if (!mm->start_data) {
 999				mm->start_data = seg->addr;
1000				mm->end_data = seg->addr + phdr->p_memsz;
1001			}
1002		}
1003
1004		seg++;
1005	}
1006
1007	return 0;
1008}
1009#endif
1010
1011/*****************************************************************************/
1012/*
1013 * map a binary by direct mmap() of the individual PT_LOAD segments
1014 */
1015static int elf_fdpic_map_file_by_direct_mmap(struct elf_fdpic_params *params,
1016					     struct file *file,
1017					     struct mm_struct *mm)
1018{
1019	struct elf_fdpic_loadseg *seg;
1020	struct elf_phdr *phdr;
1021	unsigned long load_addr, delta_vaddr;
1022	int loop, dvset;
1023
1024	load_addr = params->load_addr;
1025	delta_vaddr = 0;
1026	dvset = 0;
1027
1028	seg = params->loadmap->segs;
1029
1030	/* deal with each load segment separately */
1031	phdr = params->phdrs;
1032	for (loop = 0; loop < params->hdr.e_phnum; loop++, phdr++) {
1033		unsigned long maddr, disp, excess;
1034		int prot = 0, flags;
1035
1036		if (phdr->p_type != PT_LOAD)
1037			continue;
1038
1039		kdebug("[LOAD] va=%lx of=%lx fs=%lx ms=%lx",
1040		       (unsigned long) phdr->p_vaddr,
1041		       (unsigned long) phdr->p_offset,
1042		       (unsigned long) phdr->p_filesz,
1043		       (unsigned long) phdr->p_memsz);
1044
1045		/* determine the mapping parameters */
1046		if (phdr->p_flags & PF_R) prot |= PROT_READ;
1047		if (phdr->p_flags & PF_W) prot |= PROT_WRITE;
1048		if (phdr->p_flags & PF_X) prot |= PROT_EXEC;
1049
1050		flags = MAP_PRIVATE;
1051		maddr = 0;
1052
1053		switch (params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) {
1054		case ELF_FDPIC_FLAG_INDEPENDENT:
1055			/* PT_LOADs are independently locatable */
1056			break;
1057
1058		case ELF_FDPIC_FLAG_HONOURVADDR:
1059			/* the specified virtual address must be honoured */
1060			maddr = phdr->p_vaddr;
1061			flags |= MAP_FIXED;
1062			break;
1063
1064		case ELF_FDPIC_FLAG_CONSTDISP:
1065			/* constant displacement
1066			 * - can be mapped anywhere, but must be mapped as a
1067			 *   unit
1068			 */
1069			if (!dvset) {
1070				maddr = load_addr;
1071				delta_vaddr = phdr->p_vaddr;
1072				dvset = 1;
1073			} else {
1074				maddr = load_addr + phdr->p_vaddr - delta_vaddr;
1075				flags |= MAP_FIXED;
1076			}
1077			break;
1078
1079		case ELF_FDPIC_FLAG_CONTIGUOUS:
1080			/* contiguity handled later */
1081			break;
1082
1083		default:
1084			BUG();
1085		}
1086
1087		maddr &= PAGE_MASK;
1088
1089		/* create the mapping */
1090		disp = phdr->p_vaddr & ~PAGE_MASK;
1091		maddr = vm_mmap(file, maddr, phdr->p_memsz + disp, prot, flags,
1092				phdr->p_offset - disp);
1093
1094		kdebug("mmap[%d] <file> sz=%llx pr=%x fl=%x of=%llx --> %08lx",
1095		       loop, (unsigned long long) phdr->p_memsz + disp,
1096		       prot, flags, (unsigned long long) phdr->p_offset - disp,
1097		       maddr);
1098
1099		if (IS_ERR_VALUE(maddr))
1100			return (int) maddr;
1101
1102		if ((params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
1103		    ELF_FDPIC_FLAG_CONTIGUOUS)
1104			load_addr += PAGE_ALIGN(phdr->p_memsz + disp);
1105
1106		seg->addr = maddr + disp;
1107		seg->p_vaddr = phdr->p_vaddr;
1108		seg->p_memsz = phdr->p_memsz;
1109
1110		/* map the ELF header address if in this segment */
1111		if (phdr->p_offset == 0)
1112			params->elfhdr_addr = seg->addr;
1113
1114		/* clear the bit between beginning of mapping and beginning of
1115		 * PT_LOAD */
1116		if (prot & PROT_WRITE && disp > 0) {
1117			kdebug("clear[%d] ad=%lx sz=%lx", loop, maddr, disp);
1118			if (clear_user((void __user *) maddr, disp))
1119				return -EFAULT;
1120			maddr += disp;
1121		}
1122
1123		/* clear any space allocated but not loaded
1124		 * - on uClinux we can just clear the lot
1125		 * - on MMU linux we'll get a SIGBUS beyond the last page
1126		 *   extant in the file
1127		 */
1128		excess = phdr->p_memsz - phdr->p_filesz;
1129
1130#ifdef CONFIG_MMU
1131		unsigned long excess1
1132			= PAGE_SIZE - ((maddr + phdr->p_filesz) & ~PAGE_MASK);
1133		if (excess > excess1) {
1134			unsigned long xaddr = maddr + phdr->p_filesz + excess1;
1135			unsigned long xmaddr;
1136
1137			flags |= MAP_FIXED | MAP_ANONYMOUS;
1138			xmaddr = vm_mmap(NULL, xaddr, excess - excess1,
1139					 prot, flags, 0);
1140
1141			kdebug("mmap[%d] <anon>"
1142			       " ad=%lx sz=%lx pr=%x fl=%x of=0 --> %08lx",
1143			       loop, xaddr, excess - excess1, prot, flags,
1144			       xmaddr);
1145
1146			if (xmaddr != xaddr)
1147				return -ENOMEM;
1148		}
1149
1150		if (prot & PROT_WRITE && excess1 > 0) {
1151			kdebug("clear[%d] ad=%lx sz=%lx",
1152			       loop, maddr + phdr->p_filesz, excess1);
1153			if (clear_user((void __user *) maddr + phdr->p_filesz,
1154				       excess1))
1155				return -EFAULT;
1156		}
1157
1158#else
1159		if (excess > 0) {
1160			kdebug("clear[%d] ad=%llx sz=%lx", loop,
1161			       (unsigned long long) maddr + phdr->p_filesz,
1162			       excess);
1163			if (clear_user((void *) maddr + phdr->p_filesz, excess))
1164				return -EFAULT;
1165		}
1166#endif
1167
1168		if (mm) {
1169			if (phdr->p_flags & PF_X) {
1170				if (!mm->start_code) {
1171					mm->start_code = maddr;
1172					mm->end_code = maddr + phdr->p_memsz;
1173				}
1174			} else if (!mm->start_data) {
1175				mm->start_data = maddr;
1176				mm->end_data = maddr + phdr->p_memsz;
1177			}
1178		}
1179
1180		seg++;
1181	}
1182
1183	return 0;
1184}
1185
1186/*****************************************************************************/
1187/*
1188 * ELF-FDPIC core dumper
1189 *
1190 * Modelled on fs/exec.c:aout_core_dump()
1191 * Jeremy Fitzhardinge <jeremy@sw.oz.au>
1192 *
1193 * Modelled on fs/binfmt_elf.c core dumper
1194 */
1195#ifdef CONFIG_ELF_CORE
1196
1197struct elf_prstatus_fdpic
1198{
1199	struct elf_prstatus_common	common;
1200	elf_gregset_t pr_reg;	/* GP registers */
1201	/* When using FDPIC, the loadmap addresses need to be communicated
1202	 * to GDB in order for GDB to do the necessary relocations.  The
1203	 * fields (below) used to communicate this information are placed
1204	 * immediately after ``pr_reg'', so that the loadmap addresses may
1205	 * be viewed as part of the register set if so desired.
1206	 */
1207	unsigned long pr_exec_fdpic_loadmap;
1208	unsigned long pr_interp_fdpic_loadmap;
1209	int pr_fpvalid;		/* True if math co-processor being used.  */
1210};
1211
1212/* An ELF note in memory */
1213struct memelfnote
1214{
1215	const char *name;
1216	int type;
1217	unsigned int datasz;
1218	void *data;
1219};
1220
1221static int notesize(struct memelfnote *en)
1222{
1223	int sz;
1224
1225	sz = sizeof(struct elf_note);
1226	sz += roundup(strlen(en->name) + 1, 4);
1227	sz += roundup(en->datasz, 4);
1228
1229	return sz;
1230}
1231
1232/* #define DEBUG */
1233
1234static int writenote(struct memelfnote *men, struct coredump_params *cprm)
1235{
1236	struct elf_note en;
1237	en.n_namesz = strlen(men->name) + 1;
1238	en.n_descsz = men->datasz;
1239	en.n_type = men->type;
1240
1241	return dump_emit(cprm, &en, sizeof(en)) &&
1242		dump_emit(cprm, men->name, en.n_namesz) && dump_align(cprm, 4) &&
1243		dump_emit(cprm, men->data, men->datasz) && dump_align(cprm, 4);
1244}
1245
1246static inline void fill_elf_fdpic_header(struct elfhdr *elf, int segs)
1247{
1248	memcpy(elf->e_ident, ELFMAG, SELFMAG);
1249	elf->e_ident[EI_CLASS] = ELF_CLASS;
1250	elf->e_ident[EI_DATA] = ELF_DATA;
1251	elf->e_ident[EI_VERSION] = EV_CURRENT;
1252	elf->e_ident[EI_OSABI] = ELF_OSABI;
1253	memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD);
1254
1255	elf->e_type = ET_CORE;
1256	elf->e_machine = ELF_ARCH;
1257	elf->e_version = EV_CURRENT;
1258	elf->e_entry = 0;
1259	elf->e_phoff = sizeof(struct elfhdr);
1260	elf->e_shoff = 0;
1261	elf->e_flags = ELF_FDPIC_CORE_EFLAGS;
1262	elf->e_ehsize = sizeof(struct elfhdr);
1263	elf->e_phentsize = sizeof(struct elf_phdr);
1264	elf->e_phnum = segs;
1265	elf->e_shentsize = 0;
1266	elf->e_shnum = 0;
1267	elf->e_shstrndx = 0;
1268	return;
1269}
1270
1271static inline void fill_elf_note_phdr(struct elf_phdr *phdr, int sz, loff_t offset)
1272{
1273	phdr->p_type = PT_NOTE;
1274	phdr->p_offset = offset;
1275	phdr->p_vaddr = 0;
1276	phdr->p_paddr = 0;
1277	phdr->p_filesz = sz;
1278	phdr->p_memsz = 0;
1279	phdr->p_flags = 0;
1280	phdr->p_align = 4;
1281	return;
1282}
1283
1284static inline void __fill_note(struct memelfnote *note, const char *name, int type,
1285			       unsigned int sz, void *data)
1286{
1287	note->name = name;
1288	note->type = type;
1289	note->datasz = sz;
1290	note->data = data;
1291	return;
1292}
1293
1294#define fill_note(note, type, sz, data) \
1295	__fill_note(note, NN_ ## type, NT_ ## type, sz, data)
1296
1297/*
1298 * fill up all the fields in prstatus from the given task struct, except
1299 * registers which need to be filled up separately.
1300 */
1301static void fill_prstatus(struct elf_prstatus_common *prstatus,
1302			  struct task_struct *p, long signr)
1303{
1304	prstatus->pr_info.si_signo = prstatus->pr_cursig = signr;
1305	prstatus->pr_sigpend = p->pending.signal.sig[0];
1306	prstatus->pr_sighold = p->blocked.sig[0];
1307	rcu_read_lock();
1308	prstatus->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1309	rcu_read_unlock();
1310	prstatus->pr_pid = task_pid_vnr(p);
1311	prstatus->pr_pgrp = task_pgrp_vnr(p);
1312	prstatus->pr_sid = task_session_vnr(p);
1313	if (thread_group_leader(p)) {
1314		struct task_cputime cputime;
1315
1316		/*
1317		 * This is the record for the group leader.  It shows the
1318		 * group-wide total, not its individual thread total.
1319		 */
1320		thread_group_cputime(p, &cputime);
1321		prstatus->pr_utime = ns_to_kernel_old_timeval(cputime.utime);
1322		prstatus->pr_stime = ns_to_kernel_old_timeval(cputime.stime);
1323	} else {
1324		u64 utime, stime;
1325
1326		task_cputime(p, &utime, &stime);
1327		prstatus->pr_utime = ns_to_kernel_old_timeval(utime);
1328		prstatus->pr_stime = ns_to_kernel_old_timeval(stime);
1329	}
1330	prstatus->pr_cutime = ns_to_kernel_old_timeval(p->signal->cutime);
1331	prstatus->pr_cstime = ns_to_kernel_old_timeval(p->signal->cstime);
1332}
1333
1334static int fill_psinfo(struct elf_prpsinfo *psinfo, struct task_struct *p,
1335		       struct mm_struct *mm)
1336{
1337	const struct cred *cred;
1338	unsigned int i, len;
1339	unsigned int state;
1340
1341	/* first copy the parameters from user space */
1342	memset(psinfo, 0, sizeof(struct elf_prpsinfo));
1343
1344	len = mm->arg_end - mm->arg_start;
1345	if (len >= ELF_PRARGSZ)
1346		len = ELF_PRARGSZ - 1;
1347	if (copy_from_user(&psinfo->pr_psargs,
1348		           (const char __user *) mm->arg_start, len))
1349		return -EFAULT;
1350	for (i = 0; i < len; i++)
1351		if (psinfo->pr_psargs[i] == 0)
1352			psinfo->pr_psargs[i] = ' ';
1353	psinfo->pr_psargs[len] = 0;
1354
1355	rcu_read_lock();
1356	psinfo->pr_ppid = task_pid_vnr(rcu_dereference(p->real_parent));
1357	rcu_read_unlock();
1358	psinfo->pr_pid = task_pid_vnr(p);
1359	psinfo->pr_pgrp = task_pgrp_vnr(p);
1360	psinfo->pr_sid = task_session_vnr(p);
1361
1362	state = READ_ONCE(p->__state);
1363	i = state ? ffz(~state) + 1 : 0;
1364	psinfo->pr_state = i;
1365	psinfo->pr_sname = (i > 5) ? '.' : "RSDTZW"[i];
1366	psinfo->pr_zomb = psinfo->pr_sname == 'Z';
1367	psinfo->pr_nice = task_nice(p);
1368	psinfo->pr_flag = p->flags;
1369	rcu_read_lock();
1370	cred = __task_cred(p);
1371	SET_UID(psinfo->pr_uid, from_kuid_munged(cred->user_ns, cred->uid));
1372	SET_GID(psinfo->pr_gid, from_kgid_munged(cred->user_ns, cred->gid));
1373	rcu_read_unlock();
1374	get_task_comm(psinfo->pr_fname, p);
1375
1376	return 0;
1377}
1378
1379/* Here is the structure in which status of each thread is captured. */
1380struct elf_thread_status
1381{
1382	struct elf_thread_status *next;
1383	struct elf_prstatus_fdpic prstatus;	/* NT_PRSTATUS */
1384	elf_fpregset_t fpu;		/* NT_PRFPREG */
1385	struct memelfnote notes[2];
1386	int num_notes;
1387};
1388
1389/*
1390 * In order to add the specific thread information for the elf file format,
1391 * we need to keep a linked list of every thread's pr_status and then create
1392 * a single section for them in the final core file.
1393 */
1394static struct elf_thread_status *elf_dump_thread_status(long signr, struct task_struct *p, int *sz)
1395{
1396	const struct user_regset_view *view = task_user_regset_view(p);
1397	struct elf_thread_status *t;
1398	int i, ret;
1399
1400	t = kzalloc(sizeof(struct elf_thread_status), GFP_KERNEL);
1401	if (!t)
1402		return t;
1403
1404	fill_prstatus(&t->prstatus.common, p, signr);
1405	t->prstatus.pr_exec_fdpic_loadmap = p->mm->context.exec_fdpic_loadmap;
1406	t->prstatus.pr_interp_fdpic_loadmap = p->mm->context.interp_fdpic_loadmap;
1407	regset_get(p, &view->regsets[0],
1408		   sizeof(t->prstatus.pr_reg), &t->prstatus.pr_reg);
1409
1410	fill_note(&t->notes[0], PRSTATUS, sizeof(t->prstatus), &t->prstatus);
1411	t->num_notes++;
1412	*sz += notesize(&t->notes[0]);
1413
1414	for (i = 1; i < view->n; ++i) {
1415		const struct user_regset *regset = &view->regsets[i];
1416		if (regset->core_note_type != NT_PRFPREG)
1417			continue;
1418		if (regset->active && regset->active(p, regset) <= 0)
1419			continue;
1420		ret = regset_get(p, regset, sizeof(t->fpu), &t->fpu);
1421		if (ret >= 0)
1422			t->prstatus.pr_fpvalid = 1;
1423		break;
1424	}
1425
1426	if (t->prstatus.pr_fpvalid) {
1427		fill_note(&t->notes[1], PRFPREG, sizeof(t->fpu), &t->fpu);
1428		t->num_notes++;
1429		*sz += notesize(&t->notes[1]);
1430	}
1431	return t;
1432}
1433
1434static void fill_extnum_info(struct elfhdr *elf, struct elf_shdr *shdr4extnum,
1435			     elf_addr_t e_shoff, int segs)
1436{
1437	elf->e_shoff = e_shoff;
1438	elf->e_shentsize = sizeof(*shdr4extnum);
1439	elf->e_shnum = 1;
1440	elf->e_shstrndx = SHN_UNDEF;
1441
1442	memset(shdr4extnum, 0, sizeof(*shdr4extnum));
1443
1444	shdr4extnum->sh_type = SHT_NULL;
1445	shdr4extnum->sh_size = elf->e_shnum;
1446	shdr4extnum->sh_link = elf->e_shstrndx;
1447	shdr4extnum->sh_info = segs;
1448}
1449
1450/*
1451 * dump the segments for an MMU process
1452 */
1453static bool elf_fdpic_dump_segments(struct coredump_params *cprm,
1454				    struct core_vma_metadata *vma_meta,
1455				    int vma_count)
1456{
1457	int i;
1458
1459	for (i = 0; i < vma_count; i++) {
1460		struct core_vma_metadata *meta = vma_meta + i;
1461
1462		if (!dump_user_range(cprm, meta->start, meta->dump_size))
1463			return false;
1464	}
1465	return true;
1466}
1467
1468/*
1469 * Actual dumper
1470 *
1471 * This is a two-pass process; first we find the offsets of the bits,
1472 * and then they are actually written out.  If we run out of core limit
1473 * we just truncate.
1474 */
1475static int elf_fdpic_core_dump(struct coredump_params *cprm)
1476{
1477	int has_dumped = 0;
1478	int segs;
1479	int i;
1480	struct elfhdr *elf = NULL;
1481	loff_t offset = 0, dataoff;
1482	struct memelfnote psinfo_note, auxv_note;
1483	struct elf_prpsinfo *psinfo = NULL;	/* NT_PRPSINFO */
1484	struct elf_thread_status *thread_list = NULL;
1485	int thread_status_size = 0;
1486	elf_addr_t *auxv;
1487	struct elf_phdr *phdr4note = NULL;
1488	struct elf_shdr *shdr4extnum = NULL;
1489	Elf_Half e_phnum;
1490	elf_addr_t e_shoff;
1491	struct core_thread *ct;
1492	struct elf_thread_status *tmp;
1493
1494	/* alloc memory for large data structures: too large to be on stack */
1495	elf = kmalloc(sizeof(*elf), GFP_KERNEL);
1496	if (!elf)
1497		goto end_coredump;
1498	psinfo = kmalloc(sizeof(*psinfo), GFP_KERNEL);
1499	if (!psinfo)
1500		goto end_coredump;
1501
1502	for (ct = current->signal->core_state->dumper.next;
1503					ct; ct = ct->next) {
1504		tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1505					     ct->task, &thread_status_size);
1506		if (!tmp)
1507			goto end_coredump;
1508
1509		tmp->next = thread_list;
1510		thread_list = tmp;
1511	}
1512
1513	/* now collect the dump for the current */
1514	tmp = elf_dump_thread_status(cprm->siginfo->si_signo,
1515				     current, &thread_status_size);
1516	if (!tmp)
1517		goto end_coredump;
1518	tmp->next = thread_list;
1519	thread_list = tmp;
1520
1521	segs = cprm->vma_count + elf_core_extra_phdrs(cprm);
1522
1523	/* for notes section */
1524	segs++;
1525
1526	/* If segs > PN_XNUM(0xffff), then e_phnum overflows. To avoid
1527	 * this, kernel supports extended numbering. Have a look at
1528	 * include/linux/elf.h for further information. */
1529	e_phnum = segs > PN_XNUM ? PN_XNUM : segs;
1530
1531	/* Set up header */
1532	fill_elf_fdpic_header(elf, e_phnum);
1533
1534	has_dumped = 1;
1535	/*
1536	 * Set up the notes in similar form to SVR4 core dumps made
1537	 * with info from their /proc.
1538	 */
1539
1540	fill_psinfo(psinfo, current->group_leader, current->mm);
1541	fill_note(&psinfo_note, PRPSINFO, sizeof(*psinfo), psinfo);
1542	thread_status_size += notesize(&psinfo_note);
1543
1544	auxv = (elf_addr_t *) current->mm->saved_auxv;
1545	i = 0;
1546	do
1547		i += 2;
1548	while (auxv[i - 2] != AT_NULL);
1549	fill_note(&auxv_note, AUXV, i * sizeof(elf_addr_t), auxv);
1550	thread_status_size += notesize(&auxv_note);
1551
1552	offset = sizeof(*elf);				/* ELF header */
1553	offset += segs * sizeof(struct elf_phdr);	/* Program headers */
1554
1555	/* Write notes phdr entry */
1556	phdr4note = kmalloc(sizeof(*phdr4note), GFP_KERNEL);
1557	if (!phdr4note)
1558		goto end_coredump;
1559
1560	fill_elf_note_phdr(phdr4note, thread_status_size, offset);
1561	offset += thread_status_size;
1562
1563	/* Page-align dumped data */
1564	dataoff = offset = roundup(offset, ELF_EXEC_PAGESIZE);
1565
1566	offset += cprm->vma_data_size;
1567	offset += elf_core_extra_data_size(cprm);
1568	e_shoff = offset;
1569
1570	if (e_phnum == PN_XNUM) {
1571		shdr4extnum = kmalloc(sizeof(*shdr4extnum), GFP_KERNEL);
1572		if (!shdr4extnum)
1573			goto end_coredump;
1574		fill_extnum_info(elf, shdr4extnum, e_shoff, segs);
1575	}
1576
1577	offset = dataoff;
1578
1579	if (!dump_emit(cprm, elf, sizeof(*elf)))
1580		goto end_coredump;
1581
1582	if (!dump_emit(cprm, phdr4note, sizeof(*phdr4note)))
1583		goto end_coredump;
1584
1585	/* write program headers for segments dump */
1586	for (i = 0; i < cprm->vma_count; i++) {
1587		struct core_vma_metadata *meta = cprm->vma_meta + i;
1588		struct elf_phdr phdr;
1589		size_t sz;
1590
1591		sz = meta->end - meta->start;
1592
1593		phdr.p_type = PT_LOAD;
1594		phdr.p_offset = offset;
1595		phdr.p_vaddr = meta->start;
1596		phdr.p_paddr = 0;
1597		phdr.p_filesz = meta->dump_size;
1598		phdr.p_memsz = sz;
1599		offset += phdr.p_filesz;
1600		phdr.p_flags = 0;
1601		if (meta->flags & VM_READ)
1602			phdr.p_flags |= PF_R;
1603		if (meta->flags & VM_WRITE)
1604			phdr.p_flags |= PF_W;
1605		if (meta->flags & VM_EXEC)
1606			phdr.p_flags |= PF_X;
1607		phdr.p_align = ELF_EXEC_PAGESIZE;
1608
1609		if (!dump_emit(cprm, &phdr, sizeof(phdr)))
1610			goto end_coredump;
1611	}
1612
1613	if (!elf_core_write_extra_phdrs(cprm, offset))
1614		goto end_coredump;
1615
1616	/* write out the notes section */
1617	if (!writenote(thread_list->notes, cprm))
1618		goto end_coredump;
1619	if (!writenote(&psinfo_note, cprm))
1620		goto end_coredump;
1621	if (!writenote(&auxv_note, cprm))
1622		goto end_coredump;
1623	for (i = 1; i < thread_list->num_notes; i++)
1624		if (!writenote(thread_list->notes + i, cprm))
1625			goto end_coredump;
1626
1627	/* write out the thread status notes section */
1628	for (tmp = thread_list->next; tmp; tmp = tmp->next) {
1629		for (i = 0; i < tmp->num_notes; i++)
1630			if (!writenote(&tmp->notes[i], cprm))
1631				goto end_coredump;
1632	}
1633
1634	dump_skip_to(cprm, dataoff);
1635
1636	if (!elf_fdpic_dump_segments(cprm, cprm->vma_meta, cprm->vma_count))
1637		goto end_coredump;
1638
1639	if (!elf_core_write_extra_data(cprm))
1640		goto end_coredump;
1641
1642	if (e_phnum == PN_XNUM) {
1643		if (!dump_emit(cprm, shdr4extnum, sizeof(*shdr4extnum)))
1644			goto end_coredump;
1645	}
1646
1647	if (cprm->file->f_pos != offset) {
1648		/* Sanity check */
1649		printk(KERN_WARNING
1650		       "elf_core_dump: file->f_pos (%lld) != offset (%lld)\n",
1651		       cprm->file->f_pos, offset);
1652	}
1653
1654end_coredump:
1655	while (thread_list) {
1656		tmp = thread_list;
1657		thread_list = thread_list->next;
1658		kfree(tmp);
1659	}
1660	kfree(phdr4note);
1661	kfree(elf);
1662	kfree(psinfo);
1663	kfree(shdr4extnum);
1664	return has_dumped;
1665}
1666
1667#endif		/* CONFIG_ELF_CORE */