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/****************************************************************************//* *  linux/fs/binfmt_flat.c * *	Copyright (C) 2000-2003 David McCullough <davidm@snapgear.com> *	Copyright (C) 2002 Greg Ungerer <gerg@snapgear.com> *	Copyright (C) 2002 SnapGear, by Paul Dale <pauli@snapgear.com> *	Copyright (C) 2000, 2001 Lineo, by David McCullough <davidm@lineo.com> *  based heavily on: * *  linux/fs/binfmt_aout.c: *      Copyright (C) 1991, 1992, 1996  Linus Torvalds *  linux/fs/binfmt_flat.c for 2.0 kernel *	    Copyright (C) 1998  Kenneth Albanowski <kjahds@kjahds.com> *	JAN/99 -- coded full program relocation (gerg@snapgear.com) */ #define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt #include <linux/kernel.h>#include <linux/sched.h>#include <linux/sched/task_stack.h>#include <linux/mm.h>#include <linux/mman.h>#include <linux/errno.h>#include <linux/signal.h>#include <linux/string.h>#include <linux/fs.h>#include <linux/file.h>#include <linux/ptrace.h>#include <linux/user.h>#include <linux/slab.h>#include <linux/binfmts.h>#include <linux/personality.h>#include <linux/init.h>#include <linux/flat.h>#include <linux/uaccess.h>#include <linux/vmalloc.h> #include <asm/byteorder.h>#include <asm/unaligned.h>#include <asm/cacheflush.h>#include <asm/page.h> /****************************************************************************/ /* * User data (data section and bss) needs to be aligned. * We pick 0x20 here because it is the max value elf2flt has always * used in producing FLAT files, and because it seems to be large * enough to make all the gcc alignment related tests happy. */#define FLAT_DATA_ALIGN	(0x20) /* * User data (stack) also needs to be aligned. * Here we can be a bit looser than the data sections since this * needs to only meet arch ABI requirements. */#define FLAT_STACK_ALIGN	max_t(unsigned long, sizeof(void *), ARCH_SLAB_MINALIGN) #define RELOC_FAILED 0xff00ff01		/* Relocation incorrect somewhere */#define UNLOADED_LIB 0x7ff000ff		/* Placeholder for unused library */ struct lib_info {	struct {		unsigned long start_code;		/* Start of text segment */		unsigned long start_data;		/* Start of data segment */		unsigned long start_brk;		/* End of data segment */		unsigned long text_len;			/* Length of text segment */		unsigned long entry;			/* Start address for this module */		unsigned long build_date;		/* When this one was compiled */		bool loaded;				/* Has this library been loaded? */	} lib_list[MAX_SHARED_LIBS];}; #ifdef CONFIG_BINFMT_SHARED_FLATstatic int load_flat_shared_library(int id, struct lib_info *p);#endif static int load_flat_binary(struct linux_binprm *);static int flat_core_dump(struct coredump_params *cprm); static struct linux_binfmt flat_format = {	.module		= THIS_MODULE,	.load_binary	= load_flat_binary,	.core_dump	= flat_core_dump,	.min_coredump	= PAGE_SIZE}; /****************************************************************************//* * Routine writes a core dump image in the current directory. * Currently only a stub-function. */ static int flat_core_dump(struct coredump_params *cprm){	pr_warn("Process %s:%d received signr %d and should have core dumped\n",		current->comm, current->pid, cprm->siginfo->si_signo);	return 1;} /****************************************************************************//* * create_flat_tables() parses the env- and arg-strings in new user * memory and creates the pointer tables from them, and puts their * addresses on the "stack", recording the new stack pointer value. */ static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start){	char __user *p;	unsigned long __user *sp;	long i, len; 	p = (char __user *)arg_start;	sp = (unsigned long __user *)current->mm->start_stack; 	sp -= bprm->envc + 1;	sp -= bprm->argc + 1;	sp -= flat_argvp_envp_on_stack() ? 2 : 0;	sp -= 1;  /* &argc */ 	current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;	sp = (unsigned long __user *)current->mm->start_stack; 	__put_user(bprm->argc, sp++);	if (flat_argvp_envp_on_stack()) {		unsigned long argv, envp;		argv = (unsigned long)(sp + 2);		envp = (unsigned long)(sp + 2 + bprm->argc + 1);		__put_user(argv, sp++);		__put_user(envp, sp++);	} 	current->mm->arg_start = (unsigned long)p;	for (i = bprm->argc; i > 0; i--) {		__put_user((unsigned long)p, sp++);		len = strnlen_user(p, MAX_ARG_STRLEN);		if (!len || len > MAX_ARG_STRLEN)			return -EINVAL;		p += len;	}	__put_user(0, sp++);	current->mm->arg_end = (unsigned long)p; 	current->mm->env_start = (unsigned long) p;	for (i = bprm->envc; i > 0; i--) {		__put_user((unsigned long)p, sp++);		len = strnlen_user(p, MAX_ARG_STRLEN);		if (!len || len > MAX_ARG_STRLEN)			return -EINVAL;		p += len;	}	__put_user(0, sp++);	current->mm->env_end = (unsigned long)p; 	return 0;} /****************************************************************************/ #ifdef CONFIG_BINFMT_ZFLAT #include <linux/zlib.h> #define LBUFSIZE	4000 /* gzip flag byte */#define ASCII_FLAG   0x01 /* bit 0 set: file probably ASCII text */#define CONTINUATION 0x02 /* bit 1 set: continuation of multi-part gzip file */#define EXTRA_FIELD  0x04 /* bit 2 set: extra field present */#define ORIG_NAME    0x08 /* bit 3 set: original file name present */#define COMMENT      0x10 /* bit 4 set: file comment present */#define ENCRYPTED    0x20 /* bit 5 set: file is encrypted */#define RESERVED     0xC0 /* bit 6,7:   reserved */ static int decompress_exec(	struct linux_binprm *bprm,	unsigned long offset,	char *dst,	long len,	int fd){	unsigned char *buf;	z_stream strm;	loff_t fpos;	int ret, retval; 	pr_debug("decompress_exec(offset=%lx,buf=%p,len=%lx)\n", offset, dst, len); 	memset(&strm, 0, sizeof(strm));	strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);	if (strm.workspace == NULL) {		pr_debug("no memory for decompress workspace\n");		return -ENOMEM;	}	buf = kmalloc(LBUFSIZE, GFP_KERNEL);	if (buf == NULL) {		pr_debug("no memory for read buffer\n");		retval = -ENOMEM;		goto out_free;	} 	/* Read in first chunk of data and parse gzip header. */	fpos = offset;	ret = kernel_read(bprm->file, offset, buf, LBUFSIZE); 	strm.next_in = buf;	strm.avail_in = ret;	strm.total_in = 0;	fpos += ret; 	retval = -ENOEXEC; 	/* Check minimum size -- gzip header */	if (ret < 10) {		pr_debug("file too small?\n");		goto out_free_buf;	} 	/* Check gzip magic number */	if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {		pr_debug("unknown compression magic?\n");		goto out_free_buf;	} 	/* Check gzip method */	if (buf[2] != 8) {		pr_debug("unknown compression method?\n");		goto out_free_buf;	}	/* Check gzip flags */	if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||	    (buf[3] & RESERVED)) {		pr_debug("unknown flags?\n");		goto out_free_buf;	} 	ret = 10;	if (buf[3] & EXTRA_FIELD) {		ret += 2 + buf[10] + (buf[11] << 8);		if (unlikely(ret >= LBUFSIZE)) {			pr_debug("buffer overflow (EXTRA)?\n");			goto out_free_buf;		}	}	if (buf[3] & ORIG_NAME) {		while (ret < LBUFSIZE && buf[ret++] != 0)			;		if (unlikely(ret == LBUFSIZE)) {			pr_debug("buffer overflow (ORIG_NAME)?\n");			goto out_free_buf;		}	}	if (buf[3] & COMMENT) {		while (ret < LBUFSIZE && buf[ret++] != 0)			;		if (unlikely(ret == LBUFSIZE)) {			pr_debug("buffer overflow (COMMENT)?\n");			goto out_free_buf;		}	} 	strm.next_in += ret;	strm.avail_in -= ret; 	strm.next_out = dst;	strm.avail_out = len;	strm.total_out = 0; 	if (zlib_inflateInit2(&strm, -MAX_WBITS) != Z_OK) {		pr_debug("zlib init failed?\n");		goto out_free_buf;	} 	while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {		ret = kernel_read(bprm->file, fpos, buf, LBUFSIZE);		if (ret <= 0)			break;		len -= ret; 		strm.next_in = buf;		strm.avail_in = ret;		strm.total_in = 0;		fpos += ret;	} 	if (ret < 0) {		pr_debug("decompression failed (%d), %s\n",			ret, strm.msg);		goto out_zlib;	} 	retval = 0;out_zlib:	zlib_inflateEnd(&strm);out_free_buf:	kfree(buf);out_free:	kfree(strm.workspace);	return retval;} #endif /* CONFIG_BINFMT_ZFLAT */ /****************************************************************************/ static unsigned longcalc_reloc(unsigned long r, struct lib_info *p, int curid, int internalp){	unsigned long addr;	int id;	unsigned long start_brk;	unsigned long start_data;	unsigned long text_len;	unsigned long start_code; #ifdef CONFIG_BINFMT_SHARED_FLAT	if (r == 0)		id = curid;	/* Relocs of 0 are always self referring */	else {		id = (r >> 24) & 0xff;	/* Find ID for this reloc */		r &= 0x00ffffff;	/* Trim ID off here */	}	if (id >= MAX_SHARED_LIBS) {		pr_err("reference 0x%lx to shared library %d", r, id);		goto failed;	}	if (curid != id) {		if (internalp) {			pr_err("reloc address 0x%lx not in same module "			       "(%d != %d)", r, curid, id);			goto failed;		} else if (!p->lib_list[id].loaded &&			   load_flat_shared_library(id, p) < 0) {			pr_err("failed to load library %d", id);			goto failed;		}		/* Check versioning information (i.e. time stamps) */		if (p->lib_list[id].build_date && p->lib_list[curid].build_date &&				p->lib_list[curid].build_date < p->lib_list[id].build_date) {			pr_err("library %d is younger than %d", id, curid);			goto failed;		}	}#else	id = 0;#endif 	start_brk = p->lib_list[id].start_brk;	start_data = p->lib_list[id].start_data;	start_code = p->lib_list[id].start_code;	text_len = p->lib_list[id].text_len; 	if (!flat_reloc_valid(r, start_brk - start_data + text_len)) {		pr_err("reloc outside program 0x%lx (0 - 0x%lx/0x%lx)",		       r, start_brk-start_data+text_len, text_len);		goto failed;	} 	if (r < text_len)			/* In text segment */		addr = r + start_code;	else					/* In data segment */		addr = r - text_len + start_data; 	/* Range checked already above so doing the range tests is redundant...*/	return addr; failed:	pr_cont(", killing %s!\n", current->comm);	send_sig(SIGSEGV, current, 0); 	return RELOC_FAILED;} /****************************************************************************/ static void old_reloc(unsigned long rl){	static const char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };	flat_v2_reloc_t	r;	unsigned long __user *ptr;	unsigned long val; 	r.value = rl;#if defined(CONFIG_COLDFIRE)	ptr = (unsigned long __user *)(current->mm->start_code + r.reloc.offset);#else	ptr = (unsigned long __user *)(current->mm->start_data + r.reloc.offset);#endif	get_user(val, ptr); 	pr_debug("Relocation of variable at DATASEG+%x "		 "(address %p, currently %lx) into segment %s\n",		 r.reloc.offset, ptr, val, segment[r.reloc.type]); 	switch (r.reloc.type) {	case OLD_FLAT_RELOC_TYPE_TEXT:		val += current->mm->start_code;		break;	case OLD_FLAT_RELOC_TYPE_DATA:		val += current->mm->start_data;		break;	case OLD_FLAT_RELOC_TYPE_BSS:		val += current->mm->end_data;		break;	default:		pr_err("Unknown relocation type=%x\n", r.reloc.type);		break;	}	put_user(val, ptr); 	pr_debug("Relocation became %lx\n", val);} /****************************************************************************/ static int load_flat_file(struct linux_binprm *bprm,		struct lib_info *libinfo, int id, unsigned long *extra_stack){	struct flat_hdr *hdr;	unsigned long textpos, datapos, realdatastart;	u32 text_len, data_len, bss_len, stack_len, full_data, flags;	unsigned long len, memp, memp_size, extra, rlim;	u32 __user *reloc, *rp;	struct inode *inode;	int i, rev, relocs;	loff_t fpos;	unsigned long start_code, end_code;	ssize_t result;	int ret; 	hdr = ((struct flat_hdr *) bprm->buf);		/* exec-header */	inode = file_inode(bprm->file); 	text_len  = ntohl(hdr->data_start);	data_len  = ntohl(hdr->data_end) - ntohl(hdr->data_start);	bss_len   = ntohl(hdr->bss_end) - ntohl(hdr->data_end);	stack_len = ntohl(hdr->stack_size);	if (extra_stack) {		stack_len += *extra_stack;		*extra_stack = stack_len;	}	relocs    = ntohl(hdr->reloc_count);	flags     = ntohl(hdr->flags);	rev       = ntohl(hdr->rev);	full_data = data_len + relocs * sizeof(unsigned long); 	if (strncmp(hdr->magic, "bFLT", 4)) {		/*		 * Previously, here was a printk to tell people		 *   "BINFMT_FLAT: bad header magic".		 * But for the kernel which also use ELF FD-PIC format, this		 * error message is confusing.		 * because a lot of people do not manage to produce good		 */		ret = -ENOEXEC;		goto err;	} 	if (flags & FLAT_FLAG_KTRACE)		pr_info("Loading file: %s\n", bprm->filename); 	if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {		pr_err("bad flat file version 0x%x (supported 0x%lx and 0x%lx)\n",		       rev, FLAT_VERSION, OLD_FLAT_VERSION);		ret = -ENOEXEC;		goto err;	} 	/* Don't allow old format executables to use shared libraries */	if (rev == OLD_FLAT_VERSION && id != 0) {		pr_err("shared libraries are not available before rev 0x%lx\n",		       FLAT_VERSION);		ret = -ENOEXEC;		goto err;	} 	/*	 * Make sure the header params are sane.	 * 28 bits (256 MB) is way more than reasonable in this case.	 * If some top bits are set we have probable binary corruption.	*/	if ((text_len | data_len | bss_len | stack_len | full_data) >> 28) {		pr_err("bad header\n");		ret = -ENOEXEC;		goto err;	} 	/*	 * fix up the flags for the older format,  there were all kinds	 * of endian hacks,  this only works for the simple cases	 */	if (rev == OLD_FLAT_VERSION && flat_old_ram_flag(flags))		flags = FLAT_FLAG_RAM; #ifndef CONFIG_BINFMT_ZFLAT	if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {

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