Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1030 insertions, 0 deletions

diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
new file mode 100644
index 000000000..a6f97d86f
--- /dev/null
+++ b/fs/binfmt_flat.c
@@ -0,0 +1,1030 @@
+// SPDX-License-Identifier: GPL-2.0
+/****************************************************************************/
+/*
+ *  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_FLAT
+static 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, loff_t fpos, char *dst,
+		long len, int fd)
+{
+	unsigned char *buf;
+	z_stream strm;
+	int ret, retval;
+
+	pr_debug("decompress_exec(offset=%llx,buf=%p,len=%lx)\n", fpos, dst, len);
+
+	memset(&strm, 0, sizeof(strm));
+	strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
+	if (!strm.workspace)
+		return -ENOMEM;
+
+	buf = kmalloc(LBUFSIZE, GFP_KERNEL);
+	if (!buf) {
+		retval = -ENOMEM;
+		goto out_free;
+	}
+
+	/* Read in first chunk of data and parse gzip header. */
+	ret = kernel_read(bprm->file, buf, LBUFSIZE, &fpos);
+
+	strm.next_in = buf;
+	strm.avail_in = ret;
+	strm.total_in = 0;
+
+	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, buf, LBUFSIZE, &fpos);
+		if (ret <= 0)
+			break;
+		len -= ret;
+
+		strm.next_in = buf;
+		strm.avail_in = ret;
+		strm.total_in = 0;
+	}
+
+	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 long
+calc_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 inline u32 __user *skip_got_header(u32 __user *rp)
+{
+	if (IS_ENABLED(CONFIG_RISCV)) {
+		/*
+		 * RISC-V has a 16 byte GOT PLT header for elf64-riscv
+		 * and 8 byte GOT PLT header for elf32-riscv.
+		 * Skip the whole GOT PLT header, since it is reserved
+		 * for the dynamic linker (ld.so).
+		 */
+		u32 rp_val0, rp_val1;
+
+		if (get_user(rp_val0, rp))
+			return rp;
+		if (get_user(rp_val1, rp + 1))
+			return rp;
+
+		if (rp_val0 == 0xffffffff && rp_val1 == 0xffffffff)
+			rp += 4;
+		else if (rp_val0 == 0xffffffff)
+			rp += 2;
+	}
+	return rp;
+}
+
+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)) {
+		pr_err("Support for ZFLAT executables is not enabled.\n");
+		ret = -ENOEXEC;
+		goto err;
+	}
+#endif
+
+	/*
+	 * Check initial limits. This avoids letting people circumvent
+	 * size limits imposed on them by creating programs with large
+	 * arrays in the data or bss.
+	 */
+	rlim = rlimit(RLIMIT_DATA);
+	if (rlim >= RLIM_INFINITY)
+		rlim = ~0;
+	if (data_len + bss_len > rlim) {
+		ret = -ENOMEM;
+		goto err;
+	}
+
+	/* Flush all traces of the currently running executable */
+	if (id == 0) {
+		ret = flush_old_exec(bprm);
+		if (ret)
+			goto err;
+
+		/* OK, This is the point of no return */
+		set_personality(PER_LINUX_32BIT);
+		setup_new_exec(bprm);
+	}
+
+	/*
+	 * calculate the extra space we need to map in
+	 */
+	extra = max_t(unsigned long, bss_len + stack_len,
+			relocs * sizeof(unsigned long));
+
+	/*
+	 * there are a couple of cases here,  the separate code/data
+	 * case,  and then the fully copied to RAM case which lumps
+	 * it all together.
+	 */
+	if (!IS_ENABLED(CONFIG_MMU) && !(flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP))) {
+		/*
+		 * this should give us a ROM ptr,  but if it doesn't we don't
+		 * really care
+		 */
+		pr_debug("ROM mapping of file (we hope)\n");
+
+		textpos = vm_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
+				  MAP_PRIVATE|MAP_EXECUTABLE, 0);
+		if (!textpos || IS_ERR_VALUE(textpos)) {
+			ret = textpos;
+			if (!textpos)
+				ret = -ENOMEM;
+			pr_err("Unable to mmap process text, errno %d\n", ret);
+			goto err;
+		}
+
+		len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
+		len = PAGE_ALIGN(len);
+		realdatastart = vm_mmap(NULL, 0, len,
+			PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
+
+		if (realdatastart == 0 || IS_ERR_VALUE(realdatastart)) {
+			ret = realdatastart;
+			if (!realdatastart)
+				ret = -ENOMEM;
+			pr_err("Unable to allocate RAM for process data, "
+			       "errno %d\n", ret);
+			vm_munmap(textpos, text_len);
+			goto err;
+		}
+		datapos = ALIGN(realdatastart +
+				MAX_SHARED_LIBS * sizeof(unsigned long),
+				FLAT_DATA_ALIGN);
+
+		pr_debug("Allocated data+bss+stack (%u bytes): %lx\n",
+			 data_len + bss_len + stack_len, datapos);
+
+		fpos = ntohl(hdr->data_start);
+#ifdef CONFIG_BINFMT_ZFLAT
+		if (flags & FLAT_FLAG_GZDATA) {
+			result = decompress_exec(bprm, fpos, (char *)datapos,
+						 full_data, 0);
+		} else
+#endif
+		{
+			result = read_code(bprm->file, datapos, fpos,
+					full_data);
+		}
+		if (IS_ERR_VALUE(result)) {
+			ret = result;
+			pr_err("Unable to read data+bss, errno %d\n", ret);
+			vm_munmap(textpos, text_len);
+			vm_munmap(realdatastart, len);
+			goto err;
+		}
+
+		reloc = (u32 __user *)
+			(datapos + (ntohl(hdr->reloc_start) - text_len));
+		memp = realdatastart;
+		memp_size = len;
+	} else {
+
+		len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(u32);
+		len = PAGE_ALIGN(len);
+		textpos = vm_mmap(NULL, 0, len,
+			PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
+
+		if (!textpos || IS_ERR_VALUE(textpos)) {
+			ret = textpos;
+			if (!textpos)
+				ret = -ENOMEM;
+			pr_err("Unable to allocate RAM for process text/data, "
+			       "errno %d\n", ret);
+			goto err;
+		}
+
+		realdatastart = textpos + ntohl(hdr->data_start);
+		datapos = ALIGN(realdatastart +
+				MAX_SHARED_LIBS * sizeof(u32),
+				FLAT_DATA_ALIGN);
+
+		reloc = (u32 __user *)
+			(datapos + (ntohl(hdr->reloc_start) - text_len));
+		memp = textpos;
+		memp_size = len;
+#ifdef CONFIG_BINFMT_ZFLAT
+		/*
+		 * load it all in and treat it like a RAM load from now on
+		 */
+		if (flags & FLAT_FLAG_GZIP) {
+#ifndef CONFIG_MMU
+			result = decompress_exec(bprm, sizeof(struct flat_hdr),
+					 (((char *)textpos) + sizeof(struct flat_hdr)),
+					 (text_len + full_data
+						  - sizeof(struct flat_hdr)),
+					 0);
+			memmove((void *) datapos, (void *) realdatastart,
+					full_data);
+#else
+			/*
+			 * This is used on MMU systems mainly for testing.
+			 * Let's use a kernel buffer to simplify things.
+			 */
+			long unz_text_len = text_len - sizeof(struct flat_hdr);
+			long unz_len = unz_text_len + full_data;
+			char *unz_data = vmalloc(unz_len);
+			if (!unz_data) {
+				result = -ENOMEM;
+			} else {
+				result = decompress_exec(bprm, sizeof(struct flat_hdr),
+							 unz_data, unz_len, 0);
+				if (result == 0 &&
+				    (copy_to_user((void __user *)textpos + sizeof(struct flat_hdr),
+						  unz_data, unz_text_len) ||
+				     copy_to_user((void __user *)datapos,
+						  unz_data + unz_text_len, full_data)))
+					result = -EFAULT;
+				vfree(unz_data);
+			}
+#endif
+		} else if (flags & FLAT_FLAG_GZDATA) {
+			result = read_code(bprm->file, textpos, 0, text_len);
+			if (!IS_ERR_VALUE(result)) {
+#ifndef CONFIG_MMU
+				result = decompress_exec(bprm, text_len, (char *) datapos,
+						 full_data, 0);
+#else
+				char *unz_data = vmalloc(full_data);
+				if (!unz_data) {
+					result = -ENOMEM;
+				} else {
+					result = decompress_exec(bprm, text_len,
+						       unz_data, full_data, 0);
+					if (result == 0 &&
+					    copy_to_user((void __user *)datapos,
+							 unz_data, full_data))
+						result = -EFAULT;
+					vfree(unz_data);
+				}
+#endif
+			}
+		} else
+#endif /* CONFIG_BINFMT_ZFLAT */
+		{
+			result = read_code(bprm->file, textpos, 0, text_len);
+			if (!IS_ERR_VALUE(result))
+				result = read_code(bprm->file, datapos,
+						   ntohl(hdr->data_start),
+						   full_data);
+		}
+		if (IS_ERR_VALUE(result)) {
+			ret = result;
+			pr_err("Unable to read code+data+bss, errno %d\n", ret);
+			vm_munmap(textpos, text_len + data_len + extra +
+				MAX_SHARED_LIBS * sizeof(u32));
+			goto err;
+		}
+	}
+
+	start_code = textpos + sizeof(struct flat_hdr);
+	end_code = textpos + text_len;
+	text_len -= sizeof(struct flat_hdr); /* the real code len */
+
+	/* The main program needs a little extra setup in the task structure */
+	if (id == 0) {
+		current->mm->start_code = start_code;
+		current->mm->end_code = end_code;
+		current->mm->start_data = datapos;
+		current->mm->end_data = datapos + data_len;
+		/*
+		 * set up the brk stuff, uses any slack left in data/bss/stack
+		 * allocation.  We put the brk after the bss (between the bss
+		 * and stack) like other platforms.
+		 * Userspace code relies on the stack pointer starting out at
+		 * an address right at the end of a page.
+		 */
+		current->mm->start_brk = datapos + data_len + bss_len;
+		current->mm->brk = (current->mm->start_brk + 3) & ~3;
+#ifndef CONFIG_MMU
+		current->mm->context.end_brk = memp + memp_size - stack_len;
+#endif
+	}
+
+	if (flags & FLAT_FLAG_KTRACE) {
+		pr_info("Mapping is %lx, Entry point is %x, data_start is %x\n",
+			textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));
+		pr_info("%s %s: TEXT=%lx-%lx DATA=%lx-%lx BSS=%lx-%lx\n",
+			id ? "Lib" : "Load", bprm->filename,
+			start_code, end_code, datapos, datapos + data_len,
+			datapos + data_len, (datapos + data_len + bss_len + 3) & ~3);
+	}
+
+	/* Store the current module values into the global library structure */
+	libinfo->lib_list[id].start_code = start_code;
+	libinfo->lib_list[id].start_data = datapos;
+	libinfo->lib_list[id].start_brk = datapos + data_len + bss_len;
+	libinfo->lib_list[id].text_len = text_len;
+	libinfo->lib_list[id].loaded = 1;
+	libinfo->lib_list[id].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
+	libinfo->lib_list[id].build_date = ntohl(hdr->build_date);
+
+	/*
+	 * We just load the allocations into some temporary memory to
+	 * help simplify all this mumbo jumbo
+	 *
+	 * We've got two different sections of relocation entries.
+	 * The first is the GOT which resides at the beginning of the data segment
+	 * and is terminated with a -1.  This one can be relocated in place.
+	 * The second is the extra relocation entries tacked after the image's
+	 * data segment. These require a little more processing as the entry is
+	 * really an offset into the image which contains an offset into the
+	 * image.
+	 */
+	if (flags & FLAT_FLAG_GOTPIC) {
+		rp = skip_got_header((u32 __user *) datapos);
+		for (; ; rp++) {
+			u32 addr, rp_val;
+			if (get_user(rp_val, rp))
+				return -EFAULT;
+			if (rp_val == 0xffffffff)
+				break;
+			if (rp_val) {
+				addr = calc_reloc(rp_val, libinfo, id, 0);
+				if (addr == RELOC_FAILED) {
+					ret = -ENOEXEC;
+					goto err;
+				}
+				if (put_user(addr, rp))
+					return -EFAULT;
+			}
+		}
+	}
+
+	/*
+	 * Now run through the relocation entries.
+	 * We've got to be careful here as C++ produces relocatable zero
+	 * entries in the constructor and destructor tables which are then
+	 * tested for being not zero (which will always occur unless we're
+	 * based from address zero).  This causes an endless loop as __start
+	 * is at zero.  The solution used is to not relocate zero addresses.
+	 * This has the negative side effect of not allowing a global data
+	 * reference to be statically initialised to _stext (I've moved
+	 * __start to address 4 so that is okay).
+	 */
+	if (rev > OLD_FLAT_VERSION) {
+		u32 __maybe_unused persistent = 0;
+		for (i = 0; i < relocs; i++) {
+			u32 addr, relval;
+
+			/*
+			 * Get the address of the pointer to be
+			 * relocated (of course, the address has to be
+			 * relocated first).
+			 */
+			if (get_user(relval, reloc + i))
+				return -EFAULT;
+			relval = ntohl(relval);
+			if (flat_set_persistent(relval, &persistent))
+				continue;
+			addr = flat_get_relocate_addr(relval);
+			rp = (u32 __user *)calc_reloc(addr, libinfo, id, 1);
+			if (rp == (u32 __user *)RELOC_FAILED) {
+				ret = -ENOEXEC;
+				goto err;
+			}
+
+			/* Get the pointer's value.  */
+			ret = flat_get_addr_from_rp(rp, relval, flags,
+							&addr, &persistent);
+			if (unlikely(ret))
+				goto err;
+
+			if (addr != 0) {
+				/*
+				 * Do the relocation.  PIC relocs in the data section are
+				 * already in target order
+				 */
+				if ((flags & FLAT_FLAG_GOTPIC) == 0)
+					addr = ntohl(addr);
+				addr = calc_reloc(addr, libinfo, id, 0);
+				if (addr == RELOC_FAILED) {
+					ret = -ENOEXEC;
+					goto err;
+				}
+
+				/* Write back the relocated pointer.  */
+				ret = flat_put_addr_at_rp(rp, addr, relval);
+				if (unlikely(ret))
+					goto err;
+			}
+		}
+	} else {
+		for (i = 0; i < relocs; i++) {
+			u32 relval;
+			if (get_user(relval, reloc + i))
+				return -EFAULT;
+			relval = ntohl(relval);
+			old_reloc(relval);
+		}
+	}
+
+	flush_icache_range(start_code, end_code);
+
+	/* zero the BSS,  BRK and stack areas */
+	if (clear_user((void __user *)(datapos + data_len), bss_len +
+		       (memp + memp_size - stack_len -		/* end brk */
+		       libinfo->lib_list[id].start_brk) +	/* start brk */
+		       stack_len))
+		return -EFAULT;
+
+	return 0;
+err:
+	return ret;
+}
+
+
+/****************************************************************************/
+#ifdef CONFIG_BINFMT_SHARED_FLAT
+
+/*
+ * Load a shared library into memory.  The library gets its own data
+ * segment (including bss) but not argv/argc/environ.
+ */
+
+static int load_flat_shared_library(int id, struct lib_info *libs)
+{
+	/*
+	 * This is a fake bprm struct; only the members "buf", "file" and
+	 * "filename" are actually used.
+	 */
+	struct linux_binprm bprm;
+	int res;
+	char buf[16];
+	loff_t pos = 0;
+
+	memset(&bprm, 0, sizeof(bprm));
+
+	/* Create the file name */
+	sprintf(buf, "/lib/lib%d.so", id);
+
+	/* Open the file up */
+	bprm.filename = buf;
+	bprm.file = open_exec(bprm.filename);
+	res = PTR_ERR(bprm.file);
+	if (IS_ERR(bprm.file))
+		return res;
+
+	res = kernel_read(bprm.file, bprm.buf, BINPRM_BUF_SIZE, &pos);
+
+	if (res >= 0)
+		res = load_flat_file(&bprm, libs, id, NULL);
+
+	allow_write_access(bprm.file);
+	fput(bprm.file);
+
+	return res;
+}
+
+#endif /* CONFIG_BINFMT_SHARED_FLAT */
+/****************************************************************************/
+
+/*
+ * These are the functions used to load flat style executables and shared
+ * libraries.  There is no binary dependent code anywhere else.
+ */
+
+static int load_flat_binary(struct linux_binprm *bprm)
+{
+	struct lib_info libinfo;
+	struct pt_regs *regs = current_pt_regs();
+	unsigned long stack_len = 0;
+	unsigned long start_addr;
+	int res;
+	int i, j;
+
+	memset(&libinfo, 0, sizeof(libinfo));
+
+	/*
+	 * We have to add the size of our arguments to our stack size
+	 * otherwise it's too easy for users to create stack overflows
+	 * by passing in a huge argument list.  And yes,  we have to be
+	 * pedantic and include space for the argv/envp array as it may have
+	 * a lot of entries.
+	 */
+#ifndef CONFIG_MMU
+	stack_len += PAGE_SIZE * MAX_ARG_PAGES - bprm->p; /* the strings */
+#endif
+	stack_len += (bprm->argc + 1) * sizeof(char *);   /* the argv array */
+	stack_len += (bprm->envc + 1) * sizeof(char *);   /* the envp array */
+	stack_len = ALIGN(stack_len, FLAT_STACK_ALIGN);
+
+	res = load_flat_file(bprm, &libinfo, 0, &stack_len);
+	if (res < 0)
+		return res;
+
+	/* Update data segment pointers for all libraries */
+	for (i = 0; i < MAX_SHARED_LIBS; i++) {
+		if (!libinfo.lib_list[i].loaded)
+			continue;
+		for (j = 0; j < MAX_SHARED_LIBS; j++) {
+			unsigned long val = libinfo.lib_list[j].loaded ?
+				libinfo.lib_list[j].start_data : UNLOADED_LIB;
+			unsigned long __user *p = (unsigned long __user *)
+				libinfo.lib_list[i].start_data;
+			p -= j + 1;
+			if (put_user(val, p))
+				return -EFAULT;
+		}
+	}
+
+	install_exec_creds(bprm);
+
+	set_binfmt(&flat_format);
+
+#ifdef CONFIG_MMU
+	res = setup_arg_pages(bprm, STACK_TOP, EXSTACK_DEFAULT);
+	if (!res)
+		res = create_flat_tables(bprm, bprm->p);
+#else
+	/* Stash our initial stack pointer into the mm structure */
+	current->mm->start_stack =
+		((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
+	pr_debug("sp=%lx\n", current->mm->start_stack);
+
+	/* copy the arg pages onto the stack */
+	res = transfer_args_to_stack(bprm, &current->mm->start_stack);
+	if (!res)
+		res = create_flat_tables(bprm, current->mm->start_stack);
+#endif
+	if (res)
+		return res;
+
+	/* Fake some return addresses to ensure the call chain will
+	 * initialise library in order for us.  We are required to call
+	 * lib 1 first, then 2, ... and finally the main program (id 0).
+	 */
+	start_addr = libinfo.lib_list[0].entry;
+
+#ifdef CONFIG_BINFMT_SHARED_FLAT
+	for (i = MAX_SHARED_LIBS-1; i > 0; i--) {
+		if (libinfo.lib_list[i].loaded) {
+			/* Push previos first to call address */
+			unsigned long __user *sp;
+			current->mm->start_stack -= sizeof(unsigned long);
+			sp = (unsigned long __user *)current->mm->start_stack;
+			__put_user(start_addr, sp);
+			start_addr = libinfo.lib_list[i].entry;
+		}
+	}
+#endif
+
+#ifdef FLAT_PLAT_INIT
+	FLAT_PLAT_INIT(regs);
+#endif
+
+	finalize_exec(bprm);
+	pr_debug("start_thread(regs=0x%p, entry=0x%lx, start_stack=0x%lx)\n",
+		 regs, start_addr, current->mm->start_stack);
+	start_thread(regs, start_addr, current->mm->start_stack);
+
+	return 0;
+}
+
+/****************************************************************************/
+
+static int __init init_flat_binfmt(void)
+{
+	register_binfmt(&flat_format);
+	return 0;
+}
+core_initcall(init_flat_binfmt);
+
+/****************************************************************************/