Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Don't destroy user event fields when removal fails

   User event fields are destroyed before the event is removed from
   visibility. But that can fail leaving the still visible event with no
   fields. Move the destroying of the fields to after the event is
   successfully removed from visibility.

 - Initialize function graph state is fork before calling
   copy_exec_state()

   For non-CLONE_VM forks, copy_exec_state() allocates a new
   task_exec_state. If that allocation fails, ftrace_graph_exit_task()
   will free the tasks ret_stack pointer. Since that pointer is still
   using the parent's ret_stack, it mistakenly frees the parent's
   pointer too.

   Call ftrace_graph_init() on the task first which will NULL out the
   new tasks's ret_stack and if the copy fails, it will not free
   anything.

 - Remove FGRAPH_MAX_INDEX

   The macro FGRAPH_MAX_INDEX was added but never used. Remove it.

 - Save ent_size in function graph printing of nested functions

   The function graph tracer needs to look at the next event to see if
   the next event is the return of the current function entry. If it is,
   it prints a single line:

	ktime_get();

   Otherwise it prints it like a nested function:

	tick_nohz_irq_exit() {
	    ktime_get();
	    kcpustat_irq_exit();
	}

   In order to look at the next event, it must save the current event so
   that it has the information to print from it. It saves the event in
   the iterator descriptor called "ent". What it doesn't save is the
   ent_size of the event which is now used to know if the function graph
   arguments are to be printed. The peek doesn't save the size so the
   size used happens to be that of the size of the last event that was
   seen.

   Save the entry event size in the iterator descriptor so that the
   correct size is used.

 - Fix several errors with freeing data in the histogram code

   The histogram code had a lot of leaked or or incorrect accounting
   when failures happen. Correct them.

 - Fix histogram regression of .percent and .graph modifiers

   Up until 6.3 histogram values could have "percent" or "graph"
   modifiers that changed how they were printed. But a change that added
   restricting histograms values from being strings, stack traces and
   other modifiers inadvertently prevented them from using the percent
   and graph modifiers, which were legal use cases for values.

   Put back the percent and graph modifiers.

 - Fix various typos in the comments

 - Set the trace_clock before initializing a histogram with clock
   argument

   The histogram API allows the user to specific which trace clock to
   use via a "clock=" string. The histogram is set up first before the
   clock is checked. If the passed in clock is not valid, it exits
   without fully fixing up the histogram leaving it on the list and a
   use-after-free can trigger.

   Update the clock argument first and if it fails then exit gracefully
   before the histogram trigger is placed on any lists.

 - Restore :mod: trailer after parsing in ftrace_set_clr_event

   The function ftrace_set_clr_event() modifies the parse string and
   needs to put it back to what was passed in. It searches for ":mod:"
   via a strsep() but fails to put back the first ':' in the string.

   Add back the ':' in the passed in string.

 - Take trace_array reference when opening a tracer options file

   The options files are dynamically created and some tracers add their
   own options. When a tracer adds their own list of options, the
   trace_array holding them has an array to hold the list of options for
   each tracer. This array increases in size via a krealloc(), and the
   new entry gets a newly allocated array to hold the options of the new
   tracer being added.

   The element in each entry of the tracer's option array holds a
   pointer back to the trace_array, a pointer to the tracer it is
   associated to, a pointer to the flags of the option.

   The issue is that these arrays are freed when the trace_array is
   freed when its instance it represents is removed from the instances
   directory. There's a race that an open of one of these options files
   can happen when the instance is being removed.

   Add a new helper function to be called by the open function of the
   options file to iterate all existing trace_arrays under a lock and
   find the one that has the given option element in one of it's tracer
   arrays. If found, then update the associated trace_array's reference
   counter to keep it from being freed. If not found, have the open call
   return -ENODEV.

 - Disable interrupts when acquiring the lock in rb_wake_up_waiters()

   The function rb_wake_up_waiters() assumes it will be called in
   interrupt context and does not disable irqs when taking
   cpu_buffer->reader_lock, which can be called in hard interrupt
   context. The issue is in PREEMPT_RT, this function is called in
   thread context leaving this lock open to a deadlock.

   Take the lock with interrupts disabled.

 - Use rcu_assign_pointer() for tmp_ops filter hash

   The tmp_ops used in update_ftrace_direct_mod() assigns its
   filter_hash field directly, but that field is annotated as __rcu and
   sparse complains. Assign it with rcu_assign_pointer()

 - Fix use-after-free in enable_trigger_private_data_free()

   The trace_event_call is accessed through the event_trigger_data's
   trace_event_file pointer to put the trace_event_call on freeing. The
   issue is that the trace_event_file data may have been freed already
   causing a use-after-free. Add a field to the event_trigger_data that
   points directly to the trace_event_call so that it can decrement its
   reference directly without needing to go through the
   trace_event_file.

 - Fix accounting of buffer data remote headers

   trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount
   the number of pages is needed for the asked for size as it doesn't
   take into account the meta data on each page. Add a helper function
   to do the calculation properly and use that in these functions.

 - Catch nr_page_va overflow in ring_buffer_desc sizing

   The number of pages per remote ring buffer is capped by
   ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to
   overflow that field would silently allocate a descriptor smaller than
   what was asked for.

 - Do not resize the subbuf order if any per_cpu buffer is disabled

   The mmapping of ring buffers disables resizing the subbuffers, but it
   is done per-cpu whereas the subbuf size change is done for all the
   per_cpu buffers under the buffer->mutex. It could change the size of
   some while the mapping is happening on others. Have the resize of the
   subbuf order check all the per_cpu buffers under the lock to see if
   any of them is disabled before starting and causing an inconsistency
   between buffers that are being mapped.

* tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits)
  ring-buffer: Check resize_disabled before publishing the new subbuf order
  tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing
  tracing/remotes: Account for ring buffer page header in size calculation
  tracing: Don't dereference trace_event_file in deferred trigger free
  ftrace: Use rcu_assign_pointer() for tmp_ops filter hash
  ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters()
  tracing: Take trace_array reference when opening a tracer options file
  tracing: Fix ring_buffer_read_page_size() kernel-doc
  tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event()
  tracing: Fix memory corruption from a "STACKTRACE" histogram key
  tracing: Fix memory corruption from the histogram stacktrace modifier
  tracing: Undo the registration when enabling the histogram trigger fails
  tracing: Take the reference before publishing the named histogram trigger
  tracing: Set the trace clock before registering the histogram trigger
  tracing: Fix typo "preceeded" in comment
  tracing: Fix typo "availabe" in comment
  tracing: Let histogram values keep the percent and graph modifiers
  tracing: Keep the entry count when the histogram stats allocation fails
  tracing: Free histogram the field rejected for a bad modifier
  tracing: Free histogram the var ref when its initialization fails
  ...

1 files changed, 946 insertions, 0 deletions

diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c
new file mode 100644
index 000000000..b5b5ca1a4
--- /dev/null
+++ b/fs/binfmt_flat.c
@@ -0,0 +1,946 @@
+// 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 <linux/unaligned.h>
+#include <asm/cacheflush.h>
+#include <asm/page.h>
+#include <asm/flat.h>
+
+#ifndef flat_get_relocate_addr
+#define flat_get_relocate_addr(rel)	(rel)
+#endif
+
+/****************************************************************************/
+
+/*
+ * 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 */
+
+#define MAX_SHARED_LIBS			(1)
+
+#ifdef CONFIG_BINFMT_FLAT_NO_DATA_START_OFFSET
+#define DATA_START_OFFSET_WORDS		(0)
+#define MAX_SHARED_LIBS_UPDATE		(0)
+#else
+#define DATA_START_OFFSET_WORDS		(MAX_SHARED_LIBS)
+#define MAX_SHARED_LIBS_UPDATE		(MAX_SHARED_LIBS)
+#endif
+
+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];
+};
+
+static int load_flat_binary(struct linux_binprm *);
+
+static struct linux_binfmt flat_format = {
+	.module		= THIS_MODULE,
+	.load_binary	= load_flat_binary,
+};
+
+
+/****************************************************************************/
+/*
+ * 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;
+	if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK))
+		sp -= 2; /* argvp + envp */
+	sp -= 1;  /* &argc */
+
+	current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;
+	sp = (unsigned long __user *)current->mm->start_stack;
+
+	if (put_user(bprm->argc, sp++))
+		return -EFAULT;
+	if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) {
+		unsigned long argv, envp;
+		argv = (unsigned long)(sp + 2);
+		envp = (unsigned long)(sp + 2 + bprm->argc + 1);
+		if (put_user(argv, sp++) || put_user(envp, sp++))
+			return -EFAULT;
+	}
+
+	current->mm->arg_start = (unsigned long)p;
+	for (i = bprm->argc; i > 0; i--) {
+		if (put_user((unsigned long)p, sp++))
+			return -EFAULT;
+		len = strnlen_user(p, MAX_ARG_STRLEN);
+		if (!len || len > MAX_ARG_STRLEN)
+			return -EINVAL;
+		p += len;
+	}
+	if (put_user(0, sp++))
+		return -EFAULT;
+	current->mm->arg_end = (unsigned long)p;
+
+	current->mm->env_start = (unsigned long) p;
+	for (i = bprm->envc; i > 0; i--) {
+		if (put_user((unsigned long)p, sp++))
+			return -EFAULT;
+		len = strnlen_user(p, MAX_ARG_STRLEN);
+		if (!len || len > MAX_ARG_STRLEN)
+			return -EINVAL;
+		p += len;
+	}
+	if (put_user(0, sp++))
+		return -EFAULT;
+	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)
+{
+	unsigned long addr;
+	unsigned long start_brk;
+	unsigned long start_data;
+	unsigned long text_len;
+	unsigned long start_code;
+
+	start_brk = p->lib_list[0].start_brk;
+	start_data = p->lib_list[0].start_data;
+	start_code = p->lib_list[0].start_code;
+	text_len = p->lib_list[0].text_len;
+
+	if (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;
+}
+
+/****************************************************************************/
+
+#ifdef CONFIG_BINFMT_FLAT_OLD
+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);
+}
+#endif /* CONFIG_BINFMT_FLAT_OLD */
+
+/****************************************************************************/
+
+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, 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;
+	__be32 __user *reloc;
+	u32 __user *rp;
+	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 */
+
+	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);
+
+#ifdef CONFIG_BINFMT_FLAT_OLD
+	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;
+	}
+
+	/*
+	 * 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 &&
+	   (flags || IS_ENABLED(CONFIG_BINFMT_FLAT_OLD_ALWAYS_RAM)))
+		flags = FLAT_FLAG_RAM;
+
+#else /* CONFIG_BINFMT_FLAT_OLD */
+	if (rev != FLAT_VERSION) {
+		pr_err("bad flat file version 0x%x (supported 0x%lx)\n",
+		       rev, FLAT_VERSION);
+		ret = -ENOEXEC;
+		goto err;
+	}
+#endif /* !CONFIG_BINFMT_FLAT_OLD */
+
+	/*
+	 * 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 | relocs | full_data) >> 28) {
+		pr_err("bad header\n");
+		ret = -ENOEXEC;
+		goto err;
+	}
+
+#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 */
+	ret = begin_new_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, 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 +
+			DATA_START_OFFSET_WORDS * 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 +
+				DATA_START_OFFSET_WORDS * 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 = (__be32 __user *)
+			(datapos + (ntohl(hdr->reloc_start) - text_len));
+		memp = realdatastart;
+		memp_size = len;
+	} else {
+
+		len = text_len + data_len + extra +
+			DATA_START_OFFSET_WORDS * 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 +
+				DATA_START_OFFSET_WORDS * sizeof(u32),
+				FLAT_DATA_ALIGN);
+
+		reloc = (__be32 __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 +
+				  DATA_START_OFFSET_WORDS * 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 */
+	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",
+			"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[0].start_code = start_code;
+	libinfo->lib_list[0].start_data = datapos;
+	libinfo->lib_list[0].start_brk = datapos + data_len + bss_len;
+	libinfo->lib_list[0].text_len = text_len;
+	libinfo->lib_list[0].loaded = 1;
+	libinfo->lib_list[0].entry = (0x00ffffff & ntohl(hdr->entry)) + textpos;
+	libinfo->lib_list[0].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);
+				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) {
+		for (i = 0; i < relocs; i++) {
+			u32 addr, relval;
+			__be32 tmp;
+
+			/*
+			 * Get the address of the pointer to be
+			 * relocated (of course, the address has to be
+			 * relocated first).
+			 */
+			if (get_user(tmp, reloc + i))
+				return -EFAULT;
+			relval = ntohl(tmp);
+			addr = flat_get_relocate_addr(relval);
+			rp = (u32 __user *)calc_reloc(addr, libinfo);
+			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);
+			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) {
+					/*
+					 * Meh, the same value can have a different
+					 * byte order based on a flag..
+					 */
+					addr = ntohl((__force __be32)addr);
+				}
+				addr = calc_reloc(addr, libinfo);
+				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;
+			}
+		}
+#ifdef CONFIG_BINFMT_FLAT_OLD
+	} else {
+		for (i = 0; i < relocs; i++) {
+			__be32 relval;
+			if (get_user(relval, reloc + i))
+				return -EFAULT;
+			old_reloc(ntohl(relval));
+		}
+#endif /* CONFIG_BINFMT_FLAT_OLD */
+	}
+
+	flush_icache_user_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[0].start_brk) +	/* start brk */
+		       stack_len))
+		return -EFAULT;
+
+	return 0;
+err:
+	return ret;
+}
+
+
+/****************************************************************************/
+
+/*
+ * 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, &stack_len);
+	if (res < 0)
+		return res;
+
+	/* Update data segment pointers for all libraries */
+	for (i = 0; i < MAX_SHARED_LIBS_UPDATE; 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;
+		}
+	}
+
+	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 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);
+
+/****************************************************************************/