Revision 619b0488038224391e64fa03854651ca0f5efe56 authored by Raistlin on 26 June 2008, 16:54:09 UTC, committed by Ingo Molnar on 01 July 2008, 06:23:24 UTC
Here it is another little Oops we found while configuring invalid values
via cgroups:

echo 0 > /dev/cgroups/0/cpu.rt_period_us
or
echo 4294967296 > /dev/cgroups/0/cpu.rt_period_us

[  205.509825] divide error: 0000 [#1]
[  205.510151] Modules linked in:
[  205.510151]
[  205.510151] Pid: 2339, comm: bash Not tainted (2.6.26-rc8 #33)
[  205.510151] EIP: 0060:[<c030c6ef>] EFLAGS: 00000293 CPU: 0
[  205.510151] EIP is at div64_u64+0x5f/0x70
[  205.510151] EAX: 0000389f EBX: 00000000 ECX: 00000000 EDX: 00000000
[  205.510151] ESI: d9800000 EDI: 00000000 EBP: c6cede60 ESP: c6cede50
[  205.510151]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
[  205.510151] Process bash (pid: 2339, ti=c6cec000 task=c79be370 task.ti=c6cec000)
[  205.510151] Stack: d9800000 0000389f c05971a0 d9800000 c6cedeb4 c0214dbd 00000000 00000000
[  205.510151]        c6cede88 c0242bd8 c05377c0 c7a41b40 00000000 00000000 00000000 c05971a0
[  205.510151]        c780ed20 c7508494 c7a41b40 00000000 00000002 c6cedebc c05971a0 ffffffea
[  205.510151] Call Trace:
[  205.510151]  [<c0214dbd>] ? __rt_schedulable+0x1cd/0x240
[  205.510151]  [<c0242bd8>] ? cgroup_file_open+0x18/0xe0
[  205.510151]  [<c0214fe4>] ? tg_set_bandwidth+0xa4/0xf0
[  205.510151]  [<c0215066>] ? sched_group_set_rt_period+0x36/0x50
[  205.510151]  [<c021508e>] ? cpu_rt_period_write_uint+0xe/0x10
[  205.510151]  [<c0242dc5>] ? cgroup_file_write+0x125/0x160
[  205.510151]  [<c0232c15>] ? hrtimer_interrupt+0x155/0x190
[  205.510151]  [<c02f047f>] ? security_file_permission+0xf/0x20
[  205.510151]  [<c0277ad8>] ? rw_verify_area+0x48/0xc0
[  205.510151]  [<c0283744>] ? dupfd+0x104/0x130
[  205.510151]  [<c027838c>] ? vfs_write+0x9c/0x160
[  205.510151]  [<c0242ca0>] ? cgroup_file_write+0x0/0x160
[  205.510151]  [<c027850d>] ? sys_write+0x3d/0x70
[  205.510151]  [<c0203019>] ? sysenter_past_esp+0x6a/0x91
[  205.510151]  =======================
[  205.510151] Code: 0f 45 de 31 f6 0f ad d0 d3 ea f6 c1 20 0f 45 c2 0f 45 d6 89 45 f0 89 55 f4 8b 55 f4 31 c9 8b 45 f0 39 d3 89 c6 77 08 89 d0 31 d2 <f7> f3 89 c1 83 c4 08 89 f0 f7 f3 89 ca 5b 5e 5d c3 55 89 e5 56
[  205.510151] EIP: [<c030c6ef>] div64_u64+0x5f/0x70 SS:ESP 0068:c6cede50

The attached patch solves the issue for me.

I'm checking as soon as possible for the period not being zero since, if
it is, going ahead is useless. This way we also save a mutex_lock() and
a read_lock() wrt doing it inside tg_set_bandwidth() or
__rt_schedulable().

Signed-off-by: Dario Faggioli <raistlin@linux.it>
Signed-off-by: Michael Trimarchi <trimarchimichael@yahoo.it>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 parent 79c5379
Raw File
binfmt_flat.c
/****************************************************************************/
/*
 *  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)
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.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/stat.h>
#include <linux/fcntl.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/syscalls.h>

#include <asm/byteorder.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/unaligned.h>
#include <asm/cacheflush.h>

/****************************************************************************/

#if 0
#define DEBUG 1
#endif

#ifdef DEBUG
#define	DBG_FLT(a...)	printk(a)
#else
#define	DBG_FLT(a...)
#endif

#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 */
		short 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 *, struct pt_regs * regs);
static int flat_core_dump(long signr, struct pt_regs *regs, struct file *file, unsigned long limit);

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(long signr, struct pt_regs *regs, struct file *file, unsigned long limit)
{
	printk("Process %s:%d received signr %d and should have core dumped\n",
			current->comm, current->pid, (int) signr);
	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", returning the new stack pointer value.
 */

static unsigned long create_flat_tables(
	unsigned long pp,
	struct linux_binprm * bprm)
{
	unsigned long *argv,*envp;
	unsigned long * sp;
	char * p = (char*)pp;
	int argc = bprm->argc;
	int envc = bprm->envc;
	char uninitialized_var(dummy);

	sp = (unsigned long *) ((-(unsigned long)sizeof(char *))&(unsigned long) p);

	sp -= envc+1;
	envp = sp;
	sp -= argc+1;
	argv = sp;

	flat_stack_align(sp);
	if (flat_argvp_envp_on_stack()) {
		--sp; put_user((unsigned long) envp, sp);
		--sp; put_user((unsigned long) argv, sp);
	}

	put_user(argc,--sp);
	current->mm->arg_start = (unsigned long) p;
	while (argc-->0) {
		put_user((unsigned long) p, argv++);
		do {
			get_user(dummy, p); p++;
		} while (dummy);
	}
	put_user((unsigned long) NULL, argv);
	current->mm->arg_end = current->mm->env_start = (unsigned long) p;
	while (envc-->0) {
		put_user((unsigned long)p, envp); envp++;
		do {
			get_user(dummy, p); p++;
		} while (dummy);
	}
	put_user((unsigned long) NULL, envp);
	current->mm->env_end = (unsigned long) p;
	return (unsigned long)sp;
}

/****************************************************************************/

#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;

	DBG_FLT("decompress_exec(offset=%x,buf=%x,len=%x)\n",(int)offset, (int)dst, (int)len);

	memset(&strm, 0, sizeof(strm));
	strm.workspace = kmalloc(zlib_inflate_workspacesize(), GFP_KERNEL);
	if (strm.workspace == NULL) {
		DBG_FLT("binfmt_flat: no memory for decompress workspace\n");
		return -ENOMEM;
	}
	buf = kmalloc(LBUFSIZE, GFP_KERNEL);
	if (buf == NULL) {
		DBG_FLT("binfmt_flat: no memory for read buffer\n");
		retval = -ENOMEM;
		goto out_free;
	}

	/* Read in first chunk of data and parse gzip header. */
	fpos = offset;
	ret = bprm->file->f_op->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) {
		DBG_FLT("binfmt_flat: file too small?\n");
		goto out_free_buf;
	}

	/* Check gzip magic number */
	if ((buf[0] != 037) || ((buf[1] != 0213) && (buf[1] != 0236))) {
		DBG_FLT("binfmt_flat: unknown compression magic?\n");
		goto out_free_buf;
	}

	/* Check gzip method */
	if (buf[2] != 8) {
		DBG_FLT("binfmt_flat: unknown compression method?\n");
		goto out_free_buf;
	}
	/* Check gzip flags */
	if ((buf[3] & ENCRYPTED) || (buf[3] & CONTINUATION) ||
	    (buf[3] & RESERVED)) {
		DBG_FLT("binfmt_flat: unknown flags?\n");
		goto out_free_buf;
	}

	ret = 10;
	if (buf[3] & EXTRA_FIELD) {
		ret += 2 + buf[10] + (buf[11] << 8);
		if (unlikely(LBUFSIZE == ret)) {
			DBG_FLT("binfmt_flat: buffer overflow (EXTRA)?\n");
			goto out_free_buf;
		}
	}
	if (buf[3] & ORIG_NAME) {
		for (; ret < LBUFSIZE && (buf[ret] != 0); ret++)
			;
		if (unlikely(LBUFSIZE == ret)) {
			DBG_FLT("binfmt_flat: buffer overflow (ORIG_NAME)?\n");
			goto out_free_buf;
		}
	}
	if (buf[3] & COMMENT) {
		for (;  ret < LBUFSIZE && (buf[ret] != 0); ret++)
			;
		if (unlikely(LBUFSIZE == ret)) {
			DBG_FLT("binfmt_flat: 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) {
		DBG_FLT("binfmt_flat: zlib init failed?\n");
		goto out_free_buf;
	}

	while ((ret = zlib_inflate(&strm, Z_NO_FLUSH)) == Z_OK) {
		ret = bprm->file->f_op->read(bprm->file, buf, LBUFSIZE, &fpos);
		if (ret <= 0)
			break;
		if (ret >= (unsigned long) -4096)
			break;
		len -= ret;

		strm.next_in = buf;
		strm.avail_in = ret;
		strm.total_in = 0;
	}

	if (ret < 0) {
		DBG_FLT("binfmt_flat: 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) {
		printk("BINFMT_FLAT: reference 0x%x to shared library %d",
				(unsigned) r, id);
		goto failed;
	}
	if (curid != id) {
		if (internalp) {
			printk("BINFMT_FLAT: reloc address 0x%x not in same module "
					"(%d != %d)", (unsigned) r, curid, id);
			goto failed;
		} else if ( ! p->lib_list[id].loaded &&
				load_flat_shared_library(id, p) > (unsigned long) -4096) {
			printk("BINFMT_FLAT: 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) {
			printk("BINFMT_FLAT: 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)) {
		printk("BINFMT_FLAT: reloc outside program 0x%x (0 - 0x%x/0x%x)",
		       (int) r,(int)(start_brk-start_code),(int)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:
	printk(", killing %s!\n", current->comm);
	send_sig(SIGSEGV, current, 0);

	return RELOC_FAILED;
}

/****************************************************************************/

void old_reloc(unsigned long rl)
{
#ifdef DEBUG
	char *segment[] = { "TEXT", "DATA", "BSS", "*UNKNOWN*" };
#endif
	flat_v2_reloc_t	r;
	unsigned long *ptr;
	
	r.value = rl;
#if defined(CONFIG_COLDFIRE)
	ptr = (unsigned long *) (current->mm->start_code + r.reloc.offset);
#else
	ptr = (unsigned long *) (current->mm->start_data + r.reloc.offset);
#endif

#ifdef DEBUG
	printk("Relocation of variable at DATASEG+%x "
		"(address %p, currently %x) into segment %s\n",
		r.reloc.offset, ptr, (int)*ptr, segment[r.reloc.type]);
#endif
	
	switch (r.reloc.type) {
	case OLD_FLAT_RELOC_TYPE_TEXT:
		*ptr += current->mm->start_code;
		break;
	case OLD_FLAT_RELOC_TYPE_DATA:
		*ptr += current->mm->start_data;
		break;
	case OLD_FLAT_RELOC_TYPE_BSS:
		*ptr += current->mm->end_data;
		break;
	default:
		printk("BINFMT_FLAT: Unknown relocation type=%x\n", r.reloc.type);
		break;
	}

#ifdef DEBUG
	printk("Relocation became %x\n", (int)*ptr);
#endif
}		

/****************************************************************************/

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 = 0, datapos = 0, result;
	unsigned long realdatastart = 0;
	unsigned long text_len, data_len, bss_len, stack_len, flags;
	unsigned long len, reallen, memp = 0;
	unsigned long extra, rlim;
	unsigned long *reloc = 0, *rp;
	struct inode *inode;
	int i, rev, relocs = 0;
	loff_t fpos;
	unsigned long start_code, end_code;
	int ret;

	hdr = ((struct flat_hdr *) bprm->buf);		/* exec-header */
	inode = bprm->file->f_path.dentry->d_inode;

	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);

	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)
		printk("BINFMT_FLAT: Loading file: %s\n", bprm->filename);

	if (rev != FLAT_VERSION && rev != OLD_FLAT_VERSION) {
		printk("BINFMT_FLAT: 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) {
		printk("BINFMT_FLAT: shared libraries are not available before rev 0x%x\n",
				(int) 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 && flat_old_ram_flag(flags))
		flags = FLAT_FLAG_RAM;

#ifndef CONFIG_BINFMT_ZFLAT
	if (flags & (FLAT_FLAG_GZIP|FLAT_FLAG_GZDATA)) {
		printk("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 = current->signal->rlim[RLIMIT_DATA].rlim_cur;
	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) {
		result = flush_old_exec(bprm);
		if (result) {
			ret = result;
			goto err;
		}

		/* OK, This is the point of no return */
		set_personality(PER_LINUX_32BIT);
	}

	/*
	 * 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 ((flags & (FLAT_FLAG_RAM|FLAT_FLAG_GZIP)) == 0) {
		/*
		 * this should give us a ROM ptr,  but if it doesn't we don't
		 * really care
		 */
		DBG_FLT("BINFMT_FLAT: ROM mapping of file (we hope)\n");

		down_write(&current->mm->mmap_sem);
		textpos = do_mmap(bprm->file, 0, text_len, PROT_READ|PROT_EXEC,
				  MAP_PRIVATE|MAP_EXECUTABLE, 0);
		up_write(&current->mm->mmap_sem);
		if (!textpos  || textpos >= (unsigned long) -4096) {
			if (!textpos)
				textpos = (unsigned long) -ENOMEM;
			printk("Unable to mmap process text, errno %d\n", (int)-textpos);
			ret = textpos;
			goto err;
		}

		len = data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
		down_write(&current->mm->mmap_sem);
		realdatastart = do_mmap(0, 0, len,
			PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE, 0);
		/* Remap to use all availabe slack region space */
		if (realdatastart && (realdatastart < (unsigned long)-4096)) {
			reallen = kobjsize((void *)realdatastart);
			if (reallen > len) {
				realdatastart = do_mremap(realdatastart, len,
					reallen, MREMAP_FIXED, realdatastart);
			}
		}
		up_write(&current->mm->mmap_sem);

		if (realdatastart == 0 || realdatastart >= (unsigned long)-4096) {
			if (!realdatastart)
				realdatastart = (unsigned long) -ENOMEM;
			printk("Unable to allocate RAM for process data, errno %d\n",
					(int)-realdatastart);
			do_munmap(current->mm, textpos, text_len);
			ret = realdatastart;
			goto err;
		}
		datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);

		DBG_FLT("BINFMT_FLAT: Allocated data+bss+stack (%d bytes): %x\n",
				(int)(data_len + bss_len + stack_len), (int)datapos);

		fpos = ntohl(hdr->data_start);
#ifdef CONFIG_BINFMT_ZFLAT
		if (flags & FLAT_FLAG_GZDATA) {
			result = decompress_exec(bprm, fpos, (char *) datapos, 
						 data_len + (relocs * sizeof(unsigned long)), 0);
		} else
#endif
		{
			result = bprm->file->f_op->read(bprm->file, (char *) datapos,
					data_len + (relocs * sizeof(unsigned long)), &fpos);
		}
		if (result >= (unsigned long)-4096) {
			printk("Unable to read data+bss, errno %d\n", (int)-result);
			do_munmap(current->mm, textpos, text_len);
			do_munmap(current->mm, realdatastart, data_len + extra);
			ret = result;
			goto err;
		}

		reloc = (unsigned long *) (datapos+(ntohl(hdr->reloc_start)-text_len));
		memp = realdatastart;

	} else {

		len = text_len + data_len + extra + MAX_SHARED_LIBS * sizeof(unsigned long);
		down_write(&current->mm->mmap_sem);
		textpos = do_mmap(0, 0, len,
			PROT_READ | PROT_EXEC | PROT_WRITE, MAP_PRIVATE, 0);
		/* Remap to use all availabe slack region space */
		if (textpos && (textpos < (unsigned long) -4096)) {
			reallen = kobjsize((void *)textpos);
			if (reallen > len) {
				textpos = do_mremap(textpos, len, reallen,
					MREMAP_FIXED, textpos);
			}
		}
		up_write(&current->mm->mmap_sem);

		if (!textpos  || textpos >= (unsigned long) -4096) {
			if (!textpos)
				textpos = (unsigned long) -ENOMEM;
			printk("Unable to allocate RAM for process text/data, errno %d\n",
					(int)-textpos);
			ret = textpos;
			goto err;
		}

		realdatastart = textpos + ntohl(hdr->data_start);
		datapos = realdatastart + MAX_SHARED_LIBS * sizeof(unsigned long);
		reloc = (unsigned long *) (textpos + ntohl(hdr->reloc_start) +
				MAX_SHARED_LIBS * sizeof(unsigned long));
		memp = textpos;

#ifdef CONFIG_BINFMT_ZFLAT
		/*
		 * load it all in and treat it like a RAM load from now on
		 */
		if (flags & FLAT_FLAG_GZIP) {
			result = decompress_exec(bprm, sizeof (struct flat_hdr),
					 (((char *) textpos) + sizeof (struct flat_hdr)),
					 (text_len + data_len + (relocs * sizeof(unsigned long))
						  - sizeof (struct flat_hdr)),
					 0);
			memmove((void *) datapos, (void *) realdatastart,
					data_len + (relocs * sizeof(unsigned long)));
		} else if (flags & FLAT_FLAG_GZDATA) {
			fpos = 0;
			result = bprm->file->f_op->read(bprm->file,
					(char *) textpos, text_len, &fpos);
			if (result < (unsigned long) -4096)
				result = decompress_exec(bprm, text_len, (char *) datapos,
						 data_len + (relocs * sizeof(unsigned long)), 0);
		}
		else
#endif
		{
			fpos = 0;
			result = bprm->file->f_op->read(bprm->file,
					(char *) textpos, text_len, &fpos);
			if (result < (unsigned long) -4096) {
				fpos = ntohl(hdr->data_start);
				result = bprm->file->f_op->read(bprm->file, (char *) datapos,
					data_len + (relocs * sizeof(unsigned long)), &fpos);
			}
		}
		if (result >= (unsigned long)-4096) {
			printk("Unable to read code+data+bss, errno %d\n",(int)-result);
			do_munmap(current->mm, textpos, text_len + data_len + extra +
				MAX_SHARED_LIBS * sizeof(unsigned long));
			ret = result;
			goto err;
		}
	}

	if (flags & FLAT_FLAG_KTRACE)
		printk("Mapping is %x, Entry point is %x, data_start is %x\n",
			(int)textpos, 0x00ffffff&ntohl(hdr->entry), ntohl(hdr->data_start));

	/* The main program needs a little extra setup in the task structure */
	start_code = textpos + sizeof (struct flat_hdr);
	end_code = textpos + text_len;
	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.
		 */
		current->mm->start_brk = datapos + data_len + bss_len;
		current->mm->brk = (current->mm->start_brk + 3) & ~3;
		current->mm->context.end_brk = memp + kobjsize((void *) memp) - stack_len;
	}

	if (flags & FLAT_FLAG_KTRACE)
		printk("%s %s: TEXT=%x-%x DATA=%x-%x BSS=%x-%x\n",
			id ? "Lib" : "Load", bprm->filename,
			(int) start_code, (int) end_code,
			(int) datapos,
			(int) (datapos + data_len),
			(int) (datapos + data_len),
			(int) (((datapos + data_len + bss_len) + 3) & ~3));

	text_len -= sizeof(struct flat_hdr); /* the real code len */

	/* 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 begining 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) {
		for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) {
			unsigned long addr;
			if (*rp) {
				addr = calc_reloc(*rp, libinfo, id, 0);
				if (addr == RELOC_FAILED) {
					ret = -ENOEXEC;
					goto err;
				}
				*rp = addr;
			}
		}
	}

	/*
	 * 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) {
		unsigned long persistent = 0;
		for (i=0; i < relocs; i++) {
			unsigned long addr, relval;

			/* Get the address of the pointer to be
			   relocated (of course, the address has to be
			   relocated first).  */
			relval = ntohl(reloc[i]);
			if (flat_set_persistent (relval, &persistent))
				continue;
			addr = flat_get_relocate_addr(relval);
			rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1);
			if (rp == (unsigned long *)RELOC_FAILED) {
				ret = -ENOEXEC;
				goto err;
			}

			/* Get the pointer's value.  */
			addr = flat_get_addr_from_rp(rp, relval, flags,
							&persistent);
			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.  */
				flat_put_addr_at_rp(rp, addr, relval);
			}
		}
	} else {
		for (i=0; i < relocs; i++)
			old_reloc(ntohl(reloc[i]));
	}
	
	flush_icache_range(start_code, end_code);

	/* zero the BSS,  BRK and stack areas */
	memset((void*)(datapos + data_len), 0, bss_len + 
			(memp + kobjsize((void *) memp) - stack_len -	/* end brk */
			libinfo->lib_list[id].start_brk) +		/* start brk */
			stack_len);

	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)
{
	struct linux_binprm bprm;
	int res;
	char buf[16];

	/* 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 = prepare_binprm(&bprm);

	if (res <= (unsigned long)-4096)
		res = load_flat_file(&bprm, libs, id, NULL);
	if (bprm.file) {
		allow_write_access(bprm.file);
		fput(bprm.file);
		bprm.file = NULL;
	}
	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 pt_regs * regs)
{
	struct lib_info libinfo;
	unsigned long p = bprm->p;
	unsigned long stack_len;
	unsigned long start_addr;
	unsigned long *sp;
	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.
	 */
#define TOP_OF_ARGS (PAGE_SIZE * MAX_ARG_PAGES - sizeof(void *))
	stack_len = TOP_OF_ARGS - bprm->p;             /* the strings */
	stack_len += (bprm->argc + 1) * sizeof(char *); /* the argv array */
	stack_len += (bprm->envc + 1) * sizeof(char *); /* the envp array */

	
	res = load_flat_file(bprm, &libinfo, 0, &stack_len);
	if (res > (unsigned long)-4096)
		return res;
	
	/* Update data segment pointers for all libraries */
	for (i=0; i<MAX_SHARED_LIBS; i++)
		if (libinfo.lib_list[i].loaded)
			for (j=0; j<MAX_SHARED_LIBS; j++)
				(-(j+1))[(unsigned long *)(libinfo.lib_list[i].start_data)] =
					(libinfo.lib_list[j].loaded)?
						libinfo.lib_list[j].start_data:UNLOADED_LIB;

	compute_creds(bprm);
 	current->flags &= ~PF_FORKNOEXEC;

	set_binfmt(&flat_format);

	p = ((current->mm->context.end_brk + stack_len + 3) & ~3) - 4;
	DBG_FLT("p=%x\n", (int)p);

	/* copy the arg pages onto the stack, this could be more efficient :-) */
	for (i = TOP_OF_ARGS - 1; i >= bprm->p; i--)
		* (char *) --p =
			((char *) page_address(bprm->page[i/PAGE_SIZE]))[i % PAGE_SIZE];

	sp = (unsigned long *) create_flat_tables(p, bprm);
	
	/* 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 */
			--sp;	put_user(start_addr, sp);
			start_addr = libinfo.lib_list[i].entry;
		}
	}
#endif
	
	/* Stash our initial stack pointer into the mm structure */
	current->mm->start_stack = (unsigned long )sp;

	
	DBG_FLT("start_thread(regs=0x%x, entry=0x%x, start_stack=0x%x)\n",
		(int)regs, (int)start_addr, (int)current->mm->start_stack);
	
	start_thread(regs, start_addr, current->mm->start_stack);

	if (current->ptrace & PT_PTRACED)
		send_sig(SIGTRAP, current, 0);

	return 0;
}

/****************************************************************************/

static int __init init_flat_binfmt(void)
{
	return register_binfmt(&flat_format);
}

/****************************************************************************/

core_initcall(init_flat_binfmt);

/****************************************************************************/
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