Subject: Re: [PATCH 5/9] Restore memory address space
From: Nadia Derbey <Nadia.Derbey@bull.net>
To: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@osdl.org>,
       containers <containers@lists.linux-foundation.org>,
       "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
       linux-mm <linux-mm@kvack.org>, Thomas Gleixner <tglx@linutronix.de>,
       Ingo Molnar <mingo@elte.hu>
In-Reply-To: <20081016181421.3BA319FA@kernel>
References: <20081016181414.934C4FCC@kernel>
	 <20081016181421.3BA319FA@kernel>
Content-Type: text/plain
Date: Fri, 17 Oct 2008 10:44:30 +0200
Message-Id: <1224233070.2634.114.camel@frecb000730.frec.bull.fr>
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Sender: linux-kernel-owner@vger.kernel.org
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On Thu, 2008-10-16 at 11:14 -0700, Dave Hansen wrote:
> From: Oren Laadan <orenl@cs.columbia.edu>
> 
> Restoring the memory address space begins with nuking the existing one
> of the current process, and then reading the VMA state and contents.
> Call do_mmap_pgoffset() for each VMA and then read in the data.
> 
> Signed-off-by: Oren Laadan <orenl@cs.columbia.edu>
> Acked-by: Serge Hallyn <serue@us.ibm.com>
> Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
> ---
> 
>  linux-2.6.git-dave/arch/x86/mm/restart.c            |   64 +++
>  linux-2.6.git-dave/checkpoint/Makefile              |    2 
>  linux-2.6.git-dave/checkpoint/checkpoint_arch.h     |    2 
>  linux-2.6.git-dave/checkpoint/checkpoint_mem.h      |    5 
>  linux-2.6.git-dave/checkpoint/restart.c             |   42 ++
>  linux-2.6.git-dave/checkpoint/rstr_mem.c            |  384 ++++++++++++++++++++
>  linux-2.6.git-dave/include/asm-x86/checkpoint_hdr.h |    4 
>  linux-2.6.git-dave/include/linux/checkpoint.h       |    3 
>  8 files changed, 503 insertions(+), 3 deletions(-)
> 
> diff -puN arch/x86/mm/restart.c~v6_PATCH_5_9_Restore_memory_address_space arch/x86/mm/restart.c
> --- linux-2.6.git/arch/x86/mm/restart.c~v6_PATCH_5_9_Restore_memory_address_space	2008-10-16 10:53:36.000000000 -0700
> +++ linux-2.6.git-dave/arch/x86/mm/restart.c	2008-10-16 10:53:36.000000000 -0700
> @@ -53,8 +53,10 @@ int cr_read_thread(struct cr_ctx *ctx)
>  
>  		size = sizeof(*desc) * GDT_ENTRY_TLS_ENTRIES;
>  		desc = kmalloc(size, GFP_KERNEL);
> -		if (!desc)
> -			return -ENOMEM;
> +		if (!desc) {
> +			ret = -ENOMEM;
> +			goto out;
> +		}
>  
>  		ret = cr_kread(ctx, desc, size);
>  		if (ret >= 0) {
> @@ -189,3 +191,61 @@ int cr_read_cpu(struct cr_ctx *ctx)
>  	cr_hbuf_put(ctx, sizeof(*hh));
>  	return ret;
>  }
> +
> +int cr_read_mm_context(struct cr_ctx *ctx, struct mm_struct *mm, int parent)
> +{
> +	struct cr_hdr_mm_context *hh = cr_hbuf_get(ctx, sizeof(*hh));
> +	int n, rparent, ret = -EINVAL;
> +
> +	rparent = cr_read_obj_type(ctx, hh, sizeof(*hh), CR_HDR_MM_CONTEXT);
> +	cr_debug("parent %d rparent %d nldt %d\n", parent, rparent, hh->nldt);
> +	if (rparent < 0) {
> +		ret = rparent;
> +		goto out;
> +	}
> +	if (rparent != parent)
> +		goto out;
> +
> +	if (hh->nldt < 0 || hh->ldt_entry_size != LDT_ENTRY_SIZE)
> +		goto out;
> +
> +	/*
> +	 * to utilize the syscall modify_ldt() we first convert the data
> +	 * in the checkpoint image from 'struct desc_struct' to 'struct
> +	 * user_desc' with reverse logic of include/asm/desc.h:fill_ldt()
> +	 */
> +
> +	for (n = 0; n < hh->nldt; n++) {
> +		struct user_desc info;
> +		struct desc_struct desc;
> +		mm_segment_t old_fs;
> +
> +		ret = cr_kread(ctx, &desc, LDT_ENTRY_SIZE);
> +		if (ret < 0)
> +			goto out;
> +
> +		info.entry_number = n;
> +		info.base_addr = desc.base0 | (desc.base1 << 16);
> +		info.limit = desc.limit0;
> +		info.seg_32bit = desc.d;
> +		info.contents = desc.type >> 2;
> +		info.read_exec_only = (desc.type >> 1) ^ 1;
> +		info.limit_in_pages = desc.g;
> +		info.seg_not_present = desc.p ^ 1;
> +		info.useable = desc.avl;
> +
> +		old_fs = get_fs();
> +		set_fs(get_ds());
> +		ret = sys_modify_ldt(1, (struct user_desc __user *) &info,
> +				     sizeof(info));
> +		set_fs(old_fs);
> +
> +		if (ret < 0)
> +			goto out;
> +	}
> +
> +	ret = 0;
> + out:
> +	cr_hbuf_put(ctx, sizeof(*hh));
> +	return ret;
> +}
> diff -puN checkpoint/checkpoint_arch.h~v6_PATCH_5_9_Restore_memory_address_space checkpoint/checkpoint_arch.h
> --- linux-2.6.git/checkpoint/checkpoint_arch.h~v6_PATCH_5_9_Restore_memory_address_space	2008-10-16 10:53:36.000000000 -0700
> +++ linux-2.6.git-dave/checkpoint/checkpoint_arch.h	2008-10-16 10:53:36.000000000 -0700
> @@ -7,3 +7,5 @@ extern int cr_write_mm_context(struct cr
>  
>  extern int cr_read_thread(struct cr_ctx *ctx);
>  extern int cr_read_cpu(struct cr_ctx *ctx);
> +extern int cr_read_mm_context(struct cr_ctx *ctx,
> +			      struct mm_struct *mm, int parent);
> diff -puN checkpoint/checkpoint_mem.h~v6_PATCH_5_9_Restore_memory_address_space checkpoint/checkpoint_mem.h
> --- linux-2.6.git/checkpoint/checkpoint_mem.h~v6_PATCH_5_9_Restore_memory_address_space	2008-10-16 10:53:36.000000000 -0700
> +++ linux-2.6.git-dave/checkpoint/checkpoint_mem.h	2008-10-16 10:53:36.000000000 -0700
> @@ -38,4 +38,9 @@ static inline int cr_pgarr_is_full(struc
>  	return (pgarr->nr_used == CR_PGARR_TOTAL);
>  }
>  
> +static inline int cr_pgarr_nr_free(struct cr_pgarr *pgarr)
> +{
> +	return CR_PGARR_TOTAL - pgarr->nr_used;
> +}
> +
>  #endif /* _CHECKPOINT_CKPT_MEM_H_ */
> diff -puN checkpoint/Makefile~v6_PATCH_5_9_Restore_memory_address_space checkpoint/Makefile
> --- linux-2.6.git/checkpoint/Makefile~v6_PATCH_5_9_Restore_memory_address_space	2008-10-16 10:53:36.000000000 -0700
> +++ linux-2.6.git-dave/checkpoint/Makefile	2008-10-16 10:53:36.000000000 -0700
> @@ -3,4 +3,4 @@
>  #
>  
>  obj-$(CONFIG_CHECKPOINT_RESTART) += sys.o checkpoint.o restart.o \
> -		ckpt_mem.o
> +		ckpt_mem.o rstr_mem.o
> diff -puN checkpoint/restart.c~v6_PATCH_5_9_Restore_memory_address_space checkpoint/restart.c
> --- linux-2.6.git/checkpoint/restart.c~v6_PATCH_5_9_Restore_memory_address_space	2008-10-16 10:53:36.000000000 -0700
> +++ linux-2.6.git-dave/checkpoint/restart.c	2008-10-16 10:53:36.000000000 -0700
> @@ -78,6 +78,44 @@ int cr_read_string(struct cr_ctx *ctx, v
>  	return cr_read_obj_type(ctx, str, len, CR_HDR_STRING);
>  }
>  
> +/**
> + * cr_read_fname - read a file name
> + * @ctx: checkpoint context
> + * @fname: buffer
> + * @n: buffer length
> + */
> +int cr_read_fname(struct cr_ctx *ctx, void *fname, int flen)
> +{
> +	return cr_read_obj_type(ctx, fname, flen, CR_HDR_FNAME);
> +}
> +
> +/**
> + * cr_read_open_fname - read a file name and open a file
> + * @ctx: checkpoint context
> + * @flags: file flags
> + * @mode: file mode
> + */
> +struct file *cr_read_open_fname(struct cr_ctx *ctx, int flags, int mode)
> +{
> +	struct file *file;
> +	char *fname;
> +	int ret;
> +
> +	fname = kmalloc(PATH_MAX, GFP_KERNEL);
> +	if (!fname)
> +		return ERR_PTR(-ENOMEM);
> +
> +	ret = cr_read_fname(ctx, fname, PATH_MAX);
> +	cr_debug("fname '%s' flags %#x mode %#x\n", fname, flags, mode);
> +	if (ret >= 0)
> +		file = filp_open(fname, flags, mode);
> +	else
> +		file = ERR_PTR(ret);
> +
> +	kfree(fname);
> +	return file;
> +}
> +
>  /* read the checkpoint header */
>  static int cr_read_head(struct cr_ctx *ctx)
>  {
> @@ -177,6 +215,10 @@ static int cr_read_task(struct cr_ctx *c
>  	cr_debug("task_struct: ret %d\n", ret);
>  	if (ret < 0)
>  		goto out;
> +	ret = cr_read_mm(ctx);
> +	cr_debug("memory: ret %d\n", ret);
> +	if (ret < 0)
> +		goto out;
>  	ret = cr_read_thread(ctx);
>  	cr_debug("thread: ret %d\n", ret);
>  	if (ret < 0)
> diff -puN /dev/null checkpoint/rstr_mem.c
> --- /dev/null	2008-09-02 09:40:19.000000000 -0700
> +++ linux-2.6.git-dave/checkpoint/rstr_mem.c	2008-10-16 10:53:36.000000000 -0700
> @@ -0,0 +1,384 @@
> +/*
> + *  Restart memory contents
> + *
> + *  Copyright (C) 2008 Oren Laadan
> + *
> + *  This file is subject to the terms and conditions of the GNU General Public
> + *  License.  See the file COPYING in the main directory of the Linux
> + *  distribution for more details.
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/sched.h>
> +#include <linux/fcntl.h>
> +#include <linux/file.h>
> +#include <linux/fs.h>
> +#include <linux/pagemap.h>
> +#include <linux/mm_types.h>
> +#include <linux/mman.h>
> +#include <linux/mm.h>
> +#include <linux/err.h>
> +#include <linux/checkpoint.h>
> +#include <linux/checkpoint_hdr.h>
> +
> +#include "checkpoint_arch.h"
> +#include "checkpoint_mem.h"
> +
> +/*
> + * Unlike checkpoint, restart is executed in the context of each restarting
> + * process: vma regions are restored via a call to mmap(), and the data is
> + * read into the address space of the current process.
> + */
> +
> +
> +/**
> + * cr_read_pages_vaddrs - read addresses of pages to page-array chain
> + * @ctx - restart context
> + * @nr_pages - number of address to read
> + */
> +static int cr_read_pages_vaddrs(struct cr_ctx *ctx, unsigned long nr_pages)
> +{
> +	struct cr_pgarr *pgarr;
> +	unsigned long *vaddrp;
> +	int nr, ret;
> +
> +	while (nr_pages) {
> +		pgarr = cr_pgarr_current(ctx);
> +		if (!pgarr)
> +			return -ENOMEM;
> +		nr = cr_pgarr_nr_free(pgarr);
> +		if (nr > nr_pages)
> +			nr = nr_pages;
> +		vaddrp = &pgarr->vaddrs[pgarr->nr_used];
> +		ret = cr_kread(ctx, vaddrp, nr * sizeof(unsigned long));
> +		if (ret < 0)
> +			return ret;
> +		pgarr->nr_used += nr;
> +		nr_pages -= nr;
> +	}
> +	return 0;
> +}
> +
> +static int cr_page_read(struct cr_ctx *ctx, struct page *page, char *buf)
> +{
> +	void *ptr;
> +	int ret;
> +
> +	ret = cr_kread(ctx, buf, PAGE_SIZE);
> +	if (ret < 0)
> +		return ret;
> +
> +	ptr = kmap_atomic(page, KM_USER1);
> +	memcpy(ptr, buf, PAGE_SIZE);
> +	kunmap_atomic(page, KM_USER1);

Here too, I think this should be changed to 
kunmap_atomic(ptr, KM_USER1);

Regards,
Nadia

> +
> +	return 0;
> +}
> +
> +/**
> + * cr_read_pages_contents - read in data of pages in page-array chain
> + * @ctx - restart context
> + */
> +static int cr_read_pages_contents(struct cr_ctx *ctx)
> +{
> +	struct mm_struct *mm = current->mm;
> +	struct cr_pgarr *pgarr;
> +	unsigned long *vaddrs;
> +	char *buf;
> +	int i, ret = 0;
> +
> +	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
> +	if (!buf)
> +		return -ENOMEM;
> +
> +	down_read(&mm->mmap_sem);
> +	list_for_each_entry_reverse(pgarr, &ctx->pgarr_list, list) {
> +		vaddrs = pgarr->vaddrs;
> +		for (i = 0; i < pgarr->nr_used; i++) {
> +			struct page *page;
> +
> +			ret = get_user_pages(current, mm, vaddrs[i],
> +					     1, 1, 1, &page, NULL);
> +			if (ret < 0)
> +				goto out;
> +
> +			ret = cr_page_read(ctx, page, buf);
> +			page_cache_release(page);
> +
> +			if (ret < 0)
> +				goto out;
> +		}
> +	}
> +
> + out:
> +	up_read(&mm->mmap_sem);
> +	kfree(buf);
> +	return 0;
> +}
> +
> +/**
> + * cr_read_private_vma_contents - restore contents of a VMA with private memory
> + * @ctx - restart context
> + *
> + * Reads a header that specifies how many pages will follow, then reads
> + * a list of virtual addresses into ctx->pgarr_list page-array chain,
> + * followed by the actual contents of the corresponding pages. Iterates
> + * these steps until reaching a header specifying "0" pages, which marks
> + * the end of the contents.
> + */
> +static int cr_read_private_vma_contents(struct cr_ctx *ctx)
> +{
> +	struct cr_hdr_pgarr *hh;
> +	unsigned long nr_pages;
> +	int parent, ret = 0;
> +
> +	while (1) {
> +		hh = cr_hbuf_get(ctx, sizeof(*hh));
> +		parent = cr_read_obj_type(ctx, hh, sizeof(*hh), CR_HDR_PGARR);
> +		if (parent != 0) {
> +			if (parent < 0)
> +				ret = parent;
> +			else
> +				ret = -EINVAL;
> +			cr_hbuf_put(ctx, sizeof(*hh));
> +			break;
> +		}
> +
> +		cr_debug("nr_pages %ld\n", (unsigned long) hh->nr_pages);
> +
> +		nr_pages = hh->nr_pages;
> +		cr_hbuf_put(ctx, sizeof(*hh));
> +
> +		if (!nr_pages)
> +			break;
> +
> +		ret = cr_read_pages_vaddrs(ctx, nr_pages);
> +		if (ret < 0)
> +			break;
> +		ret = cr_read_pages_contents(ctx);
> +		if (ret < 0)
> +			break;
> +		cr_pgarr_reset_all(ctx);
> +	}
> +
> +	return ret;
> +}
> +
> +/**
> + * cr_calc_map_prot_bits - convert vm_flags to mmap protection
> + * orig_vm_flags: source vm_flags
> + */
> +static unsigned long cr_calc_map_prot_bits(unsigned long orig_vm_flags)
> +{
> +	unsigned long vm_prot = 0;
> +
> +	if (orig_vm_flags & VM_READ)
> +		vm_prot |= PROT_READ;
> +	if (orig_vm_flags & VM_WRITE)
> +		vm_prot |= PROT_WRITE;
> +	if (orig_vm_flags & VM_EXEC)
> +		vm_prot |= PROT_EXEC;
> +	if (orig_vm_flags & PROT_SEM)   /* only (?) with IPC-SHM  */
> +		vm_prot |= PROT_SEM;
> +
> +	return vm_prot;
> +}
> +
> +/**
> + * cr_calc_map_flags_bits - convert vm_flags to mmap flags
> + * orig_vm_flags: source vm_flags
> + */
> +static unsigned long cr_calc_map_flags_bits(unsigned long orig_vm_flags)
> +{
> +	unsigned long vm_flags = 0;
> +
> +	vm_flags = MAP_FIXED;
> +	if (orig_vm_flags & VM_GROWSDOWN)
> +		vm_flags |= MAP_GROWSDOWN;
> +	if (orig_vm_flags & VM_DENYWRITE)
> +		vm_flags |= MAP_DENYWRITE;
> +	if (orig_vm_flags & VM_EXECUTABLE)
> +		vm_flags |= MAP_EXECUTABLE;
> +	if (orig_vm_flags & VM_MAYSHARE)
> +		vm_flags |= MAP_SHARED;
> +	else
> +		vm_flags |= MAP_PRIVATE;
> +
> +	return vm_flags;
> +}
> +
> +static int cr_read_vma(struct cr_ctx *ctx, struct mm_struct *mm)
> +{
> +	struct cr_hdr_vma *hh = cr_hbuf_get(ctx, sizeof(*hh));
> +	unsigned long vm_size, vm_start, vm_flags, vm_prot, vm_pgoff;
> +	unsigned long addr;
> +	struct file *file = NULL;
> +	int parent, ret = -EINVAL;
> +
> +	parent = cr_read_obj_type(ctx, hh, sizeof(*hh), CR_HDR_VMA);
> +	if (parent < 0) {
> +		ret = parent;
> +		goto err;
> +	} else if (parent != 0)
> +		goto err;
> +
> +	cr_debug("vma %#lx-%#lx type %d\n", (unsigned long) hh->vm_start,
> +		 (unsigned long) hh->vm_end, (int) hh->vma_type);
> +
> +	if (hh->vm_end < hh->vm_start)
> +		goto err;
> +
> +	vm_start = hh->vm_start;
> +	vm_pgoff = hh->vm_pgoff;
> +	vm_size = hh->vm_end - hh->vm_start;
> +	vm_prot = cr_calc_map_prot_bits(hh->vm_flags);
> +	vm_flags = cr_calc_map_flags_bits(hh->vm_flags);
> +
> +	switch (hh->vma_type) {
> +
> +	case CR_VMA_ANON:		/* anonymous private mapping */
> +		if (vm_flags & VM_SHARED)
> +			goto err;
> +		/*
> +		 * vm_pgoff for anonymous mapping is the "global" page
> +		 * offset (namely from addr 0x0), so we force a zero
> +		 */
> +		vm_pgoff = 0;
> +		break;
> +
> +	case CR_VMA_FILE:		/* private mapping from a file */
> +		if (vm_flags & VM_SHARED)
> +			goto err;
> +		/*
> +		 * for private mapping using 'read-only' is sufficient
> +		 */
> +		file = cr_read_open_fname(ctx, O_RDONLY, 0);
> +		if (IS_ERR(file)) {
> +			ret = PTR_ERR(file);
> +			goto err;
> +		}
> +		break;
> +
> +	default:
> +		goto err;
> +
> +	}
> +
> +	cr_hbuf_put(ctx, sizeof(*hh));
> +
> +	down_write(&mm->mmap_sem);
> +	addr = do_mmap_pgoff(file, vm_start, vm_size,
> +			     vm_prot, vm_flags, vm_pgoff);
> +	up_write(&mm->mmap_sem);
> +	cr_debug("size %#lx prot %#lx flag %#lx pgoff %#lx => %#lx\n",
> +		 vm_size, vm_prot, vm_flags, vm_pgoff, addr);
> +
> +	/* the file (if opened) is now referenced by the vma */
> +	if (file)
> +		filp_close(file, NULL);
> +
> +	if (IS_ERR((void *) addr))
> +		return PTR_ERR((void *) addr);
> +
> +	/*
> +	 * CR_VMA_ANON: read in memory as is
> +	 * CR_VMA_FILE: read in memory as is
> +	 * (more to follow ...)
> +	 */
> +
> +	switch (hh->vma_type) {
> +	case CR_VMA_ANON:
> +	case CR_VMA_FILE:
> +		/* standard case: read the data into the memory */
> +		ret = cr_read_private_vma_contents(ctx);
> +		break;
> +	}
> +
> +	if (ret < 0)
> +		return ret;
> +
> +	cr_debug("vma retval %d\n", ret);
> +	return 0;
> +
> + err:
> +	cr_hbuf_put(ctx, sizeof(*hh));
> +	return ret;
> +}
> +
> +static int cr_destroy_mm(struct mm_struct *mm)
> +{
> +	struct vm_area_struct *vmnext = mm->mmap;
> +	struct vm_area_struct *vma;
> +	int ret;
> +
> +	while (vmnext) {
> +		vma = vmnext;
> +		vmnext = vmnext->vm_next;
> +		ret = do_munmap(mm, vma->vm_start, vma->vm_end-vma->vm_start);
> +		if (ret < 0) {
> +			pr_debug("CR: restart failed do_munmap (%d)\n", ret);
> +			return ret;
> +		}
> +	}
> +	return 0;
> +}
> +
> +int cr_read_mm(struct cr_ctx *ctx)
> +{
> +	struct cr_hdr_mm *hh = cr_hbuf_get(ctx, sizeof(*hh));
> +	struct mm_struct *mm;
> +	int nr, parent, ret;
> +
> +	parent = cr_read_obj_type(ctx, hh, sizeof(*hh), CR_HDR_MM);
> +	if (parent < 0) {
> +		ret = parent;
> +		goto out;
> +	}
> +
> +	ret = -EINVAL;
> +#if 0	/* activate when containers are used */
> +	if (parent != task_pid_vnr(current))
> +		goto out;
> +#endif
> +	cr_debug("map_count %d\n", hh->map_count);
> +
> +	/* XXX need more sanity checks */
> +	if (hh->start_code > hh->end_code ||
> +	    hh->start_data > hh->end_data || hh->map_count < 0)
> +		goto out;
> +
> +	mm = current->mm;
> +
> +	/* point of no return -- destruct current mm */
> +	down_write(&mm->mmap_sem);
> +	ret = cr_destroy_mm(mm);
> +	if (ret < 0) {
> +		up_write(&mm->mmap_sem);
> +		goto out;
> +	}
> +	mm->start_code = hh->start_code;
> +	mm->end_code = hh->end_code;
> +	mm->start_data = hh->start_data;
> +	mm->end_data = hh->end_data;
> +	mm->start_brk = hh->start_brk;
> +	mm->brk = hh->brk;
> +	mm->start_stack = hh->start_stack;
> +	mm->arg_start = hh->arg_start;
> +	mm->arg_end = hh->arg_end;
> +	mm->env_start = hh->env_start;
> +	mm->env_end = hh->env_end;
> +	up_write(&mm->mmap_sem);
> +
> +	/* FIX: need also mm->flags */
> +
> +	for (nr = hh->map_count; nr; nr--) {
> +		ret = cr_read_vma(ctx, mm);
> +		if (ret < 0)
> +			goto out;
> +	}
> +
> +	ret = cr_read_mm_context(ctx, mm, hh->objref);
> + out:
> +	cr_hbuf_put(ctx, sizeof(*hh));
> +	return ret;
> +}
> diff -puN include/asm-x86/checkpoint_hdr.h~v6_PATCH_5_9_Restore_memory_address_space include/asm-x86/checkpoint_hdr.h
> --- linux-2.6.git/include/asm-x86/checkpoint_hdr.h~v6_PATCH_5_9_Restore_memory_address_space	2008-10-16 10:53:36.000000000 -0700
> +++ linux-2.6.git-dave/include/asm-x86/checkpoint_hdr.h	2008-10-16 10:53:36.000000000 -0700
> @@ -74,4 +74,8 @@ struct cr_hdr_mm_context {
>  	__s16 nldt;
>  } __attribute__((aligned(8)));
>  
> +
> +/* misc prototypes from kernel (not defined elsewhere) */
> +asmlinkage int sys_modify_ldt(int func, void __user *ptr, unsigned long bytecount);
> +
>  #endif /* __ASM_X86_CKPT_HDR__H */
> diff -puN include/linux/checkpoint.h~v6_PATCH_5_9_Restore_memory_address_space include/linux/checkpoint.h
> --- linux-2.6.git/include/linux/checkpoint.h~v6_PATCH_5_9_Restore_memory_address_space	2008-10-16 10:53:36.000000000 -0700
> +++ linux-2.6.git-dave/include/linux/checkpoint.h	2008-10-16 10:53:36.000000000 -0700
> @@ -55,6 +55,9 @@ extern int cr_write_fname(struct cr_ctx 
>  extern int cr_read_obj(struct cr_ctx *ctx, struct cr_hdr *h, void *buf, int n);
>  extern int cr_read_obj_type(struct cr_ctx *ctx, void *buf, int n, int type);
>  extern int cr_read_string(struct cr_ctx *ctx, void *str, int len);
> +extern int cr_read_fname(struct cr_ctx *ctx, void *fname, int n);
> +extern struct file *cr_read_open_fname(struct cr_ctx *ctx,
> +				       int flags, int mode);
>  
>  extern int cr_write_mm(struct cr_ctx *ctx, struct task_struct *t);
>  extern int cr_read_mm(struct cr_ctx *ctx);
> _
> _______________________________________________
> Containers mailing list
> Containers@lists.linux-foundation.org
> https://lists.linux-foundation.org/mailman/listinfo/containers
> 
-- 
Nadia Derbey <Nadia.Derbey@bull.net>

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