<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/x86/kernel/machine_kexec_64.c, branch v3.2.47</title>
<subtitle>Linux kernel for Apalis and Colibri modules</subtitle>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/'/>
<entry>
<title>x86, cleanups: Use clear_page/copy_page rather than memset/memcpy</title>
<updated>2010-09-22T22:36:49+00:00</updated>
<author>
<name>Jan Beulich</name>
<email>JBeulich@novell.com</email>
</author>
<published>2010-09-02T12:46:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=234bb549eea16ec7d5207ba747fb8dbf489e64c1'/>
<id>234bb549eea16ec7d5207ba747fb8dbf489e64c1</id>
<content type='text'>
When operating on whole pages, use clear_page() and copy_page() in
favor of memset() and memcpy(); after all that's what they are
intended for.

Signed-off-by: Jan Beulich &lt;jbeulich@novell.com&gt;
LKML-Reference: &lt;4C7FB8CA0200007800013F51@vpn.id2.novell.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When operating on whole pages, use clear_page() and copy_page() in
favor of memset() and memcpy(); after all that's what they are
intended for.

Signed-off-by: Jan Beulich &lt;jbeulich@novell.com&gt;
LKML-Reference: &lt;4C7FB8CA0200007800013F51@vpn.id2.novell.com&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@linux.intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h</title>
<updated>2010-03-30T13:02:32+00:00</updated>
<author>
<name>Tejun Heo</name>
<email>tj@kernel.org</email>
</author>
<published>2010-03-24T08:04:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5a0e3ad6af8660be21ca98a971cd00f331318c05'/>
<id>5a0e3ad6af8660be21ca98a971cd00f331318c05</id>
<content type='text'>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -&gt; slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Guess-its-ok-by: Christoph Lameter &lt;cl@linux-foundation.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Lee Schermerhorn &lt;Lee.Schermerhorn@hp.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -&gt; slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo &lt;tj@kernel.org&gt;
Guess-its-ok-by: Christoph Lameter &lt;cl@linux-foundation.org&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Lee Schermerhorn &lt;Lee.Schermerhorn@hp.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hw-breakpoints: cleanup HW Breakpoint registers before kexec</title>
<updated>2009-06-02T20:47:00+00:00</updated>
<author>
<name>K.Prasad</name>
<email>prasad@linux.vnet.ibm.com</email>
</author>
<published>2009-06-01T18:16:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=17f557e5b5d43a2af66c969f6560ac7105020672'/>
<id>17f557e5b5d43a2af66c969f6560ac7105020672</id>
<content type='text'>
This patch disables Hardware breakpoints before doing a 'kexec' on the machine
so that the cpu doesn't keep debug registers values which would be out of
sync for the new image.

Original-patch-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: K.Prasad &lt;prasad@linux.vnet.ibm.com&gt;
Reviewed-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch disables Hardware breakpoints before doing a 'kexec' on the machine
so that the cpu doesn't keep debug registers values which would be out of
sync for the new image.

Original-patch-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: K.Prasad &lt;prasad@linux.vnet.ibm.com&gt;
Reviewed-by: Alan Stern &lt;stern@rowland.harvard.edu&gt;
Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86, kexec: fix crashdump panic with CONFIG_KEXEC_JUMP</title>
<updated>2009-05-08T05:01:05+00:00</updated>
<author>
<name>Huang Ying</name>
<email>ying.huang@intel.com</email>
</author>
<published>2009-05-08T02:51:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=6407df5ca54a511054200a1eb23f78f723ca1de4'/>
<id>6407df5ca54a511054200a1eb23f78f723ca1de4</id>
<content type='text'>
Tim Starling reported that crashdump will panic with kernel compiled
with CONFIG_KEXEC_JUMP due to null pointer deference in
machine_kexec_32.c: machine_kexec(), when deferencing
kexec_image. Refering to:

http://bugzilla.kernel.org/show_bug.cgi?id=13265

This patch fixes the BUG via replacing global variable reference:
kexec_image in machine_kexec() with local variable reference: image,
which is more appropriate, and will not be null.

Same BUG is in machine_kexec_64.c too, so fixed too in the same way.

[ Impact: fix crash on kexec ]

Reported-by: Tim Starling &lt;tstarling@wikimedia.org&gt;
Signed-off-by: Huang Ying &lt;ying.huang@intel.com&gt;
LKML-Reference: &lt;1241751101.6259.85.camel@yhuang-dev.sh.intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Tim Starling reported that crashdump will panic with kernel compiled
with CONFIG_KEXEC_JUMP due to null pointer deference in
machine_kexec_32.c: machine_kexec(), when deferencing
kexec_image. Refering to:

http://bugzilla.kernel.org/show_bug.cgi?id=13265

This patch fixes the BUG via replacing global variable reference:
kexec_image in machine_kexec() with local variable reference: image,
which is more appropriate, and will not be null.

Same BUG is in machine_kexec_64.c too, so fixed too in the same way.

[ Impact: fix crash on kexec ]

Reported-by: Tim Starling &lt;tstarling@wikimedia.org&gt;
Signed-off-by: Huang Ying &lt;ying.huang@intel.com&gt;
LKML-Reference: &lt;1241751101.6259.85.camel@yhuang-dev.sh.intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86, kexec: x86_64: add kexec jump support for x86_64</title>
<updated>2009-03-11T01:13:25+00:00</updated>
<author>
<name>Huang Ying</name>
<email>ying.huang@intel.com</email>
</author>
<published>2009-03-10T02:57:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fee7b0d84cc8c7bc5dc212901c79e93eaf83a5b5'/>
<id>fee7b0d84cc8c7bc5dc212901c79e93eaf83a5b5</id>
<content type='text'>
Impact: New major feature

This patch add kexec jump support for x86_64. More information about
kexec jump can be found in corresponding x86_32 support patch.

Signed-off-by: Huang Ying &lt;ying.huang@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Impact: New major feature

This patch add kexec jump support for x86_64. More information about
kexec jump can be found in corresponding x86_32 support patch.

Signed-off-by: Huang Ying &lt;ying.huang@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86, kexec: x86_64: add identity map for pages at image-&gt;start</title>
<updated>2009-03-11T01:13:25+00:00</updated>
<author>
<name>Huang Ying</name>
<email>ying.huang@intel.com</email>
</author>
<published>2009-03-10T02:57:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5359454701ce51a4626b1ef6eb7b16ec35bd458d'/>
<id>5359454701ce51a4626b1ef6eb7b16ec35bd458d</id>
<content type='text'>
Impact: Fix corner case that cannot yet occur

image-&gt;start may be outside of 0 ~ max_pfn, for example when jumping
back to original kernel from kexeced kenrel. This patch add identity
map for pages at image-&gt;start.

Signed-off-by: Huang Ying &lt;ying.huang@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Impact: Fix corner case that cannot yet occur

image-&gt;start may be outside of 0 ~ max_pfn, for example when jumping
back to original kernel from kexeced kenrel. This patch add identity
map for pages at image-&gt;start.

Signed-off-by: Huang Ying &lt;ying.huang@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86, kexec: fix kexec x86 coding style</title>
<updated>2009-03-11T01:13:25+00:00</updated>
<author>
<name>Huang Ying</name>
<email>ying.huang@intel.com</email>
</author>
<published>2009-03-10T02:56:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=fef3a7a17418814733ebde0b40d8e32747677c8f'/>
<id>fef3a7a17418814733ebde0b40d8e32747677c8f</id>
<content type='text'>
Impact: Cleanup

Fix some coding style issue for kexec x86.

Signed-off-by: Huang Ying &lt;ying.huang@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Impact: Cleanup

Fix some coding style issue for kexec x86.

Signed-off-by: Huang Ying &lt;ying.huang@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>x86: kexec: Use one page table in x86_64 machine_kexec</title>
<updated>2009-02-04T02:29:18+00:00</updated>
<author>
<name>Huang Ying</name>
<email>ying.huang@intel.com</email>
</author>
<published>2009-02-03T06:22:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=f5deb79679af6eb41b61112fadcda28b2a4cfb0d'/>
<id>f5deb79679af6eb41b61112fadcda28b2a4cfb0d</id>
<content type='text'>
Impact: reduce kernel BSS size by 7 pages, improve code readability

Two page tables are used in current x86_64 kexec implementation. One
is used to jump from kernel virtual address to identity map address,
the other is used to map all physical memory. In fact, on x86_64,
there is no conflict between kernel virtual address space and physical
memory space, so just one page table is sufficient. The page table
pages used to map control page are dynamically allocated to save
memory if kexec image is not loaded. ASM code used to map control page
is replaced by C code too.

Signed-off-by: Huang Ying &lt;ying.huang@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Impact: reduce kernel BSS size by 7 pages, improve code readability

Two page tables are used in current x86_64 kexec implementation. One
is used to jump from kernel virtual address to identity map address,
the other is used to map all physical memory. In fact, on x86_64,
there is no conflict between kernel virtual address space and physical
memory space, so just one page table is sufficient. The page table
pages used to map control page are dynamically allocated to save
memory if kexec image is not loaded. ASM code used to map control page
is replaced by C code too.

Signed-off-by: Huang Ying &lt;ying.huang@intel.com&gt;
Signed-off-by: H. Peter Anvin &lt;hpa@zytor.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>kexec jump</title>
<updated>2008-07-26T19:00:04+00:00</updated>
<author>
<name>Huang Ying</name>
<email>ying.huang@intel.com</email>
</author>
<published>2008-07-26T02:45:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=3ab83521378268044a448113c6aa9a9e245f4d2f'/>
<id>3ab83521378268044a448113c6aa9a9e245f4d2f</id>
<content type='text'>
This patch provides an enhancement to kexec/kdump.  It implements the
following features:

- Backup/restore memory used by the original kernel before/after
  kexec.

- Save/restore CPU state before/after kexec.

The features of this patch can be used as a general method to call program in
physical mode (paging turning off).  This can be used to call BIOS code under
Linux.

kexec-tools needs to be patched to support kexec jump. The patches and
the precompiled kexec can be download from the following URL:

       source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2
       patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2
       binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10

Usage example of calling some physical mode code and return:

1. Compile and install patched kernel with following options selected:

CONFIG_X86_32=y
CONFIG_KEXEC=y
CONFIG_PM=y
CONFIG_KEXEC_JUMP=y

2. Build patched kexec-tool or download the pre-built one.

3. Build some physical mode executable named such as "phy_mode"

4. Boot kernel compiled in step 1.

5. Load physical mode executable with /sbin/kexec. The shell command
   line can be as follow:

   /sbin/kexec --load-preserve-context --args-none phy_mode

6. Call physical mode executable with following shell command line:

   /sbin/kexec -e

Implementation point:

To support jumping without reserving memory.  One shadow backup page (source
page) is allocated for each page used by kexeced code image (destination
page).  When do kexec_load, the image of kexeced code is loaded into source
pages, and before executing, the destination pages and the source pages are
swapped, so the contents of destination pages are backupped.  Before jumping
to the kexeced code image and after jumping back to the original kernel, the
destination pages and the source pages are swapped too.

C ABI (calling convention) is used as communication protocol between
kernel and called code.

A flag named KEXEC_PRESERVE_CONTEXT for sys_kexec_load is added to
indicate that the loaded kernel image is used for jumping back.

Now, only the i386 architecture is supported.

Signed-off-by: Huang Ying &lt;ying.huang@intel.com&gt;
Acked-by: Vivek Goyal &lt;vgoyal@redhat.com&gt;
Cc: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Cc: Pavel Machek &lt;pavel@ucw.cz&gt;
Cc: Nigel Cunningham &lt;nigel@nigel.suspend2.net&gt;
Cc: "Rafael J. Wysocki" &lt;rjw@sisk.pl&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch provides an enhancement to kexec/kdump.  It implements the
following features:

- Backup/restore memory used by the original kernel before/after
  kexec.

- Save/restore CPU state before/after kexec.

The features of this patch can be used as a general method to call program in
physical mode (paging turning off).  This can be used to call BIOS code under
Linux.

kexec-tools needs to be patched to support kexec jump. The patches and
the precompiled kexec can be download from the following URL:

       source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2
       patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2
       binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10

Usage example of calling some physical mode code and return:

1. Compile and install patched kernel with following options selected:

CONFIG_X86_32=y
CONFIG_KEXEC=y
CONFIG_PM=y
CONFIG_KEXEC_JUMP=y

2. Build patched kexec-tool or download the pre-built one.

3. Build some physical mode executable named such as "phy_mode"

4. Boot kernel compiled in step 1.

5. Load physical mode executable with /sbin/kexec. The shell command
   line can be as follow:

   /sbin/kexec --load-preserve-context --args-none phy_mode

6. Call physical mode executable with following shell command line:

   /sbin/kexec -e

Implementation point:

To support jumping without reserving memory.  One shadow backup page (source
page) is allocated for each page used by kexeced code image (destination
page).  When do kexec_load, the image of kexeced code is loaded into source
pages, and before executing, the destination pages and the source pages are
swapped, so the contents of destination pages are backupped.  Before jumping
to the kexeced code image and after jumping back to the original kernel, the
destination pages and the source pages are swapped too.

C ABI (calling convention) is used as communication protocol between
kernel and called code.

A flag named KEXEC_PRESERVE_CONTEXT for sys_kexec_load is added to
indicate that the loaded kernel image is used for jumping back.

Now, only the i386 architecture is supported.

Signed-off-by: Huang Ying &lt;ying.huang@intel.com&gt;
Acked-by: Vivek Goyal &lt;vgoyal@redhat.com&gt;
Cc: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Cc: Pavel Machek &lt;pavel@ucw.cz&gt;
Cc: Nigel Cunningham &lt;nigel@nigel.suspend2.net&gt;
Cc: "Rafael J. Wysocki" &lt;rjw@sisk.pl&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branch 'auto-ftrace-next' into tracing/for-linus</title>
<updated>2008-07-14T14:11:52+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@elte.hu</email>
</author>
<published>2008-07-14T14:11:52+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=5806b81ac1c0c52665b91723fd4146a4f86e386b'/>
<id>5806b81ac1c0c52665b91723fd4146a4f86e386b</id>
<content type='text'>
Conflicts:

	arch/x86/kernel/entry_32.S
	arch/x86/kernel/process_32.c
	arch/x86/kernel/process_64.c
	arch/x86/lib/Makefile
	include/asm-x86/irqflags.h
	kernel/Makefile
	kernel/sched.c

Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Conflicts:

	arch/x86/kernel/entry_32.S
	arch/x86/kernel/process_32.c
	arch/x86/kernel/process_64.c
	arch/x86/lib/Makefile
	include/asm-x86/irqflags.h
	kernel/Makefile
	kernel/sched.c

Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</pre>
</div>
</content>
</entry>
</feed>
