<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/arch/powerpc, branch v3.4.97</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>powerpc: fix typo 'CONFIG_PPC_CPU'</title>
<updated>2014-07-07T01:49:20+00:00</updated>
<author>
<name>Paul Bolle</name>
<email>pebolle@tiscali.nl</email>
</author>
<published>2014-05-20T19:59:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=60db34152db66ac6e6b6e12c1d7229179ff4711a'/>
<id>60db34152db66ac6e6b6e12c1d7229179ff4711a</id>
<content type='text'>
commit b69a1da94f3d1589d1942b5d1b384d8cfaac4500 upstream.

Commit cd64d1697cf0 ("powerpc: mtmsrd not defined") added a check for
CONFIG_PPC_CPU were a check for CONFIG_PPC_FPU was clearly intended.

Fixes: cd64d1697cf0 ("powerpc: mtmsrd not defined")
Signed-off-by: Paul Bolle &lt;pebolle@tiscali.nl&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit b69a1da94f3d1589d1942b5d1b384d8cfaac4500 upstream.

Commit cd64d1697cf0 ("powerpc: mtmsrd not defined") added a check for
CONFIG_PPC_CPU were a check for CONFIG_PPC_FPU was clearly intended.

Fixes: cd64d1697cf0 ("powerpc: mtmsrd not defined")
Signed-off-by: Paul Bolle &lt;pebolle@tiscali.nl&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: fix typo 'CONFIG_PMAC'</title>
<updated>2014-07-07T01:49:20+00:00</updated>
<author>
<name>Paul Bolle</name>
<email>pebolle@tiscali.nl</email>
</author>
<published>2014-05-20T20:24:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=52cbee9d056662d013935f3a9857358f9e67b3d5'/>
<id>52cbee9d056662d013935f3a9857358f9e67b3d5</id>
<content type='text'>
commit 6e0fdf9af216887e0032c19d276889aad41cad00 upstream.

Commit b0d278b7d3ae ("powerpc/perf_event: Reduce latency of calling
perf_event_do_pending") added a check for CONFIG_PMAC were a check for
CONFIG_PPC_PMAC was clearly intended.

Fixes: b0d278b7d3ae ("powerpc/perf_event: Reduce latency of calling perf_event_do_pending")
Signed-off-by: Paul Bolle &lt;pebolle@tiscali.nl&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 6e0fdf9af216887e0032c19d276889aad41cad00 upstream.

Commit b0d278b7d3ae ("powerpc/perf_event: Reduce latency of calling
perf_event_do_pending") added a check for CONFIG_PMAC were a check for
CONFIG_PPC_PMAC was clearly intended.

Fixes: b0d278b7d3ae ("powerpc/perf_event: Reduce latency of calling perf_event_do_pending")
Signed-off-by: Paul Bolle &lt;pebolle@tiscali.nl&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/pseries: Fix overwritten PE state</title>
<updated>2014-07-07T01:49:20+00:00</updated>
<author>
<name>Gavin Shan</name>
<email>gwshan@linux.vnet.ibm.com</email>
</author>
<published>2014-04-24T08:00:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d5110f6e1110af13b621da160d59887f35e291ea'/>
<id>d5110f6e1110af13b621da160d59887f35e291ea</id>
<content type='text'>
commit 54f112a3837d4e7532bbedbbbf27c0de277be510 upstream.

In pseries_eeh_get_state(), EEH_STATE_UNAVAILABLE is always
overwritten by EEH_STATE_NOT_SUPPORT because of the missed
"break" there. The patch fixes the issue.

Reported-by: Joe Perches &lt;joe@perches.com&gt;
Signed-off-by: Gavin Shan &lt;gwshan@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 54f112a3837d4e7532bbedbbbf27c0de277be510 upstream.

In pseries_eeh_get_state(), EEH_STATE_UNAVAILABLE is always
overwritten by EEH_STATE_NOT_SUPPORT because of the missed
"break" there. The patch fixes the issue.

Reported-by: Joe Perches &lt;joe@perches.com&gt;
Signed-off-by: Gavin Shan &lt;gwshan@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Fix 64 bit builds with binutils 2.24</title>
<updated>2014-06-16T20:45:45+00:00</updated>
<author>
<name>Guenter Roeck</name>
<email>linux@roeck-us.net</email>
</author>
<published>2014-05-15T16:33:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=480ed1ba70b1cb6977451763a28a658844d59360'/>
<id>480ed1ba70b1cb6977451763a28a658844d59360</id>
<content type='text'>
commit 7998eb3dc700aaf499f93f50b3d77da834ef9e1d upstream.

With binutils 2.24, various 64 bit builds fail with relocation errors
such as

arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
	(.text+0x165ee): relocation truncated to fit: R_PPC64_ADDR16_HI
	against symbol `interrupt_base_book3e' defined in .text section
	in arch/powerpc/kernel/built-in.o
arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
	(.text+0x16602): relocation truncated to fit: R_PPC64_ADDR16_HI
	against symbol `interrupt_end_book3e' defined in .text section
	in arch/powerpc/kernel/built-in.o

The assembler maintainer says:

 I changed the ABI, something that had to be done but unfortunately
 happens to break the booke kernel code.  When building up a 64-bit
 value with lis, ori, shl, oris, ori or similar sequences, you now
 should use @high and @higha in place of @h and @ha.  @h and @ha
 (and their associated relocs R_PPC64_ADDR16_HI and R_PPC64_ADDR16_HA)
 now report overflow if the value is out of 32-bit signed range.
 ie. @h and @ha assume you're building a 32-bit value. This is needed
 to report out-of-range -mcmodel=medium toc pointer offsets in @toc@h
 and @toc@ha expressions, and for consistency I did the same for all
 other @h and @ha relocs.

Replacing @h with @high in one strategic location fixes the relocation
errors. This has to be done conditionally since the assembler either
supports @h or @high but not both.

Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 7998eb3dc700aaf499f93f50b3d77da834ef9e1d upstream.

With binutils 2.24, various 64 bit builds fail with relocation errors
such as

arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
	(.text+0x165ee): relocation truncated to fit: R_PPC64_ADDR16_HI
	against symbol `interrupt_base_book3e' defined in .text section
	in arch/powerpc/kernel/built-in.o
arch/powerpc/kernel/built-in.o: In function `exc_debug_crit_book3e':
	(.text+0x16602): relocation truncated to fit: R_PPC64_ADDR16_HI
	against symbol `interrupt_end_book3e' defined in .text section
	in arch/powerpc/kernel/built-in.o

The assembler maintainer says:

 I changed the ABI, something that had to be done but unfortunately
 happens to break the booke kernel code.  When building up a 64-bit
 value with lis, ori, shl, oris, ori or similar sequences, you now
 should use @high and @higha in place of @h and @ha.  @h and @ha
 (and their associated relocs R_PPC64_ADDR16_HI and R_PPC64_ADDR16_HA)
 now report overflow if the value is out of 32-bit signed range.
 ie. @h and @ha assume you're building a 32-bit value. This is needed
 to report out-of-range -mcmodel=medium toc pointer offsets in @toc@h
 and @toc@ha expressions, and for consistency I did the same for all
 other @h and @ha relocs.

Replacing @h with @high in one strategic location fixes the relocation
errors. This has to be done conditionally since the assembler either
supports @h or @high but not both.

Signed-off-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Add vr save/restore functions</title>
<updated>2014-05-18T12:25:56+00:00</updated>
<author>
<name>Andreas Schwab</name>
<email>schwab@linux-m68k.org</email>
</author>
<published>2013-12-30T14:31:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7dff32efd24849aca3ab1eabe8b867025f34a3f8'/>
<id>7dff32efd24849aca3ab1eabe8b867025f34a3f8</id>
<content type='text'>
commit 8fe9c93e7453e67b8bd09f263ec1bb0783c733fc upstream.

GCC 4.8 now generates out-of-line vr save/restore functions when
optimizing for size.  They are needed for the raid6 altivec support.

Signed-off-by: Andreas Schwab &lt;schwab@linux-m68k.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 8fe9c93e7453e67b8bd09f263ec1bb0783c733fc upstream.

GCC 4.8 now generates out-of-line vr save/restore functions when
optimizing for size.  They are needed for the raid6 altivec support.

Signed-off-by: Andreas Schwab &lt;schwab@linux-m68k.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>compiler/gcc4: Add quirk for 'asm goto' miscompilation bug</title>
<updated>2014-04-14T13:44:16+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2013-10-10T08:16:30+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d19157519c9d76828df39cae34cc0d824356f7db'/>
<id>d19157519c9d76828df39cae34cc0d824356f7db</id>
<content type='text'>
commit 3f0116c3238a96bc18ad4b4acefe4e7be32fa861 upstream.

Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down
a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto'
constructs, as outlined here:

  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670

Implement a workaround suggested by Jakub Jelinek.

Reported-and-tested-by: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Reported-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Reported-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Suggested-by: Jakub Jelinek &lt;jakub@redhat.com&gt;
Reviewed-by: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
[hq: Backported to 3.4: Adjust context]
Signed-off-by: Qiang Huang &lt;h.huangqiang@huawei.com&gt;
Cc: Li Zefan &lt;lizefan@huawei.com&gt;
Cc: Jianguo Wu &lt;wujianguo@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 3f0116c3238a96bc18ad4b4acefe4e7be32fa861 upstream.

Fengguang Wu, Oleg Nesterov and Peter Zijlstra tracked down
a kernel crash to a GCC bug: GCC miscompiles certain 'asm goto'
constructs, as outlined here:

  http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670

Implement a workaround suggested by Jakub Jelinek.

Reported-and-tested-by: Fengguang Wu &lt;fengguang.wu@intel.com&gt;
Reported-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Reported-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Suggested-by: Jakub Jelinek &lt;jakub@redhat.com&gt;
Reviewed-by: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
[hq: Backported to 3.4: Adjust context]
Signed-off-by: Qiang Huang &lt;h.huangqiang@huawei.com&gt;
Cc: Li Zefan &lt;lizefan@huawei.com&gt;
Cc: Jianguo Wu &lt;wujianguo@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Align p_dyn, p_rela and p_st symbols</title>
<updated>2014-03-24T04:37:05+00:00</updated>
<author>
<name>Anton Blanchard</name>
<email>anton@samba.org</email>
</author>
<published>2014-03-03T21:31:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ec012303c26a1d4d6251d74401ee290a063154ac'/>
<id>ec012303c26a1d4d6251d74401ee290a063154ac</id>
<content type='text'>
commit a5b2cf5b1af424ee3dd9e3ce6d5cea18cb927e67 upstream.

The 64bit relocation code places a few symbols in the text segment.
These symbols are only 4 byte aligned where they need to be 8 byte
aligned. Add an explicit alignment.

Signed-off-by: Anton Blanchard &lt;anton@samba.org&gt;
Tested-by: Laurent Dufour &lt;ldufour@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a5b2cf5b1af424ee3dd9e3ce6d5cea18cb927e67 upstream.

The 64bit relocation code places a few symbols in the text segment.
These symbols are only 4 byte aligned where they need to be 8 byte
aligned. Add an explicit alignment.

Signed-off-by: Anton Blanchard &lt;anton@samba.org&gt;
Tested-by: Laurent Dufour &lt;ldufour@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>KVM: PPC: Emulate dcbf</title>
<updated>2014-03-11T23:10:03+00:00</updated>
<author>
<name>Alexander Graf</name>
<email>agraf@suse.de</email>
</author>
<published>2013-01-17T12:50:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=67bc20f722e2d3b77566f3eac9e9f6ce1b890d23'/>
<id>67bc20f722e2d3b77566f3eac9e9f6ce1b890d23</id>
<content type='text'>
commit d3286144c92ec876da9e30320afa875699b7e0f1 upstream.

Guests can trigger MMIO exits using dcbf. Since we don't emulate cache
incoherent MMIO, just do nothing and move on.

Reported-by: Ben Collins &lt;ben.c@servergy.com&gt;
Signed-off-by: Alexander Graf &lt;agraf@suse.de&gt;
Tested-by: Ben Collins &lt;ben.c@servergy.com&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Cc: Qiang Huang &lt;h.huangqiang@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit d3286144c92ec876da9e30320afa875699b7e0f1 upstream.

Guests can trigger MMIO exits using dcbf. Since we don't emulate cache
incoherent MMIO, just do nothing and move on.

Reported-by: Ben Collins &lt;ben.c@servergy.com&gt;
Signed-off-by: Alexander Graf &lt;agraf@suse.de&gt;
Tested-by: Ben Collins &lt;ben.c@servergy.com&gt;
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings &lt;ben@decadent.org.uk&gt;
Cc: Qiang Huang &lt;h.huangqiang@huawei.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/crashdump : Fix page frame number check in copy_oldmem_page</title>
<updated>2014-03-11T23:10:00+00:00</updated>
<author>
<name>Laurent Dufour</name>
<email>ldufour@linux.vnet.ibm.com</email>
</author>
<published>2014-02-24T16:30:55+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=8dd74be4a175ff8f5818a14a9c13aa027b667cf6'/>
<id>8dd74be4a175ff8f5818a14a9c13aa027b667cf6</id>
<content type='text'>
commit f5295bd8ea8a65dc5eac608b151386314cb978f1 upstream.

In copy_oldmem_page, the current check using max_pfn and min_low_pfn to
decide if the page is backed or not, is not valid when the memory layout is
not continuous.

This happens when running as a QEMU/KVM guest, where RTAS is mapped higher
in the memory. In that case max_pfn points to the end of RTAS, and a hole
between the end of the kdump kernel and RTAS is not backed by PTEs. As a
consequence, the kdump kernel is crashing in copy_oldmem_page when accessing
in a direct way the pages in that hole.

This fix relies on the memblock's service memblock_is_region_memory to
check if the read page is part or not of the directly accessible memory.

Signed-off-by: Laurent Dufour &lt;ldufour@linux.vnet.ibm.com&gt;
Tested-by: Mahesh Salgaonkar &lt;mahesh@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit f5295bd8ea8a65dc5eac608b151386314cb978f1 upstream.

In copy_oldmem_page, the current check using max_pfn and min_low_pfn to
decide if the page is backed or not, is not valid when the memory layout is
not continuous.

This happens when running as a QEMU/KVM guest, where RTAS is mapped higher
in the memory. In that case max_pfn points to the end of RTAS, and a hole
between the end of the kdump kernel and RTAS is not backed by PTEs. As a
consequence, the kdump kernel is crashing in copy_oldmem_page when accessing
in a direct way the pages in that hole.

This fix relies on the memblock's service memblock_is_region_memory to
check if the read page is part or not of the directly accessible memory.

Signed-off-by: Laurent Dufour &lt;ldufour@linux.vnet.ibm.com&gt;
Tested-by: Mahesh Salgaonkar &lt;mahesh@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Make sure "cache" directory is removed when offlining cpu</title>
<updated>2014-02-06T19:05:48+00:00</updated>
<author>
<name>Paul Mackerras</name>
<email>paulus@samba.org</email>
</author>
<published>2014-01-18T10:14:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=988e453293f02271214645c7887638124095aa88'/>
<id>988e453293f02271214645c7887638124095aa88</id>
<content type='text'>
commit 91b973f90c1220d71923e7efe1e61f5329806380 upstream.

The code in remove_cache_dir() is supposed to remove the "cache"
subdirectory from the sysfs directory for a CPU when that CPU is
being offlined.  It tries to do this by calling kobject_put() on
the kobject for the subdirectory.  However, the subdirectory only
gets removed once the last reference goes away, and the reference
being put here may well not be the last reference.  That means
that the "cache" subdirectory may still exist when the offlining
operation has finished.  If the same CPU subsequently gets onlined,
the code tries to add a new "cache" subdirectory.  If the old
subdirectory has not yet been removed, we get a WARN_ON in the
sysfs code, with stack trace, and an error message printed on the
console.  Further, we ultimately end up with an online cpu with no
"cache" subdirectory.

This fixes it by doing an explicit kobject_del() at the point where
we want the subdirectory to go away.  kobject_del() removes the sysfs
directory even though the object still exists in memory.  The object
will get freed at some point in the future.  A subsequent onlining
operation can create a new sysfs directory, even if the old object
still exists in memory, without causing any problems.

Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

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<pre>
commit 91b973f90c1220d71923e7efe1e61f5329806380 upstream.

The code in remove_cache_dir() is supposed to remove the "cache"
subdirectory from the sysfs directory for a CPU when that CPU is
being offlined.  It tries to do this by calling kobject_put() on
the kobject for the subdirectory.  However, the subdirectory only
gets removed once the last reference goes away, and the reference
being put here may well not be the last reference.  That means
that the "cache" subdirectory may still exist when the offlining
operation has finished.  If the same CPU subsequently gets onlined,
the code tries to add a new "cache" subdirectory.  If the old
subdirectory has not yet been removed, we get a WARN_ON in the
sysfs code, with stack trace, and an error message printed on the
console.  Further, we ultimately end up with an online cpu with no
"cache" subdirectory.

This fixes it by doing an explicit kobject_del() at the point where
we want the subdirectory to go away.  kobject_del() removes the sysfs
directory even though the object still exists in memory.  The object
will get freed at some point in the future.  A subsequent onlining
operation can create a new sysfs directory, even if the old object
still exists in memory, without causing any problems.

Signed-off-by: Paul Mackerras &lt;paulus@samba.org&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
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