<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-toradex.git/arch/powerpc/kernel/ptrace.c, branch v3.2.44</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>Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux</title>
<updated>2011-11-07T03:44:47+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2011-11-07T03:44:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=32aaeffbd4a7457bf2f7448b33b5946ff2a960eb'/>
<id>32aaeffbd4a7457bf2f7448b33b5946ff2a960eb</id>
<content type='text'>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
  Revert "tracing: Include module.h in define_trace.h"
  irq: don't put module.h into irq.h for tracking irqgen modules.
  bluetooth: macroize two small inlines to avoid module.h
  ip_vs.h: fix implicit use of module_get/module_put from module.h
  nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
  include: replace linux/module.h with "struct module" wherever possible
  include: convert various register fcns to macros to avoid include chaining
  crypto.h: remove unused crypto_tfm_alg_modname() inline
  uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
  pm_runtime.h: explicitly requires notifier.h
  linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
  miscdevice.h: fix up implicit use of lists and types
  stop_machine.h: fix implicit use of smp.h for smp_processor_id
  of: fix implicit use of errno.h in include/linux/of.h
  of_platform.h: delete needless include &lt;linux/module.h&gt;
  acpi: remove module.h include from platform/aclinux.h
  miscdevice.h: delete unnecessary inclusion of module.h
  device_cgroup.h: delete needless include &lt;linux/module.h&gt;
  net: sch_generic remove redundant use of &lt;linux/module.h&gt;
  net: inet_timewait_sock doesnt need &lt;linux/module.h&gt;
  ...

Fix up trivial conflicts (other header files, and  removal of the ab3550 mfd driver) in
 - drivers/media/dvb/frontends/dibx000_common.c
 - drivers/media/video/{mt9m111.c,ov6650.c}
 - drivers/mfd/ab3550-core.c
 - include/linux/dmaengine.h
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: (230 commits)
  Revert "tracing: Include module.h in define_trace.h"
  irq: don't put module.h into irq.h for tracking irqgen modules.
  bluetooth: macroize two small inlines to avoid module.h
  ip_vs.h: fix implicit use of module_get/module_put from module.h
  nf_conntrack.h: fix up fallout from implicit moduleparam.h presence
  include: replace linux/module.h with "struct module" wherever possible
  include: convert various register fcns to macros to avoid include chaining
  crypto.h: remove unused crypto_tfm_alg_modname() inline
  uwb.h: fix implicit use of asm/page.h for PAGE_SIZE
  pm_runtime.h: explicitly requires notifier.h
  linux/dmaengine.h: fix implicit use of bitmap.h and asm/page.h
  miscdevice.h: fix up implicit use of lists and types
  stop_machine.h: fix implicit use of smp.h for smp_processor_id
  of: fix implicit use of errno.h in include/linux/of.h
  of_platform.h: delete needless include &lt;linux/module.h&gt;
  acpi: remove module.h include from platform/aclinux.h
  miscdevice.h: delete unnecessary inclusion of module.h
  device_cgroup.h: delete needless include &lt;linux/module.h&gt;
  net: sch_generic remove redundant use of &lt;linux/module.h&gt;
  net: inet_timewait_sock doesnt need &lt;linux/module.h&gt;
  ...

Fix up trivial conflicts (other header files, and  removal of the ab3550 mfd driver) in
 - drivers/media/dvb/frontends/dibx000_common.c
 - drivers/media/video/{mt9m111.c,ov6650.c}
 - drivers/mfd/ab3550-core.c
 - include/linux/dmaengine.h
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: remove non-required uses of include &lt;linux/module.h&gt;</title>
<updated>2011-10-31T23:30:44+00:00</updated>
<author>
<name>Paul Gortmaker</name>
<email>paul.gortmaker@windriver.com</email>
</author>
<published>2011-07-22T18:24:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=ead53f22dc646d91a1b6201b9f44dd47d7d88c34'/>
<id>ead53f22dc646d91a1b6201b9f44dd47d7d88c34</id>
<content type='text'>
None of the files touched here are modules, and they are not
exporting any symbols either -- so there is no need to be including
the module.h.  Builds of all the files remains successful.

Even kernel/module.c does not need to include it, since it includes
linux/moduleloader.h instead.

Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
None of the files touched here are modules, and they are not
exporting any symbols either -- so there is no need to be including
the module.h.  Builds of all the files remains successful.

Even kernel/module.c does not need to include it, since it includes
linux/moduleloader.h instead.

Signed-off-by: Paul Gortmaker &lt;paul.gortmaker@windriver.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/ptrace: Fix build with gcc 4.6</title>
<updated>2011-09-29T07:02:04+00:00</updated>
<author>
<name>Benjamin Herrenschmidt</name>
<email>benh@kernel.crashing.org</email>
</author>
<published>2011-09-26T19:37:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=e69b742a6793dc5bf16f6eedca534d4bc10d68b2'/>
<id>e69b742a6793dc5bf16f6eedca534d4bc10d68b2</id>
<content type='text'>
gcc (rightfully) complains that we are accessing beyond the
end of the fpr array (we do, to access the fpscr).

The only sane thing to do (whether anything in that code can be
called remotely sane is debatable) is to special case fpscr and
handle it as a separate statement.

I initially tried to do it it by making the array access conditional
to index &lt; PT_FPSCR and using a 3rd else leg but for some reason gcc
was unable to understand it and still spewed the warning.

So I ended up with something a tad more intricated but it seems to
build on 32-bit and on 64-bit with and without VSX.

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
gcc (rightfully) complains that we are accessing beyond the
end of the fpr array (we do, to access the fpscr).

The only sane thing to do (whether anything in that code can be
called remotely sane is debatable) is to special case fpscr and
handle it as a separate statement.

I initially tried to do it it by making the array access conditional
to index &lt; PT_FPSCR and using a 3rd else leg but for some reason gcc
was unable to understand it and still spewed the warning.

So I ended up with something a tad more intricated but it seems to
build on 32-bit and on 64-bit with and without VSX.

Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: Add context field to perf_event</title>
<updated>2011-07-01T09:06:38+00:00</updated>
<author>
<name>Avi Kivity</name>
<email>avi@redhat.com</email>
</author>
<published>2011-06-29T15:42:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=4dc0da86967d5463708631d02a70cfed5b104884'/>
<id>4dc0da86967d5463708631d02a70cfed5b104884</id>
<content type='text'>
The perf_event overflow handler does not receive any caller-derived
argument, so many callers need to resort to looking up the perf_event
in their local data structure.  This is ugly and doesn't scale if a
single callback services many perf_events.

Fix by adding a context parameter to perf_event_create_kernel_counter()
(and derived hardware breakpoints APIs) and storing it in the perf_event.
The field can be accessed from the callback as event-&gt;overflow_handler_context.
All callers are updated.

Signed-off-by: Avi Kivity &lt;avi@redhat.com&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.com
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The perf_event overflow handler does not receive any caller-derived
argument, so many callers need to resort to looking up the perf_event
in their local data structure.  This is ugly and doesn't scale if a
single callback services many perf_events.

Fix by adding a context parameter to perf_event_create_kernel_counter()
(and derived hardware breakpoints APIs) and storing it in the perf_event.
The field can be accessed from the callback as event-&gt;overflow_handler_context.
All callers are updated.

Signed-off-by: Avi Kivity &lt;avi@redhat.com&gt;
Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Link: http://lkml.kernel.org/r/1309362157-6596-2-git-send-email-avi@redhat.com
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>perf: Remove the nmi parameter from the swevent and overflow interface</title>
<updated>2011-07-01T09:06:35+00:00</updated>
<author>
<name>Peter Zijlstra</name>
<email>a.p.zijlstra@chello.nl</email>
</author>
<published>2011-06-27T12:41:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=a8b0ca17b80e92faab46ee7179ba9e99ccb61233'/>
<id>a8b0ca17b80e92faab46ee7179ba9e99ccb61233</id>
<content type='text'>
The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.

For the various event classes:

  - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
    the PMI-tail (ARM etc.)
  - tracepoint: nmi=0; since tracepoint could be from NMI context.
  - software: nmi=[0,1]; some, like the schedule thing cannot
    perform wakeups, and hence need 0.

As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).

The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.

Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Michael Cree &lt;mcree@orcon.net.nz&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Deng-Cheng Zhu &lt;dengcheng.zhu@gmail.com&gt;
Cc: Anton Blanchard &lt;anton@samba.org&gt;
Cc: Eric B Munson &lt;emunson@mgebm.net&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Paul Mundt &lt;lethal@linux-sh.org&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Jason Wessel &lt;jason.wessel@windriver.com&gt;
Cc: Don Zickus &lt;dzickus@redhat.com&gt;
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.

For the various event classes:

  - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
    the PMI-tail (ARM etc.)
  - tracepoint: nmi=0; since tracepoint could be from NMI context.
  - software: nmi=[0,1]; some, like the schedule thing cannot
    perform wakeups, and hence need 0.

As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).

The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.

Signed-off-by: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Michael Cree &lt;mcree@orcon.net.nz&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Deng-Cheng Zhu &lt;dengcheng.zhu@gmail.com&gt;
Cc: Anton Blanchard &lt;anton@samba.org&gt;
Cc: Eric B Munson &lt;emunson@mgebm.net&gt;
Cc: Heiko Carstens &lt;heiko.carstens@de.ibm.com&gt;
Cc: Paul Mundt &lt;lethal@linux-sh.org&gt;
Cc: David S. Miller &lt;davem@davemloft.net&gt;
Cc: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: Jason Wessel &lt;jason.wessel@windriver.com&gt;
Cc: Don Zickus &lt;dzickus@redhat.com&gt;
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/ftrace: Implement raw syscall tracepoints on PowerPC</title>
<updated>2011-05-26T03:38:57+00:00</updated>
<author>
<name>Ian Munsie</name>
<email>imunsie@au.ibm.com</email>
</author>
<published>2011-02-02T17:27:24+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=02424d8966d803e33cbe51469be56b5d177b4a37'/>
<id>02424d8966d803e33cbe51469be56b5d177b4a37</id>
<content type='text'>
This patch implements the raw syscall tracepoints on PowerPC and exports
them for ftrace syscalls to use.

To minimise reworking existing code, I slightly re-ordered the thread
info flags such that the new TIF_SYSCALL_TRACEPOINT bit would still fit
within the 16 bits of the andi. instruction's UI field. The instructions
in question are in /arch/powerpc/kernel/entry_{32,64}.S to and the
_TIF_SYSCALL_T_OR_A with the thread flags to see if system call tracing
is enabled.

In the case of 64bit PowerPC, arch_syscall_addr and
arch_syscall_match_sym_name are overridden to allow ftrace syscalls to
work given the unusual system call table structure and symbol names that
start with a period.

Signed-off-by: Ian Munsie &lt;imunsie@au1.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch implements the raw syscall tracepoints on PowerPC and exports
them for ftrace syscalls to use.

To minimise reworking existing code, I slightly re-ordered the thread
info flags such that the new TIF_SYSCALL_TRACEPOINT bit would still fit
within the 16 bits of the andi. instruction's UI field. The instructions
in question are in /arch/powerpc/kernel/entry_{32,64}.S to and the
_TIF_SYSCALL_T_OR_A with the thread flags to see if system call tracing
is enabled.

In the case of 64bit PowerPC, arch_syscall_addr and
arch_syscall_match_sym_name are overridden to allow ftrace syscalls to
work given the unusual system call table structure and symbol names that
start with a period.

Signed-off-by: Ian Munsie &lt;imunsie@au1.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>hw_breakpoints, powerpc: Fix CONFIG_HAVE_HW_BREAKPOINT off-case in ptrace_set_debugreg()</title>
<updated>2011-05-06T09:24:46+00:00</updated>
<author>
<name>Frederic Weisbecker</name>
<email>fweisbec@gmail.com</email>
</author>
<published>2011-05-05T23:53:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=925f83c085e1bb08435556c5b4844a60de002e31'/>
<id>925f83c085e1bb08435556c5b4844a60de002e31</id>
<content type='text'>
We make use of ptrace_get_breakpoints() / ptrace_put_breakpoints() to
protect ptrace_set_debugreg() even if CONFIG_HAVE_HW_BREAKPOINT if off.
However in this case, these APIs are not implemented.

To fix this, push the protection down inside the relevant ifdef.
Best would be to export the code inside
CONFIG_HAVE_HW_BREAKPOINT into a standalone function to cleanup
the ifdefury there and call the breakpoint ref API inside. But
as it is more invasive, this should be rather made in an -rc1.

Fixes this build error:

  arch/powerpc/kernel/ptrace.c:1594: error: implicit declaration of function 'ptrace_get_breakpoints' make[2]: ***

Reported-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: LPPC &lt;linuxppc-dev@lists.ozlabs.org&gt;
Cc: Prasad &lt;prasad@linux.vnet.ibm.com&gt;
Cc: v2.6.33.. &lt;stable@kernel.org&gt;
Link: http://lkml.kernel.org/r/1304639598-4707-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We make use of ptrace_get_breakpoints() / ptrace_put_breakpoints() to
protect ptrace_set_debugreg() even if CONFIG_HAVE_HW_BREAKPOINT if off.
However in this case, these APIs are not implemented.

To fix this, push the protection down inside the relevant ifdef.
Best would be to export the code inside
CONFIG_HAVE_HW_BREAKPOINT into a standalone function to cleanup
the ifdefury there and call the breakpoint ref API inside. But
as it is more invasive, this should be rather made in an -rc1.

Fixes this build error:

  arch/powerpc/kernel/ptrace.c:1594: error: implicit declaration of function 'ptrace_get_breakpoints' make[2]: ***

Reported-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Cc: LPPC &lt;linuxppc-dev@lists.ozlabs.org&gt;
Cc: Prasad &lt;prasad@linux.vnet.ibm.com&gt;
Cc: v2.6.33.. &lt;stable@kernel.org&gt;
Link: http://lkml.kernel.org/r/1304639598-4707-1-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar &lt;mingo@elte.hu&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc, hw_breakpoints: Fix racy access to ptrace breakpoints</title>
<updated>2011-04-25T15:33:54+00:00</updated>
<author>
<name>Frederic Weisbecker</name>
<email>fweisbec@gmail.com</email>
</author>
<published>2011-04-08T15:29:36+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=07fa7a0a8a586c01a8b416358c7012dcb9dc688d'/>
<id>07fa7a0a8a586c01a8b416358c7012dcb9dc688d</id>
<content type='text'>
While the tracer accesses ptrace breakpoints, the child task may
concurrently exit due to a SIGKILL and thus release its breakpoints
at the same time. We can then dereference some freed pointers.

To fix this, hold a reference on the child breakpoints before
manipulating them.

Reported-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Acked-by: Prasad &lt;prasad@linux.vnet.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Paul Mundt &lt;lethal@linux-sh.org&gt;
Cc: v2.6.33.. &lt;stable@kernel.org&gt;
Link: http://lkml.kernel.org/r/1302284067-7860-4-git-send-email-fweisbec@gmail.com
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
While the tracer accesses ptrace breakpoints, the child task may
concurrently exit due to a SIGKILL and thus release its breakpoints
at the same time. We can then dereference some freed pointers.

To fix this, hold a reference on the child breakpoints before
manipulating them.

Reported-by: Oleg Nesterov &lt;oleg@redhat.com&gt;
Signed-off-by: Frederic Weisbecker &lt;fweisbec@gmail.com&gt;
Acked-by: Prasad &lt;prasad@linux.vnet.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Peter Zijlstra &lt;a.p.zijlstra@chello.nl&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Paul Mundt &lt;lethal@linux-sh.org&gt;
Cc: v2.6.33.. &lt;stable@kernel.org&gt;
Link: http://lkml.kernel.org/r/1302284067-7860-4-git-send-email-fweisbec@gmail.com
</pre>
</div>
</content>
</entry>
<entry>
<title>Fix common misspellings</title>
<updated>2011-03-31T14:26:23+00:00</updated>
<author>
<name>Lucas De Marchi</name>
<email>lucas.demarchi@profusion.mobi</email>
</author>
<published>2011-03-31T01:57:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.toradex.cn/cgit/linux-toradex.git/commit/?id=25985edcedea6396277003854657b5f3cb31a628'/>
<id>25985edcedea6396277003854657b5f3cb31a628</id>
<content type='text'>
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi &lt;lucas.demarchi@profusion.mobi&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi &lt;lucas.demarchi@profusion.mobi&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/ptrace: Remove BUG_ON when full register set not available</title>
<updated>2011-03-21T00:18:14+00:00</updated>
<author>
<name>Mike Wolf</name>
<email>mjw@linux.vnet.ibm.com</email>
</author>
<published>2011-03-21T00:14:53+00:00</published>
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In some cases during a threaded core dump not all the threads will have
a full register set. This happens when the signal causing the core dump
races with a thread exiting.  The race happens when the exiting thread
has entered the kernel for the last time before the signal arrives, but
doesn't get far enough through the exit code to avoid being included
in the core dump.

So we get a thread included in the core dump which is never going to go
out to userspace again and only has a partial register set recorded

Normally we would catch each thread as it is about to go into userspace
and capture the full register set then.

However, this exiting thread is never going to go out to userspace
again, so we have no way to capture its full register set.  It doesn't
really matter, though, as this is a thread which is effectively
already dead.

So instead of hitting a BUG() in this case (a really bad choice of
action in the first place), we use a poison value for the register
values.

[BenH]: Some cosmetic/stylistic changes and fix build on ppc32

Signed-off-by: Mike Wolf &lt;mjw@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
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In some cases during a threaded core dump not all the threads will have
a full register set. This happens when the signal causing the core dump
races with a thread exiting.  The race happens when the exiting thread
has entered the kernel for the last time before the signal arrives, but
doesn't get far enough through the exit code to avoid being included
in the core dump.

So we get a thread included in the core dump which is never going to go
out to userspace again and only has a partial register set recorded

Normally we would catch each thread as it is about to go into userspace
and capture the full register set then.

However, this exiting thread is never going to go out to userspace
again, so we have no way to capture its full register set.  It doesn't
really matter, though, as this is a thread which is effectively
already dead.

So instead of hitting a BUG() in this case (a really bad choice of
action in the first place), we use a poison value for the register
values.

[BenH]: Some cosmetic/stylistic changes and fix build on ppc32

Signed-off-by: Mike Wolf &lt;mjw@linux.vnet.ibm.com&gt;
Signed-off-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
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