<feed xmlns='http://www.w3.org/2005/Atom'>
<title>litmus-rt.git/arch/parisc/mm, branch 2010.2</title>
<subtitle>The LITMUS^RT kernel.</subtitle>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/'/>
<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='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.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>parisc: rename parisc's vmalloc_start to parisc_vmalloc_start</title>
<updated>2009-09-28T03:27:04+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2009-09-28T03:26:01+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=4255f0d2a132fb38dbe5b5ad74e27ba472507415'/>
<id>4255f0d2a132fb38dbe5b5ad74e27ba472507415</id>
<content type='text'>
building kernel 2.6.32(pre), gives this compiler warning:
/linus-linux-2.6/mm/vmalloc.c: In function 'pcpu_get_vm_areas':
/linus-linux-2.6/mm/vmalloc.c:2104: warning: 'vmalloc_start' is used
uninitialized in this function

The reason is, that the code in mm/vmalloc defines a local variable called
vmalloc_start, which is already defined as global variable in parisc's code.

To avoid this kind of problems in future, I suggest to rename the parisc
variable
to parisc_vmalloc_start.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
building kernel 2.6.32(pre), gives this compiler warning:
/linus-linux-2.6/mm/vmalloc.c: In function 'pcpu_get_vm_areas':
/linus-linux-2.6/mm/vmalloc.c:2104: warning: 'vmalloc_start' is used
uninitialized in this function

The reason is, that the code in mm/vmalloc defines a local variable called
vmalloc_start, which is already defined as global variable in parisc's code.

To avoid this kind of problems in future, I suggest to rename the parisc
variable
to parisc_vmalloc_start.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arches: drop superfluous casts in nr_free_pages() callers</title>
<updated>2009-09-22T14:17:34+00:00</updated>
<author>
<name>Geert Uytterhoeven</name>
<email>Geert.Uytterhoeven@sonycom.com</email>
</author>
<published>2009-09-22T00:02:36+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=cc013a88906bad9d2832d6316de1c7dbc1c2a794'/>
<id>cc013a88906bad9d2832d6316de1c7dbc1c2a794</id>
<content type='text'>
Commit 96177299416dbccb73b54e6b344260154a445375 ("Drop free_pages()")
modified nr_free_pages() to return 'unsigned long' instead of 'unsigned
int'.  This made the casts to 'unsigned long' in most callers superfluous,
so remove them.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Geert Uytterhoeven &lt;Geert.Uytterhoeven@sonycom.com&gt;
Reviewed-by: Christoph Lameter &lt;cl@linux-foundation.org&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Acked-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
Acked-by: David S. Miller &lt;davem@davemloft.net&gt;
Acked-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
Acked-by: WANG Cong &lt;xiyou.wangcong@gmail.com&gt;
Cc: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Ivan Kokshaysky &lt;ink@jurassic.park.msu.ru&gt;
Cc: Haavard Skinnemoen &lt;hskinnemoen@atmel.com&gt;
Cc: Mikael Starvik &lt;starvik@axis.com&gt;
Cc: "Luck, Tony" &lt;tony.luck@intel.com&gt;
Cc: Hirokazu Takata &lt;takata@linux-m32r.org&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Acked-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Paul Mundt &lt;lethal@linux-sh.org&gt;
Cc: Chris Zankel &lt;zankel@tensilica.com&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&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>
Commit 96177299416dbccb73b54e6b344260154a445375 ("Drop free_pages()")
modified nr_free_pages() to return 'unsigned long' instead of 'unsigned
int'.  This made the casts to 'unsigned long' in most callers superfluous,
so remove them.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Geert Uytterhoeven &lt;Geert.Uytterhoeven@sonycom.com&gt;
Reviewed-by: Christoph Lameter &lt;cl@linux-foundation.org&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Acked-by: Russell King &lt;rmk+kernel@arm.linux.org.uk&gt;
Acked-by: David S. Miller &lt;davem@davemloft.net&gt;
Acked-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
Acked-by: WANG Cong &lt;xiyou.wangcong@gmail.com&gt;
Cc: Richard Henderson &lt;rth@twiddle.net&gt;
Cc: Ivan Kokshaysky &lt;ink@jurassic.park.msu.ru&gt;
Cc: Haavard Skinnemoen &lt;hskinnemoen@atmel.com&gt;
Cc: Mikael Starvik &lt;starvik@axis.com&gt;
Cc: "Luck, Tony" &lt;tony.luck@intel.com&gt;
Cc: Hirokazu Takata &lt;takata@linux-m32r.org&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Acked-by: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Paul Mundt &lt;lethal@linux-sh.org&gt;
Cc: Chris Zankel &lt;zankel@tensilica.com&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&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>parisc: fix compile warning in mm/init.c</title>
<updated>2009-07-03T03:34:10+00:00</updated>
<author>
<name>Kyle McMartin</name>
<email>kyle@mcmartin.ca</email>
</author>
<published>2009-06-23T15:51:43+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=20dbc9f724e02c26e30d89cf50e7ce259ab46da4'/>
<id>20dbc9f724e02c26e30d89cf50e7ce259ab46da4</id>
<content type='text'>
arch/parisc/mm/init.c: In function 'free_initmem':
381: warning: passing argument 1 of 'memset' makes pointer from integer without a cast

Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
arch/parisc/mm/init.c: In function 'free_initmem':
381: warning: passing argument 1 of 'memset' makes pointer from integer without a cast

Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>parisc: kill WARN in free_initmem when DEBUG_KERNEL</title>
<updated>2009-07-03T03:34:06+00:00</updated>
<author>
<name>Kyle McMartin</name>
<email>kyle@mcmartin.ca</email>
</author>
<published>2009-04-05T02:53:47+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=4fb11781a044552dded5342e1a78cf92a74683db'/>
<id>4fb11781a044552dded5342e1a78cf92a74683db</id>
<content type='text'>
Doing an IPI with local interrupts off triggers a warning. We
don't need to be quite so ridiculously paranoid. Also, clean up
a bit of the code a little.

Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Doing an IPI with local interrupts off triggers a warning. We
don't need to be quite so ridiculously paranoid. Also, clean up
a bit of the code a little.

Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>parisc: remove CVS keywords</title>
<updated>2009-07-03T03:34:06+00:00</updated>
<author>
<name>Alexander Beregalov</name>
<email>a.beregalov@gmail.com</email>
</author>
<published>2009-04-03T01:49:22+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=071327ec9005e9a826d088d37021ed2c88e683f7'/>
<id>071327ec9005e9a826d088d37021ed2c88e683f7</id>
<content type='text'>
Signed-off-by: Alexander Beregalov &lt;a.beregalov@gmail.com&gt;
Acked-by: Matthew Wilcox &lt;willy@linux.intel.com&gt;
Acked-by: Grant Grundler &lt;grundler@parisc-linux.org&gt;
Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Alexander Beregalov &lt;a.beregalov@gmail.com&gt;
Acked-by: Matthew Wilcox &lt;willy@linux.intel.com&gt;
Acked-by: Grant Grundler &lt;grundler@parisc-linux.org&gt;
Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Move FAULT_FLAG_xyz into handle_mm_fault() callers</title>
<updated>2009-06-21T20:08:22+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2009-04-10T16:01:23+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=d06063cc221fdefcab86589e79ddfdb7c0e14b63'/>
<id>d06063cc221fdefcab86589e79ddfdb7c0e14b63</id>
<content type='text'>
This allows the callers to now pass down the full set of FAULT_FLAG_xyz
flags to handle_mm_fault().  All callers have been (mechanically)
converted to the new calling convention, there's almost certainly room
for architectures to clean up their code and then add FAULT_FLAG_RETRY
when that support is added.

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 allows the callers to now pass down the full set of FAULT_FLAG_xyz
flags to handle_mm_fault().  All callers have been (mechanically)
converted to the new calling convention, there's almost certainly room
for architectures to clean up their code and then add FAULT_FLAG_RETRY
when that support is added.

Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>parisc: fix usage of 32bit PTE page table entries on 32bit kernels</title>
<updated>2009-03-31T02:51:33+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2009-01-18T18:16:16+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=48d27cb2299c0b2fc4d551bddb6a1005828dc0c6'/>
<id>48d27cb2299c0b2fc4d551bddb6a1005828dc0c6</id>
<content type='text'>
This patch fixes a long outstanding bug on 32bit parisc linux kernels
which prevented us from using 32bit PTE table entries (instead of 64bit
entries of which 32bit were unused).

The problem was caused by this assembler statement in the L2_ptep
macro in arch/parisc/kernel/entry.S:447:
	EXTR \va,31-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
which expanded to
	extrw,u r8,9,11,r1
and which has undefined behavior since the length value (11) extends
beyond the leftmost bit (11-1 &gt; 9).
Interestingly PA2.0 processors seem to don't care and just zero-extend
the value, while PA1.1 processors don't.

Fix this problem by detecting an address space overflow with ASM_BITS_PER_PGD
and adjusting it accordingly. To prevent such problems in the future,
some compile time sanity checks in arch/parisc/mm/init.c were added.

Since the page table now only consumes half of it's old size, we can
use the freed memory to harmonize 32- and 64bit kernels and let both
map 16MB for the initial page table.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch fixes a long outstanding bug on 32bit parisc linux kernels
which prevented us from using 32bit PTE table entries (instead of 64bit
entries of which 32bit were unused).

The problem was caused by this assembler statement in the L2_ptep
macro in arch/parisc/kernel/entry.S:447:
	EXTR \va,31-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
which expanded to
	extrw,u r8,9,11,r1
and which has undefined behavior since the length value (11) extends
beyond the leftmost bit (11-1 &gt; 9).
Interestingly PA2.0 processors seem to don't care and just zero-extend
the value, while PA1.1 processors don't.

Fix this problem by detecting an address space overflow with ASM_BITS_PER_PGD
and adjusting it accordingly. To prevent such problems in the future,
some compile time sanity checks in arch/parisc/mm/init.c were added.

Since the page table now only consumes half of it's old size, we can
use the freed memory to harmonize 32- and 64bit kernels and let both
map 16MB for the initial page table.

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>parisc: BUG_ON() cleanup</title>
<updated>2009-03-13T05:16:35+00:00</updated>
<author>
<name>Helge Deller</name>
<email>deller@gmx.de</email>
</author>
<published>2009-01-06T11:57:01+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=8980a7baf93e478205e32ec7d6ef3bfb6c0bdfa7'/>
<id>8980a7baf93e478205e32ec7d6ef3bfb6c0bdfa7</id>
<content type='text'>
- convert a few "if (xx) BUG();" to BUG_ON(xx)
- remove a few printk()s, as we get a backtrace with BUG_ON() anyway

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</content>
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<pre>
- convert a few "if (xx) BUG();" to BUG_ON(xx)
- remove a few printk()s, as we get a backtrace with BUG_ON() anyway

Signed-off-by: Helge Deller &lt;deller@gmx.de&gt;
Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</pre>
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</content>
</entry>
<entry>
<title>parisc: fix kernel crash (protection id trap) when compiling ruby1.9</title>
<updated>2009-01-05T19:16:46+00:00</updated>
<author>
<name>Kyle McMartin</name>
<email>kyle@mcmartin.ca</email>
</author>
<published>2008-12-20T02:29:06+00:00</published>
<link rel='alternate' type='text/html' href='http://rtsrv.cs.unc.edu/cgit/cgit.cgi/litmus-rt.git/commit/?id=c61c25eb02757ecf697015ef4ae3675c5e114e2e'/>
<id>c61c25eb02757ecf697015ef4ae3675c5e114e2e</id>
<content type='text'>
On Wed, Dec 17, 2008 at 11:46:05PM +0100, Helge Deller wrote:
&gt;

Honestly, I can't decide whether to apply this. It really should never
happen in the kernel, since the kernel can guarantee it won't get the
access rights failure (highest privilege level, and can set %sr and
%protid to whatever it wants.)

It really genuinely is a bug that probably should panic the kernel. The
only precedent I can easily see is x86 fixing up a bad iret with a
general protection fault, which is more or less analogous to code 27
here.

On the other hand, taking the exception on a userspace access really
isn't all that critical, and there's fundamentally little reason for the
kernel not to SIGSEGV the process, and continue...

Argh.

(btw, I've instrumented my do_sys_poll with a pile of assertions that
 %cr8 &lt;&lt; 1 == %sr3 == current-&gt;mm.context... let's see if where we're
 getting corrupted is deterministic, though, I would guess that it won't
 be.)

Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
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<pre>
On Wed, Dec 17, 2008 at 11:46:05PM +0100, Helge Deller wrote:
&gt;

Honestly, I can't decide whether to apply this. It really should never
happen in the kernel, since the kernel can guarantee it won't get the
access rights failure (highest privilege level, and can set %sr and
%protid to whatever it wants.)

It really genuinely is a bug that probably should panic the kernel. The
only precedent I can easily see is x86 fixing up a bad iret with a
general protection fault, which is more or less analogous to code 27
here.

On the other hand, taking the exception on a userspace access really
isn't all that critical, and there's fundamentally little reason for the
kernel not to SIGSEGV the process, and continue...

Argh.

(btw, I've instrumented my do_sys_poll with a pile of assertions that
 %cr8 &lt;&lt; 1 == %sr3 == current-&gt;mm.context... let's see if where we're
 getting corrupted is deterministic, though, I would guess that it won't
 be.)

Signed-off-by: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
</pre>
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</content>
</entry>
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