Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Amerigo Wang <amwang@redhat.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
Amerigo Wang [Wed, 27 Oct 2010 19:42:00 +0000 (12:42 -0700)]
scripts/namespace.pl: fix wrong source path
File::Find will do chdir automatically, so we need to get the absolute
patch with $File::Find::dir.
Reported-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Amerigo Wang <amwang@redhat.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
matt mooney [Sat, 2 Oct 2010 04:21:55 +0000 (21:21 -0700)]
Documentation/kbuild: modules.txt cleanup
A few modifications done for consistency, such as adding the shell
prompt for command line examples and trailing slash for directories.
Also corrects the module include header and fixes a few grammar
issues that I introduced.
Signed-off-by: matt mooney <mfm@muteddisk.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
matt mooney [Mon, 20 Sep 2010 06:06:36 +0000 (23:06 -0700)]
Documentation/kbuild: major edit of modules.txt sections 5-8
A follow-up to my edit of the first 4 sections.
Shift sections down by one due to the deletion of section 3; grammar
corrections along with some rewording; margin width cleanup; and
change EXTRA_CFLAGS -> ccflags-y.
Signed-off-by: matt mooney <mfm@muteddisk.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
matt mooney [Sun, 19 Sep 2010 01:33:57 +0000 (18:33 -0700)]
Documentation/kbuild: major edit of modules.txt sections 1-4
Omit needless words and sentences; reorganize and tighten sentence structure;
swap sections 2.2 and 2.3 for a more logical flow; remove section 3, therefore
shifting 4->3; add to explanations; and add section on building multiple modules.
Signed-off-by: matt mooney <mfm@muteddisk.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Nicolas Palix [Tue, 24 Aug 2010 15:39:12 +0000 (17:39 +0200)]
Coccinelle: Add misc/ifcol.cocci
Find confusingly indented code in or after an if. An if branch should
be indented. The code following an if should not be indented.
Sometimes, code after an if that is indented is actually intended to be
part of the if branch.
This has a high rate of false positives, because Coccinelle's column
calculation does not distinguish between spaces and tabs, so code that
is not visually aligned may be considered to be in the same column.
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Michal Marek <mmarek@suse.cz>
Nicolas Palix [Tue, 24 Aug 2010 15:39:11 +0000 (17:39 +0200)]
Coccinelle: Add misc/doubleinit.cocci
Find duplicate field initializations. This has a high rate of false
positives due to #ifdefs, which Coccinelle is not aware of in a structure
initialization.
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Michal Marek <mmarek@suse.cz>
Nicolas Palix [Tue, 24 Aug 2010 15:39:04 +0000 (17:39 +0200)]
Coccinelle: Add free/kfree.cocci
Find a use after free. Values of variables may imply that some
execution paths are not possible, resulting in false positives.
Another source of false positives are macros such as
SCTP_DBG_OBJCNT_DEC that do not actually evaluate their argument
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Michal Marek <mmarek@suse.cz>
Nicolas Palix [Tue, 24 Aug 2010 15:39:03 +0000 (17:39 +0200)]
Coccinelle: Add iterators/list_entry_update.cocci
list_for_each_entry uses its first argument to get from one element of
the list to the next, so it is usually not a good idea to reassign it.
The first rule finds such a reassignment and the second rule checks
that there is a path from the reassignment back to the top of the loop.
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Michal Marek <mmarek@suse.cz>
Nicolas Palix [Tue, 24 Aug 2010 15:39:02 +0000 (17:39 +0200)]
Coccinelle: Add iterators/itnull.cocci
Many iterators have the property that the first argument is always bound
to a real list element, never NULL. False positives arise for some
iterators that do not have this property, or in cases when the loop
cursor is reassigned. The latter should only happen when the matched
code is on the way to a loop exit (break, goto, or return).
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Michal Marek <mmarek@suse.cz>
Nicolas Palix [Tue, 24 Aug 2010 15:39:00 +0000 (17:39 +0200)]
Coccinelle: Add locks/mini_lock.cocci
Find missing unlocks. This semantic match considers the specific case
where the unlock is missing from an if branch, and there is a lock
before the if and an unlock after the if. False positives are due to
cases where the if branch represents a case where the function is
supposed to exit with the lock held, or where there is some preceding
function call that releases the lock.
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Michal Marek <mmarek@suse.cz>
Nicolas Palix [Tue, 24 Aug 2010 15:38:59 +0000 (17:38 +0200)]
Coccinelle: Add locks/double_lock.cocci
Find double locks. False positives may occur when some paths cannot
occur at execution, due to the values of variables, and when there is
an intervening function call that releases the lock.
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Michal Marek <mmarek@suse.cz>
Nicolas Palix [Tue, 24 Aug 2010 15:38:58 +0000 (17:38 +0200)]
Coccinelle: Add locks/call_kern.cocci
Find functions that refer to GFP_KERNEL but are called with locks held.
The proposed change of converting the GFP_KERNEL is not necessarily the
correct one. It may be desired to unlock the lock, or to not call the
function under the lock in the first place.
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Michal Marek <mmarek@suse.cz>
Nicolas Palix [Tue, 24 Aug 2010 15:38:56 +0000 (17:38 +0200)]
Coccinelle: Add null/kmerr.cocci
This semantic patch looks for kmalloc etc that are not followed by a
NULL check. It only gives a report in the case where there is some
error handling code later in the function, which may be helpful
in determining what the error handling code for the call to kmalloc etc
should be.
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Michal Marek <mmarek@suse.cz>
Martin Ettl [Sun, 21 Feb 2010 08:31:44 +0000 (09:31 +0100)]
scripts/dtc: Fix a resource leak
during a check of the current git head of the linux kernel with the
static code analysis tool cppcheck
(http://sourceforge.net/apps/mediawiki/cppcheck/index.php?title=Main_Page)
the tool discovered a resource leak in linux-2.6/scripts/dtc/fstree.c.
Please refer the attached patch, that fixes the issue.
Fixes https://bugzilla.kernel.org/show_bug.cgi?id=15363 Signed-off-by: Martin Ettl <ettl.martin@gmx.de> Cc: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Michal Marek <mmarek@suse.cz>
Nicolas Palix [Sun, 13 Jun 2010 07:26:34 +0000 (09:26 +0200)]
Add support for the C variable in the coccicheck script
This patch makes it possible to use the Coccinelle checker with the C
variable of the build system. To check only newly edited code, the
following command may be used:
'make C={1,2} CHECK="scripts/coccicheck"'
This runs every semantic patch in scripts/coccinelle by default. The
COCCI variable may additionally be used to only apply a single
semantic patch.
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Michal Marek <mmarek@suse.cz>
Nicolas Palix [Sun, 6 Jun 2010 15:15:06 +0000 (17:15 +0200)]
Add scripts/coccinelle/err_cast.cocci
Add a Coccinelle file to use the ERR_CAST function
Before the release 2.6.25, one had to use ERR_PTR(PTR_ERR(...)) to
convert the pointer type of an error. Since then, the function
ERR_CAST has been available for that purpose.
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Michal Marek <mmarek@suse.cz>
The purpose of this semantic patch is to remove
useless casts, as mentioned in the Linux documentation.
See Chapter 14 in Documentation/CodingStyle for more information.
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Michal Marek <mmarek@suse.cz>
Nicolas Palix [Sun, 6 Jun 2010 15:15:01 +0000 (17:15 +0200)]
Add a target to use the Coccinelle checker
A 'coccicheck' target is added. It can be called with four different
modes. Each one generates a different kind of output, i.e. context,
patch, org, report, according to the corresponding mode to be
activated.
The new target calls the 'coccicheck' front-end in the 'scripts'
directory with the MODE argument. Every SmPL file in the
subdirectories of 'scripts/coccinelle' is then given to the front-end
and applied to the entire source tree.
The four modes behave as follows:
'report' generates a list in the following format:
file:line:column-column: message
'patch' proposes a fix, when possible.
'context' highlights lines of interest and their context in a
diff-like style. Lines of interest are indicated with '-'.
'org' generates a report in the Org mode format of Emacs.
Signed-off-by: Nicolas Palix <npalix@diku.dk> Signed-off-by: Julia Lawall <julia@diku.dk> Acked-by: Sam Ravnborg <sam@ravnborg.org> Acked-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Michal Marek [Thu, 3 Jun 2010 08:54:58 +0000 (10:54 +0200)]
Makefile: clarify a comment
os user <gnusercn@gmail.com> writes:
From the last comment, arch makefile will override vmlinux. It seems
vmlinux will not be checked by `make'. But from my test, although
`all:' will be re-defined in arch Makefile (ARM arch), vmlinux will
still be checked and the commands associated will be executed. Should
we use another word instead of "overridden"?
Reported-by: os user <gnusercn@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Roland Dreier [Wed, 2 Jun 2010 20:56:36 +0000 (13:56 -0700)]
checkkconfigsymbols.sh: Kconfig symbols sometimes have lowercase letters
Quite a few Kconfig symbols contain lowercase letters. The current
checkkconfigsymbols.sh code only contains A-Z in the regexp it uses to
find config symbols in source code, so it comes up with the wrong symbol
to look for in Kconfig files and then generates false positives when it
doesn't find that wrong symbol. For example checking drivers/net
generates a false positive for MAC89 because the the actual config
option is MAC89x0.
Fix this by also adding a-z to the regexp.
Signed-off-by: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
Greg Thelen [Wed, 5 May 2010 17:41:44 +0000 (10:41 -0700)]
kbuild: Fix checking of scm-identifier variable
I'm looking Makefile in the -mm branch (dated 2010-04-28-16-53) and
seeing what looks like a bug in the checking of scm-identifier. The
"ifneq ($scm-identifier)" seems to always execute "ifeq
($(LOCALVERSION,)) ...". This patch fixes the checking of
scm-identifier.
Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Li Zefan [Wed, 14 Apr 2010 03:46:24 +0000 (11:46 +0800)]
gconfig: add support to show hidden options that have prompts
There's a button in gconfig to "Show all options", but I think
normally we are not interested in those configs which have no
prompt and thus can't be changed, so here I add a new button to
show hidden options which have prompts.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Li Zefan [Wed, 14 Apr 2010 03:46:02 +0000 (11:46 +0800)]
menuconfig: add support to show hidden options which have prompts
Usage:
Press <Z> to show all config symbols which have prompts.
Quote Tim Bird:
| I've been bitten by this numerous times. I most often
| use ftrace on ARM, but when I go back to x86, I almost
| always go through a sequence of searching for the
| function graph tracer in the menus, then realizing it's
| completely missing until I disable CC_OPTIMIZE_FOR_SIZE.
|
| Is there any way to have the menu item appear, but be
| unsettable unless the SIZE option is disabled? I'm
| not a Kconfig guru...
I myself found this useful too. For example, I need to test
ftrace/tracing and want to be sure all the tracing features are
enabled, so I enter the "Tracers" menu, and press <Z> to
see if there is any config hidden.
I also noticed gconfig and xconfig have a button "Show all options",
but that's a bit too much, and I think normally what we are not
interested in those configs which have no prompt thus can't be
changed by users.
Li Zefan [Wed, 14 Apr 2010 03:44:20 +0000 (11:44 +0800)]
kconfig: fix zconfdump()
zconfdump(), which is used for debugging, can't recognize P_SELECT,
P_RANGE and P_MENU (if associated with a symbol, aka "menuconfig"),
and output something like this:
config X86
boolean
default y
unknown prop 6!
unknown prop 6!
unknown prop 6!
...
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Jason Gunthorpe [Mon, 22 Mar 2010 22:49:32 +0000 (16:49 -0600)]
kbuild: Include gen_initramfs_list.sh and the file list in the .d file
Expand the dependency set used for the initrd to include the
CONFIG_INITRAMFS_SOURCE file and the generator script itself.
Otherwise changing the initramfs file list does not rebuild the CPIO.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Minor perlcritic warning:
headerdep.pl: "return" statement with explicit "undef" at line 84, column 2. See page 199 of PBP. (Severity: 5)
The rationale according to PBP is that an explicit return of undef
(contrary to most people's expectations) doesn't
always evaluate as false. It has to with the fact that perl return value
depends on context the function is called. If function is used in
list context, the appropriate return value for false is an empty list;
whereas in scalar context the return value for false is undefined.
By just using a "return" both cases are handled.
In the context of a trivial script this doesn't matter. But one script
may be cut-paste into later code (most people like me only know 50%
of perl), that is why perlcritic always complains
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Michal Marek [Wed, 10 Mar 2010 11:28:58 +0000 (12:28 +0100)]
kbuild: Generate modules.builtin in make modules_install
The previous approach didn't work if one did
make modules && make modules_install
Add modules.builtin as dependency of _modinst_, which is the target that
actually needs the file.
Reported-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
Michal Marek [Mon, 8 Mar 2010 09:26:22 +0000 (10:26 +0100)]
Revert "kbuild: specify absolute paths for cscope"
This reverts commit eb8f844c0a41c4529a7d06b7801296eca9ae67aa. Ian
Campbell writes:
> I keep my kernel source tree on a more powerful build box where I run my
> builds etc (including "make cscope") but run my editor from my
> workstation with an NFS mount to the source. This worked fine for me
> using relative paths for cscope. Using absolute paths in cscope breaks
> this previously working setup because the root path is not the same on
> both systems. I guess this is similar to moving the source tree around.
>
> Without wanting to start a flamewar it really sounds to me like we are
> working around a vim (or cscope) bug here, emacs with cscope bindings
> works fine in this configuration.
Given that absolute paths can be forced by make O=. cscope, change the
default back to relative paths.
Ian Campbell <ijc@hellion.org.uk> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Michal Marek <mmarek@suse.cz>
Michal Marek [Mon, 8 Mar 2010 09:07:12 +0000 (10:07 +0100)]
kbuild: Do not unnecessarily regenerate modules.builtin
Only regenerate it if the configuration has changed. Also, do this after
the modules build to fix errors with some weird Makefiles that are
generated during build.
Reported-by: Eric Miao <eric.y.miao@gmail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Better practice to use 3 arg open and local file handles.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Acked-by: WANG Cong <amwang@redhat.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
According to PBP; best way practice is to use local reference for file
handle and three argument open. Also perl prototypes are a mistake.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Acked-by: WANG Cong <amwang@redhat.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
Use local file handles, use three argument open.
Don't modify arguments in perl grep (use sed instead)
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Acked-by: WANG Cong <amwang@redhat.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
Turn on strict checking.
Simplify code by using "unless" statement.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Acked-by: WANG Cong <amwang@redhat.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
Use local file handle not global.
Make loop and other variables local in scope.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Cc: Hui Zhu <teawater@gmail.com> Cc: Cong Wang <amwang@redhat.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
Turn on strict checking.
Use three arguement open
Standard practice in perl is to use undef not zero for false
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Cc: Cong Wang <amwang@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
Turn on strict checking.
Use local file handles.
Use three argument open.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Cc: Cong Wang <amwang@redhat.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
Cleanup checkstack script:
* Turn on strict checking
* Fix resulting error message because the declaration syntax
was incorrect.
* Remove incorrect and misleading use of prototype
- prototype not required for this type of sort function
because $a and $b are being used in this contex
- if prototype was being used it should be for both arguments
* Use closure for sort function
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arjan van de Ven <arjan@infradead.org> Cc: Cong Wang <amwang@redhat.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Michal Marek <mmarek@suse.cz>
Tim Abbott [Sat, 20 Feb 2010 00:03:38 +0000 (01:03 +0100)]
Rename .bss.page_aligned to .bss..page_aligned.
Signed-off-by: Tim Abbott <tabbott@ksplice.com> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Tim Abbott [Sat, 20 Feb 2010 00:03:37 +0000 (01:03 +0100)]
Rename .data.page_aligned to .data..page_aligned.
Signed-off-by: Tim Abbott <tabbott@ksplice.com> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Tim Abbott [Sat, 20 Feb 2010 00:03:36 +0000 (01:03 +0100)]
powerpc: remove unused __page_aligned definition.
There is already an architecture-independent __page_aligned_data macro
for this purpose, so removing the powerpc-specific macro should be
harmless.
Signed-off-by: Tim Abbott <tabbott@ksplice.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Tim Abbott [Sat, 20 Feb 2010 00:03:35 +0000 (01:03 +0100)]
Rename .data.init_task to .data..init_task.
Signed-off-by: Tim Abbott <tabbott@ksplice.com> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Tim Abbott [Sat, 20 Feb 2010 00:03:34 +0000 (01:03 +0100)]
Rename .data.cacheline_aligned to .data..cacheline_aligned.
Signed-off-by: Tim Abbott <tabbott@ksplice.com> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com> Signed-off-by: Michal Marek <mmarek@suse.cz>
Currently looking up a structure definition in TAGS / tags takes one to
one of multiple "static struct X" definitions in arch sources, which makes
it for many structs practically impossible to get to the required header.
This patch changes the order of sources being tagged to first scan
architecture includes, then the top-level include/ directory, and only
then the rest. It also takes into account, that many architectures have
more than one include directory, i.e., not only arch/$ARCH/include, but
also arch/$ARCH/mach-X/include etc.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Reviewed-by: WANG Cong <xiyou.wangcong@gmail.com>
[mmarek@suse.cz: fix 'var+=text' bashism] Signed-off-by: Michal Marek <mmarek@suse.cz>
Andi Kleen [Tue, 2 Feb 2010 22:40:02 +0000 (14:40 -0800)]
kbuild: move -fno-dwarf2-cfi-asm to powerpc only
Better dwarf2 unwind information is a good thing, it allows better
debugging with kgdb and crash and helps systemtap.
Commit 003086497f07f7f1e67c0c295e261740f822b377 ("Build with
-fno-dwarf2-cfi-asm") disabled some CFI information globally to work
around a module loader bug on powerpc.
But this disables the better unwind tables for all architectures, not just
powerpc. Move the workaround to powerpc and also add a suitable comment
that's it really a workaround.
This improves dwarf2 unwind tables on x86 at least.
Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michal Marek <mmarek@suse.cz>