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  1. 21 5月, 2010 1 次提交
  3. 07 5月, 2010 1 次提交
    • T
      stop_machine: reimplement using cpu_stop · 3fc1f1e2
      由 Tejun Heo 提交于 
      Reimplement stop_machine using cpu_stop.  As cpu stoppers are
guaranteed to be available for all online cpus,
stop_machine_create/destroy() are no longer necessary and removed.

With resource management and synchronization handled by cpu_stop, the
new implementation is much simpler.  Asking the cpu_stop to execute
the stop_cpu() state machine on all online cpus with cpu hotplug
disabled is enough.

stop_machine itself doesn't need to manage any global resources
anymore, so all per-instance information is rolled into struct
stop_machine_data and the mutex and all static data variables are
removed.

The previous implementation created and destroyed RT workqueues as
necessary which made stop_machine() calls highly expensive on very
large machines.  According to Dimitri Sivanich, preventing the dynamic
creation/destruction makes booting faster more than twice on very
large machines.  cpu_stop resources are preallocated for all online
cpus and should have the same effect.
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Dimitri Sivanich <sivanich@sgi.com>
      3fc1f1e2
  5. 06 4月, 2010 1 次提交
    • N
      Fix up possibly racy module refcounting · 5fbfb18d
      由 Nick Piggin 提交于 
      Module refcounting is implemented with a per-cpu counter for speed.
However there is a race when tallying the counter where a reference may
be taken by one CPU and released by another.  Reference count summation
may then see the decrement without having seen the previous increment,
leading to lower than expected count.  A module which never has its
actual reference drop below 1 may return a reference count of 0 due to
this race.

Module removal generally runs under stop_machine, which prevents this
race causing bugs due to removal of in-use modules.  However there are
other real bugs in module.c code and driver code (module_refcount is
exported) where the callers do not run under stop_machine.

Fix this by maintaining running per-cpu counters for the number of
module refcount increments and the number of refcount decrements.  The
increments are tallied after the decrements, so any decrement seen will
always have its corresponding increment counted.  The final refcount is
the difference of the total increments and decrements, preventing a
low-refcount from being returned.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      5fbfb18d
  7. 01 4月, 2010 2 次提交
  9. 29 3月, 2010 2 次提交
  11. 08 3月, 2010 1 次提交
  13. 06 1月, 2010 1 次提交
  15. 05 1月, 2010 1 次提交
  17. 15 12月, 2009 1 次提交
  19. 03 12月, 2009 1 次提交
    • H
      modules: don't export section names of empty sections via sysfs · 35dead42
      由 Helge Deller 提交于 
      On the parisc architecture we face for each and every loaded kernel module
this kernel "badness warning":
  sysfs: cannot create duplicate filename '/module/ac97_bus/sections/.text'
  Badness at fs/sysfs/dir.c:487

Reason for that is, that on parisc all kernel modules do have multiple
.text sections due to the usage of the -ffunction-sections compiler flag
which is needed to reach all jump targets on this platform.

An objdump on such a kernel module gives:
Sections:
Idx Name          Size      VMA       LMA       File off  Algn
  0 .note.gnu.build-id 00000024  00000000  00000000  00000034  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, DATA
  1 .text         00000000  00000000  00000000  00000058  2**0
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  2 .text.ac97_bus_match 0000001c  00000000  00000000  00000058  2**2
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
  3 .text         00000000  00000000  00000000  000000d4  2**0
                  CONTENTS, ALLOC, LOAD, READONLY, CODE
...
Since the .text sections are empty (size of 0 bytes) and won't be
loaded by the kernel module loader anyway, I don't see a reason
why such sections need to be listed under
/sys/module/<module_name>/sections/<section_name> either.

The attached patch does solve this issue by not exporting section
names which are empty.

This fixes bugzilla http://bugzilla.kernel.org/show_bug.cgi?id=14703Signed-off-by: NHelge Deller <deller@gmx.de>
CC: rusty@rustcorp.com.au
CC: akpm@linux-foundation.org
CC: James.Bottomley@HansenPartnership.com
CC: roland@redhat.com
CC: dave@hiauly1.hia.nrc.ca
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      35dead42
  21. 29 10月, 2009 1 次提交
  23. 28 10月, 2009 1 次提交
  25. 02 10月, 2009 2 次提交
    • T
      percpu: kill legacy percpu allocator · 23fb064b
      由 Tejun Heo 提交于 
      With ia64 converted, there's no arch left which still uses legacy
percpu allocator.  Kill it.
Signed-off-by: NTejun Heo <tj@kernel.org>
Delightedly-acked-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Christoph Lameter <cl@linux-foundation.org>
      23fb064b
    • P
      module: fix up CONFIG_KALLSYMS=n build. · 3ae91c21
      由 Paul Mundt 提交于 
      Starting from commit 4a496226 "reduce
symbol table for loaded modules (v2)", the kernel/module.c build is broken
with CONFIG_KALLSYMS disabled.

  CC      kernel/module.o
kernel/module.c:1995: warning: type defaults to 'int' in declaration of 'Elf_Hdr'
kernel/module.c:1995: error: expected ';', ',' or ')' before '*' token
kernel/module.c: In function 'load_module':
kernel/module.c:2203: error: 'strmap' undeclared (first use in this function)
kernel/module.c:2203: error: (Each undeclared identifier is reported only once
kernel/module.c:2203: error: for each function it appears in.)
kernel/module.c:2239: error: 'symoffs' undeclared (first use in this function)
kernel/module.c:2239: error: implicit declaration of function 'layout_symtab'
kernel/module.c:2240: error: 'stroffs' undeclared (first use in this function)
make[1]: *** [kernel/module.o] Error 1
make: *** [kernel/module.o] Error 2

There are three different issues:

    - layout_symtab() takes a const Elf_Ehdr

    - layout_symtab() needs to return a value

    - symoffs/stroffs/strmap are referenced by the load_module() code
      despite being ifdefed out, which seems unnecessary given the noop
      behaviour of layout_symtab()/add_kallsyms() in the case of
      CONFIG_KALLSYMS=n.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
Acked-by: NJan Beulich <jbeulich@novell.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      3ae91c21
  27. 24 9月, 2009 4 次提交
  29. 23 9月, 2009 1 次提交
    • I
      modules, tracing: Remove stale struct marker signature from module_layout() · 115e8a28
      由 Ingo Molnar 提交于 
      Linus reported this new build warning:

  kernel/module.c:2951: warning: ?struct marker? declared inside parameter list
  kernel/module.c:2951: warning: its scope is only this definition or declaration, which is probably not what you want

Caused by:

  fc537766: tracing: Remove markers

module_layout() is an artificial symbol with 'significant' symbols
listed in its argument list so that it gets a proper argument types
signature that modversions can pick up to decide whether a
module is version-compatible or not. If these dont match then we
wont even look at a module.

Remove the stale marker symbol.
Reported-by: NLinus Torvalds <torvalds@linux-foundation.org>
LKML-Reference: <alpine.LFD.2.01.0909210908020.4950@localhost.localdomain>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      115e8a28
  31. 22 9月, 2009 1 次提交
  33. 19 9月, 2009 1 次提交
  35. 29 8月, 2009 1 次提交
    • I
      modules: Fix build error in the !CONFIG_KALLSYMS case · ea6bff36
      由 Ingo Molnar 提交于 
      > James Bottomley (1):
>       module: workaround duplicate section names

-tip testing found that this patch breaks the build on x86 if
CONFIG_KALLSYMS is disabled:

 kernel/module.c: In function ‘load_module’:
 kernel/module.c:2367: error: ‘struct module’ has no member named ‘sect_attrs’
 distcc[8269] ERROR: compile kernel/module.c on ph/32 failed
 make[1]: *** [kernel/module.o] Error 1
 make: *** [kernel] Error 2
 make: *** Waiting for unfinished jobs....

Commit 1b364bf4 misses the fact that section attributes are only
built and dealt with if kallsyms is enabled. The patch below fixes
this.

( note, technically speaking this should depend on CONFIG_SYSFS as
  well but this patch is correct too and keeps the #ifdef less
  intrusive - in the KALLSYMS && !SYSFS case the code is a NOP. )
Signed-off-by: NIngo Molnar <mingo@elte.hu>
[ Replaced patch with a slightly cleaner variation by James Bottomley ]
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ea6bff36
  37. 28 8月, 2009 2 次提交
  39. 17 8月, 2009 1 次提交
    • L
      tracing/events: Add module tracepoints · 7ead8b83
      由 Li Zefan 提交于 
      Add trace points to trace module_load, module_free, module_get,
module_put and module_request, and use trace_event facility to
get the trace output.

Here's the sample output:

     TASK-PID    CPU#    TIMESTAMP  FUNCTION
        | |       |          |         |
    <...>-42    [000]     1.758380: module_request: fb0 wait=1 call_site=fb_open
    ...
    <...>-60    [000]     3.269403: module_load: scsi_wait_scan
    <...>-60    [000]     3.269432: module_put: scsi_wait_scan call_site=sys_init_module refcnt=0
    <...>-61    [001]     3.273168: module_free: scsi_wait_scan
    ...
    <...>-1021  [000]    13.836081: module_load: sunrpc
    <...>-1021  [000]    13.840589: module_put: sunrpc call_site=sys_init_module refcnt=-1
    <...>-1027  [000]    13.848098: module_get: sunrpc call_site=try_module_get refcnt=0
    <...>-1027  [000]    13.848308: module_get: sunrpc call_site=get_filesystem refcnt=1
    <...>-1027  [000]    13.848692: module_put: sunrpc call_site=put_filesystem refcnt=0
    ...
 modprobe-2587  [001]  1088.437213: module_load: trace_events_sample F
 modprobe-2587  [001]  1088.437786: module_put: trace_events_sample call_site=sys_init_module refcnt=0

Note:

- the taints flag can be 'F', 'C' and/or 'P' if mod->taints != 0

- the module refcnt is percpu, so it can be negative in a
  specific cpu
Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
LKML-Reference: <4A891B3C.5030608@cn.fujitsu.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      7ead8b83
  41. 28 7月, 2009 1 次提交
  43. 09 7月, 2009 1 次提交
  45. 24 6月, 2009 1 次提交
    • T
      percpu: use dynamic percpu allocator as the default percpu allocator · e74e3962
      由 Tejun Heo 提交于 
      This patch makes most !CONFIG_HAVE_SETUP_PER_CPU_AREA archs use
dynamic percpu allocator.  The first chunk is allocated using
embedding helper and 8k is reserved for modules.  This ensures that
the new allocator behaves almost identically to the original allocator
as long as static percpu variables are concerned, so it shouldn't
introduce much breakage.

s390 and alpha use custom SHIFT_PERCPU_PTR() to work around addressing
range limit the addressing model imposes.  Unfortunately, this breaks
if the address is specified using a variable, so for now, the two
archs aren't converted.

The following architectures are affected by this change.

* sh
* arm
* cris
* mips
* sparc(32)
* blackfin
* avr32
* parisc (broken, under investigation)
* m32r
* powerpc(32)

As this change makes the dynamic allocator the default one,
CONFIG_HAVE_DYNAMIC_PER_CPU_AREA is replaced with its invert -
CONFIG_HAVE_LEGACY_PER_CPU_AREA, which is added to yet-to-be converted
archs.  These archs implement their own setup_per_cpu_areas() and the
conversion is not trivial.

* powerpc(64)
* sparc(64)
* ia64
* alpha
* s390

Boot and batch alloc/free tests on x86_32 with debug code (x86_32
doesn't use default first chunk initialization).  Compile tested on
sparc(32), powerpc(32), arm and alpha.

Kyle McMartin reported that this change breaks parisc.  The problem is
still under investigation and he is okay with pushing this patch
forward and fixing parisc later.

[ Impact: use dynamic allocator for most archs w/o custom percpu setup ]
Signed-off-by: NTejun Heo <tj@kernel.org>
Acked-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: NChristoph Lameter <cl@linux.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Mikael Starvik <starvik@axis.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Bryan Wu <cooloney@kernel.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <matthew@wil.cx>
Cc: Grant Grundler <grundler@parisc-linux.org>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
      e74e3962
  47. 19 6月, 2009 1 次提交
  49. 17 6月, 2009 1 次提交
  51. 12 6月, 2009 2 次提交
    • R
      module: trim exception table on init free. · ad6561df
      由 Rusty Russell 提交于 
      It's theoretically possible that there are exception table entries
which point into the (freed) init text of modules.  These could cause
future problems if other modules get loaded into that memory and cause
an exception as we'd see the wrong fixup.  The only case I know of is
kvm-intel.ko (when CONFIG_CC_OPTIMIZE_FOR_SIZE=n).

Amerigo fixed this long-standing FIXME in the x86 version, but this
patch is more general.

This implements trim_init_extable(); most archs are simple since they
use the standard lib/extable.c sort code.  Alpha and IA64 use relative
addresses in their fixups, so thier trimming is a slight variation.

Sparc32 is unique; it doesn't seem to define ARCH_HAS_SORT_EXTABLE,
yet it defines its own sort_extable() which overrides the one in lib.
It doesn't sort, so we have to mark deleted entries instead of
actually trimming them.
Inspired-by: NAmerigo Wang <amwang@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Cc: linux-alpha@vger.kernel.org
Cc: sparclinux@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
      ad6561df
    • C
      kmemleak: Add modules support · 4f2294b6
      由 Catalin Marinas 提交于 
      This patch handles the kmemleak operations needed for modules loading so
that memory allocations from inside a module are properly tracked.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
      4f2294b6
  53. 17 4月, 2009 1 次提交
    • S
      ftrace: use module notifier for function tracer · 93eb677d
      由 Steven Rostedt 提交于 
      The hooks in the module code for the function tracer must be called
before any of that module code runs. The function tracer hooks
modify the module (replacing calls to mcount to nops). If the code
is executed while the change occurs, then the CPU can take a GPF.

To handle the above with a bit of paranoia, I originally implemented
the hooks as calls directly from the module code.

After examining the notifier calls, it looks as though the start up
notify is called before any of the module's code is executed. This makes
the use of the notify safe with ftrace.

Only the startup notify is required to be "safe". The shutdown simply
removes the entries from the ftrace function list, and does not modify
any code.

This change has another benefit. It removes a issue with a reverse dependency
in the mutexes of ftrace_lock and module_mutex.

[ Impact: fix lock dependency bug, cleanup ]

Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      93eb677d
  55. 15 4月, 2009 2 次提交
    • S
      modules: Fix up build when CONFIG_MODULE_UNLOAD=n. · 19e4529e
      由 Stephen Rothwell 提交于 
      Commit 3d43321b ("modules: sysctl to
block module loading") introduces a modules_disabled variable that is
only defined if CONFIG_MODULE_UNLOAD is enabled, despite being used in
other places. This moves it up and fixes up the build.

  CC      kernel/module.o
kernel/module.c: In function 'sys_init_module':
kernel/module.c:2401: error: 'modules_disabled' undeclared (first use in this function)
kernel/module.c:2401: error: (Each undeclared identifier is reported only once
kernel/module.c:2401: error: for each function it appears in.)
make[1]: *** [kernel/module.o] Error 1
make: *** [kernel/module.o] Error 2
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>
Signed-off-by: NJames Morris <jmorris@namei.org>
      19e4529e
    • S
      tracing/events: add support for modules to TRACE_EVENT · 6d723736
      由 Steven Rostedt 提交于 
      Impact: allow modules to add TRACE_EVENTS on load

This patch adds the final hooks to allow modules to use the TRACE_EVENT
macro. A notifier and a data structure are used to link the TRACE_EVENTs
defined in the module to connect them with the ftrace event tracing system.

It also adds the necessary automated clean ups to the trace events when a
module is removed.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      6d723736
  57. 12 4月, 2009 1 次提交
    • L
      async: Fix module loading async-work regression · d6de2c80
      由 Linus Torvalds 提交于 
      Several drivers use asynchronous work to do device discovery, and we
synchronize with them in the compiled-in case before we actually try to
mount root filesystems etc.

However, when compiled as modules, that synchronization is missing - the
module loading completes, but the driver hasn't actually finished
probing for devices, and that means that any user mode that expects to
use the devices after the 'insmod' is now potentially broken.

We already saw one case of a similar issue in the ACPI battery code,
where the kernel itself expected the module to be all done, and unmapped
the init memory - but the async device discovery was still running.
That got hacked around by just removing the "__init" (see commit
5d38258e "ACPI battery: fix async boot
oops"), but the real fix is to just make the module loading wait for all
async work to be completed.

It will slow down module loading, but since common devices should be
built in anyway, and since the bug is really annoying and hard to handle
from user space (and caused several S3 resume regressions), the simple
fix to wait is the right one.

This fixes at least

	http://bugzilla.kernel.org/show_bug.cgi?id=13063

but probably a few other bugzilla entries too (12936, for example), and
is confirmed to fix Rafael's storage driver breakage after resume bug
report (no bugzilla entry).

We should also be able to now revert that ACPI battery fix.
Reported-and-tested-by: NRafael J. Wysocki <rjw@suse.com>
Tested-by: NHeinz Diehl <htd@fancy-poultry.org>
Acked-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      d6de2c80
  59. 07 4月, 2009 1 次提交
  61. 03 4月, 2009 1 次提交