linux-toradex.git/kernel/module.c, branch v2.6.34.15

dynamic debug: move ddebug_remove_module() down into free_module()

2010-08-02T17:29:33+00:00

commit b82bab4bbe9efa7bc7177fc20620fff19bd95484 upstream.

The command

	echo "file ec.c +p" >/sys/kernel/debug/dynamic_debug/control

causes an oops.

Move the call to ddebug_remove_module() down into free_module().  In this
way it should be called from all error paths.  Currently, we are missing
the remove if the module init routine fails.

Signed-off-by: Jason Baron 
Reported-by: Thomas Renninger 
Tested-by: Thomas Renninger 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Fix up possibly racy module refcounting

2010-04-06T02:50:02+00:00

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: Nick Piggin 
Acked-by: Rusty Russell 
Signed-off-by: Linus Torvalds

percpu, module: implement and use is_kernel/module_percpu_address()

2010-03-29T14:07:12+00:00

lockdep has custom code to check whether a pointer belongs to static
percpu area which is somewhat broken.  Implement proper
is_kernel/module_percpu_address() and replace the custom code.

On UP, percpu variables are regular static variables and can't be
distinguished from them.  Always return %false on UP.

Signed-off-by: Tejun Heo 
Acked-by: Peter Zijlstra 
Cc: Rusty Russell 
Cc: Ingo Molnar

module: encapsulate percpu handling better and record percpu_size

2010-03-29T14:07:12+00:00

Better encapsulate module static percpu area handling so that code
outsidef of CONFIG_SMP ifdef doesn't deal with mod->percpu directly
and add mod->percpu_size and record percpu_size in it.  Both percpu
fields are compiled out on UP.  While at it, mark mod->percpu w/
__percpu.

This is to prepare for is_module_percpu_address().

Signed-off-by: Tejun Heo 
Acked-by: Rusty Russell

sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on module dynamic attributes

2010-03-08T01:04:51+00:00

A little more whack-a-mole annotating the dynamic sysfs attributes.  I
had everything built into my earlier test kernel, and so I missed
these.

Signed-off-by: Eric W. Biederman 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'master' into percpu

2010-02-02T05:38:15+00:00

modules: Skip empty sections when exporting section notes

2010-01-06T09:11:29+00:00

Commit 35dead4 "modules: don't export section names of empty sections
via sysfs" changed the set of sections that have attributes, but did
not change the iteration over these attributes in add_notes_attrs().
This can lead to add_notes_attrs() creating attributes with the wrong
names or with null name pointers.

Introduce a sect_empty() function and use it in both add_sect_attrs()
and add_notes_attrs().

Reported-by: Martin Michlmayr 
Signed-off-by: Ben Hutchings 
Tested-by: Martin Michlmayr 
Cc: stable@kernel.org
Signed-off-by: Rusty Russell 
Signed-off-by: Linus Torvalds

module: Use this_cpu_xx to dynamically allocate counters

2010-01-05T06:34:50+00:00

Use cpu ops to deal with the per cpu data instead of a local_t. Reduces memory
requirements, cache footprint and decreases cycle counts.

The this_cpu_xx operations are also used for !SMP mode. Otherwise we could
not drop the use of __module_ref_addr() which would make per cpu data handling
complicated. this_cpu_xx operations have their own fallback for !SMP.

V8-V9:
- Leave include asm/module.h since ringbuffer.c depends on it. Nothing else
  does though. Another patch will deal with that.
- Remove spurious free.

Signed-off-by: Christoph Lameter 
Acked-by: Rusty Russell 
Signed-off-by: Tejun Heo

Merge branch 'kmemleak' of git://linux-arm.org/linux-2.6

2009-12-18T00:00:19+00:00

* 'kmemleak' of git://linux-arm.org/linux-2.6:
  kmemleak: fix kconfig for crc32 build error
  kmemleak: Reduce the false positives by checking for modified objects
  kmemleak: Show the age of an unreferenced object
  kmemleak: Release the object lock before calling put_object()
  kmemleak: Scan the _ftrace_events section in modules
  kmemleak: Simplify the kmemleak_scan_area() function prototype
  kmemleak: Do not use off-slab management with SLAB_NOLEAKTRACE

module: handle ppc64 relocating kcrctabs when CONFIG_RELOCATABLE=y

2009-12-15T05:58:34+00:00

powerpc applies relocations to the kcrctab.  They're absolute symbols,
but it's not completely unreasonable: other archs may too, but the
relocation is often 0.

http://lists.ozlabs.org/pipermail/linuxppc-dev/2009-November/077972.html

Inspired-by: Neil Horman 
Signed-off-by: Rusty Russell 
Tested-by: Neil Horman 
Acked-by: Paul Mackerras