Commit Graph

79 Commits

Author SHA1 Message Date
Catalin Marinas 5f369f374b mm: kmemleak: do not acquire scan_mutex in kmemleak_do_cleanup()
The kmemleak_do_cleanup() work thread already waits for the kmemleak_scan
thread to finish via kthread_stop().  Waiting in kthread_stop() while
scan_mutex is held may lead to deadlock if kmemleak_scan_thread() also
waits to acquire for scan_mutex.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-24 17:49:45 -07:00
Catalin Marinas e781a9ab48 mm: kmemleak: fix delete_object_*() race when called on the same memory block
Calling delete_object_*() on the same pointer is not a standard use case
(unless there is a bug in the code calling kmemleak_free()).  However,
during kmemleak disabling (error or user triggered via /sys), there is a
potential race between kmemleak_free() calls on a CPU and
__kmemleak_do_cleanup() on a different CPU.

The current delete_object_*() implementation first performs a look-up
holding kmemleak_lock, increments the object->use_count and then
re-acquires kmemleak_lock to remove the object from object_tree_root and
object_list.

This patch simplifies the delete_object_*() mechanism to both look up
and remove an object from the object_tree_root and object_list
atomically (guarded by kmemleak_lock).  This allows safe concurrent
calls to delete_object_*() on the same pointer without additional
locking for synchronising the kmemleak_free_enabled flag.

A side effect is a slight improvement in the delete_object_*() performance
by avoiding acquiring kmemleak_lock twice and incrementing/decrementing
object->use_count.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-24 17:49:45 -07:00
Catalin Marinas c5f3b1a51a mm: kmemleak: allow safe memory scanning during kmemleak disabling
The kmemleak scanning thread can run for minutes.  Callbacks like
kmemleak_free() are allowed during this time, the race being taken care
of by the object->lock spinlock.  Such lock also prevents a memory block
from being freed or unmapped while it is being scanned by blocking the
kmemleak_free() -> ...  -> __delete_object() function until the lock is
released in scan_object().

When a kmemleak error occurs (e.g.  it fails to allocate its metadata),
kmemleak_enabled is set and __delete_object() is no longer called on
freed objects.  If kmemleak_scan is running at the same time,
kmemleak_free() no longer waits for the object scanning to complete,
allowing the corresponding memory block to be freed or unmapped (in the
case of vfree()).  This leads to kmemleak_scan potentially triggering a
page fault.

This patch separates the kmemleak_free() enabling/disabling from the
overall kmemleak_enabled nob so that we can defer the disabling of the
object freeing tracking until the scanning thread completed.  The
kmemleak_free_part() is deliberately ignored by this patch since this is
only called during boot before the scanning thread started.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Vignesh Radhakrishnan <vigneshr@codeaurora.org>
Tested-by: Vignesh Radhakrishnan <vigneshr@codeaurora.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-24 17:49:45 -07:00
Vladimir Davydov 8f4fc071b1 gfp: add __GFP_NOACCOUNT
Not all kmem allocations should be accounted to memcg.  The following
patch gives an example when accounting of a certain type of allocations to
memcg can effectively result in a memory leak.  This patch adds the
__GFP_NOACCOUNT flag which if passed to kmalloc and friends will force the
allocation to go through the root cgroup.  It will be used by the next
patch.

Note, since in case of kmemleak enabled each kmalloc implies yet another
allocation from the kmemleak_object cache, we add __GFP_NOACCOUNT to
gfp_kmemleak_mask.

Alternatively, we could introduce a per kmem cache flag disabling
accounting for all allocations of a particular kind, but (a) we would not
be able to bypass accounting for kmalloc then and (b) a kmem cache with
this flag set could not be merged with a kmem cache without this flag,
which would increase the number of global caches and therefore
fragmentation even if the memory cgroup controller is not used.

Despite its generic name, currently __GFP_NOACCOUNT disables accounting
only for kmem allocations while user page allocations are always charged.
To catch abusing of this flag, a warning is issued on an attempt of
passing it to mem_cgroup_try_charge.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>	[4.0.x]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-14 17:55:51 -07:00
Andrey Ryabinin e79ed2f13f kmemleak: disable kasan instrumentation for kmemleak
kmalloc internally round up allocation size, and kmemleak uses rounded up
size as object's size.  This makes kasan to complain while kmemleak scans
memory or calculates of object's checksum.  The simplest solution here is
to disable kasan.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-02-13 21:21:41 -08:00
Catalin Marinas ffe2c748e2 mm: introduce kmemleak_update_trace()
The memory allocation stack trace is not always useful for debugging a
memory leak (e.g.  radix_tree_preload).  This function, when called,
updates the stack trace for an already allocated object.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06 16:08:17 -07:00
Jianpeng Ma aae0ad7ae5 mm/kmemleak.c: use %u to print ->checksum
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-06 16:08:17 -07:00
Vladimir Davydov bfc8c90139 mem-hotplug: implement get/put_online_mems
kmem_cache_{create,destroy,shrink} need to get a stable value of
cpu/node online mask, because they init/destroy/access per-cpu/node
kmem_cache parts, which can be allocated or destroyed on cpu/mem
hotplug.  To protect against cpu hotplug, these functions use
{get,put}_online_cpus.  However, they do nothing to synchronize with
memory hotplug - taking the slab_mutex does not eliminate the
possibility of race as described in patch 2.

What we need there is something like get_online_cpus, but for memory.
We already have lock_memory_hotplug, which serves for the purpose, but
it's a bit of a hammer right now, because it's backed by a mutex.  As a
result, it imposes some limitations to locking order, which are not
desirable, and can't be used just like get_online_cpus.  That's why in
patch 1 I substitute it with get/put_online_mems, which work exactly
like get/put_online_cpus except they block not cpu, but memory hotplug.

[ v1 can be found at https://lkml.org/lkml/2014/4/6/68.  I NAK'ed it by
  myself, because it used an rw semaphore for get/put_online_mems,
  making them dead lock prune.  ]

This patch (of 2):

{un}lock_memory_hotplug, which is used to synchronize against memory
hotplug, is currently backed by a mutex, which makes it a bit of a
hammer - threads that only want to get a stable value of online nodes
mask won't be able to proceed concurrently.  Also, it imposes some
strong locking ordering rules on it, which narrows down the set of its
usage scenarios.

This patch introduces get/put_online_mems, which are the same as
get/put_online_cpus, but for memory hotplug, i.e.  executing a code
inside a get/put_online_mems section will guarantee a stable value of
online nodes, present pages, etc.

lock_memory_hotplug()/unlock_memory_hotplug() are removed altogether.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Jiang Liu <liuj97@gmail.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-06-04 16:53:59 -07:00
Catalin Marinas 3551a9280b mm: postpone the disabling of kmemleak early logging
Commit 8910ae896c ("kmemleak: change some global variables to int"),
in addition to the atomic -> int conversion, moved the disabling of
kmemleak_early_log to the beginning of the kmemleak_init() function,
before the full kmemleak tracing is actually enabled.  In this small
window, kmem_cache_create() is called by kmemleak which triggers
additional memory allocation that are not traced.  This patch restores
the original logic with kmemleak_early_log disabling when kmemleak is
fully functional.

Fixes: 8910ae896c (kmemleak: change some global variables to int)

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Li Zefan <lizefan@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-05-11 17:55:48 +09:00
Li Zefan 8910ae896c kmemleak: change some global variables to int
They don't have to be atomic_t, because they are simple boolean toggles.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:20:50 -07:00
Li Zefan 5f3bf19aeb kmemleak: remove redundant code
Remove kmemleak_padding() and kmemleak_release().

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:20:50 -07:00
Li Zefan c89da70c73 kmemleak: allow freeing internal objects after kmemleak was disabled
Currently if kmemleak is disabled, the kmemleak objects can never be
freed, no matter if it's disabled by a user or due to fatal errors.

Those objects can be a big waste of memory.

    OBJS ACTIVE  USE OBJ SIZE  SLABS OBJ/SLAB CACHE SIZE NAME
  1200264 1197433  99%    0.30K  46164       26    369312K kmemleak_object

With this patch, after kmemleak was disabled you can reclaim memory
with:

	# echo clear > /sys/kernel/debug/kmemleak

Also inform users about this with a printk.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:20:50 -07:00
Li Zefan dc9b3f4249 kmemleak: free internal objects only if there're no leaks to be reported
Currently if you stop kmemleak thread before disabling kmemleak,
kmemleak objects will be freed and so you won't be able to check
previously reported leaks.

With this patch, kmemleak objects won't be freed if there're leaks that
can be reported.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03 16:20:50 -07:00
Catalin Marinas 7f88f88f83 mm: kmemleak: avoid false negatives on vmalloc'ed objects
Commit 248ac0e194 ("mm/vmalloc: remove guard page from between vmap
blocks") had the side effect of making vmap_area.va_end member point to
the next vmap_area.va_start.  This was creating an artificial reference
to vmalloc'ed objects and kmemleak was rarely reporting vmalloc() leaks.

This patch marks the vmap_area containing pointers explicitly and
reduces the min ref_count to 2 as vm_struct still contains a reference
to the vmalloc'ed object.  The kmemleak add_scan_area() function has
been improved to allow a SIZE_MAX argument covering the rest of the
object (for simpler calling sites).

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-13 12:09:07 +09:00
Jingoo Han 3dbb95f789 mm: replace strict_strtoul() with kstrtoul()
The use of strict_strtoul() is not preferred, because strict_strtoul() is
obsolete.  Thus, kstrtoul() should be used.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-09-11 15:57:11 -07:00
Sasha Levin b67bfe0d42 hlist: drop the node parameter from iterators
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:24 -08:00
Cody P Schafer 108bcc96ef mm: add & use zone_end_pfn() and zone_spans_pfn()
Add 2 helpers (zone_end_pfn() and zone_spans_pfn()) to reduce code
duplication.

This also switches to using them in compaction (where an additional
variable needed to be renamed), page_alloc, vmstat, memory_hotplug, and
kmemleak.

Note that in compaction.c I avoid calling zone_end_pfn() repeatedly
because I expect at some point the sycronization issues with start_pfn &
spanned_pages will need fixing, either by actually using the seqlock or
clever memory barrier usage.

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: David Hansen <dave@linux.vnet.ibm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23 17:50:20 -08:00
Abhijit Pawar dc053733ea mm/kmemleak.c: remove obsolete simple_strtoul
Replace the obsolete simple_strtoul() with kstrtoul().

Signed-off-by: Abhijit Pawar <abhi.c.pawar@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-12-18 15:02:15 -08:00
Michel Lespinasse 85d3a316c7 kmemleak: use rbtree instead of prio tree
kmemleak uses a tree where each node represents an allocated memory object
in order to quickly find out what object a given address is part of.
However, the objects don't overlap, so rbtrees are a better choice than
prio tree for this use.  They are both faster and have lower memory
overhead.

Tested by booting a kernel with kmemleak enabled, loading the
kmemleak_test module, and looking for the expected messages.

Signed-off-by: Michel Lespinasse <walken@google.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-10-09 16:22:39 +09:00
Michael Wang 58fac09566 kmemleak: Replace list_for_each_continue_rcu with new interface
This patch replaces list_for_each_continue_rcu() with
list_for_each_entry_continue_rcu() to save a few lines
of code and allow removing list_for_each_continue_rcu().

Signed-off-by: Michael Wang <wangyun@linux.vnet.ibm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2012-09-23 07:42:52 -07:00
Catalin Marinas b370d29ea7 kmemleak: Disable early logging when kmemleak is off by default
Commit b6693005 (kmemleak: When the early log buffer is exceeded, report
the actual number) deferred the disabling of the early logging to
kmemleak_init(). However, when CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y, the
early logging was no longer disabled causing __init kmemleak functions
to be called even after the kernel freed the init memory. This patch
disables the early logging during kmemleak_init() if kmemleak is left
disabled.

Reported-by: Dirk Gouders <gouders@et.bocholt.fh-gelsenkirchen.de>
Tested-by: Dirk Gouders <gouders@et.bocholt.fh-gelsenkirchen.de>
Tested-by: Josh Boyer <jwboyer@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-01-20 16:57:05 +00:00
Tiejun Chen b469d4329c kmemleak: Only scan non-zero-size areas
Kmemleak should only track valid scan areas with a non-zero size.
Otherwise, such area may reside just at the end of an object and
kmemleak would report "Adding scan area to unknown object".

Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-01-20 16:54:35 +00:00
Laura Abbott 029aeff5db kmemleak: Add support for memory hotplug
Ensure that memory hotplug can co-exist with kmemleak
by taking the hotplug lock before scanning the memory
banks.

Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2011-12-02 16:12:42 +00:00
Catalin Marinas f528f0b8e5 kmemleak: Handle percpu memory allocation
This patch adds kmemleak callbacks from the percpu allocator, reducing a
number of false positives caused by kmemleak not scanning such memory
blocks. The percpu chunks are never reported as leaks because of current
kmemleak limitations with the __percpu pointer not pointing directly to
the actual chunks.

Reported-by: Huajun Li <huajun.li.lee@gmail.com>
Acked-by: Christoph Lameter <cl@gentwo.org>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2011-12-02 16:12:42 +00:00
Catalin Marinas 74341703ed kmemleak: Report previously found leaks even after an error
If an error fatal to kmemleak (like memory allocation failure) happens,
kmemleak disables itself but it also removes the access to any
previously found memory leaks. This patch allows read-only access to the
kmemleak debugfs interface but disables any other action.

Reported-by: Nick Bowler <nbowler@elliptictech.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2011-12-02 16:12:42 +00:00
Catalin Marinas b66930052a kmemleak: When the early log buffer is exceeded, report the actual number
Just telling that the early log buffer has been exceeded doesn't mean
much. This patch moves the error printing to the kmemleak_init()
function and displays the actual calls to the kmemleak API during early
logging.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2011-12-02 16:12:42 +00:00
Catalin Marinas 5f79020cb9 kmemleak: Show where early_log issues come from
Based on initial patch by Steven Rostedt.

Early kmemleak warnings did not show where the actual kmemleak API had
been called from but rather just a backtrace to the kmemleak_init()
function. By having all early kmemleak logs record the stack_trace, we
can have kmemleak_init() write exactly where the problem occurred. This
patch adds the setting of the kmemleak_warning variable every time a
kmemleak warning is issued. The kmemleak_init() function checks this
variable during early log replaying and prints the log trace if there
was any warning.

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Andrew Morton <akpm@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-02 16:12:41 +00:00
Paul Gortmaker b95f1b31b7 mm: Map most files to use export.h instead of module.h
The files changed within are only using the EXPORT_SYMBOL
macro variants.  They are not using core modular infrastructure
and hence don't need module.h but only the export.h header.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 09:20:12 -04:00
Arun Sharma 60063497a9 atomic: use <linux/atomic.h>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>

Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26 16:49:47 -07:00
Catalin Marinas 52c3ce4ec5 kmemleak: Do not return a pointer to an object that kmemleak did not get
The kmemleak_seq_next() function tries to get an object (and increment
its use count) before returning it. If it could not get the last object
during list traversal (because it may have been freed), the function
should return NULL rather than a pointer to such object that it did not
get.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: <stable@kernel.org>
2011-05-19 17:35:28 +01:00
Lucas De Marchi 25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
Catalin Marinas 6ae4bd1f0b kmemleak: Allow kmemleak metadata allocations to fail
This patch adds __GFP_NORETRY and __GFP_NOMEMALLOC flags to the kmemleak
metadata allocations so that it has a smaller effect on the users of the
kernel slab allocator. Since kmemleak allocations can now fail more
often, this patch also reduces the verbosity by passing __GFP_NOWARN and
not dumping the stack trace when a kmemleak allocation fails.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Toralf Förster <toralf.foerster@gmx.de>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Ted Ts'o <tytso@mit.edu>
2011-01-27 18:32:06 +00:00
Holger Hans Peter Freyther 145b64b958 kmemleak: Fix typo in the comment
Fix typo in comment.

Signed-off-by: Holger Hans Peter Freyther <zecke@selfish.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2010-08-08 21:57:23 +01:00
Catalin Marinas a2b6bf63cb kmemleak: Add DocBook style comments to kmemleak.c
The description and parameters of the kmemleak API weren't obvious. This
patch adds comments clarifying the API usage.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-07-19 11:54:17 +01:00
Jason Baron ab0155a22a kmemleak: Introduce a default off mode for kmemleak
Introduce a new DEBUG_KMEMLEAK_DEFAULT_OFF config parameter that allows
kmemleak to be disabled by default, but enabled on the command line
via: kmemleak=on. Although a reboot is required to turn it on, its still
useful to not require a re-compile.

Signed-off-by: Jason Baron <jbaron@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-07-19 11:54:17 +01:00
Catalin Marinas a7686a45c0 kmemleak: Show more information for objects found by alias
There may be situations when an object is freed using a pointer inside
the memory block. Kmemleak should show more information to help with
debugging.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-07-19 11:54:16 +01:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
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 -> 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 <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Linus Torvalds dcc7cd0112 Merge branch 'kmemleak' of git://linux-arm.org/linux-2.6
* '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
2009-12-17 16:00:19 -08:00
Uwe Kleine-Knig 21ae2956ce tree-wide: fix typos "aquire" -> "acquire", "cumsumed" -> "consumed"
This patch was generated by

	git grep -E -i -l '[Aa]quire' | xargs -r perl -p -i -e 's/([Aa])quire/$1cquire/'

and the cumsumed was found by checking the diff for aquire.

Signed-off-by: Uwe Kleine-Knig <u.kleine-koenig@pengutronix.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-09 09:40:57 +01:00
Catalin Marinas 04609ccc40 kmemleak: Reduce the false positives by checking for modified objects
If an object was modified since it was previously suspected as leak, do
not report it. The modification check is done by calculating the
checksum (CRC32) of such object.

Several false positives are caused by objects being removed from linked
lists (e.g. allocation pools) and temporarily breaking the reference
chain since kmemleak runs concurrently with such list mutation
primitives.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-10-28 17:07:54 +00:00
Catalin Marinas fefdd336b2 kmemleak: Show the age of an unreferenced object
The jiffies shown for unreferenced objects isn't always meaningful to
people debugging kernel memory leaks. This patch adds the age as well to
the displayed information.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-10-28 17:07:54 +00:00
Catalin Marinas 0587da40be kmemleak: Release the object lock before calling put_object()
The put_object() function may free the object if the use_count
dropped to 0. There shouldn't be further accesses to such object unless
it is known that the use_count is non-zero.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-10-28 17:07:54 +00:00
Catalin Marinas c017b4be3e kmemleak: Simplify the kmemleak_scan_area() function prototype
This function was taking non-necessary arguments which can be determined
by kmemleak. The patch also modifies the calling sites.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
2009-10-28 15:11:00 +00:00
Catalin Marinas 0d5d1aadc8 kmemleak: Check for NULL pointer returned by create_object()
This patch adds NULL pointer checking in the early_alloc() function.

Reported-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-09 13:28:47 -07:00
Tetsuo Handa c1bcd6b327 kmemleak: Use GFP_ATOMIC for early_alloc().
We can't use GFP_KERNEL inside rcu_read_lock().

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-09 13:28:47 -07:00
Catalin Marinas addd72c1a9 kmemleak: Improve the "Early log buffer exceeded" error message
Based on a suggestion from Jaswinder, clarify what the user would need
to do to avoid this error message from kmemleak.

Reported-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-09-11 10:42:09 +01:00
Luis R. Rodriguez 7eb0d5e5be kmemleak: fix sparse warning for static declarations
This fixes these sparse warnings:

mm/kmemleak.c:1179:6: warning: symbol 'start_scan_thread' was not declared. Should it be static?
mm/kmemleak.c:1194:6: warning: symbol 'stop_scan_thread' was not declared. Should it be static?

Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-09-08 17:34:07 +01:00
Luis R. Rodriguez 0580a1819c kmemleak: fix sparse warning over overshadowed flags
A secondary irq_save is not required as a locking before it was
already disabling irqs.

This fixes this sparse warning:
mm/kmemleak.c:512:31: warning: symbol 'flags' shadows an earlier one
mm/kmemleak.c:448:23: originally declared here

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Acked-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-09-08 17:34:06 +01:00
Luis R. Rodriguez a1084c8779 kmemleak: move common painting code together
When painting grey or black we do the same thing, bring
this together into a helper and identify coloring grey or
black explicitly with defines. This makes this a little
easier to read.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-09-08 17:22:20 +01:00
Luis R. Rodriguez 30b3710105 kmemleak: add clear command support
In an ideal world your kmemleak output will be small, when its
not (usually during initial bootup) you can use the clear command
to ingore previously reported and unreferenced kmemleak objects. We
do this by painting all currently reported unreferenced objects grey.
We paint them grey instead of black to allow future scans on the same
objects as such objects could still potentially reference newly
allocated objects in the future.

To test a critical section on demand with a clean
/sys/kernel/debug/kmemleak you can do:

echo clear > /sys/kernel/debug/kmemleak
        test your kernel or modules
echo scan > /sys/kernel/debug/kmemleak

Then as usual to get your report with:

cat /sys/kernel/debug/kmemleak

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-09-08 16:36:08 +01:00