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2015-06-25mm: kmemleak: allow safe memory scanning during kmemleak disablingCatalin Marinas1-3/+16
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>
2015-05-15gfp: add __GFP_NOACCOUNTVladimir Davydov1-1/+2
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>
2015-02-14kmemleak: disable kasan instrumentation for kmemleakAndrey Ryabinin1-0/+6
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>
2014-06-07mm: introduce kmemleak_update_trace()Catalin Marinas1-0/+34
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>
2014-06-07mm/kmemleak.c: use %u to print ->checksumJianpeng Ma1-1/+1
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>
2014-06-05mem-hotplug: implement get/put_online_memsVladimir Davydov1-2/+2
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>
2014-05-11mm: postpone the disabling of kmemleak early loggingCatalin Marinas1-2/+2
Commit 8910ae896c8c ("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: 8910ae896c8c (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>
2014-04-04kmemleak: change some global variables to intLi Zefan1-40/+40
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>
2014-04-04kmemleak: remove redundant codeLi Zefan1-6/+1
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>
2014-04-04kmemleak: allow freeing internal objects after kmemleak was disabledLi Zefan1-14/+32
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>
2014-04-04kmemleak: free internal objects only if there're no leaks to be reportedLi Zefan1-4/+9
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>
2013-11-13mm: kmemleak: avoid false negatives on vmalloc'ed objectsCatalin Marinas1-1/+3
Commit 248ac0e1943a ("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>
2013-09-12mm: replace strict_strtoul() with kstrtoul()Jingoo Han1-1/+1
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>
2013-02-28hlist: drop the node parameter from iteratorsSasha Levin1-5/+4
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>
2013-02-24mm: add & use zone_end_pfn() and zone_spans_pfn()Cody P Schafer1-3/+2
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>
2012-12-19mm/kmemleak.c: remove obsolete simple_strtoulAbhijit Pawar1-1/+2
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>
2012-10-09kmemleak: use rbtree instead of prio treeMichel Lespinasse1-49/+51
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>
2012-09-23kmemleak: Replace list_for_each_continue_rcu with new interfaceMichael Wang1-4/+2
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>
2012-01-20kmemleak: Disable early logging when kmemleak is off by defaultCatalin Marinas1-0/+1
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>
2012-01-20kmemleak: Only scan non-zero-size areasTiejun Chen1-1/+1
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>
2011-12-02kmemleak: Add support for memory hotplugLaura Abbott1-2/+4
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>
2011-12-02kmemleak: Handle percpu memory allocationCatalin Marinas1-0/+72
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>
2011-12-02kmemleak: Report previously found leaks even after an errorCatalin Marinas1-9/+13
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>
2011-12-02kmemleak: When the early log buffer is exceeded, report the actual numberCatalin Marinas1-6/+15
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>
2011-12-02kmemleak: Show where early_log issues come fromCatalin Marinas1-9/+28
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>
2011-10-31mm: Map most files to use export.h instead of module.hPaul Gortmaker1-1/+1
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>
2011-07-27atomic: use <linux/atomic.h>Arun Sharma1-1/+1
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>
2011-05-19kmemleak: Do not return a pointer to an object that kmemleak did not getCatalin Marinas1-2/+5
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>
2011-03-31Fix common misspellingsLucas De Marchi1-3/+3
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-01-27kmemleak: Allow kmemleak metadata allocations to failCatalin Marinas1-5/+8
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>
2010-08-09kmemleak: Fix typo in the commentHolger Hans Peter Freyther1-1/+1
Fix typo in comment. Signed-off-by: Holger Hans Peter Freyther <zecke@selfish.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2010-07-19kmemleak: Add DocBook style comments to kmemleak.cCatalin Marinas1-21/+59
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>
2010-07-19kmemleak: Introduce a default off mode for kmemleakJason Baron1-1/+13
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>
2010-07-19kmemleak: Show more information for objects found by aliasCatalin Marinas1-1/+3
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>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo1-1/+0
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>
2009-12-18Merge branch 'kmemleak' of git://linux-arm.org/linux-2.6Linus Torvalds1-87/+101
* '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
2009-11-09tree-wide: fix typos "aquire" -> "acquire", "cumsumed" -> "consumed"Uwe Kleine-König1-2/+2
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-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-10-28kmemleak: Reduce the false positives by checking for modified objectsCatalin Marinas1-54/+70
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>
2009-10-28kmemleak: Show the age of an unreferenced objectCatalin Marinas1-2/+4
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>
2009-10-28kmemleak: Release the object lock before calling put_object()Catalin Marinas1-3/+6
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>
2009-10-28kmemleak: Simplify the kmemleak_scan_area() function prototypeCatalin Marinas1-28/+21
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>
2009-10-10kmemleak: Check for NULL pointer returned by create_object()Catalin Marinas1-0/+3
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>
2009-10-10kmemleak: Use GFP_ATOMIC for early_alloc().Tetsuo Handa1-1/+1
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>
2009-09-11kmemleak: Improve the "Early log buffer exceeded" error messageCatalin Marinas1-1/+2
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>
2009-09-08kmemleak: fix sparse warning for static declarationsLuis R. Rodriguez1-2/+2
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>
2009-09-08kmemleak: fix sparse warning over overshadowed flagsLuis R. Rodriguez1-4/+3
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>
2009-09-08kmemleak: move common painting code togetherLuis R. Rodriguez1-28/+41
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>
2009-09-08kmemleak: add clear command supportLuis R. Rodriguez1-0/+26
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>
2009-09-08kmemleak: use bool for true/false questionsLuis R. Rodriguez1-4/+4
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>
2009-09-08kmemleak: Do no create the clean-up thread during kmemleak_disable()Catalin Marinas1-17/+5
The kmemleak_disable() function could be called from various contexts including IRQ. It creates a clean-up thread but the kthread_create() function has restrictions on which contexts it can be called from, mainly because of the kthread_create_lock. The patch changes the kmemleak clean-up thread to a workqueue. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Eric Paris <eparis@redhat.com>