- 09 9月, 2015 1 次提交
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由 Sergey Senozhatsky 提交于
mempool_destroy() does not tolerate a NULL mempool_t pointer argument and performs a NULL-pointer dereference. This requires additional attention and effort from developers/reviewers and forces all mempool_destroy() callers to do a NULL check if (pool) mempool_destroy(pool); Or, otherwise, be invalid mempool_destroy() users. Tweak mempool_destroy() and NULL-check the pointer there. Proposed by Andrew Morton. Link: https://lkml.org/lkml/2015/6/8/583Signed-off-by: NSergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: NDavid Rientjes <rientjes@google.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Cc: Joe Perches <joe@perches.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 16 4月, 2015 3 次提交
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由 Andrey Ryabinin 提交于
Mempools keep allocated objects in reserved for situations when ordinary allocation may not be possible to satisfy. These objects shouldn't be accessed before they leave the pool. This patch poison elements when get into the pool and unpoison when they leave it. This will let KASan to detect use-after-free of mempool's elements. Signed-off-by: NAndrey Ryabinin <a.ryabinin@samsung.com> Tested-by: NDavid Rientjes <rientjes@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Chernenkov <drcheren@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
Mempools keep elements in a reserved pool for contexts in which allocation may not be possible. When an element is allocated from the reserved pool, its memory contents is the same as when it was added to the reserved pool. Because of this, elements lack any free poisoning to detect use-after-free errors. This patch adds free poisoning for elements backed by the slab allocator. This is possible because the mempool layer knows the object size of each element. When an element is added to the reserved pool, it is poisoned with POISON_FREE. When it is removed from the reserved pool, the contents are checked for POISON_FREE. If there is a mismatch, a warning is emitted to the kernel log. This is only effective for configs with CONFIG_DEBUG_SLAB or CONFIG_SLUB_DEBUG_ON. [fabio.estevam@freescale.com: use '%zu' for printing 'size_t' variable] [arnd@arndb.de: add missing include] Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com> Signed-off-by: NArnd Bergmann <arnd@arndb.de> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
All occurrences of mempools based on slab caches with object constructors have been removed from the tree, so disallow creating them. We can only dereference mem->ctor in mm/mempool.c without including mm/slab.h in include/linux/mempool.h. So simply note the restriction, just like the comment restricting usage of __GFP_ZERO, and warn on kernels with CONFIG_DEBUG_VM() if such a mempool is allocated from. We don't want to incur this check on every element allocation, so use VM_BUG_ON(). Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 15 4月, 2015 1 次提交
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由 David Rientjes 提交于
Allocating a large number of elements in atomic context could quickly deplete memory reserves, so just disallow atomic resizing entirely. Nothing currently uses mempool_resize() with anything other than GFP_KERNEL, so convert existing callers to drop the gfp_mask. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NDavid Rientjes <rientjes@google.com> Acked-by: Steffen Maier <maier@linux.vnet.ibm.com> [zfcp] Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Steve French <sfrench@samba.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 07 6月, 2014 1 次提交
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由 Catalin Marinas 提交于
When mempool_alloc() returns an existing pool object, kmemleak_alloc() is no longer called and the stack trace corresponds to the original object allocation. This patch updates the kmemleak allocation stack trace for such objects to make it more useful for debugging. Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 05 6月, 2014 1 次提交
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由 Sebastian Ott 提交于
Memory obtained via mempool_alloc is not always zeroed even when called with __GFP_ZERO. Add a note and VM_BUG_ON statement to make that clear. [akpm@linux-foundation.org: use VM_WARN_ON_ONCE] Signed-off-by: NSebastian Ott <sebott@linux.vnet.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 08 4月, 2014 1 次提交
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由 Mikulas Patocka 提交于
Add unlikely and likely hints to the function mempool_free. It lays out the code in such a way that the common path is executed straighforward and saves a cache line. Signed-off-by: NMikulas Patocka <mpatocka@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 9月, 2013 1 次提交
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由 Joe Perches 提交于
Use the helper function instead of __GFP_ZERO. Signed-off-by: NJoe Perches <joe@perches.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 25 6月, 2012 1 次提交
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由 Tejun Heo 提交于
mempool_create_node() currently assumes %GFP_KERNEL. Its only user, blk_init_free_list(), is about to be updated to use other allocation flags - add @gfp_mask argument to the function. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NJens Axboe <axboe@kernel.dk>
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- 11 1月, 2012 3 次提交
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由 Tejun Heo 提交于
mempool modifies gfp_mask so that the backing allocator doesn't try too hard or trigger warning message when there's pool to fall back on. In addition, for the first try, it removes __GFP_WAIT and IO, so that it doesn't trigger reclaim or wait when allocation can be fulfilled from pool; however, when that allocation fails and pool is empty too, it waits for the pool to be replenished before retrying. Allocation which could have succeeded after a bit of reclaim has to wait on the reserved items and it's not like mempool doesn't retry with __GFP_WAIT and IO. It just does that *after* someone returns an element, pointlessly delaying things. Fix it by retrying immediately if the first round of allocation attempts w/o __GFP_WAIT and IO fails. [akpm@linux-foundation.org: shorten the lock hold time] Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Tejun Heo 提交于
mempool_destroy() is a thin wrapper around free_pool(). The only thing it adds is BUG_ON(pool->curr_nr != pool->min_nr). The intention seems to be to enforce that all allocated elements are freed; however, the BUG_ON() can't achieve that (it doesn't know anything about objects above min_nr) and incorrect as mempool_resize() is allowed to leave the pool extended but not filled. Furthermore, panicking is way worse than any memory leak and there are better debug tools to track memory leaks. Drop the BUG_ON() from mempool_destory() and as that leaves the function identical to free_pool(), replace it. Signed-off-by: NTejun Heo <tj@kernel.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Tejun Heo 提交于
mempool_alloc/free() use undocumented smp_mb()'s. The code is slightly broken and misleading. The lockless part is in mempool_free(). It wants to determine whether the item being freed needs to be returned to the pool or backing allocator without grabbing pool->lock. Two things need to be guaranteed for correct operation. 1. pool->curr_nr + #allocated should never dip below pool->min_nr. 2. Waiters shouldn't be left dangling. For #1, The only necessary condition is that curr_nr visible at free is from after the allocation of the element being freed (details in the comment). For most cases, this is true without any barrier but there can be fringe cases where the allocated pointer is passed to the freeing task without going through memory barriers. To cover this case, wmb is necessary before returning from allocation and rmb is necessary before reading curr_nr. IOW, ALLOCATING TASK FREEING TASK update pool state after alloc; wmb(); pass pointer to freeing task; read pointer; rmb(); read pool state to free; The current code doesn't have wmb after pool update during allocation and may theoretically, on machines where unlock doesn't behave as full wmb, lead to pool depletion and deadlock. smp_wmb() needs to be added after successful allocation from reserved elements and smp_mb() in mempool_free() can be replaced with smp_rmb(). For #2, the waiter needs to add itself to waitqueue and then check the wait condition and the waker needs to update the wait condition and then wake up. Because waitqueue operations always go through full spinlock synchronization, there is no need for extra memory barriers. Furthermore, mempool_alloc() is already holding pool->lock when it decides that it needs to wait. There is no reason to do unlock - add waitqueue - test condition again. It can simply add itself to waitqueue while holding pool->lock and then unlock and sleep. This patch adds smp_wmb() after successful allocation from reserved pool, replaces smp_mb() in mempool_free() with smp_rmb() and extend pool->lock over waitqueue addition. More importantly, it explains what memory barriers do and how the lockless testing is correct. -v2: Oleg pointed out that unlock doesn't imply wmb. Added explicit smp_wmb() after successful allocation from reserved pool and updated comments accordingly. Signed-off-by: NTejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 31 10月, 2011 1 次提交
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由 Paul Gortmaker 提交于
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: NPaul Gortmaker <paul.gortmaker@windriver.com>
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- 22 9月, 2009 1 次提交
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由 Sage Weil 提交于
The kzalloc mempool zeros items when they are initially allocated, but does not rezero used items that are returned to the pool. Consequently mempool_alloc()s may return non-zeroed memory. Since there are/were only two in-tree users for mempool_create_kzalloc_pool(), and 'fixing' this in a way that will re-zero used (but not new) items before first use is non-trivial, just remove it. Signed-off-by: NSage Weil <sage@newdream.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 10 8月, 2009 1 次提交
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由 Figo.zhang 提交于
clean up type-casting twice. "size_t" is typedef as "unsigned long" in 64-bit system, and "unsigned int" in 32-bit system, and the intermediate cast to 'long' is pointless. Signed-off-by: NFigo.zhang <figo1802@gmail.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 20 10月, 2007 1 次提交
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由 Simon Arlott 提交于
Spelling fixes in mm/. Signed-off-by: NSimon Arlott <simon@fire.lp0.eu> Signed-off-by: NAdrian Bunk <bunk@kernel.org>
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- 18 7月, 2007 1 次提交
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由 Christoph Lameter 提交于
kmalloc_node() and kmem_cache_alloc_node() were not available in a zeroing variant in the past. But with __GFP_ZERO it is possible now to do zeroing while allocating. Use __GFP_ZERO to remove the explicit clearing of memory via memset whereever we can. Signed-off-by: NChristoph Lameter <clameter@sgi.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 17 7月, 2007 1 次提交
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由 Rusty Russell 提交于
Christian Borntraeger points out that mempool_free() doesn't noop when handed NULL. This is inconsistent with the other free-like functions in the kernel. Signed-off-by: NRusty Russell <rusty@rustcorp.com.au> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 12 2月, 2007 1 次提交
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由 Robert P. J. Day 提交于
A variety of (mostly) innocuous fixes to the embedded kernel-doc content in source files, including: * make multi-line initial descriptions single line * denote some function names, constants and structs as such * change erroneous opening '/*' to '/**' in a few places * reword some text for clarity Signed-off-by: NRobert P. J. Day <rpjday@mindspring.com> Cc: "Randy.Dunlap" <rdunlap@xenotime.net> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 02 9月, 2006 1 次提交
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由 Pavel Mironchik 提交于
This patch works around a complex dm-related deadlock/livelock down in the mempool allocator. Alasdair said: Several dm targets suffer from this. Mempools are not yet used correctly everywhere in device-mapper: they can get shared when devices are stacked, and some targets share them across multiple instances. I made fixing this one of the prerequisites for this patch: md-dm-reduce-stack-usage-with-stacked-block-devices.patch which in some cases makes people more likely to hit the problem. There's been some progress on this recently with (unfinished) dm-crypt patches at: http://www.kernel.org/pub/linux/kernel/people/agk/patches/2.6/editing/ (dm-crypt-move-io-to-workqueue.patch plus dependencies) and: I've no problems with a temporary workaround like that, but Milan Broz (a new Redhat developer in the Czech Republic) has started reviewing all the mempool usage in device-mapper so I'm expecting we'll soon have a proper fix for this associated problems. [He's back from holiday at the start of next week.] For now, this sad-but-safe little patch will allow the machine to recover. [akpm@osdl.org: rewrote changelog] Cc: Alasdair G Kergon <agk@redhat.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 27 3月, 2006 4 次提交
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由 Matthew Dobson 提交于
Add another allocator to the common mempool code: a kzalloc/kfree allocator This will be used by the next patch in the series to replace a mempool-backed kzalloc allocator. It is also very likely that there will be more users in the future. Signed-off-by: NMatthew Dobson <colpatch@us.ibm.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Matthew Dobson 提交于
Add another allocator to the common mempool code: a kmalloc/kfree allocator This will be used by the next patch in the series to replace duplicate mempool-backed kmalloc allocators in several places in the kernel. It is also very likely that there will be more users in the future. Signed-off-by: NMatthew Dobson <colpatch@us.ibm.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Matthew Dobson 提交于
This will be used by the next patch in the series to replace duplicate mempool-backed page allocators in 2 places in the kernel. It is also likely that there will be more users in the future. Signed-off-by: NMatthew Dobson <colpatch@us.ibm.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Eric Sesterhenn 提交于
this changes if() BUG(); constructs to BUG_ON() which is cleaner, contains unlikely() and can better optimized away. Signed-off-by: NEric Sesterhenn <snakebyte@gmx.de> Signed-off-by: NAdrian Bunk <bunk@stusta.de>
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- 22 3月, 2006 1 次提交
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由 Pekka Enberg 提交于
We have struct kmem_cache now so use it instead of the old typedef. Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 28 10月, 2005 1 次提交
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由 Al Viro 提交于
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 09 10月, 2005 1 次提交
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由 Al Viro 提交于
- added typedef unsigned int __nocast gfp_t; - replaced __nocast uses for gfp flags with gfp_t - it gives exactly the same warnings as far as sparse is concerned, doesn't change generated code (from gcc point of view we replaced unsigned int with typedef) and documents what's going on far better. Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 08 7月, 2005 1 次提交
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由 Alexey Dobriyan 提交于
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 24 6月, 2005 2 次提交
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由 Benjamin LaHaise 提交于
Here's a small patch to improve the performance of mempool_alloc by only initializing the wait queue when we're about to wait. Signed-off-by: NBenjamin LaHaise <benjamin.c.lahaise@intel.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Christoph Lameter 提交于
Patch to allocate the control structures for for ide devices on the node of the device itself (for NUMA systems). The patch depends on the Slab API change patch by Manfred and me (in mm) and the pcidev_to_node patch that I posted today. Does some realignment too. Signed-off-by: NJustin M. Forbes <jmforbes@linuxtx.org> Signed-off-by: NChristoph Lameter <christoph@lameter.com> Signed-off-by: NPravin Shelar <pravin@calsoftinc.com> Signed-off-by: NShobhit Dayal <shobhit@calsoftinc.com> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 01 5月, 2005 3 次提交
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由 akpm@osdl.org 提交于
Replace a number of memory barriers with smp_ variants. This means we won't take the unnecessary hit on UP machines. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Nick Piggin 提交于
Mempool is pretty clever. Looks too clever for its own good :) It shouldn't really know so much about page reclaim internals. - don't guess about what effective page reclaim might involve. - don't randomly flush out all dirty data if some unlikely thing happens (alloc returns NULL). page reclaim can (sort of :P) handle it. I think the main motivation is trying to avoid pool->lock at all costs. However the first allocation is attempted with __GFP_WAIT cleared, so it will be 'can_try_harder' if it hits the page allocator. So if allocation still fails, then we can probably afford to hit the pool->lock - and what's the alternative? Try page reclaim and hit zone->lru_lock? A nice upshot is that we don't need to do any fancy memory barriers or do (intentionally) racy access to pool-> fields outside the lock. Signed-off-by: NNick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 Nick Piggin 提交于
Mempools have 2 problems. The first is that mempool_alloc can possibly get stuck in __alloc_pages when they should opt to fail, and take an element from their reserved pool. The second is that it will happily eat emergency PF_MEMALLOC reserves instead of going to their reserved pools. Fix the first by passing __GFP_NORETRY in the allocation calls in mempool_alloc. Fix the second by introducing a __GFP_MEMPOOL flag which directs the page allocator not to allocate from the reserve pool. Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 17 4月, 2005 1 次提交
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由 Linus Torvalds 提交于
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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