- Dec 28, 2018
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Andrey Konovalov authored
Tag-based KASAN doesn't check memory accesses through pointers tagged with 0xff. When page_address is used to get pointer to memory that corresponds to some page, the tag of the resulting pointer gets set to 0xff, even though the allocated memory might have been tagged differently. For slab pages it's impossible to recover the correct tag to return from page_address, since the page might contain multiple slab objects tagged with different values, and we can't know in advance which one of them is going to get accessed. For non slab pages however, we can recover the tag in page_address, since the whole page was marked with the same tag. This patch adds tagging to non slab memory allocated with pagealloc. To set the tag of the pointer returned from page_address, the tag gets stored to page->flags when the memory gets allocated. Link: http://lkml.kernel.org/r/d758ddcef46a5abc9970182b9137e2fbee202a2c.1544099024.git.andreyknvl@google.com Signed-off-by:
Andrey Konovalov <andreyknvl@google.com> Reviewed-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by:
Dmitry Vyukov <dvyukov@google.com> Acked-by:
Will Deacon <will.deacon@arm.com> Cc: Christoph Lameter <cl@linux.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- Aug 17, 2018
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Marek Szyprowski authored
cma_alloc() doesn't really support gfp flags other than __GFP_NOWARN, so convert gfp_mask parameter to boolean no_warn parameter. This will help to avoid giving false feeling that this function supports standard gfp flags and callers can pass __GFP_ZERO to get zeroed buffer, what has already been an issue: see commit dd65a941 ("arm64: dma-mapping: clear buffers allocated with FORCE_CONTIGUOUS flag"). Link: http://lkml.kernel.org/r/20180709122019eucas1p2340da484acfcc932537e6014f4fd2c29~-sqTPJKij2939229392eucas1p2j@eucas1p2.samsung.com Signed-off-by:
Marek Szyprowski <m.szyprowski@samsung.com> Acked-by:
Michal Hocko <mhocko@suse.com> Acked-by:
Michał Nazarewicz <mina86@mina86.com> Acked-by:
Laura Abbott <labbott@redhat.com> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Reviewed-by:
Christoph Hellwig <hch@lst.de> Cc: Joonsoo Kim <js1304@gmail.com> Signed-off-by:
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- May 24, 2018
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Joonsoo Kim authored
This reverts the following commits that change CMA design in MM. 3d2054ad ("ARM: CMA: avoid double mapping to the CMA area if CONFIG_HIGHMEM=y") 1d47a3ec ("mm/cma: remove ALLOC_CMA") bad8c6c0 ("mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE") Ville reported a following error on i386. Inode-cache hash table entries: 65536 (order: 6, 262144 bytes) microcode: microcode updated early to revision 0x4, date = 2013-06-28 Initializing CPU#0 Initializing HighMem for node 0 (000377fe:00118000) Initializing Movable for node 0 (00000001:00118000) BUG: Bad page state in process swapper pfn:377fe page:f53effc0 count:0 mapcount:-127 mapping:00000000 index:0x0 flags: 0x80000000() raw: 80000000 00000000 00000000 ffffff80 00000000 00000100 00000200 00000001 page dumped because: nonzero mapcount Modules linked in: CPU: 0 PID: 0 Comm: swapper Not tainted 4.17.0-rc5-elk+ #145 Hardware name: Dell Inc. Latitude E5410/03VXMC, BIOS A15 07/11/2013 Call Trace: dump_stack+0x60/0x96 bad_page+0x9a/0x100 free_pages_check_bad+0x3f/0x60 free_pcppages_bulk+0x29d/0x5b0 free_unref_page_commit+0x84/0xb0 free_unref_page+0x3e/0x70 __free_pages+0x1d/0x20 free_highmem_page+0x19/0x40 add_highpages_with_active_regions+0xab/0xeb set_highmem_pages_init+0x66/0x73 mem_init+0x1b/0x1d7 start_kernel+0x17a/0x363 i386_start_kernel+0x95/0x99 startup_32_smp+0x164/0x168 The reason for this error is that the span of MOVABLE_ZONE is extended to whole node span for future CMA initialization, and, normal memory is wrongly freed here. I submitted the fix and it seems to work, but, another problem happened. It's so late time to fix the later problem so I decide to reverting the series. Reported-by:
Ville Syrjälä <ville.syrjala@linux.intel.com> Acked-by:
Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
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- Apr 11, 2018
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Joonsoo Kim authored
Patch series "mm/cma: manage the memory of the CMA area by using the ZONE_MOVABLE", v2. 0. History This patchset is the follow-up of the discussion about the "Introduce ZONE_CMA (v7)" [1]. Please reference it if more information is needed. 1. What does this patch do? This patch changes the management way for the memory of the CMA area in the MM subsystem. Currently the memory of the CMA area is managed by the zone where their pfn is belong to. However, this approach has some problems since MM subsystem doesn't have enough logic to handle the situation that different characteristic memories are in a single zone. To solve this issue, this patch try to manage all the memory of the CMA area by using the MOVABLE zone. In MM subsystem's point of view, characteristic of the memory on the MOVABLE zone and the memory of the CMA area are the same. So, managing the memory of the CMA area by using the MOVABLE zone will not have any problem. 2. Motivation There are some problems with current approach. See following. Although these problem would not be inherent and it could be fixed without this conception change, it requires many hooks addition in various code path and it would be intrusive to core MM and would be really error-prone. Therefore, I try to solve them with this new approach. Anyway, following is the problems of the current implementation. o CMA memory utilization First, following is the freepage calculation logic in MM. - For movable allocation: freepage = total freepage - For unmovable allocation: freepage = total freepage - CMA freepage Freepages on the CMA area is used after the normal freepages in the zone where the memory of the CMA area is belong to are exhausted. At that moment that the number of the normal freepages is zero, so - For movable allocation: freepage = total freepage = CMA freepage - For unmovable allocation: freepage = 0 If unmovable allocation comes at this moment, allocation request would fail to pass the watermark check and reclaim is started. After reclaim, there would exist the normal freepages so freepages on the CMA areas would not be used. FYI, there is another attempt [2] trying to solve this problem in lkml. And, as far as I know, Qualcomm also has out-of-tree solution for this problem. Useless reclaim: There is no logic to distinguish CMA pages in the reclaim path. Hence, CMA page is reclaimed even if the system just needs the page that can be usable for the kernel allocation. Atomic allocation failure: This is also related to the fallback allocation policy for the memory of the CMA area. Consider the situation that the number of the normal freepages is *zero* since the bunch of the movable allocation requests come. Kswapd would not be woken up due to following freepage calculation logic. - For movable allocation: freepage = total freepage = CMA freepage If atomic unmovable allocation request comes at this moment, it would fails due to following logic. - For unmovable allocation: freepage = total freepage - CMA freepage = 0 It was reported by Aneesh [3]. Useless compaction: Usual high-order allocation request is unmovable allocation request and it cannot be served from the memory of the CMA area. In compaction, migration scanner try to migrate the page in the CMA area and make high-order page there. As mentioned above, it cannot be usable for the unmovable allocation request so it's just waste. 3. Current approach and new approach Current approach is that the memory of the CMA area is managed by the zone where their pfn is belong to. However, these memory should be distinguishable since they have a strong limitation. So, they are marked as MIGRATE_CMA in pageblock flag and handled specially. However, as mentioned in section 2, the MM subsystem doesn't have enough logic to deal with this special pageblock so many problems raised. New approach is that the memory of the CMA area is managed by the MOVABLE zone. MM already have enough logic to deal with special zone like as HIGHMEM and MOVABLE zone. So, managing the memory of the CMA area by the MOVABLE zone just naturally work well because constraints for the memory of the CMA area that the memory should always be migratable is the same with the constraint for the MOVABLE zone. There is one side-effect for the usability of the memory of the CMA area. The use of MOVABLE zone is only allowed for a request with GFP_HIGHMEM && GFP_MOVABLE so now the memory of the CMA area is also only allowed for this gfp flag. Before this patchset, a request with GFP_MOVABLE can use them. IMO, It would not be a big issue since most of GFP_MOVABLE request also has GFP_HIGHMEM flag. For example, file cache page and anonymous page. However, file cache page for blockdev file is an exception. Request for it has no GFP_HIGHMEM flag. There is pros and cons on this exception. In my experience, blockdev file cache pages are one of the top reason that causes cma_alloc() to fail temporarily. So, we can get more guarantee of cma_alloc() success by discarding this case. Note that there is no change in admin POV since this patchset is just for internal implementation change in MM subsystem. Just one minor difference for admin is that the memory stat for CMA area will be printed in the MOVABLE zone. That's all. 4. Result Following is the experimental result related to utilization problem. 8 CPUs, 1024 MB, VIRTUAL MACHINE make -j16 <Before> CMA area: 0 MB 512 MB Elapsed-time: 92.4 186.5 pswpin: 82 18647 pswpout: 160 69839 <After> CMA : 0 MB 512 MB Elapsed-time: 93.1 93.4 pswpin: 84 46 pswpout: 183 92 akpm: "kernel test robot" reported a 26% improvement in vm-scalability.throughput: http://lkml.kernel.org/r/20180330012721.GA3845@yexl-desktop [1]: lkml.kernel.org/r/1491880640-9944-1-git-send-email-iamjoonsoo.kim@lge.com [2]: https://lkml.org/lkml/2014/10/15/623 [3]: http://www.spinics.net/lists/linux-mm/msg100562.html Link: http://lkml.kernel.org/r/1512114786-5085-2-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Tested-by:
Tony Lindgren <tony@atomide.com> Acked-by:
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- Apr 06, 2018
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Randy Dunlap authored
Currently <linux/slab.h> #includes <linux/kmemleak.h> for no obvious reason. It looks like it's only a convenience, so remove kmemleak.h from slab.h and add <linux/kmemleak.h> to any users of kmemleak_* that don't already #include it. Also remove <linux/kmemleak.h> from source files that do not use it. This is tested on i386 allmodconfig and x86_64 allmodconfig. It would be good to run it through the 0day bot for other $ARCHes. I have neither the horsepower nor the storage space for the other $ARCHes. Update: This patch has been extensively build-tested by both the 0day bot & kisskb/ozlabs build farms. Both of them reported 2 build failures for which patches are included here (in v2). [ slab.h is the second most used header file after module.h; kernel.h is right there with slab.h. There could be some minor error in the counting due to some #includes having comments after them and I didn't combine all of those. ] [akpm@linux-foundation.org: security/keys/big_key.c needs vmalloc.h, per sfr] Link: http://lkml.kernel.org/r/e4309f98-3749-93e1-4bb7-d9501a39d015@infradead.org Link: http://kisskb.ellerman.id.au/kisskb/head/13396/ Signed-off-by:
Randy Dunlap <rdunlap@infradead.org> Reviewed-by:
Ingo Molnar <mingo@kernel.org> Reported-by: Michael Ellerman <mpe@ellerman.id.au> [2 build failures] Reported-by: Fengguang Wu <fengguang.wu@intel.com> [2 build failures] Reviewed-by:
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Mike Rapoport authored
Link: http://lkml.kernel.org/r/1519585191-10180-4-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by:
Mike Rapoport <rppt@linux.vnet.ibm.com> Reviewed-by:
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- Nov 16, 2017
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Pintu Agarwal authored
It was observed that under cma_alloc fail log, pr_info was used instead of pr_err. This will lead to problems if printk debug level is set to below 7. In this case the cma_alloc failure log will not be captured in the log and it will be difficult to debug. Simply replace the pr_info with pr_err to capture failure log. Link: http://lkml.kernel.org/r/1507650633-4430-1-git-send-email-pintu.ping@gmail.com Signed-off-by:
Pintu Agarwal <pintu.ping@gmail.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jaewon Kim <jaewon31.kim@samsung.com> Cc: Doug Berger <opendmb@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
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- Oct 13, 2017
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Boris Brezillon authored
cma_alloc() unconditionally prints an INFO message when the CMA allocation fails. Make this message conditional on the non-presence of __GFP_NOWARN in gfp_mask. This patch aims at removing INFO messages that are displayed when the VC4 driver tries to allocate buffer objects. From the driver perspective an allocation failure is acceptable, and the driver can possibly do something to make following allocation succeed (like flushing the VC4 internal cache). Link: http://lkml.kernel.org/r/20171004125447.15195-1-boris.brezillon@free-electrons.com Signed-off-by:
Boris Brezillon <boris.brezillon@free-electrons.com> Acked-by:
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- Jul 10, 2017
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Doug Berger authored
The align_offset parameter is used by bitmap_find_next_zero_area_off() to represent the offset of map's base from the previous alignment boundary; the function ensures that the returned index, plus the align_offset, honors the specified align_mask. The logic introduced by commit b5be83e3 ("mm: cma: align to physical address, not CMA region position") has the cma driver calculate the offset to the *next* alignment boundary. In most cases, the base alignment is greater than that specified when making allocations, resulting in a zero offset whether we align up or down. In the example given with the commit, the base alignment (8MB) was half the requested alignment (16MB) so the math also happened to work since the offset is 8MB in both directions. However, when requesting allocations with an alignment greater than twice that of the base, the returned index would not be correctly aligned. Also, the align_order arguments of cma_bitmap_aligned_mask() and cma_bitmap_aligned_offset() should not be negative so the argument type was made unsigned. Fixes: b5be83e3 ("mm: cma: align to physical address, not CMA region position") Link: http://lkml.kernel.org/r/20170628170742.2895-1-opendmb@gmail.com Signed-off-by:
Angus Clark <angus@angusclark.org> Signed-off-by:
Doug Berger <opendmb@gmail.com> Acked-by:
Gregory Fong <gregory.0xf0@gmail.com> Cc: Doug Berger <opendmb@gmail.com> Cc: Angus Clark <angus@angusclark.org> Cc: Laura Abbott <labbott@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Shiraz Hashim <shashim@codeaurora.org> Cc: Jaewon Kim <jaewon31.kim@samsung.com> Signed-off-by:
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Anshuman Khandual authored
While activating a CMA area we check to make sure that all the PFNs in the range are inside the same zone. This is a requirement for alloc_contig_range() to work. Any CMA area failing the check is disabled for good. This happens silently right now making all future cma_alloc() allocations failure inevitable. Here we add an error message stating that the CMA area could not be activated which makes it easier to explain any future cma_alloc() failures on it. While in there, change the bail out goto label from 'err' to 'not_in_zone' which makes more sense. Link: http://lkml.kernel.org/r/20170605023729.26303-1-khandual@linux.vnet.ibm.com Signed-off-by:
Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
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- Apr 18, 2017
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Laura Abbott authored
Frameworks (e.g. Ion) may want to iterate over each possible CMA area to allow for enumeration. Introduce a function to allow a callback. Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Laura Abbott authored
Frameworks that may want to enumerate CMA heaps (e.g. Ion) will find it useful to have an explicit name attached to each region. Store the name in each CMA structure. Signed-off-by:
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- Feb 25, 2017
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Jaewon Kim authored
There are many reasons of CMA allocation failure such as EBUSY, ENOMEM, EINTR. But we did not know error reason so far. This patch prints the error value. Additionally if CONFIG_CMA_DEBUG is enabled, this patch shows bitmap status to know available pages. Actually CMA internally tries on all available regions because some regions can be failed because of EBUSY. Bitmap status is useful to know in detail on both ENONEM and EBUSY; ENOMEM: not tried at all because of no available region it could be too small total region or could be fragmentation issue EBUSY: tried some region but all failed This is an ENOMEM example with this patch. [2: Binder:714_1: 744] cma: cma_alloc: alloc failed, req-size: 256 pages, ret: -12 If CONFIG_CMA_DEBUG is enabled, avabile pages also will be shown as concatenated size@position format. So 4@572 means that there are 4 available pages at 572 position starting from 0 position. [2: Binder:714_1: 744] cma: number of available pages: 4@572+7@585+7@601+8@632+38@730+166@1114+127@1921=> 357 free of 2048 total pages Link: http://lkml.kernel.org/r/1485909785-3952-1-git-send-email-jaewon31.kim@samsung.com Signed-off-by:Jaewon Kim <jaewon31.kim@samsung.com> Acked-by:
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Lucas Stach authored
Most users of this interface just want to use it with the default GFP_KERNEL flags, but for cases where DMA memory is allocated it may be called from a different context. No functional change yet, just passing through the flag to the underlying alloc_contig_range function. Link: http://lkml.kernel.org/r/20170127172328.18574-2-l.stach@pengutronix.de Signed-off-by:
Lucas Stach <l.stach@pengutronix.de> Acked-by:
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Lucas Stach authored
Currently alloc_contig_range assumes that the compaction should be done with the default GFP_KERNEL flags. This is probably right for all current uses of this interface, but may change as CMA is used in more use-cases (including being the default DMA memory allocator on some platforms). Change the function prototype, to allow for passing through the GFP mask set by upper layers. Also respect global restrictions by applying memalloc_noio_flags to the passed in flags. Link: http://lkml.kernel.org/r/20170127172328.18574-1-l.stach@pengutronix.de Signed-off-by:
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- Jan 11, 2017
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Laura Abbott authored
6b101e2a ("mm/CMA: fix boot regression due to physical address of high_memory") added checks to use __pa_nodebug on x86 since CONFIG_DEBUG_VIRTUAL complains about high_memory not being linearlly mapped. arm64 is now getting support for CONFIG_DEBUG_VIRTUAL as well. Rather than add an explosion of arches to the #ifdef, switch to an alternate method to calculate the physical start of highmem using the page before highmem starts. This avoids the need for the #ifdef and extra __pa_nodebug calls. Reviewed-by:
Mark Rutland <mark.rutland@arm.com> Tested-by:
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- Nov 11, 2016
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Shiraz Hashim authored
CMA allocation request size is represented by size_t that gets truncated when same is passed as int to bitmap_find_next_zero_area_off. We observe that during fuzz testing when cma allocation request is too high, bitmap_find_next_zero_area_off still returns success due to the truncation. This leads to kernel crash, as subsequent code assumes that requested memory is available. Fail cma allocation in case the request breaches the corresponding cma region size. Link: http://lkml.kernel.org/r/1478189211-3467-1-git-send-email-shashim@codeaurora.org Signed-off-by:
Shiraz Hashim <shashim@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by:
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- Oct 11, 2016
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Catalin Marinas authored
Some of the kmemleak_*() callbacks in memblock, bootmem, CMA convert a physical address to a virtual one using __va(). However, such physical addresses may sometimes be located in highmem and using __va() is incorrect, leading to inconsistent object tracking in kmemleak. The following functions have been added to the kmemleak API and they take a physical address as the object pointer. They only perform the corresponding action if the address has a lowmem mapping: kmemleak_alloc_phys kmemleak_free_part_phys kmemleak_not_leak_phys kmemleak_ignore_phys The affected calling places have been updated to use the new kmemleak API. Link: http://lkml.kernel.org/r/1471531432-16503-1-git-send-email-catalin.marinas@arm.com Signed-off-by:
Catalin Marinas <catalin.marinas@arm.com> Reported-by:
Vignesh R <vigneshr@ti.com> Signed-off-by:
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- May 27, 2016
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Stephen Rothwell authored
pageblock_order can be (at least) an unsigned int or an unsigned long depending on the kernel config and architecture, so use max_t(unsigned long, ...) when comparing it. fixes these warnings: In file included from include/asm-generic/bug.h:13:0, from arch/powerpc/include/asm/bug.h:127, from include/linux/bug.h:4, from include/linux/mmdebug.h:4, from include/linux/mm.h:8, from include/linux/memblock.h:18, from mm/cma.c:28: mm/cma.c: In function 'cma_init_reserved_mem': include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast (void) (&_max1 == &_max2); ^ mm/cma.c:186:27: note: in expansion of macro 'max' alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order); ^ mm/cma.c: In function 'cma_declare_contiguous': include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast (void) (&_max1 == &_max2); ^ include/linux/kernel.h:747:9: note: in definition of macro 'max' typeof(y) _max2 = (y); ^ mm/cma.c:270:29: note: in expansion of macro 'max' (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order)); ^ include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast (void) (&_max1 == &_max2); ^ include/linux/kernel.h:747:21: note: in definition of macro 'max' typeof(y) _max2 = (y); ^ mm/cma.c:270:29: note: in expansion of macro 'max' (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order)); ^ [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20160526150748.5be38a4f@canb.auug.org.au Signed-off-by:Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by:
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- Nov 06, 2015
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Andrew Morton authored
mm/cma.c: In function 'cma_alloc': mm/cma.c:366: warning: 'pfn' may be used uninitialized in this function The patch actually improves the tracing a bit: if alloc_contig_range() fails, tracing will display the offending pfn rather than -1. Cc: Stefan Strogin <stefan.strogin@gmail.com> Cc: Michal Nazarewicz <mpn@google.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Cc: Thierry Reding <treding@nvidia.com> Signed-off-by:
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- Oct 23, 2015
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Rohit Vaswani authored
This was found during userspace fuzzing test when a large size dma cma allocation is made by driver(like ion) through userspace. show_stack+0x10/0x1c dump_stack+0x74/0xc8 kasan_report_error+0x2b0/0x408 kasan_report+0x34/0x40 __asan_storeN+0x15c/0x168 memset+0x20/0x44 __dma_alloc_coherent+0x114/0x18c Signed-off-by:
Rohit Vaswani <rvaswani@codeaurora.org> Acked-by:
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- Jun 25, 2015
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Tony Luck authored
Some high end Intel Xeon systems report uncorrectable memory errors as a recoverable machine check. Linux has included code for some time to process these and just signal the affected processes (or even recover completely if the error was in a read only page that can be replaced by reading from disk). But we have no recovery path for errors encountered during kernel code execution. Except for some very specific cases were are unlikely to ever be able to recover. Enter memory mirroring. Actually 3rd generation of memory mirroing. Gen1: All memory is mirrored Pro: No s/w enabling - h/w just gets good data from other side of the mirror Con: Halves effective memory capacity available to OS/applications Gen2: Partial memory mirror - just mirror memory begind some memory controllers Pro: Keep more of the capacity Con: Nightmare to enable. Have to choose between allocating from mirrored memory for safety vs. NUMA local memory for performance Gen3: Address range partial memory mirror - some mirror on each memory controller Pro: Can tune the amount of mirror and keep NUMA performance Con: I have to write memory management code to implement The current plan is just to use mirrored memory for kernel allocations. This has been broken into two phases: 1) This patch series - find the mirrored memory, use it for boot time allocations 2) Wade into mm/page_alloc.c and define a ZONE_MIRROR to pick up the unused mirrored memory from mm/memblock.c and only give it out to select kernel allocations (this is still being scoped because page_alloc.c is scary). This patch (of 3): Add extra "flags" to memblock to allow selection of memory based on attribute. No functional changes Signed-off-by:Tony Luck <tony.luck@intel.com> Cc: Xishi Qiu <qiuxishi@huawei.com> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Xiexiuqi <xiexiuqi@huawei.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Signed-off-by:
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Shailendra Verma authored
Signed-off-by:
Shailendra Verma <shailendra.capricorn@gmail.com> Acked-by:
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- Apr 15, 2015
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Stefan Strogin authored
Add trace events for cma_alloc() and cma_release(). The cma_alloc tracepoint is used both for successful and failed allocations, in case of allocation failure pfn=-1UL is stored and printed. Signed-off-by:
Stefan Strogin <stefan.strogin@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Nazarewicz <mpn@google.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Cc: Thierry Reding <treding@nvidia.com> Signed-off-by:
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- Apr 14, 2015
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Sasha Levin authored
Constify function parameters and use correct signness where needed. Signed-off-by:
Sasha Levin <sasha.levin@oracle.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Acked-by:
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Sasha Levin authored
Provides a userspace interface to trigger a CMA allocation. Usage: echo [pages] > alloc This would provide testing/fuzzing access to the CMA allocation paths. Signed-off-by: -
Sasha Levin authored
I've noticed that there is no interfaces exposed by CMA which would let me fuzz what's going on in there. This small patchset exposes some information out to userspace, plus adds the ability to trigger allocation and freeing from userspace. This patch (of 3): Implement a simple debugfs interface to expose information about CMA areas in the system. Useful for testing/sanity checks for CMA since it was impossible to previously retrieve this information in userspace. Signed-off-by:
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- Mar 13, 2015
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Danesh Petigara authored
The CMA aligned offset calculation is incorrect for non-zero order_per_bit values. For example, if cma->order_per_bit=1, cma->base_pfn= 0x2f800000 and align_order=12, the function returns a value of 0x17c00 instead of 0x400. This patch fixes the CMA aligned offset calculation. The previous calculation was wrong and would return too-large values for the offset, so that when cma_alloc looks for free pages in the bitmap with the requested alignment > order_per_bit, it starts too far into the bitmap and so CMA allocations will fail despite there actually being plenty of free pages remaining. It will also probably have the wrong alignment. With this change, we will get the correct offset into the bitmap. One affected user is powerpc KVM, which has kvm_cma->order_per_bit set to KVM_CMA_CHUNK_ORDER - PAGE_SHIFT, or 18 - 12 = 6. [gregory.0xf0@gmail.com: changelog additions] Signed-off-by:
Danesh Petigara <dpetigara@broadcom.com> Reviewed-by:
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- Feb 12, 2015
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George G. Davis authored
The totalcma_pages variable is not updated to account for CMA regions defined via device tree reserved-memory sub-nodes. Fix this omission by moving the calculation of totalcma_pages into cma_init_reserved_mem() instead of cma_declare_contiguous() such that it will include reserved memory used by all CMA regions. Signed-off-by:
George G. Davis <george_davis@mentor.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Acked-by:
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- Dec 19, 2014
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Pintu Kumar authored
When the system boots up, in the dmesg logs we can see the memory statistics along with total reserved as below. Memory: 458840k/458840k available, 65448k reserved, 0K highmem When CMA is enabled, still the total reserved memory remains the same. However, the CMA memory is not considered as reserved. But, when we see /proc/meminfo, the CMA memory is part of free memory. This creates confusion. This patch corrects the problem by properly subtracting the CMA reserved memory from the total reserved memory in dmesg logs. Below is the dmesg snapshot from an arm based device with 512MB RAM and 12MB single CMA region. Before this change: Memory: 458840k/458840k available, 65448k reserved, 0K highmem After this change: Memory: 458840k/458840k available, 53160k reserved, 12288k cma-reserved, 0K highmem Signed-off-by:
Pintu Kumar <pintu.k@samsung.com> Signed-off-by:
Vishnu Pratap Singh <vishnu.ps@samsung.com> Acked-by:
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- Dec 13, 2014
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Thierry Reding authored
kmemleak will add allocations as objects to a pool. The memory allocated for each object in this pool is periodically searched for pointers to other allocated objects. This only works for memory that is mapped into the kernel's virtual address space, which happens not to be the case for most CMA regions. Furthermore, CMA regions are typically used to store data transferred to or from a device and therefore don't contain pointers to other objects. Without this, the kernel crashes on the first execution of the scan_gray_list() because it tries to access highmem. Perhaps a more appropriate fix would be to reject any object that can't map to a kernel virtual address? [akpm@linux-foundation.org: add comment] [akpm@linux-foundation.org: fix comment, per Catalin] [sfr@canb.auug.org.au: include linux/io.h for phys_to_virt()] Signed-off-by:
Thierry Reding <treding@nvidia.com> Cc: Michal Nazarewicz <mina86@mina86.com> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by:
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Gregory Fong authored
The alignment in cma_alloc() was done w.r.t. the bitmap. This is a problem when, for example: - a device requires 16M (order 12) alignment - the CMA region is not 16 M aligned In such a case, can result with the CMA region starting at, say, 0x2f800000 but any allocation you make from there will be aligned from there. Requesting an allocation of 32 M with 16 M alignment will result in an allocation from 0x2f800000 to 0x31800000, which doesn't work very well if your strange device requires 16M alignment. Change to use bitmap_find_next_zero_area_off() to account for the difference in alignment at reserve-time and alloc-time. Signed-off-by:
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- Dec 11, 2014
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Joonsoo Kim authored
high_memory isn't direct mapped memory so retrieving it's physical address isn't appropriate. But, it would be useful to check physical address of highmem boundary so it's justfiable to get physical address from it. In x86, there is a validation check if CONFIG_DEBUG_VIRTUAL and it triggers following boot failure reported by Ingo. ... BUG: Int 6: CR2 00f06f53 ... Call Trace: dump_stack+0x41/0x52 early_idt_handler+0x6b/0x6b cma_declare_contiguous+0x33/0x212 dma_contiguous_reserve_area+0x31/0x4e dma_contiguous_reserve+0x11d/0x125 setup_arch+0x7b5/0xb63 start_kernel+0xb8/0x3e6 i386_start_kernel+0x79/0x7d To fix boot regression, this patch implements workaround to avoid validation check in x86 when retrieving physical address of high_memory. __pa_nodebug() used by this patch is implemented only in x86 so there is no choice but to use dirty #ifdef. [akpm@linux-foundation.org: tweak comment] Signed-off-by:
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- Oct 27, 2014
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Laurent Pinchart authored
Casting physical addresses to unsigned long and using %lu truncates the values on systems where physical addresses are larger than 32 bits. Use %pa and get rid of the cast instead. Signed-off-by:
Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> Acked-by:
Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by:
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Laurent Pinchart authored
Commit 95b0e655 ("ARM: mm: don't limit default CMA region only to low memory") extended CMA memory reservation to allow usage of high memory. It relied on commit f7426b98 ("mm: cma: adjust address limit to avoid hitting low/high memory boundary") to ensure that the reserved block never crossed the low/high memory boundary. While the implementation correctly lowered the limit, it failed to consider the case where the base..limit range crossed the low/high memory boundary with enough space on each side to reserve the requested size on either low or high memory. Rework the base and limit adjustment to fix the problem. The function now starts by rejecting the reservation altogether for fixed reservations that cross the boundary, tries to reserve from high memory first and then falls back to low memory. Signed-off-by:
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Laurent Pinchart authored
The fixed parameter to cma_declare_contiguous() tells the function whether the given base address must be honoured or should be considered as a hint only. The API considers a zero base address as meaning any base address, which must never be considered as a fixed value. Part of the implementation correctly checks both fixed and base != 0, but two locations check the fixed value only. Set fixed to false when base is 0 to fix that and simplify the code. Signed-off-by:
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Laurent Pinchart authored
If activation of the CMA area fails its mutex won't be initialized, leading to an oops at allocation time when trying to lock the mutex. Fix this by setting the cma area count field to 0 when activation fails, leading to allocation returning NULL immediately. Cc: <stable@vger.kernel.org> # v3.17 Signed-off-by:
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- Oct 14, 2014
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Marek Szyprowski authored
Add a function to create CMA region from previously reserved memory and add support for handling 'shared-dma-pool' reserved-memory device tree nodes. Based on previous code provided by Josh Cartwright <joshc@codeaurora.org> Signed-off-by:
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Weijie Yang authored
The current cma bitmap aligned mask computation is incorrect. It could cause an unexpected alignment when using cma_alloc() if the wanted align order is larger than cma->order_per_bit. Take kvm for example (PAGE_SHIFT = 12), kvm_cma->order_per_bit is set to 6. When kvm_alloc_rma() tries to alloc kvm_rma_pages, it will use 15 as the expected align value. After using the current implementation however, we get 0 as cma bitmap aligned mask other than 511. This patch fixes the cma bitmap aligned mask calculation. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by:
Weijie Yang <weijie.yang@samsung.com> Acked-by:
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- Oct 10, 2014
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Marek Szyprowski authored
Russell King recently noticed that limiting default CMA region only to low memory on ARM architecture causes serious memory management issues with machines having a lot of memory (which is mainly available as high memory). More information can be found the following thread: http://thread.gmane.org/gmane.linux.ports.arm.kernel/348441/ Those two patches removes this limit letting kernel to put default CMA region into high memory when this is possible (there is enough high memory available and architecture specific DMA limit fits). This should solve strange OOM issues on systems with lots of RAM (i.e. >1GiB) and large (>256M) CMA area. This patch (of 2): Automatically allocated regions should not cross low/high memory boundary, because such regions cannot be later correctly initialized due to spanning across two memory zones. This patch adds a check for this case and a simple code for moving region to low memory if automatically selected address might not fit completely into high memory. Signed-off-by:
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