kernel/mm, branch linux-5.17.y

mm/huge_memory: Fix xarray node memory leak

2022-06-14T16:41:49Z

commit 69a37a8ba1b408a1c7616494aa7018e4b3844cbe upstream. If xas_split_alloc() fails to allocate the necessary nodes to complete the xarray entry split, it sets the xa_state to -ENOMEM, which xas_nomem() then interprets as "Please allocate more memory", not as "Please free any unnecessary memory" (which was the intended outcome). It's confusing to use xas_nomem() to free memory in this context, so call xas_destroy() instead. Reported-by: syzbot+9e27a75a8c24f3fe75c1@syzkaller.appspotmail.com Fixes: 6b24ca4a1a8d ("mm: Use multi-index entries in the page cache") Cc: stable@vger.kernel.org Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Greg Kroah-Hartman

mm/memremap: fix missing call to untrack_pfn() in pagemap_range()

2022-06-09T08:26:28Z

commit a04e1928e2ead144dc2f369768bc0a0f3110af89 upstream. We forget to call untrack_pfn() to pair with track_pfn_remap() when range is not allowed to hotplug. Fix it by jump err_kasan. Link: https://lkml.kernel.org/r/20220531122643.25249-1-linmiaohe@huawei.com Fixes: bca3feaa0764 ("mm/memory_hotplug: prevalidate the address range being added with platform") Signed-off-by: Miaohe Lin Reviewed-by: David Hildenbrand Acked-by: Muchun Song Cc: Anshuman Khandual Cc: Oscar Salvador Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

hugetlb: fix huge_pmd_unshare address update

2022-06-09T08:26:27Z

commit 48381273f8734d28ef56a5bdf1966dd8530111bc upstream. The routine huge_pmd_unshare() is passed a pointer to an address associated with an area which may be unshared. If unshare is successful this address is updated to 'optimize' callers iterating over huge page addresses. For the optimization to work correctly, address should be updated to the last huge page in the unmapped/unshared area. However, in the common case where the passed address is PUD_SIZE aligned, the address is incorrectly updated to the address of the preceding huge page. That wastes CPU cycles as the unmapped/unshared range is scanned twice. Link: https://lkml.kernel.org/r/20220524205003.126184-1-mike.kravetz@oracle.com Fixes: 39dde65c9940 ("shared page table for hugetlb page") Signed-off-by: Mike Kravetz Acked-by: Muchun Song Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

mm/page_alloc: always attempt to allocate at least one page during bulk allocation

2022-06-09T08:26:27Z

commit c572e4888ad1be123c1516ec577ad30a700bbec4 upstream. Peter Pavlisko reported the following problem on kernel bugzilla 216007. When I try to extract an uncompressed tar archive (2.6 milion files, 760.3 GiB in size) on newly created (empty) XFS file system, after first low tens of gigabytes extracted the process hangs in iowait indefinitely. One CPU core is 100% occupied with iowait, the other CPU core is idle (on 2-core Intel Celeron G1610T). It was bisected to c9fa563072e1 ("xfs: use alloc_pages_bulk_array() for buffers") but XFS is only the messenger. The problem is that nothing is waking kswapd to reclaim some pages at a time the PCP lists cannot be refilled until some reclaim happens. The bulk allocator checks that there are some pages in the array and the original intent was that a bulk allocator did not necessarily need all the requested pages and it was best to return as quickly as possible. This was fine for the first user of the API but both NFS and XFS require the requested number of pages be available before making progress. Both could be adjusted to call the page allocator directly if a bulk allocation fails but it puts a burden on users of the API. Adjust the semantics to attempt at least one allocation via __alloc_pages() before returning so kswapd is woken if necessary. It was reported via bugzilla that the patch addressed the problem and that the tar extraction completed successfully. This may also address bug 215975 but has yet to be confirmed. BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=216007 BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=215975 Link: https://lkml.kernel.org/r/20220526091210.GC3441@techsingularity.net Fixes: 387ba26fb1cb ("mm/page_alloc: add a bulk page allocator") Signed-off-by: Mel Gorman Cc: "Darrick J. Wong" Cc: Dave Chinner Cc: Jan Kara Cc: Vlastimil Babka Cc: Jesper Dangaard Brouer Cc: Chuck Lever Cc: [5.13+] Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

Revert "mm/cma.c: remove redundant cma_mutex lock"

2022-06-09T08:26:27Z

commit 60a60e32cf91169840abcb4a80f0b0df31708ba7 upstream. This reverts commit a4efc174b382fcdb which introduced a regression issue that when there're multiple processes allocating dma memory in parallel by calling dma_alloc_coherent(), it may fail sometimes as follows: Error log: cma: cma_alloc: linux,cma: alloc failed, req-size: 148 pages, ret: -16 cma: number of available pages: 3@125+20@172+12@236+4@380+32@736+17@2287+23@2473+20@36076+99@40477+108@40852+44@41108+20@41196+108@41364+108@41620+ 108@42900+108@43156+483@44061+1763@45341+1440@47712+20@49324+20@49388+5076@49452+2304@55040+35@58141+20@58220+20@58284+ 7188@58348+84@66220+7276@66452+227@74525+6371@75549=> 33161 free of 81920 total pages When issue happened, we saw there were still 33161 pages (129M) free CMA memory and a lot available free slots for 148 pages in CMA bitmap that we want to allocate. When dumping memory info, we found that there was also ~342M normal memory, but only 1352K CMA memory left in buddy system while a lot of pageblocks were isolated. Memory info log: Normal free:351096kB min:30000kB low:37500kB high:45000kB reserved_highatomic:0KB active_anon:98060kB inactive_anon:98948kB active_file:60864kB inactive_file:31776kB unevictable:0kB writepending:0kB present:1048576kB managed:1018328kB mlocked:0kB bounce:0kB free_pcp:220kB local_pcp:192kB free_cma:1352kB lowmem_reserve[]: 0 0 0 Normal: 78*4kB (UECI) 1772*8kB (UMECI) 1335*16kB (UMECI) 360*32kB (UMECI) 65*64kB (UMCI) 36*128kB (UMECI) 16*256kB (UMCI) 6*512kB (EI) 8*1024kB (UEI) 4*2048kB (MI) 8*4096kB (EI) 8*8192kB (UI) 3*16384kB (EI) 8*32768kB (M) = 489288kB The root cause of this issue is that since commit a4efc174b382 ("mm/cma.c: remove redundant cma_mutex lock"), CMA supports concurrent memory allocation. It's possible that the memory range process A trying to alloc has already been isolated by the allocation of process B during memory migration. The problem here is that the memory range isolated during one allocation by start_isolate_page_range() could be much bigger than the real size we want to alloc due to the range is aligned to MAX_ORDER_NR_PAGES. Taking an ARMv7 platform with 1G memory as an example, when MAX_ORDER_NR_PAGES is big (e.g. 32M with max_order 14) and CMA memory is relatively small (e.g. 128M), there're only 4 MAX_ORDER slot, then it's very easy that all CMA memory may have already been isolated by other processes when one trying to allocate memory using dma_alloc_coherent(). Since current CMA code will only scan one time of whole available CMA memory, then dma_alloc_coherent() may easy fail due to contention with other processes. This patch simply falls back to the original method that using cma_mutex to make alloc_contig_range() run sequentially to avoid the issue. Link: https://lkml.kernel.org/r/20220509094551.3596244-1-aisheng.dong@nxp.com Link: https://lore.kernel.org/all/20220315144521.3810298-2-aisheng.dong@nxp.com/ Fixes: a4efc174b382 ("mm/cma.c: remove redundant cma_mutex lock") Signed-off-by: Dong Aisheng Acked-by: Minchan Kim Acked-by: David Hildenbrand Cc: Marek Szyprowski Cc: Lecopzer Chen Cc: Vlastimil Babka Cc: [5.11+] Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

mm, compaction: fast_find_migrateblock() should return pfn in the target zone

2022-06-09T08:26:20Z

commit bbe832b9db2e1ad21522f8f0bf02775fff8a0e0e upstream. At present, pages not in the target zone are added to cc->migratepages list in isolate_migratepages_block(). As a result, pages may migrate between nodes unintentionally. This would be a serious problem for older kernels without commit a984226f457f849e ("mm: memcontrol: remove the pgdata parameter of mem_cgroup_page_lruvec"), because it can corrupt the lru list by handling pages in list without holding proper lru_lock. Avoid returning a pfn outside the target zone in the case that it is not aligned with a pageblock boundary. Otherwise isolate_migratepages_block() will handle pages not in the target zone. Link: https://lkml.kernel.org/r/20220511044300.4069-1-yamamoto.rei@jp.fujitsu.com Fixes: 70b44595eafe ("mm, compaction: use free lists to quickly locate a migration source") Signed-off-by: Rei Yamamoto Reviewed-by: Miaohe Lin Acked-by: Mel Gorman Reviewed-by: Oscar Salvador Cc: Don Dutile Cc: Wonhyuk Yang Cc: Rei Yamamoto Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

zsmalloc: fix races between asynchronous zspage free and page migration

2022-06-06T06:47:53Z

commit 2505a981114dcb715f8977b8433f7540854851d8 upstream. The asynchronous zspage free worker tries to lock a zspage's entire page list without defending against page migration. Since pages which haven't yet been locked can concurrently migrate off the zspage page list while lock_zspage() churns away, lock_zspage() can suffer from a few different lethal races. It can lock a page which no longer belongs to the zspage and unsafely dereference page_private(), it can unsafely dereference a torn pointer to the next page (since there's a data race), and it can observe a spurious NULL pointer to the next page and thus not lock all of the zspage's pages (since a single page migration will reconstruct the entire page list, and create_page_chain() unconditionally zeroes out each list pointer in the process). Fix the races by using migrate_read_lock() in lock_zspage() to synchronize with page migration. Link: https://lkml.kernel.org/r/20220509024703.243847-1-sultan@kerneltoast.com Fixes: 77ff465799c602 ("zsmalloc: zs_page_migrate: skip unnecessary loops but not return -EBUSY if zspage is not inuse") Signed-off-by: Sultan Alsawaf Acked-by: Minchan Kim Cc: Nitin Gupta Cc: Sergey Senozhatsky Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

random: move randomize_page() into mm where it belongs

2022-05-30T07:27:18Z

commit 5ad7dd882e45d7fe432c32e896e2aaa0b21746ea upstream. randomize_page is an mm function. It is documented like one. It contains the history of one. It has the naming convention of one. It looks just like another very similar function in mm, randomize_stack_top(). And it has always been maintained and updated by mm people. There is no need for it to be in random.c. In the "which shape does not look like the other ones" test, pointing to randomize_page() is correct. So move randomize_page() into mm/util.c, right next to the similar randomize_stack_top() function. This commit contains no actual code changes. Cc: Andrew Morton Signed-off-by: Jason A. Donenfeld Signed-off-by: Greg Kroah-Hartman

mm/kfence: reset PG_slab and memcg_data before freeing __kfence_pool

2022-05-18T08:28:23Z

commit 2839b0999c20c9f6bf353849c69370e121e2fa1a upstream. When kfence fails to initialize kfence pool, it frees the pool. But it does not reset memcg_data and PG_slab flag. Below is a BUG because of this. Let's fix it by resetting memcg_data and PG_slab flag before free. [ 0.089149] BUG: Bad page state in process swapper/0 pfn:3d8e06 [ 0.089149] page:ffffea46cf638180 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3d8e06 [ 0.089150] memcg:ffffffff94a475d1 [ 0.089150] flags: 0x17ffffc0000200(slab|node=0|zone=2|lastcpupid=0x1fffff) [ 0.089151] raw: 0017ffffc0000200 ffffea46cf638188 ffffea46cf638188 0000000000000000 [ 0.089152] raw: 0000000000000000 0000000000000000 00000000ffffffff ffffffff94a475d1 [ 0.089152] page dumped because: page still charged to cgroup [ 0.089153] Modules linked in: [ 0.089153] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G B W 5.18.0-rc1+ #965 [ 0.089154] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 [ 0.089154] Call Trace: [ 0.089155] [ 0.089155] dump_stack_lvl+0x49/0x5f [ 0.089157] dump_stack+0x10/0x12 [ 0.089158] bad_page.cold+0x63/0x94 [ 0.089159] check_free_page_bad+0x66/0x70 [ 0.089160] __free_pages_ok+0x423/0x530 [ 0.089161] __free_pages_core+0x8e/0xa0 [ 0.089162] memblock_free_pages+0x10/0x12 [ 0.089164] memblock_free_late+0x8f/0xb9 [ 0.089165] kfence_init+0x68/0x92 [ 0.089166] start_kernel+0x789/0x992 [ 0.089167] x86_64_start_reservations+0x24/0x26 [ 0.089168] x86_64_start_kernel+0xa9/0xaf [ 0.089170] secondary_startup_64_no_verify+0xd5/0xdb [ 0.089171] Link: https://lkml.kernel.org/r/YnPG3pQrqfcgOlVa@hyeyoo Fixes: 0ce20dd84089 ("mm: add Kernel Electric-Fence infrastructure") Fixes: 8f0b36497303 ("mm: kfence: fix objcgs vector allocation") Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Marco Elver Reviewed-by: Muchun Song Cc: Alexander Potapenko Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman

mm/hwpoison: use pr_err() instead of dump_page() in get_any_page()

2022-05-18T08:28:23Z

commit 1825b93b626e99eb9a0f9f50342c7b2fa201b387 upstream. The following VM_BUG_ON_FOLIO() is triggered when memory error event happens on the (thp/folio) pages which are about to be freed: [ 1160.232771] page:00000000b36a8a0f refcount:1 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x16a000 [ 1160.236916] page:00000000b36a8a0f refcount:0 mapcount:0 mapping:0000000000000000 index:0x1 pfn:0x16a000 [ 1160.240684] flags: 0x57ffffc0800000(hwpoison|node=1|zone=2|lastcpupid=0x1fffff) [ 1160.243458] raw: 0057ffffc0800000 dead000000000100 dead000000000122 0000000000000000 [ 1160.246268] raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 [ 1160.249197] page dumped because: VM_BUG_ON_FOLIO(!folio_test_large(folio)) [ 1160.251815] ------------[ cut here ]------------ [ 1160.253438] kernel BUG at include/linux/mm.h:788! [ 1160.256162] invalid opcode: 0000 [#1] PREEMPT SMP PTI [ 1160.258172] CPU: 2 PID: 115368 Comm: mceinj.sh Tainted: G E 5.18.0-rc1-v5.18-rc1-220404-2353-005-g83111+ #3 [ 1160.262049] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1.fc35 04/01/2014 [ 1160.265103] RIP: 0010:dump_page.cold+0x27e/0x2bd [ 1160.266757] Code: fe ff ff 48 c7 c6 81 f1 5a 98 e9 4c fe ff ff 48 c7 c6 a1 95 59 98 e9 40 fe ff ff 48 c7 c6 50 bf 5a 98 48 89 ef e8 9d 04 6d ff <0f> 0b 41 f7 c4 ff 0f 00 00 0f 85 9f fd ff ff 49 8b 04 24 a9 00 00 [ 1160.273180] RSP: 0018:ffffaa2c4d59fd18 EFLAGS: 00010292 [ 1160.274969] RAX: 000000000000003e RBX: 0000000000000001 RCX: 0000000000000000 [ 1160.277263] RDX: 0000000000000001 RSI: ffffffff985995a1 RDI: 00000000ffffffff [ 1160.279571] RBP: ffffdc9c45a80000 R08: 0000000000000000 R09: 00000000ffffdfff [ 1160.281794] R10: ffffaa2c4d59fb08 R11: ffffffff98940d08 R12: ffffdc9c45a80000 [ 1160.283920] R13: ffffffff985b6f94 R14: 0000000000000000 R15: ffffdc9c45a80000 [ 1160.286641] FS: 00007eff54ce1740(0000) GS:ffff99c67bd00000(0000) knlGS:0000000000000000 [ 1160.289498] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1160.291106] CR2: 00005628381a5f68 CR3: 0000000104712003 CR4: 0000000000170ee0 [ 1160.293031] Call Trace: [ 1160.293724] [ 1160.294334] get_hwpoison_page+0x47d/0x570 [ 1160.295474] memory_failure+0x106/0xaa0 [ 1160.296474] ? security_capable+0x36/0x50 [ 1160.297524] hard_offline_page_store+0x43/0x80 [ 1160.298684] kernfs_fop_write_iter+0x11c/0x1b0 [ 1160.299829] new_sync_write+0xf9/0x160 [ 1160.300810] vfs_write+0x209/0x290 [ 1160.301835] ksys_write+0x4f/0xc0 [ 1160.302718] do_syscall_64+0x3b/0x90 [ 1160.303664] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 1160.304981] RIP: 0033:0x7eff54b018b7 As shown in the RIP address, this VM_BUG_ON in folio_entire_mapcount() is called from dump_page("hwpoison: unhandlable page") in get_any_page(). The below explains the mechanism of the race: CPU 0 CPU 1 memory_failure get_hwpoison_page get_any_page dump_page compound = PageCompound free_pages_prepare page->flags &= ~PAGE_FLAGS_CHECK_AT_PREP folio_entire_mapcount VM_BUG_ON_FOLIO(!folio_test_large(folio)) So replace dump_page() with safer one, pr_err(). Link: https://lkml.kernel.org/r/20220427053220.719866-1-naoya.horiguchi@linux.dev Fixes: 74e8ee4708a8 ("mm: Turn head_compound_mapcount() into folio_entire_mapcount()") Signed-off-by: Naoya Horiguchi Reviewed-by: John Hubbard Reviewed-by: Miaohe Lin Cc: Matthew Wilcox Cc: Christoph Hellwig Cc: Jason Gunthorpe Cc: William Kucharski Cc: Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman