The patch titled Subject: mm: soft-offline: check return value in second __get_any_page() call has been removed from the -mm tree. Its filename was mm-soft-offline-check-return-value-in-second-__get_any_page-call.patch This patch was dropped because it was merged into mainline or a subsystem tree ------------------------------------------------------ From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Subject: mm: soft-offline: check return value in second __get_any_page() call I saw the following BUG_ON triggered in a testcase where a process calls madvise(MADV_SOFT_OFFLINE) on thps, along with a background process that calls migratepages command repeatedly (doing ping-pong among different NUMA nodes) for the first process: [ 52.556731] Soft offlining page 0x60000 at 0x700000600000 [ 52.592620] __get_any_page: 0x60000 free buddy page [ 52.593451] page:ffffea0001800000 count:0 mapcount:-127 mapping: (null) index:0x1 [ 52.594767] flags: 0x1fffc0000000000() [ 52.595402] page dumped because: VM_BUG_ON_PAGE(atomic_read(&page->_count) == 0) [ 52.596602] ------------[ cut here ]------------ [ 52.597339] kernel BUG at /src/linux-dev/include/linux/mm.h:342! [ 52.598284] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC [ 52.599193] Modules linked in: cfg80211 rfkill crc32c_intel serio_raw virtio_balloon i2c_piix4 virtio_blk virtio_net ata_generic pata_acpi [ 52.600579] CPU: 3 PID: 3035 Comm: test_alloc_gene Tainted: G O 4.4.0-rc8-v4.4-rc8-160107-1501-00000-rc8+ #74 [ 52.600579] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 [ 52.600579] task: ffff88007c63d5c0 ti: ffff88007c210000 task.ti: ffff88007c210000 [ 52.600579] RIP: 0010:[<ffffffff8118998c>] [<ffffffff8118998c>] put_page+0x5c/0x60 [ 52.600579] RSP: 0018:ffff88007c213e00 EFLAGS: 00010246 [ 52.600579] RAX: 0000000000000044 RBX: ffffea0001800000 RCX: 0000000000000000 [ 52.600579] RDX: ffff88011f50f570 RSI: 0000000000000000 RDI: ffff88011f50cc18 [ 52.600579] RBP: ffff88007c213e08 R08: 000000000000000a R09: 000000000000149c [ 52.600579] R10: ffff8800dac927f8 R11: 000000000000149c R12: ffffea0001800000 [ 52.600579] R13: 0000000000060000 R14: ffffea0001800000 R15: 0000000000000065 [ 52.600579] FS: 00007feb79d7d740(0000) GS:ffff88011f500000(0000) knlGS:0000000000000000 [ 52.600579] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 52.600579] CR2: 00007f3032cd2000 CR3: 00000000da6c4000 CR4: 00000000000006e0 [ 52.600579] Stack: [ 52.600579] ffffea0001800000 ffff88007c213e28 ffffffff811eb2ee ffffea0001800000 [ 52.600579] 00000000fffffffb ffff88007c213e70 ffffffff811eccd1 0000000000000018 [ 52.600579] ffff88007c213e50 0000700000600000 0000700000601000 0000160000000000 [ 52.600579] Call Trace: [ 52.600579] [<ffffffff811eb2ee>] put_hwpoison_page+0x4e/0x80 [ 52.600579] [<ffffffff811eccd1>] soft_offline_page+0x501/0x520 [ 52.600579] [<ffffffff811bd18c>] SyS_madvise+0x6bc/0x6f0 [ 52.600579] [<ffffffff8104d0ac>] ? fpu__restore_sig+0xcc/0x320 [ 52.600579] [<ffffffff810a0003>] ? do_sigaction+0x73/0x1b0 [ 52.600579] [<ffffffff8109ceb2>] ? __set_task_blocked+0x32/0x70 [ 52.600579] [<ffffffff81652757>] entry_SYSCALL_64_fastpath+0x12/0x6a [ 52.600579] Code: 8b fc ff ff 5b 5d c3 48 89 df e8 b0 fa ff ff 48 89 df 31 f6 e8 c6 7d ff ff 5b 5d c3 48 c7 c6 08 54 a2 81 48 89 df e8 a4 c5 01 00 <0f> 0b 66 90 66 66 66 66 90 55 48 89 e5 41 55 41 54 53 48 8b 47 [ 52.600579] RIP [<ffffffff8118998c>] put_page+0x5c/0x60 [ 52.600579] RSP <ffff88007c213e00> The root cause resides in get_any_page() which retries to get a refcount of the page to be soft-offlined. This function calls put_hwpoison_page(), expecting that the target page is putback to LRU list. But it can be also freed to buddy. So the second check need to care about such case. Fixes: af8fae7c0886 ("mm/memory-failure.c: clean up soft_offline_page()") Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx> Cc: Sasha Levin <sasha.levin@xxxxxxxxxx> Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Cc: Jerome Marchand <jmarchan@xxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Steve Capper <steve.capper@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [3.9+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory-failure.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN mm/memory-failure.c~mm-soft-offline-check-return-value-in-second-__get_any_page-call mm/memory-failure.c --- a/mm/memory-failure.c~mm-soft-offline-check-return-value-in-second-__get_any_page-call +++ a/mm/memory-failure.c @@ -1575,7 +1575,7 @@ static int get_any_page(struct page *pag * Did it turn free? */ ret = __get_any_page(page, pfn, 0); - if (!PageLRU(page)) { + if (ret == 1 && !PageLRU(page)) { /* Drop page reference which is from __get_any_page() */ put_hwpoison_page(page); pr_info("soft_offline: %#lx: unknown non LRU page type %lx\n", _ Patches currently in -mm which might be from n-horiguchi@xxxxxxxxxxxxx are mm-soft-offline-clean-up-soft_offline_page.patch mm-soft-offline-exit-with-failure-for-non-anonymous-thp.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html