user/sven/linux.git/mm/memory-failure.c, branch v5.3.3

Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma

2019-07-15T02:42:11Z

Pull HMM updates from Jason Gunthorpe: "Improvements and bug fixes for the hmm interface in the kernel: - Improve clarity, locking and APIs related to the 'hmm mirror' feature merged last cycle. In linux-next we now see AMDGPU and nouveau to be using this API. - Remove old or transitional hmm APIs. These are hold overs from the past with no users, or APIs that existed only to manage cross tree conflicts. There are still a few more of these cleanups that didn't make the merge window cut off. - Improve some core mm APIs: - export alloc_pages_vma() for driver use - refactor into devm_request_free_mem_region() to manage DEVICE_PRIVATE resource reservations - refactor duplicative driver code into the core dev_pagemap struct - Remove hmm wrappers of improved core mm APIs, instead have drivers use the simplified API directly - Remove DEVICE_PUBLIC - Simplify the kconfig flow for the hmm users and core code" * tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma: (42 commits) mm: don't select MIGRATE_VMA_HELPER from HMM_MIRROR mm: remove the HMM config option mm: sort out the DEVICE_PRIVATE Kconfig mess mm: simplify ZONE_DEVICE page private data mm: remove hmm_devmem_add mm: remove hmm_vma_alloc_locked_page nouveau: use devm_memremap_pages directly nouveau: use alloc_page_vma directly PCI/P2PDMA: use the dev_pagemap internal refcount device-dax: use the dev_pagemap internal refcount memremap: provide an optional internal refcount in struct dev_pagemap memremap: replace the altmap_valid field with a PGMAP_ALTMAP_VALID flag memremap: remove the data field in struct dev_pagemap memremap: add a migrate_to_ram method to struct dev_pagemap_ops memremap: lift the devmap_enable manipulation into devm_memremap_pages memremap: pass a struct dev_pagemap to ->kill and ->cleanup memremap: move dev_pagemap callbacks into a separate structure memremap: validate the pagemap type passed to devm_memremap_pages mm: factor out a devm_request_free_mem_region helper mm: export alloc_pages_vma ...

mm/memory-failure.c: clarify error message

2019-07-12T18:05:47Z

Some user who install SIGBUS handler that does longjmp out therefore keeping the process alive is confused by the error message "[188988.765862] Memory failure: 0x1840200: Killing cellsrv:33395 due to hardware memory corruption" Slightly modify the error message to improve clarity. Link: http://lkml.kernel.org/r/1558403523-22079-1-git-send-email-jane.chu@oracle.com Signed-off-by: Jane Chu Acked-by: Naoya Horiguchi Acked-by: Pankaj Gupta Reviewed-by: Anshuman Khandual Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2019-07-09T04:48:15Z

Pull force_sig() argument change from Eric Biederman: "A source of error over the years has been that force_sig has taken a task parameter when it is only safe to use force_sig with the current task. The force_sig function is built for delivering synchronous signals such as SIGSEGV where the userspace application caused a synchronous fault (such as a page fault) and the kernel responded with a signal. Because the name force_sig does not make this clear, and because the force_sig takes a task parameter the function force_sig has been abused for sending other kinds of signals over the years. Slowly those have been fixed when the oopses have been tracked down. This set of changes fixes the remaining abusers of force_sig and carefully rips out the task parameter from force_sig and friends making this kind of error almost impossible in the future" * 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (27 commits) signal/x86: Move tsk inside of CONFIG_MEMORY_FAILURE in do_sigbus signal: Remove the signal number and task parameters from force_sig_info signal: Factor force_sig_info_to_task out of force_sig_info signal: Generate the siginfo in force_sig signal: Move the computation of force into send_signal and correct it. signal: Properly set TRACE_SIGNAL_LOSE_INFO in __send_signal signal: Remove the task parameter from force_sig_fault signal: Use force_sig_fault_to_task for the two calls that don't deliver to current signal: Explicitly call force_sig_fault on current signal/unicore32: Remove tsk parameter from __do_user_fault signal/arm: Remove tsk parameter from __do_user_fault signal/arm: Remove tsk parameter from ptrace_break signal/nds32: Remove tsk parameter from send_sigtrap signal/riscv: Remove tsk parameter from do_trap signal/sh: Remove tsk parameter from force_sig_info_fault signal/um: Remove task parameter from send_sigtrap signal/x86: Remove task parameter from send_sigtrap signal: Remove task parameter from force_sig_mceerr signal: Remove task parameter from force_sig signal: Remove task parameter from force_sigsegv ...

mm: remove MEMORY_DEVICE_PUBLIC support

2019-07-02T17:32:43Z

The code hasn't been used since it was added to the tree, and doesn't appear to actually be usable. Signed-off-by: Christoph Hellwig Reviewed-by: Jason Gunthorpe Acked-by: Michal Hocko Reviewed-by: Dan Williams Tested-by: Dan Williams Signed-off-by: Jason Gunthorpe

mm: hugetlb: soft-offline: dissolve_free_huge_page() return zero on !PageHuge

2019-06-29T08:43:45Z

madvise(MADV_SOFT_OFFLINE) often returns -EBUSY when calling soft offline for hugepages with overcommitting enabled. That was caused by the suboptimal code in current soft-offline code. See the following part: ret = migrate_pages(&pagelist, new_page, NULL, MPOL_MF_MOVE_ALL, MIGRATE_SYNC, MR_MEMORY_FAILURE); if (ret) { ... } else { /* * We set PG_hwpoison only when the migration source hugepage * was successfully dissolved, because otherwise hwpoisoned * hugepage remains on free hugepage list, then userspace will * find it as SIGBUS by allocation failure. That's not expected * in soft-offlining. */ ret = dissolve_free_huge_page(page); if (!ret) { if (set_hwpoison_free_buddy_page(page)) num_poisoned_pages_inc(); } } return ret; Here dissolve_free_huge_page() returns -EBUSY if the migration source page was freed into buddy in migrate_pages(), but even in that case we actually has a chance that set_hwpoison_free_buddy_page() succeeds. So that means current code gives up offlining too early now. dissolve_free_huge_page() checks that a given hugepage is suitable for dissolving, where we should return success for !PageHuge() case because the given hugepage is considered as already dissolved. This change also affects other callers of dissolve_free_huge_page(), which are cleaned up together. [n-horiguchi@ah.jp.nec.com: v3] Link: http://lkml.kernel.org/r/1560761476-4651-3-git-send-email-n-horiguchi@ah.jp.nec.comLink: http://lkml.kernel.org/r/1560154686-18497-3-git-send-email-n-horiguchi@ah.jp.nec.com Fixes: 6bc9b56433b76 ("mm: fix race on soft-offlining") Signed-off-by: Naoya Horiguchi Reported-by: Chen, Jerry T Tested-by: Chen, Jerry T Reviewed-by: Mike Kravetz Reviewed-by: Oscar Salvador Cc: Michal Hocko Cc: Xishi Qiu Cc: "Chen, Jerry T" Cc: "Zhuo, Qiuxu" Cc: [4.19+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: soft-offline: return -EBUSY if set_hwpoison_free_buddy_page() fails

2019-06-29T08:43:45Z

The pass/fail of soft offline should be judged by checking whether the raw error page was finally contained or not (i.e. the result of set_hwpoison_free_buddy_page()), but current code do not work like that. It might lead us to misjudge the test result when set_hwpoison_free_buddy_page() fails. Without this fix, there are cases where madvise(MADV_SOFT_OFFLINE) may not offline the original page and will not return an error. Link: http://lkml.kernel.org/r/1560154686-18497-2-git-send-email-n-horiguchi@ah.jp.nec.com Signed-off-by: Naoya Horiguchi Fixes: 6bc9b56433b76 ("mm: fix race on soft-offlining") Reviewed-by: Mike Kravetz Reviewed-by: Oscar Salvador Cc: Michal Hocko Cc: Xishi Qiu Cc: "Chen, Jerry T" Cc: "Zhuo, Qiuxu" Cc: [4.19+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 263

2019-06-05T15:30:28Z

Based on 1 normalized pattern(s): this software may be redistributed and or modified under the terms of the gnu general public license gpl version 2 only as published by the free software foundation extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 1 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Richard Fontana Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141333.676969322@linutronix.de Signed-off-by: Greg Kroah-Hartman

signal: Remove task parameter from force_sig_mceerr

2019-05-27T14:36:28Z

All of the callers pass current into force_sig_mceer so remove the task parameter to make this obvious. This also makes it clear that force_sig_mceerr passes current into force_sig_info. Signed-off-by: "Eric W. Biederman"

mm: hwpoison: fix thp split handing in soft_offline_in_use_page()

2019-03-06T05:07:13Z

When soft_offline_in_use_page() runs on a thp tail page after pmd is split, we trigger the following VM_BUG_ON_PAGE(): Memory failure: 0x3755ff: non anonymous thp __get_any_page: 0x3755ff: unknown zero refcount page type 2fffff80000000 Soft offlining pfn 0x34d805 at process virtual address 0x20fff000 page:ffffea000d360140 count:0 mapcount:0 mapping:0000000000000000 index:0x1 flags: 0x2fffff80000000() raw: 002fffff80000000 ffffea000d360108 ffffea000d360188 0000000000000000 raw: 0000000000000001 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: VM_BUG_ON_PAGE(page_ref_count(page) == 0) ------------[ cut here ]------------ kernel BUG at ./include/linux/mm.h:519! soft_offline_in_use_page() passed refcount and page lock from tail page to head page, which is not needed because we can pass any subpage to split_huge_page(). Naoya had fixed a similar issue in c3901e722b29 ("mm: hwpoison: fix thp split handling in memory_failure()"). But he missed fixing soft offline. Link: http://lkml.kernel.org/r/1551452476-24000-1-git-send-email-zhongjiang@huawei.com Fixes: 61f5d698cc97 ("mm: re-enable THP") Signed-off-by: zhongjiang Acked-by: Naoya Horiguchi Cc: Michal Hocko Cc: Hugh Dickins Cc: Kirill A. Shutemov Cc: Andrea Arcangeli Cc: [4.5+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: hwpoison: use do_send_sig_info() instead of force_sig()

2019-02-01T23:46:23Z

Currently memory_failure() is racy against process's exiting, which results in kernel crash by null pointer dereference. The root cause is that memory_failure() uses force_sig() to forcibly kill asynchronous (meaning not in the current context) processes. As discussed in thread https://lkml.org/lkml/2010/6/8/236 years ago for OOM fixes, this is not a right thing to do. OOM solves this issue by using do_send_sig_info() as done in commit d2d393099de2 ("signal: oom_kill_task: use SEND_SIG_FORCED instead of force_sig()"), so this patch is suggesting to do the same for hwpoison. do_send_sig_info() properly accesses to siglock with lock_task_sighand(), so is free from the reported race. I confirmed that the reported bug reproduces with inserting some delay in kill_procs(), and it never reproduces with this patch. Note that memory_failure() can send another type of signal using force_sig_mceerr(), and the reported race shouldn't happen on it because force_sig_mceerr() is called only for synchronous processes (i.e. BUS_MCEERR_AR happens only when some process accesses to the corrupted memory.) Link: http://lkml.kernel.org/r/20190116093046.GA29835@hori1.linux.bs1.fc.nec.co.jp Signed-off-by: Naoya Horiguchi Reported-by: Jane Chu Reviewed-by: Dan Williams Reviewed-by: William Kucharski Cc: Oleg Nesterov Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds