- 30 Nov, 2022 1 commit
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Yang Shi authored
Syzbot reported the below splat: WARNING: CPU: 1 PID: 3646 at include/linux/gfp.h:221 __alloc_pages_node include/linux/gfp.h:221 [inline] WARNING: CPU: 1 PID: 3646 at include/linux/gfp.h:221 hpage_collapse_alloc_page mm/khugepaged.c:807 [inline] WARNING: CPU: 1 PID: 3646 at include/linux/gfp.h:221 alloc_charge_hpage+0x802/0xaa0 mm/khugepaged.c:963 Modules linked in: CPU: 1 PID: 3646 Comm: syz-executor210 Not tainted 6.1.0-rc1-syzkaller-00454-ga7038524 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 RIP: 0010:__alloc_pages_node include/linux/gfp.h:221 [inline] RIP: 0010:hpage_collapse_alloc_page mm/khugepaged.c:807 [inline] RIP: 0010:alloc_charge_hpage+0x802/0xaa0 mm/khugepaged.c:963 Code: e5 01 4c 89 ee e8 6e f9 ae ff 4d 85 ed 0f 84 28 fc ff ff e8 70 fc ae ff 48 8d 6b ff 4c 8d 63 07 e9 16 fc ff ff e8 5e fc ae ff <0f> 0b e9 96 fa ff ff 41 bc 1a 00 00 00 e9 86 fd ff ff e8 47 fc ae RSP: 0018:ffffc90003fdf7d8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888077f457c0 RSI: ffffffff81cd8f42 RDI: 0000000000000001 RBP: ffff888079388c0c R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f6b48ccf700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b48a819f0 CR3: 00000000171e7000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> collapse_file+0x1ca/0x5780 mm/khugepaged.c:1715 hpage_collapse_scan_file+0xd6c/0x17a0 mm/khugepaged.c:2156 madvise_collapse+0x53a/0xb40 mm/khugepaged.c:2611 madvise_vma_behavior+0xd0a/0x1cc0 mm/madvise.c:1066 madvise_walk_vmas+0x1c7/0x2b0 mm/madvise.c:1240 do_madvise.part.0+0x24a/0x340 mm/madvise.c:1419 do_madvise mm/madvise.c:1432 [inline] __do_sys_madvise mm/madvise.c:1432 [inline] __se_sys_madvise mm/madvise.c:1430 [inline] __x64_sys_madvise+0x113/0x150 mm/madvise.c:1430 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f6b48a4eef9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6b48ccf318 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007f6b48af0048 RCX: 00007f6b48a4eef9 RDX: 0000000000000019 RSI: 0000000000600003 RDI: 0000000020000000 RBP: 00007f6b48af0040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6b48aa53a4 R13: 00007f6b48bffcbf R14: 00007f6b48ccf400 R15: 0000000000022000 </TASK> It is because khugepaged allocates pages with __GFP_THISNODE, but the preferred node is bogus. The previous patch fixed the khugepaged code to avoid allocating page from non-existing node. But it is still racy against memory hotremove. There is no synchronization with the memory hotplug so it is possible that memory gets offline during a longer taking scanning. So this warning still seems not quite helpful because: * There is no guarantee the node is online for __GFP_THISNODE context for all the callsites. * Kernel just fails the allocation regardless the warning, and it looks all callsites handle the allocation failure gracefully. Although while the warning has helped to identify a buggy code, it is not safe in general and this warning could panic the system with panic-on-warn configuration which tends to be used surprisingly often. So replace VM_WARN_ON to pr_warn(). And the warning will be triggered if __GFP_NOWARN is set since the allocator would print out warning for such case if __GFP_NOWARN is not set. [shy828301@gmail.com: rename nid to this_node and gfp to warn_gfp] Link: https://lkml.kernel.org/r/20221123193014.153983-1-shy828301@gmail.com [akpm@linux-foundation.org: fix whitespace] [akpm@linux-foundation.org: print gfp_mask instead of warn_gfp, per Michel] Link: https://lkml.kernel.org/r/20221108184357.55614-3-shy828301@gmail.com Fixes: 7d8faaf1 ("mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse") Signed-off-by:
Yang Shi <shy828301@gmail.com> Reported-by: <syzbot+0044b22d177870ee974f@syzkaller.appspotmail.com> Suggested-by:
Michal Hocko <mhocko@suse.com> Acked-by:
Andrew Morton <akpm@linux-foundation.org>
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- 23 Nov, 2022 24 commits
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Li Hua authored
If KPROBES_SANITY_TEST and ARCH_CORRECT_STACKTRACE_ON_KRETPROBE is enabled, but STACKTRACE is not set. Build failed as below: lib/test_kprobes.c: In function `stacktrace_return_handler': lib/test_kprobes.c:228:8: error: implicit declaration of function `stack_trace_save'; did you mean `stacktrace_driver'? [-Werror=implicit-function-declaration] ret = stack_trace_save(stack_buf, STACK_BUF_SIZE, 0); ^~~~~~~~~~~~~~~~ stacktrace_driver cc1: all warnings being treated as errors scripts/Makefile.build:250: recipe for target 'lib/test_kprobes.o' failed make[2]: *** [lib/test_kprobes.o] Error 1 To fix this error, Select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE is enabled. Link: https://lkml.kernel.org/r/20221121030620.63181-1-hucool.lihua@huawei.com Fixes: 1f6d3a8f ("kprobes: Add a test case for stacktrace from kretprobe handler") Signed-off-by:Li Hua <hucool.lihua@huawei.com> Acked-by:
Masami Hiramatsu (Google) <mhiramat@kernel.org> Cc: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by:
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Chen Zhongjin authored
When extending segments, nilfs_sufile_alloc() is called to get an unassigned segment, then mark it as dirty to avoid accidentally allocating the same segment in the future. But for some special cases such as a corrupted image it can be unreliable. If such corruption of the dirty state of the segment occurs, nilfs2 may reallocate a segment that is in use and pick the same segment for writing twice at the same time. This will cause the problem reported by syzkaller: https://syzkaller.appspot.com/bug?id=c7c4748e11ffcc367cef04f76e02e931833cbd24 This case started with segbuf1.segnum = 3, nextnum = 4 when constructed. It supposed segment 4 has already been allocated and marked as dirty. However the dirty state was corrupted and segment 4 usage was not dirty. For the first time nilfs_segctor_extend_segments() segment 4 was allocated again, which made segbuf2 and next segbuf3 had same segment 4. sb_getblk() will get same bh for segbuf2 and segbuf3, and this bh is added to both buffer lists of two segbuf. It makes the lists broken which causes NULL pointer dereference. Fix the problem by setting usage as dirty every time in nilfs_sufile_mark_dirty(), which is called during constructing current segment to be written out and before allocating next segment. [chenzhongjin@huawei.com: add lock protection per Ryusuke] Link: https://lkml.kernel.org/r/20221121091141.214703-1-chenzhongjin@huawei.com Link: https://lkml.kernel.org/r/20221118063304.140187-1-chenzhongjin@huawei.com Fixes: 9ff05123 ("nilfs2: segment constructor") Signed-off-by:
Chen Zhongjin <chenzhongjin@huawei.com> Reported-by: <syzbot+77e4f0...@syzkaller.appspotmail.com> Reported-by:
Liu Shixin <liushixin2@huawei.com> Acked-by:
Ryusuke Konishi <konishi.ryusuke@gmail.com> Tested-by:
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Aneesh Kumar K.V authored
balance_dirty_pages doesn't do the required dirty throttling on cgroupv1. See commit 9badce00 ("cgroup, writeback: don't enable cgroup writeback on traditional hierarchies"). Instead, the kernel depends on writeback throttling in shrink_folio_list to achieve the same goal. With large memory systems, the flusher may not be able to writeback quickly enough such that we will start finding pages in the shrink_folio_list already in writeback. Hence for cgroupv1 let's do a reclaim throttle after waking up the flusher. The below test which used to fail on a 256GB system completes till the the file system is full with this change. root@lp2:/sys/fs/cgroup/memory# mkdir test root@lp2:/sys/fs/cgroup/memory# cd test/ root@lp2:/sys/fs/cgroup/memory/test# echo 120M > memory.limit_in_bytes root@lp2:/sys/fs/cgroup/memory/test# echo $$ > tasks root@lp2:/sys/fs/cgroup/memory/test# dd if=/dev/zero of=/home/kvaneesh/test bs=1M Killed Link: https://lkml.kernel.org/r/20221118070603.84081-1-aneesh.kumar@linux.ibm.comSigned-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Suggested-by:
Johannes Weiner <hannes@cmpxchg.org> Acked-by:
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Qi Zheng authored
When we specify __GFP_NOWARN, we only expect that no warnings will be issued for current caller. But in the __should_failslab() and __should_fail_alloc_page(), the local GFP flags alter the global {failslab|fail_page_alloc}.attr, which is persistent and shared by all tasks. This is not what we expected, let's fix it. [akpm@linux-foundation.org: unexport should_fail_ex()] Link: https://lkml.kernel.org/r/20221118100011.2634-1-zhengqi.arch@bytedance.com Fixes: 3f913fc5 ("mm: fix missing handler for __GFP_NOWARN") Signed-off-by:Qi Zheng <zhengqi.arch@bytedance.com> Reported-by:
Dmitry Vyukov <dvyukov@google.com> Reviewed-by:
Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by:
Jason Gunthorpe <jgg@nvidia.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by:
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Chen Wandun authored
A softlockup occurs in scan free swap slot under huge memory pressure. The test scenario is: 64 CPU cores, 64GB memory, and 28 zram devices, the disksize of each zram device is 50MB. LATENCY_LIMIT is used to prevent softlockups in scan_swap_map_slots(), but the real loop number would more than LATENCY_LIMIT because of "goto checks and goto scan" repeatly without decreasing latency limit. In order to fix it, decrease latency_ration in advance. There is also a suspicious place that will cause softlockups in get_swap_pages(). In this function, the "goto start_over" may result in continuous scanning of the swap partition. If there is no cond_sched in scan_swap_map_slots(), it would cause a softlockup (I am not sure about this). WARN: soft lockup - CPU#11 stuck for 11s! [kswapd0:466] CPU: 11 PID: 466 Comm: kswapd@ Kdump: loaded Tainted: G dump backtrace+0x0/0x1le4 show stack+0x20/@x2c dump_stack+0xd8/0x140 watchdog print_info+0x48/0x54 watchdog_process_before_softlockup+0x98/0xa0 watchdog_timer_fn+0xlac/0x2d0 hrtimer_rum_queues+0xb0/0x130 hrtimer_interrupt+0x13c/0x3c0 arch_timer_handler_virt+0x3c/0x50 handLe_percpu_devid_irq+0x90/0x1f4 handle domain irq+0x84/0x100 gic_handle_irq+0x88/0x2b0 e11 ira+0xhB/Bx140 scan_swap_map_slots+0x678/0x890 get_swap_pages+0x29c/0x440 get_swap_page+0x120/0x2e0 add_to_swap+UX2U/0XyC shrink_page_list+0x5d0/0x152c shrink_inactive_list+0xl6c/Bx500 shrink_lruvec+0x270/0x304 WARN: soft lockup - CPU#32 stuck for 11s! [stress-ng:309915] watchdog_timer_fn+0x1ac/0x2d0 __run_hrtimer+0x98/0x2a0 __hrtimer_run_queues+0xb0/0x130 hrtimer_interrupt+0x13c/0x3c0 arch_timer_handler_virt+0x3c/0x50 handle_percpu_devid_irq+0x90/0x1f4 __handle_domain_irq+0x84/0x100 gic_handle_irq+0x88/0x2b0 el1_irq+0xb8/0x140 get_swap_pages+0x1e8/0x440 get_swap_page+0x1c8/0x2e0 add_to_swap+0x20/0x9c shrink_page_list+0x5d0/0x152c reclaim_pages+0x160/0x310 madvise_cold_or_pageout_pte_range+0x7bc/0xe3c walk_pmd_range.isra.0+0xac/0x22c walk_pud_range+0xfc/0x1c0 walk_pgd_range+0x158/0x1b0 __walk_page_range+0x64/0x100 walk_page_range+0x104/0x150 Link: https://lkml.kernel.org/r/20221118133850.3360369-1-chenwandun@huawei.com Fixes: 048c27fd ("[PATCH] swap: scan_swap_map latency breaks") Signed-off-by:
Chen Wandun <chenwandun@huawei.com> Reviewed-by:
"Huang, Ying" <ying.huang@intel.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Nanyong Sun <sunnanyong@huawei.com> Cc: <xialonglong1@huawei.com> Signed-off-by:
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Mike Kravetz authored
Commit 2b21624f ("hugetlb: freeze allocated pages before creating hugetlb pages") changed the order page flags were cleared and set in the head page. It moved the __ClearPageReserved after __SetPageHead. However, there is a check to make sure __ClearPageReserved is never done on a head page. If CONFIG_DEBUG_VM_PGFLAGS is enabled, the following BUG will be hit when creating a hugetlb gigantic page: page dumped because: VM_BUG_ON_PAGE(1 && PageCompound(page)) ------------[ cut here ]------------ kernel BUG at include/linux/page-flags.h:500! Call Trace will differ depending on whether hugetlb page is created at boot time or run time. Make sure to __ClearPageReserved BEFORE __SetPageHead. Link: https://lkml.kernel.org/r/20221118195249.178319-1-mike.kravetz@oracle.com Fixes: 2b21624f ("hugetlb: freeze allocated pages before creating hugetlb pages") Signed-off-by:
Mike Kravetz <mike.kravetz@oracle.com> Reported-by:
Muchun Song <songmuchun@bytedance.com> Tested-by:
Tarun Sahu <tsahu@linux.ibm.com> Reviewed-by:
Miaohe Lin <linmiaohe@huawei.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com> Signed-off-by:
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Marco Elver authored
Commit b1405135 ("mm/sl[au]b: generalize kmalloc subsystem") refactored large parts of the kmalloc subsystem, resulting in the stack trace pruning logic done by KFENCE to no longer work. While b1405135 attempted to fix the situation by including '__kmem_cache_free' in the list of functions KFENCE should skip through, this only works when the compiler actually optimized the tail call from kfree() to __kmem_cache_free() into a jump (and thus kfree() _not_ appearing in the full stack trace to begin with). In some configurations, the compiler no longer optimizes the tail call into a jump, and __kmem_cache_free() appears in the stack trace. This means that the pruned stack trace shown by KFENCE would include kfree() which is not intended - for example: | BUG: KFENCE: invalid free in kfree+0x7c/0x120 | | Invalid free of 0xffff8883ed8fefe0 (in kfence-#126): | kfree+0x7c/0x120 | test_double_free+0x116/0x1a9 | kunit_try_run_case+0x90/0xd0 | [...] Fix it by moving __kmem_cache_free() to the list of functions that may be tail called by an allocator entry function, making the pruning logic work in both the optimized and unoptimized tail call cases. Link: https://lkml.kernel.org/r/20221118152216.3914899-1-elver@google.com Fixes: b1405135 ("mm/sl[au]b: generalize kmalloc subsystem") Signed-off-by:
Marco Elver <elver@google.com> Reviewed-by:
Alexander Potapenko <glider@google.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Feng Tang <feng.tang@intel.com> Signed-off-by:
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Yosry Ahmed authored
SecPageTables has a tab after it instead of a space, this can break fragile parsers that depend on spaces after the stat names. Link: https://lkml.kernel.org/r/20221117043247.133294-1-yosryahmed@google.com Fixes: ebc97a52 ("mm: add NR_SECONDARY_PAGETABLE to count secondary page table uses.") Signed-off-by:
Yosry Ahmed <yosryahmed@google.com> Acked-by:
Shakeel Butt <shakeelb@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: Marc Zyngier <maz@kernel.org> Cc: Sean Christopherson <seanjc@google.com> Signed-off-by:
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Yu Zhao authored
The page reclaim isolates a batch of folios from the tail of one of the LRU lists and works on those folios one by one. For a suitable swap-backed folio, if the swap device is async, it queues that folio for writeback. After the page reclaim finishes an entire batch, it puts back the folios it queued for writeback to the head of the original LRU list. In the meantime, the page writeback flushes the queued folios also by batches. Its batching logic is independent from that of the page reclaim. For each of the folios it writes back, the page writeback calls folio_rotate_reclaimable() which tries to rotate a folio to the tail. folio_rotate_reclaimable() only works for a folio after the page reclaim has put it back. If an async swap device is fast enough, the page writeback can finish with that folio while the page reclaim is still working on the rest of the batch containing it. In this case, that folio will remain at the head and the page reclaim will not retry it before reaching there. This patch adds a retry to evict_folios(). After evict_folios() has finished an entire batch and before it puts back folios it cannot free immediately, it retries those that may have missed the rotation. Before this patch, ~60% of folios swapped to an Intel Optane missed folio_rotate_reclaimable(). After this patch, ~99% of missed folios were reclaimed upon retry. This problem affects relatively slow async swap devices like Samsung 980 Pro much less and does not affect sync swap devices like zram or zswap at all. Link: https://lkml.kernel.org/r/20221116013808.3995280-1-yuzhao@google.com Fixes: ac35a490 ("mm: multi-gen LRU: minimal implementation") Signed-off-by:
Yu Zhao <yuzhao@google.com> Cc: "Yin, Fengwei" <fengwei.yin@intel.com> Signed-off-by:
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Satya Priya authored
Add and also update email address, skakit@codeaurora.org is no longer active. Link: https://lkml.kernel.org/r/20221116105017.3018971-1-quic_c_skakit@quicinc.comSigned-off-by:
Satya Priya <quic_c_skakit@quicinc.com> Cc: Konrad Dybcio <konrad.dybcio@linaro.org> Signed-off-by:
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Alistair Popple authored
migrate_vma->cpages originally contained a count of the number of pages migrating including non-present pages which can be populated directly on the target. Commit 241f6885 ("mm/migrate_device.c: refactor migrate_vma and migrate_device_coherent_page()") inadvertantly changed this to contain just the number of pages that were unmapped. Usage of migrate_vma->cpages isn't documented, but most drivers use it to see if all the requested addresses can be migrated so restore the original behaviour. Link: https://lkml.kernel.org/r/20221111005135.1344004-1-apopple@nvidia.com Fixes: 241f6885 ("mm/migrate_device.c: refactor migrate_vma and migrate_deivce_coherent_page()") Signed-off-by:
Alistair Popple <apopple@nvidia.com> Reported-by:
Ralph Campbell <rcampbell@nvidia.com> Reviewed-by:
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Sam James authored
Add missing <linux/string.h> include for strcmp. Clang 16 makes -Wimplicit-function-declaration an error by default. Unfortunately, out of tree modules may use this in configure scripts, which means failure might cause silent miscompilation or misconfiguration. For more information, see LWN.net [0] or LLVM's Discourse [1], gentoo-dev@ [2], or the (new) c-std-porting mailing list [3]. [0] https://lwn.net/Articles/913505/ [1] https://discourse.llvm.org/t/configure-script-breakage-with-the-new-werror-implicit-function-declaration/65213 [2] https://archives.gentoo.org/gentoo-dev/message/dd9f2d3082b8b6f8dfbccb0639e6e240 [3] hosted at lists.linux.dev. [akpm@linux-foundation.org: remember "linux/"] Link: https://lkml.kernel.org/r/20221116182634.2823136-1-sam@gentoo.orgSigned-off-by:
Sam James <sam@gentoo.org> Cc: <stable@vger.kernel.org> Signed-off-by:
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Alex Hung authored
Use my personal email address. Link: https://lkml.kernel.org/r/20221114001302.671897-2-alex.hung@amd.comSigned-off-by:
Alex Hung <alexhung@gmail.com> Signed-off-by:
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Alex Hung authored
I am no longer at Canonical and add entry of my personal email address. Link: https://lkml.kernel.org/r/20221114001302.671897-1-alex.hung@amd.comSigned-off-by:
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Ian Cowan authored
When the struct_mm input, mm, was changed to a struct ma_state, mas, the documentation for the function was never updated. This updates that documentation reference. Link: https://lkml.kernel.org/r/20221114003349.41235-1-ian@linux.cowan.aeroSigned-off-by:
Ian Cowan <ian@linux.cowan.aero> Acked-by:
David Hildenbrand <david@redhat.com> Cc: Liam Howlett <liam.howlett@oracle.com> Signed-off-by:
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SeongJae Park authored
A DAMON sysfs interface user can start DAMON with a scheme, remove the sysfs directory for the scheme, and then ask update of the scheme's stats. Because the schemes stats update logic isn't aware of the situation, it results in an invalid memory access. Fix the bug by checking if the scheme sysfs directory exists. Link: https://lkml.kernel.org/r/20221114175552.1951-1-sj@kernel.org Fixes: 0ac32b8a ("mm/damon/sysfs: support DAMOS stats") Signed-off-by:
SeongJae Park <sj@kernel.org> Cc: <stable@vger.kernel.org> [v5.18] Signed-off-by:
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Alistair Popple authored
The migrate_to_ram() callback should always succeed, but in rare cases can fail usually returning VM_FAULT_SIGBUS. Commit 16ce101d ("mm/memory.c: fix race when faulting a device private page") incorrectly stopped passing the return code up the stack. Fix this by setting the ret variable, restoring the previous behaviour on migrate_to_ram() failure. Link: https://lkml.kernel.org/r/20221114115537.727371-1-apopple@nvidia.com Fixes: 16ce101d ("mm/memory.c: fix race when faulting a device private page") Signed-off-by:
Felix Kuehling <Felix.Kuehling@amd.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Alex Sierra <alex.sierra@amd.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Lyude Paul <lyude@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
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Li Liguang authored
Kswapd will reclaim memory when memory pressure is high, the annonymous memory will be compressed and stored in the zpool if zswap is enabled. The memcg_kmem_bypass() in get_obj_cgroup_from_page() will bypass the kernel thread and cause the compressed memory not be charged to its memory cgroup. Remove the memcg_kmem_bypass() call and properly charge compressed memory to its corresponding memory cgroup. Link: https://lore.kernel.org/linux-mm/CALvZod4nnn8BHYqAM4xtcR0Ddo2-Wr8uKm9h_CHWUaXw7g_DCg@mail.gmail.com/ Link: https://lkml.kernel.org/r/20221114194828.100822-1-hannes@cmpxchg.org Fixes: f4840ccf ("zswap: memcg accounting") Signed-off-by:
Li Liguang <liliguang@baidu.com> Signed-off-by:
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Mike Kravetz authored
Shared memory segments can be created that are backed by hugetlb pages. When this happens, the vmas associated with any mappings (shmat) are marked VM_HUGETLB, yet the vm_ops for such mappings are provided by ipc/shm (shm_vm_ops). There is a mechanism to call the underlying hugetlb vm_ops, and this is done for most operations. However, it is not done for open and close. This was not an issue until the introduction of the hugetlb vma_lock. This lock structure is pointed to by vm_private_data and the open/close vm_ops help maintain this structure. The special hugetlb routine called at fork took care of structure updates at fork time. However, vma_splitting is not properly handled for ipc shared memory mappings backed by hugetlb pages. This can result in a "kernel NULL pointer dereference" BUG or use after free as two vmas point to the same lock structure. Update the shm open and close routines to always call the underlying open and close routines. Link: https://lkml.kernel.org/r/20221114210018.49346-1-mike.kravetz@oracle.com Fixes: 8d9bfb26 ("hugetlb: add vma based lock for pmd sharing") Signed-off-by:
Doug Nelson <doug.nelson@intel.com> Reported-by: <syzbot+83b4134621b7c326d950@syzkaller.appspotmail.com> Cc: Alexander Mikhalitsyn <alexander.mikhalitsyn@virtuozzo.com> Cc: "Eric W . Biederman" <ebiederm@xmission.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by:
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Mukesh Ojha authored
Currently, in clang version of gcov code when module is getting removed gcov_info_add() incorrectly adds the sfn_ptr->counter to all the dst->functions and it result in the kernel panic in below crash report. Fix this by properly handling it. [ 8.899094][ T599] Unable to handle kernel write to read-only memory at virtual address ffffff80461cc000 [ 8.899100][ T599] Mem abort info: [ 8.899102][ T599] ESR = 0x9600004f [ 8.899103][ T599] EC = 0x25: DABT (current EL), IL = 32 bits [ 8.899105][ T599] SET = 0, FnV = 0 [ 8.899107][ T599] EA = 0, S1PTW = 0 [ 8.899108][ T599] FSC = 0x0f: level 3 permission fault [ 8.899110][ T599] Data abort info: [ 8.899111][ T599] ISV = 0, ISS = 0x0000004f [ 8.899113][ T599] CM = 0, WnR = 1 [ 8.899114][ T599] swapper pgtable: 4k pages, 39-bit VAs, pgdp=00000000ab8de000 [ 8.899116][ T599] [ffffff80461cc000] pgd=18000009ffcde003, p4d=18000009ffcde003, pud=18000009ffcde003, pmd=18000009ffcad003, pte=00600000c61cc787 [ 8.899124][ T599] Internal error: Oops: 9600004f [#1] PREEMPT SMP [ 8.899265][ T599] Skip md ftrace buffer dump for: 0x1609e0 .... .., [ 8.899544][ T599] CPU: 7 PID: 599 Comm: modprobe Tainted: G S OE 5.15.41-android13-8-g38e9b1af6bce #1 [ 8.899547][ T599] Hardware name: XXX (DT) [ 8.899549][ T599] pstate: 82400005 (Nzcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--) [ 8.899551][ T599] pc : gcov_info_add+0x9c/0xb8 [ 8.899557][ T599] lr : gcov_event+0x28c/0x6b8 [ 8.899559][ T599] sp : ffffffc00e733b00 [ 8.899560][ T599] x29: ffffffc00e733b00 x28: ffffffc00e733d30 x27: ffffffe8dc297470 [ 8.899563][ T599] x26: ffffffe8dc297000 x25: ffffffe8dc297000 x24: ffffffe8dc297000 [ 8.899566][ T599] x23: ffffffe8dc0a6200 x22: ffffff880f68bf20 x21: 0000000000000000 [ 8.899569][ T599] x20: ffffff880f68bf00 x19: ffffff8801babc00 x18: ffffffc00d7f9058 [ 8.899572][ T599] x17: 0000000000088793 x16: ffffff80461cbe00 x15: 9100052952800785 [ 8.899575][ T599] x14: 0000000000000200 x13: 0000000000000041 x12: 9100052952800785 [ 8.899577][ T599] x11: ffffffe8dc297000 x10: ffffffe8dc297000 x9 : ffffff80461cbc80 [ 8.899580][ T599] x8 : ffffff8801babe80 x7 : ffffffe8dc2ec000 x6 : ffffffe8dc2ed000 [ 8.899583][ T599] x5 : 000000008020001f x4 : fffffffe2006eae0 x3 : 000000008020001f [ 8.899586][ T599] x2 : ffffff8027c49200 x1 : ffffff8801babc20 x0 : ffffff80461cb3a0 [ 8.899589][ T599] Call trace: [ 8.899590][ T599] gcov_info_add+0x9c/0xb8 [ 8.899592][ T599] gcov_module_notifier+0xbc/0x120 [ 8.899595][ T599] blocking_notifier_call_chain+0xa0/0x11c [ 8.899598][ T599] do_init_module+0x2a8/0x33c [ 8.899600][ T599] load_module+0x23cc/0x261c [ 8.899602][ T599] __arm64_sys_finit_module+0x158/0x194 [ 8.899604][ T599] invoke_syscall+0x94/0x2bc [ 8.899607][ T599] el0_svc_common+0x1d8/0x34c [ 8.899609][ T599] do_el0_svc+0x40/0x54 [ 8.899611][ T599] el0_svc+0x94/0x2f0 [ 8.899613][ T599] el0t_64_sync_handler+0x88/0xec [ 8.899615][ T599] el0t_64_sync+0x1b4/0x1b8 [ 8.899618][ T599] Code: f905f56c f86e69ec f86e6a0f 8b0c01ec (f82e6a0c) [ 8.899620][ T599] ---[ end trace ed5218e9e5b6e2e6 ]--- Link: https://lkml.kernel.org/r/1668020497-13142-1-git-send-email-quic_mojha@quicinc.com Fixes: e178a5be ("gcov: clang support") Signed-off-by:
Mukesh Ojha <quic_mojha@quicinc.com> Reviewed-by:
Peter Oberparleiter <oberpar@linux.ibm.com> Tested-by:
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Gautam Menghani authored
Refactor the mm_khugepaged_scan_file tracepoint to move filename dereference to the tracepoint definition, to maintain consistency with other tracepoints[1]. [1]:lore.kernel.org/lkml/20221024111621.3ba17e2c@gandalf.local.home/ Link: https://lkml.kernel.org/r/20221026044524.54793-1-gautammenghani201@gmail.com Fixes: d41fd201 ("mm/khugepaged: add tracepoint to hpage_collapse_scan_file()") Signed-off-by:
Gautam Menghani <gautammenghani201@gmail.com> Reviewed-by:
Zach O'Keefe <zokeefe@google.com> Reviewed-by:
Steven Rostedt (Google) <rostedt@goodmis.org> Cc: David Hildenbrand <david@redhat.com> Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by:
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Charan Teja Kalla authored
Fix the below compiler warnings reported with 'make W=1 mm/'. mm/page_ext.c:178: warning: Function parameter or member 'page_ext' not described in 'page_ext_put'. [quic_pkondeti@quicinc.com: better patch title] Link: https://lkml.kernel.org/r/1667884582-2465-1-git-send-email-quic_charante@quicinc.com Fixes: b1d5488a ("mm: fix use-after free of page_ext after race with memory-offline") Signed-off-by:
Charan Teja Kalla <quic_charante@quicinc.com> Reported-by:
Vlastimil Babka <vbabka@suse.cz> Tested-by:
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Yang Shi authored
Syzbot reported the below splat: WARNING: CPU: 1 PID: 3646 at include/linux/gfp.h:221 __alloc_pages_node include/linux/gfp.h:221 [inline] WARNING: CPU: 1 PID: 3646 at include/linux/gfp.h:221 hpage_collapse_alloc_page mm/khugepaged.c:807 [inline] WARNING: CPU: 1 PID: 3646 at include/linux/gfp.h:221 alloc_charge_hpage+0x802/0xaa0 mm/khugepaged.c:963 Modules linked in: CPU: 1 PID: 3646 Comm: syz-executor210 Not tainted 6.1.0-rc1-syzkaller-00454-ga7038524 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022 RIP: 0010:__alloc_pages_node include/linux/gfp.h:221 [inline] RIP: 0010:hpage_collapse_alloc_page mm/khugepaged.c:807 [inline] RIP: 0010:alloc_charge_hpage+0x802/0xaa0 mm/khugepaged.c:963 Code: e5 01 4c 89 ee e8 6e f9 ae ff 4d 85 ed 0f 84 28 fc ff ff e8 70 fc ae ff 48 8d 6b ff 4c 8d 63 07 e9 16 fc ff ff e8 5e fc ae ff <0f> 0b e9 96 fa ff ff 41 bc 1a 00 00 00 e9 86 fd ff ff e8 47 fc ae RSP: 0018:ffffc90003fdf7d8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888077f457c0 RSI: ffffffff81cd8f42 RDI: 0000000000000001 RBP: ffff888079388c0c R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f6b48ccf700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6b48a819f0 CR3: 00000000171e7000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> collapse_file+0x1ca/0x5780 mm/khugepaged.c:1715 hpage_collapse_scan_file+0xd6c/0x17a0 mm/khugepaged.c:2156 madvise_collapse+0x53a/0xb40 mm/khugepaged.c:2611 madvise_vma_behavior+0xd0a/0x1cc0 mm/madvise.c:1066 madvise_walk_vmas+0x1c7/0x2b0 mm/madvise.c:1240 do_madvise.part.0+0x24a/0x340 mm/madvise.c:1419 do_madvise mm/madvise.c:1432 [inline] __do_sys_madvise mm/madvise.c:1432 [inline] __se_sys_madvise mm/madvise.c:1430 [inline] __x64_sys_madvise+0x113/0x150 mm/madvise.c:1430 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f6b48a4eef9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 15 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f6b48ccf318 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007f6b48af0048 RCX: 00007f6b48a4eef9 RDX: 0000000000000019 RSI: 0000000000600003 RDI: 0000000020000000 RBP: 00007f6b48af0040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6b48aa53a4 R13: 00007f6b48bffcbf R14: 00007f6b48ccf400 R15: 0000000000022000 </TASK> The khugepaged code would pick up the node with the most hit as the preferred node, and also tries to do some balance if several nodes have the same hit record. Basically it does conceptually: * If the target_node <= last_target_node, then iterate from last_target_node + 1 to MAX_NUMNODES (1024 on default config) * If the max_value == node_load[nid], then target_node = nid But there is a corner case, paritucularly for MADV_COLLAPSE, that the non-existing node may be returned as preferred node. Assuming the system has 2 nodes, the target_node is 0 and the last_target_node is 1, if MADV_COLLAPSE path is hit, the max_value may be 0, then it may return 2 for target_node, but it is actually not existing (offline), so the warn is triggered. The node balance was introduced by commit 9f1b868a ("mm: thp: khugepaged: add policy for finding target node") to satisfy "numactl --interleave=all". But interleaving is a mere hint rather than something that has hard requirements. So use nodemask to record the nodes which have the same hit record, the hugepage allocation could fallback to those nodes. And remove __GFP_THISNODE since it does disallow fallback. And if the nodemask just has one node set, it means there is one single node has the most hit record, the nodemask approach actually behaves like __GFP_THISNODE. Link: https://lkml.kernel.org/r/20221108184357.55614-2-shy828301@gmail.com Fixes: 7d8faaf1 ("mm/madvise: introduce MADV_COLLAPSE sync hugepage collapse") Signed-off-by:
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Johannes Weiner authored
During proactive reclaim, we sometimes observe severe overreclaim, with several thousand times more pages reclaimed than requested. This trace was obtained from shrink_lruvec() during such an instance: prio:0 anon_cost:1141521 file_cost:7767 nr_reclaimed:4387406 nr_to_reclaim:1047 (or_factor:4190) nr=[7161123 345 578 1111] While he reclaimer requested 4M, vmscan reclaimed close to 16G, most of it by swapping. These requests take over a minute, during which the write() to memory.reclaim is unkillably stuck inside the kernel. Digging into the source, this is caused by the proportional reclaim bailout logic. This code tries to resolve a fundamental conflict: to reclaim roughly what was requested, while also aging all LRUs fairly and in accordance to their size, swappiness, refault rates etc. The way it attempts fairness is that once the reclaim goal has been reached, it stops scanning the LRUs with the smaller remaining scan targets, and adjusts the remainder of the bigger LRUs according to how much of the smaller LRUs was scanned. It then finishes scanning that remainder regardless of the reclaim goal. This works fine if priority levels are low and the LRU lists are comparable in size. However, in this instance, the cgroup that is targeted by proactive reclaim has almost no files left - they've already been squeezed out by proactive reclaim earlier - and the remaining anon pages are hot. Anon rotations cause the priority level to drop to 0, which results in reclaim targeting all of anon (a lot) and all of file (almost nothing). By the time reclaim decides to bail, it has scanned most or all of the file target, and therefor must also scan most or all of the enormous anon target. This target is thousands of times larger than the reclaim goal, thus causing the overreclaim. The bailout code hasn't changed in years, why is this failing now? The most likely explanations are two other recent changes in anon reclaim: 1. Before the series starting with commit 5df74196 ("mm: fix LRU balancing effect of new transparent huge pages"), the VM was overall relatively reluctant to swap at all, even if swap was configured. This means the LRU balancing code didn't come into play as often as it does now, and mostly in high pressure situations where pronounced swap activity wouldn't be as surprising. 2. For historic reasons, shrink_lruvec() loops on the scan targets of all LRU lists except the active anon one, meaning it would bail if the only remaining pages to scan were active anon - even if there were a lot of them. Before the series starting with commit ccc5dc67 ("mm/vmscan: make active/inactive ratio as 1:1 for anon lru"), most anon pages would live on the active LRU; the inactive one would contain only a handful of preselected reclaim candidates. After the series, anon gets aged similarly to file, and the inactive list is the default for new anon pages as well, making it often the much bigger list. As a result, the VM is now more likely to actually finish large anon targets than before. Change the code such that only one SWAP_CLUSTER_MAX-sized nudge toward the larger LRU lists is made before bailing out on a met reclaim goal. This fixes the extreme overreclaim problem. Fairness is more subtle and harder to evaluate. No obvious misbehavior was observed on the test workload, in any case. Conceptually, fairness should primarily be a cumulative effect from regular, lower priority scans. Once the VM is in trouble and needs to escalate scan targets to make forward progress, fairness needs to take a backseat. This is also acknowledged by the myriad exceptions in get_scan_count(). This patch makes fairness decrease gradually, as it keeps fairness work static over increasing priority levels with growing scan targets. This should make more sense - although we may have to re-visit the exact values. Link: https://lkml.kernel.org/r/20220802162811.39216-1-hannes@cmpxchg.orgSigned-off-by:Rik van Riel <riel@surriel.com> Acked-by:
Mel Gorman <mgorman@techsingularity.net> Cc: Hugh Dickins <hughd@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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- 08 Nov, 2022 15 commits
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Alexander Potapenko authored
Add a blank line to make the sentence before the list render as a separate paragraph, not a definition. Link: https://lkml.kernel.org/r/20221107142255.4038811-1-glider@google.com Fixes: 93858ae7 ("kmsan: add ReST documentation") Signed-off-by:
Bagas Sanjaya <bagasdotme@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by:
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SeongJae Park authored
A user could write a name of a file under 'damon/' debugfs directory, which is not a user-created context, to 'rm_contexts' file. In the case, 'dbgfs_rm_context()' just assumes it's the valid DAMON context directory only if a file of the name exist. As a result, invalid memory access could happen as below. Fix the bug by checking if the given input is for a directory. This check can filter out non-context inputs because directories under 'damon/' debugfs directory can be created via only 'mk_contexts' file. This bug has found by syzbot[1]. [1] https://lore.kernel.org/damon/000000000000ede3ac05ec4abf8e@google.com/ Link: https://lkml.kernel.org/r/20221107165001.5717-2-sj@kernel.org Fixes: 75c1c2b5 ("mm/damon/dbgfs: support multiple contexts") Signed-off-by:
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Liam Howlett authored
In RCU mode, the node limits were being updated to the last pivot which may not be correct and would cause the metadata to be set when it shouldn't. Fix this by not setting a new limit in this case. Link: https://lkml.kernel.org/r/20221107163857.867377-1-Liam.Howlett@oracle.comSigned-off-by:
Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by:
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Liam Howlett authored
It is possible to confuse the depth tracking in the maple state by searching the same node for values. Fix the depth tracking by moving where the depth is incremented closer to where the node changes level. Also change the initial depth setting when using the root node. Link: https://lkml.kernel.org/r/20221107163814.866612-1-Liam.Howlett@oracle.comSigned-off-by:
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Naoya Horiguchi authored
The following bug is reported to be triggered when starting X on x86-32 system with i915: [ 225.777375] kernel BUG at mm/memory.c:2664! [ 225.777391] invalid opcode: 0000 [#1] PREEMPT SMP [ 225.777405] CPU: 0 PID: 2402 Comm: Xorg Not tainted 6.1.0-rc3-bdg+ #86 [ 225.777415] Hardware name: /8I865G775-G, BIOS F1 08/29/2006 [ 225.777421] EIP: __apply_to_page_range+0x24d/0x31c [ 225.777437] Code: ff ff 8b 55 e8 8b 45 cc e8 0a 11 ec ff 89 d8 83 c4 28 5b 5e 5f 5d c3 81 7d e0 a0 ef 96 c1 74 ad 8b 45 d0 e8 2d 83 49 00 eb a3 <0f> 0b 25 00 f0 ff ff 81 eb 00 00 00 40 01 c3 8b 45 ec 8b 00 e8 76 [ 225.777446] EAX: 00000001 EBX: c53a3b58 ECX: b5c00000 EDX: c258aa00 [ 225.777454] ESI: b5c00000 EDI: b5900000 EBP: c4b0fdb4 ESP: c4b0fd80 [ 225.777462] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 EFLAGS: 00010202 [ 225.777470] CR0: 80050033 CR2: b5900000 CR3: 053a3000 CR4: 000006d0 [ 225.777479] Call Trace: [ 225.777486] ? i915_memcpy_init_early+0x63/0x63 [i915] [ 225.777684] apply_to_page_range+0x21/0x27 [ 225.777694] ? i915_memcpy_init_early+0x63/0x63 [i915] [ 225.777870] remap_io_mapping+0x49/0x75 [i915] [ 225.778046] ? i915_memcpy_init_early+0x63/0x63 [i915] [ 225.778220] ? mutex_unlock+0xb/0xd [ 225.778231] ? i915_vma_pin_fence+0x6d/0xf7 [i915] [ 225.778420] vm_fault_gtt+0x2a9/0x8f1 [i915] [ 225.778644] ? lock_is_held_type+0x56/0xe7 [ 225.778655] ? lock_is_held_type+0x7a/0xe7 [ 225.778663] ? 0xc1000000 [ 225.778670] __do_fault+0x21/0x6a [ 225.778679] handle_mm_fault+0x708/0xb21 [ 225.778686] ? mt_find+0x21e/0x5ae [ 225.778696] exc_page_fault+0x185/0x705 [ 225.778704] ? doublefault_shim+0x127/0x127 [ 225.778715] handle_exception+0x130/0x130 [ 225.778723] EIP: 0xb700468a Recently pud_huge() got aware of non-present entry by commit 3a194f3f ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry") to handle some special states of gigantic page. However, it's overlooked that pud_none() always returns false when running with 2-level paging, and as a result pud_huge() can return true pointlessly. Introduce "#if CONFIG_PGTABLE_LEVELS > 2" to pud_huge() to deal with this. Link: https://lkml.kernel.org/r/20221107021010.2449306-1-naoya.horiguchi@linux.dev Fixes: 3a194f3f ("mm/hugetlb: make pud_huge() and follow_huge_pud() aware of non-present pud entry") Signed-off-by:
Naoya Horiguchi <naoya.horiguchi@nec.com> Reported-by:
Ville Syrjälä <ville.syrjala@linux.intel.com> Tested-by:
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Johannes Weiner authored
When psi annotations were added to to btrfs compression reads, the psi state tracking over add_ra_bio_pages and btrfs_submit_compressed_read was faulty. A pressure state, once entered, is never left. This results in incorrectly elevated pressure, which triggers OOM kills. pflags record the *previous* memstall state when we enter a new one. The code tried to initialize pflags to 1, and then optimize the leave call when we either didn't enter a memstall, or were already inside a nested stall. However, there can be multiple PageWorkingset pages in the bio, at which point it's that path itself that enters repeatedly and overwrites pflags. This causes us to miss the exit. Enter the stall only once if needed, then unwind correctly. erofs has the same problem, fix that up too. And move the memstall exit past submit_bio() to restore submit accounting originally added by b8e24a93 ("block: annotate refault stalls from IO submission"). Link: https://lkml.kernel.org/r/Y2UHRqthNUwuIQGS@cmpxchg.org Fixes: 4088a47e ("btrfs: add manual PSI accounting for compressed reads") Fixes: 99486c51 ("erofs: add manual PSI accounting for the compressed address space") Fixes: 118f3663 ("block: remove PSI accounting from the bio layer") Link: https://lore.kernel.org/r/d20a0a85-e415-cf78-27f9-77dd7a94bc8d@leemhuis.info/Signed-off-by:
Thorsten Leemhuis <linux@leemhuis.info> Tested-by:
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Ryusuke Konishi authored
If a nilfs2 filesystem is downgraded to read-only due to metadata corruption on disk and is remounted read/write, or if emergency read-only remount is performed, detaching a log writer and synchronizing the filesystem can be done at the same time. In these cases, use-after-free of the log writer (hereinafter nilfs->ns_writer) can happen as shown in the scenario below: Task1 Task2 -------------------------------- ------------------------------ nilfs_construct_segment nilfs_segctor_sync init_wait init_waitqueue_entry add_wait_queue schedule nilfs_remount (R/W remount case) nilfs_attach_log_writer nilfs_detach_log_writer nilfs_segctor_destroy kfree finish_wait _raw_spin_lock_irqsave __raw_spin_lock_irqsave do_raw_spin_lock debug_spin_lock_before <-- use-after-free While Task1 is sleeping, nilfs->ns_writer is freed by Task2. After Task1 waked up, Task1 accesses nilfs->ns_writer which is already freed. This scenario diagram is based on the Shigeru Yoshida's post [1]. This patch fixes the issue by not detaching nilfs->ns_writer on remount so that this UAF race doesn't happen. Along with this change, this patch also inserts a few necessary read-only checks with superblock instance where only the ns_writer pointer was used to check if the filesystem is read-only. Link: https://syzkaller.appspot.com/bug?id=79a4c002e960419ca173d55e863bd09e8112df8b Link: https://lkml.kernel.org/r/20221103141759.1836312-1-syoshida@redhat.com [1] Link: https://lkml.kernel.org/r/20221104142959.28296-1-konishi.ryusuke@gmail.comSigned-off-by:Shigeru Yoshida <syoshida@redhat.com> Tested-by:
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Alexander Potapenko authored
There is a case in exc_invalid_op handler that is executed outside the irqentry_enter()/irqentry_exit() region when an UD2 instruction is used to encode a call to __warn(). In that case the `struct pt_regs` passed to the interrupt handler is never unpoisoned by KMSAN (this is normally done in irqentry_enter()), which leads to false positives inside handle_bug(). Use kmsan_unpoison_entry_regs() to explicitly unpoison those registers before using them. Link: https://lkml.kernel.org/r/20221102110611.1085175-5-glider@google.comSigned-off-by:
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Alexander Potapenko authored
As pointed out by Peter Zijlstra, __msan_poison_alloca() does not play well with IRQ code when PREEMPT_RT is on, because in that mode even GFP_ATOMIC allocations cannot be performed. Fixing this would require making stackdepot completely lockless, which is quite challenging and may be excessive for the time being. Instead, make sure KMSAN is incompatible with PREEMPT_RT, like other debug configs are. Link: https://lkml.kernel.org/r/20221102110611.1085175-4-glider@google.com Link: https://lore.kernel.org/lkml/20221025221755.3810809-1-glider@google.com/Signed-off-by:
Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Alexander Potapenko authored
As pointed out by Masahiro Yamada, Kconfig picks up the first default entry which has true 'if' condition. Hence, the previously added check for KMSAN was never used, because it followed the checks for 64BIT and !64BIT. Put KMSAN check before others to ensure it is always applied. Link: https://lkml.kernel.org/r/20221102110611.1085175-3-glider@google.com Link: https://github.com/google/kmsan/issues/89 Link: https://lore.kernel.org/linux-mm/20221024212144.2852069-3-glider@google.com/ Fixes: 921757bc ("Kconfig.debug: disable CONFIG_FRAME_WARN for KMSAN by default") Signed-off-by:
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Alexander Potapenko authored
Make sure usercopy hooks from linux/instrumented.h are invoked for copy_from_user_nmi(). This fixes KMSAN false positives reported when dumping opcodes for a stack trace. Link: https://lkml.kernel.org/r/20221102110611.1085175-2-glider@google.comSigned-off-by:
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Alexander Potapenko authored
Without that, every call to __msan_poison_alloca() in NMI may end up allocating memory, which is NMI-unsafe. Link: https://lkml.kernel.org/r/20221102110611.1085175-1-glider@google.com Link: https://lore.kernel.org/lkml/20221025221755.3810809-1-glider@google.com/Signed-off-by:
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Vasily Gorbik authored
The kernel test robot reported build failures with a 'randconfig' on s390: >> mm/hugetlb_vmemmap.c:421:11: error: a function declaration without a prototype is deprecated in all versions of C [-Werror,-Wstrict-prototypes] core_param(hugetlb_free_vmemmap, vmemmap_optimize_enabled, bool, 0); ^ Link: https://lore.kernel.org/linux-mm/202210300751.rG3UDsuc-lkp@intel.com/ Link: https://lkml.kernel.org/r/patch.git-296b83ca939b.your-ad-here.call-01667411912-ext-5073@work.hours Fixes: 30152245 ("mm: hugetlb_vmemmap: replace early_param() with core_param()") Signed-off-by:Vasily Gorbik <gor@linux.ibm.com> Reported-by:
kernel test robot <lkp@intel.com> Reviewed-by:
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Peter Xu authored
mfill_atomic_install_pte() checks page->mapping to detect whether one page is used in the page cache. However as pointed out by Matthew, the page can logically be a tail page rather than always the head in the case of uffd minor mode with UFFDIO_CONTINUE. It means we could wrongly install one pte with shmem thp tail page assuming it's an anonymous page. It's not that clear even for anonymous page, since normally anonymous pages also have page->mapping being setup with the anon vma. It's safe here only because the only such caller to mfill_atomic_install_pte() is always passing in a newly allocated page (mcopy_atomic_pte()), whose page->mapping is not yet setup. However that's not extremely obvious either. For either of above, use page_mapping() instead. Link: https://lkml.kernel.org/r/Y2K+y7wnhC4vbnP2@x1n Fixes: 15313257 ("userfaultfd/shmem: support UFFDIO_CONTINUE for shmem") Signed-off-by:
Peter Xu <peterx@redhat.com> Reported-by:
Matthew Wilcox <willy@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Pankaj Gupta authored
virtio_pmem use devm_memremap_pages() to map the device memory. By default this memory is mapped as encrypted with SEV. Guest reboot changes the current encryption key and guest no longer properly decrypts the FSDAX device meta data. Mark the corresponding device memory region for FSDAX devices (mapped with memremap_pages) as decrypted to retain the persistent memory property. Link: https://lkml.kernel.org/r/20221102160728.3184016-1-pankaj.gupta@amd.com Fixes: b7b3c01b ("mm/memremap_pages: support multiple ranges per invocation") Signed-off-by:
Pankaj Gupta <pankaj.gupta@amd.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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