The patch titled Subject: mm: fix kernel crash in khugepaged thread has been added to the -mm tree. Its filename is mm-fix-kernel-crash-in-khugepaged-thread.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mm-fix-kernel-crash-in-khugepaged-thread.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mm-fix-kernel-crash-in-khugepaged-thread.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: yalin wang <yalin.wang2010@xxxxxxxxx> Subject: mm: fix kernel crash in khugepaged thread This crash is caused by NULL pointer deference, in page_to_pfn() marco, when page == NULL : [ 182.639154 ] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 182.639491 ] pgd = ffffffc00077a000 [ 182.639761 ] [00000000] *pgd=00000000b9422003, *pud=00000000b9422003, *pmd=00000000b9423003, *pte=0060000008000707 [ 182.640749 ] Internal error: Oops: 94000006 [#1] SMP [ 182.641197 ] Modules linked in: [ 182.641580 ] CPU: 1 PID: 26 Comm: khugepaged Tainted: G W 4.3.0-rc6-next-20151022ajb-00001-g32f3386-dirty #3 [ 182.642077 ] Hardware name: linux,dummy-virt (DT) [ 182.642227 ] task: ffffffc07957c080 ti: ffffffc079638000 task.ti: ffffffc079638000 [ 182.642598 ] PC is at khugepaged+0x378/0x1af8 [ 182.642826 ] LR is at khugepaged+0x418/0x1af8 [ 182.643047 ] pc : [<ffffffc0001980ac>] lr : [<ffffffc00019814c>] pstate: 60000145 [ 182.643490 ] sp : ffffffc07963bca0 [ 182.643650 ] x29: ffffffc07963bca0 x28: ffffffc00075c000 [ 182.644024 ] x27: ffffffc00f275040 x26: ffffffc0006c7000 [ 182.644334 ] x25: 00e8000048800f51 x24: 0000000006400000 [ 182.644687 ] x23: 0000000000000002 x22: 0000000000000000 [ 182.644972 ] x21: 0000000000000000 x20: 0000000000000000 [ 182.645446 ] x19: 0000000000000000 x18: 0000007ff86d0990 [ 182.645931 ] x17: 00000000007ef9c8 x16: ffffffc000098390 [ 182.646236 ] x15: ffffffffffffffff x14: 00000000ffffffff [ 182.646649 ] x13: 000000000000016a x12: 0000000000000000 [ 182.647046 ] x11: ffffffc07f025020 x10: 0000000000000000 [ 182.647395 ] x9 : 0000000000000048 x8 : ffffffc000721e28 [ 182.647872 ] x7 : 0000000000000000 x6 : ffffffc07f02d000 [ 182.648261 ] x5 : fffffffffffffe00 x4 : ffffffc00f275040 [ 182.648611 ] x3 : 0000000000000000 x2 : ffffffc00f2ad000 [ 182.648908 ] x1 : 0000000000000000 x0 : ffffffc000727000 [ 182.649147 ] [ 182.649252 ] Process khugepaged (pid: 26, stack limit = 0xffffffc079638020) [ 182.649724 ] Stack: (0xffffffc07963bca0 to 0xffffffc07963c000) [ 182.650141 ] bca0: ffffffc07963be30 ffffffc0000b5044 ffffffc07961fb80 ffffffc00072e630 [ 182.650587 ] bcc0: ffffffc0005d5090 0000000000000000 ffffffc000197d34 0000000000000000 [ 182.651009 ] bce0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 182.651446 ] bd00: ffffffc07963bd90 ffffffc07f1cbf80 000000004f3be003 ffffffc00f2750a4 [ 182.651956 ] bd20: ffffffc00f3bf000 ffffffc000000001 0000000000000001 ffffffc07f085740 [ 182.652520 ] bd40: ffffffc00f2ad188 ffffffc000000000 0000000006200000 ffffffc00f275040 [ 182.652972 ] bd60: ffffffc0006b1a90 ffffffc079638000 ffffffc07963be20 ffffffc00f0144d0 [ 182.653357 ] bd80: ffffffc000000000 0000000006400000 ffffffc00f0144d0 00000a0800000001 [ 182.653793 ] bda0: 0000100000000001 ffffffc000000001 ffffffc07f025000 ffffffc00f2750a8 [ 182.654226 ] bdc0: 00000001000005f8 ffffffc00075a000 0000000006a00000 ffffffc000727000 [ 182.654522 ] bde0: ffffffc0006e8478 ffffffc000000000 0000000100000000 ffffffc078fb9000 [ 182.654869 ] be00: ffffffc07963be30 ffffffc000000000 ffffffc07957c080 ffffffc0000cfc4c [ 182.655225 ] be20: ffffffc07963be20 ffffffc07963be20 0000000000000000 ffffffc000085c50 [ 182.655588 ] be40: ffffffc0000b4f64 ffffffc07961fb80 0000000000000000 0000000000000000 [ 182.656138 ] be60: 0000000000000000 ffffffc0000bee2c ffffffc0000b4f64 0000000000000000 [ 182.656609 ] be80: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 182.657145 ] bea0: ffffffc07963bea0 ffffffc07963bea0 0000000000000000 ffffffc000000000 [ 182.657475 ] bec0: ffffffc07963bec0 ffffffc07963bec0 0000000000000000 0000000000000000 [ 182.657922 ] bee0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 182.658558 ] bf00: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 182.658972 ] bf20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 182.659291 ] bf40: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 182.659722 ] bf60: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 182.660122 ] bf80: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 182.660654 ] bfa0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 182.661064 ] bfc0: 0000000000000000 0000000000000000 0000000000000000 0000000000000005 [ 182.661466 ] bfe0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 182.661848 ] Call trace: [ 182.662050 ] [<ffffffc0001980ac>] khugepaged+0x378/0x1af8 [ 182.662294 ] [<ffffffc0000b5040>] kthread+0xdc/0xf4 [ 182.662605 ] [<ffffffc000085c4c>] ret_from_fork+0xc/0x40 [ 182.663046 ] Code: 35001700 f0002c60 aa0703e3 f9009fa0 (f94000e0) [ 182.663901 ] ---[ end trace 637503d8e28ae69e ]--- [ 182.664160 ] Kernel panic - not syncing: Fatal exception [ 182.664571 ] CPU2: stopping [ 182.664794 ] CPU: 2 PID: 0 Comm: swapper/2 Tainted: G D W 4.3.0-rc6-next-20151022ajb-00001-g32f3386-dirty #3 [ 182.665248 ] Hardware name: linux,dummy-virt (DT) Signed-off-by: yalin wang <yalin.wang2010@xxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Acked-by: David Rientjes <rientjes@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/trace/events/huge_memory.h | 12 ++++++------ mm/huge_memory.c | 6 +++--- 2 files changed, 9 insertions(+), 9 deletions(-) diff -puN include/trace/events/huge_memory.h~mm-fix-kernel-crash-in-khugepaged-thread include/trace/events/huge_memory.h --- a/include/trace/events/huge_memory.h~mm-fix-kernel-crash-in-khugepaged-thread +++ a/include/trace/events/huge_memory.h @@ -46,10 +46,10 @@ SCAN_STATUS TRACE_EVENT(mm_khugepaged_scan_pmd, - TP_PROTO(struct mm_struct *mm, unsigned long pfn, bool writable, + TP_PROTO(struct mm_struct *mm, struct page *page, bool writable, bool referenced, int none_or_zero, int status, int unmapped), - TP_ARGS(mm, pfn, writable, referenced, none_or_zero, status, unmapped), + TP_ARGS(mm, page, writable, referenced, none_or_zero, status, unmapped), TP_STRUCT__entry( __field(struct mm_struct *, mm) @@ -63,7 +63,7 @@ TRACE_EVENT(mm_khugepaged_scan_pmd, TP_fast_assign( __entry->mm = mm; - __entry->pfn = pfn; + __entry->pfn = page ? page_to_pfn(page) : -1; __entry->writable = writable; __entry->referenced = referenced; __entry->none_or_zero = none_or_zero; @@ -107,10 +107,10 @@ TRACE_EVENT(mm_collapse_huge_page, TRACE_EVENT(mm_collapse_huge_page_isolate, - TP_PROTO(unsigned long pfn, int none_or_zero, + TP_PROTO(struct page *page, int none_or_zero, bool referenced, bool writable, int status), - TP_ARGS(pfn, none_or_zero, referenced, writable, status), + TP_ARGS(page, none_or_zero, referenced, writable, status), TP_STRUCT__entry( __field(unsigned long, pfn) @@ -121,7 +121,7 @@ TRACE_EVENT(mm_collapse_huge_page_isolat ), TP_fast_assign( - __entry->pfn = pfn; + __entry->pfn = page ? page_to_pfn(page) : -1; __entry->none_or_zero = none_or_zero; __entry->referenced = referenced; __entry->writable = writable; diff -puN mm/huge_memory.c~mm-fix-kernel-crash-in-khugepaged-thread mm/huge_memory.c --- a/mm/huge_memory.c~mm-fix-kernel-crash-in-khugepaged-thread +++ a/mm/huge_memory.c @@ -2346,7 +2346,7 @@ static int __collapse_huge_page_isolate( if (likely(writable)) { if (likely(referenced)) { result = SCAN_SUCCEED; - trace_mm_collapse_huge_page_isolate(page_to_pfn(page), none_or_zero, + trace_mm_collapse_huge_page_isolate(page, none_or_zero, referenced, writable, result); return 1; } @@ -2356,7 +2356,7 @@ static int __collapse_huge_page_isolate( out: release_pte_pages(pte, _pte); - trace_mm_collapse_huge_page_isolate(page_to_pfn(page), none_or_zero, + trace_mm_collapse_huge_page_isolate(page, none_or_zero, referenced, writable, result); return 0; } @@ -2852,7 +2852,7 @@ out_unmap: collapse_huge_page(mm, address, hpage, vma, node); } out: - trace_mm_khugepaged_scan_pmd(mm, page_to_pfn(page), writable, referenced, + trace_mm_khugepaged_scan_pmd(mm, page, writable, referenced, none_or_zero, result, unmapped); return ret; } _ Patches currently in -mm which might be from yalin.wang2010@xxxxxxxxx are mm-fix-kernel-crash-in-khugepaged-thread.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