* [PATCH 0/2] arm64: fix two bug about page table check
@ 2022-11-16 8:38 ` Liu Shixin
0 siblings, 0 replies; 28+ messages in thread
From: Liu Shixin @ 2022-11-16 8:38 UTC (permalink / raw)
To: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang,
Anshuman Khandual, David Hildenbrand, Rafael Aquini,
Pasha Tatashin
Cc: linux-arm-kernel, linux-kernel, Liu Shixin
Denys Vlasenko has reported two bug about page table check on arm64.
On arm64, pmd_present() contains non-leaf pmd and invalid pmd too.
When collapse hugepage, the pmd is non-leaf and should skip the check.
Use pmd_leaf() instead of pmd_present().
When split hugepage, the pmd will be marked as invalid and then populate.
So we should decrease file_map_count when invalid pmd and then increase
when populate the pmd.
Liu Shixin (2):
arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud
arm64/mm: fix incorrect file_map_count for invalid pmd/pud
arch/arm64/include/asm/pgtable.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--
2.25.1
^ permalink raw reply [flat|nested] 28+ messages in thread* [PATCH 0/2] arm64: fix two bug about page table check @ 2022-11-16 8:38 ` Liu Shixin 0 siblings, 0 replies; 28+ messages in thread From: Liu Shixin @ 2022-11-16 8:38 UTC (permalink / raw) To: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel, Liu Shixin Denys Vlasenko has reported two bug about page table check on arm64. On arm64, pmd_present() contains non-leaf pmd and invalid pmd too. When collapse hugepage, the pmd is non-leaf and should skip the check. Use pmd_leaf() instead of pmd_present(). When split hugepage, the pmd will be marked as invalid and then populate. So we should decrease file_map_count when invalid pmd and then increase when populate the pmd. Liu Shixin (2): arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud arm64/mm: fix incorrect file_map_count for invalid pmd/pud arch/arm64/include/asm/pgtable.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 28+ messages in thread
* [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud 2022-11-16 8:38 ` Liu Shixin @ 2022-11-16 8:38 ` Liu Shixin -1 siblings, 0 replies; 28+ messages in thread From: Liu Shixin @ 2022-11-16 8:38 UTC (permalink / raw) To: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel, Liu Shixin The page table check trigger BUG_ON() unexpectedly when collapse hugepage: ------------[ cut here ]------------ kernel BUG at mm/page_table_check.c:82! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750 Hardware name: linux,dummy-virt (DT) pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : page_table_check_clear.isra.0+0x258/0x3f0 lr : page_table_check_clear.isra.0+0x240/0x3f0 [...] Call trace: page_table_check_clear.isra.0+0x258/0x3f0 __page_table_check_pmd_clear+0xbc/0x108 pmdp_collapse_flush+0xb0/0x160 collapse_huge_page+0xa08/0x1080 hpage_collapse_scan_pmd+0xf30/0x1590 khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8 khugepaged+0x338/0x518 kthread+0x278/0x2f8 ret_from_fork+0x10/0x20 [...] Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it decrease file_map_count for a non-leaf pmd comes from collapse_huge_page(). and so trigger BUG_ON() unexpectedly. Fix this problem by using pmd_leaf() insteal of pmd_present() in pmd_user_accessible_page(). Moreover, use pud_leaf() for pud_user_accessible_page() too. Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") Reported-by: Denys Vlasenko <dvlasenk@redhat.com> Signed-off-by: Liu Shixin <liushixin2@huawei.com> --- arch/arm64/include/asm/pgtable.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 71a1af42f0e8..edf6625ce965 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) static inline bool pmd_user_accessible_page(pmd_t pmd) { - return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); } static inline bool pud_user_accessible_page(pud_t pud) { - return pud_present(pud) && pud_user(pud); + return pud_leaf(pud) && pud_user(pud); } #endif -- 2.25.1 ^ permalink raw reply related [flat|nested] 28+ messages in thread
* [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud @ 2022-11-16 8:38 ` Liu Shixin 0 siblings, 0 replies; 28+ messages in thread From: Liu Shixin @ 2022-11-16 8:38 UTC (permalink / raw) To: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel, Liu Shixin The page table check trigger BUG_ON() unexpectedly when collapse hugepage: ------------[ cut here ]------------ kernel BUG at mm/page_table_check.c:82! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750 Hardware name: linux,dummy-virt (DT) pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : page_table_check_clear.isra.0+0x258/0x3f0 lr : page_table_check_clear.isra.0+0x240/0x3f0 [...] Call trace: page_table_check_clear.isra.0+0x258/0x3f0 __page_table_check_pmd_clear+0xbc/0x108 pmdp_collapse_flush+0xb0/0x160 collapse_huge_page+0xa08/0x1080 hpage_collapse_scan_pmd+0xf30/0x1590 khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8 khugepaged+0x338/0x518 kthread+0x278/0x2f8 ret_from_fork+0x10/0x20 [...] Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it decrease file_map_count for a non-leaf pmd comes from collapse_huge_page(). and so trigger BUG_ON() unexpectedly. Fix this problem by using pmd_leaf() insteal of pmd_present() in pmd_user_accessible_page(). Moreover, use pud_leaf() for pud_user_accessible_page() too. Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") Reported-by: Denys Vlasenko <dvlasenk@redhat.com> Signed-off-by: Liu Shixin <liushixin2@huawei.com> --- arch/arm64/include/asm/pgtable.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 71a1af42f0e8..edf6625ce965 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) static inline bool pmd_user_accessible_page(pmd_t pmd) { - return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); } static inline bool pud_user_accessible_page(pud_t pud) { - return pud_present(pud) && pud_user(pud); + return pud_leaf(pud) && pud_user(pud); } #endif -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 28+ messages in thread
* Re: [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud 2022-11-16 8:38 ` Liu Shixin @ 2022-11-16 9:04 ` David Hildenbrand -1 siblings, 0 replies; 28+ messages in thread From: David Hildenbrand @ 2022-11-16 9:04 UTC (permalink / raw) To: Liu Shixin, Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel On 16.11.22 09:38, Liu Shixin wrote: > The page table check trigger BUG_ON() unexpectedly when collapse hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:82! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750 > Hardware name: linux,dummy-virt (DT) > pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_clear.isra.0+0x258/0x3f0 > lr : page_table_check_clear.isra.0+0x240/0x3f0 > [...] > Call trace: > page_table_check_clear.isra.0+0x258/0x3f0 > __page_table_check_pmd_clear+0xbc/0x108 > pmdp_collapse_flush+0xb0/0x160 > collapse_huge_page+0xa08/0x1080 > hpage_collapse_scan_pmd+0xf30/0x1590 > khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8 > khugepaged+0x338/0x518 > kthread+0x278/0x2f8 > ret_from_fork+0x10/0x20 > [...] > > Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it > decrease file_map_count for a non-leaf pmd comes from collapse_huge_page(). > and so trigger BUG_ON() unexpectedly. > > Fix this problem by using pmd_leaf() insteal of pmd_present() in > pmd_user_accessible_page(). Moreover, use pud_leaf() for > pud_user_accessible_page() too. > > Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") > Reported-by: Denys Vlasenko <dvlasenk@redhat.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> > --- > arch/arm64/include/asm/pgtable.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 71a1af42f0e8..edf6625ce965 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) > > static inline bool pmd_user_accessible_page(pmd_t pmd) > { > - return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > } > > static inline bool pud_user_accessible_page(pud_t pud) > { > - return pud_present(pud) && pud_user(pud); > + return pud_leaf(pud) && pud_user(pud); > } > #endif > Reviewed-by: David Hildenbrand <david@redhat.com> -- Thanks, David / dhildenb ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud @ 2022-11-16 9:04 ` David Hildenbrand 0 siblings, 0 replies; 28+ messages in thread From: David Hildenbrand @ 2022-11-16 9:04 UTC (permalink / raw) To: Liu Shixin, Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel On 16.11.22 09:38, Liu Shixin wrote: > The page table check trigger BUG_ON() unexpectedly when collapse hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:82! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750 > Hardware name: linux,dummy-virt (DT) > pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_clear.isra.0+0x258/0x3f0 > lr : page_table_check_clear.isra.0+0x240/0x3f0 > [...] > Call trace: > page_table_check_clear.isra.0+0x258/0x3f0 > __page_table_check_pmd_clear+0xbc/0x108 > pmdp_collapse_flush+0xb0/0x160 > collapse_huge_page+0xa08/0x1080 > hpage_collapse_scan_pmd+0xf30/0x1590 > khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8 > khugepaged+0x338/0x518 > kthread+0x278/0x2f8 > ret_from_fork+0x10/0x20 > [...] > > Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it > decrease file_map_count for a non-leaf pmd comes from collapse_huge_page(). > and so trigger BUG_ON() unexpectedly. > > Fix this problem by using pmd_leaf() insteal of pmd_present() in > pmd_user_accessible_page(). Moreover, use pud_leaf() for > pud_user_accessible_page() too. > > Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") > Reported-by: Denys Vlasenko <dvlasenk@redhat.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> > --- > arch/arm64/include/asm/pgtable.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 71a1af42f0e8..edf6625ce965 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) > > static inline bool pmd_user_accessible_page(pmd_t pmd) > { > - return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > } > > static inline bool pud_user_accessible_page(pud_t pud) > { > - return pud_present(pud) && pud_user(pud); > + return pud_leaf(pud) && pud_user(pud); > } > #endif > Reviewed-by: David Hildenbrand <david@redhat.com> -- Thanks, David / dhildenb _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud 2022-11-16 8:38 ` Liu Shixin @ 2022-11-16 14:59 ` Pasha Tatashin -1 siblings, 0 replies; 28+ messages in thread From: Pasha Tatashin @ 2022-11-16 14:59 UTC (permalink / raw) To: Liu Shixin Cc: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, linux-arm-kernel, linux-kernel On Wed, Nov 16, 2022 at 2:51 AM Liu Shixin <liushixin2@huawei.com> wrote: > > The page table check trigger BUG_ON() unexpectedly when collapse hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:82! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750 > Hardware name: linux,dummy-virt (DT) > pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_clear.isra.0+0x258/0x3f0 > lr : page_table_check_clear.isra.0+0x240/0x3f0 > [...] > Call trace: > page_table_check_clear.isra.0+0x258/0x3f0 > __page_table_check_pmd_clear+0xbc/0x108 > pmdp_collapse_flush+0xb0/0x160 > collapse_huge_page+0xa08/0x1080 > hpage_collapse_scan_pmd+0xf30/0x1590 > khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8 > khugepaged+0x338/0x518 > kthread+0x278/0x2f8 > ret_from_fork+0x10/0x20 > [...] > > Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it > decrease file_map_count for a non-leaf pmd comes from collapse_huge_page(). > and so trigger BUG_ON() unexpectedly. > > Fix this problem by using pmd_leaf() insteal of pmd_present() in s/insteal/instead > pmd_user_accessible_page(). Moreover, use pud_leaf() for > pud_user_accessible_page() too. > > Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") > Reported-by: Denys Vlasenko <dvlasenk@redhat.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> > --- > arch/arm64/include/asm/pgtable.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 71a1af42f0e8..edf6625ce965 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) > > static inline bool pmd_user_accessible_page(pmd_t pmd) > { > - return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > } > > static inline bool pud_user_accessible_page(pud_t pud) > { > - return pud_present(pud) && pud_user(pud); > + return pud_leaf(pud) && pud_user(pud); Thanks a lot. The x86 variants are already using p*d_leaf() in these functions. Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com> ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud @ 2022-11-16 14:59 ` Pasha Tatashin 0 siblings, 0 replies; 28+ messages in thread From: Pasha Tatashin @ 2022-11-16 14:59 UTC (permalink / raw) To: Liu Shixin Cc: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, linux-arm-kernel, linux-kernel On Wed, Nov 16, 2022 at 2:51 AM Liu Shixin <liushixin2@huawei.com> wrote: > > The page table check trigger BUG_ON() unexpectedly when collapse hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:82! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750 > Hardware name: linux,dummy-virt (DT) > pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_clear.isra.0+0x258/0x3f0 > lr : page_table_check_clear.isra.0+0x240/0x3f0 > [...] > Call trace: > page_table_check_clear.isra.0+0x258/0x3f0 > __page_table_check_pmd_clear+0xbc/0x108 > pmdp_collapse_flush+0xb0/0x160 > collapse_huge_page+0xa08/0x1080 > hpage_collapse_scan_pmd+0xf30/0x1590 > khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8 > khugepaged+0x338/0x518 > kthread+0x278/0x2f8 > ret_from_fork+0x10/0x20 > [...] > > Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it > decrease file_map_count for a non-leaf pmd comes from collapse_huge_page(). > and so trigger BUG_ON() unexpectedly. > > Fix this problem by using pmd_leaf() insteal of pmd_present() in s/insteal/instead > pmd_user_accessible_page(). Moreover, use pud_leaf() for > pud_user_accessible_page() too. > > Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") > Reported-by: Denys Vlasenko <dvlasenk@redhat.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> > --- > arch/arm64/include/asm/pgtable.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 71a1af42f0e8..edf6625ce965 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) > > static inline bool pmd_user_accessible_page(pmd_t pmd) > { > - return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > } > > static inline bool pud_user_accessible_page(pud_t pud) > { > - return pud_present(pud) && pud_user(pud); > + return pud_leaf(pud) && pud_user(pud); Thanks a lot. The x86 variants are already using p*d_leaf() in these functions. Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com> _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud 2022-11-16 8:38 ` Liu Shixin @ 2022-11-17 4:09 ` Anshuman Khandual -1 siblings, 0 replies; 28+ messages in thread From: Anshuman Khandual @ 2022-11-17 4:09 UTC (permalink / raw) To: Liu Shixin, Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel On 11/16/22 14:08, Liu Shixin wrote: > The page table check trigger BUG_ON() unexpectedly when collapse hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:82! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750 > Hardware name: linux,dummy-virt (DT) > pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_clear.isra.0+0x258/0x3f0 > lr : page_table_check_clear.isra.0+0x240/0x3f0 > [...] > Call trace: > page_table_check_clear.isra.0+0x258/0x3f0 > __page_table_check_pmd_clear+0xbc/0x108 > pmdp_collapse_flush+0xb0/0x160 > collapse_huge_page+0xa08/0x1080 > hpage_collapse_scan_pmd+0xf30/0x1590 > khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8 > khugepaged+0x338/0x518 > kthread+0x278/0x2f8 > ret_from_fork+0x10/0x20 > [...] > > Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it > decrease file_map_count for a non-leaf pmd comes from collapse_huge_page(). > and so trigger BUG_ON() unexpectedly. Could you please provide the pmd_val() on the pmd entry, that triggers this BUG_ON() here ? Only additional thing pmd_leaf() ensures, is that the entry is not a table one. #define pmd_leaf(pmd) (pmd_present(pmd) && !pmd_table(pmd)) collapse_huge_page() pmd is non-leaf because it has table bit on ? > > Fix this problem by using pmd_leaf() insteal of pmd_present() in > pmd_user_accessible_page(). Moreover, use pud_leaf() for > pud_user_accessible_page() too. > > Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") > Reported-by: Denys Vlasenko <dvlasenk@redhat.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> > --- > arch/arm64/include/asm/pgtable.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 71a1af42f0e8..edf6625ce965 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) > > static inline bool pmd_user_accessible_page(pmd_t pmd) > { > - return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > } > > static inline bool pud_user_accessible_page(pud_t pud) > { > - return pud_present(pud) && pud_user(pud); > + return pud_leaf(pud) && pud_user(pud); > } > #endif > ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud @ 2022-11-17 4:09 ` Anshuman Khandual 0 siblings, 0 replies; 28+ messages in thread From: Anshuman Khandual @ 2022-11-17 4:09 UTC (permalink / raw) To: Liu Shixin, Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel On 11/16/22 14:08, Liu Shixin wrote: > The page table check trigger BUG_ON() unexpectedly when collapse hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:82! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750 > Hardware name: linux,dummy-virt (DT) > pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_clear.isra.0+0x258/0x3f0 > lr : page_table_check_clear.isra.0+0x240/0x3f0 > [...] > Call trace: > page_table_check_clear.isra.0+0x258/0x3f0 > __page_table_check_pmd_clear+0xbc/0x108 > pmdp_collapse_flush+0xb0/0x160 > collapse_huge_page+0xa08/0x1080 > hpage_collapse_scan_pmd+0xf30/0x1590 > khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8 > khugepaged+0x338/0x518 > kthread+0x278/0x2f8 > ret_from_fork+0x10/0x20 > [...] > > Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it > decrease file_map_count for a non-leaf pmd comes from collapse_huge_page(). > and so trigger BUG_ON() unexpectedly. Could you please provide the pmd_val() on the pmd entry, that triggers this BUG_ON() here ? Only additional thing pmd_leaf() ensures, is that the entry is not a table one. #define pmd_leaf(pmd) (pmd_present(pmd) && !pmd_table(pmd)) collapse_huge_page() pmd is non-leaf because it has table bit on ? > > Fix this problem by using pmd_leaf() insteal of pmd_present() in > pmd_user_accessible_page(). Moreover, use pud_leaf() for > pud_user_accessible_page() too. > > Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") > Reported-by: Denys Vlasenko <dvlasenk@redhat.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> > --- > arch/arm64/include/asm/pgtable.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 71a1af42f0e8..edf6625ce965 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) > > static inline bool pmd_user_accessible_page(pmd_t pmd) > { > - return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > } > > static inline bool pud_user_accessible_page(pud_t pud) > { > - return pud_present(pud) && pud_user(pud); > + return pud_leaf(pud) && pud_user(pud); > } > #endif > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud 2022-11-17 4:09 ` Anshuman Khandual @ 2022-11-17 6:59 ` Liu Shixin -1 siblings, 0 replies; 28+ messages in thread From: Liu Shixin @ 2022-11-17 6:59 UTC (permalink / raw) To: Anshuman Khandual, Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel On 2022/11/17 12:09, Anshuman Khandual wrote: > > On 11/16/22 14:08, Liu Shixin wrote: >> The page table check trigger BUG_ON() unexpectedly when collapse hugepage: >> >> ------------[ cut here ]------------ >> kernel BUG at mm/page_table_check.c:82! >> Internal error: Oops - BUG: 00000000f2000800 [#1] SMP >> Dumping ftrace buffer: >> (ftrace buffer empty) >> Modules linked in: >> CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750 >> Hardware name: linux,dummy-virt (DT) >> pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) >> pc : page_table_check_clear.isra.0+0x258/0x3f0 >> lr : page_table_check_clear.isra.0+0x240/0x3f0 >> [...] >> Call trace: >> page_table_check_clear.isra.0+0x258/0x3f0 >> __page_table_check_pmd_clear+0xbc/0x108 >> pmdp_collapse_flush+0xb0/0x160 >> collapse_huge_page+0xa08/0x1080 >> hpage_collapse_scan_pmd+0xf30/0x1590 >> khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8 >> khugepaged+0x338/0x518 >> kthread+0x278/0x2f8 >> ret_from_fork+0x10/0x20 >> [...] >> >> Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it >> decrease file_map_count for a non-leaf pmd comes from collapse_huge_page(). >> and so trigger BUG_ON() unexpectedly. > Could you please provide the pmd_val() on the pmd entry, that triggers this > BUG_ON() here ? Only additional thing pmd_leaf() ensures, is that the entry > is not a table one. > > #define pmd_leaf(pmd) (pmd_present(pmd) && !pmd_table(pmd)) > > collapse_huge_page() pmd is non-leaf because it has table bit on ? The pmd_val is 0x80000004c367003. It is indeed a table entry. collapse_huge_page() will replace page table of page granularity with block granularity. Before this replace, it will call pmdp_collapse_flush() to clear the table pmd. In this function, the table pmd do the check unexpectdly and trigger the BUG_ON(). diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c index 90ab721a12a8..a5c2380bac4d 100644 --- a/mm/pgtable-generic.c +++ b/mm/pgtable-generic.c @@ -221,6 +221,7 @@ pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address, VM_BUG_ON(address & ~HPAGE_PMD_MASK); VM_BUG_ON(pmd_trans_huge(*pmdp)); + pr_err("pmd_val is 0x%lx\n", pmd_val(*pmdp)); pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp); /* collapse entails shooting down ptes not pmd */ Thanks, Liu Shixin . > >> Fix this problem by using pmd_leaf() insteal of pmd_present() in >> pmd_user_accessible_page(). Moreover, use pud_leaf() for >> pud_user_accessible_page() too. >> >> Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") >> Reported-by: Denys Vlasenko <dvlasenk@redhat.com> >> Signed-off-by: Liu Shixin <liushixin2@huawei.com> >> --- >> arch/arm64/include/asm/pgtable.h | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h >> index 71a1af42f0e8..edf6625ce965 100644 >> --- a/arch/arm64/include/asm/pgtable.h >> +++ b/arch/arm64/include/asm/pgtable.h >> @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) >> >> static inline bool pmd_user_accessible_page(pmd_t pmd) >> { >> - return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); >> + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); >> } >> >> static inline bool pud_user_accessible_page(pud_t pud) >> { >> - return pud_present(pud) && pud_user(pud); >> + return pud_leaf(pud) && pud_user(pud); >> } >> #endif >> > . > ^ permalink raw reply related [flat|nested] 28+ messages in thread
* Re: [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud @ 2022-11-17 6:59 ` Liu Shixin 0 siblings, 0 replies; 28+ messages in thread From: Liu Shixin @ 2022-11-17 6:59 UTC (permalink / raw) To: Anshuman Khandual, Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel On 2022/11/17 12:09, Anshuman Khandual wrote: > > On 11/16/22 14:08, Liu Shixin wrote: >> The page table check trigger BUG_ON() unexpectedly when collapse hugepage: >> >> ------------[ cut here ]------------ >> kernel BUG at mm/page_table_check.c:82! >> Internal error: Oops - BUG: 00000000f2000800 [#1] SMP >> Dumping ftrace buffer: >> (ftrace buffer empty) >> Modules linked in: >> CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750 >> Hardware name: linux,dummy-virt (DT) >> pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) >> pc : page_table_check_clear.isra.0+0x258/0x3f0 >> lr : page_table_check_clear.isra.0+0x240/0x3f0 >> [...] >> Call trace: >> page_table_check_clear.isra.0+0x258/0x3f0 >> __page_table_check_pmd_clear+0xbc/0x108 >> pmdp_collapse_flush+0xb0/0x160 >> collapse_huge_page+0xa08/0x1080 >> hpage_collapse_scan_pmd+0xf30/0x1590 >> khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8 >> khugepaged+0x338/0x518 >> kthread+0x278/0x2f8 >> ret_from_fork+0x10/0x20 >> [...] >> >> Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it >> decrease file_map_count for a non-leaf pmd comes from collapse_huge_page(). >> and so trigger BUG_ON() unexpectedly. > Could you please provide the pmd_val() on the pmd entry, that triggers this > BUG_ON() here ? Only additional thing pmd_leaf() ensures, is that the entry > is not a table one. > > #define pmd_leaf(pmd) (pmd_present(pmd) && !pmd_table(pmd)) > > collapse_huge_page() pmd is non-leaf because it has table bit on ? The pmd_val is 0x80000004c367003. It is indeed a table entry. collapse_huge_page() will replace page table of page granularity with block granularity. Before this replace, it will call pmdp_collapse_flush() to clear the table pmd. In this function, the table pmd do the check unexpectdly and trigger the BUG_ON(). diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c index 90ab721a12a8..a5c2380bac4d 100644 --- a/mm/pgtable-generic.c +++ b/mm/pgtable-generic.c @@ -221,6 +221,7 @@ pmd_t pmdp_collapse_flush(struct vm_area_struct *vma, unsigned long address, VM_BUG_ON(address & ~HPAGE_PMD_MASK); VM_BUG_ON(pmd_trans_huge(*pmdp)); + pr_err("pmd_val is 0x%lx\n", pmd_val(*pmdp)); pmd = pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp); /* collapse entails shooting down ptes not pmd */ Thanks, Liu Shixin . > >> Fix this problem by using pmd_leaf() insteal of pmd_present() in >> pmd_user_accessible_page(). Moreover, use pud_leaf() for >> pud_user_accessible_page() too. >> >> Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") >> Reported-by: Denys Vlasenko <dvlasenk@redhat.com> >> Signed-off-by: Liu Shixin <liushixin2@huawei.com> >> --- >> arch/arm64/include/asm/pgtable.h | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h >> index 71a1af42f0e8..edf6625ce965 100644 >> --- a/arch/arm64/include/asm/pgtable.h >> +++ b/arch/arm64/include/asm/pgtable.h >> @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) >> >> static inline bool pmd_user_accessible_page(pmd_t pmd) >> { >> - return pmd_present(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); >> + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); >> } >> >> static inline bool pud_user_accessible_page(pud_t pud) >> { >> - return pud_present(pud) && pud_user(pud); >> + return pud_leaf(pud) && pud_user(pud); >> } >> #endif >> > . > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 28+ messages in thread
* Re: [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud 2022-11-16 8:38 ` Liu Shixin @ 2022-11-21 15:57 ` Denys Vlasenko -1 siblings, 0 replies; 28+ messages in thread From: Denys Vlasenko @ 2022-11-21 15:57 UTC (permalink / raw) To: Liu Shixin, Catalin Marinas, Will Deacon, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel On 11/16/22 09:38, Liu Shixin wrote: > The page table check trigger BUG_ON() unexpectedly when collapse hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:82! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750 > Hardware name: linux,dummy-virt (DT) > pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_clear.isra.0+0x258/0x3f0 > lr : page_table_check_clear.isra.0+0x240/0x3f0 > [...] > Call trace: > page_table_check_clear.isra.0+0x258/0x3f0 > __page_table_check_pmd_clear+0xbc/0x108 > pmdp_collapse_flush+0xb0/0x160 > collapse_huge_page+0xa08/0x1080 > hpage_collapse_scan_pmd+0xf30/0x1590 > khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8 > khugepaged+0x338/0x518 > kthread+0x278/0x2f8 > ret_from_fork+0x10/0x20 > [...] > > Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it > decrease file_map_count for a non-leaf pmd comes from collapse_huge_page(). > and so trigger BUG_ON() unexpectedly. > > Fix this problem by using pmd_leaf() insteal of pmd_present() in > pmd_user_accessible_page(). Moreover, use pud_leaf() for > pud_user_accessible_page() too. > > Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") > Reported-by: Denys Vlasenko <dvlasenk@redhat.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> Tested on 6.0.6 kernel, no oopses anymore. ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud @ 2022-11-21 15:57 ` Denys Vlasenko 0 siblings, 0 replies; 28+ messages in thread From: Denys Vlasenko @ 2022-11-21 15:57 UTC (permalink / raw) To: Liu Shixin, Catalin Marinas, Will Deacon, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel On 11/16/22 09:38, Liu Shixin wrote: > The page table check trigger BUG_ON() unexpectedly when collapse hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:82! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 6 PID: 68 Comm: khugepaged Not tainted 6.1.0-rc3+ #750 > Hardware name: linux,dummy-virt (DT) > pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_clear.isra.0+0x258/0x3f0 > lr : page_table_check_clear.isra.0+0x240/0x3f0 > [...] > Call trace: > page_table_check_clear.isra.0+0x258/0x3f0 > __page_table_check_pmd_clear+0xbc/0x108 > pmdp_collapse_flush+0xb0/0x160 > collapse_huge_page+0xa08/0x1080 > hpage_collapse_scan_pmd+0xf30/0x1590 > khugepaged_scan_mm_slot.constprop.0+0x52c/0xac8 > khugepaged+0x338/0x518 > kthread+0x278/0x2f8 > ret_from_fork+0x10/0x20 > [...] > > Since pmd_user_accessible_page() doesn't check if a pmd is leaf, it > decrease file_map_count for a non-leaf pmd comes from collapse_huge_page(). > and so trigger BUG_ON() unexpectedly. > > Fix this problem by using pmd_leaf() insteal of pmd_present() in > pmd_user_accessible_page(). Moreover, use pud_leaf() for > pud_user_accessible_page() too. > > Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") > Reported-by: Denys Vlasenko <dvlasenk@redhat.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> Tested on 6.0.6 kernel, no oopses anymore. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 28+ messages in thread
* [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud 2022-11-16 8:38 ` Liu Shixin @ 2022-11-16 8:38 ` Liu Shixin -1 siblings, 0 replies; 28+ messages in thread From: Liu Shixin @ 2022-11-16 8:38 UTC (permalink / raw) To: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel, Liu Shixin The page table check trigger BUG_ON() unexpectedly when split hugepage: ------------[ cut here ]------------ kernel BUG at mm/page_table_check.c:119! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 Hardware name: linux,dummy-virt (DT) pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : page_table_check_set.isra.0+0x398/0x468 lr : page_table_check_set.isra.0+0x1c0/0x468 [...] Call trace: page_table_check_set.isra.0+0x398/0x468 __page_table_check_pte_set+0x160/0x1c0 __split_huge_pmd_locked+0x900/0x1648 __split_huge_pmd+0x28c/0x3b8 unmap_page_range+0x428/0x858 unmap_single_vma+0xf4/0x1c8 zap_page_range+0x2b0/0x410 madvise_vma_behavior+0xc44/0xe78 do_madvise+0x280/0x698 __arm64_sys_madvise+0x90/0xe8 invoke_syscall.constprop.0+0xdc/0x1d8 do_el0_svc+0xf4/0x3f8 el0_svc+0x58/0x120 el0t_64_sync_handler+0xb8/0xc0 el0t_64_sync+0x19c/0x1a0 [...] On arm64, pmd_present() will return true even if the pmd is invalid. So in pmdp_invalidate() the file_map_count will not only decrease once but also increase once. Then in set_pte_at(), the file_map_count increase again, and so trigger BUG_ON() unexpectedly. Fix this problem by adding pmd_valid() in pmd_user_accessible_page(). Moreover, add pud_valid() for pud_user_accessible_page() too. Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") Reported-by: Denys Vlasenko <dvlasenk@redhat.com> Signed-off-by: Liu Shixin <liushixin2@huawei.com> --- arch/arm64/include/asm/pgtable.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index edf6625ce965..56e178de75e7 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) static inline bool pmd_user_accessible_page(pmd_t pmd) { - return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)) && pmd_valid(pmd); } static inline bool pud_user_accessible_page(pud_t pud) { - return pud_leaf(pud) && pud_user(pud); + return pud_leaf(pud) && pud_user(pud) && pud_valid(pud); } #endif -- 2.25.1 ^ permalink raw reply related [flat|nested] 28+ messages in thread
* [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud @ 2022-11-16 8:38 ` Liu Shixin 0 siblings, 0 replies; 28+ messages in thread From: Liu Shixin @ 2022-11-16 8:38 UTC (permalink / raw) To: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel, Liu Shixin The page table check trigger BUG_ON() unexpectedly when split hugepage: ------------[ cut here ]------------ kernel BUG at mm/page_table_check.c:119! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 Hardware name: linux,dummy-virt (DT) pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : page_table_check_set.isra.0+0x398/0x468 lr : page_table_check_set.isra.0+0x1c0/0x468 [...] Call trace: page_table_check_set.isra.0+0x398/0x468 __page_table_check_pte_set+0x160/0x1c0 __split_huge_pmd_locked+0x900/0x1648 __split_huge_pmd+0x28c/0x3b8 unmap_page_range+0x428/0x858 unmap_single_vma+0xf4/0x1c8 zap_page_range+0x2b0/0x410 madvise_vma_behavior+0xc44/0xe78 do_madvise+0x280/0x698 __arm64_sys_madvise+0x90/0xe8 invoke_syscall.constprop.0+0xdc/0x1d8 do_el0_svc+0xf4/0x3f8 el0_svc+0x58/0x120 el0t_64_sync_handler+0xb8/0xc0 el0t_64_sync+0x19c/0x1a0 [...] On arm64, pmd_present() will return true even if the pmd is invalid. So in pmdp_invalidate() the file_map_count will not only decrease once but also increase once. Then in set_pte_at(), the file_map_count increase again, and so trigger BUG_ON() unexpectedly. Fix this problem by adding pmd_valid() in pmd_user_accessible_page(). Moreover, add pud_valid() for pud_user_accessible_page() too. Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") Reported-by: Denys Vlasenko <dvlasenk@redhat.com> Signed-off-by: Liu Shixin <liushixin2@huawei.com> --- arch/arm64/include/asm/pgtable.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index edf6625ce965..56e178de75e7 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) static inline bool pmd_user_accessible_page(pmd_t pmd) { - return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)) && pmd_valid(pmd); } static inline bool pud_user_accessible_page(pud_t pud) { - return pud_leaf(pud) && pud_user(pud); + return pud_leaf(pud) && pud_user(pud) && pud_valid(pud); } #endif -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply related [flat|nested] 28+ messages in thread
* Re: [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud 2022-11-16 8:38 ` Liu Shixin @ 2022-11-16 9:08 ` David Hildenbrand -1 siblings, 0 replies; 28+ messages in thread From: David Hildenbrand @ 2022-11-16 9:08 UTC (permalink / raw) To: Liu Shixin, Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel On 16.11.22 09:38, Liu Shixin wrote: > The page table check trigger BUG_ON() unexpectedly when split hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:119! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 > Hardware name: linux,dummy-virt (DT) > pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_set.isra.0+0x398/0x468 > lr : page_table_check_set.isra.0+0x1c0/0x468 > [...] > Call trace: > page_table_check_set.isra.0+0x398/0x468 > __page_table_check_pte_set+0x160/0x1c0 > __split_huge_pmd_locked+0x900/0x1648 > __split_huge_pmd+0x28c/0x3b8 > unmap_page_range+0x428/0x858 > unmap_single_vma+0xf4/0x1c8 > zap_page_range+0x2b0/0x410 > madvise_vma_behavior+0xc44/0xe78 > do_madvise+0x280/0x698 > __arm64_sys_madvise+0x90/0xe8 > invoke_syscall.constprop.0+0xdc/0x1d8 > do_el0_svc+0xf4/0x3f8 > el0_svc+0x58/0x120 > el0t_64_sync_handler+0xb8/0xc0 > el0t_64_sync+0x19c/0x1a0 > [...] > > On arm64, pmd_present() will return true even if the pmd is invalid. I assume that's because of the pmd_present_invalid() check. ... I wonder why that behavior was chosen. Sounds error-prone to me. Fix LGHTM, but I am not an arm64 pgtable expert. -- Thanks, David / dhildenb ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud @ 2022-11-16 9:08 ` David Hildenbrand 0 siblings, 0 replies; 28+ messages in thread From: David Hildenbrand @ 2022-11-16 9:08 UTC (permalink / raw) To: Liu Shixin, Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin Cc: linux-arm-kernel, linux-kernel On 16.11.22 09:38, Liu Shixin wrote: > The page table check trigger BUG_ON() unexpectedly when split hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:119! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 > Hardware name: linux,dummy-virt (DT) > pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_set.isra.0+0x398/0x468 > lr : page_table_check_set.isra.0+0x1c0/0x468 > [...] > Call trace: > page_table_check_set.isra.0+0x398/0x468 > __page_table_check_pte_set+0x160/0x1c0 > __split_huge_pmd_locked+0x900/0x1648 > __split_huge_pmd+0x28c/0x3b8 > unmap_page_range+0x428/0x858 > unmap_single_vma+0xf4/0x1c8 > zap_page_range+0x2b0/0x410 > madvise_vma_behavior+0xc44/0xe78 > do_madvise+0x280/0x698 > __arm64_sys_madvise+0x90/0xe8 > invoke_syscall.constprop.0+0xdc/0x1d8 > do_el0_svc+0xf4/0x3f8 > el0_svc+0x58/0x120 > el0t_64_sync_handler+0xb8/0xc0 > el0t_64_sync+0x19c/0x1a0 > [...] > > On arm64, pmd_present() will return true even if the pmd is invalid. I assume that's because of the pmd_present_invalid() check. ... I wonder why that behavior was chosen. Sounds error-prone to me. Fix LGHTM, but I am not an arm64 pgtable expert. -- Thanks, David / dhildenb _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud 2022-11-16 9:08 ` David Hildenbrand @ 2022-11-16 15:46 ` Mark Rutland -1 siblings, 0 replies; 28+ messages in thread From: Mark Rutland @ 2022-11-16 15:46 UTC (permalink / raw) To: David Hildenbrand Cc: Liu Shixin, Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin, linux-arm-kernel, linux-kernel On Wed, Nov 16, 2022 at 10:08:27AM +0100, David Hildenbrand wrote: > On 16.11.22 09:38, Liu Shixin wrote: > > The page table check trigger BUG_ON() unexpectedly when split hugepage: > > > > ------------[ cut here ]------------ > > kernel BUG at mm/page_table_check.c:119! > > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > > Dumping ftrace buffer: > > (ftrace buffer empty) > > Modules linked in: > > CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 > > Hardware name: linux,dummy-virt (DT) > > pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > > pc : page_table_check_set.isra.0+0x398/0x468 > > lr : page_table_check_set.isra.0+0x1c0/0x468 > > [...] > > Call trace: > > page_table_check_set.isra.0+0x398/0x468 > > __page_table_check_pte_set+0x160/0x1c0 > > __split_huge_pmd_locked+0x900/0x1648 > > __split_huge_pmd+0x28c/0x3b8 > > unmap_page_range+0x428/0x858 > > unmap_single_vma+0xf4/0x1c8 > > zap_page_range+0x2b0/0x410 > > madvise_vma_behavior+0xc44/0xe78 > > do_madvise+0x280/0x698 > > __arm64_sys_madvise+0x90/0xe8 > > invoke_syscall.constprop.0+0xdc/0x1d8 > > do_el0_svc+0xf4/0x3f8 > > el0_svc+0x58/0x120 > > el0t_64_sync_handler+0xb8/0xc0 > > el0t_64_sync+0x19c/0x1a0 > > [...] > > > > On arm64, pmd_present() will return true even if the pmd is invalid. > > I assume that's because of the pmd_present_invalid() check. > > ... I wonder why that behavior was chosen. Sounds error-prone to me. That seems to be down to commit: b65399f6111b03df ("arm64/mm: Change THP helpers to comply with generic MM semantics") ... apparently because Andrea Arcangelli said this was necessary in: https://lore.kernel.org/lkml/20181017020930.GN30832@redhat.com/ ... but that does see to contradict what's said in: Documentation/mm/arch_pgtable_helpers.rst ... which just says: pmd_present Tests a valid mapped PMD ... and it's not clear to me why this *only* applies to the PMD level. Anshuman? Thanks, Mark. ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud @ 2022-11-16 15:46 ` Mark Rutland 0 siblings, 0 replies; 28+ messages in thread From: Mark Rutland @ 2022-11-16 15:46 UTC (permalink / raw) To: David Hildenbrand Cc: Liu Shixin, Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin, linux-arm-kernel, linux-kernel On Wed, Nov 16, 2022 at 10:08:27AM +0100, David Hildenbrand wrote: > On 16.11.22 09:38, Liu Shixin wrote: > > The page table check trigger BUG_ON() unexpectedly when split hugepage: > > > > ------------[ cut here ]------------ > > kernel BUG at mm/page_table_check.c:119! > > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > > Dumping ftrace buffer: > > (ftrace buffer empty) > > Modules linked in: > > CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 > > Hardware name: linux,dummy-virt (DT) > > pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > > pc : page_table_check_set.isra.0+0x398/0x468 > > lr : page_table_check_set.isra.0+0x1c0/0x468 > > [...] > > Call trace: > > page_table_check_set.isra.0+0x398/0x468 > > __page_table_check_pte_set+0x160/0x1c0 > > __split_huge_pmd_locked+0x900/0x1648 > > __split_huge_pmd+0x28c/0x3b8 > > unmap_page_range+0x428/0x858 > > unmap_single_vma+0xf4/0x1c8 > > zap_page_range+0x2b0/0x410 > > madvise_vma_behavior+0xc44/0xe78 > > do_madvise+0x280/0x698 > > __arm64_sys_madvise+0x90/0xe8 > > invoke_syscall.constprop.0+0xdc/0x1d8 > > do_el0_svc+0xf4/0x3f8 > > el0_svc+0x58/0x120 > > el0t_64_sync_handler+0xb8/0xc0 > > el0t_64_sync+0x19c/0x1a0 > > [...] > > > > On arm64, pmd_present() will return true even if the pmd is invalid. > > I assume that's because of the pmd_present_invalid() check. > > ... I wonder why that behavior was chosen. Sounds error-prone to me. That seems to be down to commit: b65399f6111b03df ("arm64/mm: Change THP helpers to comply with generic MM semantics") ... apparently because Andrea Arcangelli said this was necessary in: https://lore.kernel.org/lkml/20181017020930.GN30832@redhat.com/ ... but that does see to contradict what's said in: Documentation/mm/arch_pgtable_helpers.rst ... which just says: pmd_present Tests a valid mapped PMD ... and it's not clear to me why this *only* applies to the PMD level. Anshuman? Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud 2022-11-16 15:46 ` Mark Rutland @ 2022-11-17 4:24 ` Anshuman Khandual -1 siblings, 0 replies; 28+ messages in thread From: Anshuman Khandual @ 2022-11-17 4:24 UTC (permalink / raw) To: Mark Rutland, David Hildenbrand Cc: Liu Shixin, Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, David Hildenbrand, Rafael Aquini, Pasha Tatashin, linux-arm-kernel, linux-kernel On 11/16/22 21:16, Mark Rutland wrote: > On Wed, Nov 16, 2022 at 10:08:27AM +0100, David Hildenbrand wrote: >> On 16.11.22 09:38, Liu Shixin wrote: >>> The page table check trigger BUG_ON() unexpectedly when split hugepage: >>> >>> ------------[ cut here ]------------ >>> kernel BUG at mm/page_table_check.c:119! >>> Internal error: Oops - BUG: 00000000f2000800 [#1] SMP >>> Dumping ftrace buffer: >>> (ftrace buffer empty) >>> Modules linked in: >>> CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 >>> Hardware name: linux,dummy-virt (DT) >>> pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) >>> pc : page_table_check_set.isra.0+0x398/0x468 >>> lr : page_table_check_set.isra.0+0x1c0/0x468 >>> [...] >>> Call trace: >>> page_table_check_set.isra.0+0x398/0x468 >>> __page_table_check_pte_set+0x160/0x1c0 >>> __split_huge_pmd_locked+0x900/0x1648 >>> __split_huge_pmd+0x28c/0x3b8 >>> unmap_page_range+0x428/0x858 >>> unmap_single_vma+0xf4/0x1c8 >>> zap_page_range+0x2b0/0x410 >>> madvise_vma_behavior+0xc44/0xe78 >>> do_madvise+0x280/0x698 >>> __arm64_sys_madvise+0x90/0xe8 >>> invoke_syscall.constprop.0+0xdc/0x1d8 >>> do_el0_svc+0xf4/0x3f8 >>> el0_svc+0x58/0x120 >>> el0t_64_sync_handler+0xb8/0xc0 >>> el0t_64_sync+0x19c/0x1a0 >>> [...] >>> >>> On arm64, pmd_present() will return true even if the pmd is invalid. >> >> I assume that's because of the pmd_present_invalid() check. >> >> ... I wonder why that behavior was chosen. Sounds error-prone to me. > > That seems to be down to commit: > > b65399f6111b03df ("arm64/mm: Change THP helpers to comply with generic MM semantics") > > ... apparently because Andrea Arcangelli said this was necessary in: > > https://lore.kernel.org/lkml/20181017020930.GN30832@redhat.com/ > > ... but that does see to contradict what's said in: > > Documentation/mm/arch_pgtable_helpers.rst > > ... which just says: > > pmd_present Tests a valid mapped PMD It should be as follows instead, will update. Not sure about PUD level though, where anon THP is not supported (AFAIK). +---------------------------+--------------------------------------------------+ | pmd_present | Tests if pmd_page() points to valid memory page | +---------------------------+--------------------------------------------------+ > > ... and it's not clear to me why this *only* applies to the PMD level. > > Anshuman? Because THP is supported at PMD level. As Andrea had explained earlier, pmd_present() should return positive if pmd_page() on the entry points to valid memory irrespective of whether the entry is valid/mapped or not. That is the semantics expected in generic THP during PMD split, collapse, migration etc and other memory code walking past such PMD entries. That was my understanding. ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud @ 2022-11-17 4:24 ` Anshuman Khandual 0 siblings, 0 replies; 28+ messages in thread From: Anshuman Khandual @ 2022-11-17 4:24 UTC (permalink / raw) To: Mark Rutland, David Hildenbrand Cc: Liu Shixin, Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, David Hildenbrand, Rafael Aquini, Pasha Tatashin, linux-arm-kernel, linux-kernel On 11/16/22 21:16, Mark Rutland wrote: > On Wed, Nov 16, 2022 at 10:08:27AM +0100, David Hildenbrand wrote: >> On 16.11.22 09:38, Liu Shixin wrote: >>> The page table check trigger BUG_ON() unexpectedly when split hugepage: >>> >>> ------------[ cut here ]------------ >>> kernel BUG at mm/page_table_check.c:119! >>> Internal error: Oops - BUG: 00000000f2000800 [#1] SMP >>> Dumping ftrace buffer: >>> (ftrace buffer empty) >>> Modules linked in: >>> CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 >>> Hardware name: linux,dummy-virt (DT) >>> pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) >>> pc : page_table_check_set.isra.0+0x398/0x468 >>> lr : page_table_check_set.isra.0+0x1c0/0x468 >>> [...] >>> Call trace: >>> page_table_check_set.isra.0+0x398/0x468 >>> __page_table_check_pte_set+0x160/0x1c0 >>> __split_huge_pmd_locked+0x900/0x1648 >>> __split_huge_pmd+0x28c/0x3b8 >>> unmap_page_range+0x428/0x858 >>> unmap_single_vma+0xf4/0x1c8 >>> zap_page_range+0x2b0/0x410 >>> madvise_vma_behavior+0xc44/0xe78 >>> do_madvise+0x280/0x698 >>> __arm64_sys_madvise+0x90/0xe8 >>> invoke_syscall.constprop.0+0xdc/0x1d8 >>> do_el0_svc+0xf4/0x3f8 >>> el0_svc+0x58/0x120 >>> el0t_64_sync_handler+0xb8/0xc0 >>> el0t_64_sync+0x19c/0x1a0 >>> [...] >>> >>> On arm64, pmd_present() will return true even if the pmd is invalid. >> >> I assume that's because of the pmd_present_invalid() check. >> >> ... I wonder why that behavior was chosen. Sounds error-prone to me. > > That seems to be down to commit: > > b65399f6111b03df ("arm64/mm: Change THP helpers to comply with generic MM semantics") > > ... apparently because Andrea Arcangelli said this was necessary in: > > https://lore.kernel.org/lkml/20181017020930.GN30832@redhat.com/ > > ... but that does see to contradict what's said in: > > Documentation/mm/arch_pgtable_helpers.rst > > ... which just says: > > pmd_present Tests a valid mapped PMD It should be as follows instead, will update. Not sure about PUD level though, where anon THP is not supported (AFAIK). +---------------------------+--------------------------------------------------+ | pmd_present | Tests if pmd_page() points to valid memory page | +---------------------------+--------------------------------------------------+ > > ... and it's not clear to me why this *only* applies to the PMD level. > > Anshuman? Because THP is supported at PMD level. As Andrea had explained earlier, pmd_present() should return positive if pmd_page() on the entry points to valid memory irrespective of whether the entry is valid/mapped or not. That is the semantics expected in generic THP during PMD split, collapse, migration etc and other memory code walking past such PMD entries. That was my understanding. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud 2022-11-16 8:38 ` Liu Shixin @ 2022-11-16 15:18 ` Pasha Tatashin -1 siblings, 0 replies; 28+ messages in thread From: Pasha Tatashin @ 2022-11-16 15:18 UTC (permalink / raw) To: Liu Shixin Cc: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, linux-arm-kernel, linux-kernel On Wed, Nov 16, 2022 at 2:51 AM Liu Shixin <liushixin2@huawei.com> wrote: > > The page table check trigger BUG_ON() unexpectedly when split hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:119! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 > Hardware name: linux,dummy-virt (DT) > pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_set.isra.0+0x398/0x468 > lr : page_table_check_set.isra.0+0x1c0/0x468 > [...] > Call trace: > page_table_check_set.isra.0+0x398/0x468 > __page_table_check_pte_set+0x160/0x1c0 > __split_huge_pmd_locked+0x900/0x1648 > __split_huge_pmd+0x28c/0x3b8 > unmap_page_range+0x428/0x858 > unmap_single_vma+0xf4/0x1c8 > zap_page_range+0x2b0/0x410 > madvise_vma_behavior+0xc44/0xe78 > do_madvise+0x280/0x698 > __arm64_sys_madvise+0x90/0xe8 > invoke_syscall.constprop.0+0xdc/0x1d8 > do_el0_svc+0xf4/0x3f8 > el0_svc+0x58/0x120 > el0t_64_sync_handler+0xb8/0xc0 > el0t_64_sync+0x19c/0x1a0 > [...] > > On arm64, pmd_present() will return true even if the pmd is invalid. > in pmdp_invalidate() the file_map_count will not only decrease once but > also increase once. Then in set_pte_at(), the file_map_count increase > again, and so trigger BUG_ON() unexpectedly. > static inline bool pmd_user_accessible_page(pmd_t pmd) > { > - return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)) && pmd_valid(pmd); > } > > static inline bool pud_user_accessible_page(pud_t pud) > { > - return pud_leaf(pud) && pud_user(pud); > + return pud_leaf(pud) && pud_user(pud) && pud_valid(pud); This looks closer to x86 where the check is directly: pmd_val(pmd) & _PAGE_PRESENT, without PTE_PROT_NONE that is part of pmd_present() Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com> Thanks, Pasha ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud @ 2022-11-16 15:18 ` Pasha Tatashin 0 siblings, 0 replies; 28+ messages in thread From: Pasha Tatashin @ 2022-11-16 15:18 UTC (permalink / raw) To: Liu Shixin Cc: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, linux-arm-kernel, linux-kernel On Wed, Nov 16, 2022 at 2:51 AM Liu Shixin <liushixin2@huawei.com> wrote: > > The page table check trigger BUG_ON() unexpectedly when split hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:119! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 > Hardware name: linux,dummy-virt (DT) > pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_set.isra.0+0x398/0x468 > lr : page_table_check_set.isra.0+0x1c0/0x468 > [...] > Call trace: > page_table_check_set.isra.0+0x398/0x468 > __page_table_check_pte_set+0x160/0x1c0 > __split_huge_pmd_locked+0x900/0x1648 > __split_huge_pmd+0x28c/0x3b8 > unmap_page_range+0x428/0x858 > unmap_single_vma+0xf4/0x1c8 > zap_page_range+0x2b0/0x410 > madvise_vma_behavior+0xc44/0xe78 > do_madvise+0x280/0x698 > __arm64_sys_madvise+0x90/0xe8 > invoke_syscall.constprop.0+0xdc/0x1d8 > do_el0_svc+0xf4/0x3f8 > el0_svc+0x58/0x120 > el0t_64_sync_handler+0xb8/0xc0 > el0t_64_sync+0x19c/0x1a0 > [...] > > On arm64, pmd_present() will return true even if the pmd is invalid. > in pmdp_invalidate() the file_map_count will not only decrease once but > also increase once. Then in set_pte_at(), the file_map_count increase > again, and so trigger BUG_ON() unexpectedly. > static inline bool pmd_user_accessible_page(pmd_t pmd) > { > - return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)) && pmd_valid(pmd); > } > > static inline bool pud_user_accessible_page(pud_t pud) > { > - return pud_leaf(pud) && pud_user(pud); > + return pud_leaf(pud) && pud_user(pud) && pud_valid(pud); This looks closer to x86 where the check is directly: pmd_val(pmd) & _PAGE_PRESENT, without PTE_PROT_NONE that is part of pmd_present() Acked-by: Pasha Tatashin <pasha.tatashin@soleen.com> Thanks, Pasha _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud 2022-11-16 8:38 ` Liu Shixin @ 2022-11-16 15:52 ` Mark Rutland -1 siblings, 0 replies; 28+ messages in thread From: Mark Rutland @ 2022-11-16 15:52 UTC (permalink / raw) To: Liu Shixin Cc: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin, linux-arm-kernel, linux-kernel On Wed, Nov 16, 2022 at 04:38:11PM +0800, Liu Shixin wrote: > The page table check trigger BUG_ON() unexpectedly when split hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:119! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 > Hardware name: linux,dummy-virt (DT) > pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_set.isra.0+0x398/0x468 > lr : page_table_check_set.isra.0+0x1c0/0x468 > [...] > Call trace: > page_table_check_set.isra.0+0x398/0x468 > __page_table_check_pte_set+0x160/0x1c0 > __split_huge_pmd_locked+0x900/0x1648 > __split_huge_pmd+0x28c/0x3b8 > unmap_page_range+0x428/0x858 > unmap_single_vma+0xf4/0x1c8 > zap_page_range+0x2b0/0x410 > madvise_vma_behavior+0xc44/0xe78 > do_madvise+0x280/0x698 > __arm64_sys_madvise+0x90/0xe8 > invoke_syscall.constprop.0+0xdc/0x1d8 > do_el0_svc+0xf4/0x3f8 > el0_svc+0x58/0x120 > el0t_64_sync_handler+0xb8/0xc0 > el0t_64_sync+0x19c/0x1a0 > [...] > > On arm64, pmd_present() will return true even if the pmd is invalid. So > in pmdp_invalidate() the file_map_count will not only decrease once but > also increase once. Then in set_pte_at(), the file_map_count increase > again, and so trigger BUG_ON() unexpectedly. It's not clear to me how pmd_present() relates to p?d_user_accessible_page() below. How are they related? (or is this a copy-paste error)? > Fix this problem by adding pmd_valid() in pmd_user_accessible_page(). > Moreover, add pud_valid() for pud_user_accessible_page() too. > > Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") > Reported-by: Denys Vlasenko <dvlasenk@redhat.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> > --- > arch/arm64/include/asm/pgtable.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index edf6625ce965..56e178de75e7 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) > > static inline bool pmd_user_accessible_page(pmd_t pmd) > { > - return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)) && pmd_valid(pmd); > } > > static inline bool pud_user_accessible_page(pud_t pud) > { > - return pud_leaf(pud) && pud_user(pud); > + return pud_leaf(pud) && pud_user(pud) && pud_valid(pud); I think these p?d_valid() checks should be first for clarity, since the other bits aren't necessarily meaningful for !valid entries. Thanks, Mark. ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud @ 2022-11-16 15:52 ` Mark Rutland 0 siblings, 0 replies; 28+ messages in thread From: Mark Rutland @ 2022-11-16 15:52 UTC (permalink / raw) To: Liu Shixin Cc: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin, linux-arm-kernel, linux-kernel On Wed, Nov 16, 2022 at 04:38:11PM +0800, Liu Shixin wrote: > The page table check trigger BUG_ON() unexpectedly when split hugepage: > > ------------[ cut here ]------------ > kernel BUG at mm/page_table_check.c:119! > Internal error: Oops - BUG: 00000000f2000800 [#1] SMP > Dumping ftrace buffer: > (ftrace buffer empty) > Modules linked in: > CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 > Hardware name: linux,dummy-virt (DT) > pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : page_table_check_set.isra.0+0x398/0x468 > lr : page_table_check_set.isra.0+0x1c0/0x468 > [...] > Call trace: > page_table_check_set.isra.0+0x398/0x468 > __page_table_check_pte_set+0x160/0x1c0 > __split_huge_pmd_locked+0x900/0x1648 > __split_huge_pmd+0x28c/0x3b8 > unmap_page_range+0x428/0x858 > unmap_single_vma+0xf4/0x1c8 > zap_page_range+0x2b0/0x410 > madvise_vma_behavior+0xc44/0xe78 > do_madvise+0x280/0x698 > __arm64_sys_madvise+0x90/0xe8 > invoke_syscall.constprop.0+0xdc/0x1d8 > do_el0_svc+0xf4/0x3f8 > el0_svc+0x58/0x120 > el0t_64_sync_handler+0xb8/0xc0 > el0t_64_sync+0x19c/0x1a0 > [...] > > On arm64, pmd_present() will return true even if the pmd is invalid. So > in pmdp_invalidate() the file_map_count will not only decrease once but > also increase once. Then in set_pte_at(), the file_map_count increase > again, and so trigger BUG_ON() unexpectedly. It's not clear to me how pmd_present() relates to p?d_user_accessible_page() below. How are they related? (or is this a copy-paste error)? > Fix this problem by adding pmd_valid() in pmd_user_accessible_page(). > Moreover, add pud_valid() for pud_user_accessible_page() too. > > Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") > Reported-by: Denys Vlasenko <dvlasenk@redhat.com> > Signed-off-by: Liu Shixin <liushixin2@huawei.com> > --- > arch/arm64/include/asm/pgtable.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index edf6625ce965..56e178de75e7 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) > > static inline bool pmd_user_accessible_page(pmd_t pmd) > { > - return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); > + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)) && pmd_valid(pmd); > } > > static inline bool pud_user_accessible_page(pud_t pud) > { > - return pud_leaf(pud) && pud_user(pud); > + return pud_leaf(pud) && pud_user(pud) && pud_valid(pud); I think these p?d_valid() checks should be first for clarity, since the other bits aren't necessarily meaningful for !valid entries. Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud 2022-11-16 15:52 ` Mark Rutland @ 2022-11-17 3:15 ` Liu Shixin -1 siblings, 0 replies; 28+ messages in thread From: Liu Shixin @ 2022-11-17 3:15 UTC (permalink / raw) To: Mark Rutland Cc: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin, linux-arm-kernel, linux-kernel On 2022/11/16 23:52, Mark Rutland wrote: > On Wed, Nov 16, 2022 at 04:38:11PM +0800, Liu Shixin wrote: >> The page table check trigger BUG_ON() unexpectedly when split hugepage: >> >> ------------[ cut here ]------------ >> kernel BUG at mm/page_table_check.c:119! >> Internal error: Oops - BUG: 00000000f2000800 [#1] SMP >> Dumping ftrace buffer: >> (ftrace buffer empty) >> Modules linked in: >> CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 >> Hardware name: linux,dummy-virt (DT) >> pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) >> pc : page_table_check_set.isra.0+0x398/0x468 >> lr : page_table_check_set.isra.0+0x1c0/0x468 >> [...] >> Call trace: >> page_table_check_set.isra.0+0x398/0x468 >> __page_table_check_pte_set+0x160/0x1c0 >> __split_huge_pmd_locked+0x900/0x1648 >> __split_huge_pmd+0x28c/0x3b8 >> unmap_page_range+0x428/0x858 >> unmap_single_vma+0xf4/0x1c8 >> zap_page_range+0x2b0/0x410 >> madvise_vma_behavior+0xc44/0xe78 >> do_madvise+0x280/0x698 >> __arm64_sys_madvise+0x90/0xe8 >> invoke_syscall.constprop.0+0xdc/0x1d8 >> do_el0_svc+0xf4/0x3f8 >> el0_svc+0x58/0x120 >> el0t_64_sync_handler+0xb8/0xc0 >> el0t_64_sync+0x19c/0x1a0 >> [...] >> >> On arm64, pmd_present() will return true even if the pmd is invalid. So >> in pmdp_invalidate() the file_map_count will not only decrease once but >> also increase once. Then in set_pte_at(), the file_map_count increase >> again, and so trigger BUG_ON() unexpectedly. > It's not clear to me how pmd_present() relates to p?d_user_accessible_page() > below. How are they related? (or is this a copy-paste error)? Yes, should be pmd_leaf(). In the previous patch, pmd_present() has already replaced with pmd_leaf(). Thanks for your careful discovery. Will fix in next version. >> Fix this problem by adding pmd_valid() in pmd_user_accessible_page(). >> Moreover, add pud_valid() for pud_user_accessible_page() too. >> >> Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") >> Reported-by: Denys Vlasenko <dvlasenk@redhat.com> >> Signed-off-by: Liu Shixin <liushixin2@huawei.com> >> --- >> arch/arm64/include/asm/pgtable.h | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h >> index edf6625ce965..56e178de75e7 100644 >> --- a/arch/arm64/include/asm/pgtable.h >> +++ b/arch/arm64/include/asm/pgtable.h >> @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) >> >> static inline bool pmd_user_accessible_page(pmd_t pmd) >> { >> - return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); >> + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)) && pmd_valid(pmd); >> } >> >> static inline bool pud_user_accessible_page(pud_t pud) >> { >> - return pud_leaf(pud) && pud_user(pud); >> + return pud_leaf(pud) && pud_user(pud) && pud_valid(pud); > I think these p?d_valid() checks should be first for clarity, since the other > bits aren't necessarily meaningful for !valid entries. Thanks for your advice. > > Thanks, > Mark. > > . > ^ permalink raw reply [flat|nested] 28+ messages in thread
* Re: [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud @ 2022-11-17 3:15 ` Liu Shixin 0 siblings, 0 replies; 28+ messages in thread From: Liu Shixin @ 2022-11-17 3:15 UTC (permalink / raw) To: Mark Rutland Cc: Catalin Marinas, Will Deacon, Denys Vlasenko, Kefeng Wang, Anshuman Khandual, David Hildenbrand, Rafael Aquini, Pasha Tatashin, linux-arm-kernel, linux-kernel On 2022/11/16 23:52, Mark Rutland wrote: > On Wed, Nov 16, 2022 at 04:38:11PM +0800, Liu Shixin wrote: >> The page table check trigger BUG_ON() unexpectedly when split hugepage: >> >> ------------[ cut here ]------------ >> kernel BUG at mm/page_table_check.c:119! >> Internal error: Oops - BUG: 00000000f2000800 [#1] SMP >> Dumping ftrace buffer: >> (ftrace buffer empty) >> Modules linked in: >> CPU: 7 PID: 210 Comm: transhuge-stres Not tainted 6.1.0-rc3+ #748 >> Hardware name: linux,dummy-virt (DT) >> pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) >> pc : page_table_check_set.isra.0+0x398/0x468 >> lr : page_table_check_set.isra.0+0x1c0/0x468 >> [...] >> Call trace: >> page_table_check_set.isra.0+0x398/0x468 >> __page_table_check_pte_set+0x160/0x1c0 >> __split_huge_pmd_locked+0x900/0x1648 >> __split_huge_pmd+0x28c/0x3b8 >> unmap_page_range+0x428/0x858 >> unmap_single_vma+0xf4/0x1c8 >> zap_page_range+0x2b0/0x410 >> madvise_vma_behavior+0xc44/0xe78 >> do_madvise+0x280/0x698 >> __arm64_sys_madvise+0x90/0xe8 >> invoke_syscall.constprop.0+0xdc/0x1d8 >> do_el0_svc+0xf4/0x3f8 >> el0_svc+0x58/0x120 >> el0t_64_sync_handler+0xb8/0xc0 >> el0t_64_sync+0x19c/0x1a0 >> [...] >> >> On arm64, pmd_present() will return true even if the pmd is invalid. So >> in pmdp_invalidate() the file_map_count will not only decrease once but >> also increase once. Then in set_pte_at(), the file_map_count increase >> again, and so trigger BUG_ON() unexpectedly. > It's not clear to me how pmd_present() relates to p?d_user_accessible_page() > below. How are they related? (or is this a copy-paste error)? Yes, should be pmd_leaf(). In the previous patch, pmd_present() has already replaced with pmd_leaf(). Thanks for your careful discovery. Will fix in next version. >> Fix this problem by adding pmd_valid() in pmd_user_accessible_page(). >> Moreover, add pud_valid() for pud_user_accessible_page() too. >> >> Fixes: 42b2547137f5 ("arm64/mm: enable ARCH_SUPPORTS_PAGE_TABLE_CHECK") >> Reported-by: Denys Vlasenko <dvlasenk@redhat.com> >> Signed-off-by: Liu Shixin <liushixin2@huawei.com> >> --- >> arch/arm64/include/asm/pgtable.h | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h >> index edf6625ce965..56e178de75e7 100644 >> --- a/arch/arm64/include/asm/pgtable.h >> +++ b/arch/arm64/include/asm/pgtable.h >> @@ -863,12 +863,12 @@ static inline bool pte_user_accessible_page(pte_t pte) >> >> static inline bool pmd_user_accessible_page(pmd_t pmd) >> { >> - return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); >> + return pmd_leaf(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)) && pmd_valid(pmd); >> } >> >> static inline bool pud_user_accessible_page(pud_t pud) >> { >> - return pud_leaf(pud) && pud_user(pud); >> + return pud_leaf(pud) && pud_user(pud) && pud_valid(pud); > I think these p?d_valid() checks should be first for clarity, since the other > bits aren't necessarily meaningful for !valid entries. Thanks for your advice. > > Thanks, > Mark. > > . > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 28+ messages in thread
end of thread, other threads:[~2022-11-21 16:01 UTC | newest] Thread overview: 28+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-11-16 8:38 [PATCH 0/2] arm64: fix two bug about page table check Liu Shixin 2022-11-16 8:38 ` Liu Shixin 2022-11-16 8:38 ` [PATCH 1/2] arm64/mm: fix incorrect file_map_count for non-leaf pmd/pud Liu Shixin 2022-11-16 8:38 ` Liu Shixin 2022-11-16 9:04 ` David Hildenbrand 2022-11-16 9:04 ` David Hildenbrand 2022-11-16 14:59 ` Pasha Tatashin 2022-11-16 14:59 ` Pasha Tatashin 2022-11-17 4:09 ` Anshuman Khandual 2022-11-17 4:09 ` Anshuman Khandual 2022-11-17 6:59 ` Liu Shixin 2022-11-17 6:59 ` Liu Shixin 2022-11-21 15:57 ` Denys Vlasenko 2022-11-21 15:57 ` Denys Vlasenko 2022-11-16 8:38 ` [PATCH 2/2] arm64/mm: fix incorrect file_map_count for invalid pmd/pud Liu Shixin 2022-11-16 8:38 ` Liu Shixin 2022-11-16 9:08 ` David Hildenbrand 2022-11-16 9:08 ` David Hildenbrand 2022-11-16 15:46 ` Mark Rutland 2022-11-16 15:46 ` Mark Rutland 2022-11-17 4:24 ` Anshuman Khandual 2022-11-17 4:24 ` Anshuman Khandual 2022-11-16 15:18 ` Pasha Tatashin 2022-11-16 15:18 ` Pasha Tatashin 2022-11-16 15:52 ` Mark Rutland 2022-11-16 15:52 ` Mark Rutland 2022-11-17 3:15 ` Liu Shixin 2022-11-17 3:15 ` Liu Shixin
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