From f003c03bd29e6f46fef1b9a8e8d636ac732286d5 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 24 Jun 2021 18:39:01 -0700 Subject: [PATCH 01/24] mm: page_vma_mapped_walk(): use page for pvmw->page Patch series "mm: page_vma_mapped_walk() cleanup and THP fixes". I've marked all of these for stable: many are merely cleanups, but I think they are much better before the main fix than after. This patch (of 11): page_vma_mapped_walk() cleanup: sometimes the local copy of pvwm->page was used, sometimes pvmw->page itself: use the local copy "page" throughout. Link: https://lkml.kernel.org/r/589b358c-febc-c88e-d4c2-7834b37fa7bf@google.com Link: https://lkml.kernel.org/r/88e67645-f467-c279-bf5e-af4b5c6b13eb@google.com Signed-off-by: Hugh Dickins Reviewed-by: Alistair Popple Acked-by: Kirill A. Shutemov Reviewed-by: Peter Xu Cc: Yang Shi Cc: Wang Yugui Cc: Matthew Wilcox Cc: Ralph Campbell Cc: Zi Yan Cc: Will Deacon Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_vma_mapped.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index e37bd43904af7..a6dbf714ca152 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -156,7 +156,7 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) if (pvmw->pte) goto next_pte; - if (unlikely(PageHuge(pvmw->page))) { + if (unlikely(PageHuge(page))) { /* when pud is not present, pte will be NULL */ pvmw->pte = huge_pte_offset(mm, pvmw->address, page_size(page)); if (!pvmw->pte) @@ -217,8 +217,7 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) * cannot return prematurely, while zap_huge_pmd() has * cleared *pmd but not decremented compound_mapcount(). */ - if ((pvmw->flags & PVMW_SYNC) && - PageTransCompound(pvmw->page)) { + if ((pvmw->flags & PVMW_SYNC) && PageTransCompound(page)) { spinlock_t *ptl = pmd_lock(mm, pvmw->pmd); spin_unlock(ptl); @@ -234,9 +233,9 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) return true; next_pte: /* Seek to next pte only makes sense for THP */ - if (!PageTransHuge(pvmw->page) || PageHuge(pvmw->page)) + if (!PageTransHuge(page) || PageHuge(page)) return not_found(pvmw); - end = vma_address_end(pvmw->page, pvmw->vma); + end = vma_address_end(page, pvmw->vma); do { pvmw->address += PAGE_SIZE; if (pvmw->address >= end) From 6d0fd5987657cb0c9756ce684e3a74c0f6351728 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 24 Jun 2021 18:39:04 -0700 Subject: [PATCH 02/24] mm: page_vma_mapped_walk(): settle PageHuge on entry page_vma_mapped_walk() cleanup: get the hugetlbfs PageHuge case out of the way at the start, so no need to worry about it later. Link: https://lkml.kernel.org/r/e31a483c-6d73-a6bb-26c5-43c3b880a2@google.com Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Reviewed-by: Peter Xu Cc: Alistair Popple Cc: "Kirill A. Shutemov" Cc: Matthew Wilcox Cc: Ralph Campbell Cc: Wang Yugui Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_vma_mapped.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index a6dbf714ca152..7c0504641fb8b 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -153,10 +153,11 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) if (pvmw->pmd && !pvmw->pte) return not_found(pvmw); - if (pvmw->pte) - goto next_pte; - if (unlikely(PageHuge(page))) { + /* The only possible mapping was handled on last iteration */ + if (pvmw->pte) + return not_found(pvmw); + /* when pud is not present, pte will be NULL */ pvmw->pte = huge_pte_offset(mm, pvmw->address, page_size(page)); if (!pvmw->pte) @@ -168,6 +169,9 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) return not_found(pvmw); return true; } + + if (pvmw->pte) + goto next_pte; restart: pgd = pgd_offset(mm, pvmw->address); if (!pgd_present(*pgd)) @@ -233,7 +237,7 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) return true; next_pte: /* Seek to next pte only makes sense for THP */ - if (!PageTransHuge(page) || PageHuge(page)) + if (!PageTransHuge(page)) return not_found(pvmw); end = vma_address_end(page, pvmw->vma); do { From 3306d3119ceacc43ea8b141a73e21fea68eec30c Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 24 Jun 2021 18:39:07 -0700 Subject: [PATCH 03/24] mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd page_vma_mapped_walk() cleanup: re-evaluate pmde after taking lock, then use it in subsequent tests, instead of repeatedly dereferencing pointer. Link: https://lkml.kernel.org/r/53fbc9d-891e-46b2-cb4b-468c3b19238e@google.com Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Reviewed-by: Peter Xu Cc: Alistair Popple Cc: Matthew Wilcox Cc: Ralph Campbell Cc: Wang Yugui Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_vma_mapped.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 7c0504641fb8b..8f972b05a0de2 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -191,18 +191,19 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) pmde = READ_ONCE(*pvmw->pmd); if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde)) { pvmw->ptl = pmd_lock(mm, pvmw->pmd); - if (likely(pmd_trans_huge(*pvmw->pmd))) { + pmde = *pvmw->pmd; + if (likely(pmd_trans_huge(pmde))) { if (pvmw->flags & PVMW_MIGRATION) return not_found(pvmw); - if (pmd_page(*pvmw->pmd) != page) + if (pmd_page(pmde) != page) return not_found(pvmw); return true; - } else if (!pmd_present(*pvmw->pmd)) { + } else if (!pmd_present(pmde)) { if (thp_migration_supported()) { if (!(pvmw->flags & PVMW_MIGRATION)) return not_found(pvmw); - if (is_migration_entry(pmd_to_swp_entry(*pvmw->pmd))) { - swp_entry_t entry = pmd_to_swp_entry(*pvmw->pmd); + if (is_migration_entry(pmd_to_swp_entry(pmde))) { + swp_entry_t entry = pmd_to_swp_entry(pmde); if (migration_entry_to_page(entry) != page) return not_found(pvmw); From e2e1d4076c77b3671cf8ce702535ae7dee3acf89 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 24 Jun 2021 18:39:10 -0700 Subject: [PATCH 04/24] mm: page_vma_mapped_walk(): prettify PVMW_MIGRATION block page_vma_mapped_walk() cleanup: rearrange the !pmd_present() block to follow the same "return not_found, return not_found, return true" pattern as the block above it (note: returning not_found there is never premature, since existence or prior existence of huge pmd guarantees good alignment). Link: https://lkml.kernel.org/r/378c8650-1488-2edf-9647-32a53cf2e21@google.com Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Reviewed-by: Peter Xu Cc: Alistair Popple Cc: Matthew Wilcox Cc: Ralph Campbell Cc: Wang Yugui Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_vma_mapped.c | 30 ++++++++++++++---------------- 1 file changed, 14 insertions(+), 16 deletions(-) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 8f972b05a0de2..261fc929b08d6 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -198,24 +198,22 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) if (pmd_page(pmde) != page) return not_found(pvmw); return true; - } else if (!pmd_present(pmde)) { - if (thp_migration_supported()) { - if (!(pvmw->flags & PVMW_MIGRATION)) - return not_found(pvmw); - if (is_migration_entry(pmd_to_swp_entry(pmde))) { - swp_entry_t entry = pmd_to_swp_entry(pmde); + } + if (!pmd_present(pmde)) { + swp_entry_t entry; - if (migration_entry_to_page(entry) != page) - return not_found(pvmw); - return true; - } - } - return not_found(pvmw); - } else { - /* THP pmd was split under us: handle on pte level */ - spin_unlock(pvmw->ptl); - pvmw->ptl = NULL; + if (!thp_migration_supported() || + !(pvmw->flags & PVMW_MIGRATION)) + return not_found(pvmw); + entry = pmd_to_swp_entry(pmde); + if (!is_migration_entry(entry) || + migration_entry_to_page(entry) != page) + return not_found(pvmw); + return true; } + /* THP pmd was split under us: handle on pte level */ + spin_unlock(pvmw->ptl); + pvmw->ptl = NULL; } else if (!pmd_present(pmde)) { /* * If PVMW_SYNC, take and drop THP pmd lock so that we From 448282487483d6fa5b2eeeafaa0acc681e544a9c Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 24 Jun 2021 18:39:14 -0700 Subject: [PATCH 05/24] mm: page_vma_mapped_walk(): crossing page table boundary page_vma_mapped_walk() cleanup: adjust the test for crossing page table boundary - I believe pvmw->address is always page-aligned, but nothing else here assumed that; and remember to reset pvmw->pte to NULL after unmapping the page table, though I never saw any bug from that. Link: https://lkml.kernel.org/r/799b3f9c-2a9e-dfef-5d89-26e9f76fd97@google.com Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Cc: Alistair Popple Cc: Matthew Wilcox Cc: Peter Xu Cc: Ralph Campbell Cc: Wang Yugui Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_vma_mapped.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 261fc929b08d6..9c87b3090a1ba 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -244,16 +244,16 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) if (pvmw->address >= end) return not_found(pvmw); /* Did we cross page table boundary? */ - if (pvmw->address % PMD_SIZE == 0) { - pte_unmap(pvmw->pte); + if ((pvmw->address & (PMD_SIZE - PAGE_SIZE)) == 0) { if (pvmw->ptl) { spin_unlock(pvmw->ptl); pvmw->ptl = NULL; } + pte_unmap(pvmw->pte); + pvmw->pte = NULL; goto restart; - } else { - pvmw->pte++; } + pvmw->pte++; } while (pte_none(*pvmw->pte)); if (!pvmw->ptl) { From b3807a91aca7d21c05d5790612e49969117a72b9 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 24 Jun 2021 18:39:17 -0700 Subject: [PATCH 06/24] mm: page_vma_mapped_walk(): add a level of indentation page_vma_mapped_walk() cleanup: add a level of indentation to much of the body, making no functional change in this commit, but reducing the later diff when this is all converted to a loop. [hughd@google.com: : page_vma_mapped_walk(): add a level of indentation fix] Link: https://lkml.kernel.org/r/7f817555-3ce1-c785-e438-87d8efdcaf26@google.com Link: https://lkml.kernel.org/r/efde211-f3e2-fe54-977-ef481419e7f3@google.com Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Cc: Alistair Popple Cc: Matthew Wilcox Cc: Peter Xu Cc: Ralph Campbell Cc: Wang Yugui Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_vma_mapped.c | 105 ++++++++++++++++++++++--------------------- 1 file changed, 55 insertions(+), 50 deletions(-) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 9c87b3090a1ba..5b5832d063382 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -173,62 +173,67 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) if (pvmw->pte) goto next_pte; restart: - pgd = pgd_offset(mm, pvmw->address); - if (!pgd_present(*pgd)) - return false; - p4d = p4d_offset(pgd, pvmw->address); - if (!p4d_present(*p4d)) - return false; - pud = pud_offset(p4d, pvmw->address); - if (!pud_present(*pud)) - return false; - pvmw->pmd = pmd_offset(pud, pvmw->address); - /* - * Make sure the pmd value isn't cached in a register by the - * compiler and used as a stale value after we've observed a - * subsequent update. - */ - pmde = READ_ONCE(*pvmw->pmd); - if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde)) { - pvmw->ptl = pmd_lock(mm, pvmw->pmd); - pmde = *pvmw->pmd; - if (likely(pmd_trans_huge(pmde))) { - if (pvmw->flags & PVMW_MIGRATION) - return not_found(pvmw); - if (pmd_page(pmde) != page) - return not_found(pvmw); - return true; - } - if (!pmd_present(pmde)) { - swp_entry_t entry; + { + pgd = pgd_offset(mm, pvmw->address); + if (!pgd_present(*pgd)) + return false; + p4d = p4d_offset(pgd, pvmw->address); + if (!p4d_present(*p4d)) + return false; + pud = pud_offset(p4d, pvmw->address); + if (!pud_present(*pud)) + return false; - if (!thp_migration_supported() || - !(pvmw->flags & PVMW_MIGRATION)) - return not_found(pvmw); - entry = pmd_to_swp_entry(pmde); - if (!is_migration_entry(entry) || - migration_entry_to_page(entry) != page) - return not_found(pvmw); - return true; - } - /* THP pmd was split under us: handle on pte level */ - spin_unlock(pvmw->ptl); - pvmw->ptl = NULL; - } else if (!pmd_present(pmde)) { + pvmw->pmd = pmd_offset(pud, pvmw->address); /* - * If PVMW_SYNC, take and drop THP pmd lock so that we - * cannot return prematurely, while zap_huge_pmd() has - * cleared *pmd but not decremented compound_mapcount(). + * Make sure the pmd value isn't cached in a register by the + * compiler and used as a stale value after we've observed a + * subsequent update. */ - if ((pvmw->flags & PVMW_SYNC) && PageTransCompound(page)) { - spinlock_t *ptl = pmd_lock(mm, pvmw->pmd); + pmde = READ_ONCE(*pvmw->pmd); - spin_unlock(ptl); + if (pmd_trans_huge(pmde) || is_pmd_migration_entry(pmde)) { + pvmw->ptl = pmd_lock(mm, pvmw->pmd); + pmde = *pvmw->pmd; + if (likely(pmd_trans_huge(pmde))) { + if (pvmw->flags & PVMW_MIGRATION) + return not_found(pvmw); + if (pmd_page(pmde) != page) + return not_found(pvmw); + return true; + } + if (!pmd_present(pmde)) { + swp_entry_t entry; + + if (!thp_migration_supported() || + !(pvmw->flags & PVMW_MIGRATION)) + return not_found(pvmw); + entry = pmd_to_swp_entry(pmde); + if (!is_migration_entry(entry) || + migration_entry_to_page(entry) != page) + return not_found(pvmw); + return true; + } + /* THP pmd was split under us: handle on pte level */ + spin_unlock(pvmw->ptl); + pvmw->ptl = NULL; + } else if (!pmd_present(pmde)) { + /* + * If PVMW_SYNC, take and drop THP pmd lock so that we + * cannot return prematurely, while zap_huge_pmd() has + * cleared *pmd but not decremented compound_mapcount(). + */ + if ((pvmw->flags & PVMW_SYNC) && + PageTransCompound(page)) { + spinlock_t *ptl = pmd_lock(mm, pvmw->pmd); + + spin_unlock(ptl); + } + return false; } - return false; + if (!map_pte(pvmw)) + goto next_pte; } - if (!map_pte(pvmw)) - goto next_pte; while (1) { unsigned long end; From 474466301dfd8b39a10c01db740645f3f7ae9a28 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 24 Jun 2021 18:39:20 -0700 Subject: [PATCH 07/24] mm: page_vma_mapped_walk(): use goto instead of while (1) page_vma_mapped_walk() cleanup: add a label this_pte, matching next_pte, and use "goto this_pte", in place of the "while (1)" loop at the end. Link: https://lkml.kernel.org/r/a52b234a-851-3616-2525-f42736e8934@google.com Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Cc: Alistair Popple Cc: Matthew Wilcox Cc: Peter Xu Cc: Ralph Campbell Cc: Wang Yugui Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_vma_mapped.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 5b5832d063382..6b9320340f1b4 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -144,6 +144,7 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) { struct mm_struct *mm = pvmw->vma->vm_mm; struct page *page = pvmw->page; + unsigned long end; pgd_t *pgd; p4d_t *p4d; pud_t *pud; @@ -233,10 +234,7 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) } if (!map_pte(pvmw)) goto next_pte; - } - while (1) { - unsigned long end; - +this_pte: if (check_pte(pvmw)) return true; next_pte: @@ -265,6 +263,7 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) pvmw->ptl = pte_lockptr(mm, pvmw->pmd); spin_lock(pvmw->ptl); } + goto this_pte; } } From a765c417d876cc635f628365ec9aa6f09470069a Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 24 Jun 2021 18:39:23 -0700 Subject: [PATCH 08/24] mm: page_vma_mapped_walk(): get vma_address_end() earlier page_vma_mapped_walk() cleanup: get THP's vma_address_end() at the start, rather than later at next_pte. It's a little unnecessary overhead on the first call, but makes for a simpler loop in the following commit. Link: https://lkml.kernel.org/r/4542b34d-862f-7cb4-bb22-e0df6ce830a2@google.com Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Cc: Alistair Popple Cc: Matthew Wilcox Cc: Peter Xu Cc: Ralph Campbell Cc: Wang Yugui Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_vma_mapped.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index 6b9320340f1b4..df89ea3df4f42 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -171,6 +171,15 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) return true; } + /* + * Seek to next pte only makes sense for THP. + * But more important than that optimization, is to filter out + * any PageKsm page: whose page->index misleads vma_address() + * and vma_address_end() to disaster. + */ + end = PageTransCompound(page) ? + vma_address_end(page, pvmw->vma) : + pvmw->address + PAGE_SIZE; if (pvmw->pte) goto next_pte; restart: @@ -238,10 +247,6 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) if (check_pte(pvmw)) return true; next_pte: - /* Seek to next pte only makes sense for THP */ - if (!PageTransHuge(page)) - return not_found(pvmw); - end = vma_address_end(page, pvmw->vma); do { pvmw->address += PAGE_SIZE; if (pvmw->address >= end) From a9a7504d9beaf395481faa91e70e2fd08f7a3dde Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 24 Jun 2021 18:39:26 -0700 Subject: [PATCH 09/24] mm/thp: fix page_vma_mapped_walk() if THP mapped by ptes Running certain tests with a DEBUG_VM kernel would crash within hours, on the total_mapcount BUG() in split_huge_page_to_list(), while trying to free up some memory by punching a hole in a shmem huge page: split's try_to_unmap() was unable to find all the mappings of the page (which, on a !DEBUG_VM kernel, would then keep the huge page pinned in memory). Crash dumps showed two tail pages of a shmem huge page remained mapped by pte: ptes in a non-huge-aligned vma of a gVisor process, at the end of a long unmapped range; and no page table had yet been allocated for the head of the huge page to be mapped into. Although designed to handle these odd misaligned huge-page-mapped-by-pte cases, page_vma_mapped_walk() falls short by returning false prematurely when !pmd_present or !pud_present or !p4d_present or !pgd_present: there are cases when a huge page may span the boundary, with ptes present in the next. Restructure page_vma_mapped_walk() as a loop to continue in these cases, while keeping its layout much as before. Add a step_forward() helper to advance pvmw->address across those boundaries: originally I tried to use mm's standard p?d_addr_end() macros, but hit the same crash 512 times less often: because of the way redundant levels are folded together, but folded differently in different configurations, it was just too difficult to use them correctly; and step_forward() is simpler anyway. Link: https://lkml.kernel.org/r/fedb8632-1798-de42-f39e-873551d5bc81@google.com Fixes: ace71a19cec5 ("mm: introduce page_vma_mapped_walk()") Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Cc: Alistair Popple Cc: Matthew Wilcox Cc: Peter Xu Cc: Ralph Campbell Cc: Wang Yugui Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_vma_mapped.c | 34 +++++++++++++++++++++++++--------- 1 file changed, 25 insertions(+), 9 deletions(-) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index df89ea3df4f42..a4e962b510c7a 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -116,6 +116,13 @@ static bool check_pte(struct page_vma_mapped_walk *pvmw) return pfn_is_match(pvmw->page, pfn); } +static void step_forward(struct page_vma_mapped_walk *pvmw, unsigned long size) +{ + pvmw->address = (pvmw->address + size) & ~(size - 1); + if (!pvmw->address) + pvmw->address = ULONG_MAX; +} + /** * page_vma_mapped_walk - check if @pvmw->page is mapped in @pvmw->vma at * @pvmw->address @@ -183,16 +190,22 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) if (pvmw->pte) goto next_pte; restart: - { + do { pgd = pgd_offset(mm, pvmw->address); - if (!pgd_present(*pgd)) - return false; + if (!pgd_present(*pgd)) { + step_forward(pvmw, PGDIR_SIZE); + continue; + } p4d = p4d_offset(pgd, pvmw->address); - if (!p4d_present(*p4d)) - return false; + if (!p4d_present(*p4d)) { + step_forward(pvmw, P4D_SIZE); + continue; + } pud = pud_offset(p4d, pvmw->address); - if (!pud_present(*pud)) - return false; + if (!pud_present(*pud)) { + step_forward(pvmw, PUD_SIZE); + continue; + } pvmw->pmd = pmd_offset(pud, pvmw->address); /* @@ -239,7 +252,8 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) spin_unlock(ptl); } - return false; + step_forward(pvmw, PMD_SIZE); + continue; } if (!map_pte(pvmw)) goto next_pte; @@ -269,7 +283,9 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) spin_lock(pvmw->ptl); } goto this_pte; - } + } while (pvmw->address < end); + + return false; } /** From a7a69d8ba88d8dcee7ef00e91d413a4bd003a814 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 24 Jun 2021 18:39:30 -0700 Subject: [PATCH 10/24] mm/thp: another PVMW_SYNC fix in page_vma_mapped_walk() Aha! Shouldn't that quick scan over pte_none()s make sure that it holds ptlock in the PVMW_SYNC case? That too might have been responsible for BUGs or WARNs in split_huge_page_to_list() or its unmap_page(), though I've never seen any. Link: https://lkml.kernel.org/r/1bdf384c-8137-a149-2a1e-475a4791c3c@google.com Link: https://lore.kernel.org/linux-mm/20210412180659.B9E3.409509F4@e16-tech.com/ Fixes: ace71a19cec5 ("mm: introduce page_vma_mapped_walk()") Signed-off-by: Hugh Dickins Acked-by: Kirill A. Shutemov Tested-by: Wang Yugui Cc: Alistair Popple Cc: Matthew Wilcox Cc: Peter Xu Cc: Ralph Campbell Cc: Will Deacon Cc: Yang Shi Cc: Zi Yan Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_vma_mapped.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c index a4e962b510c7a..a4435311754b0 100644 --- a/mm/page_vma_mapped.c +++ b/mm/page_vma_mapped.c @@ -276,6 +276,10 @@ bool page_vma_mapped_walk(struct page_vma_mapped_walk *pvmw) goto restart; } pvmw->pte++; + if ((pvmw->flags & PVMW_SYNC) && !pvmw->ptl) { + pvmw->ptl = pte_lockptr(mm, pvmw->pmd); + spin_lock(pvmw->ptl); + } } while (pte_none(*pvmw->pte)); if (!pvmw->ptl) { From 8fd0c1b0647a6bda4067ee0cd61e8395954b6f28 Mon Sep 17 00:00:00 2001 From: Pavel Skripkin Date: Thu, 24 Jun 2021 18:39:33 -0700 Subject: [PATCH 11/24] nilfs2: fix memory leak in nilfs_sysfs_delete_device_group My local syzbot instance hit memory leak in nilfs2. The problem was in missing kobject_put() in nilfs_sysfs_delete_device_group(). kobject_del() does not call kobject_cleanup() for passed kobject and it leads to leaking duped kobject name if kobject_put() was not called. Fail log: BUG: memory leak unreferenced object 0xffff8880596171e0 (size 8): comm "syz-executor379", pid 8381, jiffies 4294980258 (age 21.100s) hex dump (first 8 bytes): 6c 6f 6f 70 30 00 00 00 loop0... backtrace: kstrdup+0x36/0x70 mm/util.c:60 kstrdup_const+0x53/0x80 mm/util.c:83 kvasprintf_const+0x108/0x190 lib/kasprintf.c:48 kobject_set_name_vargs+0x56/0x150 lib/kobject.c:289 kobject_add_varg lib/kobject.c:384 [inline] kobject_init_and_add+0xc9/0x160 lib/kobject.c:473 nilfs_sysfs_create_device_group+0x150/0x800 fs/nilfs2/sysfs.c:999 init_nilfs+0xe26/0x12b0 fs/nilfs2/the_nilfs.c:637 Link: https://lkml.kernel.org/r/20210612140559.20022-1-paskripkin@gmail.com Fixes: da7141fb78db ("nilfs2: add /sys/fs/nilfs2/ group") Signed-off-by: Pavel Skripkin Acked-by: Ryusuke Konishi Cc: Michael L. Semon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nilfs2/sysfs.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/nilfs2/sysfs.c b/fs/nilfs2/sysfs.c index 303d71430bdd1..9c6c0e2e5880a 100644 --- a/fs/nilfs2/sysfs.c +++ b/fs/nilfs2/sysfs.c @@ -1053,6 +1053,7 @@ void nilfs_sysfs_delete_device_group(struct the_nilfs *nilfs) nilfs_sysfs_delete_superblock_group(nilfs); nilfs_sysfs_delete_segctor_group(nilfs); kobject_del(&nilfs->ns_dev_kobj); + kobject_put(&nilfs->ns_dev_kobj); kfree(nilfs->ns_dev_subgroups); } From 15a64f5a8870b5610b616a4aa753262dfaa5d76e Mon Sep 17 00:00:00 2001 From: Claudio Imbrenda Date: Thu, 24 Jun 2021 18:39:36 -0700 Subject: [PATCH 12/24] mm/vmalloc: add vmalloc_no_huge Patch series "mm: add vmalloc_no_huge and use it", v4. Add vmalloc_no_huge() and export it, so modules can allocate memory with small pages. Use the newly added vmalloc_no_huge() in KVM on s390 to get around a hardware limitation. This patch (of 2): Commit 121e6f3258fe3 ("mm/vmalloc: hugepage vmalloc mappings") added support for hugepage vmalloc mappings, it also added the flag VM_NO_HUGE_VMAP for __vmalloc_node_range to request the allocation to be performed with 0-order non-huge pages. This flag is not accessible when calling vmalloc, the only option is to call directly __vmalloc_node_range, which is not exported. This means that a module can't vmalloc memory with small pages. Case in point: KVM on s390x needs to vmalloc a large area, and it needs to be mapped with non-huge pages, because of a hardware limitation. This patch adds the function vmalloc_no_huge, which works like vmalloc, but it is guaranteed to always back the mapping using small pages. This new function is exported, therefore it is usable by modules. [akpm@linux-foundation.org: whitespace fixes, per Christoph] Link: https://lkml.kernel.org/r/20210614132357.10202-1-imbrenda@linux.ibm.com Link: https://lkml.kernel.org/r/20210614132357.10202-2-imbrenda@linux.ibm.com Fixes: 121e6f3258fe3 ("mm/vmalloc: hugepage vmalloc mappings") Signed-off-by: Claudio Imbrenda Reviewed-by: Uladzislau Rezki (Sony) Acked-by: Nicholas Piggin Reviewed-by: David Hildenbrand Acked-by: David Rientjes Cc: Uladzislau Rezki (Sony) Cc: Catalin Marinas Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Christoph Hellwig Cc: Cornelia Huck Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/vmalloc.h | 1 + mm/vmalloc.c | 17 +++++++++++++++++ 2 files changed, 18 insertions(+) diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 4d668abb63917..bfaaf0b6fa766 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -135,6 +135,7 @@ extern void *__vmalloc_node_range(unsigned long size, unsigned long align, const void *caller); void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask, int node, const void *caller); +void *vmalloc_no_huge(unsigned long size); extern void vfree(const void *addr); extern void vfree_atomic(const void *addr); diff --git a/mm/vmalloc.c b/mm/vmalloc.c index a13ac524f6ff8..fada19e17814c 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2998,6 +2998,23 @@ void *vmalloc(unsigned long size) } EXPORT_SYMBOL(vmalloc); +/** + * vmalloc_no_huge - allocate virtually contiguous memory using small pages + * @size: allocation size + * + * Allocate enough non-huge pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vmalloc_no_huge(unsigned long size) +{ + return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, + GFP_KERNEL, PAGE_KERNEL, VM_NO_HUGE_VMAP, + NUMA_NO_NODE, __builtin_return_address(0)); +} +EXPORT_SYMBOL(vmalloc_no_huge); + /** * vzalloc - allocate virtually contiguous memory with zero fill * @size: allocation size From 185cca24e977411495d57ec71e43350b69c08e63 Mon Sep 17 00:00:00 2001 From: Claudio Imbrenda Date: Thu, 24 Jun 2021 18:39:39 -0700 Subject: [PATCH 13/24] KVM: s390: prepare for hugepage vmalloc The Create Secure Configuration Ultravisor Call does not support using large pages for the virtual memory area. This is a hardware limitation. This patch replaces the vzalloc call with an almost equivalent call to the newly introduced vmalloc_no_huge function, which guarantees that only small pages will be used for the backing. The new call will not clear the allocated memory, but that has never been an actual requirement. Link: https://lkml.kernel.org/r/20210614132357.10202-3-imbrenda@linux.ibm.com Fixes: 121e6f3258fe3 ("mm/vmalloc: hugepage vmalloc mappings") Signed-off-by: Claudio Imbrenda Reviewed-by: Janosch Frank Acked-by: Christian Borntraeger Acked-by: Nicholas Piggin Reviewed-by: David Hildenbrand Cc: Nicholas Piggin Cc: Uladzislau Rezki (Sony) Cc: Catalin Marinas Cc: Thomas Gleixner Cc: Ingo Molnar Cc: David Rientjes Cc: Christoph Hellwig Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/s390/kvm/pv.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c index 813b6e93dc836..c8841f476e913 100644 --- a/arch/s390/kvm/pv.c +++ b/arch/s390/kvm/pv.c @@ -140,7 +140,12 @@ static int kvm_s390_pv_alloc_vm(struct kvm *kvm) /* Allocate variable storage */ vlen = ALIGN(virt * ((npages * PAGE_SIZE) / HPAGE_SIZE), PAGE_SIZE); vlen += uv_info.guest_virt_base_stor_len; - kvm->arch.pv.stor_var = vzalloc(vlen); + /* + * The Create Secure Configuration Ultravisor Call does not support + * using large pages for the virtual memory area. + * This is a hardware limitation. + */ + kvm->arch.pv.stor_var = vmalloc_no_huge(vlen); if (!kvm->arch.pv.stor_var) goto out_err; return 0; From 7ca3027b726be681c8e6292b5a81ebcde7581710 Mon Sep 17 00:00:00 2001 From: Daniel Axtens Date: Thu, 24 Jun 2021 18:39:42 -0700 Subject: [PATCH 14/24] mm/vmalloc: unbreak kasan vmalloc support In commit 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings"), __vmalloc_node_range was changed such that __get_vm_area_node was no longer called with the requested/real size of the vmalloc allocation, but rather with a rounded-up size. This means that __get_vm_area_node called kasan_unpoision_vmalloc() with a rounded up size rather than the real size. This led to it allowing access to too much memory and so missing vmalloc OOBs and failing the kasan kunit tests. Pass the real size and the desired shift into __get_vm_area_node. This allows it to round up the size for the underlying allocators while still unpoisioning the correct quantity of shadow memory. Adjust the other call-sites to pass in PAGE_SHIFT for the shift value. Link: https://lkml.kernel.org/r/20210617081330.98629-1-dja@axtens.net Link: https://bugzilla.kernel.org/show_bug.cgi?id=213335 Fixes: 121e6f3258fe ("mm/vmalloc: hugepage vmalloc mappings") Signed-off-by: Daniel Axtens Tested-by: David Gow Reviewed-by: Nicholas Piggin Reviewed-by: Uladzislau Rezki (Sony) Tested-by: Andrey Konovalov Acked-by: Andrey Konovalov Cc: Dmitry Vyukov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index fada19e17814c..d0a7d89be091e 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2344,15 +2344,16 @@ static void clear_vm_uninitialized_flag(struct vm_struct *vm) } static struct vm_struct *__get_vm_area_node(unsigned long size, - unsigned long align, unsigned long flags, unsigned long start, - unsigned long end, int node, gfp_t gfp_mask, const void *caller) + unsigned long align, unsigned long shift, unsigned long flags, + unsigned long start, unsigned long end, int node, + gfp_t gfp_mask, const void *caller) { struct vmap_area *va; struct vm_struct *area; unsigned long requested_size = size; BUG_ON(in_interrupt()); - size = PAGE_ALIGN(size); + size = ALIGN(size, 1ul << shift); if (unlikely(!size)) return NULL; @@ -2384,8 +2385,8 @@ struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags, unsigned long start, unsigned long end, const void *caller) { - return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE, - GFP_KERNEL, caller); + return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, start, end, + NUMA_NO_NODE, GFP_KERNEL, caller); } /** @@ -2401,7 +2402,8 @@ struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags, */ struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) { - return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END, + return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, + VMALLOC_START, VMALLOC_END, NUMA_NO_NODE, GFP_KERNEL, __builtin_return_address(0)); } @@ -2409,7 +2411,8 @@ struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, const void *caller) { - return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END, + return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, + VMALLOC_START, VMALLOC_END, NUMA_NO_NODE, GFP_KERNEL, caller); } @@ -2902,9 +2905,9 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, } again: - size = PAGE_ALIGN(size); - area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNINITIALIZED | - vm_flags, start, end, node, gfp_mask, caller); + area = __get_vm_area_node(real_size, align, shift, VM_ALLOC | + VM_UNINITIALIZED | vm_flags, start, end, node, + gfp_mask, caller); if (!area) { warn_alloc(gfp_mask, NULL, "vmalloc size %lu allocation failure: " @@ -2923,6 +2926,7 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, */ clear_vm_uninitialized_flag(area); + size = PAGE_ALIGN(size); kmemleak_vmalloc(area, size, gfp_mask); return addr; From 34b3d5344719d14fd2185b2d9459b3abcb8cf9d8 Mon Sep 17 00:00:00 2001 From: Petr Mladek Date: Thu, 24 Jun 2021 18:39:45 -0700 Subject: [PATCH 15/24] kthread_worker: split code for canceling the delayed work timer Patch series "kthread_worker: Fix race between kthread_mod_delayed_work() and kthread_cancel_delayed_work_sync()". This patchset fixes the race between kthread_mod_delayed_work() and kthread_cancel_delayed_work_sync() including proper return value handling. This patch (of 2): Simple code refactoring as a preparation step for fixing a race between kthread_mod_delayed_work() and kthread_cancel_delayed_work_sync(). It does not modify the existing behavior. Link: https://lkml.kernel.org/r/20210610133051.15337-2-pmladek@suse.com Signed-off-by: Petr Mladek Cc: Cc: Martin Liu Cc: Minchan Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Oleg Nesterov Cc: Tejun Heo Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kthread.c | 46 +++++++++++++++++++++++++++++----------------- 1 file changed, 29 insertions(+), 17 deletions(-) diff --git a/kernel/kthread.c b/kernel/kthread.c index fe3f2a40d61e8..121a0e1fc6595 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -1092,6 +1092,33 @@ void kthread_flush_work(struct kthread_work *work) } EXPORT_SYMBOL_GPL(kthread_flush_work); +/* + * Make sure that the timer is neither set nor running and could + * not manipulate the work list_head any longer. + * + * The function is called under worker->lock. The lock is temporary + * released but the timer can't be set again in the meantime. + */ +static void kthread_cancel_delayed_work_timer(struct kthread_work *work, + unsigned long *flags) +{ + struct kthread_delayed_work *dwork = + container_of(work, struct kthread_delayed_work, work); + struct kthread_worker *worker = work->worker; + + /* + * del_timer_sync() must be called to make sure that the timer + * callback is not running. The lock must be temporary released + * to avoid a deadlock with the callback. In the meantime, + * any queuing is blocked by setting the canceling counter. + */ + work->canceling++; + raw_spin_unlock_irqrestore(&worker->lock, *flags); + del_timer_sync(&dwork->timer); + raw_spin_lock_irqsave(&worker->lock, *flags); + work->canceling--; +} + /* * This function removes the work from the worker queue. Also it makes sure * that it won't get queued later via the delayed work's timer. @@ -1106,23 +1133,8 @@ static bool __kthread_cancel_work(struct kthread_work *work, bool is_dwork, unsigned long *flags) { /* Try to cancel the timer if exists. */ - if (is_dwork) { - struct kthread_delayed_work *dwork = - container_of(work, struct kthread_delayed_work, work); - struct kthread_worker *worker = work->worker; - - /* - * del_timer_sync() must be called to make sure that the timer - * callback is not running. The lock must be temporary released - * to avoid a deadlock with the callback. In the meantime, - * any queuing is blocked by setting the canceling counter. - */ - work->canceling++; - raw_spin_unlock_irqrestore(&worker->lock, *flags); - del_timer_sync(&dwork->timer); - raw_spin_lock_irqsave(&worker->lock, *flags); - work->canceling--; - } + if (is_dwork) + kthread_cancel_delayed_work_timer(work, flags); /* * Try to remove the work from a worker list. It might either From 5fa54346caf67b4b1b10b1f390316ae466da4d53 Mon Sep 17 00:00:00 2001 From: Petr Mladek Date: Thu, 24 Jun 2021 18:39:48 -0700 Subject: [PATCH 16/24] kthread: prevent deadlock when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync() The system might hang with the following backtrace: schedule+0x80/0x100 schedule_timeout+0x48/0x138 wait_for_common+0xa4/0x134 wait_for_completion+0x1c/0x2c kthread_flush_work+0x114/0x1cc kthread_cancel_work_sync.llvm.16514401384283632983+0xe8/0x144 kthread_cancel_delayed_work_sync+0x18/0x2c xxxx_pm_notify+0xb0/0xd8 blocking_notifier_call_chain_robust+0x80/0x194 pm_notifier_call_chain_robust+0x28/0x4c suspend_prepare+0x40/0x260 enter_state+0x80/0x3f4 pm_suspend+0x60/0xdc state_store+0x108/0x144 kobj_attr_store+0x38/0x88 sysfs_kf_write+0x64/0xc0 kernfs_fop_write_iter+0x108/0x1d0 vfs_write+0x2f4/0x368 ksys_write+0x7c/0xec It is caused by the following race between kthread_mod_delayed_work() and kthread_cancel_delayed_work_sync(): CPU0 CPU1 Context: Thread A Context: Thread B kthread_mod_delayed_work() spin_lock() __kthread_cancel_work() spin_unlock() del_timer_sync() kthread_cancel_delayed_work_sync() spin_lock() __kthread_cancel_work() spin_unlock() del_timer_sync() spin_lock() work->canceling++ spin_unlock spin_lock() queue_delayed_work() // dwork is put into the worker->delayed_work_list spin_unlock() kthread_flush_work() // flush_work is put at the tail of the dwork wait_for_completion() Context: IRQ kthread_delayed_work_timer_fn() spin_lock() list_del_init(&work->node); spin_unlock() BANG: flush_work is not longer linked and will never get proceed. The problem is that kthread_mod_delayed_work() checks work->canceling flag before canceling the timer. A simple solution is to (re)check work->canceling after __kthread_cancel_work(). But then it is not clear what should be returned when __kthread_cancel_work() removed the work from the queue (list) and it can't queue it again with the new @delay. The return value might be used for reference counting. The caller has to know whether a new work has been queued or an existing one was replaced. The proper solution is that kthread_mod_delayed_work() will remove the work from the queue (list) _only_ when work->canceling is not set. The flag must be checked after the timer is stopped and the remaining operations can be done under worker->lock. Note that kthread_mod_delayed_work() could remove the timer and then bail out. It is fine. The other canceling caller needs to cancel the timer as well. The important thing is that the queue (list) manipulation is done atomically under worker->lock. Link: https://lkml.kernel.org/r/20210610133051.15337-3-pmladek@suse.com Fixes: 9a6b06c8d9a220860468a ("kthread: allow to modify delayed kthread work") Signed-off-by: Petr Mladek Reported-by: Martin Liu Cc: Cc: Minchan Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Oleg Nesterov Cc: Tejun Heo Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kthread.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) diff --git a/kernel/kthread.c b/kernel/kthread.c index 121a0e1fc6595..0fccf7d0c6a16 100644 --- a/kernel/kthread.c +++ b/kernel/kthread.c @@ -1120,8 +1120,11 @@ static void kthread_cancel_delayed_work_timer(struct kthread_work *work, } /* - * This function removes the work from the worker queue. Also it makes sure - * that it won't get queued later via the delayed work's timer. + * This function removes the work from the worker queue. + * + * It is called under worker->lock. The caller must make sure that + * the timer used by delayed work is not running, e.g. by calling + * kthread_cancel_delayed_work_timer(). * * The work might still be in use when this function finishes. See the * current_work proceed by the worker. @@ -1129,13 +1132,8 @@ static void kthread_cancel_delayed_work_timer(struct kthread_work *work, * Return: %true if @work was pending and successfully canceled, * %false if @work was not pending */ -static bool __kthread_cancel_work(struct kthread_work *work, bool is_dwork, - unsigned long *flags) +static bool __kthread_cancel_work(struct kthread_work *work) { - /* Try to cancel the timer if exists. */ - if (is_dwork) - kthread_cancel_delayed_work_timer(work, flags); - /* * Try to remove the work from a worker list. It might either * be from worker->work_list or from worker->delayed_work_list. @@ -1188,11 +1186,23 @@ bool kthread_mod_delayed_work(struct kthread_worker *worker, /* Work must not be used with >1 worker, see kthread_queue_work() */ WARN_ON_ONCE(work->worker != worker); - /* Do not fight with another command that is canceling this work. */ + /* + * Temporary cancel the work but do not fight with another command + * that is canceling the work as well. + * + * It is a bit tricky because of possible races with another + * mod_delayed_work() and cancel_delayed_work() callers. + * + * The timer must be canceled first because worker->lock is released + * when doing so. But the work can be removed from the queue (list) + * only when it can be queued again so that the return value can + * be used for reference counting. + */ + kthread_cancel_delayed_work_timer(work, &flags); if (work->canceling) goto out; + ret = __kthread_cancel_work(work); - ret = __kthread_cancel_work(work, true, &flags); fast_queue: __kthread_queue_delayed_work(worker, dwork, delay); out: @@ -1214,7 +1224,10 @@ static bool __kthread_cancel_work_sync(struct kthread_work *work, bool is_dwork) /* Work must not be used with >1 worker, see kthread_queue_work(). */ WARN_ON_ONCE(work->worker != worker); - ret = __kthread_cancel_work(work, is_dwork, &flags); + if (is_dwork) + kthread_cancel_delayed_work_timer(work, &flags); + + ret = __kthread_cancel_work(work); if (worker->current_work != work) goto out_fast; From fe19bd3dae3d15d2fbfdb3de8839a6ea0fe94264 Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Thu, 24 Jun 2021 18:39:52 -0700 Subject: [PATCH 17/24] mm, futex: fix shared futex pgoff on shmem huge page If more than one futex is placed on a shmem huge page, it can happen that waking the second wakes the first instead, and leaves the second waiting: the key's shared.pgoff is wrong. When 3.11 commit 13d60f4b6ab5 ("futex: Take hugepages into account when generating futex_key"), the only shared huge pages came from hugetlbfs, and the code added to deal with its exceptional page->index was put into hugetlb source. Then that was missed when 4.8 added shmem huge pages. page_to_pgoff() is what others use for this nowadays: except that, as currently written, it gives the right answer on hugetlbfs head, but nonsense on hugetlbfs tails. Fix that by calling hugetlbfs-specific hugetlb_basepage_index() on PageHuge tails as well as on head. Yes, it's unconventional to declare hugetlb_basepage_index() there in pagemap.h, rather than in hugetlb.h; but I do not expect anything but page_to_pgoff() ever to need it. [akpm@linux-foundation.org: give hugetlb_basepage_index() prototype the correct scope] Link: https://lkml.kernel.org/r/b17d946b-d09-326e-b42a-52884c36df32@google.com Fixes: 800d8c63b2e9 ("shmem: add huge pages support") Reported-by: Neel Natu Signed-off-by: Hugh Dickins Reviewed-by: Matthew Wilcox (Oracle) Acked-by: Thomas Gleixner Cc: "Kirill A. Shutemov" Cc: Zhang Yi Cc: Mel Gorman Cc: Mike Kravetz Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Darren Hart Cc: Davidlohr Bueso Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/hugetlb.h | 16 ---------------- include/linux/pagemap.h | 13 +++++++------ kernel/futex.c | 3 +-- mm/hugetlb.c | 5 +---- 4 files changed, 9 insertions(+), 28 deletions(-) diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h index 6504346a19473..3c0117656745a 100644 --- a/include/linux/hugetlb.h +++ b/include/linux/hugetlb.h @@ -741,17 +741,6 @@ static inline int hstate_index(struct hstate *h) return h - hstates; } -pgoff_t __basepage_index(struct page *page); - -/* Return page->index in PAGE_SIZE units */ -static inline pgoff_t basepage_index(struct page *page) -{ - if (!PageCompound(page)) - return page->index; - - return __basepage_index(page); -} - extern int dissolve_free_huge_page(struct page *page); extern int dissolve_free_huge_pages(unsigned long start_pfn, unsigned long end_pfn); @@ -988,11 +977,6 @@ static inline int hstate_index(struct hstate *h) return 0; } -static inline pgoff_t basepage_index(struct page *page) -{ - return page->index; -} - static inline int dissolve_free_huge_page(struct page *page) { return 0; diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index e89df447fae32..0f1b34dbf3a2e 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -516,7 +516,7 @@ static inline struct page *read_mapping_page(struct address_space *mapping, } /* - * Get index of the page with in radix-tree + * Get index of the page within radix-tree (but not for hugetlb pages). * (TODO: remove once hugetlb pages will have ->index in PAGE_SIZE) */ static inline pgoff_t page_to_index(struct page *page) @@ -535,15 +535,16 @@ static inline pgoff_t page_to_index(struct page *page) return pgoff; } +extern pgoff_t hugetlb_basepage_index(struct page *page); + /* - * Get the offset in PAGE_SIZE. - * (TODO: hugepage should have ->index in PAGE_SIZE) + * Get the offset in PAGE_SIZE (even for hugetlb pages). + * (TODO: hugetlb pages should have ->index in PAGE_SIZE) */ static inline pgoff_t page_to_pgoff(struct page *page) { - if (unlikely(PageHeadHuge(page))) - return page->index << compound_order(page); - + if (unlikely(PageHuge(page))) + return hugetlb_basepage_index(page); return page_to_index(page); } diff --git a/kernel/futex.c b/kernel/futex.c index 4938a00bc7857..408cad5e89680 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -35,7 +35,6 @@ #include #include #include -#include #include #include #include @@ -650,7 +649,7 @@ static int get_futex_key(u32 __user *uaddr, bool fshared, union futex_key *key, key->both.offset |= FUT_OFF_INODE; /* inode-based key */ key->shared.i_seq = get_inode_sequence_number(inode); - key->shared.pgoff = basepage_index(tail); + key->shared.pgoff = page_to_pgoff(tail); rcu_read_unlock(); } diff --git a/mm/hugetlb.c b/mm/hugetlb.c index e0a5f9cbbece9..5ba5a0da6d572 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1588,15 +1588,12 @@ struct address_space *hugetlb_page_mapping_lock_write(struct page *hpage) return NULL; } -pgoff_t __basepage_index(struct page *page) +pgoff_t hugetlb_basepage_index(struct page *page) { struct page *page_head = compound_head(page); pgoff_t index = page_index(page_head); unsigned long compound_idx; - if (!PageHuge(page_head)) - return page_index(page); - if (compound_order(page_head) >= MAX_ORDER) compound_idx = page_to_pfn(page) - page_to_pfn(page_head); else From 171936ddaf97e6f4e1264f4128bb5cf15691339c Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Thu, 24 Jun 2021 18:39:55 -0700 Subject: [PATCH 18/24] mm/memory-failure: use a mutex to avoid memory_failure() races Patch series "mm,hwpoison: fix sending SIGBUS for Action Required MCE", v5. I wrote this patchset to materialize what I think is the current allowable solution mentioned by the previous discussion [1]. I simply borrowed Tony's mutex patch and Aili's return code patch, then I queued another one to find error virtual address in the best effort manner. I know that this is not a perfect solution, but should work for some typical case. [1]: https://lore.kernel.org/linux-mm/20210331192540.2141052f@alex-virtual-machine/ This patch (of 2): There can be races when multiple CPUs consume poison from the same page. The first into memory_failure() atomically sets the HWPoison page flag and begins hunting for tasks that map this page. Eventually it invalidates those mappings and may send a SIGBUS to the affected tasks. But while all that work is going on, other CPUs see a "success" return code from memory_failure() and so they believe the error has been handled and continue executing. Fix by wrapping most of the internal parts of memory_failure() in a mutex. [akpm@linux-foundation.org: make mf_mutex local to memory_failure()] Link: https://lkml.kernel.org/r/20210521030156.2612074-1-nao.horiguchi@gmail.com Link: https://lkml.kernel.org/r/20210521030156.2612074-2-nao.horiguchi@gmail.com Signed-off-by: Tony Luck Signed-off-by: Naoya Horiguchi Reviewed-by: Borislav Petkov Reviewed-by: Oscar Salvador Cc: Aili Yao Cc: Andy Lutomirski Cc: Borislav Petkov Cc: David Hildenbrand Cc: Jue Wang Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory-failure.c | 36 +++++++++++++++++++++++------------- 1 file changed, 23 insertions(+), 13 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 0143d32bc6663..a7fc1cd6765a1 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1429,9 +1429,10 @@ int memory_failure(unsigned long pfn, int flags) struct page *hpage; struct page *orig_head; struct dev_pagemap *pgmap; - int res; + int res = 0; unsigned long page_flags; bool retry = true; + static DEFINE_MUTEX(mf_mutex); if (!sysctl_memory_failure_recovery) panic("Memory failure on page %lx", pfn); @@ -1449,13 +1450,18 @@ int memory_failure(unsigned long pfn, int flags) return -ENXIO; } + mutex_lock(&mf_mutex); + try_again: - if (PageHuge(p)) - return memory_failure_hugetlb(pfn, flags); + if (PageHuge(p)) { + res = memory_failure_hugetlb(pfn, flags); + goto unlock_mutex; + } + if (TestSetPageHWPoison(p)) { pr_err("Memory failure: %#lx: already hardware poisoned\n", pfn); - return 0; + goto unlock_mutex; } orig_head = hpage = compound_head(p); @@ -1488,17 +1494,19 @@ int memory_failure(unsigned long pfn, int flags) res = MF_FAILED; } action_result(pfn, MF_MSG_BUDDY, res); - return res == MF_RECOVERED ? 0 : -EBUSY; + res = res == MF_RECOVERED ? 0 : -EBUSY; } else { action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED); - return -EBUSY; + res = -EBUSY; } + goto unlock_mutex; } if (PageTransHuge(hpage)) { if (try_to_split_thp_page(p, "Memory Failure") < 0) { action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED); - return -EBUSY; + res = -EBUSY; + goto unlock_mutex; } VM_BUG_ON_PAGE(!page_count(p), p); } @@ -1522,7 +1530,7 @@ int memory_failure(unsigned long pfn, int flags) if (PageCompound(p) && compound_head(p) != orig_head) { action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED); res = -EBUSY; - goto out; + goto unlock_page; } /* @@ -1542,14 +1550,14 @@ int memory_failure(unsigned long pfn, int flags) num_poisoned_pages_dec(); unlock_page(p); put_page(p); - return 0; + goto unlock_mutex; } if (hwpoison_filter(p)) { if (TestClearPageHWPoison(p)) num_poisoned_pages_dec(); unlock_page(p); put_page(p); - return 0; + goto unlock_mutex; } /* @@ -1573,7 +1581,7 @@ int memory_failure(unsigned long pfn, int flags) if (!hwpoison_user_mappings(p, pfn, flags, &p)) { action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED); res = -EBUSY; - goto out; + goto unlock_page; } /* @@ -1582,13 +1590,15 @@ int memory_failure(unsigned long pfn, int flags) if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) { action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED); res = -EBUSY; - goto out; + goto unlock_page; } identify_page_state: res = identify_page_state(pfn, p, page_flags); -out: +unlock_page: unlock_page(p); +unlock_mutex: + mutex_unlock(&mf_mutex); return res; } EXPORT_SYMBOL_GPL(memory_failure); From 47af12bae17f99b5e77f8651cb7f3e1877610acf Mon Sep 17 00:00:00 2001 From: Aili Yao Date: Thu, 24 Jun 2021 18:39:58 -0700 Subject: [PATCH 19/24] mm,hwpoison: return -EHWPOISON to denote that the page has already been poisoned When memory_failure() is called with MF_ACTION_REQUIRED on the page that has already been hwpoisoned, memory_failure() could fail to send SIGBUS to the affected process, which results in infinite loop of MCEs. Currently memory_failure() returns 0 if it's called for already hwpoisoned page, then the caller, kill_me_maybe(), could return without sending SIGBUS to current process. An action required MCE is raised when the current process accesses to the broken memory, so no SIGBUS means that the current process continues to run and access to the error page again soon, so running into MCE loop. This issue can arise for example in the following scenarios: - Two or more threads access to the poisoned page concurrently. If local MCE is enabled, MCE handler independently handles the MCE events. So there's a race among MCE events, and the second or latter threads fall into the situation in question. - If there was a precedent memory error event and memory_failure() for the event failed to unmap the error page for some reason, the subsequent memory access to the error page triggers the MCE loop situation. To fix the issue, make memory_failure() return an error code when the error page has already been hwpoisoned. This allows memory error handler to control how it sends signals to userspace. And make sure that any process touching a hwpoisoned page should get a SIGBUS even in "already hwpoisoned" path of memory_failure() as is done in page fault path. Link: https://lkml.kernel.org/r/20210521030156.2612074-3-nao.horiguchi@gmail.com Signed-off-by: Aili Yao Signed-off-by: Naoya Horiguchi Reviewed-by: Oscar Salvador Cc: Andy Lutomirski Cc: Borislav Petkov Cc: Borislav Petkov Cc: David Hildenbrand Cc: Jue Wang Cc: Tony Luck Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory-failure.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index a7fc1cd6765a1..f24105db7081f 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1253,7 +1253,7 @@ static int memory_failure_hugetlb(unsigned long pfn, int flags) if (TestSetPageHWPoison(head)) { pr_err("Memory failure: %#lx: already hardware poisoned\n", pfn); - return 0; + return -EHWPOISON; } num_poisoned_pages_inc(); @@ -1461,6 +1461,7 @@ int memory_failure(unsigned long pfn, int flags) if (TestSetPageHWPoison(p)) { pr_err("Memory failure: %#lx: already hardware poisoned\n", pfn); + res = -EHWPOISON; goto unlock_mutex; } From ea6d0630100b285f059d0a8d8e86f38a46407536 Mon Sep 17 00:00:00 2001 From: Naoya Horiguchi Date: Thu, 24 Jun 2021 18:40:01 -0700 Subject: [PATCH 20/24] mm/hwpoison: do not lock page again when me_huge_page() successfully recovers Currently me_huge_page() temporary unlocks page to perform some actions then locks it again later. My testcase (which calls hard-offline on some tail page in a hugetlb, then accesses the address of the hugetlb range) showed that page allocation code detects this page lock on buddy page and printed out "BUG: Bad page state" message. check_new_page_bad() does not consider a page with __PG_HWPOISON as bad page, so this flag works as kind of filter, but this filtering doesn't work in this case because the "bad page" is not the actual hwpoisoned page. So stop locking page again. Actions to be taken depend on the page type of the error, so page unlocking should be done in ->action() callbacks. So let's make it assumed and change all existing callbacks that way. Link: https://lkml.kernel.org/r/20210609072029.74645-1-nao.horiguchi@gmail.com Fixes: commit 78bb920344b8 ("mm: hwpoison: dissolve in-use hugepage in unrecoverable memory error") Signed-off-by: Naoya Horiguchi Cc: Oscar Salvador Cc: Michal Hocko Cc: Tony Luck Cc: "Aneesh Kumar K.V" Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memory-failure.c | 44 ++++++++++++++++++++++++++++++-------------- 1 file changed, 30 insertions(+), 14 deletions(-) diff --git a/mm/memory-failure.c b/mm/memory-failure.c index f24105db7081f..6f5f78885ab42 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -658,6 +658,7 @@ static int truncate_error_page(struct page *p, unsigned long pfn, */ static int me_kernel(struct page *p, unsigned long pfn) { + unlock_page(p); return MF_IGNORED; } @@ -667,6 +668,7 @@ static int me_kernel(struct page *p, unsigned long pfn) static int me_unknown(struct page *p, unsigned long pfn) { pr_err("Memory failure: %#lx: Unknown page state\n", pfn); + unlock_page(p); return MF_FAILED; } @@ -675,6 +677,7 @@ static int me_unknown(struct page *p, unsigned long pfn) */ static int me_pagecache_clean(struct page *p, unsigned long pfn) { + int ret; struct address_space *mapping; delete_from_lru_cache(p); @@ -683,8 +686,10 @@ static int me_pagecache_clean(struct page *p, unsigned long pfn) * For anonymous pages we're done the only reference left * should be the one m_f() holds. */ - if (PageAnon(p)) - return MF_RECOVERED; + if (PageAnon(p)) { + ret = MF_RECOVERED; + goto out; + } /* * Now truncate the page in the page cache. This is really @@ -698,7 +703,8 @@ static int me_pagecache_clean(struct page *p, unsigned long pfn) /* * Page has been teared down in the meanwhile */ - return MF_FAILED; + ret = MF_FAILED; + goto out; } /* @@ -706,7 +712,10 @@ static int me_pagecache_clean(struct page *p, unsigned long pfn) * * Open: to take i_mutex or not for this? Right now we don't. */ - return truncate_error_page(p, pfn, mapping); + ret = truncate_error_page(p, pfn, mapping); +out: + unlock_page(p); + return ret; } /* @@ -782,24 +791,26 @@ static int me_pagecache_dirty(struct page *p, unsigned long pfn) */ static int me_swapcache_dirty(struct page *p, unsigned long pfn) { + int ret; + ClearPageDirty(p); /* Trigger EIO in shmem: */ ClearPageUptodate(p); - if (!delete_from_lru_cache(p)) - return MF_DELAYED; - else - return MF_FAILED; + ret = delete_from_lru_cache(p) ? MF_FAILED : MF_DELAYED; + unlock_page(p); + return ret; } static int me_swapcache_clean(struct page *p, unsigned long pfn) { + int ret; + delete_from_swap_cache(p); - if (!delete_from_lru_cache(p)) - return MF_RECOVERED; - else - return MF_FAILED; + ret = delete_from_lru_cache(p) ? MF_FAILED : MF_RECOVERED; + unlock_page(p); + return ret; } /* @@ -820,6 +831,7 @@ static int me_huge_page(struct page *p, unsigned long pfn) mapping = page_mapping(hpage); if (mapping) { res = truncate_error_page(hpage, pfn, mapping); + unlock_page(hpage); } else { res = MF_FAILED; unlock_page(hpage); @@ -834,7 +846,6 @@ static int me_huge_page(struct page *p, unsigned long pfn) page_ref_inc(p); res = MF_RECOVERED; } - lock_page(hpage); } return res; @@ -866,6 +877,8 @@ static struct page_state { unsigned long mask; unsigned long res; enum mf_action_page_type type; + + /* Callback ->action() has to unlock the relevant page inside it. */ int (*action)(struct page *p, unsigned long pfn); } error_states[] = { { reserved, reserved, MF_MSG_KERNEL, me_kernel }, @@ -929,6 +942,7 @@ static int page_action(struct page_state *ps, struct page *p, int result; int count; + /* page p should be unlocked after returning from ps->action(). */ result = ps->action(p, pfn); count = page_count(p) - 1; @@ -1313,7 +1327,7 @@ static int memory_failure_hugetlb(unsigned long pfn, int flags) goto out; } - res = identify_page_state(pfn, p, page_flags); + return identify_page_state(pfn, p, page_flags); out: unlock_page(head); return res; @@ -1596,6 +1610,8 @@ int memory_failure(unsigned long pfn, int flags) identify_page_state: res = identify_page_state(pfn, p, page_flags); + mutex_unlock(&mf_mutex); + return res; unlock_page: unlock_page(p); unlock_mutex: From b08e50dd64489e3997029d204f761cb57a3762d2 Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Thu, 24 Jun 2021 18:40:04 -0700 Subject: [PATCH 21/24] mm/page_alloc: __alloc_pages_bulk(): do bounds check before accessing array In the event that somebody would call this with an already fully populated page_array, the last loop iteration would do an access beyond the end of page_array. It's of course extremely unlikely that would ever be done, but this triggers my internal static analyzer. Also, if it really is not supposed to be invoked this way (i.e., with no NULL entries in page_array), the nr_populated Acked-by: Mel Gorman Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d1f5de1c1283b..7124bb00219de 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5053,7 +5053,7 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid, * Skip populated array elements to determine if any pages need * to be allocated before disabling IRQs. */ - while (page_array && page_array[nr_populated] && nr_populated < nr_pages) + while (page_array && nr_populated < nr_pages && page_array[nr_populated]) nr_populated++; /* Use the single page allocator for one page. */ From b3b64ebd38225d8032b5db42938d969b602040c2 Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 24 Jun 2021 18:40:07 -0700 Subject: [PATCH 22/24] mm/page_alloc: do bulk array bounds check after checking populated elements Dan Carpenter reported the following The patch 0f87d9d30f21: "mm/page_alloc: add an array-based interface to the bulk page allocator" from Apr 29, 2021, leads to the following static checker warning: mm/page_alloc.c:5338 __alloc_pages_bulk() warn: potentially one past the end of array 'page_array[nr_populated]' The problem can occur if an array is passed in that is fully populated. That potentially ends up allocating a single page and storing it past the end of the array. This patch returns 0 if the array is fully populated. Link: https://lkml.kernel.org/r/20210618125102.GU30378@techsingularity.net Fixes: 0f87d9d30f21 ("mm/page_alloc: add an array-based interface to the bulk page allocator") Signed-off-by: Mel Gorman Reported-by: Dan Carpenter Cc: Jesper Dangaard Brouer Cc: Vlastimil Babka Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 7124bb00219de..ef2265f86b913 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -5056,6 +5056,10 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid, while (page_array && nr_populated < nr_pages && page_array[nr_populated]) nr_populated++; + /* Already populated array? */ + if (unlikely(page_array && nr_pages - nr_populated == 0)) + return 0; + /* Use the single page allocator for one page. */ if (nr_pages - nr_populated == 1) goto failed; From ee924d3ddd4561b7e6671bd431ff55bb9a24c47c Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marek=20Beh=C3=BAn?= Date: Thu, 24 Jun 2021 18:40:10 -0700 Subject: [PATCH 23/24] MAINTAINERS: fix Marek's identity again MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Fix my name to use diacritics, since MAINTAINERS supports it. Fix my e-mail address in MAINTAINERS' marvell10g PHY driver description, I accidentally put my other e-mail address here. Link: https://lkml.kernel.org/r/20210616113624.19351-1-kabel@kernel.org Signed-off-by: Marek Behún Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- MAINTAINERS | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/MAINTAINERS b/MAINTAINERS index 8c5ee008301a6..1d959fcbcbe12 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1816,7 +1816,7 @@ F: drivers/pinctrl/pinctrl-gemini.c F: drivers/rtc/rtc-ftrtc010.c ARM/CZ.NIC TURRIS SUPPORT -M: Marek Behun +M: Marek Behún S: Maintained W: https://www.turris.cz/ F: Documentation/ABI/testing/debugfs-moxtet @@ -10946,7 +10946,7 @@ F: include/linux/mv643xx.h MARVELL MV88X3310 PHY DRIVER M: Russell King -M: Marek Behun +M: Marek Behún L: netdev@vger.kernel.org S: Maintained F: drivers/net/phy/marvell10g.c From 72a461adbe88acf6a8cc5dba7720cf94d7056154 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Marek=20Beh=C3=BAn?= Date: Thu, 24 Jun 2021 18:40:13 -0700 Subject: [PATCH 24/24] mailmap: add Marek's other e-mail address and identity without diacritics MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some of my commits were sent with identities Marek Behun Marek Behún while the correct one is Marek Behún Put this into mailmap so that git shortlog prints all my commits under one identity. Link: https://lkml.kernel.org/r/20210616113624.19351-2-kabel@kernel.org Signed-off-by: Marek Behún Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- .mailmap | 2 ++ 1 file changed, 2 insertions(+) diff --git a/.mailmap b/.mailmap index c79a78766c07f..db58eedb44f1d 100644 --- a/.mailmap +++ b/.mailmap @@ -212,6 +212,8 @@ Manivannan Sadhasivam Manivannan Sadhasivam Marcin Nowakowski Marc Zyngier +Marek Behún +Marek Behún Marek Behun Mark Brown Mark Starovoytov Mark Yao