From b512719f771a82180211c9a315b8a7f628832b3d Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Thu, 26 Jul 2018 16:37:08 -0700 Subject: [PATCH 01/11] delayacct: fix crash in delayacct_blkio_end() after delayacct init failure While forking, if delayacct init fails due to memory shortage, it continues expecting all delayacct users to check task->delays pointer against NULL before dereferencing it, which all of them used to do. Commit c96f5471ce7d ("delayacct: Account blkio completion on the correct task"), while updating delayacct_blkio_end() to take the target task instead of always using %current, made the function test NULL on %current->delays and then continue to operated on @p->delays. If %current succeeded init while @p didn't, it leads to the following crash. BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 IP: __delayacct_blkio_end+0xc/0x40 PGD 8000001fd07e1067 P4D 8000001fd07e1067 PUD 1fcffbb067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 4 PID: 25774 Comm: QIOThread0 Not tainted 4.16.0-9_fbk1_rc2_1180_g6b593215b4d7 #9 RIP: 0010:__delayacct_blkio_end+0xc/0x40 Call Trace: try_to_wake_up+0x2c0/0x600 autoremove_wake_function+0xe/0x30 __wake_up_common+0x74/0x120 wake_up_page_bit+0x9c/0xe0 mpage_end_io+0x27/0x70 blk_update_request+0x78/0x2c0 scsi_end_request+0x2c/0x1e0 scsi_io_completion+0x20b/0x5f0 blk_mq_complete_request+0xa2/0x100 ata_scsi_qc_complete+0x79/0x400 ata_qc_complete_multiple+0x86/0xd0 ahci_handle_port_interrupt+0xc9/0x5c0 ahci_handle_port_intr+0x54/0xb0 ahci_single_level_irq_intr+0x3b/0x60 __handle_irq_event_percpu+0x43/0x190 handle_irq_event_percpu+0x20/0x50 handle_irq_event+0x2a/0x50 handle_edge_irq+0x80/0x1c0 handle_irq+0xaf/0x120 do_IRQ+0x41/0xc0 common_interrupt+0xf/0xf Fix it by updating delayacct_blkio_end() check @p->delays instead. Link: http://lkml.kernel.org/r/20180724175542.GP1934745@devbig577.frc2.facebook.com Fixes: c96f5471ce7d ("delayacct: Account blkio completion on the correct task") Signed-off-by: Tejun Heo Reported-by: Dave Jones Debugged-by: Dave Jones Reviewed-by: Andrew Morton Cc: Josh Snyder Cc: [4.15+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/delayacct.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/delayacct.h b/include/linux/delayacct.h index e6c0448ebcc7..31c865d1842e 100644 --- a/include/linux/delayacct.h +++ b/include/linux/delayacct.h @@ -124,7 +124,7 @@ static inline void delayacct_blkio_start(void) static inline void delayacct_blkio_end(struct task_struct *p) { - if (current->delays) + if (p->delays) __delayacct_blkio_end(p); delayacct_clear_flag(DELAYACCT_PF_BLKIO); } From 03758dbbe2b5c0627b361ad5b4a2c60f9964ccde Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 26 Jul 2018 16:37:12 -0700 Subject: [PATCH 02/11] kasan: only select SLUB_DEBUG with SYSFS=y Building with KASAN and SLUB but without sysfs now results in a build-time error: WARNING: unmet direct dependencies detected for SLUB_DEBUG Depends on [n]: SLUB [=y] && SYSFS [=n] Selected by [y]: - KASAN [=y] && HAVE_ARCH_KASAN [=y] && (SLUB [=y] || SLAB [=n] && !DEBUG_SLAB [=n]) && SLUB [=y] mm/slub.c:4565:12: error: 'list_locations' defined but not used [-Werror=unused-function] static int list_locations(struct kmem_cache *s, char *buf, ^~~~~~~~~~~~~~ mm/slub.c:4406:13: error: 'validate_slab_cache' defined but not used [-Werror=unused-function] static long validate_slab_cache(struct kmem_cache *s) This disallows that broken configuration in Kconfig. Link: http://lkml.kernel.org/r/20180709154019.1693026-1-arnd@arndb.de Fixes: dd275caf4a0d ("kasan: depend on CONFIG_SLUB_DEBUG") Signed-off-by: Arnd Bergmann Cc: "Jason A. Donenfeld" Cc: Arnd Bergmann Cc: Shakeel Butt Cc: Andrey Ryabinin Cc: Christoph Lameter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Kconfig.kasan | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan index c253c1b46c6b..befb127507c0 100644 --- a/lib/Kconfig.kasan +++ b/lib/Kconfig.kasan @@ -5,7 +5,7 @@ if HAVE_ARCH_KASAN config KASAN bool "KASan: runtime memory debugger" - depends on SLUB || (SLAB && !DEBUG_SLAB) + depends on (SLUB && SYSFS) || (SLAB && !DEBUG_SLAB) select SLUB_DEBUG if SLUB select CONSTRUCTORS select STACKDEPOT From 15d36fecd0bdc7510b70a0e5ec6671140b3fce0c Mon Sep 17 00:00:00 2001 From: Dave Jiang Date: Thu, 26 Jul 2018 16:37:15 -0700 Subject: [PATCH 03/11] mm: disallow mappings that conflict for devm_memremap_pages() When pmem namespaces created are smaller than section size, this can cause an issue during removal and gpf was observed: general protection fault: 0000 1 SMP PTI CPU: 36 PID: 3941 Comm: ndctl Tainted: G W 4.14.28-1.el7uek.x86_64 #2 task: ffff88acda150000 task.stack: ffffc900233a4000 RIP: 0010:__put_page+0x56/0x79 Call Trace: devm_memremap_pages_release+0x155/0x23a release_nodes+0x21e/0x260 devres_release_all+0x3c/0x48 device_release_driver_internal+0x15c/0x207 device_release_driver+0x12/0x14 unbind_store+0xba/0xd8 drv_attr_store+0x27/0x31 sysfs_kf_write+0x3f/0x46 kernfs_fop_write+0x10f/0x18b __vfs_write+0x3a/0x16d vfs_write+0xb2/0x1a1 SyS_write+0x55/0xb9 do_syscall_64+0x79/0x1ae entry_SYSCALL_64_after_hwframe+0x3d/0x0 Add code to check whether we have a mapping already in the same section and prevent additional mappings from being created if that is the case. Link: http://lkml.kernel.org/r/152909478401.50143.312364396244072931.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang Cc: Dan Williams Cc: Robert Elliott Cc: Jeff Moyer Cc: Matthew Wilcox Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/memremap.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/kernel/memremap.c b/kernel/memremap.c index 5857267a4af5..a734b1747466 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -176,10 +176,27 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) unsigned long pfn, pgoff, order; pgprot_t pgprot = PAGE_KERNEL; int error, nid, is_ram; + struct dev_pagemap *conflict_pgmap; align_start = res->start & ~(SECTION_SIZE - 1); align_size = ALIGN(res->start + resource_size(res), SECTION_SIZE) - align_start; + align_end = align_start + align_size - 1; + + conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_start), NULL); + if (conflict_pgmap) { + dev_WARN(dev, "Conflicting mapping in same section\n"); + put_dev_pagemap(conflict_pgmap); + return ERR_PTR(-ENOMEM); + } + + conflict_pgmap = get_dev_pagemap(PHYS_PFN(align_end), NULL); + if (conflict_pgmap) { + dev_WARN(dev, "Conflicting mapping in same section\n"); + put_dev_pagemap(conflict_pgmap); + return ERR_PTR(-ENOMEM); + } + is_ram = region_intersects(align_start, align_size, IORESOURCE_SYSTEM_RAM, IORES_DESC_NONE); @@ -199,7 +216,6 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap) mutex_lock(&pgmap_lock); error = 0; - align_end = align_start + align_size - 1; foreach_order_pgoff(res, order, pgoff) { error = __radix_tree_insert(&pgmap_radix, From f075faa300acc4f6301e348acde0a4580ed5f77c Mon Sep 17 00:00:00 2001 From: Davidlohr Bueso Date: Thu, 26 Jul 2018 16:37:19 -0700 Subject: [PATCH 04/11] ipc/sem.c: prevent queue.status tearing in semop In order for load/store tearing prevention to work, _all_ accesses to the variable in question need to be done around READ and WRITE_ONCE() macros. Ensure everyone does so for q->status variable for semtimedop(). Link: http://lkml.kernel.org/r/20180717052654.676-1-dave@stgolabs.net Signed-off-by: Davidlohr Bueso Cc: Manfred Spraul Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- ipc/sem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ipc/sem.c b/ipc/sem.c index 5af1943ad782..76e95e4f3aa2 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -2118,7 +2118,7 @@ static long do_semtimedop(int semid, struct sembuf __user *tsops, } do { - queue.status = -EINTR; + WRITE_ONCE(queue.status, -EINTR); queue.sleeper = current; __set_current_state(TASK_INTERRUPTIBLE); From 31c5bda3a656089f01963d290a40ccda181f816e Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 26 Jul 2018 16:37:22 -0700 Subject: [PATCH 05/11] mm: fix exports that inadvertently make put_page() EXPORT_SYMBOL_GPL MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit e76384884344 ("mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS") added two EXPORT_SYMBOL_GPL() symbols, but these symbols are required by the inlined put_page(), thus accidentally making put_page() a GPL export only. This breaks OpenAFS (at least). Mark them EXPORT_SYMBOL() instead. Link: http://lkml.kernel.org/r/153128611970.2928.11310692420711601254.stgit@dwillia2-desk3.amr.corp.intel.com Fixes: e76384884344 ("mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS") Signed-off-by: Dan Williams Reported-by: Joe Gorse Reported-by: John Hubbard Tested-by: Joe Gorse Tested-by: John Hubbard Cc: Jérôme Glisse Cc: Mark Vitale Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/memremap.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/memremap.c b/kernel/memremap.c index a734b1747466..38283363da06 100644 --- a/kernel/memremap.c +++ b/kernel/memremap.c @@ -321,7 +321,7 @@ EXPORT_SYMBOL_GPL(get_dev_pagemap); #ifdef CONFIG_DEV_PAGEMAP_OPS DEFINE_STATIC_KEY_FALSE(devmap_managed_key); -EXPORT_SYMBOL_GPL(devmap_managed_key); +EXPORT_SYMBOL(devmap_managed_key); static atomic_t devmap_enable; /* @@ -362,5 +362,5 @@ void __put_devmap_managed_page(struct page *page) } else if (!count) __put_page(page); } -EXPORT_SYMBOL_GPL(__put_devmap_managed_page); +EXPORT_SYMBOL(__put_devmap_managed_page); #endif /* CONFIG_DEV_PAGEMAP_OPS */ From 027232da7c7c1c7f04383f93bd798e475dde5285 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 26 Jul 2018 16:37:25 -0700 Subject: [PATCH 06/11] mm: introduce vma_init() Not all VMAs allocated with vm_area_alloc(). Some of them allocated on stack or in data segment. The new helper can be use to initialize VMA properly regardless where it was allocated. Link: http://lkml.kernel.org/r/20180724121139.62570-2-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Acked-by: Linus Torvalds Reviewed-by: Andrew Morton Cc: Dmitry Vyukov Cc: Oleg Nesterov Cc: Andrea Arcangeli Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mm.h | 6 ++++++ kernel/fork.c | 6 ++---- 2 files changed, 8 insertions(+), 4 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index d3a3842316b8..31540f166987 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -452,6 +452,12 @@ struct vm_operations_struct { unsigned long addr); }; +static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm) +{ + vma->vm_mm = mm; + INIT_LIST_HEAD(&vma->anon_vma_chain); +} + struct mmu_gather; struct inode; diff --git a/kernel/fork.c b/kernel/fork.c index a191c05e757d..1b27babc4c78 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -312,10 +312,8 @@ struct vm_area_struct *vm_area_alloc(struct mm_struct *mm) { struct vm_area_struct *vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL); - if (vma) { - vma->vm_mm = mm; - INIT_LIST_HEAD(&vma->anon_vma_chain); - } + if (vma) + vma_init(vma, mm); return vma; } From 2c4541e24c55e2847bede93e33d749280edd429a Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 26 Jul 2018 16:37:30 -0700 Subject: [PATCH 07/11] mm: use vma_init() to initialize VMAs on stack and data segments Make sure to initialize all VMAs properly, not only those which come from vm_area_cachep. Link: http://lkml.kernel.org/r/20180724121139.62570-3-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Acked-by: Linus Torvalds Reviewed-by: Andrew Morton Cc: Dmitry Vyukov Cc: Oleg Nesterov Cc: Andrea Arcangeli Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/arm/kernel/process.c | 1 + arch/arm/mach-rpc/ecard.c | 2 +- arch/arm64/include/asm/tlb.h | 4 +++- arch/arm64/mm/hugetlbpage.c | 7 +++++-- arch/ia64/include/asm/tlb.h | 2 +- arch/ia64/mm/init.c | 2 +- arch/x86/um/mem_32.c | 2 +- fs/hugetlbfs/inode.c | 2 ++ mm/mempolicy.c | 1 + mm/shmem.c | 1 + 10 files changed, 17 insertions(+), 7 deletions(-) diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c index 225d1c58d2de..d9c299133111 100644 --- a/arch/arm/kernel/process.c +++ b/arch/arm/kernel/process.c @@ -338,6 +338,7 @@ static struct vm_area_struct gate_vma = { static int __init gate_vma_init(void) { + vma_init(&gate_vma, NULL); gate_vma.vm_page_prot = PAGE_READONLY_EXEC; return 0; } diff --git a/arch/arm/mach-rpc/ecard.c b/arch/arm/mach-rpc/ecard.c index 39aef4876ed4..8db62cc54a6a 100644 --- a/arch/arm/mach-rpc/ecard.c +++ b/arch/arm/mach-rpc/ecard.c @@ -237,8 +237,8 @@ static void ecard_init_pgtables(struct mm_struct *mm) memcpy(dst_pgd, src_pgd, sizeof(pgd_t) * (EASI_SIZE / PGDIR_SIZE)); + vma_init(&vma, mm); vma.vm_flags = VM_EXEC; - vma.vm_mm = mm; flush_tlb_range(&vma, IO_START, IO_START + IO_SIZE); flush_tlb_range(&vma, EASI_START, EASI_START + EASI_SIZE); diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h index ffdaea7954bb..d87f2d646caa 100644 --- a/arch/arm64/include/asm/tlb.h +++ b/arch/arm64/include/asm/tlb.h @@ -37,7 +37,9 @@ static inline void __tlb_remove_table(void *_table) static inline void tlb_flush(struct mmu_gather *tlb) { - struct vm_area_struct vma = { .vm_mm = tlb->mm, }; + struct vm_area_struct vma; + + vma_init(&vma, tlb->mm); /* * The ASID allocator will either invalidate the ASID or mark diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c index ecc6818191df..1854e49aa18a 100644 --- a/arch/arm64/mm/hugetlbpage.c +++ b/arch/arm64/mm/hugetlbpage.c @@ -108,11 +108,13 @@ static pte_t get_clear_flush(struct mm_struct *mm, unsigned long pgsize, unsigned long ncontig) { - struct vm_area_struct vma = { .vm_mm = mm }; + struct vm_area_struct vma; pte_t orig_pte = huge_ptep_get(ptep); bool valid = pte_valid(orig_pte); unsigned long i, saddr = addr; + vma_init(&vma, mm); + for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) { pte_t pte = ptep_get_and_clear(mm, addr, ptep); @@ -145,9 +147,10 @@ static void clear_flush(struct mm_struct *mm, unsigned long pgsize, unsigned long ncontig) { - struct vm_area_struct vma = { .vm_mm = mm }; + struct vm_area_struct vma; unsigned long i, saddr = addr; + vma_init(&vma, mm); for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) pte_clear(mm, addr, ptep); diff --git a/arch/ia64/include/asm/tlb.h b/arch/ia64/include/asm/tlb.h index 44f0ac0df308..db89e7306081 100644 --- a/arch/ia64/include/asm/tlb.h +++ b/arch/ia64/include/asm/tlb.h @@ -120,7 +120,7 @@ ia64_tlb_flush_mmu_tlbonly(struct mmu_gather *tlb, unsigned long start, unsigned */ struct vm_area_struct vma; - vma.vm_mm = tlb->mm; + vma_init(&vma, tlb->mm); /* flush the address range from the tlb: */ flush_tlb_range(&vma, start, end); /* now flush the virt. page-table area mapping the address range: */ diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c index bdb14a369137..e6c6dfd98de2 100644 --- a/arch/ia64/mm/init.c +++ b/arch/ia64/mm/init.c @@ -273,7 +273,7 @@ static struct vm_area_struct gate_vma; static int __init gate_vma_init(void) { - gate_vma.vm_mm = NULL; + vma_init(&gate_vma, NULL); gate_vma.vm_start = FIXADDR_USER_START; gate_vma.vm_end = FIXADDR_USER_END; gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC; diff --git a/arch/x86/um/mem_32.c b/arch/x86/um/mem_32.c index 744afdc18cf3..56c44d865f7b 100644 --- a/arch/x86/um/mem_32.c +++ b/arch/x86/um/mem_32.c @@ -16,7 +16,7 @@ static int __init gate_vma_init(void) if (!FIXADDR_USER_START) return 0; - gate_vma.vm_mm = NULL; + vma_init(&gate_vma, NULL); gate_vma.vm_start = FIXADDR_USER_START; gate_vma.vm_end = FIXADDR_USER_END; gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC; diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index d508c7844681..40d4c66c7751 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -411,6 +411,7 @@ static void remove_inode_hugepages(struct inode *inode, loff_t lstart, bool truncate_op = (lend == LLONG_MAX); memset(&pseudo_vma, 0, sizeof(struct vm_area_struct)); + vma_init(&pseudo_vma, current->mm); pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED); pagevec_init(&pvec); next = start; @@ -595,6 +596,7 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset, * as input to create an allocation policy. */ memset(&pseudo_vma, 0, sizeof(struct vm_area_struct)); + vma_init(&pseudo_vma, mm); pseudo_vma.vm_flags = (VM_HUGETLB | VM_MAYSHARE | VM_SHARED); pseudo_vma.vm_file = file; diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 9ac49ef17b4e..01f1a14facc4 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -2505,6 +2505,7 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol) /* Create pseudo-vma that contains just the policy */ memset(&pvma, 0, sizeof(struct vm_area_struct)); + vma_init(&pvma, NULL); pvma.vm_end = TASK_SIZE; /* policy covers entire file */ mpol_set_shared_policy(sp, &pvma, new); /* adds ref */ diff --git a/mm/shmem.c b/mm/shmem.c index 2cab84403055..41b9bbf24e16 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1421,6 +1421,7 @@ static void shmem_pseudo_vma_init(struct vm_area_struct *vma, { /* Create a pseudo vma that just contains the policy */ memset(vma, 0, sizeof(*vma)); + vma_init(vma, NULL); /* Bias interleave by inode number to distribute better across nodes */ vma->vm_pgoff = index + info->vfs_inode.i_ino; vma->vm_policy = mpol_shared_policy_lookup(&info->policy, index); From bfd40eaff5abb9f62c8ef94ca13ed0d94a560f10 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Thu, 26 Jul 2018 16:37:35 -0700 Subject: [PATCH 08/11] mm: fix vma_is_anonymous() false-positives vma_is_anonymous() relies on ->vm_ops being NULL to detect anonymous VMA. This is unreliable as ->mmap may not set ->vm_ops. False-positive vma_is_anonymous() may lead to crashes: next ffff8801ce5e7040 prev ffff8801d20eca50 mm ffff88019c1e13c0 prot 27 anon_vma ffff88019680cdd8 vm_ops 0000000000000000 pgoff 0 file ffff8801b2ec2d00 private_data 0000000000000000 flags: 0xff(read|write|exec|shared|mayread|maywrite|mayexec|mayshare) ------------[ cut here ]------------ kernel BUG at mm/memory.c:1422! invalid opcode: 0000 [#1] SMP KASAN CPU: 0 PID: 18486 Comm: syz-executor3 Not tainted 4.18.0-rc3+ #136 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:zap_pmd_range mm/memory.c:1421 [inline] RIP: 0010:zap_pud_range mm/memory.c:1466 [inline] RIP: 0010:zap_p4d_range mm/memory.c:1487 [inline] RIP: 0010:unmap_page_range+0x1c18/0x2220 mm/memory.c:1508 Call Trace: unmap_single_vma+0x1a0/0x310 mm/memory.c:1553 zap_page_range_single+0x3cc/0x580 mm/memory.c:1644 unmap_mapping_range_vma mm/memory.c:2792 [inline] unmap_mapping_range_tree mm/memory.c:2813 [inline] unmap_mapping_pages+0x3a7/0x5b0 mm/memory.c:2845 unmap_mapping_range+0x48/0x60 mm/memory.c:2880 truncate_pagecache+0x54/0x90 mm/truncate.c:800 truncate_setsize+0x70/0xb0 mm/truncate.c:826 simple_setattr+0xe9/0x110 fs/libfs.c:409 notify_change+0xf13/0x10f0 fs/attr.c:335 do_truncate+0x1ac/0x2b0 fs/open.c:63 do_sys_ftruncate+0x492/0x560 fs/open.c:205 __do_sys_ftruncate fs/open.c:215 [inline] __se_sys_ftruncate fs/open.c:213 [inline] __x64_sys_ftruncate+0x59/0x80 fs/open.c:213 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Reproducer: #include #include #include #include #include #include #include #include #include #include #include #define KCOV_INIT_TRACE _IOR('c', 1, unsigned long) #define KCOV_ENABLE _IO('c', 100) #define KCOV_DISABLE _IO('c', 101) #define COVER_SIZE (1024<<10) #define KCOV_TRACE_PC 0 #define KCOV_TRACE_CMP 1 int main(int argc, char **argv) { int fd; unsigned long *cover; system("mount -t debugfs none /sys/kernel/debug"); fd = open("/sys/kernel/debug/kcov", O_RDWR); ioctl(fd, KCOV_INIT_TRACE, COVER_SIZE); cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long), PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); munmap(cover, COVER_SIZE * sizeof(unsigned long)); cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long), PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); memset(cover, 0, COVER_SIZE * sizeof(unsigned long)); ftruncate(fd, 3UL << 20); return 0; } This can be fixed by assigning anonymous VMAs own vm_ops and not relying on it being NULL. If ->mmap() failed to set ->vm_ops, mmap_region() will set it to dummy_vm_ops. This way we will have non-NULL ->vm_ops for all VMAs. Link: http://lkml.kernel.org/r/20180724121139.62570-4-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov Reported-by: syzbot+3f84280d52be9b7083cc@syzkaller.appspotmail.com Acked-by: Linus Torvalds Reviewed-by: Andrew Morton Cc: Dmitry Vyukov Cc: Oleg Nesterov Cc: Andrea Arcangeli Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/mem.c | 1 + fs/exec.c | 1 + include/linux/mm.h | 8 ++++++++ mm/mmap.c | 3 +++ mm/nommu.c | 2 ++ 5 files changed, 15 insertions(+) diff --git a/drivers/char/mem.c b/drivers/char/mem.c index ffeb60d3434c..df66a9dd0aae 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -708,6 +708,7 @@ static int mmap_zero(struct file *file, struct vm_area_struct *vma) #endif if (vma->vm_flags & VM_SHARED) return shmem_zero_setup(vma); + vma_set_anonymous(vma); return 0; } diff --git a/fs/exec.c b/fs/exec.c index 72e961a62adb..bdd0eacefdf5 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -293,6 +293,7 @@ static int __bprm_mm_init(struct linux_binprm *bprm) bprm->vma = vma = vm_area_alloc(mm); if (!vma) return -ENOMEM; + vma_set_anonymous(vma); if (down_write_killable(&mm->mmap_sem)) { err = -EINTR; diff --git a/include/linux/mm.h b/include/linux/mm.h index 31540f166987..7ba6d356d18f 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -454,10 +454,18 @@ struct vm_operations_struct { static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm) { + static const struct vm_operations_struct dummy_vm_ops = {}; + vma->vm_mm = mm; + vma->vm_ops = &dummy_vm_ops; INIT_LIST_HEAD(&vma->anon_vma_chain); } +static inline void vma_set_anonymous(struct vm_area_struct *vma) +{ + vma->vm_ops = NULL; +} + struct mmu_gather; struct inode; diff --git a/mm/mmap.c b/mm/mmap.c index ff1944d8d458..17bbf4d3e24f 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1778,6 +1778,8 @@ unsigned long mmap_region(struct file *file, unsigned long addr, error = shmem_zero_setup(vma); if (error) goto free_vma; + } else { + vma_set_anonymous(vma); } vma_link(mm, vma, prev, rb_link, rb_parent); @@ -2983,6 +2985,7 @@ static int do_brk_flags(unsigned long addr, unsigned long len, unsigned long fla return -ENOMEM; } + vma_set_anonymous(vma); vma->vm_start = addr; vma->vm_end = addr + len; vma->vm_pgoff = pgoff; diff --git a/mm/nommu.c b/mm/nommu.c index 1d22fdbf7d7c..9fc9e43335b6 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1145,6 +1145,8 @@ static int do_mmap_private(struct vm_area_struct *vma, if (ret < len) memset(base + ret, 0, len - ret); + } else { + vma_set_anonymous(vma); } return 0; From fa3fc2ad99b4f025446d1cff589a8d2dd7db92f2 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Thu, 26 Jul 2018 16:37:38 -0700 Subject: [PATCH 09/11] include/linux/eventfd.h: include linux/errno.h The new gasket staging driver ran into a randconfig build failure when CONFIG_EVENTFD is disabled: In file included from drivers/staging/gasket/gasket_interrupt.h:11, from drivers/staging/gasket/gasket_interrupt.c:4: include/linux/eventfd.h: In function 'eventfd_ctx_fdget': include/linux/eventfd.h:51:9: error: implicit declaration of function 'ERR_PTR' [-Werror=implicit-function-declaration] I can't see anything wrong with including eventfd.h before err.h, so the easiest fix is to make it possible to do this by including the file where it is needed. Link: http://lkml.kernel.org/r/20180724110737.3985088-1-arnd@arndb.de Fixes: 9a69f5087ccc ("drivers/staging: Gasket driver framework + Apex driver") Signed-off-by: Arnd Bergmann Cc: Eric Biggers Cc: Al Viro Cc: Greg Kroah-Hartman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/eventfd.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h index 7094718b653b..ffcc7724ca21 100644 --- a/include/linux/eventfd.h +++ b/include/linux/eventfd.h @@ -11,6 +11,7 @@ #include #include +#include /* * CAREFUL: Check include/uapi/asm-generic/fcntl.h when defining From 16e536ef47f567289a5699abee9ff7bb304bc12d Mon Sep 17 00:00:00 2001 From: Li Wang Date: Thu, 26 Jul 2018 16:37:42 -0700 Subject: [PATCH 10/11] zswap: re-check zswap_is_full() after do zswap_shrink() /sys/../zswap/stored_pages keeps rising in a zswap test with "zswap.max_pool_percent=0" parameter. But it should not compress or store pages any more since there is no space in the compressed pool. Reproduce steps: 1. Boot kernel with "zswap.enabled=1" 2. Set the max_pool_percent to 0 # echo 0 > /sys/module/zswap/parameters/max_pool_percent 3. Do memory stress test to see if some pages have been compressed # stress --vm 1 --vm-bytes $mem_available"M" --timeout 60s 4. Watching the 'stored_pages' number increasing or not The root cause is: When zswap_max_pool_percent is set to 0 via kernel parameter, zswap_is_full() will always return true due to zswap_shrink(). But if the shinking is able to reclain a page successfully the code then proceeds to compressing/storing another page, so the value of stored_pages will keep changing. To solve the issue, this patch adds a zswap_is_full() check again after zswap_shrink() to make sure it's now under the max_pool_percent, and to not compress/store if we reached the limit. Link: http://lkml.kernel.org/r/20180530103936.17812-1-liwang@redhat.com Signed-off-by: Li Wang Acked-by: Dan Streetman Cc: Seth Jennings Cc: Huang Ying Cc: Yu Zhao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/zswap.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/mm/zswap.c b/mm/zswap.c index 7d34e69507e3..cd91fd9d96b8 100644 --- a/mm/zswap.c +++ b/mm/zswap.c @@ -1026,6 +1026,15 @@ static int zswap_frontswap_store(unsigned type, pgoff_t offset, ret = -ENOMEM; goto reject; } + + /* A second zswap_is_full() check after + * zswap_shrink() to make sure it's now + * under the max_pool_percent + */ + if (zswap_is_full()) { + ret = -ENOMEM; + goto reject; + } } /* allocate entry */ From d97e5e6160c0e0a23963ec198c7cb1c69e6bf9e8 Mon Sep 17 00:00:00 2001 From: Shakeel Butt Date: Thu, 26 Jul 2018 16:37:45 -0700 Subject: [PATCH 11/11] kvm, mm: account shadow page tables to kmemcg MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The size of kvm's shadow page tables corresponds to the size of the guest virtual machines on the system. Large VMs can spend a significant amount of memory as shadow page tables which can not be left as system memory overhead. So, account shadow page tables to the kmemcg. [shakeelb@google.com: replace (GFP_KERNEL|__GFP_ACCOUNT) with GFP_KERNEL_ACCOUNT] Link: http://lkml.kernel.org/r/20180629140224.205849-1-shakeelb@google.com Link: http://lkml.kernel.org/r/20180627181349.149778-1-shakeelb@google.com Signed-off-by: Shakeel Butt Cc: Michal Hocko Cc: Johannes Weiner Cc: Vladimir Davydov Cc: Paolo Bonzini Cc: Greg Thelen Cc: Radim Krčmář Cc: Peter Feiner Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/x86/kvm/mmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index d594690d8b95..6b8f11521c41 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -890,7 +890,7 @@ static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache, if (cache->nobjs >= min) return 0; while (cache->nobjs < ARRAY_SIZE(cache->objects)) { - page = (void *)__get_free_page(GFP_KERNEL); + page = (void *)__get_free_page(GFP_KERNEL_ACCOUNT); if (!page) return -ENOMEM; cache->objects[cache->nobjs++] = page;