user/sven/linux.git/mm, branch v3.4.93

mm: highmem: don't treat PKMAP_ADDR(LAST_PKMAP) as a highmem address

2014-06-11T19:04:22Z

commit 498c2280212327858e521e9d21345d4cc2637f54 upstream. kmap_to_page returns the corresponding struct page for a virtual address of an arbitrary mapping. This works by checking whether the address falls in the pkmap region and using the pkmap page tables instead of the linear mapping if appropriate. Unfortunately, the bounds checking means that PKMAP_ADDR(LAST_PKMAP) is incorrectly treated as a highmem address and we can end up walking off the end of pkmap_page_table and subsequently passing junk to pte_page. This patch fixes the bound check to stay within the pkmap tables. Signed-off-by: Will Deacon Cc: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Cc: Yijing Wang Signed-off-by: Greg Kroah-Hartman

mm: highmem: export kmap_to_page for modules

2014-06-11T19:04:17Z

commit f0263d2d222e9e25f2587e51a9dc58c6fb2a9352 upstream. Some virtio device drivers (9p) need to translate high virtual addresses to physical addresses, which are inserted into the virtqueue for processing by userspace. This patch exports the kmap_to_page symbol, so that the affected drivers can be compiled as modules. Signed-off-by: Will Deacon Signed-off-by: Rusty Russell Signed-off-by: Ben Hutchings Cc: Yijing Wang Signed-off-by: Greg Kroah-Hartman

mm: add kmap_to_page()

2014-06-11T19:04:17Z

commit fcb8996728fb59eddf84678df7cb213b2c9a2e26 upstream. This is extracted from Mel Gorman's commit 5a178119b0fb ('mm: add support for direct_IO to highmem pages') upstream. Required to backport commit b9cdc88df8e6 ('virtio: 9p: correctly pass physical address to userspace for high pages'). Cc: Mel Gorman Cc: Rik van Riel Cc: Andrew Morton Signed-off-by: Ben Hutchings Cc: Yijing Wang Signed-off-by: Greg Kroah-Hartman

mm: rmap: fix use-after-free in __put_anon_vma

2014-06-11T19:04:13Z

commit 624483f3ea82598ab0f62f1bdb9177f531ab1892 upstream. While working address sanitizer for kernel I've discovered use-after-free bug in __put_anon_vma. For the last anon_vma, anon_vma->root freed before child anon_vma. Later in anon_vma_free(anon_vma) we are referencing to already freed anon_vma->root to check rwsem. This fixes it by freeing the child anon_vma before freeing anon_vma->root. Signed-off-by: Andrey Ryabinin Acked-by: Peter Zijlstra Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

mm/memory-failure.c: fix memory leak by race between poison and unpoison

2014-06-11T19:04:11Z

commit 3e030ecc0fc7de10fd0da10c1c19939872a31717 upstream. When a memory error happens on an in-use page or (free and in-use) hugepage, the victim page is isolated with its refcount set to one. When you try to unpoison it later, unpoison_memory() calls put_page() for it twice in order to bring the page back to free page pool (buddy or free hugepage list). However, if another memory error occurs on the page which we are unpoisoning, memory_failure() returns without releasing the refcount which was incremented in the same call at first, which results in memory leak and unconsistent num_poisoned_pages statistics. This patch fixes it. Signed-off-by: Naoya Horiguchi Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

percpu: make pcpu_alloc_chunk() use pcpu_mem_free() instead of kfree()

2014-06-07T23:02:03Z

commit 5a838c3b60e3a36ade764cf7751b8f17d7c9c2da upstream. pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) + BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long) It hardly could be ever bigger than PAGE_SIZE even for large-scale machine, but for consistency with its couterpart pcpu_mem_zalloc(), use pcpu_mem_free() instead. Commit b4916cb17c26 ("percpu: make pcpu_free_chunk() use pcpu_mem_free() instead of kfree()") addressed this problem, but missed this one. tj: commit message updated Signed-off-by: Jianyu Zhan Signed-off-by: Tejun Heo Fixes: 099a19d91ca4 ("percpu: allow limited allocation before slab is online) Signed-off-by: Greg Kroah-Hartman

hwpoison, hugetlb: lock_page/unlock_page does not match for handling a free hugepage

2014-06-07T23:02:01Z

commit b985194c8c0a130ed155b71662e39f7eaea4876f upstream. For handling a free hugepage in memory failure, the race will happen if another thread hwpoisoned this hugepage concurrently. So we need to check PageHWPoison instead of !PageHWPoison. If hwpoison_filter(p) returns true or a race happens, then we need to unlock_page(hpage). Signed-off-by: Chen Yucong Reviewed-by: Naoya Horiguchi Tested-by: Naoya Horiguchi Reviewed-by: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

mm: make fixup_user_fault() check the vma access rights too

2014-06-07T23:02:00Z

commit 1b17844b29ae042576bea588164f2f1e9590a8bc upstream. fixup_user_fault() is used by the futex code when the direct user access fails, and the futex code wants it to either map in the page in a usable form or return an error. It relied on handle_mm_fault() to map the page, and correctly checked the error return from that, but while that does map the page, it doesn't actually guarantee that the page will be mapped with sufficient permissions to be then accessed. So do the appropriate tests of the vma access rights by hand. [ Side note: arguably handle_mm_fault() could just do that itself, but we have traditionally done it in the caller, because some callers - notably get_user_pages() - have been able to access pages even when they are mapped with PROT_NONE. Maybe we should re-visit that design decision, but in the meantime this is the minimal patch. ] Found by Dave Jones running his trinity tool. Reported-by: Dave Jones Acked-by: Hugh Dickins Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()

2014-06-07T23:01:57Z

commit 7848a4bf51b34f41fcc9bd77e837126d99ae84e3 upstream. soft lockup in freeing gigantic hugepage fixed in commit 55f67141a892 "mm: hugetlb: fix softlockup when a large number of hugepages are freed." can happen in return_unused_surplus_pages(), so let's fix it. Signed-off-by: Masayoshi Mizuma Signed-off-by: Naoya Horiguchi Cc: Joonsoo Kim Cc: Michal Hocko Cc: Aneesh Kumar Cc: KOSAKI Motohiro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

mm: hugetlb: fix softlockup when a large number of hugepages are freed.

2014-05-06T14:51:45Z

commit 55f67141a8927b2be3e51840da37b8a2320143ed upstream. When I decrease the value of nr_hugepage in procfs a lot, softlockup happens. It is because there is no chance of context switch during this process. On the other hand, when I allocate a large number of hugepages, there is some chance of context switch. Hence softlockup doesn't happen during this process. So it's necessary to add the context switch in the freeing process as same as allocating process to avoid softlockup. When I freed 12 TB hugapages with kernel-2.6.32-358.el6, the freeing process occupied a CPU over 150 seconds and following softlockup message appeared twice or more. $ echo 6000000 > /proc/sys/vm/nr_hugepages $ cat /proc/sys/vm/nr_hugepages 6000000 $ grep ^Huge /proc/meminfo HugePages_Total: 6000000 HugePages_Free: 6000000 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 2048 kB $ echo 0 > /proc/sys/vm/nr_hugepages BUG: soft lockup - CPU#16 stuck for 67s! [sh:12883] ... Pid: 12883, comm: sh Not tainted 2.6.32-358.el6.x86_64 #1 Call Trace: free_pool_huge_page+0xb8/0xd0 set_max_huge_pages+0x128/0x190 hugetlb_sysctl_handler_common+0x113/0x140 hugetlb_sysctl_handler+0x1e/0x20 proc_sys_call_handler+0x97/0xd0 proc_sys_write+0x14/0x20 vfs_write+0xb8/0x1a0 sys_write+0x51/0x90 __audit_syscall_exit+0x265/0x290 system_call_fastpath+0x16/0x1b I have not confirmed this problem with upstream kernels because I am not able to prepare the machine equipped with 12TB memory now. However I confirmed that the amount of decreasing hugepages was directly proportional to the amount of required time. I measured required times on a smaller machine. It showed 130-145 hugepages decreased in a millisecond. Amount of decreasing Required time Decreasing rate hugepages (msec) (pages/msec) ------------------------------------------------------------ 10,000 pages == 20GB 70 - 74 135-142 30,000 pages == 60GB 208 - 229 131-144 It means decrement of 6TB hugepages will trigger softlockup with the default threshold 20sec, in this decreasing rate. Signed-off-by: Masayoshi Mizuma Cc: Joonsoo Kim Cc: Michal Hocko Cc: Wanpeng Li Cc: Aneesh Kumar Cc: KOSAKI Motohiro Cc: Naoya Horiguchi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman