1. 17 8月, 2017 2 次提交
  2. 16 8月, 2017 2 次提交
  3. 15 8月, 2017 1 次提交
  4. 14 8月, 2017 1 次提交
    • J
      net: export some generic xdp helpers · 7c497478
      Jason Wang 提交于
      This patch tries to export some generic xdp helpers to drivers. This
      can let driver to do XDP for a specific skb. This is useful for the
      case when the packet is hard to be processed at page level directly
      (e.g jumbo/GSO frame).
      
      With this patch, there's no need for driver to forbid the XDP set when
      configuration is not suitable. Instead, it can defer the XDP for
      packets that is hard to be processed directly after skb is created.
      Signed-off-by: NJason Wang <jasowang@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      7c497478
  5. 11 8月, 2017 5 次提交
    • M
      mm: fix MADV_[FREE|DONTNEED] TLB flush miss problem · 99baac21
      Minchan Kim 提交于
      Nadav reported parallel MADV_DONTNEED on same range has a stale TLB
      problem and Mel fixed it[1] and found same problem on MADV_FREE[2].
      
      Quote from Mel Gorman:
       "The race in question is CPU 0 running madv_free and updating some PTEs
        while CPU 1 is also running madv_free and looking at the same PTEs.
        CPU 1 may have writable TLB entries for a page but fail the pte_dirty
        check (because CPU 0 has updated it already) and potentially fail to
        flush.
      
        Hence, when madv_free on CPU 1 returns, there are still potentially
        writable TLB entries and the underlying PTE is still present so that a
        subsequent write does not necessarily propagate the dirty bit to the
        underlying PTE any more. Reclaim at some unknown time at the future
        may then see that the PTE is still clean and discard the page even
        though a write has happened in the meantime. I think this is possible
        but I could have missed some protection in madv_free that prevents it
        happening."
      
      This patch aims for solving both problems all at once and is ready for
      other problem with KSM, MADV_FREE and soft-dirty story[3].
      
      TLB batch API(tlb_[gather|finish]_mmu] uses [inc|dec]_tlb_flush_pending
      and mmu_tlb_flush_pending so that when tlb_finish_mmu is called, we can
      catch there are parallel threads going on.  In that case, forcefully,
      flush TLB to prevent for user to access memory via stale TLB entry
      although it fail to gather page table entry.
      
      I confirmed this patch works with [4] test program Nadav gave so this
      patch supersedes "mm: Always flush VMA ranges affected by zap_page_range
      v2" in current mmotm.
      
      NOTE:
      
      This patch modifies arch-specific TLB gathering interface(x86, ia64,
      s390, sh, um).  It seems most of architecture are straightforward but
      s390 need to be careful because tlb_flush_mmu works only if
      mm->context.flush_mm is set to non-zero which happens only a pte entry
      really is cleared by ptep_get_and_clear and friends.  However, this
      problem never changes the pte entries but need to flush to prevent
      memory access from stale tlb.
      
      [1] http://lkml.kernel.org/r/20170725101230.5v7gvnjmcnkzzql3@techsingularity.net
      [2] http://lkml.kernel.org/r/20170725100722.2dxnmgypmwnrfawp@suse.de
      [3] http://lkml.kernel.org/r/BD3A0EBE-ECF4-41D4-87FA-C755EA9AB6BD@gmail.com
      [4] https://patchwork.kernel.org/patch/9861621/
      
      [minchan@kernel.org: decrease tlb flush pending count in tlb_finish_mmu]
        Link: http://lkml.kernel.org/r/20170808080821.GA31730@bbox
      Link: http://lkml.kernel.org/r/20170802000818.4760-7-namit@vmware.comSigned-off-by: NMinchan Kim <minchan@kernel.org>
      Signed-off-by: NNadav Amit <namit@vmware.com>
      Reported-by: NNadav Amit <namit@vmware.com>
      Reported-by: NMel Gorman <mgorman@techsingularity.net>
      Acked-by: NMel Gorman <mgorman@techsingularity.net>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Russell King <linux@armlinux.org.uk>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Nadav Amit <nadav.amit@gmail.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      99baac21
    • M
      mm: make tlb_flush_pending global · 0a2dd266
      Minchan Kim 提交于
      Currently, tlb_flush_pending is used only for CONFIG_[NUMA_BALANCING|
      COMPACTION] but upcoming patches to solve subtle TLB flush batching
      problem will use it regardless of compaction/NUMA so this patch doesn't
      remove the dependency.
      
      [akpm@linux-foundation.org: remove more ifdefs from world's ugliest printk statement]
      Link: http://lkml.kernel.org/r/20170802000818.4760-6-namit@vmware.comSigned-off-by: NMinchan Kim <minchan@kernel.org>
      Signed-off-by: NNadav Amit <namit@vmware.com>
      Acked-by: NMel Gorman <mgorman@techsingularity.net>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Nadav Amit <nadav.amit@gmail.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Russell King <linux@armlinux.org.uk>
      Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0a2dd266
    • M
      mm: refactor TLB gathering API · 56236a59
      Minchan Kim 提交于
      This patch is a preparatory patch for solving race problems caused by
      TLB batch.  For that, we will increase/decrease TLB flush pending count
      of mm_struct whenever tlb_[gather|finish]_mmu is called.
      
      Before making it simple, this patch separates architecture specific part
      and rename it to arch_tlb_[gather|finish]_mmu and generic part just
      calls it.
      
      It shouldn't change any behavior.
      
      Link: http://lkml.kernel.org/r/20170802000818.4760-5-namit@vmware.comSigned-off-by: NMinchan Kim <minchan@kernel.org>
      Signed-off-by: NNadav Amit <namit@vmware.com>
      Acked-by: NMel Gorman <mgorman@techsingularity.net>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Russell King <linux@armlinux.org.uk>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: Nadav Amit <nadav.amit@gmail.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      56236a59
    • N
      mm: migrate: fix barriers around tlb_flush_pending · 0a2c4048
      Nadav Amit 提交于
      Reading tlb_flush_pending while the page-table lock is taken does not
      require a barrier, since the lock/unlock already acts as a barrier.
      Removing the barrier in mm_tlb_flush_pending() to address this issue.
      
      However, migrate_misplaced_transhuge_page() calls mm_tlb_flush_pending()
      while the page-table lock is already released, which may present a
      problem on architectures with weak memory model (PPC).  To deal with
      this case, a new parameter is added to mm_tlb_flush_pending() to
      indicate if it is read without the page-table lock taken, and calling
      smp_mb__after_unlock_lock() in this case.
      
      Link: http://lkml.kernel.org/r/20170802000818.4760-3-namit@vmware.comSigned-off-by: NNadav Amit <namit@vmware.com>
      Acked-by: NRik van Riel <riel@redhat.com>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Mel Gorman <mgorman@suse.de>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: Nadav Amit <nadav.amit@gmail.com>
      Cc: Russell King <linux@armlinux.org.uk>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0a2c4048
    • N
      mm: migrate: prevent racy access to tlb_flush_pending · 16af97dc
      Nadav Amit 提交于
      Patch series "fixes of TLB batching races", v6.
      
      It turns out that Linux TLB batching mechanism suffers from various
      races.  Races that are caused due to batching during reclamation were
      recently handled by Mel and this patch-set deals with others.  The more
      fundamental issue is that concurrent updates of the page-tables allow
      for TLB flushes to be batched on one core, while another core changes
      the page-tables.  This other core may assume a PTE change does not
      require a flush based on the updated PTE value, while it is unaware that
      TLB flushes are still pending.
      
      This behavior affects KSM (which may result in memory corruption) and
      MADV_FREE and MADV_DONTNEED (which may result in incorrect behavior).  A
      proof-of-concept can easily produce the wrong behavior of MADV_DONTNEED.
      Memory corruption in KSM is harder to produce in practice, but was
      observed by hacking the kernel and adding a delay before flushing and
      replacing the KSM page.
      
      Finally, there is also one memory barrier missing, which may affect
      architectures with weak memory model.
      
      This patch (of 7):
      
      Setting and clearing mm->tlb_flush_pending can be performed by multiple
      threads, since mmap_sem may only be acquired for read in
      task_numa_work().  If this happens, tlb_flush_pending might be cleared
      while one of the threads still changes PTEs and batches TLB flushes.
      
      This can lead to the same race between migration and
      change_protection_range() that led to the introduction of
      tlb_flush_pending.  The result of this race was data corruption, which
      means that this patch also addresses a theoretically possible data
      corruption.
      
      An actual data corruption was not observed, yet the race was was
      confirmed by adding assertion to check tlb_flush_pending is not set by
      two threads, adding artificial latency in change_protection_range() and
      using sysctl to reduce kernel.numa_balancing_scan_delay_ms.
      
      Link: http://lkml.kernel.org/r/20170802000818.4760-2-namit@vmware.com
      Fixes: 20841405 ("mm: fix TLB flush race between migration, and
      change_protection_range")
      Signed-off-by: NNadav Amit <namit@vmware.com>
      Acked-by: NMel Gorman <mgorman@suse.de>
      Acked-by: NRik van Riel <riel@redhat.com>
      Acked-by: NMinchan Kim <minchan@kernel.org>
      Cc: Andy Lutomirski <luto@kernel.org>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Andrea Arcangeli <aarcange@redhat.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: Russell King <linux@armlinux.org.uk>
      Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      16af97dc
  6. 10 8月, 2017 2 次提交
    • J
      nvmet_fc: add defer_req callback for deferment of cmd buffer return · 0fb228d3
      James Smart 提交于
      At queue creation, the transport allocates a local job struct
      (struct nvmet_fc_fcp_iod) for each possible element of the queue.
      When a new CMD is received from the wire, a jobs struct is allocated
      from the queue and then used for the duration of the command.
      The job struct contains buffer space for the wire command iu. Thus,
      upon allocation of the job struct, the cmd iu buffer is copied to
      the job struct and the LLDD may immediately free/reuse the CMD IU
      buffer passed in the call.
      
      However, in some circumstances, due to the packetized nature of FC
      and the api of the FC LLDD which may issue a hw command to send the
      wire response, but the LLDD may not get the hw completion for the
      command and upcall the nvmet_fc layer before a new command may be
      asynchronously received on the wire. In other words, its possible
      for the initiator to get the response from the wire, thus believe a
      command slot free, and send a new command iu. The new command iu
      may be received by the LLDD and passed to the transport before the
      LLDD had serviced the hw completion and made the teardown calls for
      the original job struct. As such, there is no available job struct
      available for the new io. E.g. it appears like the host sent more
      queue elements than the queue size. It didn't based on it's
      understanding.
      
      Rather than treat this as a hard connection failure queue the new
      request until the job struct does free up. As the buffer isn't
      copied as there's no job struct, a special return value must be
      returned to the LLDD to signify to hold off on recycling the cmd
      iu buffer.  And later, when a job struct is allocated and the
      buffer copied, a new LLDD callback is introduced to notify the
      LLDD and allow it to recycle it's command iu buffer.
      Signed-off-by: NJames Smart <james.smart@broadcom.com>
      Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      0fb228d3
    • W
      sock: fix zerocopy_success regression with msg_zerocopy · 0a4a060b
      Willem de Bruijn 提交于
      Do not use uarg->zerocopy outside msg_zerocopy. In other paths the
      field is not explicitly initialized and aliases another field.
      
      Those paths have only one reference so do not need this intermediate
      variable. Call uarg->callback directly.
      
      Fixes: 1f8b977a ("sock: enable MSG_ZEROCOPY")
      Signed-off-by: NWillem de Bruijn <willemb@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0a4a060b
  7. 09 8月, 2017 2 次提交
    • E
      bpf/verifier: track signed and unsigned min/max values · b03c9f9f
      Edward Cree 提交于
      Allows us to, sometimes, combine information from a signed check of one
       bound and an unsigned check of the other.
      We now track the full range of possible values, rather than restricting
       ourselves to [0, 1<<30) and considering anything beyond that as
       unknown.  While this is probably not necessary, it makes the code more
       straightforward and symmetrical between signed and unsigned bounds.
      Signed-off-by: NEdward Cree <ecree@solarflare.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b03c9f9f
    • E
      bpf/verifier: rework value tracking · f1174f77
      Edward Cree 提交于
      Unifies adjusted and unadjusted register value types (e.g. FRAME_POINTER is
       now just a PTR_TO_STACK with zero offset).
      Tracks value alignment by means of tracking known & unknown bits.  This
       also replaces the 'reg->imm' (leading zero bits) calculations for (what
       were) UNKNOWN_VALUEs.
      If pointer leaks are allowed, and adjust_ptr_min_max_vals returns -EACCES,
       treat the pointer as an unknown scalar and try again, because we might be
       able to conclude something about the result (e.g. pointer & 0x40 is either
       0 or 0x40).
      Verifier hooks in the netronome/nfp driver were changed to match the new
       data structures.
      Signed-off-by: NEdward Cree <ecree@solarflare.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      f1174f77
  8. 08 8月, 2017 9 次提交
  9. 07 8月, 2017 12 次提交
  10. 05 8月, 2017 1 次提交
  11. 04 8月, 2017 3 次提交
    • W
      sock: ulimit on MSG_ZEROCOPY pages · a91dbff5
      Willem de Bruijn 提交于
      Bound the number of pages that a user may pin.
      
      Follow the lead of perf tools to maintain a per-user bound on memory
      locked pages commit 789f90fc ("perf_counter: per user mlock gift")
      Signed-off-by: NWillem de Bruijn <willemb@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a91dbff5
    • W
      sock: MSG_ZEROCOPY notification coalescing · 4ab6c99d
      Willem de Bruijn 提交于
      In the simple case, each sendmsg() call generates data and eventually
      a zerocopy ready notification N, where N indicates the Nth successful
      invocation of sendmsg() with the MSG_ZEROCOPY flag on this socket.
      
      TCP and corked sockets can cause send() calls to append new data to an
      existing sk_buff and, thus, ubuf_info. In that case the notification
      must hold a range. odify ubuf_info to store a inclusive range [N..N+m]
      and add skb_zerocopy_realloc() to optionally extend an existing range.
      
      Also coalesce notifications in this common case: if a notification
      [1, 1] is about to be queued while [0, 0] is the queue tail, just modify
      the head of the queue to read [0, 1].
      
      Coalescing is limited to a few TSO frames worth of data to bound
      notification latency.
      Signed-off-by: NWillem de Bruijn <willemb@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4ab6c99d
    • W
      sock: enable MSG_ZEROCOPY · 1f8b977a
      Willem de Bruijn 提交于
      Prepare the datapath for refcounted ubuf_info. Clone ubuf_info with
      skb_zerocopy_clone() wherever needed due to skb split, merge, resize
      or clone.
      
      Split skb_orphan_frags into two variants. The split, merge, .. paths
      support reference counted zerocopy buffers, so do not do a deep copy.
      Add skb_orphan_frags_rx for paths that may loop packets to receive
      sockets. That is not allowed, as it may cause unbounded latency.
      Deep copy all zerocopy copy buffers, ref-counted or not, in this path.
      
      The exact locations to modify were chosen by exhaustively searching
      through all code that might modify skb_frag references and/or the
      the SKBTX_DEV_ZEROCOPY tx_flags bit.
      
      The changes err on the safe side, in two ways.
      
      (1) legacy ubuf_info paths virtio and tap are not modified. They keep
          a 1:1 ubuf_info to sk_buff relationship. Calls to skb_orphan_frags
          still call skb_copy_ubufs and thus copy frags in this case.
      
      (2) not all copies deep in the stack are addressed yet. skb_shift,
          skb_split and skb_try_coalesce can be refined to avoid copying.
          These are not in the hot path and this patch is hairy enough as
          is, so that is left for future refinement.
      Signed-off-by: NWillem de Bruijn <willemb@google.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1f8b977a