1. 06 7月, 2011 4 次提交
  2. 12 6月, 2011 1 次提交
    • J
      virtio_net: introduce VIRTIO_NET_HDR_F_DATA_VALID · 10a8d94a
      Jason Wang 提交于
      There's no need for the guest to validate the checksum if it have been
      validated by host nics. So this patch introduces a new flag -
      VIRTIO_NET_HDR_F_DATA_VALID which is used to bypass the checksum
      examing in guest. The backend (tap/macvtap) may set this flag when
      met skbs with CHECKSUM_UNNECESSARY to save cpu utilization.
      
      No feature negotiation is needed as old driver just ignore this flag.
      
      Iperf shows 12%-30% performance improvement for UDP traffic. For TCP,
      when gro is on no difference as it produces skb with partial
      checksum. But when gro is disabled, 20% or even higher improvement
      could be measured by netperf.
      Signed-off-by: NJason Wang <jasowang@redhat.com>
      Acked-by: NMichael S. Tsirkin <mst@redhat.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      10a8d94a
  3. 07 6月, 2011 1 次提交
  4. 06 6月, 2011 2 次提交
  5. 02 6月, 2011 1 次提交
  6. 24 5月, 2011 1 次提交
    • D
      net: convert %p usage to %pK · 71338aa7
      Dan Rosenberg 提交于
      The %pK format specifier is designed to hide exposed kernel pointers,
      specifically via /proc interfaces.  Exposing these pointers provides an
      easy target for kernel write vulnerabilities, since they reveal the
      locations of writable structures containing easily triggerable function
      pointers.  The behavior of %pK depends on the kptr_restrict sysctl.
      
      If kptr_restrict is set to 0, no deviation from the standard %p behavior
      occurs.  If kptr_restrict is set to 1, the default, if the current user
      (intended to be a reader via seq_printf(), etc.) does not have CAP_SYSLOG
      (currently in the LSM tree), kernel pointers using %pK are printed as 0's.
       If kptr_restrict is set to 2, kernel pointers using %pK are printed as
      0's regardless of privileges.  Replacing with 0's was chosen over the
      default "(null)", which cannot be parsed by userland %p, which expects
      "(nil)".
      
      The supporting code for kptr_restrict and %pK are currently in the -mm
      tree.  This patch converts users of %p in net/ to %pK.  Cases of printing
      pointers to the syslog are not covered, since this would eliminate useful
      information for postmortem debugging and the reading of the syslog is
      already optionally protected by the dmesg_restrict sysctl.
      Signed-off-by: NDan Rosenberg <drosenberg@vsecurity.com>
      Cc: James Morris <jmorris@namei.org>
      Cc: Eric Dumazet <eric.dumazet@gmail.com>
      Cc: Thomas Graf <tgraf@infradead.org>
      Cc: Eugene Teo <eugeneteo@kernel.org>
      Cc: Kees Cook <kees.cook@canonical.com>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: David S. Miller <davem@davemloft.net>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Eric Paris <eparis@parisplace.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      71338aa7
  7. 28 4月, 2011 1 次提交
    • E
      net: filter: Just In Time compiler for x86-64 · 0a14842f
      Eric Dumazet 提交于
      In order to speedup packet filtering, here is an implementation of a
      JIT compiler for x86_64
      
      It is disabled by default, and must be enabled by the admin.
      
      echo 1 >/proc/sys/net/core/bpf_jit_enable
      
      It uses module_alloc() and module_free() to get memory in the 2GB text
      kernel range since we call helpers functions from the generated code.
      
      EAX : BPF A accumulator
      EBX : BPF X accumulator
      RDI : pointer to skb   (first argument given to JIT function)
      RBP : frame pointer (even if CONFIG_FRAME_POINTER=n)
      r9d : skb->len - skb->data_len (headlen)
      r8  : skb->data
      
      To get a trace of generated code, use :
      
      echo 2 >/proc/sys/net/core/bpf_jit_enable
      
      Example of generated code :
      
      # tcpdump -p -n -s 0 -i eth1 host 192.168.20.0/24
      
      flen=18 proglen=147 pass=3 image=ffffffffa00b5000
      JIT code: ffffffffa00b5000: 55 48 89 e5 48 83 ec 60 48 89 5d f8 44 8b 4f 60
      JIT code: ffffffffa00b5010: 44 2b 4f 64 4c 8b 87 b8 00 00 00 be 0c 00 00 00
      JIT code: ffffffffa00b5020: e8 24 7b f7 e0 3d 00 08 00 00 75 28 be 1a 00 00
      JIT code: ffffffffa00b5030: 00 e8 fe 7a f7 e0 24 00 3d 00 14 a8 c0 74 49 be
      JIT code: ffffffffa00b5040: 1e 00 00 00 e8 eb 7a f7 e0 24 00 3d 00 14 a8 c0
      JIT code: ffffffffa00b5050: 74 36 eb 3b 3d 06 08 00 00 74 07 3d 35 80 00 00
      JIT code: ffffffffa00b5060: 75 2d be 1c 00 00 00 e8 c8 7a f7 e0 24 00 3d 00
      JIT code: ffffffffa00b5070: 14 a8 c0 74 13 be 26 00 00 00 e8 b5 7a f7 e0 24
      JIT code: ffffffffa00b5080: 00 3d 00 14 a8 c0 75 07 b8 ff ff 00 00 eb 02 31
      JIT code: ffffffffa00b5090: c0 c9 c3
      
      BPF program is 144 bytes long, so native program is almost same size ;)
      
      (000) ldh      [12]
      (001) jeq      #0x800           jt 2    jf 8
      (002) ld       [26]
      (003) and      #0xffffff00
      (004) jeq      #0xc0a81400      jt 16   jf 5
      (005) ld       [30]
      (006) and      #0xffffff00
      (007) jeq      #0xc0a81400      jt 16   jf 17
      (008) jeq      #0x806           jt 10   jf 9
      (009) jeq      #0x8035          jt 10   jf 17
      (010) ld       [28]
      (011) and      #0xffffff00
      (012) jeq      #0xc0a81400      jt 16   jf 13
      (013) ld       [38]
      (014) and      #0xffffff00
      (015) jeq      #0xc0a81400      jt 16   jf 17
      (016) ret      #65535
      (017) ret      #0
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
      Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
      Cc: Ben Hutchings <bhutchings@solarflare.com>
      Cc: Hagen Paul Pfeifer <hagen@jauu.net>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0a14842f
  8. 08 3月, 2011 1 次提交
  9. 12 2月, 2011 1 次提交
  10. 20 1月, 2011 1 次提交
  11. 19 1月, 2011 1 次提交
  12. 17 12月, 2010 1 次提交
  13. 11 12月, 2010 1 次提交
  14. 09 12月, 2010 3 次提交
  15. 07 12月, 2010 2 次提交
  16. 22 11月, 2010 1 次提交
  17. 20 11月, 2010 1 次提交
    • E
      filter: optimize sk_run_filter · 93aaae2e
      Eric Dumazet 提交于
      Remove pc variable to avoid arithmetic to compute fentry at each filter
      instruction. Jumps directly manipulate fentry pointer.
      
      As the last instruction of filter[] is guaranteed to be a RETURN, and
      all jumps are before the last instruction, we dont need to check filter
      bounds (number of instructions in filter array) at each iteration, so we
      remove it from sk_run_filter() params.
      
      On x86_32 remove f_k var introduced in commit 57fe93b3
      (filter: make sure filters dont read uninitialized memory)
      
      Note : We could use a CONFIG_ARCH_HAS_{FEW|MANY}_REGISTERS in order to
      avoid too many ifdefs in this code.
      
      This helps compiler to use cpu registers to hold fentry and A
      accumulator.
      
      On x86_32, this saves 401 bytes, and more important, sk_run_filter()
      runs much faster because less register pressure (One less conditional
      branch per BPF instruction)
      
      # size net/core/filter.o net/core/filter_pre.o
         text    data     bss     dec     hex filename
         2948       0       0    2948     b84 net/core/filter.o
         3349       0       0    3349     d15 net/core/filter_pre.o
      
      on x86_64 :
      # size net/core/filter.o net/core/filter_pre.o
         text    data     bss     dec     hex filename
         5173       0       0    5173    1435 net/core/filter.o
         5224       0       0    5224    1468 net/core/filter_pre.o
      Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
      Acked-by: NChangli Gao <xiaosuo@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      93aaae2e
  18. 17 11月, 2010 1 次提交
    • N
      packet: Enhance AF_PACKET implementation to not require high order contiguous... · 0e3125c7
      Neil Horman 提交于
      packet: Enhance AF_PACKET implementation to not require high order contiguous memory allocation (v4)
      MIME-Version: 1.0
      Content-Type: text/plain; charset=UTF-8
      Content-Transfer-Encoding: 8bit
      
      Version 4 of this patch.
      
      Change notes:
      1) Removed extra memset.  Didn't think kcalloc added a GFP_ZERO the way kzalloc did :)
      
      Summary:
      It was shown to me recently that systems under high load were driven very deep
      into swap when tcpdump was run.  The reason this happened was because the
      AF_PACKET protocol has a SET_RINGBUFFER socket option that allows the user space
      application to specify how many entries an AF_PACKET socket will have and how
      large each entry will be.  It seems the default setting for tcpdump is to set
      the ring buffer to 32 entries of 64 Kb each, which implies 32 order 5
      allocation.  Thats difficult under good circumstances, and horrid under memory
      pressure.
      
      I thought it would be good to make that a bit more usable.  I was going to do a
      simple conversion of the ring buffer from contigous pages to iovecs, but
      unfortunately, the metadata which AF_PACKET places in these buffers can easily
      span a page boundary, and given that these buffers get mapped into user space,
      and the data layout doesn't easily allow for a change to padding between frames
      to avoid that, a simple iovec change is just going to break user space ABI
      consistency.
      
      So I've done this, I've added a three tiered mechanism to the af_packet set_ring
      socket option.  It attempts to allocate memory in the following order:
      
      1) Using __get_free_pages with GFP_NORETRY set, so as to fail quickly without
      digging into swap
      
      2) Using vmalloc
      
      3) Using __get_free_pages with GFP_NORETRY clear, causing us to try as hard as
      needed to get the memory
      
      The effect is that we don't disturb the system as much when we're under load,
      while still being able to conduct tcpdumps effectively.
      
      Tested successfully by me.
      Signed-off-by: NNeil Horman <nhorman@tuxdriver.com>
      Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
      Acked-by: NMaciej Żenczykowski <zenczykowski@gmail.com>
      Reported-by: NMaciej Żenczykowski <zenczykowski@gmail.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0e3125c7
  19. 13 11月, 2010 1 次提交
  20. 11 11月, 2010 1 次提交
  21. 19 8月, 2010 1 次提交
  22. 02 6月, 2010 1 次提交
    • S
      packet_mmap: expose hw packet timestamps to network packet capture utilities · 614f60fa
      Scott McMillan 提交于
      This patch adds a setting, PACKET_TIMESTAMP, to specify the packet
      timestamp source that is exported to capture utilities like tcpdump by
      packet_mmap.
      
      PACKET_TIMESTAMP accepts the same integer bit field as
      SO_TIMESTAMPING.  However, only the SOF_TIMESTAMPING_SYS_HARDWARE and
      SOF_TIMESTAMPING_RAW_HARDWARE values are currently recognized by
      PACKET_TIMESTAMP.  SOF_TIMESTAMPING_SYS_HARDWARE takes precedence over
      SOF_TIMESTAMPING_RAW_HARDWARE if both bits are set.
      
      If PACKET_TIMESTAMP is not set, a software timestamp generated inside
      the networking stack is used (the behavior before this setting was
      added).
      Signed-off-by: NScott McMillan <scott.a.mcmillan@intel.com>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      614f60fa
  23. 17 4月, 2010 1 次提交
  24. 13 4月, 2010 1 次提交
  25. 04 4月, 2010 2 次提交
  26. 30 3月, 2010 1 次提交
    • T
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking... · 5a0e3ad6
      Tejun Heo 提交于
      include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
      
      percpu.h is included by sched.h and module.h and thus ends up being
      included when building most .c files.  percpu.h includes slab.h which
      in turn includes gfp.h making everything defined by the two files
      universally available and complicating inclusion dependencies.
      
      percpu.h -> slab.h dependency is about to be removed.  Prepare for
      this change by updating users of gfp and slab facilities include those
      headers directly instead of assuming availability.  As this conversion
      needs to touch large number of source files, the following script is
      used as the basis of conversion.
      
        http://userweb.kernel.org/~tj/misc/slabh-sweep.py
      
      The script does the followings.
      
      * Scan files for gfp and slab usages and update includes such that
        only the necessary includes are there.  ie. if only gfp is used,
        gfp.h, if slab is used, slab.h.
      
      * When the script inserts a new include, it looks at the include
        blocks and try to put the new include such that its order conforms
        to its surrounding.  It's put in the include block which contains
        core kernel includes, in the same order that the rest are ordered -
        alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
        doesn't seem to be any matching order.
      
      * If the script can't find a place to put a new include (mostly
        because the file doesn't have fitting include block), it prints out
        an error message indicating which .h file needs to be added to the
        file.
      
      The conversion was done in the following steps.
      
      1. The initial automatic conversion of all .c files updated slightly
         over 4000 files, deleting around 700 includes and adding ~480 gfp.h
         and ~3000 slab.h inclusions.  The script emitted errors for ~400
         files.
      
      2. Each error was manually checked.  Some didn't need the inclusion,
         some needed manual addition while adding it to implementation .h or
         embedding .c file was more appropriate for others.  This step added
         inclusions to around 150 files.
      
      3. The script was run again and the output was compared to the edits
         from #2 to make sure no file was left behind.
      
      4. Several build tests were done and a couple of problems were fixed.
         e.g. lib/decompress_*.c used malloc/free() wrappers around slab
         APIs requiring slab.h to be added manually.
      
      5. The script was run on all .h files but without automatically
         editing them as sprinkling gfp.h and slab.h inclusions around .h
         files could easily lead to inclusion dependency hell.  Most gfp.h
         inclusion directives were ignored as stuff from gfp.h was usually
         wildly available and often used in preprocessor macros.  Each
         slab.h inclusion directive was examined and added manually as
         necessary.
      
      6. percpu.h was updated not to include slab.h.
      
      7. Build test were done on the following configurations and failures
         were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
         distributed build env didn't work with gcov compiles) and a few
         more options had to be turned off depending on archs to make things
         build (like ipr on powerpc/64 which failed due to missing writeq).
      
         * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
         * powerpc and powerpc64 SMP allmodconfig
         * sparc and sparc64 SMP allmodconfig
         * ia64 SMP allmodconfig
         * s390 SMP allmodconfig
         * alpha SMP allmodconfig
         * um on x86_64 SMP allmodconfig
      
      8. percpu.h modifications were reverted so that it could be applied as
         a separate patch and serve as bisection point.
      
      Given the fact that I had only a couple of failures from tests on step
      6, I'm fairly confident about the coverage of this conversion patch.
      If there is a breakage, it's likely to be something in one of the arch
      headers which should be easily discoverable easily on most builds of
      the specific arch.
      Signed-off-by: NTejun Heo <tj@kernel.org>
      Guess-its-ok-by: NChristoph Lameter <cl@linux-foundation.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
      5a0e3ad6
  27. 03 3月, 2010 1 次提交
  28. 26 2月, 2010 1 次提交
  29. 25 2月, 2010 1 次提交
    • P
      net: Add checking to rcu_dereference() primitives · a898def2
      Paul E. McKenney 提交于
      Update rcu_dereference() primitives to use new lockdep-based
      checking. The rcu_dereference() in __in6_dev_get() may be
      protected either by rcu_read_lock() or RTNL, per Eric Dumazet.
      The rcu_dereference() in __sk_free() is protected by the fact
      that it is never reached if an update could change it.  Check
      for this by using rcu_dereference_check() to verify that the
      struct sock's ->sk_wmem_alloc counter is zero.
      Acked-by: NEric Dumazet <eric.dumazet@gmail.com>
      Acked-by: NDavid S. Miller <davem@davemloft.net>
      Signed-off-by: NPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: laijs@cn.fujitsu.com
      Cc: dipankar@in.ibm.com
      Cc: mathieu.desnoyers@polymtl.ca
      Cc: josh@joshtriplett.org
      Cc: dvhltc@us.ibm.com
      Cc: niv@us.ibm.com
      Cc: peterz@infradead.org
      Cc: rostedt@goodmis.org
      Cc: Valdis.Kletnieks@vt.edu
      Cc: dhowells@redhat.com
      LKML-Reference: <1266887105-1528-5-git-send-email-paulmck@linux.vnet.ibm.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      a898def2
  30. 23 2月, 2010 1 次提交
  31. 11 2月, 2010 1 次提交
  32. 06 2月, 2010 1 次提交