1. 19 8月, 2014 7 次提交
    • L
      ASoC: Remove support for legacy snd_soc_platform IO · 75af7c08
      Lars-Peter Clausen 提交于
      There were never any actual users of this in upstream and by we have with
      regmap a replacement in place, which should be used by new drivers.
      Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
      Signed-off-by: NMark Brown <broonie@linaro.org>
      75af7c08
    • L
      ASoC: Automatically initialize regmap for all components · 886f5692
      Lars-Peter Clausen 提交于
      So far regmap is only automatically initialized for CODECs. Now that we have the
      infrastructure in place to let components have DAPM widgets and controls that
      want to use the generic regmap based IO also make sure to automatically
      initialize regmap for all components.
      Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
      Signed-off-by: NMark Brown <broonie@linaro.org>
      886f5692
    • L
      ASoC: Pass component instead of DAPM context to AUX dev init callback · 57bf7726
      Lars-Peter Clausen 提交于
      Given that the component is the containing structure it makes more sense to pass
      the component rather than the DAPM context to the AUX dev init callback.
      Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
      Signed-off-by: NMark Brown <broonie@linaro.org>
      57bf7726
    • L
      ASoC: Move AUX dev support to the component level · 65d9361f
      Lars-Peter Clausen 提交于
      This patch makes it possible to register arbitrary components as a AUX dev
      for a card. This was previously only possible for CODEC components. With
      componentization having made it possible for components to have DAPM contexts
      and controls there is no reason why AUX devs should be artificially limited to
      snd_soc_codec devices.
      Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
      Signed-off-by: NMark Brown <broonie@linaro.org>
      65d9361f
    • L
      ASoC: Add component level probe/remove support · 61aca564
      Lars-Peter Clausen 提交于
      Now that we have a unified probe and remove path make sure to call them for all
      components. soc_{probe,remove}_component are responsible for setting up the DAPM
      context for the component, initialize the component prefix, manage the debugfs
      entries as well as do the registration of table based controls and DAPM
      elements. They also call the component drivers probe and remove callbacks. This
      patch makes these things available for generic snd_soc_component drivers rather
      than only having them for snd_soc_codec and snd_soc_platform drivers.
      Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
      Signed-off-by: NMark Brown <broonie@linaro.org>
      61aca564
    • L
      ASoC: Consolidate platform and CODEC probe/remove · f1d45cc3
      Lars-Peter Clausen 提交于
      The platform and CODEC probe and remove code is now largely identical. This
      patch consolidates it at the component level.
      
      The resulting code is slightly larger due to all the boiler plate code setting
      up the indirection for the table based control and DAPM registration.  Once all
      drivers have been update to no longer use the snd_soc_codec_driver and
      snd_soc_platform_driver specific fields for this the indirection can be removed
      again.
      
      This patch contains two noteworthy hacks that are only meant to be temporary to
      be able to update drivers and the core in separate incremental patches.
      
      The first hack is related to that some DPCM platforms expect that the DAPM
      widgets for the DAIs of a snd_soc_component are created in the DAPM context of
      the snd_soc_platform that has the same parent device. For handling this the
      steal_sibling_dai_widgets attribute is introduced. It gets set for
      snd_soc_platforms that register DAPM elements. When creating the DAI widgets for
      a component this flag is checked and if it is found on one of the siblings the
      component will not create any DAI widgets in its own DAPM context. If the
      attribute is set on a platform it will look for siblings components and create
      DAI widgets for them in its own context. The fix for this will be to update
      the offending drivers to only register a single component rather than two.
      
      The second hack deals with the fact that the ASoC card suspend and resume code
      still needs a list of CODECs that have been registered for the card. To handle
      this the generic probe and remove path have a check to see if the component is
      CODEC and if yes add/remove it to the card's CODEC list. While it is possible to
      clean up the suspend/resume code to not need the CODEC list anymore this is a
      bit of a chicken and egg problem since it will become easier to clean up the
      suspend/resume code once there is a unified component layer.
      Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
      Signed-off-by: NMark Brown <broonie@linaro.org>
      f1d45cc3
    • L
      ASoC: Move debugfs registration to the component level · 81c7cfd1
      Lars-Peter Clausen 提交于
      The debugfs registration is mostly identical between platforms and CODECs. This
      patches consolidates the two implementations at the component level.
      
      Unfortunately there are still a couple of CODEC specific debugfs files that are
      related to legacy ASoC IO that need to be registered. For this a new callback is
      added to the component struct that will be initialized when a CODEC is
      registered and will be used to register the CODEC specific files. Once there are
      no drivers left using legacy IO this can be removed again.
      Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
      Signed-off-by: NMark Brown <broonie@linaro.org>
      81c7cfd1
  2. 15 8月, 2014 6 次提交
    • T
      rhashtable: fix annotations for rht_for_each_entry_rcu() · 93f56081
      Thomas Graf 提交于
      Call rcu_deference_raw() directly from within rht_for_each_entry_rcu()
      as list_for_each_entry_rcu() does.
      
      Fixes the following sparse warnings:
      net/netlink/af_netlink.c:2906:25:    expected struct rhash_head const *__mptr
      net/netlink/af_netlink.c:2906:25:    got struct rhash_head [noderef] <asn:4>*<noident>
      
      Fixes: e341694e ("netlink: Convert netlink_lookup() to use RCU protected hash table")
      Signed-off-by: NThomas Graf <tgraf@suug.ch>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      93f56081
    • T
      rhashtable: unexport and make rht_obj() static · c91eee56
      Thomas Graf 提交于
      No need to export rht_obj(), all inner to outer object translations
      occur internally. It was intended to be used with rht_for_each() which
      now primarily serves as the iterator for rhashtable_remove_pprev() to
      effectively flush and free the full table.
      Signed-off-by: NThomas Graf <tgraf@suug.ch>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      c91eee56
    • T
      rhashtable: RCU annotations for next pointers · 5300fdcb
      Thomas Graf 提交于
      Properly annotate next pointers as access is RCU protected in
      the lookup path.
      Signed-off-by: NThomas Graf <tgraf@suug.ch>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      5300fdcb
    • H
      tcp: don't allow syn packets without timestamps to pass tcp_tw_recycle logic · a26552af
      Hannes Frederic Sowa 提交于
      tcp_tw_recycle heavily relies on tcp timestamps to build a per-host
      ordering of incoming connections and teardowns without the need to
      hold state on a specific quadruple for TCP_TIMEWAIT_LEN, but only for
      the last measured RTO. To do so, we keep the last seen timestamp in a
      per-host indexed data structure and verify if the incoming timestamp
      in a connection request is strictly greater than the saved one during
      last connection teardown. Thus we can verify later on that no old data
      packets will be accepted by the new connection.
      
      During moving a socket to time-wait state we already verify if timestamps
      where seen on a connection. Only if that was the case we let the
      time-wait socket expire after the RTO, otherwise normal TCP_TIMEWAIT_LEN
      will be used. But we don't verify this on incoming SYN packets. If a
      connection teardown was less than TCP_PAWS_MSL seconds in the past we
      cannot guarantee to not accept data packets from an old connection if
      no timestamps are present. We should drop this SYN packet. This patch
      closes this loophole.
      
      Please note, this patch does not make tcp_tw_recycle in any way more
      usable but only adds another safety check:
      Sporadic drops of SYN packets because of reordering in the network or
      in the socket backlog queues can happen. Users behing NAT trying to
      connect to a tcp_tw_recycle enabled server can get caught in blackholes
      and their connection requests may regullary get dropped because hosts
      behind an address translator don't have synchronized tcp timestamp clocks.
      tcp_tw_recycle cannot work if peers don't have tcp timestamps enabled.
      
      In general, use of tcp_tw_recycle is disadvised.
      
      Cc: Eric Dumazet <eric.dumazet@gmail.com>
      Cc: Florian Westphal <fw@strlen.de>
      Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      a26552af
    • N
      tcp: fix tcp_release_cb() to dispatch via address family for mtu_reduced() · 4fab9071
      Neal Cardwell 提交于
      Make sure we use the correct address-family-specific function for
      handling MTU reductions from within tcp_release_cb().
      
      Previously AF_INET6 sockets were incorrectly always using the IPv6
      code path when sometimes they were handling IPv4 traffic and thus had
      an IPv4 dst.
      Signed-off-by: NNeal Cardwell <ncardwell@google.com>
      Signed-off-by: NEric Dumazet <edumazet@google.com>
      Diagnosed-by: NWillem de Bruijn <willemb@google.com>
      Fixes: 563d34d0 ("tcp: dont drop MTU reduction indications")
      Reviewed-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      4fab9071
    • A
      tcp: don't use timestamp from repaired skb-s to calculate RTT (v2) · 9d186cac
      Andrey Vagin 提交于
      We don't know right timestamp for repaired skb-s. Wrong RTT estimations
      isn't good, because some congestion modules heavily depends on it.
      
      This patch adds the TCPCB_REPAIRED flag, which is included in
      TCPCB_RETRANS.
      
      Thanks to Eric for the advice how to fix this issue.
      
      This patch fixes the warning:
      [  879.562947] WARNING: CPU: 0 PID: 2825 at net/ipv4/tcp_input.c:3078 tcp_ack+0x11f5/0x1380()
      [  879.567253] CPU: 0 PID: 2825 Comm: socket-tcpbuf-l Not tainted 3.16.0-next-20140811 #1
      [  879.567829] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
      [  879.568177]  0000000000000000 00000000c532680c ffff880039643d00 ffffffff817aa2d2
      [  879.568776]  0000000000000000 ffff880039643d38 ffffffff8109afbd ffff880039d6ba80
      [  879.569386]  ffff88003a449800 000000002983d6bd 0000000000000000 000000002983d6bc
      [  879.569982] Call Trace:
      [  879.570264]  [<ffffffff817aa2d2>] dump_stack+0x4d/0x66
      [  879.570599]  [<ffffffff8109afbd>] warn_slowpath_common+0x7d/0xa0
      [  879.570935]  [<ffffffff8109b0ea>] warn_slowpath_null+0x1a/0x20
      [  879.571292]  [<ffffffff816d0a05>] tcp_ack+0x11f5/0x1380
      [  879.571614]  [<ffffffff816d10bd>] tcp_rcv_established+0x1ed/0x710
      [  879.571958]  [<ffffffff816dc9da>] tcp_v4_do_rcv+0x10a/0x370
      [  879.572315]  [<ffffffff81657459>] release_sock+0x89/0x1d0
      [  879.572642]  [<ffffffff816c81a0>] do_tcp_setsockopt.isra.36+0x120/0x860
      [  879.573000]  [<ffffffff8110a52e>] ? rcu_read_lock_held+0x6e/0x80
      [  879.573352]  [<ffffffff816c8912>] tcp_setsockopt+0x32/0x40
      [  879.573678]  [<ffffffff81654ac4>] sock_common_setsockopt+0x14/0x20
      [  879.574031]  [<ffffffff816537b0>] SyS_setsockopt+0x80/0xf0
      [  879.574393]  [<ffffffff817b40a9>] system_call_fastpath+0x16/0x1b
      [  879.574730] ---[ end trace a17cbc38eb8c5c00 ]---
      
      v2: moving setting of skb->when for repaired skb-s in tcp_write_xmit,
          where it's set for other skb-s.
      
      Fixes: 431a9124 ("tcp: timestamp SYN+DATA messages")
      Fixes: 740b0f18 ("tcp: switch rtt estimations to usec resolution")
      Cc: Eric Dumazet <edumazet@google.com>
      Cc: Pavel Emelyanov <xemul@parallels.com>
      Cc: "David S. Miller" <davem@davemloft.net>
      Signed-off-by: NAndrey Vagin <avagin@openvz.org>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      9d186cac
  3. 13 8月, 2014 3 次提交
  4. 12 8月, 2014 1 次提交
    • V
      net: Always untag vlan-tagged traffic on input. · 0d5501c1
      Vlad Yasevich 提交于
      Currently the functionality to untag traffic on input resides
      as part of the vlan module and is build only when VLAN support
      is enabled in the kernel.  When VLAN is disabled, the function
      vlan_untag() turns into a stub and doesn't really untag the
      packets.  This seems to create an interesting interaction
      between VMs supporting checksum offloading and some network drivers.
      
      There are some drivers that do not allow the user to change
      tx-vlan-offload feature of the driver.  These drivers also seem
      to assume that any VLAN-tagged traffic they transmit will
      have the vlan information in the vlan_tci and not in the vlan
      header already in the skb.  When transmitting skbs that already
      have tagged data with partial checksum set, the checksum doesn't
      appear to be updated correctly by the card thus resulting in a
      failure to establish TCP connections.
      
      The following is a packet trace taken on the receiver where a
      sender is a VM with a VLAN configued.  The host VM is running on
      doest not have VLAN support and the outging interface on the
      host is tg3:
      10:12:43.503055 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q
      (0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27243,
      offset 0, flags [DF], proto TCP (6), length 60)
          10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect
      -> 0x48d9), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val
      4294837885 ecr 0,nop,wscale 7], length 0
      10:12:44.505556 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q
      (0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27244,
      offset 0, flags [DF], proto TCP (6), length 60)
          10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect
      -> 0x44ee), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val
      4294838888 ecr 0,nop,wscale 7], length 0
      
      This connection finally times out.
      
      I've only access to the TG3 hardware in this configuration thus have
      only tested this with TG3 driver.  There are a lot of other drivers
      that do not permit user changes to vlan acceleration features, and
      I don't know if they all suffere from a similar issue.
      
      The patch attempt to fix this another way.  It moves the vlan header
      stipping code out of the vlan module and always builds it into the
      kernel network core.  This way, even if vlan is not supported on
      a virtualizatoin host, the virtual machines running on top of such
      host will still work with VLANs enabled.
      
      CC: Patrick McHardy <kaber@trash.net>
      CC: Nithin Nayak Sujir <nsujir@broadcom.com>
      CC: Michael Chan <mchan@broadcom.com>
      CC: Jiri Pirko <jiri@resnulli.us>
      Signed-off-by: NVladislav Yasevich <vyasevic@redhat.com>
      Acked-by: NJiri Pirko <jiri@resnulli.us>
      Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      0d5501c1
  5. 11 8月, 2014 3 次提交
  6. 10 8月, 2014 2 次提交
  7. 09 8月, 2014 18 次提交
    • A
      drm/ttm: expose CPU address of DMA-allocated pages · 3d50d4dc
      Alexandre Courbot 提交于
      Pages allocated using the DMA API have a coherent memory mapping. Make
      this mapping visible to drivers so they can decide to use it instead of
      creating their own redundant one.
      Signed-off-by: NAlexandre Courbot <acourbot@nvidia.com>
      Acked-by: NDavid Airlie <airlied@linux.ie>
      Signed-off-by: NBen Skeggs <bskeggs@redhat.com>
      3d50d4dc
    • V
      kexec: verify the signature of signed PE bzImage · 8e7d8381
      Vivek Goyal 提交于
      This is the final piece of the puzzle of verifying kernel image signature
      during kexec_file_load() syscall.
      
      This patch calls into PE file routines to verify signature of bzImage.  If
      signature are valid, kexec_file_load() succeeds otherwise it fails.
      
      Two new config options have been introduced.  First one is
      CONFIG_KEXEC_VERIFY_SIG.  This option enforces that kernel has to be
      validly signed otherwise kernel load will fail.  If this option is not
      set, no signature verification will be done.  Only exception will be when
      secureboot is enabled.  In that case signature verification should be
      automatically enforced when secureboot is enabled.  But that will happen
      when secureboot patches are merged.
      
      Second config option is CONFIG_KEXEC_BZIMAGE_VERIFY_SIG.  This option
      enables signature verification support on bzImage.  If this option is not
      set and previous one is set, kernel image loading will fail because kernel
      does not have support to verify signature of bzImage.
      
      I tested these patches with both "pesign" and "sbsign" signed bzImages.
      
      I used signing_key.priv key and signing_key.x509 cert for signing as
      generated during kernel build process (if module signing is enabled).
      
      Used following method to sign bzImage.
      
      pesign
      ======
      - Convert DER format cert to PEM format cert
      openssl x509 -in signing_key.x509 -inform DER -out signing_key.x509.PEM -outform
      PEM
      
      - Generate a .p12 file from existing cert and private key file
      openssl pkcs12 -export -out kernel-key.p12 -inkey signing_key.priv -in
      signing_key.x509.PEM
      
      - Import .p12 file into pesign db
      pk12util -i /tmp/kernel-key.p12 -d /etc/pki/pesign
      
      - Sign bzImage
      pesign -i /boot/vmlinuz-3.16.0-rc3+ -o /boot/vmlinuz-3.16.0-rc3+.signed.pesign
      -c "Glacier signing key - Magrathea" -s
      
      sbsign
      ======
      sbsign --key signing_key.priv --cert signing_key.x509.PEM --output
      /boot/vmlinuz-3.16.0-rc3+.signed.sbsign /boot/vmlinuz-3.16.0-rc3+
      
      Patch details:
      
      Well all the hard work is done in previous patches.  Now bzImage loader
      has just call into that code and verify whether bzImage signature are
      valid or not.
      
      Also create two config options.  First one is CONFIG_KEXEC_VERIFY_SIG.
      This option enforces that kernel has to be validly signed otherwise kernel
      load will fail.  If this option is not set, no signature verification will
      be done.  Only exception will be when secureboot is enabled.  In that case
      signature verification should be automatically enforced when secureboot is
      enabled.  But that will happen when secureboot patches are merged.
      
      Second config option is CONFIG_KEXEC_BZIMAGE_VERIFY_SIG.  This option
      enables signature verification support on bzImage.  If this option is not
      set and previous one is set, kernel image loading will fail because kernel
      does not have support to verify signature of bzImage.
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Matt Fleming <matt@console-pimps.org>
      Cc: David Howells <dhowells@redhat.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8e7d8381
    • V
      kexec: support kexec/kdump on EFI systems · 6a2c20e7
      Vivek Goyal 提交于
      This patch does two things.  It passes EFI run time mappings to second
      kernel in bootparams efi_info.  Second kernel parse this info and create
      new mappings in second kernel.  That means mappings in first and second
      kernel will be same.  This paves the way to enable EFI in kexec kernel.
      
      This patch also prepares and passes EFI setup data through bootparams.
      This contains bunch of information about various tables and their
      addresses.
      
      These information gathering and passing has been written along the lines
      of what current kexec-tools is doing to make kexec work with UEFI.
      
      [akpm@linux-foundation.org: s/get_efi/efi_get/g, per Matt]
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Cc: Matt Fleming <matt@console-pimps.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      6a2c20e7
    • V
      kexec-bzImage64: support for loading bzImage using 64bit entry · 27f48d3e
      Vivek Goyal 提交于
      This is loader specific code which can load bzImage and set it up for
      64bit entry.  This does not take care of 32bit entry or real mode entry.
      
      32bit mode entry can be implemented if somebody needs it.
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      27f48d3e
    • V
      kexec: load and relocate purgatory at kernel load time · 12db5562
      Vivek Goyal 提交于
      Load purgatory code in RAM and relocate it based on the location.
      Relocation code has been inspired by module relocation code and purgatory
      relocation code in kexec-tools.
      
      Also compute the checksums of loaded kexec segments and store them in
      purgatory.
      
      Arch independent code provides this functionality so that arch dependent
      bootloaders can make use of it.
      
      Helper functions are provided to get/set symbol values in purgatory which
      are used by bootloaders later to set things like stack and entry point of
      second kernel etc.
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      12db5562
    • V
      kexec: implementation of new syscall kexec_file_load · cb105258
      Vivek Goyal 提交于
      Previous patch provided the interface definition and this patch prvides
      implementation of new syscall.
      
      Previously segment list was prepared in user space.  Now user space just
      passes kernel fd, initrd fd and command line and kernel will create a
      segment list internally.
      
      This patch contains generic part of the code.  Actual segment preparation
      and loading is done by arch and image specific loader.  Which comes in
      next patch.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      cb105258
    • V
      kexec: new syscall kexec_file_load() declaration · f0895685
      Vivek Goyal 提交于
      This is the new syscall kexec_file_load() declaration/interface.  I have
      reserved the syscall number only for x86_64 so far.  Other architectures
      (including i386) can reserve syscall number when they enable the support
      for this new syscall.
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      f0895685
    • V
      kexec: make kexec_segment user buffer pointer a union · 815d5704
      Vivek Goyal 提交于
      So far kexec_segment->buf was always a user space pointer as user space
      passed the array of kexec_segment structures and kernel copied it.
      
      But with new system call, list of kexec segments will be prepared by
      kernel and kexec_segment->buf will point to a kernel memory.
      
      So while I was adding code where I made assumption that ->buf is pointing
      to kernel memory, sparse started giving warning.
      
      Make ->buf a union.  And where a user space pointer is expected, access it
      using ->buf and where a kernel space pointer is expected, access it using
      ->kbuf.  That takes care of sparse warnings.
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      815d5704
    • V
      resource: provide new functions to walk through resources · 8c86e70a
      Vivek Goyal 提交于
      I have added two more functions to walk through resources.
      
      Currently walk_system_ram_range() deals with pfn and /proc/iomem can
      contain partial pages.  By dealing in pfn, callback function loses the
      info that last page of a memory range is a partial page and not the full
      page.  So I implemented walk_system_ram_res() which returns u64 values to
      callback functions and now it properly return start and end address.
      
      walk_system_ram_range() uses find_next_system_ram() to find the next ram
      resource.  This in turn only travels through siblings of top level child
      and does not travers through all the nodes of the resoruce tree.  I also
      need another function where I can walk through all the resources, for
      example figure out where "GART" aperture is.  Figure out where ACPI memory
      is.
      
      So I wrote another function walk_iomem_res() which walks through all
      /proc/iomem resources and returns matches as asked by caller.  Caller can
      specify "name" of resource, start and end and flags.
      
      Got rid of find_next_system_ram_res() and instead implemented more generic
      find_next_iomem_res() which can be used to traverse top level children
      only based on an argument.
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8c86e70a
    • V
      kexec: rename unusebale_pages to unusable_pages · 7d3e2bca
      Vivek Goyal 提交于
      Let's use the more common "unusable".
      
      This patch was originally written and posted by Boris. I am including it
      in this patch series.
      Signed-off-by: NBorislav Petkov <bp@suse.de>
      Signed-off-by: NVivek Goyal <vgoyal@redhat.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Yinghai Lu <yinghai@kernel.org>
      Cc: Eric Biederman <ebiederm@xmission.com>
      Cc: H. Peter Anvin <hpa@zytor.com>
      Cc: Matthew Garrett <mjg59@srcf.ucam.org>
      Cc: Greg Kroah-Hartman <greg@kroah.com>
      Cc: Dave Young <dyoung@redhat.com>
      Cc: WANG Chao <chaowang@redhat.com>
      Cc: Baoquan He <bhe@redhat.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7d3e2bca
    • D
      shm: add memfd_create() syscall · 9183df25
      David Herrmann 提交于
      memfd_create() is similar to mmap(MAP_ANON), but returns a file-descriptor
      that you can pass to mmap().  It can support sealing and avoids any
      connection to user-visible mount-points.  Thus, it's not subject to quotas
      on mounted file-systems, but can be used like malloc()'ed memory, but with
      a file-descriptor to it.
      
      memfd_create() returns the raw shmem file, so calls like ftruncate() can
      be used to modify the underlying inode.  Also calls like fstat() will
      return proper information and mark the file as regular file.  If you want
      sealing, you can specify MFD_ALLOW_SEALING.  Otherwise, sealing is not
      supported (like on all other regular files).
      
      Compared to O_TMPFILE, it does not require a tmpfs mount-point and is not
      subject to a filesystem size limit.  It is still properly accounted to
      memcg limits, though, and to the same overcommit or no-overcommit
      accounting as all user memory.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Acked-by: NHugh Dickins <hughd@google.com>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Ryan Lortie <desrt@desrt.ca>
      Cc: Lennart Poettering <lennart@poettering.net>
      Cc: Daniel Mack <zonque@gmail.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9183df25
    • D
      shm: add sealing API · 40e041a2
      David Herrmann 提交于
      If two processes share a common memory region, they usually want some
      guarantees to allow safe access. This often includes:
        - one side cannot overwrite data while the other reads it
        - one side cannot shrink the buffer while the other accesses it
        - one side cannot grow the buffer beyond previously set boundaries
      
      If there is a trust-relationship between both parties, there is no need
      for policy enforcement.  However, if there's no trust relationship (eg.,
      for general-purpose IPC) sharing memory-regions is highly fragile and
      often not possible without local copies.  Look at the following two
      use-cases:
      
        1) A graphics client wants to share its rendering-buffer with a
           graphics-server. The memory-region is allocated by the client for
           read/write access and a second FD is passed to the server. While
           scanning out from the memory region, the server has no guarantee that
           the client doesn't shrink the buffer at any time, requiring rather
           cumbersome SIGBUS handling.
        2) A process wants to perform an RPC on another process. To avoid huge
           bandwidth consumption, zero-copy is preferred. After a message is
           assembled in-memory and a FD is passed to the remote side, both sides
           want to be sure that neither modifies this shared copy, anymore. The
           source may have put sensible data into the message without a separate
           copy and the target may want to parse the message inline, to avoid a
           local copy.
      
      While SIGBUS handling, POSIX mandatory locking and MAP_DENYWRITE provide
      ways to achieve most of this, the first one is unproportionally ugly to
      use in libraries and the latter two are broken/racy or even disabled due
      to denial of service attacks.
      
      This patch introduces the concept of SEALING.  If you seal a file, a
      specific set of operations is blocked on that file forever.  Unlike locks,
      seals can only be set, never removed.  Hence, once you verified a specific
      set of seals is set, you're guaranteed that no-one can perform the blocked
      operations on this file, anymore.
      
      An initial set of SEALS is introduced by this patch:
        - SHRINK: If SEAL_SHRINK is set, the file in question cannot be reduced
                  in size. This affects ftruncate() and open(O_TRUNC).
        - GROW: If SEAL_GROW is set, the file in question cannot be increased
                in size. This affects ftruncate(), fallocate() and write().
        - WRITE: If SEAL_WRITE is set, no write operations (besides resizing)
                 are possible. This affects fallocate(PUNCH_HOLE), mmap() and
                 write().
        - SEAL: If SEAL_SEAL is set, no further seals can be added to a file.
                This basically prevents the F_ADD_SEAL operation on a file and
                can be set to prevent others from adding further seals that you
                don't want.
      
      The described use-cases can easily use these seals to provide safe use
      without any trust-relationship:
      
        1) The graphics server can verify that a passed file-descriptor has
           SEAL_SHRINK set. This allows safe scanout, while the client is
           allowed to increase buffer size for window-resizing on-the-fly.
           Concurrent writes are explicitly allowed.
        2) For general-purpose IPC, both processes can verify that SEAL_SHRINK,
           SEAL_GROW and SEAL_WRITE are set. This guarantees that neither
           process can modify the data while the other side parses it.
           Furthermore, it guarantees that even with writable FDs passed to the
           peer, it cannot increase the size to hit memory-limits of the source
           process (in case the file-storage is accounted to the source).
      
      The new API is an extension to fcntl(), adding two new commands:
        F_GET_SEALS: Return a bitset describing the seals on the file. This
                     can be called on any FD if the underlying file supports
                     sealing.
        F_ADD_SEALS: Change the seals of a given file. This requires WRITE
                     access to the file and F_SEAL_SEAL may not already be set.
                     Furthermore, the underlying file must support sealing and
                     there may not be any existing shared mapping of that file.
                     Otherwise, EBADF/EPERM is returned.
                     The given seals are _added_ to the existing set of seals
                     on the file. You cannot remove seals again.
      
      The fcntl() handler is currently specific to shmem and disabled on all
      files. A file needs to explicitly support sealing for this interface to
      work. A separate syscall is added in a follow-up, which creates files that
      support sealing. There is no intention to support this on other
      file-systems. Semantics are unclear for non-volatile files and we lack any
      use-case right now. Therefore, the implementation is specific to shmem.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Acked-by: NHugh Dickins <hughd@google.com>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Ryan Lortie <desrt@desrt.ca>
      Cc: Lennart Poettering <lennart@poettering.net>
      Cc: Daniel Mack <zonque@gmail.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      40e041a2
    • D
      mm: allow drivers to prevent new writable mappings · 4bb5f5d9
      David Herrmann 提交于
      This patch (of 6):
      
      The i_mmap_writable field counts existing writable mappings of an
      address_space.  To allow drivers to prevent new writable mappings, make
      this counter signed and prevent new writable mappings if it is negative.
      This is modelled after i_writecount and DENYWRITE.
      
      This will be required by the shmem-sealing infrastructure to prevent any
      new writable mappings after the WRITE seal has been set.  In case there
      exists a writable mapping, this operation will fail with EBUSY.
      
      Note that we rely on the fact that iff you already own a writable mapping,
      you can increase the counter without using the helpers.  This is the same
      that we do for i_writecount.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Acked-by: NHugh Dickins <hughd@google.com>
      Cc: Michael Kerrisk <mtk.manpages@gmail.com>
      Cc: Ryan Lortie <desrt@desrt.ca>
      Cc: Lennart Poettering <lennart@poettering.net>
      Cc: Daniel Mack <zonque@gmail.com>
      Cc: Andy Lutomirski <luto@amacapital.net>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      4bb5f5d9
    • J
      pci-dma-compat: add pci_zalloc_consistent helper · 82bf0baa
      Joe Perches 提交于
      Add this helper for consistency with pci_zalloc_coherent
      and the ability to remove unnecessary memset(,0,) uses.
      Signed-off-by: NJoe Perches <joe@perches.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
      Cc: "John W. Linville" <linville@tuxdriver.com>
      Cc: "Stephen M. Cameron" <scameron@beardog.cce.hp.com>
      Cc: Adam Radford <linuxraid@lsi.com>
      Cc: Chaoming Li <chaoming_li@realsil.com.cn>
      Cc: Chas Williams <chas@cmf.nrl.navy.mil>
      Cc: Christian Benvenuti <benve@cisco.com>
      Cc: Christopher Harrer <charrer@alacritech.com>
      Cc: Dario Ballabio <ballabio_dario@emc.com>
      Cc: David Airlie <airlied@linux.ie>
      Cc: Don Fry <pcnet32@frontier.com>
      Cc: Faisal Latif <faisal.latif@intel.com>
      Cc: Forest Bond <forest@alittletooquiet.net>
      Cc: Govindarajulu Varadarajan <_govind@gmx.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Hal Rosenstock <hal.rosenstock@gmail.com>
      Cc: Hans Verkuil <hverkuil@xs4all.nl>
      Cc: Jayamohan Kallickal <jayamohan.kallickal@emulex.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
      Cc: Larry Finger <Larry.Finger@lwfinger.net>
      Cc: Lennert Buytenhek <buytenh@wantstofly.org>
      Cc: Lior Dotan <liodot@gmail.com>
      Cc: Manish Chopra <manish.chopra@qlogic.com>
      Cc: Manohar Vanga <manohar.vanga@gmail.com>
      Cc: Martyn Welch <martyn.welch@ge.com>
      Cc: Mauro Carvalho Chehab <m.chehab@samsung.com>
      Cc: Michael Neuffer <mike@i-Connect.Net>
      Cc: Mirko Lindner <mlindner@marvell.com>
      Cc: Neel Patel <neepatel@cisco.com>
      Cc: Neela Syam Kolli <megaraidlinux@lsi.com>
      Cc: Rajesh Borundia <rajesh.borundia@qlogic.com>
      Cc: Roland Dreier <roland@kernel.org>
      Cc: Ron Mercer <ron.mercer@qlogic.com>
      Cc: Samuel Ortiz <samuel@sortiz.org>
      Cc: Sean Hefty <sean.hefty@intel.com>
      Cc: Shahed Shaikh <shahed.shaikh@qlogic.com>
      Cc: Sony Chacko <sony.chacko@qlogic.com>
      Cc: Stanislav Yakovlev <stas.yakovlev@gmail.com>
      Cc: Stephen Hemminger <stephen@networkplumber.org>
      Cc: Steve Wise <swise@opengridcomputing.com>
      Cc: Sujith Sankar <ssujith@cisco.com>
      Cc: Tom Tucker <tom@opengridcomputing.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      82bf0baa
    • A
      arm64,ia64,ppc,s390,sh,tile,um,x86,mm: remove default gate area · a6c19dfe
      Andy Lutomirski 提交于
      The core mm code will provide a default gate area based on
      FIXADDR_USER_START and FIXADDR_USER_END if
      !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR).
      
      This default is only useful for ia64.  arm64, ppc, s390, sh, tile, 64-bit
      UML, and x86_32 have their own code just to disable it.  arm, 32-bit UML,
      and x86_64 have gate areas, but they have their own implementations.
      
      This gets rid of the default and moves the code into ia64.
      
      This should save some code on architectures without a gate area: it's now
      possible to inline the gate_area functions in the default case.
      Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
      Acked-by: NNathan Lynch <nathan_lynch@mentor.com>
      Acked-by: NH. Peter Anvin <hpa@linux.intel.com>
      Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [in principle]
      Acked-by: Richard Weinberger <richard@nod.at> [for um]
      Acked-by: Will Deacon <will.deacon@arm.com> [for arm64]
      Cc: Catalin Marinas <catalin.marinas@arm.com>
      Cc: Will Deacon <will.deacon@arm.com>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Chris Metcalf <cmetcalf@tilera.com>
      Cc: Jeff Dike <jdike@addtoit.com>
      Cc: Richard Weinberger <richard@nod.at>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: Nathan Lynch <Nathan_Lynch@mentor.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a6c19dfe
    • L
      lib/scatterlist: make ARCH_HAS_SG_CHAIN an actual Kconfig · 308c09f1
      Laura Abbott 提交于
      Rather than have architectures #define ARCH_HAS_SG_CHAIN in an
      architecture specific scatterlist.h, make it a proper Kconfig option and
      use that instead.  At same time, remove the header files are are now
      mostly useless and just include asm-generic/scatterlist.h.
      
      [sfr@canb.auug.org.au: powerpc files now need asm/dma.h]
      Signed-off-by: NLaura Abbott <lauraa@codeaurora.org>
      Acked-by: Thomas Gleixner <tglx@linutronix.de>			[x86]
      Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>	[powerpc]
      Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
      Cc: Russell King <linux@arm.linux.org.uk>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: Fenghua Yu <fenghua.yu@intel.com>
      Cc: Paul Mackerras <paulus@samba.org>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "James E.J. Bottomley" <JBottomley@parallels.com>
      Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      308c09f1
    • J
      shm: remove unneeded extern for function · 2f137d66
      Jack Miller 提交于
      A small cleanup while changing adjacent code.  Extern is not needed for
      functions and only one declaration had it so remove it from the odd line.
      Signed-off-by: NMilton Miller <miltonm@bga.com>
      Signed-off-by: NJack Miller <millerjo@us.ibm.com>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Cc: Anton Blanchard <anton@samba.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2f137d66
    • J
      shm: make exit_shm work proportional to task activity · ab602f79
      Jack Miller 提交于
      This is small set of patches our team has had kicking around for a few
      versions internally that fixes tasks getting hung on shm_exit when there
      are many threads hammering it at once.
      
      Anton wrote a simple test to cause the issue:
      
        http://ozlabs.org/~anton/junkcode/bust_shm_exit.c
      
      Before applying this patchset, this test code will cause either hanging
      tracebacks or pthread out of memory errors.
      
      After this patchset, it will still produce output like:
      
        root@somehost:~# ./bust_shm_exit 1024 160
        ...
        INFO: rcu_sched detected stalls on CPUs/tasks: {} (detected by 116, t=2111 jiffies, g=241, c=240, q=7113)
        INFO: Stall ended before state dump start
        ...
      
      But the task will continue to run along happily, so we consider this an
      improvement over hanging, even if it's a bit noisy.
      
      This patch (of 3):
      
      exit_shm obtains the ipc_ns shm rwsem for write and holds it while it
      walks every shared memory segment in the namespace.  Thus the amount of
      work is related to the number of shm segments in the namespace not the
      number of segments that might need to be cleaned.
      
      In addition, this occurs after the task has been notified the thread has
      exited, so the number of tasks waiting for the ns shm rwsem can grow
      without bound until memory is exausted.
      
      Add a list to the task struct of all shmids allocated by this task.  Init
      the list head in copy_process.  Use the ns->rwsem for locking.  Add
      segments after id is added, remove before removing from id.
      
      On unshare of NEW_IPCNS orphan any ids as if the task had exited, similar
      to handling of semaphore undo.
      
      I chose a define for the init sequence since its a simple list init,
      otherwise it would require a function call to avoid include loops between
      the semaphore code and the task struct.  Converting the list_del to
      list_del_init for the unshare cases would remove the exit followed by
      init, but I left it blow up if not inited.
      Signed-off-by: NMilton Miller <miltonm@bga.com>
      Signed-off-by: NJack Miller <millerjo@us.ibm.com>
      Cc: Davidlohr Bueso <davidlohr@hp.com>
      Cc: Manfred Spraul <manfred@colorfullife.com>
      Cc: Anton Blanchard <anton@samba.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ab602f79