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  1. May 31, 2019
  2. Mar 01, 2019
  3. Feb 08, 2019
  4. Feb 01, 2019
  5. Jan 04, 2019
  6. Dec 07, 2018
    • H.J. Lu's avatar
      x86: Treat R_X86_64_PLT32 as R_X86_64_PC32 · 2673e6c9
      H.J. Lu authored
      
      commit b21ebf2f upstream.
      
      On i386, there are 2 types of PLTs, PIC and non-PIC.  PIE and shared
      objects must use PIC PLT.  To use PIC PLT, you need to load
      _GLOBAL_OFFSET_TABLE_ into EBX first.  There is no need for that on
      x86-64 since x86-64 uses PC-relative PLT.
      
      On x86-64, for 32-bit PC-relative branches, we can generate PLT32
      relocation, instead of PC32 relocation, which can also be used as
      a marker for 32-bit PC-relative branches.  Linker can always reduce
      PLT32 relocation to PC32 if function is defined locally.   Local
      functions should use PC32 relocation.  As far as Linux kernel is
      concerned, R_X86_64_PLT32 can be treated the same as R_X86_64_PC32
      since Linux kernel doesn't use PLT.
      
      R_X86_64_PLT32 for 32-bit PC-relative branches has been enabled in
      binutils master branch which will become binutils 2.31.
      
      [ hjl is working on having better documentation on this all, but a few
        more notes from him:
      
         "PLT32 relocation is used as marker for PC-relative branches. Because
          of EBX, it looks odd to generate PLT32 relocation on i386 when EBX
          doesn't have GOT.
      
          As for symbol resolution, PLT32 and PC32 relocations are almost
          interchangeable. But when linker sees PLT32 relocation against a
          protected symbol, it can resolved locally at link-time since it is
          used on a branch instruction. Linker can't do that for PC32
          relocation"
      
        but for the kernel use, the two are basically the same, and this
        commit gets things building and working with the current binutils
        master   - Linus ]
      
      Change-Id: I7582fa6b33b3de2ce107b53a685afc16cd79072c
      Signed-off-by: default avatarH.J. Lu <hjl.tools@gmail.com>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Cc: Matthias Kaehlcke <mka@chromium.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      2673e6c9
  7. Dec 05, 2018
  8. Dec 04, 2018
    • Christoph Paasch's avatar
      net: Set sk_prot_creator when cloning sockets to the right proto · befb4fd1
      Christoph Paasch authored
      
      
      [ Upstream commit 9d538fa6 ]
      
      sk->sk_prot and sk->sk_prot_creator can differ when the app uses
      IPV6_ADDRFORM (transforming an IPv6-socket to an IPv4-one).
      Which is why sk_prot_creator is there to make sure that sk_prot_free()
      does the kmem_cache_free() on the right kmem_cache slab.
      
      Now, if such a socket gets transformed back to a listening socket (using
      connect() with AF_UNSPEC) we will allocate an IPv4 tcp_sock through
      sk_clone_lock() when a new connection comes in. But sk_prot_creator will
      still point to the IPv6 kmem_cache (as everything got copied in
      sk_clone_lock()). When freeing, we will thus put this
      memory back into the IPv6 kmem_cache although it was allocated in the
      IPv4 cache. I have seen memory corruption happening because of this.
      
      With slub-debugging and MEMCG_KMEM enabled this gives the warning
      	"cache_from_obj: Wrong slab cache. TCPv6 but object is from TCP"
      
      A C-program to trigger this:
      
      void main(void)
      {
              int fd = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
              int new_fd, newest_fd, client_fd;
              struct sockaddr_in6 bind_addr;
              struct sockaddr_in bind_addr4, client_addr1, client_addr2;
              struct sockaddr unsp;
              int val;
      
              memset(&bind_addr, 0, sizeof(bind_addr));
              bind_addr.sin6_family = AF_INET6;
              bind_addr.sin6_port = ntohs(42424);
      
              memset(&client_addr1, 0, sizeof(client_addr1));
              client_addr1.sin_family = AF_INET;
              client_addr1.sin_port = ntohs(42424);
              client_addr1.sin_addr.s_addr = inet_addr("127.0.0.1");
      
              memset(&client_addr2, 0, sizeof(client_addr2));
              client_addr2.sin_family = AF_INET;
              client_addr2.sin_port = ntohs(42421);
              client_addr2.sin_addr.s_addr = inet_addr("127.0.0.1");
      
              memset(&unsp, 0, sizeof(unsp));
              unsp.sa_family = AF_UNSPEC;
      
              bind(fd, (struct sockaddr *)&bind_addr, sizeof(bind_addr));
      
              listen(fd, 5);
      
              client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
              connect(client_fd, (struct sockaddr *)&client_addr1, sizeof(client_addr1));
              new_fd = accept(fd, NULL, NULL);
              close(fd);
      
              val = AF_INET;
              setsockopt(new_fd, SOL_IPV6, IPV6_ADDRFORM, &val, sizeof(val));
      
              connect(new_fd, &unsp, sizeof(unsp));
      
              memset(&bind_addr4, 0, sizeof(bind_addr4));
              bind_addr4.sin_family = AF_INET;
              bind_addr4.sin_port = ntohs(42421);
              bind(new_fd, (struct sockaddr *)&bind_addr4, sizeof(bind_addr4));
      
              listen(new_fd, 5);
      
              client_fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
              connect(client_fd, (struct sockaddr *)&client_addr2, sizeof(client_addr2));
      
              newest_fd = accept(new_fd, NULL, NULL);
              close(new_fd);
      
              close(client_fd);
              close(new_fd);
      }
      
      As far as I can see, this bug has been there since the beginning of the
      git-days.
      
      Signed-off-by: default avatarChristoph Paasch <cpaasch@apple.com>
      Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      befb4fd1
  9. Nov 22, 2018
    • mifl's avatar
      netfilter: x_tables: add unmerged changes · bf3a6835
      mifl authored
      
      In the commit:
      15061668 Merge 3.18.37 into android-3.18
      
      The following commits was skipped in the files:
      net/ipv4/netfilter/arp_tables.c
      net/ipv4/netfilter/ip_tables.c
      net/ipv6/netfilter/ip6_tables.c
      
      62e6fd20 netfilter: x_tables: add and use xt_check_entry_offsets
      dda46754 netfilter: x_tables: kill check_entry helper
      7ef13f49 netfilter: x_tables: add compat version of xt_check_entry_offsets
      7ef13f49 netfilter: x_tables: check for bogus target offset
      
      Change-Id: Ia1833950282df3dc5ef3a6f2185ef3d5f814410c
      Signed-off-by: default avatarmifl <mifl.pc@gmail.com>
      bf3a6835
  10. Nov 14, 2018
  11. Nov 05, 2018
  12. Nov 02, 2018
  13. Oct 09, 2018
  14. Aug 30, 2018
  15. Aug 07, 2018
  16. Jul 06, 2018
    • Mel Gorman's avatar
      futex: Remove requirement for lock_page() in get_futex_key() · b3d4fefa
      Mel Gorman authored
      
      commit 65d8fc77 upstream.
      
      When dealing with key handling for shared futexes, we can drastically reduce
      the usage/need of the page lock. 1) For anonymous pages, the associated futex
      object is the mm_struct which does not require the page lock. 2) For inode
      based, keys, we can check under RCU read lock if the page mapping is still
      valid and take reference to the inode. This just leaves one rare race that
      requires the page lock in the slow path when examining the swapcache.
      
      Additionally realtime users currently have a problem with the page lock being
      contended for unbounded periods of time during futex operations.
      
      Task A
           get_futex_key()
           lock_page()
          ---> preempted
      
      Now any other task trying to lock that page will have to wait until
      task A gets scheduled back in, which is an unbound time.
      
      With this patch, we pretty much have a lockless futex_get_key().
      
      Experiments show that this patch can boost/speedup the hashing of shared
      futexes with the perf futex benchmarks (which is good for measuring such
      change) by up to 45% when there are high (> 100) thread counts on a 60 core
      Westmere. Lower counts are pretty much in the noise range or less than 10%,
      but mid range can be seen at over 30% overall throughput (hash ops/sec).
      This makes anon-mem shared futexes much closer to its private counterpart.
      
      Signed-off-by: default avatarMel Gorman <mgorman@suse.de>
      [ Ported on top of thp refcount rework, changelog, comments, fixes. ]
      Signed-off-by: default avatarDavidlohr Bueso <dbueso@suse.de>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Chris Mason <clm@fb.com>
      Cc: Darren Hart <dvhart@linux.intel.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
      Cc: dave@stgolabs.net
      Link: http://lkml.kernel.org/r/1455045314-8305-3-git-send-email-dave@stgolabs.net
      
      
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      Signed-off-by: default avatarChenbo Feng <fengc@google.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    • Seunghun Han's avatar
      x86/MCE: Serialize sysfs changes · dd2d3d97
      Seunghun Han authored
      
      commit b3b7c479 upstream.
      
      The check_interval file in
      
        /sys/devices/system/machinecheck/machinecheck<cpu number>
      
      directory is a global timer value for MCE polling. If it is changed by one
      CPU, mce_restart() broadcasts the event to other CPUs to delete and restart
      the MCE polling timer and __mcheck_cpu_init_timer() reinitializes the
      mce_timer variable.
      
      If more than one CPU writes a specific value to the check_interval file
      concurrently, mce_timer is not protected from such concurrent accesses and
      all kinds of explosions happen. Since only root can write to those sysfs
      variables, the issue is not a big deal security-wise.
      
      However, concurrent writes to these configuration variables is void of
      reason so the proper thing to do is to serialize the access with a mutex.
      
      Boris:
      
       - Make store_int_with_restart() use device_store_ulong() to filter out
         negative intervals
       - Limit min interval to 1 second
       - Correct locking
       - Massage commit message
      
      Signed-off-by: default avatarSeunghun Han <kkamagui@gmail.com>
      Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
      Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Tony Luck <tony.luck@intel.com>
      Cc: linux-edac <linux-edac@vger.kernel.org>
      Cc: stable@vger.kernel.org
      Link: http://lkml.kernel.org/r/20180302202706.9434-1-kkamagui@gmail.com
      
      
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      dd2d3d97
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