1. 02 Aug, 2019 2 commits
  2. 18 Jul, 2019 3 commits
    • Daniel Jordan's avatar
      padata: use smp_mb in padata_reorder to avoid orphaned padata jobs · cf144f81
      Daniel Jordan authored
      Testing padata with the tcrypt module on a 5.2 kernel...
      
          # modprobe tcrypt alg="pcrypt(rfc4106(gcm(aes)))" type=3
          # modprobe tcrypt mode=211 sec=1
      
      ...produces this splat:
      
          INFO: task modprobe:10075 blocked for more than 120 seconds.
                Not tainted 5.2.0-base+ #16
          modprobe        D    0 10075  10064 0x80004080
          Call Trace:
           ? __schedule+0x4dd/0x610
           ? ring_buffer_unlock_commit+0x23/0x100
           schedule+0x6c/0x90
           schedule_timeout+0x3b/0x320
           ? trace_buffer_unlock_commit_regs+0x4f/0x1f0
           wait_for_common+0x160/0x1a0
           ? wake_up_q+0x80/0x80
           { crypto_wait_req }             # entries in braces added by hand
           { do_one_aead_op }
           { test_aead_jiffies }
           test_aead_speed.constprop.17+0x681/0xf30 [tcrypt]
           do_test+0x4053/0x6a2b [tcrypt]
           ? 0xffffffffa00f4000
           tcrypt_mod_init+0x50/0x1000 [tcrypt]
           ...
      
      The second modprobe command never finishes because in padata_reorder,
      CPU0's load of reorder_objects is executed before the unlocking store in
      spin_unlock_bh(pd->lock), causing CPU0 to miss CPU1's increment:
      
      CPU0                                 CPU1
      
      padata_reorder                       padata_do_serial
        LOAD reorder_objects  // 0
                                             INC reorder_objects  // 1
                                             padata_reorder
                                               TRYLOCK pd->lock   // failed
        UNLOCK pd->lock
      
      CPU0 deletes the timer before returning from padata_reorder and since no
      other job is submitted to padata, modprobe waits indefinitely.
      
      Add a pair of full barriers to guarantee proper ordering:
      
      CPU0                                 CPU1
      
      padata_reorder                       padata_do_serial
        UNLOCK pd->lock
        smp_mb()
        LOAD reorder_objects
                                             INC reorder_objects
                                             smp_mb__after_atomic()
                                             padata_reorder
                                               TRYLOCK pd->lock
      
      smp_mb__after_atomic is needed so the read part of the trylock operation
      comes after the INC, as Andrea points out.   Thanks also to Andrea for
      help with writing a litmus test.
      
      Fixes: 16295bec ("padata: Generic parallelization/serialization interface")
      Signed-off-by: default avatarDaniel Jordan <daniel.m.jordan@oracle.com>
      Cc: <stable@vger.kernel.org>
      Cc: Andrea Parri <andrea.parri@amarulasolutions.com>
      Cc: Boqun Feng <boqun.feng@gmail.com>
      Cc: Herbert Xu <herbert@gondor.apana.org.au>
      Cc: Paul E. McKenney <paulmck@linux.ibm.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Steffen Klassert <steffen.klassert@secunet.com>
      Cc: linux-arch@vger.kernel.org
      Cc: linux-crypto@vger.kernel.org
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      cf144f81
    • David Rientjes's avatar
      crypto: ccp - Fix SEV_VERSION_GREATER_OR_EQUAL · 83bf4251
      David Rientjes authored
      SEV_VERSION_GREATER_OR_EQUAL() will fail if upgrading from 2.2 to 3.1, for
      example, because the minor version is not equal to or greater than the
      major.
      
      Fix this and move to a static inline function for appropriate type
      checking.
      
      Fixes: edd303ff ("crypto: ccp - Add DOWNLOAD_FIRMWARE SEV command")
      Reported-by: default avatarCfir Cohen <cfir@google.com>
      Signed-off-by: default avatarDavid Rientjes <rientjes@google.com>
      Acked-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
      Acked-by: default avatarGary R Hook <gary.hook@amd.com>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      83bf4251
    • Cfir Cohen's avatar
      crypto: ccp/gcm - use const time tag comparison. · 538a5a07
      Cfir Cohen authored
      Avoid leaking GCM tag through timing side channel.
      
      Fixes: 36cf515b ("crypto: ccp - Enable support for AES GCM on v5 CCPs")
      Cc: <stable@vger.kernel.org> # v4.12+
      Signed-off-by: default avatarCfir Cohen <cfir@google.com>
      Acked-by: default avatarGary R Hook <ghook@amd.com>
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      538a5a07
  3. 12 Jul, 2019 3 commits
  4. 03 Jul, 2019 14 commits
  5. 28 Jun, 2019 1 commit
  6. 27 Jun, 2019 10 commits
  7. 20 Jun, 2019 7 commits