1. 25 Jan, 2017 22 commits
  2. 20 Jan, 2017 16 commits
  3. 19 Jan, 2017 2 commits
    • Arnd Bergmann's avatar
      lkdtm: hide stack overflow warning for corrupt-stack test · 7a11a1d1
      Arnd Bergmann authored
      After the latest change to make sure the compiler actually does a memset,
      it is now smart enough to flag the stack overflow at compile time,
      at least with gcc-7.0:
      
      drivers/misc/lkdtm_bugs.c: In function 'lkdtm_CORRUPT_STACK':
      drivers/misc/lkdtm_bugs.c:88:144: warning: 'memset' writing 64 bytes into a region of size 8 overflows the destination [-Wstringop-overflow=]
      
      To outsmart the compiler again, this moves the memset into a noinline
      function where (for now) it doesn't see that we intentionally write
      broken code here.
      
      Fixes: c55d2400 ("lkdtm: Prevent the compiler from optimising lkdtm_CORRUPT_STACK()")
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Acked-by: default avatarKees Cook <keescook@chromium.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      7a11a1d1
    • Suzuki K Poulose's avatar
      coresight: STM: Balance enable/disable · 4474f4c4
      Suzuki K Poulose authored
      The stm is automatically enabled when an application sets the policy
      via ->link() call back by using coresight_enable(), which keeps the
      refcount of the current users of the STM. However, the unlink() callback
      issues stm_disable() directly, which leaves the STM turned off, without
      the coresight layer knowing about it. This prevents any further uses
      of the STM hardware as the coresight layer still thinks the STM is
      turned on and doesn't enable the hardware when required. Even manually
      enabling the STM via sysfs can't really enable the hw.
      
      e.g,
      
       $ echo 1 > $CS_DEVS/$ETR/enable_sink
       $ mkdir -p $CONFIG_FS/stp-policy/$source.0/stm_test/
       $ echo 32768 65535 > $CONFIG_FS/stp-policy/$source.0/stm_test/channels
       $ echo 64 > $CS_DEVS/$source/traceid
       $ ./stm_app
       Sending 64000 byte blocks of pattern 0 at 0us intervals
       Success to map channel(32768~32783) to 0xffffa95fa000
       Sending on channel 32768
       $ dd if=/dev/$ETR of=~/trace.bin.1
       597+1 records in
       597+1 records out
       305920 bytes (306 kB) copied, 0.399952 s, 765 kB/s
       $ ./stm_app
       Sending 64000 byte blocks of pattern 0 at 0us intervals
       Success to map channel(32768~32783) to 0xffff7e9e2000
       Sending on channel 32768
       $ dd if=/dev/$ETR of=~/trace.bin.2
       0+0 records in
       0+0 records out
       0 bytes (0 B) copied, 0.0232083 s, 0.0 kB/s
      
       Note that we don't get any data from the ETR for the second session.
      
       Also dmesg shows :
      
       [   77.520458] coresight-tmc 20800000.etr: TMC-ETR enabled
       [   77.537097] coresight-replicator etr_replicator@20890000: REPLICATOR enabled
       [   77.558828] coresight-replicator main_replicator@208a0000: REPLICATOR enabled
       [   77.581068] coresight-funnel 208c0000.main_funnel: FUNNEL inport 0 enabled
       [   77.602217] coresight-tmc 20840000.etf: TMC-ETF enabled
       [   77.618422] coresight-stm 20860000.stm: STM tracing enabled
       [  139.554252] coresight-stm 20860000.stm: STM tracing disabled
        # End of first tracing session
       [  146.351135] coresight-tmc 20800000.etr: TMC read start
       [  146.514486] coresight-tmc 20800000.etr: TMC read end
        # Note that the STM is not turned on via stm_generic_link()->coresight_enable()
        # and hence none of the components are turned on.
       [  152.479080] coresight-tmc 20800000.etr: TMC read start
       [  152.542632] coresight-tmc 20800000.etr: TMC read end
      
      This patch fixes the problem by balancing the unlink operation by using
      the coresight_disable(), keeping the coresight layer in sync with the
      hardware state and thus allowing normal usage of the STM component.
      
      Fixes: commit 237483aa ("coresight: stm: adding driver for CoreSight STM component")
      Cc: Pratik Patel <pratikp@codeaurora.org>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: stable@vger.kernel.org # 4.7+
      Acked-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
      Reviewed-by: default avatarChunyan Zhang <zhang.chunyan@linaro.org>
      Reported-by: default avatarRobert Walker <robert.walker@arm.com>
      Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      4474f4c4