1. 19 Sep, 2018 5 commits
  2. 15 Sep, 2018 3 commits
    • Breno Leitao's avatar
      selftests/powerpc: Kill child processes on SIGINT · e33c8a28
      Breno Leitao authored
      [ Upstream commit 7c27a26e ]
      
      There are some powerpc selftests, as tm/tm-unavailable, that run for a long
      period (>120 seconds), and if it is interrupted, as pressing CRTL-C
      (SIGINT), the foreground process (harness) dies but the child process and
      threads continue to execute (with PPID = 1 now) in background.
      
      In this case, you'd think the whole test exited, but there are remaining
      threads and processes being executed in background. Sometimes these
      zombies processes are doing annoying things, as consuming the whole CPU or
      dumping things to STDOUT.
      
      This patch fixes this problem by attaching an empty signal handler to
      SIGINT in the harness process. This handler will interrupt (EINTR) the
      parent process waitpid() call, letting the code to follow through the
      normal flow, which will kill all the processes in the child process group.
      
      This patch also fixes a typo.
      Signed-off-by: default avatarBreno Leitao <leitao@debian.org>
      Signed-off-by: default avatarGustavo Romero <gromero@linux.vnet.ibm.com>
      Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
      Signed-off-by: default avatarSasha Levin <alexander.levin@microsoft.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e33c8a28
    • Sandipan Das's avatar
      perf probe powerpc: Fix trace event post-processing · 6952b4ed
      Sandipan Das authored
      [ Upstream commit 354b064b ]
      
      In some cases, a symbol may have multiple aliases. Attempting to add an
      entry probe for such symbols results in a probe being added at an
      incorrect location while it fails altogether for return probes. This is
      only applicable for binaries with debug information.
      
      During the arch-dependent post-processing, the offset from the start of
      the symbol at which the probe is to be attached is determined and added
      to the start address of the symbol to get the probe's location.  In case
      there are multiple aliases, this offset gets added multiple times for
      each alias of the symbol and we end up with an incorrect probe location.
      
      This can be verified on a powerpc64le system as shown below.
      
        $ nm /lib/modules/$(uname -r)/build/vmlinux | grep "sys_open$"
        ...
        c000000000414290 T __se_sys_open
        c000000000414290 T sys_open
      
        $ objdump -d /lib/modules/$(uname -r)/build/vmlinux | grep -A 10 "<__se_sys_open>:"
      
        c000000000414290 <__se_sys_open>:
        c000000000414290:       19 01 4c 3c     addis   r2,r12,281
        c000000000414294:       70 c4 42 38     addi    r2,r2,-15248
        c000000000414298:       a6 02 08 7c     mflr    r0
        c00000000041429c:       e8 ff a1 fb     std     r29,-24(r1)
        c0000000004142a0:       f0 ff c1 fb     std     r30,-16(r1)
        c0000000004142a4:       f8 ff e1 fb     std     r31,-8(r1)
        c0000000004142a8:       10 00 01 f8     std     r0,16(r1)
        c0000000004142ac:       c1 ff 21 f8     stdu    r1,-64(r1)
        c0000000004142b0:       78 23 9f 7c     mr      r31,r4
        c0000000004142b4:       78 1b 7e 7c     mr      r30,r3
      
        For both the entry probe and the return probe, the probe location
        should be _text+4276888 (0xc000000000414298). Since another alias
        exists for 'sys_open', the post-processing code will end up adding
        the offset (8 for powerpc64le) twice and perf will attempt to add
        the probe at _text+4276896 (0xc0000000004142a0) instead.
      
      Before:
      
        # perf probe -v -a sys_open
      
        probe-definition(0): sys_open
        symbol:sys_open file:(null) line:0 offset:0 return:0 lazy:(null)
        0 arguments
        Looking at the vmlinux_path (8 entries long)
        Using /lib/modules/4.18.0-rc8+/build/vmlinux for symbols
        Open Debuginfo file: /lib/modules/4.18.0-rc8+/build/vmlinux
        Try to find probe point from debuginfo.
        Symbol sys_open address found : c000000000414290
        Matched function: __se_sys_open [2ad03a0]
        Probe point found: __se_sys_open+0
        Found 1 probe_trace_events.
        Opening /sys/kernel/debug/tracing/kprobe_events write=1
        Writing event: p:probe/sys_open _text+4276896
        Added new event:
          probe:sys_open       (on sys_open)
        ...
      
        # perf probe -v -a sys_open%return $retval
      
        probe-definition(0): sys_open%return
        symbol:sys_open file:(null) line:0 offset:0 return:1 lazy:(null)
        0 arguments
        Looking at the vmlinux_path (8 entries long)
        Using /lib/modules/4.18.0-rc8+/build/vmlinux for symbols
        Open Debuginfo file: /lib/modules/4.18.0-rc8+/build/vmlinux
        Try to find probe point from debuginfo.
        Symbol sys_open address found : c000000000414290
        Matched function: __se_sys_open [2ad03a0]
        Probe point found: __se_sys_open+0
        Found 1 probe_trace_events.
        Opening /sys/kernel/debug/tracing/README write=0
        Opening /sys/kernel/debug/tracing/kprobe_events write=1
        Parsing probe_events: p:probe/sys_open _text+4276896
        Group:probe Event:sys_open probe:p
        Writing event: r:probe/sys_open__return _text+4276896
        Failed to write event: Invalid argument
          Error: Failed to add events. Reason: Invalid argument (Code: -22)
      
      After:
      
        # perf probe -v -a sys_open
      
        probe-definition(0): sys_open
        symbol:sys_open file:(null) line:0 offset:0 return:0 lazy:(null)
        0 arguments
        Looking at the vmlinux_path (8 entries long)
        Using /lib/modules/4.18.0-rc8+/build/vmlinux for symbols
        Open Debuginfo file: /lib/modules/4.18.0-rc8+/build/vmlinux
        Try to find probe point from debuginfo.
        Symbol sys_open address found : c000000000414290
        Matched function: __se_sys_open [2ad03a0]
        Probe point found: __se_sys_open+0
        Found 1 probe_trace_events.
        Opening /sys/kernel/debug/tracing/kprobe_events write=1
        Writing event: p:probe/sys_open _text+4276888
        Added new event:
          probe:sys_open       (on sys_open)
        ...
      
        # perf probe -v -a sys_open%return $retval
      
        probe-definition(0): sys_open%return
        symbol:sys_open file:(null) line:0 offset:0 return:1 lazy:(null)
        0 arguments
        Looking at the vmlinux_path (8 entries long)
        Using /lib/modules/4.18.0-rc8+/build/vmlinux for symbols
        Open Debuginfo file: /lib/modules/4.18.0-rc8+/build/vmlinux
        Try to find probe point from debuginfo.
        Symbol sys_open address found : c000000000414290
        Matched function: __se_sys_open [2ad03a0]
        Probe point found: __se_sys_open+0
        Found 1 probe_trace_events.
        Opening /sys/kernel/debug/tracing/README write=0
        Opening /sys/kernel/debug/tracing/kprobe_events write=1
        Parsing probe_events: p:probe/sys_open _text+4276888
        Group:probe Event:sys_open probe:p
        Writing event: r:probe/sys_open__return _text+4276888
        Added new event:
          probe:sys_open__return (on sys_open%return)
        ...
      Reported-by: default avatarAneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Signed-off-by: default avatarSandipan Das <sandipan@linux.ibm.com>
      Acked-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
      Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
      Fixes: 99e608b5 ("perf probe ppc64le: Fix probe location when using DWARF")
      Link: http://lkml.kernel.org/r/20180809161929.35058-1-sandipan@linux.ibm.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: default avatarSasha Levin <alexander.levin@microsoft.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      6952b4ed
    • Benno Evers's avatar
      perf tools: Check for null when copying nsinfo. · 5e51aa84
      Benno Evers authored
      [ Upstream commit 3f4417d6 ]
      
      The argument to nsinfo__copy() was assumed to be valid, but some code paths
      exist that will lead to NULL being passed.
      
      In particular, running 'perf script -D' on a perf.data file containing an
      PERF_RECORD_MMAP event associating the '[vdso]' dso with pid 0 earlier in
      the event stream will lead to a segfault.
      
      Since all calling code is already checking for a non-null return value,
      just return NULL for this case as well.
      Signed-off-by: default avatarBenno Evers <bevers@mesosphere.com>
      Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
      Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Krister Johansen <kjlx@templeofstupid.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Link: http://lkml.kernel.org/r/20180810133614.9925-1-bevers@mesosphere.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      Signed-off-by: default avatarSasha Levin <alexander.levin@microsoft.com>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      5e51aa84
  3. 09 Sep, 2018 1 commit
  4. 05 Sep, 2018 4 commits
  5. 24 Aug, 2018 21 commits
  6. 15 Aug, 2018 1 commit
  7. 03 Aug, 2018 5 commits