1. 02 6月, 2009 1 次提交
    • S
      ftrace: add kernel command line function filtering · 2af15d6a
      Steven Rostedt 提交于
      When using ftrace=function on the command line to trace functions
      on boot up, one can not filter out functions that are commonly called.
      
      This patch adds two new ftrace command line commands.
      
        ftrace_notrace=function-list
        ftrace_filter=function-list
      
      Where function-list is a comma separated list of functions to filter.
      The ftrace_notrace will make the functions listed not be included
      in the function tracing, and ftrace_filter will only trace the functions
      listed.
      
      These two act the same as the debugfs/tracing/set_ftrace_notrace and
      debugfs/tracing/set_ftrace_filter respectively.
      
      The simple glob expressions that are allowed by the filter files can also
      be used by the command line interface.
      
      	ftrace_notrace=rcu*,*lock,*spin*
      
      Will not trace any function that starts with rcu, ends with lock, or has
      the word spin in it.
      
      Note, if the self tests are enabled, they may interfere with the filtering
      set by the command lines.
      Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>
      2af15d6a
  2. 28 5月, 2009 2 次提交
    • Z
      ftrace: don't convert function's local variable name in macro · f2aebaee
      Zhaolei 提交于
      "call" is an argument of macro, but it is also used as a local
      variable name of function in macro.
      We should keep this local variable name distinct from any
      CPP macro parameter name if both are in the same macro scope,
      although it hasn't caused any problem yet.
      
      [ Impact: robustify macro ]
      Signed-off-by: NZhao Lei <zhaolei@cn.fujitsu.com>
      Acked-by: NSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      f2aebaee
    • H
      trace: disable preemption before taking raw spinlocks · 5b6045a9
      Heiko Carstens 提交于
      s390 code uses smp_processor_id() in __raw_spin_lock() code which
      reveals that a (raw) spinlock is taken without preemption disabled.
      This can potentially deadlock.
      
      To fix this explicitly disable and enable preemption.
      
      BUG: using smp_processor_id() in preemptible [00000000] code: cat/2278
      caller is trace_find_cmdline+0x40/0xfc
      CPU: 0 Not tainted 2.6.30-rc7-dirty #39
      Process cat (pid: 2278, task: 000000003faedb68, ksp: 000000003b33b988)
      000000003b33b988 000000003b33bae0 0000000000000002 0000000000000000
             000000003b33bb80 000000003b33baf8 000000003b33baf8 00000000000175d6
             0000000000000001 000000003b33b988 000000003f9b0000 000000000000000b
             000000000000000c 000000003b33bb40 000000003b33bae0 0000000000000000
             0000000000000000 00000000000175d6 000000003b33bae0 000000003b33bb28
      Call Trace:
      ([<00000000000174b2>] show_trace+0x112/0x170)
       [<0000000000017582>] show_stack+0x72/0x100
       [<0000000000441538>] dump_stack+0xc8/0xd8
       [<000000000025c350>] debug_smp_processor_id+0x114/0x130
       [<00000000000bf0e4>] trace_find_cmdline+0x40/0xfc
       [<00000000000c35d4>] trace_print_context+0x58/0xac
       [<00000000000bb676>] print_trace_line+0x416/0x470
       [<00000000000bc8fe>] s_show+0x4e/0x428
       [<000000000013834e>] seq_read+0x36a/0x5d4
       [<0000000000112a78>] vfs_read+0xc8/0x174
       [<0000000000112c58>] SyS_read+0x74/0xc4
       [<000000000002c7ae>] sysc_noemu+0x10/0x16
       [<000002000012436c>] 0x2000012436c
      1 lock held by cat/2278:
       #0:  (&p->lock){+.+.+.}, at: [<0000000000138056>] seq_read+0x72/0x5d4
      
      [ Impact: fix preempt-unsafe raw spinlock ]
      Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
      Acked-by: NSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      5b6045a9
  3. 27 5月, 2009 5 次提交
  4. 26 5月, 2009 5 次提交
    • Z
      ftrace: clean up of using ftrace_event_enable_disable() · 0e907c99
      Zhaolei 提交于
      Always use ftrace_event_enable_disable() to enable/disable an event
      so that we can factorize out the event toggling code.
      
      [ Impact: factorize and cleanup event tracing code ]
      Signed-off-by: NZhao Lei <zhaolei@cn.fujitsu.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Tom Zanussi <tzanussi@gmail.com>
      LKML-Reference: <4A14FDFE.2080402@cn.fujitsu.com>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      0e907c99
    • Z
      ftrace: Add task_comm support for trace_event · b11c53e1
      Zhaolei 提交于
      If we enable a trace event alone without any tracer running (such as
      function tracer, sched switch tracer, etc...) it can't output enough
      task command information.
      
      We need to use the tracing_{start/stop}_cmdline_record() helpers
      which are designed to keep track of cmdlines for any tasks that
      were scheduled during the tracing.
      
      Before this patch:
       # echo 1 > debugfs/tracing/events/sched/sched_switch/enable
       # cat debugfs/tracing/trace
       # tracer: nop
       #
       #           TASK-PID    CPU#    TIMESTAMP  FUNCTION
       #              | |       |          |         |
                  <...>-2289  [000] 526276.724790: sched_switch: task bash:2289 [120] ==> sshd:2287 [120]
                  <...>-2287  [000] 526276.725231: sched_switch: task sshd:2287 [120] ==> bash:2289 [120]
                  <...>-2289  [000] 526276.725452: sched_switch: task bash:2289 [120] ==> sshd:2287 [120]
                  <...>-2287  [000] 526276.727181: sched_switch: task sshd:2287 [120] ==> swapper:0 [140]
                 <idle>-0     [000] 526277.032734: sched_switch: task swapper:0 [140] ==> events/0:5 [115]
                  <...>-5     [000] 526277.032782: sched_switch: task events/0:5 [115] ==> swapper:0 [140]
       ...
      
      After this patch:
       # tracer: nop
       #
       #           TASK-PID    CPU#    TIMESTAMP  FUNCTION
       #              | |       |          |         |
                   bash-2269  [000] 527347.989229: sched_switch: task bash:2269 [120] ==> sshd:2267 [120]
                   sshd-2267  [000] 527347.990960: sched_switch: task sshd:2267 [120] ==> bash:2269 [120]
                   bash-2269  [000] 527347.991143: sched_switch: task bash:2269 [120] ==> sshd:2267 [120]
                   sshd-2267  [000] 527347.992959: sched_switch: task sshd:2267 [120] ==> swapper:0 [140]
                 <idle>-0     [000] 527348.531989: sched_switch: task swapper:0 [140] ==> events/0:5 [115]
               events/0-5     [000] 527348.532115: sched_switch: task events/0:5 [115] ==> swapper:0 [140]
       ...
      
      Changelog:
      v1->v2: Update Kconfig to select CONTEXT_SWITCH_TRACER in
              ENABLE_EVENT_TRACING
      v2->v3: v2 can solve problem that was caused by config EVENT_TRACING
              alone, but when CONFIG_FTRACE is off and CONFIG_TRACING is
              selected by other config, compile fail happened again.
              This version solves it.
      
      [ Impact: fix incomplete output of event tracing ]
      Signed-off-by: NZhao Lei <zhaolei@cn.fujitsu.com>
      Cc: Tom Zanussi <tzanussi@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <4A14FDFE.2080402@cn.fujitsu.com>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      b11c53e1
    • P
      kmemtrace: fix kernel parameter documentation · 29fcefba
      Pekka Enberg 提交于
      The kmemtrace.enable kernel parameter no longer works. To enable
      kmemtrace at boot-time, you must pass "ftrace=kmemtrace" instead.
      
      [ Impact: remove obsolete kernel parameter documentation ]
      
      Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
      Signed-off-by: NPekka Enberg <penberg@cs.helsinki.fi>
      LKML-Reference: <alpine.DEB.2.00.0905241112190.10296@rocky>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      29fcefba
    • L
      tracing/events: change the type of __str_loc_item to unsigned short · b0aae68c
      Li Zefan 提交于
      When defining a dynamic size string, we add __str_loc_##item to the
      trace entry, and it stores the location of the actual string in
      entry->_str_data[]
      
      'unsigned short' should be sufficient to store this information, thus
      we save 2 bytes per dyn-size string in the ring buffer.
      
      [ Impact: reduce memory occupied by dyn-size strings in ring buffer ]
      Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <4A14EDB6.2050507@cn.fujitsu.com>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      b0aae68c
    • L
      tracing: add trace_event_read_lock() · 4f535968
      Lai Jiangshan 提交于
      I found that there is nothing to protect event_hash in
      ftrace_find_event(). Rcu protects the event hashlist
      but not the event itself while we use it after its extraction
      through ftrace_find_event().
      
      This lack of a proper locking in this spot opens a race
      window between any event dereferencing and module removal.
      
      Eg:
      
      --Task A--
      
      print_trace_line(trace) {
        event = find_ftrace_event(trace)
      
      --Task B--
      
      trace_module_remove_events(mod) {
        list_trace_events_module(ev, mod) {
          unregister_ftrace_event(ev->event) {
            hlist_del(ev->event->node)
              list_del(....)
          }
        }
      }
      |--> module removed, the event has been dropped
      
      --Task A--
      
        event->print(trace); // Dereferencing freed memory
      
      If the event retrieved belongs to a module and this module
      is concurrently removed, we may end up dereferencing a data
      from a freed module.
      
      RCU could solve this, but it would add latency to the kernel and
      forbid tracers output callbacks to call any sleepable code.
      So this fix converts 'trace_event_mutex' to a read/write semaphore,
      and adds trace_event_read_lock() to protect ftrace_find_event().
      
      [ Impact: fix possible freed memory dereference in ftrace ]
      Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com>
      Acked-by: NSteven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <4A114806.7090302@cn.fujitsu.com>
      Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
      4f535968
  5. 21 5月, 2009 1 次提交
  6. 19 5月, 2009 2 次提交
    • S
      blktrace: remove debugfs entries on bad path · fd51d251
      Stefan Raspl 提交于
      debugfs directory entries for devices are not removed on some
      of the failure pathes in do_blk_trace_setup().
      One way to reproduce is to start blktrace on multiple devices
      with insufficient Vmalloc space: Devices will fail with
      a message like this:
      
      	BLKTRACESETUP(2) /dev/sdu failed: 5/Input/output error
      
      If so, the respective entries in debugfs
      (e.g. /sys/kernel/debug/block/sdu) will remain and subsequent
      attempts to start blktrace on the respective devices will not
      succeed due to existing directories.
      
      [ Impact: fix /debug/tracing file cleanup corner case ]
      Signed-off-by: NStefan Raspl <stefan.raspl@linux.vnet.ibm.com>
      Acked-by: NLi Zefan <lizf@cn.fujitsu.com>
      Cc: Li Zefan <lizf@cn.fujitsu.com>
      Cc: schwidefsky@de.ibm.com
      Cc: heiko.carstens@de.ibm.com
      LKML-Reference: <4A1266CC.5040801@linux.vnet.ibm.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      fd51d251
    • L
      tracing/events: Documentation updates · 143c145e
      Li Zefan 提交于
      - fix some typos
      - document the difference between '>' and '>>'
      - document the 'enable' toggle
      - remove section "Defining an event-enabled tracepoint", since it's
        out-dated and sample/trace_events/ already serves this purpose.
      
      v2: add "Updated by Li Zefan"
      
      [ Impact: make documentation up-to-date ]
      Signed-off-by: NLi Zefan <lizf@cn.fujitsu.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: "Theodore Ts'o" <tytso@mit.edu>
      LKML-Reference: <4A125503.5060406@cn.fujitsu.com>
      Signed-off-by: NIngo Molnar <mingo@elte.hu>
      143c145e
  7. 18 5月, 2009 2 次提交
  8. 16 5月, 2009 12 次提交
  9. 15 5月, 2009 10 次提交