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  1. Jun 02, 2009
    • Zhaolei's avatar
      trace_workqueue: use list_for_each_entry() instead of list_for_each_entry_safe() · 1fdfca9c
      Zhaolei authored
      
      
      No need to use list_for_each_entry_safe() in iteration without deleting
      any node, we can use list_for_each_entry() instead.
      
      [ Impact: cleanup ]
      
      Signed-off-by: default avatarZhao Lei <zhaolei@cn.fujitsu.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Tom Zanussi <tzanussi@gmail.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      1fdfca9c
    • Zhaolei's avatar
      ftrace, workqueuetrace: make workqueue tracepoints use TRACE_EVENT macro · fb39125f
      Zhaolei authored
      
      
      v3: zhaolei@cn.fujitsu.com: Change TRACE_EVENT definition to new format
          introduced by Steven Rostedt: consolidate trace and trace_event headers
      v2: kosaki@jp.fujitsu.com: print the function names instead of addr, and zap
          the work addr
      v1: zhaolei@cn.fujitsu.com: Make workqueue tracepoints use TRACE_EVENT macro
      
      TRACE_EVENT is a more generic way to define tracepoints.
      Doing so adds these new capabilities to the tracepoints:
      
        - zero-copy and per-cpu splice() tracing
        - binary tracing without printf overhead
        - structured logging records exposed under /debug/tracing/events
        - trace events embedded in function tracer output and other plugins
        - user-defined, per tracepoint filter expressions
      
      Then, this patch converts DEFINE_TRACE to TRACE_EVENT in workqueue related
      tracepoints.
      
      [ Impact: expand workqueue tracer to events tracing ]
      
      Signed-off-by: default avatarZhao Lei <zhaolei@cn.fujitsu.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Cc: Tom Zanussi <tzanussi@gmail.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Andrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      fb39125f
  2. May 28, 2009
    • Zhaolei's avatar
      ftrace: don't convert function's local variable name in macro · f2aebaee
      Zhaolei authored
      
      
      "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: default avatarZhao Lei <zhaolei@cn.fujitsu.com>
      Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      f2aebaee
    • Heiko Carstens's avatar
      trace: disable preemption before taking raw spinlocks · 5b6045a9
      Heiko Carstens authored
      
      
      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: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
      Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      5b6045a9
  3. May 27, 2009
  4. May 26, 2009
    • Zhaolei's avatar
      ftrace: clean up of using ftrace_event_enable_disable() · 0e907c99
      Zhaolei authored
      
      
      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: default avatarZhao 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: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      0e907c99
    • Zhaolei's avatar
      ftrace: Add task_comm support for trace_event · b11c53e1
      Zhaolei authored
      
      
      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: default avatarZhao 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: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      b11c53e1
    • Pekka Enberg's avatar
      kmemtrace: fix kernel parameter documentation · 29fcefba
      Pekka Enberg authored
      
      
      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: default avatarPekka Enberg <penberg@cs.helsinki.fi>
      LKML-Reference: <alpine.DEB.2.00.0905241112190.10296@rocky>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      29fcefba
    • Li Zefan's avatar
      tracing/events: change the type of __str_loc_item to unsigned short · b0aae68c
      Li Zefan authored
      
      
      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: default avatarLi Zefan <lizf@cn.fujitsu.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <4A14EDB6.2050507@cn.fujitsu.com>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      b0aae68c
    • Lai Jiangshan's avatar
      tracing: add trace_event_read_lock() · 4f535968
      Lai Jiangshan authored
      
      
      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: default avatarLai Jiangshan <laijs@cn.fujitsu.com>
      Acked-by: default avatarSteven Rostedt <rostedt@goodmis.org>
      LKML-Reference: <4A114806.7090302@cn.fujitsu.com>
      Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
      4f535968
  5. May 21, 2009
  6. May 19, 2009
    • Stefan Raspl's avatar
      blktrace: remove debugfs entries on bad path · fd51d251
      Stefan Raspl authored
      
      
      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: default avatarStefan Raspl <stefan.raspl@linux.vnet.ibm.com>
      Acked-by: default avatarLi 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: default avatarIngo Molnar <mingo@elte.hu>
      fd51d251
    • Li Zefan's avatar
      tracing/events: Documentation updates · 143c145e
      Li Zefan authored
      
      
      - 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: default avatarLi 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: default avatarIngo Molnar <mingo@elte.hu>
      143c145e
  7. May 18, 2009
  8. May 16, 2009
  9. May 15, 2009
    • Linus Torvalds's avatar
      Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 · 5d41343a
      Linus Torvalds authored
      * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
        ext4: Fix race in ext4_inode_info.i_cached_extent
        ext4: Clear the unwritten buffer_head flag after the extent is initialized
        ext4: Use a fake block number for delayed new buffer_head
        ext4: Fix sub-block zeroing for writes into preallocated extents
      5d41343a
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6 · c244450d
      Linus Torvalds authored
      * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
        ASoC: DaVinci EVM board support buildfixes
        ASoC: DaVinci I2S updates
        ASoC: davinci-pcm buildfixes
        ALSA: pcsp: fix printk format warning
        ALSA: riptide: postfix increment and off by one
        pxa2xx-ac97: fix reset gpio mode setting
        ASoC: soc-core: fix crash when removing not instantiated card
      c244450d
    • Linus Torvalds's avatar
      Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb · ade385e4
      Linus Torvalds authored
      * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb:
        kgdb: gdb documentation fix
        kgdb,i386: use address that SP register points to in the exception frame
        sysrq, intel_fb: fix sysrq g collision
      ade385e4
    • Linus Torvalds's avatar
      Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block · c6538499
      Linus Torvalds authored
      * 'for-linus' of git://git.kernel.dk/linux-2.6-block:
        Revert "mm: add /proc controls for pdflush threads"
        viocd: needs to depend on BLOCK
        block: fix the bio_vec array index out-of-bounds test
      c6538499
    • Linus Torvalds's avatar
      Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc · 662f11cf
      Linus Torvalds authored
      * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
        powerpc: Fix PCI ROM access
        powerpc/pseries: Really fix the oprofile CPU type on pseries
        serial/nwpserial: Fix wrong register read address and add interrupt acknowledge.
        powerpc/cell: Make ptcal more reliable
        powerpc: Allow mem=x cmdline to work with 4G+
        powerpc/mpic: Fix incorrect allocation of interrupt rev-map
        powerpc: Fix oprofile sampling of marked events on POWER7
        powerpc/iseries: Fix pci breakage due to bad dma_data initialization
        powerpc: Fix mktree build error on Mac OS X host
        powerpc/virtex: Fix duplicate level irq events.
        powerpc/virtex: Add uImage to the default images list
        powerpc/boot: add simpleImage.* to clean-files list
        powerpc/8xx: Update defconfigs
        powerpc/embedded6xx: Update defconfigs
        powerpc/86xx: Update defconfigs
        powerpc/85xx: Update defconfigs
        powerpc/83xx: Update defconfigs
        powerpc/fsl_soc: Remove mpc83xx_wdt_init, again
      662f11cf
    • Sukadev Bhattiprolu's avatar
      devpts: correctly set default options · 1f71ebed
      Sukadev Bhattiprolu authored
      
      
      devpts_get_sb() calls memset(0) to clear mount options and calls
      parse_mount_options() if user specified any mount options.
      
      The memset(0) is bogus since the 'mode' and 'ptmxmode' options are
      non-zero by default.  parse_mount_options() restores options to default
      anyway and can properly deal with NULL mount options.
      
      So in devpts_get_sb() remove memset(0) and call parse_mount_options() even
      for NULL mount options.
      
      Bug reported by Eric Paris: http://lkml.org/lkml/2009/5/7/448.
      
      Signed-off-by: default avatarSukadev Bhattiprolu <sukadev@us.ibm.com>
      Tested-by: default avatarMarc Dionne <marc.c.dionne@gmail.com>
      Reported-by: default avatarEric Paris <eparis@redhat.com>
      Cc: Christoph Hellwig <hch@lst.de>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Acked-by: default avatarSerge Hallyn <serue@us.ibm.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
      Reviewed-by: default avatar"H. Peter Anvin" <hpa@zytor.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      1f71ebed
    • Takashi Iwai's avatar
      Merge branch 'fix/asoc' into for-linus · 60befb97
      Takashi Iwai authored
      * fix/asoc:
        ASoC: DaVinci EVM board support buildfixes
        ASoC: DaVinci I2S updates
        ASoC: davinci-pcm buildfixes
        pxa2xx-ac97: fix reset gpio mode setting
        ASoC: soc-core: fix crash when removing not instantiated card
      60befb97
    • Takashi Iwai's avatar
      Merge branch 'fix/misc' into for-linus · a3d2b755
      Takashi Iwai authored
      * fix/misc:
        ALSA: pcsp: fix printk format warning
        ALSA: riptide: postfix increment and off by one
      a3d2b755
    • Theodore Ts'o's avatar
      ext4: Fix race in ext4_inode_info.i_cached_extent · 2ec0ae3a
      Theodore Ts'o authored
      
      
      If two CPU's simultaneously call ext4_ext_get_blocks() at the same
      time, there is nothing protecting the i_cached_extent structure from
      being used and updated at the same time.  This could potentially cause
      the wrong location on disk to be read or written to, including
      potentially causing the corruption of the block group descriptors
      and/or inode table.
      
      This bug has been in the ext4 code since almost the very beginning of
      ext4's development.  Fortunately once the data is stored in the page
      cache cache, ext4_get_blocks() doesn't need to be called, so trying to
      replicate this problem to the point where we could identify its root
      cause was *extremely* difficult.  Many thanks to Kevin Shanahan for
      working over several months to be able to reproduce this easily so we
      could finally nail down the cause of the corruption.
      
      Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
      Reviewed-by: default avatar"Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
      2ec0ae3a