summaryrefslogtreecommitdiff
path: root/kernel/trace
AgeCommit message (Collapse)Author
2010-10-20ring-buffer: Bind time extend and data events togetherSteven Rostedt
When the time between two timestamps is greater than 2^27 nanosecs (~134 ms) a time extend event is added that extends the time difference to 59 bits (~18 years). This is due to events only having a 27 bit field to store time. Currently this time extend is a separate event. We add it just before the event data that is being written to the buffer. But before the event data is committed, the event data can also be discarded (as with the case of filters). But because the time extend has already been committed, it will stay in the buffer. If lots of events are being filtered and no event is being written, then every 134ms a time extend can be added to the buffer without any data attached. To keep from filling the entire buffer with time extends, a time extend will never be the first event in a page because the page timestamp can be used. Time extends can only fill the rest of a page with some data at the beginning. This patch binds the time extend with the data. The difference here is that the time extend is not committed before the data is added. Instead, when a time extend is needed, the space reserved on the ring buffer is the time extend + the data event size. The time extend is added to the first part of the reserved block and the data is added to the second. The time extend event is passed back to the reserver, but since the reserver also uses a function to find the data portion of the reserved block, no changes to the ring buffer interface need to be made. When a commit is discarded, we now remove both the time extend and the event. With this approach no more than one time extend can be in the buffer in a row. Data must always follow a time extend. Thanks to Mathieu Desnoyers for suggesting this idea. Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-20ring-buffer: Pass delta by value and not by referenceSteven Rostedt
The delta between events is passed to the timestamp code by reference and the timestamp code will reset the value. But it can be reset from the caller. No need to pass it in by reference. By changing the call to pass by value, lets gcc optimize the code a bit more where it can store the delta in a register and not worry about updating the reference. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-20ring-buffer: Pass timestamp by value and not by referenceSteven Rostedt
The original code for the ring buffer had locations that modified the timestamp and that change was used by the callers. Now, the timestamp is not reused by the callers and there is no reason to pass it by reference. By changing the call to pass by value, lets gcc optimize the code a bit more where it can store the timestamp in a register and not worry about updating the reference. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-19ring-buffer: Make write slow path out of lineSteven Rostedt
Gcc inlines the slow path of the ring buffer write which can hurt performance. This patch simply forces the slow path function rb_move_tail() to always be a function. The ring_buffer_benchmark module with reader_disabled=1 shows that this patch changes the time to record an event from 135 ns to 132 ns. (3 ns or 2.22% improvement) Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-10-12ring-buffer: Fix typo of time extends per pageSteven Rostedt
Time stamps for the ring buffer are created by the difference between two events. Each page of the ring buffer holds a full 64 bit timestamp. Each event has a 27 bit delta stamp from the last event. The unit of time is nanoseconds, so 27 bits can hold ~134 milliseconds. If two events happen more than 134 milliseconds apart, a time extend is inserted to add more bits for the delta. The time extend has 59 bits, which is good for ~18 years. Currently the time extend is committed separately from the event. If an event is discarded before it is committed, due to filtering, the time extend still exists. If all events are being filtered, then after ~134 milliseconds a new time extend will be added to the buffer. This can only happen till the end of the page. Since each page holds a full timestamp, there is no reason to add a time extend to the beginning of a page. Time extends can only fill a page that has actual data at the beginning, so there is no fear that time extends will fill more than a page without any data. When reading an event, a loop is made to skip over time extends since they are only used to maintain the time stamp and are never given to the caller. As a paranoid check to prevent the loop running forever, with the knowledge that time extends may only fill a page, a check is made that tests the iteration of the loop, and if the iteration is more than the number of time extends that can fit in a page a warning is printed and the ring buffer is disabled (all of ftrace is also disabled with it). There is another event type that is called a TIMESTAMP which can hold 64 bits of data in the theoretical case that two events happen 18 years apart. This code has not been implemented, but the name of this event exists, as well as the structure for it. The size of a TIMESTAMP is 16 bytes, where as a time extend is only 8 bytes. The macro used to calculate how many time extends can fit on a page used the TIMESTAMP size instead of the time extend size cutting the amount in half. The following test case can easily trigger the warning since we only need to have half the page filled with time extends to trigger the warning: # cd /sys/kernel/debug/tracing/ # echo function > current_tracer # echo 'common_pid < 0' > events/ftrace/function/filter # echo > trace # echo 1 > trace_marker # sleep 120 # cat trace Enabling the function tracer and then setting the filter to only trace functions where the process id is negative (no events), then clearing the trace buffer to ensure that we have nothing in the buffer, then write to trace_marker to add an event to the beginning of a page, sleep for 2 minutes (only 35 seconds is probably needed, but this guarantees the bug), and then finally reading the trace which will trigger the bug. This patch fixes the typo and prevents the false positive of that warning. Reported-by: Hans J. Koch <hjk@linutronix.de> Tested-by: Hans J. Koch <hjk@linutronix.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Stable Kernel <stable@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-10Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: tracing: t_start: reset FTRACE_ITER_HASH in case of seek/pread perf symbols: Fix multiple initialization of symbol system perf: Fix CPU hotplug perf, trace: Fix module leak tracing/kprobe: Fix handling of C-unlike argument names tracing/kprobes: Fix handling of argument names perf probe: Fix handling of arguments names perf probe: Fix return probe support tracing/kprobe: Fix a memory leak in error case tracing: Do not allow llseek to set_ftrace_filter
2010-09-09tracing: t_start: reset FTRACE_ITER_HASH in case of seek/preadChris Wright
Be sure to avoid entering t_show() with FTRACE_ITER_HASH set without having properly started the iterator to iterate the hash. This case is degenerate and, as discovered by Robert Swiecki, can cause t_hash_show() to misuse a pointer. This causes a NULL ptr deref with possible security implications. Tracked as CVE-2010-3079. Cc: Robert Swiecki <swiecki@google.com> Cc: Eugene Teo <eugene@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-09perf, trace: Fix module leakLi Zefan
Commit 1c024eca (perf, trace: Optimize tracepoints by using per-tracepoint-per-cpu hlist to track events) caused a module refcount leak. Reported-And-Tested-by: Avi Kivity <avi@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4C7E1F12.8030304@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-09-08Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: gcc-4.6: kernel/*: Fix unused but set warnings mutex: Fix annotations to include it in kernel-locking docbook pid: make setpgid() system call use RCU read-side critical section MAINTAINERS: Add RCU's public git tree
2010-09-08tracing/kprobe: Fix handling of C-unlike argument namesMasami Hiramatsu
Check the argument name whether it is invalid (not C-like symbol name). This makes event format simple. Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> LKML-Reference: <20100827113912.22882.62313.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-09-08tracing/kprobes: Fix handling of argument namesMasami Hiramatsu
Set "argN" name for each argument automatically if it has no specified name. Since dynamic trace event(kprobe_events) accepts special characters for its argument, its format can show those special characters (e.g. '$', '%', '+'). However, perf can't parse those format because of the character (especially '%') mess up the format. This sets "argX" name for those arguments if user omitted the argument names. E.g. # echo 'p do_fork %ax IP=%ip $stack' > tracing/kprobe_events # cat tracing/kprobe_events p:kprobes/p_do_fork_0 do_fork arg1=%ax IP=%ip arg3=$stack Reported-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> LKML-Reference: <20100827113906.22882.59312.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-09-08tracing/kprobe: Fix a memory leak in error caseMasami Hiramatsu
Fix a memory leak which happens when a field name conflicts with others. In error case, free_trace_probe() will free all arguments until nr_args, so this increments nr_args the begining of the loop instead of the end. Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> LKML-Reference: <20100827113846.22882.12670.stgit@ltc236.sdl.hitachi.co.jp> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-09-08tracing: Do not allow llseek to set_ftrace_filterSteven Rostedt
Reading the file set_ftrace_filter does three things. 1) shows whether or not filters are set for the function tracer 2) shows what functions are set for the function tracer 3) shows what triggers are set on any functions 3 is independent from 1 and 2. The way this file currently works is that it is a state machine, and as you read it, it may change state. But this assumption breaks when you use lseek() on the file. The state machine gets out of sync and the t_show() may use the wrong pointer and cause a kernel oops. Luckily, this will only kill the app that does the lseek, but the app dies while holding a mutex. This prevents anyone else from using the set_ftrace_filter file (or any other function tracing file for that matter). A real fix for this is to rewrite the code, but that is too much for a -rc release or stable. This patch simply disables llseek on the set_ftrace_filter() file for now, and we can do the proper fix for the next major release. Reported-by: Robert Swiecki <swiecki@google.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Tavis Ormandy <taviso@google.com> Cc: Eugene Teo <eugene@redhat.com> Cc: vendor-sec@lst.de Cc: <stable@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-09-05gcc-4.6: kernel/*: Fix unused but set warningsAndi Kleen
No real bugs I believe, just some dead code. Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: andi@firstfloor.org Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-31tracing: Fix a race in function profileLi Zefan
While we are reading trace_stat/functionX and someone just disabled function_profile at that time, we can trigger this: divide error: 0000 [#1] PREEMPT SMP ... EIP is at function_stat_show+0x90/0x230 ... This fix just takes the ftrace_profile_lock and checks if rec->counter is 0. If it's 0, we know the profile buffer has been reset. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: stable@kernel.org LKML-Reference: <4C723644.4040708@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-25tracing/trace_stack: Fix stack trace on ppc64Anton Blanchard
save_stack_trace() stores the instruction pointer, not the function descriptor. On ppc64 the trace stack code currently dereferences the instruction pointer and shows 8 bytes of instructions in our backtraces: # cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (26 entries) ----- ---- -------- 0) 5424 112 0x6000000048000004 1) 5312 160 0x60000000ebad01b0 2) 5152 160 0x2c23000041c20030 3) 4992 240 0x600000007c781b79 4) 4752 160 0xe84100284800000c 5) 4592 192 0x600000002fa30000 6) 4400 256 0x7f1800347b7407e0 7) 4144 208 0xe89f0108f87f0070 8) 3936 272 0xe84100282fa30000 Since we aren't dealing with function descriptors, use %pS instead of %pF to fix it: # cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (26 entries) ----- ---- -------- 0) 5424 112 ftrace_call+0x4/0x8 1) 5312 160 .current_io_context+0x28/0x74 2) 5152 160 .get_io_context+0x48/0xa0 3) 4992 240 .cfq_set_request+0x94/0x4c4 4) 4752 160 .elv_set_request+0x60/0x84 5) 4592 192 .get_request+0x2d4/0x468 6) 4400 256 .get_request_wait+0x7c/0x258 7) 4144 208 .__make_request+0x49c/0x610 8) 3936 272 .generic_make_request+0x390/0x434 Signed-off-by: Anton Blanchard <anton@samba.org> Cc: rostedt@goodmis.org Cc: fweisbec@gmail.com LKML-Reference: <20100825013238.GE28360@kryten> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-16Merge branch 'tip/perf/urgent-3' of ↵Steven Rostedt
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into trace/tip/perf/urgent-4 Conflicts: kernel/trace/trace_events.c Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-13tracing: Sanitize value returned from write(trace_marker, "...", len)Marcin Slusarz
When userspace code writes non-new-line-terminated string to trace_marker file, write handler appends new-line and returns number of bytes written to trace buffer, so write(fd, "abc", 3) will return 4 That's unexpected and unfortunately it confuses glibc's fprintf function. Example: int main() { fprintf(stderr, "abc"); return 0; } $ gcc test.c -o test $ echo mmiotrace > /sys/kernel/debug/tracing/current_tracer $ ./test 2>/sys/kernel/debug/tracing/trace_marker results in infinite loop: write(fd, "abc", 3) = 4 write(fd, "", 1) = 0 write(fd, "", 1) = 0 write(fd, "", 1) = 0 write(fd, "", 1) = 0 write(fd, "", 1) = 0 write(fd, "", 1) = 0 write(fd, "", 1) = 0 (...) ...and kernel trace buffer full of empty markers. Fix it by sanitizing write return value. Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> LKML-Reference: <20100727231801.GB2826@joi.lan> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-12tracing/events: Convert format output to seq_fileSteven Rostedt
Two new events were added that broke the current format output. Both from the SCSI system: scsi_dispatch_cmd_done and scsi_dispatch_cmd_timeout The reason is that their print_fmt exceeded a page size. Since the output of the format used simple_read_from_buffer and trace_seq, it was limited to a page size in output. This patch converts the printing of the format of an event into seq_file, which allows greater than a page size to be shown. I diffed all event formats comparing the output with and without this patch. All matched except for the above two, which showed just: FORMAT TOO BIG without this patch, but now properly displays the output with this patch. v2: Remove updating *pos in seq start function. [ Thanks to Li Zefan for pointing that out ] Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Kei Tokunaga <tokunaga.keiich@jp.fujitsu.com> Cc: James Bottomley <James.Bottomley@suse.de> Cc: Tomohiro Kusumi <kusumi.tomohiro@jp.fujitsu.com> Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-12block: add secure discardAdrian Hunter
Secure discard is the same as discard except that all copies of the discarded sectors (perhaps created by garbage collection) must also be erased. Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com> Acked-by: Jens Axboe <axboe@kernel.dk> Cc: Kyungmin Park <kmpark@infradead.org> Cc: Madhusudhan Chikkature <madhu.cr@ti.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Ben Gardiner <bengardiner@nanometrics.ca> Cc: <linux-mmc@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-10Merge branch 'for-2.6.36' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.36' of git://git.kernel.dk/linux-2.6-block: (149 commits) block: make sure that REQ_* types are seen even with CONFIG_BLOCK=n xen-blkfront: fix missing out label blkdev: fix blkdev_issue_zeroout return value block: update request stacking methods to support discards block: fix missing export of blk_types.h writeback: fix bad _bh spinlock nesting drbd: revert "delay probes", feature is being re-implemented differently drbd: Initialize all members of sync_conf to their defaults [Bugz 315] drbd: Disable delay probes for the upcomming release writeback: cleanup bdi_register writeback: add new tracepoints writeback: remove unnecessary init_timer call writeback: optimize periodic bdi thread wakeups writeback: prevent unnecessary bdi threads wakeups writeback: move bdi threads exiting logic to the forker thread writeback: restructure bdi forker loop a little writeback: move last_active to bdi writeback: do not remove bdi from bdi_list writeback: simplify bdi code a little writeback: do not lose wake-ups in bdi threads ... Fixed up pretty trivial conflicts in drivers/block/virtio_blk.c and drivers/scsi/scsi_error.c as per Jens.
2010-08-07Merge branch 'bkl/core' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing * 'bkl/core' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing: do_coredump: Do not take BKL init: Remove the BKL from startup code
2010-08-07Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (55 commits) workqueue: mark init_workqueues() as early_initcall() workqueue: explain for_each_*cwq_cpu() iterators fscache: fix build on !CONFIG_SYSCTL slow-work: kill it gfs2: use workqueue instead of slow-work drm: use workqueue instead of slow-work cifs: use workqueue instead of slow-work fscache: drop references to slow-work fscache: convert operation to use workqueue instead of slow-work fscache: convert object to use workqueue instead of slow-work workqueue: fix how cpu number is stored in work->data workqueue: fix mayday_mask handling on UP workqueue: fix build problem on !CONFIG_SMP workqueue: fix locking in retry path of maybe_create_worker() async: use workqueue for worker pool workqueue: remove WQ_SINGLE_CPU and use WQ_UNBOUND instead workqueue: implement unbound workqueue workqueue: prepare for WQ_UNBOUND implementation libata: take advantage of cmwq and remove concurrency limitations workqueue: fix worker management invocation without pending works ... Fixed up conflicts in fs/cifs/* as per Tejun. Other trivial conflicts in include/linux/workqueue.h, kernel/trace/Kconfig and kernel/workqueue.c
2010-08-07block: push BKL into blktrace ioctlsArnd Bergmann
The blktrace driver currently needs the BKL, but we should not need to take that in the block layer, so just push it down into the driver itself. It is quite likely that the BKL is not actually required in blktrace code and could be removed in a follow-on patch. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Christoph Hellwig <hch@infradead.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07block: unify flags for struct bio and struct requestChristoph Hellwig
Remove the current bio flags and reuse the request flags for the bio, too. This allows to more easily trace the type of I/O from the filesystem down to the block driver. There were two flags in the bio that were missing in the requests: BIO_RW_UNPLUG and BIO_RW_AHEAD. Also I've renamed two request flags that had a superflous RW in them. Note that the flags are in bio.h despite having the REQ_ name - as blkdev.h includes bio.h that is the only way to go for now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-07block: remove wrappers for request type/flagsChristoph Hellwig
Remove all the trivial wrappers for the cmd_type and cmd_flags fields in struct requests. This allows much easier grepping for different request types instead of unwinding through macros. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-06Merge branch 'timers-timekeeping-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-timekeeping-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: um: Fix read_persistent_clock fallout kgdb: Do not access xtime directly powerpc: Clean up obsolete code relating to decrementer and timebase powerpc: Rework VDSO gettimeofday to prevent time going backwards clocksource: Add __clocksource_updatefreq_hz/khz methods x86: Convert common clocksources to use clocksource_register_hz/khz timekeeping: Make xtime and wall_to_monotonic static hrtimer: Cleanup direct access to wall_to_monotonic um: Convert to use read_persistent_clock timkeeping: Fix update_vsyscall to provide wall_to_monotonic offset powerpc: Cleanup xtime usage powerpc: Simplify update_vsyscall time: Kill off CONFIG_GENERIC_TIME time: Implement timespec_add x86: Fix vtime/file timestamp inconsistencies Trivial conflicts in Documentation/feature-removal-schedule.txt Much less trivial conflicts in arch/powerpc/kernel/time.c resolved as per Thomas' earlier merge commit 47916be4e28c ("Merge branch 'powerpc.cherry-picks' into timers/clocksource")
2010-08-06tracing: Fix ring_buffer_read_page reading out of page boundaryHuang Ying
With the configuration: CONFIG_DEBUG_PAGEALLOC=y and Shaohua's patch: [PATCH]x86: make spurious_fault check correct pte bit Function call graph trace with the following will trigger a page fault. # cd /sys/kernel/debug/tracing/ # echo function_graph > current_tracer # cat per_cpu/cpu1/trace_pipe_raw > /dev/null BUG: unable to handle kernel paging request at ffff880006e99000 IP: [<ffffffff81085572>] rb_event_length+0x1/0x3f PGD 1b19063 PUD 1b1d063 PMD 3f067 PTE 6e99160 Oops: 0000 [#1] SMP DEBUG_PAGEALLOC last sysfs file: /sys/devices/virtual/net/lo/operstate CPU 1 Modules linked in: Pid: 1982, comm: cat Not tainted 2.6.35-rc6-aes+ #300 /Bochs RIP: 0010:[<ffffffff81085572>] [<ffffffff81085572>] rb_event_length+0x1/0x3f RSP: 0018:ffff880006475e38 EFLAGS: 00010006 RAX: 0000000000000ff0 RBX: ffff88000786c630 RCX: 000000000000001d RDX: ffff880006e98000 RSI: 0000000000000ff0 RDI: ffff880006e99000 RBP: ffff880006475eb8 R08: 000000145d7008bd R09: 0000000000000000 R10: 0000000000008000 R11: ffffffff815d9336 R12: ffff880006d08000 R13: ffff880006e605d8 R14: 0000000000000000 R15: 0000000000000018 FS: 00007f2b83e456f0(0000) GS:ffff880002100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: ffff880006e99000 CR3: 00000000064a8000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process cat (pid: 1982, threadinfo ffff880006474000, task ffff880006e40770) Stack: ffff880006475eb8 ffffffff8108730f 0000000000000ff0 000000145d7008bd <0> ffff880006e98010 ffff880006d08010 0000000000000296 ffff88000786c640 <0> ffffffff81002956 0000000000000000 ffff8800071f4680 ffff8800071f4680 Call Trace: [<ffffffff8108730f>] ? ring_buffer_read_page+0x15a/0x24a [<ffffffff81002956>] ? return_to_handler+0x15/0x2f [<ffffffff8108a575>] tracing_buffers_read+0xb9/0x164 [<ffffffff810debfe>] vfs_read+0xaf/0x150 [<ffffffff81002941>] return_to_handler+0x0/0x2f [<ffffffff810248b0>] __bad_area_nosemaphore+0x17e/0x1a1 [<ffffffff81002941>] return_to_handler+0x0/0x2f [<ffffffff810248e6>] bad_area_nosemaphore+0x13/0x15 Code: 80 25 b2 16 b3 00 fe c9 c3 55 48 89 e5 f0 80 0d a4 16 b3 00 02 c9 c3 55 31 c0 48 89 e5 48 83 3d 94 16 b3 00 01 c9 0f 94 c0 c3 55 <8a> 0f 48 89 e5 83 e1 1f b8 08 00 00 00 0f b6 d1 83 fa 1e 74 27 RIP [<ffffffff81085572>] rb_event_length+0x1/0x3f RSP <ffff880006475e38> CR2: ffff880006e99000 ---[ end trace a6877bb92ccb36bb ]--- The root cause is that ring_buffer_read_page() may read out of page boundary, because the boundary checking is done after reading. This is fixed via doing boundary checking before reading. Reported-by: Shaohua Li <shaohua.li@intel.com> Cc: <stable@kernel.org> Signed-off-by: Huang Ying <ying.huang@intel.com> LKML-Reference: <1280297641.2771.307.camel@yhuang-dev> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-06Merge branch 'sched-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (27 commits) sched: Use correct macro to display sched_child_runs_first in /proc/sched_debug sched: No need for bootmem special cases sched: Revert nohz_ratelimit() for now sched: Reduce update_group_power() calls sched: Update rq->clock for nohz balanced cpus sched: Fix spelling of sibling sched, cpuset: Drop __cpuexit from cpu hotplug callbacks sched: Fix the racy usage of thread_group_cputimer() in fastpath_timer_check() sched: run_posix_cpu_timers: Don't check ->exit_state, use lock_task_sighand() sched: thread_group_cputime: Simplify, document the "alive" check sched: Remove the obsolete exit_state/signal hacks sched: task_tick_rt: Remove the obsolete ->signal != NULL check sched: __sched_setscheduler: Read the RLIMIT_RTPRIO value lockless sched: Fix comments to make them DocBook happy sched: Fix fix_small_capacity powerpc: Exclude arch_sd_sibiling_asym_packing() on UP powerpc: Enable asymmetric SMT scheduling on POWER7 sched: Add asymmetric group packing option for sibling domain sched: Fix capacity calculations for SMT4 sched: Change nohz idle load balancing logic to push model ...
2010-08-06Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (162 commits) tracing/kprobes: unregister_trace_probe needs to be called under mutex perf: expose event__process function perf events: Fix mmap offset determination perf, powerpc: fsl_emb: Restore setting perf_sample_data.period perf, powerpc: Convert the FSL driver to use local64_t perf tools: Don't keep unreferenced maps when unmaps are detected perf session: Invalidate last_match when removing threads from rb_tree perf session: Free the ref_reloc_sym memory at the right place x86,mmiotrace: Add support for tracing STOS instruction perf, sched migration: Librarize task states and event headers helpers perf, sched migration: Librarize the GUI class perf, sched migration: Make the GUI class client agnostic perf, sched migration: Make it vertically scrollable perf, sched migration: Parameterize cpu height and spacing perf, sched migration: Fix key bindings perf, sched migration: Ignore unhandled task states perf, sched migration: Handle ignored migrate out events perf: New migration tool overview tracing: Drop cpparg() macro perf: Use tracepoint_synchronize_unregister() to flush any pending tracepoint call ... Fix up trivial conflicts in Makefile and drivers/cpufreq/cpufreq.c
2010-08-06tracing: Fix an unallocated memory access in function_graphShaohua Li
With CONFIG_DEBUG_PAGEALLOC, I observed an unallocated memory access in function_graph trace. It appears we find a small size entry in ring buffer, but we access it as a big size entry. The access overflows the page size and touches an unallocated page. Cc: <stable@kernel.org> Signed-off-by: Shaohua Li <shaohua.li@intel.com> LKML-Reference: <1280217994.32400.76.camel@sli10-desk.sh.intel.com> [ Added a comment to explain the problem - SDR ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-08-05ftrace,kdb: Allow dumping a specific cpu's buffer with ftdumpJason Wessel
In systems with more than one processor it is desirable to look at the per cpu trace buffers. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> CC: Frederic Weisbecker <fweisbec@gmail.com>
2010-08-05ftrace,kdb: Extend kdb to be able to dump the ftrace bufferJason Wessel
Add in a helper function to allow the kdb shell to dump the ftrace buffer. Modify trace.c to expose the capability to iterate over the ftrace buffer in a read only capacity. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> CC: Frederic Weisbecker <fweisbec@gmail.com>
2010-08-04tracing/kprobes: unregister_trace_probe needs to be called under mutexSrikar Dronamraju
Comment in unregister_trace_probe() says probe_lock will be held when it gets called. However there is a case where it might called without the probe_lock being held. Also since we are traversing the probe_list and deleting an element from the probe_list, probe_lock should be held. This was first pointed in uprobes traceevent review by Frederic Weisbecker here. (http://lkml.org/lkml/2010/5/12/106) Cc: Ingo Molnar <mingo@elte.hu> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20100630084548.GA10325@linux.vnet.ibm.com> Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-08-02perf: Use tracepoint_synchronize_unregister() to flush any pending ↵Frederic Weisbecker
tracepoint call We use synchronize_sched() to ensure a tracepoint won't be called while/after we release the perf buffers it references. But the tracepoint API has its own API for that: tracepoint_synchronize_unregister(). Use it instead as it's self-explanatory and eases maintainance. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com>
2010-07-27time: Kill off CONFIG_GENERIC_TIMEJohn Stultz
Now that all arches have been converted over to use generic time via clocksources or arch_gettimeoffset(), we can remove the GENERIC_TIME config option and simplify the generic code. Signed-off-by: John Stultz <johnstul@us.ibm.com> LKML-Reference: <1279068988-21864-4-git-send-email-johnstul@us.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2010-07-23Merge branch 'tip/perf/core' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/core
2010-07-22trace: strlen() return doesn't account for the NULLDan Carpenter
We need to add one to the strlen() return because of the NULL character. The type->name here generally comes from the kernel and I don't think any of them come close to being MAX_TRACER_SIZE (100) characters long so this is basically a cleanup. Signed-off-by: Dan Carpenter <error27@gmail.com> LKML-Reference: <20100710100644.GV19184@bicker> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-07-21Merge branch 'linus' into sched/coreIngo Molnar
Merge reason: Move from the -rc3 to the almost-rc6 base. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-21tracing: Shrink max latency ringbuffer if unnecessaryKOSAKI Motohiro
Documentation/trace/ftrace.txt says buffer_size_kb: This sets or displays the number of kilobytes each CPU buffer can hold. The tracer buffers are the same size for each CPU. The displayed number is the size of the CPU buffer and not total size of all buffers. The trace buffers are allocated in pages (blocks of memory that the kernel uses for allocation, usually 4 KB in size). If the last page allocated has room for more bytes than requested, the rest of the page will be used, making the actual allocation bigger than requested. ( Note, the size may not be a multiple of the page size due to buffer management overhead. ) This can only be updated when the current_tracer is set to "nop". But it's incorrect. currently total memory consumption is 'buffer_size_kb x CPUs x 2'. Why two times difference is there? because ftrace implicitly allocate the buffer for max latency too. That makes sad result when admin want to use large buffer. (If admin want full logging and makes detail analysis). example, If admin have 24 CPUs machine and write 200MB to buffer_size_kb, the system consume ~10GB memory (200MB x 24 x 2). umm.. 5GB memory waste is usually unacceptable. Fortunatelly, almost all users don't use max latency feature. The max latency buffer can be disabled easily. This patch shrink buffer size of the max latency buffer if unnecessary. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> LKML-Reference: <20100701104554.DA2D.A69D9226@jp.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-07-20tracing: Reduce latency and remove percpu trace_seqLai Jiangshan
__print_flags() and __print_symbolic() use percpu trace_seq: 1) Its memory is allocated at compile time, it wastes memory if we don't use tracing. 2) It is percpu data and it wastes more memory for multi-cpus system. 3) It disables preemption when it executes its core routine "trace_seq_printf(s, "%s: ", #call);" and introduces latency. So we move this trace_seq to struct trace_iterator. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4C078350.7090106@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-07-20trace: Reorder struct ring_buffer_per_cpu to remove padding on 64bitRichard Kennedy
Reorder structure to remove 8 bytes of padding on 64 bit builds. This shrinks the size to 128 bytes so allowing allocation from a smaller slab & needed one fewer cache lines. Signed-off-by: Richard Kennedy <richard@rsk.demon.co.uk> LKML-Reference: <1269516456.2054.8.camel@localhost> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-07-20tracing: Allow to disable cmdline recordingLi Zefan
We found that even enabling a single trace event that will rarely be triggered can add big overhead to context switch. (lmbench context switch test) ------------------------------------------------- 2p/0K 2p/16K 2p/64K 8p/16K 8p/64K 16p/16K 16p/64K ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw ctxsw ------ ------ ------ ------ ------ ------- ------- 2.19 2.3 2.21 2.56 2.13 2.54 2.07 2.39 2.51 2.35 2.75 2.27 2.81 2.24 The overhead is 6% ~ 11%. It's because when a trace event is enabled 3 tracepoints (sched_switch, sched_wakeup, sched_wakeup_new) will be activated to map pid to cmdname. We'd like to avoid this overhead, so add a trace option '(no)record-cmd' to allow to disable cmdline recording. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4C2D57F4.2050204@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-07-20tracing: Use generic_file_llseek for debugfsArnd Bergmann
The default for llseek will change to no_llseek, so the tracing debugfs files need to add explicit .llseek assignments. Since we're dealing with regular files from a VFS perspective, use generic_file_llseek. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: John Kacur <jkacur@redhat.com> Cc: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <1278538820-1392-10-git-send-email-arnd@arndb.de> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-07-20tracing: Remove special tracesFrederic Weisbecker
Special traces type was only used by sysprof. Lets remove it now that sysprof ftrace plugin has been dropped. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Soeren Sandmann <sandmann@daimi.au.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com>
2010-07-20tracing: Remove sysprof ftrace pluginFrederic Weisbecker
The sysprof ftrace plugin doesn't seem to be seriously used somewhere. There is a branch in the sysprof tree that makes an interface to it, but the real sysprof tool uses either its own module or perf events. Drop the sysprof ftrace plugin then, as it's mostly useless. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Soeren Sandmann <sandmann@daimi.au.dk> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com>
2010-07-15tracing: Remove ksym tracerFrederic Weisbecker
The ksym (breakpoint) ftrace plugin has been superseded by perf tools that are much more poweful to use the cpu breakpoints. This tracer doesn't bring more feature. It has been deprecated for a while now, lets remove it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-07-09init: Remove the BKL from startup codeArnd Bergmann
I have shown by code review that no driver takes the BKL at init time any more, so whatever the init code was locking against is no longer there and it is now safe to remove the BKL there. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Steven Rostedt <rostedt@goodmis> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-07-05tracing/kprobes: Support "string" typeMasami Hiramatsu
Support string type tracing and printing in kprobe-tracer. This allows user to trace string data in kernel including __user data. Note that sometimes __user data may not be accessed if it is paged-out (sorry, but kprobes operation should be done in atomic, we can not wait for page-in). Commiter note: Fixed up conflicts with b7e2ece. Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20100519195724.2885.18788.stgit@localhost6.localdomain6> Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2010-06-29workqueue: temporarily remove workqueue tracingTejun Heo
Strip tracing code from workqueue and remove workqueue tracing. This is temporary measure till concurrency managed workqueue is complete. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Frederic Weisbecker <fweisbec@gmail.com>