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2010-03-10perf: Drop the obsolete profile naming for trace eventsFrederic Weisbecker
Drop the obsolete "profile" naming used by perf for trace events. Perf can now do more than simple events counting, so generalize the API naming. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jason Baron <jbaron@redhat.com>
2010-03-10perf: Take a hot regs snapshot for trace eventsFrederic Weisbecker
We are taking a wrong regs snapshot when a trace event triggers. Either we use get_irq_regs(), which gives us the interrupted registers if we are in an interrupt, or we use task_pt_regs() which gives us the state before we entered the kernel, assuming we are lucky enough to be no kernel thread, in which case task_pt_regs() returns the initial set of regs when the kernel thread was started. What we want is different. We need a hot snapshot of the regs, so that we can get the instruction pointer to record in the sample, the frame pointer for the callchain, and some other things. Let's use the new perf_fetch_caller_regs() for that. Comparison with perf record -e lock: -R -a -f -g Before: perf [kernel] [k] __do_softirq | --- __do_softirq | |--55.16%-- __open | --44.84%-- __write_nocancel After: perf [kernel] [k] perf_tp_event | --- perf_tp_event | |--41.07%-- lock_acquire | | | |--39.36%-- _raw_spin_lock | | | | | |--7.81%-- hrtimer_interrupt | | | smp_apic_timer_interrupt | | | apic_timer_interrupt The old case was producing unreliable callchains. Now having right frame and instruction pointers, we have the trace we want. Also syscalls and kprobe events already have the right regs, let's use them instead of wasting a retrieval. v2: Follow the rename perf_save_regs() -> perf_fetch_caller_regs() Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Jason Baron <jbaron@redhat.com> Cc: Archs <linux-arch@vger.kernel.org>
2010-03-03Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: add __percpu sparse annotations to what's left percpu: add __percpu sparse annotations to fs percpu: add __percpu sparse annotations to core kernel subsystems local_t: Remove leftover local.h this_cpu: Remove pageset_notifier this_cpu: Page allocator conversion percpu, x86: Generic inc / dec percpu instructions local_t: Move local.h include to ringbuffer.c and ring_buffer_benchmark.c module: Use this_cpu_xx to dynamically allocate counters local_t: Remove cpu_local_xx macros percpu: refactor the code in pcpu_[de]populate_chunk() percpu: remove compile warnings caused by __verify_pcpu_ptr() percpu: make accessors check for percpu pointer in sparse percpu: add __percpu for sparse. percpu: make access macros universal percpu: remove per_cpu__ prefix.
2010-03-01Merge branch 'for-2.6.34' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.34' of git://git.kernel.dk/linux-2.6-block: (38 commits) block: don't access jiffies when initialising io_context cfq: remove 8 bytes of padding from cfq_rb_root on 64 bit builds block: fix for "Consolidate phys_segment and hw_segment limits" cfq-iosched: quantum check tweak blktrace: perform cleanup after setup error blkdev: fix merge_bvec_fn return value checks cfq-iosched: requests "in flight" vs "in driver" clarification cciss: Fix problem with scatter gather elements in the scsi half of the driver cciss: eliminate unnecessary pointer use in cciss scsi code cciss: do not use void pointer for scsi hba data cciss: factor out scatter gather chain block mapping code cciss: fix scatter gather chain block dma direction kludge cciss: simplify scatter gather code cciss: factor out scatter gather chain block allocation and freeing cciss: detect bad alignment of scsi commands at build time cciss: clarify command list padding calculation cfq-iosched: rethink seeky detection for SSDs cfq-iosched: rework seeky detection block: remove padding from io_context on 64bit builds block: Consolidate phys_segment and hw_segment limits ...
2010-02-28blktrace: perform cleanup after setup errorDmitry Monakhov
Currently even if BLKTRACESETUP ioctl has failed user must call BLKTRACETEARDOWN to be shure what all staff was cleaned, which is contr-intuitive. Let's setup ioctl make necessery cleanup by it self. Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-02-28Merge 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: (172 commits) perf_event, amd: Fix spinlock initialization perf_event: Fix preempt warning in perf_clock() perf tools: Flush maps on COMM events perf_events, x86: Split PMU definitions into separate files perf annotate: Handle samples not at objdump output addr boundaries perf_events, x86: Remove superflous MSR writes perf_events: Simplify code by removing cpu argument to hw_perf_group_sched_in() perf_events, x86: AMD event scheduling perf_events: Add new start/stop PMU callbacks perf_events: Report the MMAP pgoff value in bytes perf annotate: Defer allocating sym_priv->hist array perf symbols: Improve debugging information about symtab origins perf top: Use a macro instead of a constant variable perf symbols: Check the right return variable perf/scripts: Tag syscall_name helper as not yet available perf/scripts: Add perf-trace-python Documentation perf/scripts: Remove unnecessary PyTuple resizes perf/scripts: Add syscall tracing scripts perf/scripts: Add Python scripting engine perf/scripts: Remove check-perf-trace from listed scripts ... Fix trivial conflict in tools/perf/util/probe-event.c
2010-02-27Merge branch 'tip/tracing/core' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/core
2010-02-27Merge branch 'tracing/core' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing into tracing/core
2010-02-26ftrace: Add function names to dangling } in function graph tracerSteven Rostedt
The function graph tracer is currently the most invasive tracer in the ftrace family. It can easily overflow the buffer even with 10megs per CPU. This means that events can often be lost. On start up, or after events are lost, if the function return is recorded but the function enter was lost, all we get to see is the exiting '}'. Here is how a typical trace output starts: [tracing] cat trace # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 0) + 91.897 us | } 0) ! 567.961 us | } 0) <========== | 0) ! 579.083 us | _raw_spin_lock_irqsave(); 0) 4.694 us | _raw_spin_unlock_irqrestore(); 0) ! 594.862 us | } 0) ! 603.361 us | } 0) ! 613.574 us | } 0) ! 623.554 us | } 0) 3.653 us | fget_light(); 0) | sock_poll() { There are a series of '}' with no matching "func() {". There's no information to what functions these ending brackets belong to. This patch adds a stack on the per cpu structure used in outputting the function graph tracer to keep track of what function was outputted. Then on a function exit event, it checks the depth to see if the function exit has a matching entry event. If it does, then it only prints the '}', otherwise it adds the function name after the '}'. This allows function exit events to show what function they belong to at trace output startup, when the entry was lost due to ring buffer overflow, or even after a new task is scheduled in. Here is what the above trace will look like after this patch: [tracing] cat trace # tracer: function_graph # # CPU DURATION FUNCTION CALLS # | | | | | | | 0) + 91.897 us | } (irq_exit) 0) ! 567.961 us | } (smp_apic_timer_interrupt) 0) <========== | 0) ! 579.083 us | _raw_spin_lock_irqsave(); 0) 4.694 us | _raw_spin_unlock_irqrestore(); 0) ! 594.862 us | } (add_wait_queue) 0) ! 603.361 us | } (__pollwait) 0) ! 613.574 us | } (tcp_poll) 0) ! 623.554 us | } (sock_poll) 0) 3.653 us | fget_light(); 0) | sock_poll() { Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-26Merge branch 'tip/tracing/core' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into tracing/core
2010-02-26Merge commit 'v2.6.33' into tracing/coreIngo Molnar
Conflicts: scripts/recordmcount.pl Merge reason: Merge up to v2.6.33. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-25tracing: Simplify memory recycle of trace_define_fieldWenji Huang
Discard freeing field->type since it is not necessary. Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Wenji Huang <wenji.huang@oracle.com> LKML-Reference: <1266997226-6833-5-git-send-email-wenji.huang@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-25tracing: Remove unnecessary variable in print_graph_returnWenji Huang
The "cpu" variable is declared at the start of the function and also within a branch, with the exact same initialization. Remove the local variable of the same name in the branch. Signed-off-by: Wenji Huang <wenji.huang@oracle.com> LKML-Reference: <1266997226-6833-3-git-send-email-wenji.huang@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-25tracing: Fix typo of info text in trace_kprobe.cWenji Huang
Signed-off-by: Wenji Huang <wenji.huang@oracle.com> LKML-Reference: <1266997226-6833-2-git-send-email-wenji.huang@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-25tracing: Fix typo in prof_sysexit_enable()Wenji Huang
Signed-off-by: Wenji Huang <wenji.huang@oracle.com> LKML-Reference: <1266997226-6833-1-git-send-email-wenji.huang@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-25tracing: Remove CONFIG_TRACE_POWER from kernel configLi Zefan
The power tracer has been converted to power trace events. Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4B84D50E.4070806@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-25tracing: Fix ftrace_event_call alignment for use with gcc 4.5Jeff Mahoney
GCC 4.5 introduces behavior that forces the alignment of structures to use the largest possible value. The default value is 32 bytes, so if some structures are defined with a 4-byte alignment and others aren't declared with an alignment constraint at all - it will align at 32-bytes. For things like the ftrace events, this results in a non-standard array. When initializing the ftrace subsystem, we traverse the _ftrace_events section and call the initialization callback for each event. When the structures are misaligned, we could be treating another part of the structure (or the zeroed out space between them) as a function pointer. This patch forces the alignment for all the ftrace_event_call structures to 4 bytes. Without this patch, the kernel fails to boot very early when built with gcc 4.5. It's trivial to check the alignment of the members of the array, so it might be worthwhile to add something to the build system to do that automatically. Unfortunately, that only covers this case. I've asked one of the gcc developers about adding a warning when this condition is seen. Cc: stable@kernel.org Signed-off-by: Jeff Mahoney <jeffm@suse.com> LKML-Reference: <4B85770B.6010901@suse.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-17tracing/kprobes: Make Kconfig dependencies genericHeiko Carstens
KPROBES_EVENT actually depends on the regs and stack access API (b1cf540f) and not on x86. So introduce a new config option which architectures can select if they have the API implemented and switch x86. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> LKML-Reference: <20100210162517.GB6933@osiris.boeblingen.de.ibm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-02-17tracing: Unify arch_syscall_addr() implementationsMike Frysinger
Most implementations of arch_syscall_addr() are the same, so create a default version in common code and move the one piece that differs (the syscall table) to asm/syscall.h. New arch ports don't have to waste time copying & pasting this simple function. The s390/sparc versions need to be different, so document why. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1264498803-17278-1-git-send-email-vapier@gentoo.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-02-14tracing/kprobes: Fix probe parsingHeiko Carstens
Trying to add a probe like: echo p:myprobe 0x10000 > /sys/kernel/debug/tracing/kprobe_events will fail since the wrong pointer is passed to strict_strtoul when trying to convert the address to an unsigned long. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <20100210162346.GA6933@osiris.boeblingen.de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-11ftrace: Allow to remove a single function from function graph filterLi Zefan
I don't see why we can only clear all functions from the filter. After patching: # echo sys_open > set_graph_function # echo sys_close >> set_graph_function # cat set_graph_function sys_open sys_close # echo '!sys_close' >> set_graph_function # cat set_graph_function sys_open Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4B726388.2000408@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-09tracing: Add correct/incorrect to sort keys for branch annotation outputSteven Rostedt
The branch annotation is a bit difficult to see the worst offenders because it only sorts by percentage: correct incorrect % Function File Line ------- --------- - -------- ---- ---- 0 163 100 qdisc_restart sch_generic.c 179 0 163 100 pfifo_fast_dequeue sch_generic.c 447 0 4 100 pskb_trim_rcsum skbuff.h 1689 0 4 100 llc_rcv llc_input.c 170 0 18 100 psmouse_interrupt psmouse-base.c 304 0 3 100 atkbd_interrupt atkbd.c 389 0 5 100 usb_alloc_dev usb.c 437 0 11 100 vsscanf vsprintf.c 1897 0 2 100 IS_ERR err.h 34 0 23 100 __rmqueue_fallback page_alloc.c 865 0 4 100 probe_wakeup_sched_switch trace_sched_wakeup.c 142 0 3 100 move_masked_irq migration.c 11 Adding the incorrect and correct values as sort keys makes this file a bit more informative: correct incorrect % Function File Line ------- --------- - -------- ---- ---- 0 366541 100 audit_syscall_entry auditsc.c 1637 0 366538 100 audit_syscall_exit auditsc.c 1685 0 115839 100 sched_info_switch sched_stats.h 269 0 74567 100 sched_info_queued sched_stats.h 222 0 66578 100 sched_info_dequeued sched_stats.h 177 0 15113 100 trace_workqueue_insertion workqueue.h 38 0 15107 100 trace_workqueue_execution workqueue.h 45 0 3622 100 syscall_trace_leave ptrace.c 1772 0 2750 100 sched_move_task sched.c 10100 0 2750 100 sched_move_task sched.c 10110 0 1815 100 pre_schedule_rt sched_rt.c 1462 0 837 100 audit_alloc auditsc.c 879 0 814 100 tcp_mss_split_point tcp_output.c 1302 Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-04ftrace: Remove record freezingMasami Hiramatsu
Remove record freezing. Because kprobes never puts probe on ftrace's mcount call anymore, it doesn't need ftrace to check whether kprobes on it. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: przemyslaw@pawelczyk.it Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20100202214925.4694.73469.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-04ftrace/alternatives: Introducing *_text_reserved functionsMasami Hiramatsu
Introducing *_text_reserved functions for checking the text address range is partially reserved or not. This patch provides checking routines for x86 smp alternatives and dynamic ftrace. Since both functions modify fixed pieces of kernel text, they should reserve and protect those from other dynamic text modifier, like kprobes. This will also be extended when introducing other subsystems which modify fixed pieces of kernel text. Dynamic text modifiers should avoid those. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: przemyslaw@pawelczyk.it Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Jim Keniston <jkenisto@us.ibm.com> Cc: Mathieu Desnoyers <compudj@krystal.dyndns.org> Cc: Jason Baron <jbaron@redhat.com> LKML-Reference: <20100202214911.4694.16587.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-02-02tracing: Fix circular dead lock in stack traceLai Jiangshan
When we cat <debugfs>/tracing/stack_trace, we may cause circular lock: sys_read() t_start() arch_spin_lock(&max_stack_lock); t_show() seq_printf(), vsnprintf() .... /* they are all trace-able, when they are traced, max_stack_lock may be required again. */ The following script can trigger this circular dead lock very easy: #!/bin/bash echo 1 > /proc/sys/kernel/stack_tracer_enabled mount -t debugfs xxx /mnt > /dev/null 2>&1 ( # make check_stack() zealous to require max_stack_lock for ((; ;)) { echo 1 > /mnt/tracing/stack_max_size } ) & for ((; ;)) { cat /mnt/tracing/stack_trace > /dev/null } To fix this bug, we increase the percpu trace_active before require the lock. Reported-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4B67D4F9.9080905@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-02-02Merge branch 'master' into percpuTejun Heo
2010-01-29Merge branch 'perf/urgent' into perf/coreIngo Molnar
Merge reason: We want to queue up a dependent patch. Also update to later -rc's. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-29tracing/kprobe: Cleanup unused return value of tracing functionsXiao Guangrong
The return values of the kprobe's tracing functions are meaningless, lets remove these. Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <4B60E9A3.2040505@cn.fujitsu.com> [fweisbec@gmail: whitespace fixes, drop useless void returns in end of functions] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-01-29perf: Factorize trace events raw sample buffer operationsXiao Guangrong
Introduce ftrace_perf_buf_prepare() and ftrace_perf_buf_submit() to gather the common code that operates on raw events sampling buffer. This cleans up redundant code between regular trace events, syscall events and kprobe events. Changelog v1->v2: - Rename function name as per Masami and Frederic's suggestion - Add __kprobes for ftrace_perf_buf_prepare() and make ftrace_perf_buf_submit() inline as per Masami's suggestion - Export ftrace_perf_buf_prepare since modules will use it Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Jason Baron <jbaron@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> LKML-Reference: <4B60E92D.9000808@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-01-29tracing: Simplify test for function_graph tracing start pointLai Jiangshan
In the function graph tracer, a calling function is to be traced only when it is enabled through the set_graph_function file, or when it is nested in an enabled function. Current code uses TSK_TRACE_FL_GRAPH to test whether it is nested or not. Looking at the code, we can get this: (trace->depth > 0) <==> (TSK_TRACE_FL_GRAPH is set) trace->depth is more explicit to tell that it is nested. So we use trace->depth directly and simplify the code. No functionality is changed. TSK_TRACE_FL_GRAPH is not removed yet, it is left for future usage. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4B4DB0B6.7040607@cn.fujitsu.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-01-26tracing/documentation: Cover new frame pointer semanticsMike Frysinger
Update the graph tracer examples to cover the new frame pointer semantics (in terms of passing it along). Move the HAVE_FUNCTION_GRAPH_FP_TEST docs out of the Kconfig, into the right place, and expand on the details. Signed-off-by: Mike Frysinger <vapier@gentoo.org> LKML-Reference: <1264165967-18938-1-git-send-email-vapier@gentoo.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-26ring-buffer: Check for end of page in iteratorSteven Rostedt
If the iterator comes to an empty page for some reason, or if the page is emptied by a consuming read. The iterator code currently does not check if the iterator is pass the contents, and may return a false entry. This patch adds a check to the ring buffer iterator to test if the current page has been completely read and sets the iterator to the next page if necessary. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-26ring-buffer: Check if ring buffer iterator has stale dataSteven Rostedt
Usually reads of the ring buffer is performed by a single task. There are two types of reads from the ring buffer. One is a consuming read which will consume the entry that was read and the next read will be the entry that follows. The other is an iterator that will let the user read the contents of the ring buffer without modifying it. When an iterator is allocated, writes to the ring buffer are disabled to protect the iterator. The problem exists when consuming reads happen while an iterator is allocated. Specifically, the kind of read that swaps out an entire page (used by splice) and replaces it with a new read. If the iterator is on the page that is swapped out, then the next read may read from this swapped out page and return garbage. This patch adds a check when reading the iterator to make sure that the iterator contents are still valid. If a consuming read has taken place, the iterator is reset. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-25tracing: Prevent kernel oops with corrupted bufferSteven Rostedt
If the contents of the ftrace ring buffer gets corrupted and the trace file is read, it could create a kernel oops (usualy just killing the user task thread). This is caused by the checking of the pid in the buffer. If the pid is negative, it still references the cmdline cache array, which could point to an invalid address. The simple fix is to test for negative PIDs. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-17tracing/kprobe: Update kprobe tracing self test for new syntaxMasami Hiramatsu
Update kprobe tracing self test for new syntax (it supports deleting individual probes, and drops $argN support) and behavior change (new probes are disabled in default). This selftest includes the following checks: - Adding function-entry probe and return probe with arguments. - Enabling these probes. - Deleting it individually. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20100114051211.7814.29436.stgit@localhost6.localdomain6> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-17tracing: Drop the tr check from the graph tracing pathFrederic Weisbecker
Each time we save a function entry from the function graph tracer, we check if the trace array is set, which is wasteful because it is set anyway before we start the tracer. All we need is to ensure we have good read and write orderings. When we set the trace array, we just need to guarantee it to be visible before starting tracing. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> LKML-Reference: <1263453795-7496-1-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-14tracing/filters: Add comment for match callbacksLi Zefan
We should be clear on 2 things: - the length parameter of a match callback includes tailing '\0'. - the string to be searched might not be NULL-terminated. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4B4E8770.7000608@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14tracing/filters: Fix MATCH_FULL filter matching for PTR_STRINGLi Zefan
MATCH_FULL matching for PTR_STRING is not working correctly: # echo 'func == vt' > events/bkl/lock_kernel/filter # echo 1 > events/bkl/lock_kernel/enable ... # cat trace Xorg-1484 [000] 1973.392586: lock_kernel: ... func=vt_ioctl() gpm-1402 [001] 1974.027740: lock_kernel: ... func=vt_ioctl() We should pass to regex.match(..., len) the length (including '\0') of the source string instead of the length of the pattern string. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4B4E8763.5070707@cn.fujitsu.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14tracing/filters: Fix MATCH_MIDDLE_ONLY filter matchingLi Zefan
The @str might not be NULL-terminated if it's of type DYN_STRING or STATIC_STRING, so we should use strnstr() instead of strstr(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4B4E8753.2000102@cn.fujitsu.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14tracing/filters: Fix MATCH_END_ONLY filter matchingLi Zefan
For '*foo' pattern, we should allow any string ending with 'foo', but event filtering incorrectly disallows strings like bar_foo_foo: Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4B4E8735.6070604@cn.fujitsu.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14tracing/filters: Fix MATCH_FRONT_ONLY filter matchingLi Zefan
MATCH_FRONT_ONLY actually is a full matching: # ./perf record -R -f -a -e lock:lock_acquire \ --filter 'name ~rcu_*' sleep 1 # ./perf trace (no output) We should pass the length of the pattern string to strncmp(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4B4E8721.5090301@cn.fujitsu.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-14ftrace: Fix MATCH_END_ONLY function filterLi Zefan
For '*foo' pattern, we should allow any string ending with 'foo', but ftrace filter incorrectly disallows strings like bar_foo_foo: # echo '*io' > set_ftrace_filter # cat set_ftrace_filter | grep 'req_bio_endio' # cat available_filter_functions | grep 'req_bio_endio' req_bio_endio Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <4B4E870E.6060607@cn.fujitsu.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-13tracing/kprobe: Drop function argument access syntaxMasami Hiramatsu
Drop function argument access syntax, because the function arguments depend on not only architecture but also compile-options and function API. And now, we have perf-probe for finding register/memory assigned to each argument. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: systemtap <systemtap@sources.redhat.com> Cc: DLE <dle-develop@lists.sourceforge.net> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Roland McGrath <roland@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Neuling <mikey@neuling.org> Cc: linuxppc-dev@ozlabs.org LKML-Reference: <20100105224648.19431.52309.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-13Merge branch 'perf/urgent' into perf/coreIngo Molnar
Merge reason: queue up dependent patch, update to -rc4 Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-01-06ring-buffer: Add rb_list_head() wrapper around new reader page next fieldSteven Rostedt
If the very unlikely case happens where the writer moves the head by one between where the head page is read and where the new reader page is assigned _and_ the writer then writes and wraps the entire ring buffer so that the head page is back to what was originally read as the head page, the page to be swapped will have a corrupted next pointer. Simple solution is to wrap the assignment of the next pointer with a rb_list_head(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06ring-buffer: Wrap a list.next reference with rb_list_head()David Sharp
This reference at the end of rb_get_reader_page() was causing off-by-one writes to the prev pointer of the page after the reader page when that page is the head page, and therefore the reader page has the RB_PAGE_HEAD flag in its list.next pointer. This eventually results in a GPF in a subsequent call to rb_set_head_page() (usually from rb_get_reader_page()) when that prev pointer is dereferenced. The dereferenced register would characteristically have an address that appears shifted left by one byte (eg, ffxxxxxxxxxxxxyy instead of ffffxxxxxxxxxxxx) due to being written at an address one byte too high. Signed-off-by: David Sharp <dhsharp@google.com> LKML-Reference: <1262826727-9090-1-git-send-email-dhsharp@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06tracing: Add stack dump to trace_printk if stacktrace option is setSteven Rostedt
If the ftrace stacktrace option is set, then add the stack dumps to trace_printk. Requested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06tracing: Consolidate protection of reader access to the ring bufferLai Jiangshan
At the beginning, access to the ring buffer was fully serialized by trace_types_lock. Patch d7350c3f4569 gives more freedom to readers, and patch b04cc6b1f6 adds code to protect trace_pipe and cpu#/trace_pipe. But actually it is not enough, ring buffer readers are not always read-only, they may consume data. This patch makes accesses to trace, trace_pipe, trace_pipe_raw cpu#/trace, cpu#/trace_pipe and cpu#/trace_pipe_raw serialized. And removes tracing_reader_cpumask which is used to protect trace_pipe. Details: Ring buffer serializes readers, but it is low level protection. The validity of the events (which returns by ring_buffer_peek() ..etc) are not protected by ring buffer. The content of events may become garbage if we allow another process to consume these events concurrently: A) the page of the consumed events may become a normal page (not reader page) in ring buffer, and this page will be rewritten by the events producer. B) The page of the consumed events may become a page for splice_read, and this page will be returned to system. This patch adds trace_access_lock() and trace_access_unlock() primitives. These primitives allow multi process access to different cpu ring buffers concurrently. These primitives don't distinguish read-only and read-consume access. Multi read-only access is also serialized. And we don't use these primitives when we open files, we only use them when we read files. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4B447D52.1050602@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06tracing: Remove show_format and related macros from TRACE_EVENTLai Jiangshan
The previous patches added the use of print_fmt string and changes the trace_define_field() function to also create the fields and format output for the event format files. text data bss dec hex filename 5857201 1355780 9336808 16549789 fc879d vmlinux 5884589 1351684 9337896 16574169 fce6d9 vmlinux-orig The above shows the size of the vmlinux after this patch set compared to the vmlinux-orig which is before the patch set. This saves us 27k on text, 1k on bss and adds just 4k of data. The total savings of 24k in size. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4B273D4D.40604@cn.fujitsu.com> Acked-by: Masami Hiramatsu <mhiramat@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2010-01-06tracing: Use defined fields and print_fmt to print formatsLai Jiangshan
The calls ftrace_format_##call() and ftrace_define_fields_##call() are almost duplicate in functionality. With the addition of the print_fmt in previous patches, these two functions can be merged into one. The trace_define_field() defines the fields and links them into the struct ftrace_event_call. The previous patches introduced the print_fmt field and this can now be used with the trace_define_field() to create the event format file fields and print_fmt field. The struct ftrace_event_call->fields are used to print the fields The struct ftrace_event_call->print_fmt is used to print the "print fmt: XXXXXXXXXXX" line. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> LKML-Reference: <4B273D49.5000006@cn.fujitsu.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>