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2015-05-13tracing: Rename struct ftrace_subsystem_dir to trace_subsystem_dirSteven Rostedt (Red Hat)1-13/+13
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structure ftrace_subsystem_dir holds the information about trace event subsystems. It should not be named ftrace, rename it to trace_subsystem_dir. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_event_name() to trace_event_name()Steven Rostedt (Red Hat)1-13/+13
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. ftrace_event_name() returns the name of an event tracepoint, has nothing to do with function tracing. Rename it to trace_event_name(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_event_buffer to trace_event_buffer.Steven Rostedt (Red Hat)1-7/+7
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The ftrace_event_buffer functions and data structures are for trace_events and not for function hooks. Rename them to trace_event_buffer*. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_event_{call,class} to trace_event_{call,class}Steven Rostedt (Red Hat)1-40/+40
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structures ftrace_event_call and ftrace_event_class have nothing to do with the function hooks, and are really trace_event structures. Rename ftrace_event_* to trace_event_*. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename ftrace_event_file to trace_event_fileSteven Rostedt (Red Hat)1-46/+46
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The structure ftrace_event_file is really about trace events and not "ftrace". Rename it to trace_event_file. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-05-13tracing: Rename (un)register_ftrace_event() to (un)register_trace_event()Steven Rostedt (Red Hat)1-5/+5
The name "ftrace" really refers to the function hook infrastructure. It is not about the trace_events. The functions (un)register_ftrace_event() is really about trace_events, and the name should be register_trace_event() instead. Also renamed ftrace_event_reg() to trace_event_reg() for the same reason. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-04-26Merge branch 'for-linus' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull fourth vfs update from Al Viro: "d_inode() annotations from David Howells (sat in for-next since before the beginning of merge window) + four assorted fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: RCU pathwalk breakage when running into a symlink overmounting something fix I_DIO_WAKEUP definition direct-io: only inc/dec inode->i_dio_count for file systems fs/9p: fix readdir() VFS: assorted d_backing_inode() annotations VFS: fs/inode.c helpers: d_inode() annotations VFS: fs/cachefiles: d_backing_inode() annotations VFS: fs library helpers: d_inode() annotations VFS: assorted weird filesystems: d_inode() annotations VFS: normal filesystems (and lustre): d_inode() annotations VFS: security/: d_inode() annotations VFS: security/: d_backing_inode() annotations VFS: net/: d_inode() annotations VFS: net/unix: d_backing_inode() annotations VFS: kernel/: d_inode() annotations VFS: audit: d_backing_inode() annotations VFS: Fix up some ->d_inode accesses in the chelsio driver VFS: Cachefiles should perform fs modifications on the top layer only VFS: AF_UNIX sockets should call mknod on the top layer only
2015-04-22Merge tag 'trace-v4.1-2' of ↵Linus Torvalds1-1/+14
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "This adds three fixes for the tracing code. The first is a bug when ftrace_dump_on_oops is triggered in atomic context and function graph tracer is the tracer that is being reported. The second fix is bad parsing of the trace_events from the kernel command line, where it would ignore specific events if the system name is used with defining the event(it enables all events within the system). The last one is a fix to the TRACE_DEFINE_ENUM(), where a check was missing to see if the ptr was incremented to the end of the string, but the loop increments it again and can miss the nul delimiter to stop processing" * tag 'trace-v4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Fix possible out of bounds memory access when parsing enums tracing: Fix incorrect enabling of trace events by boot cmdline tracing: Handle ftrace_dump() atomic context in graph_trace_open()
2015-04-17tracing: Fix possible out of bounds memory access when parsing enumsSteven Rostedt (Red Hat)1-0/+6
The code that replaces the enum names with the enum values in the tracepoints' format files could possible miss the end of string nul character. This was caused by processing things like backslashes, quotes and other tokens. After processing the tokens, a check for the nul character needed to be done before continuing the loop, because the loop incremented the pointer before doing the check, which could bypass the nul character. Link: http://lkml.kernel.org/r/552E661D.5060502@oracle.com Reported-by: Sasha Levin <sasha.levin@oracle.com> # via KASan Tested-by: Andrey Ryabinin <a.ryabinin@samsung.com> Fixes: 0c564a538aa9 "tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-04-16tracing: Fix incorrect enabling of trace events by boot cmdlineJoonsoo Kim1-1/+8
There is a problem that trace events are not properly enabled with boot cmdline. The problem is that if we pass "trace_event=kmem:mm_page_alloc" to the boot cmdline, it enables all kmem trace events, and not just the page_alloc event. This is caused by the parsing mechanism. When we parse the cmdline, the buffer contents is modified due to tokenization. And, if we use this buffer again, we will get the wrong result. Unfortunately, this buffer is be accessed three times to set trace events properly at boot time. So, we need to handle this situation. There is already code handling ",", but we need another for ":". This patch adds it. Link: http://lkml.kernel.org/r/1429159484-22977-1-git-send-email-iamjoonsoo.kim@lge.com Cc: stable@vger.kernel.org # 3.19+ Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> [ added missing return ret; ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-04-15VFS: kernel/: d_inode() annotationsDavid Howells1-2/+2
relayfs and tracefs are dealing with inodes of their own; those two act as filesystem drivers Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-14Merge tag 'trace-v4.1' of ↵Linus Torvalds1-1/+120
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "Some clean ups and small fixes, but the biggest change is the addition of the TRACE_DEFINE_ENUM() macro that can be used by tracepoints. Tracepoints have helper functions for the TP_printk() called __print_symbolic() and __print_flags() that lets a numeric number be displayed as a a human comprehensible text. What is placed in the TP_printk() is also shown in the tracepoint format file such that user space tools like perf and trace-cmd can parse the binary data and express the values too. Unfortunately, the way the TRACE_EVENT() macro works, anything placed in the TP_printk() will be shown pretty much exactly as is. The problem arises when enums are used. That's because unlike macros, enums will not be changed into their values by the C pre-processor. Thus, the enum string is exported to the format file, and this makes it useless for user space tools. The TRACE_DEFINE_ENUM() solves this by converting the enum strings in the TP_printk() format into their number, and that is what is shown to user space. For example, the tracepoint tlb_flush currently has this in its format file: __print_symbolic(REC->reason, { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" }, { TLB_REMOTE_SHOOTDOWN, "remote shootdown" }, { TLB_LOCAL_SHOOTDOWN, "local shootdown" }, { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" }) After adding: TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH); TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN); TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN); TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN); Its format file will contain this: __print_symbolic(REC->reason, { 0, "flush on task switch" }, { 1, "remote shootdown" }, { 2, "local shootdown" }, { 3, "local mm shootdown" })" * tag 'trace-v4.1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (27 commits) tracing: Add enum_map file to show enums that have been mapped writeback: Export enums used by tracepoint to user space v4l: Export enums used by tracepoints to user space SUNRPC: Export enums in tracepoints to user space mm: tracing: Export enums in tracepoints to user space irq/tracing: Export enums in tracepoints to user space f2fs: Export the enums in the tracepoints to userspace net/9p/tracing: Export enums in tracepoints to userspace x86/tlb/trace: Export enums in used by tlb_flush tracepoint tracing/samples: Update the trace-event-sample.h with TRACE_DEFINE_ENUM() tracing: Allow for modules to convert their enums to values tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their values tracing: Update trace-event-sample with TRACE_SYSTEM_VAR documentation tracing: Give system name a pointer brcmsmac: Move each system tracepoints to their own header iwlwifi: Move each system tracepoints to their own header mac80211: Move message tracepoints to their own header tracing: Add TRACE_SYSTEM_VAR to xhci-hcd tracing: Add TRACE_SYSTEM_VAR to kvm-s390 tracing: Add TRACE_SYSTEM_VAR to intel-sst ...
2015-04-08tracing: Allow for modules to convert their enums to valuesSteven Rostedt (Red Hat)1-1/+1
Update the infrastructure such that modules that declare TRACE_DEFINE_ENUM() will have those enums converted into their values in the tracepoint print fmt strings. Link: http://lkml.kernel.org/r/87vbhjp74q.fsf@rustcorp.com.au Acked-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-04-08tracing: Add TRACE_DEFINE_ENUM() macro to map enums to their valuesSteven Rostedt (Red Hat)1-0/+119
Several tracepoints use the helper functions __print_symbolic() or __print_flags() and pass in enums that do the mapping between the binary data stored and the value to print. This works well for reading the ASCII trace files, but when the data is read via userspace tools such as perf and trace-cmd, the conversion of the binary value to a human string format is lost if an enum is used, as userspace does not have access to what the ENUM is. For example, the tracepoint trace_tlb_flush() has: __print_symbolic(REC->reason, { TLB_FLUSH_ON_TASK_SWITCH, "flush on task switch" }, { TLB_REMOTE_SHOOTDOWN, "remote shootdown" }, { TLB_LOCAL_SHOOTDOWN, "local shootdown" }, { TLB_LOCAL_MM_SHOOTDOWN, "local mm shootdown" }) Which maps the enum values to the strings they represent. But perf and trace-cmd do no know what value TLB_LOCAL_MM_SHOOTDOWN is, and would not be able to map it. With TRACE_DEFINE_ENUM(), developers can place these in the event header files and ftrace will convert the enums to their values: By adding: TRACE_DEFINE_ENUM(TLB_FLUSH_ON_TASK_SWITCH); TRACE_DEFINE_ENUM(TLB_REMOTE_SHOOTDOWN); TRACE_DEFINE_ENUM(TLB_LOCAL_SHOOTDOWN); TRACE_DEFINE_ENUM(TLB_LOCAL_MM_SHOOTDOWN); $ cat /sys/kernel/debug/tracing/events/tlb/tlb_flush/format [...] __print_symbolic(REC->reason, { 0, "flush on task switch" }, { 1, "remote shootdown" }, { 2, "local shootdown" }, { 3, "local mm shootdown" }) The above is what userspace expects to see, and tools do not need to be modified to parse them. Link: http://lkml.kernel.org/r/20150403013802.220157513@goodmis.org Cc: Guilherme Cox <cox@computer.org> Cc: Tony Luck <tony.luck@gmail.com> Cc: Xie XiuQi <xiexiuqi@huawei.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-12Merge tag 'trace-v3.20' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "The updates included in this pull request for ftrace are: o Several clean ups to the code One such clean up was to convert to 64 bit time keeping, in the ring buffer benchmark code. o Adding of __print_array() helper macro for TRACE_EVENT() o Updating the sample/trace_events/ to add samples of different ways to make trace events. Lots of features have been added since the sample code was made, and these features are mostly unknown. Developers have been making their own hacks to do things that are already available. o Performance improvements. Most notably, I found a performance bug where a waiter that is waiting for a full page from the ring buffer will see that a full page is not available, and go to sleep. The sched event caused by it going to sleep would cause it to wake up again. It would see that there was still not a full page, and go back to sleep again, and that would wake it up again, until finally it would see a full page. This change has been marked for stable. Other improvements include removing global locks from fast paths" * tag 'trace-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Do not wake up a splice waiter when page is not full tracing: Fix unmapping loop in tracing_mark_write tracing: Add samples of DECLARE_EVENT_CLASS() and DEFINE_EVENT() tracing: Add TRACE_EVENT_FN example tracing: Add TRACE_EVENT_CONDITION sample tracing: Update the TRACE_EVENT fields available in the sample code tracing: Separate out initializing top level dir from instances tracing: Make tracing_init_dentry_tr() static trace: Use 64-bit timekeeping tracing: Add array printing helper tracing: Remove newline from trace_printk warning banner tracing: Use IS_ERR() check for return value of tracing_init_dentry() tracing: Remove unneeded includes of debugfs.h and fs.h tracing: Remove taking of trace_types_lock in pipe files tracing: Add ref count to tracer for when they are being read by pipe
2015-02-03tracing: Convert the tracing facility over to use tracefsSteven Rostedt (Red Hat)1-16/+16
debugfs was fine for the tracing facility as a quick way to get an interface. Now that tracing has matured, it should separate itself from debugfs such that it can be mounted separately without needing to mount all of debugfs with it. That is, users resist using tracing because it requires mounting debugfs. Having tracing have its own file system lets users get the features of tracing without needing to bring in the rest of the kernel's debug infrastructure. Another reason for tracefs is that debubfs does not support mkdir. Currently, to create instances, one does a mkdir in the tracing/instance directory. This is implemented via a hack that forces debugfs to do something it is not intended on doing. By converting over to tracefs, this hack can be removed and mkdir can be properly implemented. This patch does not address this yet, but it lays the ground work for that to be done. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-02-02Merge branch 'debugfs_automount' of ↵Steven Rostedt (Red Hat)1-14/+55
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs into trace/ftrace/tracefs Pull in Al Viro's changes to debugfs that implement the new primitive: debugfs_create_automount(), that creates a directory in debugfs that will safely mount another file system automatically when debugfs is mounted. This will let tracefs automount itself on top of debugfs/tracing directory.
2015-01-22tracing: Use IS_ERR() check for return value of tracing_init_dentry()Steven Rostedt (Red Hat)1-1/+1
tracing_init_dentry() will soon return NULL as a valid pointer for the top level tracing directroy. NULL can not be used as an error value. Instead, switch to ERR_PTR() and check the return status with IS_ERR(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2015-01-15tracing: Fix enabling of syscall events on the command lineSteven Rostedt (Red Hat)1-14/+55
Commit 5f893b2639b2 "tracing: Move enabling tracepoints to just after rcu_init()" broke the enabling of system call events from the command line. The reason was that the enabling of command line trace events was moved before PID 1 started, and the syscall tracepoints require that all tasks have the TIF_SYSCALL_TRACEPOINT flag set. But the swapper task (pid 0) is not part of that. Since the swapper task is the only task that is running at this early in boot, no task gets the flag set, and the tracepoint never gets reached. Instead of setting the swapper task flag (there should be no reason to do that), re-enabled trace events again after the init thread (PID 1) has been started. It requires disabling all command line events and re-enabling them, as just enabling them again will not reset the logic to set the TIF_SYSCALL_TRACEPOINT flag, as the syscall tracepoint will be fooled into thinking that it was already set, and wont try setting it again. For this reason, we must first disable it and re-enable it. Link: http://lkml.kernel.org/r/1421188517-18312-1-git-send-email-mpe@ellerman.id.au Link: http://lkml.kernel.org/r/20150115040506.216066449@goodmis.org Reported-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-16Merge tag 'trace-3.19-2' of ↵Linus Torvalds1-2/+40
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "As the merge window is still open, and this code was not as complex as I thought it might be. I'm pushing this in now. This will allow Thomas to debug his irq work for 3.20. This adds two new features: 1) Allow traceopoints to be enabled right after mm_init(). By passing in the trace_event= kernel command line parameter, tracepoints can be enabled at boot up. For debugging things like the initialization of interrupts, it is needed to have tracepoints enabled very early. People have asked about this before and this has been on my todo list. As it can be helpful for Thomas to debug his upcoming 3.20 IRQ work, I'm pushing this now. This way he can add tracepoints into the IRQ set up and have users enable them when things go wrong. 2) Have the tracepoints printed via printk() (the console) when they are triggered. If the irq code locks up or reboots the box, having the tracepoint output go into the kernel ring buffer is useless for debugging. But being able to add the tp_printk kernel command line option along with the trace_event= option will have these tracepoints printed as they occur, and that can be really useful for debugging early lock up or reboot problems. This code is not that intrusive and it passed all my tests. Thomas tried them out too and it works for his needs. Link: http://lkml.kernel.org/r/20141214201609.126831471@goodmis.org" * tag 'trace-3.19-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Add tp_printk cmdline to have tracepoints go to printk() tracing: Move enabling tracepoints to just after rcu_init()
2014-12-15tracing: Add tp_printk cmdline to have tracepoints go to printk()Steven Rostedt (Red Hat)1-0/+32
Add the kernel command line tp_printk option that will have tracepoints that are active sent to printk() as well as to the trace buffer. Passing "tp_printk" will activate this. To turn it off, the sysctl /proc/sys/kernel/tracepoint_printk can have '0' echoed into it. Note, this only works if the cmdline option is used. Echoing 1 into the sysctl file without the cmdline option will have no affect. Note, this is a dangerous option. Having high frequency tracepoints send their data to printk() can possibly cause a live lock. This is another reason why this is only active if the command line option is used. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanos Suggested-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-15tracing: Move enabling tracepoints to just after rcu_init()Steven Rostedt (Red Hat)1-2/+8
Enabling tracepoints at boot up can be very useful. The tracepoint can be initialized right after RCU has been. There's no need to wait for the early_initcall() to be called. That's too late for some things that can use tracepoints for debugging. Move the logic to enable tracepoints out of the initcalls and into init/main.c to right after rcu_init(). This also allows trace_printk() to be used early too. Link: http://lkml.kernel.org/r/alpine.DEB.2.11.1412121539300.16494@nanos Link: http://lkml.kernel.org/r/20141214164104.307127356@goodmis.org Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-12-10Merge tag 'trace-seq-buf-3.19' of ↵Linus Torvalds1-3/+6
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull nmi-safe seq_buf printk update from Steven Rostedt: "This code is a fork from the trace-3.19 pull as it needed the trace_seq clean ups from that branch. This code solves the issue of performing stack dumps from NMI context. The issue is that printk() is not safe from NMI context as if the NMI were to trigger when a printk() was being performed, the NMI could deadlock from the printk() internal locks. This has been seen in practice. With lots of review from Petr Mladek, this code went through several iterations, and we feel that it is now at a point of quality to be accepted into mainline. Here's what is contained in this patch set: - Creates a "seq_buf" generic buffer utility that allows a descriptor to be passed around where functions can write their own "printk()" formatted strings into it. The generic version was pulled out of the trace_seq() code that was made specifically for tracing. - The seq_buf code was change to model the seq_file code. I have a patch (not included for 3.19) that converts the seq_file.c code over to use seq_buf.c like the trace_seq.c code does. This was done to make sure that seq_buf.c is compatible with seq_file.c. I may try to get that patch in for 3.20. - The seq_buf.c file was moved to lib/ to remove it from being dependent on CONFIG_TRACING. - The printk() was updated to allow for a per_cpu "override" of the internal calls. That is, instead of writing to the console, a call to printk() may do something else. This made it easier to allow the NMI to change what printk() does in order to call dump_stack() without needing to update that code as well. - Finally, the dump_stack from all CPUs via NMI code was converted to use the seq_buf code. The caller to trigger the NMI code would wait till all the NMIs finished, and then it would print the seq_buf data to the console safely from a non NMI context One added bonus is that this code also makes the NMI dump stack work on PREEMPT_RT kernels. As printk() includes sleeping locks on PREEMPT_RT, printk() only writes to console if the console does not use any rt_mutex converted spin locks. Which a lot do" * tag 'trace-seq-buf-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: x86/nmi: Fix use of unallocated cpumask_var_t printk/percpu: Define printk_func when printk is not defined x86/nmi: Perform a safe NMI stack trace on all CPUs printk: Add per_cpu printk func to allow printk to be diverted seq_buf: Move the seq_buf code to lib/ seq-buf: Make seq_buf_bprintf() conditional on CONFIG_BINARY_PRINTF tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions tracing: Have seq_buf use full buffer seq_buf: Add seq_buf_can_fit() helper function tracing: Add paranoid size check in trace_printk_seq() tracing: Use trace_seq_used() and seq_buf_used() instead of len tracing: Clean up tracing_fill_pipe_page() seq_buf: Create seq_buf_used() to find out how much was written tracing: Add a seq_buf_clear() helper and clear len and readpos in init tracing: Convert seq_buf fields to be like seq_file fields tracing: Convert seq_buf_path() to be like seq_path() tracing: Create seq_buf layer in trace_seq
2014-12-10Merge tag 'trace-3.19' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "There was a lot of clean ups and minor fixes. One of those clean ups was to the trace_seq code. It also removed the return values to the trace_seq_*() functions and use trace_seq_has_overflowed() to see if the buffer filled up or not. This is similar to work being done to the seq_file code as well in another tree. Some of the other goodies include: - Added some "!" (NOT) logic to the tracing filter. - Fixed the frame pointer logic to the x86_64 mcount trampolines - Added the logic for dynamic trampolines on !CONFIG_PREEMPT systems. That is, the ftrace trampoline can be dynamically allocated and be called directly by functions that only have a single hook to them" * tag 'trace-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (55 commits) tracing: Truncated output is better than nothing tracing: Add additional marks to signal very large time deltas Documentation: describe trace_buf_size parameter more accurately tracing: Allow NOT to filter AND and OR clauses tracing: Add NOT to filtering logic ftrace/fgraph/x86: Have prepare_ftrace_return() take ip as first parameter ftrace/x86: Get rid of ftrace_caller_setup ftrace/x86: Have save_mcount_regs macro also save stack frames if needed ftrace/x86: Add macro MCOUNT_REG_SIZE for amount of stack used to save mcount regs ftrace/x86: Simplify save_mcount_regs on getting RIP ftrace/x86: Have save_mcount_regs store RIP in %rdi for first parameter ftrace/x86: Rename MCOUNT_SAVE_FRAME and add more detailed comments ftrace/x86: Move MCOUNT_SAVE_FRAME out of header file ftrace/x86: Have static tracing also use ftrace_caller_setup ftrace/x86: Have static function tracing always test for function graph kprobes: Add IPMODIFY flag to kprobe_ftrace_ops ftrace, kprobes: Support IPMODIFY flag to find IP modify conflict kprobes/ftrace: Recover original IP if pre_handler doesn't change it tracing/trivial: Fix typos and make an int into a bool tracing: Deletion of an unnecessary check before iput() ...
2014-11-19tracing: Use trace_seq_used() and seq_buf_used() instead of lenSteven Rostedt (Red Hat)1-3/+6
As the seq_buf->len will soon be +1 size when there's an overflow, we must use trace_seq_used() or seq_buf_used() methods to get the real length. This will prevent buffer overflow issues if just the len of the seq_buf descriptor is used to copy memory. Link: http://lkml.kernel.org/r/20141114121911.09ba3d38@gandalf.local.home Reported-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-19tracing: Create seq_buf layer in trace_seqSteven Rostedt (Red Hat)1-3/+3
Create a seq_buf layer that trace_seq sits on. The seq_buf will not be limited to page size. This will allow other usages of seq_buf instead of a hard set PAGE_SIZE one that trace_seq has. Link: http://lkml.kernel.org/r/20141104160221.864997179@goodmis.org Link: http://lkml.kernel.org/r/20141114011412.170377300@goodmis.org Tested-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Jiri Kosina <jkosina@suse.cz> Reviewed-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-13tracing: Replace seq_printf by simpler equivalentsRasmus Villemoes1-2/+2
Using seq_printf to print a simple string or a single character is a lot more expensive than it needs to be, since seq_puts and seq_putc exist. These patches do seq_printf(m, s) -> seq_puts(m, s) seq_printf(m, "%s", s) -> seq_puts(m, s) seq_printf(m, "%c", c) -> seq_putc(m, c) Subsequent patches will simplify further. Link: http://lkml.kernel.org/r/1415479332-25944-2-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-11-03move d_rcu from overlapping d_child to overlapping d_aliasAl Viro1-1/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-08tracing: Robustify wait loopPeter Zijlstra1-1/+4
The pending nested sleep debugging triggered on the potential stale TASK_INTERRUPTIBLE in this code. While there, fix the loop such that we won't revert to a while(1) yield() 'spin' loop if we ever get a spurious wakeup. And fix the actual issue by properly terminating the 'wait' loop by setting TASK_RUNNING. Link: http://lkml.kernel.org/p/20141008165110.GA14547@worktop.programming.kicks-ass.net Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-08-04Merge tag 'trace-3.17-2' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing filter cleanups from Steven Rostedt: "Oleg Nesterov did several clean ups with the tracing filter code. As he found some small bugs that went into 3.16, and these changes were based on that, I had to apply his changes to a separate branch than my main development branch. This was based on work that was already pulled into 3.16, and is a separate pull request to keep from having local merges in my pull request" * tag 'trace-3.17-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Kill "filter_string" arg of replace_preds() tracing: Change apply_subsystem_event_filter() paths to check file->system == dir tracing: Kill ftrace_event_call->files tracing/uprobes: Kill the dead TRACE_EVENT_FL_USE_CALL_FILTER logic tracing: Kill call_filter_disable() tracing: Kill destroy_call_preds() tracing: Kill destroy_preds() and destroy_file_preds()
2014-08-04Merge tag 'trace-3.17' of ↵Linus Torvalds1-29/+27
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "This pull request has a lot of work done. The main thing is the changes to the ftrace function callback infrastructure. It's introducing a way to allow different functions to call directly different trampolines instead of all calling the same "mcount" one. The only user of this for now is the function graph tracer, which always had a different trampoline, but the function tracer trampoline was called and did basically nothing, and then the function graph tracer trampoline was called. The difference now, is that the function graph tracer trampoline can be called directly if a function is only being traced by the function graph trampoline. If function tracing is also happening on the same function, the old way is still done. The accounting for this takes up more memory when function graph tracing is activated, as it needs to keep track of which functions it uses. I have a new way that wont take as much memory, but it's not ready yet for this merge window, and will have to wait for the next one. Another big change was the removal of the ftrace_start/stop() calls that were used by the suspend/resume code that stopped function tracing when entering into suspend and resume paths. The stop of ftrace was done because there was some function that would crash the system if one called smp_processor_id()! The stop/start was a big hammer to solve the issue at the time, which was when ftrace was first introduced into Linux. Now ftrace has better infrastructure to debug such issues, and I found the problem function and labeled it with "notrace" and function tracing can now safely be activated all the way down into the guts of suspend and resume Other changes include clean ups of uprobe code, clean up of the trace_seq() code, and other various small fixes and clean ups to ftrace and tracing" * tag 'trace-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (57 commits) ftrace: Add warning if tramp hash does not match nr_trampolines ftrace: Fix trampoline hash update check on rec->flags ring-buffer: Use rb_page_size() instead of open coded head_page size ftrace: Rename ftrace_ops field from trampolines to nr_trampolines tracing: Convert local function_graph functions to static ftrace: Do not copy old hash when resetting tracing: let user specify tracing_thresh after selecting function_graph ring-buffer: Always run per-cpu ring buffer resize with schedule_work_on() tracing: Remove function_trace_stop and HAVE_FUNCTION_TRACE_MCOUNT_TEST s390/ftrace: remove check of obsolete variable function_trace_stop arm64, ftrace: Remove check of obsolete variable function_trace_stop Blackfin: ftrace: Remove check of obsolete variable function_trace_stop metag: ftrace: Remove check of obsolete variable function_trace_stop microblaze: ftrace: Remove check of obsolete variable function_trace_stop MIPS: ftrace: Remove check of obsolete variable function_trace_stop parisc: ftrace: Remove check of obsolete variable function_trace_stop sh: ftrace: Remove check of obsolete variable function_trace_stop sparc64,ftrace: Remove check of obsolete variable function_trace_stop tile: ftrace: Remove check of obsolete variable function_trace_stop ftrace: x86: Remove check of obsolete variable function_trace_stop ...
2014-07-16tracing: Kill destroy_call_preds()Oleg Nesterov1-1/+2
Remove destroy_call_preds(). Its only caller, __trace_remove_event_call(), can use free_event_filter() and nullify ->filter by hand. Perhaps we could keep this trivial helper although imo it is pointless, but then it should be static in trace_events.c. Link: http://lkml.kernel.org/p/20140715184816.GA20495@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-16tracing: Kill destroy_preds() and destroy_file_preds()Oleg Nesterov1-1/+0
destroy_preds() makes no sense. The only caller, event_remove(), actually wants destroy_file_preds(). __trace_remove_event_call() does destroy_call_preds() which takes care of call->filter. And after the previous change we can simply remove destroy_preds() from event_remove(), we are going to call remove_event_from_tracers() which in turn calls remove_event_file_dir()->free_event_filter(). Link: http://lkml.kernel.org/p/20140715184813.GA20488@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-14tracing: instance_rmdir() leaks ftrace_event_file->filterOleg Nesterov1-0/+1
instance_rmdir() path destroys the event files but forgets to free file->filter. Change remove_event_file_dir() to free_event_filter(). Link: http://lkml.kernel.org/p/20140711190638.GA19517@redhat.com Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Tom Zanussi <tom.zanussi@linux.intel.com> Cc: "zhangwei(Jovi)" <jovi.zhangwei@huawei.com> Cc: stable@vger.kernel.org # 3.11+ Fixes: f6a84bdc75b5 "tracing: Introduce remove_event_file_dir()" Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-07-01tracing: Convert pr_warning() to pr_warn() in trace_events.cFabian Frederick1-29/+27
Convert pr_warning to standard pr_warn Define pr_fmt(fmt) fmt to avoid any future default fmt definition Link: http://lkml.kernel.org/p/1402141388-21144-1-git-send-email-fabf@skynet.be Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-06-06tracing: Return error if ftrace_trace_arrays list is emptyYoshihiro YUNOMAE1-0/+13
ftrace_trace_arrays links global_trace.list. However, global_trace is not added to ftrace_trace_arrays if trace_alloc_buffers() failed. As the result, ftrace_trace_arrays becomes an empty list. If ftrace_trace_arrays is an empty list, current top_trace_array() returns an invalid pointer. As the result, the kernel can induce memory corruption or panic. Current implementation does not check whether ftrace_trace_arrays is empty list or not. So, in this patch, if ftrace_trace_arrays is empty list, top_trace_array() returns NULL. Moreover, this patch makes all functions calling top_trace_array() handle it appropriately. Link: http://lkml.kernel.org/p/20140605223517.32311.99233.stgit@yunodevel Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-04-08tracepoint: Use struct pointer instead of name hash for reg/unreg tracepointsMathieu Desnoyers1-23/+32
Register/unregister tracepoint probes with struct tracepoint pointer rather than tracepoint name. This change, which vastly simplifies tracepoint.c, has been proposed by Steven Rostedt. It also removes 8.8kB (mostly of text) to the vmlinux size. From this point on, the tracers need to pass a struct tracepoint pointer to probe register/unregister. A probe can now only be connected to a tracepoint that exists. Moreover, tracers are responsible for unregistering the probe before the module containing its associated tracepoint is unloaded. text data bss dec hex filename 10443444 4282528 10391552 25117524 17f4354 vmlinux.orig 10434930 4282848 10391552 25109330 17f2352 vmlinux Link: http://lkml.kernel.org/r/1396992381-23785-2-git-send-email-mathieu.desnoyers@efficios.com CC: Ingo Molnar <mingo@kernel.org> CC: Frederic Weisbecker <fweisbec@gmail.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Frank Ch. Eigler <fche@redhat.com> CC: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> [ SDR - fixed return val in void func in tracepoint_module_going() ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-04-03Merge tag 'trace-3.15' of ↵Linus Torvalds1-0/+30
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "Most of the changes were largely clean ups, and some documentation. But there were a few features that were added: Uprobes now work with event triggers and multi buffers and have support under ftrace and perf. The big feature is that the function tracer can now be used within the multi buffer instances. That is, you can now trace some functions in one buffer, others in another buffer, all functions in a third buffer and so on. They are basically agnostic from each other. This only works for the function tracer and not for the function graph trace, although you can have the function graph tracer running in the top level buffer (or any tracer for that matter) and have different function tracing going on in the sub buffers" * tag 'trace-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (45 commits) tracing: Add BUG_ON when stack end location is over written tracepoint: Remove unused API functions Revert "tracing: Move event storage for array from macro to standalone function" ftrace: Constify ftrace_text_reserved tracepoints: API doc update to tracepoint_probe_register() return value tracepoints: API doc update to data argument ftrace: Fix compilation warning about control_ops_free ftrace/x86: BUG when ftrace recovery fails ftrace: Warn on error when modifying ftrace function ftrace: Remove freelist from struct dyn_ftrace ftrace: Do not pass data to ftrace_dyn_arch_init ftrace: Pass retval through return in ftrace_dyn_arch_init() ftrace: Inline the code from ftrace_dyn_table_alloc() ftrace: Cleanup of global variables ftrace_new_pgs and ftrace_update_cnt tracing: Evaluate len expression only once in __dynamic_array macro tracing: Correctly expand len expressions from __dynamic_array macro tracing/module: Replace include of tracepoint.h with jump_label.h in module.h tracing: Fix event header migrate.h to include tracepoint.h tracing: Fix event header writeback.h to include tracepoint.h tracing: Warn if a tracepoint is not set via debugfs ...
2014-03-21Revert "tracing: Move event storage for array from macro to standalone function"Steven Rostedt (Red Hat)1-0/+6
I originally wrote commit 35bb4399bd0e to shrink the size of the overhead of tracepoints by several kilobytes. Later, I received a patch from Vaibhav Nagarnaik that fixed a bug in the same code that this commit touches. Not only did it fix a bug, it also removed code and shrunk the size of the overhead of trace events even more than this commit did. Since this commit is scheduled for 3.15 and Vaibhav's patch is already in mainline, I need to revert this patch in order to keep it from conflicting with Vaibhav's patch. Not to mention, Vaibhav's patch makes this patch obsolete. Link: http://lkml.kernel.org/r/20140320225637.0226041b@gandalf.local.home Cc: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-03-20tracing: Fix array size mismatch in format stringVaibhav Nagarnaik1-6/+0
In event format strings, the array size is reported in two locations. One in array subscript and then via the "size:" attribute. The values reported there have a mismatch. For e.g., in sched:sched_switch the prev_comm and next_comm character arrays have subscript values as [32] where as the actual field size is 16. name: sched_switch ID: 301 format: field:unsigned short common_type; offset:0; size:2; signed:0; field:unsigned char common_flags; offset:2; size:1; signed:0; field:unsigned char common_preempt_count; offset:3; size:1;signed:0; field:int common_pid; offset:4; size:4; signed:1; field:char prev_comm[32]; offset:8; size:16; signed:1; field:pid_t prev_pid; offset:24; size:4; signed:1; field:int prev_prio; offset:28; size:4; signed:1; field:long prev_state; offset:32; size:8; signed:1; field:char next_comm[32]; offset:40; size:16; signed:1; field:pid_t next_pid; offset:56; size:4; signed:1; field:int next_prio; offset:60; size:4; signed:1; After bisection, the following commit was blamed: 92edca0 tracing: Use direct field, type and system names This commit removes the duplication of strings for field->name and field->type assuming that all the strings passed in __trace_define_field() are immutable. This is not true for arrays, where the type string is created in event_storage variable and field->type for all array fields points to event_storage. Use __stringify() to create a string constant for the type string. Also, get rid of event_storage and event_storage_mutex that are not needed anymore. also, an added benefit is that this reduces the overhead of events a bit more: text data bss dec hex filename 8424787 2036472 1302528 11763787 b3804b vmlinux 8420814 2036408 1302528 11759750 b37086 vmlinux.patched Link: http://lkml.kernel.org/r/1392349908-29685-1-git-send-email-vnagarnaik@google.com Cc: Laurent Chavey <chavey@google.com> Cc: stable@vger.kernel.org # 3.10+ Signed-off-by: Vaibhav Nagarnaik <vnagarnaik@google.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-03-07tracing: Use helper functions in event assignment to shrink macro sizeSteven Rostedt1-0/+30
The functions that assign the contents for the ftrace events are defined by the TRACE_EVENT() macros. Each event has its own unique way to assign data to its buffer. When you have over 500 events, that means there's 500 functions assigning data uniquely for each event (not really that many, as DECLARE_EVENT_CLASS() and multiple DEFINE_EVENT()s will only need a single function). By making helper functions in the core kernel to do some of the work instead, we can shrink the size of the kernel down a bit. With a kernel configured with 502 events, the change in size was: text data bss dec hex filename 12987390 1913504 9785344 24686238 178ae9e /tmp/vmlinux 12959102 1913504 9785344 24657950 178401e /tmp/vmlinux.patched That's a total of 28288 bytes, which comes down to 56 bytes per event. Link: http://lkml.kernel.org/r/20120810034708.370808175@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-03-07tracing: Move event storage for array from macro to standalone functionSteven Rostedt1-6/+0
The code that shows array fields for events is defined for all events. This can add up quite a bit when you have over 500 events. By making helper functions in the core kernel to do the work instead, we can shrink the size of the kernel down a bit. With a kernel configured with 502 events, the change in size was: text data bss dec hex filename 12990946 1913568 9785344 24689858 178bcc2 /tmp/vmlinux 12987390 1913504 9785344 24686238 178ae9e /tmp/vmlinux.patched That's a total of 3556 bytes, which comes down to 7 bytes per event. Although it's not much, this code is just called at initialization of the events. Link: http://lkml.kernel.org/r/20120810034708.084036335@goodmis.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2014-03-03tracing: Do not add event files for modules that fail tracepointsSteven Rostedt (Red Hat)1-0/+10
If a module fails to add its tracepoints due to module tainting, do not create the module event infrastructure in the debugfs directory. As the events will not work and worse yet, they will silently fail, making the user wonder why the events they enable do not display anything. Having a warning on module load and the events not visible to the users will make the cause of the problem much clearer. Link: http://lkml.kernel.org/r/20140227154923.265882695@goodmis.org Fixes: 6d723736e472 "tracing/events: add support for modules to TRACE_EVENT" Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: stable@vger.kernel.org # 2.6.31+ Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-21tracing: Move ftrace_event_file() out of DYNAMIC_FTRACE ifdefSteven Rostedt (Red Hat)1-13/+13
Now that event triggers use ftrace_event_file(), it needs to be outside the #ifdef CONFIG_DYNAMIC_FTRACE, as it can now be used when that is not defined. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-21tracing: Add 'enable_event' and 'disable_event' event trigger commandsTom Zanussi1-1/+1
Add 'enable_event' and 'disable_event' event_command commands. enable_event and disable_event event triggers are added by the user via these commands in a similar way and using practically the same syntax as the analagous 'enable_event' and 'disable_event' ftrace function commands, but instead of writing to the set_ftrace_filter file, the enable_event and disable_event triggers are written to the per-event 'trigger' files: echo 'enable_event:system:event' > .../othersys/otherevent/trigger echo 'disable_event:system:event' > .../othersys/otherevent/trigger The above commands will enable or disable the 'system:event' trace events whenever the othersys:otherevent events are hit. This also adds a 'count' version that limits the number of times the command will be invoked: echo 'enable_event:system:event:N' > .../othersys/otherevent/trigger echo 'disable_event:system:event:N' > .../othersys/otherevent/trigger Where N is the number of times the command will be invoked. The above commands will will enable or disable the 'system:event' trace events whenever the othersys:otherevent events are hit, but only N times. This also makes the find_event_file() helper function extern, since it's useful to use from other places, such as the event triggers code, so make it accessible. Link: http://lkml.kernel.org/r/f825f3048c3f6b026ee37ae5825f9fc373451828.1382622043.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-20tracing: Add basic event trigger frameworkTom Zanussi1-5/+16
Add a 'trigger' file for each trace event, enabling 'trace event triggers' to be set for trace events. 'trace event triggers' are patterned after the existing 'ftrace function triggers' implementation except that triggers are written to per-event 'trigger' files instead of to a single file such as the 'set_ftrace_filter' used for ftrace function triggers. The implementation is meant to be entirely separate from ftrace function triggers, in order to keep the respective implementations relatively simple and to allow them to diverge. The event trigger functionality is built on top of SOFT_DISABLE functionality. It adds a TRIGGER_MODE bit to the ftrace_event_file flags which is checked when any trace event fires. Triggers set for a particular event need to be checked regardless of whether that event is actually enabled or not - getting an event to fire even if it's not enabled is what's already implemented by SOFT_DISABLE mode, so trigger mode directly reuses that. Event trigger essentially inherit the soft disable logic in __ftrace_event_enable_disable() while adding a bit of logic and trigger reference counting via tm_ref on top of that in a new trace_event_trigger_enable_disable() function. Because the base __ftrace_event_enable_disable() code now needs to be invoked from outside trace_events.c, a wrapper is also added for those usages. The triggers for an event are actually invoked via a new function, event_triggers_call(), and code is also added to invoke them for ftrace_raw_event calls as well as syscall events. The main part of the patch creates a new trace_events_trigger.c file to contain the trace event triggers implementation. The standard open, read, and release file operations are implemented here. The open() implementation sets up for the various open modes of the 'trigger' file. It creates and attaches the trigger iterator and sets up the command parser. If opened for reading set up the trigger seq_ops. The read() implementation parses the event trigger written to the 'trigger' file, looks up the trigger command, and passes it along to that event_command's func() implementation for command-specific processing. The release() implementation does whatever cleanup is needed to release the 'trigger' file, like releasing the parser and trigger iterator, etc. A couple of functions for event command registration and unregistration are added, along with a list to add them to and a mutex to protect them, as well as an (initially empty) registration function to add the set of commands that will be added by future commits, and call to it from the trace event initialization code. also added are a couple trigger-specific data structures needed for these implementations such as a trigger iterator and a struct for trigger-specific data. A couple structs consisting mostly of function meant to be implemented in command-specific ways, event_command and event_trigger_ops, are used by the generic event trigger command implementations. They're being put into trace.h alongside the other trace_event data structures and functions, in the expectation that they'll be needed in several trace_event-related files such as trace_events_trigger.c and trace_events.c. The event_command.func() function is meant to be called by the trigger parsing code in order to add a trigger instance to the corresponding event. It essentially coordinates adding a live trigger instance to the event, and arming the triggering the event. Every event_command func() implementation essentially does the same thing for any command: - choose ops - use the value of param to choose either a number or count version of event_trigger_ops specific to the command - do the register or unregister of those ops - associate a filter, if specified, with the triggering event The reg() and unreg() ops allow command-specific implementations for event_trigger_op registration and unregistration, and the get_trigger_ops() op allows command-specific event_trigger_ops selection to be parameterized. When a trigger instance is added, the reg() op essentially adds that trigger to the triggering event and arms it, while unreg() does the opposite. The set_filter() function is used to associate a filter with the trigger - if the command doesn't specify a set_filter() implementation, the command will ignore filters. Each command has an associated trigger_type, which serves double duty, both as a unique identifier for the command as well as a value that can be used for setting a trigger mode bit during trigger invocation. The signature of func() adds a pointer to the event_command struct, used to invoke those functions, along with a command_data param that can be passed to the reg/unreg functions. This allows func() implementations to use command-specific blobs and supports code re-use. The event_trigger_ops.func() command corrsponds to the trigger 'probe' function that gets called when the triggering event is actually invoked. The other functions are used to list the trigger when needed, along with a couple mundane book-keeping functions. This also moves event_file_data() into trace.h so it can be used outside of trace_events.c. Link: http://lkml.kernel.org/r/316d95061accdee070aac8e5750afba0192fa5b9.1382622043.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Idea-by: Steve Rostedt <rostedt@goodmis.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-12-05tracing: Only run synchronize_sched() at instance deletion timeSteven Rostedt1-0/+3
It has been reported that boot up with FTRACE_SELFTEST enabled can take a very long time. There can be stalls of over a minute. This was tracked down to the synchronize_sched() called when a system call event is disabled. As the self tests enable and disable thousands of events, this makes the synchronize_sched() get called thousands of times. The synchornize_sched() was added with d562aff93bfb53 "tracing: Add support for SOFT_DISABLE to syscall events" which caused this regression (added in 3.13-rc1). The synchronize_sched() is to protect against the events being accessed when a tracer instance is being deleted. When an instance is being deleted all the events associated to it are unregistered. The synchronize_sched() makes sure that no more users are running when it finishes. Instead of calling synchronize_sched() for all syscall events, we only need to call it once, after the events are unregistered and before the instance is deleted. The event_mutex is held during this action to prevent new users from enabling events. Link: http://lkml.kernel.org/r/20131203124120.427b9661@gandalf.local.home Reported-by: Petr Mladek <pmladek@suse.cz> Acked-by: Tom Zanussi <tom.zanussi@linux.intel.com> Acked-by: Petr Mladek <pmladek@suse.cz> Tested-by: Petr Mladek <pmladek@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-06tracing: Do not assign filp->private_data to freed memoryGeyslan G. Bem1-1/+8
In system_tr_open(), the filp->private_data can be assigned the 'dir' variable even if it was freed. This is on the error path, and is harmless because the error return code will prevent filp->private_data from being used. But for correctness, we should not assign it to a recently freed variable, as that can cause static tools to give false warnings. Also have both subsystem_open() and system_tr_open() return -ENODEV if tracing has been disabled. Link: http://lkml.kernel.org/r/1383764571-7318-1-git-send-email-geyslan@gmail.com Signed-off-by: Geyslan G. Bem <geyslan@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-11-05tracing: Update event filters for multibufferTom Zanussi1-11/+12
The trace event filters are still tied to event calls rather than event files, which means you don't get what you'd expect when using filters in the multibuffer case: Before: # echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # mkdir /sys/kernel/debug/tracing/instances/test1 # echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 2048 # cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter bytes_alloc > 2048 Setting the filter in tracing/instances/test1/events shouldn't affect the same event in tracing/events as it does above. After: # echo 'bytes_alloc > 8192' > /sys/kernel/debug/tracing/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # mkdir /sys/kernel/debug/tracing/instances/test1 # echo 'bytes_alloc > 2048' > /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/filter bytes_alloc > 8192 # cat /sys/kernel/debug/tracing/instances/test1/events/kmem/kmalloc/filter bytes_alloc > 2048 We'd like to just move the filter directly from ftrace_event_call to ftrace_event_file, but there are a couple cases that don't yet have multibuffer support and therefore have to continue using the current event_call-based filters. For those cases, a new USE_CALL_FILTER bit is added to the event_call flags, whose main purpose is to keep the old behavior for those cases until they can be updated with multibuffer support; at that point, the USE_CALL_FILTER flag (and the new associated call_filter_check_discard() function) can go away. The multibuffer support also made filter_current_check_discard() redundant, so this change removes that function as well and replaces it with filter_check_discard() (or call_filter_check_discard() as appropriate). Link: http://lkml.kernel.org/r/f16e9ce4270c62f46b2e966119225e1c3cca7e60.1382620672.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2013-08-21tracing: Kill the !CONFIG_MODULES code in trace_events.cOleg Nesterov1-12/+6
Move trace_module_nb under CONFIG_MODULES and kill the dummy trace_module_notify(). Imho it doesn't make sense to define "struct notifier_block" and its .notifier_call just to avoid "ifdef" in event_trace_init(), and all other !CONFIG_MODULES code has already gone away. Link: http://lkml.kernel.org/r/20130731173137.GA31043@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>