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* clocksource: Use a plain u64 instead of cycle_tThomas Gleixner2016-12-251-2/+2
| | | | | | | | | | | | | | | | | | | | | There is no point in having an extra type for extra confusion. u64 is unambiguous. Conversion was done with the following coccinelle script: @rem@ @@ -typedef u64 cycle_t; @fix@ typedef cycle_t; @@ -cycle_t +u64 Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org>
* Merge tag 'trace-v4.10' of ↵Linus Torvalds2016-12-151-0/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "This release has a few updates: - STM can hook into the function tracer - Function filtering now supports more advance glob matching - Ftrace selftests updates and added tests - Softirq tag in traces now show only softirqs - ARM nop added to non traced locations at compile time - New trace_marker_raw file that allows for binary input - Optimizations to the ring buffer - Removal of kmap in trace_marker - Wakeup and irqsoff tracers now adhere to the set_graph_notrace file - Other various fixes and clean ups" * tag 'trace-v4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (42 commits) selftests: ftrace: Shift down default message verbosity kprobes/trace: Fix kprobe selftest for newer gcc tracing/kprobes: Add a helper method to return number of probe hits tracing/rb: Init the CPU mask on allocation tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results tracing/fgraph: Have wakeup and irqsoff tracers ignore graph functions too fgraph: Handle a case where a tracer ignores set_graph_notrace tracing: Replace kmap with copy_from_user() in trace_marker writing ftrace/x86_32: Set ftrace_stub to weak to prevent gcc from using short jumps to it tracing: Allow benchmark to be enabled at early_initcall() tracing: Have system enable return error if one of the events fail tracing: Do not start benchmark on boot up tracing: Have the reg function allow to fail ring-buffer: Force rb_end_commit() and rb_set_commit_to_write() inline ring-buffer: Froce rb_update_write_stamp() to be inlined ring-buffer: Force inline of hotpath helper functions tracing: Make __buffer_unlock_commit() always_inline tracing: Make tracepoint_printk a static_key ring-buffer: Always inline rb_event_data() ring-buffer: Make rb_reserve_next_event() always inlined ...
| * ftrace: Support full glob matchingMasami Hiramatsu2016-11-141-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use glob_match() to support flexible glob wildcards (*,?) and character classes ([) for ftrace. Since the full glob matching is slower than the current partial matching routines(*pat, pat*, *pat*), this leaves those routines and just add MATCH_GLOB for complex glob expression. e.g. ---- [root@localhost tracing]# echo 'sched*group' > set_ftrace_filter [root@localhost tracing]# cat set_ftrace_filter sched_free_group sched_change_group sched_create_group sched_online_group sched_destroy_group sched_offline_group [root@localhost tracing]# echo '[Ss]y[Ss]_*' > set_ftrace_filter [root@localhost tracing]# head set_ftrace_filter sys_arch_prctl sys_rt_sigreturn sys_ioperm SyS_iopl sys_modify_ldt SyS_mmap SyS_set_thread_area SyS_get_thread_area SyS_set_tid_address sys_fork ---- Link: http://lkml.kernel.org/r/147566869501.29136.6462645009894738056.stgit@devbox Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge tag 'pstore-v4.10-rc1' of ↵Linus Torvalds2016-12-131-0/+17
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull pstore updates from Kees Cook: "Improvements and fixes to pstore subsystem: - add additional checks for bad platform data - remove bounce buffer in console writer - protect read/unlink race with a mutex - correctly give up during dump locking failures - increase ftrace bandwidth by splitting ftrace buffers per CPU" * tag 'pstore-v4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: ramoops: add pdata NULL check to ramoops_probe pstore: Convert console write to use ->write_buf pstore: Protect unlink with read_mutex pstore: Use global ftrace filters for function trace filtering ftrace: Provide API to use global filtering for ftrace ops pstore: Clarify context field przs as dprzs pstore: improve error report for failed setup pstore: Merge per-CPU ftrace records into one pstore: Add ftrace timestamp counter ramoops: Split ftrace buffer space into per-CPU zones pstore: Make ramoops_init_przs generic for other prz arrays pstore: Allow prz to control need for locking pstore: Warn on PSTORE_TYPE_PMSG using deprecated function pstore: Make spinlock per zone instead of global pstore: Actually give up during locking failure
| * ftrace: Provide API to use global filtering for ftrace opsJoel Fernandes2016-11-161-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently the global_ops filtering hash is not available to outside users registering for function tracing. Provide an API for those users to be able to choose global filtering. This is in preparation for pstore's ftrace feature to be able to use the global filters. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Kees Cook <keescook@chromium.org> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Joel Fernandes <joelaf@google.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Kees Cook <keescook@chromium.org>
* | ftrace: Add more checks for FTRACE_FL_DISABLED in processing ip recordsSteven Rostedt (Red Hat)2016-11-141-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a module is first loaded and its function ip records are added to the ftrace list of functions to modify, they are set to DISABLED, as their text is still in a read only state. When the module is fully loaded, and can be updated, the flag is cleared, and if their's any functions that should be tracing them, it is updated at that moment. But there's several locations that do record accounting and should ignore records that are marked as disabled, or they can cause issues. Alexei already fixed one location, but others need to be addressed. Cc: stable@vger.kernel.org Fixes: b7ffffbb46f2 "ftrace: Add infrastructure for delayed enabling of module functions" Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ftrace: Ignore FTRACE_FL_DISABLED while walking dyn_ftrace recordsAlexei Starovoitov2016-11-141-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | ftrace_shutdown() checks for sanity of ftrace records and if dyn_ftrace->flags is not zero, it will warn. It can happen that 'flags' are set to FTRACE_FL_DISABLED at this point, since some module was loaded, but before ftrace_module_enable() cleared the flags for this module. In other words the module.c is doing: ftrace_module_init(mod); // calls ftrace_update_code() that sets flags=FTRACE_FL_DISABLED ... // here ftrace_shutdown() is called that warns, since err = prepare_coming_module(mod); // didn't have a chance to clear FTRACE_FL_DISABLED Fix it by ignoring disabled records. It's similar to what __ftrace_hash_rec_update() is already doing. Link: http://lkml.kernel.org/r/1478560460-3818619-1-git-send-email-ast@fb.com Cc: stable@vger.kernel.org Fixes: b7ffffbb46f2 "ftrace: Add infrastructure for delayed enabling of module functions" Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Access ret_stack->subtime only in the function profilerNamhyung Kim2016-09-011-0/+6
| | | | | | | | | | | | | | The subtime is used only for function profiler with function graph tracer enabled. Move the definition of subtime under CONFIG_FUNCTION_PROFILER to reduce the memory usage. Also move the initialization of subtime into the graph entry callback. Link: http://lkml.kernel.org/r/20160831025529.24018-1-namhyung@kernel.org Cc: Ingo Molnar <mingo@kernel.org> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Move toplevel init out of ftrace_init_tracefs()Steven Rostedt (Red Hat)2016-07-051-6/+10
| | | | | | | | | | | | | | | | | | | | | Commit 345ddcc882d8 ("ftrace: Have set_ftrace_pid use the bitmap like events do") placed ftrace_init_tracefs into the instance creation, and encapsulated the top level updating with an if conditional, as the top level only gets updated at boot up. Unfortunately, this triggers section mismatch errors as the init functions are called from a function that can be called later, and the section mismatch logic is unaware of the if conditional that would prevent it from happening at run time. To make everyone happy, create a separate ftrace_init_tracefs_toplevel() routine that only gets called by init functions, and this will be what calls other init functions for the toplevel directory. Link: http://lkml.kernel.org/r/20160704102139.19cbc0d9@gandalf.local.home Reported-by: kbuild test robot <fengguang.wu@intel.com> Reported-by: Arnd Bergmann <arnd@arndb.de> Fixes: 345ddcc882d8 ("ftrace: Have set_ftrace_pid use the bitmap like events do") Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Have set_ftrace_pid use the bitmap like events doSteven Rostedt (Red Hat)2016-06-201-177/+136
| | | | | | | | | Convert set_ftrace_pid to use the bitmap like set_event_pid does. This allows for instances to use the pid filtering as well, and will allow for function-fork option to set if the children of a traced function should be traced or not. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge tag 'trace-v4.7-2' of ↵Linus Torvalds2016-05-231-3/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull motr tracing updates from Steven Rostedt: "Three more changes. - I forgot that I had another selftest to stress test the ftrace instance creation. It was actually suppose to go into the 4.6 merge window, but I never committed it. I almost forgot about it again, but noticed it was missing from your tree. - Soumya PN sent me a clean up patch to not disable interrupts when taking the tasklist_lock for read, as it's unnecessary because that lock is never taken for write in irq context. - Newer gcc's can cause the jump in the function_graph code to the global ftrace_stub label to be a short jump instead of a long one. As that jump is dynamically converted to jump to the trace code to do function graph tracing, and that conversion expects a long jump it can corrupt the ftrace_stub itself (it's directly after that call). One way to prevent gcc from using a short jump is to declare the ftrace_stub as a weak function, which we do here to keep gcc from optimizing too much" * tag 'trace-v4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ftrace/x86: Set ftrace_stub to weak to prevent gcc from using short jumps to it ftrace: Don't disable irqs when taking the tasklist_lock read_lock ftracetest: Add instance created, delete, read and enable event test
| * ftrace: Don't disable irqs when taking the tasklist_lock read_lockSoumya PN2016-05-201-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In ftrace.c inside the function alloc_retstack_tasklist() (which will be invoked when function_graph tracing is on) the tasklist_lock is being held as reader while iterating through a list of threads. Here the lock is being held as reader with irqs disabled. The tasklist_lock is never write_locked in interrupt context so it is safe to not disable interrupts for the duration of read_lock in this block which, can be significant, given the block of code iterates through all threads. Hence changing the code to call read_lock() and read_unlock() instead of read_lock_irqsave() and read_unlock_irqrestore(). A similar change was made in commits: 8063e41d2ffc ("tracing: Change syscall_*regfunc() to check PF_KTHREAD and use for_each_process_thread()")' and 3472eaa1f12e ("sched: normalize_rt_tasks(): Don't use _irqsave for tasklist_lock, use task_rq_lock()")' Link: http://lkml.kernel.org/r/1463500874-77480-1-git-send-email-soumya.p.n@hpe.com Signed-off-by: Soumya PN <soumya.p.n@hpe.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ftrace: Match dot symbols when searching functions on ppc64Thiago Jung Bauermann2016-04-271-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the ppc64 big endian ABI, function symbols point to function descriptors. The symbols which point to the function entry points have a dot in front of the function name. Consequently, when the ftrace filter mechanism searches for the symbol corresponding to an entry point address, it gets the dot symbol. As a result, ftrace filter users have to be aware of this ABI detail on ppc64 and prepend a dot to the function name when setting the filter. The perf probe command insulates the user from this by ignoring the dot in front of the symbol name when matching function names to symbols, but the sysfs interface does not. This patch makes the ftrace filter mechanism do the same when searching symbols. Fixes the following failure in ftracetest's kprobe_ftrace.tc: .../kprobe_ftrace.tc: line 9: echo: write error: Invalid argument That failure is on this line of kprobe_ftrace.tc: echo _do_fork > set_ftrace_filter This is because there's no _do_fork entry in the functions list: # cat available_filter_functions | grep _do_fork ._do_fork This change introduces no regressions on the perf and ftracetest testsuite results. Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: linuxppc-dev@lists.ozlabs.org Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | Merge branch 'topic/livepatch' into nextMichael Ellerman2016-04-181-1/+13
|\ \ | |/ |/| | | | | Merge the support for live patching on ppc64le using mprofile-kernel. This branch has also been merged into the livepatching tree for v4.7.
| * ftrace: Make ftrace_location_range() globalMichael Ellerman2016-04-141-1/+13
| | | | | | | | | | | | | | | | | | In order to support live patching on powerpc we would like to call ftrace_location_range(), so make it global. Signed-off-by: Torsten Duwe <duwe@suse.de> Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | Merge tag 'trace-v4.6' of ↵Linus Torvalds2016-03-241-18/+23
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "Nothing major this round. Mostly small clean ups and fixes. Some visible changes: - A new flag was added to distinguish traces done in NMI context. - Preempt tracer now shows functions where preemption is disabled but interrupts are still enabled. Other notes: - Updates were done to function tracing to allow better performance with perf. - Infrastructure code has been added to allow for a new histogram feature for recording live trace event histograms that can be configured by simple user commands. The feature itself was just finished, but needs a round in linux-next before being pulled. This only includes some infrastructure changes that will be needed" * tag 'trace-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (22 commits) tracing: Record and show NMI state tracing: Fix trace_printk() to print when not using bprintk() tracing: Remove redundant reset per-CPU buff in irqsoff tracer x86: ftrace: Fix the misleading comment for arch/x86/kernel/ftrace.c tracing: Fix crash from reading trace_pipe with sendfile tracing: Have preempt(irqs)off trace preempt disabled functions tracing: Fix return while holding a lock in register_tracer() ftrace: Use kasprintf() in ftrace_profile_tracefs() ftrace: Update dynamic ftrace calls only if necessary ftrace: Make ftrace_hash_rec_enable return update bool tracing: Fix typoes in code comment and printk in trace_nop.c tracing, writeback: Replace cgroup path to cgroup ino tracing: Use flags instead of bool in trigger structure tracing: Add an unreg_all() callback to trigger commands tracing: Add needs_rec flag to event triggers tracing: Add a per-event-trigger 'paused' field tracing: Add get_syscall_name() tracing: Add event record param to trigger_ops.func() tracing: Make event trigger functions available tracing: Make ftrace_event_field checking functions available ...
| * | ftrace: Use kasprintf() in ftrace_profile_tracefs()Geliang Tang2016-03-181-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use kasprintf() instead of kmalloc() and snprintf(). Link: http://lkml.kernel.org/r/135a7bc36e51fd9eaa57124dd2140285b771f738.1458050835.git.geliangtang@163.com Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Geliang Tang <geliangtang@163.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | ftrace: Update dynamic ftrace calls only if necessaryJiri Olsa2016-03-181-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently dynamic ftrace calls are updated any time the ftrace_ops is un/registered. If we do this update only when it's needed, we save lot of time for perf system wide ftrace function sampling/counting. The reason is that for system wide sampling/counting, perf creates event for each cpu in the system. Each event then registers separate copy of ftrace_ops, which ends up in FTRACE_UPDATE_CALLS updates. On servers with many cpus that means serious stall (240 cpus server): Counting: # time ./perf stat -e ftrace:function -a sleep 1 Performance counter stats for 'system wide': 370,663 ftrace:function 1.401427505 seconds time elapsed real 3m51.743s user 0m0.023s sys 3m48.569s Sampling: # time ./perf record -e ftrace:function -a sleep 1 [ perf record: Woken up 0 times to write data ] Warning: Processed 141200 events and lost 5 chunks! [ perf record: Captured and wrote 10.703 MB perf.data (135950 samples) ] real 2m31.429s user 0m0.213s sys 2m29.494s There's no reason to do the FTRACE_UPDATE_CALLS update for each event in perf case, because all the ftrace_ops always share the same filter, so the updated calls are always the same. It's required that only first ftrace_ops registration does the FTRACE_UPDATE_CALLS update (also sometimes the second if the first one used the trampoline), but the rest can be only cheaply linked into the ftrace_ops list. Counting: # time ./perf stat -e ftrace:function -a sleep 1 Performance counter stats for 'system wide': 398,571 ftrace:function 1.377503733 seconds time elapsed real 0m2.787s user 0m0.005s sys 0m1.883s Sampling: # time ./perf record -e ftrace:function -a sleep 1 [ perf record: Woken up 0 times to write data ] Warning: Processed 261730 events and lost 9 chunks! [ perf record: Captured and wrote 19.907 MB perf.data (256293 samples) ] real 1m31.948s user 0m0.309s sys 1m32.051s Link: http://lkml.kernel.org/r/1458138873-1553-6-git-send-email-jolsa@kernel.org Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * | ftrace: Make ftrace_hash_rec_enable return update boolJiri Olsa2016-03-181-10/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change __ftrace_hash_rec_update to return true in case we need to update dynamic ftrace call records. It return false in case no update is needed. Link: http://lkml.kernel.org/r/1458138873-1553-5-git-send-email-jolsa@kernel.org Acked-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | kernel/...: convert pr_warning to pr_warnJoe Perches2016-03-221-4/+3
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the more common logging method with the eventual goal of removing pr_warning altogether. Miscellanea: - Realign arguments - Coalesce formats - Add missing space between a few coalesced formats Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> [kernel/power/suspend.c] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* / ftrace/module: remove ftrace module notifierJessica Yu2016-02-171-35/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | Remove the ftrace module notifier in favor of directly calling ftrace_module_enable() and ftrace_release_mod() in the module loader. Hard-coding the function calls directly in the module loader removes dependence on the module notifier call chain and provides better visibility and control over what gets called when, which is important to kernel utilities such as livepatch. This fixes a notifier ordering issue in which the ftrace module notifier (and hence ftrace_module_enable()) for coming modules was being called after klp_module_notify(), which caused livepatch modules to initialize incorrectly. This patch removes dependence on the module notifier call chain in favor of hard coding the corresponding function calls in the module loader. This ensures that ftrace and livepatch code get called in the correct order on patch module load and unload. Fixes: 5156dca34a3e ("ftrace: Fix the race between ftrace and insmod") Signed-off-by: Jessica Yu <jeyu@redhat.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Reviewed-by: Petr Mladek <pmladek@suse.cz> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* ftrace: Fix the race between ftrace and insmodQiu Peiyang2016-01-071-9/+16
| | | | | | | | | | | | | | | | | | | | | | We hit ftrace_bug report when booting Android on a 64bit ATOM SOC chip. Basically, there is a race between insmod and ftrace_run_update_code. After load_module=>ftrace_module_init, another thread jumps in to call ftrace_run_update_code=>ftrace_arch_code_modify_prepare =>set_all_modules_text_rw, to change all modules as RW. Since the new module is at MODULE_STATE_UNFORMED, the text attribute is not changed. Then, the 2nd thread goes ahead to change codes. However, load_module continues to call complete_formation=>set_section_ro_nx, then 2nd thread would fail when probing the module's TEXT. The patch fixes it by using notifier to delay the enabling of ftrace records to the time when module is at state MODULE_STATE_COMING. Link: http://lkml.kernel.org/r/567CE628.3000609@intel.com Signed-off-by: Qiu Peiyang <peiyangx.qiu@intel.com> Signed-off-by: Zhang Yanmin <yanmin.zhang@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Add infrastructure for delayed enabling of module functionsSteven Rostedt (Red Hat)2016-01-071-55/+106
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Qiu Peiyang pointed out that there's a race when enabling function tracing and loading a module. In order to make the modifications of converting nops in the prologue of functions into callbacks, the text needs to be converted from read-only to read-write. When enabling function tracing, the text permission is updated, the functions are modified, and then they are put back. When loading a module, the updates to convert function calls to mcount is done before the module text is set to read-only. But after it is done, the module text is visible by the function tracer. Thus we have the following race: CPU 0 CPU 1 ----- ----- start function tracing set text to read-write load_module add functions to ftrace set module text read-only update all functions to callbacks modify module functions too < Can't it's read-only > When this happens, ftrace detects the issue and disables itself till the next reboot. To fix this, a new DISABLED flag is added for ftrace records, which all module functions get when they are added. Then later, after the module code is all set, the records will have the DISABLED flag cleared, and they will be enabled if any callback wants all functions to be traced. Note, this doesn't add the delay to later. It simply changes the ftrace_module_init() to do both the setting of DISABLED records, and then immediately calls the enable code. This helps with testing this new code as it has the same behavior as previously. Another change will come after this to have the ftrace_module_enable() called after the text is set to read-only. Cc: Qiu Peiyang <peiyangx.qiu@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Clean up ftrace_module_init() codeSteven Rostedt (Red Hat)2015-12-231-6/+3
| | | | | | | | The start and end variables were only used when ftrace_module_init() was split up into multiple functions. No need to keep them around after the merger. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Join functions ftrace_module_init() and ftrace_init_module()Abel Vesa2015-12-231-9/+6
| | | | | | | | | | Simple cleanup. No need for two functions here. The whole work can simply be done inside 'ftrace_module_init'. Link: http://lkml.kernel.org/r/1449067197-5718-1-git-send-email-abelvesa@linux.com Signed-off-by: Abel Vesa <abelvesa@linux.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Have ftrace_ops_get_func() handle RCU and PER_CPU flags tooSteven Rostedt (Red Hat)2015-12-231-12/+18
| | | | | | | | | | | | | | | | | | | | Jiri Olsa noted that the change to replace the control_ops did not update the trampoline for when running perf on a single CPU and with CONFIG_PREEMPT disabled (where dynamic ops, like perf, can use trampolines directly). The result was that perf function could be called when RCU is not watching as well as not handle the ftrace_local_disable(). Modify the ftrace_ops_get_func() to also check the RCU and PER_CPU ops flags and use the recursive function if they are set. The recursive function is modified to check those flags and execute the appropriate checks if they are set. Link: http://lkml.kernel.org/r/20151201134213.GA14155@krava.brq.redhat.com Reported-by: Jiri Olsa <jolsa@redhat.com> Patch-fixed-up-by: Jiri Olsa <jolsa@redhat.com> Tested-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Remove use of control list and opsSteven Rostedt (Red Hat)2015-12-231-88/+38
| | | | | | | | | | | | | | | | Currently perf has its own list function within the ftrace infrastructure that seems to be used only to allow for it to have per-cpu disabling as well as a check to make sure that it's not called while RCU is not watching. It uses something called the "control_ops" which is used to iterate over ops under it with the control_list_func(). The problem is that this control_ops and control_list_func unnecessarily complicates the code. By replacing FTRACE_OPS_FL_CONTROL with two new flags (FTRACE_OPS_FL_RCU and FTRACE_OPS_FL_PER_CPU) we can remove all the code that is special with the control ops and add the needed checks within the generic ftrace_list_func(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Fix output of enabled_functions for showing trampSteven Rostedt (Red Hat)2015-12-231-3/+4
| | | | | | | | | | | | | | | When showing all tramps registered to a ftrace record in the file enabled_functions, it exits the loop with ops == NULL. But then it is suppose to show the function on the ops->trampoline and add_trampoline_func() is called with the given ops. But because ops is now NULL (to exit the loop), it always shows the static trampoline instead of the one that is really registered to the record. The call to add_trampoline_func() that shows the trampoline for the given ops needs to be called at every iteration. Fixes: 39daa7b9e895 "ftrace: Show all tramps registered to a record on ftrace_bug()" Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Fix a typo in commentLi Bin2015-12-231-1/+1
| | | | | | | | | s/ARCH_SUPPORT_FTARCE_OPS/ARCH_SUPPORTS_FTRACE_OPS/ Link: http://lkml.kernel.org/r/1448879016-8659-1-git-send-email-huawei.libin@huawei.com Signed-off-by: Li Bin <huawei.libin@huawei.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Show all tramps registered to a record on ftrace_bug()Steven Rostedt (Red Hat)2015-11-251-9/+37
| | | | | | | | | | | | | | When an anomaly is detected in the function call modification code, ftrace_bug() is called to disable function tracing as well as give any information that may help debug the problem. Currently, only the first found trampoline that is attached to the failed record is reported. Instead, show all trampolines that are hooked to it. Also, not only show the ops pointer but also report the function it calls. While at it, add this info to the enabled_functions debug file too. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Add variable ftrace_expected for archs to show expected codeSteven Rostedt (Red Hat)2015-11-251-2/+7
| | | | | | | | | | | | | | When an anomaly is found while modifying function code, ftrace_bug() is called which disables the function tracing infrastructure and reports information about what failed. If the code that is to be replaced does not match what is expected, then actual code is shown. Currently there is no arch generic way to show what was expected. Add a new variable pointer calld ftrace_expected that the arch code can set to point to what it expected so that ftrace_bug() can report the actual text as well as the text that was expected to be there. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* ftrace: Add new type to distinguish what kind of ftrace_bug()Steven Rostedt (Red Hat)2015-11-251-1/+36
| | | | | | | | | | | | | | | | | | The ftrace function hook utility has several internal checks to make sure that whatever it modifies is exactly what it expects to be modifying. This is essential as modifying running code can be extremely dangerous to the system. When an anomaly is detected, ftrace_bug() is called which sends a splat to the console and disables function tracing. There's some extra information that is printed to help diagnose the issue. One thing that is missing though is output of what ftrace was doing at the time of the crash. Was it updating a call site or perhaps converting a call site to a nop? A new global enum variable is created to state what ftrace was doing at the time of the anomaly, and this is reported in ftrace_bug(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge tag 'trace-v4.4' of ↵Linus Torvalds2015-11-061-93/+104
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracking updates from Steven Rostedt: "Most of the changes are clean ups and small fixes. Some of them have stable tags to them. I searched through my INBOX just as the merge window opened and found lots of patches to pull. I ran them through all my tests and they were in linux-next for a few days. Features added this release: ---------------------------- - Module globbing. You can now filter function tracing to several modules. # echo '*:mod:*snd*' > set_ftrace_filter (Dmitry Safonov) - Tracer specific options are now visible even when the tracer is not active. It was rather annoying that you can only see and modify tracer options after enabling the tracer. Now they are in the options/ directory even when the tracer is not active. Although they are still only visible when the tracer is active in the trace_options file. - Trace options are now per instance (although some of the tracer specific options are global) - New tracefs file: set_event_pid. If any pid is added to this file, then all events in the instance will filter out events that are not part of this pid. sched_switch and sched_wakeup events handle next and the wakee pids" * tag 'trace-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (68 commits) tracefs: Fix refcount imbalance in start_creating() tracing: Put back comma for empty fields in boot string parsing tracing: Apply tracer specific options from kernel command line. tracing: Add some documentation about set_event_pid ring_buffer: Remove unneeded smp_wmb() before wakeup of reader benchmark tracing: Allow dumping traces without tracking trace started cpus ring_buffer: Fix more races when terminating the producer in the benchmark ring_buffer: Do no not complete benchmark reader too early tracing: Remove redundant TP_ARGS redefining tracing: Rename max_stack_lock to stack_trace_max_lock tracing: Allow arch-specific stack tracer recordmcount: arm64: Replace the ignored mcount call into nop recordmcount: Fix endianness handling bug for nop_mcount tracepoints: Fix documentation of RCU lockdep checks tracing: ftrace_event_is_function() can return boolean tracing: is_legal_op() can return boolean ring-buffer: rb_event_is_commit() can return boolean ring-buffer: rb_per_cpu_empty() can return boolean ring_buffer: ring_buffer_empty{cpu}() can return boolean ring-buffer: rb_is_reader_page() can return boolean ...
| * ftrace: add module globbingDmitry Safonov2015-10-211-15/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extend module command for function filter selection with globbing. It uses the same globbing as function filter. sh# echo '*alloc*:mod:*' > set_ftrace_filter Will trace any function with the letters 'alloc' in the name in any module but not in kernel. sh# echo '!*alloc*:mod:ipv6' >> set_ftrace_filter Will prevent from tracing functions with 'alloc' in the name from module ipv6 (do not forget to append to set_ftrace_filter file). sh# echo '*alloc*:mod:!ipv6' > set_ftrace_filter Will trace functions with 'alloc' in the name from kernel and any module except ipv6. sh# echo '*alloc*:mod:!*' > set_ftrace_filter Will trace any function with the letters 'alloc' in the name only from kernel, but not from any module. sh# echo '*:mod:!*' > set_ftrace_filter or sh# echo ':mod:!' > set_ftrace_filter Will trace every function in the kernel, but will not trace functions from any module. sh# echo '*:mod:*' > set_ftrace_filter or sh# echo ':mod:' > set_ftrace_filter As the opposite will trace all functions from all modules, but not from kernel. sh# echo '*:mod:*snd*' > set_ftrace_filter Will trace your sound drivers only (if any). Link: http://lkml.kernel.org/r/1443545176-3215-4-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> [ Made format changes ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Introduce ftrace_glob structureDmitry Safonov2015-10-211-38/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | ftrace_match parameters are very related and I reduce the number of local variables & parameters with it. This is also preparation for module globbing as it would introduce more realated variables & parameters. Link: http://lkml.kernel.org/r/1443545176-3215-3-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> [ Made some formatting changes ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Clarify code for mod commandDmitry Safonov2015-10-161-27/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | "Not" is too abstract variable name - changed to clear_filter. Removed ftrace_match_module_records function: comparison with !* or * not does the general code in filter_parse_regex() as it works without mod command for sh# echo '!*' > /sys/kernel/debug/tracing/set_ftrace_filter Link: http://lkml.kernel.org/r/1443545176-3215-2-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Remove redundant strsep in mod_callbackDmitry Safonov2015-10-141-10/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By now there isn't any subcommand for mod. Before: sh$ echo '*:mod:ipv6:a' > set_ftrace_filter sh$ echo '*:mod:ipv6' > set_ftrace_filter had the same results, but now first will result in: sh$ echo '*:mod:ipv6:a' > set_ftrace_filter -bash: echo: write error: Invalid argument Also, I clarified ftrace_mod_callback code a little. Link: http://lkml.kernel.org/r/1443545176-3215-1-git-send-email-0x7f454c46@gmail.com Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> [ converted 'if (ret == 0)' to 'if (!ret)' ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * ftrace: Remove redundant swap functionRasmus Villemoes2015-10-011-12/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | To cover the common case of sorting an array of pointers, Daniel Wagner recently modified the library sort() to use a specific swap function for size==8, in addition to the size==4 case which was already handled. Since sizeof(long) is either 4 or 8, ftrace_swap_ips() is redundant and we can just let sort() pick an appropriate and fast swap callback. Link: http://lkml.kernel.org/r/1441834023-13130-1-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
| * tracing: Move sleep-time and graph-time options out of the core trace_flagsSteven Rostedt (Red Hat)2015-09-301-2/+17
| | | | | | | | | | | | | | | | | | The sleep-time and graph-time options are only for the function graph tracer and are not used by anything else. As tracer options are now visible when the tracer is not activated, its better to move the function graph specific tracer options into the function graph tracer. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | sched/core: Fix trace_sched_switch()Peter Zijlstra2015-10-061-1/+1
|/ | | | | | | | | | | | | | | __trace_sched_switch_state() is the last remaining PREEMPT_ACTIVE user, move trace_sched_switch() from prepare_task_switch() to __schedule() and propagate the @preempt argument. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge tag 'trace-v4.3' of ↵Linus Torvalds2015-09-081-2/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing update from Steven Rostedt: "Mostly this is just clean ups and micro optimizations. The changes with more meat are: - Allowing the trace event filters to filter on CPU number and process ids - Two new markers for trace output latency were added (10 and 100 msec latencies) - Have tracing_thresh filter function profiling time I also worked on modifying the ring buffer code for some future work, and moved the adding of the timestamp around. One of my changes caused a regression, and since other changes were built on top of it and already tested, I had to operate a revert of that change. Instead of rebasing, this change set has the code that caused a regression as well as the code to revert that change without touching the other changes that were made on top of it" * tag 'trace-v4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: ring-buffer: Revert "ring-buffer: Get timestamp after event is allocated" tracing: Don't make assumptions about length of string on task rename tracing: Allow triggers to filter for CPU ids and process names ftrace: Format MCOUNT_ADDR address as type unsigned long tracing: Introduce two additional marks for delay ftrace: Fix function_graph duration spacing with 7-digits ftrace: add tracing_thresh to function profile tracing: Clean up stack tracing and fix fentry updates ring-buffer: Reorganize function locations ring-buffer: Make sure event has enough room for extend and padding ring-buffer: Get timestamp after event is allocated ring-buffer: Move the adding of the extended timestamp out of line ring-buffer: Add event descriptor to simplify passing data ftrace: correct the counter increment for trace_buffer data tracing: Fix for non-continuous cpu ids tracing: Prefer kcalloc over kzalloc with multiply
| * ftrace: add tracing_thresh to function profileUmesh Tiwari2015-07-211-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | This patch extends tracing_thresh functionality to function profile tracer. If tracing_thresh is set, print those entries only, whose average is > tracing thresh. Link: http://lkml.kernel.org/r/1434972488-8571-1-git-send-email-umesh.t@samsung.com Signed-off-by: Umesh Tiwari <umesh.t@samsung.com> [ Removed unnecessary 'moved' comment ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | ftrace: Fix breakage of set_ftrace_pidSteven Rostedt (Red Hat)2015-07-241-18/+34
|/ | | | | | | | | | | | | | | Commit 4104d326b670 ("ftrace: Remove global function list and call function directly") simplified the ftrace code by removing the global_ops list with a new design. But this cleanup also broke the filtering of PIDs that are added to the set_ftrace_pid file. Add back the proper hooks to have pid filtering working once again. Cc: stable@vger.kernel.org # 3.16+ Reported-by: Matt Fleming <matt@console-pimps.org> Reported-by: Richard Weinberger <richard.weinberger@gmail.com> Tested-by: Matt Fleming <matt@console-pimps.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* Merge tag 'trace-v4.1' of ↵Linus Torvalds2015-04-141-8/+14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * ftrace/x86: Let dynamic trampolines call ops->func even for dynamic fopsSteven Rostedt (Red Hat)2015-04-021-8/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Dynamically allocated trampolines call ftrace_ops_get_func to get the function which they should call. For dynamic fops (FTRACE_OPS_FL_DYNAMIC flag is set) ftrace_ops_list_func is always returned. This is reasonable for static trampolines but goes against the main advantage of dynamic ones, that is avoidance of going through the list of all registered callbacks for functions that are only being traced by a single callback. We can fix it by returning ops->func (or recursion safe version) from ftrace_ops_get_func whenever it is possible for dynamic trampolines. Note that dynamic trampolines are not allowed for dynamic fops if CONFIG_PREEMPT=y. Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1501291023000.25445@pobox.suse.cz Link: http://lkml.kernel.org/r/1424357773-13536-1-git-send-email-mbenes@suse.cz Reported-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | Merge tag 'trace-4.1-tracefs' of ↵Linus Torvalds2015-04-141-11/+11
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracefs from Steven Rostedt: "This adds the new tracefs file system. This has been in linux-next for more than one release, as I had it ready for the 4.0 merge window, but a last minute thing that needed to go into Linux first had to be done. That was that perf hard coded the file system number when reading /sys/kernel/debugfs/tracing directory making sure that the path had the debugfs mount # before it would parse the tracing file. This broke other use cases of perf, and the check is removed. Now when mounting /sys/kernel/debug, tracefs is automatically mounted in /sys/kernel/debug/tracing such that old tools will still see that path as expected. But now system admins can mount tracefs directly and not need to mount debugfs, which can expose security issues. A new directory is created when tracefs is configured such that system admins can now mount it separately (/sys/kernel/tracing)" * tag 'trace-4.1-tracefs' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Have mkdir and rmdir be part of tracefs tracefs: Add directory /sys/kernel/tracing tracing: Automatically mount tracefs on debugfs/tracing tracing: Convert the tracing facility over to use tracefs tracefs: Add new tracefs file system tracing: Create cmdline tracer options on tracing fs init tracing: Only create tracer options files if directory exists debugfs: Provide a file creation function that also takes an initial size
| * tracing: Convert the tracing facility over to use tracefsSteven Rostedt (Red Hat)2015-02-031-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * Merge branch 'debugfs_automount' of ↵Steven Rostedt (Red Hat)2015-02-021-8/+45
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.
* | | ftrace: Fix ftrace enable ordering of sysctl ftrace_enabledSteven Rostedt (Red Hat)2015-03-091-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some archs (specifically PowerPC), are sensitive with the ordering of the enabling of the calls to function tracing and setting of the function to use to be traced. That is, update_ftrace_function() sets what function the ftrace_caller trampoline should call. Some archs require this to be set before calling ftrace_run_update_code(). Another bug was discovered, that ftrace_startup_sysctl() called ftrace_run_update_code() directly. If the function the ftrace_caller trampoline changes, then it will not be updated. Instead a call to ftrace_startup_enable() should be called because it tests to see if the callback changed since the code was disabled, and will tell the arch to update appropriately. Most archs do not need this notification, but PowerPC does. The problem could be seen by the following commands: # echo 0 > /proc/sys/kernel/ftrace_enabled # echo function > /sys/kernel/debug/tracing/current_tracer # echo 1 > /proc/sys/kernel/ftrace_enabled # cat /sys/kernel/debug/tracing/trace The trace will show that function tracing was not active. Cc: stable@vger.kernel.org # 2.6.27+ Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
* | | ftrace: Fix en(dis)able graph caller when en(dis)abling record via sysctlPratyush Anand2015-03-091-6/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When ftrace is enabled globally through the proc interface, we must check if ftrace_graph_active is set. If it is set, then we should also pass the FTRACE_START_FUNC_RET command to ftrace_run_update_code(). Similarly, when ftrace is disabled globally through the proc interface, we must check if ftrace_graph_active is set. If it is set, then we should also pass the FTRACE_STOP_FUNC_RET command to ftrace_run_update_code(). Consider the following situation. # echo 0 > /proc/sys/kernel/ftrace_enabled After this ftrace_enabled = 0. # echo function_graph > /sys/kernel/debug/tracing/current_tracer Since ftrace_enabled = 0, ftrace_enable_ftrace_graph_caller() is never called. # echo 1 > /proc/sys/kernel/ftrace_enabled Now ftrace_enabled will be set to true, but still ftrace_enable_ftrace_graph_caller() will not be called, which is not desired. Further if we execute the following after this: # echo nop > /sys/kernel/debug/tracing/current_tracer Now since ftrace_enabled is set it will call ftrace_disable_ftrace_graph_caller(), which causes a kernel warning on the ARM platform. On the ARM platform, when ftrace_enable_ftrace_graph_caller() is called, it checks whether the old instruction is a nop or not. If it's not a nop, then it returns an error. If it is a nop then it replaces instruction at that address with a branch to ftrace_graph_caller. ftrace_disable_ftrace_graph_caller() behaves just the opposite. Therefore, if generic ftrace code ever calls either ftrace_enable_ftrace_graph_caller() or ftrace_disable_ftrace_graph_caller() consecutively two times in a row, then it will return an error, which will cause the generic ftrace code to raise a warning. Note, x86 does not have an issue with this because the architecture specific code for ftrace_enable_ftrace_graph_caller() and ftrace_disable_ftrace_graph_caller() does not check the previous state, and calling either of these functions twice in a row has no ill effect. Link: http://lkml.kernel.org/r/e4fbe64cdac0dd0e86a3bf914b0f83c0b419f146.1425666454.git.panand@redhat.com Cc: stable@vger.kernel.org # 2.6.31+ Signed-off-by: Pratyush Anand <panand@redhat.com> [ removed extra if (ftrace_start_up) and defined ftrace_graph_active as 0 if CONFIG_FUNCTION_GRAPH_TRACER is not set. ] Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
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