user/sven/linux.git/kernel/trace, branch v4.19.1

tracing: Fix synthetic event to allow semicolon at end

2018-10-19T21:25:11Z

Fix synthetic event to allow independent semicolon at end. The synthetic_events interface accepts a semicolon after the last word if there is no space. # echo "myevent u64 var;" >> synthetic_events But if there is a space, it returns an error. # echo "myevent u64 var ;" > synthetic_events sh: write error: Invalid argument This behavior is difficult for users to understand. Let's allow the last independent semicolon too. Link: http://lkml.kernel.org/r/153986835420.18251.2191216690677025744.stgit@devbox Cc: Shuah Khan Cc: Tom Zanussi Cc: stable@vger.kernel.org Fixes: commit 4b147936fa50 ("tracing: Add support for 'synthetic' events") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: Fix synthetic event to accept unsigned modifier

2018-10-19T21:25:11Z

Fix synthetic event to accept unsigned modifier for its field type correctly. Currently, synthetic_events interface returns error for "unsigned" modifiers as below; # echo "myevent unsigned long var" >> synthetic_events sh: write error: Invalid argument This is because argv_split() breaks "unsigned long" into "unsigned" and "long", but parse_synth_field() doesn't expected it. With this fix, synthetic_events can handle the "unsigned long" correctly like as below; # echo "myevent unsigned long var" >> synthetic_events # cat synthetic_events myevent unsigned long var Link: http://lkml.kernel.org/r/153986832571.18251.8448135724590496531.stgit@devbox Cc: Shuah Khan Cc: Tom Zanussi Cc: stable@vger.kernel.org Fixes: commit 4b147936fa50 ("tracing: Add support for 'synthetic' events") Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: Use trace_clock_local() for looping in preemptirq_delay_test.c

2018-10-17T19:35:33Z

The preemptirq_delay_test module is used for the ftrace selftest code that tests the latency tracers. The problem is that it uses ktime for the delay loop, and then checks the tracer to see if the delay loop is caught, but the tracer uses trace_clock_local() which uses various different other clocks to measure the latency. As ktime uses the clock cycles, and the code then converts that to nanoseconds, it causes rounding errors, and the preemptirq latency tests are failing due to being off by 1 (it expects to see a delay of 500000 us, but the delay is only 499999 us). This is happening due to a rounding error in the ktime (which is totally legit). The purpose of the test is to see if it can catch the delay, not to test the accuracy between trace_clock_local() and ktime_get(). Best to use apples to apples, and have the delay loop use the same clock as the latency tracer does. Cc: stable@vger.kernel.org Fixes: f96e8577da102 ("lib: Add module for testing preemptoff/irqsoff latency tracers") Acked-by: Joel Fernandes (Google) Signed-off-by: Steven Rostedt (VMware)

ring-buffer: Allow for rescheduling when removing pages

2018-09-17T22:15:11Z

When reducing ring buffer size, pages are removed by scheduling a work item on each CPU for the corresponding CPU ring buffer. After the pages are removed from ring buffer linked list, the pages are free()d in a tight loop. The loop does not give up CPU until all pages are removed. In a worst case behavior, when lot of pages are to be freed, it can cause system stall. After the pages are removed from the list, the free() can happen while the work is rescheduled. Call cond_resched() in the loop to prevent the system hangup. Link: http://lkml.kernel.org/r/20180907223129.71994-1-vnagarnaik@google.com Cc: stable@vger.kernel.org Fixes: 83f40318dab00 ("ring-buffer: Make removal of ring buffer pages atomic") Reported-by: Jason Behmer Signed-off-by: Vaibhav Nagarnaik Signed-off-by: Steven Rostedt (VMware)

Merge tag 'trace-v4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2018-08-23T20:07:00Z

Pull tracing fixes from Steven Rostedt: "Masami found an off by one bug in the code that keeps "notrace" functions from being traced by kprobes. During my testing, I found that there's places that we may want to add kprobes to notrace, thus we may end up changing this code before 4.19 is released. The history behind this change is that we found that adding kprobes to various notrace functions caused the kernel to crashed. We took the safe route and decided not to allow kprobes to trace any notrace function. But because notrace is added to functions that just cause weird side effects to the function tracer, but are still safe, preventing kprobes for all notrace functios may be too much of a big hammer. One such place is __schedule() is marked notrace, to keep function tracer from doing strange recursive loops when it gets traced with NEED_RESCHED set. With this change, one can not add kprobes to the scheduler. Masami also added code to use gcov on ftrace" * tag 'trace-v4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing/kprobes: Fix to check notrace function with correct range tracing: Allow gcov profiling on only ftrace subsystem

Merge tag 'for-4.19/post-20180822' of git://git.kernel.dk/linux-block

2018-08-22T20:38:05Z

Pull more block updates from Jens Axboe: - Set of bcache fixes and changes (Coly) - The flush warn fix (me) - Small series of BFQ fixes (Paolo) - wbt hang fix (Ming) - blktrace fix (Steven) - blk-mq hardware queue count update fix (Jianchao) - Various little fixes * tag 'for-4.19/post-20180822' of git://git.kernel.dk/linux-block: (31 commits) block/DAC960.c: make some arrays static const, shrinks object size blk-mq: sync the update nr_hw_queues with blk_mq_queue_tag_busy_iter blk-mq: init hctx sched after update ctx and hctx mapping block: remove duplicate initialization tracing/blktrace: Fix to allow setting same value pktcdvd: fix setting of 'ret' error return for a few cases block: change return type to bool block, bfq: return nbytes and not zero from struct cftype .write() method block, bfq: improve code of bfq_bfqq_charge_time block, bfq: reduce write overcharge block, bfq: always update the budget of an entity when needed block, bfq: readd missing reset of parent-entity service blk-wbt: fix IO hang in wbt_wait() block: don't warn for flush on read-only device bcache: add the missing comments for smp_mb()/smp_wmb() bcache: remove unnecessary space before ioctl function pointer arguments bcache: add missing SPDX header bcache: move open brace at end of function definitions to next line bcache: add static const prefix to char * array declarations bcache: fix code comments style ...

tracing/kprobes: Fix to check notrace function with correct range

2018-08-21T13:41:12Z

Fix within_notrace_func() to check notrace function correctly. Since the ftrace_location_range(start, end) function checks the range inclusively (start <= ftrace-loc <= end), the end address must not include the entry address of next function. However, within_notrace_func() uses kallsyms_lookup_size_offset() to get the function size and calculate the end address from adding the size to the entry address. This means the end address is the entry address of the next function. In the result, within_notrace_func() fails to find notrace function if the next function of the target function is ftraced. Let's subtract 1 from the end address so that ftrace_location_range() can check it correctly. Link: http://lkml.kernel.org/r/153485669706.16611.17726752296213785504.stgit@devbox Fixes: commit 45408c4f9250 ("tracing: kprobes: Prohibit probing on notrace function") Reported-by: Michael Rodin Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

tracing: Allow gcov profiling on only ftrace subsystem

2018-08-21T13:11:49Z

Add GCOV_PROFILE_FTRACE to allow gcov profiling on only files in ftrace subsystem. This config option will be used for checking kselftest/ftrace coverage. Link: http://lkml.kernel.org/r/153483647755.32472.4746349899604275441.stgit@devbox Signed-off-by: Masami Hiramatsu Signed-off-by: Steven Rostedt (VMware)

Merge tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2018-08-21T01:32:00Z

Pull tracing updates from Steven Rostedt: - Restructure of lockdep and latency tracers This is the biggest change. Joel Fernandes restructured the hooks from irqs and preemption disabling and enabling. He got rid of a lot of the preprocessor #ifdef mess that they caused. He turned both lockdep and the latency tracers to use trace events inserted in the preempt/irqs disabling paths. But unfortunately, these started to cause issues in corner cases. Thus, parts of the code was reverted back to where lockdep and the latency tracers just get called directly (without using the trace events). But because the original change cleaned up the code very nicely we kept that, as well as the trace events for preempt and irqs disabling, but they are limited to not being called in NMIs. - Have trace events use SRCU for "rcu idle" calls. This was required for the preempt/irqs off trace events. But it also had to not allow them to be called in NMI context. Waiting till Paul makes an NMI safe SRCU API. - New notrace SRCU API to allow trace events to use SRCU. - Addition of mcount-nop option support - SPDX headers replacing GPL templates. - Various other fixes and clean ups. - Some fixes are marked for stable, but were not fully tested before the merge window opened. * tag 'trace-v4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (44 commits) tracing: Fix SPDX format headers to use C++ style comments tracing: Add SPDX License format tags to tracing files tracing: Add SPDX License format to bpf_trace.c blktrace: Add SPDX License format header s390/ftrace: Add -mfentry and -mnop-mcount support tracing: Add -mcount-nop option support tracing: Avoid calling cc-option -mrecord-mcount for every Makefile tracing: Handle CC_FLAGS_FTRACE more accurately Uprobe: Additional argument arch_uprobe to uprobe_write_opcode() Uprobes: Simplify uprobe_register() body tracepoints: Free early tracepoints after RCU is initialized uprobes: Use synchronize_rcu() not synchronize_sched() tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister() ftrace: Remove unused pointer ftrace_swapper_pid tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage" tracing/irqsoff: Handle preempt_count for different configs tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage" tracing: irqsoff: Account for additional preempt_disable trace: Use rcu_dereference_raw for hooks from trace-event subsystem tracing/kprobes: Fix within_notrace_func() to check only notrace functions ...

tracing: Fix SPDX format headers to use C++ style comments

2018-08-16T23:08:06Z

The Linux kernel adopted the SPDX License format headers to ease license compliance management, and uses the C++ '//' style comments for the SPDX header tags. Some files in the tracing directory used the C style /* */ comments for them. To be consistent across all files, replace the /* */ C style SPDX tags with the C++ // SPDX tags. Signed-off-by: Steven Rostedt (VMware)