Pull tracing updates from
- allow module init functions to be traced
- clean up some unused or not used by config events (saves space)
- clean up of trace histogram code
- add support for preempt and interrupt enabled/disable events
- other various clean ups
* tag 'trace-v4.15' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (30 commits)
tracing, thermal: Hide cpu cooling trace events when not in use
tracing, thermal: Hide devfreq trace events when not in use
ftrace: Kill FTRACE_OPS_FL_PER_CPU
perf/ftrace: Small cleanup
perf/ftrace: Fix function trace events
perf/ftrace: Revert ("perf/ftrace: Fix double traces of perf on ftrace:function")
tracing, dma-buf: Remove unused trace event dma_fence_annotate_wait_on
tracing, memcg, vmscan: Hide trace events when not in use
tracing/xen: Hide events that are not used when X86_PAE is not defined
tracing: mark trace_test_buffer as __maybe_unused
printk: Remove superfluous memory barriers from printk_safe
ftrace: Clear hashes of stale ips of init memory
tracing: Add support for preempt and irq enable/disable events
tracing: Prepare to add preempt and irq trace events
ftrace/kallsyms: Have /proc/kallsyms show saved mod init functions
ftrace: Add freeing algorithm to free ftrace_mod_maps
ftrace: Save module init functions kallsyms symbols for tracing
ftrace: Allow module init functions to be traced
ftrace: Add a ftrace_free_mem() function for modules to use
tracing: Reimplement log2
...
Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The one and only user of FTRACE_OPS_FL_PER_CPU is gone, remove the lot. Link: http://lkml.kernel.org/r/20171011080224.372422809@infradead.org Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Preempt and irq trace events can be used for tracing the start and end of an atomic section which can be used by a trace viewer like systrace to graphically view the start and end of an atomic section and correlate them with latencies and scheduling issues. This also serves as a prelude to using synthetic events or probes to rewrite the preempt and irqsoff tracers, along with numerous benefits of using trace events features for these events. Link: http://lkml.kernel.org/r/20171006005432.14244-3-joelaf@google.com Link: http://lkml.kernel.org/r/20171010225137.17370-1-joelaf@google.com Cc: Peter Zilstra <peterz@infradead.org> Cc: kernel-team@android.com Signed-off-by: Joel Fernandes <joelaf@google.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If a module is loaded while tracing is enabled, then there's a possibility that the module init functions were traced. These functions have their name and address stored by ftrace such that it can translate the function address that is written into the buffer into a human readable function name. As userspace tools may be doing the same, they need a way to map function names to their address as well. This is done through reading /proc/kallsyms. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
If function tracing is active when the module init functions are freed, then
store them to be referenced by kallsyms. As module init functions can now be
traced on module load, they were useless:
># echo ':mod:snd_seq' > set_ftrace_filter
># echo function > current_tracer
># modprobe snd_seq
># cat trace
# tracer: function
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / delay
# TASK-PID CPU# |||| TIMESTAMP FUNCTION
# | | | |||| | |
modprobe-2786 [000] .... 3189.037874: 0xffffffffa0860000 <-do_one_initcall
modprobe-2786 [000] .... 3189.037876: 0xffffffffa086004d <-0xffffffffa086000f
modprobe-2786 [000] .... 3189.037876: 0xffffffffa086010d <-0xffffffffa0860018
modprobe-2786 [000] .... 3189.037877: 0xffffffffa086011a <-0xffffffffa0860021
modprobe-2786 [000] .... 3189.037877: 0xffffffffa0860080 <-0xffffffffa086002a
modprobe-2786 [000] .... 3189.039523: 0xffffffffa0860400 <-0xffffffffa0860033
modprobe-2786 [000] .... 3189.039523: 0xffffffffa086038a <-0xffffffffa086041c
modprobe-2786 [000] .... 3189.039591: 0xffffffffa086038a <-0xffffffffa0860436
modprobe-2786 [000] .... 3189.039657: 0xffffffffa086038a <-0xffffffffa0860450
modprobe-2786 [000] .... 3189.039719: 0xffffffffa0860127 <-0xffffffffa086003c
modprobe-2786 [000] .... 3189.039742: snd_seq_create_kernel_client <-0xffffffffa08601f6
When the output is shown, the kallsyms for the module init functions have
already been freed, and the output of the trace can not convert them to
their function names.
Now this looks like this:
# tracer: function
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / delay
# TASK-PID CPU# |||| TIMESTAMP FUNCTION
# | | | |||| | |
modprobe-2463 [002] .... 174.243237: alsa_seq_init <-do_one_initcall
modprobe-2463 [002] .... 174.243239: client_init_data <-alsa_seq_init
modprobe-2463 [002] .... 174.243240: snd_sequencer_memory_init <-alsa_seq_init
modprobe-2463 [002] .... 174.243240: snd_seq_queues_init <-alsa_seq_init
modprobe-2463 [002] .... 174.243240: snd_sequencer_device_init <-alsa_seq_init
modprobe-2463 [002] .... 174.244860: snd_seq_info_init <-alsa_seq_init
modprobe-2463 [002] .... 174.244861: create_info_entry <-snd_seq_info_init
modprobe-2463 [002] .... 174.244936: create_info_entry <-snd_seq_info_init
modprobe-2463 [002] .... 174.245003: create_info_entry <-snd_seq_info_init
modprobe-2463 [002] .... 174.245072: snd_seq_system_client_init <-alsa_seq_init
modprobe-2463 [002] .... 174.245094: snd_seq_create_kernel_client <-snd_seq_system_client_init
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In order to be able to trace module init functions, the module code needs to tell ftrace what is being freed when the init sections are freed. Use the code that the main init calls to tell ftrace to free the main init sections. This requires passing in a start and end address to free. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
stack_tracer_disable()/stack_tracer_enable() had been using the wrong
name for the config symbol to enable their preempt-debugging checks --
fix with a word swap.
Link: http://lkml.kernel.org/r/20170831154036.4xldyakmmhuts5x7@hatter.bewilderbeest.net
Cc: stable@vger.kernel.org
Fixes: 8aaf1ee70e ("tracing: Rename trace_active to disable_stack_tracer and inline its modification")
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
The variables which are processed by RCU functions should be annotated as RCU, otherwise sparse will report the errors like below: "error: incompatible types in comparison expression (different address spaces)" Link: http://lkml.kernel.org/r/1496823171-7758-1-git-send-email-zhang.chunyan@linaro.org Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org> [ Updated to not be 100% 80 column strict ] Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When a module filter is added to set_ftrace_filter, if the module is not loaded, it is cached. This should be considered an active filter, and function tracing should be filtered by this. That is, if a cached module filter is the only filter set, then no function tracing should be happening, as all the functions available will be filtered out. This makes sense, as the reason to add a cached module filter, is to trace the module when you load it. There shouldn't be any other tracing happening until then. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>