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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-30 09:22:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-30 09:22:00 -0700 |
| commit | 034dd340b08be1f2f0477ad16131d609f9dbd53c (patch) | |
| tree | 2536f4b2d7893ccd916b5abdf3c454ad6edc03c2 /Documentation/tools | |
| download | linux-stable-034dd340b08be1f2f0477ad16131d609f9dbd53c.tar.gz linux-stable-034dd340b08be1f2f0477ad16131d609f9dbd53c.zip | |
Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted
Pull tracing fixes from Steven Rostedt:
- Fix error output of boot instance creation failure
Currently if a boot instance creation fails, instead of printing out
the name of the instance that failed, it prints "(null)". That is
because it prints "cur_str" that had already been processed by
strsep(). Print the saved name instead.
While at it, print the error code of the failure.
- Fix use-after-free for same named historgrams
Histograms can be named so that they can be used in multiple events.
But if the named histogram has a variable attached, the second event
that uses the named histogram which duplicates it and needs to free
the original after duplication leaves the old variable in place and
still visible. If another histogram uses than variable, it will use
the stale one which will try to reference the freed duplicate
histogram and crash the kernel.
Free the duplicate variables along with the duplicated histogram
data.
- Check return value of kthread_run() in event self test
The events self tests uses a kthread for testing but does not check
if it succeeded in creating a kthread. If the kthread creation were
to fail, the code will still try to call kthread_stop() on the error
returned.
- Fix race between reading trace_pipe and updating subbuffer size
If a user is reading the trace_pipe file at the same time they update
the ring buffer sub-buffer size, can cause the trace_pipe read to
read stale data. Add trace_access_lock() around updating the ring
buffer sub-buffer size.
- Fix eventfs_inode on failure path in creation of the events directory
In the creation of the "events" directory, if after allocating the
eventfs_inode a failure is detected, it calls cleanup_ei() which
calls free_ei(). The free_ei() will test if eventfs_inode being freed
has no children. It is a bug if it does. But on the failure case of
the creation of the "events" directory, the children lists have not
yet been initialized and the free will trigger a warning because
list_empty() on an uninitialized list returns false.
Move the initialization into init_ei() where it makes more sense and
makes sure that a created eventfs_inode has its lists initialized
upon creation.
- Check return value of kthread_run() in ftrace direct sample code
The sample code that shows how to use the ftrace direct calls does
not test the return of kthread_run() to see if it succeeds. Return a
failure if the kthread_run() doesn't succeed.
- Clear user events state on fork in case of alloc failure
On fork, the child gets a pointer to the parent's user events state.
It makes a copy of it then updates the child's pointer to it. But if
the allocation fails, the duplication function leaves the child with
a pointer to its parent's descriptor. When the child cleans up its
data, it will free the parent's descriptor while the parent is still
using it.
In the duplication function, set the child's user_event_mm to NULL
before testing if the allocation succeeded, and when it exits it will
not free the parent's descriptor.
- Fix retry exhaustion in simple ring buffer reader swap
simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
post-decrements it only after a failed link replacement. On the final
attempt, a successful replacement leaves retry at zero, while a
failed replacement leaves it at -1.
But the check for success expects the retry value to be non-zero and
exits with an error on zero. This is the opposite result. Fix it.
- Fail nicely when the remote swap_reader_page() returns an error
Currently, if the swap_reader_page() of a remote buffer fails, it
triggers a WARN_ON_ONCE() and continues normally. Instead, have it
exit with an error and a pr_warn() print instead of a full WARNING.
* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ring-buffer: Stop remote reader update when page swap fails
tracing: Fix retry exhaustion in simple ring buffer reader swap
tracing/user_events: Clear copied tracing state before fork duplication
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
eventfs: Initialize ei->children and ei->list in init_ei()
tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
tracing: Fix crash passing ERR_PTR to kthread_stop()
tracing: Fix use-after-free with same-name named triggers
tracing: Fix logged instance name on creation failure
Diffstat (limited to 'Documentation/tools')
45 files changed, 2074 insertions, 0 deletions
diff --git a/Documentation/tools/feat.rst b/Documentation/tools/feat.rst new file mode 100644 index 000000000..021560eb6 --- /dev/null +++ b/Documentation/tools/feat.rst @@ -0,0 +1,10 @@ +.. SPDX-License-Identifier: GPL-2.0 + +==================================== +Documentation features parser module +==================================== + +.. automodule:: lib.python.feat.parse_features + :members: + :show-inheritance: + :undoc-members: diff --git a/Documentation/tools/index.rst b/Documentation/tools/index.rst new file mode 100644 index 000000000..1adf4a6f9 --- /dev/null +++ b/Documentation/tools/index.rst @@ -0,0 +1,16 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============ +Kernel tools +============ + +This book covers user-space tools that are shipped with the kernel source; +more additions are needed here: + +.. toctree:: + :maxdepth: 1 + + rtla/index + rv/index + python + sbom/sbom diff --git a/Documentation/tools/jobserver.rst b/Documentation/tools/jobserver.rst new file mode 100644 index 000000000..31eaf25a8 --- /dev/null +++ b/Documentation/tools/jobserver.rst @@ -0,0 +1,10 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================= +Job server module +================= + +.. automodule:: lib.python.jobserver + :members: + :show-inheritance: + :undoc-members: diff --git a/Documentation/tools/kabi.rst b/Documentation/tools/kabi.rst new file mode 100644 index 000000000..92812a20f --- /dev/null +++ b/Documentation/tools/kabi.rst @@ -0,0 +1,13 @@ +.. SPDX-License-Identifier: GPL-2.0 + +===================================== +Kernel ABI documentation tool modules +===================================== + +.. toctree:: + :maxdepth: 2 + + kabi_parser + kabi_regex + kabi_symbols + kabi_helpers diff --git a/Documentation/tools/kabi_helpers.rst b/Documentation/tools/kabi_helpers.rst new file mode 100644 index 000000000..5c6ec6081 --- /dev/null +++ b/Documentation/tools/kabi_helpers.rst @@ -0,0 +1,11 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================= +Ancillary classes +================= + +.. automodule:: lib.python.abi.helpers + :members: + :member-order: bysource + :show-inheritance: + :undoc-members: diff --git a/Documentation/tools/kabi_parser.rst b/Documentation/tools/kabi_parser.rst new file mode 100644 index 000000000..95826da21 --- /dev/null +++ b/Documentation/tools/kabi_parser.rst @@ -0,0 +1,10 @@ +.. SPDX-License-Identifier: GPL-2.0 + +===================================== +Kernel ABI documentation parser class +===================================== + +.. automodule:: lib.python.abi.abi_parser + :members: + :show-inheritance: + :undoc-members: diff --git a/Documentation/tools/kabi_regex.rst b/Documentation/tools/kabi_regex.rst new file mode 100644 index 000000000..bfc3a0d91 --- /dev/null +++ b/Documentation/tools/kabi_regex.rst @@ -0,0 +1,10 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================= +ABI regex search symbol class +============================= + +.. automodule:: lib.python.abi.abi_regex + :members: + :show-inheritance: + :undoc-members: diff --git a/Documentation/tools/kabi_symbols.rst b/Documentation/tools/kabi_symbols.rst new file mode 100644 index 000000000..c75a9380f --- /dev/null +++ b/Documentation/tools/kabi_symbols.rst @@ -0,0 +1,10 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========================================= +System ABI documentation validation class +========================================= + +.. automodule:: lib.python.abi.system_symbols + :members: + :show-inheritance: + :undoc-members: diff --git a/Documentation/tools/kdoc.rst b/Documentation/tools/kdoc.rst new file mode 100644 index 000000000..e51ba159d --- /dev/null +++ b/Documentation/tools/kdoc.rst @@ -0,0 +1,12 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================== +Kernel-doc modules +================== + +.. toctree:: + :maxdepth: 2 + + kdoc_parser + kdoc_output + kdoc_ancillary diff --git a/Documentation/tools/kdoc_ancillary.rst b/Documentation/tools/kdoc_ancillary.rst new file mode 100644 index 000000000..249753744 --- /dev/null +++ b/Documentation/tools/kdoc_ancillary.rst @@ -0,0 +1,63 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================= +Ancillary classes +================= + +Argparse formatter class +======================== + +.. automodule:: lib.python.kdoc.enrich_formatter + :members: + :show-inheritance: + :undoc-members: + +Regular expression class handler +================================ + +.. automodule:: lib.python.kdoc.kdoc_re + :members: + :show-inheritance: + :undoc-members: + + +C tokenizer +=========== + +.. automodule:: lib.python.kdoc.c_lex + :members: + :show-inheritance: + :undoc-members: + + +Chinese, Japanese and Korean variable fonts handler +=================================================== + +.. automodule:: lib.python.kdoc.latex_fonts + :members: + :show-inheritance: + :undoc-members: + +Kernel C file include logic +=========================== + +.. automodule:: lib.python.kdoc.parse_data_structs + :members: + :show-inheritance: + :undoc-members: + +Python version ancillary methods +================================ + +.. automodule:: lib.python.kdoc.python_version + :members: + :show-inheritance: + :undoc-members: + +Write output on YAML file +========================= + +.. automodule:: lib.python.kdoc.kdoc_yaml_file + :members: + :show-inheritance: + :undoc-members: diff --git a/Documentation/tools/kdoc_output.rst b/Documentation/tools/kdoc_output.rst new file mode 100644 index 000000000..08fd271ec --- /dev/null +++ b/Documentation/tools/kdoc_output.rst @@ -0,0 +1,14 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================= +Kernel-doc output stage +======================= + +Output handler for man pages and ReST +===================================== + +.. automodule:: lib.python.kdoc.kdoc_output + :members: + :show-inheritance: + :undoc-members: + diff --git a/Documentation/tools/kdoc_parser.rst b/Documentation/tools/kdoc_parser.rst new file mode 100644 index 000000000..55b202173 --- /dev/null +++ b/Documentation/tools/kdoc_parser.rst @@ -0,0 +1,37 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================= +Kernel-doc parser stage +======================= + +C replacement rules used by the parser +====================================== + +.. automodule:: lib.python.kdoc.xforms_lists + :members: + :show-inheritance: + :undoc-members: + +File handler classes +==================== + +.. automodule:: lib.python.kdoc.kdoc_files + :members: + :show-inheritance: + :undoc-members: + +Parsed item data class +====================== + +.. automodule:: lib.python.kdoc.kdoc_item + :members: + :show-inheritance: + :undoc-members: + +Parser classes and methods +========================== + +.. automodule:: lib.python.kdoc.kdoc_parser + :members: + :show-inheritance: + :undoc-members: diff --git a/Documentation/tools/python.rst b/Documentation/tools/python.rst new file mode 100644 index 000000000..3b7299161 --- /dev/null +++ b/Documentation/tools/python.rst @@ -0,0 +1,15 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================ +Python libraries +================ + +.. toctree:: + :maxdepth: 4 + + jobserver + feat + kdoc + kabi + + unittest diff --git a/Documentation/tools/rtla/Makefile b/Documentation/tools/rtla/Makefile new file mode 100644 index 000000000..093af6d7a --- /dev/null +++ b/Documentation/tools/rtla/Makefile @@ -0,0 +1,53 @@ +# SPDX-License-Identifier: GPL-2.0-only +# Based on bpftool's Documentation Makefile + +INSTALL ?= install +RM ?= rm -f +RMDIR ?= rmdir --ignore-fail-on-non-empty + +PREFIX ?= /usr/share +MANDIR ?= $(PREFIX)/man +MAN1DIR = $(MANDIR)/man1 + +MAN1_RST = $(wildcard rtla*.rst) + +_DOC_MAN1 = $(patsubst %.rst,%.1,$(MAN1_RST)) +DOC_MAN1 = $(addprefix $(OUTPUT),$(_DOC_MAN1)) + +RST2MAN_DEP := $(shell command -v rst2man 2>/dev/null) +RST2MAN_OPTS += --verbose + +TEST_RST2MAN = $(shell sh -c "rst2man --version > /dev/null 2>&1 || echo n") + +$(OUTPUT)%.1: %.rst +ifndef RST2MAN_DEP + $(info ********************************************) + $(info ** NOTICE: rst2man not found) + $(info **) + $(info ** Consider installing the latest rst2man from your) + $(info ** distribution, e.g., 'dnf install python3-docutils' on Fedora,) + $(info ** or from source:) + $(info **) + $(info ** https://docutils.sourceforge.io/docs/dev/repository.html ) + $(info **) + $(info ********************************************) + $(error NOTICE: rst2man required to generate man pages) +endif + rst2man $(RST2MAN_OPTS) $< > $@ + +man1: $(DOC_MAN1) +man: man1 + +clean: + $(RM) $(DOC_MAN1) + +install: man + $(INSTALL) -d -m 755 $(DESTDIR)$(MAN1DIR) + $(INSTALL) -m 644 $(DOC_MAN1) $(DESTDIR)$(MAN1DIR) + +uninstall: + $(RM) $(addprefix $(DESTDIR)$(MAN1DIR)/,$(_DOC_MAN1)) + $(RMDIR) $(DESTDIR)$(MAN1DIR) + +.PHONY: man man1 clean install uninstall +.DEFAULT_GOAL := man diff --git a/Documentation/tools/rtla/common_appendix.txt b/Documentation/tools/rtla/common_appendix.txt new file mode 100644 index 000000000..ad610ed02 --- /dev/null +++ b/Documentation/tools/rtla/common_appendix.txt @@ -0,0 +1,63 @@ +.. SPDX-License-Identifier: GPL-2.0 + +UNSETTING OPTIONS +================= + +The effect of most command line options can be reverted by prepending "no-" to +the long variant of the option, for example: + +$ rtla timerlat top -p 100 --no-period + +resets the period back to the default value of 1000 us. + +If a command line option sets multiple RTLA parameters at once, the inverted +option will revert all of them, even if they were not set by the particular +option. For example, since using "--auto" implies "--trace", specifying +"--trace --no-auto" will also disable trace output, just like if "--no-trace" +was specified. + + +SIGINT BEHAVIOR +=============== + +On the first SIGINT, RTLA exits after collecting all outstanding samples up to +the point of receiving the signal. + +When receiving more than one SIGINT, RTLA discards any outstanding samples, and +exits while displaying only samples that have already been processed. + +If SIGINT is received during RTLA cleanup, RTLA exits immediately via +the default signal handler. + +Note: For the purpose of SIGINT behavior, the expiry of duration specified via +the -d/--duration option is treated as equivalent to receiving a SIGINT. For +example, a SIGINT received after duration expired but samples have not been +processed yet will drop any outstanding samples. + +Also note that when using the timerlat tool in BPF mode, samples are processed +in-kernel; RTLA only copies them out to display them to the user. A second +SIGINT does not affect in-kernel sample aggregation. + +EXIT STATUS +=========== + +:: + + 0 Passed: the test did not hit the stop tracing condition + 1 Error: invalid argument + 2 Failed: the test hit the stop tracing condition + 129 Help: either user requested help or incorrect option was specified + +REPORTING BUGS +============== +Report bugs to <linux-kernel@vger.kernel.org> +and <linux-trace-devel@vger.kernel.org> + +LICENSE +======= +**rtla** is Free Software licensed under the GNU GPLv2 + +COPYING +======= +Copyright \(C) 2021 Red Hat, Inc. Free use of this software is granted under +the terms of the GNU Public License (GPL). diff --git a/Documentation/tools/rtla/common_hist_options.txt b/Documentation/tools/rtla/common_hist_options.txt new file mode 100644 index 000000000..df53ff835 --- /dev/null +++ b/Documentation/tools/rtla/common_hist_options.txt @@ -0,0 +1,23 @@ +**-b**, **--bucket-size** *N* + + Set the histogram bucket size (default *1*). + +**-E**, **--entries** *N* + + Set the number of entries of the histogram (default 256). + +**--no-header** + + Do not print header. + +**--no-summary** + + Do not print summary. + +**--no-index** + + Do not print index. + +**--with-zeros** + + Print zero only entries. diff --git a/Documentation/tools/rtla/common_options.txt b/Documentation/tools/rtla/common_options.txt new file mode 100644 index 000000000..38da1cf44 --- /dev/null +++ b/Documentation/tools/rtla/common_options.txt @@ -0,0 +1,140 @@ +**-c**, **--cpus** *cpu-list* + + Set the |tool| tracer to run the sample threads in the cpu-list. + + By default, the |tool| tracer runs the sample threads on all CPUs. + +**-H**, **--house-keeping** *cpu-list* + + Run rtla control threads only on the given cpu-list. + + If omitted, rtla will attempt to auto-migrate its main thread to any CPU that is not running any workload threads. + +**-d**, **--duration** *time[s|m|h|d]* + + Set the duration of the session. + +**-D**, **--debug** + + Print debug info. + +**-e**, **--event** *sys:event* + + Enable an event in the trace (**-t**) session. The argument can be a specific event, e.g., **-e** *sched:sched_switch*, or all events of a system group, e.g., **-e** *sched*. Multiple **-e** are allowed. It is only active when **-t** or **-a** are set. + + This option cannot be unset. + +**--filter** *<filter>* + + Filter the previous **-e** *sys:event* event with *<filter>*. For further information about event filtering see https://www.kernel.org/doc/html/latest/trace/events.html#event-filtering. + + This option cannot be unset. + +**--trigger** *<trigger>* + Enable a trace event trigger to the previous **-e** *sys:event*. + If the *hist:* trigger is activated, the output histogram will be automatically saved to a file named *system_event_hist.txt*. + For example, the command: + + rtla <command> <mode> -t -e osnoise:irq_noise --trigger="hist:key=desc,duration/1000:sort=desc,duration/1000:vals=hitcount" + + Will automatically save the content of the histogram associated to *osnoise:irq_noise* event in *osnoise_irq_noise_hist.txt*. + + For further information about event trigger see https://www.kernel.org/doc/html/latest/trace/events.html#event-triggers. + + This option cannot be unset. + +**-P**, **--priority** *o:prio|r:prio|f:prio|d:runtime:period* + + Set scheduling parameters to the |tool| tracer threads, the format to set the priority are: + + - *o:prio* - use SCHED_OTHER with *prio*; + - *r:prio* - use SCHED_RR with *prio*; + - *f:prio* - use SCHED_FIFO with *prio*; + - *d:runtime[us|ms|s]:period[us|ms|s]* - use SCHED_DEADLINE with *runtime* and *period* in nanoseconds. + + If not set, tracer threads keep their default priority. For rtla user threads, it is set to SCHED_FIFO with priority 95. For kernel threads, see *osnoise* and *timerlat* tracer documentation for the running kernel version. + +**-C**, **--cgroup** \[*cgroup*] + + Set a *cgroup* to the tracer's threads. If the **-C** option is passed without arguments, the tracer's thread will inherit **rtla**'s *cgroup*. Otherwise, the threads will be placed on the *cgroup* passed to the option. + + If not set, the behavior differs between workload types. User workloads created by rtla will inherit rtla's cgroup. Kernel workloads are assigned the root cgroup. + +**--warm-up** *s* + + After starting the workload, let it run for *s* seconds before starting collecting the data, allowing the system to warm-up. Statistical data generated during warm-up is discarded. + +**--trace-buffer-size** *kB* + Set the per-cpu trace buffer size in kB for the tracing output. + + If not set, the default tracefs buffer size is used. + +**--on-threshold** *action* + + Defines an action to be executed when tracing is stopped on a latency threshold + specified by |threshold|. + + Multiple --on-threshold actions may be specified, and they will be executed in + the order they are provided. If any action fails, subsequent actions in the list + will not be executed. + + Supported actions are: + + - *trace[,file=<filename>]* + + Saves trace output, optionally taking a filename. Alternative to -t/--trace. + Note that unlike -t/--trace, specifying this multiple times will result in + the trace being saved multiple times, and --no-trace will not disable trace + output when enabled through this option. + + - *signal,num=<sig>,pid=<pid>* + + Sends signal to process. "parent" might be specified in place of pid to target + the parent process of rtla. + + - *shell,command=<command>* + + Execute shell command. + + - *continue* + + Continue tracing after actions are executed instead of stopping. + + Example: + + $ rtla |tool| |thresharg| 20 --on-threshold trace + --on-threshold shell,command="grep ipi_send |tracer|\_trace.txt" + --on-threshold signal,num=2,pid=parent + + This will save a trace with the default filename "|tracer|\_trace.txt", print its + lines that contain the text "ipi_send" on standard output, and send signal 2 + (SIGINT) to the parent process. + + Performance Considerations: + + |actionsperf| + + This option cannot be unset. + +**--on-end** *action* + + Defines an action to be executed at the end of tracing. + + Multiple --on-end actions can be specified, and they will be executed in the order + they are provided. If any action fails, subsequent actions in the list will not be + executed. + + See the documentation for **--on-threshold** for the list of supported actions, with + the exception that *continue* has no effect. + + Example: + + $ rtla |tool| -d 5s --on-end trace + + This runs rtla with the default options, and saves trace output at the end. + + This option cannot be unset. + +**-h**, **--help** + + Print help menu. diff --git a/Documentation/tools/rtla/common_osnoise_description.txt b/Documentation/tools/rtla/common_osnoise_description.txt new file mode 100644 index 000000000..d5d61615b --- /dev/null +++ b/Documentation/tools/rtla/common_osnoise_description.txt @@ -0,0 +1,8 @@ +The **rtla osnoise** tool is an interface for the *osnoise* tracer. The +*osnoise* tracer dispatches a kernel thread per-cpu. These threads read the +time in a loop while with preemption, softirq and IRQs enabled, thus +allowing all the sources of operating system noise during its execution. +The *osnoise*'s tracer threads take note of the delta between each time +read, along with an interference counter of all sources of interference. +At the end of each period, the *osnoise* tracer displays a summary of +the results. diff --git a/Documentation/tools/rtla/common_osnoise_options.txt b/Documentation/tools/rtla/common_osnoise_options.txt new file mode 100644 index 000000000..5fc70c001 --- /dev/null +++ b/Documentation/tools/rtla/common_osnoise_options.txt @@ -0,0 +1,43 @@ +.. |threshold| replace:: **-a/--auto**, **-s/--stop**, or **-S/--stop-total** +.. |thresharg| replace:: -s +.. |tracer| replace:: osnoise + +.. |actionsperf| replace:: + Due to implementational limitations, actions might be delayed + up to one second after tracing is stopped. + +**-a**, **--auto** *us* + + Set the automatic trace mode. This mode sets some commonly used options + while debugging the system. It is equivalent to use **-s** *us* **-T 1 -t**. + +**-p**, **--period** *us* + + Set the *osnoise* tracer period in microseconds. + +**-r**, **--runtime** *us* + + Set the *osnoise* tracer runtime in microseconds. + +**-s**, **--stop** *us* + + Stop the trace if a single sample is higher than the argument in microseconds. + If **-T** is set, it will also save the trace to the output. + + This option cannot be unset. + +**-S**, **--stop-total** *us* + + Stop the trace if the total sample is higher than the argument in microseconds. + If **-T** is set, it will also save the trace to the output. + + This option cannot be unset. + +**-T**, **--threshold** *us* + + Specify the minimum delta between two time reads to be considered noise. + The default threshold is *5 us*. + +**-t**, **--trace** \[*file*] + + Save the stopped trace to [*file|osnoise_trace.txt*]. diff --git a/Documentation/tools/rtla/common_timerlat_aa.txt b/Documentation/tools/rtla/common_timerlat_aa.txt new file mode 100644 index 000000000..077029e6b --- /dev/null +++ b/Documentation/tools/rtla/common_timerlat_aa.txt @@ -0,0 +1,7 @@ +**--dump-tasks** + + prints the task running on all CPUs if stop conditions are met (depends on !--no-aa) + +**--no-aa** + + disable auto-analysis, reducing rtla timerlat cpu usage diff --git a/Documentation/tools/rtla/common_timerlat_description.txt b/Documentation/tools/rtla/common_timerlat_description.txt new file mode 100644 index 000000000..49fcae3ff --- /dev/null +++ b/Documentation/tools/rtla/common_timerlat_description.txt @@ -0,0 +1,18 @@ +The **rtla timerlat** tool is an interface for the *timerlat* tracer. The +*timerlat* tracer dispatches a kernel thread per-cpu. These threads +set a periodic timer to wake themselves up and go back to sleep. After +the wakeup, they collect and generate useful information for the +debugging of operating system timer latency. + +The *timerlat* tracer outputs information in two ways. It periodically +prints the timer latency at the timer *IRQ* handler and the *Thread* +handler. It also enables the trace of the most relevant information via +**osnoise:** tracepoints. + +The **rtla timerlat** tool sets the options of the *timerlat* tracer +and collects and displays a summary of the results. By default, +the collection is done synchronously in kernel space using a dedicated +BPF program attached to the *timerlat* tracer. If either BPF or +the **osnoise:timerlat_sample** tracepoint it attaches to is +unavailable, the **rtla timerlat** tool falls back to using tracefs to +process the data asynchronously in user space. diff --git a/Documentation/tools/rtla/common_timerlat_options.txt b/Documentation/tools/rtla/common_timerlat_options.txt new file mode 100644 index 000000000..e36898438 --- /dev/null +++ b/Documentation/tools/rtla/common_timerlat_options.txt @@ -0,0 +1,112 @@ +.. |threshold| replace:: **-a/--auto**, **-i/--irq**, or **-T/--thread** +.. |thresharg| replace:: -T +.. |tracer| replace:: timerlat + +.. |actionsperf| replace:: + For time-sensitive actions, it is recommended to run **rtla timerlat** with BPF + support and RT priority. Note that due to implementational limitations, actions + might be delayed up to one second after tracing is stopped if BPF mode is not + available or disabled. + +**-a**, **--auto** *us* + + Set the automatic trace mode. This mode sets some commonly used options + while debugging the system. It is equivalent to use **-T** *us* **-s** *us* + **-t**. By default, *timerlat* tracer uses FIFO:95 for *timerlat* threads, + thus equivalent to **-P** *f:95*. + +**-p**, **--period** *us* + + Set the *timerlat* tracer period in microseconds. + +**-i**, **--irq** *us* + + Stop trace if the *IRQ* latency is higher than the argument in us. + + This option cannot be unset. + +**-T**, **--thread** *us* + + Stop trace if the *Thread* latency is higher than the argument in us. + + This option cannot be unset. + +**-s**, **--stack** *us* + + Save the stack trace at the *IRQ* if a *Thread* latency is higher than the + argument in us. + +**-t**, **--trace** \[*file*] + + Save the stopped trace to [*file|timerlat_trace.txt*]. + +**--dma-latency** *us* + Set the /dev/cpu_dma_latency to *us*, aiming to bound exit from idle latencies. + *cyclictest* sets this value to *0* by default, use **--dma-latency** *0* to have + similar results. + +**--deepest-idle-state** *n* + Disable idle states higher than *n* for cpus that are running timerlat threads to + reduce exit from idle latencies. If *n* is -1, all idle states are disabled. + On exit from timerlat, the idle state setting is restored to its original state + before running timerlat. + + Requires rtla to be built with libcpupower. + +**-k**, **--kernel-threads** + + Use timerlat kernel-space threads, in contrast of **-u**. + +**-u**, **--user-threads** + + Set timerlat to run without a workload, and then dispatches user-space workloads + to wait on the timerlat_fd. Once the workload is awakened, it goes to sleep again + adding so the measurement for the kernel-to-user and user-to-kernel to the tracer + output. **--user-threads** will be used unless the user specify **-k**. + +**-U**, **--user-load** + + Set timerlat to run without workload, waiting for the user to dispatch a per-cpu + task that waits for a new period on the tracing/osnoise/per_cpu/cpu$ID/timerlat_fd. + See linux/tools/rtla/example/timerlat_load.py for an example of user-load code. + +**--bpf-action** *bpf-program* + + Loads a BPF program from an ELF file and executes it when a latency threshold is exceeded. + + The BPF program must be a valid ELF file loadable with libbpf. The program must contain + a function named ``action_handler``, stored in an ELF section with the ``tp_`` prefix. + The prefix is used by libbpf to set BPF program type to BPF_PROG_TYPE_TRACEPOINT. + + The program receives a ``struct trace_event_raw_timerlat_sample`` parameter + containing timerlat sample data. + + An example is provided in ``tools/tracing/rtla/example/timerlat_bpf_action.c``. + This example demonstrates how to create a BPF program that prints latency information using + bpf_trace_printk() when a threshold is exceeded. + + **Note**: BPF actions require BPF support to be available. If BPF is not available + or disabled, the tool falls back to tracefs mode and BPF actions are not supported. + +**--stack-format** *format* + + Adjust the format of the stack trace printed during auto-analysis. + + The supported values for *format* are: + + * **truncate** Print the stack trace up to the first unknown address (default). + * **skip** Skip unknown addresses. + * **full** Print the entire stack trace, including unknown addresses. + + For unknown addresses, the raw pointer is printed. + +**-A**, **--aligned** *us* + + Align wake-up of timerlat threads to a set offset in microseconds. + + The alignment will be applied when the threads wake up at the start of tracing while + the timer for the first cycle is armed. Each thread sets its timer to the wake-up time + of the previous thread plus the alignment. + + This option may be used with any non-negative argument, including zero, which will + align threads so that they wake up all at the same time. diff --git a/Documentation/tools/rtla/common_top_options.txt b/Documentation/tools/rtla/common_top_options.txt new file mode 100644 index 000000000..f48878938 --- /dev/null +++ b/Documentation/tools/rtla/common_top_options.txt @@ -0,0 +1,3 @@ +**-q**, **--quiet** + + Print only a summary at the end of the session. diff --git a/Documentation/tools/rtla/index.rst b/Documentation/tools/rtla/index.rst new file mode 100644 index 000000000..7664d6d0c --- /dev/null +++ b/Documentation/tools/rtla/index.rst @@ -0,0 +1,20 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================================ +The realtime Linux analysis tool +================================ + +RTLA provides a set of tools for the analysis of the kernel's realtime +behavior on specific hardware. + +.. toctree:: + :maxdepth: 1 + + rtla + rtla-osnoise + rtla-osnoise-hist + rtla-osnoise-top + rtla-timerlat + rtla-timerlat-hist + rtla-timerlat-top + rtla-hwnoise diff --git a/Documentation/tools/rtla/rtla-hwnoise.rst b/Documentation/tools/rtla/rtla-hwnoise.rst new file mode 100644 index 000000000..5930bbca4 --- /dev/null +++ b/Documentation/tools/rtla/rtla-hwnoise.rst @@ -0,0 +1,109 @@ +.. SPDX-License-Identifier: GPL-2.0 + +.. |tool| replace:: hwnoise + +============ +rtla-hwnoise +============ +------------------------------------------ +Detect and quantify hardware-related noise +------------------------------------------ + +:Manual section: 1 + +SYNOPSIS +======== + +**rtla hwnoise** [*OPTIONS*] + +DESCRIPTION +=========== + +**rtla hwnoise** collects the periodic summary from the *osnoise* tracer +running with *interrupts disabled*. By disabling interrupts, and the scheduling +of threads as a consequence, only non-maskable interrupts and hardware-related +noise is allowed. + +The tool also allows the configurations of the *osnoise* tracer and the +collection of the tracer output. + +OPTIONS +======= +.. include:: common_osnoise_options.txt + +.. include:: common_top_options.txt + +.. include:: common_options.txt + +EXAMPLE +======= +In the example below, the **rtla hwnoise** tool is set to run on CPUs *1-7* +on a system with 8 cores/16 threads with hyper-threading enabled. + +The tool is set to detect any noise higher than *one microsecond*, +to run for *ten minutes*, displaying a summary of the report at the +end of the session:: + + # rtla hwnoise -c 1-7 -T 1 -d 10m -q + Hardware-related Noise + duration: 0 00:10:00 | time is in us + CPU Period Runtime Noise % CPU Aval Max Noise Max Single HW NMI + 1 #599 599000000 138 99.99997 3 3 4 74 + 2 #599 599000000 85 99.99998 3 3 4 75 + 3 #599 599000000 86 99.99998 4 3 6 75 + 4 #599 599000000 81 99.99998 4 4 2 75 + 5 #599 599000000 85 99.99998 2 2 2 75 + 6 #599 599000000 76 99.99998 2 2 0 75 + 7 #599 599000000 77 99.99998 3 3 0 75 + + +The first column shows the *CPU*, and the second column shows how many +*Periods* the tool ran during the session. The *Runtime* is the time +the tool effectively runs on the CPU. The *Noise* column is the sum of +all noise that the tool observed, and the *% CPU Aval* is the relation +between the *Runtime* and *Noise*. + +The *Max Noise* column is the maximum hardware noise the tool detected in a +single period, and the *Max Single* is the maximum single noise seen. + +The *HW* and *NMI* columns show the total number of *hardware* and *NMI* noise +occurrence observed by the tool. + +For example, *CPU 3* ran *599* periods of *1 second Runtime*. The CPU received +*86 us* of noise during the entire execution, leaving *99.99997 %* of CPU time +for the application. In the worst single period, the CPU caused *4 us* of +noise to the application, but it was certainly caused by more than one single +noise, as the *Max Single* noise was of *3 us*. The CPU has *HW noise,* at a +rate of *six occurrences*/*ten minutes*. The CPU also has *NMIs*, at a higher +frequency: around *seven per second*. + +The tool should report *0* hardware-related noise in the ideal situation. +For example, by disabling hyper-threading to remove the hardware noise, +and disabling the TSC watchdog to remove the NMI (it is possible to identify +this using tracing options of **rtla hwnoise**), it was possible to reach +the ideal situation in the same hardware:: + + # rtla hwnoise -c 1-7 -T 1 -d 10m -q + Hardware-related Noise + duration: 0 00:10:00 | time is in us + CPU Period Runtime Noise % CPU Aval Max Noise Max Single HW NMI + 1 #599 599000000 0 100.00000 0 0 0 0 + 2 #599 599000000 0 100.00000 0 0 0 0 + 3 #599 599000000 0 100.00000 0 0 0 0 + 4 #599 599000000 0 100.00000 0 0 0 0 + 5 #599 599000000 0 100.00000 0 0 0 0 + 6 #599 599000000 0 100.00000 0 0 0 0 + 7 #599 599000000 0 100.00000 0 0 0 0 + +SEE ALSO +======== + +**rtla-osnoise**\(1) + +`Osnoise tracer <https://docs.kernel.org/trace/osnoise-tracer.html>`__ + +AUTHOR +====== +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.txt diff --git a/Documentation/tools/rtla/rtla-osnoise-hist.rst b/Documentation/tools/rtla/rtla-osnoise-hist.rst new file mode 100644 index 000000000..6ddea2c6d --- /dev/null +++ b/Documentation/tools/rtla/rtla-osnoise-hist.rst @@ -0,0 +1,68 @@ +.. |tool| replace:: osnoise hist + +=================== +rtla-osnoise-hist +=================== +------------------------------------------------------ +Display a histogram of the osnoise tracer samples +------------------------------------------------------ + +:Manual section: 1 + +SYNOPSIS +======== +**rtla osnoise hist** [*OPTIONS*] + +DESCRIPTION +=========== +.. include:: common_osnoise_description.txt + +The **rtla osnoise hist** tool collects all **osnoise:sample_threshold** +occurrence in a histogram, displaying the results in a user-friendly way. +The tool also allows many configurations of the *osnoise* tracer and the +collection of the tracer output. + +OPTIONS +======= +.. include:: common_osnoise_options.txt + +.. include:: common_hist_options.txt + +.. include:: common_options.txt + +EXAMPLE +======= +In the example below, *osnoise* tracer threads are set to run with real-time +priority *FIFO:1*, on CPUs *0-11*, for *900ms* at each period (*1s* by +default). The reason for reducing the runtime is to avoid starving the +**rtla** tool. The tool is also set to run for *one minute*. The output +histogram is set to group outputs in buckets of *10us* and *25* entries:: + + [root@f34 ~/]# rtla osnoise hist -P F:1 -c 0-11 -r 900000 -d 1M -b 10 -E 25 + # RTLA osnoise histogram + # Time unit is microseconds (us) + # Duration: 0 00:01:00 + Index CPU-000 CPU-001 CPU-002 CPU-003 CPU-004 CPU-005 CPU-006 CPU-007 CPU-008 CPU-009 CPU-010 CPU-011 + 0 42982 46287 51779 53740 52024 44817 49898 36500 50408 50128 49523 52377 + 10 12224 8356 2912 878 2667 10155 4573 18894 4214 4836 5708 2413 + 20 8 5 12 2 13 24 20 41 29 53 39 39 + 30 1 1 0 0 10 3 6 19 15 31 30 38 + 40 0 0 0 0 0 4 2 7 2 3 8 11 + 50 0 0 0 0 0 0 0 0 0 1 1 2 + over: 0 0 0 0 0 0 0 0 0 0 0 0 + count: 55215 54649 54703 54620 54714 55003 54499 55461 54668 55052 55309 54880 + min: 0 0 0 0 0 0 0 0 0 0 0 0 + avg: 0 0 0 0 0 0 0 0 0 0 0 0 + max: 30 30 20 20 30 40 40 40 40 50 50 50 + +SEE ALSO +======== +**rtla-osnoise**\(1), **rtla-osnoise-top**\(1) + +`Osnoise tracer <https://docs.kernel.org/trace/osnoise-tracer.html>`__ + +AUTHOR +====== +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.txt diff --git a/Documentation/tools/rtla/rtla-osnoise-top.rst b/Documentation/tools/rtla/rtla-osnoise-top.rst new file mode 100644 index 000000000..b91c02ac2 --- /dev/null +++ b/Documentation/tools/rtla/rtla-osnoise-top.rst @@ -0,0 +1,63 @@ +.. |tool| replace:: osnoise top + +=================== +rtla-osnoise-top +=================== +----------------------------------------------- +Display a summary of the operating system noise +----------------------------------------------- + +:Manual section: 1 + +SYNOPSIS +======== +**rtla osnoise top** [*OPTIONS*] + +DESCRIPTION +=========== +.. include:: common_osnoise_description.txt + +**rtla osnoise top** collects the periodic summary from the *osnoise* tracer, +including the counters of the occurrence of the interference source, +displaying the results in a user-friendly format. + +The tool also allows many configurations of the *osnoise* tracer and the +collection of the tracer output. + +OPTIONS +======= +.. include:: common_osnoise_options.txt + +.. include:: common_top_options.txt + +.. include:: common_options.txt + +EXAMPLE +======= +In the example below, the **rtla osnoise top** tool is set to run with a +real-time priority *FIFO:1*, on CPUs *0-3*, for *900ms* at each period +(*1s* by default). The reason for reducing the runtime is to avoid starving +the rtla tool. The tool is also set to run for *one minute* and to display +a summary of the report at the end of the session:: + + [root@f34 ~]# rtla osnoise top -P F:1 -c 0-3 -r 900000 -d 1M -q + Operating System Noise + duration: 0 00:01:00 | time is in us + CPU Period Runtime Noise % CPU Aval Max Noise Max Single HW NMI IRQ Softirq Thread + 0 #59 53100000 304896 99.42580 6978 56 549 0 53111 1590 13 + 1 #59 53100000 338339 99.36282 8092 24 399 0 53130 1448 31 + 2 #59 53100000 290842 99.45227 6582 39 855 0 53110 1406 12 + 3 #59 53100000 204935 99.61405 6251 33 290 0 53156 1460 12 + +SEE ALSO +======== + +**rtla-osnoise**\(1), **rtla-osnoise-hist**\(1) + +`Osnoise tracer <https://docs.kernel.org/trace/osnoise-tracer.html>`__ + +AUTHOR +====== +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.txt diff --git a/Documentation/tools/rtla/rtla-osnoise.rst b/Documentation/tools/rtla/rtla-osnoise.rst new file mode 100644 index 000000000..decd9e11f --- /dev/null +++ b/Documentation/tools/rtla/rtla-osnoise.rst @@ -0,0 +1,59 @@ +=============== +rtla-osnoise +=============== +------------------------------------------------------------------ +Measure the operating system noise +------------------------------------------------------------------ + +:Manual section: 1 + +SYNOPSIS +======== +**rtla osnoise** [*MODE*] ... + +DESCRIPTION +=========== + +.. include:: common_osnoise_description.txt + +The *osnoise* tracer outputs information in two ways. It periodically prints +a summary of the noise of the operating system, including the counters of +the occurrence of the source of interference. It also provides information +for each noise via the **osnoise:** tracepoints. The **rtla osnoise top** +mode displays information about the periodic summary from the *osnoise* tracer. +The **rtla osnoise hist** mode displays information about the noise using +the **osnoise:** tracepoints. For further details, please refer to the +respective man page. + +MODES +===== +**top** + + Prints the summary from osnoise tracer. + +**hist** + + Prints a histogram of osnoise samples. + +If no MODE is given, the top mode is called, passing the arguments. + +OPTIONS +======= + +**-h**, **--help** + + Display the help text. + +For other options, see the man page for the corresponding mode. + +SEE ALSO +======== +**rtla-osnoise-top**\(1), **rtla-osnoise-hist**\(1) + +`Osnoise tracer <https://docs.kernel.org/trace/osnoise-tracer.html>`__ + +AUTHOR +====== +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.txt diff --git a/Documentation/tools/rtla/rtla-timerlat-hist.rst b/Documentation/tools/rtla/rtla-timerlat-hist.rst new file mode 100644 index 000000000..dab75677b --- /dev/null +++ b/Documentation/tools/rtla/rtla-timerlat-hist.rst @@ -0,0 +1,113 @@ +.. |tool| replace:: timerlat hist + +===================== +rtla-timerlat-hist +===================== +------------------------------------------------ +Histograms of the operating system timer latency +------------------------------------------------ + +:Manual section: 1 + +SYNOPSIS +======== +**rtla timerlat hist** [*OPTIONS*] ... + +DESCRIPTION +=========== + +.. include:: common_timerlat_description.txt + +The **rtla timerlat hist** displays a histogram of each tracer event +occurrence. This tool uses the periodic information, and the +**osnoise:** tracepoints are enabled when using the **-T** option. + +OPTIONS +======= + +.. include:: common_timerlat_options.txt + +.. include:: common_hist_options.txt + +.. include:: common_options.txt + +.. include:: common_timerlat_aa.txt + +EXAMPLE +======= +In the example below, **rtla timerlat hist** is set to run for *10* minutes, +in the cpus *0-4*, *skipping zero* only lines. Moreover, **rtla timerlat +hist** will change the priority of the *timerlat* threads to run under +*SCHED_DEADLINE* priority, with a *100us* runtime every *1ms* period. The +*1ms* period is also passed to the *timerlat* tracer. Auto-analysis is disabled +to reduce overhead :: + + [root@alien ~]# timerlat hist -d 10m -c 0-4 -P d:100us:1ms -p 1000 --no-aa + # RTLA timerlat histogram + # Time unit is microseconds (us) + # Duration: 0 00:10:00 + Index IRQ-000 Thr-000 IRQ-001 Thr-001 IRQ-002 Thr-002 IRQ-003 Thr-003 IRQ-004 Thr-004 + 0 276489 0 206089 0 466018 0 481102 0 205546 0 + 1 318327 35487 388149 30024 94531 48382 83082 71078 388026 55730 + 2 3282 122584 4019 126527 28231 109012 23311 89309 4568 98739 + 3 940 11815 837 9863 6209 16227 6895 17196 910 9780 + 4 444 17287 424 11574 2097 38443 2169 36736 462 13476 + 5 206 43291 255 25581 1223 101908 1304 101137 236 28913 + 6 132 101501 96 64584 635 213774 757 215471 99 73453 + 7 74 169347 65 124758 350 57466 441 53639 69 148573 + 8 53 85183 31 156751 229 9052 306 9026 39 139907 + 9 22 10387 12 42762 161 2554 225 2689 19 26192 + 10 13 1898 8 5770 114 1247 128 1405 13 3772 + 11 9 560 9 924 71 686 76 765 8 713 + 12 4 256 2 360 50 411 64 474 3 278 + 13 2 167 2 172 43 256 53 350 4 180 + 14 1 88 1 116 15 198 42 223 0 115 + 15 2 63 3 94 11 139 20 150 0 58 + 16 2 37 0 56 5 78 10 102 0 39 + 17 0 18 0 28 4 57 8 80 0 15 + 18 0 8 0 17 2 50 6 56 0 12 + 19 0 9 0 5 0 19 0 48 0 18 + 20 0 4 0 8 0 11 2 27 0 4 + 21 0 2 0 3 1 9 1 18 0 6 + 22 0 1 0 3 1 7 0 3 0 5 + 23 0 2 0 4 0 2 0 7 0 2 + 24 0 2 0 2 1 3 0 3 0 5 + 25 0 0 0 1 0 1 0 1 0 3 + 26 0 1 0 0 0 2 0 2 0 0 + 27 0 0 0 3 0 1 0 0 0 1 + 28 0 0 0 3 0 0 0 1 0 0 + 29 0 0 0 2 0 2 0 1 0 3 + 30 0 1 0 0 0 0 0 0 0 0 + 31 0 1 0 0 0 0 0 2 0 2 + 32 0 0 0 1 0 2 0 0 0 0 + 33 0 0 0 2 0 0 0 0 0 1 + 34 0 0 0 0 0 0 0 0 0 2 + 35 0 1 0 1 0 0 0 0 0 1 + 36 0 1 0 0 0 1 0 1 0 0 + 37 0 0 0 1 0 0 0 0 0 0 + 40 0 0 0 0 0 1 0 1 0 0 + 41 0 0 0 0 0 0 0 0 0 1 + 42 0 0 0 0 0 0 0 0 0 1 + 44 0 0 0 0 0 1 0 0 0 0 + 46 0 0 0 0 0 0 0 1 0 0 + 47 0 0 0 0 0 0 0 0 0 1 + 50 0 0 0 0 0 0 0 0 0 1 + 54 0 0 0 1 0 0 0 0 0 0 + 58 0 0 0 1 0 0 0 0 0 0 + over: 0 0 0 0 0 0 0 0 0 0 + count: 600002 600002 600002 600002 600002 600002 600002 600002 600002 600002 + min: 0 1 0 1 0 1 0 1 0 1 + avg: 0 5 0 5 0 4 0 4 0 5 + max: 16 36 15 58 24 44 21 46 13 50 + +SEE ALSO +======== +**rtla-timerlat**\(1), **rtla-timerlat-top**\(1) + +`Timerlat tracer <https://docs.kernel.org/trace/timerlat-tracer.html>`__ + +AUTHOR +====== +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.txt diff --git a/Documentation/tools/rtla/rtla-timerlat-top.rst b/Documentation/tools/rtla/rtla-timerlat-top.rst new file mode 100644 index 000000000..05959f1a4 --- /dev/null +++ b/Documentation/tools/rtla/rtla-timerlat-top.rst @@ -0,0 +1,136 @@ +.. |tool| replace:: timerlat top + +==================== +rtla-timerlat-top +==================== +------------------------------------------- +Measures the operating system timer latency +------------------------------------------- + +:Manual section: 1 + +SYNOPSIS +======== +**rtla timerlat top** [*OPTIONS*] ... + +DESCRIPTION +=========== + +.. include:: common_timerlat_description.txt + +The **rtla timerlat top** displays a summary of the periodic output +from the *timerlat* tracer. It also provides information for each +operating system noise via the **osnoise:** tracepoints that can be +seen with the option **-T**. + +OPTIONS +======= + +.. include:: common_timerlat_options.txt + +.. include:: common_top_options.txt + +.. include:: common_options.txt + +.. include:: common_timerlat_aa.txt + +**--aa-only** *us* + + Set stop tracing conditions and run without collecting and displaying statistics. + Print the auto-analysis if the system hits the stop tracing condition. This option + is useful to reduce rtla timerlat CPU, enabling the debug without the overhead of + collecting the statistics. + +EXAMPLE +======= + +In the example below, the timerlat tracer is dispatched in cpus *1-23* in the +automatic trace mode, instructing the tracer to stop if a *40 us* latency or +higher is found:: + + # timerlat -a 40 -c 1-23 -q + Timer Latency + 0 00:00:12 | IRQ Timer Latency (us) | Thread Timer Latency (us) + CPU COUNT | cur min avg max | cur min avg max + 1 #12322 | 0 0 1 15 | 10 3 9 31 + 2 #12322 | 3 0 1 12 | 10 3 9 23 + 3 #12322 | 1 0 1 21 | 8 2 8 34 + 4 #12322 | 1 0 1 17 | 10 2 11 33 + 5 #12322 | 0 0 1 12 | 8 3 8 25 + 6 #12322 | 1 0 1 14 | 16 3 11 35 + 7 #12322 | 0 0 1 14 | 9 2 8 29 + 8 #12322 | 1 0 1 22 | 9 3 9 34 + 9 #12322 | 0 0 1 14 | 8 2 8 24 + 10 #12322 | 1 0 0 12 | 9 3 8 24 + 11 #12322 | 0 0 0 15 | 6 2 7 29 + 12 #12321 | 1 0 0 13 | 5 3 8 23 + 13 #12319 | 0 0 1 14 | 9 3 9 26 + 14 #12321 | 1 0 0 13 | 6 2 8 24 + 15 #12321 | 1 0 1 15 | 12 3 11 27 + 16 #12318 | 0 0 1 13 | 7 3 10 24 + 17 #12319 | 0 0 1 13 | 11 3 9 25 + 18 #12318 | 0 0 0 12 | 8 2 8 20 + 19 #12319 | 0 0 1 18 | 10 2 9 28 + 20 #12317 | 0 0 0 20 | 9 3 8 34 + 21 #12318 | 0 0 0 13 | 8 3 8 28 + 22 #12319 | 0 0 1 11 | 8 3 10 22 + 23 #12320 | 28 0 1 28 | 41 3 11 41 + rtla timerlat hit stop tracing + ## CPU 23 hit stop tracing, analyzing it ## + IRQ handler delay: 27.49 us (65.52 %) + IRQ latency: 28.13 us + Timerlat IRQ duration: 9.59 us (22.85 %) + Blocking thread: 3.79 us (9.03 %) + objtool:49256 3.79 us + Blocking thread stacktrace + -> timerlat_irq + -> __hrtimer_run_queues + -> hrtimer_interrupt + -> __sysvec_apic_timer_interrupt + -> sysvec_apic_timer_interrupt + -> asm_sysvec_apic_timer_interrupt + -> _raw_spin_unlock_irqrestore + -> cgroup_rstat_flush_locked + -> cgroup_rstat_flush_irqsafe + -> mem_cgroup_flush_stats + -> mem_cgroup_wb_stats + -> balance_dirty_pages + -> balance_dirty_pages_ratelimited_flags + -> btrfs_buffered_write + -> btrfs_do_write_iter + -> vfs_write + -> __x64_sys_pwrite64 + -> do_syscall_64 + -> entry_SYSCALL_64_after_hwframe + ------------------------------------------------------------------------ + Thread latency: 41.96 us (100%) + + The system has exit from idle latency! + Max timerlat IRQ latency from idle: 17.48 us in cpu 4 + Saving trace to timerlat_trace.txt + +In this case, the major factor was the delay suffered by the *IRQ handler* +that handles **timerlat** wakeup: *65.52%*. This can be caused by the +current thread masking interrupts, which can be seen in the blocking +thread stacktrace: the current thread (*objtool:49256*) disabled interrupts +via *raw spin lock* operations inside mem cgroup, while doing write +syscall in a btrfs file system. + +The raw trace is saved in the **timerlat_trace.txt** file for further analysis. + +Note that **rtla timerlat** was dispatched without changing *timerlat* tracer +threads' priority. That is generally not needed because these threads have +priority *FIFO:95* by default, which is a common priority used by real-time +kernel developers to analyze scheduling delays. + +SEE ALSO +-------- +**rtla-timerlat**\(1), **rtla-timerlat-hist**\(1) + +`Timerlat tracer <https://docs.kernel.org/trace/timerlat-tracer.html>`__ + +AUTHOR +------ +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.txt diff --git a/Documentation/tools/rtla/rtla-timerlat.rst b/Documentation/tools/rtla/rtla-timerlat.rst new file mode 100644 index 000000000..63718c52a --- /dev/null +++ b/Documentation/tools/rtla/rtla-timerlat.rst @@ -0,0 +1,54 @@ +================ +rtla-timerlat +================ +------------------------------------------- +Measures the operating system timer latency +------------------------------------------- + +:Manual section: 1 + +SYNOPSIS +======== +**rtla timerlat** [*MODE*] ... + +DESCRIPTION +=========== + +.. include:: common_timerlat_description.txt + +The **rtla timerlat top** mode displays a summary of the periodic output +from the *timerlat* tracer. The **rtla timerlat hist** mode displays +a histogram of each tracer event occurrence. For further details, please +refer to the respective man page. + +MODES +===== +**top** + + Prints the summary from *timerlat* tracer. + +**hist** + + Prints a histogram of timerlat samples. + +If no *MODE* is given, the top mode is called, passing the arguments. + +OPTIONS +======= +**-h**, **--help** + + Display the help text. + +For other options, see the man page for the corresponding mode. + +SEE ALSO +======== +**rtla-timerlat-top**\(1), **rtla-timerlat-hist**\(1) + +`Timerlat tracer <https://docs.kernel.org/trace/timerlat-tracer.html>`__ + +AUTHOR +====== +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.txt diff --git a/Documentation/tools/rtla/rtla.rst b/Documentation/tools/rtla/rtla.rst new file mode 100644 index 000000000..6df1296b8 --- /dev/null +++ b/Documentation/tools/rtla/rtla.rst @@ -0,0 +1,52 @@ +========= +rtla +========= +-------------------------------- +Real-time Linux Analysis tool +-------------------------------- + +:Manual section: 1 + +SYNOPSIS +======== +**rtla** *COMMAND* [*OPTIONS*] + +DESCRIPTION +=========== +The **rtla** is a meta-tool that includes a set of commands that aims to +analyze the real-time properties of Linux. But instead of testing Linux +as a black box, **rtla** leverages kernel tracing capabilities to provide +precise information about the properties and root causes of unexpected +results. + +COMMANDS +======== +**hwnoise** + + Detect and quantify hardware-related noise. + +**osnoise** + + Gives information about the operating system noise (osnoise). + +**timerlat** + + Measures the IRQ and thread timer latency. + +OPTIONS +======= +**-h**, **--help** + + Display the help text. + +For other options, see the man page for the corresponding command. + +SEE ALSO +======== +**rtla-hwnoise**\(1), **rtla-osnoise**\(1), **rtla-timerlat**\(1) + +AUTHOR +====== +Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.txt diff --git a/Documentation/tools/rv/Makefile b/Documentation/tools/rv/Makefile new file mode 100644 index 000000000..ec8713c1b --- /dev/null +++ b/Documentation/tools/rv/Makefile @@ -0,0 +1,52 @@ +# SPDX-License-Identifier: GPL-2.0-only + +INSTALL ?= install +RM ?= rm -f +RMDIR ?= rmdir --ignore-fail-on-non-empty + +PREFIX ?= /usr/share +MANDIR ?= $(PREFIX)/man +MAN1DIR = $(MANDIR)/man1 + +MAN1_RST = $(wildcard rv*.rst) + +_DOC_MAN1 = $(patsubst %.rst,%.1,$(MAN1_RST)) +DOC_MAN1 = $(addprefix $(OUTPUT),$(_DOC_MAN1)) + +RST2MAN_DEP := $(shell command -v rst2man 2>/dev/null) +RST2MAN_OPTS += --verbose + +TEST_RST2MAN = $(shell sh -c "rst2man --version > /dev/null 2>&1 || echo n") + +$(OUTPUT)%.1: %.rst +ifndef RST2MAN_DEP + $(info ********************************************) + $(info ** NOTICE: rst2man not found) + $(info **) + $(info ** Consider installing the latest rst2man from your) + $(info ** distribution, e.g., 'dnf install python3-docutils' on Fedora,) + $(info ** or from source:) + $(info **) + $(info ** https://docutils.sourceforge.io/docs/dev/repository.html ) + $(info **) + $(info ********************************************) + $(error NOTICE: rst2man required to generate man pages) +endif + rst2man $(RST2MAN_OPTS) $< > $@ + +man1: $(DOC_MAN1) +man: man1 + +clean: + $(RM) $(DOC_MAN1) + +install: man + $(INSTALL) -d -m 755 $(DESTDIR)$(MAN1DIR) + $(INSTALL) -m 644 $(DOC_MAN1) $(DESTDIR)$(MAN1DIR) + +uninstall: + $(RM) $(addprefix $(DESTDIR)$(MAN1DIR)/,$(_DOC_MAN1)) + $(RMDIR) $(DESTDIR)$(MAN1DIR) + +.PHONY: man man1 clean install uninstall +.DEFAULT_GOAL := man diff --git a/Documentation/tools/rv/common_appendix.rst b/Documentation/tools/rv/common_appendix.rst new file mode 100644 index 000000000..f4239192b --- /dev/null +++ b/Documentation/tools/rv/common_appendix.rst @@ -0,0 +1,16 @@ +REPORTING BUGS +============== + +Report bugs to <linux-kernel@vger.kernel.org> +and <linux-trace-devel@vger.kernel.org> + +LICENSE +======= + +**rv** is Free Software licensed under the GNU GPLv2 + +COPYING +======= + +Copyright \(C) 2022 Red Hat, Inc. Free use of this software is granted under +the terms of the GNU Public License (GPL). diff --git a/Documentation/tools/rv/common_ikm.rst b/Documentation/tools/rv/common_ikm.rst new file mode 100644 index 000000000..e50a5f8a7 --- /dev/null +++ b/Documentation/tools/rv/common_ikm.rst @@ -0,0 +1,21 @@ +**-h**, **--help** + + Print the monitor's options and the available reactors list. + +**-r**, **--reactor** *reactor* + + Enables the *reactor*. See **-h** for a list of available reactors. + +**-s**, **--self** + + When tracing (**-t**), also print the events that happened during the **rv** + command itself. If the **rv** command itself generates too many events, + the tool might get busy processing its own events only. + +**-t**, **--trace** + + Trace monitor's events and error. + +**-v**, **--verbose** + + Print debug messages. diff --git a/Documentation/tools/rv/index.rst b/Documentation/tools/rv/index.rst new file mode 100644 index 000000000..2aaa01c9f --- /dev/null +++ b/Documentation/tools/rv/index.rst @@ -0,0 +1,19 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================== +Runtime verification (rv) tool +============================== + +**rv** tool provides the interface for a collection of runtime verification +(rv) monitors. + +.. toctree:: + :maxdepth: 1 + + rv + rv-list + rv-mon + rv-mon-wip + rv-mon-wwnr + rv-mon-sched + rv-mon-stall diff --git a/Documentation/tools/rv/rv-list.rst b/Documentation/tools/rv/rv-list.rst new file mode 100644 index 000000000..51e4608f9 --- /dev/null +++ b/Documentation/tools/rv/rv-list.rst @@ -0,0 +1,43 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======= +rv-list +======= +----------------------- +List available monitors +----------------------- + +:Manual section: 1 + +SYNOPSIS +======== + +**rv list** [*OPTIONS*] + +DESCRIPTION +=========== + +The **rv list** command prints all available monitors. These monitors +can be enabled using the **rv mon** command. + +OPTIONS +======= + +**-h**, **--help** + + Print help menu. + +SEE ALSO +======== + +**rv**\(1), **rv-mon**\(1) + +Linux kernel *RV* documentation: +<https://www.kernel.org/doc/html/latest/trace/rv/index.html> + +AUTHOR +====== + +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.rst diff --git a/Documentation/tools/rv/rv-mon-sched.rst b/Documentation/tools/rv/rv-mon-sched.rst new file mode 100644 index 000000000..da0fe4c79 --- /dev/null +++ b/Documentation/tools/rv/rv-mon-sched.rst @@ -0,0 +1,69 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============ +rv-mon-sched +============ +----------------------------- +Scheduler monitors collection +----------------------------- + +:Manual section: 1 + +SYNOPSIS +======== + +**rv mon sched** [*OPTIONS*] + +**rv mon <NESTED_MONITOR>** [*OPTIONS*] + +**rv mon sched:<NESTED_MONITOR>** [*OPTIONS*] + +DESCRIPTION +=========== + +The scheduler monitor collection is a container for several monitors to model +the behaviour of the scheduler. Each monitor describes a specification that +the scheduler should follow. + +As a monitor container, it will enable all nested monitors and set them +according to OPTIONS. +Nevertheless nested monitors can also be activated independently both by name +and by specifying sched: , e.g. to enable only monitor tss you can do any of: + + # rv mon sched:tss + + # rv mon tss + +See kernel documentation for further information about this monitor: +<https://docs.kernel.org/trace/rv/monitor_sched.html> + +OPTIONS +======= + +.. include:: common_ikm.rst + +NESTED MONITOR +============== + +The available nested monitors are: + * scpd: schedule called with preemption disabled + * snep: schedule does not enable preempt + * sncid: schedule not called with interrupt disabled + * snroc: set non runnable on its own context + * sco: scheduling context operations + * tss: task switch while scheduling + +SEE ALSO +======== + +**rv**\(1), **rv-mon**\(1) + +Linux kernel *RV* documentation: +<https://www.kernel.org/doc/html/latest/trace/rv/index.html> + +AUTHOR +====== + +Written by Gabriele Monaco <gmonaco@redhat.com> + +.. include:: common_appendix.rst diff --git a/Documentation/tools/rv/rv-mon-stall.rst b/Documentation/tools/rv/rv-mon-stall.rst new file mode 100644 index 000000000..c79d7c2e4 --- /dev/null +++ b/Documentation/tools/rv/rv-mon-stall.rst @@ -0,0 +1,44 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============ +rv-mon-stall +============ +-------------------- +Stalled task monitor +-------------------- + +:Manual section: 1 + +SYNOPSIS +======== + +**rv mon stall** [*OPTIONS*] + +DESCRIPTION +=========== + +The stalled task (**stall**) monitor is a sample per-task timed monitor that +checks if tasks are scheduled within a defined threshold after they are ready. + +See kernel documentation for further information about this monitor: +<https://docs.kernel.org/trace/rv/monitor_stall.html> + +OPTIONS +======= + +.. include:: common_ikm.rst + +SEE ALSO +======== + +**rv**\(1), **rv-mon**\(1) + +Linux kernel *RV* documentation: +<https://www.kernel.org/doc/html/latest/trace/rv/index.html> + +AUTHOR +====== + +Written by Gabriele Monaco <gmonaco@redhat.com> + +.. include:: common_appendix.rst diff --git a/Documentation/tools/rv/rv-mon-wip.rst b/Documentation/tools/rv/rv-mon-wip.rst new file mode 100644 index 000000000..2d42104d6 --- /dev/null +++ b/Documentation/tools/rv/rv-mon-wip.rst @@ -0,0 +1,44 @@ +.. SPDX-License-Identifier: GPL-2.0 + +========== +rv-mon-wip +========== +---------------------------- +Wakeup In Preemptive monitor +---------------------------- + +:Manual section: 1 + +SYNOPSIS +======== + +**rv mon wip** [*OPTIONS*] + +DESCRIPTION +=========== + +The wakeup in preemptive (**wip**) monitor is a sample per-cpu monitor that +checks if the wakeup events always take place with preemption disabled. + +See kernel documentation for further information about this monitor: +<https://docs.kernel.org/trace/rv/monitor_wip.html> + +OPTIONS +======= + +.. include:: common_ikm.rst + +SEE ALSO +======== + +**rv**\(1), **rv-mon**\(1) + +Linux kernel *RV* documentation: +<https://www.kernel.org/doc/html/latest/trace/rv/index.html> + +AUTHOR +====== + +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.rst diff --git a/Documentation/tools/rv/rv-mon-wwnr.rst b/Documentation/tools/rv/rv-mon-wwnr.rst new file mode 100644 index 000000000..a18f3fd54 --- /dev/null +++ b/Documentation/tools/rv/rv-mon-wwnr.rst @@ -0,0 +1,43 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=========== +rv-mon-wwnr +=========== +-------------------------------- +Wakeup While Not Running monitor +-------------------------------- + +:Manual section: 1 + +SYNOPSIS +======== + +**rv mon wip** [*OPTIONS*] + +DESCRIPTION +=========== + +The wakeup while not running (**wwnr**) is a per-task sample monitor. + +See kernel documentation for further information about this monitor: +<https://docs.kernel.org/trace/rv/monitor_wwnr.html> + +OPTIONS +======= + +.. include:: common_ikm.rst + +SEE ALSO +======== + +**rv**\(1), **rv-mon**\(1) + +Linux kernel *RV* documentation: +<https://www.kernel.org/doc/html/latest/trace/rv/index.html> + +AUTHOR +====== + +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.rst diff --git a/Documentation/tools/rv/rv-mon.rst b/Documentation/tools/rv/rv-mon.rst new file mode 100644 index 000000000..4d86fd55e --- /dev/null +++ b/Documentation/tools/rv/rv-mon.rst @@ -0,0 +1,55 @@ +.. SPDX-License-Identifier: GPL-2.0 + +====== +rv-mon +====== +----------------------- +List available monitors +----------------------- + +:Manual section: 1 + +SYNOPSIS +======== + +**rv mon** [*-h*] **monitor_name** [*-h*] [*MONITOR OPTIONS*] + +DESCRIPTION +=========== + +The **rv mon** command runs the monitor named *monitor_name*. Each monitor +has its own set of options. The **rv list** command shows all available +monitors. + +OPTIONS +======= + +**-h**, **--help** + + Print help menu. + +AVAILABLE MONITORS +================== + +The **rv** tool provides the interface for a set of monitors. Use the +**rv list** command to list all available monitors. + +Each monitor has its own set of options. See man **rv-mon**-*monitor_name* +for details about each specific monitor. Also, running **rv mon** +**monitor_name** **-h** display the help menu with the available +options. + +SEE ALSO +======== + +**rv**\(1), **rv-mon**\(1) + +Linux kernel *RV* documentation: +<https://www.kernel.org/doc/html/latest/trace/rv/index.html> + +AUTHOR +====== + +Written by Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.rst diff --git a/Documentation/tools/rv/rv.rst b/Documentation/tools/rv/rv.rst new file mode 100644 index 000000000..cee93dc21 --- /dev/null +++ b/Documentation/tools/rv/rv.rst @@ -0,0 +1,63 @@ +.. SPDX-License-Identifier: GPL-2.0 + +== +rv +== +-------------------- +Runtime Verification +-------------------- + +:Manual section: 1 + +SYNOPSIS +======== + +**rv** *COMMAND* [*OPTIONS*] + +DESCRIPTION +=========== + +Runtime Verification (**RV**) is a lightweight (yet rigorous) method +for formal verification with a practical approach for complex systems. +Instead of relying on a fine-grained model of a system (e.g., a +re-implementation a instruction level), RV works by analyzing the trace +of the system's actual execution, comparing it against a formal +specification of the system behavior. + +The **rv** tool provides the interface for a collection of runtime +verification (rv) monitors. + +COMMANDS +======== + +**list** + + List all available monitors. + +**mon** + + Run monitor. + +OPTIONS +======= + +**-h**, **--help** + + Display the help text. + +For other options, see the man page for the corresponding command. + +SEE ALSO +======== + +**rv-list**\(1), **rv-mon**\(1) + +Linux kernel *RV* documentation: +<https://www.kernel.org/doc/html/latest/trace/rv/index.html> + +AUTHOR +====== + +Daniel Bristot de Oliveira <bristot@kernel.org> + +.. include:: common_appendix.rst diff --git a/Documentation/tools/sbom/sbom.rst b/Documentation/tools/sbom/sbom.rst new file mode 100644 index 000000000..029b08b6a --- /dev/null +++ b/Documentation/tools/sbom/sbom.rst @@ -0,0 +1,206 @@ +.. SPDX-License-Identifier: GPL-2.0-only OR MIT +.. Copyright (C) 2025 TNG Technology Consulting GmbH + +KernelSbom +========== + +Introduction +------------ + +KernelSbom is a Python script ``scripts/sbom/sbom.py`` that can be +executed after a successful kernel build. When invoked, KernelSbom +analyzes all files involved in the build and generates Software Bill of +Materials (SBOM) documents in SPDX 3.0.1 format. +The generated SBOM documents capture: + +* **Final output artifacts**, typically the kernel image and modules +* **All source files** that contributed to the build with metadata + and licensing information +* **Details of the build process**, including intermediate artifacts + and the build commands linking source files to the final output + artifacts + +KernelSbom is originally developed in the +`KernelSbom repository <https://github.com/TNG/KernelSbom>`_. + +Requirements +------------ + +Python 3.10 or later. No libraries or other dependencies are required. + +Basic Usage +----------- + +Run the ``make sbom`` target. +For example:: + + $ make defconfig O=kernel_build + $ make sbom O=kernel_build -j$(nproc) + +This will trigger a kernel build. After all build outputs have been +generated, KernelSbom produces three SPDX documents in the root +directory of the object tree: + +* ``sbom-source.spdx.json`` + Describes all source files involved in the build and + associates each file with its corresponding license expression. + +* ``sbom-output.spdx.json`` + Captures all final build outputs (kernel image and ``.ko`` module files) + and includes build metadata such as environment variables and + a hash of the ``.config`` file used for the build. + +* ``sbom-build.spdx.json`` + Imports files from the source and output documents and describes every + intermediate build artifact. For each artifact, it records the exact + build command used and establishes the relationship between + input files and generated outputs. + +When invoking the sbom target, it is recommended to perform +out-of-tree builds using ``O=<objtree>``. KernelSbom classifies files as +source files when they are located in the source tree and not in the +object tree. For in-tree builds, where the source and object trees are +the same directory, this distinction can no longer be made reliably. +In that case, KernelSbom does not generate a dedicated source SBOM. +Instead, source files are included in the build SBOM. + +Standalone Usage +---------------- + +KernelSbom can also be used as a standalone script to generate +SPDX documents for specific build outputs. For example, after a +successful x86 kernel build, KernelSbom can generate SPDX documents +for the ``bzImage`` kernel image:: + + $ SRCARCH=x86 python3 scripts/sbom/sbom.py \ + --src-tree . \ + --obj-tree ./kernel_build \ + --roots arch/x86/boot/bzImage \ + --generate-spdx \ + --generate-used-files \ + --prettify-json \ + --debug + +Note that when KernelSbom is invoked outside of the ``make`` process, +the environment variables used during compilation are not available and +therefore cannot be included in the generated SPDX documents. It is +recommended to set at least the ``SRCARCH`` environment variable to the +architecture for which the build was performed. + +For a full list of command-line options, run:: + + $ python3 scripts/sbom/sbom.py --help + +Output Format +------------- + +KernelSbom generates documents conforming to the +`SPDX 3.0.1 specification <https://spdx.github.io/spdx-spec/v3.0.1/>`_ +serialized as JSON-LD. + +To reduce file size, the output documents use the JSON-LD ``@context`` +to define custom prefixes for ``spdxId`` values. While this is compliant +with the SPDX specification, only a limited number of tools in the +current SPDX ecosystem support custom JSON-LD contexts. To use such +tools with the generated documents, the custom JSON-LD context must +be expanded before providing the documents. +See https://lists.spdx.org/g/Spdx-tech/message/6064 for more information. + +How it Works +------------ + +KernelSbom operates in two major phases: + +1. **Generate the cmd graph**, an acyclic directed dependency graph. +2. **Generate SPDX documents** based on the cmd graph. + +KernelSbom begins from the root artifacts specified by the user, e.g., +``arch/x86/boot/bzImage``. For each root artifact, it collects all +dependencies required to build that artifact. The dependencies come +from multiple sources: + +* **.cmd files**: The primary source is the ``.cmd`` file of the + generated artifact, e.g., ``arch/x86/boot/.bzImage.cmd``. These files + contain the exact command used to build the artifact and often include + an explicit list of input dependencies. By parsing the ``.cmd`` + file, the full list of dependencies can be obtained. + +* **.incbin statements**: The second source are include binary + ``.incbin`` statements in ``.S`` assembly files. + +* **Hardcoded dependencies**: Unfortunately, not all build dependencies + can be found via ``.cmd`` files and ``.incbin`` statements. Some build + dependencies are directly defined in Makefiles or Kbuild files. + Parsing these files is considered too complex for the scope of this + project. Instead, the remaining gaps of the graph are filled using a + list of manually defined dependencies, see + ``scripts/sbom/sbom/cmd_graph/hardcoded_dependencies.py``. This list is + known to be incomplete. However, analysis of the cmd graph indicates a + ~99% completeness. For more information about the completeness analysis, + see `KernelSbom #95 <https://github.com/TNG/KernelSbom/issues/95>`_. + +Given the list of dependency files, KernelSbom recursively processes +each file, expanding the dependency chain all the way to the version +controlled source files. The result is a complete dependency graph +where nodes represent files, and edges represent "file A was used to +build file B" relationships. + +Using the cmd graph, KernelSbom produces three SPDX documents. +For every file in the graph, KernelSbom: + +* Parses ``SPDX-License-Identifier`` headers, +* Computes file hashes, +* Estimates the file type based on extension and path, +* Records build relationships between files. + +Each root output file is additionally associated with an SPDX Package +element that captures version information, license data, and copyright. + +Advanced Usage +-------------- + +Including Kernel Modules +~~~~~~~~~~~~~~~~~~~~~~~~ + +The list of all ``.ko`` kernel modules produced during a build can be +extracted from the ``modules.order`` file within the object tree. +For example:: + + $ echo "arch/x86/boot/bzImage" > sbom-roots.txt + $ sed 's/\.o$/.ko/' ./kernel_build/modules.order >> sbom-roots.txt + +Then use the generated roots file:: + + $ SRCARCH=x86 python3 scripts/sbom/sbom.py \ + --src-tree . \ + --obj-tree ./kernel_build \ + --roots-file sbom-roots.txt \ + --generate-spdx + +Equal Source and Object Trees +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +When the source tree and object tree are identical (for example, when +building in-tree), source files can no longer be reliably distinguished +from generated files. +In this scenario, KernelSbom does not produce a dedicated +``sbom-source.spdx.json`` document. Instead, both source files and build +artifacts are included together in ``sbom-build.spdx.json``, and +``sbom.used-files.txt`` lists all files referenced in the build document. + +Unknown Build Commands +~~~~~~~~~~~~~~~~~~~~~~ + +Because the kernel supports a wide range of configurations and versions, +KernelSbom may encounter build commands in ``.cmd`` files that it does +not yet support. By default, KernelSbom will fail if an unknown build +command is encountered. + +If you still wish to generate SPDX documents despite unsupported +commands, you can use the ``--do-not-fail-on-unknown-build-command`` +option. KernelSbom will continue and produce the documents, although +the resulting SBOM will be incomplete. + +This option should only be used when the missing portion of the +dependency graph is small and an incomplete SBOM is acceptable for +your use case. diff --git a/Documentation/tools/unittest.rst b/Documentation/tools/unittest.rst new file mode 100644 index 000000000..0fa871674 --- /dev/null +++ b/Documentation/tools/unittest.rst @@ -0,0 +1,24 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=============== +Python unittest +=============== + +Checking consistency of python modules can be complex. Sometimes, it is +useful to define a set of unit tests to help checking them. + +While the actual test implementation is usecase dependent, Python already +provides a standard way to add unit tests by using ``import unittest``. + +Using such class, requires setting up a test suite. Also, the default format +is a little bit awkward. To improve it and provide a more uniform way to +report errors, some unittest classes and functions are defined. + + +Unittest helper module +====================== + +.. automodule:: lib.python.unittest_helper + :members: + :show-inheritance: + :undoc-members: |