kernel/linux.git/tools/testing/selftests/ftrace, branch v6.18.22

selftests/ftrace: traceonoff_triggers: strip off names

2026-01-08T09:16:52+00:00

[ Upstream commit b889b4fb4cbea3ca7eb9814075d6a51936394bd9 ] The func_traceonoff_triggers.tc sometimes goes to fail on my board, Kunpeng-920. [root@localhost]# ./ftracetest ./test.d/ftrace/func_traceonoff_triggers.tc -l fail.log === Ftrace unit tests === [1] ftrace - test for function traceon/off triggers [FAIL] [2] (instance) ftrace - test for function traceon/off triggers [UNSUPPORTED] I look up the log, and it shows that the md5sum is different between csum1 and csum2. ++ cnt=611 ++ sleep .1 +++ cnt_trace +++ grep -v '^#' trace +++ wc -l ++ cnt2=611 ++ '[' 611 -ne 611 ']' +++ cat tracing_on ++ on=0 ++ '[' 0 '!=' 0 ']' +++ md5sum trace ++ csum1='76896aa74362fff66a6a5f3cf8a8a500 trace' ++ sleep .1 +++ md5sum trace ++ csum2='ee8625a21c058818fc26e45c1ed3f6de trace' ++ '[' '76896aa74362fff66a6a5f3cf8a8a500 trace' '!=' 'ee8625a21c058818fc26e45c1ed3f6de trace' ']' ++ fail 'Tracing file is still changing' ++ echo Tracing file is still changing Tracing file is still changing ++ exit_fail ++ exit 1 So I directly dump the trace file before md5sum, the diff shows that: [root@localhost]# diff trace_1.log trace_2.log -y --suppress-common-lines dockerd-12285 [036] d.... 18385.510290: sched_stat | <...>-12285 [036] d.... 18385.510290: sched_stat dockerd-12285 [036] d.... 18385.510291: sched_swit | <...>-12285 [036] d.... 18385.510291: sched_swit <...>-740 [044] d.... 18385.602859: sched_stat | kworker/44:1-740 [044] d.... 18385.602859: sched_stat <...>-740 [044] d.... 18385.602860: sched_swit | kworker/44:1-740 [044] d.... 18385.602860: sched_swit And we can see that <...> filed be filled with names. We can strip off the names there to fix that. After strip off the names: kworker/u257:0-12 [019] d..2. 2528.758910: sched_stat | -12 [019] d..2. 2528.758910: sched_stat_runtime: comm=k kworker/u257:0-12 [019] d..2. 2528.758912: sched_swit | -12 [019] d..2. 2528.758912: sched_switch: prev_comm=kw -0 [000] d.s5. 2528.762318: sched_waki | -0 [000] d.s5. 2528.762318: sched_waking: comm=sshd pi -0 [037] dNh2. 2528.762326: sched_wake | -0 [037] dNh2. 2528.762326: sched_wakeup: comm=sshd pi -0 [037] d..2. 2528.762334: sched_swit | -0 [037] d..2. 2528.762334: sched_switch: prev_comm=sw Link: https://lore.kernel.org/r/20230818013226.2182299-1-zouyipeng@huawei.com Fixes: d87b29179aa0 ("selftests: ftrace: Use md5sum to take less time of checking logs") Suggested-by: Steven Rostedt (Google) Signed-off-by: Yipeng Zou Acked-by: Masami Hiramatsu (Google) Reviewed-by: Steven Rostedt (Google) Signed-off-by: Shuah Khan Signed-off-by: Sasha Levin

selftests/tracing: Run sample events to clear page cache events

2025-11-11T01:00:07+00:00

The tracing selftest "event-filter-function.tc" was failing because it first runs the "sample_events" function that triggers the kmem_cache_free event and it looks at what function was used during a call to "ls". But the first time it calls this, it could trigger events that are used to pull pages into the page cache. The rest of the test uses the function it finds during that call to see if it will be called in subsequent "sample_events" calls. But if there's no need to pull pages into the page cache, it will not trigger that function and the test will fail. Call the "sample_events" twice to trigger all the page cache work before it calls it to find a function to use in subsequent checks. Cc: stable@vger.kernel.org Fixes: eb50d0f250e96 ("selftests/ftrace: Choose target function for filter test from samples") Signed-off-by: Steven Rostedt (Google) Acked-by: Masami Hiramatsu (Google) Signed-off-by: Shuah Khan

Merge tag 'probes-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2025-07-30T22:38:01+00:00

Pull probes updates from Masami Hiramatsu: "Stack usage reduction for probe events: - Allocate string buffers from the heap for uprobe, eprobe, kprobe, and fprobe events to avoid stack overflow - Allocate traceprobe_parse_context from the heap to prevent potential stack overflow - Fix a typo in the above commit New features for eprobe and tprobe events: - Add support for arrays in eprobes - Support multiple tprobes on the same tracepoint Improve efficiency: - Register fprobe-events only when it is enabled to reduce overhead - Register tracepoints for tprobe events only when enabled to resolve a lock dependency Code Cleanup: - Add kerneldoc for traceprobe_parse_event_name() and __get_insn_slot() - Sort #include alphabetically in the probes code - Remove the unused 'mod' field from the tprobe-event - Clean up the entry-arg storing code in probe-events Selftest update - Enable fprobe events before checking enable_functions in selftests" * tag 'probes-v6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: trace_fprobe: Fix typo of the semicolon tracing: Have eprobes handle arrays tracing: probes: Add a kerneldoc for traceprobe_parse_event_name() tracing: uprobe-event: Allocate string buffers from heap tracing: eprobe-event: Allocate string buffers from heap tracing: kprobe-event: Allocate string buffers from heap tracing: fprobe-event: Allocate string buffers from heap tracing: probe: Allocate traceprobe_parse_context from heap tracing: probes: Sort #include alphabetically kprobes: Add missing kerneldoc for __get_insn_slot tracing: tprobe-events: Register tracepoint when enable tprobe event selftests: tracing: Enable fprobe events before checking enable_functions tracing: fprobe-events: Register fprobe-events only when it is enabled tracing: tprobe-events: Support multiple tprobes on the same tracepoint tracing: tprobe-events: Remove mod field from tprobe-event tracing: probe-events: Cleanup entry-arg storing code

selftests/tracing: Fix false failure of subsystem event test

2025-07-24T21:52:20+00:00

The subsystem event test enables all "sched" events and makes sure there's at least 3 different events in the output. It used to cat the entire trace file to | wc -l, but on slow machines, that could last a very long time. To solve that, it was changed to just read the first 100 lines of the trace file. This can cause false failures as some events repeat so often, that the 100 lines that are examined could possibly be of only one event. Instead, create an awk script that looks for 3 different events and will exit out after it finds them. This will find the 3 events the test looks for (eventually if it works), and still exit out after the test is satisfied and not cause slower machines to run forever. Link: https://lore.kernel.org/r/20250721134212.53c3e140@batman.local.home Reported-by: Tengda Wu Closes: https://lore.kernel.org/all/20250710130134.591066-1-wutengda@huaweicloud.com/ Fixes: 1a4ea83a6e67 ("selftests/ftrace: Limit length in subsystem-enable tests") Signed-off-by: Steven Rostedt (Google) Signed-off-by: Shuah Khan

selftests: tracing: Use mutex_unlock for testing glob filter

2025-07-07T21:34:10+00:00

Since commit c5b6ababd21a ("locking/mutex: implement mutex_trylock_nested") makes mutex_trylock() as an inlined function if CONFIG_DEBUG_LOCK_ALLOC=y, we can not use mutex_trylock() for testing the glob filter of ftrace. Use mutex_unlock instead. Link: https://lore.kernel.org/r/175151680309.2149615.9795104805153538717.stgit@mhiramat.tok.corp.google.com Signed-off-by: Masami Hiramatsu (Google) Acked-by: Steven Rostedt (Google) Signed-off-by: Shuah Khan

selftests: tracing: Enable fprobe events before checking enable_functions

2025-07-02T00:45:21+00:00

Since the fprobe is not registered before enabling the fprobe events, enable_functions is also empty before enabling it. Thus the tests which checking enable_functions must ensure the event is enabled before testing the enable_functions. Link: https://lore.kernel.org/all/174343538009.843280.6583146613234713007.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google)

selftests/ftrace: Convert poll to a gen_file

2025-05-09T18:43:10+00:00

Poll program is a helper to ftracetest, thus make it a generic file and remove it from being run as a test. Currently when executing tests using $ make run_tests CC poll TAP version 13 1..2 # timeout set to 0 # selftests: ftrace: poll # Error: Polling file is not specified not ok 1 selftests: ftrace: poll # exit=255 Fix this by using TEST_GEN_FILES to build the 'poll' binary as a helper rather than as a test. Fixes: 80c3e28528ff ("selftests/tracing: Add hist poll() support test") Link: https://lore.kernel.org/r/20250409044632.363285-1-Ayush.jain3@amd.com Signed-off-by: Ayush Jain Acked-by: Steven Rostedt (Google) Signed-off-by: Shuah Khan

Merge tag 'trace-v6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2025-04-19T18:57:36+00:00

Pull tracing fixes from Steven Rostedt: - Initialize hash variables in ftrace subops logic The fix that simplified the ftrace subops logic opened a path where some variables could be used without being initialized, and done subtly where the compiler did not catch it. Initialize those variables to the EMPTY_HASH, which is the default hash. - Reinitialize the hash pointers after they are freed Some of the hash pointers in the subop logic were freed but may still be referenced later. To prevent use-after-free bugs, initialize them back to the EMPTY_HASH. - Free the ftrace hashes when they are replaced The fix that simplified the subops logic updated some hash pointers, but left the original hash that they were pointing to where they are no longer used. This caused a memory leak. Free the hashes that are pointed to by the pointers when they are replaced. - Fix size initialization of ftrace direct function hash The ftrace direct function hash used by BPF initialized the hash size incorrectly. It checked the size of items to a hard coded 32, which made the hash bit size of 5. The hash size is supposed to be limited by the bit size of the hash, as the bitmask is allowed to be greater than 5. Rework the size check to first pass the number of elements to fls() and then compare that to FTRACE_HASH_MAX_BITS before allocating the hash. - Fix format output of ftrace_graph_ent_entry event The field depth of the ftrace_graph_ent_entry event is of size 4 but the output showed it as unsigned long and use "%lu". Change it to unsigned int and use "%u" in the print format that is displayed to user space. - Fix the trace event filter on strings Events can be filtered on numbers or string values. The return value checked from strncpy_from_kernel_nofault() and strncpy_from_user_nofault() was used to determine if reading the strings would fault or not. It would return fault if the value was non zero, which is basically meant that it was always considering the read as a fault. - Add selftest to test trace event string filtering In order to catch the breakage of the string filtering, add a self test to make sure that it continues to work. * tag 'trace-v6.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: selftests: Add testing a user string to filters tracing: Fix filter string testing ftrace: Fix type of ftrace_graph_ent_entry.depth ftrace: fix incorrect hash size in register_ftrace_direct() ftrace: Free ftrace hashes after they are replaced in the subops code ftrace: Reinitialize hash to EMPTY_HASH after freeing ftrace: Initialize variables for ftrace_startup/shutdown_subops()

tracing: selftests: Add testing a user string to filters

2025-04-18T15:26:01+00:00

Running the following commands was broken: # cd /sys/kernel/tracing # echo "filename.ustring ~ \"/proc*\"" > events/syscalls/sys_enter_openat/filter # echo 1 > events/syscalls/sys_enter_openat/enable # ls /proc/$$/maps # cat trace And would produce nothing when it should have produced something like: ls-1192 [007] ..... 8169.828333: sys_openat(dfd: ffffffffffffff9c, filename: 7efc18359904, flags: 80000, mode: 0) Add a test to check this case so that it will be caught if it breaks again. Link: https://lore.kernel.org/linux-trace-kernel/20250417183003.505835fb@gandalf.local.home/ Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Shuah Khan Link: https://lore.kernel.org/20250418101208.38dc81f5@gandalf.local.home Signed-off-by: Steven Rostedt (Google)

selftests/ftrace: Differentiate bash and dash in dynevent_limitations.tc

2025-04-16T18:47:41+00:00

bash and dash evaluate variables differently. dash will evaluate '\\' every time it is read whereas bash does not. TEST_STRING="$TEST_STRING \\$i" echo $TEST_STRING With i=123 On bash, that will print "\123" but on dash, that will print the escape sequence of \123 as the \ will be interpreted again in the echo. The dynevent_limitations.tc test created a very large list of arguments to test the maximum number of arguments to pass to the dynamic events file. It had a loop of: TEST_STRING=$1 # Acceptable for i in `seq 1 $MAX_ARGS`; do TEST_STRING="$TEST_STRING \\$i" done echo "$TEST_STRING" >> dynamic_events This worked fine on bash, but when run on dash it failed. This was due to dash interpreting the "\\$i" twice. Once when it was assigned to TEST_STRING and a second time with the echo $TEST_STRING. bash does not process the backslash more than the first time. To solve this, assign a double backslash to a variable "bs" and then echo it to "ts". If "ts" changes, it is dash, if not, it is bash. Then update "bs" accordingly, and use that to assign TEST_STRING. Now this could possibly just check if "$BASH" is defined or not, but this is testing if the issue exists and not just which shell is being used. Link: https://lore.kernel.org/r/20250414210900.4de5e8b9@gandalf.local.home Fixes: 581a7b26ab364 ("selftests/ftrace: Add dynamic events argument limitation test case") Reported-by: Mark Brown Closes: https://lore.kernel.org/all/350786cc-9e40-4396-ab95-4f10d69122fb@sirena.org.uk/ Signed-off-by: Steven Rostedt (Google) Acked-by: Masami Hiramatsu (Google) Signed-off-by: Shuah Khan