On 16/10/2024 2:46 pm, Steven Rostedt wrote:
On Wed, 16 Oct 2024 09:33:00 +0100 Metin Kaya <metin.kaya@xxxxxxx> wrote:I could successfully apply the patch on 4cbebed79b1f ("libtracefs: Documentation: Add missing documentation to meson.build"). The unit tests at [1] passes with this patch. Just for the records, there are some unit test failures in libtracefs (they were there even before the patch): $ sudo ./utest/trace-utest CUnit - A unit testing framework for C - Version 2.1-3 http://cunit.sourceforge.net/ Memory mapped buffers not supported Suite: tracefs library Test: Test tracefs/debugfs mounting ...FAILED 1. tracefs-utest.c:1806 - ret == 0Note, if you have anything in the /sys/kernel/tracing directory (including gdb instances of trace-cmd), it will fail to unmount. I tripped over this too.
I ran "trace-cmd reset && umount /sys/kernel/tracing" before the unit test. And this error is gone.
Test: trace cpu read ...passed Test: trace cpu read_buf_percent ...passed Test: trace cpu pipe ...passed Test: trace pid events filter ...passed Test: trace pid function filter ...passed Test: trace sql ...passed Test: trace sql trace onmax ...passed Test: trace sql trace onchange ...passed Test: trace sql snapshot onmax ...passed Test: trace sql snapshot onchange ...passed Test: trace sql save onmax ...passed Test: trace sql save onchange ...passed Test: trace sql trace and snapshot onmax ...passed Test: trace sql trace and snapshot onchange ...passed Test: tracing file / directory APIs ...passed Test: instance file / directory APIs ...passed Test: instance file descriptor ...passed Test: instance reset ...passed Test: systems and events APIs ...passed Test: tracefs_iterate_snapshot_events API ...passed Test: tracefs_iterate_raw_events API ...FAILED 1. tracefs-utest.c:235 - ret == sizeof(struct test_sample) 2. tracefs-utest.c:235 - ret == sizeof(struct test_sample)Did you do a trace-cmd reset before running the tests?
Yes. And one of these failures still persists:
Test: tracefs_iterate_snapshot_events API ...FAILED
1. tracefs-utest.c:235 - ret == sizeof(struct test_sample)
Test: Follow events ...passed Test: Follow events clear ...passed Test: tracefs_tracers API ...passed Test: tracefs_local events API ...passed Test: tracefs_instances_walk API ...passed Test: tracefs_get_clock API ...passed Test: tracing on / off ...passed Test: tracing options ...passed Test: custom system directory ...passed Test: ftrace marker ...passed Test: kprobes ...passed Test: synthetic events ...passed Test: eprobes ...passed Test: uprobes ...FAILED 1. tracefs-utest.c:2222 - ret == 0 2. tracefs-utest.c:2222 - ret == 0Did you have left over uprobes?
Nope. I ran "trace-cmd reset" before the test and confirmed no uprobes are left. But still getting these failures.
Run Summary: Type Total Ran Passed Failed Inactive suites 1 1 n/a 0 0 tests 36 36 33 3 0 asserts 30341119 30341119 30341114 5 n/a Elapsed time = 124.937 seconds With that, Reviewed-by: Metin Kaya <metin.kaya@xxxxxxx> Thanks a lot for fixing it promptly! [1] https://lore.kernel.org/all/20241015140840.4183007-1-metin.kaya@xxxxxxx/Sorry, I need to revoke my Reviewed-by. Because, "trace-cmd reset" cannot destroy uretprobes after this patch. # cd /sys/kernel/tracing/ /sys/kernel/tracing # cat uprobe_events /sys/kernel/tracing # echo 'r /bin/bash:0x4245c0' > uprobe_events /sys/kernel/tracing # cat uprobe_events r:uprobes/p_bash_0x4245c0 /bin/bash:0x00000000004245c0 /sys/kernel/tracing # trace-cmd reset /sys/kernel/tracing # cat uprobe_events r:uprobes/p_bash_0x4245c0 /bin/bash:0x00000000004245c0 OTOH, "trace-cmd reset" is able to destroy uretprobes if there is also a kprobe in addition to a uretprobe:Oops, I know why. I had a bug in the code that collects all the probes and looks at different files. It assumed that if the return of tracefs_instance_file_read() returns NULL from kprobe_events, it is an error. But that function also returns NULL if the file is empty. I changed the code from: content = tracefs_instance_file_read(NULL, desc->file, NULL); if (!content) return -1; to: if (!tracefs_file_exists(NULL, desc->file)) return -1; content = tracefs_instance_file_read(NULL, desc->file, NULL); /* File exists, but may be empty */ if (!content) return 0; I'll send out a v2. Thanks for testing. I'll also add more tests to the libtracefs utest to check for this too. -- Steve/sys/kernel/tracing # cat dynamic_events /sys/kernel/tracing # cat uprobe_events /sys/kernel/tracing # echo 'p do_sys_open' > kprobe_events /sys/kernel/tracing # echo 'r /bin/bash:0x4245c0' > uprobe_events /sys/kernel/tracing # cat dynamic_events p:kprobes/p_do_sys_open_0 do_sys_open r:uprobes/p_bash_0x4245c0 /bin/bash:0x00000000004245c0 /sys/kernel/tracing # cat uprobe_events r:uprobes/p_bash_0x4245c0 /bin/bash:0x00000000004245c0 /sys/kernel/tracing # trace-cmd reset /sys/kernel/tracing # cat dynamic_events /sys/kernel/tracing # cat uprobe_events /sys/kernel/tracing #
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