gh-98894: Fix dtrace tests in shared builds

[stratakis]

When Python is configured with --with-dtrace and --enable-shared, its USDT probes are in libpython, not the executable. The SystemTap and BPFTrace backends in test_dtrace were searching the executable, causing the tests to fail or time out. This PR makes both backends target the object containing the probes. Static builds are unaffected.

On Fedora, this can be reproduced by running test_dtrace for BPFTrace as sudo and for SystemTap either as sudo or as a user in the stapusr and stapdev groups.

Also added a commit to truncate the output of the tools as it can be quite verbose when it errors out (you can inspect by running the same tests without sudo).

• Issue: Some DTrace probes are broken in 3.11 #98894

[stratakis]

cc @vstinner

[stratakis]

Rebased to fix conflicts

[vstinner]

Python configured with: ./configure --with-pydebug --with-dtrace --enable-shared.

Without the change, I get:

# LANG= LD_LIBRARY_PATH=$PWD ./python -m test -v test_dtrace 
== CPython 3.16.0a0 (heads/main:ed716551e13, Jul 13 2026, 07:59:05) [GCC 16.1.1 20260515 (Red Hat 16.1.1-2)]
== Linux-7.0.12-201.fc44.x86_64-x86_64-with-glibc2.43 little-endian
== Python build: debug shared dtrace
== cwd: /home/vstinner/python/main/build/test_python_worker_3188349æ
== CPU count: 10 (process) / 12 (system)
== encodings: locale=UTF-8 FS=utf-8
== resources: all test resources are disabled, use -u option to unskip tests

Using random seed: 3520453529
0:00:00 load avg: 2.02 mem: 22.5 MiB Run 1 test sequentially in a single process
0:00:00 load avg: 2.02 mem: 22.5 MiB [1/1] test_dtrace
setUpClass (test.test_dtrace.BPFTraceNormalTests) ... skipped 'bpftrace timed out during usability check'
setUpClass (test.test_dtrace.BPFTraceOptimizedTests) ... skipped 'bpftrace timed out during usability check'
test_filter_probe_rows_ignores_warnings (test.test_dtrace.BPFTraceOutputTests.test_filter_probe_rows_ignores_warnings) ... ok
readelf version: 2.46
test_check_probes (test.test_dtrace.CheckDtraceProbes.test_check_probes) ... ok
test_missing_probes (test.test_dtrace.CheckDtraceProbes.test_missing_probes) ... expected failure
skipped 'dtrace(1) failed: /usr/sbin/dtrace invalid option -q\nUsage /usr/sbin/dtrace [--help] [-h | -G] [-C [-I<Path>]] -s File.d [-o <File>]'
setUpClass (test.test_dtrace.DTraceOptimizedTests) ... skipped 'dtrace(1) failed: /usr/sbin/dtrace invalid option -q\nUsage /usr/sbin/dtrace [--help] [-h | -G] [-C [-I<Path>]] -s File.d [-o <File>]'
setUpClass (test.test_dtrace.SystemTapNormalTests) ... skipped 'stap(1) failed: parse error: expected literal string or number\n        saw: operator \'*\' at /usr/share/systemtap/tapset/libvirt_probes-64.stp:204:3\n     source:   *cert = user_string($arg4);\n               ^\n\n1 parse error.\nstap_69e06176e3befa287a4f6741352860fa_990_src.c:12:10: fatal error: runtime_defines.h: No such file or directory\n   12 | #include "runtime_defines.h"\n      |          ^~~~~~~~~~~~~~~~~~~\ncompilation terminated.\nmake[2]: *** [/usr/src/kernels/7.0.12-201.fc44.x86_64/scripts/Makefile.build:289: stap_69e06176e3befa287a4f6741352860fa_990_src.o] Error 1\nmake[2]: *** Waiting for unfinished jobs....\nstap_symbols.c:3:10: fatal error: sym.h: No such file or directory\n    3 | #include <sym.h>\n      |          ^~~~~~~\ncompilation terminated.\nmake[2]: *** [/usr/src/kernels/7.0.12-201.fc44.x86_64/scripts/Makefile.build:289: stap_symbols.o] Error 1\nmake[1]: *** [/usr/src/kernels/7.0.12-201.fc44.x86_64/Makefile:2140: .] Error 2\nmake: *** [Makefile:248: __sub-make] Error 2\nWARNING: kbuild exited with status: 2\nPass 4: compilation failed.  [man error::pass4]\nKernel version 7.0.12 is outside tested range 3.10 ... 7.0'
setUpClass (test.test_dtrace.SystemTapOptimizedTests) ... skipped 'stap(1) failed: parse error: expected literal string or number\n        saw: operator \'*\' at /usr/share/systemtap/tapset/libvirt_probes-64.stp:204:3\n     source:   *cert = user_string($arg4);\n               ^\n\n1 parse error.\nstap_69e06176e3befa287a4f6741352860fa_990_src.c:12:10: fatal error: runtime_defines.h: No such file or directory\n   12 | #include "runtime_defines.h"\n      |          ^~~~~~~~~~~~~~~~~~~\ncompilation terminated.\nmake[2]: *** [/usr/src/kernels/7.0.12-201.fc44.x86_64/scripts/Makefile.build:289: stap_69e06176e3befa287a4f6741352860fa_990_src.o] Error 1\nmake[2]: *** Waiting for unfinished jobs....\nstap_symbols.c:3:10: fatal error: sym.h: No such file or directory\n    3 | #include <sym.h>\n      |          ^~~~~~~\ncompilation terminated.\nmake[2]: *** [/usr/src/kernels/7.0.12-201.fc44.x86_64/scripts/Makefile.build:289: stap_symbols.o] Error 1\nmake[1]: *** [/usr/src/kernels/7.0.12-201.fc44.x86_64/Makefile:2140: .] Error 2\nmake: *** [Makefile:248: __sub-make] Error 2\nWARNING: kbuild exited with status: 2\nPass 4: compilation failed.  [man error::pass4]\nKernel version 7.0.12 is outside tested range 3.10 ... 7.0'

----------------------------------------------------------------------
Ran 3 tests in 24.814s

OK (skipped=6, expected failures=1)
0:00:24 load avg: 1.75 mem: 22.9 MiB [1/1] test_dtrace passed

== Tests result: SUCCESS ==

1 test OK.

Total duration: 24.9 sec
Total tests: run=3 skipped=6
Total test files: run=1/1
Result: SUCCESS

[stratakis]

The systemtap tests require the same kernel-devel package as the running kernel, if it's not there the test will be skipped.

[vstinner]

I tested again the change. Python built with ./configure --with-pydebug --with-dtrace --enable-shared and test_dtrace runs as root.

Without the change:

setUpClass (test.test_dtrace.BPFTraceNormalTests) ... skipped 'bpftrace timed out during usability check'
setUpClass (test.test_dtrace.BPFTraceOptimizedTests) ... skipped 'bpftrace timed out during usability check'
test_filter_probe_rows_ignores_warnings (test.test_dtrace.BPFTraceOutputTests.test_filter_probe_rows_ignores_warnings) ... ok
readelf version: 2.46
test_check_probes (test.test_dtrace.CheckDtraceProbes.test_check_probes) ... ok
test_missing_probes (test.test_dtrace.CheckDtraceProbes.test_missing_probes) ... expected failure
skipped 'dtrace(1) failed: /usr/sbin/dtrace invalid option -q\nUsage /usr/sbin/dtrace [--help] [-h | -G] [-C [-I<Path>]] -s File.d [-o <File>]'
setUpClass (test.test_dtrace.DTraceOptimizedTests) ... skipped 'dtrace(1) failed: /usr/sbin/dtrace invalid option -q\nUsage /usr/sbin/dtrace [--help] [-h | -G] [-C [-I<Path>]] -s File.d [-o <File>]'
setUpClass (test.test_dtrace.SystemTapNormalTests) ... skipped 'stap(1) failed: parse error: expected literal string or number\n        saw: operator \'*\' at /usr/share/systemtap/tapset/libvirt_probes-64.stp:204:3\n     source:   *cert = user_string($arg4);\n               ^\n\n1 parse error.\nstap_ad00f0008fef1242c8a51840ffeb6b1e_983_src.c:12:10: fatal error: runtime_defines.h: No such file or directory\n   12 | #include "runtime_defines.h"\n      |          ^~~~~~~~~~~~~~~~~~~\ncompilation terminated.\nmake[2]: *** [/usr/src/kernels/7.1.4-204.fc44.x86_64/scripts/Makefile.build:289: stap_ad00f0008fef1242c8a51840ffeb6b1e_983_src.o] Error 1\nmake[2]: *** Waiting for unfinished jobs....\nstap_symbols.c:3:10: fatal error: sym.h: No such file or directory\n    3 | #include <sym.h>\n      |          ^~~~~~~\ncompilation terminated.\nmake[2]: *** [/usr/src/kernels/7.1.4-204.fc44.x86_64/scripts/Makefile.build:289: stap_symbols.o] Error 1\nmake[1]: *** [/usr/src/kernels/7.1.4-204.fc44.x86_64/Makefile:2192: .] Error 2\nmake: *** [Makefile:248: __sub-make] Error 2\nWARNING: kbuild exited with status: 2\nPass 4: compilation failed.  [man error::pass4]\nKernel version 7.1.4 is outside tested range 3.10 ... 7.0'
setUpClass (test.test_dtrace.SystemTapOptimizedTests) ... skipped 'stap(1) failed: parse error: expected literal string or number\n        saw: operator \'*\' at /usr/share/systemtap/tapset/libvirt_probes-64.stp:204:3\n     source:   *cert = user_string($arg4);\n               ^\n\n1 parse error.\nstap_ad00f0008fef1242c8a51840ffeb6b1e_983_src.c:12:10: fatal error: runtime_defines.h: No such file or directory\n   12 | #include "runtime_defines.h"\n      |          ^~~~~~~~~~~~~~~~~~~\ncompilation terminated.\nmake[2]: *** [/usr/src/kernels/7.1.4-204.fc44.x86_64/scripts/Makefile.build:289: stap_ad00f0008fef1242c8a51840ffeb6b1e_983_src.o] Error 1\nmake[2]: *** Waiting for unfinished jobs....\nstap_symbols.c:3:10: fatal error: sym.h: No such file or directory\n    3 | #include <sym.h>\n      |          ^~~~~~~\ncompilation terminated.\nmake[2]: *** [/usr/src/kernels/7.1.4-204.fc44.x86_64/scripts/Makefile.build:289: stap_symbols.o] Error 1\nmake[1]: *** [/usr/src/kernels/7.1.4-204.fc44.x86_64/Makefile:2192: .] Error 2\nmake: *** [Makefile:248: __sub-make] Error 2\nWARNING: kbuild exited with status: 2\nPass 4: compilation failed.  [man error::pass4]\nKernel version 7.1.4 is outside tested range 3.10 ... 7.0'

----------------------------------------------------------------------
Ran 3 tests in 24.678s

OK (skipped=6, expected failures=1)
...
Total tests: run=3 skipped=6
Total test files: run=1/1

With the change:

test_function_entry_return (test.test_dtrace.BPFTraceNormalTests.test_function_entry_return) ... ok
test_gc (test.test_dtrace.BPFTraceNormalTests.test_gc) ... ok
test_verify_call_opcodes (test.test_dtrace.BPFTraceNormalTests.test_verify_call_opcodes)
Ensure our call stack test hits all function call opcodes ... ok
test_function_entry_return (test.test_dtrace.BPFTraceOptimizedTests.test_function_entry_return) ... ok
test_gc (test.test_dtrace.BPFTraceOptimizedTests.test_gc) ... ok
test_verify_call_opcodes (test.test_dtrace.BPFTraceOptimizedTests.test_verify_call_opcodes)
Ensure our call stack test hits all function call opcodes ... ok
test_filter_probe_rows_ignores_warnings (test.test_dtrace.BPFTraceOutputTests.test_filter_probe_rows_ignores_warnings) ... ok
readelf version: 2.46
test_check_probes (test.test_dtrace.CheckDtraceProbes.test_check_probes) ... ok
test_missing_probes (test.test_dtrace.CheckDtraceProbes.test_missing_probes) ... expected failure
skipped 'dtrace(1) failed: /usr/sbin/dtrace invalid option -q; Usage /usr/sbin/dtrace [--help] [-h | -G] [-C [-I<Path>]] -s File.d [-o <File>]'
setUpClass (test.test_dtrace.DTraceOptimizedTests) ... skipped 'dtrace(1) failed: /usr/sbin/dtrace invalid option -q; Usage /usr/sbin/dtrace [--help] [-h | -G] [-C [-I<Path>]] -s File.d [-o <File>]'
setUpClass (test.test_dtrace.SystemTapNormalTests) ... skipped "stap(1) failed: parse error: expected literal string or number; saw: operator '*' at /usr/share/systemtap/tapset/libvirt_probes-64.stp:204:3; source:   *cert = user_string($arg4);; ... (18 lines omitted)"
setUpClass (test.test_dtrace.SystemTapOptimizedTests) ... skipped "stap(1) failed: parse error: expected literal string or number; saw: operator '*' at /usr/share/systemtap/tapset/libvirt_probes-64.stp:204:3; source:   *cert = user_string($arg4);; ... (18 lines omitted)"

----------------------------------------------------------------------
Ran 9 tests in 7.410s

OK (skipped=4, expected failures=1)
...
Total tests: run=9 skipped=4
Total test files: run=1/1

So we get: "Total tests: run=3 skipped=6" => "Total tests: run=9 skipped=4". 6 more tests are run thanks to the change.

With the change, BPFTraceNormalTests and BPFTraceOptimizedTests tests are run.

[stratakis]

Should be backported on 3.15 as well.

[miss-islington-app]

Thanks @stratakis for the PR, and @vstinner for merging it 🌮🎉.. I'm working now to backport this PR to: 3.15.
🐍🍒⛏🤖

[bedevere-app]

GH-155803 is a backport of this pull request to the 3.15 branch.