kunit: fix longest symbol length test
Subsystems (4)
PATCH RESEND v3 1/1 kunit: fix longest symbol length test
The kunit test that checks the longests symbol length [1], has triggered warnings in some pilelines when symbol prefixes are used [2][3]. The test will to depend on !PREFIX_SYMBOLS and !CFI_CLANG as sujested in [4] and on !GCOV_KERNEL.
[1] https://lore.kernel.org/rust-for-linux/CABVgOSm=5Q0fM6neBhxSbOUHBgNzmwf2V22vsYC10YRBT=kN1g@mail.gmail.com/T/#t
[2] https://lore.kernel.org/all/[email protected]/T/#u
[3] https://lore.kernel.org/rust-for-linux/[email protected]/T/#t
[4] https://lore.kernel.org/linux-kselftest/20250427200916.GA1661412@ax162/T/#t
--- lib/Kconfig.debug | 1 + lib/tests/longest_symbol_kunit.c | 3 +-- 2 files changed, 2 insertions(+), 2 deletions(-)
lib/Kconfig.debug +1 -0
@@ -2885,6 +2885,7 @@ config FORTIFY_KUNIT_TEST config LONGEST_SYM_KUNIT_TEST tristate "Test the longest symbol possible" if !KUNIT_ALL_TESTS depends on KUNIT && KPROBES + depends on !PREFIX_SYMBOLS && !CFI_CLANG && !GCOV_KERNEL default KUNIT_ALL_TESTS help Tests the longest symbol possible
lib/tests/longest_symbol_kunit.c +1 -2
@@ -3,8 +3,7 @@* Test the longest symbol length. Execute with: * ./tools/testing/kunit/kunit.py run longest-symbol * --arch=x86_64 --kconfig_add CONFIG_KPROBES=y --kconfig_add CONFIG_MODULES=y -* --kconfig_add CONFIG_RETPOLINE=n --kconfig_add CONFIG_CFI_CLANG=n -* --kconfig_add CONFIG_MITIGATION_RETPOLINE=n +* --kconfig_add CONFIG_CPU_MITIGATIONS=n --kconfig_add CONFIG_GCOV_KERNEL=n */ #define pr_fmt (fmt) KBUILD_MODNAME ": " fmt
base-commit: 772b78c2abd85586bb90b23adff89f7303c704c7
Signature · 1 line
2.39.2
Quoted 46 lines · Sergio González Collado
The kunit test that checks the longests symbol length [1], has triggered warnings in some pilelines when symbol prefixes are used [2][3]. The test will to depend on !PREFIX_SYMBOLS and !CFI_CLANG as sujested in [4] and on !GCOV_KERNEL.
[1] https://lore.kernel.org/rust-for-linux/CABVgOSm=5Q0fM6neBhxSbOUHBgNzmwf2V22vsYC10YRBT=kN1g@mail.gmail.com/T/#t
[2] https://lore.kernel.org/all/[email protected]/T/#u
[3] https://lore.kernel.org/rust-for-linux/[email protected]/T/#t
[4] https://lore.kernel.org/linux-kselftest/20250427200916.GA1661412@ax162/T/#tReviewed-by Rae Moar <[email protected]>Signed-off-by Sergio González Collado <[email protected]>Acked-by Randy Dunlap <[email protected]>Tested-by Randy Dunlap <[email protected]>--- lib/Kconfig.debug | 1 + lib/tests/longest_symbol_kunit.c | 3 +-- 2 files changed, 2 insertions(+), 2 deletions(-)lib/Kconfig.debug +1
-0@@ -2885,6 +2885,7 @@ config FORTIFY_KUNIT_TEST config LONGEST_SYM_KUNIT_TEST tristate "Test the longest symbol possible" if !KUNIT_ALL_TESTS depends on KUNIT && KPROBES + depends on !PREFIX_SYMBOLS && !CFI_CLANG && !GCOV_KERNEL default KUNIT_ALL_TESTS help Tests the longest symbol possiblelib/tests/longest_symbol_kunit.c +1
-2@@ -3,8 +3,7 @@* Test the longest symbol length. Execute with: * ./tools/testing/kunit/kunit.py run longest-symbol * --arch=x86_64 --kconfig_add CONFIG_KPROBES=y --kconfig_add CONFIG_MODULES=y -* --kconfig_add CONFIG_RETPOLINE=n --kconfig_add CONFIG_CFI_CLANG=n -* --kconfig_add CONFIG_MITIGATION_RETPOLINE=n +* --kconfig_add CONFIG_CPU_MITIGATIONS=n --kconfig_add CONFIG_GCOV_KERNEL=n */ #define pr_fmt (fmt) KBUILD_MODNAME ": " fmt
Quoted 1 line
base-commit:
772b78c2abd85586bb90b23adff89f7303c704c7
So this will obviously 'work'. But what I don't understand is the purpose of this test. Why can't we amend the test itself to use KSYM_NAME_LEN-8 (or whatever the actual magic value is) and recognise that we don't have full control over the symbol names; despite using C.
Hello,
The initial goal was to verify that a KSYM_NAME_LEN of 512 was
working as expected. It also fixed an issue in /x86/tools/insn_decoder_test.c.
This fix is indeed quite trivial, I just implemented the suggested
ideas. Amend the test using KSYM_NAME_LEN-8 doesn't really seem to me to fix the underlying problem (I also don't know if there is any magic value).
Take into account that he actual warnings that have been reported in
the CI ("Please increase KSYM_NAME_LEN both in kernel and kallsyms.c")
are not from this test, but from
https://elixir.bootlin.com/linux/v6.15/source/scripts/kallsyms.c#L146,
the test has just make that warning evident. Would removing that comment be a better solution?
Nevertheless, acknowledging that we don't have full control over the
symbols' names, is also an interesting insight.
I will be happy to address the issue in one way or another, no problem there.
Regards,
Sergio
Quoted 11 lines · Sergio González Collado
The kunit test that checks the longests symbol length [1], has triggered warnings in some pilelines when symbol prefixes are used [2][3]. The test will to depend on !PREFIX_SYMBOLS and !CFI_CLANG as sujested in [4] and on !GCOV_KERNEL.
[1] https://lore.kernel.org/rust-for-linux/CABVgOSm=5Q0fM6neBhxSbOUHBgNzmwf2V22vsYC10YRBT=kN1g@mail.gmail.com/T/#t
[2] https://lore.kernel.org/all/[email protected]/T/#u
[3] https://lore.kernel.org/rust-for-linux/[email protected]/T/#t
[4] https://lore.kernel.org/linux-kselftest/20250427200916.GA1661412@ax162/T/#t
Quoted 4 lines
Reviewed-by Rae Moar <[email protected]>Signed-off-by Sergio González Collado <[email protected]>Acked-by Randy Dunlap <[email protected]>Tested-by Randy Dunlap <[email protected]>
Hello!
Thanks for resending! I don't believe this has been accepted yet. So I've added it to the list of patches to get accepted for the kselftest/kunit branch.
Thanks!
-Rae
Quoted 36 lines
--- lib/Kconfig.debug | 1 + lib/tests/longest_symbol_kunit.c | 3 +-- 2 files changed, 2 insertions(+), 2 deletions(-)lib/Kconfig.debug +1
-0@@ -2885,6 +2885,7 @@ config FORTIFY_KUNIT_TEST config LONGEST_SYM_KUNIT_TEST tristate "Test the longest symbol possible" if !KUNIT_ALL_TESTS depends on KUNIT && KPROBES + depends on !PREFIX_SYMBOLS && !CFI_CLANG && !GCOV_KERNEL default KUNIT_ALL_TESTS help Tests the longest symbol possiblelib/tests/longest_symbol_kunit.c +1
-2@@ -3,8 +3,7 @@* Test the longest symbol length. Execute with: * ./tools/testing/kunit/kunit.py run longest-symbol * --arch=x86_64 --kconfig_add CONFIG_KPROBES=y --kconfig_add CONFIG_MODULES=y -* --kconfig_add CONFIG_RETPOLINE=n --kconfig_add CONFIG_CFI_CLANG=n -* --kconfig_add CONFIG_MITIGATION_RETPOLINE=n +* --kconfig_add CONFIG_CPU_MITIGATIONS=n --kconfig_add CONFIG_GCOV_KERNEL=n */ #define pr_fmt (fmt) KBUILD_MODNAME ": " fmtbase-commit:
772b78c2abd85586bb90b23adff89f7303c704c7--
2.39.2