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=5Q0fM6neBhxSbOUHBgNzmwf2V22v... [2] https://lore.kernel.org/all/20250328112156.2614513-1-arnd@kernel.org/T/#u [3] https://lore.kernel.org/rust-for-linux/bbd03b37-c4d9-4a92-9be2-75aaf8c19815@... [4] https://lore.kernel.org/linux-kselftest/20250427200916.GA1661412@ax162/T/#t
Reviewed-by: Rae Moar rmoar@google.com Signed-off-by: Sergio González Collado sergio.collado@gmail.com Acked-by: Randy Dunlap rdunlap@infradead.org Tested-by: Randy Dunlap rdunlap@infradead.org --- lib/Kconfig.debug | 1 + lib/tests/longest_symbol_kunit.c | 3 +-- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ebe33181b6e6..4a75a52803b6 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -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 diff --git a/lib/tests/longest_symbol_kunit.c b/lib/tests/longest_symbol_kunit.c index e3c28ff1807f..9b4de3050ba7 100644 --- a/lib/tests/longest_symbol_kunit.c +++ b/lib/tests/longest_symbol_kunit.c @@ -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
On Sun, Jul 06, 2025 at 10:18:55PM +0200, Sergio González Collado wrote:
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=5Q0fM6neBhxSbOUHBgNzmwf2V22v... [2] https://lore.kernel.org/all/20250328112156.2614513-1-arnd@kernel.org/T/#u [3] https://lore.kernel.org/rust-for-linux/bbd03b37-c4d9-4a92-9be2-75aaf8c19815@... [4] https://lore.kernel.org/linux-kselftest/20250427200916.GA1661412@ax162/T/#t
Reviewed-by: Rae Moar rmoar@google.com Signed-off-by: Sergio González Collado sergio.collado@gmail.com Acked-by: Randy Dunlap rdunlap@infradead.org Tested-by: Randy Dunlap rdunlap@infradead.org
lib/Kconfig.debug | 1 + lib/tests/longest_symbol_kunit.c | 3 +-- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ebe33181b6e6..4a75a52803b6 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -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
diff --git a/lib/tests/longest_symbol_kunit.c b/lib/tests/longest_symbol_kunit.c index e3c28ff1807f..9b4de3050ba7 100644 --- a/lib/tests/longest_symbol_kunit.c +++ b/lib/tests/longest_symbol_kunit.c @@ -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
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
On Sun, Jul 6, 2025 at 4:19 PM Sergio González Collado sergio.collado@gmail.com wrote:
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=5Q0fM6neBhxSbOUHBgNzmwf2V22v... [2] https://lore.kernel.org/all/20250328112156.2614513-1-arnd@kernel.org/T/#u [3] https://lore.kernel.org/rust-for-linux/bbd03b37-c4d9-4a92-9be2-75aaf8c19815@... [4] https://lore.kernel.org/linux-kselftest/20250427200916.GA1661412@ax162/T/#t
Reviewed-by: Rae Moar rmoar@google.com Signed-off-by: Sergio González Collado sergio.collado@gmail.com Acked-by: Randy Dunlap rdunlap@infradead.org Tested-by: Randy Dunlap rdunlap@infradead.org
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
lib/Kconfig.debug | 1 + lib/tests/longest_symbol_kunit.c | 3 +-- 2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ebe33181b6e6..4a75a52803b6 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -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 possiblediff --git a/lib/tests/longest_symbol_kunit.c b/lib/tests/longest_symbol_kunit.c index e3c28ff1807f..9b4de3050ba7 100644 --- a/lib/tests/longest_symbol_kunit.c +++ b/lib/tests/longest_symbol_kunit.c @@ -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
2.39.2
linux-kselftest-mirror@lists.linaro.org
-
Peter Zijlstra -
Rae Moar -
Sergio González Collado