On Wed, Aug 20, 2025, Mark Brown wrote:
On Tue, Jun 24, 2025 at 04:19:30PM -0700, Sean Christopherson wrote:
Rename is_signed_type() to is_signed_var() to avoid colliding with a macro of the same name defined by linux/overflow.h. Note, overflow.h's version takes a type as the input, whereas the harness's version takes a variable!
This patch is in -next and is causing widespread breakage in the selftests -next on at least arm and arm64 due to:
make --silent --keep-going --jobs=15 O=/build/stage/build-work INSTALL_PATH=/build/stage/build-work/kselftest_install ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- CROSS_COMPILE_COMPAT=arm-linux-gnueabihf- kselftest-install
...
In file included from test-pcmtest-driver.c:10: ../kselftest_harness.h:59:10: fatal error: linux/overflow.h: No such file or directory 59 | #include <linux/overflow.h> | ^~~~~~~~~~~~~~~~~~ compilation terminated.
Argh, many selftests don't add tools/include to their include path. The least awful thing I can think of is to go with a minimal fix to avoid the collision. AFAICT, nothing outside of kselftest_harness.h uses is_signed_type(), so this shouldn't cause a different flavor of breakage?
-- From: Sean Christopherson seanjc@google.com Date: Tue, 24 Jun 2025 16:19:30 -0700 Subject: [PATCH] selftests: harness: Rework is_signed_type() to avoid collision with overflow.h
Rename is_signed_type() to is_signed_var() to avoid colliding with a macro of the same name defined by tools' linux/overflow.h. This fixes warnings (and presumably potential test failures) in tests that utilize the selftests harness and happen to (indirectly) include overflow.h.
In file included from tools/include/linux/bits.h:34, from tools/include/linux/bitops.h:14, from tools/include/linux/hashtable.h:13, from include/kvm_util.h:11, from x86/userspace_msr_exit_test.c:11: tools/include/linux/overflow.h:31:9: error: "is_signed_type" redefined [-Werror] 31 | #define is_signed_type(type) (((type)(-1)) < (type)1) | ^~~~~~~~~~~~~~ In file included from include/kvm_test_harness.h:11, from x86/userspace_msr_exit_test.c:9: ../kselftest_harness.h:754:9: note: this is the location of the previous definition 754 | #define is_signed_type(var) (!!(((__typeof__(var))(-1)) < (__typeof__(var))1)) | ^~~~~~~~~~~~~~
Use a separate definition, at least for now, as many selftests build without tools/include in their include path.
Fixes: fc92099902fb ("tools headers: Synchronize linux/bits.h with the kernel sources") Cc: Vincent Mailhol mailhol.vincent@wanadoo.fr Cc: Arnaldo Carvalho de Melo acme@redhat.com Link: https://lore.kernel.org/r/20250624231930.583689-1-seanjc@google.com Signed-off-by: Sean Christopherson seanjc@google.com --- tools/testing/selftests/kselftest_harness.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kselftest_harness.h b/tools/testing/selftests/kselftest_harness.h index 2925e47db995..8516e8434bc4 100644 --- a/tools/testing/selftests/kselftest_harness.h +++ b/tools/testing/selftests/kselftest_harness.h @@ -751,7 +751,7 @@ for (; _metadata->trigger; _metadata->trigger = \ __bail(_assert, _metadata))
-#define is_signed_type(var) (!!(((__typeof__(var))(-1)) < (__typeof__(var))1)) +#define is_signed_var(var) (!!(((__typeof__(var))(-1)) < (__typeof__(var))1))
#define __EXPECT(_expected, _expected_str, _seen, _seen_str, _t, _assert) do { \ /* Avoid multiple evaluation of the cases */ \ @@ -759,7 +759,7 @@ __typeof__(_seen) __seen = (_seen); \ if (!(__exp _t __seen)) { \ /* Report with actual signedness to avoid weird output. */ \ - switch (is_signed_type(__exp) * 2 + is_signed_type(__seen)) { \ + switch (is_signed_var(__exp) * 2 + is_signed_var(__seen)) { \ case 0: { \ uintmax_t __exp_print = (uintmax_t)__exp; \ uintmax_t __seen_print = (uintmax_t)__seen; \
base-commit: 923fcb3dbc0246fc5207093c0049af4c56f20e41 --