[PATCH v2] tests/tcg: Skip failing ppc64 multi-threaded tests

[Nicholas Piggin]

In Gitlab CI, some ppc64 multi-threaded tcg tests crash when run in the
clang-user job with an assertion failure in glibc that seems to
indicate corruption:

  signals: allocatestack.c:223: allocate_stack:
    Assertion `powerof2 (pagesize_m1 + 1)' failed.

Disable these tests for now.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 tests/tcg/ppc64/Makefile.target | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/tests/tcg/ppc64/Makefile.target b/tests/tcg/ppc64/Makefile.target
index 8c3e4e4038..509a20be2b 100644
--- a/tests/tcg/ppc64/Makefile.target
+++ b/tests/tcg/ppc64/Makefile.target
@@ -11,6 +11,18 @@ config-cc.mak: Makefile
 
 -include config-cc.mak
 
+# multi-threaded tests are known to fail (e.g., clang-user CI job)
+# See: https://gitlab.com/qemu-project/qemu/-/issues/2456
+run-signals: signals
+       $(call skip-test, $<, "BROKEN (flaky with clang) ")
+run-plugin-signals-with-%:
+       $(call skip-test, $<, "BROKEN (flaky with clang) ")
+
+run-threadcount: threadcount
+       $(call skip-test, $<, "BROKEN (flaky with clang) ")
+run-plugin-threadcount-with-%:
+       $(call skip-test, $<, "BROKEN (flaky with clang) ")
+
 ifneq ($(CROSS_CC_HAS_POWER8_VECTOR),)
 PPC64_TESTS=bcdsub non_signalling_xscv
 endif
-- 
2.45.2