[#MDEV-28091] PERFORMANCE_SCHEMA unit tests fail due to memory misalignment

On my system, 3 unit tests for performance_schema failed with SIGSEGV, on MariaDB Server 10.9. The reason turned out to be that the SIMD instruction MOVAPS was executed in create_thread() on a pointer that was only aligned to 128 bits (16 bytes), not the required 256 or 512 bits.

The reason turned out to be that the mocked up pfs_malloc() failed to return properly aligned memory (64 bytes or 512 bits in the case of AMD64):

diff --git a/storage/perfschema/unittest/stub_pfs_global.h b/storage/perfschema/unittest/stub_pfs_global.h

index 8a1f9216ba2..3d7d818cc51 100644

--- a/storage/perfschema/unittest/stub_pfs_global.h

+++ b/storage/perfschema/unittest/stub_pfs_global.h

@@ -24,6 +24,9 @@

 #include <my_sys.h>

 #include <pfs_global.h>

 #include <string.h>

+#ifdef HAVE_MEMALIGN

+# include <malloc.h>

+#endif

 bool pfs_initialized= false;

@@ -43,7 +46,15 @@ void *pfs_malloc(size_t size, myf)

   if (--stub_alloc_fails_after_count <= 0)

     return NULL;

+#ifndef PFS_ALIGNEMENT

   void *ptr= malloc(size);

+#elif defined HAVE_MEMALIGN

+  void *ptr= memalign(PFS_ALIGNEMENT, size);

+#elif defined HAVE_ALIGNED_MALLOC

+  void *ptr= _aligned_malloc(size, PFS_ALIGNEMENT);

+#else

+# error "Missing implementation"

+#endif

   if (ptr != NULL)

     memset(ptr, 0, size);

   return ptr;

[MDEV-28091] PERFORMANCE_SCHEMA unit tests fail due to memory misalignment Created: 2022-03-16 Updated: 2022-03-16 Resolved: 2022-03-16
Status:	Closed
Project:	MariaDB Server
Component/s:	Performance Schema, Tests
Affects Version/s:	10.2, 10.3, 10.4, 10.5, 10.6, 10.7, 10.8, 10.9
Fix Version/s:	10.2.44, 10.3.35, 10.4.25, 10.5.16, 10.6.8, 10.7.4, 10.8.3

[MDEV-28091] PERFORMANCE_SCHEMA unit tests fail due to memory misalignment Created: 2022-03-16 Updated: 2022-03-16 Resolved: 2022-03-16