After updating to the March 2024 security patch on Pixel 6, Vulkan applications now run into a SIGSEGV in the cmarp_backend_thread with the tombstone:
#00 pc 00000000017d8518 /vendor/lib64/egl/libGLES_mali.so (hal::halp::execution_complete_callback(cmar_event*, int, void*)+88) (BuildId: 9a91c3c0b3746b5c)
#01 pc 00000000017e9224 /vendor/lib64/egl/libGLES_mali.so (cmarp_event_call_all_deferred_callbacks+244) (BuildId: 9a91c3c0b3746b5c)
#02 pc 00000000017ebf0c /vendor/lib64/egl/libGLES_mali.so (cmarp_backend_thread+1116) (BuildId: 9a91c3c0b3746b5c)
#03 pc 00000000000ca7cc /apex/com.android.runtime/lib64/bionic/libc.so (__pthread_start(void*)+204) (BuildId: 33ad5959e2b38fc822cda3c642e16c94)
#04 pc 00000000000607b0 /apex/com.android.runtime/lib64/bionic/libc.so (__start_thread+64) (BuildId: 33ad5959e2b38fc822cda3c642e16c94)
This appears only on the Pixel 6 and only in release builds, debug builds execute without major errors oddly enough.
A couple of questions to help resolve this issue.
1. What's the purpose of the cmarp_backend_thread?
2. Are there common reasons why cmarp_backend_thread may attempt to resolve an event callback with some NULL or invalid data that isn't a memory stomp? I find it unlikely that cmar_event* is NULL but the void* in the argument reads like it should be additional user data that can be NULL
Thanks for the bug report, we've raised it with the OEM and it is being handled off-forum