15618 2024-10-11 13:21:18 +0000 qemuarmv5: mrc considered an illegal instruction (as used by python 3.13) 2024-10-17 14:34:12 +0000 1 1 7 Build System, Metadata & Runtime BSPs bsps-oe-core unspecified x86 Multiple RESOLVED ReportedUpstream Medium+ normal 5.2 M1 1 alex.kanavin ross.burton diego.russo richard.purdie ross.burton --- --- No (bug/feature does not impact docs) oldest_to_newest 99842 0 alex.kanavin 2024-10-11 13:21:18 +0000 Python 3.13 introduced usage of mrc instructions via inline assembly: https://github.com/python/cpython/blob/main/Include/object.h#L195 https://github.com/python/cpython/blob/main/Include/internal/mimalloc/mimalloc/prim.h#L172 https://github.com/python/cpython/blob/main/Include/internal/mimalloc/mimalloc/prim.h#L199 This seems to work ok in qemuarm (I didn't specifically confirm that these code paths are executed though), but in qemuarmv5 it throws 'Illegal instruction'. It isn't clear if qemu makes incorrect decisions, or the instruction as specified by python is indeed not universal on arm hardware. For now, I was able to disable the use of it via disabling mimalloc feature on armv5 targets. 99855 1 ross.burton 2024-10-14 10:53:13 +0000 Filed upstream at https://github.com/python/cpython/issues/125444. 99904 2 ross.burton 2024-10-17 14:34:12 +0000 Upstream has now resolved this issue in the 3.13.x branch and we don't have 3.13.0 yet. Closing as filed upstream, we'll backport the fix for the upgrade.