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> +} __attribute__((aligned(8 * sizeof(__u64)))); Actually bumping the alignment from 32 to 64 is not correct here, because the kernel still has to deal with legacy userspace which align struct rseq on 32 bytes only. What I can do instead is change the value returned by getauxval(AT_RSEQ_ALIGN) from 32 to 64, thus requesting that newer userspace align its allocation on 64-byte. I'll prepare an updated patch series. Thanks, Mathieu -- Mathieu Desnoyers EfficiOS Inc. https://www.efficios.com