https://bugs.winehq.org/show_bug.cgi?id=48274 --- Comment #9 from Paul Gofman <gofmanp(a)gmail.com> --- Created attachment 65958 --> https://bugs.winehq.org/attachment.cgi?id=65958 force stack alignment in syscall dispatcher Looks like syscall thunks violate stack alignment. The segfaulting instruction in NtQuerySystemInformation is like this: vmovaps %xmm6,0x1090(%rsp) This is aligned 16-byte SSE register load which segfaults on most CPUs if the actual address is unaligned. The "good" builds have explicit stack alignments in functions' prologues: -- 7bcad2e1: 48 83 e4 f0 and $0xfffffffffffffff0,%rsp 7bcad2e5: 48 81 ec 90 10 00 00 sub $0x1090,%rsp 7bcad2ec: c7 84 24 40 01 00 00 movl $0x0,0x140(%rsp) 7bcad2f3: 00 00 00 00 7bcad2f7: c5 f8 29 b4 24 90 10 vmovaps %xmm6,0x1090(%rsp) -- The library attached in the previous comment does not have an alignment but is still using the same aligned stores / loads, assuming x64 ABI which requires rsp + 8 to be 16 bytes aligned on function entry. Does the attached patch help? -- Do not reply to this email, post in Bugzilla using the above URL to reply. You are receiving this mail because: You are watching all bug changes.