حبيب محمد الأمين محمد الهـاد <ha.ala...@gmail.com> writes:
> I reproduced your same error, and figured out the cause. I'll just embed > it as a diff inline, you'll spot it in the script instantly :). AFAICT we are out of the cross-compilation woods and straight into the OpenBSD mitigations paradise :) I pushed a tiny patch which takes care of -fPIC at which point cross-compiling works: % _build/stage1/bin/aarch64-unknown-openbsd-ghc -o a /tmp/a.hs It produces a somewhat working binary: % file a a: ELF 64-bit LSB shared object, AArch64, version 1 % ./a Hello World [1] 13634 trace trap (core dumped) ./a (gdb) r Starting program: /home/greg/a Hello World Program received signal SIGTRAP, Trace/breakpoint trap. 0x0000001f6f167a1c in StgRun () (gdb) bt #0 0x0000001f6f167a1c in StgRun () #1 0x000000702fc5caf0 [PAC] in ?? () Backtrace stopped: previous frame inner to this frame (corrupt stack?) (gdb) disassemble Dump of assembler code for function StgRun: 0x0000001f6f167950 <+0>: bti c 0x0000001f6f167954 <+4>: adrp x15, 0x1f6f1bf000 0x0000001f6f167958 <+8>: ldr x15, [x15, #2952] 0x0000001f6f16795c <+12>: eor x15, x15, x30 0x0000001f6f167960 <+16>: paciasp 0x0000001f6f167964 <+20>: str x30, [sp, #-96]! 0x0000001f6f167968 <+24>: stp x28, x27, [sp, #16] 0x0000001f6f16796c <+28>: stp x26, x25, [sp, #32] 0x0000001f6f167970 <+32>: stp x24, x23, [sp, #48] 0x0000001f6f167974 <+36>: stp x22, x21, [sp, #64] 0x0000001f6f167978 <+40>: stp x20, x19, [sp, #80] 0x0000001f6f16797c <+44>: stp x29, x30, [sp, #-16]! 0x0000001f6f167980 <+48>: mov x29, sp 0x0000001f6f167984 <+52>: stp x16, x17, [sp, #-16]! 0x0000001f6f167988 <+56>: stp x19, x20, [sp, #-16]! 0x0000001f6f16798c <+60>: stp x21, x22, [sp, #-16]! 0x0000001f6f167990 <+64>: stp x23, x24, [sp, #-16]! 0x0000001f6f167994 <+68>: stp x25, x26, [sp, #-16]! 0x0000001f6f167998 <+72>: stp x27, x28, [sp, #-16]! 0x0000001f6f16799c <+76>: stp d8, d9, [sp, #-16]! 0x0000001f6f1679a0 <+80>: stp d10, d11, [sp, #-16]! 0x0000001f6f1679a4 <+84>: stp d12, d13, [sp, #-16]! 0x0000001f6f1679a8 <+88>: stp d14, d15, [sp, #-16]! 0x0000001f6f1679ac <+92>: sub sp, sp, #0x4, lsl #12 0x0000001f6f1679b0 <+96>: mov x19, x1 0x0000001f6f1679b4 <+100>: br x0 0x0000001f6f1679b8 <+104>: add sp, sp, #0x4, lsl #12 0x0000001f6f1679bc <+108>: mov x0, x22 0x0000001f6f1679c0 <+112>: ldp d14, d15, [sp], #16 0x0000001f6f1679c4 <+116>: ldp d12, d13, [sp], #16 0x0000001f6f1679c8 <+120>: ldp d10, d11, [sp], #16 0x0000001f6f1679cc <+124>: ldp d8, d9, [sp], #16 0x0000001f6f1679d0 <+128>: ldp x27, x28, [sp], #16 0x0000001f6f1679d4 <+132>: ldp x25, x26, [sp], #16 0x0000001f6f1679d8 <+136>: ldp x23, x24, [sp], #16 0x0000001f6f1679dc <+140>: ldp x21, x22, [sp], #16 0x0000001f6f1679e0 <+144>: ldp x19, x20, [sp], #16 0x0000001f6f1679e4 <+148>: ldp x16, x17, [sp], #16 0x0000001f6f1679e8 <+152>: ldp x29, x30, [sp], #16 0x0000001f6f1679ec <+156>: ldp x20, x19, [sp, #80] 0x0000001f6f1679f0 <+160>: ldp x22, x21, [sp, #64] 0x0000001f6f1679f4 <+164>: ldp x24, x23, [sp, #48] 0x0000001f6f1679f8 <+168>: ldp x26, x25, [sp, #32] 0x0000001f6f1679fc <+172>: ldp x28, x27, [sp, #16] 0x0000001f6f167a00 <+176>: ldr x30, [sp], #96 0x0000001f6f167a04 <+180>: adrp x9, 0x1f6f1bf000 0x0000001f6f167a08 <+184>: autiasp 0x0000001f6f167a0c <+188>: ldr x9, [x9, #2952] 0x0000001f6f167a10 <+192>: eor x15, x15, x30 0x0000001f6f167a14 <+196>: subs x15, x15, x9 0x0000001f6f167a18 <+200>: cbz x15, 0x1f6f167a20 <StgRun+208> => 0x0000001f6f167a1c <+204>: brk #0x1 0x0000001f6f167a20 <+208>: ret End of assembler dump. This code is very special (it is mostly coded in arm64 assembly[0]). We could really use help from somebody who understands what is happening in our arm64 epilogue that this magical Haskell runtime is running afoul of. It looks like retguard, so maybe just somehow marking this function with no-retguard-please is enough? My hypothesis for why the same works on amd64 is they have an explicit retq, so we don't get to inject retguard in there. That function is like this: $ objdump -d /usr/local/lib/ghc-9.6.6/lib/x86_64-openbsd-ghc-9.6.6/rts-1.0.2/libHSrts-1.0.2.a ... 4f: 4c 8b 64 24 10 mov 0x10(%rsp),%r12 54: 4c 8b 6c 24 18 mov 0x18(%rsp),%r13 59: 4c 8b 74 24 20 mov 0x20(%rsp),%r14 5e: 4c 8b 7c 24 28 mov 0x28(%rsp),%r15 63: 48 83 c4 30 add $0x30,%rsp 67: c3 retq 68: 4c 33 1c 24 xor (%rsp),%r11 6c: 4c 3b 1d 00 00 00 00 cmp 0(%rip),%r11 # 73 <StgReturn+0x37> 73: 74 0a je 7f <StgReturn+0x43> 75: cc int3 76: cc int3 77: cc int3 78: cc int3 79: cc int3 7a: cc int3 7b: cc int3 7c: cc int3 7d: cc int3 7e: cc int3 7f: c3 retq [0]https://gitlab.haskell.org/blackgnezdo/ghc/-/blob/ghc-9.10.1-openbsd/rts/StgCRun.c?ref_type=heads#L833 Thanks Greg
