#10375: arm: ghci hits an illegal instruction -------------------------------------+------------------------------------- Reporter: erikd | Owner: Type: bug | Status: new Priority: high | Milestone: 7.10.3 Component: Runtime System | Version: 7.10.1 (Linker) | Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: arm Type of failure: GHCi crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by erikd): Since I know that this is some problem with the function `hSetBuffering` when it is being loaded by the runtime linker I added a printf to `rts/Linker.c` to print the address of the `hSetBuffering` related functions when they are loaded. Running this now looks like: {{{ $ inplace/bin/ghc-stage2 --interactive GHCi, version 7.11.20150912: http://www.haskell.org/ghc/ :? for help lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering1_entry is 0xb3f3d3cd lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering1_entry is 0xb3f3d3cd lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering1_info is 0xb421f738 lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering1_closure is 0xb421d5b0 lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering_entry is 0xb3f3d471 lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering_info is 0xb421f718 lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering1_entry is 0xb3f3d3cd turnOffBuffering start turnOffBuffering middle Illegal instruction }}} If I now load this into gdb, run it until it crashes I get: {{{ GHCi, version 7.11.20150912: http://www.haskell.org/ghc/ :? for help lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering1_entry is 0xb3f503cd lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering1_entry is 0xb3f503cd lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering1_info is 0xb4232738 lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering1_closure is 0xb42305b0 lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering_entry is 0xb3f50471 lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering_info is 0xb4232718 lookupSymbol: value of base_GHCziIOziHandle_hSetBuffering1_entry is 0xb3f503cd turnOffBuffering start turnOffBuffering middle Program received signal SIGILL, Illegal instruction. 0x04004e5c in stg_ap_v_fast () (gdb) disass base_GHCziIOziHandle_hSetBuffering1_entry Dump of assembler code for function base_GHCziIOziHandle_hSetBuffering1_entry: 0x03d423c4 <+0>: movw r3, #58688 ; 0xe540 0x03d423c8 <+4>: movt r3, #1181 ; 0x49d 0x03d423cc <+8>: ldr.w r2, [r3, #808] ; 0x328 0x03d423d0 <+12>: subs r2, #4 }}} For some reason, the address of `base_GHCziIOziHandle_hSetBuffering1_entry` in GDB is not the address printed by the runtime linker. Even more confusingly, disassembling the address the `0xb3f3d3cd` fails, possibly because its outside the memory map. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10375#comment:48 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler