From 91b2014b569ce6b367355040004804a133a45b91 Mon Sep 17 00:00:00 2001 From: Simon Marlow Date: Thu, 15 Nov 2007 13:16:35 +0000 Subject: [PATCH] FIX #1679: crash on returning from a foreign call We forgot to save a pointer to the BCO over the foreign call. Doing enough allocation and GC during the call could provoke a crash. --- rts/Interpreter.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/rts/Interpreter.c b/rts/Interpreter.c index 77f3058..6e70de8 100644 --- a/rts/Interpreter.c +++ b/rts/Interpreter.c @@ -1334,9 +1334,14 @@ run_BCO: // on the stack frame to describe this chunk of stack. // Sp -= ret_dyn_size; - ((StgRetDyn *)Sp)->liveness = NO_PTRS | N_NONPTRS(stk_offset); + ((StgRetDyn *)Sp)->liveness = R1_PTR | N_NONPTRS(stk_offset); ((StgRetDyn *)Sp)->info = (StgInfoTable *)&stg_gc_gen_info; + // save obj (pointer to the current BCO), since this + // might move during the call. We use the R1 slot in the + // RET_DYN frame for this, hence R1_PTR above. + ((StgRetDyn *)Sp)->payload[0] = (StgClosure *)obj; + SAVE_STACK_POINTERS; tok = suspendThread(&cap->r); @@ -1357,6 +1362,16 @@ run_BCO: // And restart the thread again, popping the RET_DYN frame. cap = (Capability *)((void *)((unsigned char*)resumeThread(tok) - sizeof(StgFunTable))); LOAD_STACK_POINTERS; + + // Re-load the pointer to the BCO from the RET_DYN frame, + // it might have moved during the call. Also reload the + // pointers to the components of the BCO. + obj = ((StgRetDyn *)Sp)->payload[0]; + bco = (StgBCO*)obj; + instrs = (StgWord16*)(bco->instrs->payload); + literals = (StgWord*)(&bco->literals->payload[0]); + ptrs = (StgPtr*)(&bco->ptrs->payload[0]); + Sp += ret_dyn_size; // Save the Haskell thread's current value of errno -- 1.7.10.4