#15508: concprog001 fails with various errors when compiled with -prof -------------------------------------+------------------------------------- Reporter: osa1 | Owner: (none) Type: bug | Status: new Priority: high | Milestone: 8.6.1 Component: Profiling | Version: 8.5 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D5051 Wiki Page: | -------------------------------------+------------------------------------- Comment (by osa1): So, as shown in the description this program crashes in many ways. I started debugging with one of those errors, and found out that at some point `cap->r.rCCCS` (a capability's "current cost centre" stack) actually points to a heap closure instead of a cost centre stack: {{{
print cap->r.rCCCS $13 = (struct CostCentreStack_ *) 0x4200213000
call printClosure(cap->r.rCCCS) integer-gmp:GHC.Integer.Type.S#((nil)#) }}}
Then when this capability does allocation `accountAllocation` overwrites a info table pointer in this line {{{ CCS_ALLOC(cap->r.rCCCS,n); // Storage.c:802 }}} CCS_ALLOC defined as: {{{ #define CCS_ALLOC(ccs, size) (ccs)->mem_alloc += ((size)-sizeofW(StgProfHeader)) }}} mem_alloc is at this address: {{{
print &cap->r.rCCCS->mem_alloc $15 = (StgWord64 *) 0x4200213048 }}}
Which is also the info ptr of another closure: {{{
print &((StgClosure*)0x4200213048)->header.info $20 = (const StgInfoTable **) 0x4200213048 }}}
Originally this closure is; {{{
call printClosure(0x4200213048) BLACKHOLE(0x42000dfa40) }}}
So this assignment causes a memory corruption. Note that I'm using `+RTS -DS` during all this so any heap location that is not filled with 0 are actually in use. (collected space is filled with 0s with `-DS`) -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/15508#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler