#7621: Cross-build for QNX ARM smashes stack when using FunPtr wrappers -----------------------------+---------------------------------------------- Reporter: singpolyma | Owner: Type: bug | Status: new Priority: normal | Component: Compiler (FFI) Version: 7.6.1 | Keywords: qnx unregistered cross-compile Os: Unknown/Multiple | Architecture: arm Failure: Runtime crash | Blockedby: Blocking: | Related: -----------------------------+---------------------------------------------- Comment(by singpolyma): Core file from a similar run and crash, too big to upload to Trac so I put it at https://singpolyma.net/ghc/7621-Main.core.xz -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7621#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#7621: Cross-build for QNX ARM smashes stack when using FunPtr wrappers -----------------------------------------------+---------------------------- Reporter: singpolyma | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler (FFI) | Version: 7.6.1 Keywords: qnx unregistered cross-compile | Os: QNX Architecture: arm | Failure: Runtime crash Difficulty: Unknown | Testcase: Blockedby: | Blocking: 7610 Related: | -----------------------------------------------+---------------------------- Changes (by simonmar): * milestone: => 7.8.1 Comment: Data point: the test case succeeds for me, with an unregisterised build for Raspberry Pi using both the C backend and LLVM. LLVM version 2.9. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7621#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#7621: Cross-build for QNX ARM smashes stack when using FunPtr wrappers -------------------------------------------------+-------------------------- Reporter: singpolyma | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler (FFI) | Version: 7.6.1 Keywords: qnx unregisterised cross-compile | Os: QNX Architecture: arm | Failure: Runtime crash Difficulty: Unknown | Testcase: Blockedby: | Blocking: 7610 Related: | -------------------------------------------------+-------------------------- Changes (by singpolyma): * keywords: qnx unregistered cross-compile => qnx unregisterised cross- compile * status: infoneeded => new Comment: I just build an unregisterised compiler via-C from HEAD (since #7620 is fixed) and it also has this issue. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7621#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#7621: Cross-build for QNX ARM smashes stack when using FunPtr wrappers -------------------------------------------------+-------------------------- Reporter: singpolyma | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler (FFI) | Version: 7.7 Keywords: qnx unregisterised cross-compile | Os: QNX Architecture: arm | Failure: Runtime crash Difficulty: Unknown | Testcase: Blockedby: | Blocking: 7610 Related: | -------------------------------------------------+-------------------------- Comment(by singpolyma): I just built a registerised QNX ARM cross-compiler with llvm-3.0, and this also occurs on binaries produced by that compiler. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7621#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#7621: Cross-build for QNX ARM smashes stack when using FunPtr wrappers -------------------------------------------------+-------------------------- Reporter: singpolyma | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler (FFI) | Version: 7.7 Keywords: qnx unregisterised cross-compile | Os: QNX Architecture: arm | Failure: Runtime crash Difficulty: Unknown | Testcase: Blockedby: | Blocking: 7610 Related: | -------------------------------------------------+-------------------------- Comment(by psycotica0): I've looked into this, and have decided that whether or not GHC is correct, libffi is definitely worong. The following code works under arm-linux-gnueabi and native, but not under qnx: {{{ #include #include /* Acts like puts with the file given at time of enclosure. */ void puts_binding(ffi_cif *cif, unsigned int *ret, void* args[], FILE *stream) { *ret = fputs(*(char **)args[0], stream); } int main() { ffi_cif cif; ffi_type *args[1]; ffi_closure *closure; int (*bound_puts)(char *); int rc; /* Allocate closure and bound_puts */ closure = ffi_closure_alloc(sizeof(ffi_closure), &bound_puts); if (closure) { /* Initialize the argument info vectors */ args[0] = &ffi_type_pointer; /* Initialize the cif */ if (ffi_prep_cif(&cif, FFI_DEFAULT_ABI, 1, // if (ffi_prep_cif(&cif, FFI_VFP, 1, // if (ffi_prep_cif(&cif, FFI_SYSV, 1, &ffi_type_uint, args) == FFI_OK) { /* Initialize the closure, setting stream to stdout */ if (ffi_prep_closure_loc(closure, &cif, puts_binding, stdout, bound_puts) == FFI_OK) { rc = bound_puts("Hello World!"); /* rc now holds the result of the call to fputs */ } } } /* Deallocate both closure, and bound_puts */ ffi_closure_free(closure); return 0; } }}} The formatting's a little off, because I cut and paste it from the libffi documentation. So, that crashes stacks when built with gcc and run on qnx. I looked into libffi some and found that the problem seems to be in two calls of `__clear_cache`, which are meant to clear arm's instruction and data caches, since it's doing tricky stuff in there. They appear to be causing trouble, though... Seems like this person [http://community.qnx.com/sf/discussion/do/listPosts/projects.bazaar/discussi... was having the same trouble with Python on QNX] `__clear_cache` appears to be Linux syscall thing on ARM for this, and while the code is building on QNX, maybe it works differently there, or is broken? Either way, I think I'll have to work on this with the FFI people unless any of you know what's up. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7621#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#7621: Cross-build for QNX ARM smashes stack when using FunPtr wrappers -------------------------------------------------+-------------------------- Reporter: singpolyma | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler (FFI) | Version: 7.7 Keywords: qnx unregisterised cross-compile | Os: QNX Architecture: arm | Failure: Runtime crash Difficulty: Unknown | Testcase: Blockedby: | Blocking: 7610 Related: | -------------------------------------------------+-------------------------- Comment(by igloo): psycotica0, I have no idea. If you're able to sort this out with upstream then that would be great, thanks! -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7621#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler