diff options
Diffstat (limited to 'rts/StgCRun.c')
| -rw-r--r-- | rts/StgCRun.c | 49 |
1 files changed, 29 insertions, 20 deletions
diff --git a/rts/StgCRun.c b/rts/StgCRun.c index 934926e0f3..ddb19b468b 100644 --- a/rts/StgCRun.c +++ b/rts/StgCRun.c @@ -89,25 +89,6 @@ StgFunPtr StgReturn(void) } #else /* !USE_MINIINTERPRETER */ - -#if defined(mingw32_HOST_OS) -/* - * Note [Windows Stack allocations] - * - * On windows the stack has to be allocated 4k at a time, otherwise - * we get a segfault. The C compiler knows how to do this (it calls - * _alloca()), so we make sure that we can allocate as much stack as - * we need. However since we are doing a local stack allocation and the value - * isn't valid outside the frame, compilers are free to optimize this allocation - * and the corresponding stack check away. So to prevent that we request that - * this function never be optimized (See #14669). */ -STG_NO_OPTIMIZE StgWord8 *win32AllocStack(void) -{ - StgWord8 stack[RESERVED_C_STACK_BYTES + 16 + 12]; - return stack; -} -#endif - /* ----------------------------------------------------------------------------- x86 architecture -------------------------------------------------------------------------- */ @@ -159,7 +140,21 @@ STG_NO_OPTIMIZE StgWord8 *win32AllocStack(void) * * If you edit the sequence below be sure to update the unwinding information * for stg_stop_thread in StgStartup.cmm. - */ + * + * Note [Windows Stack allocations] + * + * On windows the stack has to be allocated 4k at a time, otherwise + * we get a segfault. This is done by using a helper ___chkstk_ms that is + * provided by libgcc. The Haskell side already knows how to handle this +(see GHC.CmmToAsm.X86.Instr.needs_probe_call) + * but we need to do the same from STG. Previously we would drop the stack + * in StgRun but would only make it valid whenever the scheduler loop ran. + * + * This approach was fundamentally broken in that it falls apart when you + * take a signal from the OS (See #14669, #18601, #18548 and #18496). + * Concretely this means we must always keep the stack valid. + * */ + static void GNUC3_ATTRIBUTE(used) StgRunIsImplementedInAssembler(void) @@ -179,7 +174,13 @@ StgRunIsImplementedInAssembler(void) * bytes from here - this is a requirement of the C ABI, so * that C code can assign SSE2 registers directly to/from * stack locations. + * + * See Note [Windows Stack allocations] */ +#if defined(mingw32_HOST_OS) + "movl %0, %%eax\n\t" + "call ___chkstk_ms\n\t" +#endif "subl %0, %%esp\n\t" /* @@ -376,6 +377,14 @@ StgRunIsImplementedInAssembler(void) STG_HIDDEN STG_RUN "\n" #endif STG_RUN ":\n\t" + /* + * See Note [Windows Stack allocations] + */ +#if defined(mingw32_HOST_OS) + "movq %1, %%rax\n\t" + "addq %0, %%rax\n\t" + "callq ___chkstk_ms\n\t" +#endif "subq %1, %%rsp\n\t" "movq %%rsp, %%rax\n\t" "subq %0, %%rsp\n\t" |