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Revert "[llvm] Add a wrapper around the GC poll icall so it can be ca…
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…lled with a cold calling convention."

This reverts commit ad86022. The commit was part of 870aec4 ( mono#16191 ).

It breaks `block_guard_restore_aligment_on_exit.exe` on Linux/AMD64 FullAOT+LLVM.

```
(lldb) p obj->vtable->klass->name
(const char *) $6 = 0x00007ffff431952a "ThreadAbortException"
(lldb) bt
* thread mono#4, name = 'mono-sgen', stop reason = step over
  * frame #0: 0x000055555587dfc8 mono-sgen`mono_handle_exception_internal(ctx=0x00007ffff2f89330, obj=0x00007ffff5c077f8, resume=0, out_ji=0x0000000000000000) at mini-exceptions.c:2485
    frame #1: 0x000055555587fbf1 mono-sgen`mono_handle_exception(ctx=0x00007ffff2f89330, void_obj=0x00007ffff5c077f8) at mini-exceptions.c:3034
    frame #2: 0x0000555555945ed6 mono-sgen`mono_amd64_throw_exception(dummy1=140737316419576, dummy2=140737269765200, dummy3=140737018598112, dummy4=0, dummy5=0, dummy6=0, mctx=0x00007ffff2f894f0, exc=0x00007ffff5c077f8, rethrow=1, preserve_ips=1) at exceptions-amd64.c:403
    frame mono#3: 0x00007ffff3ad091d mscorlib.dll.so`rethrow_preserve_exception + 173
    frame mono#4: 0x00007ffff2f8b648 block_guard_restore_aligment_on_exit.exe.so`icall_cold_wrapper_263 + 136
    frame mono#5: 0x00007ffff2f8bc3d block_guard_restore_aligment_on_exit.exe.so`Driver_InnerFunc + 141
    frame mono#6: 0x00007ffff2f8bd20 block_guard_restore_aligment_on_exit.exe.so`Driver_Func + 32
    frame mono#7: 0x00007ffff344c6d8 mscorlib.dll.so`System_Threading_ThreadHelper_ThreadStart_Context_object + 168
    frame mono#8: 0x00007ffff344a5c3 mscorlib.dll.so`System_Threading_ExecutionContext_Run_System_Threading_ExecutionContext_System_Threading_ContextCallback_object_bool + 35
    frame mono#9: 0x00007ffff344a555 mscorlib.dll.so`System_Threading_ExecutionContext_Run_System_Threading_ExecutionContext_System_Threading_ContextCallback_object + 53
    frame mono#10: 0x00007ffff344c7e8 mscorlib.dll.so`System_Threading_ThreadHelper_ThreadStart + 56
    frame mono#11: 0x00007ffff3ab2d92 mscorlib.dll.so`wrapper_runtime_invoke_object_runtime_invoke_dynamic_intptr_intptr_intptr_intptr + 290
    frame mono#12: 0x000055555582e3ae mono-sgen`mono_jit_runtime_invoke(method=0x0000555557626f58, obj=0x00007ffff5c00630, params=0x00007ffff2f89df8, exc=0x00007ffff2f89ae0, error=0x00007ffff2f89e00) at mini-runtime.c:3152
    frame mono#13: 0x0000555555bb0da2 mono-sgen`do_runtime_invoke(method=0x0000555557626f58, obj=0x00007ffff5c00630, params=0x00007ffff2f89df8, exc=0x0000000000000000, error=0x00007ffff2f89e00) at object.c:3017
    frame mono#14: 0x0000555555bb1155 mono-sgen`mono_runtime_invoke_checked(method=0x0000555557626f58, obj=0x00007ffff5c00630, params=0x00007ffff2f89df8, error=0x00007ffff2f89e00) at object.c:3185
    frame mono#15: 0x0000555555bb3572 mono-sgen`mono_runtime_delegate_try_invoke(delegate=0x00007ffff5c00630, params=0x00007ffff2f89df8, exc=0x0000000000000000, error=0x00007ffff2f89e00) at object.c:4386
    frame mono#16: 0x0000555555bb3698 mono-sgen`mono_runtime_delegate_invoke_checked(delegate=0x00007ffff5c00630, params=0x00007ffff2f89df8, error=0x00007ffff2f89e00) at object.c:4417
    frame mono#17: 0x0000555555bd61be mono-sgen`start_wrapper_internal(start_info=0x0000000000000000, stack_ptr=0x00007ffff2f8b000) at threads.c:1242
    frame mono#18: 0x0000555555bd6334 mono-sgen`start_wrapper(data=0x000055555762ab80) at threads.c:1295
    frame mono#19: 0x00007ffff736a6db libpthread.so.0`start_thread + 219
    frame mono#20: 0x00007ffff675488f libc.so.6`__GI___clone at clone.S:95
```

EH doesn't know how to unwind `icall_cold_wrapper_263`.  Solution isn't obvious so let's revert it for now.
  • Loading branch information
@lewurm
lewurm committed Aug 22, 2019
1 parent 5c9be2d commit 3213ace
Showing 1 changed file with 26 additions and 74 deletions.
100 changes: 26 additions & 74 deletions mono/mini/mini-llvm.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1806,41 +1806,6 @@ compute_aot_got_offset (MonoLLVMModule *module, MonoJumpInfo *ji, LLVMTypeRef ll
return got_offset;
}

/* Allocate a GOT slot for TYPE/DATA, and emit IR to load it */
static LLVMValueRef
get_aotconst_typed_module (MonoLLVMModule *module, LLVMBuilderRef builder, MonoJumpInfoType type, gconstpointer data, LLVMTypeRef llvm_type)
{
guint32 got_offset;
LLVMValueRef indexes [2];
LLVMValueRef got_entry_addr, load;
char *name = NULL;

MonoJumpInfo tmp_ji;
tmp_ji.type = type;
tmp_ji.data.target = data;

MonoJumpInfo *ji = mono_aot_patch_info_dup (&tmp_ji);

got_offset = compute_aot_got_offset (module, ji, llvm_type);
module->max_got_offset = MAX (module->max_got_offset, got_offset);

indexes [0] = LLVMConstInt (LLVMInt32Type (), 0, FALSE);
indexes [1] = LLVMConstInt (LLVMInt32Type (), (gssize)got_offset, FALSE);
got_entry_addr = LLVMBuildGEP (builder, module->got_var, indexes, 2, "");

name = get_aotconst_name (type, data, got_offset);
if (llvm_type) {
load = LLVMBuildLoad (builder, got_entry_addr, "");
load = LLVMBuildBitCast (builder, load, llvm_type, name);
} else {
load = LLVMBuildLoad (builder, got_entry_addr, name ? name : "");
}
g_free (name);
//set_invariant_load_flag (load);

return load;
}

static LLVMValueRef
get_aotconst_typed (EmitContext *ctx, MonoJumpInfoType type, gconstpointer data, LLVMTypeRef llvm_type)
{
Expand Down Expand Up @@ -3056,39 +3021,6 @@ emit_init_icall_wrapper (MonoLLVMModule *module, MonoAotInitSubtype subtype)
return func;
}

/* Emit a wrapper around the parameterless JIT icall ICALL_ID with a cold calling convention */
static LLVMValueRef
emit_icall_cold_wrapper (MonoLLVMModule *module, MonoJitICallId icall_id)
{
LLVMModuleRef lmodule = module->lmodule;
LLVMValueRef func, callee;
LLVMBasicBlockRef entry_bb;
LLVMBuilderRef builder;
LLVMTypeRef sig;
char *name;

name = g_strdup_printf ("icall_cold_wrapper_%d", icall_id);

func = LLVMAddFunction (lmodule, name, LLVMFunctionType (LLVMVoidType (), NULL, 0, FALSE));
sig = LLVMFunctionType (LLVMVoidType (), NULL, 0, FALSE);
LLVMSetLinkage (func, LLVMInternalLinkage);
mono_llvm_add_func_attr (func, LLVM_ATTR_NO_INLINE);
set_cold_cconv (func);

entry_bb = LLVMAppendBasicBlock (func, "ENTRY");
builder = LLVMCreateBuilder ();
LLVMPositionBuilderAtEnd (builder, entry_bb);

callee = get_aotconst_typed_module (module, builder, MONO_PATCH_INFO_JIT_ICALL_ID, GUINT_TO_POINTER (icall_id), LLVMPointerType (sig, 0));
LLVMBuildCall (builder, callee, NULL, 0, "");

LLVMBuildRetVoid (builder);

LLVMVerifyFunction(func, LLVMAbortProcessAction);
LLVMDisposeBuilder (builder);
return func;
}

/*
* Emit wrappers around the C icalls used to initialize llvm methods, to
* make the calling code smaller and to enable usage of the llvm
Expand Down Expand Up @@ -3124,17 +3056,18 @@ static void
emit_gc_safepoint_poll (MonoLLVMModule *module)
{
LLVMModuleRef lmodule = module->lmodule;
LLVMValueRef func, flag_addr, val_ptr, val, cmp, args [2], icall_wrapper;
LLVMValueRef func, indexes [2], got_entry_addr, flag_addr, val_ptr, callee, val, cmp, args [2];
LLVMBasicBlockRef entry_bb, poll_bb, exit_bb;
LLVMBuilderRef builder;
LLVMTypeRef sig;

icall_wrapper = emit_icall_cold_wrapper (module, MONO_JIT_ICALL_mono_threads_state_poll);
MonoJumpInfo *ji;
int got_offset;

sig = LLVMFunctionType0 (LLVMVoidType (), FALSE);
func = mono_llvm_get_or_insert_gc_safepoint_poll (lmodule);
mono_llvm_add_func_attr (func, LLVM_ATTR_NO_UNWIND);
LLVMSetLinkage (func, LLVMWeakODRLinkage);
// set_cold_cconv (func);

entry_bb = LLVMAppendBasicBlock (func, "gc.safepoint_poll.entry");
poll_bb = LLVMAppendBasicBlock (func, "gc.safepoint_poll.poll");
Expand All @@ -3145,7 +3078,16 @@ emit_gc_safepoint_poll (MonoLLVMModule *module)
/* entry: */
LLVMPositionBuilderAtEnd (builder, entry_bb);

flag_addr = get_aotconst_typed_module (module, builder, MONO_PATCH_INFO_GC_SAFE_POINT_FLAG, NULL, LLVMPointerType (IntPtrType (), 0));
/* get_aotconst */
ji = g_new0 (MonoJumpInfo, 1);
ji->type = MONO_PATCH_INFO_GC_SAFE_POINT_FLAG;
ji = mono_aot_patch_info_dup (ji);
got_offset = compute_aot_got_offset (module, ji, IntPtrType ());
module->max_got_offset = MAX (module->max_got_offset, got_offset);
indexes [0] = LLVMConstInt (LLVMInt32Type (), 0, FALSE);
indexes [1] = LLVMConstInt (LLVMInt32Type (), got_offset, FALSE);
got_entry_addr = LLVMBuildGEP (builder, module->got_var, indexes, 2, "");
flag_addr = LLVMBuildLoad (builder, got_entry_addr, "");
val_ptr = LLVMBuildLoad (builder, flag_addr, "");
val = LLVMBuildPtrToInt (builder, val_ptr, IntPtrType (), "");
cmp = LLVMBuildICmp (builder, LLVMIntEQ, val, LLVMConstNull (LLVMTypeOf (val)), "");
Expand All @@ -3157,8 +3099,18 @@ emit_gc_safepoint_poll (MonoLLVMModule *module)
/* poll: */
LLVMPositionBuilderAtEnd(builder, poll_bb);

LLVMValueRef call = LLVMBuildCall (builder, icall_wrapper, NULL, 0, "");
set_call_cold_cconv (call);
ji = g_new0 (MonoJumpInfo, 1);
ji->type = MONO_PATCH_INFO_JIT_ICALL_ID;
ji->data.jit_icall_id = MONO_JIT_ICALL_mono_threads_state_poll;
ji = mono_aot_patch_info_dup (ji);
got_offset = compute_aot_got_offset (module, ji, sig);
module->max_got_offset = MAX (module->max_got_offset, got_offset);
indexes [0] = LLVMConstInt (LLVMInt32Type (), 0, FALSE);
indexes [1] = LLVMConstInt (LLVMInt32Type (), got_offset, FALSE);
got_entry_addr = LLVMBuildGEP (builder, module->got_var, indexes, 2, "");
callee = LLVMBuildLoad (builder, got_entry_addr, "");
callee = LLVMBuildBitCast (builder, callee, LLVMPointerType (sig, 0), "");
LLVMBuildCall (builder, callee, NULL, 0, "");
LLVMBuildBr(builder, exit_bb);

/* exit: */
Expand Down

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