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<body><div>Yeah but it seems that's set automatically on the other end, so that's not a real problem.<br></div>
<div><br></div>
<div>Turns out that, since I don't use libc I didn't have:<br></div>
<div><br></div>
<div>_load_config_used<br></div>
<div><br></div>
<div>which has to be setup to make it all work. Once introduced everything started working again (odd that this used to work without, I think LLD must have started to set a " I need safeseh" bit at some point).<br></div>
<div><br></div>
<div>Thanks!<br></div>
<div><br></div>
<div><br></div>
<div>On Mon, Aug 20, 2018, at 22:13, Reid Kleckner wrote:<br></div>
<blockquote type="cite"><div dir="ltr"><div>Oh, apparently we did this:<br></div>
<div><br></div>
<div><div>void WinException::endModule() {<br></div>
<div> auto &OS = *Asm->OutStreamer;<br></div>
<div> const Module *M = MMI->getModule();<br></div>
<div> for (const Function &F : *M)<br></div>
<div> if (F.hasFnAttribute("safeseh"))<br></div>
<div> OS.EmitCOFFSafeSEH(Asm->getSymbol(&F));<br></div>
<div>}<br></div>
</div>
<div><br></div>
<div>And we add the attribute in the state number store insertion pass. That's not very discoverable. :(<br></div>
<div><br></div>
<div>So, I guess just add the "safeseh" string attribute to your personality declaration and you're set.<br></div>
</div>
<div><br></div>
<div defang_data-gmailquote="yes"><div dir="ltr">On Mon, Aug 20, 2018 at 11:04 AM Carlo Kok <<a href="mailto:ck@remobjects.com">ck@remobjects.com</a>> wrote:<br></div>
<blockquote defang_data-gmailquote="yes" style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0.8ex;border-left-color:rgb(204, 204, 204);border-left-style:solid;border-left-width:1px;padding-left:1ex;"><div><u></u><br></div>
<div><div>Indeed, it's 32bits x86 and there's no .safeseh or anything like it, even readobj -coff-load-config says nothing:<br></div>
<div><br></div>
<div>File: ConsoleApplication830.exe<br></div>
<div>Format: COFF-i386<br></div>
<div>Arch: i386<br></div>
<div>AddressSize: 32bit<br></div>
<div><br></div>
<div><br></div>
<div>Now I know what to look for, thanks!<br></div>
<div><br></div>
<div><br></div>
<div>On Mon, Aug 20, 2018, at 18:46, Reid Kleckner wrote:<br></div>
<blockquote type="cite"><div dir="ltr"><div>This is 32-bit x86, right? Sounds like the exception handler did not appear in the /safeseh table.<br></div>
<div><br></div>
<div>If you emit a standalone .s file, do you see something like `.safeseh
_elements_exception_handler` somewhere in there? If not, that's a problem. I think it would also be a problem if
_elements_exception_handler is imported. If so, try making a thunk for it.<br></div>
<div><br></div>
<div>You can also try running `dumpbin /loadconfig` (or equivalently llvm-readobj -coff-load-config) on your binary to confirm that the RVA of _elements_exception_handler appears in the safe seh table.<br></div>
</div>
<div><br></div>
<div><div dir="ltr">On Mon, Aug 20, 2018 at 7:00 AM Carlo Kok via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org">llvm-dev@lists.llvm.org</a>> wrote:<br></div>
<blockquote style="margin-top:0px;margin-right:0px;margin-bottom:0px;margin-left:0.8ex;border-left-color:rgb(204, 204, 204);border-left-style:solid;border-left-width:1px;padding-left:1ex;"><div>Hi,<br></div>
<div><br></div>
<div>I'm getting:<br></div>
<div><br></div>
<div>Unhandled exception at 0x00C211F0 in ConsoleApplication830.exe: 0xC00001A5: An invalid exception handler routine has been detected (parameters: 0x00000001).<br></div>
<div><br></div>
<div>With some fairly simple SEH enabled routine:<br></div>
<div><br></div>
<div>define i32 @__elements_entry_point_main(%._gt2a_RemObjects_d_Elements_d_System_d_Array_t_1s*) #0 personality i8* bitcast (i32 ()* @_elements_exception_handler to i8*) !dbg !61 {<br></div>
<div>BasicBlock0:<br></div>
<div> %1 = alloca %._gt2a_RemObjects_d_Elements_d_System_d_Array_t_1s*<br></div>
<div> store %._gt2a_RemObjects_d_Elements_d_System_d_Array_t_1s* %0, %._gt2a_RemObjects_d_Elements_d_System_d_Array_t_1s** %1<br></div>
<div> call void @llvm.dbg.declare(metadata %._gt2a_RemObjects_d_Elements_d_System_d_Array_t_1s** %1, metadata !86, metadata !DIExpression()), !dbg !88<br></div>
<div> %csLoc0 = alloca i32, !dbg !88<br></div>
<div> store i32 0, i32* %csLoc0, !dbg !88<br></div>
<div> br label %BasicBlock1, !dbg !88<br></div>
<div><br></div>
<div>BasicBlock1: ; preds = %BasicBlock0<br></div>
<div> call void @llvm.dbg.declare(metadata i32* %csLoc0, metadata !89, metadata !DIExpression()), !dbg !91<br></div>
<div> store i32 0, i32* %csLoc0, !dbg !91<br></div>
<div> invoke void @ms_t1d_ConsoleApplication4_d_Program2_m1()<br></div>
<div> to label %BasicBlock2 unwind label %2, !dbg !92<br></div>
<div><br></div>
<div>BasicBlock2: ; preds = %BasicBlock1<br></div>
<div> br label %BasicBlock3, !dbg !93<br></div>
<div><br></div>
<div>; <label>:2: ; preds = %BasicBlock1<br></div>
<div> %3 = catchswitch within none [label %BasicBlock4] unwind to caller, !dbg !93<br></div>
<div><br></div>
<div>BasicBlock3: ; preds = %BasicBlock5, %BasicBlock2<br></div>
<div> %4 = load i32, i32* %csLoc0, !dbg !94<br></div>
<div> ret i32 %4, !dbg !94<br></div>
<div><br></div>
<div>BasicBlock4: ; preds = %2<br></div>
<div> %5 = catchpad within %3 [{ i8*, i8* }* @0, i32 0, i8* null], !dbg !93<br></div>
<div> catchret from %5 to label %BasicBlock5, !dbg !95<br></div>
<div><br></div>
<div>BasicBlock5: ; preds = %BasicBlock4<br></div>
<div> br label %BasicBlock3, !dbg !95<br></div>
<div><br></div>
<div>BasicBlock6: ; No predecessors!<br></div>
<div> unreachable, !dbg !94<br></div>
<div>}<br></div>
<div><br></div>
<div><br></div>
<div>(_elements_exception_handler is my exception handler routine which I added to the LLVM source, compatible with the standard VC++ one). My question is,<br></div>
<div><br></div>
<div>is there something special I need to do to make SEH work (I'm using LLVM LLD to compile it, from 3 months ago, but latest doesn't give a different result)? I can't find anything real about that exception code.<br></div>
<div><br></div>
<div>0x00C211F0 DOES point to the generated code used for SEH:<br></div>
<div><br></div>
<div>00C211F0 | 57 | push edi |<br></div>
<div>00C211F1 | 56 | push esi |<br></div>
<div>00C211F2 | 83EC 10 | sub esp,10 |<br></div>
<div>00C211F5 | 8B4424 28 | mov eax,dword ptr ss:[esp+28] |<br></div>
<div>00C211F9 | 8B4C24 24 | mov ecx,dword ptr ss:[esp+24] |<br></div>
<div>00C211FD | 8B5424 20 | mov edx,dword ptr ss:[esp+20] |<br></div>
<div>00C21201 | 8B7424 1C | mov esi,dword ptr ss:[esp+1C] |<br></div>
<div>00C21205 | BF 54DCC800 | mov edi,consoleapplication830.C8DC54 |<br></div>
<div>00C2120A | 894424 0C | mov dword ptr ss:[esp+C],eax |<br></div>
<div>00C2120E | 89F8 | mov eax,edi |<br></div>
<div>00C21210 | 897424 08 | mov dword ptr ss:[esp+8],esi |<br></div>
<div>00C21214 | 894C24 04 | mov dword ptr ss:[esp+4],ecx |<br></div>
<div>00C21218 | 891424 | mov dword ptr ss:[esp],edx |<br></div>
<div>00C2121B | 83C4 10 | add esp,10 |<br></div>
<div>00C2121E | 5E | pop esi |<br></div>
<div>00C2121F | 5F | pop edi |<br></div>
<div>00C21220 | E9 7B270100 | jmp <consoleapplication830.RemObjects.Elements.System.Exte |<br></div>
<div><br></div>
<div>Which seems fine.<br></div>
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</blockquote></div>
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