[llvm-dev] lld-link crash when linking intrinsics lib

Wed Feb 27 16:16:31 PST 2019

On Wed, Feb 27, 2019 at 4:05 PM Peter Collingbourne <pcc at google.com> wrote:

> Hmm, you might need something like the ELF linker's r338434/r339301 in the
> COFF linker.
>

Are you going to do that? If we need to port it in a straightforward way, I
think I can do that, though.

Peter
>
> On Wed, Feb 27, 2019 at 4:01 PM Rui Ueyama <ruiu at google.com> wrote:
>
>> +Peter Collingbourne <pcc at chromium.org>
>>
>> LTO is used in this test case, and one source file defines its own
>> `memset` function while the other file uses llvm.memset. Looks like LTO is
>> confused by the user-defined memset. Could you take a look?
>>
>> Steven,
>>
>> Do you need to use LTO? I thought that LTO is a workaround to not produce
>> an object file that cannot be handled by your ELF-to-COFF translation tool.
>> If you are now doing a regular cross build, I guess you can remove -flto.
>>
>> On Wed, Feb 27, 2019 at 3:00 PM Rui Ueyama <ruiu at google.com> wrote:
>>
>>> Hi Steven,
>>>
>>> I confirmed that lld-link crashes with these inputs. That shouldn't
>>> happen. I'll debug this and get back to you. Thank you for reporting.
>>>
>>> On Tue, Feb 26, 2019 at 8:20 PM Shi, Steven <steven.shi at intel.com>
>>> wrote:
>>>
>>>> Hello Rui,
>>>>
>>>> I met couples of lld-link crash when enable the clang-cl + lld-link
>>>> build toolchain for Uefi firmware. Below is a simplified example (main.c
>>>> and intrinsics.c).
>>>>
>>>> Uefi firmware is self-contained and doesn’t depend on the compiler
>>>> intrinsics implementation, so we have our own intrinsics lib. It is weird
>>>> that if I don’t use the llvm-lib but directly “lld-link /NODEFAULTLIB
>>>> /ENTRY:main  main.obj intrinsics.obj”, the below example can pass link.
>>>> Please advise what’s wrong in this example.
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> $ cat main.c
>>>>
>>>> typedef struct {
>>>>
>>>>   struct MAP_LIST {
>>>>
>>>>     unsigned long long  VirtualAddress;
>>>>
>>>>     void              *MapCookie;
>>>>
>>>>   } MapList[100];
>>>>
>>>> } SNP_DRIVER;
>>>>
>>>> SNP_DRIVER snp_instance;
>>>>
>>>> int main()
>>>>
>>>> {
>>>>
>>>>   SNP_DRIVER  *Snp;
>>>>
>>>>   Snp = &snp_instance;
>>>>
>>>>   for (int Index = 0; Index < 100; Index++) {
>>>>
>>>>     Snp->MapList[Index].VirtualAddress = 0;
>>>>
>>>>     Snp->MapList[Index].MapCookie      = 0;
>>>>
>>>>   }
>>>>
>>>>   return 0;
>>>>
>>>> }
>>>>
>>>>
>>>>
>>>> $ cat intrinsics.c
>>>>
>>>> void * memset (void *dest, int ch, size_t count)
>>>>
>>>> {
>>>>
>>>>   volatile char  *Pointer;
>>>>
>>>>   Pointer = (char *)dest;
>>>>
>>>>   while (count-- != 0) {
>>>>
>>>>     *(Pointer++) = (char)ch;
>>>>
>>>>   }
>>>>
>>>>   return dest;
>>>>
>>>> }
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> $ "/home/jshi19/llvm/releaseinstall/bin/clang-cl" /Fomain.obj /c
>>>> --target=x86_64-pc-win32-coff -m64 /O1b2s -flto main.c
>>>>
>>>> $ "/home/jshi19/llvm/releaseinstall/bin/clang-cl" /Fointrinsics.obj /c
>>>> --target=x86_64-pc-win32-coff -m64 /O1b2s -flto intrinsics.c
>>>>
>>>> $ "/home/jshi19/llvm/releaseinstall/bin/llvm-lib" /OUT:intrinsics.lib
>>>> intrinsics.obj
>>>>
>>>> $ "/home/jshi19/llvm/releaseinstall/bin/lld-link" /NODEFAULTLIB
>>>> /ENTRY:main  main.obj intrinsics.lib
>>>>
>>>> Stack dump:
>>>>
>>>> 0.      Program arguments:
>>>> /home/jshi19/llvm/releaseinstall/bin/lld-link /NODEFAULTLIB /ENTRY:main
>>>> main.obj intrinsics.lib
>>>>
>>>> #0 0x0000559a34ba5e4a llvm::sys::PrintStackTrace(llvm::raw_ostream&)
>>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x272e4a)
>>>>
>>>> #1 0x0000559a34ba3d14 llvm::sys::RunSignalHandlers()
>>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x270d14)
>>>>
>>>> #2 0x0000559a34ba3e52 SignalHandler(int)
>>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x270e52)
>>>>
>>>> #3 0x00007f896c8ea890 __restore_rt
>>>> (/lib/x86_64-linux-gnu/libpthread.so.0+0x12890)
>>>>
>>>> #4 0x0000559a34c11325
>>>> lld::coff::markLive(llvm::ArrayRef<lld::coff::Chunk*>)
>>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x2de325)
>>>>
>>>> #5 0x0000559a34bf0220 lld::coff::LinkerDriver::link(llvm::ArrayRef<char
>>>> const*>) (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x2bd220)
>>>>
>>>> #6 0x0000559a34bf0478 lld::coff::link(llvm::ArrayRef<char const*>,
>>>> bool, llvm::raw_ostream&)
>>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x2bd478)
>>>>
>>>> #7 0x0000559a34b2a300 main
>>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x1f7300)
>>>>
>>>> #8 0x00007f896b3c1b97 __libc_start_main
>>>> /build/glibc-OTsEL5/glibc-2.27/csu/../csu/libc-start.c:344:0
>>>>
>>>> #9 0x0000559a34b8c27a _start
>>>> (/home/jshi19/llvm/releaseinstall/bin/lld-link+0x25927a)
>>>>
>>>> Segmentation fault (core dumped)
>>>>
>>>>
>>>>
>>>> $ "/home/jshi19/llvm/releaseinstall/bin/clang-cl" --version
>>>>
>>>> clang version 9.0.0 (https://github.com/llvm-mirror/clang.git
>>>> 1f02068469ff18f5fc5728cafe9d96ee5f66c5b9) (
>>>> https://github.com/llvm-project/llvm.git
>>>> 330395ea4fce35b019b33797ff751be029a1f866)
>>>>
>>>> Target: x86_64-pc-windows-msvc
>>>>
>>>> Thread model: posix
>>>>
>>>> InstalledDir: /home/jshi19/llvm/releaseinstall/bin
>>>>
>>>>
>>>>
>>>> $ "/home/jshi19/llvm/releaseinstall/bin/lld-link" --version
>>>>
>>>> LLD 9.0.0 (https://github.com/llvm-mirror/lld.git
>>>> aa7adc0ec804b689771f11d52e39f83a16378f5f)
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> Thanks
>>>>
>>>>
>>>>
>>>> *Steven Shi*
>>>>
>>>> *Intel\SSG\FID\Firmware Infrastructure*
>>>>
>>>>
>>>>
>>>
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