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

[Rui Ueyama via llvm-dev]

+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*
>>
>>
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20190227/93aab076/attachment.html>