Hi,
I am encountering a problem that I do not know how to debug. I would
greatly appreciate any guidance on this issue.
On Windows when I run Lua test cases from JITed code I am getting
following error:
Unhandled exception at 0x00007FFCEEEAC500 (ntdll.dll) in lua.exe:
0xC0000028: An invalid or unaligned stack was encountered during an
unwind operation.
This is happening when the Lua code is attempting to call longjmp().
The Lua test case that triggers this is a recursive call as shown below.
function err_on_n (n)
if n==0 then error(); exit(1);
else err_on_n (n-1); exit(1);
end
end
do
function dummy (n)
if n > 0 then
assert(not pcall(err_on_n, n))
dummy(n-1)
end
end
end
dummy(10)
I have a struct that is created on the stack in the JIT compiler, and
this error is triggered when I add a field to the struct - if I remove
the field the error stops. The struct is not very large in size - it
is only 392 bytes with the new field.
If I allocate this struct on the heap the error goes away.
Note that just adding the field triggers the error even if I have no
other code changes.
The error occurs in Release build but not in Debug build.
I am using Visual C++ 2013 - 64-bit, and LLVM 3.6.0 on Windows.
I see no other unexpected behaviour - all the other tests pass.
All tests pass on Ubuntu, using LLVM 3.5.1 and gcc 4.8.2.
Of course I am currently assuming that somewhere my program is
corrupting memory - but as I have no other signs of a memory
corruption - the issue may be something else.
Any tips on what the problem might be would be gratefully received.
Thanks and Regards
Dibyendu
See r227426 from Clang. setjmp on Win64 is really weird. There is a hidden second parameter that you may need to fill in with @llvm.frameaddress. On Mon, Mar 30, 2015 at 3:59 PM, Dibyendu Majumdar <mobile at majumdar.org.uk> wrote:> Hi, > > I am encountering a problem that I do not know how to debug. I would > greatly appreciate any guidance on this issue. > > On Windows when I run Lua test cases from JITed code I am getting > following error: > > Unhandled exception at 0x00007FFCEEEAC500 (ntdll.dll) in lua.exe: > 0xC0000028: An invalid or unaligned stack was encountered during an > unwind operation. > > This is happening when the Lua code is attempting to call longjmp(). > > The Lua test case that triggers this is a recursive call as shown below. > > function err_on_n (n) > if n==0 then error(); exit(1); > else err_on_n (n-1); exit(1); > end > end > > do > function dummy (n) > if n > 0 then > assert(not pcall(err_on_n, n)) > dummy(n-1) > end > end > end > > dummy(10) > > > I have a struct that is created on the stack in the JIT compiler, and > this error is triggered when I add a field to the struct - if I remove > the field the error stops. The struct is not very large in size - it > is only 392 bytes with the new field. > > If I allocate this struct on the heap the error goes away. > > Note that just adding the field triggers the error even if I have no > other code changes. > > The error occurs in Release build but not in Debug build. > I am using Visual C++ 2013 - 64-bit, and LLVM 3.6.0 on Windows. > I see no other unexpected behaviour - all the other tests pass. > > All tests pass on Ubuntu, using LLVM 3.5.1 and gcc 4.8.2. > > Of course I am currently assuming that somewhere my program is > corrupting memory - but as I have no other signs of a memory > corruption - the issue may be something else. > > Any tips on what the problem might be would be gratefully received. > > Thanks and Regards > Dibyendu > _______________________________________________ > LLVM Developers mailing list > LLVMdev at cs.uiuc.edu http://llvm.cs.uiuc.edu > http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20150330/a4bba2b7/attachment.html>
Hi, I constructed a minimal Lua program that reproduces the problem. Essentially the problem occurs if a JITed function is recursively called - and there is a longjmp from the inner call. Example: function rais(n) if n == 0 then error() else rais(n-1) end end ravi.compile(rais) function caller(n) pcall(rais,n) end ravi.compile(caller) caller(1) Here the call to error() triggers a longjmp. The pcall() calls setjmp. The error only occurs on Windows as reported earlier. I ran valgrind on Ubuntu to see if I could detect any memory issues. Valgrind reports 6 errors of following type - not sure if this is an issue or not. ==66154===66154== HEAP SUMMARY: ==66154== in use at exit: 115,521 bytes in 720 blocks ==66154== total heap usage: 9,357 allocs, 8,637 frees, 3,887,031 bytes allocated ==66154===66154== 152 bytes in 1 blocks are possibly lost in loss record 378 of 423 ==66154== at 0x4C2AB80: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so) ==66154== by 0x516AD4D: llvm::MDNode::getMDNode(llvm::LLVMContext&, llvm::ArrayRef<llvm::Value*>, llvm::MDNode::FunctionLocalness, bool) (in /home/dylan/github/ravi/build/libravi.so) ==66154== by 0x516A2B8: llvm::MDBuilder::createTBAAStructTagNode(llvm::MDNode*, llvm::MDNode*, unsigned long) (in /home/dylan/github/ravi/build/libravi.so) ==66154== by 0x5068961: ravi::LuaLLVMTypes::LuaLLVMTypes(llvm::LLVMContext&) (in /home/dylan/github/ravi/build/libravi.so) ==66154== by 0x5063EF6: ravi::RaviJITStateImpl::RaviJITStateImpl() (in /home/dylan/github/ravi/build/libravi.so) ==66154== by 0x50644FD: raviV_initjit (in /home/dylan/github/ravi/build/libravi.so) ==66154== by 0x5057DF5: lua_newstate (in /home/dylan/github/ravi/build/libravi.so) ==66154== by 0x503641E: luaL_newstate (in /home/dylan/github/ravi/build/libravi.so) ==66154== by 0x401674: main (in /home/dylan/github/ravi/build/lua) On 30 March 2015 at 23:59, Dibyendu Majumdar <mobile at majumdar.org.uk> wrote:> Hi, > > I am encountering a problem that I do not know how to debug. I would > greatly appreciate any guidance on this issue. > > On Windows when I run Lua test cases from JITed code I am getting > following error: > > Unhandled exception at 0x00007FFCEEEAC500 (ntdll.dll) in lua.exe: > 0xC0000028: An invalid or unaligned stack was encountered during an > unwind operation. > > This is happening when the Lua code is attempting to call longjmp(). > > The Lua test case that triggers this is a recursive call as shown below. > > function err_on_n (n) > if n==0 then error(); exit(1); > else err_on_n (n-1); exit(1); > end > end > > do > function dummy (n) > if n > 0 then > assert(not pcall(err_on_n, n)) > dummy(n-1) > end > end > end > > dummy(10) > > > I have a struct that is created on the stack in the JIT compiler, and > this error is triggered when I add a field to the struct - if I remove > the field the error stops. The struct is not very large in size - it > is only 392 bytes with the new field. > > If I allocate this struct on the heap the error goes away. > > Note that just adding the field triggers the error even if I have no > other code changes. > > The error occurs in Release build but not in Debug build. > I am using Visual C++ 2013 - 64-bit, and LLVM 3.6.0 on Windows. > I see no other unexpected behaviour - all the other tests pass. > > All tests pass on Ubuntu, using LLVM 3.5.1 and gcc 4.8.2. > > Of course I am currently assuming that somewhere my program is > corrupting memory - but as I have no other signs of a memory > corruption - the issue may be something else. > > Any tips on what the problem might be would be gratefully received. > > Thanks and Regards > Dibyendu
On Tue, Mar 31, 2015 at 3:31 PM, Dibyendu Majumdar <mobile at majumdar.org.uk> wrote:> Hi, > > I constructed a minimal Lua program that reproduces the problem. > Essentially the problem occurs if a JITed function is recursively > called - and there is a longjmp from the inner call. Example: > > function rais(n) > if n == 0 then error() > else rais(n-1) > end > end > ravi.compile(rais) > > function caller(n) > pcall(rais,n) > end > ravi.compile(caller) > > caller(1) > > Here the call to error() triggers a longjmp. The pcall() calls setjmp. > The error only occurs on Windows as reported earlier. >This isn't enough info to solve the problem. Pasting the LLVM IR or C code that calls setjmp and a stack trace of the crash might help figure it out, though.> I ran valgrind on Ubuntu to see if I could detect any memory issues. > Valgrind reports 6 errors of following type - not sure if this is an > issue or not. >These memory leaks look unrelated. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20150401/427166a5/attachment.html>