Horton

Re: broken JIT support on Fedora 40

Thomas Munro <thomas.munro@gmail.com>

View thread View on postgr.es
From: Thomas Munro <thomas.munro@gmail.com>
To: Daniel Gustafsson <daniel@yesql.se>
Cc: Pavel Stehule <pavel.stehule@gmail.com>, Robert Haas <robertmhaas@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Dmitry Dolgov <9erthalion6@gmail.com>
Date: 2024-03-15T00:54:38Z
Lists: pgsql-hackers 
For me it seems that the LLVMRunPasses() call, new in

commit 76200e5ee469e4a9db5f9514b9d0c6a31b496bff
Author: Thomas Munro <tmunro@postgresql.org>
Date:   Wed Oct 18 22:15:54 2023 +1300

    jit: Changes for LLVM 17.

is reaching code that segfaults inside libLLVM, specifically in
llvm::InlineFunction(llvm::CallBase&, llvm::InlineFunctionInfo&, bool,
llvm::AAResults*, bool, llvm::Function*).  First obvious question
would be: is that NULL argument still acceptable?  Perhaps it wants
our LLVMTargetMachineRef there:

       err = LLVMRunPasses(module, passes, NULL, options);

But then when we see what is does with that argument, it arrives at a
place that apparently accepts nullptr.

https://github.com/llvm/llvm-project/blob/6b2bab2839c7a379556a10287034bd55906d7094/llvm/lib/Passes/PassBuilderBindings.cpp#L56
https://github.com/llvm/llvm-project/blob/6b2bab2839c7a379556a10287034bd55906d7094/llvm/include/llvm/Passes/PassBuilder.h#L124

Hrmph.  Might need an assertion build to learn more.  I'll try to look
again next week or so.

Commits

  1. Run LLVM verify pass on IR in assert builds.

  2. Fix illegal attribute propagation in LLVM JIT.

  3. Track LLVM 18 changes.

  4. jit: Changes for LLVM 17.